xref: /vim-8.2.3635/src/window.c (revision 7c63fbc4)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read a list of people who contributed.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 #include "vim.h"
11 
12 static int path_is_url(char_u *p);
13 static void cmd_with_count(char *cmd, char_u *bufp, size_t bufsize, long Prenum);
14 static void win_init(win_T *newp, win_T *oldp, int flags);
15 static void win_init_some(win_T *newp, win_T *oldp);
16 static void frame_comp_pos(frame_T *topfrp, int *row, int *col);
17 static void frame_setheight(frame_T *curfrp, int height);
18 static void frame_setwidth(frame_T *curfrp, int width);
19 static void win_exchange(long);
20 static void win_rotate(int, int);
21 static void win_totop(int size, int flags);
22 static void win_equal_rec(win_T *next_curwin, int current, frame_T *topfr, int dir, int col, int row, int width, int height);
23 static int last_window(void);
24 static int close_last_window_tabpage(win_T *win, int free_buf, tabpage_T *prev_curtab);
25 static win_T *win_free_mem(win_T *win, int *dirp, tabpage_T *tp);
26 static frame_T *win_altframe(win_T *win, tabpage_T *tp);
27 static tabpage_T *alt_tabpage(void);
28 static win_T *frame2win(frame_T *frp);
29 static int frame_has_win(frame_T *frp, win_T *wp);
30 static void frame_new_height(frame_T *topfrp, int height, int topfirst, int wfh);
31 static int frame_fixed_height(frame_T *frp);
32 static int frame_fixed_width(frame_T *frp);
33 static void frame_add_statusline(frame_T *frp);
34 static void frame_new_width(frame_T *topfrp, int width, int leftfirst, int wfw);
35 static void frame_add_vsep(frame_T *frp);
36 static int frame_minwidth(frame_T *topfrp, win_T *next_curwin);
37 static void frame_fix_width(win_T *wp);
38 static int win_alloc_firstwin(win_T *oldwin);
39 static void new_frame(win_T *wp);
40 static tabpage_T *alloc_tabpage(void);
41 static int leave_tabpage(buf_T *new_curbuf, int trigger_leave_autocmds);
42 static void enter_tabpage(tabpage_T *tp, buf_T *old_curbuf, int trigger_enter_autocmds, int trigger_leave_autocmds);
43 static void frame_fix_height(win_T *wp);
44 static int frame_minheight(frame_T *topfrp, win_T *next_curwin);
45 static void win_enter_ext(win_T *wp, int undo_sync, int no_curwin, int trigger_new_autocmds, int trigger_enter_autocmds, int trigger_leave_autocmds);
46 static void win_free(win_T *wp, tabpage_T *tp);
47 static void frame_append(frame_T *after, frame_T *frp);
48 static void frame_insert(frame_T *before, frame_T *frp);
49 static void frame_remove(frame_T *frp);
50 static void win_goto_ver(int up, long count);
51 static void win_goto_hor(int left, long count);
52 static void frame_add_height(frame_T *frp, int n);
53 static void last_status_rec(frame_T *fr, int statusline);
54 
55 static void make_snapshot_rec(frame_T *fr, frame_T **frp);
56 static void clear_snapshot(tabpage_T *tp, int idx);
57 static void clear_snapshot_rec(frame_T *fr);
58 static int check_snapshot_rec(frame_T *sn, frame_T *fr);
59 static win_T *restore_snapshot_rec(frame_T *sn, frame_T *fr);
60 
61 static int frame_check_height(frame_T *topfrp, int height);
62 static int frame_check_width(frame_T *topfrp, int width);
63 
64 static win_T *win_alloc(win_T *after, int hidden);
65 
66 #define URL_SLASH	1		/* path_is_url() has found "://" */
67 #define URL_BACKSLASH	2		/* path_is_url() has found ":\\" */
68 
69 #define NOWIN		(win_T *)-1	/* non-existing window */
70 
71 #define ROWS_AVAIL (Rows - p_ch - tabline_height())
72 
73 static char *m_onlyone = N_("Already only one window");
74 
75 /*
76  * all CTRL-W window commands are handled here, called from normal_cmd().
77  */
78     void
79 do_window(
80     int		nchar,
81     long	Prenum,
82     int		xchar)	    /* extra char from ":wincmd gx" or NUL */
83 {
84     long	Prenum1;
85     win_T	*wp;
86 #if defined(FEAT_SEARCHPATH) || defined(FEAT_FIND_ID)
87     char_u	*ptr;
88     linenr_T    lnum = -1;
89 #endif
90 #ifdef FEAT_FIND_ID
91     int		type = FIND_DEFINE;
92     int		len;
93 #endif
94     char_u	cbuf[40];
95 
96     if (Prenum == 0)
97 	Prenum1 = 1;
98     else
99 	Prenum1 = Prenum;
100 
101 #ifdef FEAT_CMDWIN
102 # define CHECK_CMDWIN \
103     do { \
104 	if (cmdwin_type != 0) \
105 	{ \
106 	    EMSG(_(e_cmdwin)); \
107 	    return; \
108 	} \
109     } while (0)
110 #else
111 # define CHECK_CMDWIN do { /**/ } while (0)
112 #endif
113 
114     switch (nchar)
115     {
116 /* split current window in two parts, horizontally */
117     case 'S':
118     case Ctrl_S:
119     case 's':
120 		CHECK_CMDWIN;
121 		reset_VIsual_and_resel();	/* stop Visual mode */
122 #ifdef FEAT_QUICKFIX
123 		/* When splitting the quickfix window open a new buffer in it,
124 		 * don't replicate the quickfix buffer. */
125 		if (bt_quickfix(curbuf))
126 		    goto newwindow;
127 #endif
128 #ifdef FEAT_GUI
129 		need_mouse_correct = TRUE;
130 #endif
131 		(void)win_split((int)Prenum, 0);
132 		break;
133 
134 /* split current window in two parts, vertically */
135     case Ctrl_V:
136     case 'v':
137 		CHECK_CMDWIN;
138 		reset_VIsual_and_resel();	/* stop Visual mode */
139 #ifdef FEAT_QUICKFIX
140 		/* When splitting the quickfix window open a new buffer in it,
141 		 * don't replicate the quickfix buffer. */
142 		if (bt_quickfix(curbuf))
143 		    goto newwindow;
144 #endif
145 #ifdef FEAT_GUI
146 		need_mouse_correct = TRUE;
147 #endif
148 		(void)win_split((int)Prenum, WSP_VERT);
149 		break;
150 
151 /* split current window and edit alternate file */
152     case Ctrl_HAT:
153     case '^':
154 		CHECK_CMDWIN;
155 		reset_VIsual_and_resel();	/* stop Visual mode */
156 		cmd_with_count("split #", cbuf, sizeof(cbuf), Prenum);
157 		do_cmdline_cmd(cbuf);
158 		break;
159 
160 /* open new window */
161     case Ctrl_N:
162     case 'n':
163 		CHECK_CMDWIN;
164 		reset_VIsual_and_resel();	/* stop Visual mode */
165 #ifdef FEAT_QUICKFIX
166 newwindow:
167 #endif
168 		if (Prenum)
169 		    /* window height */
170 		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
171 		else
172 		    cbuf[0] = NUL;
173 #if defined(FEAT_QUICKFIX)
174 		if (nchar == 'v' || nchar == Ctrl_V)
175 		    STRCAT(cbuf, "v");
176 #endif
177 		STRCAT(cbuf, "new");
178 		do_cmdline_cmd(cbuf);
179 		break;
180 
181 /* quit current window */
182     case Ctrl_Q:
183     case 'q':
184 		reset_VIsual_and_resel();	/* stop Visual mode */
185 		cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
186 		do_cmdline_cmd(cbuf);
187 		break;
188 
189 /* close current window */
190     case Ctrl_C:
191     case 'c':
192 		reset_VIsual_and_resel();	/* stop Visual mode */
193 		cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
194 		do_cmdline_cmd(cbuf);
195 		break;
196 
197 #if defined(FEAT_QUICKFIX)
198 /* close preview window */
199     case Ctrl_Z:
200     case 'z':
201 		CHECK_CMDWIN;
202 		reset_VIsual_and_resel();	/* stop Visual mode */
203 		do_cmdline_cmd((char_u *)"pclose");
204 		break;
205 
206 /* cursor to preview window */
207     case 'P':
208 		FOR_ALL_WINDOWS(wp)
209 		    if (wp->w_p_pvw)
210 			break;
211 		if (wp == NULL)
212 		    EMSG(_("E441: There is no preview window"));
213 		else
214 		    win_goto(wp);
215 		break;
216 #endif
217 
218 /* close all but current window */
219     case Ctrl_O:
220     case 'o':
221 		CHECK_CMDWIN;
222 		reset_VIsual_and_resel();	/* stop Visual mode */
223 		cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
224 		do_cmdline_cmd(cbuf);
225 		break;
226 
227 /* cursor to next window with wrap around */
228     case Ctrl_W:
229     case 'w':
230 /* cursor to previous window with wrap around */
231     case 'W':
232 		CHECK_CMDWIN;
233 		if (ONE_WINDOW && Prenum != 1)	/* just one window */
234 		    beep_flush();
235 		else
236 		{
237 		    if (Prenum)			/* go to specified window */
238 		    {
239 			for (wp = firstwin; --Prenum > 0; )
240 			{
241 			    if (wp->w_next == NULL)
242 				break;
243 			    else
244 				wp = wp->w_next;
245 			}
246 		    }
247 		    else
248 		    {
249 			if (nchar == 'W')	    /* go to previous window */
250 			{
251 			    wp = curwin->w_prev;
252 			    if (wp == NULL)
253 				wp = lastwin;	    /* wrap around */
254 			}
255 			else			    /* go to next window */
256 			{
257 			    wp = curwin->w_next;
258 			    if (wp == NULL)
259 				wp = firstwin;	    /* wrap around */
260 			}
261 		    }
262 		    win_goto(wp);
263 		}
264 		break;
265 
266 /* cursor to window below */
267     case 'j':
