xref: /vim-8.2.3635/src/window.c (revision 2a953fcf)
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 win_T *win_free_mem(win_T *win, int *dirp, tabpage_T *tp);
24 static frame_T *win_altframe(win_T *win, tabpage_T *tp);
25 static tabpage_T *alt_tabpage(void);
26 static win_T *frame2win(frame_T *frp);
27 static int frame_has_win(frame_T *frp, win_T *wp);
28 static void frame_new_height(frame_T *topfrp, int height, int topfirst, int wfh);
29 static int frame_fixed_height(frame_T *frp);
30 static int frame_fixed_width(frame_T *frp);
31 static void frame_add_statusline(frame_T *frp);
32 static void frame_new_width(frame_T *topfrp, int width, int leftfirst, int wfw);
33 static void frame_add_vsep(frame_T *frp);
34 static int frame_minwidth(frame_T *topfrp, win_T *next_curwin);
35 static void frame_fix_width(win_T *wp);
36 static int win_alloc_firstwin(win_T *oldwin);
37 static void new_frame(win_T *wp);
38 static tabpage_T *alloc_tabpage(void);
39 static int leave_tabpage(buf_T *new_curbuf, int trigger_leave_autocmds);
40 static void enter_tabpage(tabpage_T *tp, buf_T *old_curbuf, int trigger_enter_autocmds, int trigger_leave_autocmds);
41 static void frame_fix_height(win_T *wp);
42 static int frame_minheight(frame_T *topfrp, win_T *next_curwin);
43 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);
44 static void win_free(win_T *wp, tabpage_T *tp);
45 static void frame_append(frame_T *after, frame_T *frp);
46 static void frame_insert(frame_T *before, frame_T *frp);
47 static void frame_remove(frame_T *frp);
48 static void win_goto_ver(int up, long count);
49 static void win_goto_hor(int left, long count);
50 static void frame_add_height(frame_T *frp, int n);
51 static void last_status_rec(frame_T *fr, int statusline);
52 
53 static void make_snapshot_rec(frame_T *fr, frame_T **frp);
54 static void clear_snapshot(tabpage_T *tp, int idx);
55 static void clear_snapshot_rec(frame_T *fr);
56 static int check_snapshot_rec(frame_T *sn, frame_T *fr);
57 static win_T *restore_snapshot_rec(frame_T *sn, frame_T *fr);
58 
59 static int frame_check_height(frame_T *topfrp, int height);
60 static int frame_check_width(frame_T *topfrp, int width);
61 
62 static win_T *win_alloc(win_T *after, int hidden);
63 
64 #define URL_SLASH	1		/* path_is_url() has found "://" */
65 #define URL_BACKSLASH	2		/* path_is_url() has found ":\\" */
66 
67 #define NOWIN		(win_T *)-1	/* non-existing window */
68 
69 #define ROWS_AVAIL (Rows - p_ch - tabline_height())
70 
71 static char *m_onlyone = N_("Already only one window");
72 
73 /*
74  * all CTRL-W window commands are handled here, called from normal_cmd().
75  */
76     void
77 do_window(
78     int		nchar,
79     long	Prenum,
80     int		xchar)	    /* extra char from ":wincmd gx" or NUL */
81 {
82     long	Prenum1;
83     win_T	*wp;
84 #if defined(FEAT_SEARCHPATH) || defined(FEAT_FIND_ID)
85     char_u	*ptr;
86     linenr_T    lnum = -1;
87 #endif
88 #ifdef FEAT_FIND_ID
89     int		type = FIND_DEFINE;
90     int		len;
91 #endif
92     char_u	cbuf[40];
93 
94     if (Prenum == 0)
95 	Prenum1 = 1;
96     else
97 	Prenum1 = Prenum;
98 
99 #ifdef FEAT_CMDWIN
100 # define CHECK_CMDWIN \
101     do { \
102 	if (cmdwin_type != 0) \
103 	{ \
104 	    emsg(_(e_cmdwin)); \
105 	    return; \
106 	} \
107     } while (0)
108 #else
109 # define CHECK_CMDWIN do { /**/ } while (0)
110 #endif
111 
112     switch (nchar)
113     {
114 /* split current window in two parts, horizontally */
115     case 'S':
116     case Ctrl_S:
117     case 's':
118 		CHECK_CMDWIN;
119 		reset_VIsual_and_resel();	/* stop Visual mode */
120 #ifdef FEAT_QUICKFIX
121 		/* When splitting the quickfix window open a new buffer in it,
122 		 * don't replicate the quickfix buffer. */
123 		if (bt_quickfix(curbuf))
124 		    goto newwindow;
125 #endif
126 #ifdef FEAT_GUI
127 		need_mouse_correct = TRUE;
128 #endif
129 		(void)win_split((int)Prenum, 0);
130 		break;
131 
132 /* split current window in two parts, vertically */
133     case Ctrl_V:
134     case 'v':
135 		CHECK_CMDWIN;
136 		reset_VIsual_and_resel();	/* stop Visual mode */
137 #ifdef FEAT_QUICKFIX
138 		/* When splitting the quickfix window open a new buffer in it,
139 		 * don't replicate the quickfix buffer. */
140 		if (bt_quickfix(curbuf))
141 		    goto newwindow;
142 #endif
143 #ifdef FEAT_GUI
144 		need_mouse_correct = TRUE;
145 #endif
146 		(void)win_split((int)Prenum, WSP_VERT);
147 		break;
148 
149 /* split current window and edit alternate file */
150     case Ctrl_HAT:
151     case '^':
152 		CHECK_CMDWIN;
153 		reset_VIsual_and_resel();	/* stop Visual mode */
154 
155 		if (buflist_findnr(Prenum == 0
156 					? curwin->w_alt_fnum : Prenum) == NULL)
157 		{
158 		    if (Prenum == 0)
159 			emsg(_(e_noalt));
160 		    else
161 			semsg(_("E92: Buffer %ld not found"), Prenum);
162 		    break;
163 		}
164 
165 		if (!curbuf_locked() && win_split(0, 0) == OK)
166 		    (void)buflist_getfile(
167 			    Prenum == 0 ? curwin->w_alt_fnum : Prenum,
168 			    (linenr_T)0, GETF_ALT, FALSE);
169 		break;
170 
171 /* open new window */
172     case Ctrl_N:
173     case 'n':
174 		CHECK_CMDWIN;
175 		reset_VIsual_and_resel();	/* stop Visual mode */
176 #ifdef FEAT_QUICKFIX
177 newwindow:
178 #endif
179 		if (Prenum)
180 		    /* window height */
181 		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
182 		else
183 		    cbuf[0] = NUL;
184 #if defined(FEAT_QUICKFIX)
185 		if (nchar == 'v' || nchar == Ctrl_V)
186 		    STRCAT(cbuf, "v");
187 #endif
188 		STRCAT(cbuf, "new");
189 		do_cmdline_cmd(cbuf);
190 		break;
191 
192 /* quit current window */
193     case Ctrl_Q:
194     case 'q':
195 		reset_VIsual_and_resel();	/* stop Visual mode */
196 		cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
197 		do_cmdline_cmd(cbuf);
198 		break;
199 
200 /* close current window */
201     case Ctrl_C:
202     case 'c':
203 		reset_VIsual_and_resel();	/* stop Visual mode */
204 		cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
205 		do_cmdline_cmd(cbuf);
206 		break;
207 
208 #if defined(FEAT_QUICKFIX)
209 /* close preview window */
210     case Ctrl_Z:
211     case 'z':
212 		CHECK_CMDWIN;
213 		reset_VIsual_and_resel();	/* stop Visual mode */
214 		do_cmdline_cmd((char_u *)"pclose");
215 		break;
216 
217 /* cursor to preview window */
218     case 'P':
219 		FOR_ALL_WINDOWS(wp)
220 		    if (wp->w_p_pvw)
221 			break;
222 		if (wp == NULL)
223 		    emsg(_("E441: There is no preview window"));
224 		else
225 		    win_goto(wp);
226 		break;
227 #endif
228 
229 /* close all but current window */
230     case Ctrl_O:
231     case 'o':
232 		CHECK_CMDWIN;
233 		reset_VIsual_and_resel();	/* stop Visual mode */
234 		cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
235 		do_cmdline_cmd(cbuf);
236 		break;
237 
238 /* cursor to next window with wrap around */
239     case Ctrl_W:
240     case 'w':
241 /* cursor to previous window with wrap around */
242     case 'W':
243 		CHECK_CMDWIN;
244 		if (ONE_WINDOW && Prenum != 1)	/* just one window */
245 		    beep_flush();
246 		else
247 		{
248 		    if (Prenum)			/* go to specified window */
249 		    {
250 			for (wp = firstwin; --Prenum > 0; )
251 			{
252 			    if (wp->w_next == NULL)
253 				break;
254 			    else
255 				wp = wp->w_next;
256 			}
257 		    }
258 		    else
259 		    {
260 			if (nchar == 'W')	    /* go to previous window */
261 			{
262 			    wp = curwin->w_prev;
263 			    if (wp == NULL)
264 				wp = lastwin;	    /* wrap around */
265 			}
266 			else			    /* go to next window */
267 			{
268 			    wp = curwin->w_next;
269 			    if (wp == NULL)
270 				wp = firstwin;	    /* wrap around */
271 			}
272 		    }
273 		    win_goto(wp);
274 		}
275 		break;
276 
277 /* cursor to window below */
278     case 'j':
279     case K_DOWN:
280     case Ctrl_J:
281 		CHECK_CMDWIN;
282 		win_goto_ver(FALSE, Prenum1);
283 		break;
284 
285 /* cursor to window above */
286     case 'k':
287     case K_UP:
288     case Ctrl_K:
289 		CHECK_CMDWIN;
290 		win_goto_ver(TRUE, Prenum1);
291 		break;
292 
293 /* cursor to left window */
294     case 'h':
295     case K_LEFT:
296     case Ctrl_H:
297     case K_BS:
298 		CHECK_CMDWIN;
299 		win_goto_hor(TRUE, Prenum1);
300 		break;
301 
302 /* cursor to right window */
303     case 'l':
304     case K_RIGHT:
305     case Ctrl_L:
306 		CHECK_CMDWIN;
307 		win_goto_hor(FALSE, Prenum1);
308 		break;
309 
310 /* move window to new tab page */
311     case 'T':
312 		if (one_window())
313 		    msg(_(m_onlyone));
314 		else
315 		{
316 		    tabpage_T	*oldtab = curtab;
317 		    tabpage_T	*newtab;
318 
319 		    /* First create a new tab with the window, then go back to
320 		     * the old tab and close the window there. */
321 		    wp = curwin;
322 		    if (win_new_tabpage((int)Prenum) == OK
323 						     && valid_tabpage(oldtab))
324 		    {
325 			newtab = curtab;
326 			goto_tabpage_tp(oldtab, TRUE, TRUE);
327 			if (curwin == wp)
328 			    win_close(curwin, FALSE);
329 			if (valid_tabpage(newtab))
330 			    goto_tabpage_tp(newtab, TRUE, TRUE);
331 		    }
332 		}
333 		break;
334 
335 /* cursor to top-left window */
336     case 't':
337     case Ctrl_T:
338 		win_goto(firstwin);
339 		break;
340 
341 /* cursor to bottom-right window */
342     case 'b':
343     case Ctrl_B:
344 		win_goto(lastwin);
345 		break;
346 
347 /* cursor to last accessed (previous) window */
348     case 'p':
349     case Ctrl_P:
350 		if (!win_valid(prevwin))
351 		    beep_flush();
352 		else
353 		    win_goto(prevwin);
354 		break;
355 
356 /* exchange current and next window */
357     case 'x':
358     case Ctrl_X:
359 		CHECK_CMDWIN;
360 		win_exchange(Prenum);
361 		break;
362 
363 /* rotate windows downwards */
364     case Ctrl_R:
365     case 'r':
366 		CHECK_CMDWIN;
367 		reset_VIsual_and_resel();	/* stop Visual mode */
368 		win_rotate(FALSE, (int)Prenum1);    /* downwards */
369 		break;
370 
371 /* rotate windows upwards */
372     case 'R':
373 		CHECK_CMDWIN;
374 		reset_VIsual_and_resel();	/* stop Visual mode */
375 		win_rotate(TRUE, (int)Prenum1);	    /* upwards */
376 		break;
377 
378 /* move window to the very top/bottom/left/right */
379     case 'K':
380     case 'J':
381     case 'H':
382     case 'L':
383 		CHECK_CMDWIN;
384 		win_totop((int)Prenum,
385 			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
386 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
387 		break;
388 
389 /* make all windows the same height */
390     case '=':
391 #ifdef FEAT_GUI
392 		need_mouse_correct = TRUE;
393 #endif
394 		win_equal(NULL, FALSE, 'b');
395 		break;
396 
397 /* increase current window height */
398     case '+':
399 #ifdef FEAT_GUI
400 		need_mouse_correct = TRUE;
401 #endif
402 		win_setheight(curwin->w_height + (int)Prenum1);
403 		break;
404 
405 /* decrease current window height */
406     case '-':
407 #ifdef FEAT_GUI
408 		need_mouse_correct = TRUE;
409 #endif
410 		win_setheight(curwin->w_height - (int)Prenum1);
411 		break;
412 
413 /* set current window height */
414     case Ctrl__:
415     case '_':
416 #ifdef FEAT_GUI
417 		need_mouse_correct = TRUE;
418 #endif
419 		win_setheight(Prenum ? (int)Prenum : 9999);
420 		break;
421 
422 /* increase current window width */
423     case '>':
424 #ifdef FEAT_GUI
425 		need_mouse_correct = TRUE;
426 #endif
427 		win_setwidth(curwin->w_width + (int)Prenum1);
428 		break;
429 
430 /* decrease current window width */
431     case '<':
432 #ifdef FEAT_GUI
433 		need_mouse_correct = TRUE;
434 #endif
435 		win_setwidth(curwin->w_width - (int)Prenum1);
436 		break;
437 
438 /* set current window width */
439     case '|':
440 #ifdef FEAT_GUI
441 		need_mouse_correct = TRUE;
442 #endif
443 		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
444 		break;
445 
446 /* jump to tag and split window if tag exists (in preview window) */
447 #if defined(FEAT_QUICKFIX)
448     case '}':
449 		CHECK_CMDWIN;
450 		if (Prenum)
451 		    g_do_tagpreview = Prenum;
452 		else
453 		    g_do_tagpreview = p_pvh;
454 #endif
455 		/* FALLTHROUGH */
456     case ']':
457     case Ctrl_RSB:
458 		CHECK_CMDWIN;
459 		/* keep Visual mode, can select words to use as a tag */
460 		if (Prenum)
461 		    postponed_split = Prenum;
462 		else
463 		    postponed_split = -1;
464 #ifdef FEAT_QUICKFIX
465 		if (nchar != '}')
466 		    g_do_tagpreview = 0;
467 #endif
468 
469 		/* Execute the command right here, required when "wincmd ]"
470 		 * was used in a function. */
471 		do_nv_ident(Ctrl_RSB, NUL);
472 		break;
473 
474 #ifdef FEAT_SEARCHPATH
475 /* edit file name under cursor in a new window */
476     case 'f':
477     case 'F':
478     case Ctrl_F:
479 wingotofile:
480 		CHECK_CMDWIN;
481 
482 		ptr = grab_file_name(Prenum1, &lnum);
483 		if (ptr != NULL)
484 		{
485 		    tabpage_T	*oldtab = curtab;
486 		    win_T	*oldwin = curwin;
487 # ifdef FEAT_GUI
488 		    need_mouse_correct = TRUE;
489 # endif
490 		    setpcmark();
491 		    if (win_split(0, 0) == OK)
492 		    {
493 			RESET_BINDING(curwin);
494 			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
495 						   ECMD_HIDE, NULL) == FAIL)
496 			{
497 			    /* Failed to open the file, close the window
498 			     * opened for it. */
499 			    win_close(curwin, FALSE);
500 			    goto_tabpage_win(oldtab, oldwin);
501 			}
502 			else if (nchar == 'F' && lnum >= 0)
503 			{
504 			    curwin->w_cursor.lnum = lnum;
505 			    check_cursor_lnum();
506 			    beginline(BL_SOL | BL_FIX);
507 			}
508 		    }
509 		    vim_free(ptr);
510 		}
511 		break;
512 #endif
513 
514 #ifdef FEAT_FIND_ID
515 /* Go to the first occurrence of the identifier under cursor along path in a
516  * new window -- webb
517  */
518     case 'i':			    /* Go to any match */
519     case Ctrl_I:
520 		type = FIND_ANY;
521 		/* FALLTHROUGH */
522     case 'd':			    /* Go to definition, using 'define' */
523     case Ctrl_D:
524 		CHECK_CMDWIN;
525 		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
526 		    break;
527 		find_pattern_in_path(ptr, 0, len, TRUE,
528 			Prenum == 0 ? TRUE : FALSE, type,
529 			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
530 		curwin->w_set_curswant = TRUE;
531 		break;
532 #endif
533 
534 /* Quickfix window only: view the result under the cursor in a new split. */
535 #if defined(FEAT_QUICKFIX)
536     case K_KENTER:
537     case CAR:
538 		if (bt_quickfix(curbuf))
539 		    qf_view_result(TRUE);
540 		break;
541 #endif
542 
543 /* CTRL-W g  extended commands */
544     case 'g':
545     case Ctrl_G:
546 		CHECK_CMDWIN;
547 #ifdef USE_ON_FLY_SCROLL
548 		dont_scroll = TRUE;		/* disallow scrolling here */
549 #endif
550 		++no_mapping;
551 		++allow_keys;   /* no mapping for xchar, but allow key codes */
552 		if (xchar == NUL)
553 		    xchar = plain_vgetc();
554 		LANGMAP_ADJUST(xchar, TRUE);
555 		--no_mapping;
556 		--allow_keys;
557 #ifdef FEAT_CMDL_INFO
558 		(void)add_to_showcmd(xchar);
559 #endif
560 		switch (xchar)
561 		{
562 #if defined(FEAT_QUICKFIX)
563 		    case '}':
564 			xchar = Ctrl_RSB;
565 			if (Prenum)
566 			    g_do_tagpreview = Prenum;
567 			else
568 			    g_do_tagpreview = p_pvh;
569 #endif
570 			/* FALLTHROUGH */
571 		    case ']':
572 		    case Ctrl_RSB:
573 			/* keep Visual mode, can select words to use as a tag */
574 			if (Prenum)
575 			    postponed_split = Prenum;
576 			else
577 			    postponed_split = -1;
578 
579 			/* Execute the command right here, required when
580 			 * "wincmd g}" was used in a function. */
581 			do_nv_ident('g', xchar);
582 			break;
583 
584 #ifdef FEAT_SEARCHPATH
585 		    case 'f':	    /* CTRL-W gf: "gf" in a new tab page */
586 		    case 'F':	    /* CTRL-W gF: "gF" in a new tab page */
587 			cmdmod.tab = tabpage_index(curtab) + 1;
588 			nchar = xchar;
589 			goto wingotofile;
590 #endif
591 		    default:
592 			beep_flush();
593 			break;
594 		}
595 		break;
596 
597     default:	beep_flush();
598 		break;
599     }
600 }
601 
602 /*
603  * Figure out the address type for ":wnncmd".
604  */
605     void
606 get_wincmd_addr_type(char_u *arg, exarg_T *eap)
607 {
608     switch (*arg)
609     {
610     case 'S':
611     case Ctrl_S:
612     case 's':
613     case Ctrl_N:
614     case 'n':
615     case 'j':
616     case Ctrl_J:
617     case 'k':
618     case Ctrl_K:
619     case 'T':
620     case Ctrl_R:
621     case 'r':
622     case 'R':
623     case 'K':
624     case 'J':
625     case '+':
626     case '-':
627     case Ctrl__:
628     case '_':
629     case '|':
630     case ']':
631     case Ctrl_RSB:
632     case 'g':
633     case Ctrl_G:
634     case Ctrl_V:
635     case 'v':
636     case 'h':
637     case Ctrl_H:
638     case 'l':
639     case Ctrl_L:
640     case 'H':
641     case 'L':
642     case '>':
643     case '<':
644 #if defined(FEAT_QUICKFIX)
645     case '}':
646 #endif
647 #ifdef FEAT_SEARCHPATH
648     case 'f':
649     case 'F':
650     case Ctrl_F:
651 #endif
652 #ifdef FEAT_FIND_ID
653     case 'i':
654     case Ctrl_I:
655     case 'd':
656     case Ctrl_D:
657 #endif
658 		/* window size or any count */
659 		eap->addr_type = ADDR_LINES;
660 		break;
661 
662     case Ctrl_HAT:
663     case '^':
664 		/* buffer number */
665 		eap->addr_type = ADDR_BUFFERS;
666 		break;
667 
668     case Ctrl_Q:
669     case 'q':
670     case Ctrl_C:
671     case 'c':
672     case Ctrl_O:
673     case 'o':
674     case Ctrl_W:
675     case 'w':
676     case 'W':
677     case 'x':
678     case Ctrl_X:
679 		/* window number */
680 		eap->addr_type = ADDR_WINDOWS;
681 		break;
682 
683 #if defined(FEAT_QUICKFIX)
684     case Ctrl_Z:
685     case 'z':
686     case 'P':
687 #endif
688     case 't':
689     case Ctrl_T:
690     case 'b':
691     case Ctrl_B:
692     case 'p':
693     case Ctrl_P:
694     case '=':
695     case CAR:
696 		/* no count */
697 		eap->addr_type = 0;
698 		break;
699     }
700 }
701 
702     static void
703 cmd_with_count(
704     char	*cmd,
705     char_u	*bufp,
706     size_t	bufsize,
707     long	Prenum)
708 {
709     size_t	len = STRLEN(cmd);
710 
711     STRCPY(bufp, cmd);
712     if (Prenum > 0)
713 	vim_snprintf((char *)bufp + len, bufsize - len, "%ld", Prenum);
714 }
715 
716 /*
717  * split the current window, implements CTRL-W s and :split
718  *
719  * "size" is the height or width for the new window, 0 to use half of current
720  * height or width.
721  *
722  * "flags":
723  * WSP_ROOM: require enough room for new window
724  * WSP_VERT: vertical split.
725  * WSP_TOP:  open window at the top-left of the shell (help window).
726  * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
727  * WSP_HELP: creating the help window, keep layout snapshot
728  *
729  * return FAIL for failure, OK otherwise
730  */
731     int
732 win_split(int size, int flags)
733 {
734     /* When the ":tab" modifier was used open a new tab page instead. */
735     if (may_open_tabpage() == OK)
736 	return OK;
737 
738     /* Add flags from ":vertical", ":topleft" and ":botright". */
739     flags |= cmdmod.split;
740     if ((flags & WSP_TOP) && (flags & WSP_BOT))
741     {
742 	emsg(_("E442: Can't split topleft and botright at the same time"));
743 	return FAIL;
744     }
745 
746     /* When creating the help window make a snapshot of the window layout.
747      * Otherwise clear the snapshot, it's now invalid. */
748     if (flags & WSP_HELP)
749 	make_snapshot(SNAP_HELP_IDX);
750     else
751 	clear_snapshot(curtab, SNAP_HELP_IDX);
752 
753     return win_split_ins(size, flags, NULL, 0);
754 }
755 
756 /*
757  * When "new_wp" is NULL: split the current window in two.
758  * When "new_wp" is not NULL: insert this window at the far
759  * top/left/right/bottom.
760  * return FAIL for failure, OK otherwise
761  */
762     int
763 win_split_ins(
764     int		size,
765     int		flags,
766     win_T	*new_wp,
767     int		dir)
768 {
769     win_T	*wp = new_wp;
770     win_T	*oldwin;
771     int		new_size = size;
772     int		i;
773     int		need_status = 0;
774     int		do_equal = FALSE;
775     int		needed;
776     int		available;
777     int		oldwin_height = 0;
778     int		layout;
779     frame_T	*frp, *curfrp, *frp2, *prevfrp;
780     int		before;
781     int		minheight;
782     int		wmh1;
783     int		did_set_fraction = FALSE;
784 
785     if (flags & WSP_TOP)
786 	oldwin = firstwin;
787     else if (flags & WSP_BOT)
788 	oldwin = lastwin;
789     else
790 	oldwin = curwin;
791 
792     /* add a status line when p_ls == 1 and splitting the first window */
793     if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
794     {
795 	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
796 	{
797 	    emsg(_(e_noroom));
798 	    return FAIL;
799 	}
800 	need_status = STATUS_HEIGHT;
801     }
802 
803 #ifdef FEAT_GUI
804     /* May be needed for the scrollbars that are going to change. */
805     if (gui.in_use)
806 	out_flush();
807 #endif
808 
809     if (flags & WSP_VERT)
810     {
811 	int	wmw1;
812 	int	minwidth;
813 
814 	layout = FR_ROW;
815 
816 	/*
817 	 * Check if we are able to split the current window and compute its
818 	 * width.
819 	 */
820 	/* Current window requires at least 1 space. */
821 	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
822 	needed = wmw1 + 1;
823 	if (flags & WSP_ROOM)
824 	    needed += p_wiw - wmw1;
825 	if (flags & (WSP_BOT | WSP_TOP))
826 	{
827 	    minwidth = frame_minwidth(topframe, NOWIN);
828 	    available = topframe->fr_width;
829 	    needed += minwidth;
830 	}
831 	else if (p_ea)
832 	{
833 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
834 	    prevfrp = oldwin->w_frame;
835 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
836 							frp = frp->fr_parent)
837 	    {
838 		if (frp->fr_layout == FR_ROW)
839 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
840 			if (frp2 != prevfrp)
841 			    minwidth += frame_minwidth(frp2, NOWIN);
842 		prevfrp = frp;
843 	    }
844 	    available = topframe->fr_width;
845 	    needed += minwidth;
846 	}
847 	else
848 	{
849 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
850 	    available = oldwin->w_frame->fr_width;
851 	    needed += minwidth;
852 	}
853 	if (available < needed && new_wp == NULL)
854 	{
855 	    emsg(_(e_noroom));
856 	    return FAIL;
857 	}
858 	if (new_size == 0)
859 	    new_size = oldwin->w_width / 2;
860 	if (new_size > available - minwidth - 1)
861 	    new_size = available - minwidth - 1;
862 	if (new_size < wmw1)
863 	    new_size = wmw1;
864 
865 	/* if it doesn't fit in the current window, need win_equal() */
866 	if (oldwin->w_width - new_size - 1 < p_wmw)
867 	    do_equal = TRUE;
868 
869 	/* We don't like to take lines for the new window from a
870 	 * 'winfixwidth' window.  Take them from a window to the left or right
871 	 * instead, if possible. Add one for the separator. */
872 	if (oldwin->w_p_wfw)
873 	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
874 
875 	/* Only make all windows the same width if one of them (except oldwin)
876 	 * is wider than one of the split windows. */
877 	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
878 	   && oldwin->w_frame->fr_parent != NULL)
879 	{
880 	    frp = oldwin->w_frame->fr_parent->fr_child;
881 	    while (frp != NULL)
882 	    {
883 		if (frp->fr_win != oldwin && frp->fr_win != NULL
884 			&& (frp->fr_win->w_width > new_size
885 			    || frp->fr_win->w_width > oldwin->w_width
886 							      - new_size - 1))
887 		{
888 		    do_equal = TRUE;
889 		    break;
890 		}
891 		frp = frp->fr_next;
892 	    }
893 	}
894     }
895     else
896     {
897 	layout = FR_COL;
898 
899 	/*
900 	 * Check if we are able to split the current window and compute its
901 	 * height.
