xref: /vim-8.2.3635/src/window.c (revision fc65cabb)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read a list of people who contributed.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 #include "vim.h"
11 
12 static int path_is_url(char_u *p);
13 static void cmd_with_count(char *cmd, char_u *bufp, size_t bufsize, long Prenum);
14 static void win_init(win_T *newp, win_T *oldp, int flags);
15 static void win_init_some(win_T *newp, win_T *oldp);
16 static void frame_comp_pos(frame_T *topfrp, int *row, int *col);
17 static void frame_setheight(frame_T *curfrp, int height);
18 static void frame_setwidth(frame_T *curfrp, int width);
19 static void win_exchange(long);
20 static void win_rotate(int, int);
21 static void win_totop(int size, int flags);
22 static void win_equal_rec(win_T *next_curwin, int current, frame_T *topfr, int dir, int col, int row, int width, int height);
23 static int last_window(void);
24 static int close_last_window_tabpage(win_T *win, int free_buf, tabpage_T *prev_curtab);
25 static win_T *win_free_mem(win_T *win, int *dirp, tabpage_T *tp);
26 static frame_T *win_altframe(win_T *win, tabpage_T *tp);
27 static tabpage_T *alt_tabpage(void);
28 static win_T *frame2win(frame_T *frp);
29 static int frame_has_win(frame_T *frp, win_T *wp);
30 static void frame_new_height(frame_T *topfrp, int height, int topfirst, int wfh);
31 static int frame_fixed_height(frame_T *frp);
32 static int frame_fixed_width(frame_T *frp);
33 static void frame_add_statusline(frame_T *frp);
34 static void frame_new_width(frame_T *topfrp, int width, int leftfirst, int wfw);
35 static void frame_add_vsep(frame_T *frp);
36 static int frame_minwidth(frame_T *topfrp, win_T *next_curwin);
37 static void frame_fix_width(win_T *wp);
38 static int win_alloc_firstwin(win_T *oldwin);
39 static void new_frame(win_T *wp);
40 static tabpage_T *alloc_tabpage(void);
41 static int leave_tabpage(buf_T *new_curbuf, int trigger_leave_autocmds);
42 static void enter_tabpage(tabpage_T *tp, buf_T *old_curbuf, int trigger_enter_autocmds, int trigger_leave_autocmds);
43 static void frame_fix_height(win_T *wp);
44 static int frame_minheight(frame_T *topfrp, win_T *next_curwin);
45 static void win_enter_ext(win_T *wp, int undo_sync, int no_curwin, int trigger_new_autocmds, int trigger_enter_autocmds, int trigger_leave_autocmds);
46 static void win_free(win_T *wp, tabpage_T *tp);
47 static void frame_append(frame_T *after, frame_T *frp);
48 static void frame_insert(frame_T *before, frame_T *frp);
49 static void frame_remove(frame_T *frp);
50 static void win_goto_ver(int up, long count);
51 static void win_goto_hor(int left, long count);
52 static void frame_add_height(frame_T *frp, int n);
53 static void last_status_rec(frame_T *fr, int statusline);
54 
55 static void make_snapshot_rec(frame_T *fr, frame_T **frp);
56 static void clear_snapshot(tabpage_T *tp, int idx);
57 static void clear_snapshot_rec(frame_T *fr);
58 static int check_snapshot_rec(frame_T *sn, frame_T *fr);
59 static win_T *restore_snapshot_rec(frame_T *sn, frame_T *fr);
60 
61 static int frame_check_height(frame_T *topfrp, int height);
62 static int frame_check_width(frame_T *topfrp, int width);
63 
64 static win_T *win_alloc(win_T *after, int hidden);
65 
66 #define URL_SLASH	1		/* path_is_url() has found "://" */
67 #define URL_BACKSLASH	2		/* path_is_url() has found ":\\" */
68 
69 #define NOWIN		(win_T *)-1	/* non-existing window */
70 
71 #define ROWS_AVAIL (Rows - p_ch - tabline_height())
72 
73 static char *m_onlyone = N_("Already only one window");
74 
75 /*
76  * all CTRL-W window commands are handled here, called from normal_cmd().
77  */
78     void
79 do_window(
80     int		nchar,
81     long	Prenum,
82     int		xchar)	    /* extra char from ":wincmd gx" or NUL */
83 {
84     long	Prenum1;
85     win_T	*wp;
86 #if defined(FEAT_SEARCHPATH) || defined(FEAT_FIND_ID)
87     char_u	*ptr;
88     linenr_T    lnum = -1;
89 #endif
90 #ifdef FEAT_FIND_ID
91     int		type = FIND_DEFINE;
92     int		len;
93 #endif
94     char_u	cbuf[40];
95 
96     if (Prenum == 0)
97 	Prenum1 = 1;
98     else
99 	Prenum1 = Prenum;
100 
101 #ifdef FEAT_CMDWIN
102 # define CHECK_CMDWIN \
103     do { \
104 	if (cmdwin_type != 0) \
105 	{ \
106 	    EMSG(_(e_cmdwin)); \
107 	    return; \
108 	} \
109     } while (0)
110 #else
111 # define CHECK_CMDWIN do { /**/ } while (0)
112 #endif
113 
114     switch (nchar)
115     {
116 /* split current window in two parts, horizontally */
117     case 'S':
118     case Ctrl_S:
119     case 's':
120 		CHECK_CMDWIN;
121 		reset_VIsual_and_resel();	/* stop Visual mode */
122 #ifdef FEAT_QUICKFIX
123 		/* When splitting the quickfix window open a new buffer in it,
124 		 * don't replicate the quickfix buffer. */
125 		if (bt_quickfix(curbuf))
126 		    goto newwindow;
127 #endif
128 #ifdef FEAT_GUI
129 		need_mouse_correct = TRUE;
130 #endif
131 		(void)win_split((int)Prenum, 0);
132 		break;
133 
134 /* split current window in two parts, vertically */
135     case Ctrl_V:
136     case 'v':
137 		CHECK_CMDWIN;
138 		reset_VIsual_and_resel();	/* stop Visual mode */
139 #ifdef FEAT_QUICKFIX
140 		/* When splitting the quickfix window open a new buffer in it,
141 		 * don't replicate the quickfix buffer. */
142 		if (bt_quickfix(curbuf))
143 		    goto newwindow;
144 #endif
145 #ifdef FEAT_GUI
146 		need_mouse_correct = TRUE;
147 #endif
148 		(void)win_split((int)Prenum, WSP_VERT);
149 		break;
150 
151 /* split current window and edit alternate file */
152     case Ctrl_HAT:
153     case '^':
154 		CHECK_CMDWIN;
155 		reset_VIsual_and_resel();	/* stop Visual mode */
156 		cmd_with_count("split #", cbuf, sizeof(cbuf), Prenum);
157 		do_cmdline_cmd(cbuf);
158 		break;
159 
160 /* open new window */
161     case Ctrl_N:
162     case 'n':
163 		CHECK_CMDWIN;
164 		reset_VIsual_and_resel();	/* stop Visual mode */
165 #ifdef FEAT_QUICKFIX
166 newwindow:
167 #endif
168 		if (Prenum)
169 		    /* window height */
170 		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
171 		else
172 		    cbuf[0] = NUL;
173 #if defined(FEAT_QUICKFIX)
174 		if (nchar == 'v' || nchar == Ctrl_V)
175 		    STRCAT(cbuf, "v");
176 #endif
177 		STRCAT(cbuf, "new");
178 		do_cmdline_cmd(cbuf);
179 		break;
180 
181 /* quit current window */
182     case Ctrl_Q:
183     case 'q':
184 		reset_VIsual_and_resel();	/* stop Visual mode */
185 		cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
186 		do_cmdline_cmd(cbuf);
187 		break;
188 
189 /* close current window */
190     case Ctrl_C:
191     case 'c':
192 		reset_VIsual_and_resel();	/* stop Visual mode */
193 		cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
194 		do_cmdline_cmd(cbuf);
195 		break;
196 
197 #if defined(FEAT_QUICKFIX)
198 /* close preview window */
199     case Ctrl_Z:
200     case 'z':
201 		CHECK_CMDWIN;
202 		reset_VIsual_and_resel();	/* stop Visual mode */
203 		do_cmdline_cmd((char_u *)"pclose");
204 		break;
205 
206 /* cursor to preview window */
207     case 'P':
208 		FOR_ALL_WINDOWS(wp)
209 		    if (wp->w_p_pvw)
210 			break;
211 		if (wp == NULL)
212 		    EMSG(_("E441: There is no preview window"));
213 		else
214 		    win_goto(wp);
215 		break;
216 #endif
217 
218 /* close all but current window */
219     case Ctrl_O:
220     case 'o':
221 		CHECK_CMDWIN;
222 		reset_VIsual_and_resel();	/* stop Visual mode */
223 		cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
224 		do_cmdline_cmd(cbuf);
225 		break;
226 
227 /* cursor to next window with wrap around */
228     case Ctrl_W:
229     case 'w':
230 /* cursor to previous window with wrap around */
231     case 'W':
232 		CHECK_CMDWIN;
233 		if (ONE_WINDOW && Prenum != 1)	/* just one window */
234 		    beep_flush();
235 		else
236 		{
237 		    if (Prenum)			/* go to specified window */
238 		    {
239 			for (wp = firstwin; --Prenum > 0; )
240 			{
241 			    if (wp->w_next == NULL)
242 				break;
243 			    else
244 				wp = wp->w_next;
245 			}
246 		    }
247 		    else
248 		    {
249 			if (nchar == 'W')	    /* go to previous window */
250 			{
251 			    wp = curwin->w_prev;
252 			    if (wp == NULL)
253 				wp = lastwin;	    /* wrap around */
254 			}
255 			else			    /* go to next window */
256 			{
257 			    wp = curwin->w_next;
258 			    if (wp == NULL)
259 				wp = firstwin;	    /* wrap around */
260 			}
261 		    }
262 		    win_goto(wp);
263 		}
264 		break;
265 
266 /* cursor to window below */
267     case 'j':
268     case K_DOWN:
269     case Ctrl_J:
270 		CHECK_CMDWIN;
271 		win_goto_ver(FALSE, Prenum1);
272 		break;
273 
274 /* cursor to window above */
275     case 'k':
276     case K_UP:
277     case Ctrl_K:
278 		CHECK_CMDWIN;
279 		win_goto_ver(TRUE, Prenum1);
280 		break;
281 
282 /* cursor to left window */
283     case 'h':
284     case K_LEFT:
285     case Ctrl_H:
286     case K_BS:
287 		CHECK_CMDWIN;
288 		win_goto_hor(TRUE, Prenum1);
289 		break;
290 
291 /* cursor to right window */
292     case 'l':
293     case K_RIGHT:
294     case Ctrl_L:
295 		CHECK_CMDWIN;
296 		win_goto_hor(FALSE, Prenum1);
297 		break;
298 
299 /* move window to new tab page */
300     case 'T':
301 		if (one_window())
302 		    MSG(_(m_onlyone));
303 		else
304 		{
305 		    tabpage_T	*oldtab = curtab;
306 		    tabpage_T	*newtab;
307 
308 		    /* First create a new tab with the window, then go back to
309 		     * the old tab and close the window there. */
310 		    wp = curwin;
311 		    if (win_new_tabpage((int)Prenum) == OK
312 						     && valid_tabpage(oldtab))
313 		    {
314 			newtab = curtab;
315 			goto_tabpage_tp(oldtab, TRUE, TRUE);
316 			if (curwin == wp)
317 			    win_close(curwin, FALSE);
318 			if (valid_tabpage(newtab))
319 			    goto_tabpage_tp(newtab, TRUE, TRUE);
320 		    }
321 		}
322 		break;
323 
324 /* cursor to top-left window */
325     case 't':
326     case Ctrl_T:
327 		win_goto(firstwin);
328 		break;
329 
330 /* cursor to bottom-right window */
331     case 'b':
332     case Ctrl_B:
333 		win_goto(lastwin);
334 		break;
335 
336 /* cursor to last accessed (previous) window */
337     case 'p':
338     case Ctrl_P:
339 		if (!win_valid(prevwin))
340 		    beep_flush();
341 		else
342 		    win_goto(prevwin);
343 		break;
344 
345 /* exchange current and next window */
346     case 'x':
347     case Ctrl_X:
348 		CHECK_CMDWIN;
349 		win_exchange(Prenum);
350 		break;
351 
352 /* rotate windows downwards */
353     case Ctrl_R:
354     case 'r':
355 		CHECK_CMDWIN;
356 		reset_VIsual_and_resel();	/* stop Visual mode */
357 		win_rotate(FALSE, (int)Prenum1);    /* downwards */
358 		break;
359 
360 /* rotate windows upwards */
361     case 'R':
362 		CHECK_CMDWIN;
363 		reset_VIsual_and_resel();	/* stop Visual mode */
364 		win_rotate(TRUE, (int)Prenum1);	    /* upwards */
365 		break;
366 
367 /* move window to the very top/bottom/left/right */
368     case 'K':
369     case 'J':
370     case 'H':
371     case 'L':
372 		CHECK_CMDWIN;
373 		win_totop((int)Prenum,
374 			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
375 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
376 		break;
377 
378 /* make all windows the same height */
379     case '=':
380 #ifdef FEAT_GUI
381 		need_mouse_correct = TRUE;
382 #endif
383 		win_equal(NULL, FALSE, 'b');
384 		break;
385 
386 /* increase current window height */
387     case '+':
388 #ifdef FEAT_GUI
389 		need_mouse_correct = TRUE;
390 #endif
391 		win_setheight(curwin->w_height + (int)Prenum1);
392 		break;
393 
394 /* decrease current window height */
395     case '-':
396 #ifdef FEAT_GUI
397 		need_mouse_correct = TRUE;
398 #endif
399 		win_setheight(curwin->w_height - (int)Prenum1);
400 		break;
401 
402 /* set current window height */
403     case Ctrl__:
404     case '_':
405 #ifdef FEAT_GUI
406 		need_mouse_correct = TRUE;
407 #endif
408 		win_setheight(Prenum ? (int)Prenum : 9999);
409 		break;
410 
411 /* increase current window width */
412     case '>':
413 #ifdef FEAT_GUI
414 		need_mouse_correct = TRUE;
415 #endif
416 		win_setwidth(curwin->w_width + (int)Prenum1);
417 		break;
418 
419 /* decrease current window width */
420     case '<':
421 #ifdef FEAT_GUI
422 		need_mouse_correct = TRUE;
423 #endif
424 		win_setwidth(curwin->w_width - (int)Prenum1);
425 		break;
426 
427 /* set current window width */
428     case '|':
429 #ifdef FEAT_GUI
430 		need_mouse_correct = TRUE;
431 #endif
432 		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
433 		break;
434 
435 /* jump to tag and split window if tag exists (in preview window) */
436 #if defined(FEAT_QUICKFIX)
437     case '}':
438 		CHECK_CMDWIN;
439 		if (Prenum)
440 		    g_do_tagpreview = Prenum;
441 		else
442 		    g_do_tagpreview = p_pvh;
443 #endif
444 		/* FALLTHROUGH */
445     case ']':
446     case Ctrl_RSB:
447 		CHECK_CMDWIN;
448 		/* keep Visual mode, can select words to use as a tag */
449 		if (Prenum)
450 		    postponed_split = Prenum;
451 		else
452 		    postponed_split = -1;
453 #ifdef FEAT_QUICKFIX
454 		if (nchar != '}')
455 		    g_do_tagpreview = 0;
456 #endif
457 
458 		/* Execute the command right here, required when "wincmd ]"
459 		 * was used in a function. */
460 		do_nv_ident(Ctrl_RSB, NUL);
461 		break;
462 
463 #ifdef FEAT_SEARCHPATH
464 /* edit file name under cursor in a new window */
465     case 'f':
466     case 'F':
467     case Ctrl_F:
468 wingotofile:
469 		CHECK_CMDWIN;
470 
471 		ptr = grab_file_name(Prenum1, &lnum);
472 		if (ptr != NULL)
473 		{
474 		    tabpage_T	*oldtab = curtab;
475 		    win_T	*oldwin = curwin;
476 # ifdef FEAT_GUI
477 		    need_mouse_correct = TRUE;
478 # endif
479 		    setpcmark();
480 		    if (win_split(0, 0) == OK)
481 		    {
482 			RESET_BINDING(curwin);
483 			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
484 						   ECMD_HIDE, NULL) == FAIL)
485 			{
486 			    /* Failed to open the file, close the window
487 			     * opened for it. */
488 			    win_close(curwin, FALSE);
489 			    goto_tabpage_win(oldtab, oldwin);
490 			}
491 			else if (nchar == 'F' && lnum >= 0)
492 			{
493 			    curwin->w_cursor.lnum = lnum;
494 			    check_cursor_lnum();
495 			    beginline(BL_SOL | BL_FIX);
496 			}
497 		    }
498 		    vim_free(ptr);
499 		}
500 		break;
501 #endif
502 
503 #ifdef FEAT_FIND_ID
504 /* Go to the first occurrence of the identifier under cursor along path in a
505  * new window -- webb
506  */
507     case 'i':			    /* Go to any match */
508     case Ctrl_I:
509 		type = FIND_ANY;
510 		/* FALLTHROUGH */
511     case 'd':			    /* Go to definition, using 'define' */
512     case Ctrl_D:
513 		CHECK_CMDWIN;
514 		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
515 		    break;
516 		find_pattern_in_path(ptr, 0, len, TRUE,
517 			Prenum == 0 ? TRUE : FALSE, type,
518 			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
519 		curwin->w_set_curswant = TRUE;
520 		break;
521 #endif
522 
523 /* Quickfix window only: view the result under the cursor in a new split. */
524 #if defined(FEAT_QUICKFIX)
525     case K_KENTER:
526     case CAR:
527 		if (bt_quickfix(curbuf))
528 		    qf_view_result(TRUE);
529 		break;
530 #endif
531 
532 /* CTRL-W g  extended commands */
533     case 'g':
534     case Ctrl_G:
535 		CHECK_CMDWIN;
536 #ifdef USE_ON_FLY_SCROLL
537 		dont_scroll = TRUE;		/* disallow scrolling here */
538 #endif
539 		++no_mapping;
540 		++allow_keys;   /* no mapping for xchar, but allow key codes */
541 		if (xchar == NUL)
542 		    xchar = plain_vgetc();
543 		LANGMAP_ADJUST(xchar, TRUE);
544 		--no_mapping;
545 		--allow_keys;
546 #ifdef FEAT_CMDL_INFO
547 		(void)add_to_showcmd(xchar);
548 #endif
549 		switch (xchar)
550 		{
551 #if defined(FEAT_QUICKFIX)
552 		    case '}':
553 			xchar = Ctrl_RSB;
554 			if (Prenum)
555 			    g_do_tagpreview = Prenum;
556 			else
557 			    g_do_tagpreview = p_pvh;
558 #endif
559 			/* FALLTHROUGH */
560 		    case ']':
561 		    case Ctrl_RSB:
562 			/* keep Visual mode, can select words to use as a tag */
563 			if (Prenum)
564 			    postponed_split = Prenum;
565 			else
566 			    postponed_split = -1;
567 
568 			/* Execute the command right here, required when
569 			 * "wincmd g}" was used in a function. */
570 			do_nv_ident('g', xchar);
571 			break;
572 
573 #ifdef FEAT_SEARCHPATH
574 		    case 'f':	    /* CTRL-W gf: "gf" in a new tab page */
575 		    case 'F':	    /* CTRL-W gF: "gF" in a new tab page */
576 			cmdmod.tab = tabpage_index(curtab) + 1;
577 			nchar = xchar;
578 			goto wingotofile;
579 #endif
580 		    default:
581 			beep_flush();
582 			break;
583 		}
584 		break;
585 
586     default:	beep_flush();
587 		break;
588     }
589 }
590 
591 /*
592  * Figure out the address type for ":wnncmd".
593  */
594     void
595 get_wincmd_addr_type(char_u *arg, exarg_T *eap)
596 {
597     switch (*arg)
598     {
599     case 'S':
600     case Ctrl_S:
601     case 's':
602     case Ctrl_N:
603     case 'n':
604     case 'j':
605     case Ctrl_J:
606     case 'k':
607     case Ctrl_K:
608     case 'T':
609     case Ctrl_R:
610     case 'r':
611     case 'R':
612     case 'K':
613     case 'J':
614     case '+':
615     case '-':
616     case Ctrl__:
617     case '_':
618     case '|':
619     case ']':
620     case Ctrl_RSB:
621     case 'g':
622     case Ctrl_G:
623     case Ctrl_V:
624     case 'v':
625     case 'h':
626     case Ctrl_H:
627     case 'l':
628     case Ctrl_L:
629     case 'H':
630     case 'L':
631     case '>':
632     case '<':
633 #if defined(FEAT_QUICKFIX)
634     case '}':
635 #endif
636 #ifdef FEAT_SEARCHPATH
637     case 'f':
638     case 'F':
639     case Ctrl_F:
640 #endif
641 #ifdef FEAT_FIND_ID
642     case 'i':
643     case Ctrl_I:
644     case 'd':
645     case Ctrl_D:
646 #endif
647 		/* window size or any count */
648 		eap->addr_type = ADDR_LINES;
649 		break;
650 
651     case Ctrl_HAT:
652     case '^':
653 		/* buffer number */
654 		eap->addr_type = ADDR_BUFFERS;
655 		break;
656 
657     case Ctrl_Q:
658     case 'q':
659     case Ctrl_C:
660     case 'c':
661     case Ctrl_O:
662     case 'o':
663     case Ctrl_W:
664     case 'w':
665     case 'W':
666     case 'x':
667     case Ctrl_X:
668 		/* window number */
669 		eap->addr_type = ADDR_WINDOWS;
670 		break;
671 
672 #if defined(FEAT_QUICKFIX)
673     case Ctrl_Z:
674     case 'z':
675     case 'P':
676 #endif
677     case 't':
678     case Ctrl_T:
679     case 'b':
680     case Ctrl_B:
681     case 'p':
682     case Ctrl_P:
683     case '=':
684     case CAR:
685 		/* no count */
686 		eap->addr_type = 0;
687 		break;
688     }
689 }
690 
691     static void
692 cmd_with_count(
693     char	*cmd,
694     char_u	*bufp,
695     size_t	bufsize,
696     long	Prenum)
697 {
698     size_t	len = STRLEN(cmd);
699 
700     STRCPY(bufp, cmd);
701     if (Prenum > 0)
702 	vim_snprintf((char *)bufp + len, bufsize - len, "%ld", Prenum);
703 }
704 
705 /*
706  * split the current window, implements CTRL-W s and :split
707  *
708  * "size" is the height or width for the new window, 0 to use half of current
709  * height or width.
710  *
711  * "flags":
712  * WSP_ROOM: require enough room for new window
713  * WSP_VERT: vertical split.
714  * WSP_TOP:  open window at the top-left of the shell (help window).
715  * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
716  * WSP_HELP: creating the help window, keep layout snapshot
717  *
718  * return FAIL for failure, OK otherwise
719  */
720     int
721 win_split(int size, int flags)
722 {
723     /* When the ":tab" modifier was used open a new tab page instead. */
724     if (may_open_tabpage() == OK)
725 	return OK;
726 
727     /* Add flags from ":vertical", ":topleft" and ":botright". */
728     flags |= cmdmod.split;
729     if ((flags & WSP_TOP) && (flags & WSP_BOT))
730     {
731 	EMSG(_("E442: Can't split topleft and botright at the same time"));
732 	return FAIL;
733     }
734 
735     /* When creating the help window make a snapshot of the window layout.
736      * Otherwise clear the snapshot, it's now invalid. */
737     if (flags & WSP_HELP)
738 	make_snapshot(SNAP_HELP_IDX);
739     else
740 	clear_snapshot(curtab, SNAP_HELP_IDX);
741 
742     return win_split_ins(size, flags, NULL, 0);
743 }
744 
745 /*
746  * When "new_wp" is NULL: split the current window in two.
747  * When "new_wp" is not NULL: insert this window at the far
748  * top/left/right/bottom.
749  * return FAIL for failure, OK otherwise
750  */
751     int
752 win_split_ins(
753     int		size,
754     int		flags,
755     win_T	*new_wp,
756     int		dir)
757 {
758     win_T	*wp = new_wp;
759     win_T	*oldwin;
760     int		new_size = size;
761     int		i;
762     int		need_status = 0;
763     int		do_equal = FALSE;
764     int		needed;
765     int		available;
766     int		oldwin_height = 0;
767     int		layout;
768     frame_T	*frp, *curfrp, *frp2, *prevfrp;
769     int		before;
770     int		minheight;
771     int		wmh1;
772     int		did_set_fraction = FALSE;
773 
774     if (flags & WSP_TOP)
775 	oldwin = firstwin;
776     else if (flags & WSP_BOT)
777 	oldwin = lastwin;
778     else
779 	oldwin = curwin;
780 
781     /* add a status line when p_ls == 1 and splitting the first window */
782     if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
783     {
784 	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
785 	{
786 	    EMSG(_(e_noroom));
787 	    return FAIL;
788 	}
789 	need_status = STATUS_HEIGHT;
790     }
791 
792 #ifdef FEAT_GUI
793     /* May be needed for the scrollbars that are going to change. */
794     if (gui.in_use)
795 	out_flush();
796 #endif
797 
798     if (flags & WSP_VERT)
799     {
800 	int	wmw1;
801 	int	minwidth;
802 
803 	layout = FR_ROW;
804 
805 	/*
806 	 * Check if we are able to split the current window and compute its
807 	 * width.
808 	 */
809 	/* Current window requires at least 1 space. */
810 	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
811 	needed = wmw1 + 1;
812 	if (flags & WSP_ROOM)
813 	    needed += p_wiw - wmw1;
814 	if (flags & (WSP_BOT | WSP_TOP))
815 	{
816 	    minwidth = frame_minwidth(topframe, NOWIN);
817 	    available = topframe->fr_width;
818 	    needed += minwidth;
819 	}
820 	else if (p_ea)
821 	{
822 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
823 	    prevfrp = oldwin->w_frame;
824 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
825 							frp = frp->fr_parent)
826 	    {
827 		if (frp->fr_layout == FR_ROW)
828 		    for (frp2 = frp->fr_child; frp2 != NULL;
829 							frp2 = frp2->fr_next)
830 			if (frp2 != prevfrp)
831 			    minwidth += frame_minwidth(frp2, NOWIN);
832 		prevfrp = frp;
833 	    }
834 	    available = topframe->fr_width;
835 	    needed += minwidth;
836 	}
837 	else
838 	{
839 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
840 	    available = oldwin->w_frame->fr_width;
841 	    needed += minwidth;
842 	}
843 	if (available < needed && new_wp == NULL)
844 	{
845 	    EMSG(_(e_noroom));
846 	    return FAIL;
847 	}
848 	if (new_size == 0)
849 	    new_size = oldwin->w_width / 2;
850 	if (new_size > available - minwidth - 1)
851 	    new_size = available - minwidth - 1;
852 	if (new_size < wmw1)
853 	    new_size = wmw1;
854 
855 	/* if it doesn't fit in the current window, need win_equal() */
856 	if (oldwin->w_width - new_size - 1 < p_wmw)
857 	    do_equal = TRUE;
858 
859 	/* We don't like to take lines for the new window from a
860 	 * 'winfixwidth' window.  Take them from a window to the left or right
861 	 * instead, if possible. Add one for the separator. */
862 	if (oldwin->w_p_wfw)
863 	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
864 
865 	/* Only make all windows the same width if one of them (except oldwin)
866 	 * is wider than one of the split windows. */
867 	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
868 	   && oldwin->w_frame->fr_parent != NULL)
869 	{
870 	    frp = oldwin->w_frame->fr_parent->fr_child;
871 	    while (frp != NULL)
872 	    {
873 		if (frp->fr_win != oldwin && frp->fr_win != NULL
874 			&& (frp->fr_win->w_width > new_size
875 			    || frp->fr_win->w_width > oldwin->w_width
876 							      - new_size - 1))
877 		{
878 		    do_equal = TRUE;
879 		    break;
880 		}
881 		frp = frp->fr_next;
882 	    }
883 	}
884     }
885     else
886     {
887 	layout = FR_COL;
888 
889 	/*
890 	 * Check if we are able to split the current window and compute its
891 	 * height.