268     case K_DOWN:
269     case Ctrl_J:
270 		CHECK_CMDWIN;
271 		win_goto_ver(FALSE, Prenum1);
272 		break;
273 
274 /* cursor to window above */
275     case 'k':
276     case K_UP:
277     case Ctrl_K:
278 		CHECK_CMDWIN;
279 		win_goto_ver(TRUE, Prenum1);
280 		break;
281 
282 /* cursor to left window */
283     case 'h':
284     case K_LEFT:
285     case Ctrl_H:
286     case K_BS:
287 		CHECK_CMDWIN;
288 		win_goto_hor(TRUE, Prenum1);
289 		break;
290 
291 /* cursor to right window */
292     case 'l':
293     case K_RIGHT:
294     case Ctrl_L:
295 		CHECK_CMDWIN;
296 		win_goto_hor(FALSE, Prenum1);
297 		break;
298 
299 /* move window to new tab page */
300     case 'T':
301 		if (one_window())
302 		    MSG(_(m_onlyone));
303 		else
304 		{
305 		    tabpage_T	*oldtab = curtab;
306 		    tabpage_T	*newtab;
307 
308 		    /* First create a new tab with the window, then go back to
309 		     * the old tab and close the window there. */
310 		    wp = curwin;
311 		    if (win_new_tabpage((int)Prenum) == OK
312 						     && valid_tabpage(oldtab))
313 		    {
314 			newtab = curtab;
315 			goto_tabpage_tp(oldtab, TRUE, TRUE);
316 			if (curwin == wp)
317 			    win_close(curwin, FALSE);
318 			if (valid_tabpage(newtab))
319 			    goto_tabpage_tp(newtab, TRUE, TRUE);
320 		    }
321 		}
322 		break;
323 
324 /* cursor to top-left window */
325     case 't':
326     case Ctrl_T:
327 		win_goto(firstwin);
328 		break;
329 
330 /* cursor to bottom-right window */
331     case 'b':
332     case Ctrl_B:
333 		win_goto(lastwin);
334 		break;
335 
336 /* cursor to last accessed (previous) window */
337     case 'p':
338     case Ctrl_P:
339 		if (!win_valid(prevwin))
340 		    beep_flush();
341 		else
342 		    win_goto(prevwin);
343 		break;
344 
345 /* exchange current and next window */
346     case 'x':
347     case Ctrl_X:
348 		CHECK_CMDWIN;
349 		win_exchange(Prenum);
350 		break;
351 
352 /* rotate windows downwards */
353     case Ctrl_R:
354     case 'r':
355 		CHECK_CMDWIN;
356 		reset_VIsual_and_resel();	/* stop Visual mode */
357 		win_rotate(FALSE, (int)Prenum1);    /* downwards */
358 		break;
359 
360 /* rotate windows upwards */
361     case 'R':
362 		CHECK_CMDWIN;
363 		reset_VIsual_and_resel();	/* stop Visual mode */
364 		win_rotate(TRUE, (int)Prenum1);	    /* upwards */
365 		break;
366 
367 /* move window to the very top/bottom/left/right */
368     case 'K':
369     case 'J':
370     case 'H':
371     case 'L':
372 		CHECK_CMDWIN;
373 		win_totop((int)Prenum,
374 			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
375 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
376 		break;
377 
378 /* make all windows the same height */
379     case '=':
380 #ifdef FEAT_GUI
381 		need_mouse_correct = TRUE;
382 #endif
383 		win_equal(NULL, FALSE, 'b');
384 		break;
385 
386 /* increase current window height */
387     case '+':
388 #ifdef FEAT_GUI
389 		need_mouse_correct = TRUE;
390 #endif
391 		win_setheight(curwin->w_height + (int)Prenum1);
392 		break;
393 
394 /* decrease current window height */
395     case '-':
396 #ifdef FEAT_GUI
397 		need_mouse_correct = TRUE;
398 #endif
399 		win_setheight(curwin->w_height - (int)Prenum1);
400 		break;
401 
402 /* set current window height */
403     case Ctrl__:
404     case '_':
405 #ifdef FEAT_GUI
406 		need_mouse_correct = TRUE;
407 #endif
408 		win_setheight(Prenum ? (int)Prenum : 9999);
409 		break;
410 
411 /* increase current window width */
412     case '>':
413 #ifdef FEAT_GUI
414 		need_mouse_correct = TRUE;
415 #endif
416 		win_setwidth(curwin->w_width + (int)Prenum1);
417 		break;
418 
419 /* decrease current window width */
420     case '<':
421 #ifdef FEAT_GUI
422 		need_mouse_correct = TRUE;
423 #endif
424 		win_setwidth(curwin->w_width - (int)Prenum1);
425 		break;
426 
427 /* set current window width */
428     case '|':
429 #ifdef FEAT_GUI
430 		need_mouse_correct = TRUE;
431 #endif
432 		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
433 		break;
434 
435 /* jump to tag and split window if tag exists (in preview window) */
436 #if defined(FEAT_QUICKFIX)
437     case '}':
438 		CHECK_CMDWIN;
439 		if (Prenum)
440 		    g_do_tagpreview = Prenum;
441 		else
442 		    g_do_tagpreview = p_pvh;
443 #endif
444 		/* FALLTHROUGH */
445     case ']':
446     case Ctrl_RSB:
447 		CHECK_CMDWIN;
448 		/* keep Visual mode, can select words to use as a tag */
449 		if (Prenum)
450 		    postponed_split = Prenum;
451 		else
452 		    postponed_split = -1;
453 #ifdef FEAT_QUICKFIX
454 		if (nchar != '}')
455 		    g_do_tagpreview = 0;
456 #endif
457 
458 		/* Execute the command right here, required when "wincmd ]"
459 		 * was used in a function. */
460 		do_nv_ident(Ctrl_RSB, NUL);
461 		break;
462 
463 #ifdef FEAT_SEARCHPATH
464 /* edit file name under cursor in a new window */
465     case 'f':
466     case 'F':
467     case Ctrl_F:
468 wingotofile:
469 		CHECK_CMDWIN;
470 
471 		ptr = grab_file_name(Prenum1, &lnum);
472 		if (ptr != NULL)
473 		{
474 		    tabpage_T	*oldtab = curtab;
475 		    win_T	*oldwin = curwin;
476 # ifdef FEAT_GUI
477 		    need_mouse_correct = TRUE;
478 # endif
479 		    setpcmark();
480 		    if (win_split(0, 0) == OK)
481 		    {
482 			RESET_BINDING(curwin);
483 			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
484 						   ECMD_HIDE, NULL) == FAIL)
485 			{
486 			    /* Failed to open the file, close the window
487 			     * opened for it. */
488 			    win_close(curwin, FALSE);
489 			    goto_tabpage_win(oldtab, oldwin);
490 			}
491 			else if (nchar == 'F' && lnum >= 0)
492 			{
493 			    curwin->w_cursor.lnum = lnum;
494 			    check_cursor_lnum();
495 			    beginline(BL_SOL | BL_FIX);
496 			}
497 		    }
498 		    vim_free(ptr);
499 		}
500 		break;
501 #endif
502 
503 #ifdef FEAT_FIND_ID
504 /* Go to the first occurrence of the identifier under cursor along path in a
505  * new window -- webb
506  */
507     case 'i':			    /* Go to any match */
508     case Ctrl_I:
509 		type = FIND_ANY;
510 		/* FALLTHROUGH */
511     case 'd':			    /* Go to definition, using 'define' */
512     case Ctrl_D:
513 		CHECK_CMDWIN;
514 		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
515 		    break;
516 		find_pattern_in_path(ptr, 0, len, TRUE,
517 			Prenum == 0 ? TRUE : FALSE, type,
518 			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
519 		curwin->w_set_curswant = TRUE;
520 		break;
521 #endif
522 
523     case K_KENTER:
524     case CAR:
525 #if defined(FEAT_QUICKFIX)
526 		/*
527 		 * In a quickfix window a <CR> jumps to the error under the
528 		 * cursor in a new window.
529 		 */
530 		if (bt_quickfix(curbuf))
531 		{
532 		    sprintf((char *)cbuf, "split +%ld%s",
533 				(long)curwin->w_cursor.lnum,
534 				(curwin->w_llist_ref == NULL) ? "cc" : "ll");
535 		    do_cmdline_cmd(cbuf);
536 		}
537 #endif
538 		break;
539 
540 
541 /* CTRL-W g  extended commands */
542     case 'g':
543     case Ctrl_G:
544 		CHECK_CMDWIN;
545 #ifdef USE_ON_FLY_SCROLL
546 		dont_scroll = TRUE;		/* disallow scrolling here */
547 #endif
548 		++no_mapping;
549 		++allow_keys;   /* no mapping for xchar, but allow key codes */
550 		if (xchar == NUL)
551 		    xchar = plain_vgetc();
552 		LANGMAP_ADJUST(xchar, TRUE);
553 		--no_mapping;
554 		--allow_keys;
555 #ifdef FEAT_CMDL_INFO
556 		(void)add_to_showcmd(xchar);
557 #endif
558 		switch (xchar)
559 		{
560 #if defined(FEAT_QUICKFIX)
561 		    case '}':
562 			xchar = Ctrl_RSB;
563 			if (Prenum)
564 			    g_do_tagpreview = Prenum;
565 			else
566 			    g_do_tagpreview = p_pvh;
567 #endif
568 			/* FALLTHROUGH */
569 		    case ']':
570 		    case Ctrl_RSB:
571 			/* keep Visual mode, can select words to use as a tag */
572 			if (Prenum)
573 			    postponed_split = Prenum;
574 			else
575 			    postponed_split = -1;
576 
577 			/* Execute the command right here, required when
578 			 * "wincmd g}" was used in a function. */
579 			do_nv_ident('g', xchar);
580 			break;
581 
582 #ifdef FEAT_SEARCHPATH
583 		    case 'f':	    /* CTRL-W gf: "gf" in a new tab page */
584 		    case 'F':	    /* CTRL-W gF: "gF" in a new tab page */
585 			cmdmod.tab = tabpage_index(curtab) + 1;
586 			nchar = xchar;
587 			goto wingotofile;
588 #endif
589 		    default:
590 			beep_flush();
591 			break;
592 		}
593 		break;
594 
595     default:	beep_flush();
596 		break;
597     }
598 }
599 
600 /*
601  * Figure out the address type for ":wnncmd".