902 	 */
903 	/* Current window requires at least 1 space. */
904 	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
905 	needed = wmh1 + STATUS_HEIGHT;
906 	if (flags & WSP_ROOM)
907 	    needed += p_wh - wmh1;
908 	if (flags & (WSP_BOT | WSP_TOP))
909 	{
910 	    minheight = frame_minheight(topframe, NOWIN) + need_status;
911 	    available = topframe->fr_height;
912 	    needed += minheight;
913 	}
914 	else if (p_ea)
915 	{
916 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
917 	    prevfrp = oldwin->w_frame;
918 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
919 							frp = frp->fr_parent)
920 	    {
921 		if (frp->fr_layout == FR_COL)
922 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
923 			if (frp2 != prevfrp)
924 			    minheight += frame_minheight(frp2, NOWIN);
925 		prevfrp = frp;
926 	    }
927 	    available = topframe->fr_height;
928 	    needed += minheight;
929 	}
930 	else
931 	{
932 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
933 	    available = oldwin->w_frame->fr_height;
934 	    needed += minheight;
935 	}
936 	if (available < needed && new_wp == NULL)
937 	{
938 	    emsg(_(e_noroom));
939 	    return FAIL;
940 	}
941 	oldwin_height = oldwin->w_height;
942 	if (need_status)
943 	{
944 	    oldwin->w_status_height = STATUS_HEIGHT;
945 	    oldwin_height -= STATUS_HEIGHT;
946 	}
947 	if (new_size == 0)
948 	    new_size = oldwin_height / 2;
949 	if (new_size > available - minheight - STATUS_HEIGHT)
950 	    new_size = available - minheight - STATUS_HEIGHT;
951 	if (new_size < wmh1)
952 	    new_size = wmh1;
953 
954 	/* if it doesn't fit in the current window, need win_equal() */
955 	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
956 	    do_equal = TRUE;
957 
958 	/* We don't like to take lines for the new window from a
959 	 * 'winfixheight' window.  Take them from a window above or below
960 	 * instead, if possible. */
961 	if (oldwin->w_p_wfh)
962 	{
963 	    /* Set w_fraction now so that the cursor keeps the same relative
964 	     * vertical position using the old height. */
965 	    set_fraction(oldwin);
966 	    did_set_fraction = TRUE;
967 
968 	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
969 								      oldwin);
970 	    oldwin_height = oldwin->w_height;
971 	    if (need_status)
972 		oldwin_height -= STATUS_HEIGHT;
973 	}
974 
975 	/* Only make all windows the same height if one of them (except oldwin)
976 	 * is higher than one of the split windows. */
977 	if (!do_equal && p_ea && size == 0 && *p_ead != 'h'
978 	   && oldwin->w_frame->fr_parent != NULL)
979 	{
980 	    frp = oldwin->w_frame->fr_parent->fr_child;
981 	    while (frp != NULL)
982 	    {
983 		if (frp->fr_win != oldwin && frp->fr_win != NULL
984 			&& (frp->fr_win->w_height > new_size
985 			    || frp->fr_win->w_height > oldwin_height - new_size
986 							      - STATUS_HEIGHT))
987 		{
988 		    do_equal = TRUE;
989 		    break;
990 		}
991 		frp = frp->fr_next;
992 	    }
993 	}
994     }
995 
996     /*
997      * allocate new window structure and link it in the window list
998      */
999     if ((flags & WSP_TOP) == 0
1000 	    && ((flags & WSP_BOT)
1001 		|| (flags & WSP_BELOW)
1002 		|| (!(flags & WSP_ABOVE)
1003 		    && ( (flags & WSP_VERT) ? p_spr : p_sb))))
1004     {
1005 	/* new window below/right of current one */
1006 	if (new_wp == NULL)
1007 	    wp = win_alloc(oldwin, FALSE);
1008 	else
1009 	    win_append(oldwin, wp);
1010     }
1011     else
1012     {
1013 	if (new_wp == NULL)
1014 	    wp = win_alloc(oldwin->w_prev, FALSE);
1015 	else
1016 	    win_append(oldwin->w_prev, wp);
1017     }
1018 
1019     if (new_wp == NULL)
1020     {
1021 	if (wp == NULL)
1022 	    return FAIL;
1023 
1024 	new_frame(wp);
1025 	if (wp->w_frame == NULL)
1026 	{
1027 	    win_free(wp, NULL);
1028 	    return FAIL;
1029 	}
1030 
1031 	/* make the contents of the new window the same as the current one */
1032 	win_init(wp, curwin, flags);
1033     }
1034 
1035     /*
1036      * Reorganise the tree of frames to insert the new window.
1037      */
1038     if (flags & (WSP_TOP | WSP_BOT))
1039     {
1040 	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
1041 	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
1042 	{
1043 	    curfrp = topframe->fr_child;
1044 	    if (flags & WSP_BOT)
1045 		while (curfrp->fr_next != NULL)
1046 		    curfrp = curfrp->fr_next;
1047 	}
1048 	else
1049 	    curfrp = topframe;
1050 	before = (flags & WSP_TOP);
1051     }
1052     else
1053     {
1054 	curfrp = oldwin->w_frame;
1055 	if (flags & WSP_BELOW)
1056 	    before = FALSE;
1057 	else if (flags & WSP_ABOVE)
1058 	    before = TRUE;
1059 	else if (flags & WSP_VERT)
1060 	    before = !p_spr;
1061 	else
1062 	    before = !p_sb;
1063     }
1064     if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
1065     {
1066 	/* Need to create a new frame in the tree to make a branch. */
1067 	frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
1068 	*frp = *curfrp;
1069 	curfrp->fr_layout = layout;
1070 	frp->fr_parent = curfrp;
1071 	frp->fr_next = NULL;
1072 	frp->fr_prev = NULL;
1073 	curfrp->fr_child = frp;
1074 	curfrp->fr_win = NULL;
1075 	curfrp = frp;
1076 	if (frp->fr_win != NULL)
1077 	    oldwin->w_frame = frp;
1078 	else
1079 	    FOR_ALL_FRAMES(frp, frp->fr_child)
1080 		frp->fr_parent = curfrp;
1081     }
1082 
1083     if (new_wp == NULL)
1084 	frp = wp->w_frame;
1085     else
1086 	frp = new_wp->w_frame;
1087     frp->fr_parent = curfrp->fr_parent;
1088 
1089     /* Insert the new frame at the right place in the frame list. */
1090     if (before)
1091 	frame_insert(curfrp, frp);
1092     else
1093 	frame_append(curfrp, frp);
1094 
1095     /* Set w_fraction now so that the cursor keeps the same relative
1096      * vertical position. */
1097     if (!did_set_fraction)
1098 	set_fraction(oldwin);
1099     wp->w_fraction = oldwin->w_fraction;
1100 
1101     if (flags & WSP_VERT)
1102     {
1103 	wp->w_p_scr = curwin->w_p_scr;
1104 
1105 	if (need_status)
1106 	{
1107 	    win_new_height(oldwin, oldwin->w_height - 1);
1108 	    oldwin->w_status_height = need_status;
1109 	}
1110 	if (flags & (WSP_TOP | WSP_BOT))
1111 	{
1112 	    /* set height and row of new window to full height */
1113 	    wp->w_winrow = tabline_height();
1114 	    win_new_height(wp, curfrp->fr_height - (p_ls > 0)
1115 							  - WINBAR_HEIGHT(wp));
1116 	    wp->w_status_height = (p_ls > 0);
1117 	}
1118 	else
1119 	{
1120 	    /* height and row of new window is same as current window */
1121 	    wp->w_winrow = oldwin->w_winrow;
1122 	    win_new_height(wp, VISIBLE_HEIGHT(oldwin));
1123 	    wp->w_status_height = oldwin->w_status_height;
1124 	}
1125 	frp->fr_height = curfrp->fr_height;
1126 
1127 	/* "new_size" of the current window goes to the new window, use
1128 	 * one column for the vertical separator */
1129 	win_new_width(wp, new_size);
1130 	if (before)
1131 	    wp->w_vsep_width = 1;
1132 	else
1133 	{
1134 	    wp->w_vsep_width = oldwin->w_vsep_width;
1135 	    oldwin->w_vsep_width = 1;
1136 	}
1137 	if (flags & (WSP_TOP | WSP_BOT))
1138 	{
1139 	    if (flags & WSP_BOT)
1140 		frame_add_vsep(curfrp);
1141 	    /* Set width of neighbor frame */
1142 	    frame_new_width(curfrp, curfrp->fr_width
1143 		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
1144 								       FALSE);
1145 	}
1146 	else
1147 	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
1148 	if (before)	/* new window left of current one */
1149 	{
1150 	    wp->w_wincol = oldwin->w_wincol;
1151 	    oldwin->w_wincol += new_size + 1;
1152 	}
1153 	else		/* new window right of current one */
1154 	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
1155 	frame_fix_width(oldwin);
1156 	frame_fix_width(wp);
1157     }
1158     else
1159     {
1160 	/* width and column of new window is same as current window */
1161 	if (flags & (WSP_TOP | WSP_BOT))
1162 	{
1163 	    wp->w_wincol = 0;
1164 	    win_new_width(wp, Columns);
1165 	    wp->w_vsep_width = 0;
1166 	}
1167 	else
1168 	{
1169 	    wp->w_wincol = oldwin->w_wincol;
1170 	    win_new_width(wp, oldwin->w_width);
1171 	    wp->w_vsep_width = oldwin->w_vsep_width;
1172 	}
1173 	frp->fr_width = curfrp->fr_width;
1174 
1175 	/* "new_size" of the current window goes to the new window, use
1176 	 * one row for the status line */
1177 	win_new_height(wp, new_size);
1178 	if (flags & (WSP_TOP | WSP_BOT))
1179 	{
1180 	    int new_fr_height = curfrp->fr_height - new_size
1181 							  + WINBAR_HEIGHT(wp) ;
1182 
1183 	    if (!((flags & WSP_BOT) && p_ls == 0))
1184 		new_fr_height -= STATUS_HEIGHT;
1185 	    frame_new_height(curfrp, new_fr_height, flags & WSP_TOP, FALSE);
1186 	}
1187 	else
1188 	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
1189 	if (before)	/* new window above current one */
1190 	{
1191 	    wp->w_winrow = oldwin->w_winrow;
1192 	    wp->w_status_height = STATUS_HEIGHT;
1193 	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
1194 	}
1195 	else		/* new window below current one */
1196 	{
1197 	    wp->w_winrow = oldwin->w_winrow + VISIBLE_HEIGHT(oldwin)
1198 							       + STATUS_HEIGHT;
1199 	    wp->w_status_height = oldwin->w_status_height;
1200 	    if (!(flags & WSP_BOT))
1201 		oldwin->w_status_height = STATUS_HEIGHT;
1202 	}
1203 	if (flags & WSP_BOT)
1204 	    frame_add_statusline(curfrp);
1205 	frame_fix_height(wp);
1206 	frame_fix_height(oldwin);
1207     }
1208 
1209     if (flags & (WSP_TOP | WSP_BOT))
1210 	(void)win_comp_pos();
1211 
1212     /*
1213      * Both windows need redrawing
1214      */
1215     redraw_win_later(wp, NOT_VALID);
1216     wp->w_redr_status = TRUE;
1217     redraw_win_later(oldwin, NOT_VALID);
1218     oldwin->w_redr_status = TRUE;
1219 
1220     if (need_status)
1221     {
1222 	msg_row = Rows - 1;
1223 	msg_col = sc_col;
1224 	msg_clr_eos_force();	/* Old command/ruler may still be there */
1225 	comp_col();
1226 	msg_row = Rows - 1;
1227 	msg_col = 0;	/* put position back at start of line */
1228     }
1229 
1230     /*
1231      * equalize the window sizes.
1232      */
1233     if (do_equal || dir != 0)
1234 	win_equal(wp, TRUE,
1235 		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
1236 		: dir == 'h' ? 'b' : 'v');
1237 
1238     /* Don't change the window height/width to 'winheight' / 'winwidth' if a
1239      * size was given. */
1240     if (flags & WSP_VERT)
1241     {
1242 	i = p_wiw;
1243 	if (size != 0)
1244 	    p_wiw = size;
1245 
1246 # ifdef FEAT_GUI
1247 	/* When 'guioptions' includes 'L' or 'R' may have to add scrollbars. */
1248 	if (gui.in_use)
1249 	    gui_init_which_components(NULL);
1250 # endif
1251     }
1252     else
1253     {
1254 	i = p_wh;
1255 	if (size != 0)
1256 	    p_wh = size;
1257     }
1258 
1259 #ifdef FEAT_JUMPLIST
1260     /* Keep same changelist position in new window. */
1261     wp->w_changelistidx = oldwin->w_changelistidx;
1262 #endif
1263 
1264     /*
1265      * make the new window the current window
1266      */
1267     win_enter_ext(wp, FALSE, FALSE, TRUE, TRUE, TRUE);
1268     if (flags & WSP_VERT)
1269 	p_wiw = i;
1270     else
1271 	p_wh = i;
1272 
1273     return OK;
1274 }
1275 
1276 
1277 /*
1278  * Initialize window "newp" from window "oldp".
1279  * Used when splitting a window and when creating a new tab page.
1280  * The windows will both edit the same buffer.
1281  * WSP_NEWLOC may be specified in flags to prevent the location list from
1282  * being copied.
1283  */
1284     static void
1285 win_init(win_T *newp, win_T *oldp, int flags UNUSED)
1286 {
1287     int		i;
1288 
1289     newp->w_buffer = oldp->w_buffer;
1290 #ifdef FEAT_SYN_HL
1291     newp->w_s = &(oldp->w_buffer->b_s);
1292 #endif
1293     oldp->w_buffer->b_nwindows++;
1294     newp->w_cursor = oldp->w_cursor;
1295     newp->w_valid = 0;
1296     newp->w_curswant = oldp->w_curswant;
1297     newp->w_set_curswant = oldp->w_set_curswant;
1298     newp->w_topline = oldp->w_topline;
1299 #ifdef FEAT_DIFF
1300     newp->w_topfill = oldp->w_topfill;
1301 #endif
1302     newp->w_leftcol = oldp->w_leftcol;
1303     newp->w_pcmark = oldp->w_pcmark;
1304     newp->w_prev_pcmark = oldp->w_prev_pcmark;
1305     newp->w_alt_fnum = oldp->w_alt_fnum;
1306     newp->w_wrow = oldp->w_wrow;
1307     newp->w_fraction = oldp->w_fraction;
1308     newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
1309 #ifdef FEAT_JUMPLIST
1310     copy_jumplist(oldp, newp);
1311 #endif
1312 #ifdef FEAT_QUICKFIX
1313     if (flags & WSP_NEWLOC)
1314     {
1315 	/* Don't copy the location list.  */
1316 	newp->w_llist = NULL;
1317 	newp->w_llist_ref = NULL;
1318     }
1319     else
1320 	copy_loclist_stack(oldp, newp);
1321 #endif
1322     newp->w_localdir = (oldp->w_localdir == NULL)
1323 				    ? NULL : vim_strsave(oldp->w_localdir);
1324 
1325     /* copy tagstack and folds */
1326     for (i = 0; i < oldp->w_tagstacklen; i++)
1327     {
1328 	newp->w_tagstack[i] = oldp->w_tagstack[i];
1329 	if (newp->w_tagstack[i].tagname != NULL)
1330 	    newp->w_tagstack[i].tagname =
1331 				   vim_strsave(newp->w_tagstack[i].tagname);
1332     }
1333     newp->w_tagstackidx = oldp->w_tagstackidx;
1334     newp->w_tagstacklen = oldp->w_tagstacklen;
1335 #ifdef FEAT_FOLDING
1336     copyFoldingState(oldp, newp);
1337 #endif
1338 
1339     win_init_some(newp, oldp);
1340 
1341 #ifdef FEAT_SYN_HL
1342     check_colorcolumn(newp);
1343 #endif
1344 }
1345 
1346 /*
1347  * Initialize window "newp" from window "old".
1348  * Only the essential things are copied.
1349  */
1350     static void
1351 win_init_some(win_T *newp, win_T *oldp)
1352 {
1353     /* Use the same argument list. */
1354     newp->w_alist = oldp->w_alist;
1355     ++newp->w_alist->al_refcount;
1356     newp->w_arg_idx = oldp->w_arg_idx;
1357 
1358     /* copy options from existing window */
1359     win_copy_options(oldp, newp);
1360 }
1361 
1362 
1363 /*
1364  * Check if "win" is a pointer to an existing window in the current tab page.
1365  */
1366     int
1367 win_valid(win_T *win)
1368 {
1369     win_T	*wp;
1370 
1371     if (win == NULL)
1372 	return FALSE;
1373     FOR_ALL_WINDOWS(wp)
1374 	if (wp == win)
1375 	    return TRUE;
1376     return FALSE;
1377 }
1378 
1379 /*
1380  * Check if "win" is a pointer to an existing window in any tab page.
1381  */
1382     int
1383 win_valid_any_tab(win_T *win)
1384 {
1385     win_T	*wp;
1386     tabpage_T	*tp;
1387 
1388     if (win == NULL)
1389 	return FALSE;
1390     FOR_ALL_TABPAGES(tp)
1391     {
1392 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
1393 	{
1394 	    if (wp == win)
1395 		return TRUE;
1396 	}
1397     }
1398     return FALSE;
1399 }
1400 
1401 /*
1402  * Return the number of windows.
1403  */
1404     int
1405 win_count(void)
1406 {
1407     win_T	*wp;
1408     int		count = 0;
1409 
1410     FOR_ALL_WINDOWS(wp)
1411 	++count;
1412     return count;
1413 }
1414 
1415 /*
1416  * Make "count" windows on the screen.
1417  * Return actual number of windows on the screen.
1418  * Must be called when there is just one window, filling the whole screen
1419  * (excluding the command line).
1420  */
1421     int
1422 make_windows(
1423     int		count,
1424     int		vertical UNUSED)  /* split windows vertically if TRUE */
1425 {
1426     int		maxcount;
1427     int		todo;
1428 
1429     if (vertical)
1430     {
1431 	/* Each windows needs at least 'winminwidth' lines and a separator
1432 	 * column. */
1433 	maxcount = (curwin->w_width + curwin->w_vsep_width
1434 					     - (p_wiw - p_wmw)) / (p_wmw + 1);
1435     }
1436     else
1437     {
1438 	/* Each window needs at least 'winminheight' lines and a status line. */
1439 	maxcount = (VISIBLE_HEIGHT(curwin) + curwin->w_status_height
1440 				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
1441     }
1442 
1443     if (maxcount < 2)
1444 	maxcount = 2;
1445     if (count > maxcount)
1446 	count = maxcount;
1447 
1448     /*
1449      * add status line now, otherwise first window will be too big
1450      */
1451     if (count > 1)
1452 	last_status(TRUE);
1453 
1454     /*
1455      * Don't execute autocommands while creating the windows.  Must do that
1456      * when putting the buffers in the windows.
1457      */
1458     block_autocmds();
1459 
1460     /* todo is number of windows left to create */
1461     for (todo = count - 1; todo > 0; --todo)
1462 	if (vertical)
1463 	{
1464 	    if (win_split(curwin->w_width - (curwin->w_width - todo)
1465 			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
1466 		break;
1467 	}
1468 	else
1469 	{
1470 	    if (win_split(curwin->w_height - (curwin->w_height - todo
1471 			    * STATUS_HEIGHT) / (todo + 1)
1472 			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
1473 		break;
1474 	}
1475 
1476     unblock_autocmds();
1477 
1478     /* return actual number of windows */
1479     return (count - todo);
1480 }
1481 
1482 /*
1483  * Exchange current and next window
1484  */
1485     static void
1486 win_exchange(long Prenum)
1487 {
1488     frame_T	*frp;
1489     frame_T	*frp2;
1490     win_T	*wp;
1491     win_T	*wp2;
1492     int		temp;
1493 
1494     if (ONE_WINDOW)	    /* just one window */
1495     {
1496 	beep_flush();
1497 	return;
1498     }
1499 
1500 #ifdef FEAT_GUI
1501     need_mouse_correct = TRUE;
1502 #endif
1503 
1504     /*
1505      * find window to exchange with
1506      */
1507     if (Prenum)
1508     {
1509 	frp = curwin->w_frame->fr_parent->fr_child;
1510 	while (frp != NULL && --Prenum > 0)
1511 	    frp = frp->fr_next;
1512     }
1513     else if (curwin->w_frame->fr_next != NULL)	/* Swap with next */
1514 	frp = curwin->w_frame->fr_next;
1515     else    /* Swap last window in row/col with previous */
1516 	frp = curwin->w_frame->fr_prev;
1517 
1518     /* We can only exchange a window with another window, not with a frame
1519      * containing windows. */
1520     if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
1521 	return;
1522     wp = frp->fr_win;
1523 
1524 /*
1525  * 1. remove curwin from the list. Remember after which window it was in wp2
1526  * 2. insert curwin before wp in the list
1527  * if wp != wp2
1528  *    3. remove wp from the list
1529  *    4. insert wp after wp2
1530  * 5. exchange the status line height and vsep width.
1531  */
1532     wp2 = curwin->w_prev;
1533     frp2 = curwin->w_frame->fr_prev;
1534     if (wp->w_prev != curwin)
1535     {
1536 	win_remove(curwin, NULL);
1537 	frame_remove(curwin->w_frame);
1538 	win_append(wp->w_prev, curwin);
1539 	frame_insert(frp, curwin->w_frame);
1540     }
1541     if (wp != wp2)
1542     {
1543 	win_remove(wp, NULL);
1544 	frame_remove(wp->w_frame);
1545 	win_append(wp2, wp);
1546 	if (frp2 == NULL)
1547 	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
1548 	else
1549 	    frame_append(frp2, wp->w_frame);
1550     }
1551     temp = curwin->w_status_height;
1552     curwin->w_status_height = wp->w_status_height;
1553     wp->w_status_height = temp;
1554     temp = curwin->w_vsep_width;
1555     curwin->w_vsep_width = wp->w_vsep_width;
1556     wp->w_vsep_width = temp;
1557 
1558     /* If the windows are not in the same frame, exchange the sizes to avoid
1559      * messing up the window layout.  Otherwise fix the frame sizes. */
1560     if (curwin->w_frame->fr_parent != wp->w_frame->fr_parent)
1561     {
1562 	temp = curwin->w_height;
1563 	curwin->w_height = wp->w_height;
1564 	wp->w_height = temp;
1565 	temp = curwin->w_width;
1566 	curwin->w_width = wp->w_width;
1567 	wp->w_width = temp;
1568     }
1569     else
1570     {
1571 	frame_fix_height(curwin);
1572 	frame_fix_height(wp);
1573 	frame_fix_width(curwin);
1574 	frame_fix_width(wp);
1575     }
1576 
1577     (void)win_comp_pos();		/* recompute window positions */
1578 
1579     win_enter(wp, TRUE);
1580     redraw_all_later(NOT_VALID);
1581 }
1582 
1583 /*
1584  * rotate windows: if upwards TRUE the second window becomes the first one
1585  *		   if upwards FALSE the first window becomes the second one
1586  */
1587     static void
1588 win_rotate(int upwards, int count)
1589 {
1590     win_T	*wp1;
1591     win_T	*wp2;
1592     frame_T	*frp;
1593     int		n;
1594 
1595     if (ONE_WINDOW)		/* nothing to do */
1596     {
1597 	beep_flush();
1598 	return;
1599     }
1600 
1601 #ifdef FEAT_GUI
1602     need_mouse_correct = TRUE;
1603 #endif
1604 
1605     /* Check if all frames in this row/col have one window. */
1606     FOR_ALL_FRAMES(frp, curwin->w_frame->fr_parent->fr_child)
1607 	if (frp->fr_win == NULL)
1608 	{
1609 	    emsg(_("E443: Cannot rotate when another window is split"));
1610 	    return;
1611 	}
1612 
1613     while (count--)
1614     {
1615 	if (upwards)		/* first window becomes last window */
1616 	{
1617 	    /* remove first window/frame from the list */
1618 	    frp = curwin->w_frame->fr_parent->fr_child;
1619 	    wp1 = frp->fr_win;
1620 	    win_remove(wp1, NULL);
1621 	    frame_remove(frp);
1622 
1623 	    /* find last frame and append removed window/frame after it */
1624 	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
1625 		;
1626 	    win_append(frp->fr_win, wp1);
1627 	    frame_append(frp, wp1->w_frame);
1628 
1629 	    wp2 = frp->fr_win;		/* previously last window */
1630 	}
1631 	else			/* last window becomes first window */
1632 	{
1633 	    /* find last window/frame in the list and remove it */
1634 	    for (frp = curwin->w_frame; frp->fr_next != NULL;
1635 							   frp = frp->fr_next)
1636 		;
1637 	    wp1 = frp->fr_win;
1638 	    wp2 = wp1->w_prev;		    /* will become last window */
1639 	    win_remove(wp1, NULL);
1640 	    frame_remove(frp);
1641 
1642 	    /* append the removed window/frame before the first in the list */
1643 	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
1644 	    frame_insert(frp->fr_parent->fr_child, frp);
1645 	}
1646 
1647 	/* exchange status height and vsep width of old and new last window */
1648 	n = wp2->w_status_height;
1649 	wp2->w_status_height = wp1->w_status_height;
1650 	wp1->w_status_height = n;
1651 	frame_fix_height(wp1);
1652 	frame_fix_height(wp2);
1653 	n = wp2->w_vsep_width;
1654 	wp2->w_vsep_width = wp1->w_vsep_width;
1655 	wp1->w_vsep_width = n;
1656 	frame_fix_width(wp1);
1657 	frame_fix_width(wp2);
1658 
1659 	/* recompute w_winrow and w_wincol for all windows */
1660 	(void)win_comp_pos();
1661     }
1662 
1663     redraw_all_later(NOT_VALID);
1664 }
1665 
1666 /*
1667  * Move the current window to the very top/bottom/left/right of the screen.
1668  */
1669     static void
1670 win_totop(int size, int flags)
1671 {
1672     int		dir;
1673     int		height = curwin->w_height;
1674 
1675     if (ONE_WINDOW)
1676     {
1677 	beep_flush();
1678 	return;
1679     }
1680 
1681     /* Remove the window and frame from the tree of frames. */
1682     (void)winframe_remove(curwin, &dir, NULL);
1683     win_remove(curwin, NULL);
1684     last_status(FALSE);	    /* may need to remove last status line */
1685     (void)win_comp_pos();   /* recompute window positions */
1686 
1687     /* Split a window on the desired side and put the window there. */
1688     (void)win_split_ins(size, flags, curwin, dir);
1689     if (!(flags & WSP_VERT))
1690     {
1691 	win_setheight(height);
1692 	if (p_ea)
1693 	    win_equal(curwin, TRUE, 'v');
1694     }
1695 
1696 #if defined(FEAT_GUI)
1697     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
1698      * scrollbars.  Have to update them anyway. */
1699     gui_may_update_scrollbars();
1700 #endif
1701 }
1702 
1703 /*
1704  * Move window "win1" to below/right of "win2" and make "win1" the current
1705  * window.  Only works within the same frame!
1706  */
1707     void
1708 win_move_after(win_T *win1, win_T *win2)
1709 {
1710     int		height;
1711 
1712     /* check if the arguments are reasonable */
1713     if (win1 == win2)
1714 	return;
1715 
1716     /* check if there is something to do */
1717     if (win2->w_next != win1)
1718     {
1719 	/* may need move the status line/vertical separator of the last window
1720 	 * */
1721 	if (win1 == lastwin)
1722 	{
1723 	    height = win1->w_prev->w_status_height;
1724 	    win1->w_prev->w_status_height = win1->w_status_height;
1725 	    win1->w_status_height = height;
1726 	    if (win1->w_prev->w_vsep_width == 1)
1727 	    {
1728 		/* Remove the vertical separator from the last-but-one window,
1729 		 * add it to the last window.  Adjust the frame widths. */
1730 		win1->w_prev->w_vsep_width = 0;
1731 		win1->w_prev->w_frame->fr_width -= 1;
1732 		win1->w_vsep_width = 1;
1733 		win1->w_frame->fr_width += 1;
1734 	    }
1735 	}
1736 	else if (win2 == lastwin)
1737 	{
1738 	    height = win1->w_status_height;
1739 	    win1->w_status_height = win2->w_status_height;
1740 	    win2->w_status_height = height;
1741 	    if (win1->w_vsep_width == 1)
1742 	    {
1743 		/* Remove the vertical separator from win1, add it to the last
1744 		 * window, win2.  Adjust the frame widths. */
1745 		win2->w_vsep_width = 1;
1746 		win2->w_frame->fr_width += 1;
1747 		win1->w_vsep_width = 0;
1748 		win1->w_frame->fr_width -= 1;
1749 	    }
1750 	}
1751 	win_remove(win1, NULL);
1752 	frame_remove(win1->w_frame);
1753 	win_append(win2, win1);
1754 	frame_append(win2->w_frame, win1->w_frame);
1755 
1756 	(void)win_comp_pos();	/* recompute w_winrow for all windows */
1757 	redraw_later(NOT_VALID);
1758     }
1759     win_enter(win1, FALSE);
1760 }
1761 
1762 /*
1763  * Make all windows the same height.
1764  * 'next_curwin' will soon be the current window, make sure it has enough
1765  * rows.
1766  */
1767     void
1768 win_equal(
1769     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1770     int		current,	/* do only frame with current window */
1771     int		dir)		/* 'v' for vertically, 'h' for horizontally,
1772 				   'b' for both, 0 for using p_ead */
1773 {
1774     if (dir == 0)
1775 	dir = *p_ead;
1776     win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
1777 		      topframe, dir, 0, tabline_height(),
1778 					   (int)Columns, topframe->fr_height);
1779 }
1780 
1781 /*
1782  * Set a frame to a new position and height, spreading the available room
1783  * equally over contained frames.
1784  * The window "next_curwin" (if not NULL) should at least get the size from
1785  * 'winheight' and 'winwidth' if possible.