892 	 */
893 	/* Current window requires at least 1 space. */
894 	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
895 	needed = wmh1 + STATUS_HEIGHT;
896 	if (flags & WSP_ROOM)
897 	    needed += p_wh - wmh1;
898 	if (flags & (WSP_BOT | WSP_TOP))
899 	{
900 	    minheight = frame_minheight(topframe, NOWIN) + need_status;
901 	    available = topframe->fr_height;
902 	    needed += minheight;
903 	}
904 	else if (p_ea)
905 	{
906 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
907 	    prevfrp = oldwin->w_frame;
908 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
909 							frp = frp->fr_parent)
910 	    {
911 		if (frp->fr_layout == FR_COL)
912 		    for (frp2 = frp->fr_child; frp2 != NULL;
913 							frp2 = frp2->fr_next)
914 			if (frp2 != prevfrp)
915 			    minheight += frame_minheight(frp2, NOWIN);
916 		prevfrp = frp;
917 	    }
918 	    available = topframe->fr_height;
919 	    needed += minheight;
920 	}
921 	else
922 	{
923 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
924 	    available = oldwin->w_frame->fr_height;
925 	    needed += minheight;
926 	}
927 	if (available < needed && new_wp == NULL)
928 	{
929 	    EMSG(_(e_noroom));
930 	    return FAIL;
931 	}
932 	oldwin_height = oldwin->w_height;
933 	if (need_status)
934 	{
935 	    oldwin->w_status_height = STATUS_HEIGHT;
936 	    oldwin_height -= STATUS_HEIGHT;
937 	}
938 	if (new_size == 0)
939 	    new_size = oldwin_height / 2;
940 	if (new_size > available - minheight - STATUS_HEIGHT)
941 	    new_size = available - minheight - STATUS_HEIGHT;
942 	if (new_size < wmh1)
943 	    new_size = wmh1;
944 
945 	/* if it doesn't fit in the current window, need win_equal() */
946 	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
947 	    do_equal = TRUE;
948 
949 	/* We don't like to take lines for the new window from a
950 	 * 'winfixheight' window.  Take them from a window above or below
951 	 * instead, if possible. */
952 	if (oldwin->w_p_wfh)
953 	{
954 	    /* Set w_fraction now so that the cursor keeps the same relative
955 	     * vertical position using the old height. */
956 	    set_fraction(oldwin);
957 	    did_set_fraction = TRUE;
958 
959 	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
960 								      oldwin);
961 	    oldwin_height = oldwin->w_height;
962 	    if (need_status)
963 		oldwin_height -= STATUS_HEIGHT;
964 	}
965 
966 	/* Only make all windows the same height if one of them (except oldwin)
967 	 * is higher than one of the split windows. */
968 	if (!do_equal && p_ea && size == 0 && *p_ead != 'h'
969 	   && oldwin->w_frame->fr_parent != NULL)
970 	{
971 	    frp = oldwin->w_frame->fr_parent->fr_child;
972 	    while (frp != NULL)
973 	    {
974 		if (frp->fr_win != oldwin && frp->fr_win != NULL
975 			&& (frp->fr_win->w_height > new_size
976 			    || frp->fr_win->w_height > oldwin_height - new_size
977 							      - STATUS_HEIGHT))
978 		{
979 		    do_equal = TRUE;
980 		    break;
981 		}
982 		frp = frp->fr_next;
983 	    }
984 	}
985     }
986 
987     /*
988      * allocate new window structure and link it in the window list
989      */
990     if ((flags & WSP_TOP) == 0
991 	    && ((flags & WSP_BOT)
992 		|| (flags & WSP_BELOW)
993 		|| (!(flags & WSP_ABOVE)
994 		    && ( (flags & WSP_VERT) ? p_spr : p_sb))))
995     {
996 	/* new window below/right of current one */
997 	if (new_wp == NULL)
998 	    wp = win_alloc(oldwin, FALSE);
999 	else
1000 	    win_append(oldwin, wp);
1001     }
1002     else
1003     {
1004 	if (new_wp == NULL)
1005 	    wp = win_alloc(oldwin->w_prev, FALSE);
1006 	else
1007 	    win_append(oldwin->w_prev, wp);
1008     }
1009 
1010     if (new_wp == NULL)
1011     {
1012 	if (wp == NULL)
1013 	    return FAIL;
1014 
1015 	new_frame(wp);
1016 	if (wp->w_frame == NULL)
1017 	{
1018 	    win_free(wp, NULL);
1019 	    return FAIL;
1020 	}
1021 
1022 	/* make the contents of the new window the same as the current one */
1023 	win_init(wp, curwin, flags);
1024     }
1025 
1026     /*
1027      * Reorganise the tree of frames to insert the new window.
1028      */
1029     if (flags & (WSP_TOP | WSP_BOT))
1030     {
1031 	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
1032 	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
1033 	{
1034 	    curfrp = topframe->fr_child;
1035 	    if (flags & WSP_BOT)
1036 		while (curfrp->fr_next != NULL)
1037 		    curfrp = curfrp->fr_next;
1038 	}
1039 	else
1040 	    curfrp = topframe;
1041 	before = (flags & WSP_TOP);
1042     }
1043     else
1044     {
1045 	curfrp = oldwin->w_frame;
1046 	if (flags & WSP_BELOW)
1047 	    before = FALSE;
1048 	else if (flags & WSP_ABOVE)
1049 	    before = TRUE;
1050 	else if (flags & WSP_VERT)
1051 	    before = !p_spr;
1052 	else
1053 	    before = !p_sb;
1054     }
1055     if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
1056     {
1057 	/* Need to create a new frame in the tree to make a branch. */
1058 	frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
1059 	*frp = *curfrp;
1060 	curfrp->fr_layout = layout;
1061 	frp->fr_parent = curfrp;
1062 	frp->fr_next = NULL;
1063 	frp->fr_prev = NULL;
1064 	curfrp->fr_child = frp;
1065 	curfrp->fr_win = NULL;
1066 	curfrp = frp;
1067 	if (frp->fr_win != NULL)
1068 	    oldwin->w_frame = frp;
1069 	else
1070 	    for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
1071 		frp->fr_parent = curfrp;
1072     }
1073 
1074     if (new_wp == NULL)
1075 	frp = wp->w_frame;
1076     else
1077 	frp = new_wp->w_frame;
1078     frp->fr_parent = curfrp->fr_parent;
1079 
1080     /* Insert the new frame at the right place in the frame list. */
1081     if (before)
1082 	frame_insert(curfrp, frp);
1083     else
1084 	frame_append(curfrp, frp);
1085 
1086     /* Set w_fraction now so that the cursor keeps the same relative
1087      * vertical position. */
1088     if (!did_set_fraction)
1089 	set_fraction(oldwin);
1090     wp->w_fraction = oldwin->w_fraction;
1091 
1092     if (flags & WSP_VERT)
1093     {
1094 	wp->w_p_scr = curwin->w_p_scr;
1095 
1096 	if (need_status)
1097 	{
1098 	    win_new_height(oldwin, oldwin->w_height - 1);
1099 	    oldwin->w_status_height = need_status;
1100 	}
1101 	if (flags & (WSP_TOP | WSP_BOT))
1102 	{
1103 	    /* set height and row of new window to full height */
1104 	    wp->w_winrow = tabline_height();
1105 	    win_new_height(wp, curfrp->fr_height - (p_ls > 0)
1106 							  - WINBAR_HEIGHT(wp));
1107 	    wp->w_status_height = (p_ls > 0);
1108 	}
1109 	else
1110 	{
1111 	    /* height and row of new window is same as current window */
1112 	    wp->w_winrow = oldwin->w_winrow;
1113 	    win_new_height(wp, VISIBLE_HEIGHT(oldwin));
1114 	    wp->w_status_height = oldwin->w_status_height;
1115 	}
1116 	frp->fr_height = curfrp->fr_height;
1117 
1118 	/* "new_size" of the current window goes to the new window, use
1119 	 * one column for the vertical separator */
1120 	win_new_width(wp, new_size);
1121 	if (before)
1122 	    wp->w_vsep_width = 1;
1123 	else
1124 	{
1125 	    wp->w_vsep_width = oldwin->w_vsep_width;
1126 	    oldwin->w_vsep_width = 1;
1127 	}
1128 	if (flags & (WSP_TOP | WSP_BOT))
1129 	{
1130 	    if (flags & WSP_BOT)
1131 		frame_add_vsep(curfrp);
1132 	    /* Set width of neighbor frame */
1133 	    frame_new_width(curfrp, curfrp->fr_width
1134 		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
1135 								       FALSE);
1136 	}
1137 	else
1138 	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
1139 	if (before)	/* new window left of current one */
1140 	{
1141 	    wp->w_wincol = oldwin->w_wincol;
1142 	    oldwin->w_wincol += new_size + 1;
1143 	}
1144 	else		/* new window right of current one */
1145 	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
1146 	frame_fix_width(oldwin);
1147 	frame_fix_width(wp);
1148     }
1149     else
1150     {
1151 	/* width and column of new window is same as current window */
1152 	if (flags & (WSP_TOP | WSP_BOT))
1153 	{
1154 	    wp->w_wincol = 0;
1155 	    win_new_width(wp, Columns);
1156 	    wp->w_vsep_width = 0;
1157 	}
1158 	else
1159 	{
1160 	    wp->w_wincol = oldwin->w_wincol;
1161 	    win_new_width(wp, oldwin->w_width);
1162 	    wp->w_vsep_width = oldwin->w_vsep_width;
1163 	}
1164 	frp->fr_width = curfrp->fr_width;
1165 
1166 	/* "new_size" of the current window goes to the new window, use
1167 	 * one row for the status line */
1168 	win_new_height(wp, new_size);
1169 	if (flags & (WSP_TOP | WSP_BOT))
1170 	{
1171 	    int new_fr_height = curfrp->fr_height - new_size
1172 							  + WINBAR_HEIGHT(wp) ;
1173 
1174 	    if (!((flags & WSP_BOT) && p_ls == 0))
1175 		new_fr_height -= STATUS_HEIGHT;
1176 	    frame_new_height(curfrp, new_fr_height, flags & WSP_TOP, FALSE);
1177 	}
1178 	else
1179 	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
1180 	if (before)	/* new window above current one */
1181 	{
1182 	    wp->w_winrow = oldwin->w_winrow;
1183 	    wp->w_status_height = STATUS_HEIGHT;
1184 	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
1185 	}
1186 	else		/* new window below current one */
1187 	{
1188 	    wp->w_winrow = oldwin->w_winrow + VISIBLE_HEIGHT(oldwin)
1189 							       + STATUS_HEIGHT;
1190 	    wp->w_status_height = oldwin->w_status_height;
1191 	    if (!(flags & WSP_BOT))
1192 		oldwin->w_status_height = STATUS_HEIGHT;
1193 	}
1194 	if (flags & WSP_BOT)
1195 	    frame_add_statusline(curfrp);
1196 	frame_fix_height(wp);
1197 	frame_fix_height(oldwin);
1198     }
1199 
1200     if (flags & (WSP_TOP | WSP_BOT))
1201 	(void)win_comp_pos();
1202 
1203     /*
1204      * Both windows need redrawing
1205      */
1206     redraw_win_later(wp, NOT_VALID);
1207     wp->w_redr_status = TRUE;
1208     redraw_win_later(oldwin, NOT_VALID);
1209     oldwin->w_redr_status = TRUE;
1210 
1211     if (need_status)
1212     {
1213 	msg_row = Rows - 1;
1214 	msg_col = sc_col;
1215 	msg_clr_eos_force();	/* Old command/ruler may still be there */
1216 	comp_col();
1217 	msg_row = Rows - 1;
1218 	msg_col = 0;	/* put position back at start of line */
1219     }
1220 
1221     /*
1222      * equalize the window sizes.
1223      */
1224     if (do_equal || dir != 0)
1225 	win_equal(wp, TRUE,
1226 		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
1227 		: dir == 'h' ? 'b' : 'v');
1228 
1229     /* Don't change the window height/width to 'winheight' / 'winwidth' if a
1230      * size was given. */
1231     if (flags & WSP_VERT)
1232     {
1233 	i = p_wiw;
1234 	if (size != 0)
1235 	    p_wiw = size;
1236 
1237 # ifdef FEAT_GUI
1238 	/* When 'guioptions' includes 'L' or 'R' may have to add scrollbars. */
1239 	if (gui.in_use)
1240 	    gui_init_which_components(NULL);
1241 # endif
1242     }
1243     else
1244     {
1245 	i = p_wh;
1246 	if (size != 0)
1247 	    p_wh = size;
1248     }
1249 
1250 #ifdef FEAT_JUMPLIST
1251     /* Keep same changelist position in new window. */
1252     wp->w_changelistidx = oldwin->w_changelistidx;
1253 #endif
1254 
1255     /*
1256      * make the new window the current window
1257      */
1258     win_enter_ext(wp, FALSE, FALSE, TRUE, TRUE, TRUE);
1259     if (flags & WSP_VERT)
1260 	p_wiw = i;
1261     else
1262 	p_wh = i;
1263 
1264     return OK;
1265 }
1266 
1267 
1268 /*
1269  * Initialize window "newp" from window "oldp".
1270  * Used when splitting a window and when creating a new tab page.
1271  * The windows will both edit the same buffer.
1272  * WSP_NEWLOC may be specified in flags to prevent the location list from
1273  * being copied.
1274  */
1275     static void
1276 win_init(win_T *newp, win_T *oldp, int flags UNUSED)
1277 {
1278     int		i;
1279 
1280     newp->w_buffer = oldp->w_buffer;
1281 #ifdef FEAT_SYN_HL
1282     newp->w_s = &(oldp->w_buffer->b_s);
1283 #endif
1284     oldp->w_buffer->b_nwindows++;
1285     newp->w_cursor = oldp->w_cursor;
1286     newp->w_valid = 0;
1287     newp->w_curswant = oldp->w_curswant;
1288     newp->w_set_curswant = oldp->w_set_curswant;
1289     newp->w_topline = oldp->w_topline;
1290 #ifdef FEAT_DIFF
1291     newp->w_topfill = oldp->w_topfill;
1292 #endif
1293     newp->w_leftcol = oldp->w_leftcol;
1294     newp->w_pcmark = oldp->w_pcmark;
1295     newp->w_prev_pcmark = oldp->w_prev_pcmark;
1296     newp->w_alt_fnum = oldp->w_alt_fnum;
1297     newp->w_wrow = oldp->w_wrow;
1298     newp->w_fraction = oldp->w_fraction;
1299     newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
1300 #ifdef FEAT_JUMPLIST
1301     copy_jumplist(oldp, newp);
1302 #endif
1303 #ifdef FEAT_QUICKFIX
1304     if (flags & WSP_NEWLOC)
1305     {
1306 	/* Don't copy the location list.  */
1307 	newp->w_llist = NULL;
1308 	newp->w_llist_ref = NULL;
1309     }
1310     else
1311 	copy_loclist(oldp, newp);
1312 #endif
1313     newp->w_localdir = (oldp->w_localdir == NULL)
1314 				    ? NULL : vim_strsave(oldp->w_localdir);
1315 
1316     /* copy tagstack and folds */
1317     for (i = 0; i < oldp->w_tagstacklen; i++)
1318     {
1319 	newp->w_tagstack[i] = oldp->w_tagstack[i];
1320 	if (newp->w_tagstack[i].tagname != NULL)
1321 	    newp->w_tagstack[i].tagname =
1322 				   vim_strsave(newp->w_tagstack[i].tagname);
1323     }
1324     newp->w_tagstackidx = oldp->w_tagstackidx;
1325     newp->w_tagstacklen = oldp->w_tagstacklen;
1326 #ifdef FEAT_FOLDING
1327     copyFoldingState(oldp, newp);
1328 #endif
1329 
1330     win_init_some(newp, oldp);
1331 
1332 #ifdef FEAT_SYN_HL
1333     check_colorcolumn(newp);
1334 #endif
1335 }
1336 
1337 /*
1338  * Initialize window "newp" from window "old".
1339  * Only the essential things are copied.
1340  */
1341     static void
1342 win_init_some(win_T *newp, win_T *oldp)
1343 {
1344     /* Use the same argument list. */
1345     newp->w_alist = oldp->w_alist;
1346     ++newp->w_alist->al_refcount;
1347     newp->w_arg_idx = oldp->w_arg_idx;
1348 
1349     /* copy options from existing window */
1350     win_copy_options(oldp, newp);
1351 }
1352 
1353 
1354 /*
1355  * Check if "win" is a pointer to an existing window in the current tab page.
1356  */
1357     int
1358 win_valid(win_T *win)
1359 {
1360     win_T	*wp;
1361 
1362     if (win == NULL)
1363 	return FALSE;
1364     FOR_ALL_WINDOWS(wp)
1365 	if (wp == win)
1366 	    return TRUE;
1367     return FALSE;
1368 }
1369 
1370 /*
1371  * Check if "win" is a pointer to an existing window in any tab page.
1372  */
1373     int
1374 win_valid_any_tab(win_T *win)
1375 {
1376     win_T	*wp;
1377     tabpage_T	*tp;
1378 
1379     if (win == NULL)
1380 	return FALSE;
1381     FOR_ALL_TABPAGES(tp)
1382     {
1383 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
1384 	{
1385 	    if (wp == win)
1386 		return TRUE;
1387 	}
1388     }
1389     return FALSE;
1390 }
1391 
1392 /*
1393  * Return the number of windows.
1394  */
1395     int
1396 win_count(void)
1397 {
1398     win_T	*wp;
1399     int		count = 0;
1400 
1401     FOR_ALL_WINDOWS(wp)
1402 	++count;
1403     return count;
1404 }
1405 
1406 /*
1407  * Make "count" windows on the screen.
1408  * Return actual number of windows on the screen.
1409  * Must be called when there is just one window, filling the whole screen
1410  * (excluding the command line).
1411  */
1412     int
1413 make_windows(
1414     int		count,
1415     int		vertical UNUSED)  /* split windows vertically if TRUE */
1416 {
1417     int		maxcount;
1418     int		todo;
1419 
1420     if (vertical)
1421     {
1422 	/* Each windows needs at least 'winminwidth' lines and a separator
1423 	 * column. */
1424 	maxcount = (curwin->w_width + curwin->w_vsep_width
1425 					     - (p_wiw - p_wmw)) / (p_wmw + 1);
1426     }
1427     else
1428     {
1429 	/* Each window needs at least 'winminheight' lines and a status line. */
1430 	maxcount = (VISIBLE_HEIGHT(curwin) + curwin->w_status_height
1431 				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
1432     }
1433 
1434     if (maxcount < 2)
1435 	maxcount = 2;
1436     if (count > maxcount)
1437 	count = maxcount;
1438 
1439     /*
1440      * add status line now, otherwise first window will be too big
1441      */
1442     if (count > 1)
1443 	last_status(TRUE);
1444 
1445     /*
1446      * Don't execute autocommands while creating the windows.  Must do that
1447      * when putting the buffers in the windows.
1448      */
1449     block_autocmds();
1450 
1451     /* todo is number of windows left to create */
1452     for (todo = count - 1; todo > 0; --todo)
1453 	if (vertical)
1454 	{
1455 	    if (win_split(curwin->w_width - (curwin->w_width - todo)
1456 			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
1457 		break;
1458 	}
1459 	else
1460 	{
1461 	    if (win_split(curwin->w_height - (curwin->w_height - todo
1462 			    * STATUS_HEIGHT) / (todo + 1)
1463 			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
1464 		break;
1465 	}
1466 
1467     unblock_autocmds();
1468 
1469     /* return actual number of windows */
1470     return (count - todo);
1471 }
1472 
1473 /*
1474  * Exchange current and next window
1475  */
1476     static void
1477 win_exchange(long Prenum)
1478 {
1479     frame_T	*frp;
1480     frame_T	*frp2;
1481     win_T	*wp;
1482     win_T	*wp2;
1483     int		temp;
1484 
1485     if (ONE_WINDOW)	    /* just one window */
1486     {
1487 	beep_flush();
1488 	return;
1489     }
1490 
1491 #ifdef FEAT_GUI
1492     need_mouse_correct = TRUE;
1493 #endif
1494 
1495     /*
1496      * find window to exchange with
1497      */
1498     if (Prenum)
1499     {
1500 	frp = curwin->w_frame->fr_parent->fr_child;
1501 	while (frp != NULL && --Prenum > 0)
1502 	    frp = frp->fr_next;
1503     }
1504     else if (curwin->w_frame->fr_next != NULL)	/* Swap with next */
1505 	frp = curwin->w_frame->fr_next;
1506     else    /* Swap last window in row/col with previous */
1507 	frp = curwin->w_frame->fr_prev;
1508 
1509     /* We can only exchange a window with another window, not with a frame
1510      * containing windows. */
1511     if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
1512 	return;
1513     wp = frp->fr_win;
1514 
1515 /*
1516  * 1. remove curwin from the list. Remember after which window it was in wp2
1517  * 2. insert curwin before wp in the list
1518  * if wp != wp2
1519  *    3. remove wp from the list
1520  *    4. insert wp after wp2
1521  * 5. exchange the status line height and vsep width.
1522  */
1523     wp2 = curwin->w_prev;
1524     frp2 = curwin->w_frame->fr_prev;
1525     if (wp->w_prev != curwin)
1526     {
1527 	win_remove(curwin, NULL);
1528 	frame_remove(curwin->w_frame);
1529 	win_append(wp->w_prev, curwin);
1530 	frame_insert(frp, curwin->w_frame);
1531     }
1532     if (wp != wp2)
1533     {
1534 	win_remove(wp, NULL);
1535 	frame_remove(wp->w_frame);
1536 	win_append(wp2, wp);
1537 	if (frp2 == NULL)
1538 	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
1539 	else
1540 	    frame_append(frp2, wp->w_frame);
1541     }
1542     temp = curwin->w_status_height;
1543     curwin->w_status_height = wp->w_status_height;
1544     wp->w_status_height = temp;
1545     temp = curwin->w_vsep_width;
1546     curwin->w_vsep_width = wp->w_vsep_width;
1547     wp->w_vsep_width = temp;
1548 
1549     /* If the windows are not in the same frame, exchange the sizes to avoid
1550      * messing up the window layout.  Otherwise fix the frame sizes. */
1551     if (curwin->w_frame->fr_parent != wp->w_frame->fr_parent)
1552     {
1553 	temp = curwin->w_height;
1554 	curwin->w_height = wp->w_height;
1555 	wp->w_height = temp;
1556 	temp = curwin->w_width;
1557 	curwin->w_width = wp->w_width;
1558 	wp->w_width = temp;
1559     }
1560     else
1561     {
1562 	frame_fix_height(curwin);
1563 	frame_fix_height(wp);
1564 	frame_fix_width(curwin);
1565 	frame_fix_width(wp);
1566     }
1567 
1568     (void)win_comp_pos();		/* recompute window positions */
1569 
1570     win_enter(wp, TRUE);
1571     redraw_later(CLEAR);
1572 }
1573 
1574 /*
1575  * rotate windows: if upwards TRUE the second window becomes the first one
1576  *		   if upwards FALSE the first window becomes the second one
1577  */
1578     static void
1579 win_rotate(int upwards, int count)
1580 {
1581     win_T	*wp1;
1582     win_T	*wp2;
1583     frame_T	*frp;
1584     int		n;
1585 
1586     if (ONE_WINDOW)		/* nothing to do */
1587     {
1588 	beep_flush();
1589 	return;
1590     }
1591 
1592 #ifdef FEAT_GUI
1593     need_mouse_correct = TRUE;
1594 #endif
1595 
1596     /* Check if all frames in this row/col have one window. */
1597     for (frp = curwin->w_frame->fr_parent->fr_child; frp != NULL;
1598 							   frp = frp->fr_next)
1599 	if (frp->fr_win == NULL)
1600 	{
1601 	    EMSG(_("E443: Cannot rotate when another window is split"));
1602 	    return;
1603 	}
1604 
1605     while (count--)
1606     {
1607 	if (upwards)		/* first window becomes last window */
1608 	{
1609 	    /* remove first window/frame from the list */
1610 	    frp = curwin->w_frame->fr_parent->fr_child;
1611 	    wp1 = frp->fr_win;
1612 	    win_remove(wp1, NULL);
1613 	    frame_remove(frp);
1614 
1615 	    /* find last frame and append removed window/frame after it */
1616 	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
1617 		;
1618 	    win_append(frp->fr_win, wp1);
1619 	    frame_append(frp, wp1->w_frame);
1620 
1621 	    wp2 = frp->fr_win;		/* previously last window */
1622 	}
1623 	else			/* last window becomes first window */
1624 	{
1625 	    /* find last window/frame in the list and remove it */
1626 	    for (frp = curwin->w_frame; frp->fr_next != NULL;
1627 							   frp = frp->fr_next)
1628 		;
1629 	    wp1 = frp->fr_win;
1630 	    wp2 = wp1->w_prev;		    /* will become last window */
1631 	    win_remove(wp1, NULL);
1632 	    frame_remove(frp);
1633 
1634 	    /* append the removed window/frame before the first in the list */
1635 	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
1636 	    frame_insert(frp->fr_parent->fr_child, frp);
1637 	}
1638 
1639 	/* exchange status height and vsep width of old and new last window */
1640 	n = wp2->w_status_height;
1641 	wp2->w_status_height = wp1->w_status_height;
1642 	wp1->w_status_height = n;
1643 	frame_fix_height(wp1);
1644 	frame_fix_height(wp2);
1645 	n = wp2->w_vsep_width;
1646 	wp2->w_vsep_width = wp1->w_vsep_width;
1647 	wp1->w_vsep_width = n;
1648 	frame_fix_width(wp1);
1649 	frame_fix_width(wp2);
1650 
1651 	/* recompute w_winrow and w_wincol for all windows */
1652 	(void)win_comp_pos();
1653     }
1654 
1655     redraw_later(CLEAR);
1656 }
1657 
1658 /*
1659  * Move the current window to the very top/bottom/left/right of the screen.
1660  */
1661     static void
1662 win_totop(int size, int flags)
1663 {
1664     int		dir;
1665     int		height = curwin->w_height;
1666 
1667     if (ONE_WINDOW)
1668     {
1669 	beep_flush();
1670 	return;
1671     }
1672 
1673     /* Remove the window and frame from the tree of frames. */
1674     (void)winframe_remove(curwin, &dir, NULL);
1675     win_remove(curwin, NULL);
1676     last_status(FALSE);	    /* may need to remove last status line */
1677     (void)win_comp_pos();   /* recompute window positions */
1678 
1679     /* Split a window on the desired side and put the window there. */
1680     (void)win_split_ins(size, flags, curwin, dir);
1681     if (!(flags & WSP_VERT))
1682     {
1683 	win_setheight(height);
1684 	if (p_ea)
1685 	    win_equal(curwin, TRUE, 'v');
1686     }
1687 
1688 #if defined(FEAT_GUI)
1689     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
1690      * scrollbars.  Have to update them anyway. */
1691     gui_may_update_scrollbars();
1692 #endif
1693 }
1694 
1695 /*
1696  * Move window "win1" to below/right of "win2" and make "win1" the current
1697  * window.  Only works within the same frame!
1698  */
1699     void
1700 win_move_after(win_T *win1, win_T *win2)
1701 {
1702     int		height;
1703 
1704     /* check if the arguments are reasonable */
1705     if (win1 == win2)
1706 	return;
1707 
1708     /* check if there is something to do */
1709     if (win2->w_next != win1)
1710     {
1711 	/* may need move the status line/vertical separator of the last window
1712 	 * */
1713 	if (win1 == lastwin)
1714 	{
1715 	    height = win1->w_prev->w_status_height;
1716 	    win1->w_prev->w_status_height = win1->w_status_height;
1717 	    win1->w_status_height = height;
1718 	    if (win1->w_prev->w_vsep_width == 1)
1719 	    {
1720 		/* Remove the vertical separator from the last-but-one window,
1721 		 * add it to the last window.  Adjust the frame widths. */
1722 		win1->w_prev->w_vsep_width = 0;
1723 		win1->w_prev->w_frame->fr_width -= 1;
1724 		win1->w_vsep_width = 1;
1725 		win1->w_frame->fr_width += 1;
1726 	    }
1727 	}
1728 	else if (win2 == lastwin)
1729 	{
1730 	    height = win1->w_status_height;
1731 	    win1->w_status_height = win2->w_status_height;
1732 	    win2->w_status_height = height;
1733 	    if (win1->w_vsep_width == 1)
1734 	    {
1735 		/* Remove the vertical separator from win1, add it to the last
1736 		 * window, win2.  Adjust the frame widths. */
1737 		win2->w_vsep_width = 1;
1738 		win2->w_frame->fr_width += 1;
1739 		win1->w_vsep_width = 0;
1740 		win1->w_frame->fr_width -= 1;
1741 	    }
1742 	}
1743 	win_remove(win1, NULL);
1744 	frame_remove(win1->w_frame);
1745 	win_append(win2, win1);
1746 	frame_append(win2->w_frame, win1->w_frame);
1747 
1748 	(void)win_comp_pos();	/* recompute w_winrow for all windows */
1749 	redraw_later(NOT_VALID);
1750     }
1751     win_enter(win1, FALSE);
1752 }
1753 
1754 /*
1755  * Make all windows the same height.
1756  * 'next_curwin' will soon be the current window, make sure it has enough
1757  * rows.
1758  */
1759     void
1760 win_equal(
1761     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1762     int		current,	/* do only frame with current window */
1763     int		dir)		/* 'v' for vertically, 'h' for horizontally,
1764 				   'b' for both, 0 for using p_ead */
1765 {
1766     if (dir == 0)
1767 	dir = *p_ead;
1768     win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
1769 		      topframe, dir, 0, tabline_height(),
1770 					   (int)Columns, topframe->fr_height);
1771 }
1772 
1773 /*
1774  * Set a frame to a new position and height, spreading the available room
1775  * equally over contained frames.
1776  * The window "next_curwin" (if not NULL) should at least get the size from
1777  * 'winheight' and 'winwidth' if possible.