602  */
603     void
604 get_wincmd_addr_type(char_u *arg, exarg_T *eap)
605 {
606     switch (*arg)
607     {
608     case 'S':
609     case Ctrl_S:
610     case 's':
611     case Ctrl_N:
612     case 'n':
613     case 'j':
614     case Ctrl_J:
615     case 'k':
616     case Ctrl_K:
617     case 'T':
618     case Ctrl_R:
619     case 'r':
620     case 'R':
621     case 'K':
622     case 'J':
623     case '+':
624     case '-':
625     case Ctrl__:
626     case '_':
627     case '|':
628     case ']':
629     case Ctrl_RSB:
630     case 'g':
631     case Ctrl_G:
632     case Ctrl_V:
633     case 'v':
634     case 'h':
635     case Ctrl_H:
636     case 'l':
637     case Ctrl_L:
638     case 'H':
639     case 'L':
640     case '>':
641     case '<':
642 #if defined(FEAT_QUICKFIX)
643     case '}':
644 #endif
645 #ifdef FEAT_SEARCHPATH
646     case 'f':
647     case 'F':
648     case Ctrl_F:
649 #endif
650 #ifdef FEAT_FIND_ID
651     case 'i':
652     case Ctrl_I:
653     case 'd':
654     case Ctrl_D:
655 #endif
656 		/* window size or any count */
657 		eap->addr_type = ADDR_LINES;
658 		break;
659 
660     case Ctrl_HAT:
661     case '^':
662 		/* buffer number */
663 		eap->addr_type = ADDR_BUFFERS;
664 		break;
665 
666     case Ctrl_Q:
667     case 'q':
668     case Ctrl_C:
669     case 'c':
670     case Ctrl_O:
671     case 'o':
672     case Ctrl_W:
673     case 'w':
674     case 'W':
675     case 'x':
676     case Ctrl_X:
677 		/* window number */
678 		eap->addr_type = ADDR_WINDOWS;
679 		break;
680 
681 #if defined(FEAT_QUICKFIX)
682     case Ctrl_Z:
683     case 'z':
684     case 'P':
685 #endif
686     case 't':
687     case Ctrl_T:
688     case 'b':
689     case Ctrl_B:
690     case 'p':
691     case Ctrl_P:
692     case '=':
693     case CAR:
694 		/* no count */
695 		eap->addr_type = 0;
696 		break;
697     }
698 }
699 
700     static void
701 cmd_with_count(
702     char	*cmd,
703     char_u	*bufp,
704     size_t	bufsize,
705     long	Prenum)
706 {
707     size_t	len = STRLEN(cmd);
708 
709     STRCPY(bufp, cmd);
710     if (Prenum > 0)
711 	vim_snprintf((char *)bufp + len, bufsize - len, "%ld", Prenum);
712 }
713 
714 /*
715  * split the current window, implements CTRL-W s and :split
716  *
717  * "size" is the height or width for the new window, 0 to use half of current
718  * height or width.
719  *
720  * "flags":
721  * WSP_ROOM: require enough room for new window
722  * WSP_VERT: vertical split.
723  * WSP_TOP:  open window at the top-left of the shell (help window).
724  * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
725  * WSP_HELP: creating the help window, keep layout snapshot
726  *
727  * return FAIL for failure, OK otherwise
728  */
729     int
730 win_split(int size, int flags)
731 {
732     /* When the ":tab" modifier was used open a new tab page instead. */
733     if (may_open_tabpage() == OK)
734 	return OK;
735 
736     /* Add flags from ":vertical", ":topleft" and ":botright". */
737     flags |= cmdmod.split;
738     if ((flags & WSP_TOP) && (flags & WSP_BOT))
739     {
740 	EMSG(_("E442: Can't split topleft and botright at the same time"));
741 	return FAIL;
742     }
743 
744     /* When creating the help window make a snapshot of the window layout.
745      * Otherwise clear the snapshot, it's now invalid. */
746     if (flags & WSP_HELP)
747 	make_snapshot(SNAP_HELP_IDX);
748     else
749 	clear_snapshot(curtab, SNAP_HELP_IDX);
750 
751     return win_split_ins(size, flags, NULL, 0);
752 }
753 
754 /*
755  * When "new_wp" is NULL: split the current window in two.
756  * When "new_wp" is not NULL: insert this window at the far
757  * top/left/right/bottom.
758  * return FAIL for failure, OK otherwise
759  */
760     int
761 win_split_ins(
762     int		size,
763     int		flags,
764     win_T	*new_wp,
765     int		dir)
766 {
767     win_T	*wp = new_wp;
768     win_T	*oldwin;
769     int		new_size = size;
770     int		i;
771     int		need_status = 0;
772     int		do_equal = FALSE;
773     int		needed;
774     int		available;
775     int		oldwin_height = 0;
776     int		layout;
777     frame_T	*frp, *curfrp, *frp2, *prevfrp;
778     int		before;
779     int		minheight;
780     int		wmh1;
781     int		did_set_fraction = FALSE;
782 
783     if (flags & WSP_TOP)
784 	oldwin = firstwin;
785     else if (flags & WSP_BOT)
786 	oldwin = lastwin;
787     else
788 	oldwin = curwin;
789 
790     /* add a status line when p_ls == 1 and splitting the first window */
791     if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
792     {
793 	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
794 	{
795 	    EMSG(_(e_noroom));
796 	    return FAIL;
797 	}
798 	need_status = STATUS_HEIGHT;
799     }
800 
801 #ifdef FEAT_GUI
802     /* May be needed for the scrollbars that are going to change. */
803     if (gui.in_use)
804 	out_flush();
805 #endif
806 
807     if (flags & WSP_VERT)
808     {
809 	int	wmw1;
810 	int	minwidth;
811 
812 	layout = FR_ROW;
813 
814 	/*
815 	 * Check if we are able to split the current window and compute its
816 	 * width.
817 	 */
818 	/* Current window requires at least 1 space. */
819 	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
820 	needed = wmw1 + 1;
821 	if (flags & WSP_ROOM)
822 	    needed += p_wiw - wmw1;
823 	if (flags & (WSP_BOT | WSP_TOP))
824 	{
825 	    minwidth = frame_minwidth(topframe, NOWIN);
826 	    available = topframe->fr_width;
827 	    needed += minwidth;
828 	}
829 	else if (p_ea)
830 	{
831 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
832 	    prevfrp = oldwin->w_frame;
833 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
834 							frp = frp->fr_parent)
835 	    {
836 		if (frp->fr_layout == FR_ROW)
837 		    for (frp2 = frp->fr_child; frp2 != NULL;
838 							frp2 = frp2->fr_next)
839 			if (frp2 != prevfrp)
840 			    minwidth += frame_minwidth(frp2, NOWIN);
841 		prevfrp = frp;
842 	    }
843 	    available = topframe->fr_width;
844 	    needed += minwidth;
845 	}
846 	else
847 	{
848 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
849 	    available = oldwin->w_frame->fr_width;
850 	    needed += minwidth;
851 	}
852 	if (available < needed && new_wp == NULL)
853 	{
854 	    EMSG(_(e_noroom));
855 	    return FAIL;
856 	}
857 	if (new_size == 0)
858 	    new_size = oldwin->w_width / 2;
859 	if (new_size > available - minwidth - 1)
860 	    new_size = available - minwidth - 1;
861 	if (new_size < wmw1)
862 	    new_size = wmw1;
863 
864 	/* if it doesn't fit in the current window, need win_equal() */
865 	if (oldwin->w_width - new_size - 1 < p_wmw)
866 	    do_equal = TRUE;
867 
868 	/* We don't like to take lines for the new window from a
869 	 * 'winfixwidth' window.  Take them from a window to the left or right
870 	 * instead, if possible. Add one for the separator. */
871 	if (oldwin->w_p_wfw)
872 	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
873 
874 	/* Only make all windows the same width if one of them (except oldwin)
875 	 * is wider than one of the split windows. */
876 	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
877 	   && oldwin->w_frame->fr_parent != NULL)
878 	{
879 	    frp = oldwin->w_frame->fr_parent->fr_child;
880 	    while (frp != NULL)
881 	    {
882 		if (frp->fr_win != oldwin && frp->fr_win != NULL
883 			&& (frp->fr_win->w_width > new_size
884 			    || frp->fr_win->w_width > oldwin->w_width
885 							      - new_size - 1))
886 		{
887 		    do_equal = TRUE;
888 		    break;
889 		}
890 		frp = frp->fr_next;
891 	    }
892 	}
893     }
894     else
895     {
896 	layout = FR_COL;
897 
898 	/*
899 	 * Check if we are able to split the current window and compute its
900 	 * height.
901 	 */
902 	/* Current window requires at least 1 space. */
903 	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
904 	needed = wmh1 + STATUS_HEIGHT;
905 	if (flags & WSP_ROOM)
906 	    needed += p_wh - wmh1;
907 	if (flags & (WSP_BOT | WSP_TOP))
908 	{
909 	    minheight = frame_minheight(topframe, NOWIN) + need_status;
910 	    available = topframe->fr_height;
911 	    needed += minheight;
912 	}
913 	else if (p_ea)
914 	{
915 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
916 	    prevfrp = oldwin->w_frame;
917 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
918 							frp = frp->fr_parent)
919 	    {
920 		if (frp->fr_layout == FR_COL)
921 		    for (frp2 = frp->fr_child; frp2 != NULL;
922 							frp2 = frp2->fr_next)
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 (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
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(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_later(CLEAR);
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 (frp = curwin->w_frame->fr_parent->fr_child; frp != NULL;
1607 							   frp = frp->fr_next)
1608 	if (frp->fr_win == NULL)
1609 	{
1610 	    EMSG(_("E443: Cannot rotate when another window is split"));
1611 	    return;
1612 	}
1613 
1614     while (count--)
1615     {
1616 	if (upwards)		/* first window becomes last window */
1617 	{
1618 	    /* remove first window/frame from the list */
1619 	    frp = curwin->w_frame->fr_parent->fr_child;
1620 	    wp1 = frp->fr_win;
1621 	    win_remove(wp1, NULL);
1622 	    frame_remove(frp);
1623 
1624 	    /* find last frame and append removed window/frame after it */
1625 	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
1626 		;
1627 	    win_append(frp->fr_win, wp1);
1628 	    frame_append(frp, wp1->w_frame);
1629 
1630 	    wp2 = frp->fr_win;		/* previously last window */
1631 	}
1632 	else			/* last window becomes first window */
1633 	{
1634 	    /* find last window/frame in the list and remove it */
1635 	    for (frp = curwin->w_frame; frp->fr_next != NULL;
1636 							   frp = frp->fr_next)
1637 		;
1638 	    wp1 = frp->fr_win;
1639 	    wp2 = wp1->w_prev;		    /* will become last window */
1640 	    win_remove(wp1, NULL);
1641 	    frame_remove(frp);
1642 
1643 	    /* append the removed window/frame before the first in the list */
1644 	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
1645 	    frame_insert(frp->fr_parent->fr_child, frp);
1646 	}
1647 
1648 	/* exchange status height and vsep width of old and new last window */
1649 	n = wp2->w_status_height;
1650 	wp2->w_status_height = wp1->w_status_height;
1651 	wp1->w_status_height = n;
1652 	frame_fix_height(wp1);
1653 	frame_fix_height(wp2);
1654 	n = wp2->w_vsep_width;
1655 	wp2->w_vsep_width = wp1->w_vsep_width;
1656 	wp1->w_vsep_width = n;
1657 	frame_fix_width(wp1);
1658 	frame_fix_width(wp2);
1659 
1660 	/* recompute w_winrow and w_wincol for all windows */
1661 	(void)win_comp_pos();
1662     }
1663 
1664     redraw_later(CLEAR);
1665 }
1666 
1667 /*
1668  * Move the current window to the very top/bottom/left/right of the screen.