1786  */
1787     static void
1788 win_equal_rec(
1789     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1790     int		current,	/* do only frame with current window */
1791     frame_T	*topfr,		/* frame to set size off */
1792     int		dir,		/* 'v', 'h' or 'b', see win_equal() */
1793     int		col,		/* horizontal position for frame */
1794     int		row,		/* vertical position for frame */
1795     int		width,		/* new width of frame */
1796     int		height)		/* new height of frame */
1797 {
1798     int		n, m;
1799     int		extra_sep = 0;
1800     int		wincount, totwincount = 0;
1801     frame_T	*fr;
1802     int		next_curwin_size = 0;
1803     int		room = 0;
1804     int		new_size;
1805     int		has_next_curwin = 0;
1806     int		hnc;
1807 
1808     if (topfr->fr_layout == FR_LEAF)
1809     {
1810 	/* Set the width/height of this frame.
1811 	 * Redraw when size or position changes */
1812 	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
1813 		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
1814 	   )
1815 	{
1816 	    topfr->fr_win->w_winrow = row;
1817 	    frame_new_height(topfr, height, FALSE, FALSE);
1818 	    topfr->fr_win->w_wincol = col;
1819 	    frame_new_width(topfr, width, FALSE, FALSE);
1820 	    redraw_all_later(NOT_VALID);
1821 	}
1822     }
1823     else if (topfr->fr_layout == FR_ROW)
1824     {
1825 	topfr->fr_width = width;
1826 	topfr->fr_height = height;
1827 
1828 	if (dir != 'v')			/* equalize frame widths */
1829 	{
1830 	    /* Compute the maximum number of windows horizontally in this
1831 	     * frame. */
1832 	    n = frame_minwidth(topfr, NOWIN);
1833 	    /* add one for the rightmost window, it doesn't have a separator */
1834 	    if (col + width == Columns)
1835 		extra_sep = 1;
1836 	    else
1837 		extra_sep = 0;
1838 	    totwincount = (n + extra_sep) / (p_wmw + 1);
1839 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1840 
1841 	    /*
1842 	     * Compute width for "next_curwin" window and room available for
1843 	     * other windows.
1844 	     * "m" is the minimal width when counting p_wiw for "next_curwin".
1845 	     */
1846 	    m = frame_minwidth(topfr, next_curwin);
1847 	    room = width - m;
1848 	    if (room < 0)
1849 	    {
1850 		next_curwin_size = p_wiw + room;
1851 		room = 0;
1852 	    }
1853 	    else
1854 	    {
1855 		next_curwin_size = -1;
1856 		FOR_ALL_FRAMES(fr, topfr->fr_child)
1857 		{
1858 		    /* If 'winfixwidth' set keep the window width if
1859 		     * possible.
1860 		     * Watch out for this window being the next_curwin. */
1861 		    if (frame_fixed_width(fr))
1862 		    {
1863 			n = frame_minwidth(fr, NOWIN);
1864 			new_size = fr->fr_width;
1865 			if (frame_has_win(fr, next_curwin))
1866 			{
1867 			    room += p_wiw - p_wmw;
1868 			    next_curwin_size = 0;
1869 			    if (new_size < p_wiw)
1870 				new_size = p_wiw;
1871 			}
1872 			else
1873 			    /* These windows don't use up room. */
1874 			    totwincount -= (n + (fr->fr_next == NULL
1875 					      ? extra_sep : 0)) / (p_wmw + 1);
1876 			room -= new_size - n;
1877 			if (room < 0)
1878 			{
1879 			    new_size += room;
1880 			    room = 0;
1881 			}
1882 			fr->fr_newwidth = new_size;
1883 		    }
1884 		}
1885 		if (next_curwin_size == -1)
1886 		{
1887 		    if (!has_next_curwin)
1888 			next_curwin_size = 0;
1889 		    else if (totwincount > 1
1890 			    && (room + (totwincount - 2))
1891 						  / (totwincount - 1) > p_wiw)
1892 		    {
1893 			/* Can make all windows wider than 'winwidth', spread
1894 			 * the room equally. */
1895 			next_curwin_size = (room + p_wiw
1896 					    + (totwincount - 1) * p_wmw
1897 					    + (totwincount - 1)) / totwincount;
1898 			room -= next_curwin_size - p_wiw;
1899 		    }
1900 		    else
1901 			next_curwin_size = p_wiw;
1902 		}
1903 	    }
1904 
1905 	    if (has_next_curwin)
1906 		--totwincount;		/* don't count curwin */
1907 	}
1908 
1909 	FOR_ALL_FRAMES(fr, topfr->fr_child)
1910 	{
1911 	    wincount = 1;
1912 	    if (fr->fr_next == NULL)
1913 		/* last frame gets all that remains (avoid roundoff error) */
1914 		new_size = width;
1915 	    else if (dir == 'v')
1916 		new_size = fr->fr_width;
1917 	    else if (frame_fixed_width(fr))
1918 	    {
1919 		new_size = fr->fr_newwidth;
1920 		wincount = 0;	    /* doesn't count as a sizeable window */
1921 	    }
1922 	    else
1923 	    {
1924 		/* Compute the maximum number of windows horiz. in "fr". */
1925 		n = frame_minwidth(fr, NOWIN);
1926 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
1927 								/ (p_wmw + 1);
1928 		m = frame_minwidth(fr, next_curwin);
1929 		if (has_next_curwin)
1930 		    hnc = frame_has_win(fr, next_curwin);
1931 		else
1932 		    hnc = FALSE;
1933 		if (hnc)	    /* don't count next_curwin */
1934 		    --wincount;
1935 		if (totwincount == 0)
1936 		    new_size = room;
1937 		else
1938 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
1939 								/ totwincount;
1940 		if (hnc)	    /* add next_curwin size */
1941 		{
1942 		    next_curwin_size -= p_wiw - (m - n);
1943 		    new_size += next_curwin_size;
1944 		    room -= new_size - next_curwin_size;
1945 		}
1946 		else
1947 		    room -= new_size;
1948 		new_size += n;
1949 	    }
1950 
1951 	    /* Skip frame that is full width when splitting or closing a
1952 	     * window, unless equalizing all frames. */
1953 	    if (!current || dir != 'v' || topfr->fr_parent != NULL
1954 		    || (new_size != fr->fr_width)
1955 		    || frame_has_win(fr, next_curwin))
1956 		win_equal_rec(next_curwin, current, fr, dir, col, row,
1957 							    new_size, height);
1958 	    col += new_size;
1959 	    width -= new_size;
1960 	    totwincount -= wincount;
1961 	}
1962     }
1963     else /* topfr->fr_layout == FR_COL */
1964     {
1965 	topfr->fr_width = width;
1966 	topfr->fr_height = height;
1967 
1968 	if (dir != 'h')			/* equalize frame heights */
1969 	{
1970 	    /* Compute maximum number of windows vertically in this frame. */
1971 	    n = frame_minheight(topfr, NOWIN);
1972 	    /* add one for the bottom window if it doesn't have a statusline */
1973 	    if (row + height == cmdline_row && p_ls == 0)
1974 		extra_sep = 1;
1975 	    else
1976 		extra_sep = 0;
1977 	    totwincount = (n + extra_sep) / (p_wmh + 1);
1978 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1979 
1980 	    /*
1981 	     * Compute height for "next_curwin" window and room available for
1982 	     * other windows.
1983 	     * "m" is the minimal height when counting p_wh for "next_curwin".
1984 	     */
1985 	    m = frame_minheight(topfr, next_curwin);
1986 	    room = height - m;
1987 	    if (room < 0)
1988 	    {
1989 		/* The room is less then 'winheight', use all space for the
1990 		 * current window. */
1991 		next_curwin_size = p_wh + room;
1992 		room = 0;
1993 	    }
1994 	    else
1995 	    {
1996 		next_curwin_size = -1;
1997 		FOR_ALL_FRAMES(fr, topfr->fr_child)
1998 		{
1999 		    /* If 'winfixheight' set keep the window height if
2000 		     * possible.
2001 		     * Watch out for this window being the next_curwin. */
2002 		    if (frame_fixed_height(fr))
2003 		    {
2004 			n = frame_minheight(fr, NOWIN);
2005 			new_size = fr->fr_height;
2006 			if (frame_has_win(fr, next_curwin))
2007 			{
2008 			    room += p_wh - p_wmh;
2009 			    next_curwin_size = 0;
2010 			    if (new_size < p_wh)
2011 				new_size = p_wh;
2012 			}
2013 			else
2014 			    /* These windows don't use up room. */
2015 			    totwincount -= (n + (fr->fr_next == NULL
2016 					      ? extra_sep : 0)) / (p_wmh + 1);
2017 			room -= new_size - n;
2018 			if (room < 0)
2019 			{
2020 			    new_size += room;
2021 			    room = 0;
2022 			}
2023 			fr->fr_newheight = new_size;
2024 		    }
2025 		}
2026 		if (next_curwin_size == -1)
2027 		{
2028 		    if (!has_next_curwin)
2029 			next_curwin_size = 0;
2030 		    else if (totwincount > 1
2031 			    && (room + (totwincount - 2))
2032 						   / (totwincount - 1) > p_wh)
2033 		    {
2034 			/* can make all windows higher than 'winheight',
2035 			 * spread the room equally. */
2036 			next_curwin_size = (room + p_wh
2037 					   + (totwincount - 1) * p_wmh
2038 					   + (totwincount - 1)) / totwincount;
2039 			room -= next_curwin_size - p_wh;
2040 		    }
2041 		    else
2042 			next_curwin_size = p_wh;
2043 		}
2044 	    }
2045 
2046 	    if (has_next_curwin)
2047 		--totwincount;		/* don't count curwin */
2048 	}
2049 
2050 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2051 	{
2052 	    wincount = 1;
2053 	    if (fr->fr_next == NULL)
2054 		/* last frame gets all that remains (avoid roundoff error) */
2055 		new_size = height;
2056 	    else if (dir == 'h')
2057 		new_size = fr->fr_height;
2058 	    else if (frame_fixed_height(fr))
2059 	    {
2060 		new_size = fr->fr_newheight;
2061 		wincount = 0;	    /* doesn't count as a sizeable window */
2062 	    }
2063 	    else
2064 	    {
2065 		/* Compute the maximum number of windows vert. in "fr". */
2066 		n = frame_minheight(fr, NOWIN);
2067 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2068 								/ (p_wmh + 1);
2069 		m = frame_minheight(fr, next_curwin);
2070 		if (has_next_curwin)
2071 		    hnc = frame_has_win(fr, next_curwin);
2072 		else
2073 		    hnc = FALSE;
2074 		if (hnc)	    /* don't count next_curwin */
2075 		    --wincount;
2076 		if (totwincount == 0)
2077 		    new_size = room;
2078 		else
2079 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2080 								/ totwincount;
2081 		if (hnc)	    /* add next_curwin size */
2082 		{
2083 		    next_curwin_size -= p_wh - (m - n);
2084 		    new_size += next_curwin_size;
2085 		    room -= new_size - next_curwin_size;
2086 		}
2087 		else
2088 		    room -= new_size;
2089 		new_size += n;
2090 	    }
2091 	    /* Skip frame that is full width when splitting or closing a
2092 	     * window, unless equalizing all frames. */
2093 	    if (!current || dir != 'h' || topfr->fr_parent != NULL
2094 		    || (new_size != fr->fr_height)
2095 		    || frame_has_win(fr, next_curwin))
2096 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2097 							     width, new_size);
2098 	    row += new_size;
2099 	    height -= new_size;
2100 	    totwincount -= wincount;
2101 	}
2102     }
2103 }
2104 
2105 #ifdef FEAT_JOB_CHANNEL
2106     static void
2107 leaving_window(win_T *win)
2108 {
2109     // Only matters for a prompt window.
2110     if (!bt_prompt(win->w_buffer))
2111 	return;
2112 
2113     // When leaving a prompt window stop Insert mode and perhaps restart
2114     // it when entering that window again.
2115     win->w_buffer->b_prompt_insert = restart_edit;
2116     if (restart_edit != 0 && mode_displayed)
2117 	clear_cmdline = TRUE;		/* unshow mode later */
2118     restart_edit = NUL;
2119 
2120     // When leaving the window (or closing the window) was done from a
2121     // callback we need to break out of the Insert mode loop and restart Insert
2122     // mode when entering the window again.
2123     if (State & INSERT)
2124     {
2125 	stop_insert_mode = TRUE;
2126 	if (win->w_buffer->b_prompt_insert == NUL)
2127 	    win->w_buffer->b_prompt_insert = 'A';
2128     }
2129 }
2130 
2131     static void
2132 entering_window(win_T *win)
2133 {
2134     // Only matters for a prompt window.
2135     if (!bt_prompt(win->w_buffer))
2136 	return;
2137 
2138     // When switching to a prompt buffer that was in Insert mode, don't stop
2139     // Insert mode, it may have been set in leaving_window().
2140     if (win->w_buffer->b_prompt_insert != NUL)
2141 	stop_insert_mode = FALSE;
2142 
2143     // When entering the prompt window restart Insert mode if we were in Insert
2144     // mode when we left it.
2145     restart_edit = win->w_buffer->b_prompt_insert;
2146 }
2147 #endif
2148 
2149 /*
2150  * Close all windows for buffer "buf".
2151  */
2152     void
2153 close_windows(
2154     buf_T	*buf,
2155     int		keep_curwin)	    /* don't close "curwin" */
2156 {
2157     win_T	*wp;
2158     tabpage_T   *tp, *nexttp;
2159     int		h = tabline_height();
2160     int		count = tabpage_index(NULL);
2161 
2162     ++RedrawingDisabled;
2163 
2164     for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
2165     {
2166 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
2167 		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
2168 	{
2169 	    if (win_close(wp, FALSE) == FAIL)
2170 		/* If closing the window fails give up, to avoid looping
2171 		 * forever. */
2172 		break;
2173 
2174 	    /* Start all over, autocommands may change the window layout. */
2175 	    wp = firstwin;
2176 	}
2177 	else
2178 	    wp = wp->w_next;
2179     }
2180 
2181     /* Also check windows in other tab pages. */
2182     for (tp = first_tabpage; tp != NULL; tp = nexttp)
2183     {
2184 	nexttp = tp->tp_next;
2185 	if (tp != curtab)
2186 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
2187 		if (wp->w_buffer == buf
2188 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
2189 		{
2190 		    win_close_othertab(wp, FALSE, tp);
2191 
2192 		    /* Start all over, the tab page may be closed and
2193 		     * autocommands may change the window layout. */
2194 		    nexttp = first_tabpage;
2195 		    break;
2196 		}
2197     }
2198 
2199     --RedrawingDisabled;
2200 
2201     if (count != tabpage_index(NULL))
2202 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2203 
2204     redraw_tabline = TRUE;
2205     if (h != tabline_height())
2206 	shell_new_rows();
2207 }
2208 
2209 /*
2210  * Return TRUE if the current window is the only window that exists (ignoring
2211  * "aucmd_win").
2212  * Returns FALSE if there is a window, possibly in another tab page.
2213  */
2214     static int
2215 last_window(void)
2216 {
2217     return (one_window() && first_tabpage->tp_next == NULL);
2218 }
2219 
2220 /*
2221  * Return TRUE if there is only one window other than "aucmd_win" in the
2222  * current tab page.
2223  */
2224     int
2225 one_window(void)
2226 {
2227     win_T	*wp;
2228     int		seen_one = FALSE;
2229 
2230     FOR_ALL_WINDOWS(wp)
2231     {
2232 	if (wp != aucmd_win)
2233 	{
2234 	    if (seen_one)
2235 		return FALSE;
2236 	    seen_one = TRUE;
2237 	}
2238     }
2239     return TRUE;
2240 }
2241 
2242 /*
2243  * Close the possibly last window in a tab page.
2244  * Returns TRUE when the window was closed already.
2245  */
2246     static int
2247 close_last_window_tabpage(
2248     win_T	*win,
2249     int		free_buf,
2250     tabpage_T   *prev_curtab)
2251 {
2252     if (ONE_WINDOW)
2253     {
2254 	buf_T	*old_curbuf = curbuf;
2255 
2256 	/*
2257 	 * Closing the last window in a tab page.  First go to another tab
2258 	 * page and then close the window and the tab page.  This avoids that
2259 	 * curwin and curtab are invalid while we are freeing memory, they may
2260 	 * be used in GUI events.
2261 	 * Don't trigger autocommands yet, they may use wrong values, so do
2262 	 * that below.
2263 	 */
2264 	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
2265 	redraw_tabline = TRUE;
2266 
2267 	/* Safety check: Autocommands may have closed the window when jumping
2268 	 * to the other tab page. */
2269 	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
2270 	{
2271 	    int	    h = tabline_height();
2272 
2273 	    win_close_othertab(win, free_buf, prev_curtab);
2274 	    if (h != tabline_height())
2275 		shell_new_rows();
2276 	}
2277 #ifdef FEAT_JOB_CHANNEL
2278 	entering_window(curwin);
2279 #endif
2280 	/* Since goto_tabpage_tp above did not trigger *Enter autocommands, do
2281 	 * that now. */
2282 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2283 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
2284 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
2285 	if (old_curbuf != curbuf)
2286 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2287 	return TRUE;
2288     }
2289     return FALSE;
2290 }
2291 
2292 /*
2293  * Close window "win".  Only works for the current tab page.
2294  * If "free_buf" is TRUE related buffer may be unloaded.
2295  *
2296  * Called by :quit, :close, :xit, :wq and findtag().
2297  * Returns FAIL when the window was not closed.
2298  */
2299     int
2300 win_close(win_T *win, int free_buf)
2301 {
2302     win_T	*wp;
2303     int		other_buffer = FALSE;
2304     int		close_curwin = FALSE;
2305     int		dir;
2306     int		help_window = FALSE;
2307     tabpage_T   *prev_curtab = curtab;
2308     frame_T	*win_frame = win->w_frame->fr_parent;
2309 
2310     if (last_window())
2311     {
2312 	emsg(_("E444: Cannot close last window"));
2313 	return FAIL;
2314     }
2315 
2316     if (win->w_closing || (win->w_buffer != NULL
2317 					       && win->w_buffer->b_locked > 0))
2318 	return FAIL; /* window is already being closed */
2319     if (win == aucmd_win)
2320     {
2321 	emsg(_("E813: Cannot close autocmd window"));
2322 	return FAIL;
2323     }
2324     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
2325     {
2326 	emsg(_("E814: Cannot close window, only autocmd window would remain"));
2327 	return FAIL;
2328     }
2329 
2330     /* When closing the last window in a tab page first go to another tab page
2331      * and then close the window and the tab page to avoid that curwin and
2332      * curtab are invalid while we are freeing memory. */
2333     if (close_last_window_tabpage(win, free_buf, prev_curtab))
2334       return FAIL;
2335 
2336     /* When closing the help window, try restoring a snapshot after closing
2337      * the window.  Otherwise clear the snapshot, it's now invalid. */
2338     if (bt_help(win->w_buffer))
2339 	help_window = TRUE;
2340     else
2341 	clear_snapshot(curtab, SNAP_HELP_IDX);
2342 
2343     if (win == curwin)
2344     {
2345 #ifdef FEAT_JOB_CHANNEL
2346 	leaving_window(curwin);
2347 #endif
2348 	/*
2349 	 * Guess which window is going to be the new current window.
2350 	 * This may change because of the autocommands (sigh).
2351 	 */
2352 	wp = frame2win(win_altframe(win, NULL));
2353 
2354 	/*
2355 	 * Be careful: If autocommands delete the window or cause this window
2356 	 * to be the last one left, return now.
2357 	 */
2358 	if (wp->w_buffer != curbuf)
2359 	{
2360 	    other_buffer = TRUE;
2361 	    win->w_closing = TRUE;
2362 	    apply_autocmds(EVENT_BUFLEAVE, 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 	}
2369 	win->w_closing = TRUE;
2370 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
2371 	if (!win_valid(win))
2372 	    return FAIL;
2373 	win->w_closing = FALSE;
2374 	if (last_window())
2375 	    return FAIL;
2376 #ifdef FEAT_EVAL
2377 	/* autocmds may abort script processing */
2378 	if (aborting())
2379 	    return FAIL;
2380 #endif
2381     }
2382 
2383 #ifdef FEAT_GUI
2384     /* Avoid trouble with scrollbars that are going to be deleted in
2385      * win_free(). */
2386     if (gui.in_use)
2387 	out_flush();
2388 #endif
2389 
2390 #ifdef FEAT_SYN_HL
2391     /* Free independent synblock before the buffer is freed. */
2392     if (win->w_buffer != NULL)
2393 	reset_synblock(win);
2394 #endif
2395 
2396     /*
2397      * Close the link to the buffer.
2398      */
2399     if (win->w_buffer != NULL)
2400     {
2401 	bufref_T    bufref;
2402 
2403 	set_bufref(&bufref, curbuf);
2404 	win->w_closing = TRUE;
2405 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, TRUE);
2406 	if (win_valid_any_tab(win))
2407 	    win->w_closing = FALSE;
2408 	/* Make sure curbuf is valid. It can become invalid if 'bufhidden' is
2409 	 * "wipe". */
2410 	if (!bufref_valid(&bufref))
2411 	    curbuf = firstbuf;
2412     }
2413 
2414     if (only_one_window() && win_valid(win) && win->w_buffer == NULL
2415 	    && (last_window() || curtab != prev_curtab
2416 		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
2417     {
2418 	/* Autocommands have closed all windows, quit now.  Restore
2419 	 * curwin->w_buffer, otherwise writing viminfo may fail. */
2420 	if (curwin->w_buffer == NULL)
2421 	    curwin->w_buffer = curbuf;
2422 	getout(0);
2423     }
2424 
2425     /* Autocommands may have moved to another tab page. */
2426     if (curtab != prev_curtab && win_valid_any_tab(win)
2427 						      && win->w_buffer == NULL)
2428     {
2429 	/* Need to close the window anyway, since the buffer is NULL. */
2430 	win_close_othertab(win, FALSE, prev_curtab);
2431 	return FAIL;
2432     }
2433 
2434     /* Autocommands may have closed the window already or closed the only
2435      * other window. */
2436     if (!win_valid(win) || last_window()
2437 	    || close_last_window_tabpage(win, free_buf, prev_curtab))
2438 	return FAIL;
2439 
2440     /* Free the memory used for the window and get the window that received
2441      * the screen space. */
2442     wp = win_free_mem(win, &dir, NULL);
2443 
2444     /* Make sure curwin isn't invalid.  It can cause severe trouble when
2445      * printing an error message.  For win_equal() curbuf needs to be valid
2446      * too. */
2447     if (win == curwin)
2448     {
2449 	curwin = wp;
2450 #ifdef FEAT_QUICKFIX
2451 	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
2452 	{
2453 	    /*
2454 	     * If the cursor goes to the preview or the quickfix window, try
2455 	     * finding another window to go to.
2456 	     */
2457 	    for (;;)
2458 	    {
2459 		if (wp->w_next == NULL)
2460 		    wp = firstwin;
2461 		else
2462 		    wp = wp->w_next;
2463 		if (wp == curwin)
2464 		    break;
2465 		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
2466 		{
2467 		    curwin = wp;
2468 		    break;
2469 		}
2470 	    }
2471 	}
2472 #endif
2473 	curbuf = curwin->w_buffer;
2474 	close_curwin = TRUE;
2475 
2476 	/* The cursor position may be invalid if the buffer changed after last
2477 	 * using the window. */
2478 	check_cursor();
2479     }
2480     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
2481 	/* If the frame of the closed window contains the new current window,
2482 	 * only resize that frame.  Otherwise resize all windows. */
2483 	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
2484     else
2485 	win_comp_pos();
2486     if (close_curwin)
2487     {
2488 	win_enter_ext(wp, FALSE, TRUE, FALSE, TRUE, TRUE);
2489 	if (other_buffer)
2490 	    /* careful: after this wp and win may be invalid! */
2491 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2492     }
2493 
2494     /*
2495      * If last window has a status line now and we don't want one,
2496      * remove the status line.
2497      */
2498     last_status(FALSE);
2499 
2500     /* After closing the help window, try restoring the window layout from
2501      * before it was opened. */
2502     if (help_window)
2503 	restore_snapshot(SNAP_HELP_IDX, close_curwin);
2504 
2505 #if defined(FEAT_GUI)
2506     /* When 'guioptions' includes 'L' or 'R' may have to remove scrollbars. */
2507     if (gui.in_use && !win_hasvertsplit())
2508 	gui_init_which_components(NULL);
2509 #endif
2510 
2511     redraw_all_later(NOT_VALID);
2512     return OK;
2513 }
2514 
2515 /*
2516  * Close window "win" in tab page "tp", which is not the current tab page.
2517  * This may be the last window in that tab page and result in closing the tab,
2518  * thus "tp" may become invalid!
2519  * Caller must check if buffer is hidden and whether the tabline needs to be
2520  * updated.
2521  */
2522     void
2523 win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
2524 {
2525     win_T	*wp;
2526     int		dir;
2527     tabpage_T   *ptp = NULL;
2528     int		free_tp = FALSE;
2529 
2530     /* Get here with win->w_buffer == NULL when win_close() detects the tab
2531      * page changed. */
2532     if (win->w_closing || (win->w_buffer != NULL
2533 					       && win->w_buffer->b_locked > 0))
2534 	return; /* window is already being closed */
2535 
2536     if (win->w_buffer != NULL)
2537 	/* Close the link to the buffer. */
2538 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, FALSE);
2539 
2540     /* Careful: Autocommands may have closed the tab page or made it the
2541      * current tab page.  */
2542     for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
2543 	;
2544     if (ptp == NULL || tp == curtab)
2545 	return;
2546 
2547     /* Autocommands may have closed the window already. */
2548     for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
2549 	;
2550     if (wp == NULL)
2551 	return;
2552 
2553     /* When closing the last window in a tab page remove the tab page. */
2554     if (tp->tp_firstwin == tp->tp_lastwin)
2555     {
2556 	if (tp == first_tabpage)
2557 	    first_tabpage = tp->tp_next;
2558 	else
2559 	{
2560 	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
2561 							   ptp = ptp->tp_next)
2562 		;
2563 	    if (ptp == NULL)
2564 	    {
2565 		internal_error("win_close_othertab()");
2566 		return;
2567 	    }
2568 	    ptp->tp_next = tp->tp_next;
2569 	}
2570 	free_tp = TRUE;
2571     }
2572 
2573     /* Free the memory used for the window. */
2574     win_free_mem(win, &dir, tp);
2575 
2576     if (free_tp)
2577 	free_tabpage(tp);
2578 }
2579 
2580 /*
2581  * Free the memory used for a window.
2582  * Returns a pointer to the window that got the freed up space.
2583  */
2584     static win_T *
2585 win_free_mem(
2586     win_T	*win,
2587     int		*dirp,		/* set to 'v' or 'h' for direction if 'ea' */
2588     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2589 {
2590     frame_T	*frp;
2591     win_T	*wp;
2592 
2593     /* Remove the window and its frame from the tree of frames. */
2594     frp = win->w_frame;
2595     wp = winframe_remove(win, dirp, tp);
2596     vim_free(frp);
2597     win_free(win, tp);
2598 
2599     /* When deleting the current window of another tab page select a new
2600      * current window. */
2601     if (tp != NULL && win == tp->tp_curwin)
2602 	tp->tp_curwin = wp;
2603 
2604     return wp;
2605 }
2606 
2607 #if defined(EXITFREE) || defined(PROTO)
2608     void
2609 win_free_all(void)
2610 {
2611     int		dummy;
2612 
2613     while (first_tabpage->tp_next != NULL)
2614 	tabpage_close(TRUE);
2615 
2616     if (aucmd_win != NULL)
2617     {
2618 	(void)win_free_mem(aucmd_win, &dummy, NULL);
2619 	aucmd_win = NULL;
2620     }
2621 
2622     while (firstwin != NULL)
2623 	(void)win_free_mem(firstwin, &dummy, NULL);
2624 
2625     /* No window should be used after this. Set curwin to NULL to crash
2626      * instead of using freed memory. */
2627     curwin = NULL;
2628 }
2629 #endif
2630 
2631 /*
2632  * Remove a window and its frame from the tree of frames.
2633  * Returns a pointer to the window that got the freed up space.
2634  */
2635     win_T *
2636 winframe_remove(
2637     win_T	*win,
2638     int		*dirp UNUSED,	/* set to 'v' or 'h' for direction if 'ea' */
2639     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2640 {
2641     frame_T	*frp, *frp2, *frp3;
2642     frame_T	*frp_close = win->w_frame;
2643     win_T	*wp;
2644 
2645     /*
2646      * If there is only one window there is nothing to remove.
2647      */
2648     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2649 	return NULL;
2650 
2651     /*
2652      * Remove the window from its frame.