1778  */
1779     static void
1780 win_equal_rec(
1781     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1782     int		current,	/* do only frame with current window */
1783     frame_T	*topfr,		/* frame to set size off */
1784     int		dir,		/* 'v', 'h' or 'b', see win_equal() */
1785     int		col,		/* horizontal position for frame */
1786     int		row,		/* vertical position for frame */
1787     int		width,		/* new width of frame */
1788     int		height)		/* new height of frame */
1789 {
1790     int		n, m;
1791     int		extra_sep = 0;
1792     int		wincount, totwincount = 0;
1793     frame_T	*fr;
1794     int		next_curwin_size = 0;
1795     int		room = 0;
1796     int		new_size;
1797     int		has_next_curwin = 0;
1798     int		hnc;
1799 
1800     if (topfr->fr_layout == FR_LEAF)
1801     {
1802 	/* Set the width/height of this frame.
1803 	 * Redraw when size or position changes */
1804 	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
1805 		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
1806 	   )
1807 	{
1808 	    topfr->fr_win->w_winrow = row;
1809 	    frame_new_height(topfr, height, FALSE, FALSE);
1810 	    topfr->fr_win->w_wincol = col;
1811 	    frame_new_width(topfr, width, FALSE, FALSE);
1812 	    redraw_all_later(CLEAR);
1813 	}
1814     }
1815     else if (topfr->fr_layout == FR_ROW)
1816     {
1817 	topfr->fr_width = width;
1818 	topfr->fr_height = height;
1819 
1820 	if (dir != 'v')			/* equalize frame widths */
1821 	{
1822 	    /* Compute the maximum number of windows horizontally in this
1823 	     * frame. */
1824 	    n = frame_minwidth(topfr, NOWIN);
1825 	    /* add one for the rightmost window, it doesn't have a separator */
1826 	    if (col + width == Columns)
1827 		extra_sep = 1;
1828 	    else
1829 		extra_sep = 0;
1830 	    totwincount = (n + extra_sep) / (p_wmw + 1);
1831 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1832 
1833 	    /*
1834 	     * Compute width for "next_curwin" window and room available for
1835 	     * other windows.
1836 	     * "m" is the minimal width when counting p_wiw for "next_curwin".
1837 	     */
1838 	    m = frame_minwidth(topfr, next_curwin);
1839 	    room = width - m;
1840 	    if (room < 0)
1841 	    {
1842 		next_curwin_size = p_wiw + room;
1843 		room = 0;
1844 	    }
1845 	    else
1846 	    {
1847 		next_curwin_size = -1;
1848 		for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
1849 		{
1850 		    /* If 'winfixwidth' set keep the window width if
1851 		     * possible.
1852 		     * Watch out for this window being the next_curwin. */
1853 		    if (frame_fixed_width(fr))
1854 		    {
1855 			n = frame_minwidth(fr, NOWIN);
1856 			new_size = fr->fr_width;
1857 			if (frame_has_win(fr, next_curwin))
1858 			{
1859 			    room += p_wiw - p_wmw;
1860 			    next_curwin_size = 0;
1861 			    if (new_size < p_wiw)
1862 				new_size = p_wiw;
1863 			}
1864 			else
1865 			    /* These windows don't use up room. */
1866 			    totwincount -= (n + (fr->fr_next == NULL
1867 					      ? extra_sep : 0)) / (p_wmw + 1);
1868 			room -= new_size - n;
1869 			if (room < 0)
1870 			{
1871 			    new_size += room;
1872 			    room = 0;
1873 			}
1874 			fr->fr_newwidth = new_size;
1875 		    }
1876 		}
1877 		if (next_curwin_size == -1)
1878 		{
1879 		    if (!has_next_curwin)
1880 			next_curwin_size = 0;
1881 		    else if (totwincount > 1
1882 			    && (room + (totwincount - 2))
1883 						  / (totwincount - 1) > p_wiw)
1884 		    {
1885 			/* Can make all windows wider than 'winwidth', spread
1886 			 * the room equally. */
1887 			next_curwin_size = (room + p_wiw
1888 					    + (totwincount - 1) * p_wmw
1889 					    + (totwincount - 1)) / totwincount;
1890 			room -= next_curwin_size - p_wiw;
1891 		    }
1892 		    else
1893 			next_curwin_size = p_wiw;
1894 		}
1895 	    }
1896 
1897 	    if (has_next_curwin)
1898 		--totwincount;		/* don't count curwin */
1899 	}
1900 
1901 	for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
1902 	{
1903 	    wincount = 1;
1904 	    if (fr->fr_next == NULL)
1905 		/* last frame gets all that remains (avoid roundoff error) */
1906 		new_size = width;
1907 	    else if (dir == 'v')
1908 		new_size = fr->fr_width;
1909 	    else if (frame_fixed_width(fr))
1910 	    {
1911 		new_size = fr->fr_newwidth;
1912 		wincount = 0;	    /* doesn't count as a sizeable window */
1913 	    }
1914 	    else
1915 	    {
1916 		/* Compute the maximum number of windows horiz. in "fr". */
1917 		n = frame_minwidth(fr, NOWIN);
1918 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
1919 								/ (p_wmw + 1);
1920 		m = frame_minwidth(fr, next_curwin);
1921 		if (has_next_curwin)
1922 		    hnc = frame_has_win(fr, next_curwin);
1923 		else
1924 		    hnc = FALSE;
1925 		if (hnc)	    /* don't count next_curwin */
1926 		    --wincount;
1927 		if (totwincount == 0)
1928 		    new_size = room;
1929 		else
1930 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
1931 								/ totwincount;
1932 		if (hnc)	    /* add next_curwin size */
1933 		{
1934 		    next_curwin_size -= p_wiw - (m - n);
1935 		    new_size += next_curwin_size;
1936 		    room -= new_size - next_curwin_size;
1937 		}
1938 		else
1939 		    room -= new_size;
1940 		new_size += n;
1941 	    }
1942 
1943 	    /* Skip frame that is full width when splitting or closing a
1944 	     * window, unless equalizing all frames. */
1945 	    if (!current || dir != 'v' || topfr->fr_parent != NULL
1946 		    || (new_size != fr->fr_width)
1947 		    || frame_has_win(fr, next_curwin))
1948 		win_equal_rec(next_curwin, current, fr, dir, col, row,
1949 							    new_size, height);
1950 	    col += new_size;
1951 	    width -= new_size;
1952 	    totwincount -= wincount;
1953 	}
1954     }
1955     else /* topfr->fr_layout == FR_COL */
1956     {
1957 	topfr->fr_width = width;
1958 	topfr->fr_height = height;
1959 
1960 	if (dir != 'h')			/* equalize frame heights */
1961 	{
1962 	    /* Compute maximum number of windows vertically in this frame. */
1963 	    n = frame_minheight(topfr, NOWIN);
1964 	    /* add one for the bottom window if it doesn't have a statusline */
1965 	    if (row + height == cmdline_row && p_ls == 0)
1966 		extra_sep = 1;
1967 	    else
1968 		extra_sep = 0;
1969 	    totwincount = (n + extra_sep) / (p_wmh + 1);
1970 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1971 
1972 	    /*
1973 	     * Compute height for "next_curwin" window and room available for
1974 	     * other windows.
1975 	     * "m" is the minimal height when counting p_wh for "next_curwin".
1976 	     */
1977 	    m = frame_minheight(topfr, next_curwin);
1978 	    room = height - m;
1979 	    if (room < 0)
1980 	    {
1981 		/* The room is less then 'winheight', use all space for the
1982 		 * current window. */
1983 		next_curwin_size = p_wh + room;
1984 		room = 0;
1985 	    }
1986 	    else
1987 	    {
1988 		next_curwin_size = -1;
1989 		for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
1990 		{
1991 		    /* If 'winfixheight' set keep the window height if
1992 		     * possible.
1993 		     * Watch out for this window being the next_curwin. */
1994 		    if (frame_fixed_height(fr))
1995 		    {
1996 			n = frame_minheight(fr, NOWIN);
1997 			new_size = fr->fr_height;
1998 			if (frame_has_win(fr, next_curwin))
1999 			{
2000 			    room += p_wh - p_wmh;
2001 			    next_curwin_size = 0;
2002 			    if (new_size < p_wh)
2003 				new_size = p_wh;
2004 			}
2005 			else
2006 			    /* These windows don't use up room. */
2007 			    totwincount -= (n + (fr->fr_next == NULL
2008 					      ? extra_sep : 0)) / (p_wmh + 1);
2009 			room -= new_size - n;
2010 			if (room < 0)
2011 			{
2012 			    new_size += room;
2013 			    room = 0;
2014 			}
2015 			fr->fr_newheight = new_size;
2016 		    }
2017 		}
2018 		if (next_curwin_size == -1)
2019 		{
2020 		    if (!has_next_curwin)
2021 			next_curwin_size = 0;
2022 		    else if (totwincount > 1
2023 			    && (room + (totwincount - 2))
2024 						   / (totwincount - 1) > p_wh)
2025 		    {
2026 			/* can make all windows higher than 'winheight',
2027 			 * spread the room equally. */
2028 			next_curwin_size = (room + p_wh
2029 					   + (totwincount - 1) * p_wmh
2030 					   + (totwincount - 1)) / totwincount;
2031 			room -= next_curwin_size - p_wh;
2032 		    }
2033 		    else
2034 			next_curwin_size = p_wh;
2035 		}
2036 	    }
2037 
2038 	    if (has_next_curwin)
2039 		--totwincount;		/* don't count curwin */
2040 	}
2041 
2042 	for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
2043 	{
2044 	    wincount = 1;
2045 	    if (fr->fr_next == NULL)
2046 		/* last frame gets all that remains (avoid roundoff error) */
2047 		new_size = height;
2048 	    else if (dir == 'h')
2049 		new_size = fr->fr_height;
2050 	    else if (frame_fixed_height(fr))
2051 	    {
2052 		new_size = fr->fr_newheight;
2053 		wincount = 0;	    /* doesn't count as a sizeable window */
2054 	    }
2055 	    else
2056 	    {
2057 		/* Compute the maximum number of windows vert. in "fr". */
2058 		n = frame_minheight(fr, NOWIN);
2059 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2060 								/ (p_wmh + 1);
2061 		m = frame_minheight(fr, next_curwin);
2062 		if (has_next_curwin)
2063 		    hnc = frame_has_win(fr, next_curwin);
2064 		else
2065 		    hnc = FALSE;
2066 		if (hnc)	    /* don't count next_curwin */
2067 		    --wincount;
2068 		if (totwincount == 0)
2069 		    new_size = room;
2070 		else
2071 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2072 								/ totwincount;
2073 		if (hnc)	    /* add next_curwin size */
2074 		{
2075 		    next_curwin_size -= p_wh - (m - n);
2076 		    new_size += next_curwin_size;
2077 		    room -= new_size - next_curwin_size;
2078 		}
2079 		else
2080 		    room -= new_size;
2081 		new_size += n;
2082 	    }
2083 	    /* Skip frame that is full width when splitting or closing a
2084 	     * window, unless equalizing all frames. */
2085 	    if (!current || dir != 'h' || topfr->fr_parent != NULL
2086 		    || (new_size != fr->fr_height)
2087 		    || frame_has_win(fr, next_curwin))
2088 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2089 							     width, new_size);
2090 	    row += new_size;
2091 	    height -= new_size;
2092 	    totwincount -= wincount;
2093 	}
2094     }
2095 }
2096 
2097 #ifdef FEAT_JOB_CHANNEL
2098     static void
2099 leaving_window(win_T *win)
2100 {
2101     // Only matters for a prompt window.
2102     if (!bt_prompt(win->w_buffer))
2103 	return;
2104 
2105     // When leaving a prompt window stop Insert mode and perhaps restart
2106     // it when entering that window again.
2107     win->w_buffer->b_prompt_insert = restart_edit;
2108     if (restart_edit != 0 && mode_displayed)
2109 	clear_cmdline = TRUE;		/* unshow mode later */
2110     restart_edit = NUL;
2111 
2112     // When leaving the window (or closing the window) was done from a
2113     // callback we need to break out of the Insert mode loop and restart Insert
2114     // mode when entering the window again.
2115     if (State & INSERT)
2116     {
2117 	stop_insert_mode = TRUE;
2118 	if (win->w_buffer->b_prompt_insert == NUL)
2119 	    win->w_buffer->b_prompt_insert = 'A';
2120     }
2121 }
2122 
2123     static void
2124 entering_window(win_T *win)
2125 {
2126     // Only matters for a prompt window.
2127     if (!bt_prompt(win->w_buffer))
2128 	return;
2129 
2130     // When switching to a prompt buffer that was in Insert mode, don't stop
2131     // Insert mode, it may have been set in leaving_window().
2132     if (win->w_buffer->b_prompt_insert != NUL)
2133 	stop_insert_mode = FALSE;
2134 
2135     // When entering the prompt window restart Insert mode if we were in Insert
2136     // mode when we left it.
2137     restart_edit = win->w_buffer->b_prompt_insert;
2138 }
2139 #endif
2140 
2141 /*
2142  * Close all windows for buffer "buf".
2143  */
2144     void
2145 close_windows(
2146     buf_T	*buf,
2147     int		keep_curwin)	    /* don't close "curwin" */
2148 {
2149     win_T	*wp;
2150     tabpage_T   *tp, *nexttp;
2151     int		h = tabline_height();
2152     int		count = tabpage_index(NULL);
2153 
2154     ++RedrawingDisabled;
2155 
2156     for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
2157     {
2158 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
2159 		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
2160 	{
2161 	    if (win_close(wp, FALSE) == FAIL)
2162 		/* If closing the window fails give up, to avoid looping
2163 		 * forever. */
2164 		break;
2165 
2166 	    /* Start all over, autocommands may change the window layout. */
2167 	    wp = firstwin;
2168 	}
2169 	else
2170 	    wp = wp->w_next;
2171     }
2172 
2173     /* Also check windows in other tab pages. */
2174     for (tp = first_tabpage; tp != NULL; tp = nexttp)
2175     {
2176 	nexttp = tp->tp_next;
2177 	if (tp != curtab)
2178 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
2179 		if (wp->w_buffer == buf
2180 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
2181 		{
2182 		    win_close_othertab(wp, FALSE, tp);
2183 
2184 		    /* Start all over, the tab page may be closed and
2185 		     * autocommands may change the window layout. */
2186 		    nexttp = first_tabpage;
2187 		    break;
2188 		}
2189     }
2190 
2191     --RedrawingDisabled;
2192 
2193     if (count != tabpage_index(NULL))
2194 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2195 
2196     redraw_tabline = TRUE;
2197     if (h != tabline_height())
2198 	shell_new_rows();
2199 }
2200 
2201 /*
2202  * Return TRUE if the current window is the only window that exists (ignoring
2203  * "aucmd_win").
2204  * Returns FALSE if there is a window, possibly in another tab page.
2205  */
2206     static int
2207 last_window(void)
2208 {
2209     return (one_window() && first_tabpage->tp_next == NULL);
2210 }
2211 
2212 /*
2213  * Return TRUE if there is only one window other than "aucmd_win" in the
2214  * current tab page.
2215  */
2216     int
2217 one_window(void)
2218 {
2219     win_T	*wp;
2220     int		seen_one = FALSE;
2221 
2222     FOR_ALL_WINDOWS(wp)
2223     {
2224 	if (wp != aucmd_win)
2225 	{
2226 	    if (seen_one)
2227 		return FALSE;
2228 	    seen_one = TRUE;
2229 	}
2230     }
2231     return TRUE;
2232 }
2233 
2234 /*
2235  * Close the possibly last window in a tab page.
2236  * Returns TRUE when the window was closed already.
2237  */
2238     static int
2239 close_last_window_tabpage(
2240     win_T	*win,
2241     int		free_buf,
2242     tabpage_T   *prev_curtab)
2243 {
2244     if (ONE_WINDOW)
2245     {
2246 	buf_T	*old_curbuf = curbuf;
2247 
2248 	/*
2249 	 * Closing the last window in a tab page.  First go to another tab
2250 	 * page and then close the window and the tab page.  This avoids that
2251 	 * curwin and curtab are invalid while we are freeing memory, they may
2252 	 * be used in GUI events.
2253 	 * Don't trigger autocommands yet, they may use wrong values, so do
2254 	 * that below.
2255 	 */
2256 	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
2257 	redraw_tabline = TRUE;
2258 
2259 	/* Safety check: Autocommands may have closed the window when jumping
2260 	 * to the other tab page. */
2261 	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
2262 	{
2263 	    int	    h = tabline_height();
2264 
2265 	    win_close_othertab(win, free_buf, prev_curtab);
2266 	    if (h != tabline_height())
2267 		shell_new_rows();
2268 	}
2269 #ifdef FEAT_JOB_CHANNEL
2270 	entering_window(curwin);
2271 #endif
2272 	/* Since goto_tabpage_tp above did not trigger *Enter autocommands, do
2273 	 * that now. */
2274 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2275 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
2276 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
2277 	if (old_curbuf != curbuf)
2278 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2279 	return TRUE;
2280     }
2281     return FALSE;
2282 }
2283 
2284 /*
2285  * Close window "win".  Only works for the current tab page.
2286  * If "free_buf" is TRUE related buffer may be unloaded.
2287  *
2288  * Called by :quit, :close, :xit, :wq and findtag().
2289  * Returns FAIL when the window was not closed.
2290  */
2291     int
2292 win_close(win_T *win, int free_buf)
2293 {
2294     win_T	*wp;
2295     int		other_buffer = FALSE;
2296     int		close_curwin = FALSE;
2297     int		dir;
2298     int		help_window = FALSE;
2299     tabpage_T   *prev_curtab = curtab;
2300     frame_T	*win_frame = win->w_frame->fr_parent;
2301 
2302     if (last_window())
2303     {
2304 	EMSG(_("E444: Cannot close last window"));
2305 	return FAIL;
2306     }
2307 
2308     if (win->w_closing || (win->w_buffer != NULL
2309 					       && win->w_buffer->b_locked > 0))
2310 	return FAIL; /* window is already being closed */
2311     if (win == aucmd_win)
2312     {
2313 	EMSG(_("E813: Cannot close autocmd window"));
2314 	return FAIL;
2315     }
2316     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
2317     {
2318 	EMSG(_("E814: Cannot close window, only autocmd window would remain"));
2319 	return FAIL;
2320     }
2321 
2322     /* When closing the last window in a tab page first go to another tab page
2323      * and then close the window and the tab page to avoid that curwin and
2324      * curtab are invalid while we are freeing memory. */
2325     if (close_last_window_tabpage(win, free_buf, prev_curtab))
2326       return FAIL;
2327 
2328     /* When closing the help window, try restoring a snapshot after closing
2329      * the window.  Otherwise clear the snapshot, it's now invalid. */
2330     if (bt_help(win->w_buffer))
2331 	help_window = TRUE;
2332     else
2333 	clear_snapshot(curtab, SNAP_HELP_IDX);
2334 
2335     if (win == curwin)
2336     {
2337 #ifdef FEAT_JOB_CHANNEL
2338 	leaving_window(curwin);
2339 #endif
2340 	/*
2341 	 * Guess which window is going to be the new current window.
2342 	 * This may change because of the autocommands (sigh).
2343 	 */
2344 	wp = frame2win(win_altframe(win, NULL));
2345 
2346 	/*
2347 	 * Be careful: If autocommands delete the window or cause this window
2348 	 * to be the last one left, return now.
2349 	 */
2350 	if (wp->w_buffer != curbuf)
2351 	{
2352 	    other_buffer = TRUE;
2353 	    win->w_closing = TRUE;
2354 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
2355 	    if (!win_valid(win))
2356 		return FAIL;
2357 	    win->w_closing = FALSE;
2358 	    if (last_window())
2359 		return FAIL;
2360 	}
2361 	win->w_closing = TRUE;
2362 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
2363 	if (!win_valid(win))
2364 	    return FAIL;
2365 	win->w_closing = FALSE;
2366 	if (last_window())
2367 	    return FAIL;
2368 #ifdef FEAT_EVAL
2369 	/* autocmds may abort script processing */
2370 	if (aborting())
2371 	    return FAIL;
2372 #endif
2373     }
2374 
2375 #ifdef FEAT_GUI
2376     /* Avoid trouble with scrollbars that are going to be deleted in
2377      * win_free(). */
2378     if (gui.in_use)
2379 	out_flush();
2380 #endif
2381 
2382 #ifdef FEAT_SYN_HL
2383     /* Free independent synblock before the buffer is freed. */
2384     if (win->w_buffer != NULL)
2385 	reset_synblock(win);
2386 #endif
2387 
2388     /*
2389      * Close the link to the buffer.
2390      */
2391     if (win->w_buffer != NULL)
2392     {
2393 	bufref_T    bufref;
2394 
2395 	set_bufref(&bufref, curbuf);
2396 	win->w_closing = TRUE;
2397 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, TRUE);
2398 	if (win_valid_any_tab(win))
2399 	    win->w_closing = FALSE;
2400 	/* Make sure curbuf is valid. It can become invalid if 'bufhidden' is
2401 	 * "wipe". */
2402 	if (!bufref_valid(&bufref))
2403 	    curbuf = firstbuf;
2404     }
2405 
2406     if (only_one_window() && win_valid(win) && win->w_buffer == NULL
2407 	    && (last_window() || curtab != prev_curtab
2408 		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
2409     {
2410 	/* Autocommands have closed all windows, quit now.  Restore
2411 	 * curwin->w_buffer, otherwise writing viminfo may fail. */
2412 	if (curwin->w_buffer == NULL)
2413 	    curwin->w_buffer = curbuf;
2414 	getout(0);
2415     }
2416 
2417     /* Autocommands may have moved to another tab page. */
2418     if (curtab != prev_curtab && win_valid_any_tab(win)
2419 						      && win->w_buffer == NULL)
2420     {
2421 	/* Need to close the window anyway, since the buffer is NULL. */
2422 	win_close_othertab(win, FALSE, prev_curtab);
2423 	return FAIL;
2424     }
2425 
2426     /* Autocommands may have closed the window already or closed the only
2427      * other window. */
2428     if (!win_valid(win) || last_window()
2429 	    || close_last_window_tabpage(win, free_buf, prev_curtab))
2430 	return FAIL;
2431 
2432     /* Free the memory used for the window and get the window that received
2433      * the screen space. */
2434     wp = win_free_mem(win, &dir, NULL);
2435 
2436     /* Make sure curwin isn't invalid.  It can cause severe trouble when
2437      * printing an error message.  For win_equal() curbuf needs to be valid
2438      * too. */
2439     if (win == curwin)
2440     {
2441 	curwin = wp;
2442 #ifdef FEAT_QUICKFIX
2443 	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
2444 	{
2445 	    /*
2446 	     * If the cursor goes to the preview or the quickfix window, try
2447 	     * finding another window to go to.
2448 	     */
2449 	    for (;;)
2450 	    {
2451 		if (wp->w_next == NULL)
2452 		    wp = firstwin;
2453 		else
2454 		    wp = wp->w_next;
2455 		if (wp == curwin)
2456 		    break;
2457 		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
2458 		{
2459 		    curwin = wp;
2460 		    break;
2461 		}
2462 	    }
2463 	}
2464 #endif
2465 	curbuf = curwin->w_buffer;
2466 	close_curwin = TRUE;
2467 
2468 	/* The cursor position may be invalid if the buffer changed after last
2469 	 * using the window. */
2470 	check_cursor();
2471     }
2472     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
2473 	/* If the frame of the closed window contains the new current window,
2474 	 * only resize that frame.  Otherwise resize all windows. */
2475 	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
2476     else
2477 	win_comp_pos();
2478     if (close_curwin)
2479     {
2480 	win_enter_ext(wp, FALSE, TRUE, FALSE, TRUE, TRUE);
2481 	if (other_buffer)
2482 	    /* careful: after this wp and win may be invalid! */
2483 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2484     }
2485 
2486     /*
2487      * If last window has a status line now and we don't want one,
2488      * remove the status line.
2489      */
2490     last_status(FALSE);
2491 
2492     /* After closing the help window, try restoring the window layout from
2493      * before it was opened. */
2494     if (help_window)
2495 	restore_snapshot(SNAP_HELP_IDX, close_curwin);
2496 
2497 #if defined(FEAT_GUI)
2498     /* When 'guioptions' includes 'L' or 'R' may have to remove scrollbars. */
2499     if (gui.in_use && !win_hasvertsplit())
2500 	gui_init_which_components(NULL);
2501 #endif
2502 
2503     redraw_all_later(NOT_VALID);
2504     return OK;
2505 }
2506 
2507 /*
2508  * Close window "win" in tab page "tp", which is not the current tab page.
2509  * This may be the last window in that tab page and result in closing the tab,
2510  * thus "tp" may become invalid!
2511  * Caller must check if buffer is hidden and whether the tabline needs to be
2512  * updated.
2513  */
2514     void
2515 win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
2516 {
2517     win_T	*wp;
2518     int		dir;
2519     tabpage_T   *ptp = NULL;
2520     int		free_tp = FALSE;
2521 
2522     /* Get here with win->w_buffer == NULL when win_close() detects the tab
2523      * page changed. */
2524     if (win->w_closing || (win->w_buffer != NULL
2525 					       && win->w_buffer->b_locked > 0))
2526 	return; /* window is already being closed */
2527 
2528     if (win->w_buffer != NULL)
2529 	/* Close the link to the buffer. */
2530 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, FALSE);
2531 
2532     /* Careful: Autocommands may have closed the tab page or made it the
2533      * current tab page.  */
2534     for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
2535 	;
2536     if (ptp == NULL || tp == curtab)
2537 	return;
2538 
2539     /* Autocommands may have closed the window already. */
2540     for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
2541 	;
2542     if (wp == NULL)
2543 	return;
2544 
2545     /* When closing the last window in a tab page remove the tab page. */
2546     if (tp->tp_firstwin == tp->tp_lastwin)
2547     {
2548 	if (tp == first_tabpage)
2549 	    first_tabpage = tp->tp_next;
2550 	else
2551 	{
2552 	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
2553 							   ptp = ptp->tp_next)
2554 		;
2555 	    if (ptp == NULL)
2556 	    {
2557 		internal_error("win_close_othertab()");
2558 		return;
2559 	    }
2560 	    ptp->tp_next = tp->tp_next;
2561 	}
2562 	free_tp = TRUE;
2563     }
2564 
2565     /* Free the memory used for the window. */
2566     win_free_mem(win, &dir, tp);
2567 
2568     if (free_tp)
2569 	free_tabpage(tp);
2570 }
2571 
2572 /*
2573  * Free the memory used for a window.
2574  * Returns a pointer to the window that got the freed up space.
2575  */
2576     static win_T *
2577 win_free_mem(
2578     win_T	*win,
2579     int		*dirp,		/* set to 'v' or 'h' for direction if 'ea' */
2580     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2581 {
2582     frame_T	*frp;
2583     win_T	*wp;
2584 
2585     /* Remove the window and its frame from the tree of frames. */
2586     frp = win->w_frame;
2587     wp = winframe_remove(win, dirp, tp);
2588     vim_free(frp);
2589     win_free(win, tp);
2590 
2591     /* When deleting the current window of another tab page select a new
2592      * current window. */
2593     if (tp != NULL && win == tp->tp_curwin)
2594 	tp->tp_curwin = wp;
2595 
2596     return wp;
2597 }
2598 
2599 #if defined(EXITFREE) || defined(PROTO)
2600     void
2601 win_free_all(void)
2602 {
2603     int		dummy;
2604 
2605     while (first_tabpage->tp_next != NULL)
2606 	tabpage_close(TRUE);
2607 
2608     if (aucmd_win != NULL)
2609     {
2610 	(void)win_free_mem(aucmd_win, &dummy, NULL);
2611 	aucmd_win = NULL;
2612     }
2613 
2614     while (firstwin != NULL)
2615 	(void)win_free_mem(firstwin, &dummy, NULL);
2616 
2617     /* No window should be used after this. Set curwin to NULL to crash
2618      * instead of using freed memory. */
2619     curwin = NULL;
2620 }
2621 #endif
2622 
2623 /*
2624  * Remove a window and its frame from the tree of frames.
2625  * Returns a pointer to the window that got the freed up space.
2626  */
2627     win_T *
2628 winframe_remove(
2629     win_T	*win,
2630     int		*dirp UNUSED,	/* set to 'v' or 'h' for direction if 'ea' */
2631     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2632 {
2633     frame_T	*frp, *frp2, *frp3;
2634     frame_T	*frp_close = win->w_frame;
2635     win_T	*wp;
2636 
2637     /*
2638      * If there is only one window there is nothing to remove.
2639      */
2640     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2641 	return NULL;
2642 
2643     /*
2644      * Remove the window from its frame.