1669  */
1670     static void
1671 win_totop(int size, int flags)
1672 {
1673     int		dir;
1674     int		height = curwin->w_height;
1675 
1676     if (ONE_WINDOW)
1677     {
1678 	beep_flush();
1679 	return;
1680     }
1681 
1682     /* Remove the window and frame from the tree of frames. */
1683     (void)winframe_remove(curwin, &dir, NULL);
1684     win_remove(curwin, NULL);
1685     last_status(FALSE);	    /* may need to remove last status line */
1686     (void)win_comp_pos();   /* recompute window positions */
1687 
1688     /* Split a window on the desired side and put the window there. */
1689     (void)win_split_ins(size, flags, curwin, dir);
1690     if (!(flags & WSP_VERT))
1691     {
1692 	win_setheight(height);
1693 	if (p_ea)
1694 	    win_equal(curwin, TRUE, 'v');
1695     }
1696 
1697 #if defined(FEAT_GUI)
1698     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
1699      * scrollbars.  Have to update them anyway. */
1700     gui_may_update_scrollbars();
1701 #endif
1702 }
1703 
1704 /*
1705  * Move window "win1" to below/right of "win2" and make "win1" the current
1706  * window.  Only works within the same frame!
1707  */
1708     void
1709 win_move_after(win_T *win1, win_T *win2)
1710 {
1711     int		height;
1712 
1713     /* check if the arguments are reasonable */
1714     if (win1 == win2)
1715 	return;
1716 
1717     /* check if there is something to do */
1718     if (win2->w_next != win1)
1719     {
1720 	/* may need move the status line/vertical separator of the last window
1721 	 * */
1722 	if (win1 == lastwin)
1723 	{
1724 	    height = win1->w_prev->w_status_height;
1725 	    win1->w_prev->w_status_height = win1->w_status_height;
1726 	    win1->w_status_height = height;
1727 	    if (win1->w_prev->w_vsep_width == 1)
1728 	    {
1729 		/* Remove the vertical separator from the last-but-one window,
1730 		 * add it to the last window.  Adjust the frame widths. */
1731 		win1->w_prev->w_vsep_width = 0;
1732 		win1->w_prev->w_frame->fr_width -= 1;
1733 		win1->w_vsep_width = 1;
1734 		win1->w_frame->fr_width += 1;
1735 	    }
1736 	}
1737 	else if (win2 == lastwin)
1738 	{
1739 	    height = win1->w_status_height;
1740 	    win1->w_status_height = win2->w_status_height;
1741 	    win2->w_status_height = height;
1742 	    if (win1->w_vsep_width == 1)
1743 	    {
1744 		/* Remove the vertical separator from win1, add it to the last
1745 		 * window, win2.  Adjust the frame widths. */
1746 		win2->w_vsep_width = 1;
1747 		win2->w_frame->fr_width += 1;
1748 		win1->w_vsep_width = 0;
1749 		win1->w_frame->fr_width -= 1;
1750 	    }
1751 	}
1752 	win_remove(win1, NULL);
1753 	frame_remove(win1->w_frame);
1754 	win_append(win2, win1);
1755 	frame_append(win2->w_frame, win1->w_frame);
1756 
1757 	(void)win_comp_pos();	/* recompute w_winrow for all windows */
1758 	redraw_later(NOT_VALID);
1759     }
1760     win_enter(win1, FALSE);
1761 }
1762 
1763 /*
1764  * Make all windows the same height.
1765  * 'next_curwin' will soon be the current window, make sure it has enough
1766  * rows.
1767  */
1768     void
1769 win_equal(
1770     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1771     int		current,	/* do only frame with current window */
1772     int		dir)		/* 'v' for vertically, 'h' for horizontally,
1773 				   'b' for both, 0 for using p_ead */
1774 {
1775     if (dir == 0)
1776 	dir = *p_ead;
1777     win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
1778 		      topframe, dir, 0, tabline_height(),
1779 					   (int)Columns, topframe->fr_height);
1780 }
1781 
1782 /*
1783  * Set a frame to a new position and height, spreading the available room
1784  * equally over contained frames.
1785  * The window "next_curwin" (if not NULL) should at least get the size from
1786  * 'winheight' and 'winwidth' if possible.
1787  */
1788     static void
1789 win_equal_rec(
1790     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1791     int		current,	/* do only frame with current window */
1792     frame_T	*topfr,		/* frame to set size off */
1793     int		dir,		/* 'v', 'h' or 'b', see win_equal() */
1794     int		col,		/* horizontal position for frame */
1795     int		row,		/* vertical position for frame */
1796     int		width,		/* new width of frame */
1797     int		height)		/* new height of frame */
1798 {
1799     int		n, m;
1800     int		extra_sep = 0;
1801     int		wincount, totwincount = 0;
1802     frame_T	*fr;
1803     int		next_curwin_size = 0;
1804     int		room = 0;
1805     int		new_size;
1806     int		has_next_curwin = 0;
1807     int		hnc;
1808 
1809     if (topfr->fr_layout == FR_LEAF)
1810     {
1811 	/* Set the width/height of this frame.
1812 	 * Redraw when size or position changes */
1813 	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
1814 		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
1815 	   )
1816 	{
1817 	    topfr->fr_win->w_winrow = row;
1818 	    frame_new_height(topfr, height, FALSE, FALSE);
1819 	    topfr->fr_win->w_wincol = col;
1820 	    frame_new_width(topfr, width, FALSE, FALSE);
1821 	    redraw_all_later(CLEAR);
1822 	}
1823     }
1824     else if (topfr->fr_layout == FR_ROW)
1825     {
1826 	topfr->fr_width = width;
1827 	topfr->fr_height = height;
1828 
1829 	if (dir != 'v')			/* equalize frame widths */
1830 	{
1831 	    /* Compute the maximum number of windows horizontally in this
1832 	     * frame. */
1833 	    n = frame_minwidth(topfr, NOWIN);
1834 	    /* add one for the rightmost window, it doesn't have a separator */
1835 	    if (col + width == Columns)
1836 		extra_sep = 1;
1837 	    else
1838 		extra_sep = 0;
1839 	    totwincount = (n + extra_sep) / (p_wmw + 1);
1840 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1841 
1842 	    /*
1843 	     * Compute width for "next_curwin" window and room available for
1844 	     * other windows.
1845 	     * "m" is the minimal width when counting p_wiw for "next_curwin".
1846 	     */
1847 	    m = frame_minwidth(topfr, next_curwin);
1848 	    room = width - m;
1849 	    if (room < 0)
1850 	    {
1851 		next_curwin_size = p_wiw + room;
1852 		room = 0;
1853 	    }
1854 	    else
1855 	    {
1856 		next_curwin_size = -1;
1857 		for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
1858 		{
1859 		    /* If 'winfixwidth' set keep the window width if
1860 		     * possible.
1861 		     * Watch out for this window being the next_curwin. */
1862 		    if (frame_fixed_width(fr))
1863 		    {
1864 			n = frame_minwidth(fr, NOWIN);
1865 			new_size = fr->fr_width;
1866 			if (frame_has_win(fr, next_curwin))
1867 			{
1868 			    room += p_wiw - p_wmw;
1869 			    next_curwin_size = 0;
1870 			    if (new_size < p_wiw)
1871 				new_size = p_wiw;
1872 			}
1873 			else
1874 			    /* These windows don't use up room. */
1875 			    totwincount -= (n + (fr->fr_next == NULL
1876 					      ? extra_sep : 0)) / (p_wmw + 1);
1877 			room -= new_size - n;
1878 			if (room < 0)
1879 			{
1880 			    new_size += room;
1881 			    room = 0;
1882 			}
1883 			fr->fr_newwidth = new_size;
1884 		    }
1885 		}
1886 		if (next_curwin_size == -1)
1887 		{
1888 		    if (!has_next_curwin)
1889 			next_curwin_size = 0;
1890 		    else if (totwincount > 1
1891 			    && (room + (totwincount - 2))
1892 						  / (totwincount - 1) > p_wiw)
1893 		    {
1894 			/* Can make all windows wider than 'winwidth', spread
1895 			 * the room equally. */
1896 			next_curwin_size = (room + p_wiw
1897 					    + (totwincount - 1) * p_wmw
1898 					    + (totwincount - 1)) / totwincount;
1899 			room -= next_curwin_size - p_wiw;
1900 		    }
1901 		    else
1902 			next_curwin_size = p_wiw;
1903 		}
1904 	    }
1905 
1906 	    if (has_next_curwin)
1907 		--totwincount;		/* don't count curwin */
1908 	}
1909 
1910 	for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
1911 	{
1912 	    wincount = 1;
1913 	    if (fr->fr_next == NULL)
1914 		/* last frame gets all that remains (avoid roundoff error) */
1915 		new_size = width;
1916 	    else if (dir == 'v')
1917 		new_size = fr->fr_width;
1918 	    else if (frame_fixed_width(fr))
1919 	    {
1920 		new_size = fr->fr_newwidth;
1921 		wincount = 0;	    /* doesn't count as a sizeable window */
1922 	    }
1923 	    else
1924 	    {
1925 		/* Compute the maximum number of windows horiz. in "fr". */
1926 		n = frame_minwidth(fr, NOWIN);
1927 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
1928 								/ (p_wmw + 1);
1929 		m = frame_minwidth(fr, next_curwin);
1930 		if (has_next_curwin)
1931 		    hnc = frame_has_win(fr, next_curwin);
1932 		else
1933 		    hnc = FALSE;
1934 		if (hnc)	    /* don't count next_curwin */
1935 		    --wincount;
1936 		if (totwincount == 0)
1937 		    new_size = room;
1938 		else
1939 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
1940 								/ totwincount;
1941 		if (hnc)	    /* add next_curwin size */
1942 		{
1943 		    next_curwin_size -= p_wiw - (m - n);
1944 		    new_size += next_curwin_size;
1945 		    room -= new_size - next_curwin_size;
1946 		}
1947 		else
1948 		    room -= new_size;
1949 		new_size += n;
1950 	    }
1951 
1952 	    /* Skip frame that is full width when splitting or closing a
1953 	     * window, unless equalizing all frames. */
1954 	    if (!current || dir != 'v' || topfr->fr_parent != NULL
1955 		    || (new_size != fr->fr_width)
1956 		    || frame_has_win(fr, next_curwin))
1957 		win_equal_rec(next_curwin, current, fr, dir, col, row,
1958 							    new_size, height);
1959 	    col += new_size;
1960 	    width -= new_size;
1961 	    totwincount -= wincount;
1962 	}
1963     }
1964     else /* topfr->fr_layout == FR_COL */
1965     {
1966 	topfr->fr_width = width;
1967 	topfr->fr_height = height;
1968 
1969 	if (dir != 'h')			/* equalize frame heights */
1970 	{
1971 	    /* Compute maximum number of windows vertically in this frame. */
1972 	    n = frame_minheight(topfr, NOWIN);
1973 	    /* add one for the bottom window if it doesn't have a statusline */
1974 	    if (row + height == cmdline_row && p_ls == 0)
1975 		extra_sep = 1;
1976 	    else
1977 		extra_sep = 0;
1978 	    totwincount = (n + extra_sep) / (p_wmh + 1);
1979 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1980 
1981 	    /*
1982 	     * Compute height for "next_curwin" window and room available for
1983 	     * other windows.