2653      */
2654     frp2 = win_altframe(win, tp);
2655     wp = frame2win(frp2);
2656 
2657     /* Remove this frame from the list of frames. */
2658     frame_remove(frp_close);
2659 
2660     if (frp_close->fr_parent->fr_layout == FR_COL)
2661     {
2662 	/* When 'winfixheight' is set, try to find another frame in the column
2663 	 * (as close to the closed frame as possible) to distribute the height
2664 	 * to. */
2665 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
2666 	{
2667 	    frp = frp_close->fr_prev;
2668 	    frp3 = frp_close->fr_next;
2669 	    while (frp != NULL || frp3 != NULL)
2670 	    {
2671 		if (frp != NULL)
2672 		{
2673 		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfh)
2674 		    {
2675 			frp2 = frp;
2676 			wp = frp->fr_win;
2677 			break;
2678 		    }
2679 		    frp = frp->fr_prev;
2680 		}
2681 		if (frp3 != NULL)
2682 		{
2683 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
2684 		    {
2685 			frp2 = frp3;
2686 			wp = frp3->fr_win;
2687 			break;
2688 		    }
2689 		    frp3 = frp3->fr_next;
2690 		}
2691 	    }
2692 	}
2693 	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
2694 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2695 	*dirp = 'v';
2696     }
2697     else
2698     {
2699 	/* When 'winfixwidth' is set, try to find another frame in the column
2700 	 * (as close to the closed frame as possible) to distribute the width
2701 	 * to. */
2702 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
2703 	{
2704 	    frp = frp_close->fr_prev;
2705 	    frp3 = frp_close->fr_next;
2706 	    while (frp != NULL || frp3 != NULL)
2707 	    {
2708 		if (frp != NULL)
2709 		{
2710 		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfw)
2711 		    {
2712 			frp2 = frp;
2713 			wp = frp->fr_win;
2714 			break;
2715 		    }
2716 		    frp = frp->fr_prev;
2717 		}
2718 		if (frp3 != NULL)
2719 		{
2720 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
2721 		    {
2722 			frp2 = frp3;
2723 			wp = frp3->fr_win;
2724 			break;
2725 		    }
2726 		    frp3 = frp3->fr_next;
2727 		}
2728 	    }
2729 	}
2730 	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
2731 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2732 	*dirp = 'h';
2733     }
2734 
2735     /* If rows/columns go to a window below/right its positions need to be
2736      * updated.  Can only be done after the sizes have been updated. */
2737     if (frp2 == frp_close->fr_next)
2738     {
2739 	int row = win->w_winrow;
2740 	int col = win->w_wincol;
2741 
2742 	frame_comp_pos(frp2, &row, &col);
2743     }
2744 
2745     if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
2746     {
2747 	/* There is no other frame in this list, move its info to the parent
2748 	 * and remove it. */
2749 	frp2->fr_parent->fr_layout = frp2->fr_layout;
2750 	frp2->fr_parent->fr_child = frp2->fr_child;
2751 	FOR_ALL_FRAMES(frp, frp2->fr_child)
2752 	    frp->fr_parent = frp2->fr_parent;
2753 	frp2->fr_parent->fr_win = frp2->fr_win;
2754 	if (frp2->fr_win != NULL)
2755 	    frp2->fr_win->w_frame = frp2->fr_parent;
2756 	frp = frp2->fr_parent;
2757 	if (topframe->fr_child == frp2)
2758 	    topframe->fr_child = frp;
2759 	vim_free(frp2);
2760 
2761 	frp2 = frp->fr_parent;
2762 	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
2763 	{
2764 	    /* The frame above the parent has the same layout, have to merge
2765 	     * the frames into this list. */
2766 	    if (frp2->fr_child == frp)
2767 		frp2->fr_child = frp->fr_child;
2768 	    frp->fr_child->fr_prev = frp->fr_prev;
2769 	    if (frp->fr_prev != NULL)
2770 		frp->fr_prev->fr_next = frp->fr_child;
2771 	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
2772 	    {
2773 		frp3->fr_parent = frp2;
2774 		if (frp3->fr_next == NULL)
2775 		{
2776 		    frp3->fr_next = frp->fr_next;
2777 		    if (frp->fr_next != NULL)
2778 			frp->fr_next->fr_prev = frp3;
2779 		    break;
2780 		}
2781 	    }
2782 	    if (topframe->fr_child == frp)
2783 		topframe->fr_child = frp2;
2784 	    vim_free(frp);
2785 	}
2786     }
2787 
2788     return wp;
2789 }
2790 
2791 /*
2792  * Return a pointer to the frame that will receive the empty screen space that
2793  * is left over after "win" is closed.
2794  *
2795  * If 'splitbelow' or 'splitright' is set, the space goes above or to the left
2796  * by default.  Otherwise, the free space goes below or to the right.  The
2797  * result is that opening a window and then immediately closing it will
2798  * preserve the initial window layout.  The 'wfh' and 'wfw' settings are
2799  * respected when possible.
2800  */
2801     static frame_T *
2802 win_altframe(
2803     win_T	*win,
2804     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2805 {
2806     frame_T	*frp;
2807     frame_T	*other_fr, *target_fr;
2808 
2809     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2810 	return alt_tabpage()->tp_curwin->w_frame;
2811 
2812     frp = win->w_frame;
2813 
2814     if (frp->fr_prev == NULL)
2815 	return frp->fr_next;
2816     if (frp->fr_next == NULL)
2817 	return frp->fr_prev;
2818 
2819     target_fr = frp->fr_next;
2820     other_fr  = frp->fr_prev;
2821     if (p_spr || p_sb)
2822     {
2823 	target_fr = frp->fr_prev;
2824 	other_fr  = frp->fr_next;
2825     }
2826 
2827     /* If 'wfh' or 'wfw' is set for the target and not for the alternate
2828      * window, reverse the selection. */
2829     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
2830     {
2831 	if (frame_fixed_width(target_fr) && !frame_fixed_width(other_fr))
2832 	    target_fr = other_fr;
2833     }
2834     else
2835     {
2836 	if (frame_fixed_height(target_fr) && !frame_fixed_height(other_fr))
2837 	    target_fr = other_fr;
2838     }
2839 
2840     return target_fr;
2841 }
2842 
2843 /*
2844  * Return the tabpage that will be used if the current one is closed.
2845  */
2846     static tabpage_T *
2847 alt_tabpage(void)
2848 {
2849     tabpage_T	*tp;
2850 
2851     /* Use the next tab page if possible. */
2852     if (curtab->tp_next != NULL)
2853 	return curtab->tp_next;
2854 
2855     /* Find the last but one tab page. */
2856     for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
2857 	;
2858     return tp;
2859 }
2860 
2861 /*
2862  * Find the left-upper window in frame "frp".
2863  */
2864     static win_T *
2865 frame2win(frame_T *frp)
2866 {
2867     while (frp->fr_win == NULL)
2868 	frp = frp->fr_child;
2869     return frp->fr_win;
2870 }
2871 
2872 /*
2873  * Return TRUE if frame "frp" contains window "wp".
2874  */
2875     static int
2876 frame_has_win(frame_T *frp, win_T *wp)
2877 {
2878     frame_T	*p;
2879 
2880     if (frp->fr_layout == FR_LEAF)
2881 	return frp->fr_win == wp;
2882 
2883     FOR_ALL_FRAMES(p, frp->fr_child)
2884 	if (frame_has_win(p, wp))
2885 	    return TRUE;
2886     return FALSE;
2887 }
2888 
2889 /*
2890  * Set a new height for a frame.  Recursively sets the height for contained
2891  * frames and windows.  Caller must take care of positions.
2892  */
2893     static void
2894 frame_new_height(
2895     frame_T	*topfrp,
2896     int		height,
2897     int		topfirst,	/* resize topmost contained frame first */
2898     int		wfh)		/* obey 'winfixheight' when there is a choice;
2899 				   may cause the height not to be set */
2900 {
2901     frame_T	*frp;
2902     int		extra_lines;
2903     int		h;
2904 
2905     if (topfrp->fr_win != NULL)
2906     {
2907 	/* Simple case: just one window. */
2908 	win_new_height(topfrp->fr_win,
2909 				    height - topfrp->fr_win->w_status_height
2910 					      - WINBAR_HEIGHT(topfrp->fr_win));
2911     }
2912     else if (topfrp->fr_layout == FR_ROW)
2913     {
2914 	do
2915 	{
2916 	    /* All frames in this row get the same new height. */
2917 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
2918 	    {
2919 		frame_new_height(frp, height, topfirst, wfh);
2920 		if (frp->fr_height > height)
2921 		{
2922 		    /* Could not fit the windows, make the whole row higher. */
2923 		    height = frp->fr_height;
2924 		    break;
2925 		}
2926 	    }
2927 	}
2928 	while (frp != NULL);
2929     }
2930     else    /* fr_layout == FR_COL */
2931     {
2932 	/* Complicated case: Resize a column of frames.  Resize the bottom
2933 	 * frame first, frames above that when needed. */
2934 
2935 	frp = topfrp->fr_child;
2936 	if (wfh)
2937 	    /* Advance past frames with one window with 'wfh' set. */
2938 	    while (frame_fixed_height(frp))
2939 	    {
2940 		frp = frp->fr_next;
2941 		if (frp == NULL)
2942 		    return;	    /* no frame without 'wfh', give up */
2943 	    }
2944 	if (!topfirst)
2945 	{
2946 	    /* Find the bottom frame of this column */
2947 	    while (frp->fr_next != NULL)
2948 		frp = frp->fr_next;
2949 	    if (wfh)
2950 		/* Advance back for frames with one window with 'wfh' set. */
2951 		while (frame_fixed_height(frp))
2952 		    frp = frp->fr_prev;
2953 	}
2954 
2955 	extra_lines = height - topfrp->fr_height;
2956 	if (extra_lines < 0)
2957 	{
2958 	    /* reduce height of contained frames, bottom or top frame first */
2959 	    while (frp != NULL)
2960 	    {
2961 		h = frame_minheight(frp, NULL);
2962 		if (frp->fr_height + extra_lines < h)
2963 		{
2964 		    extra_lines += frp->fr_height - h;
2965 		    frame_new_height(frp, h, topfirst, wfh);
2966 		}
2967 		else
2968 		{
2969 		    frame_new_height(frp, frp->fr_height + extra_lines,
2970 							       topfirst, wfh);
2971 		    break;
2972 		}
2973 		if (topfirst)
2974 		{
2975 		    do
2976 			frp = frp->fr_next;
2977 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2978 		}
2979 		else
2980 		{
2981 		    do
2982 			frp = frp->fr_prev;
2983 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2984 		}
2985 		/* Increase "height" if we could not reduce enough frames. */
2986 		if (frp == NULL)
2987 		    height -= extra_lines;
2988 	    }
2989 	}
2990 	else if (extra_lines > 0)
2991 	{
2992 	    /* increase height of bottom or top frame */
2993 	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
2994 	}
2995     }
2996     topfrp->fr_height = height;
2997 }
2998 
2999 /*
3000  * Return TRUE if height of frame "frp" should not be changed because of
3001  * the 'winfixheight' option.
3002  */
3003     static int
3004 frame_fixed_height(frame_T *frp)
3005 {
3006     /* frame with one window: fixed height if 'winfixheight' set. */
3007     if (frp->fr_win != NULL)
3008 	return frp->fr_win->w_p_wfh;
3009 
3010     if (frp->fr_layout == FR_ROW)
3011     {
3012 	/* The frame is fixed height if one of the frames in the row is fixed
3013 	 * height. */
3014 	FOR_ALL_FRAMES(frp, frp->fr_child)
3015 	    if (frame_fixed_height(frp))
3016 		return TRUE;
3017 	return FALSE;
3018     }
3019 
3020     /* frp->fr_layout == FR_COL: The frame is fixed height if all of the
3021      * frames in the row are fixed height. */
3022     FOR_ALL_FRAMES(frp, frp->fr_child)
3023 	if (!frame_fixed_height(frp))
3024 	    return FALSE;
3025     return TRUE;
3026 }
3027 
3028 /*
3029  * Return TRUE if width of frame "frp" should not be changed because of
3030  * the 'winfixwidth' option.
3031  */
3032     static int
3033 frame_fixed_width(frame_T *frp)
3034 {
3035     /* frame with one window: fixed width if 'winfixwidth' set. */
3036     if (frp->fr_win != NULL)
3037 	return frp->fr_win->w_p_wfw;
3038 
3039     if (frp->fr_layout == FR_COL)
3040     {
3041 	/* The frame is fixed width if one of the frames in the row is fixed
3042 	 * width. */
3043 	FOR_ALL_FRAMES(frp, frp->fr_child)
3044 	    if (frame_fixed_width(frp))
3045 		return TRUE;
3046 	return FALSE;
3047     }
3048 
3049     /* frp->fr_layout == FR_ROW: The frame is fixed width if all of the
3050      * frames in the row are fixed width. */
3051     FOR_ALL_FRAMES(frp, frp->fr_child)
3052 	if (!frame_fixed_width(frp))
3053 	    return FALSE;
3054     return TRUE;
3055 }
3056 
3057 /*
3058  * Add a status line to windows at the bottom of "frp".
3059  * Note: Does not check if there is room!
3060  */
3061     static void
3062 frame_add_statusline(frame_T *frp)
3063 {
3064     win_T	*wp;
3065 
3066     if (frp->fr_layout == FR_LEAF)
3067     {
3068 	wp = frp->fr_win;
3069 	if (wp->w_status_height == 0)
3070 	{
3071 	    if (wp->w_height > 0)	/* don't make it negative */
3072 		--wp->w_height;
3073 	    wp->w_status_height = STATUS_HEIGHT;
3074 	}
3075     }
3076     else if (frp->fr_layout == FR_ROW)
3077     {
3078 	/* Handle all the frames in the row. */
3079 	FOR_ALL_FRAMES(frp, frp->fr_child)
3080 	    frame_add_statusline(frp);
3081     }
3082     else /* frp->fr_layout == FR_COL */
3083     {
3084 	/* Only need to handle the last frame in the column. */
3085 	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
3086 	    ;
3087 	frame_add_statusline(frp);
3088     }
3089 }
3090 
3091 /*
3092  * Set width of a frame.  Handles recursively going through contained frames.
3093  * May remove separator line for windows at the right side (for win_close()).
3094  */
3095     static void
3096 frame_new_width(
3097     frame_T	*topfrp,
3098     int		width,
3099     int		leftfirst,	/* resize leftmost contained frame first */
3100     int		wfw)		/* obey 'winfixwidth' when there is a choice;
3101 				   may cause the width not to be set */
3102 {
3103     frame_T	*frp;
3104     int		extra_cols;
3105     int		w;
3106     win_T	*wp;
3107 
3108     if (topfrp->fr_layout == FR_LEAF)
3109     {
3110 	/* Simple case: just one window. */
3111 	wp = topfrp->fr_win;
3112 	/* Find out if there are any windows right of this one. */
3113 	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
3114 	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
3115 		break;
3116 	if (frp->fr_parent == NULL)
3117 	    wp->w_vsep_width = 0;
3118 	win_new_width(wp, width - wp->w_vsep_width);
3119     }
3120     else if (topfrp->fr_layout == FR_COL)
3121     {
3122 	do
3123 	{
3124 	    /* All frames in this column get the same new width. */
3125 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3126 	    {
3127 		frame_new_width(frp, width, leftfirst, wfw);
3128 		if (frp->fr_width > width)
3129 		{
3130 		    /* Could not fit the windows, make whole column wider. */
3131 		    width = frp->fr_width;
3132 		    break;
3133 		}
3134 	    }
3135 	} while (frp != NULL);
3136     }
3137     else    /* fr_layout == FR_ROW */
3138     {
3139 	/* Complicated case: Resize a row of frames.  Resize the rightmost
3140 	 * frame first, frames left of it when needed. */
3141 
3142 	frp = topfrp->fr_child;
3143 	if (wfw)
3144 	    /* Advance past frames with one window with 'wfw' set. */
3145 	    while (frame_fixed_width(frp))
3146 	    {
3147 		frp = frp->fr_next;
3148 		if (frp == NULL)
3149 		    return;	    /* no frame without 'wfw', give up */
3150 	    }
3151 	if (!leftfirst)
3152 	{
3153 	    /* Find the rightmost frame of this row */
3154 	    while (frp->fr_next != NULL)
3155 		frp = frp->fr_next;
3156 	    if (wfw)
3157 		/* Advance back for frames with one window with 'wfw' set. */
3158 		while (frame_fixed_width(frp))
3159 		    frp = frp->fr_prev;
3160 	}
3161 
3162 	extra_cols = width - topfrp->fr_width;
3163 	if (extra_cols < 0)
3164 	{
3165 	    /* reduce frame width, rightmost frame first */
3166 	    while (frp != NULL)
3167 	    {
3168 		w = frame_minwidth(frp, NULL);
3169 		if (frp->fr_width + extra_cols < w)
3170 		{
3171 		    extra_cols += frp->fr_width - w;
3172 		    frame_new_width(frp, w, leftfirst, wfw);
3173 		}
3174 		else
3175 		{
3176 		    frame_new_width(frp, frp->fr_width + extra_cols,
3177 							      leftfirst, wfw);
3178 		    break;
3179 		}
3180 		if (leftfirst)
3181 		{
3182 		    do
3183 			frp = frp->fr_next;
3184 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3185 		}
3186 		else
3187 		{
3188 		    do
3189 			frp = frp->fr_prev;
3190 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3191 		}
3192 		/* Increase "width" if we could not reduce enough frames. */
3193 		if (frp == NULL)
3194 		    width -= extra_cols;
3195 	    }
3196 	}
3197 	else if (extra_cols > 0)
3198 	{
3199 	    /* increase width of rightmost frame */
3200 	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
3201 	}
3202     }
3203     topfrp->fr_width = width;
3204 }
3205 
3206 /*
3207  * Add the vertical separator to windows at the right side of "frp".
3208  * Note: Does not check if there is room!
3209  */
3210     static void
3211 frame_add_vsep(frame_T *frp)
3212 {
3213     win_T	*wp;
3214 
3215     if (frp->fr_layout == FR_LEAF)
3216     {
3217 	wp = frp->fr_win;
3218 	if (wp->w_vsep_width == 0)
3219 	{
3220 	    if (wp->w_width > 0)	/* don't make it negative */
3221 		--wp->w_width;
3222 	    wp->w_vsep_width = 1;
3223 	}
3224     }
3225     else if (frp->fr_layout == FR_COL)
3226     {
3227 	/* Handle all the frames in the column. */
3228 	FOR_ALL_FRAMES(frp, frp->fr_child)
3229 	    frame_add_vsep(frp);
3230     }
3231     else /* frp->fr_layout == FR_ROW */
3232     {
3233 	/* Only need to handle the last frame in the row. */
3234 	frp = frp->fr_child;
3235 	while (frp->fr_next != NULL)
3236 	    frp = frp->fr_next;
3237 	frame_add_vsep(frp);
3238     }
3239 }
3240 
3241 /*
3242  * Set frame width from the window it contains.
3243  */
3244     static void
3245 frame_fix_width(win_T *wp)
3246 {
3247     wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
3248 }
3249 
3250 /*
3251  * Set frame height from the window it contains.
3252  */
3253     static void
3254 frame_fix_height(win_T *wp)
3255 {
3256     wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
3257 }
3258 
3259 /*
3260  * Compute the minimal height for frame "topfrp".
3261  * Uses the 'winminheight' option.
3262  * When "next_curwin" isn't NULL, use p_wh for this window.
3263  * When "next_curwin" is NOWIN, don't use at least one line for the current
3264  * window.
3265  */
3266     static int
3267 frame_minheight(frame_T *topfrp, win_T *next_curwin)
3268 {
3269     frame_T	*frp;
3270     int		m;
3271     int		n;
3272 
3273     if (topfrp->fr_win != NULL)
3274     {
3275 	if (topfrp->fr_win == next_curwin)
3276 	    m = p_wh + topfrp->fr_win->w_status_height;
3277 	else
3278 	{
3279 	    /* window: minimal height of the window plus status line */
3280 	    m = p_wmh + topfrp->fr_win->w_status_height;
3281 	    if (topfrp->fr_win == curwin && next_curwin == NULL)
3282 	    {
3283 		/* Current window is minimal one line high and WinBar is
3284 		 * visible. */
3285 		if (p_wmh == 0)
3286 		    ++m;
3287 		m += WINBAR_HEIGHT(curwin);
3288 	    }
3289 	}
3290     }
3291     else if (topfrp->fr_layout == FR_ROW)
3292     {
3293 	/* get the minimal height from each frame in this row */
3294 	m = 0;
3295 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3296 	{
3297 	    n = frame_minheight(frp, next_curwin);
3298 	    if (n > m)
3299 		m = n;
3300 	}
3301     }
3302     else
3303     {
3304 	/* Add up the minimal heights for all frames in this column. */
3305 	m = 0;
3306 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3307 	    m += frame_minheight(frp, next_curwin);
3308     }
3309 
3310     return m;
3311 }
3312 
3313 /*
3314  * Compute the minimal width for frame "topfrp".
3315  * When "next_curwin" isn't NULL, use p_wiw for this window.
3316  * When "next_curwin" is NOWIN, don't use at least one column for the current
3317  * window.
3318  */
3319     static int
3320 frame_minwidth(
3321     frame_T	*topfrp,
3322     win_T	*next_curwin)	/* use p_wh and p_wiw for next_curwin */
3323 {
3324     frame_T	*frp;
3325     int		m, n;
3326 
3327     if (topfrp->fr_win != NULL)
3328     {
3329 	if (topfrp->fr_win == next_curwin)
3330 	    m = p_wiw + topfrp->fr_win->w_vsep_width;
3331 	else
3332 	{
3333 	    /* window: minimal width of the window plus separator column */
3334 	    m = p_wmw + topfrp->fr_win->w_vsep_width;
3335 	    /* Current window is minimal one column wide */
3336 	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
3337 		++m;
3338 	}
3339     }
3340     else if (topfrp->fr_layout == FR_COL)
3341     {
3342 	/* get the minimal width from each frame in this column */
3343 	m = 0;
3344 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3345 	{
3346 	    n = frame_minwidth(frp, next_curwin);
3347 	    if (n > m)
3348 		m = n;
3349 	}
3350     }
3351     else
3352     {
3353 	/* Add up the minimal widths for all frames in this row. */
3354 	m = 0;
3355 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3356 	    m += frame_minwidth(frp, next_curwin);
3357     }
3358 
3359     return m;
3360 }
3361 
3362 
3363 /*
3364  * Try to close all windows except current one.
3365  * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
3366  * used and the buffer was modified.
3367  *
3368  * Used by ":bdel" and ":only".
3369  */
3370     void
3371 close_others(
3372     int		message,
3373     int		forceit)	    /* always hide all other windows */
3374 {
3375     win_T	*wp;
3376     win_T	*nextwp;
3377     int		r;
3378 
3379     if (one_window())
3380     {
3381 	if (message && !autocmd_busy)
3382 	    msg(_(m_onlyone));
3383 	return;
3384     }
3385 
3386     /* Be very careful here: autocommands may change the window layout. */
3387     for (wp = firstwin; win_valid(wp); wp = nextwp)
3388     {
3389 	nextwp = wp->w_next;
3390 	if (wp != curwin)		/* don't close current window */
3391 	{
3392 
3393 	    /* Check if it's allowed to abandon this window */
3394 	    r = can_abandon(wp->w_buffer, forceit);
3395 	    if (!win_valid(wp))		/* autocommands messed wp up */
3396 	    {
3397 		nextwp = firstwin;
3398 		continue;
3399 	    }
3400 	    if (!r)
3401 	    {
3402 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
3403 		if (message && (p_confirm || cmdmod.confirm) && p_write)
3404 		{
3405 		    dialog_changed(wp->w_buffer, FALSE);
3406 		    if (!win_valid(wp))		/* autocommands messed wp up */
3407 		    {
3408 			nextwp = firstwin;
3409 			continue;
3410 		    }
3411 		}
3412 		if (bufIsChanged(wp->w_buffer))
3413 #endif
3414 		    continue;
3415 	    }
3416 	    win_close(wp, !buf_hide(wp->w_buffer)
3417 					       && !bufIsChanged(wp->w_buffer));
3418 	}
3419     }
3420 
3421     if (message && !ONE_WINDOW)
3422 	emsg(_("E445: Other window contains changes"));
3423 }
3424 
3425 /*
3426  * Init the current window "curwin".
3427  * Called when a new file is being edited.
3428  */
3429     void
3430 curwin_init(void)
3431 {
3432     win_init_empty(curwin);
3433 }
3434 
3435     void
3436 win_init_empty(win_T *wp)
3437 {
3438     redraw_win_later(wp, NOT_VALID);
3439     wp->w_lines_valid = 0;
3440     wp->w_cursor.lnum = 1;
3441     wp->w_curswant = wp->w_cursor.col = 0;
3442     wp->w_cursor.coladd = 0;
3443     wp->w_pcmark.lnum = 1;	/* pcmark not cleared but set to line 1 */
3444     wp->w_pcmark.col = 0;
3445     wp->w_prev_pcmark.lnum = 0;
3446     wp->w_prev_pcmark.col = 0;
3447     wp->w_topline = 1;
3448 #ifdef FEAT_DIFF
3449     wp->w_topfill = 0;
3450 #endif
3451     wp->w_botline = 2;
3452 #ifdef FEAT_FKMAP
3453     if (wp->w_p_rl)
3454 	wp->w_farsi = W_CONV + W_R_L;
3455     else
3456 	wp->w_farsi = W_CONV;
3457 #endif
3458 #ifdef FEAT_SYN_HL
3459     wp->w_s = &wp->w_buffer->b_s;
3460 #endif
3461 }
3462 
3463 /*
3464  * Allocate the first window and put an empty buffer in it.
3465  * Called from main().
3466  * Return FAIL when something goes wrong (out of memory).
3467  */
3468     int
3469 win_alloc_first(void)
3470 {
3471     if (win_alloc_firstwin(NULL) == FAIL)
3472 	return FAIL;
3473 
3474     first_tabpage = alloc_tabpage();
3475     if (first_tabpage == NULL)
3476 	return FAIL;
3477     first_tabpage->tp_topframe = topframe;
3478     curtab = first_tabpage;
3479 
3480     return OK;
3481 }
3482 
3483 /*
3484  * Init "aucmd_win".  This can only be done after the first
3485  * window is fully initialized, thus it can't be in win_alloc_first().
3486  */
3487     void
3488 win_alloc_aucmd_win(void)
3489 {
3490     aucmd_win = win_alloc(NULL, TRUE);
3491     if (aucmd_win != NULL)
3492     {
3493 	win_init_some(aucmd_win, curwin);
3494 	RESET_BINDING(aucmd_win);
3495 	new_frame(aucmd_win);
3496     }
3497 }
3498 
3499 /*
3500  * Allocate the first window or the first window in a new tab page.
3501  * When "oldwin" is NULL create an empty buffer for it.
3502  * When "oldwin" is not NULL copy info from it to the new window.
3503  * Return FAIL when something goes wrong (out of memory).
3504  */
3505     static int
3506 win_alloc_firstwin(win_T *oldwin)
3507 {
3508     curwin = win_alloc(NULL, FALSE);
3509     if (oldwin == NULL)
3510     {
3511 	/* Very first window, need to create an empty buffer for it and
3512 	 * initialize from scratch. */
3513 	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
3514 	if (curwin == NULL || curbuf == NULL)
3515 	    return FAIL;
3516 	curwin->w_buffer = curbuf;
3517 #ifdef FEAT_SYN_HL
3518 	curwin->w_s = &(curbuf->b_s);
3519 #endif
3520 	curbuf->b_nwindows = 1;	/* there is one window */
3521 	curwin->w_alist = &global_alist;
3522 	curwin_init();		/* init current window */
3523     }
3524     else
3525     {
3526 	/* First window in new tab page, initialize it from "oldwin". */
3527 	win_init(curwin, oldwin, 0);
3528 
3529 	/* We don't want cursor- and scroll-binding in the first window. */
3530 	RESET_BINDING(curwin);
3531     }
3532 
3533     new_frame(curwin);
3534     if (curwin->w_frame == NULL)
3535 	return FAIL;
3536     topframe = curwin->w_frame;
3537     topframe->fr_width = Columns;
3538     topframe->fr_height = Rows - p_ch;
3539 
3540     return OK;
3541 }
3542 
3543 /*
3544  * Create a frame for window "wp".
3545  */
3546     static void
3547 new_frame(win_T *wp)
3548 {
3549     frame_T *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
3550 
3551     wp->w_frame = frp;
3552     if (frp != NULL)
3553     {
3554 	frp->fr_layout = FR_LEAF;
3555 	frp->fr_win = wp;
3556     }
3557 }
3558 
3559 /*
3560  * Initialize the window and frame size to the maximum.
3561  */
3562     void
3563 win_init_size(void)
3564 {
3565     firstwin->w_height = ROWS_AVAIL;
3566     topframe->fr_height = ROWS_AVAIL;
3567     firstwin->w_width = Columns;
3568     topframe->fr_width = Columns;
3569 }
3570 
3571 /*
3572  * Allocate a new tabpage_T and init the values.
3573  * Returns NULL when out of memory.