2645      */
2646     frp2 = win_altframe(win, tp);
2647     wp = frame2win(frp2);
2648 
2649     /* Remove this frame from the list of frames. */
2650     frame_remove(frp_close);
2651 
2652     if (frp_close->fr_parent->fr_layout == FR_COL)
2653     {
2654 	/* When 'winfixheight' is set, try to find another frame in the column
2655 	 * (as close to the closed frame as possible) to distribute the height
2656 	 * to. */
2657 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
2658 	{
2659 	    frp = frp_close->fr_prev;
2660 	    frp3 = frp_close->fr_next;
2661 	    while (frp != NULL || frp3 != NULL)
2662 	    {
2663 		if (frp != NULL)
2664 		{
2665 		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfh)
2666 		    {
2667 			frp2 = frp;
2668 			wp = frp->fr_win;
2669 			break;
2670 		    }
2671 		    frp = frp->fr_prev;
2672 		}
2673 		if (frp3 != NULL)
2674 		{
2675 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
2676 		    {
2677 			frp2 = frp3;
2678 			wp = frp3->fr_win;
2679 			break;
2680 		    }
2681 		    frp3 = frp3->fr_next;
2682 		}
2683 	    }
2684 	}
2685 	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
2686 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2687 	*dirp = 'v';
2688     }
2689     else
2690     {
2691 	/* When 'winfixwidth' is set, try to find another frame in the column
2692 	 * (as close to the closed frame as possible) to distribute the width
2693 	 * to. */
2694 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
2695 	{
2696 	    frp = frp_close->fr_prev;
2697 	    frp3 = frp_close->fr_next;
2698 	    while (frp != NULL || frp3 != NULL)
2699 	    {
2700 		if (frp != NULL)
2701 		{
2702 		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfw)
2703 		    {
2704 			frp2 = frp;
2705 			wp = frp->fr_win;
2706 			break;
2707 		    }
2708 		    frp = frp->fr_prev;
2709 		}
2710 		if (frp3 != NULL)
2711 		{
2712 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
2713 		    {
2714 			frp2 = frp3;
2715 			wp = frp3->fr_win;
2716 			break;
2717 		    }
2718 		    frp3 = frp3->fr_next;
2719 		}
2720 	    }
2721 	}
2722 	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
2723 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2724 	*dirp = 'h';
2725     }
2726 
2727     /* If rows/columns go to a window below/right its positions need to be
2728      * updated.  Can only be done after the sizes have been updated. */
2729     if (frp2 == frp_close->fr_next)
2730     {
2731 	int row = win->w_winrow;
2732 	int col = win->w_wincol;
2733 
2734 	frame_comp_pos(frp2, &row, &col);
2735     }
2736 
2737     if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
2738     {
2739 	/* There is no other frame in this list, move its info to the parent
2740 	 * and remove it. */
2741 	frp2->fr_parent->fr_layout = frp2->fr_layout;
2742 	frp2->fr_parent->fr_child = frp2->fr_child;
2743 	for (frp = frp2->fr_child; frp != NULL; frp = frp->fr_next)
2744 	    frp->fr_parent = frp2->fr_parent;
2745 	frp2->fr_parent->fr_win = frp2->fr_win;
2746 	if (frp2->fr_win != NULL)
2747 	    frp2->fr_win->w_frame = frp2->fr_parent;
2748 	frp = frp2->fr_parent;
2749 	if (topframe->fr_child == frp2)
2750 	    topframe->fr_child = frp;
2751 	vim_free(frp2);
2752 
2753 	frp2 = frp->fr_parent;
2754 	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
2755 	{
2756 	    /* The frame above the parent has the same layout, have to merge
2757 	     * the frames into this list. */
2758 	    if (frp2->fr_child == frp)
2759 		frp2->fr_child = frp->fr_child;
2760 	    frp->fr_child->fr_prev = frp->fr_prev;
2761 	    if (frp->fr_prev != NULL)
2762 		frp->fr_prev->fr_next = frp->fr_child;
2763 	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
2764 	    {
2765 		frp3->fr_parent = frp2;
2766 		if (frp3->fr_next == NULL)
2767 		{
2768 		    frp3->fr_next = frp->fr_next;
2769 		    if (frp->fr_next != NULL)
2770 			frp->fr_next->fr_prev = frp3;
2771 		    break;
2772 		}
2773 	    }
2774 	    if (topframe->fr_child == frp)
2775 		topframe->fr_child = frp2;
2776 	    vim_free(frp);
2777 	}
2778     }
2779 
2780     return wp;
2781 }
2782 
2783 /*
2784  * Return a pointer to the frame that will receive the empty screen space that
2785  * is left over after "win" is closed.
2786  *
2787  * If 'splitbelow' or 'splitright' is set, the space goes above or to the left
2788  * by default.  Otherwise, the free space goes below or to the right.  The
2789  * result is that opening a window and then immediately closing it will
2790  * preserve the initial window layout.  The 'wfh' and 'wfw' settings are
2791  * respected when possible.
2792  */
2793     static frame_T *
2794 win_altframe(
2795     win_T	*win,
2796     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2797 {
2798     frame_T	*frp;
2799     frame_T	*other_fr, *target_fr;
2800 
2801     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2802 	return alt_tabpage()->tp_curwin->w_frame;
2803 
2804     frp = win->w_frame;
2805 
2806     if (frp->fr_prev == NULL)
2807 	return frp->fr_next;
2808     if (frp->fr_next == NULL)
2809 	return frp->fr_prev;
2810 
2811     target_fr = frp->fr_next;
2812     other_fr  = frp->fr_prev;
2813     if (p_spr || p_sb)
2814     {
2815 	target_fr = frp->fr_prev;
2816 	other_fr  = frp->fr_next;
2817     }
2818 
2819     /* If 'wfh' or 'wfw' is set for the target and not for the alternate
2820      * window, reverse the selection. */
2821     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
2822     {
2823 	if (frame_fixed_width(target_fr) && !frame_fixed_width(other_fr))
2824 	    target_fr = other_fr;
2825     }
2826     else
2827     {
2828 	if (frame_fixed_height(target_fr) && !frame_fixed_height(other_fr))
2829 	    target_fr = other_fr;
2830     }
2831 
2832     return target_fr;
2833 }
2834 
2835 /*
2836  * Return the tabpage that will be used if the current one is closed.
2837  */
2838     static tabpage_T *
2839 alt_tabpage(void)
2840 {
2841     tabpage_T	*tp;
2842 
2843     /* Use the next tab page if possible. */
2844     if (curtab->tp_next != NULL)
2845 	return curtab->tp_next;
2846 
2847     /* Find the last but one tab page. */
2848     for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
2849 	;
2850     return tp;
2851 }
2852 
2853 /*
2854  * Find the left-upper window in frame "frp".
2855  */
2856     static win_T *
2857 frame2win(frame_T *frp)
2858 {
2859     while (frp->fr_win == NULL)
2860 	frp = frp->fr_child;
2861     return frp->fr_win;
2862 }
2863 
2864 /*
2865  * Return TRUE if frame "frp" contains window "wp".
2866  */
2867     static int
2868 frame_has_win(frame_T *frp, win_T *wp)
2869 {
2870     frame_T	*p;
2871 
2872     if (frp->fr_layout == FR_LEAF)
2873 	return frp->fr_win == wp;
2874 
2875     for (p = frp->fr_child; p != NULL; p = p->fr_next)
2876 	if (frame_has_win(p, wp))
2877 	    return TRUE;
2878     return FALSE;
2879 }
2880 
2881 /*
2882  * Set a new height for a frame.  Recursively sets the height for contained
2883  * frames and windows.  Caller must take care of positions.
2884  */
2885     static void
2886 frame_new_height(
2887     frame_T	*topfrp,
2888     int		height,
2889     int		topfirst,	/* resize topmost contained frame first */
2890     int		wfh)		/* obey 'winfixheight' when there is a choice;
2891 				   may cause the height not to be set */
2892 {
2893     frame_T	*frp;
2894     int		extra_lines;
2895     int		h;
2896 
2897     if (topfrp->fr_win != NULL)
2898     {
2899 	/* Simple case: just one window. */
2900 	win_new_height(topfrp->fr_win,
2901 				    height - topfrp->fr_win->w_status_height
2902 					      - WINBAR_HEIGHT(topfrp->fr_win));
2903     }
2904     else if (topfrp->fr_layout == FR_ROW)
2905     {
2906 	do
2907 	{
2908 	    /* All frames in this row get the same new height. */
2909 	    for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
2910 	    {
2911 		frame_new_height(frp, height, topfirst, wfh);
2912 		if (frp->fr_height > height)
2913 		{
2914 		    /* Could not fit the windows, make the whole row higher. */
2915 		    height = frp->fr_height;
2916 		    break;
2917 		}
2918 	    }
2919 	}
2920 	while (frp != NULL);
2921     }
2922     else    /* fr_layout == FR_COL */
2923     {
2924 	/* Complicated case: Resize a column of frames.  Resize the bottom
2925 	 * frame first, frames above that when needed. */
2926 
2927 	frp = topfrp->fr_child;
2928 	if (wfh)
2929 	    /* Advance past frames with one window with 'wfh' set. */
2930 	    while (frame_fixed_height(frp))
2931 	    {
2932 		frp = frp->fr_next;
2933 		if (frp == NULL)
2934 		    return;	    /* no frame without 'wfh', give up */
2935 	    }
2936 	if (!topfirst)
2937 	{
2938 	    /* Find the bottom frame of this column */
2939 	    while (frp->fr_next != NULL)
2940 		frp = frp->fr_next;
2941 	    if (wfh)
2942 		/* Advance back for frames with one window with 'wfh' set. */
2943 		while (frame_fixed_height(frp))
2944 		    frp = frp->fr_prev;
2945 	}
2946 
2947 	extra_lines = height - topfrp->fr_height;
2948 	if (extra_lines < 0)
2949 	{
2950 	    /* reduce height of contained frames, bottom or top frame first */
2951 	    while (frp != NULL)
2952 	    {
2953 		h = frame_minheight(frp, NULL);
2954 		if (frp->fr_height + extra_lines < h)
2955 		{
2956 		    extra_lines += frp->fr_height - h;
2957 		    frame_new_height(frp, h, topfirst, wfh);
2958 		}
2959 		else
2960 		{
2961 		    frame_new_height(frp, frp->fr_height + extra_lines,
2962 							       topfirst, wfh);
2963 		    break;
2964 		}
2965 		if (topfirst)
2966 		{
2967 		    do
2968 			frp = frp->fr_next;
2969 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2970 		}
2971 		else
2972 		{
2973 		    do
2974 			frp = frp->fr_prev;
2975 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2976 		}
2977 		/* Increase "height" if we could not reduce enough frames. */
2978 		if (frp == NULL)
2979 		    height -= extra_lines;
2980 	    }
2981 	}
2982 	else if (extra_lines > 0)
2983 	{
2984 	    /* increase height of bottom or top frame */
2985 	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
2986 	}
2987     }
2988     topfrp->fr_height = height;
2989 }
2990 
2991 /*
2992  * Return TRUE if height of frame "frp" should not be changed because of
2993  * the 'winfixheight' option.
2994  */
2995     static int
2996 frame_fixed_height(frame_T *frp)
2997 {
2998     /* frame with one window: fixed height if 'winfixheight' set. */
2999     if (frp->fr_win != NULL)
3000 	return frp->fr_win->w_p_wfh;
3001 
3002     if (frp->fr_layout == FR_ROW)
3003     {
3004 	/* The frame is fixed height if one of the frames in the row is fixed
3005 	 * height. */
3006 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3007 	    if (frame_fixed_height(frp))
3008 		return TRUE;
3009 	return FALSE;
3010     }
3011 
3012     /* frp->fr_layout == FR_COL: The frame is fixed height if all of the
3013      * frames in the row are fixed height. */
3014     for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3015 	if (!frame_fixed_height(frp))
3016 	    return FALSE;
3017     return TRUE;
3018 }
3019 
3020 /*
3021  * Return TRUE if width of frame "frp" should not be changed because of
3022  * the 'winfixwidth' option.
3023  */
3024     static int
3025 frame_fixed_width(frame_T *frp)
3026 {
3027     /* frame with one window: fixed width if 'winfixwidth' set. */
3028     if (frp->fr_win != NULL)
3029 	return frp->fr_win->w_p_wfw;
3030 
3031     if (frp->fr_layout == FR_COL)
3032     {
3033 	/* The frame is fixed width if one of the frames in the row is fixed
3034 	 * width. */
3035 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3036 	    if (frame_fixed_width(frp))
3037 		return TRUE;
3038 	return FALSE;
3039     }
3040 
3041     /* frp->fr_layout == FR_ROW: The frame is fixed width if all of the
3042      * frames in the row are fixed width. */
3043     for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3044 	if (!frame_fixed_width(frp))
3045 	    return FALSE;
3046     return TRUE;
3047 }
3048 
3049 /*
3050  * Add a status line to windows at the bottom of "frp".
3051  * Note: Does not check if there is room!
3052  */
3053     static void
3054 frame_add_statusline(frame_T *frp)
3055 {
3056     win_T	*wp;
3057 
3058     if (frp->fr_layout == FR_LEAF)
3059     {
3060 	wp = frp->fr_win;
3061 	if (wp->w_status_height == 0)
3062 	{
3063 	    if (wp->w_height > 0)	/* don't make it negative */
3064 		--wp->w_height;
3065 	    wp->w_status_height = STATUS_HEIGHT;
3066 	}
3067     }
3068     else if (frp->fr_layout == FR_ROW)
3069     {
3070 	/* Handle all the frames in the row. */
3071 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3072 	    frame_add_statusline(frp);
3073     }
3074     else /* frp->fr_layout == FR_COL */
3075     {
3076 	/* Only need to handle the last frame in the column. */
3077 	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
3078 	    ;
3079 	frame_add_statusline(frp);
3080     }
3081 }
3082 
3083 /*
3084  * Set width of a frame.  Handles recursively going through contained frames.
3085  * May remove separator line for windows at the right side (for win_close()).
3086  */
3087     static void
3088 frame_new_width(
3089     frame_T	*topfrp,
3090     int		width,
3091     int		leftfirst,	/* resize leftmost contained frame first */
3092     int		wfw)		/* obey 'winfixwidth' when there is a choice;
3093 				   may cause the width not to be set */
3094 {
3095     frame_T	*frp;
3096     int		extra_cols;
3097     int		w;
3098     win_T	*wp;
3099 
3100     if (topfrp->fr_layout == FR_LEAF)
3101     {
3102 	/* Simple case: just one window. */
3103 	wp = topfrp->fr_win;
3104 	/* Find out if there are any windows right of this one. */
3105 	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
3106 	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
3107 		break;
3108 	if (frp->fr_parent == NULL)
3109 	    wp->w_vsep_width = 0;
3110 	win_new_width(wp, width - wp->w_vsep_width);
3111     }
3112     else if (topfrp->fr_layout == FR_COL)
3113     {
3114 	do
3115 	{
3116 	    /* All frames in this column get the same new width. */
3117 	    for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3118 	    {
3119 		frame_new_width(frp, width, leftfirst, wfw);
3120 		if (frp->fr_width > width)
3121 		{
3122 		    /* Could not fit the windows, make whole column wider. */
3123 		    width = frp->fr_width;
3124 		    break;
3125 		}
3126 	    }
3127 	} while (frp != NULL);
3128     }
3129     else    /* fr_layout == FR_ROW */
3130     {
3131 	/* Complicated case: Resize a row of frames.  Resize the rightmost
3132 	 * frame first, frames left of it when needed. */
3133 
3134 	frp = topfrp->fr_child;
3135 	if (wfw)
3136 	    /* Advance past frames with one window with 'wfw' set. */
3137 	    while (frame_fixed_width(frp))
3138 	    {
3139 		frp = frp->fr_next;
3140 		if (frp == NULL)
3141 		    return;	    /* no frame without 'wfw', give up */
3142 	    }
3143 	if (!leftfirst)
3144 	{
3145 	    /* Find the rightmost frame of this row */
3146 	    while (frp->fr_next != NULL)
3147 		frp = frp->fr_next;
3148 	    if (wfw)
3149 		/* Advance back for frames with one window with 'wfw' set. */
3150 		while (frame_fixed_width(frp))
3151 		    frp = frp->fr_prev;
3152 	}
3153 
3154 	extra_cols = width - topfrp->fr_width;
3155 	if (extra_cols < 0)
3156 	{
3157 	    /* reduce frame width, rightmost frame first */
3158 	    while (frp != NULL)
3159 	    {
3160 		w = frame_minwidth(frp, NULL);
3161 		if (frp->fr_width + extra_cols < w)
3162 		{
3163 		    extra_cols += frp->fr_width - w;
3164 		    frame_new_width(frp, w, leftfirst, wfw);
3165 		}
3166 		else
3167 		{
3168 		    frame_new_width(frp, frp->fr_width + extra_cols,
3169 							      leftfirst, wfw);
3170 		    break;
3171 		}
3172 		if (leftfirst)
3173 		{
3174 		    do
3175 			frp = frp->fr_next;
3176 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3177 		}
3178 		else
3179 		{
3180 		    do
3181 			frp = frp->fr_prev;
3182 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3183 		}
3184 		/* Increase "width" if we could not reduce enough frames. */
3185 		if (frp == NULL)
3186 		    width -= extra_cols;
3187 	    }
3188 	}
3189 	else if (extra_cols > 0)
3190 	{
3191 	    /* increase width of rightmost frame */
3192 	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
3193 	}
3194     }
3195     topfrp->fr_width = width;
3196 }
3197 
3198 /*
3199  * Add the vertical separator to windows at the right side of "frp".
3200  * Note: Does not check if there is room!
3201  */
3202     static void
3203 frame_add_vsep(frame_T *frp)
3204 {
3205     win_T	*wp;
3206 
3207     if (frp->fr_layout == FR_LEAF)
3208     {
3209 	wp = frp->fr_win;
3210 	if (wp->w_vsep_width == 0)
3211 	{
3212 	    if (wp->w_width > 0)	/* don't make it negative */
3213 		--wp->w_width;
3214 	    wp->w_vsep_width = 1;
3215 	}
3216     }
3217     else if (frp->fr_layout == FR_COL)
3218     {
3219 	/* Handle all the frames in the column. */
3220 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3221 	    frame_add_vsep(frp);
3222     }
3223     else /* frp->fr_layout == FR_ROW */
3224     {
3225 	/* Only need to handle the last frame in the row. */
3226 	frp = frp->fr_child;
3227 	while (frp->fr_next != NULL)
3228 	    frp = frp->fr_next;
3229 	frame_add_vsep(frp);
3230     }
3231 }
3232 
3233 /*
3234  * Set frame width from the window it contains.
3235  */
3236     static void
3237 frame_fix_width(win_T *wp)
3238 {
3239     wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
3240 }
3241 
3242 /*
3243  * Set frame height from the window it contains.
3244  */
3245     static void
3246 frame_fix_height(win_T *wp)
3247 {
3248     wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
3249 }
3250 
3251 /*
3252  * Compute the minimal height for frame "topfrp".
3253  * Uses the 'winminheight' option.
3254  * When "next_curwin" isn't NULL, use p_wh for this window.
3255  * When "next_curwin" is NOWIN, don't use at least one line for the current
3256  * window.
3257  */
3258     static int
3259 frame_minheight(frame_T *topfrp, win_T *next_curwin)
3260 {
3261     frame_T	*frp;
3262     int		m;
3263     int		n;
3264 
3265     if (topfrp->fr_win != NULL)
3266     {
3267 	if (topfrp->fr_win == next_curwin)
3268 	    m = p_wh + topfrp->fr_win->w_status_height;
3269 	else
3270 	{
3271 	    /* window: minimal height of the window plus status line */
3272 	    m = p_wmh + topfrp->fr_win->w_status_height;
3273 	    if (topfrp->fr_win == curwin && next_curwin == NULL)
3274 	    {
3275 		/* Current window is minimal one line high and WinBar is
3276 		 * visible. */
3277 		if (p_wmh == 0)
3278 		    ++m;
3279 		m += WINBAR_HEIGHT(curwin);
3280 	    }
3281 	}
3282     }
3283     else if (topfrp->fr_layout == FR_ROW)
3284     {
3285 	/* get the minimal height from each frame in this row */
3286 	m = 0;
3287 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3288 	{
3289 	    n = frame_minheight(frp, next_curwin);
3290 	    if (n > m)
3291 		m = n;
3292 	}
3293     }
3294     else
3295     {
3296 	/* Add up the minimal heights for all frames in this column. */
3297 	m = 0;
3298 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3299 	    m += frame_minheight(frp, next_curwin);
3300     }
3301 
3302     return m;
3303 }
3304 
3305 /*
3306  * Compute the minimal width for frame "topfrp".
3307  * When "next_curwin" isn't NULL, use p_wiw for this window.
3308  * When "next_curwin" is NOWIN, don't use at least one column for the current
3309  * window.
3310  */
3311     static int
3312 frame_minwidth(
3313     frame_T	*topfrp,
3314     win_T	*next_curwin)	/* use p_wh and p_wiw for next_curwin */
3315 {
3316     frame_T	*frp;
3317     int		m, n;
3318 
3319     if (topfrp->fr_win != NULL)
3320     {
3321 	if (topfrp->fr_win == next_curwin)
3322 	    m = p_wiw + topfrp->fr_win->w_vsep_width;
3323 	else
3324 	{
3325 	    /* window: minimal width of the window plus separator column */
3326 	    m = p_wmw + topfrp->fr_win->w_vsep_width;
3327 	    /* Current window is minimal one column wide */
3328 	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
3329 		++m;
3330 	}
3331     }
3332     else if (topfrp->fr_layout == FR_COL)
3333     {
3334 	/* get the minimal width from each frame in this column */
3335 	m = 0;
3336 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3337 	{
3338 	    n = frame_minwidth(frp, next_curwin);
3339 	    if (n > m)
3340 		m = n;
3341 	}
3342     }
3343     else
3344     {
3345 	/* Add up the minimal widths for all frames in this row. */
3346 	m = 0;
3347 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3348 	    m += frame_minwidth(frp, next_curwin);
3349     }
3350 
3351     return m;
3352 }
3353 
3354 
3355 /*
3356  * Try to close all windows except current one.
3357  * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
3358  * used and the buffer was modified.
3359  *
3360  * Used by ":bdel" and ":only".
3361  */
3362     void
3363 close_others(
3364     int		message,
3365     int		forceit)	    /* always hide all other windows */
3366 {
3367     win_T	*wp;
3368     win_T	*nextwp;
3369     int		r;
3370 
3371     if (one_window())
3372     {
3373 	if (message && !autocmd_busy)
3374 	    MSG(_(m_onlyone));
3375 	return;
3376     }
3377 
3378     /* Be very careful here: autocommands may change the window layout. */
3379     for (wp = firstwin; win_valid(wp); wp = nextwp)
3380     {
3381 	nextwp = wp->w_next;
3382 	if (wp != curwin)		/* don't close current window */
3383 	{
3384 
3385 	    /* Check if it's allowed to abandon this window */
3386 	    r = can_abandon(wp->w_buffer, forceit);
3387 	    if (!win_valid(wp))		/* autocommands messed wp up */
3388 	    {
3389 		nextwp = firstwin;
3390 		continue;
3391 	    }
3392 	    if (!r)
3393 	    {
3394 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
3395 		if (message && (p_confirm || cmdmod.confirm) && p_write)
3396 		{
3397 		    dialog_changed(wp->w_buffer, FALSE);
3398 		    if (!win_valid(wp))		/* autocommands messed wp up */
3399 		    {
3400 			nextwp = firstwin;
3401 			continue;
3402 		    }
3403 		}
3404 		if (bufIsChanged(wp->w_buffer))
3405 #endif
3406 		    continue;
3407 	    }
3408 	    win_close(wp, !buf_hide(wp->w_buffer)
3409 					       && !bufIsChanged(wp->w_buffer));
3410 	}
3411     }
3412 
3413     if (message && !ONE_WINDOW)
3414 	EMSG(_("E445: Other window contains changes"));
3415 }
3416 
3417 /*
3418  * Init the current window "curwin".
3419  * Called when a new file is being edited.
3420  */
3421     void
3422 curwin_init(void)
3423 {
3424     win_init_empty(curwin);
3425 }
3426 
3427     void
3428 win_init_empty(win_T *wp)
3429 {
3430     redraw_win_later(wp, NOT_VALID);
3431     wp->w_lines_valid = 0;
3432     wp->w_cursor.lnum = 1;
3433     wp->w_curswant = wp->w_cursor.col = 0;
3434 #ifdef FEAT_VIRTUALEDIT
3435     wp->w_cursor.coladd = 0;
3436 #endif
3437     wp->w_pcmark.lnum = 1;	/* pcmark not cleared but set to line 1 */
3438     wp->w_pcmark.col = 0;
3439     wp->w_prev_pcmark.lnum = 0;
3440     wp->w_prev_pcmark.col = 0;
3441     wp->w_topline = 1;
3442 #ifdef FEAT_DIFF
3443     wp->w_topfill = 0;
3444 #endif
3445     wp->w_botline = 2;
3446 #ifdef FEAT_FKMAP
3447     if (wp->w_p_rl)
3448 	wp->w_farsi = W_CONV + W_R_L;
3449     else
3450 	wp->w_farsi = W_CONV;
3451 #endif
3452 #ifdef FEAT_SYN_HL
3453     wp->w_s = &wp->w_buffer->b_s;
3454 #endif
3455 }
3456 
3457 /*
3458  * Allocate the first window and put an empty buffer in it.
3459  * Called from main().
3460  * Return FAIL when something goes wrong (out of memory).
3461  */
3462     int
3463 win_alloc_first(void)
3464 {
3465     if (win_alloc_firstwin(NULL) == FAIL)
3466 	return FAIL;
3467 
3468     first_tabpage = alloc_tabpage();
3469     if (first_tabpage == NULL)
3470 	return FAIL;
3471     first_tabpage->tp_topframe = topframe;
3472     curtab = first_tabpage;
3473 
3474     return OK;
3475 }
3476 
3477 /*
3478  * Init "aucmd_win".  This can only be done after the first
3479  * window is fully initialized, thus it can't be in win_alloc_first().
3480  */
3481     void
3482 win_alloc_aucmd_win(void)
3483 {
3484     aucmd_win = win_alloc(NULL, TRUE);
3485     if (aucmd_win != NULL)
3486     {
3487 	win_init_some(aucmd_win, curwin);
3488 	RESET_BINDING(aucmd_win);
3489 	new_frame(aucmd_win);
3490     }
3491 }
3492 
3493 /*
3494  * Allocate the first window or the first window in a new tab page.
3495  * When "oldwin" is NULL create an empty buffer for it.
3496  * When "oldwin" is not NULL copy info from it to the new window.
3497  * Return FAIL when something goes wrong (out of memory).
3498  */
3499     static int
3500 win_alloc_firstwin(win_T *oldwin)
3501 {
3502     curwin = win_alloc(NULL, FALSE);
3503     if (oldwin == NULL)
3504     {
3505 	/* Very first window, need to create an empty buffer for it and
3506 	 * initialize from scratch. */
3507 	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
3508 	if (curwin == NULL || curbuf == NULL)
3509 	    return FAIL;
3510 	curwin->w_buffer = curbuf;
3511 #ifdef FEAT_SYN_HL
3512 	curwin->w_s = &(curbuf->b_s);
3513 #endif
3514 	curbuf->b_nwindows = 1;	/* there is one window */
3515 	curwin->w_alist = &global_alist;
3516 	curwin_init();		/* init current window */
3517     }
3518     else
3519     {
3520 	/* First window in new tab page, initialize it from "oldwin". */
3521 	win_init(curwin, oldwin, 0);
3522 
3523 	/* We don't want cursor- and scroll-binding in the first window. */
3524 	RESET_BINDING(curwin);
3525     }
3526 
3527     new_frame(curwin);
3528     if (curwin->w_frame == NULL)
3529 	return FAIL;
3530     topframe = curwin->w_frame;
3531     topframe->fr_width = Columns;
3532     topframe->fr_height = Rows - p_ch;
3533 
3534     return OK;
3535 }
3536 
3537 /*
3538  * Create a frame for window "wp".
3539  */
3540     static void
3541 new_frame(win_T *wp)
3542 {
3543     frame_T *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
3544 
3545     wp->w_frame = frp;
3546     if (frp != NULL)
3547     {
3548 	frp->fr_layout = FR_LEAF;
3549 	frp->fr_win = wp;
3550     }
3551 }
3552 
3553 /*
3554  * Initialize the window and frame size to the maximum.
3555  */
3556     void
3557 win_init_size(void)
3558 {
3559     firstwin->w_height = ROWS_AVAIL;
3560     topframe->fr_height = ROWS_AVAIL;
3561     firstwin->w_width = Columns;
3562     topframe->fr_width = Columns;
3563 }
3564 
3565 /*
3566  * Allocate a new tabpage_T and init the values.
3567  * Returns NULL when out of memory.