1984 	     * "m" is the minimal height when counting p_wh for "next_curwin".
1985 	     */
1986 	    m = frame_minheight(topfr, next_curwin);
1987 	    room = height - m;
1988 	    if (room < 0)
1989 	    {
1990 		/* The room is less then 'winheight', use all space for the
1991 		 * current window. */
1992 		next_curwin_size = p_wh + room;
1993 		room = 0;
1994 	    }
1995 	    else
1996 	    {
1997 		next_curwin_size = -1;
1998 		for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
1999 		{
2000 		    /* If 'winfixheight' set keep the window height if
2001 		     * possible.
2002 		     * Watch out for this window being the next_curwin. */
2003 		    if (frame_fixed_height(fr))
2004 		    {
2005 			n = frame_minheight(fr, NOWIN);
2006 			new_size = fr->fr_height;
2007 			if (frame_has_win(fr, next_curwin))
2008 			{
2009 			    room += p_wh - p_wmh;
2010 			    next_curwin_size = 0;
2011 			    if (new_size < p_wh)
2012 				new_size = p_wh;
2013 			}
2014 			else
2015 			    /* These windows don't use up room. */
2016 			    totwincount -= (n + (fr->fr_next == NULL
2017 					      ? extra_sep : 0)) / (p_wmh + 1);
2018 			room -= new_size - n;
2019 			if (room < 0)
2020 			{
2021 			    new_size += room;
2022 			    room = 0;
2023 			}
2024 			fr->fr_newheight = new_size;
2025 		    }
2026 		}
2027 		if (next_curwin_size == -1)
2028 		{
2029 		    if (!has_next_curwin)
2030 			next_curwin_size = 0;
2031 		    else if (totwincount > 1
2032 			    && (room + (totwincount - 2))
2033 						   / (totwincount - 1) > p_wh)
2034 		    {
2035 			/* can make all windows higher than 'winheight',
2036 			 * spread the room equally. */
2037 			next_curwin_size = (room + p_wh
2038 					   + (totwincount - 1) * p_wmh
2039 					   + (totwincount - 1)) / totwincount;
2040 			room -= next_curwin_size - p_wh;
2041 		    }
2042 		    else
2043 			next_curwin_size = p_wh;
2044 		}
2045 	    }
2046 
2047 	    if (has_next_curwin)
2048 		--totwincount;		/* don't count curwin */
2049 	}
2050 
2051 	for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
2052 	{
2053 	    wincount = 1;
2054 	    if (fr->fr_next == NULL)
2055 		/* last frame gets all that remains (avoid roundoff error) */
2056 		new_size = height;
2057 	    else if (dir == 'h')
2058 		new_size = fr->fr_height;
2059 	    else if (frame_fixed_height(fr))
2060 	    {
2061 		new_size = fr->fr_newheight;
2062 		wincount = 0;	    /* doesn't count as a sizeable window */
2063 	    }
2064 	    else
2065 	    {
2066 		/* Compute the maximum number of windows vert. in "fr". */
2067 		n = frame_minheight(fr, NOWIN);
2068 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2069 								/ (p_wmh + 1);
2070 		m = frame_minheight(fr, next_curwin);
2071 		if (has_next_curwin)
2072 		    hnc = frame_has_win(fr, next_curwin);
2073 		else
2074 		    hnc = FALSE;
2075 		if (hnc)	    /* don't count next_curwin */
2076 		    --wincount;
2077 		if (totwincount == 0)
2078 		    new_size = room;
2079 		else
2080 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2081 								/ totwincount;
2082 		if (hnc)	    /* add next_curwin size */
2083 		{
2084 		    next_curwin_size -= p_wh - (m - n);
2085 		    new_size += next_curwin_size;
2086 		    room -= new_size - next_curwin_size;
2087 		}
2088 		else
2089 		    room -= new_size;
2090 		new_size += n;
2091 	    }
2092 	    /* Skip frame that is full width when splitting or closing a
2093 	     * window, unless equalizing all frames. */
2094 	    if (!current || dir != 'h' || topfr->fr_parent != NULL
2095 		    || (new_size != fr->fr_height)
2096 		    || frame_has_win(fr, next_curwin))
2097 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2098 							     width, new_size);
2099 	    row += new_size;
2100 	    height -= new_size;
2101 	    totwincount -= wincount;
2102 	}
2103     }
2104 }
2105 
2106 /*
2107  * Close all windows for buffer "buf".
2108  */
2109     void
2110 close_windows(
2111     buf_T	*buf,
2112     int		keep_curwin)	    /* don't close "curwin" */
2113 {
2114     win_T	*wp;
2115     tabpage_T   *tp, *nexttp;
2116     int		h = tabline_height();
2117     int		count = tabpage_index(NULL);
2118 
2119     ++RedrawingDisabled;
2120 
2121     for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
2122     {
2123 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
2124 		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
2125 	{
2126 	    if (win_close(wp, FALSE) == FAIL)
2127 		/* If closing the window fails give up, to avoid looping
2128 		 * forever. */
2129 		break;
2130 
2131 	    /* Start all over, autocommands may change the window layout. */
2132 	    wp = firstwin;
2133 	}
2134 	else
2135 	    wp = wp->w_next;
2136     }
2137 
2138     /* Also check windows in other tab pages. */
2139     for (tp = first_tabpage; tp != NULL; tp = nexttp)
2140     {
2141 	nexttp = tp->tp_next;
2142 	if (tp != curtab)
2143 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
2144 		if (wp->w_buffer == buf
2145 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
2146 		{
2147 		    win_close_othertab(wp, FALSE, tp);
2148 
2149 		    /* Start all over, the tab page may be closed and
2150 		     * autocommands may change the window layout. */
2151 		    nexttp = first_tabpage;
2152 		    break;
2153 		}
2154     }
2155 
2156     --RedrawingDisabled;
2157 
2158     if (count != tabpage_index(NULL))
2159 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2160 
2161     redraw_tabline = TRUE;
2162     if (h != tabline_height())
2163 	shell_new_rows();
2164 }
2165 
2166 /*
2167  * Return TRUE if the current window is the only window that exists (ignoring
2168  * "aucmd_win").
2169  * Returns FALSE if there is a window, possibly in another tab page.
2170  */
2171     static int
2172 last_window(void)
2173 {
2174     return (one_window() && first_tabpage->tp_next == NULL);
2175 }
2176 
2177 /*
2178  * Return TRUE if there is only one window other than "aucmd_win" in the
2179  * current tab page.
2180  */
2181     int
2182 one_window(void)
2183 {
2184     win_T	*wp;
2185     int		seen_one = FALSE;
2186 
2187     FOR_ALL_WINDOWS(wp)
2188     {
2189 	if (wp != aucmd_win)
2190 	{
2191 	    if (seen_one)
2192 		return FALSE;
2193 	    seen_one = TRUE;
2194 	}
2195     }
2196     return TRUE;
2197 }
2198 
2199 /*
2200  * Close the possibly last window in a tab page.
2201  * Returns TRUE when the window was closed already.
2202  */
2203     static int
2204 close_last_window_tabpage(
2205     win_T	*win,
2206     int		free_buf,
2207     tabpage_T   *prev_curtab)
2208 {
2209     if (ONE_WINDOW)
2210     {
2211 	buf_T	*old_curbuf = curbuf;
2212 
2213 	/*
2214 	 * Closing the last window in a tab page.  First go to another tab
2215 	 * page and then close the window and the tab page.  This avoids that
2216 	 * curwin and curtab are invalid while we are freeing memory, they may
2217 	 * be used in GUI events.
2218 	 * Don't trigger autocommands yet, they may use wrong values, so do
2219 	 * that below.
2220 	 */
2221 	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
2222 	redraw_tabline = TRUE;
2223 
2224 	/* Safety check: Autocommands may have closed the window when jumping
2225 	 * to the other tab page. */
2226 	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
2227 	{
2228 	    int	    h = tabline_height();
2229 
2230 	    win_close_othertab(win, free_buf, prev_curtab);
2231 	    if (h != tabline_height())
2232 		shell_new_rows();
2233 	}
2234 	/* Since goto_tabpage_tp above did not trigger *Enter autocommands, do
2235 	 * that now. */
2236 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2237 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
2238 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
2239 	if (old_curbuf != curbuf)
2240 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2241 	return TRUE;
2242     }
2243     return FALSE;
2244 }
2245 
2246 /*
2247  * Close window "win".  Only works for the current tab page.
2248  * If "free_buf" is TRUE related buffer may be unloaded.
2249  *
2250  * Called by :quit, :close, :xit, :wq and findtag().
2251  * Returns FAIL when the window was not closed.
2252  */
2253     int
2254 win_close(win_T *win, int free_buf)
2255 {
2256     win_T	*wp;
2257     int		other_buffer = FALSE;
2258     int		close_curwin = FALSE;
2259     int		dir;
2260     int		help_window = FALSE;
2261     tabpage_T   *prev_curtab = curtab;
2262     frame_T	*win_frame = win->w_frame->fr_parent;
2263 
2264     if (last_window())
2265     {
2266 	EMSG(_("E444: Cannot close last window"));
2267 	return FAIL;
2268     }
2269 
2270     if (win->w_closing || (win->w_buffer != NULL
2271 					       && win->w_buffer->b_locked > 0))
2272 	return FAIL; /* window is already being closed */
2273     if (win == aucmd_win)
2274     {
2275 	EMSG(_("E813: Cannot close autocmd window"));
2276 	return FAIL;
2277     }
2278     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
2279     {
2280 	EMSG(_("E814: Cannot close window, only autocmd window would remain"));
2281 	return FAIL;
2282     }
2283 
2284     /* When closing the last window in a tab page first go to another tab page
2285      * and then close the window and the tab page to avoid that curwin and
2286      * curtab are invalid while we are freeing memory. */
2287     if (close_last_window_tabpage(win, free_buf, prev_curtab))
2288       return FAIL;
2289 
2290     /* When closing the help window, try restoring a snapshot after closing
2291      * the window.  Otherwise clear the snapshot, it's now invalid. */
2292     if (bt_help(win->w_buffer))
2293 	help_window = TRUE;
2294     else
2295 	clear_snapshot(curtab, SNAP_HELP_IDX);
2296 
2297     if (win == curwin)
2298     {
2299 	/*
2300 	 * Guess which window is going to be the new current window.