3574  */
3575     static tabpage_T *
3576 alloc_tabpage(void)
3577 {
3578     tabpage_T	*tp;
3579 # ifdef FEAT_GUI
3580     int		i;
3581 # endif
3582 
3583 
3584     tp = (tabpage_T *)alloc_clear((unsigned)sizeof(tabpage_T));
3585     if (tp == NULL)
3586 	return NULL;
3587 
3588 # ifdef FEAT_EVAL
3589     /* init t: variables */
3590     tp->tp_vars = dict_alloc();
3591     if (tp->tp_vars == NULL)
3592     {
3593 	vim_free(tp);
3594 	return NULL;
3595     }
3596     init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
3597 # endif
3598 
3599 # ifdef FEAT_GUI
3600     for (i = 0; i < 3; i++)
3601 	tp->tp_prev_which_scrollbars[i] = -1;
3602 # endif
3603 # ifdef FEAT_DIFF
3604     tp->tp_diff_invalid = TRUE;
3605 # endif
3606     tp->tp_ch_used = p_ch;
3607 
3608     return tp;
3609 }
3610 
3611     void
3612 free_tabpage(tabpage_T *tp)
3613 {
3614     int idx;
3615 
3616 # ifdef FEAT_DIFF
3617     diff_clear(tp);
3618 # endif
3619     for (idx = 0; idx < SNAP_COUNT; ++idx)
3620 	clear_snapshot(tp, idx);
3621 #ifdef FEAT_EVAL
3622     vars_clear(&tp->tp_vars->dv_hashtab);	/* free all t: variables */
3623     hash_init(&tp->tp_vars->dv_hashtab);
3624     unref_var_dict(tp->tp_vars);
3625 #endif
3626 
3627 #ifdef FEAT_PYTHON
3628     python_tabpage_free(tp);
3629 #endif
3630 
3631 #ifdef FEAT_PYTHON3
3632     python3_tabpage_free(tp);
3633 #endif
3634 
3635     vim_free(tp);
3636 }
3637 
3638 /*
3639  * Create a new Tab page with one window.
3640  * It will edit the current buffer, like after ":split".
3641  * When "after" is 0 put it just after the current Tab page.
3642  * Otherwise put it just before tab page "after".
3643  * Return FAIL or OK.
3644  */
3645     int
3646 win_new_tabpage(int after)
3647 {
3648     tabpage_T	*tp = curtab;
3649     tabpage_T	*newtp;
3650     int		n;
3651 
3652     newtp = alloc_tabpage();
3653     if (newtp == NULL)
3654 	return FAIL;
3655 
3656     /* Remember the current windows in this Tab page. */
3657     if (leave_tabpage(curbuf, TRUE) == FAIL)
3658     {
3659 	vim_free(newtp);
3660 	return FAIL;
3661     }
3662     curtab = newtp;
3663 
3664     /* Create a new empty window. */
3665     if (win_alloc_firstwin(tp->tp_curwin) == OK)
3666     {
3667 	/* Make the new Tab page the new topframe. */
3668 	if (after == 1)
3669 	{
3670 	    /* New tab page becomes the first one. */
3671 	    newtp->tp_next = first_tabpage;
3672 	    first_tabpage = newtp;
3673 	}
3674 	else
3675 	{
3676 	    if (after > 0)
3677 	    {
3678 		/* Put new tab page before tab page "after". */
3679 		n = 2;
3680 		for (tp = first_tabpage; tp->tp_next != NULL
3681 					       && n < after; tp = tp->tp_next)
3682 		    ++n;
3683 	    }
3684 	    newtp->tp_next = tp->tp_next;
3685 	    tp->tp_next = newtp;
3686 	}
3687 	win_init_size();
3688 	firstwin->w_winrow = tabline_height();
3689 	win_comp_scroll(curwin);
3690 
3691 	newtp->tp_topframe = topframe;
3692 	last_status(FALSE);
3693 
3694 #if defined(FEAT_GUI)
3695 	/* When 'guioptions' includes 'L' or 'R' may have to remove or add
3696 	 * scrollbars.  Have to update them anyway. */
3697 	gui_may_update_scrollbars();
3698 #endif
3699 #ifdef FEAT_JOB_CHANNEL
3700 	entering_window(curwin);
3701 #endif
3702 
3703 	redraw_all_later(NOT_VALID);
3704 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
3705 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
3706 	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
3707 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3708 	return OK;
3709     }
3710 
3711     /* Failed, get back the previous Tab page */
3712     enter_tabpage(curtab, curbuf, TRUE, TRUE);
3713     return FAIL;
3714 }
3715 
3716 /*
3717  * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
3718  * like with ":split".
3719  * Returns OK if a new tab page was created, FAIL otherwise.
3720  */
3721     int
3722 may_open_tabpage(void)
3723 {
3724     int		n = (cmdmod.tab == 0) ? postponed_split_tab : cmdmod.tab;
3725 
3726     if (n != 0)
3727     {
3728 	cmdmod.tab = 0;	    /* reset it to avoid doing it twice */
3729 	postponed_split_tab = 0;
3730 	return win_new_tabpage(n);
3731     }
3732     return FAIL;
3733 }
3734 
3735 /*
3736  * Create up to "maxcount" tabpages with empty windows.
3737  * Returns the number of resulting tab pages.
3738  */
3739     int
3740 make_tabpages(int maxcount)
3741 {
3742     int		count = maxcount;
3743     int		todo;
3744 
3745     /* Limit to 'tabpagemax' tabs. */
3746     if (count > p_tpm)
3747 	count = p_tpm;
3748 
3749     /*
3750      * Don't execute autocommands while creating the tab pages.  Must do that
3751      * when putting the buffers in the windows.
3752      */
3753     block_autocmds();
3754 
3755     for (todo = count - 1; todo > 0; --todo)
3756 	if (win_new_tabpage(0) == FAIL)
3757 	    break;
3758 
3759     unblock_autocmds();
3760 
3761     /* return actual number of tab pages */
3762     return (count - todo);
3763 }
3764 
3765 /*
3766  * Return TRUE when "tpc" points to a valid tab page.
3767  */
3768     int
3769 valid_tabpage(tabpage_T *tpc)
3770 {
3771     tabpage_T	*tp;
3772 
3773     FOR_ALL_TABPAGES(tp)
3774 	if (tp == tpc)
3775 	    return TRUE;
3776     return FALSE;
3777 }
3778 
3779 /*
3780  * Return TRUE when "tpc" points to a valid tab page and at least one window is
3781  * valid.
3782  */
3783     int
3784 valid_tabpage_win(tabpage_T *tpc)
3785 {
3786     tabpage_T	*tp;
3787     win_T	*wp;
3788 
3789     FOR_ALL_TABPAGES(tp)
3790     {
3791 	if (tp == tpc)
3792 	{
3793 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
3794 	    {
3795 		if (win_valid_any_tab(wp))
3796 		    return TRUE;
3797 	    }
3798 	    return FALSE;
3799 	}
3800     }
3801     /* shouldn't happen */
3802     return FALSE;
3803 }
3804 
3805 /*
3806  * Close tabpage "tab", assuming it has no windows in it.
3807  * There must be another tabpage or this will crash.
3808  */
3809     void
3810 close_tabpage(tabpage_T *tab)
3811 {
3812     tabpage_T	*ptp;
3813 
3814     if (tab == first_tabpage)
3815     {
3816 	first_tabpage = tab->tp_next;
3817 	ptp = first_tabpage;
3818     }
3819     else
3820     {
3821 	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
3822 							    ptp = ptp->tp_next)
3823 	    ;
3824 	assert(ptp != NULL);
3825 	ptp->tp_next = tab->tp_next;
3826     }
3827 
3828     goto_tabpage_tp(ptp, FALSE, FALSE);
3829     free_tabpage(tab);
3830 }
3831 
3832 /*
3833  * Find tab page "n" (first one is 1).  Returns NULL when not found.
3834  */
3835     tabpage_T *
3836 find_tabpage(int n)
3837 {
3838     tabpage_T	*tp;
3839     int		i = 1;
3840 
3841     for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
3842 	++i;
3843     return tp;
3844 }
3845 
3846 /*
3847  * Get index of tab page "tp".  First one has index 1.
3848  * When not found returns number of tab pages plus one.
3849  */
3850     int
3851 tabpage_index(tabpage_T *ftp)
3852 {
3853     int		i = 1;
3854     tabpage_T	*tp;
3855 
3856     for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
3857 	++i;
3858     return i;
3859 }
3860 
3861 /*
3862  * Prepare for leaving the current tab page.
3863  * When autocommands change "curtab" we don't leave the tab page and return
3864  * FAIL.
3865  * Careful: When OK is returned need to get a new tab page very very soon!
3866  */
3867     static int
3868 leave_tabpage(
3869     buf_T	*new_curbuf UNUSED,    /* what is going to be the new curbuf,
3870 				       NULL if unknown */
3871     int		trigger_leave_autocmds UNUSED)
3872 {
3873     tabpage_T	*tp = curtab;
3874 
3875 #ifdef FEAT_JOB_CHANNEL
3876     leaving_window(curwin);
3877 #endif
3878     reset_VIsual_and_resel();	/* stop Visual mode */
3879     if (trigger_leave_autocmds)
3880     {
3881 	if (new_curbuf != curbuf)
3882 	{
3883 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
3884 	    if (curtab != tp)
3885 		return FAIL;
3886 	}
3887 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
3888 	if (curtab != tp)
3889 	    return FAIL;
3890 	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
3891 	if (curtab != tp)
3892 	    return FAIL;
3893     }
3894 #if defined(FEAT_GUI)
3895     /* Remove the scrollbars.  They may be added back later. */
3896     if (gui.in_use)
3897 	gui_remove_scrollbars();
3898 #endif
3899     tp->tp_curwin = curwin;
3900     tp->tp_prevwin = prevwin;
3901     tp->tp_firstwin = firstwin;
3902     tp->tp_lastwin = lastwin;
3903     tp->tp_old_Rows = Rows;
3904     tp->tp_old_Columns = Columns;
3905     firstwin = NULL;
3906     lastwin = NULL;
3907     return OK;
3908 }
3909 
3910 /*
3911  * Start using tab page "tp".
3912  * Only to be used after leave_tabpage() or freeing the current tab page.
3913  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
3914  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
3915  */
3916     static void
3917 enter_tabpage(
3918     tabpage_T	*tp,
3919     buf_T	*old_curbuf UNUSED,
3920     int		trigger_enter_autocmds,
3921     int		trigger_leave_autocmds)
3922 {
3923     int		old_off = tp->tp_firstwin->w_winrow;
3924     win_T	*next_prevwin = tp->tp_prevwin;
3925 
3926     curtab = tp;
3927     firstwin = tp->tp_firstwin;
3928     lastwin = tp->tp_lastwin;
3929     topframe = tp->tp_topframe;
3930 
3931     /* We would like doing the TabEnter event first, but we don't have a
3932      * valid current window yet, which may break some commands.
3933      * This triggers autocommands, thus may make "tp" invalid. */
3934     win_enter_ext(tp->tp_curwin, FALSE, TRUE, FALSE,
3935 			      trigger_enter_autocmds, trigger_leave_autocmds);
3936     prevwin = next_prevwin;
3937 
3938     last_status(FALSE);		/* status line may appear or disappear */
3939     (void)win_comp_pos();	/* recompute w_winrow for all windows */
3940 #ifdef FEAT_DIFF
3941     diff_need_scrollbind = TRUE;
3942 #endif
3943 
3944     /* The tabpage line may have appeared or disappeared, may need to resize
3945      * the frames for that.  When the Vim window was resized need to update
3946      * frame sizes too.  Use the stored value of p_ch, so that it can be
3947      * different for each tab page. */
3948     p_ch = curtab->tp_ch_used;
3949     if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
3950 #ifdef FEAT_GUI_TABLINE
3951 			    && !gui_use_tabline()
3952 #endif
3953 		))
3954 	shell_new_rows();
3955     if (curtab->tp_old_Columns != Columns && starting == 0)
3956 	shell_new_columns();	/* update window widths */
3957 
3958 #if defined(FEAT_GUI)
3959     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
3960      * scrollbars.  Have to update them anyway. */
3961     gui_may_update_scrollbars();
3962 #endif
3963 
3964     /* Apply autocommands after updating the display, when 'rows' and
3965      * 'columns' have been set correctly. */
3966     if (trigger_enter_autocmds)
3967     {
3968 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3969 	if (old_curbuf != curbuf)
3970 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
3971     }
3972 
3973     redraw_all_later(NOT_VALID);
3974 }
3975 
3976 /*
3977  * Go to tab page "n".  For ":tab N" and "Ngt".
3978  * When "n" is 9999 go to the last tab page.
3979  */
3980     void
3981 goto_tabpage(int n)
3982 {
3983     tabpage_T	*tp;
3984     tabpage_T	*ttp;
3985     int		i;
3986 
3987     if (text_locked())
3988     {
3989 	/* Not allowed when editing the command line. */
3990 	text_locked_msg();
3991 	return;
3992     }
3993 
3994     /* If there is only one it can't work. */
3995     if (first_tabpage->tp_next == NULL)
3996     {
3997 	if (n > 1)
3998 	    beep_flush();
3999 	return;
4000     }
4001 
4002     if (n == 0)
4003     {
4004 	/* No count, go to next tab page, wrap around end. */
4005 	if (curtab->tp_next == NULL)
4006 	    tp = first_tabpage;
4007 	else
4008 	    tp = curtab->tp_next;
4009     }
4010     else if (n < 0)
4011     {
4012 	/* "gT": go to previous tab page, wrap around end.  "N gT" repeats
4013 	 * this N times. */
4014 	ttp = curtab;
4015 	for (i = n; i < 0; ++i)
4016 	{
4017 	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
4018 		    tp = tp->tp_next)
4019 		;
4020 	    ttp = tp;
4021 	}
4022     }
4023     else if (n == 9999)
4024     {
4025 	/* Go to last tab page. */
4026 	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
4027 	    ;
4028     }
4029     else
4030     {
4031 	/* Go to tab page "n". */
4032 	tp = find_tabpage(n);
4033 	if (tp == NULL)
4034 	{
4035 	    beep_flush();
4036 	    return;
4037 	}
4038     }
4039 
4040     goto_tabpage_tp(tp, TRUE, TRUE);
4041 
4042 #ifdef FEAT_GUI_TABLINE
4043     if (gui_use_tabline())
4044 	gui_mch_set_curtab(tabpage_index(curtab));
4045 #endif
4046 }
4047 
4048 /*
4049  * Go to tabpage "tp".
4050  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4051  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4052  * Note: doesn't update the GUI tab.
4053  */
4054     void
4055 goto_tabpage_tp(
4056     tabpage_T	*tp,
4057     int		trigger_enter_autocmds,
4058     int		trigger_leave_autocmds)
4059 {
4060     /* Don't repeat a message in another tab page. */
4061     set_keep_msg(NULL, 0);
4062 
4063     if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
4064 					trigger_leave_autocmds) == OK)
4065     {
4066 	if (valid_tabpage(tp))
4067 	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
4068 		    trigger_leave_autocmds);
4069 	else
4070 	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
4071 		    trigger_leave_autocmds);
4072     }
4073 }
4074 
4075 /*
4076  * Enter window "wp" in tab page "tp".
4077  * Also updates the GUI tab.
4078  */
4079     void
4080 goto_tabpage_win(tabpage_T *tp, win_T *wp)
4081 {
4082     goto_tabpage_tp(tp, TRUE, TRUE);
4083     if (curtab == tp && win_valid(wp))
4084     {
4085 	win_enter(wp, TRUE);
4086 # ifdef FEAT_GUI_TABLINE
4087 	if (gui_use_tabline())
4088 	    gui_mch_set_curtab(tabpage_index(curtab));
4089 # endif
4090     }
4091 }
4092 
4093 /*
4094  * Move the current tab page to after tab page "nr".
4095  */
4096     void
4097 tabpage_move(int nr)
4098 {
4099     int		n = 1;
4100     tabpage_T	*tp, *tp_dst;
4101 
4102     if (first_tabpage->tp_next == NULL)
4103 	return;
4104 
4105     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
4106 	++n;
4107 
4108     if (tp == curtab || (nr > 0 && tp->tp_next != NULL
4109 						    && tp->tp_next == curtab))
4110 	return;
4111 
4112     tp_dst = tp;
4113 
4114     /* Remove the current tab page from the list of tab pages. */
4115     if (curtab == first_tabpage)
4116 	first_tabpage = curtab->tp_next;
4117     else
4118     {
4119 	FOR_ALL_TABPAGES(tp)
4120 	    if (tp->tp_next == curtab)
4121 		break;
4122 	if (tp == NULL)	/* "cannot happen" */
4123 	    return;
4124 	tp->tp_next = curtab->tp_next;
4125     }
4126 
4127     /* Re-insert it at the specified position. */
4128     if (nr <= 0)
4129     {
4130 	curtab->tp_next = first_tabpage;
4131 	first_tabpage = curtab;
4132     }
4133     else
4134     {
4135 	curtab->tp_next = tp_dst->tp_next;
4136 	tp_dst->tp_next = curtab;
4137     }
4138 
4139     /* Need to redraw the tabline.  Tab page contents doesn't change. */
4140     redraw_tabline = TRUE;
4141 }
4142 
4143 
4144 /*
4145  * Go to another window.
4146  * When jumping to another buffer, stop Visual mode.  Do this before
4147  * changing windows so we can yank the selection into the '*' register.
4148  * When jumping to another window on the same buffer, adjust its cursor
4149  * position to keep the same Visual area.
4150  */
4151     void
4152 win_goto(win_T *wp)
4153 {
4154 #ifdef FEAT_CONCEAL
4155     win_T	*owp = curwin;
4156 #endif
4157 
4158     if (text_locked())
4159     {
4160 	beep_flush();
4161 	text_locked_msg();
4162 	return;
4163     }
4164     if (curbuf_locked())
4165 	return;
4166 
4167     if (wp->w_buffer != curbuf)
4168 	reset_VIsual_and_resel();
4169     else if (VIsual_active)
4170 	wp->w_cursor = curwin->w_cursor;
4171 
4172 #ifdef FEAT_GUI
4173     need_mouse_correct = TRUE;
4174 #endif
4175     win_enter(wp, TRUE);
4176 
4177 #ifdef FEAT_CONCEAL
4178     // Conceal cursor line in previous window, unconceal in current window.
4179     if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
4180 	redrawWinline(owp, owp->w_cursor.lnum);
4181     if (curwin->w_p_cole > 0 && !msg_scrolled)
4182 	need_cursor_line_redraw = TRUE;
4183 #endif
4184 }
4185 
4186 #if defined(FEAT_PERL) || defined(PROTO)
4187 /*
4188  * Find window number "winnr" (counting top to bottom).
4189  */
4190     win_T *
4191 win_find_nr(int winnr)
4192 {
4193     win_T	*wp;
4194 
4195     FOR_ALL_WINDOWS(wp)
4196 	if (--winnr == 0)
4197 	    break;
4198     return wp;
4199 }
4200 #endif
4201 
4202 #if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
4203 /*
4204  * Find the tabpage for window "win".
4205  */
4206     tabpage_T *
4207 win_find_tabpage(win_T *win)
4208 {
4209     win_T	*wp;
4210     tabpage_T	*tp;
4211 
4212     FOR_ALL_TAB_WINDOWS(tp, wp)
4213 	    if (wp == win)
4214 		return tp;
4215     return NULL;
4216 }
4217 #endif
4218 
4219 /*
4220  * Move to window above or below "count" times.
4221  */
4222     static void
4223 win_goto_ver(
4224     int		up,		/* TRUE to go to win above */
4225     long	count)
4226 {
4227     frame_T	*fr;
4228     frame_T	*nfr;
4229     frame_T	*foundfr;
4230 
4231     foundfr = curwin->w_frame;
4232     while (count--)
4233     {
4234 	/*
4235 	 * First go upwards in the tree of frames until we find a upwards or
4236 	 * downwards neighbor.
4237 	 */
4238 	fr = foundfr;
4239 	for (;;)
4240 	{
4241 	    if (fr == topframe)
4242 		goto end;
4243 	    if (up)
4244 		nfr = fr->fr_prev;
4245 	    else
4246 		nfr = fr->fr_next;
4247 	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
4248 		break;
4249 	    fr = fr->fr_parent;
4250 	}
4251 
4252 	/*
4253 	 * Now go downwards to find the bottom or top frame in it.
4254 	 */
4255 	for (;;)
4256 	{
4257 	    if (nfr->fr_layout == FR_LEAF)
4258 	    {
4259 		foundfr = nfr;
4260 		break;
4261 	    }
4262 	    fr = nfr->fr_child;
4263 	    if (nfr->fr_layout == FR_ROW)
4264 	    {
4265 		/* Find the frame at the cursor row. */
4266 		while (fr->fr_next != NULL
4267 			&& frame2win(fr)->w_wincol + fr->fr_width
4268 					 <= curwin->w_wincol + curwin->w_wcol)
4269 		    fr = fr->fr_next;
4270 	    }
4271 	    if (nfr->fr_layout == FR_COL && up)
4272 		while (fr->fr_next != NULL)
4273 		    fr = fr->fr_next;
4274 	    nfr = fr;
4275 	}
4276     }
4277 end:
4278     if (foundfr != NULL)
4279 	win_goto(foundfr->fr_win);
4280 }
4281 
4282 /*
4283  * Move to left or right window.
4284  */
4285     static void
4286 win_goto_hor(
4287     int		left,		/* TRUE to go to left win */
4288     long	count)
4289 {
4290     frame_T	*fr;
4291     frame_T	*nfr;
4292     frame_T	*foundfr;
4293 
4294     foundfr = curwin->w_frame;
4295     while (count--)
4296     {
4297 	/*
4298 	 * First go upwards in the tree of frames until we find a left or
4299 	 * right neighbor.
4300 	 */
4301 	fr = foundfr;
4302 	for (;;)
4303 	{
4304 	    if (fr == topframe)
4305 		goto end;
4306 	    if (left)
4307 		nfr = fr->fr_prev;
4308 	    else
4309 		nfr = fr->fr_next;
4310 	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
4311 		break;
4312 	    fr = fr->fr_parent;
4313 	}
4314 
4315 	/*
4316 	 * Now go downwards to find the leftmost or rightmost frame in it.
4317 	 */
4318 	for (;;)
4319 	{
4320 	    if (nfr->fr_layout == FR_LEAF)
4321 	    {
4322 		foundfr = nfr;
4323 		break;
4324 	    }
4325 	    fr = nfr->fr_child;
4326 	    if (nfr->fr_layout == FR_COL)
4327 	    {
4328 		/* Find the frame at the cursor row. */
4329 		while (fr->fr_next != NULL
4330 			&& frame2win(fr)->w_winrow + fr->fr_height
4331 					 <= curwin->w_winrow + curwin->w_wrow)
4332 		    fr = fr->fr_next;
4333 	    }
4334 	    if (nfr->fr_layout == FR_ROW && left)
4335 		while (fr->fr_next != NULL)
4336 		    fr = fr->fr_next;
4337 	    nfr = fr;
4338 	}
4339     }
4340 end:
4341     if (foundfr != NULL)
4342 	win_goto(foundfr->fr_win);
4343 }
4344 
4345 /*
4346  * Make window "wp" the current window.
4347  */
4348     void
4349 win_enter(win_T *wp, int undo_sync)
4350 {
4351     win_enter_ext(wp, undo_sync, FALSE, FALSE, TRUE, TRUE);
4352 }
4353 
4354 /*
4355  * Make window wp the current window.
4356  * Can be called with "curwin_invalid" TRUE, which means that curwin has just
4357  * been closed and isn't valid.
4358  */
4359     static void
4360 win_enter_ext(
4361     win_T	*wp,
4362     int		undo_sync,
4363     int		curwin_invalid,
4364     int		trigger_new_autocmds,
4365     int		trigger_enter_autocmds,
4366     int		trigger_leave_autocmds)
4367 {
4368     int		other_buffer = FALSE;
4369 
4370     if (wp == curwin && !curwin_invalid)	/* nothing to do */
4371 	return;
4372 
4373 #ifdef FEAT_JOB_CHANNEL
4374     if (!curwin_invalid)
4375 	leaving_window(curwin);
4376 #endif
4377 
4378     if (!curwin_invalid && trigger_leave_autocmds)
4379     {
4380 	/*
4381 	 * Be careful: If autocommands delete the window, return now.
4382 	 */
4383 	if (wp->w_buffer != curbuf)
4384 	{
4385 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4386 	    other_buffer = TRUE;
4387 	    if (!win_valid(wp))
4388 		return;
4389 	}
4390 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4391 	if (!win_valid(wp))
4392 	    return;
4393 #ifdef FEAT_EVAL
4394 	/* autocmds may abort script processing */
4395 	if (aborting())
4396 	    return;
4397 #endif
4398     }
4399 
4400     /* sync undo before leaving the current buffer */
4401     if (undo_sync && curbuf != wp->w_buffer)
4402 	u_sync(FALSE);
4403 
4404     /* Might need to scroll the old window before switching, e.g., when the
4405      * cursor was moved. */
4406     update_topline();
4407 
4408     /* may have to copy the buffer options when 'cpo' contains 'S' */
4409     if (wp->w_buffer != curbuf)
4410 	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
4411     if (!curwin_invalid)
4412     {
4413 	prevwin = curwin;	/* remember for CTRL-W p */
4414 	curwin->w_redr_status = TRUE;
4415     }
4416     curwin = wp;
4417     curbuf = wp->w_buffer;
4418     check_cursor();
4419     if (!virtual_active())
4420 	curwin->w_cursor.coladd = 0;
4421     changed_line_abv_curs();	/* assume cursor position needs updating */
4422 
4423     if (curwin->w_localdir != NULL)
4424     {
4425 	/* Window has a local directory: Save current directory as global
4426 	 * directory (unless that was done already) and change to the local
4427 	 * directory. */
4428 	if (globaldir == NULL)
4429 	{
4430 	    char_u	cwd[MAXPATHL];
4431 
4432 	    if (mch_dirname(cwd, MAXPATHL) == OK)
4433 		globaldir = vim_strsave(cwd);
4434 	}
4435 	if (mch_chdir((char *)curwin->w_localdir) == 0)
4436 	    shorten_fnames(TRUE);
4437     }
4438     else if (globaldir != NULL)
4439     {
4440 	/* Window doesn't have a local directory and we are not in the global
4441 	 * directory: Change to the global directory. */
4442 	vim_ignored = mch_chdir((char *)globaldir);
4443 	VIM_CLEAR(globaldir);
4444 	shorten_fnames(TRUE);
4445     }
4446 
4447 #ifdef FEAT_JOB_CHANNEL
4448     entering_window(curwin);
4449 #endif
4450     if (trigger_new_autocmds)
4451 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
4452     if (trigger_enter_autocmds)
4453     {
4454 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
4455 	if (other_buffer)
4456 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4457     }
4458 
4459 #ifdef FEAT_TITLE
4460     maketitle();
4461 #endif
4462     curwin->w_redr_status = TRUE;
4463     redraw_tabline = TRUE;
4464     if (restart_edit)
4465 	redraw_later(VALID);	/* causes status line redraw */
4466 
4467     /* set window height to desired minimal value */
4468     if (curwin->w_height < p_wh && !curwin->w_p_wfh)
4469 	win_setheight((int)p_wh);
4470     else if (curwin->w_height == 0)
4471 	win_setheight(1);
4472 
4473     /* set window width to desired minimal value */
4474     if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
4475 	win_setwidth((int)p_wiw);
4476 
4477 #ifdef FEAT_MOUSE
4478     setmouse();			/* in case jumped to/from help buffer */
4479 #endif
4480 
4481     /* Change directories when the 'acd' option is set. */
4482     DO_AUTOCHDIR;
4483 }
4484 
4485 
4486 /*
4487  * Jump to the first open window that contains buffer "buf", if one exists.
4488  * Returns a pointer to the window found, otherwise NULL.
4489  */
4490     win_T *
4491 buf_jump_open_win(buf_T *buf)
4492 {
4493     win_T	*wp = NULL;
4494 
4495     if (curwin->w_buffer == buf)
4496 	wp = curwin;
4497     else
4498 	FOR_ALL_WINDOWS(wp)
4499 	    if (wp->w_buffer == buf)
4500 		break;
4501     if (wp != NULL)
4502 	win_enter(wp, FALSE);
4503     return wp;
4504 }
4505 
4506 /*
4507  * Jump to the first open window in any tab page that contains buffer "buf",
4508  * if one exists.
4509  * Returns a pointer to the window found, otherwise NULL.
4510  */
4511     win_T *
4512 buf_jump_open_tab(buf_T *buf)
4513 {
4514     win_T	*wp = buf_jump_open_win(buf);
4515     tabpage_T	*tp;
4516 
4517     if (wp != NULL)
4518 	return wp;
4519 
4520     FOR_ALL_TABPAGES(tp)
4521 	if (tp != curtab)
4522 	{
4523 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
4524 		if (wp->w_buffer == buf)
4525 		    break;
4526 	    if (wp != NULL)
4527 	    {
4528 		goto_tabpage_win(tp, wp);
4529 		if (curwin != wp)
4530 		    wp = NULL;	/* something went wrong */
4531 		break;
4532 	    }
4533 	}
4534     return wp;
4535 }
4536 
4537 static int last_win_id = LOWEST_WIN_ID - 1;
4538 
4539 /*
4540  * Allocate a window structure and link it in the window list when "hidden" is
4541  * FALSE.