3568  */
3569     static tabpage_T *
3570 alloc_tabpage(void)
3571 {
3572     tabpage_T	*tp;
3573 # ifdef FEAT_GUI
3574     int		i;
3575 # endif
3576 
3577 
3578     tp = (tabpage_T *)alloc_clear((unsigned)sizeof(tabpage_T));
3579     if (tp == NULL)
3580 	return NULL;
3581 
3582 # ifdef FEAT_EVAL
3583     /* init t: variables */
3584     tp->tp_vars = dict_alloc();
3585     if (tp->tp_vars == NULL)
3586     {
3587 	vim_free(tp);
3588 	return NULL;
3589     }
3590     init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
3591 # endif
3592 
3593 # ifdef FEAT_GUI
3594     for (i = 0; i < 3; i++)
3595 	tp->tp_prev_which_scrollbars[i] = -1;
3596 # endif
3597 # ifdef FEAT_DIFF
3598     tp->tp_diff_invalid = TRUE;
3599 # endif
3600     tp->tp_ch_used = p_ch;
3601 
3602     return tp;
3603 }
3604 
3605     void
3606 free_tabpage(tabpage_T *tp)
3607 {
3608     int idx;
3609 
3610 # ifdef FEAT_DIFF
3611     diff_clear(tp);
3612 # endif
3613     for (idx = 0; idx < SNAP_COUNT; ++idx)
3614 	clear_snapshot(tp, idx);
3615 #ifdef FEAT_EVAL
3616     vars_clear(&tp->tp_vars->dv_hashtab);	/* free all t: variables */
3617     hash_init(&tp->tp_vars->dv_hashtab);
3618     unref_var_dict(tp->tp_vars);
3619 #endif
3620 
3621 #ifdef FEAT_PYTHON
3622     python_tabpage_free(tp);
3623 #endif
3624 
3625 #ifdef FEAT_PYTHON3
3626     python3_tabpage_free(tp);
3627 #endif
3628 
3629     vim_free(tp);
3630 }
3631 
3632 /*
3633  * Create a new Tab page with one window.
3634  * It will edit the current buffer, like after ":split".
3635  * When "after" is 0 put it just after the current Tab page.
3636  * Otherwise put it just before tab page "after".
3637  * Return FAIL or OK.
3638  */
3639     int
3640 win_new_tabpage(int after)
3641 {
3642     tabpage_T	*tp = curtab;
3643     tabpage_T	*newtp;
3644     int		n;
3645 
3646     newtp = alloc_tabpage();
3647     if (newtp == NULL)
3648 	return FAIL;
3649 
3650     /* Remember the current windows in this Tab page. */
3651     if (leave_tabpage(curbuf, TRUE) == FAIL)
3652     {
3653 	vim_free(newtp);
3654 	return FAIL;
3655     }
3656     curtab = newtp;
3657 
3658     /* Create a new empty window. */
3659     if (win_alloc_firstwin(tp->tp_curwin) == OK)
3660     {
3661 	/* Make the new Tab page the new topframe. */
3662 	if (after == 1)
3663 	{
3664 	    /* New tab page becomes the first one. */
3665 	    newtp->tp_next = first_tabpage;
3666 	    first_tabpage = newtp;
3667 	}
3668 	else
3669 	{
3670 	    if (after > 0)
3671 	    {
3672 		/* Put new tab page before tab page "after". */
3673 		n = 2;
3674 		for (tp = first_tabpage; tp->tp_next != NULL
3675 					       && n < after; tp = tp->tp_next)
3676 		    ++n;
3677 	    }
3678 	    newtp->tp_next = tp->tp_next;
3679 	    tp->tp_next = newtp;
3680 	}
3681 	win_init_size();
3682 	firstwin->w_winrow = tabline_height();
3683 	win_comp_scroll(curwin);
3684 
3685 	newtp->tp_topframe = topframe;
3686 	last_status(FALSE);
3687 
3688 #if defined(FEAT_GUI)
3689 	/* When 'guioptions' includes 'L' or 'R' may have to remove or add
3690 	 * scrollbars.  Have to update them anyway. */
3691 	gui_may_update_scrollbars();
3692 #endif
3693 #ifdef FEAT_JOB_CHANNEL
3694 	entering_window(curwin);
3695 #endif
3696 
3697 	redraw_all_later(CLEAR);
3698 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
3699 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
3700 	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
3701 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3702 	return OK;
3703     }
3704 
3705     /* Failed, get back the previous Tab page */
3706     enter_tabpage(curtab, curbuf, TRUE, TRUE);
3707     return FAIL;
3708 }
3709 
3710 /*
3711  * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
3712  * like with ":split".
3713  * Returns OK if a new tab page was created, FAIL otherwise.
3714  */
3715     int
3716 may_open_tabpage(void)
3717 {
3718     int		n = (cmdmod.tab == 0) ? postponed_split_tab : cmdmod.tab;
3719 
3720     if (n != 0)
3721     {
3722 	cmdmod.tab = 0;	    /* reset it to avoid doing it twice */
3723 	postponed_split_tab = 0;
3724 	return win_new_tabpage(n);
3725     }
3726     return FAIL;
3727 }
3728 
3729 /*
3730  * Create up to "maxcount" tabpages with empty windows.
3731  * Returns the number of resulting tab pages.
3732  */
3733     int
3734 make_tabpages(int maxcount)
3735 {
3736     int		count = maxcount;
3737     int		todo;
3738 
3739     /* Limit to 'tabpagemax' tabs. */
3740     if (count > p_tpm)
3741 	count = p_tpm;
3742 
3743     /*
3744      * Don't execute autocommands while creating the tab pages.  Must do that
3745      * when putting the buffers in the windows.
3746      */
3747     block_autocmds();
3748 
3749     for (todo = count - 1; todo > 0; --todo)
3750 	if (win_new_tabpage(0) == FAIL)
3751 	    break;
3752 
3753     unblock_autocmds();
3754 
3755     /* return actual number of tab pages */
3756     return (count - todo);
3757 }
3758 
3759 /*
3760  * Return TRUE when "tpc" points to a valid tab page.
3761  */
3762     int
3763 valid_tabpage(tabpage_T *tpc)
3764 {
3765     tabpage_T	*tp;
3766 
3767     FOR_ALL_TABPAGES(tp)
3768 	if (tp == tpc)
3769 	    return TRUE;
3770     return FALSE;
3771 }
3772 
3773 /*
3774  * Return TRUE when "tpc" points to a valid tab page and at least one window is
3775  * valid.
3776  */
3777     int
3778 valid_tabpage_win(tabpage_T *tpc)
3779 {
3780     tabpage_T	*tp;
3781     win_T	*wp;
3782 
3783     FOR_ALL_TABPAGES(tp)
3784     {
3785 	if (tp == tpc)
3786 	{
3787 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
3788 	    {
3789 		if (win_valid_any_tab(wp))
3790 		    return TRUE;
3791 	    }
3792 	    return FALSE;
3793 	}
3794     }
3795     /* shouldn't happen */
3796     return FALSE;
3797 }
3798 
3799 /*
3800  * Close tabpage "tab", assuming it has no windows in it.
3801  * There must be another tabpage or this will crash.
3802  */
3803     void
3804 close_tabpage(tabpage_T *tab)
3805 {
3806     tabpage_T	*ptp;
3807 
3808     if (tab == first_tabpage)
3809     {
3810 	first_tabpage = tab->tp_next;
3811 	ptp = first_tabpage;
3812     }
3813     else
3814     {
3815 	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
3816 							    ptp = ptp->tp_next)
3817 	    ;
3818 	assert(ptp != NULL);
3819 	ptp->tp_next = tab->tp_next;
3820     }
3821 
3822     goto_tabpage_tp(ptp, FALSE, FALSE);
3823     free_tabpage(tab);
3824 }
3825 
3826 /*
3827  * Find tab page "n" (first one is 1).  Returns NULL when not found.
3828  */
3829     tabpage_T *
3830 find_tabpage(int n)
3831 {
3832     tabpage_T	*tp;
3833     int		i = 1;
3834 
3835     for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
3836 	++i;
3837     return tp;
3838 }
3839 
3840 /*
3841  * Get index of tab page "tp".  First one has index 1.
3842  * When not found returns number of tab pages plus one.
3843  */
3844     int
3845 tabpage_index(tabpage_T *ftp)
3846 {
3847     int		i = 1;
3848     tabpage_T	*tp;
3849 
3850     for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
3851 	++i;
3852     return i;
3853 }
3854 
3855 /*
3856  * Prepare for leaving the current tab page.
3857  * When autocommands change "curtab" we don't leave the tab page and return
3858  * FAIL.
3859  * Careful: When OK is returned need to get a new tab page very very soon!
3860  */
3861     static int
3862 leave_tabpage(
3863     buf_T	*new_curbuf UNUSED,    /* what is going to be the new curbuf,
3864 				       NULL if unknown */
3865     int		trigger_leave_autocmds UNUSED)
3866 {
3867     tabpage_T	*tp = curtab;
3868 
3869 #ifdef FEAT_JOB_CHANNEL
3870     leaving_window(curwin);
3871 #endif
3872     reset_VIsual_and_resel();	/* stop Visual mode */
3873     if (trigger_leave_autocmds)
3874     {
3875 	if (new_curbuf != curbuf)
3876 	{
3877 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
3878 	    if (curtab != tp)
3879 		return FAIL;
3880 	}
3881 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
3882 	if (curtab != tp)
3883 	    return FAIL;
3884 	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
3885 	if (curtab != tp)
3886 	    return FAIL;
3887     }
3888 #if defined(FEAT_GUI)
3889     /* Remove the scrollbars.  They may be added back later. */
3890     if (gui.in_use)
3891 	gui_remove_scrollbars();
3892 #endif
3893     tp->tp_curwin = curwin;
3894     tp->tp_prevwin = prevwin;
3895     tp->tp_firstwin = firstwin;
3896     tp->tp_lastwin = lastwin;
3897     tp->tp_old_Rows = Rows;
3898     tp->tp_old_Columns = Columns;
3899     firstwin = NULL;
3900     lastwin = NULL;
3901     return OK;
3902 }
3903 
3904 /*
3905  * Start using tab page "tp".
3906  * Only to be used after leave_tabpage() or freeing the current tab page.
3907  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
3908  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
3909  */
3910     static void
3911 enter_tabpage(
3912     tabpage_T	*tp,
3913     buf_T	*old_curbuf UNUSED,
3914     int		trigger_enter_autocmds,
3915     int		trigger_leave_autocmds)
3916 {
3917     int		old_off = tp->tp_firstwin->w_winrow;
3918     win_T	*next_prevwin = tp->tp_prevwin;
3919 
3920     curtab = tp;
3921     firstwin = tp->tp_firstwin;
3922     lastwin = tp->tp_lastwin;
3923     topframe = tp->tp_topframe;
3924 
3925     /* We would like doing the TabEnter event first, but we don't have a
3926      * valid current window yet, which may break some commands.
3927      * This triggers autocommands, thus may make "tp" invalid. */
3928     win_enter_ext(tp->tp_curwin, FALSE, TRUE, FALSE,
3929 			      trigger_enter_autocmds, trigger_leave_autocmds);
3930     prevwin = next_prevwin;
3931 
3932     last_status(FALSE);		/* status line may appear or disappear */
3933     (void)win_comp_pos();	/* recompute w_winrow for all windows */
3934     must_redraw = CLEAR;	/* need to redraw everything */
3935 #ifdef FEAT_DIFF
3936     diff_need_scrollbind = TRUE;
3937 #endif
3938 
3939     /* The tabpage line may have appeared or disappeared, may need to resize
3940      * the frames for that.  When the Vim window was resized need to update
3941      * frame sizes too.  Use the stored value of p_ch, so that it can be
3942      * different for each tab page. */
3943     p_ch = curtab->tp_ch_used;
3944     if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
3945 #ifdef FEAT_GUI_TABLINE
3946 			    && !gui_use_tabline()
3947 #endif
3948 		))
3949 	shell_new_rows();
3950     if (curtab->tp_old_Columns != Columns && starting == 0)
3951 	shell_new_columns();	/* update window widths */
3952 
3953 #if defined(FEAT_GUI)
3954     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
3955      * scrollbars.  Have to update them anyway. */
3956     gui_may_update_scrollbars();
3957 #endif
3958 
3959     /* Apply autocommands after updating the display, when 'rows' and
3960      * 'columns' have been set correctly. */
3961     if (trigger_enter_autocmds)
3962     {
3963 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3964 	if (old_curbuf != curbuf)
3965 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
3966     }
3967 
3968     redraw_all_later(CLEAR);
3969 }
3970 
3971 /*
3972  * Go to tab page "n".  For ":tab N" and "Ngt".
3973  * When "n" is 9999 go to the last tab page.
3974  */
3975     void
3976 goto_tabpage(int n)
3977 {
3978     tabpage_T	*tp;
3979     tabpage_T	*ttp;
3980     int		i;
3981 
3982     if (text_locked())
3983     {
3984 	/* Not allowed when editing the command line. */
3985 	text_locked_msg();
3986 	return;
3987     }
3988 
3989     /* If there is only one it can't work. */
3990     if (first_tabpage->tp_next == NULL)
3991     {
3992 	if (n > 1)
3993 	    beep_flush();
3994 	return;
3995     }
3996 
3997     if (n == 0)
3998     {
3999 	/* No count, go to next tab page, wrap around end. */
4000 	if (curtab->tp_next == NULL)
4001 	    tp = first_tabpage;
4002 	else
4003 	    tp = curtab->tp_next;
4004     }
4005     else if (n < 0)
4006     {
4007 	/* "gT": go to previous tab page, wrap around end.  "N gT" repeats
4008 	 * this N times. */
4009 	ttp = curtab;
4010 	for (i = n; i < 0; ++i)
4011 	{
4012 	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
4013 		    tp = tp->tp_next)
4014 		;
4015 	    ttp = tp;
4016 	}
4017     }
4018     else if (n == 9999)
4019     {
4020 	/* Go to last tab page. */
4021 	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
4022 	    ;
4023     }
4024     else
4025     {
4026 	/* Go to tab page "n". */
4027 	tp = find_tabpage(n);
4028 	if (tp == NULL)
4029 	{
4030 	    beep_flush();
4031 	    return;
4032 	}
4033     }
4034 
4035     goto_tabpage_tp(tp, TRUE, TRUE);
4036 
4037 #ifdef FEAT_GUI_TABLINE
4038     if (gui_use_tabline())
4039 	gui_mch_set_curtab(tabpage_index(curtab));
4040 #endif
4041 }
4042 
4043 /*
4044  * Go to tabpage "tp".
4045  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4046  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4047  * Note: doesn't update the GUI tab.
4048  */
4049     void
4050 goto_tabpage_tp(
4051     tabpage_T	*tp,
4052     int		trigger_enter_autocmds,
4053     int		trigger_leave_autocmds)
4054 {
4055     /* Don't repeat a message in another tab page. */
4056     set_keep_msg(NULL, 0);
4057 
4058     if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
4059 					trigger_leave_autocmds) == OK)
4060     {
4061 	if (valid_tabpage(tp))
4062 	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
4063 		    trigger_leave_autocmds);
4064 	else
4065 	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
4066 		    trigger_leave_autocmds);
4067     }
4068 }
4069 
4070 /*
4071  * Enter window "wp" in tab page "tp".
4072  * Also updates the GUI tab.
4073  */
4074     void
4075 goto_tabpage_win(tabpage_T *tp, win_T *wp)
4076 {
4077     goto_tabpage_tp(tp, TRUE, TRUE);
4078     if (curtab == tp && win_valid(wp))
4079     {
4080 	win_enter(wp, TRUE);
4081 # ifdef FEAT_GUI_TABLINE
4082 	if (gui_use_tabline())
4083 	    gui_mch_set_curtab(tabpage_index(curtab));
4084 # endif
4085     }
4086 }
4087 
4088 /*
4089  * Move the current tab page to after tab page "nr".
4090  */
4091     void
4092 tabpage_move(int nr)
4093 {
4094     int		n = 1;
4095     tabpage_T	*tp, *tp_dst;
4096 
4097     if (first_tabpage->tp_next == NULL)
4098 	return;
4099 
4100     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
4101 	++n;
4102 
4103     if (tp == curtab || (nr > 0 && tp->tp_next != NULL
4104 						    && tp->tp_next == curtab))
4105 	return;
4106 
4107     tp_dst = tp;
4108 
4109     /* Remove the current tab page from the list of tab pages. */
4110     if (curtab == first_tabpage)
4111 	first_tabpage = curtab->tp_next;
4112     else
4113     {
4114 	FOR_ALL_TABPAGES(tp)
4115 	    if (tp->tp_next == curtab)
4116 		break;
4117 	if (tp == NULL)	/* "cannot happen" */
4118 	    return;
4119 	tp->tp_next = curtab->tp_next;
4120     }
4121 
4122     /* Re-insert it at the specified position. */
4123     if (nr <= 0)
4124     {
4125 	curtab->tp_next = first_tabpage;
4126 	first_tabpage = curtab;
4127     }
4128     else
4129     {
4130 	curtab->tp_next = tp_dst->tp_next;
4131 	tp_dst->tp_next = curtab;
4132     }
4133 
4134     /* Need to redraw the tabline.  Tab page contents doesn't change. */
4135     redraw_tabline = TRUE;
4136 }
4137 
4138 
4139 /*
4140  * Go to another window.
4141  * When jumping to another buffer, stop Visual mode.  Do this before
4142  * changing windows so we can yank the selection into the '*' register.
4143  * When jumping to another window on the same buffer, adjust its cursor
4144  * position to keep the same Visual area.
4145  */
4146     void
4147 win_goto(win_T *wp)
4148 {
4149 #ifdef FEAT_CONCEAL
4150     win_T	*owp = curwin;
4151 #endif
4152 
4153     if (text_locked())
4154     {
4155 	beep_flush();
4156 	text_locked_msg();
4157 	return;
4158     }
4159     if (curbuf_locked())
4160 	return;
4161 
4162     if (wp->w_buffer != curbuf)
4163 	reset_VIsual_and_resel();
4164     else if (VIsual_active)
4165 	wp->w_cursor = curwin->w_cursor;
4166 
4167 #ifdef FEAT_GUI
4168     need_mouse_correct = TRUE;
4169 #endif
4170     win_enter(wp, TRUE);
4171 
4172 #ifdef FEAT_CONCEAL
4173     /* Conceal cursor line in previous window, unconceal in current window. */
4174     if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
4175 	update_single_line(owp, owp->w_cursor.lnum);
4176     if (curwin->w_p_cole > 0 && !msg_scrolled)
4177 	need_cursor_line_redraw = TRUE;
4178 #endif
4179 }
4180 
4181 #if defined(FEAT_PERL) || defined(PROTO)
4182 /*
4183  * Find window number "winnr" (counting top to bottom).
4184  */
4185     win_T *
4186 win_find_nr(int winnr)
4187 {
4188     win_T	*wp;
4189 
4190     FOR_ALL_WINDOWS(wp)
4191 	if (--winnr == 0)
4192 	    break;
4193     return wp;
4194 }
4195 #endif
4196 
4197 #if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
4198 /*
4199  * Find the tabpage for window "win".
4200  */
4201     tabpage_T *
4202 win_find_tabpage(win_T *win)
4203 {
4204     win_T	*wp;
4205     tabpage_T	*tp;
4206 
4207     FOR_ALL_TAB_WINDOWS(tp, wp)
4208 	    if (wp == win)
4209 		return tp;
4210     return NULL;
4211 }
4212 #endif
4213 
4214 /*
4215  * Move to window above or below "count" times.
4216  */
4217     static void
4218 win_goto_ver(
4219     int		up,		/* TRUE to go to win above */
4220     long	count)
4221 {
4222     frame_T	*fr;
4223     frame_T	*nfr;
4224     frame_T	*foundfr;
4225 
4226     foundfr = curwin->w_frame;
4227     while (count--)
4228     {
4229 	/*
4230 	 * First go upwards in the tree of frames until we find a upwards or
4231 	 * downwards neighbor.
4232 	 */
4233 	fr = foundfr;
4234 	for (;;)
4235 	{
4236 	    if (fr == topframe)
4237 		goto end;
4238 	    if (up)
4239 		nfr = fr->fr_prev;
4240 	    else
4241 		nfr = fr->fr_next;
4242 	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
4243 		break;
4244 	    fr = fr->fr_parent;
4245 	}
4246 
4247 	/*
4248 	 * Now go downwards to find the bottom or top frame in it.
4249 	 */
4250 	for (;;)
4251 	{
4252 	    if (nfr->fr_layout == FR_LEAF)
4253 	    {
4254 		foundfr = nfr;
4255 		break;
4256 	    }
4257 	    fr = nfr->fr_child;
4258 	    if (nfr->fr_layout == FR_ROW)
4259 	    {
4260 		/* Find the frame at the cursor row. */
4261 		while (fr->fr_next != NULL
4262 			&& frame2win(fr)->w_wincol + fr->fr_width
4263 					 <= curwin->w_wincol + curwin->w_wcol)
4264 		    fr = fr->fr_next;
4265 	    }
4266 	    if (nfr->fr_layout == FR_COL && up)
4267 		while (fr->fr_next != NULL)
4268 		    fr = fr->fr_next;
4269 	    nfr = fr;
4270 	}
4271     }
4272 end:
4273     if (foundfr != NULL)
4274 	win_goto(foundfr->fr_win);
4275 }
4276 
4277 /*
4278  * Move to left or right window.
4279  */
4280     static void
4281 win_goto_hor(
4282     int		left,		/* TRUE to go to left win */
4283     long	count)
4284 {
4285     frame_T	*fr;
4286     frame_T	*nfr;
4287     frame_T	*foundfr;
4288 
4289     foundfr = curwin->w_frame;
4290     while (count--)
4291     {
4292 	/*
4293 	 * First go upwards in the tree of frames until we find a left or
4294 	 * right neighbor.
4295 	 */
4296 	fr = foundfr;
4297 	for (;;)
4298 	{
4299 	    if (fr == topframe)
4300 		goto end;
4301 	    if (left)
4302 		nfr = fr->fr_prev;
4303 	    else
4304 		nfr = fr->fr_next;
4305 	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
4306 		break;
4307 	    fr = fr->fr_parent;
4308 	}
4309 
4310 	/*
4311 	 * Now go downwards to find the leftmost or rightmost frame in it.
4312 	 */
4313 	for (;;)
4314 	{
4315 	    if (nfr->fr_layout == FR_LEAF)
4316 	    {
4317 		foundfr = nfr;
4318 		break;
4319 	    }
4320 	    fr = nfr->fr_child;
4321 	    if (nfr->fr_layout == FR_COL)
4322 	    {
4323 		/* Find the frame at the cursor row. */
4324 		while (fr->fr_next != NULL
4325 			&& frame2win(fr)->w_winrow + fr->fr_height
4326 					 <= curwin->w_winrow + curwin->w_wrow)
4327 		    fr = fr->fr_next;
4328 	    }
4329 	    if (nfr->fr_layout == FR_ROW && left)
4330 		while (fr->fr_next != NULL)
4331 		    fr = fr->fr_next;
4332 	    nfr = fr;
4333 	}
4334     }
4335 end:
4336     if (foundfr != NULL)
4337 	win_goto(foundfr->fr_win);
4338 }
4339 
4340 /*
4341  * Make window "wp" the current window.
4342  */
4343     void
4344 win_enter(win_T *wp, int undo_sync)
4345 {
4346     win_enter_ext(wp, undo_sync, FALSE, FALSE, TRUE, TRUE);
4347 }
4348 
4349 /*
4350  * Make window wp the current window.
4351  * Can be called with "curwin_invalid" TRUE, which means that curwin has just
4352  * been closed and isn't valid.
4353  */
4354     static void
4355 win_enter_ext(
4356     win_T	*wp,
4357     int		undo_sync,
4358     int		curwin_invalid,
4359     int		trigger_new_autocmds,
4360     int		trigger_enter_autocmds,
4361     int		trigger_leave_autocmds)
4362 {
4363     int		other_buffer = FALSE;
4364 
4365     if (wp == curwin && !curwin_invalid)	/* nothing to do */
4366 	return;
4367 
4368 #ifdef FEAT_JOB_CHANNEL
4369     if (!curwin_invalid)
4370 	leaving_window(curwin);
4371 #endif
4372 
4373     if (!curwin_invalid && trigger_leave_autocmds)
4374     {
4375 	/*
4376 	 * Be careful: If autocommands delete the window, return now.
4377 	 */
4378 	if (wp->w_buffer != curbuf)
4379 	{
4380 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4381 	    other_buffer = TRUE;
4382 	    if (!win_valid(wp))
4383 		return;
4384 	}
4385 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4386 	if (!win_valid(wp))
4387 	    return;
4388 #ifdef FEAT_EVAL
4389 	/* autocmds may abort script processing */
4390 	if (aborting())
4391 	    return;
4392 #endif
4393     }
4394 
4395     /* sync undo before leaving the current buffer */
4396     if (undo_sync && curbuf != wp->w_buffer)
4397 	u_sync(FALSE);
4398 
4399     /* Might need to scroll the old window before switching, e.g., when the
4400      * cursor was moved. */
4401     update_topline();
4402 
4403     /* may have to copy the buffer options when 'cpo' contains 'S' */
4404     if (wp->w_buffer != curbuf)
4405 	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
4406     if (!curwin_invalid)
4407     {
4408 	prevwin = curwin;	/* remember for CTRL-W p */
4409 	curwin->w_redr_status = TRUE;
4410     }
4411     curwin = wp;
4412     curbuf = wp->w_buffer;
4413     check_cursor();
4414 #ifdef FEAT_VIRTUALEDIT
4415     if (!virtual_active())
4416 	curwin->w_cursor.coladd = 0;
4417 #endif
4418     changed_line_abv_curs();	/* assume cursor position needs updating */
4419 
4420     if (curwin->w_localdir != NULL)
4421     {
4422 	/* Window has a local directory: Save current directory as global
4423 	 * directory (unless that was done already) and change to the local
4424 	 * directory. */
4425 	if (globaldir == NULL)
4426 	{
4427 	    char_u	cwd[MAXPATHL];
4428 
4429 	    if (mch_dirname(cwd, MAXPATHL) == OK)
4430 		globaldir = vim_strsave(cwd);
4431 	}
4432 	if (mch_chdir((char *)curwin->w_localdir) == 0)
4433 	    shorten_fnames(TRUE);
4434     }
4435     else if (globaldir != NULL)
4436     {
4437 	/* Window doesn't have a local directory and we are not in the global
4438 	 * directory: Change to the global directory. */
4439 	ignored = mch_chdir((char *)globaldir);
4440 	VIM_CLEAR(globaldir);
4441 	shorten_fnames(TRUE);
4442     }
4443 
4444 #ifdef FEAT_JOB_CHANNEL
4445     entering_window(curwin);
4446 #endif
4447     if (trigger_new_autocmds)
4448 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
4449     if (trigger_enter_autocmds)
4450     {
4451 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
4452 	if (other_buffer)
4453 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4454     }
4455 
4456 #ifdef FEAT_TITLE
4457     maketitle();
4458 #endif
4459     curwin->w_redr_status = TRUE;
4460     redraw_tabline = TRUE;
4461     if (restart_edit)
4462 	redraw_later(VALID);	/* causes status line redraw */
4463 
4464     /* set window height to desired minimal value */
4465     if (curwin->w_height < p_wh && !curwin->w_p_wfh)
4466 	win_setheight((int)p_wh);
4467     else if (curwin->w_height == 0)
4468 	win_setheight(1);
4469 
4470     /* set window width to desired minimal value */
4471     if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
4472 	win_setwidth((int)p_wiw);
4473 
4474 #ifdef FEAT_MOUSE
4475     setmouse();			/* in case jumped to/from help buffer */
4476 #endif
4477 
4478     /* Change directories when the 'acd' option is set. */
4479     DO_AUTOCHDIR;
4480 }
4481 
4482 
4483 /*
4484  * Jump to the first open window that contains buffer "buf", if one exists.
4485  * Returns a pointer to the window found, otherwise NULL.
4486  */
4487     win_T *
4488 buf_jump_open_win(buf_T *buf)
4489 {
4490     win_T	*wp = NULL;
4491 
4492     if (curwin->w_buffer == buf)
4493 	wp = curwin;
4494     else
4495 	FOR_ALL_WINDOWS(wp)
4496 	    if (wp->w_buffer == buf)
4497 		break;
4498     if (wp != NULL)
4499 	win_enter(wp, FALSE);
4500     return wp;
4501 }
4502 
4503 /*
4504  * Jump to the first open window in any tab page that contains buffer "buf",
4505  * if one exists.
4506  * Returns a pointer to the window found, otherwise NULL.
4507  */
4508     win_T *
4509 buf_jump_open_tab(buf_T *buf)
4510 {
4511     win_T	*wp = buf_jump_open_win(buf);
4512     tabpage_T	*tp;
4513 
4514     if (wp != NULL)
4515 	return wp;
4516 
4517     FOR_ALL_TABPAGES(tp)
4518 	if (tp != curtab)
4519 	{
4520 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
4521 		if (wp->w_buffer == buf)
4522 		    break;
4523 	    if (wp != NULL)
4524 	    {
4525 		goto_tabpage_win(tp, wp);
4526 		if (curwin != wp)
4527 		    wp = NULL;	/* something went wrong */
4528 		break;
4529 	    }
4530 	}
4531     return wp;
4532 }
4533 
4534 static int last_win_id = LOWEST_WIN_ID - 1;
4535 
4536 /*
4537  * Allocate a window structure and link it in the window list when "hidden" is
4538  * FALSE.