2301 	 * This may change because of the autocommands (sigh).
2302 	 */
2303 	wp = frame2win(win_altframe(win, NULL));
2304 
2305 	/*
2306 	 * Be careful: If autocommands delete the window or cause this window
2307 	 * to be the last one left, return now.
2308 	 */
2309 	if (wp->w_buffer != curbuf)
2310 	{
2311 	    other_buffer = TRUE;
2312 	    win->w_closing = TRUE;
2313 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
2314 	    if (!win_valid(win))
2315 		return FAIL;
2316 	    win->w_closing = FALSE;
2317 	    if (last_window())
2318 		return FAIL;
2319 	}
2320 	win->w_closing = TRUE;
2321 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
2322 	if (!win_valid(win))
2323 	    return FAIL;
2324 	win->w_closing = FALSE;
2325 	if (last_window())
2326 	    return FAIL;
2327 #ifdef FEAT_EVAL
2328 	/* autocmds may abort script processing */
2329 	if (aborting())
2330 	    return FAIL;
2331 #endif
2332     }
2333 
2334 #ifdef FEAT_GUI
2335     /* Avoid trouble with scrollbars that are going to be deleted in
2336      * win_free(). */
2337     if (gui.in_use)
2338 	out_flush();
2339 #endif
2340 
2341 #ifdef FEAT_SYN_HL
2342     /* Free independent synblock before the buffer is freed. */
2343     if (win->w_buffer != NULL)
2344 	reset_synblock(win);
2345 #endif
2346 
2347     /*
2348      * Close the link to the buffer.
2349      */
2350     if (win->w_buffer != NULL)
2351     {
2352 	bufref_T    bufref;
2353 
2354 	set_bufref(&bufref, curbuf);
2355 	win->w_closing = TRUE;
2356 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, TRUE);
2357 	if (win_valid_any_tab(win))
2358 	    win->w_closing = FALSE;
2359 	/* Make sure curbuf is valid. It can become invalid if 'bufhidden' is
2360 	 * "wipe". */
2361 	if (!bufref_valid(&bufref))
2362 	    curbuf = firstbuf;
2363     }
2364 
2365     if (only_one_window() && win_valid(win) && win->w_buffer == NULL
2366 	    && (last_window() || curtab != prev_curtab
2367 		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
2368     {
2369 	/* Autocommands have closed all windows, quit now.  Restore
2370 	 * curwin->w_buffer, otherwise writing viminfo may fail. */
2371 	if (curwin->w_buffer == NULL)
2372 	    curwin->w_buffer = curbuf;
2373 	getout(0);
2374     }
2375 
2376     /* Autocommands may have moved to another tab page. */
2377     if (curtab != prev_curtab && win_valid_any_tab(win)
2378 						      && win->w_buffer == NULL)
2379     {
2380 	/* Need to close the window anyway, since the buffer is NULL. */
2381 	win_close_othertab(win, FALSE, prev_curtab);
2382 	return FAIL;
2383     }
2384 
2385     /* Autocommands may have closed the window already or closed the only
2386      * other window. */
2387     if (!win_valid(win) || last_window()
2388 	    || close_last_window_tabpage(win, free_buf, prev_curtab))
2389 	return FAIL;
2390 
2391     /* Free the memory used for the window and get the window that received
2392      * the screen space. */
2393     wp = win_free_mem(win, &dir, NULL);
2394 
2395     /* Make sure curwin isn't invalid.  It can cause severe trouble when
2396      * printing an error message.  For win_equal() curbuf needs to be valid
2397      * too. */
2398     if (win == curwin)
2399     {
2400 	curwin = wp;
2401 #ifdef FEAT_QUICKFIX
2402 	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
2403 	{
2404 	    /*
2405 	     * If the cursor goes to the preview or the quickfix window, try
2406 	     * finding another window to go to.
2407 	     */
2408 	    for (;;)
2409 	    {
2410 		if (wp->w_next == NULL)
2411 		    wp = firstwin;
2412 		else
2413 		    wp = wp->w_next;
2414 		if (wp == curwin)
2415 		    break;
2416 		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
2417 		{
2418 		    curwin = wp;
2419 		    break;
2420 		}
2421 	    }
2422 	}
2423 #endif
2424 	curbuf = curwin->w_buffer;
2425 	close_curwin = TRUE;
2426 
2427 	/* The cursor position may be invalid if the buffer changed after last
2428 	 * using the window. */
2429 	check_cursor();
2430     }
2431     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
2432 	/* If the frame of the closed window contains the new current window,
2433 	 * only resize that frame.  Otherwise resize all windows. */
2434 	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
2435     else
2436 	win_comp_pos();
2437     if (close_curwin)
2438     {
2439 	win_enter_ext(wp, FALSE, TRUE, FALSE, TRUE, TRUE);
2440 	if (other_buffer)
2441 	    /* careful: after this wp and win may be invalid! */
2442 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2443     }
2444 
2445     /*
2446      * If last window has a status line now and we don't want one,
2447      * remove the status line.
2448      */
2449     last_status(FALSE);
2450 
2451     /* After closing the help window, try restoring the window layout from
2452      * before it was opened. */
2453     if (help_window)
2454 	restore_snapshot(SNAP_HELP_IDX, close_curwin);
2455 
2456 #if defined(FEAT_GUI)
2457     /* When 'guioptions' includes 'L' or 'R' may have to remove scrollbars. */
2458     if (gui.in_use && !win_hasvertsplit())
2459 	gui_init_which_components(NULL);
2460 #endif
2461 
2462     redraw_all_later(NOT_VALID);
2463     return OK;
2464 }
2465 
2466 /*
2467  * Close window "win" in tab page "tp", which is not the current tab page.
2468  * This may be the last window in that tab page and result in closing the tab,
2469  * thus "tp" may become invalid!
2470  * Caller must check if buffer is hidden and whether the tabline needs to be
2471  * updated.
2472  */
2473     void
2474 win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
2475 {
2476     win_T	*wp;
2477     int		dir;
2478     tabpage_T   *ptp = NULL;
2479     int		free_tp = FALSE;
2480 
2481     /* Get here with win->w_buffer == NULL when win_close() detects the tab
2482      * page changed. */
2483     if (win->w_closing || (win->w_buffer != NULL
2484 					       && win->w_buffer->b_locked > 0))
2485 	return; /* window is already being closed */
2486 
2487     if (win->w_buffer != NULL)
2488 	/* Close the link to the buffer. */
2489 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, FALSE);
2490 
2491     /* Careful: Autocommands may have closed the tab page or made it the
2492      * current tab page.  */
2493     for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
2494 	;
2495     if (ptp == NULL || tp == curtab)
2496 	return;
2497 
2498     /* Autocommands may have closed the window already. */
2499     for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
2500 	;
2501     if (wp == NULL)
2502 	return;
2503 
2504     /* When closing the last window in a tab page remove the tab page. */
2505     if (tp->tp_firstwin == tp->tp_lastwin)
2506     {
2507 	if (tp == first_tabpage)
2508 	    first_tabpage = tp->tp_next;
2509 	else
2510 	{
2511 	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
2512 							   ptp = ptp->tp_next)
2513 		;
2514 	    if (ptp == NULL)
2515 	    {
2516 		internal_error("win_close_othertab()");
2517 		return;
2518 	    }
2519 	    ptp->tp_next = tp->tp_next;
2520 	}
2521 	free_tp = TRUE;
2522     }
2523 
2524     /* Free the memory used for the window. */
2525     win_free_mem(win, &dir, tp);
2526 
2527     if (free_tp)
2528 	free_tabpage(tp);
2529 }
2530 
2531 /*
2532  * Free the memory used for a window.
2533  * Returns a pointer to the window that got the freed up space.
2534  */
2535     static win_T *
2536 win_free_mem(
2537     win_T	*win,
2538     int		*dirp,		/* set to 'v' or 'h' for direction if 'ea' */
2539     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2540 {
2541     frame_T	*frp;
2542     win_T	*wp;
2543 
2544     /* Remove the window and its frame from the tree of frames. */
2545     frp = win->w_frame;
2546     wp = winframe_remove(win, dirp, tp);
2547     vim_free(frp);
2548     win_free(win, tp);
2549 
2550     /* When deleting the current window of another tab page select a new
2551      * current window. */
2552     if (tp != NULL && win == tp->tp_curwin)
2553 	tp->tp_curwin = wp;
2554 
2555     return wp;
2556 }
2557 
2558 #if defined(EXITFREE) || defined(PROTO)
2559     void
2560 win_free_all(void)
2561 {
2562     int		dummy;
2563 
2564     while (first_tabpage->tp_next != NULL)
2565 	tabpage_close(TRUE);
2566 
2567     if (aucmd_win != NULL)
2568     {
2569 	(void)win_free_mem(aucmd_win, &dummy, NULL);
2570 	aucmd_win = NULL;
2571     }
2572 
2573     while (firstwin != NULL)
2574 	(void)win_free_mem(firstwin, &dummy, NULL);
2575 
2576     /* No window should be used after this. Set curwin to NULL to crash
2577      * instead of using freed memory. */
2578     curwin = NULL;
2579 }
2580 #endif
2581 
2582 /*
2583  * Remove a window and its frame from the tree of frames.
2584  * Returns a pointer to the window that got the freed up space.
2585  */
2586     win_T *
2587 winframe_remove(
2588     win_T	*win,
2589     int		*dirp UNUSED,	/* set to 'v' or 'h' for direction if 'ea' */
2590     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2591 {
2592     frame_T	*frp, *frp2, *frp3;
2593     frame_T	*frp_close = win->w_frame;
2594     win_T	*wp;
2595 
2596     /*
2597      * If there is only one window there is nothing to remove.
2598      */
2599     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2600 	return NULL;
2601 
2602     /*
2603      * Remove the window from its frame.