4542  */
4543     static win_T *
4544 win_alloc(win_T *after UNUSED, int hidden UNUSED)
4545 {
4546     win_T	*new_wp;
4547 
4548     /*
4549      * allocate window structure and linesizes arrays
4550      */
4551     new_wp = (win_T *)alloc_clear((unsigned)sizeof(win_T));
4552     if (new_wp == NULL)
4553 	return NULL;
4554 
4555     if (win_alloc_lines(new_wp) == FAIL)
4556     {
4557 	vim_free(new_wp);
4558 	return NULL;
4559     }
4560 
4561     new_wp->w_id = ++last_win_id;
4562 
4563 #ifdef FEAT_EVAL
4564     /* init w: variables */
4565     new_wp->w_vars = dict_alloc();
4566     if (new_wp->w_vars == NULL)
4567     {
4568 	win_free_lsize(new_wp);
4569 	vim_free(new_wp);
4570 	return NULL;
4571     }
4572     init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
4573 #endif
4574 
4575     /* Don't execute autocommands while the window is not properly
4576      * initialized yet.  gui_create_scrollbar() may trigger a FocusGained
4577      * event. */
4578     block_autocmds();
4579 
4580     /*
4581      * link the window in the window list
4582      */
4583     if (!hidden)
4584 	win_append(after, new_wp);
4585     new_wp->w_wincol = 0;
4586     new_wp->w_width = Columns;
4587 
4588     /* position the display and the cursor at the top of the file. */
4589     new_wp->w_topline = 1;
4590 #ifdef FEAT_DIFF
4591     new_wp->w_topfill = 0;
4592 #endif
4593     new_wp->w_botline = 2;
4594     new_wp->w_cursor.lnum = 1;
4595     new_wp->w_scbind_pos = 1;
4596 
4597     /* We won't calculate w_fraction until resizing the window */
4598     new_wp->w_fraction = 0;
4599     new_wp->w_prev_fraction_row = -1;
4600 
4601 #ifdef FEAT_GUI
4602     if (gui.in_use)
4603     {
4604 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
4605 		SBAR_LEFT, new_wp);
4606 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
4607 		SBAR_RIGHT, new_wp);
4608     }
4609 #endif
4610 #ifdef FEAT_FOLDING
4611     foldInitWin(new_wp);
4612 #endif
4613     unblock_autocmds();
4614 #ifdef FEAT_SEARCH_EXTRA
4615     new_wp->w_match_head = NULL;
4616     new_wp->w_next_match_id = 4;
4617 #endif
4618     return new_wp;
4619 }
4620 
4621 /*
4622  * Remove window 'wp' from the window list and free the structure.
4623  */
4624     static void
4625 win_free(
4626     win_T	*wp,
4627     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4628 {
4629     int		i;
4630     buf_T	*buf;
4631     wininfo_T	*wip;
4632 
4633 #ifdef FEAT_FOLDING
4634     clearFolding(wp);
4635 #endif
4636 
4637     /* reduce the reference count to the argument list. */
4638     alist_unlink(wp->w_alist);
4639 
4640     /* Don't execute autocommands while the window is halfway being deleted.
4641      * gui_mch_destroy_scrollbar() may trigger a FocusGained event. */
4642     block_autocmds();
4643 
4644 #ifdef FEAT_LUA
4645     lua_window_free(wp);
4646 #endif
4647 
4648 #ifdef FEAT_MZSCHEME
4649     mzscheme_window_free(wp);
4650 #endif
4651 
4652 #ifdef FEAT_PERL
4653     perl_win_free(wp);
4654 #endif
4655 
4656 #ifdef FEAT_PYTHON
4657     python_window_free(wp);
4658 #endif
4659 
4660 #ifdef FEAT_PYTHON3
4661     python3_window_free(wp);
4662 #endif
4663 
4664 #ifdef FEAT_TCL
4665     tcl_window_free(wp);
4666 #endif
4667 
4668 #ifdef FEAT_RUBY
4669     ruby_window_free(wp);
4670 #endif
4671 
4672     clear_winopt(&wp->w_onebuf_opt);
4673     clear_winopt(&wp->w_allbuf_opt);
4674 
4675 #ifdef FEAT_EVAL
4676     vars_clear(&wp->w_vars->dv_hashtab);	/* free all w: variables */
4677     hash_init(&wp->w_vars->dv_hashtab);
4678     unref_var_dict(wp->w_vars);
4679 #endif
4680 
4681     {
4682 	tabpage_T	*ttp;
4683 
4684 	if (prevwin == wp)
4685 	    prevwin = NULL;
4686 	FOR_ALL_TABPAGES(ttp)
4687 	    if (ttp->tp_prevwin == wp)
4688 		ttp->tp_prevwin = NULL;
4689     }
4690     win_free_lsize(wp);
4691 
4692     for (i = 0; i < wp->w_tagstacklen; ++i)
4693 	vim_free(wp->w_tagstack[i].tagname);
4694 
4695     vim_free(wp->w_localdir);
4696 
4697     /* Remove the window from the b_wininfo lists, it may happen that the
4698      * freed memory is re-used for another window. */
4699     FOR_ALL_BUFFERS(buf)
4700 	for (wip = buf->b_wininfo; wip != NULL; wip = wip->wi_next)
4701 	    if (wip->wi_win == wp)
4702 		wip->wi_win = NULL;
4703 
4704 #ifdef FEAT_SEARCH_EXTRA
4705     clear_matches(wp);
4706 #endif
4707 
4708 #ifdef FEAT_JUMPLIST
4709     free_jumplist(wp);
4710 #endif
4711 
4712 #ifdef FEAT_QUICKFIX
4713     qf_free_all(wp);
4714 #endif
4715 
4716 #ifdef FEAT_GUI
4717     if (gui.in_use)
4718     {
4719 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
4720 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
4721     }
4722 #endif /* FEAT_GUI */
4723 
4724 #ifdef FEAT_MENU
4725     remove_winbar(wp);
4726 #endif
4727 
4728 #ifdef FEAT_SYN_HL
4729     vim_free(wp->w_p_cc_cols);
4730 #endif
4731 
4732     if (wp != aucmd_win)
4733 	win_remove(wp, tp);
4734     if (autocmd_busy)
4735     {
4736 	wp->w_next = au_pending_free_win;
4737 	au_pending_free_win = wp;
4738     }
4739     else
4740 	vim_free(wp);
4741 
4742     unblock_autocmds();
4743 }
4744 
4745 /*
4746  * Append window "wp" in the window list after window "after".
4747  */
4748     void
4749 win_append(win_T *after, win_T *wp)
4750 {
4751     win_T	*before;
4752 
4753     if (after == NULL)	    /* after NULL is in front of the first */
4754 	before = firstwin;
4755     else
4756 	before = after->w_next;
4757 
4758     wp->w_next = before;
4759     wp->w_prev = after;
4760     if (after == NULL)
4761 	firstwin = wp;
4762     else
4763 	after->w_next = wp;
4764     if (before == NULL)
4765 	lastwin = wp;
4766     else
4767 	before->w_prev = wp;
4768 }
4769 
4770 /*
4771  * Remove a window from the window list.
4772  */
4773     void
4774 win_remove(
4775     win_T	*wp,
4776     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4777 {
4778     if (wp->w_prev != NULL)
4779 	wp->w_prev->w_next = wp->w_next;
4780     else if (tp == NULL)
4781 	firstwin = curtab->tp_firstwin = wp->w_next;
4782     else
4783 	tp->tp_firstwin = wp->w_next;
4784 
4785     if (wp->w_next != NULL)
4786 	wp->w_next->w_prev = wp->w_prev;
4787     else if (tp == NULL)
4788 	lastwin = curtab->tp_lastwin = wp->w_prev;
4789     else
4790 	tp->tp_lastwin = wp->w_prev;
4791 }
4792 
4793 /*
4794  * Append frame "frp" in a frame list after frame "after".
4795  */
4796     static void
4797 frame_append(frame_T *after, frame_T *frp)
4798 {
4799     frp->fr_next = after->fr_next;
4800     after->fr_next = frp;
4801     if (frp->fr_next != NULL)
4802 	frp->fr_next->fr_prev = frp;
4803     frp->fr_prev = after;
4804 }
4805 
4806 /*
4807  * Insert frame "frp" in a frame list before frame "before".
4808  */
4809     static void
4810 frame_insert(frame_T *before, frame_T *frp)
4811 {
4812     frp->fr_next = before;
4813     frp->fr_prev = before->fr_prev;
4814     before->fr_prev = frp;
4815     if (frp->fr_prev != NULL)
4816 	frp->fr_prev->fr_next = frp;
4817     else
4818 	frp->fr_parent->fr_child = frp;
4819 }
4820 
4821 /*
4822  * Remove a frame from a frame list.
4823  */
4824     static void
4825 frame_remove(frame_T *frp)
4826 {
4827     if (frp->fr_prev != NULL)
4828 	frp->fr_prev->fr_next = frp->fr_next;
4829     else
4830     {
4831 	frp->fr_parent->fr_child = frp->fr_next;
4832 	/* special case: topframe->fr_child == frp */
4833 	if (topframe->fr_child == frp)
4834 	    topframe->fr_child = frp->fr_next;
4835     }
4836     if (frp->fr_next != NULL)
4837 	frp->fr_next->fr_prev = frp->fr_prev;
4838 }
4839 
4840 /*
4841  * Allocate w_lines[] for window "wp".
4842  * Return FAIL for failure, OK for success.
4843  */
4844     int
4845 win_alloc_lines(win_T *wp)
4846 {
4847     wp->w_lines_valid = 0;
4848     wp->w_lines = (wline_T *)alloc_clear((unsigned)(Rows * sizeof(wline_T)));
4849     if (wp->w_lines == NULL)
4850 	return FAIL;
4851     return OK;
4852 }
4853 
4854 /*
4855  * free lsize arrays for a window
4856  */
4857     void
4858 win_free_lsize(win_T *wp)
4859 {
4860     /* TODO: why would wp be NULL here? */
4861     if (wp != NULL)
4862 	VIM_CLEAR(wp->w_lines);
4863 }
4864 
4865 /*
4866  * Called from win_new_shellsize() after Rows changed.
4867  * This only does the current tab page, others must be done when made active.
4868  */
4869     void
4870 shell_new_rows(void)
4871 {
4872     int		h = (int)ROWS_AVAIL;
4873 
4874     if (firstwin == NULL)	/* not initialized yet */
4875 	return;
4876     if (h < frame_minheight(topframe, NULL))
4877 	h = frame_minheight(topframe, NULL);
4878 
4879     /* First try setting the heights of windows with 'winfixheight'.  If
4880      * that doesn't result in the right height, forget about that option. */
4881     frame_new_height(topframe, h, FALSE, TRUE);
4882     if (!frame_check_height(topframe, h))
4883 	frame_new_height(topframe, h, FALSE, FALSE);
4884 
4885     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4886     compute_cmdrow();
4887     curtab->tp_ch_used = p_ch;
4888 
4889 #if 0
4890     /* Disabled: don't want making the screen smaller make a window larger. */
4891     if (p_ea)
4892 	win_equal(curwin, FALSE, 'v');
4893 #endif
4894 }
4895 
4896 /*
4897  * Called from win_new_shellsize() after Columns changed.
4898  */
4899     void
4900 shell_new_columns(void)
4901 {
4902     if (firstwin == NULL)	/* not initialized yet */
4903 	return;
4904 
4905     /* First try setting the widths of windows with 'winfixwidth'.  If that
4906      * doesn't result in the right width, forget about that option. */
4907     frame_new_width(topframe, (int)Columns, FALSE, TRUE);
4908     if (!frame_check_width(topframe, Columns))
4909 	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
4910 
4911     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4912 #if 0
4913     /* Disabled: don't want making the screen smaller make a window larger. */
4914     if (p_ea)
4915 	win_equal(curwin, FALSE, 'h');
4916 #endif
4917 }
4918 
4919 #if defined(FEAT_CMDWIN) || defined(PROTO)
4920 /*
4921  * Save the size of all windows in "gap".
4922  */
4923     void
4924 win_size_save(garray_T *gap)
4925 
4926 {
4927     win_T	*wp;
4928 
4929     ga_init2(gap, (int)sizeof(int), 1);
4930     if (ga_grow(gap, win_count() * 2) == OK)
4931 	FOR_ALL_WINDOWS(wp)
4932 	{
4933 	    ((int *)gap->ga_data)[gap->ga_len++] =
4934 					       wp->w_width + wp->w_vsep_width;
4935 	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
4936 	}
4937 }
4938 
4939 /*
4940  * Restore window sizes, but only if the number of windows is still the same.
4941  * Does not free the growarray.
4942  */
4943     void
4944 win_size_restore(garray_T *gap)
4945 {
4946     win_T	*wp;
4947     int		i, j;
4948 
4949     if (win_count() * 2 == gap->ga_len)
4950     {
4951 	/* The order matters, because frames contain other frames, but it's
4952 	 * difficult to get right. The easy way out is to do it twice. */
4953 	for (j = 0; j < 2; ++j)
4954 	{
4955 	    i = 0;
4956 	    FOR_ALL_WINDOWS(wp)
4957 	    {
4958 		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
4959 		win_setheight_win(((int *)gap->ga_data)[i++], wp);
4960 	    }
4961 	}
4962 	/* recompute the window positions */
4963 	(void)win_comp_pos();
4964     }
4965 }
4966 #endif /* FEAT_CMDWIN */
4967 
4968 /*
4969  * Update the position for all windows, using the width and height of the
4970  * frames.
4971  * Returns the row just after the last window.
4972  */
4973     int
4974 win_comp_pos(void)
4975 {
4976     int		row = tabline_height();
4977     int		col = 0;
4978 
4979     frame_comp_pos(topframe, &row, &col);
4980     return row;
4981 }
4982 
4983 /*
4984  * Update the position of the windows in frame "topfrp", using the width and
4985  * height of the frames.
4986  * "*row" and "*col" are the top-left position of the frame.  They are updated
4987  * to the bottom-right position plus one.
4988  */
4989     static void
4990 frame_comp_pos(frame_T *topfrp, int *row, int *col)
4991 {
4992     win_T	*wp;
4993     frame_T	*frp;
4994     int		startcol;
4995     int		startrow;
4996     int		h;
4997 
4998     wp = topfrp->fr_win;
4999     if (wp != NULL)
5000     {
5001 	if (wp->w_winrow != *row || wp->w_wincol != *col)
5002 	{
5003 	    /* position changed, redraw */
5004 	    wp->w_winrow = *row;
5005 	    wp->w_wincol = *col;
5006 	    redraw_win_later(wp, NOT_VALID);
5007 	    wp->w_redr_status = TRUE;
5008 	}
5009 	/* WinBar will not show if the window height is zero */
5010 	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
5011 	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
5012 	*col += wp->w_width + wp->w_vsep_width;
5013     }
5014     else
5015     {
5016 	startrow = *row;
5017 	startcol = *col;
5018 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
5019 	{
5020 	    if (topfrp->fr_layout == FR_ROW)
5021 		*row = startrow;	/* all frames are at the same row */
5022 	    else
5023 		*col = startcol;	/* all frames are at the same col */
5024 	    frame_comp_pos(frp, row, col);
5025 	}
5026     }
5027 }
5028 
5029 /*
5030  * Set current window height and take care of repositioning other windows to
5031  * fit around it.
5032  */
5033     void
5034 win_setheight(int height)
5035 {
5036     win_setheight_win(height, curwin);
5037 }
5038 
5039 /*
5040  * Set the window height of window "win" and take care of repositioning other
5041  * windows to fit around it.
5042  */
5043     void
5044 win_setheight_win(int height, win_T *win)
5045 {
5046     int		row;
5047 
5048     if (win == curwin)
5049     {
5050 	/* Always keep current window at least one line high, even when
5051 	 * 'winminheight' is zero. */
5052 	if (height < p_wmh)
5053 	    height = p_wmh;
5054 	if (height == 0)
5055 	    height = 1;
5056 	height += WINBAR_HEIGHT(curwin);
5057     }
5058 
5059     frame_setheight(win->w_frame, height + win->w_status_height);
5060 
5061     /* recompute the window positions */
5062     row = win_comp_pos();
5063 
5064     /*
5065      * If there is extra space created between the last window and the command
5066      * line, clear it.
5067      */
5068     if (full_screen && msg_scrolled == 0 && row < cmdline_row)
5069 	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5070     cmdline_row = row;
5071     msg_row = row;
5072     msg_col = 0;
5073 
5074     redraw_all_later(NOT_VALID);
5075 }
5076 
5077 /*
5078  * Set the height of a frame to "height" and take care that all frames and
5079  * windows inside it are resized.  Also resize frames on the left and right if
5080  * the are in the same FR_ROW frame.
5081  *
5082  * Strategy:
5083  * If the frame is part of a FR_COL frame, try fitting the frame in that
5084  * frame.  If that doesn't work (the FR_COL frame is too small), recursively
5085  * go to containing frames to resize them and make room.
5086  * If the frame is part of a FR_ROW frame, all frames must be resized as well.
5087  * Check for the minimal height of the FR_ROW frame.
5088  * At the top level we can also use change the command line height.
5089  */
5090     static void
5091 frame_setheight(frame_T *curfrp, int height)
5092 {
5093     int		room;		/* total number of lines available */
5094     int		take;		/* number of lines taken from other windows */
5095     int		room_cmdline;	/* lines available from cmdline */
5096     int		run;
5097     frame_T	*frp;
5098     int		h;
5099     int		room_reserved;
5100 
5101     /* If the height already is the desired value, nothing to do. */
5102     if (curfrp->fr_height == height)
5103 	return;
5104 
5105     if (curfrp->fr_parent == NULL)
5106     {
5107 	/* topframe: can only change the command line */
5108 	if (height > ROWS_AVAIL)
5109 	    height = ROWS_AVAIL;
5110 	if (height > 0)
5111 	    frame_new_height(curfrp, height, FALSE, FALSE);
5112     }
5113     else if (curfrp->fr_parent->fr_layout == FR_ROW)
5114     {
5115 	/* Row of frames: Also need to resize frames left and right of this
5116 	 * one.  First check for the minimal height of these. */
5117 	h = frame_minheight(curfrp->fr_parent, NULL);
5118 	if (height < h)
5119 	    height = h;
5120 	frame_setheight(curfrp->fr_parent, height);
5121     }
5122     else
5123     {
5124 	/*
5125 	 * Column of frames: try to change only frames in this column.
5126 	 */
5127 	/*
5128 	 * Do this twice:
5129 	 * 1: compute room available, if it's not enough try resizing the
5130 	 *    containing frame.
5131 	 * 2: compute the room available and adjust the height to it.
5132 	 * Try not to reduce the height of a window with 'winfixheight' set.
5133 	 */
5134 	for (run = 1; run <= 2; ++run)
5135 	{
5136 	    room = 0;
5137 	    room_reserved = 0;
5138 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5139 	    {
5140 		if (frp != curfrp
5141 			&& frp->fr_win != NULL
5142 			&& frp->fr_win->w_p_wfh)
5143 		    room_reserved += frp->fr_height;
5144 		room += frp->fr_height;
5145 		if (frp != curfrp)
5146 		    room -= frame_minheight(frp, NULL);
5147 	    }
5148 	    if (curfrp->fr_width != Columns)
5149 		room_cmdline = 0;
5150 	    else
5151 	    {
5152 		room_cmdline = Rows - p_ch - (lastwin->w_winrow
5153 						+ VISIBLE_HEIGHT(lastwin)
5154 						+ lastwin->w_status_height);
5155 		if (room_cmdline < 0)
5156 		    room_cmdline = 0;
5157 	    }
5158 
5159 	    if (height <= room + room_cmdline)
5160 		break;
5161 	    if (run == 2 || curfrp->fr_width == Columns)
5162 	    {
5163 		if (height > room + room_cmdline)
5164 		    height = room + room_cmdline;
5165 		break;
5166 	    }
5167 	    frame_setheight(curfrp->fr_parent, height
5168 		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
5169 	}
5170 
5171 	/*
5172 	 * Compute the number of lines we will take from others frames (can be
5173 	 * negative!).
5174 	 */
5175 	take = height - curfrp->fr_height;
5176 
5177 	/* If there is not enough room, also reduce the height of a window
5178 	 * with 'winfixheight' set. */
5179 	if (height > room + room_cmdline - room_reserved)
5180 	    room_reserved = room + room_cmdline - height;
5181 	/* If there is only a 'winfixheight' window and making the
5182 	 * window smaller, need to make the other window taller. */
5183 	if (take < 0 && room - curfrp->fr_height < room_reserved)
5184 	    room_reserved = 0;
5185 
5186 	if (take > 0 && room_cmdline > 0)
5187 	{
5188 	    /* use lines from cmdline first */
5189 	    if (take < room_cmdline)
5190 		room_cmdline = take;
5191 	    take -= room_cmdline;
5192 	    topframe->fr_height += room_cmdline;
5193 	}
5194 
5195 	/*
5196 	 * set the current frame to the new height
5197 	 */
5198 	frame_new_height(curfrp, height, FALSE, FALSE);
5199 
5200 	/*
5201 	 * First take lines from the frames after the current frame.  If
5202 	 * that is not enough, takes lines from frames above the current
5203 	 * frame.
5204 	 */
5205 	for (run = 0; run < 2; ++run)
5206 	{
5207 	    if (run == 0)
5208 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5209 	    else
5210 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5211 	    while (frp != NULL && take != 0)
5212 	    {
5213 		h = frame_minheight(frp, NULL);
5214 		if (room_reserved > 0
5215 			&& frp->fr_win != NULL
5216 			&& frp->fr_win->w_p_wfh)
5217 		{
5218 		    if (room_reserved >= frp->fr_height)
5219 			room_reserved -= frp->fr_height;
5220 		    else
5221 		    {
5222 			if (frp->fr_height - room_reserved > take)
5223 			    room_reserved = frp->fr_height - take;
5224 			take -= frp->fr_height - room_reserved;
5225 			frame_new_height(frp, room_reserved, FALSE, FALSE);
5226 			room_reserved = 0;
5227 		    }
5228 		}
5229 		else
5230 		{
5231 		    if (frp->fr_height - take < h)
5232 		    {
5233 			take -= frp->fr_height - h;
5234 			frame_new_height(frp, h, FALSE, FALSE);
5235 		    }
5236 		    else
5237 		    {
5238 			frame_new_height(frp, frp->fr_height - take,
5239 								FALSE, FALSE);
5240 			take = 0;
5241 		    }
5242 		}
5243 		if (run == 0)
5244 		    frp = frp->fr_next;
5245 		else
5246 		    frp = frp->fr_prev;
5247 	    }
5248 	}
5249     }
5250 }
5251 
5252 /*
5253  * Set current window width and take care of repositioning other windows to
5254  * fit around it.
5255  */
5256     void
5257 win_setwidth(int width)
5258 {
5259     win_setwidth_win(width, curwin);
5260 }
5261 
5262     void
5263 win_setwidth_win(int width, win_T *wp)
5264 {
5265     /* Always keep current window at least one column wide, even when
5266      * 'winminwidth' is zero. */
5267     if (wp == curwin)
5268     {
5269 	if (width < p_wmw)
5270 	    width = p_wmw;
5271 	if (width == 0)
5272 	    width = 1;
5273     }
5274 
5275     frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
5276 
5277     /* recompute the window positions */
5278     (void)win_comp_pos();
5279 
5280     redraw_all_later(NOT_VALID);
5281 }
5282 
5283 /*
5284  * Set the width of a frame to "width" and take care that all frames and
5285  * windows inside it are resized.  Also resize frames above and below if the
5286  * are in the same FR_ROW frame.
5287  *
5288  * Strategy is similar to frame_setheight().
5289  */
5290     static void
5291 frame_setwidth(frame_T *curfrp, int width)
5292 {
5293     int		room;		/* total number of lines available */
5294     int		take;		/* number of lines taken from other windows */
5295     int		run;
5296     frame_T	*frp;
5297     int		w;
5298     int		room_reserved;
5299 
5300     /* If the width already is the desired value, nothing to do. */
5301     if (curfrp->fr_width == width)
5302 	return;
5303 
5304     if (curfrp->fr_parent == NULL)
5305 	/* topframe: can't change width */
5306 	return;
5307 
5308     if (curfrp->fr_parent->fr_layout == FR_COL)
5309     {
5310 	/* Column of frames: Also need to resize frames above and below of
5311 	 * this one.  First check for the minimal width of these. */
5312 	w = frame_minwidth(curfrp->fr_parent, NULL);
5313 	if (width < w)
5314 	    width = w;
5315 	frame_setwidth(curfrp->fr_parent, width);
5316     }
5317     else
5318     {
5319 	/*
5320 	 * Row of frames: try to change only frames in this row.
5321 	 *
5322 	 * Do this twice:
5323 	 * 1: compute room available, if it's not enough try resizing the
5324 	 *    containing frame.
5325 	 * 2: compute the room available and adjust the width to it.
5326 	 */
5327 	for (run = 1; run <= 2; ++run)
5328 	{
5329 	    room = 0;
5330 	    room_reserved = 0;
5331 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5332 	    {
5333 		if (frp != curfrp
5334 			&& frp->fr_win != NULL
5335 			&& frp->fr_win->w_p_wfw)
5336 		    room_reserved += frp->fr_width;
5337 		room += frp->fr_width;
5338 		if (frp != curfrp)
5339 		    room -= frame_minwidth(frp, NULL);
5340 	    }
5341 
5342 	    if (width <= room)
5343 		break;
5344 	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
5345 	    {
5346 		if (width > room)
5347 		    width = room;
5348 		break;
5349 	    }
5350 	    frame_setwidth(curfrp->fr_parent, width
5351 		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
5352 	}
5353 
5354 	/*
5355 	 * Compute the number of lines we will take from others frames (can be
5356 	 * negative!).
5357 	 */
5358 	take = width - curfrp->fr_width;
5359 
5360 	/* If there is not enough room, also reduce the width of a window
5361 	 * with 'winfixwidth' set. */
5362 	if (width > room - room_reserved)
5363 	    room_reserved = room - width;
5364 	/* If there is only a 'winfixwidth' window and making the
5365 	 * window smaller, need to make the other window narrower. */
5366 	if (take < 0 && room - curfrp->fr_width < room_reserved)
5367 	    room_reserved = 0;
5368 
5369 	/*
5370 	 * set the current frame to the new width
5371 	 */
5372 	frame_new_width(curfrp, width, FALSE, FALSE);
5373 
5374 	/*
5375 	 * First take lines from the frames right of the current frame.  If
5376 	 * that is not enough, takes lines from frames left of the current
5377 	 * frame.
5378 	 */
5379 	for (run = 0; run < 2; ++run)
5380 	{
5381 	    if (run == 0)
5382 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5383 	    else
5384 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5385 	    while (frp != NULL && take != 0)
5386 	    {
5387 		w = frame_minwidth(frp, NULL);
5388 		if (room_reserved > 0
5389 			&& frp->fr_win != NULL
5390 			&& frp->fr_win->w_p_wfw)
5391 		{
5392 		    if (room_reserved >= frp->fr_width)
5393 			room_reserved -= frp->fr_width;
5394 		    else
5395 		    {
5396 			if (frp->fr_width - room_reserved > take)
5397 			    room_reserved = frp->fr_width - take;
5398 			take -= frp->fr_width - room_reserved;
5399 			frame_new_width(frp, room_reserved, FALSE, FALSE);
5400 			room_reserved = 0;
5401 		    }
5402 		}
5403 		else
5404 		{
5405 		    if (frp->fr_width - take < w)
5406 		    {
5407 			take -= frp->fr_width - w;
5408 			frame_new_width(frp, w, FALSE, FALSE);
5409 		    }
5410 		    else
5411 		    {
5412 			frame_new_width(frp, frp->fr_width - take,
5413 								FALSE, FALSE);
5414 			take = 0;
5415 		    }
5416 		}
5417 		if (run == 0)
5418 		    frp = frp->fr_next;
5419 		else
5420 		    frp = frp->fr_prev;
5421 	    }
5422 	}
5423     }
5424 }
5425 
5426 /*
5427  * Check 'winminheight' for a valid value and reduce it if needed.
5428  */
5429     void
5430 win_setminheight(void)
5431 {
5432     int		room;
5433     int		needed;
5434     int		first = TRUE;
5435 
5436     // loop until there is a 'winminheight' that is possible
5437     while (p_wmh > 0)
5438     {
5439 	room = Rows - p_ch;
5440 	needed = frame_minheight(topframe, NULL);
5441 	if (room >= needed)
5442 	    break;
5443 	--p_wmh;
5444 	if (first)
5445 	{
5446 	    emsg(_(e_noroom));
5447 	    first = FALSE;
5448 	}
5449     }
5450 }
5451 
5452 /*
5453  * Check 'winminwidth' for a valid value and reduce it if needed.