4539  */
4540     static win_T *
4541 win_alloc(win_T *after UNUSED, int hidden UNUSED)
4542 {
4543     win_T	*new_wp;
4544 
4545     /*
4546      * allocate window structure and linesizes arrays
4547      */
4548     new_wp = (win_T *)alloc_clear((unsigned)sizeof(win_T));
4549     if (new_wp == NULL)
4550 	return NULL;
4551 
4552     if (win_alloc_lines(new_wp) == FAIL)
4553     {
4554 	vim_free(new_wp);
4555 	return NULL;
4556     }
4557 
4558     new_wp->w_id = ++last_win_id;
4559 
4560 #ifdef FEAT_EVAL
4561     /* init w: variables */
4562     new_wp->w_vars = dict_alloc();
4563     if (new_wp->w_vars == NULL)
4564     {
4565 	win_free_lsize(new_wp);
4566 	vim_free(new_wp);
4567 	return NULL;
4568     }
4569     init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
4570 #endif
4571 
4572     /* Don't execute autocommands while the window is not properly
4573      * initialized yet.  gui_create_scrollbar() may trigger a FocusGained
4574      * event. */
4575     block_autocmds();
4576 
4577     /*
4578      * link the window in the window list
4579      */
4580     if (!hidden)
4581 	win_append(after, new_wp);
4582     new_wp->w_wincol = 0;
4583     new_wp->w_width = Columns;
4584 
4585     /* position the display and the cursor at the top of the file. */
4586     new_wp->w_topline = 1;
4587 #ifdef FEAT_DIFF
4588     new_wp->w_topfill = 0;
4589 #endif
4590     new_wp->w_botline = 2;
4591     new_wp->w_cursor.lnum = 1;
4592     new_wp->w_scbind_pos = 1;
4593 
4594     /* We won't calculate w_fraction until resizing the window */
4595     new_wp->w_fraction = 0;
4596     new_wp->w_prev_fraction_row = -1;
4597 
4598 #ifdef FEAT_GUI
4599     if (gui.in_use)
4600     {
4601 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
4602 		SBAR_LEFT, new_wp);
4603 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
4604 		SBAR_RIGHT, new_wp);
4605     }
4606 #endif
4607 #ifdef FEAT_FOLDING
4608     foldInitWin(new_wp);
4609 #endif
4610     unblock_autocmds();
4611 #ifdef FEAT_SEARCH_EXTRA
4612     new_wp->w_match_head = NULL;
4613     new_wp->w_next_match_id = 4;
4614 #endif
4615     return new_wp;
4616 }
4617 
4618 /*
4619  * Remove window 'wp' from the window list and free the structure.
4620  */
4621     static void
4622 win_free(
4623     win_T	*wp,
4624     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4625 {
4626     int		i;
4627     buf_T	*buf;
4628     wininfo_T	*wip;
4629 
4630 #ifdef FEAT_FOLDING
4631     clearFolding(wp);
4632 #endif
4633 
4634     /* reduce the reference count to the argument list. */
4635     alist_unlink(wp->w_alist);
4636 
4637     /* Don't execute autocommands while the window is halfway being deleted.
4638      * gui_mch_destroy_scrollbar() may trigger a FocusGained event. */
4639     block_autocmds();
4640 
4641 #ifdef FEAT_LUA
4642     lua_window_free(wp);
4643 #endif
4644 
4645 #ifdef FEAT_MZSCHEME
4646     mzscheme_window_free(wp);
4647 #endif
4648 
4649 #ifdef FEAT_PERL
4650     perl_win_free(wp);
4651 #endif
4652 
4653 #ifdef FEAT_PYTHON
4654     python_window_free(wp);
4655 #endif
4656 
4657 #ifdef FEAT_PYTHON3
4658     python3_window_free(wp);
4659 #endif
4660 
4661 #ifdef FEAT_TCL
4662     tcl_window_free(wp);
4663 #endif
4664 
4665 #ifdef FEAT_RUBY
4666     ruby_window_free(wp);
4667 #endif
4668 
4669     clear_winopt(&wp->w_onebuf_opt);
4670     clear_winopt(&wp->w_allbuf_opt);
4671 
4672 #ifdef FEAT_EVAL
4673     vars_clear(&wp->w_vars->dv_hashtab);	/* free all w: variables */
4674     hash_init(&wp->w_vars->dv_hashtab);
4675     unref_var_dict(wp->w_vars);
4676 #endif
4677 
4678     {
4679 	tabpage_T	*ttp;
4680 
4681 	if (prevwin == wp)
4682 	    prevwin = NULL;
4683 	FOR_ALL_TABPAGES(ttp)
4684 	    if (ttp->tp_prevwin == wp)
4685 		ttp->tp_prevwin = NULL;
4686     }
4687     win_free_lsize(wp);
4688 
4689     for (i = 0; i < wp->w_tagstacklen; ++i)
4690 	vim_free(wp->w_tagstack[i].tagname);
4691 
4692     vim_free(wp->w_localdir);
4693 
4694     /* Remove the window from the b_wininfo lists, it may happen that the
4695      * freed memory is re-used for another window. */
4696     FOR_ALL_BUFFERS(buf)
4697 	for (wip = buf->b_wininfo; wip != NULL; wip = wip->wi_next)
4698 	    if (wip->wi_win == wp)
4699 		wip->wi_win = NULL;
4700 
4701 #ifdef FEAT_SEARCH_EXTRA
4702     clear_matches(wp);
4703 #endif
4704 
4705 #ifdef FEAT_JUMPLIST
4706     free_jumplist(wp);
4707 #endif
4708 
4709 #ifdef FEAT_QUICKFIX
4710     qf_free_all(wp);
4711 #endif
4712 
4713 #ifdef FEAT_GUI
4714     if (gui.in_use)
4715     {
4716 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
4717 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
4718     }
4719 #endif /* FEAT_GUI */
4720 
4721 #ifdef FEAT_MENU
4722     remove_winbar(wp);
4723 #endif
4724 
4725 #ifdef FEAT_SYN_HL
4726     vim_free(wp->w_p_cc_cols);
4727 #endif
4728 
4729     if (wp != aucmd_win)
4730 	win_remove(wp, tp);
4731     if (autocmd_busy)
4732     {
4733 	wp->w_next = au_pending_free_win;
4734 	au_pending_free_win = wp;
4735     }
4736     else
4737 	vim_free(wp);
4738 
4739     unblock_autocmds();
4740 }
4741 
4742 /*
4743  * Append window "wp" in the window list after window "after".
4744  */
4745     void
4746 win_append(win_T *after, win_T *wp)
4747 {
4748     win_T	*before;
4749 
4750     if (after == NULL)	    /* after NULL is in front of the first */
4751 	before = firstwin;
4752     else
4753 	before = after->w_next;
4754 
4755     wp->w_next = before;
4756     wp->w_prev = after;
4757     if (after == NULL)
4758 	firstwin = wp;
4759     else
4760 	after->w_next = wp;
4761     if (before == NULL)
4762 	lastwin = wp;
4763     else
4764 	before->w_prev = wp;
4765 }
4766 
4767 /*
4768  * Remove a window from the window list.
4769  */
4770     void
4771 win_remove(
4772     win_T	*wp,
4773     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4774 {
4775     if (wp->w_prev != NULL)
4776 	wp->w_prev->w_next = wp->w_next;
4777     else if (tp == NULL)
4778 	firstwin = curtab->tp_firstwin = wp->w_next;
4779     else
4780 	tp->tp_firstwin = wp->w_next;
4781 
4782     if (wp->w_next != NULL)
4783 	wp->w_next->w_prev = wp->w_prev;
4784     else if (tp == NULL)
4785 	lastwin = curtab->tp_lastwin = wp->w_prev;
4786     else
4787 	tp->tp_lastwin = wp->w_prev;
4788 }
4789 
4790 /*
4791  * Append frame "frp" in a frame list after frame "after".
4792  */
4793     static void
4794 frame_append(frame_T *after, frame_T *frp)
4795 {
4796     frp->fr_next = after->fr_next;
4797     after->fr_next = frp;
4798     if (frp->fr_next != NULL)
4799 	frp->fr_next->fr_prev = frp;
4800     frp->fr_prev = after;
4801 }
4802 
4803 /*
4804  * Insert frame "frp" in a frame list before frame "before".
4805  */
4806     static void
4807 frame_insert(frame_T *before, frame_T *frp)
4808 {
4809     frp->fr_next = before;
4810     frp->fr_prev = before->fr_prev;
4811     before->fr_prev = frp;
4812     if (frp->fr_prev != NULL)
4813 	frp->fr_prev->fr_next = frp;
4814     else
4815 	frp->fr_parent->fr_child = frp;
4816 }
4817 
4818 /*
4819  * Remove a frame from a frame list.
4820  */
4821     static void
4822 frame_remove(frame_T *frp)
4823 {
4824     if (frp->fr_prev != NULL)
4825 	frp->fr_prev->fr_next = frp->fr_next;
4826     else
4827     {
4828 	frp->fr_parent->fr_child = frp->fr_next;
4829 	/* special case: topframe->fr_child == frp */
4830 	if (topframe->fr_child == frp)
4831 	    topframe->fr_child = frp->fr_next;
4832     }
4833     if (frp->fr_next != NULL)
4834 	frp->fr_next->fr_prev = frp->fr_prev;
4835 }
4836 
4837 /*
4838  * Allocate w_lines[] for window "wp".
4839  * Return FAIL for failure, OK for success.
4840  */
4841     int
4842 win_alloc_lines(win_T *wp)
4843 {
4844     wp->w_lines_valid = 0;
4845     wp->w_lines = (wline_T *)alloc_clear((unsigned)(Rows * sizeof(wline_T)));
4846     if (wp->w_lines == NULL)
4847 	return FAIL;
4848     return OK;
4849 }
4850 
4851 /*
4852  * free lsize arrays for a window
4853  */
4854     void
4855 win_free_lsize(win_T *wp)
4856 {
4857     /* TODO: why would wp be NULL here? */
4858     if (wp != NULL)
4859 	VIM_CLEAR(wp->w_lines);
4860 }
4861 
4862 /*
4863  * Called from win_new_shellsize() after Rows changed.
4864  * This only does the current tab page, others must be done when made active.
4865  */
4866     void
4867 shell_new_rows(void)
4868 {
4869     int		h = (int)ROWS_AVAIL;
4870 
4871     if (firstwin == NULL)	/* not initialized yet */
4872 	return;
4873     if (h < frame_minheight(topframe, NULL))
4874 	h = frame_minheight(topframe, NULL);
4875 
4876     /* First try setting the heights of windows with 'winfixheight'.  If
4877      * that doesn't result in the right height, forget about that option. */
4878     frame_new_height(topframe, h, FALSE, TRUE);
4879     if (!frame_check_height(topframe, h))
4880 	frame_new_height(topframe, h, FALSE, FALSE);
4881 
4882     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4883     compute_cmdrow();
4884     curtab->tp_ch_used = p_ch;
4885 
4886 #if 0
4887     /* Disabled: don't want making the screen smaller make a window larger. */
4888     if (p_ea)
4889 	win_equal(curwin, FALSE, 'v');
4890 #endif
4891 }
4892 
4893 /*
4894  * Called from win_new_shellsize() after Columns changed.
4895  */
4896     void
4897 shell_new_columns(void)
4898 {
4899     if (firstwin == NULL)	/* not initialized yet */
4900 	return;
4901 
4902     /* First try setting the widths of windows with 'winfixwidth'.  If that
4903      * doesn't result in the right width, forget about that option. */
4904     frame_new_width(topframe, (int)Columns, FALSE, TRUE);
4905     if (!frame_check_width(topframe, Columns))
4906 	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
4907 
4908     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4909 #if 0
4910     /* Disabled: don't want making the screen smaller make a window larger. */
4911     if (p_ea)
4912 	win_equal(curwin, FALSE, 'h');
4913 #endif
4914 }
4915 
4916 #if defined(FEAT_CMDWIN) || defined(PROTO)
4917 /*
4918  * Save the size of all windows in "gap".
4919  */
4920     void
4921 win_size_save(garray_T *gap)
4922 
4923 {
4924     win_T	*wp;
4925 
4926     ga_init2(gap, (int)sizeof(int), 1);
4927     if (ga_grow(gap, win_count() * 2) == OK)
4928 	FOR_ALL_WINDOWS(wp)
4929 	{
4930 	    ((int *)gap->ga_data)[gap->ga_len++] =
4931 					       wp->w_width + wp->w_vsep_width;
4932 	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
4933 	}
4934 }
4935 
4936 /*
4937  * Restore window sizes, but only if the number of windows is still the same.
4938  * Does not free the growarray.
4939  */
4940     void
4941 win_size_restore(garray_T *gap)
4942 {
4943     win_T	*wp;
4944     int		i, j;
4945 
4946     if (win_count() * 2 == gap->ga_len)
4947     {
4948 	/* The order matters, because frames contain other frames, but it's
4949 	 * difficult to get right. The easy way out is to do it twice. */
4950 	for (j = 0; j < 2; ++j)
4951 	{
4952 	    i = 0;
4953 	    FOR_ALL_WINDOWS(wp)
4954 	    {
4955 		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
4956 		win_setheight_win(((int *)gap->ga_data)[i++], wp);
4957 	    }
4958 	}
4959 	/* recompute the window positions */
4960 	(void)win_comp_pos();
4961     }
4962 }
4963 #endif /* FEAT_CMDWIN */
4964 
4965 /*
4966  * Update the position for all windows, using the width and height of the
4967  * frames.
4968  * Returns the row just after the last window.
4969  */
4970     int
4971 win_comp_pos(void)
4972 {
4973     int		row = tabline_height();
4974     int		col = 0;
4975 
4976     frame_comp_pos(topframe, &row, &col);
4977     return row;
4978 }
4979 
4980 /*
4981  * Update the position of the windows in frame "topfrp", using the width and
4982  * height of the frames.
4983  * "*row" and "*col" are the top-left position of the frame.  They are updated
4984  * to the bottom-right position plus one.
4985  */
4986     static void
4987 frame_comp_pos(frame_T *topfrp, int *row, int *col)
4988 {
4989     win_T	*wp;
4990     frame_T	*frp;
4991     int		startcol;
4992     int		startrow;
4993     int		h;
4994 
4995     wp = topfrp->fr_win;
4996     if (wp != NULL)
4997     {
4998 	if (wp->w_winrow != *row || wp->w_wincol != *col)
4999 	{
5000 	    /* position changed, redraw */
5001 	    wp->w_winrow = *row;
5002 	    wp->w_wincol = *col;
5003 	    redraw_win_later(wp, NOT_VALID);
5004 	    wp->w_redr_status = TRUE;
5005 	}
5006 	/* WinBar will not show if the window height is zero */
5007 	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
5008 	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
5009 	*col += wp->w_width + wp->w_vsep_width;
5010     }
5011     else
5012     {
5013 	startrow = *row;
5014 	startcol = *col;
5015 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
5016 	{
5017 	    if (topfrp->fr_layout == FR_ROW)
5018 		*row = startrow;	/* all frames are at the same row */
5019 	    else
5020 		*col = startcol;	/* all frames are at the same col */
5021 	    frame_comp_pos(frp, row, col);
5022 	}
5023     }
5024 }
5025 
5026 /*
5027  * Set current window height and take care of repositioning other windows to
5028  * fit around it.
5029  */
5030     void
5031 win_setheight(int height)
5032 {
5033     win_setheight_win(height, curwin);
5034 }
5035 
5036 /*
5037  * Set the window height of window "win" and take care of repositioning other
5038  * windows to fit around it.
5039  */
5040     void
5041 win_setheight_win(int height, win_T *win)
5042 {
5043     int		row;
5044 
5045     if (win == curwin)
5046     {
5047 	/* Always keep current window at least one line high, even when
5048 	 * 'winminheight' is zero. */
5049 	if (height < p_wmh)
5050 	    height = p_wmh;
5051 	if (height == 0)
5052 	    height = 1;
5053 	height += WINBAR_HEIGHT(curwin);
5054     }
5055 
5056     frame_setheight(win->w_frame, height + win->w_status_height);
5057 
5058     /* recompute the window positions */
5059     row = win_comp_pos();
5060 
5061     /*
5062      * If there is extra space created between the last window and the command
5063      * line, clear it.
5064      */
5065     if (full_screen && msg_scrolled == 0 && row < cmdline_row)
5066 	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5067     cmdline_row = row;
5068     msg_row = row;
5069     msg_col = 0;
5070 
5071     redraw_all_later(NOT_VALID);
5072 }
5073 
5074 /*
5075  * Set the height of a frame to "height" and take care that all frames and
5076  * windows inside it are resized.  Also resize frames on the left and right if
5077  * the are in the same FR_ROW frame.
5078  *
5079  * Strategy:
5080  * If the frame is part of a FR_COL frame, try fitting the frame in that
5081  * frame.  If that doesn't work (the FR_COL frame is too small), recursively
5082  * go to containing frames to resize them and make room.
5083  * If the frame is part of a FR_ROW frame, all frames must be resized as well.
5084  * Check for the minimal height of the FR_ROW frame.
5085  * At the top level we can also use change the command line height.
5086  */
5087     static void
5088 frame_setheight(frame_T *curfrp, int height)
5089 {
5090     int		room;		/* total number of lines available */
5091     int		take;		/* number of lines taken from other windows */
5092     int		room_cmdline;	/* lines available from cmdline */
5093     int		run;
5094     frame_T	*frp;
5095     int		h;
5096     int		room_reserved;
5097 
5098     /* If the height already is the desired value, nothing to do. */
5099     if (curfrp->fr_height == height)
5100 	return;
5101 
5102     if (curfrp->fr_parent == NULL)
5103     {
5104 	/* topframe: can only change the command line */
5105 	if (height > ROWS_AVAIL)
5106 	    height = ROWS_AVAIL;
5107 	if (height > 0)
5108 	    frame_new_height(curfrp, height, FALSE, FALSE);
5109     }
5110     else if (curfrp->fr_parent->fr_layout == FR_ROW)
5111     {
5112 	/* Row of frames: Also need to resize frames left and right of this
5113 	 * one.  First check for the minimal height of these. */
5114 	h = frame_minheight(curfrp->fr_parent, NULL);
5115 	if (height < h)
5116 	    height = h;
5117 	frame_setheight(curfrp->fr_parent, height);
5118     }
5119     else
5120     {
5121 	/*
5122 	 * Column of frames: try to change only frames in this column.
5123 	 */
5124 	/*
5125 	 * Do this twice:
5126 	 * 1: compute room available, if it's not enough try resizing the
5127 	 *    containing frame.
5128 	 * 2: compute the room available and adjust the height to it.
5129 	 * Try not to reduce the height of a window with 'winfixheight' set.
5130 	 */
5131 	for (run = 1; run <= 2; ++run)
5132 	{
5133 	    room = 0;
5134 	    room_reserved = 0;
5135 	    for (frp = curfrp->fr_parent->fr_child; frp != NULL;
5136 							   frp = frp->fr_next)
5137 	    {
5138 		if (frp != curfrp
5139 			&& frp->fr_win != NULL
5140 			&& frp->fr_win->w_p_wfh)
5141 		    room_reserved += frp->fr_height;
5142 		room += frp->fr_height;
5143 		if (frp != curfrp)
5144 		    room -= frame_minheight(frp, NULL);
5145 	    }
5146 	    if (curfrp->fr_width != Columns)
5147 		room_cmdline = 0;
5148 	    else
5149 	    {
5150 		room_cmdline = Rows - p_ch - (lastwin->w_winrow
5151 						+ VISIBLE_HEIGHT(lastwin)
5152 						+ lastwin->w_status_height);
5153 		if (room_cmdline < 0)
5154 		    room_cmdline = 0;
5155 	    }
5156 
5157 	    if (height <= room + room_cmdline)
5158 		break;
5159 	    if (run == 2 || curfrp->fr_width == Columns)
5160 	    {
5161 		if (height > room + room_cmdline)
5162 		    height = room + room_cmdline;
5163 		break;
5164 	    }
5165 	    frame_setheight(curfrp->fr_parent, height
5166 		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
5167 	}
5168 
5169 	/*
5170 	 * Compute the number of lines we will take from others frames (can be
5171 	 * negative!).
5172 	 */
5173 	take = height - curfrp->fr_height;
5174 
5175 	/* If there is not enough room, also reduce the height of a window
5176 	 * with 'winfixheight' set. */
5177 	if (height > room + room_cmdline - room_reserved)
5178 	    room_reserved = room + room_cmdline - height;
5179 	/* If there is only a 'winfixheight' window and making the
5180 	 * window smaller, need to make the other window taller. */
5181 	if (take < 0 && room - curfrp->fr_height < room_reserved)
5182 	    room_reserved = 0;
5183 
5184 	if (take > 0 && room_cmdline > 0)
5185 	{
5186 	    /* use lines from cmdline first */
5187 	    if (take < room_cmdline)
5188 		room_cmdline = take;
5189 	    take -= room_cmdline;
5190 	    topframe->fr_height += room_cmdline;
5191 	}
5192 
5193 	/*
5194 	 * set the current frame to the new height
5195 	 */
5196 	frame_new_height(curfrp, height, FALSE, FALSE);
5197 
5198 	/*
5199 	 * First take lines from the frames after the current frame.  If
5200 	 * that is not enough, takes lines from frames above the current
5201 	 * frame.
5202 	 */
5203 	for (run = 0; run < 2; ++run)
5204 	{
5205 	    if (run == 0)
5206 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5207 	    else
5208 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5209 	    while (frp != NULL && take != 0)
5210 	    {
5211 		h = frame_minheight(frp, NULL);
5212 		if (room_reserved > 0
5213 			&& frp->fr_win != NULL
5214 			&& frp->fr_win->w_p_wfh)
5215 		{
5216 		    if (room_reserved >= frp->fr_height)
5217 			room_reserved -= frp->fr_height;
5218 		    else
5219 		    {
5220 			if (frp->fr_height - room_reserved > take)
5221 			    room_reserved = frp->fr_height - take;
5222 			take -= frp->fr_height - room_reserved;
5223 			frame_new_height(frp, room_reserved, FALSE, FALSE);
5224 			room_reserved = 0;
5225 		    }
5226 		}
5227 		else
5228 		{
5229 		    if (frp->fr_height - take < h)
5230 		    {
5231 			take -= frp->fr_height - h;
5232 			frame_new_height(frp, h, FALSE, FALSE);
5233 		    }
5234 		    else
5235 		    {
5236 			frame_new_height(frp, frp->fr_height - take,
5237 								FALSE, FALSE);
5238 			take = 0;
5239 		    }
5240 		}
5241 		if (run == 0)
5242 		    frp = frp->fr_next;
5243 		else
5244 		    frp = frp->fr_prev;
5245 	    }
5246 	}
5247     }
5248 }
5249 
5250 /*
5251  * Set current window width and take care of repositioning other windows to
5252  * fit around it.
5253  */
5254     void
5255 win_setwidth(int width)
5256 {
5257     win_setwidth_win(width, curwin);
5258 }
5259 
5260     void
5261 win_setwidth_win(int width, win_T *wp)
5262 {
5263     /* Always keep current window at least one column wide, even when
5264      * 'winminwidth' is zero. */
5265     if (wp == curwin)
5266     {
5267 	if (width < p_wmw)
5268 	    width = p_wmw;
5269 	if (width == 0)
5270 	    width = 1;
5271     }
5272 
5273     frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
5274 
5275     /* recompute the window positions */
5276     (void)win_comp_pos();
5277 
5278     redraw_all_later(NOT_VALID);
5279 }
5280 
5281 /*
5282  * Set the width of a frame to "width" and take care that all frames and
5283  * windows inside it are resized.  Also resize frames above and below if the
5284  * are in the same FR_ROW frame.
5285  *
5286  * Strategy is similar to frame_setheight().
5287  */
5288     static void
5289 frame_setwidth(frame_T *curfrp, int width)
5290 {
5291     int		room;		/* total number of lines available */
5292     int		take;		/* number of lines taken from other windows */
5293     int		run;
5294     frame_T	*frp;
5295     int		w;
5296     int		room_reserved;
5297 
5298     /* If the width already is the desired value, nothing to do. */
5299     if (curfrp->fr_width == width)
5300 	return;
5301 
5302     if (curfrp->fr_parent == NULL)
5303 	/* topframe: can't change width */
5304 	return;
5305 
5306     if (curfrp->fr_parent->fr_layout == FR_COL)
5307     {
5308 	/* Column of frames: Also need to resize frames above and below of
5309 	 * this one.  First check for the minimal width of these. */
5310 	w = frame_minwidth(curfrp->fr_parent, NULL);
5311 	if (width < w)
5312 	    width = w;
5313 	frame_setwidth(curfrp->fr_parent, width);
5314     }
5315     else
5316     {
5317 	/*
5318 	 * Row of frames: try to change only frames in this row.
5319 	 *
5320 	 * Do this twice:
5321 	 * 1: compute room available, if it's not enough try resizing the
5322 	 *    containing frame.
5323 	 * 2: compute the room available and adjust the width to it.
5324 	 */
5325 	for (run = 1; run <= 2; ++run)
5326 	{
5327 	    room = 0;
5328 	    room_reserved = 0;
5329 	    for (frp = curfrp->fr_parent->fr_child; frp != NULL;
5330 							   frp = frp->fr_next)
5331 	    {
5332 		if (frp != curfrp
5333 			&& frp->fr_win != NULL
5334 			&& frp->fr_win->w_p_wfw)
5335 		    room_reserved += frp->fr_width;
5336 		room += frp->fr_width;
5337 		if (frp != curfrp)
5338 		    room -= frame_minwidth(frp, NULL);
5339 	    }
5340 
5341 	    if (width <= room)
5342 		break;
5343 	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
5344 	    {
5345 		if (width > room)
5346 		    width = room;
5347 		break;
5348 	    }
5349 	    frame_setwidth(curfrp->fr_parent, width
5350 		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
5351 	}
5352 
5353 	/*
5354 	 * Compute the number of lines we will take from others frames (can be
5355 	 * negative!).
5356 	 */
5357 	take = width - curfrp->fr_width;
5358 
5359 	/* If there is not enough room, also reduce the width of a window
5360 	 * with 'winfixwidth' set. */
5361 	if (width > room - room_reserved)
5362 	    room_reserved = room - width;
5363 	/* If there is only a 'winfixwidth' window and making the
5364 	 * window smaller, need to make the other window narrower. */
5365 	if (take < 0 && room - curfrp->fr_width < room_reserved)
5366 	    room_reserved = 0;
5367 
5368 	/*
5369 	 * set the current frame to the new width
5370 	 */
5371 	frame_new_width(curfrp, width, FALSE, FALSE);
5372 
5373 	/*
5374 	 * First take lines from the frames right of the current frame.  If
5375 	 * that is not enough, takes lines from frames left of the current
5376 	 * frame.
5377 	 */
5378 	for (run = 0; run < 2; ++run)
5379 	{
5380 	    if (run == 0)
5381 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5382 	    else
5383 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5384 	    while (frp != NULL && take != 0)
5385 	    {
5386 		w = frame_minwidth(frp, NULL);
5387 		if (room_reserved > 0
5388 			&& frp->fr_win != NULL
5389 			&& frp->fr_win->w_p_wfw)
5390 		{
5391 		    if (room_reserved >= frp->fr_width)
5392 			room_reserved -= frp->fr_width;
5393 		    else
5394 		    {
5395 			if (frp->fr_width - room_reserved > take)
5396 			    room_reserved = frp->fr_width - take;
5397 			take -= frp->fr_width - room_reserved;
5398 			frame_new_width(frp, room_reserved, FALSE, FALSE);
5399 			room_reserved = 0;
5400 		    }
5401 		}
5402 		else
5403 		{
5404 		    if (frp->fr_width - take < w)
5405 		    {
5406 			take -= frp->fr_width - w;
5407 			frame_new_width(frp, w, FALSE, FALSE);
5408 		    }
5409 		    else
5410 		    {
5411 			frame_new_width(frp, frp->fr_width - take,
5412 								FALSE, FALSE);
5413 			take = 0;
5414 		    }
5415 		}
5416 		if (run == 0)
5417 		    frp = frp->fr_next;
5418 		else
5419 		    frp = frp->fr_prev;
5420 	    }
5421 	}
5422     }
5423 }
5424 
5425 /*
5426  * Check 'winminheight' for a valid value and reduce it if needed.
5427  */
5428     void
5429 win_setminheight(void)
5430 {
5431     int		room;
5432     int		needed;
5433     int		first = TRUE;
5434 
5435     // loop until there is a 'winminheight' that is possible
5436     while (p_wmh > 0)
5437     {
5438 	room = Rows - p_ch;
5439 	needed = frame_minheight(topframe, NULL);
5440 	if (room >= needed)
5441 	    break;
5442 	--p_wmh;
5443 	if (first)
5444 	{
5445 	    EMSG(_(e_noroom));
5446 	    first = FALSE;
5447 	}
5448     }
5449 }
5450 
5451 /*
5452  * Check 'winminwidth' for a valid value and reduce it if needed.