2604      */
2605     frp2 = win_altframe(win, tp);
2606     wp = frame2win(frp2);
2607 
2608     /* Remove this frame from the list of frames. */
2609     frame_remove(frp_close);
2610 
2611     if (frp_close->fr_parent->fr_layout == FR_COL)
2612     {
2613 	/* When 'winfixheight' is set, try to find another frame in the column
2614 	 * (as close to the closed frame as possible) to distribute the height
2615 	 * to. */
2616 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
2617 	{
2618 	    frp = frp_close->fr_prev;
2619 	    frp3 = frp_close->fr_next;
2620 	    while (frp != NULL || frp3 != NULL)
2621 	    {
2622 		if (frp != NULL)
2623 		{
2624 		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfh)
2625 		    {
2626 			frp2 = frp;
2627 			wp = frp->fr_win;
2628 			break;
2629 		    }
2630 		    frp = frp->fr_prev;
2631 		}
2632 		if (frp3 != NULL)
2633 		{
2634 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
2635 		    {
2636 			frp2 = frp3;
2637 			wp = frp3->fr_win;
2638 			break;
2639 		    }
2640 		    frp3 = frp3->fr_next;
2641 		}
2642 	    }
2643 	}
2644 	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
2645 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2646 	*dirp = 'v';
2647     }
2648     else
2649     {
2650 	/* When 'winfixwidth' is set, try to find another frame in the column
2651 	 * (as close to the closed frame as possible) to distribute the width
2652 	 * to. */
2653 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
2654 	{
2655 	    frp = frp_close->fr_prev;
2656 	    frp3 = frp_close->fr_next;
2657 	    while (frp != NULL || frp3 != NULL)
2658 	    {
2659 		if (frp != NULL)
2660 		{
2661 		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfw)
2662 		    {
2663 			frp2 = frp;
2664 			wp = frp->fr_win;
2665 			break;
2666 		    }
2667 		    frp = frp->fr_prev;
2668 		}
2669 		if (frp3 != NULL)
2670 		{
2671 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
2672 		    {
2673 			frp2 = frp3;
2674 			wp = frp3->fr_win;
2675 			break;
2676 		    }
2677 		    frp3 = frp3->fr_next;
2678 		}
2679 	    }
2680 	}
2681 	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
2682 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2683 	*dirp = 'h';
2684     }
2685 
2686     /* If rows/columns go to a window below/right its positions need to be
2687      * updated.  Can only be done after the sizes have been updated. */
2688     if (frp2 == frp_close->fr_next)
2689     {
2690 	int row = win->w_winrow;
2691 	int col = win->w_wincol;
2692 
2693 	frame_comp_pos(frp2, &row, &col);
2694     }
2695 
2696     if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
2697     {
2698 	/* There is no other frame in this list, move its info to the parent
2699 	 * and remove it. */
2700 	frp2->fr_parent->fr_layout = frp2->fr_layout;
2701 	frp2->fr_parent->fr_child = frp2->fr_child;
2702 	for (frp = frp2->fr_child; frp != NULL; frp = frp->fr_next)
2703 	    frp->fr_parent = frp2->fr_parent;
2704 	frp2->fr_parent->fr_win = frp2->fr_win;
2705 	if (frp2->fr_win != NULL)
2706 	    frp2->fr_win->w_frame = frp2->fr_parent;
2707 	frp = frp2->fr_parent;
2708 	if (topframe->fr_child == frp2)
2709 	    topframe->fr_child = frp;
2710 	vim_free(frp2);
2711 
2712 	frp2 = frp->fr_parent;
2713 	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
2714 	{
2715 	    /* The frame above the parent has the same layout, have to merge
2716 	     * the frames into this list. */
2717 	    if (frp2->fr_child == frp)
2718 		frp2->fr_child = frp->fr_child;
2719 	    frp->fr_child->fr_prev = frp->fr_prev;
2720 	    if (frp->fr_prev != NULL)
2721 		frp->fr_prev->fr_next = frp->fr_child;
2722 	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
2723 	    {
2724 		frp3->fr_parent = frp2;
2725 		if (frp3->fr_next == NULL)
2726 		{
2727 		    frp3->fr_next = frp->fr_next;
2728 		    if (frp->fr_next != NULL)
2729 			frp->fr_next->fr_prev = frp3;
2730 		    break;
2731 		}
2732 	    }
2733 	    if (topframe->fr_child == frp)
2734 		topframe->fr_child = frp2;
2735 	    vim_free(frp);
2736 	}
2737     }
2738 
2739     return wp;
2740 }
2741 
2742 /*
2743  * Return a pointer to the frame that will receive the empty screen space that
2744  * is left over after "win" is closed.
2745  *
2746  * If 'splitbelow' or 'splitright' is set, the space goes above or to the left
2747  * by default.  Otherwise, the free space goes below or to the right.  The
2748  * result is that opening a window and then immediately closing it will
2749  * preserve the initial window layout.  The 'wfh' and 'wfw' settings are
2750  * respected when possible.
2751  */
2752     static frame_T *
2753 win_altframe(
2754     win_T	*win,
2755     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2756 {
2757     frame_T	*frp;
2758     frame_T	*other_fr, *target_fr;
2759 
2760     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2761 	return alt_tabpage()->tp_curwin->w_frame;
2762 
2763     frp = win->w_frame;
2764 
2765     if (frp->fr_prev == NULL)
2766 	return frp->fr_next;
2767     if (frp->fr_next == NULL)
2768 	return frp->fr_prev;
2769 
2770     target_fr = frp->fr_next;
2771     other_fr  = frp->fr_prev;
2772     if (p_spr || p_sb)
2773     {
2774 	target_fr = frp->fr_prev;
2775 	other_fr  = frp->fr_next;
2776     }
2777 
2778     /* If 'wfh' or 'wfw' is set for the target and not for the alternate
2779      * window, reverse the selection. */
2780     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
2781     {
2782 	if (frame_fixed_width(target_fr) && !frame_fixed_width(other_fr))
2783 	    target_fr = other_fr;
2784     }
2785     else
2786     {
2787 	if (frame_fixed_height(target_fr) && !frame_fixed_height(other_fr))
2788 	    target_fr = other_fr;
2789     }
2790 
2791     return target_fr;
2792 }
2793 
2794 /*
2795  * Return the tabpage that will be used if the current one is closed.
2796  */
2797     static tabpage_T *
2798 alt_tabpage(void)
2799 {
2800     tabpage_T	*tp;
2801 
2802     /* Use the next tab page if possible. */
2803     if (curtab->tp_next != NULL)
2804 	return curtab->tp_next;
2805 
2806     /* Find the last but one tab page. */
2807     for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
2808 	;
2809     return tp;
2810 }
2811 
2812 /*
2813  * Find the left-upper window in frame "frp".
2814  */
2815     static win_T *
2816 frame2win(frame_T *frp)
2817 {
2818     while (frp->fr_win == NULL)
2819 	frp = frp->fr_child;
2820     return frp->fr_win;
2821 }
2822 
2823 /*
2824  * Return TRUE if frame "frp" contains window "wp".
2825  */
2826     static int
2827 frame_has_win(frame_T *frp, win_T *wp)
2828 {
2829     frame_T	*p;
2830 
2831     if (frp->fr_layout == FR_LEAF)
2832 	return frp->fr_win == wp;
2833 
2834     for (p = frp->fr_child; p != NULL; p = p->fr_next)
2835 	if (frame_has_win(p, wp))
2836 	    return TRUE;
2837     return FALSE;
2838 }
2839 
2840 /*
2841  * Set a new height for a frame.  Recursively sets the height for contained
2842  * frames and windows.  Caller must take care of positions.
2843  */
2844     static void
2845 frame_new_height(
2846     frame_T	*topfrp,
2847     int		height,
2848     int		topfirst,	/* resize topmost contained frame first */
2849     int		wfh)		/* obey 'winfixheight' when there is a choice;
2850 				   may cause the height not to be set */
2851 {
2852     frame_T	*frp;
2853     int		extra_lines;
2854     int		h;
2855 
2856     if (topfrp->fr_win != NULL)
2857     {
2858 	/* Simple case: just one window. */
2859 	win_new_height(topfrp->fr_win,
2860 				    height - topfrp->fr_win->w_status_height
2861 					      - WINBAR_HEIGHT(topfrp->fr_win));
2862     }
2863     else if (topfrp->fr_layout == FR_ROW)
2864     {
2865 	do
2866 	{
2867 	    /* All frames in this row get the same new height. */
2868 	    for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
2869 	    {
2870 		frame_new_height(frp, height, topfirst, wfh);
2871 		if (frp->fr_height > height)
2872 		{
2873 		    /* Could not fit the windows, make the whole row higher. */
2874 		    height = frp->fr_height;
2875 		    break;
2876 		}
2877 	    }
2878 	}
2879 	while (frp != NULL);
2880     }
2881     else    /* fr_layout == FR_COL */
2882     {
2883 	/* Complicated case: Resize a column of frames.  Resize the bottom
2884 	 * frame first, frames above that when needed. */
2885 
2886 	frp = topfrp->fr_child;
2887 	if (wfh)
2888 	    /* Advance past frames with one window with 'wfh' set. */
2889 	    while (frame_fixed_height(frp))
2890 	    {
2891 		frp = frp->fr_next;
2892 		if (frp == NULL)
2893 		    return;	    /* no frame without 'wfh', give up */
2894 	    }
2895 	if (!topfirst)
2896 	{
2897 	    /* Find the bottom frame of this column */
2898 	    while (frp->fr_next != NULL)
2899 		frp = frp->fr_next;
2900 	    if (wfh)
2901 		/* Advance back for frames with one window with 'wfh' set. */
2902 		while (frame_fixed_height(frp))
2903 		    frp = frp->fr_prev;
2904 	}
2905 
2906 	extra_lines = height - topfrp->fr_height;
2907 	if (extra_lines < 0)
2908 	{
2909 	    /* reduce height of contained frames, bottom or top frame first */
2910 	    while (frp != NULL)
2911 	    {
2912 		h = frame_minheight(frp, NULL);
2913 		if (frp->fr_height + extra_lines < h)
2914 		{
2915 		    extra_lines += frp->fr_height - h;
2916 		    frame_new_height(frp, h, topfirst, wfh);
2917 		}
2918 		else
2919 		{
2920 		    frame_new_height(frp, frp->fr_height + extra_lines,
2921 							       topfirst, wfh);
2922 		    break;
2923 		}
2924 		if (topfirst)
2925 		{
2926 		    do
2927 			frp = frp->fr_next;
2928 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2929 		}
2930 		else
2931 		{
2932 		    do
2933 			frp = frp->fr_prev;
2934 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2935 		}
2936 		/* Increase "height" if we could not reduce enough frames. */
2937 		if (frp == NULL)
2938 		    height -= extra_lines;
2939 	    }
2940 	}
2941 	else if (extra_lines > 0)
2942 	{
2943 	    /* increase height of bottom or top frame */
2944 	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
2945 	}
2946     }
2947     topfrp->fr_height = height;
2948 }
2949 
2950 /*
2951  * Return TRUE if height of frame "frp" should not be changed because of
2952  * the 'winfixheight' option.