5454  */
5455     void
5456 win_setminwidth(void)
5457 {
5458     int		room;
5459     int		needed;
5460     int		first = TRUE;
5461 
5462     // loop until there is a 'winminheight' that is possible
5463     while (p_wmw > 0)
5464     {
5465 	room = Columns;
5466 	needed = frame_minwidth(topframe, NULL);
5467 	if (room >= needed)
5468 	    break;
5469 	--p_wmw;
5470 	if (first)
5471 	{
5472 	    emsg(_(e_noroom));
5473 	    first = FALSE;
5474 	}
5475     }
5476 }
5477 
5478 #if defined(FEAT_MOUSE) || defined(PROTO)
5479 
5480 /*
5481  * Status line of dragwin is dragged "offset" lines down (negative is up).
5482  */
5483     void
5484 win_drag_status_line(win_T *dragwin, int offset)
5485 {
5486     frame_T	*curfr;
5487     frame_T	*fr;
5488     int		room;
5489     int		row;
5490     int		up;	/* if TRUE, drag status line up, otherwise down */
5491     int		n;
5492 
5493     fr = dragwin->w_frame;
5494     curfr = fr;
5495     if (fr != topframe)		/* more than one window */
5496     {
5497 	fr = fr->fr_parent;
5498 	/* When the parent frame is not a column of frames, its parent should
5499 	 * be. */
5500 	if (fr->fr_layout != FR_COL)
5501 	{
5502 	    curfr = fr;
5503 	    if (fr != topframe)	/* only a row of windows, may drag statusline */
5504 		fr = fr->fr_parent;
5505 	}
5506     }
5507 
5508     /* If this is the last frame in a column, may want to resize the parent
5509      * frame instead (go two up to skip a row of frames). */
5510     while (curfr != topframe && curfr->fr_next == NULL)
5511     {
5512 	if (fr != topframe)
5513 	    fr = fr->fr_parent;
5514 	curfr = fr;
5515 	if (fr != topframe)
5516 	    fr = fr->fr_parent;
5517     }
5518 
5519     if (offset < 0) /* drag up */
5520     {
5521 	up = TRUE;
5522 	offset = -offset;
5523 	/* sum up the room of the current frame and above it */
5524 	if (fr == curfr)
5525 	{
5526 	    /* only one window */
5527 	    room = fr->fr_height - frame_minheight(fr, NULL);
5528 	}
5529 	else
5530 	{
5531 	    room = 0;
5532 	    for (fr = fr->fr_child; ; fr = fr->fr_next)
5533 	    {
5534 		room += fr->fr_height - frame_minheight(fr, NULL);
5535 		if (fr == curfr)
5536 		    break;
5537 	    }
5538 	}
5539 	fr = curfr->fr_next;		/* put fr at frame that grows */
5540     }
5541     else    /* drag down */
5542     {
5543 	up = FALSE;
5544 	/*
5545 	 * Only dragging the last status line can reduce p_ch.
5546 	 */
5547 	room = Rows - cmdline_row;
5548 	if (curfr->fr_next == NULL)
5549 	    room -= 1;
5550 	else
5551 	    room -= p_ch;
5552 	if (room < 0)
5553 	    room = 0;
5554 	/* sum up the room of frames below of the current one */
5555 	FOR_ALL_FRAMES(fr, curfr->fr_next)
5556 	    room += fr->fr_height - frame_minheight(fr, NULL);
5557 	fr = curfr;			/* put fr at window that grows */
5558     }
5559 
5560     if (room < offset)		/* Not enough room */
5561 	offset = room;		/* Move as far as we can */
5562     if (offset <= 0)
5563 	return;
5564 
5565     /*
5566      * Grow frame fr by "offset" lines.
5567      * Doesn't happen when dragging the last status line up.
5568      */
5569     if (fr != NULL)
5570 	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
5571 
5572     if (up)
5573 	fr = curfr;		/* current frame gets smaller */
5574     else
5575 	fr = curfr->fr_next;	/* next frame gets smaller */
5576 
5577     /*
5578      * Now make the other frames smaller.
5579      */
5580     while (fr != NULL && offset > 0)
5581     {
5582 	n = frame_minheight(fr, NULL);
5583 	if (fr->fr_height - offset <= n)
5584 	{
5585 	    offset -= fr->fr_height - n;
5586 	    frame_new_height(fr, n, !up, FALSE);
5587 	}
5588 	else
5589 	{
5590 	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
5591 	    break;
5592 	}
5593 	if (up)
5594 	    fr = fr->fr_prev;
5595 	else
5596 	    fr = fr->fr_next;
5597     }
5598     row = win_comp_pos();
5599     screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5600     cmdline_row = row;
5601     p_ch = Rows - cmdline_row;
5602     if (p_ch < 1)
5603 	p_ch = 1;
5604     curtab->tp_ch_used = p_ch;
5605     redraw_all_later(SOME_VALID);
5606     showmode();
5607 }
5608 
5609 /*
5610  * Separator line of dragwin is dragged "offset" lines right (negative is left).
5611  */
5612     void
5613 win_drag_vsep_line(win_T *dragwin, int offset)
5614 {
5615     frame_T	*curfr;
5616     frame_T	*fr;
5617     int		room;
5618     int		left;	/* if TRUE, drag separator line left, otherwise right */
5619     int		n;
5620 
5621     fr = dragwin->w_frame;
5622     if (fr == topframe)		/* only one window (cannot happen?) */
5623 	return;
5624     curfr = fr;
5625     fr = fr->fr_parent;
5626     /* When the parent frame is not a row of frames, its parent should be. */
5627     if (fr->fr_layout != FR_ROW)
5628     {
5629 	if (fr == topframe)	/* only a column of windows (cannot happen?) */
5630 	    return;
5631 	curfr = fr;
5632 	fr = fr->fr_parent;
5633     }
5634 
5635     /* If this is the last frame in a row, may want to resize a parent
5636      * frame instead. */
5637     while (curfr->fr_next == NULL)
5638     {
5639 	if (fr == topframe)
5640 	    break;
5641 	curfr = fr;
5642 	fr = fr->fr_parent;
5643 	if (fr != topframe)
5644 	{
5645 	    curfr = fr;
5646 	    fr = fr->fr_parent;
5647 	}
5648     }
5649 
5650     if (offset < 0) /* drag left */
5651     {
5652 	left = TRUE;
5653 	offset = -offset;
5654 	/* sum up the room of the current frame and left of it */
5655 	room = 0;
5656 	for (fr = fr->fr_child; ; fr = fr->fr_next)
5657 	{
5658 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5659 	    if (fr == curfr)
5660 		break;
5661 	}
5662 	fr = curfr->fr_next;		/* put fr at frame that grows */
5663     }
5664     else    /* drag right */
5665     {
5666 	left = FALSE;
5667 	/* sum up the room of frames right of the current one */
5668 	room = 0;
5669 	FOR_ALL_FRAMES(fr, curfr->fr_next)
5670 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5671 	fr = curfr;			/* put fr at window that grows */
5672     }
5673 
5674     if (room < offset)		/* Not enough room */
5675 	offset = room;		/* Move as far as we can */
5676     if (offset <= 0)		/* No room at all, quit. */
5677 	return;
5678     if (fr == NULL)
5679 	return;			/* Safety check, should not happen. */
5680 
5681     /* grow frame fr by offset lines */
5682     frame_new_width(fr, fr->fr_width + offset, left, FALSE);
5683 
5684     /* shrink other frames: current and at the left or at the right */
5685     if (left)
5686 	fr = curfr;		/* current frame gets smaller */
5687     else
5688 	fr = curfr->fr_next;	/* next frame gets smaller */
5689 
5690     while (fr != NULL && offset > 0)
5691     {
5692 	n = frame_minwidth(fr, NULL);
5693 	if (fr->fr_width - offset <= n)
5694 	{
5695 	    offset -= fr->fr_width - n;
5696 	    frame_new_width(fr, n, !left, FALSE);
5697 	}
5698 	else
5699 	{
5700 	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
5701 	    break;
5702 	}
5703 	if (left)
5704 	    fr = fr->fr_prev;
5705 	else
5706 	    fr = fr->fr_next;
5707     }
5708     (void)win_comp_pos();
5709     redraw_all_later(NOT_VALID);
5710 }
5711 #endif /* FEAT_MOUSE */
5712 
5713 #define FRACTION_MULT	16384L
5714 
5715 /*
5716  * Set wp->w_fraction for the current w_wrow and w_height.
5717  * Has no effect when the window is less than two lines.
5718  */
5719     void
5720 set_fraction(win_T *wp)
5721 {
5722     if (wp->w_height > 1)
5723 	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
5724 				    + wp->w_height / 2) / (long)wp->w_height;
5725 }
5726 
5727 /*
5728  * Set the height of a window.
5729  * "height" excludes any window toolbar.
5730  * This takes care of the things inside the window, not what happens to the
5731  * window position, the frame or to other windows.
5732  */
5733     void
5734 win_new_height(win_T *wp, int height)
5735 {
5736     int		prev_height = wp->w_height;
5737 
5738     /* Don't want a negative height.  Happens when splitting a tiny window.
5739      * Will equalize heights soon to fix it. */
5740     if (height < 0)
5741 	height = 0;
5742     if (wp->w_height == height)
5743 	return;	    /* nothing to do */
5744 
5745     if (wp->w_height > 0)
5746     {
5747 	if (wp == curwin)
5748 	    /* w_wrow needs to be valid. When setting 'laststatus' this may
5749 	     * call win_new_height() recursively. */
5750 	    validate_cursor();
5751 	if (wp->w_height != prev_height)
5752 	    return;  /* Recursive call already changed the size, bail out here
5753 			to avoid the following to mess things up. */
5754 	if (wp->w_wrow != wp->w_prev_fraction_row)
5755 	    set_fraction(wp);
5756     }
5757 
5758     wp->w_height = height;
5759     wp->w_skipcol = 0;
5760 
5761     /* There is no point in adjusting the scroll position when exiting.  Some
5762      * values might be invalid. */
5763     if (!exiting)
5764 	scroll_to_fraction(wp, prev_height);
5765 }
5766 
5767     void
5768 scroll_to_fraction(win_T *wp, int prev_height)
5769 {
5770     linenr_T	lnum;
5771     int		sline, line_size;
5772     int		height = wp->w_height;
5773 
5774     /* Don't change w_topline when height is zero.  Don't set w_topline when
5775      * 'scrollbind' is set and this isn't the current window. */
5776     if (height > 0 && (!wp->w_p_scb || wp == curwin))
5777     {
5778 	/*
5779 	 * Find a value for w_topline that shows the cursor at the same
5780 	 * relative position in the window as before (more or less).
5781 	 */
5782 	lnum = wp->w_cursor.lnum;
5783 	if (lnum < 1)		/* can happen when starting up */
5784 	    lnum = 1;
5785 	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L
5786 					 + FRACTION_MULT / 2) / FRACTION_MULT;
5787 	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
5788 	sline = wp->w_wrow - line_size;
5789 
5790 	if (sline >= 0)
5791 	{
5792 	    /* Make sure the whole cursor line is visible, if possible. */
5793 	    int rows = plines_win(wp, lnum, FALSE);
5794 
5795 	    if (sline > wp->w_height - rows)
5796 	    {
5797 		sline = wp->w_height - rows;
5798 		wp->w_wrow -= rows - line_size;
5799 	    }
5800 	}
5801 
5802 	if (sline < 0)
5803 	{
5804 	    /*
5805 	     * Cursor line would go off top of screen if w_wrow was this high.
5806 	     * Make cursor line the first line in the window.  If not enough
5807 	     * room use w_skipcol;
5808 	     */
5809 	    wp->w_wrow = line_size;
5810 	    if (wp->w_wrow >= wp->w_height
5811 				       && (wp->w_width - win_col_off(wp)) > 0)
5812 	    {
5813 		wp->w_skipcol += wp->w_width - win_col_off(wp);
5814 		--wp->w_wrow;
5815 		while (wp->w_wrow >= wp->w_height)
5816 		{
5817 		    wp->w_skipcol += wp->w_width - win_col_off(wp)
5818 							   + win_col_off2(wp);
5819 		    --wp->w_wrow;
5820 		}
5821 	    }
5822 	    set_topline(wp, lnum);
5823 	}
5824 	else if (sline > 0)
5825 	{
5826 	    while (sline > 0 && lnum > 1)
5827 	    {
5828 #ifdef FEAT_FOLDING
5829 		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
5830 		if (lnum == 1)
5831 		{
5832 		    /* first line in buffer is folded */
5833 		    line_size = 1;
5834 		    --sline;
5835 		    break;
5836 		}
5837 #endif
5838 		--lnum;
5839 #ifdef FEAT_DIFF
5840 		if (lnum == wp->w_topline)
5841 		    line_size = plines_win_nofill(wp, lnum, TRUE)
5842 							      + wp->w_topfill;
5843 		else
5844 #endif
5845 		    line_size = plines_win(wp, lnum, TRUE);
5846 		sline -= line_size;
5847 	    }
5848 
5849 	    if (sline < 0)
5850 	    {
5851 		/*
5852 		 * Line we want at top would go off top of screen.  Use next
5853 		 * line instead.
5854 		 */
5855 #ifdef FEAT_FOLDING
5856 		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
5857 #endif
5858 		lnum++;
5859 		wp->w_wrow -= line_size + sline;
5860 	    }
5861 	    else if (sline > 0)
5862 	    {
5863 		/* First line of file reached, use that as topline. */
5864 		lnum = 1;
5865 		wp->w_wrow -= sline;
5866 	    }
5867 
5868 	    set_topline(wp, lnum);
5869 	}
5870     }
5871 
5872     if (wp == curwin)
5873     {
5874 	if (p_so)
5875 	    update_topline();
5876 	curs_columns(FALSE);	/* validate w_wrow */
5877     }
5878     if (prev_height > 0)
5879 	wp->w_prev_fraction_row = wp->w_wrow;
5880 
5881     win_comp_scroll(wp);
5882     redraw_win_later(wp, SOME_VALID);
5883     wp->w_redr_status = TRUE;
5884     invalidate_botline_win(wp);
5885 }
5886 
5887 /*
5888  * Set the width of a window.
5889  */
5890     void
5891 win_new_width(win_T *wp, int width)
5892 {
5893     wp->w_width = width;
5894     wp->w_lines_valid = 0;
5895     changed_line_abv_curs_win(wp);
5896     invalidate_botline_win(wp);
5897     if (wp == curwin)
5898     {
5899 	update_topline();
5900 	curs_columns(TRUE);	/* validate w_wrow */
5901     }
5902     redraw_win_later(wp, NOT_VALID);
5903     wp->w_redr_status = TRUE;
5904 }
5905 
5906     void
5907 win_comp_scroll(win_T *wp)
5908 {
5909     wp->w_p_scr = ((unsigned)wp->w_height >> 1);
5910     if (wp->w_p_scr == 0)
5911 	wp->w_p_scr = 1;
5912 }
5913 
5914 /*
5915  * command_height: called whenever p_ch has been changed
5916  */
5917     void
5918 command_height(void)
5919 {
5920     int		h;
5921     frame_T	*frp;
5922     int		old_p_ch = curtab->tp_ch_used;
5923 
5924     /* Use the value of p_ch that we remembered.  This is needed for when the
5925      * GUI starts up, we can't be sure in what order things happen.  And when
5926      * p_ch was changed in another tab page. */
5927     curtab->tp_ch_used = p_ch;
5928 
5929     /* Find bottom frame with width of screen. */
5930     frp = lastwin->w_frame;
5931     while (frp->fr_width != Columns && frp->fr_parent != NULL)
5932 	frp = frp->fr_parent;
5933 
5934     /* Avoid changing the height of a window with 'winfixheight' set. */
5935     while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
5936 						      && frp->fr_win->w_p_wfh)
5937 	frp = frp->fr_prev;
5938 
5939     if (starting != NO_SCREEN)
5940     {
5941 	cmdline_row = Rows - p_ch;
5942 
5943 	if (p_ch > old_p_ch)		    /* p_ch got bigger */
5944 	{
5945 	    while (p_ch > old_p_ch)
5946 	    {
5947 		if (frp == NULL)
5948 		{
5949 		    emsg(_(e_noroom));
5950 		    p_ch = old_p_ch;
5951 		    curtab->tp_ch_used = p_ch;
5952 		    cmdline_row = Rows - p_ch;
5953 		    break;
5954 		}
5955 		h = frp->fr_height - frame_minheight(frp, NULL);
5956 		if (h > p_ch - old_p_ch)
5957 		    h = p_ch - old_p_ch;
5958 		old_p_ch += h;
5959 		frame_add_height(frp, -h);
5960 		frp = frp->fr_prev;
5961 	    }
5962 
5963 	    /* Recompute window positions. */
5964 	    (void)win_comp_pos();
5965 
5966 	    /* clear the lines added to cmdline */
5967 	    if (full_screen)
5968 		screen_fill((int)(cmdline_row), (int)Rows, 0,
5969 						   (int)Columns, ' ', ' ', 0);
5970 	    msg_row = cmdline_row;
5971 	    redraw_cmdline = TRUE;
5972 	    return;
5973 	}
5974 
5975 	if (msg_row < cmdline_row)
5976 	    msg_row = cmdline_row;
5977 	redraw_cmdline = TRUE;
5978     }
5979     frame_add_height(frp, (int)(old_p_ch - p_ch));
5980 
5981     /* Recompute window positions. */
5982     if (frp != lastwin->w_frame)
5983 	(void)win_comp_pos();
5984 }
5985 
5986 /*
5987  * Resize frame "frp" to be "n" lines higher (negative for less high).
5988  * Also resize the frames it is contained in.
5989  */
5990     static void
5991 frame_add_height(frame_T *frp, int n)
5992 {
5993     frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
5994     for (;;)
5995     {
5996 	frp = frp->fr_parent;
5997 	if (frp == NULL)
5998 	    break;
5999 	frp->fr_height += n;
6000     }
6001 }
6002 
6003 /*
6004  * Add or remove a status line for the bottom window(s), according to the
6005  * value of 'laststatus'.
6006  */
6007     void
6008 last_status(
6009     int		morewin)	/* pretend there are two or more windows */
6010 {
6011     /* Don't make a difference between horizontal or vertical split. */
6012     last_status_rec(topframe, (p_ls == 2
6013 			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
6014 }
6015 
6016     static void
6017 last_status_rec(frame_T *fr, int statusline)
6018 {
6019     frame_T	*fp;
6020     win_T	*wp;
6021 
6022     if (fr->fr_layout == FR_LEAF)
6023     {
6024 	wp = fr->fr_win;
6025 	if (wp->w_status_height != 0 && !statusline)
6026 	{
6027 	    /* remove status line */
6028 	    win_new_height(wp, wp->w_height + 1);
6029 	    wp->w_status_height = 0;
6030 	    comp_col();
6031 	}
6032 	else if (wp->w_status_height == 0 && statusline)
6033 	{
6034 	    /* Find a frame to take a line from. */
6035 	    fp = fr;
6036 	    while (fp->fr_height <= frame_minheight(fp, NULL))
6037 	    {
6038 		if (fp == topframe)
6039 		{
6040 		    emsg(_(e_noroom));
6041 		    return;
6042 		}
6043 		/* In a column of frames: go to frame above.  If already at
6044 		 * the top or in a row of frames: go to parent. */
6045 		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
6046 		    fp = fp->fr_prev;
6047 		else
6048 		    fp = fp->fr_parent;
6049 	    }
6050 	    wp->w_status_height = 1;
6051 	    if (fp != fr)
6052 	    {
6053 		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
6054 		frame_fix_height(wp);
6055 		(void)win_comp_pos();
6056 	    }
6057 	    else
6058 		win_new_height(wp, wp->w_height - 1);
6059 	    comp_col();
6060 	    redraw_all_later(SOME_VALID);
6061 	}
6062     }
6063     else if (fr->fr_layout == FR_ROW)
6064     {
6065 	/* vertically split windows, set status line for each one */
6066 	FOR_ALL_FRAMES(fp, fr->fr_child)
6067 	    last_status_rec(fp, statusline);
6068     }
6069     else
6070     {
6071 	/* horizontally split window, set status line for last one */
6072 	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
6073 	    ;
6074 	last_status_rec(fp, statusline);
6075     }
6076 }
6077 
6078 /*
6079  * Return the number of lines used by the tab page line.
6080  */
6081     int
6082 tabline_height(void)
6083 {
6084 #ifdef FEAT_GUI_TABLINE
6085     /* When the GUI has the tabline then this always returns zero. */
6086     if (gui_use_tabline())
6087 	return 0;
6088 #endif
6089     switch (p_stal)
6090     {
6091 	case 0: return 0;
6092 	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
6093     }
6094     return 1;
6095 }
6096 
6097 #if defined(FEAT_SEARCHPATH) || defined(PROTO)
6098 /*
6099  * Get the file name at the cursor.
6100  * If Visual mode is active, use the selected text if it's in one line.
6101  * Returns the name in allocated memory, NULL for failure.
6102  */
6103     char_u *
6104 grab_file_name(long count, linenr_T *file_lnum)
6105 {
6106     int options = FNAME_MESS|FNAME_EXP|FNAME_REL|FNAME_UNESC;
6107 
6108     if (VIsual_active)
6109     {
6110 	int	len;
6111 	char_u	*ptr;
6112 
6113 	if (get_visual_text(NULL, &ptr, &len) == FAIL)
6114 	    return NULL;
6115 	return find_file_name_in_path(ptr, len, options,
6116 						     count, curbuf->b_ffname);
6117     }
6118     return file_name_at_cursor(options | FNAME_HYP, count, file_lnum);
6119 }
6120 
6121 /*
6122  * Return the file name under or after the cursor.
6123  *
6124  * The 'path' option is searched if the file name is not absolute.
6125  * The string returned has been alloc'ed and should be freed by the caller.
6126  * NULL is returned if the file name or file is not found.
6127  *
6128  * options:
6129  * FNAME_MESS	    give error messages
6130  * FNAME_EXP	    expand to path
6131  * FNAME_HYP	    check for hypertext link
6132  * FNAME_INCL	    apply "includeexpr"
6133  */
6134     char_u *
6135 file_name_at_cursor(int options, long count, linenr_T *file_lnum)
6136 {
6137     return file_name_in_line(ml_get_curline(),
6138 		      curwin->w_cursor.col, options, count, curbuf->b_ffname,
6139 		      file_lnum);
6140 }
6141 
6142 /*
6143  * Return the name of the file under or after ptr[col].
6144  * Otherwise like file_name_at_cursor().
6145  */
6146     char_u *
6147 file_name_in_line(
6148     char_u	*line,
6149     int		col,
6150     int		options,
6151     long	count,
6152     char_u	*rel_fname,	/* file we are searching relative to */
6153     linenr_T	*file_lnum)	/* line number after the file name */
6154 {
6155     char_u	*ptr;
6156     int		len;
6157     int		in_type = TRUE;
6158     int		is_url = FALSE;
6159 
6160     /*
6161      * search forward for what could be the start of a file name
6162      */
6163     ptr = line + col;
6164     while (*ptr != NUL && !vim_isfilec(*ptr))
6165 	MB_PTR_ADV(ptr);
6166     if (*ptr == NUL)		/* nothing found */
6167     {
6168 	if (options & FNAME_MESS)
6169 	    emsg(_("E446: No file name under cursor"));
6170 	return NULL;
6171     }
6172 
6173     /*
6174      * Search backward for first char of the file name.
6175      * Go one char back to ":" before "//" even when ':' is not in 'isfname'.
6176      */
6177     while (ptr > line)
6178     {
6179 	if (has_mbyte && (len = (*mb_head_off)(line, ptr - 1)) > 0)
6180 	    ptr -= len + 1;
6181 	else if (vim_isfilec(ptr[-1])
6182 		|| ((options & FNAME_HYP) && path_is_url(ptr - 1)))
6183 	    --ptr;
6184 	else
6185 	    break;
6186     }
6187 
6188     /*
6189      * Search forward for the last char of the file name.
6190      * Also allow "://" when ':' is not in 'isfname'.
6191      */
6192     len = 0;
6193     while (vim_isfilec(ptr[len]) || (ptr[len] == '\\' && ptr[len + 1] == ' ')
6194 			 || ((options & FNAME_HYP) && path_is_url(ptr + len))
6195 			 || (is_url && vim_strchr((char_u *)"?&=", ptr[len]) != NULL))
6196     {
6197 	/* After type:// we also include ?, & and = as valid characters, so that
6198 	 * http://google.com?q=this&that=ok works. */
6199 	if ((ptr[len] >= 'A' && ptr[len] <= 'Z') || (ptr[len] >= 'a' && ptr[len] <= 'z'))
6200 	{
6201 	    if (in_type && path_is_url(ptr + len + 1))
6202 		is_url = TRUE;
6203 	}
6204 	else
6205 	    in_type = FALSE;
6206 
6207 	if (ptr[len] == '\\')
6208 	    /* Skip over the "\" in "\ ". */
6209 	    ++len;
6210 	if (has_mbyte)
6211 	    len += (*mb_ptr2len)(ptr + len);
6212 	else
6213 	    ++len;
6214     }
6215 
6216     /*
6217      * If there is trailing punctuation, remove it.
6218      * But don't remove "..", could be a directory name.
6219      */
6220     if (len > 2 && vim_strchr((char_u *)".,:;!", ptr[len - 1]) != NULL
6221 						       && ptr[len - 2] != '.')
6222 	--len;
6223 
6224     if (file_lnum != NULL)
6225     {
6226 	char_u *p;
6227 
6228 	/* Get the number after the file name and a separator character */
6229 	p = ptr + len;
6230 	p = skipwhite(p);
6231 	if (*p != NUL)
6232 	{
6233 	    if (!isdigit(*p))
6234 		++p;		    /* skip the separator */
6235 	    p = skipwhite(p);
6236 	    if (isdigit(*p))
6237 		*file_lnum = (int)getdigits(&p);
6238 	}
6239     }
6240 
6241     return find_file_name_in_path(ptr, len, options, count, rel_fname);
6242 }
6243 
6244 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6245     static char_u *
6246 eval_includeexpr(char_u *ptr, int len)
6247 {
6248     char_u	*res;
6249 
6250     set_vim_var_string(VV_FNAME, ptr, len);
6251     res = eval_to_string_safe(curbuf->b_p_inex, NULL,
6252 		      was_set_insecurely((char_u *)"includeexpr", OPT_LOCAL));
6253     set_vim_var_string(VV_FNAME, NULL, 0);
6254     return res;
6255 }
6256 #endif
6257 
6258 /*
6259  * Return the name of the file ptr[len] in 'path'.
6260  * Otherwise like file_name_at_cursor().
6261  */
6262     char_u *
6263 find_file_name_in_path(
6264     char_u	*ptr,
6265     int		len,
6266     int		options,
6267     long	count,
6268     char_u	*rel_fname)	/* file we are searching relative to */
6269 {
6270     char_u	*file_name;
6271     int		c;
6272 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6273     char_u	*tofree = NULL;
6274 
6275     if ((options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
6276     {
6277 	tofree = eval_includeexpr(ptr, len);
6278 	if (tofree != NULL)
6279 	{
6280 	    ptr = tofree;
6281 	    len = (int)STRLEN(ptr);
6282 	}
6283     }
6284 # endif
6285 
6286     if (options & FNAME_EXP)
6287     {
6288 	file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
6289 							     TRUE, rel_fname);
6290 
6291 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6292 	/*
6293 	 * If the file could not be found in a normal way, try applying
6294 	 * 'includeexpr' (unless done already).
6295 	 */
6296 	if (file_name == NULL
6297 		&& !(options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
6298 	{
6299 	    tofree = eval_includeexpr(ptr, len);
6300 	    if (tofree != NULL)
6301 	    {
6302 		ptr = tofree;
6303 		len = (int)STRLEN(ptr);
6304 		file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
6305 							     TRUE, rel_fname);
6306 	    }
6307 	}
6308 # endif
6309 	if (file_name == NULL && (options & FNAME_MESS))
6310 	{
6311 	    c = ptr[len];
6312 	    ptr[len] = NUL;
6313 	    semsg(_("E447: Can't find file \"%s\" in path"), ptr);
6314 	    ptr[len] = c;
6315 	}
6316 
6317 	/* Repeat finding the file "count" times.  This matters when it
6318 	 * appears several times in the path. */
6319 	while (file_name != NULL && --count > 0)
6320 	{
6321 	    vim_free(file_name);
6322 	    file_name = find_file_in_path(ptr, len, options, FALSE, rel_fname);
6323 	}
6324     }
6325     else
6326 	file_name = vim_strnsave(ptr, len);
6327 
6328 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6329     vim_free(tofree);
6330 # endif
6331 
6332     return file_name;
6333 }
6334 #endif /* FEAT_SEARCHPATH */
6335 
6336 /*
6337  * Check if the "://" of a URL is at the pointer, return URL_SLASH.
6338  * Also check for ":\\", which MS Internet Explorer accepts, return
6339  * URL_BACKSLASH.