5453  */
5454     void
5455 win_setminwidth(void)
5456 {
5457     int		room;
5458     int		needed;
5459     int		first = TRUE;
5460 
5461     // loop until there is a 'winminheight' that is possible
5462     while (p_wmw > 0)
5463     {
5464 	room = Columns;
5465 	needed = frame_minwidth(topframe, NULL);
5466 	if (room >= needed)
5467 	    break;
5468 	--p_wmw;
5469 	if (first)
5470 	{
5471 	    EMSG(_(e_noroom));
5472 	    first = FALSE;
5473 	}
5474     }
5475 }
5476 
5477 #if defined(FEAT_MOUSE) || defined(PROTO)
5478 
5479 /*
5480  * Status line of dragwin is dragged "offset" lines down (negative is up).
5481  */
5482     void
5483 win_drag_status_line(win_T *dragwin, int offset)
5484 {
5485     frame_T	*curfr;
5486     frame_T	*fr;
5487     int		room;
5488     int		row;
5489     int		up;	/* if TRUE, drag status line up, otherwise down */
5490     int		n;
5491 
5492     fr = dragwin->w_frame;
5493     curfr = fr;
5494     if (fr != topframe)		/* more than one window */
5495     {
5496 	fr = fr->fr_parent;
5497 	/* When the parent frame is not a column of frames, its parent should
5498 	 * be. */
5499 	if (fr->fr_layout != FR_COL)
5500 	{
5501 	    curfr = fr;
5502 	    if (fr != topframe)	/* only a row of windows, may drag statusline */
5503 		fr = fr->fr_parent;
5504 	}
5505     }
5506 
5507     /* If this is the last frame in a column, may want to resize the parent
5508      * frame instead (go two up to skip a row of frames). */
5509     while (curfr != topframe && curfr->fr_next == NULL)
5510     {
5511 	if (fr != topframe)
5512 	    fr = fr->fr_parent;
5513 	curfr = fr;
5514 	if (fr != topframe)
5515 	    fr = fr->fr_parent;
5516     }
5517 
5518     if (offset < 0) /* drag up */
5519     {
5520 	up = TRUE;
5521 	offset = -offset;
5522 	/* sum up the room of the current frame and above it */
5523 	if (fr == curfr)
5524 	{
5525 	    /* only one window */
5526 	    room = fr->fr_height - frame_minheight(fr, NULL);
5527 	}
5528 	else
5529 	{
5530 	    room = 0;
5531 	    for (fr = fr->fr_child; ; fr = fr->fr_next)
5532 	    {
5533 		room += fr->fr_height - frame_minheight(fr, NULL);
5534 		if (fr == curfr)
5535 		    break;
5536 	    }
5537 	}
5538 	fr = curfr->fr_next;		/* put fr at frame that grows */
5539     }
5540     else    /* drag down */
5541     {
5542 	up = FALSE;
5543 	/*
5544 	 * Only dragging the last status line can reduce p_ch.
5545 	 */
5546 	room = Rows - cmdline_row;
5547 	if (curfr->fr_next == NULL)
5548 	    room -= 1;
5549 	else
5550 	    room -= p_ch;
5551 	if (room < 0)
5552 	    room = 0;
5553 	/* sum up the room of frames below of the current one */
5554 	for (fr = curfr->fr_next; fr != NULL; fr = fr->fr_next)
5555 	    room += fr->fr_height - frame_minheight(fr, NULL);
5556 	fr = curfr;			/* put fr at window that grows */
5557     }
5558 
5559     if (room < offset)		/* Not enough room */
5560 	offset = room;		/* Move as far as we can */
5561     if (offset <= 0)
5562 	return;
5563 
5564     /*
5565      * Grow frame fr by "offset" lines.
5566      * Doesn't happen when dragging the last status line up.
5567      */
5568     if (fr != NULL)
5569 	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
5570 
5571     if (up)
5572 	fr = curfr;		/* current frame gets smaller */
5573     else
5574 	fr = curfr->fr_next;	/* next frame gets smaller */
5575 
5576     /*
5577      * Now make the other frames smaller.
5578      */
5579     while (fr != NULL && offset > 0)
5580     {
5581 	n = frame_minheight(fr, NULL);
5582 	if (fr->fr_height - offset <= n)
5583 	{
5584 	    offset -= fr->fr_height - n;
5585 	    frame_new_height(fr, n, !up, FALSE);
5586 	}
5587 	else
5588 	{
5589 	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
5590 	    break;
5591 	}
5592 	if (up)
5593 	    fr = fr->fr_prev;
5594 	else
5595 	    fr = fr->fr_next;
5596     }
5597     row = win_comp_pos();
5598     screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5599     cmdline_row = row;
5600     p_ch = Rows - cmdline_row;
5601     if (p_ch < 1)
5602 	p_ch = 1;
5603     curtab->tp_ch_used = p_ch;
5604     redraw_all_later(SOME_VALID);
5605     showmode();
5606 }
5607 
5608 /*
5609  * Separator line of dragwin is dragged "offset" lines right (negative is left).
5610  */
5611     void
5612 win_drag_vsep_line(win_T *dragwin, int offset)
5613 {
5614     frame_T	*curfr;
5615     frame_T	*fr;
5616     int		room;
5617     int		left;	/* if TRUE, drag separator line left, otherwise right */
5618     int		n;
5619 
5620     fr = dragwin->w_frame;
5621     if (fr == topframe)		/* only one window (cannot happen?) */
5622 	return;
5623     curfr = fr;
5624     fr = fr->fr_parent;
5625     /* When the parent frame is not a row of frames, its parent should be. */
5626     if (fr->fr_layout != FR_ROW)
5627     {
5628 	if (fr == topframe)	/* only a column of windows (cannot happen?) */
5629 	    return;
5630 	curfr = fr;
5631 	fr = fr->fr_parent;
5632     }
5633 
5634     /* If this is the last frame in a row, may want to resize a parent
5635      * frame instead. */
5636     while (curfr->fr_next == NULL)
5637     {
5638 	if (fr == topframe)
5639 	    break;
5640 	curfr = fr;
5641 	fr = fr->fr_parent;
5642 	if (fr != topframe)
5643 	{
5644 	    curfr = fr;
5645 	    fr = fr->fr_parent;
5646 	}
5647     }
5648 
5649     if (offset < 0) /* drag left */
5650     {
5651 	left = TRUE;
5652 	offset = -offset;
5653 	/* sum up the room of the current frame and left of it */
5654 	room = 0;
5655 	for (fr = fr->fr_child; ; fr = fr->fr_next)
5656 	{
5657 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5658 	    if (fr == curfr)
5659 		break;
5660 	}
5661 	fr = curfr->fr_next;		/* put fr at frame that grows */
5662     }
5663     else    /* drag right */
5664     {
5665 	left = FALSE;
5666 	/* sum up the room of frames right of the current one */
5667 	room = 0;
5668 	for (fr = curfr->fr_next; fr != NULL; fr = fr->fr_next)
5669 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5670 	fr = curfr;			/* put fr at window that grows */
5671     }
5672 
5673     if (room < offset)		/* Not enough room */
5674 	offset = room;		/* Move as far as we can */
5675     if (offset <= 0)		/* No room at all, quit. */
5676 	return;
5677     if (fr == NULL)
5678 	return;			/* Safety check, should not happen. */
5679 
5680     /* grow frame fr by offset lines */
5681     frame_new_width(fr, fr->fr_width + offset, left, FALSE);
5682 
5683     /* shrink other frames: current and at the left or at the right */
5684     if (left)
5685 	fr = curfr;		/* current frame gets smaller */
5686     else
5687 	fr = curfr->fr_next;	/* next frame gets smaller */
5688 
5689     while (fr != NULL && offset > 0)
5690     {
5691 	n = frame_minwidth(fr, NULL);
5692 	if (fr->fr_width - offset <= n)
5693 	{
5694 	    offset -= fr->fr_width - n;
5695 	    frame_new_width(fr, n, !left, FALSE);
5696 	}
5697 	else
5698 	{
5699 	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
5700 	    break;
5701 	}
5702 	if (left)
5703 	    fr = fr->fr_prev;
5704 	else
5705 	    fr = fr->fr_next;
5706     }
5707     (void)win_comp_pos();
5708     redraw_all_later(NOT_VALID);
5709 }
5710 #endif /* FEAT_MOUSE */
5711 
5712 #define FRACTION_MULT	16384L
5713 
5714 /*
5715  * Set wp->w_fraction for the current w_wrow and w_height.
5716  * Has no effect when the window is less than two lines.
5717  */
5718     void
5719 set_fraction(win_T *wp)
5720 {
5721     if (wp->w_height > 1)
5722 	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
5723 				    + wp->w_height / 2) / (long)wp->w_height;
5724 }
5725 
5726 /*
5727  * Set the height of a window.
5728  * "height" excludes any window toolbar.
5729  * This takes care of the things inside the window, not what happens to the
5730  * window position, the frame or to other windows.
5731  */
5732     void
5733 win_new_height(win_T *wp, int height)
5734 {
5735     int		prev_height = wp->w_height;
5736 
5737     /* Don't want a negative height.  Happens when splitting a tiny window.
5738      * Will equalize heights soon to fix it. */
5739     if (height < 0)
5740 	height = 0;
5741     if (wp->w_height == height)
5742 	return;	    /* nothing to do */
5743 
5744     if (wp->w_height > 0)
5745     {
5746 	if (wp == curwin)
5747 	    /* w_wrow needs to be valid. When setting 'laststatus' this may
5748 	     * call win_new_height() recursively. */
5749 	    validate_cursor();
5750 	if (wp->w_height != prev_height)
5751 	    return;  /* Recursive call already changed the size, bail out here
5752 			to avoid the following to mess things up. */
5753 	if (wp->w_wrow != wp->w_prev_fraction_row)
5754 	    set_fraction(wp);
5755     }
5756 
5757     wp->w_height = height;
5758     wp->w_skipcol = 0;
5759 
5760     /* There is no point in adjusting the scroll position when exiting.  Some
5761      * values might be invalid. */
5762     if (!exiting)
5763 	scroll_to_fraction(wp, prev_height);
5764 }
5765 
5766     void
5767 scroll_to_fraction(win_T *wp, int prev_height)
5768 {
5769     linenr_T	lnum;
5770     int		sline, line_size;
5771     int		height = wp->w_height;
5772 
5773     /* Don't change w_topline when height is zero.  Don't set w_topline when
5774      * 'scrollbind' is set and this isn't the current window. */
5775     if (height > 0 && (!wp->w_p_scb || wp == curwin))
5776     {
5777 	/*
5778 	 * Find a value for w_topline that shows the cursor at the same
5779 	 * relative position in the window as before (more or less).
5780 	 */
5781 	lnum = wp->w_cursor.lnum;
5782 	if (lnum < 1)		/* can happen when starting up */
5783 	    lnum = 1;
5784 	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L
5785 					 + FRACTION_MULT / 2) / FRACTION_MULT;
5786 	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
5787 	sline = wp->w_wrow - line_size;
5788 
5789 	if (sline >= 0)
5790 	{
5791 	    /* Make sure the whole cursor line is visible, if possible. */
5792 	    int rows = plines_win(wp, lnum, FALSE);
5793 
5794 	    if (sline > wp->w_height - rows)
5795 	    {
5796 		sline = wp->w_height - rows;
5797 		wp->w_wrow -= rows - line_size;
5798 	    }
5799 	}
5800 
5801 	if (sline < 0)
5802 	{
5803 	    /*
5804 	     * Cursor line would go off top of screen if w_wrow was this high.
5805 	     * Make cursor line the first line in the window.  If not enough
5806 	     * room use w_skipcol;
5807 	     */
5808 	    wp->w_wrow = line_size;
5809 	    if (wp->w_wrow >= wp->w_height
5810 				       && (wp->w_width - win_col_off(wp)) > 0)
5811 	    {
5812 		wp->w_skipcol += wp->w_width - win_col_off(wp);
5813 		--wp->w_wrow;
5814 		while (wp->w_wrow >= wp->w_height)
5815 		{
5816 		    wp->w_skipcol += wp->w_width - win_col_off(wp)
5817 							   + win_col_off2(wp);
5818 		    --wp->w_wrow;
5819 		}
5820 	    }
5821 	    set_topline(wp, lnum);
5822 	}
5823 	else if (sline > 0)
5824 	{
5825 	    while (sline > 0 && lnum > 1)
5826 	    {
5827 #ifdef FEAT_FOLDING
5828 		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
5829 		if (lnum == 1)
5830 		{
5831 		    /* first line in buffer is folded */
5832 		    line_size = 1;
5833 		    --sline;
5834 		    break;
5835 		}
5836 #endif
5837 		--lnum;
5838 #ifdef FEAT_DIFF
5839 		if (lnum == wp->w_topline)
5840 		    line_size = plines_win_nofill(wp, lnum, TRUE)
5841 							      + wp->w_topfill;
5842 		else
5843 #endif
5844 		    line_size = plines_win(wp, lnum, TRUE);
5845 		sline -= line_size;
5846 	    }
5847 
5848 	    if (sline < 0)
5849 	    {
5850 		/*
5851 		 * Line we want at top would go off top of screen.  Use next
5852 		 * line instead.
5853 		 */
5854 #ifdef FEAT_FOLDING
5855 		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
5856 #endif
5857 		lnum++;
5858 		wp->w_wrow -= line_size + sline;
5859 	    }
5860 	    else if (sline > 0)
5861 	    {
5862 		/* First line of file reached, use that as topline. */
5863 		lnum = 1;
5864 		wp->w_wrow -= sline;
5865 	    }
5866 
5867 	    set_topline(wp, lnum);
5868 	}
5869     }
5870 
5871     if (wp == curwin)
5872     {
5873 	if (p_so)
5874 	    update_topline();
5875 	curs_columns(FALSE);	/* validate w_wrow */
5876     }
5877     if (prev_height > 0)
5878 	wp->w_prev_fraction_row = wp->w_wrow;
5879 
5880     win_comp_scroll(wp);
5881     redraw_win_later(wp, SOME_VALID);
5882     wp->w_redr_status = TRUE;
5883     invalidate_botline_win(wp);
5884 }
5885 
5886 /*
5887  * Set the width of a window.
5888  */
5889     void
5890 win_new_width(win_T *wp, int width)
5891 {
5892     wp->w_width = width;
5893     wp->w_lines_valid = 0;
5894     changed_line_abv_curs_win(wp);
5895     invalidate_botline_win(wp);
5896     if (wp == curwin)
5897     {
5898 	update_topline();
5899 	curs_columns(TRUE);	/* validate w_wrow */
5900     }
5901     redraw_win_later(wp, NOT_VALID);
5902     wp->w_redr_status = TRUE;
5903 }
5904 
5905     void
5906 win_comp_scroll(win_T *wp)
5907 {
5908     wp->w_p_scr = ((unsigned)wp->w_height >> 1);
5909     if (wp->w_p_scr == 0)
5910 	wp->w_p_scr = 1;
5911 }
5912 
5913 /*
5914  * command_height: called whenever p_ch has been changed
5915  */
5916     void
5917 command_height(void)
5918 {
5919     int		h;
5920     frame_T	*frp;
5921     int		old_p_ch = curtab->tp_ch_used;
5922 
5923     /* Use the value of p_ch that we remembered.  This is needed for when the
5924      * GUI starts up, we can't be sure in what order things happen.  And when
5925      * p_ch was changed in another tab page. */
5926     curtab->tp_ch_used = p_ch;
5927 
5928     /* Find bottom frame with width of screen. */
5929     frp = lastwin->w_frame;
5930     while (frp->fr_width != Columns && frp->fr_parent != NULL)
5931 	frp = frp->fr_parent;
5932 
5933     /* Avoid changing the height of a window with 'winfixheight' set. */
5934     while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
5935 						      && frp->fr_win->w_p_wfh)
5936 	frp = frp->fr_prev;
5937 
5938     if (starting != NO_SCREEN)
5939     {
5940 	cmdline_row = Rows - p_ch;
5941 
5942 	if (p_ch > old_p_ch)		    /* p_ch got bigger */
5943 	{
5944 	    while (p_ch > old_p_ch)
5945 	    {
5946 		if (frp == NULL)
5947 		{
5948 		    EMSG(_(e_noroom));
5949 		    p_ch = old_p_ch;
5950 		    curtab->tp_ch_used = p_ch;
5951 		    cmdline_row = Rows - p_ch;
5952 		    break;
5953 		}
5954 		h = frp->fr_height - frame_minheight(frp, NULL);
5955 		if (h > p_ch - old_p_ch)
5956 		    h = p_ch - old_p_ch;
5957 		old_p_ch += h;
5958 		frame_add_height(frp, -h);
5959 		frp = frp->fr_prev;
5960 	    }
5961 
5962 	    /* Recompute window positions. */
5963 	    (void)win_comp_pos();
5964 
5965 	    /* clear the lines added to cmdline */
5966 	    if (full_screen)
5967 		screen_fill((int)(cmdline_row), (int)Rows, 0,
5968 						   (int)Columns, ' ', ' ', 0);
5969 	    msg_row = cmdline_row;
5970 	    redraw_cmdline = TRUE;
5971 	    return;
5972 	}
5973 
5974 	if (msg_row < cmdline_row)
5975 	    msg_row = cmdline_row;
5976 	redraw_cmdline = TRUE;
5977     }
5978     frame_add_height(frp, (int)(old_p_ch - p_ch));
5979 
5980     /* Recompute window positions. */
5981     if (frp != lastwin->w_frame)
5982 	(void)win_comp_pos();
5983 }
5984 
5985 /*
5986  * Resize frame "frp" to be "n" lines higher (negative for less high).
5987  * Also resize the frames it is contained in.
5988  */
5989     static void
5990 frame_add_height(frame_T *frp, int n)
5991 {
5992     frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
5993     for (;;)
5994     {
5995 	frp = frp->fr_parent;
5996 	if (frp == NULL)
5997 	    break;
5998 	frp->fr_height += n;
5999     }
6000 }
6001 
6002 /*
6003  * Add or remove a status line for the bottom window(s), according to the
6004  * value of 'laststatus'.
6005  */
6006     void
6007 last_status(
6008     int		morewin)	/* pretend there are two or more windows */
6009 {
6010     /* Don't make a difference between horizontal or vertical split. */
6011     last_status_rec(topframe, (p_ls == 2
6012 			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
6013 }
6014 
6015     static void
6016 last_status_rec(frame_T *fr, int statusline)
6017 {
6018     frame_T	*fp;
6019     win_T	*wp;
6020 
6021     if (fr->fr_layout == FR_LEAF)
6022     {
6023 	wp = fr->fr_win;
6024 	if (wp->w_status_height != 0 && !statusline)
6025 	{
6026 	    /* remove status line */
6027 	    win_new_height(wp, wp->w_height + 1);
6028 	    wp->w_status_height = 0;
6029 	    comp_col();
6030 	}
6031 	else if (wp->w_status_height == 0 && statusline)
6032 	{
6033 	    /* Find a frame to take a line from. */
6034 	    fp = fr;
6035 	    while (fp->fr_height <= frame_minheight(fp, NULL))
6036 	    {
6037 		if (fp == topframe)
6038 		{
6039 		    EMSG(_(e_noroom));
6040 		    return;
6041 		}
6042 		/* In a column of frames: go to frame above.  If already at
6043 		 * the top or in a row of frames: go to parent. */
6044 		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
6045 		    fp = fp->fr_prev;
6046 		else
6047 		    fp = fp->fr_parent;
6048 	    }
6049 	    wp->w_status_height = 1;
6050 	    if (fp != fr)
6051 	    {
6052 		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
6053 		frame_fix_height(wp);
6054 		(void)win_comp_pos();
6055 	    }
6056 	    else
6057 		win_new_height(wp, wp->w_height - 1);
6058 	    comp_col();
6059 	    redraw_all_later(SOME_VALID);
6060 	}
6061     }
6062     else if (fr->fr_layout == FR_ROW)
6063     {
6064 	/* vertically split windows, set status line for each one */
6065 	for (fp = fr->fr_child; fp != NULL; fp = fp->fr_next)
6066 	    last_status_rec(fp, statusline);
6067     }
6068     else
6069     {
6070 	/* horizontally split window, set status line for last one */
6071 	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
6072 	    ;
6073 	last_status_rec(fp, statusline);
6074     }
6075 }
6076 
6077 /*
6078  * Return the number of lines used by the tab page line.
6079  */
6080     int
6081 tabline_height(void)
6082 {
6083 #ifdef FEAT_GUI_TABLINE
6084     /* When the GUI has the tabline then this always returns zero. */
6085     if (gui_use_tabline())
6086 	return 0;
6087 #endif
6088     switch (p_stal)
6089     {
6090 	case 0: return 0;
6091 	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
6092     }
6093     return 1;
6094 }
6095 
6096 #if defined(FEAT_SEARCHPATH) || defined(PROTO)
6097 /*
6098  * Get the file name at the cursor.
6099  * If Visual mode is active, use the selected text if it's in one line.
6100  * Returns the name in allocated memory, NULL for failure.
6101  */
6102     char_u *
6103 grab_file_name(long count, linenr_T *file_lnum)
6104 {
6105     int options = FNAME_MESS|FNAME_EXP|FNAME_REL|FNAME_UNESC;
6106 
6107     if (VIsual_active)
6108     {
6109 	int	len;
6110 	char_u	*ptr;
6111 
6112 	if (get_visual_text(NULL, &ptr, &len) == FAIL)
6113 	    return NULL;
6114 	return find_file_name_in_path(ptr, len, options,
6115 						     count, curbuf->b_ffname);
6116     }
6117     return file_name_at_cursor(options | FNAME_HYP, count, file_lnum);
6118 }
6119 
6120 /*
6121  * Return the file name under or after the cursor.
6122  *
6123  * The 'path' option is searched if the file name is not absolute.
6124  * The string returned has been alloc'ed and should be freed by the caller.
6125  * NULL is returned if the file name or file is not found.
6126  *
6127  * options:
6128  * FNAME_MESS	    give error messages
6129  * FNAME_EXP	    expand to path
6130  * FNAME_HYP	    check for hypertext link
6131  * FNAME_INCL	    apply "includeexpr"
6132  */
6133     char_u *
6134 file_name_at_cursor(int options, long count, linenr_T *file_lnum)
6135 {
6136     return file_name_in_line(ml_get_curline(),
6137 		      curwin->w_cursor.col, options, count, curbuf->b_ffname,
6138 		      file_lnum);
6139 }
6140 
6141 /*
6142  * Return the name of the file under or after ptr[col].
6143  * Otherwise like file_name_at_cursor().
6144  */
6145     char_u *
6146 file_name_in_line(
6147     char_u	*line,
6148     int		col,
6149     int		options,
6150     long	count,
6151     char_u	*rel_fname,	/* file we are searching relative to */
6152     linenr_T	*file_lnum)	/* line number after the file name */
6153 {
6154     char_u	*ptr;
6155     int		len;
6156     int		in_type = TRUE;
6157     int		is_url = FALSE;
6158 
6159     /*
6160      * search forward for what could be the start of a file name
6161      */
6162     ptr = line + col;
6163     while (*ptr != NUL && !vim_isfilec(*ptr))
6164 	MB_PTR_ADV(ptr);
6165     if (*ptr == NUL)		/* nothing found */
6166     {
6167 	if (options & FNAME_MESS)
6168 	    EMSG(_("E446: No file name under cursor"));
6169 	return NULL;
6170     }
6171 
6172     /*
6173      * Search backward for first char of the file name.
6174      * Go one char back to ":" before "//" even when ':' is not in 'isfname'.
6175      */
6176     while (ptr > line)
6177     {
6178 #ifdef FEAT_MBYTE
6179 	if (has_mbyte && (len = (*mb_head_off)(line, ptr - 1)) > 0)
6180 	    ptr -= len + 1;
6181 	else
6182 #endif
6183 	if (vim_isfilec(ptr[-1])
6184 		|| ((options & FNAME_HYP) && path_is_url(ptr - 1)))
6185 	    --ptr;
6186 	else
6187 	    break;
6188     }
6189 
6190     /*
6191      * Search forward for the last char of the file name.
6192      * Also allow "://" when ':' is not in 'isfname'.
6193      */
6194     len = 0;
6195     while (vim_isfilec(ptr[len]) || (ptr[len] == '\\' && ptr[len + 1] == ' ')
6196 			 || ((options & FNAME_HYP) && path_is_url(ptr + len))
6197 			 || (is_url && vim_strchr((char_u *)"?&=", ptr[len]) != NULL))
6198     {
6199 	/* After type:// we also include ?, & and = as valid characters, so that
6200 	 * http://google.com?q=this&that=ok works. */
6201 	if ((ptr[len] >= 'A' && ptr[len] <= 'Z') || (ptr[len] >= 'a' && ptr[len] <= 'z'))
6202 	{
6203 	    if (in_type && path_is_url(ptr + len + 1))
6204 		is_url = TRUE;
6205 	}
6206 	else
6207 	    in_type = FALSE;
6208 
6209 	if (ptr[len] == '\\')
6210 	    /* Skip over the "\" in "\ ". */
6211 	    ++len;
6212 #ifdef FEAT_MBYTE
6213 	if (has_mbyte)
6214 	    len += (*mb_ptr2len)(ptr + len);
6215 	else
6216 #endif
6217 	    ++len;
6218     }
6219 
6220     /*
6221      * If there is trailing punctuation, remove it.
6222      * But don't remove "..", could be a directory name.
6223      */
6224     if (len > 2 && vim_strchr((char_u *)".,:;!", ptr[len - 1]) != NULL
6225 						       && ptr[len - 2] != '.')
6226 	--len;
6227 
6228     if (file_lnum != NULL)
6229     {
6230 	char_u *p;
6231 
6232 	/* Get the number after the file name and a separator character */
6233 	p = ptr + len;
6234 	p = skipwhite(p);
6235 	if (*p != NUL)
6236 	{
6237 	    if (!isdigit(*p))
6238 		++p;		    /* skip the separator */
6239 	    p = skipwhite(p);
6240 	    if (isdigit(*p))
6241 		*file_lnum = (int)getdigits(&p);
6242 	}
6243     }
6244 
6245     return find_file_name_in_path(ptr, len, options, count, rel_fname);
6246 }
6247 
6248 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6249 static char_u *eval_includeexpr(char_u *ptr, int len);
6250 
6251     static char_u *
6252 eval_includeexpr(char_u *ptr, int len)
6253 {
6254     char_u	*res;
6255 
6256     set_vim_var_string(VV_FNAME, ptr, len);
6257     res = eval_to_string_safe(curbuf->b_p_inex, NULL,
6258 		      was_set_insecurely((char_u *)"includeexpr", OPT_LOCAL));
6259     set_vim_var_string(VV_FNAME, NULL, 0);
6260     return res;
6261 }
6262 #endif
6263 
6264 /*
6265  * Return the name of the file ptr[len] in 'path'.
6266  * Otherwise like file_name_at_cursor().
6267  */
6268     char_u *
6269 find_file_name_in_path(
6270     char_u	*ptr,
6271     int		len,
6272     int		options,
6273     long	count,
6274     char_u	*rel_fname)	/* file we are searching relative to */
6275 {
6276     char_u	*file_name;
6277     int		c;
6278 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6279     char_u	*tofree = NULL;
6280 
6281     if ((options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
6282     {
6283 	tofree = eval_includeexpr(ptr, len);
6284 	if (tofree != NULL)
6285 	{
6286 	    ptr = tofree;
6287 	    len = (int)STRLEN(ptr);
6288 	}
6289     }
6290 # endif
6291 
6292     if (options & FNAME_EXP)
6293     {
6294 	file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
6295 							     TRUE, rel_fname);
6296 
6297 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6298 	/*
6299 	 * If the file could not be found in a normal way, try applying
6300 	 * 'includeexpr' (unless done already).
6301 	 */
6302 	if (file_name == NULL
6303 		&& !(options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
6304 	{
6305 	    tofree = eval_includeexpr(ptr, len);
6306 	    if (tofree != NULL)
6307 	    {
6308 		ptr = tofree;
6309 		len = (int)STRLEN(ptr);
6310 		file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
6311 							     TRUE, rel_fname);
6312 	    }
6313 	}
6314 # endif
6315 	if (file_name == NULL && (options & FNAME_MESS))
6316 	{
6317 	    c = ptr[len];
6318 	    ptr[len] = NUL;
6319 	    EMSG2(_("E447: Can't find file \"%s\" in path"), ptr);
6320 	    ptr[len] = c;
6321 	}
6322 
6323 	/* Repeat finding the file "count" times.  This matters when it
6324 	 * appears several times in the path. */
6325 	while (file_name != NULL && --count > 0)
6326 	{
6327 	    vim_free(file_name);
6328 	    file_name = find_file_in_path(ptr, len, options, FALSE, rel_fname);
6329 	}
6330     }
6331     else
6332 	file_name = vim_strnsave(ptr, len);
6333 
6334 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6335     vim_free(tofree);
6336 # endif
6337 
6338     return file_name;
6339 }
6340 #endif /* FEAT_SEARCHPATH */
6341 
6342 /*
6343  * Check if the "://" of a URL is at the pointer, return URL_SLASH.
6344  * Also check for ":\\", which MS Internet Explorer accepts, return
6345  * URL_BACKSLASH.