6340  */
6341     static int
6342 path_is_url(char_u *p)
6343 {
6344     if (STRNCMP(p, "://", (size_t)3) == 0)
6345 	return URL_SLASH;
6346     else if (STRNCMP(p, ":\\\\", (size_t)3) == 0)
6347 	return URL_BACKSLASH;
6348     return 0;
6349 }
6350 
6351 /*
6352  * Check if "fname" starts with "name://".  Return URL_SLASH if it does.
6353  * Return URL_BACKSLASH for "name:\\".
6354  * Return zero otherwise.
6355  */
6356     int
6357 path_with_url(char_u *fname)
6358 {
6359     char_u *p;
6360 
6361     for (p = fname; isalpha(*p); ++p)
6362 	;
6363     return path_is_url(p);
6364 }
6365 
6366 /*
6367  * Return TRUE if "name" is a full (absolute) path name or URL.
6368  */
6369     int
6370 vim_isAbsName(char_u *name)
6371 {
6372     return (path_with_url(name) != 0 || mch_isFullName(name));
6373 }
6374 
6375 /*
6376  * Get absolute file name into buffer "buf[len]".
6377  *
6378  * return FAIL for failure, OK otherwise
6379  */
6380     int
6381 vim_FullName(
6382     char_u	*fname,
6383     char_u	*buf,
6384     int		len,
6385     int		force)	    /* force expansion even when already absolute */
6386 {
6387     int		retval = OK;
6388     int		url;
6389 
6390     *buf = NUL;
6391     if (fname == NULL)
6392 	return FAIL;
6393 
6394     url = path_with_url(fname);
6395     if (!url)
6396 	retval = mch_FullName(fname, buf, len, force);
6397     if (url || retval == FAIL)
6398     {
6399 	/* something failed; use the file name (truncate when too long) */
6400 	vim_strncpy(buf, fname, len - 1);
6401     }
6402 #if defined(MSWIN)
6403     slash_adjust(buf);
6404 #endif
6405     return retval;
6406 }
6407 
6408 /*
6409  * Return the minimal number of rows that is needed on the screen to display
6410  * the current number of windows.
6411  */
6412     int
6413 min_rows(void)
6414 {
6415     int		total;
6416     tabpage_T	*tp;
6417     int		n;
6418 
6419     if (firstwin == NULL)	/* not initialized yet */
6420 	return MIN_LINES;
6421 
6422     total = 0;
6423     FOR_ALL_TABPAGES(tp)
6424     {
6425 	n = frame_minheight(tp->tp_topframe, NULL);
6426 	if (total < n)
6427 	    total = n;
6428     }
6429     total += tabline_height();
6430     total += 1;		/* count the room for the command line */
6431     return total;
6432 }
6433 
6434 /*
6435  * Return TRUE if there is only one window (in the current tab page), not
6436  * counting a help or preview window, unless it is the current window.
6437  * Does not count "aucmd_win".
6438  */
6439     int
6440 only_one_window(void)
6441 {
6442     int		count = 0;
6443     win_T	*wp;
6444 
6445     /* If there is another tab page there always is another window. */
6446     if (first_tabpage->tp_next != NULL)
6447 	return FALSE;
6448 
6449     FOR_ALL_WINDOWS(wp)
6450 	if (wp->w_buffer != NULL
6451 		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
6452 # ifdef FEAT_QUICKFIX
6453 		    || wp->w_p_pvw
6454 # endif
6455 	     ) || wp == curwin) && wp != aucmd_win)
6456 	    ++count;
6457     return (count <= 1);
6458 }
6459 
6460 /*
6461  * Correct the cursor line number in other windows.  Used after changing the
6462  * current buffer, and before applying autocommands.
6463  * When "do_curwin" is TRUE, also check current window.
6464  */
6465     void
6466 check_lnums(int do_curwin)
6467 {
6468     win_T	*wp;
6469     tabpage_T	*tp;
6470 
6471     FOR_ALL_TAB_WINDOWS(tp, wp)
6472 	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
6473 	{
6474 	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
6475 		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
6476 	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
6477 		wp->w_topline = curbuf->b_ml.ml_line_count;
6478 	}
6479 }
6480 
6481 /*
6482  * A snapshot of the window sizes, to restore them after closing the help
6483  * window.
6484  * Only these fields are used:
6485  * fr_layout
6486  * fr_width
6487  * fr_height
6488  * fr_next
6489  * fr_child
6490  * fr_win (only valid for the old curwin, NULL otherwise)
6491  */
6492 
6493 /*
6494  * Create a snapshot of the current frame sizes.
6495  */
6496     void
6497 make_snapshot(int idx)
6498 {
6499     clear_snapshot(curtab, idx);
6500     make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
6501 }
6502 
6503     static void
6504 make_snapshot_rec(frame_T *fr, frame_T **frp)
6505 {
6506     *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
6507     if (*frp == NULL)
6508 	return;
6509     (*frp)->fr_layout = fr->fr_layout;
6510     (*frp)->fr_width = fr->fr_width;
6511     (*frp)->fr_height = fr->fr_height;
6512     if (fr->fr_next != NULL)
6513 	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
6514     if (fr->fr_child != NULL)
6515 	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
6516     if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
6517 	(*frp)->fr_win = curwin;
6518 }
6519 
6520 /*
6521  * Remove any existing snapshot.
6522  */
6523     static void
6524 clear_snapshot(tabpage_T *tp, int idx)
6525 {
6526     clear_snapshot_rec(tp->tp_snapshot[idx]);
6527     tp->tp_snapshot[idx] = NULL;
6528 }
6529 
6530     static void
6531 clear_snapshot_rec(frame_T *fr)
6532 {
6533     if (fr != NULL)
6534     {
6535 	clear_snapshot_rec(fr->fr_next);
6536 	clear_snapshot_rec(fr->fr_child);
6537 	vim_free(fr);
6538     }
6539 }
6540 
6541 /*
6542  * Restore a previously created snapshot, if there is any.
6543  * This is only done if the screen size didn't change and the window layout is
6544  * still the same.
6545  */
6546     void
6547 restore_snapshot(
6548     int		idx,
6549     int		close_curwin)	    /* closing current window */
6550 {
6551     win_T	*wp;
6552 
6553     if (curtab->tp_snapshot[idx] != NULL
6554 	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
6555 	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
6556 	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
6557     {
6558 	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
6559 	win_comp_pos();
6560 	if (wp != NULL && close_curwin)
6561 	    win_goto(wp);
6562 	redraw_all_later(NOT_VALID);
6563     }
6564     clear_snapshot(curtab, idx);
6565 }
6566 
6567 /*
6568  * Check if frames "sn" and "fr" have the same layout, same following frames
6569  * and same children.  And the window pointer is valid.
6570  */
6571     static int
6572 check_snapshot_rec(frame_T *sn, frame_T *fr)
6573 {
6574     if (sn->fr_layout != fr->fr_layout
6575 	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
6576 	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
6577 	    || (sn->fr_next != NULL
6578 		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
6579 	    || (sn->fr_child != NULL
6580 		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
6581 	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
6582 	return FAIL;
6583     return OK;
6584 }
6585 
6586 /*
6587  * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
6588  * following frames and children.
6589  * Returns a pointer to the old current window, or NULL.
6590  */
6591     static win_T *
6592 restore_snapshot_rec(frame_T *sn, frame_T *fr)
6593 {
6594     win_T	*wp = NULL;
6595     win_T	*wp2;
6596 
6597     fr->fr_height = sn->fr_height;
6598     fr->fr_width = sn->fr_width;
6599     if (fr->fr_layout == FR_LEAF)
6600     {
6601 	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
6602 	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
6603 	wp = sn->fr_win;
6604     }
6605     if (sn->fr_next != NULL)
6606     {
6607 	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
6608 	if (wp2 != NULL)
6609 	    wp = wp2;
6610     }
6611     if (sn->fr_child != NULL)
6612     {
6613 	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
6614 	if (wp2 != NULL)
6615 	    wp = wp2;
6616     }
6617     return wp;
6618 }
6619 
6620 #if defined(FEAT_EVAL) || defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \
6621 	|| defined(PROTO)
6622 /*
6623  * Set "win" to be the curwin and "tp" to be the current tab page.
6624  * restore_win() MUST be called to undo, also when FAIL is returned.
6625  * No autocommands will be executed until restore_win() is called.
6626  * When "no_display" is TRUE the display won't be affected, no redraw is
6627  * triggered, another tabpage access is limited.
6628  * Returns FAIL if switching to "win" failed.
6629  */
6630     int
6631 switch_win(
6632     win_T	**save_curwin,
6633     tabpage_T	**save_curtab,
6634     win_T	*win,
6635     tabpage_T	*tp,
6636     int		no_display)
6637 {
6638     block_autocmds();
6639     *save_curwin = curwin;
6640     if (tp != NULL)
6641     {
6642 	*save_curtab = curtab;
6643 	if (no_display)
6644 	{
6645 	    curtab->tp_firstwin = firstwin;
6646 	    curtab->tp_lastwin = lastwin;
6647 	    curtab = tp;
6648 	    firstwin = curtab->tp_firstwin;
6649 	    lastwin = curtab->tp_lastwin;
6650 	}
6651 	else
6652 	    goto_tabpage_tp(tp, FALSE, FALSE);
6653     }
6654     if (!win_valid(win))
6655 	return FAIL;
6656     curwin = win;
6657     curbuf = curwin->w_buffer;
6658     return OK;
6659 }
6660 
6661 /*
6662  * Restore current tabpage and window saved by switch_win(), if still valid.
6663  * When "no_display" is TRUE the display won't be affected, no redraw is
6664  * triggered.
6665  */
6666     void
6667 restore_win(
6668     win_T	*save_curwin UNUSED,
6669     tabpage_T	*save_curtab UNUSED,
6670     int		no_display UNUSED)
6671 {
6672     if (save_curtab != NULL && valid_tabpage(save_curtab))
6673     {
6674 	if (no_display)
6675 	{
6676 	    curtab->tp_firstwin = firstwin;
6677 	    curtab->tp_lastwin = lastwin;
6678 	    curtab = save_curtab;
6679 	    firstwin = curtab->tp_firstwin;
6680 	    lastwin = curtab->tp_lastwin;
6681 	}
6682 	else
6683 	    goto_tabpage_tp(save_curtab, FALSE, FALSE);
6684     }
6685     if (win_valid(save_curwin))
6686     {
6687 	curwin = save_curwin;
6688 	curbuf = curwin->w_buffer;
6689     }
6690     unblock_autocmds();
6691 }
6692 
6693 /*
6694  * Make "buf" the current buffer.  restore_buffer() MUST be called to undo.
6695  * No autocommands will be executed.  Use aucmd_prepbuf() if there are any.
6696  */
6697     void
6698 switch_buffer(bufref_T *save_curbuf, buf_T *buf)
6699 {
6700     block_autocmds();
6701     set_bufref(save_curbuf, curbuf);
6702     --curbuf->b_nwindows;
6703     curbuf = buf;
6704     curwin->w_buffer = buf;
6705     ++curbuf->b_nwindows;
6706 }
6707 
6708 /*
6709  * Restore the current buffer after using switch_buffer().
6710  */
6711     void
6712 restore_buffer(bufref_T *save_curbuf)
6713 {
6714     unblock_autocmds();
6715     /* Check for valid buffer, just in case. */
6716     if (bufref_valid(save_curbuf))
6717     {
6718 	--curbuf->b_nwindows;
6719 	curwin->w_buffer = save_curbuf->br_buf;
6720 	curbuf = save_curbuf->br_buf;
6721 	++curbuf->b_nwindows;
6722     }
6723 }
6724 #endif
6725 
6726 #if defined(FEAT_GUI) || defined(PROTO)
6727 /*
6728  * Return TRUE if there is any vertically split window.
6729  */
6730     int
6731 win_hasvertsplit(void)
6732 {
6733     frame_T	*fr;
6734 
6735     if (topframe->fr_layout == FR_ROW)
6736 	return TRUE;
6737 
6738     if (topframe->fr_layout == FR_COL)
6739 	FOR_ALL_FRAMES(fr, topframe->fr_child)
6740 	    if (fr->fr_layout == FR_ROW)
6741 		return TRUE;
6742 
6743     return FALSE;
6744 }
6745 #endif
6746 
6747 #if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
6748 /*
6749  * Add match to the match list of window 'wp'.  The pattern 'pat' will be
6750  * highlighted with the group 'grp' with priority 'prio'.
6751  * Optionally, a desired ID 'id' can be specified (greater than or equal to 1).
6752  * If no particular ID is desired, -1 must be specified for 'id'.
6753  * Return ID of added match, -1 on failure.
6754  */
6755     int
6756 match_add(
6757     win_T	*wp,
6758     char_u	*grp,
6759     char_u	*pat,
6760     int		prio,
6761     int		id,
6762     list_T	*pos_list,
6763     char_u      *conceal_char UNUSED) /* pointer to conceal replacement char */
6764 {
6765     matchitem_T	*cur;
6766     matchitem_T	*prev;
6767     matchitem_T	*m;
6768     int		hlg_id;
6769     regprog_T	*regprog = NULL;
6770     int		rtype = SOME_VALID;
6771 
6772     if (*grp == NUL || (pat != NULL && *pat == NUL))
6773 	return -1;
6774     if (id < -1 || id == 0)
6775     {
6776 	semsg(_("E799: Invalid ID: %d (must be greater than or equal to 1)"), id);
6777 	return -1;
6778     }
6779     if (id != -1)
6780     {
6781 	cur = wp->w_match_head;
6782 	while (cur != NULL)
6783 	{
6784 	    if (cur->id == id)
6785 	    {
6786 		semsg(_("E801: ID already taken: %d"), id);
6787 		return -1;
6788 	    }
6789 	    cur = cur->next;
6790 	}
6791     }
6792     if ((hlg_id = syn_namen2id(grp, (int)STRLEN(grp))) == 0)
6793     {
6794 	semsg(_(e_nogroup), grp);
6795 	return -1;
6796     }
6797     if (pat != NULL && (regprog = vim_regcomp(pat, RE_MAGIC)) == NULL)
6798     {
6799 	semsg(_(e_invarg2), pat);
6800 	return -1;
6801     }
6802 
6803     /* Find available match ID. */
6804     while (id == -1)
6805     {
6806 	cur = wp->w_match_head;
6807 	while (cur != NULL && cur->id != wp->w_next_match_id)
6808 	    cur = cur->next;
6809 	if (cur == NULL)
6810 	    id = wp->w_next_match_id;
6811 	wp->w_next_match_id++;
6812     }
6813 
6814     /* Build new match. */
6815     m = (matchitem_T *)alloc_clear(sizeof(matchitem_T));
6816     m->id = id;
6817     m->priority = prio;
6818     m->pattern = pat == NULL ? NULL : vim_strsave(pat);
6819     m->hlg_id = hlg_id;
6820     m->match.regprog = regprog;
6821     m->match.rmm_ic = FALSE;
6822     m->match.rmm_maxcol = 0;
6823 # if defined(FEAT_CONCEAL)
6824     m->conceal_char = 0;
6825     if (conceal_char != NULL)
6826 	m->conceal_char = (*mb_ptr2char)(conceal_char);
6827 # endif
6828 
6829     /* Set up position matches */
6830     if (pos_list != NULL)
6831     {
6832 	linenr_T	toplnum = 0;
6833 	linenr_T	botlnum = 0;
6834 	listitem_T	*li;
6835 	int		i;
6836 
6837 	for (i = 0, li = pos_list->lv_first; li != NULL && i < MAXPOSMATCH;
6838 							i++, li = li->li_next)
6839 	{
6840 	    linenr_T	lnum = 0;
6841 	    colnr_T	col = 0;
6842 	    int		len = 1;
6843 	    list_T	*subl;
6844 	    listitem_T	*subli;
6845 	    int		error = FALSE;
6846 
6847 	    if (li->li_tv.v_type == VAR_LIST)
6848 	    {
6849 		subl = li->li_tv.vval.v_list;
6850 		if (subl == NULL)
6851 		    goto fail;
6852 		subli = subl->lv_first;
6853 		if (subli == NULL)
6854 		    goto fail;
6855 		lnum = tv_get_number_chk(&subli->li_tv, &error);
6856 		if (error == TRUE)
6857 		    goto fail;
6858 		if (lnum == 0)
6859 		{
6860 		    --i;
6861 		    continue;
6862 		}
6863 		m->pos.pos[i].lnum = lnum;
6864 		subli = subli->li_next;
6865 		if (subli != NULL)
6866 		{
6867 		    col = tv_get_number_chk(&subli->li_tv, &error);
6868 		    if (error == TRUE)
6869 			goto fail;
6870 		    subli = subli->li_next;
6871 		    if (subli != NULL)
6872 		    {
6873 			len = tv_get_number_chk(&subli->li_tv, &error);
6874 			if (error == TRUE)
6875 			    goto fail;
6876 		    }
6877 		}
6878 		m->pos.pos[i].col = col;
6879 		m->pos.pos[i].len = len;
6880 	    }
6881 	    else if (li->li_tv.v_type == VAR_NUMBER)
6882 	    {
6883 		if (li->li_tv.vval.v_number == 0)
6884 		{
6885 		    --i;
6886 		    continue;
6887 		}
6888 		m->pos.pos[i].lnum = li->li_tv.vval.v_number;
6889 		m->pos.pos[i].col = 0;
6890 		m->pos.pos[i].len = 0;
6891 	    }
6892 	    else
6893 	    {
6894 		emsg(_("List or number required"));
6895 		goto fail;
6896 	    }
6897 	    if (toplnum == 0 || lnum < toplnum)
6898 		toplnum = lnum;
6899 	    if (botlnum == 0 || lnum >= botlnum)
6900 		botlnum = lnum + 1;
6901 	}
6902 
6903 	/* Calculate top and bottom lines for redrawing area */
6904 	if (toplnum != 0)
6905 	{
6906 	    if (wp->w_buffer->b_mod_set)
6907 	    {
6908 		if (wp->w_buffer->b_mod_top > toplnum)
6909 		    wp->w_buffer->b_mod_top = toplnum;
6910 		if (wp->w_buffer->b_mod_bot < botlnum)
6911 		    wp->w_buffer->b_mod_bot = botlnum;
6912 	    }
6913 	    else
6914 	    {
6915 		wp->w_buffer->b_mod_set = TRUE;
6916 		wp->w_buffer->b_mod_top = toplnum;
6917 		wp->w_buffer->b_mod_bot = botlnum;
6918 		wp->w_buffer->b_mod_xlines = 0;
6919 	    }
6920 	    m->pos.toplnum = toplnum;
6921 	    m->pos.botlnum = botlnum;
6922 	    rtype = VALID;
6923 	}
6924     }
6925 
6926     /* Insert new match.  The match list is in ascending order with regard to
6927      * the match priorities. */
6928     cur = wp->w_match_head;
6929     prev = cur;
6930     while (cur != NULL && prio >= cur->priority)
6931     {
6932 	prev = cur;
6933 	cur = cur->next;
6934     }
6935     if (cur == prev)
6936 	wp->w_match_head = m;
6937     else
6938 	prev->next = m;
6939     m->next = cur;
6940 
6941     redraw_later(rtype);
6942     return id;
6943 
6944 fail:
6945     vim_free(m);
6946     return -1;
6947 }
6948 
6949 /*
6950  * Delete match with ID 'id' in the match list of window 'wp'.
6951  * Print error messages if 'perr' is TRUE.
6952  */
6953     int
6954 match_delete(win_T *wp, int id, int perr)
6955 {
6956     matchitem_T	*cur = wp->w_match_head;
6957     matchitem_T	*prev = cur;
6958     int		rtype = SOME_VALID;
6959 
6960     if (id < 1)
6961     {
6962 	if (perr == TRUE)
6963 	    semsg(_("E802: Invalid ID: %d (must be greater than or equal to 1)"),
6964 									  id);
6965 	return -1;
6966     }
6967     while (cur != NULL && cur->id != id)
6968     {
6969 	prev = cur;
6970 	cur = cur->next;
6971     }
6972     if (cur == NULL)
6973     {
6974 	if (perr == TRUE)
6975 	    semsg(_("E803: ID not found: %d"), id);
6976 	return -1;
6977     }
6978     if (cur == prev)
6979 	wp->w_match_head = cur->next;
6980     else
6981 	prev->next = cur->next;
6982     vim_regfree(cur->match.regprog);
6983     vim_free(cur->pattern);
6984     if (cur->pos.toplnum != 0)
6985     {
6986 	if (wp->w_buffer->b_mod_set)
6987 	{
6988 	    if (wp->w_buffer->b_mod_top > cur->pos.toplnum)
6989 		wp->w_buffer->b_mod_top = cur->pos.toplnum;
6990 	    if (wp->w_buffer->b_mod_bot < cur->pos.botlnum)
6991 		wp->w_buffer->b_mod_bot = cur->pos.botlnum;
6992 	}
6993 	else
6994 	{
6995 	    wp->w_buffer->b_mod_set = TRUE;
6996 	    wp->w_buffer->b_mod_top = cur->pos.toplnum;
6997 	    wp->w_buffer->b_mod_bot = cur->pos.botlnum;
6998 	    wp->w_buffer->b_mod_xlines = 0;
6999 	}
7000 	rtype = VALID;
7001     }
7002     vim_free(cur);
7003     redraw_later(rtype);
7004     return 0;
7005 }
7006 
7007 /*
7008  * Delete all matches in the match list of window 'wp'.
7009  */
7010     void
7011 clear_matches(win_T *wp)
7012 {
7013     matchitem_T *m;
7014 
7015     while (wp->w_match_head != NULL)
7016     {
7017 	m = wp->w_match_head->next;
7018 	vim_regfree(wp->w_match_head->match.regprog);
7019 	vim_free(wp->w_match_head->pattern);
7020 	vim_free(wp->w_match_head);
7021 	wp->w_match_head = m;
7022     }
7023     redraw_later(SOME_VALID);
7024 }
7025 
7026 /*
7027  * Get match from ID 'id' in window 'wp'.
7028  * Return NULL if match not found.
7029  */
7030     matchitem_T *
7031 get_match(win_T *wp, int id)
7032 {
7033     matchitem_T *cur = wp->w_match_head;
7034 
7035     while (cur != NULL && cur->id != id)
7036 	cur = cur->next;
7037     return cur;
7038 }
7039 #endif
7040 
7041 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
7042     int
7043 get_win_number(win_T *wp, win_T *first_win)
7044 {
7045     int		i = 1;
7046     win_T	*w;
7047 
7048     for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
7049 	++i;
7050 
7051     if (w == NULL)
7052 	return 0;
7053     else
7054 	return i;
7055 }
7056 
7057     int
7058 get_tab_number(tabpage_T *tp UNUSED)
7059 {
7060     int		i = 1;
7061     tabpage_T	*t;
7062 
7063     for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
7064 	++i;
7065 
7066     if (t == NULL)
7067 	return 0;
7068     else
7069 	return i;
7070 }
7071 #endif
7072 
7073 /*
7074  * Return TRUE if "topfrp" and its children are at the right height.
7075  */
7076     static int
7077 frame_check_height(frame_T *topfrp, int height)
7078 {
7079     frame_T *frp;
7080 
7081     if (topfrp->fr_height != height)
7082 	return FALSE;
7083 
7084     if (topfrp->fr_layout == FR_ROW)
7085 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
7086 	    if (frp->fr_height != height)
7087 		return FALSE;
7088 
7089     return TRUE;
7090 }
7091 
7092 /*
7093  * Return TRUE if "topfrp" and its children are at the right width.
7094  */
7095     static int
7096 frame_check_width(frame_T *topfrp, int width)
7097 {
7098     frame_T *frp;
7099 
7100     if (topfrp->fr_width != width)
7101 	return FALSE;
7102 
7103     if (topfrp->fr_layout == FR_COL)
7104 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
7105 	    if (frp->fr_width != width)
7106 		return FALSE;
7107 
7108     return TRUE;
7109 }
7110 
7111 #if defined(FEAT_EVAL) || defined(PROTO)
7112     int
7113 win_getid(typval_T *argvars)
7114 {
7115     int	    winnr;
7116     win_T   *wp;
7117 
7118     if (argvars[0].v_type == VAR_UNKNOWN)
7119 	return curwin->w_id;
7120     winnr = tv_get_number(&argvars[0]);
7121     if (winnr > 0)
7122     {
7123 	if (argvars[1].v_type == VAR_UNKNOWN)
7124 	    wp = firstwin;
7125 	else
7126 	{
7127 	    tabpage_T	*tp;
7128 	    int		tabnr = tv_get_number(&argvars[1]);
7129 
7130 	    FOR_ALL_TABPAGES(tp)
7131 		if (--tabnr == 0)
7132 		    break;
7133 	    if (tp == NULL)
7134 		return -1;
7135 	    if (tp == curtab)
7136 		wp = firstwin;
7137 	    else
7138 		wp = tp->tp_firstwin;
7139 	}
7140 	for ( ; wp != NULL; wp = wp->w_next)
7141 	    if (--winnr == 0)
7142 		return wp->w_id;
7143     }
7144     return 0;
7145 }
7146 
7147     int
7148 win_gotoid(typval_T *argvars)
7149 {
7150     win_T	*wp;
7151     tabpage_T   *tp;
7152     int		id = tv_get_number(&argvars[0]);
7153 
7154     FOR_ALL_TAB_WINDOWS(tp, wp)
7155 	    if (wp->w_id == id)
7156 	    {
7157 		goto_tabpage_win(tp, wp);
7158 		return 1;
7159 	    }
7160     return 0;
7161 }
7162 
7163     void
7164 win_id2tabwin(typval_T *argvars, list_T *list)
7165 {
7166     win_T	*wp;
7167     tabpage_T   *tp;
7168     int		winnr = 1;
7169     int		tabnr = 1;
7170     int		id = tv_get_number(&argvars[0]);
7171 
7172     FOR_ALL_TABPAGES(tp)
7173     {
7174 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
7175 	{
7176 	    if (wp->w_id == id)
7177 	    {
7178 		list_append_number(list, tabnr);
7179 		list_append_number(list, winnr);
7180 		return;
7181 	    }
7182 	    ++winnr;
7183 	}
7184 	++tabnr;
7185 	winnr = 1;
7186     }
7187     list_append_number(list, 0);
7188     list_append_number(list, 0);
7189 }
7190 
7191     win_T *
7192 win_id2wp(typval_T *argvars)
7193 {
7194     win_T	*wp;
7195     tabpage_T   *tp;
7196     int		id = tv_get_number(&argvars[0]);
7197 
7198     FOR_ALL_TAB_WINDOWS(tp, wp)
7199 	if (wp->w_id == id)
7200 	    return wp;
7201 
7202     return NULL;
7203 }
7204 
7205     int
7206 win_id2win(typval_T *argvars)
7207 {
7208     win_T   *wp;
7209     int	    nr = 1;
7210     int	    id = tv_get_number(&argvars[0]);
7211 
7212     FOR_ALL_WINDOWS(wp)
7213     {
7214 	if (wp->w_id == id)
7215 	    return nr;
7216 	++nr;
7217     }
7218     return 0;
7219 }
7220 
7221     void
7222 win_findbuf(typval_T *argvars, list_T *list)
7223 {
7224     win_T	*wp;
7225     tabpage_T   *tp;
7226     int		bufnr = tv_get_number(&argvars[0]);
7227 
7228     FOR_ALL_TAB_WINDOWS(tp, wp)
7229 	    if (wp->w_buffer->b_fnum == bufnr)
7230 		list_append_number(list, wp->w_id);
7231 }
7232 
7233 /*
7234  * Get the layout of the given tab page for winlayout().
7235  */
7236     void
7237 get_framelayout(frame_T *fr, list_T *l, int outer)
7238 {
7239     frame_T	*child;
7240     list_T	*fr_list;
7241     list_T	*win_list;
7242 
7243     if (fr == NULL)
7244 	return;
7245 
7246     if (outer)
7247 	// outermost call from f_winlayout()
7248 	fr_list = l;
7249     else
7250     {
7251 	fr_list = list_alloc();
7252 	if (fr_list == NULL)
7253 	    return;
7254 	list_append_list(l, fr_list);
7255     }
7256 
7257     if (fr->fr_layout == FR_LEAF)
7258     {
7259 	if (fr->fr_win != NULL)
7260 	{
7261 	    list_append_string(fr_list, (char_u *)"leaf", -1);
7262 	    list_append_number(fr_list, fr->fr_win->w_id);
7263 	}
7264     }
7265     else
7266     {
7267 	list_append_string(fr_list,
7268 	     fr->fr_layout == FR_ROW ?  (char_u *)"row" : (char_u *)"col", -1);
7269 
7270 	win_list = list_alloc();
7271 	if (win_list == NULL)
7272 	    return;
7273 	list_append_list(fr_list, win_list);
7274 	child = fr->fr_child;
7275 	while (child != NULL)
7276 	{
7277 	    get_framelayout(child, win_list, FALSE);
7278 	    child = child->fr_next;
7279 	}
7280     }
7281 }
7282 #endif
7283