6346  */
6347     static int
6348 path_is_url(char_u *p)
6349 {
6350     if (STRNCMP(p, "://", (size_t)3) == 0)
6351 	return URL_SLASH;
6352     else if (STRNCMP(p, ":\\\\", (size_t)3) == 0)
6353 	return URL_BACKSLASH;
6354     return 0;
6355 }
6356 
6357 /*
6358  * Check if "fname" starts with "name://".  Return URL_SLASH if it does.
6359  * Return URL_BACKSLASH for "name:\\".
6360  * Return zero otherwise.
6361  */
6362     int
6363 path_with_url(char_u *fname)
6364 {
6365     char_u *p;
6366 
6367     for (p = fname; isalpha(*p); ++p)
6368 	;
6369     return path_is_url(p);
6370 }
6371 
6372 /*
6373  * Return TRUE if "name" is a full (absolute) path name or URL.
6374  */
6375     int
6376 vim_isAbsName(char_u *name)
6377 {
6378     return (path_with_url(name) != 0 || mch_isFullName(name));
6379 }
6380 
6381 /*
6382  * Get absolute file name into buffer "buf[len]".
6383  *
6384  * return FAIL for failure, OK otherwise
6385  */
6386     int
6387 vim_FullName(
6388     char_u	*fname,
6389     char_u	*buf,
6390     int		len,
6391     int		force)	    /* force expansion even when already absolute */
6392 {
6393     int		retval = OK;
6394     int		url;
6395 
6396     *buf = NUL;
6397     if (fname == NULL)
6398 	return FAIL;
6399 
6400     url = path_with_url(fname);
6401     if (!url)
6402 	retval = mch_FullName(fname, buf, len, force);
6403     if (url || retval == FAIL)
6404     {
6405 	/* something failed; use the file name (truncate when too long) */
6406 	vim_strncpy(buf, fname, len - 1);
6407     }
6408 #if defined(MSWIN)
6409     slash_adjust(buf);
6410 #endif
6411     return retval;
6412 }
6413 
6414 /*
6415  * Return the minimal number of rows that is needed on the screen to display
6416  * the current number of windows.
6417  */
6418     int
6419 min_rows(void)
6420 {
6421     int		total;
6422     tabpage_T	*tp;
6423     int		n;
6424 
6425     if (firstwin == NULL)	/* not initialized yet */
6426 	return MIN_LINES;
6427 
6428     total = 0;
6429     FOR_ALL_TABPAGES(tp)
6430     {
6431 	n = frame_minheight(tp->tp_topframe, NULL);
6432 	if (total < n)
6433 	    total = n;
6434     }
6435     total += tabline_height();
6436     total += 1;		/* count the room for the command line */
6437     return total;
6438 }
6439 
6440 /*
6441  * Return TRUE if there is only one window (in the current tab page), not
6442  * counting a help or preview window, unless it is the current window.
6443  * Does not count "aucmd_win".
6444  */
6445     int
6446 only_one_window(void)
6447 {
6448     int		count = 0;
6449     win_T	*wp;
6450 
6451     /* If there is another tab page there always is another window. */
6452     if (first_tabpage->tp_next != NULL)
6453 	return FALSE;
6454 
6455     FOR_ALL_WINDOWS(wp)
6456 	if (wp->w_buffer != NULL
6457 		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
6458 # ifdef FEAT_QUICKFIX
6459 		    || wp->w_p_pvw
6460 # endif
6461 	     ) || wp == curwin) && wp != aucmd_win)
6462 	    ++count;
6463     return (count <= 1);
6464 }
6465 
6466 /*
6467  * Correct the cursor line number in other windows.  Used after changing the
6468  * current buffer, and before applying autocommands.
6469  * When "do_curwin" is TRUE, also check current window.
6470  */
6471     void
6472 check_lnums(int do_curwin)
6473 {
6474     win_T	*wp;
6475     tabpage_T	*tp;
6476 
6477     FOR_ALL_TAB_WINDOWS(tp, wp)
6478 	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
6479 	{
6480 	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
6481 		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
6482 	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
6483 		wp->w_topline = curbuf->b_ml.ml_line_count;
6484 	}
6485 }
6486 
6487 /*
6488  * A snapshot of the window sizes, to restore them after closing the help
6489  * window.
6490  * Only these fields are used:
6491  * fr_layout
6492  * fr_width
6493  * fr_height
6494  * fr_next
6495  * fr_child
6496  * fr_win (only valid for the old curwin, NULL otherwise)
6497  */
6498 
6499 /*
6500  * Create a snapshot of the current frame sizes.
6501  */
6502     void
6503 make_snapshot(int idx)
6504 {
6505     clear_snapshot(curtab, idx);
6506     make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
6507 }
6508 
6509     static void
6510 make_snapshot_rec(frame_T *fr, frame_T **frp)
6511 {
6512     *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
6513     if (*frp == NULL)
6514 	return;
6515     (*frp)->fr_layout = fr->fr_layout;
6516     (*frp)->fr_width = fr->fr_width;
6517     (*frp)->fr_height = fr->fr_height;
6518     if (fr->fr_next != NULL)
6519 	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
6520     if (fr->fr_child != NULL)
6521 	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
6522     if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
6523 	(*frp)->fr_win = curwin;
6524 }
6525 
6526 /*
6527  * Remove any existing snapshot.
6528  */
6529     static void
6530 clear_snapshot(tabpage_T *tp, int idx)
6531 {
6532     clear_snapshot_rec(tp->tp_snapshot[idx]);
6533     tp->tp_snapshot[idx] = NULL;
6534 }
6535 
6536     static void
6537 clear_snapshot_rec(frame_T *fr)
6538 {
6539     if (fr != NULL)
6540     {
6541 	clear_snapshot_rec(fr->fr_next);
6542 	clear_snapshot_rec(fr->fr_child);
6543 	vim_free(fr);
6544     }
6545 }
6546 
6547 /*
6548  * Restore a previously created snapshot, if there is any.
6549  * This is only done if the screen size didn't change and the window layout is
6550  * still the same.
6551  */
6552     void
6553 restore_snapshot(
6554     int		idx,
6555     int		close_curwin)	    /* closing current window */
6556 {
6557     win_T	*wp;
6558 
6559     if (curtab->tp_snapshot[idx] != NULL
6560 	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
6561 	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
6562 	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
6563     {
6564 	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
6565 	win_comp_pos();
6566 	if (wp != NULL && close_curwin)
6567 	    win_goto(wp);
6568 	redraw_all_later(CLEAR);
6569     }
6570     clear_snapshot(curtab, idx);
6571 }
6572 
6573 /*
6574  * Check if frames "sn" and "fr" have the same layout, same following frames
6575  * and same children.  And the window pointer is valid.
6576  */
6577     static int
6578 check_snapshot_rec(frame_T *sn, frame_T *fr)
6579 {
6580     if (sn->fr_layout != fr->fr_layout
6581 	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
6582 	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
6583 	    || (sn->fr_next != NULL
6584 		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
6585 	    || (sn->fr_child != NULL
6586 		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
6587 	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
6588 	return FAIL;
6589     return OK;
6590 }
6591 
6592 /*
6593  * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
6594  * following frames and children.
6595  * Returns a pointer to the old current window, or NULL.
6596  */
6597     static win_T *
6598 restore_snapshot_rec(frame_T *sn, frame_T *fr)
6599 {
6600     win_T	*wp = NULL;
6601     win_T	*wp2;
6602 
6603     fr->fr_height = sn->fr_height;
6604     fr->fr_width = sn->fr_width;
6605     if (fr->fr_layout == FR_LEAF)
6606     {
6607 	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
6608 	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
6609 	wp = sn->fr_win;
6610     }
6611     if (sn->fr_next != NULL)
6612     {
6613 	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
6614 	if (wp2 != NULL)
6615 	    wp = wp2;
6616     }
6617     if (sn->fr_child != NULL)
6618     {
6619 	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
6620 	if (wp2 != NULL)
6621 	    wp = wp2;
6622     }
6623     return wp;
6624 }
6625 
6626 #if defined(FEAT_EVAL) || defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \
6627 	|| defined(PROTO)
6628 /*
6629  * Set "win" to be the curwin and "tp" to be the current tab page.
6630  * restore_win() MUST be called to undo, also when FAIL is returned.
6631  * No autocommands will be executed until restore_win() is called.
6632  * When "no_display" is TRUE the display won't be affected, no redraw is
6633  * triggered, another tabpage access is limited.
6634  * Returns FAIL if switching to "win" failed.
6635  */
6636     int
6637 switch_win(
6638     win_T	**save_curwin,
6639     tabpage_T	**save_curtab,
6640     win_T	*win,
6641     tabpage_T	*tp,
6642     int		no_display)
6643 {
6644     block_autocmds();
6645     *save_curwin = curwin;
6646     if (tp != NULL)
6647     {
6648 	*save_curtab = curtab;
6649 	if (no_display)
6650 	{
6651 	    curtab->tp_firstwin = firstwin;
6652 	    curtab->tp_lastwin = lastwin;
6653 	    curtab = tp;
6654 	    firstwin = curtab->tp_firstwin;
6655 	    lastwin = curtab->tp_lastwin;
6656 	}
6657 	else
6658 	    goto_tabpage_tp(tp, FALSE, FALSE);
6659     }
6660     if (!win_valid(win))
6661 	return FAIL;
6662     curwin = win;
6663     curbuf = curwin->w_buffer;
6664     return OK;
6665 }
6666 
6667 /*
6668  * Restore current tabpage and window saved by switch_win(), if still valid.
6669  * When "no_display" is TRUE the display won't be affected, no redraw is
6670  * triggered.
6671  */
6672     void
6673 restore_win(
6674     win_T	*save_curwin UNUSED,
6675     tabpage_T	*save_curtab UNUSED,
6676     int		no_display UNUSED)
6677 {
6678     if (save_curtab != NULL && valid_tabpage(save_curtab))
6679     {
6680 	if (no_display)
6681 	{
6682 	    curtab->tp_firstwin = firstwin;
6683 	    curtab->tp_lastwin = lastwin;
6684 	    curtab = save_curtab;
6685 	    firstwin = curtab->tp_firstwin;
6686 	    lastwin = curtab->tp_lastwin;
6687 	}
6688 	else
6689 	    goto_tabpage_tp(save_curtab, FALSE, FALSE);
6690     }
6691     if (win_valid(save_curwin))
6692     {
6693 	curwin = save_curwin;
6694 	curbuf = curwin->w_buffer;
6695     }
6696     unblock_autocmds();
6697 }
6698 
6699 /*
6700  * Make "buf" the current buffer.  restore_buffer() MUST be called to undo.
6701  * No autocommands will be executed.  Use aucmd_prepbuf() if there are any.
6702  */
6703     void
6704 switch_buffer(bufref_T *save_curbuf, buf_T *buf)
6705 {
6706     block_autocmds();
6707     set_bufref(save_curbuf, curbuf);
6708     --curbuf->b_nwindows;
6709     curbuf = buf;
6710     curwin->w_buffer = buf;
6711     ++curbuf->b_nwindows;
6712 }
6713 
6714 /*
6715  * Restore the current buffer after using switch_buffer().
6716  */
6717     void
6718 restore_buffer(bufref_T *save_curbuf)
6719 {
6720     unblock_autocmds();
6721     /* Check for valid buffer, just in case. */
6722     if (bufref_valid(save_curbuf))
6723     {
6724 	--curbuf->b_nwindows;
6725 	curwin->w_buffer = save_curbuf->br_buf;
6726 	curbuf = save_curbuf->br_buf;
6727 	++curbuf->b_nwindows;
6728     }
6729 }
6730 #endif
6731 
6732 #if defined(FEAT_GUI) || defined(PROTO)
6733 /*
6734  * Return TRUE if there is any vertically split window.
6735  */
6736     int
6737 win_hasvertsplit(void)
6738 {
6739     frame_T	*fr;
6740 
6741     if (topframe->fr_layout == FR_ROW)
6742 	return TRUE;
6743 
6744     if (topframe->fr_layout == FR_COL)
6745 	for (fr = topframe->fr_child; fr != NULL; fr = fr->fr_next)
6746 	    if (fr->fr_layout == FR_ROW)
6747 		return TRUE;
6748 
6749     return FALSE;
6750 }
6751 #endif
6752 
6753 #if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
6754 /*
6755  * Add match to the match list of window 'wp'.  The pattern 'pat' will be
6756  * highlighted with the group 'grp' with priority 'prio'.
6757  * Optionally, a desired ID 'id' can be specified (greater than or equal to 1).
6758  * If no particular ID is desired, -1 must be specified for 'id'.
6759  * Return ID of added match, -1 on failure.
6760  */
6761     int
6762 match_add(
6763     win_T	*wp,
6764     char_u	*grp,
6765     char_u	*pat,
6766     int		prio,
6767     int		id,
6768     list_T	*pos_list,
6769     char_u      *conceal_char UNUSED) /* pointer to conceal replacement char */
6770 {
6771     matchitem_T	*cur;
6772     matchitem_T	*prev;
6773     matchitem_T	*m;
6774     int		hlg_id;
6775     regprog_T	*regprog = NULL;
6776     int		rtype = SOME_VALID;
6777 
6778     if (*grp == NUL || (pat != NULL && *pat == NUL))
6779 	return -1;
6780     if (id < -1 || id == 0)
6781     {
6782 	EMSGN(_("E799: Invalid ID: %ld (must be greater than or equal to 1)"), id);
6783 	return -1;
6784     }
6785     if (id != -1)
6786     {
6787 	cur = wp->w_match_head;
6788 	while (cur != NULL)
6789 	{
6790 	    if (cur->id == id)
6791 	    {
6792 		EMSGN(_("E801: ID already taken: %ld"), id);
6793 		return -1;
6794 	    }
6795 	    cur = cur->next;
6796 	}
6797     }
6798     if ((hlg_id = syn_namen2id(grp, (int)STRLEN(grp))) == 0)
6799     {
6800 	EMSG2(_(e_nogroup), grp);
6801 	return -1;
6802     }
6803     if (pat != NULL && (regprog = vim_regcomp(pat, RE_MAGIC)) == NULL)
6804     {
6805 	EMSG2(_(e_invarg2), pat);
6806 	return -1;
6807     }
6808 
6809     /* Find available match ID. */
6810     while (id == -1)
6811     {
6812 	cur = wp->w_match_head;
6813 	while (cur != NULL && cur->id != wp->w_next_match_id)
6814 	    cur = cur->next;
6815 	if (cur == NULL)
6816 	    id = wp->w_next_match_id;
6817 	wp->w_next_match_id++;
6818     }
6819 
6820     /* Build new match. */
6821     m = (matchitem_T *)alloc_clear(sizeof(matchitem_T));
6822     m->id = id;
6823     m->priority = prio;
6824     m->pattern = pat == NULL ? NULL : vim_strsave(pat);
6825     m->hlg_id = hlg_id;
6826     m->match.regprog = regprog;
6827     m->match.rmm_ic = FALSE;
6828     m->match.rmm_maxcol = 0;
6829 # if defined(FEAT_CONCEAL) && defined(FEAT_MBYTE)
6830     m->conceal_char = 0;
6831     if (conceal_char != NULL)
6832 	m->conceal_char = (*mb_ptr2char)(conceal_char);
6833 # endif
6834 
6835     /* Set up position matches */
6836     if (pos_list != NULL)
6837     {
6838 	linenr_T	toplnum = 0;
6839 	linenr_T	botlnum = 0;
6840 	listitem_T	*li;
6841 	int		i;
6842 
6843 	for (i = 0, li = pos_list->lv_first; li != NULL && i < MAXPOSMATCH;
6844 							i++, li = li->li_next)
6845 	{
6846 	    linenr_T	lnum = 0;
6847 	    colnr_T	col = 0;
6848 	    int		len = 1;
6849 	    list_T	*subl;
6850 	    listitem_T	*subli;
6851 	    int		error = FALSE;
6852 
6853 	    if (li->li_tv.v_type == VAR_LIST)
6854 	    {
6855 		subl = li->li_tv.vval.v_list;
6856 		if (subl == NULL)
6857 		    goto fail;
6858 		subli = subl->lv_first;
6859 		if (subli == NULL)
6860 		    goto fail;
6861 		lnum = get_tv_number_chk(&subli->li_tv, &error);
6862 		if (error == TRUE)
6863 		    goto fail;
6864 		if (lnum == 0)
6865 		{
6866 		    --i;
6867 		    continue;
6868 		}
6869 		m->pos.pos[i].lnum = lnum;
6870 		subli = subli->li_next;
6871 		if (subli != NULL)
6872 		{
6873 		    col = get_tv_number_chk(&subli->li_tv, &error);
6874 		    if (error == TRUE)
6875 			goto fail;
6876 		    subli = subli->li_next;
6877 		    if (subli != NULL)
6878 		    {
6879 			len = get_tv_number_chk(&subli->li_tv, &error);
6880 			if (error == TRUE)
6881 			    goto fail;
6882 		    }
6883 		}
6884 		m->pos.pos[i].col = col;
6885 		m->pos.pos[i].len = len;
6886 	    }
6887 	    else if (li->li_tv.v_type == VAR_NUMBER)
6888 	    {
6889 		if (li->li_tv.vval.v_number == 0)
6890 		{
6891 		    --i;
6892 		    continue;
6893 		}
6894 		m->pos.pos[i].lnum = li->li_tv.vval.v_number;
6895 		m->pos.pos[i].col = 0;
6896 		m->pos.pos[i].len = 0;
6897 	    }
6898 	    else
6899 	    {
6900 		EMSG(_("List or number required"));
6901 		goto fail;
6902 	    }
6903 	    if (toplnum == 0 || lnum < toplnum)
6904 		toplnum = lnum;
6905 	    if (botlnum == 0 || lnum >= botlnum)
6906 		botlnum = lnum + 1;
6907 	}
6908 
6909 	/* Calculate top and bottom lines for redrawing area */
6910 	if (toplnum != 0)
6911 	{
6912 	    if (wp->w_buffer->b_mod_set)
6913 	    {
6914 		if (wp->w_buffer->b_mod_top > toplnum)
6915 		    wp->w_buffer->b_mod_top = toplnum;
6916 		if (wp->w_buffer->b_mod_bot < botlnum)
6917 		    wp->w_buffer->b_mod_bot = botlnum;
6918 	    }
6919 	    else
6920 	    {
6921 		wp->w_buffer->b_mod_set = TRUE;
6922 		wp->w_buffer->b_mod_top = toplnum;
6923 		wp->w_buffer->b_mod_bot = botlnum;
6924 		wp->w_buffer->b_mod_xlines = 0;
6925 	    }
6926 	    m->pos.toplnum = toplnum;
6927 	    m->pos.botlnum = botlnum;
6928 	    rtype = VALID;
6929 	}
6930     }
6931 
6932     /* Insert new match.  The match list is in ascending order with regard to
6933      * the match priorities. */
6934     cur = wp->w_match_head;
6935     prev = cur;
6936     while (cur != NULL && prio >= cur->priority)
6937     {
6938 	prev = cur;
6939 	cur = cur->next;
6940     }
6941     if (cur == prev)
6942 	wp->w_match_head = m;
6943     else
6944 	prev->next = m;
6945     m->next = cur;
6946 
6947     redraw_later(rtype);
6948     return id;
6949 
6950 fail:
6951     vim_free(m);
6952     return -1;
6953 }
6954 
6955 /*
6956  * Delete match with ID 'id' in the match list of window 'wp'.
6957  * Print error messages if 'perr' is TRUE.
6958  */
6959     int
6960 match_delete(win_T *wp, int id, int perr)
6961 {
6962     matchitem_T	*cur = wp->w_match_head;
6963     matchitem_T	*prev = cur;
6964     int		rtype = SOME_VALID;
6965 
6966     if (id < 1)
6967     {
6968 	if (perr == TRUE)
6969 	    EMSGN(_("E802: Invalid ID: %ld (must be greater than or equal to 1)"),
6970 									  id);
6971 	return -1;
6972     }
6973     while (cur != NULL && cur->id != id)
6974     {
6975 	prev = cur;
6976 	cur = cur->next;
6977     }
6978     if (cur == NULL)
6979     {
6980 	if (perr == TRUE)
6981 	    EMSGN(_("E803: ID not found: %ld"), id);
6982 	return -1;
6983     }
6984     if (cur == prev)
6985 	wp->w_match_head = cur->next;
6986     else
6987 	prev->next = cur->next;
6988     vim_regfree(cur->match.regprog);
6989     vim_free(cur->pattern);
6990     if (cur->pos.toplnum != 0)
6991     {
6992 	if (wp->w_buffer->b_mod_set)
6993 	{
6994 	    if (wp->w_buffer->b_mod_top > cur->pos.toplnum)
6995 		wp->w_buffer->b_mod_top = cur->pos.toplnum;
6996 	    if (wp->w_buffer->b_mod_bot < cur->pos.botlnum)
6997 		wp->w_buffer->b_mod_bot = cur->pos.botlnum;
6998 	}
6999 	else
7000 	{
7001 	    wp->w_buffer->b_mod_set = TRUE;
7002 	    wp->w_buffer->b_mod_top = cur->pos.toplnum;
7003 	    wp->w_buffer->b_mod_bot = cur->pos.botlnum;
7004 	    wp->w_buffer->b_mod_xlines = 0;
7005 	}
7006 	rtype = VALID;
7007     }
7008     vim_free(cur);
7009     redraw_later(rtype);
7010     return 0;
7011 }
7012 
7013 /*
7014  * Delete all matches in the match list of window 'wp'.
7015  */
7016     void
7017 clear_matches(win_T *wp)
7018 {
7019     matchitem_T *m;
7020 
7021     while (wp->w_match_head != NULL)
7022     {
7023 	m = wp->w_match_head->next;
7024 	vim_regfree(wp->w_match_head->match.regprog);
7025 	vim_free(wp->w_match_head->pattern);
7026 	vim_free(wp->w_match_head);
7027 	wp->w_match_head = m;
7028     }
7029     redraw_later(SOME_VALID);
7030 }
7031 
7032 /*
7033  * Get match from ID 'id' in window 'wp'.
7034  * Return NULL if match not found.
7035  */
7036     matchitem_T *
7037 get_match(win_T *wp, int id)
7038 {
7039     matchitem_T *cur = wp->w_match_head;
7040 
7041     while (cur != NULL && cur->id != id)
7042 	cur = cur->next;
7043     return cur;
7044 }
7045 #endif
7046 
7047 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
7048     int
7049 get_win_number(win_T *wp, win_T *first_win)
7050 {
7051     int		i = 1;
7052     win_T	*w;
7053 
7054     for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
7055 	++i;
7056 
7057     if (w == NULL)
7058 	return 0;
7059     else
7060 	return i;
7061 }
7062 
7063     int
7064 get_tab_number(tabpage_T *tp UNUSED)
7065 {
7066     int		i = 1;
7067     tabpage_T	*t;
7068 
7069     for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
7070 	++i;
7071 
7072     if (t == NULL)
7073 	return 0;
7074     else
7075 	return i;
7076 }
7077 #endif
7078 
7079 /*
7080  * Return TRUE if "topfrp" and its children are at the right height.
7081  */
7082     static int
7083 frame_check_height(frame_T *topfrp, int height)
7084 {
7085     frame_T *frp;
7086 
7087     if (topfrp->fr_height != height)
7088 	return FALSE;
7089 
7090     if (topfrp->fr_layout == FR_ROW)
7091 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
7092 	    if (frp->fr_height != height)
7093 		return FALSE;
7094 
7095     return TRUE;
7096 }
7097 
7098 /*
7099  * Return TRUE if "topfrp" and its children are at the right width.
7100  */
7101     static int
7102 frame_check_width(frame_T *topfrp, int width)
7103 {
7104     frame_T *frp;
7105 
7106     if (topfrp->fr_width != width)
7107 	return FALSE;
7108 
7109     if (topfrp->fr_layout == FR_COL)
7110 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
7111 	    if (frp->fr_width != width)
7112 		return FALSE;
7113 
7114     return TRUE;
7115 }
7116 
7117 #if defined(FEAT_EVAL) || defined(PROTO)
7118     int
7119 win_getid(typval_T *argvars)
7120 {
7121     int	    winnr;
7122     win_T   *wp;
7123 
7124     if (argvars[0].v_type == VAR_UNKNOWN)
7125 	return curwin->w_id;
7126     winnr = get_tv_number(&argvars[0]);
7127     if (winnr > 0)
7128     {
7129 	if (argvars[1].v_type == VAR_UNKNOWN)
7130 	    wp = firstwin;
7131 	else
7132 	{
7133 	    tabpage_T	*tp;
7134 	    int		tabnr = get_tv_number(&argvars[1]);
7135 
7136 	    FOR_ALL_TABPAGES(tp)
7137 		if (--tabnr == 0)
7138 		    break;
7139 	    if (tp == NULL)
7140 		return -1;
7141 	    if (tp == curtab)
7142 		wp = firstwin;
7143 	    else
7144 		wp = tp->tp_firstwin;
7145 	}
7146 	for ( ; wp != NULL; wp = wp->w_next)
7147 	    if (--winnr == 0)
7148 		return wp->w_id;
7149     }
7150     return 0;
7151 }
7152 
7153     int
7154 win_gotoid(typval_T *argvars)
7155 {
7156     win_T	*wp;
7157     tabpage_T   *tp;
7158     int		id = get_tv_number(&argvars[0]);
7159 
7160     FOR_ALL_TAB_WINDOWS(tp, wp)
7161 	    if (wp->w_id == id)
7162 	    {
7163 		goto_tabpage_win(tp, wp);
7164 		return 1;
7165 	    }
7166     return 0;
7167 }
7168 
7169     void
7170 win_id2tabwin(typval_T *argvars, list_T *list)
7171 {
7172     win_T	*wp;
7173     tabpage_T   *tp;
7174     int		winnr = 1;
7175     int		tabnr = 1;
7176     int		id = get_tv_number(&argvars[0]);
7177 
7178     FOR_ALL_TABPAGES(tp)
7179     {
7180 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
7181 	{
7182 	    if (wp->w_id == id)
7183 	    {
7184 		list_append_number(list, tabnr);
7185 		list_append_number(list, winnr);
7186 		return;
7187 	    }
7188 	    ++winnr;
7189 	}
7190 	++tabnr;
7191 	winnr = 1;
7192     }
7193     list_append_number(list, 0);
7194     list_append_number(list, 0);
7195 }
7196 
7197     win_T *
7198 win_id2wp(typval_T *argvars)
7199 {
7200     win_T	*wp;
7201     tabpage_T   *tp;
7202     int		id = get_tv_number(&argvars[0]);
7203 
7204     FOR_ALL_TAB_WINDOWS(tp, wp)
7205 	if (wp->w_id == id)
7206 	    return wp;
7207 
7208     return NULL;
7209 }
7210 
7211     int
7212 win_id2win(typval_T *argvars)
7213 {
7214     win_T   *wp;
7215     int	    nr = 1;
7216     int	    id = get_tv_number(&argvars[0]);
7217 
7218     FOR_ALL_WINDOWS(wp)
7219     {
7220 	if (wp->w_id == id)
7221 	    return nr;
7222 	++nr;
7223     }
7224     return 0;
7225 }
7226 
7227     void
7228 win_findbuf(typval_T *argvars, list_T *list)
7229 {
7230     win_T	*wp;
7231     tabpage_T   *tp;
7232     int		bufnr = get_tv_number(&argvars[0]);
7233 
7234     FOR_ALL_TAB_WINDOWS(tp, wp)
7235 	    if (wp->w_buffer->b_fnum == bufnr)
7236 		list_append_number(list, wp->w_id);
7237 }
7238 
7239 /*
7240  * Get the layout of the given tab page for winlayout().
7241  */
7242     void
7243 get_framelayout(frame_T *fr, list_T *l, int outer)
7244 {
7245     frame_T	*child;
7246     list_T	*fr_list;
7247     list_T	*win_list;
7248 
7249     if (fr == NULL)
7250 	return;
7251 
7252     if (outer)
7253 	// outermost call from f_winlayout()
7254 	fr_list = l;
7255     else
7256     {
7257 	fr_list = list_alloc();
7258 	if (fr_list == NULL)
7259 	    return;
7260 	list_append_list(l, fr_list);
7261     }
7262 
7263     if (fr->fr_layout == FR_LEAF)
7264     {
7265 	if (fr->fr_win != NULL)
7266 	{
7267 	    list_append_string(fr_list, (char_u *)"leaf", -1);
7268 	    list_append_number(fr_list, fr->fr_win->w_id);
7269 	}
7270     }
7271     else
7272     {
7273 	list_append_string(fr_list,
7274 	     fr->fr_layout == FR_ROW ?  (char_u *)"row" : (char_u *)"col", -1);
7275 
7276 	win_list = list_alloc();
7277 	if (win_list == NULL)
7278 	    return;
7279 	list_append_list(fr_list, win_list);
7280 	child = fr->fr_child;
7281 	while (child != NULL)
7282 	{
7283 	    get_framelayout(child, win_list, FALSE);
7284 	    child = child->fr_next;
7285 	}
7286     }
7287 }
7288 #endif
7289