2953  */
2954     static int
2955 frame_fixed_height(frame_T *frp)
2956 {
2957     /* frame with one window: fixed height if 'winfixheight' set. */
2958     if (frp->fr_win != NULL)
2959 	return frp->fr_win->w_p_wfh;
2960 
2961     if (frp->fr_layout == FR_ROW)
2962     {
2963 	/* The frame is fixed height if one of the frames in the row is fixed
2964 	 * height. */
2965 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
2966 	    if (frame_fixed_height(frp))
2967 		return TRUE;
2968 	return FALSE;
2969     }
2970 
2971     /* frp->fr_layout == FR_COL: The frame is fixed height if all of the
2972      * frames in the row are fixed height. */
2973     for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
2974 	if (!frame_fixed_height(frp))
2975 	    return FALSE;
2976     return TRUE;
2977 }
2978 
2979 /*
2980  * Return TRUE if width of frame "frp" should not be changed because of
2981  * the 'winfixwidth' option.
2982  */
2983     static int
2984 frame_fixed_width(frame_T *frp)
2985 {
2986     /* frame with one window: fixed width if 'winfixwidth' set. */
2987     if (frp->fr_win != NULL)
2988 	return frp->fr_win->w_p_wfw;
2989 
2990     if (frp->fr_layout == FR_COL)
2991     {
2992 	/* The frame is fixed width if one of the frames in the row is fixed
2993 	 * width. */
2994 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
2995 	    if (frame_fixed_width(frp))
2996 		return TRUE;
2997 	return FALSE;
2998     }
2999 
3000     /* frp->fr_layout == FR_ROW: The frame is fixed width if all of the
3001      * frames in the row are fixed width. */
3002     for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3003 	if (!frame_fixed_width(frp))
3004 	    return FALSE;
3005     return TRUE;
3006 }
3007 
3008 /*
3009  * Add a status line to windows at the bottom of "frp".
3010  * Note: Does not check if there is room!
3011  */
3012     static void
3013 frame_add_statusline(frame_T *frp)
3014 {
3015     win_T	*wp;
3016 
3017     if (frp->fr_layout == FR_LEAF)
3018     {
3019 	wp = frp->fr_win;
3020 	if (wp->w_status_height == 0)
3021 	{
3022 	    if (wp->w_height > 0)	/* don't make it negative */
3023 		--wp->w_height;
3024 	    wp->w_status_height = STATUS_HEIGHT;
3025 	}
3026     }
3027     else if (frp->fr_layout == FR_ROW)
3028     {
3029 	/* Handle all the frames in the row. */
3030 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3031 	    frame_add_statusline(frp);
3032     }
3033     else /* frp->fr_layout == FR_COL */
3034     {
3035 	/* Only need to handle the last frame in the column. */
3036 	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
3037 	    ;
3038 	frame_add_statusline(frp);
3039     }
3040 }
3041 
3042 /*
3043  * Set width of a frame.  Handles recursively going through contained frames.
3044  * May remove separator line for windows at the right side (for win_close()).
3045  */
3046     static void
3047 frame_new_width(
3048     frame_T	*topfrp,
3049     int		width,
3050     int		leftfirst,	/* resize leftmost contained frame first */
3051     int		wfw)		/* obey 'winfixwidth' when there is a choice;
3052 				   may cause the width not to be set */
3053 {
3054     frame_T	*frp;
3055     int		extra_cols;
3056     int		w;
3057     win_T	*wp;
3058 
3059     if (topfrp->fr_layout == FR_LEAF)
3060     {
3061 	/* Simple case: just one window. */
3062 	wp = topfrp->fr_win;
3063 	/* Find out if there are any windows right of this one. */
3064 	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
3065 	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
3066 		break;
3067 	if (frp->fr_parent == NULL)
3068 	    wp->w_vsep_width = 0;
3069 	win_new_width(wp, width - wp->w_vsep_width);
3070     }
3071     else if (topfrp->fr_layout == FR_COL)
3072     {
3073 	do
3074 	{
3075 	    /* All frames in this column get the same new width. */
3076 	    for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3077 	    {
3078 		frame_new_width(frp, width, leftfirst, wfw);
3079 		if (frp->fr_width > width)
3080 		{
3081 		    /* Could not fit the windows, make whole column wider. */
3082 		    width = frp->fr_width;
3083 		    break;
3084 		}
3085 	    }
3086 	} while (frp != NULL);
3087     }
3088     else    /* fr_layout == FR_ROW */
3089     {
3090 	/* Complicated case: Resize a row of frames.  Resize the rightmost
3091 	 * frame first, frames left of it when needed. */
3092 
3093 	frp = topfrp->fr_child;
3094 	if (wfw)
3095 	    /* Advance past frames with one window with 'wfw' set. */
3096 	    while (frame_fixed_width(frp))
3097 	    {
3098 		frp = frp->fr_next;
3099 		if (frp == NULL)
3100 		    return;	    /* no frame without 'wfw', give up */
3101 	    }
3102 	if (!leftfirst)
3103 	{
3104 	    /* Find the rightmost frame of this row */
3105 	    while (frp->fr_next != NULL)
3106 		frp = frp->fr_next;
3107 	    if (wfw)
3108 		/* Advance back for frames with one window with 'wfw' set. */
3109 		while (frame_fixed_width(frp))
3110 		    frp = frp->fr_prev;
3111 	}
3112 
3113 	extra_cols = width - topfrp->fr_width;
3114 	if (extra_cols < 0)
3115 	{
3116 	    /* reduce frame width, rightmost frame first */
3117 	    while (frp != NULL)
3118 	    {
3119 		w = frame_minwidth(frp, NULL);
3120 		if (frp->fr_width + extra_cols < w)
3121 		{
3122 		    extra_cols += frp->fr_width - w;
3123 		    frame_new_width(frp, w, leftfirst, wfw);
3124 		}
3125 		else
3126 		{
3127 		    frame_new_width(frp, frp->fr_width + extra_cols,
3128 							      leftfirst, wfw);
3129 		    break;
3130 		}
3131 		if (leftfirst)
3132 		{
3133 		    do
3134 			frp = frp->fr_next;
3135 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3136 		}
3137 		else
3138 		{
3139 		    do
3140 			frp = frp->fr_prev;
3141 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3142 		}
3143 		/* Increase "width" if we could not reduce enough frames. */
3144 		if (frp == NULL)
3145 		    width -= extra_cols;
3146 	    }
3147 	}
3148 	else if (extra_cols > 0)
3149 	{
3150 	    /* increase width of rightmost frame */
3151 	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
3152 	}
3153     }
3154     topfrp->fr_width = width;
3155 }
3156 
3157 /*
3158  * Add the vertical separator to windows at the right side of "frp".
3159  * Note: Does not check if there is room!
3160  */
3161     static void
3162 frame_add_vsep(frame_T *frp)
3163 {
3164     win_T	*wp;
3165 
3166     if (frp->fr_layout == FR_LEAF)
3167     {
3168 	wp = frp->fr_win;
3169 	if (wp->w_vsep_width == 0)
3170 	{
3171 	    if (wp->w_width > 0)	/* don't make it negative */
3172 		--wp->w_width;
3173 	    wp->w_vsep_width = 1;
3174 	}
3175     }
3176     else if (frp->fr_layout == FR_COL)
3177     {
3178 	/* Handle all the frames in the column. */
3179 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3180 	    frame_add_vsep(frp);
3181     }
3182     else /* frp->fr_layout == FR_ROW */
3183     {
3184 	/* Only need to handle the last frame in the row. */
3185 	frp = frp->fr_child;
3186 	while (frp->fr_next != NULL)
3187 	    frp = frp->fr_next;
3188 	frame_add_vsep(frp);
3189     }
3190 }
3191 
3192 /*
3193  * Set frame width from the window it contains.
3194  */
3195     static void
3196 frame_fix_width(win_T *wp)
3197 {
3198     wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
3199 }
3200 
3201 /*
3202  * Set frame height from the window it contains.
3203  */
3204     static void
3205 frame_fix_height(win_T *wp)
3206 {
3207     wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
3208 }
3209 
3210 /*
3211  * Compute the minimal height for frame "topfrp".
3212  * Uses the 'winminheight' option.
3213  * When "next_curwin" isn't NULL, use p_wh for this window.
3214  * When "next_curwin" is NOWIN, don't use at least one line for the current
3215  * window.
3216  */
3217     static int
3218 frame_minheight(frame_T *topfrp, win_T *next_curwin)
3219 {
3220     frame_T	*frp;
3221     int		m;
3222     int		n;
3223 
3224     if (topfrp->fr_win != NULL)
3225     {
3226 	if (topfrp->fr_win == next_curwin)
3227 	    m = p_wh + topfrp->fr_win->w_status_height;
3228 	else
3229 	{
3230 	    /* window: minimal height of the window plus status line */
3231 	    m = p_wmh + topfrp->fr_win->w_status_height;
3232 	    if (topfrp->fr_win == curwin && next_curwin == NULL)
3233 	    {
3234 		/* Current window is minimal one line high and WinBar is
3235 		 * visible. */
3236 		if (p_wmh == 0)
3237 		    ++m;
3238 		m += WINBAR_HEIGHT(curwin);
3239 	    }
3240 	}
3241     }
3242     else if (topfrp->fr_layout == FR_ROW)
3243     {
3244 	/* get the minimal height from each frame in this row */
3245 	m = 0;
3246 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3247 	{
3248 	    n = frame_minheight(frp, next_curwin);
3249 	    if (n > m)
3250 		m = n;
3251 	}
3252     }
3253     else
3254     {
3255 	/* Add up the minimal heights for all frames in this column. */
3256 	m = 0;
3257 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3258 	    m += frame_minheight(frp, next_curwin);
3259     }
3260 
3261     return m;
3262 }
3263 
3264 /*
3265  * Compute the minimal width for frame "topfrp".
3266  * When "next_curwin" isn't NULL, use p_wiw for this window.
3267  * When "next_curwin" is NOWIN, don't use at least one column for the current
3268  * window.
3269  */
3270     static int
3271 frame_minwidth(
3272     frame_T	*topfrp,
3273     win_T	*next_curwin)	/* use p_wh and p_wiw for next_curwin */
3274 {
3275     frame_T	*frp;
3276     int		m, n;
3277 
3278     if (topfrp->fr_win != NULL)
3279     {
3280 	if (topfrp->fr_win == next_curwin)
3281 	    m = p_wiw + topfrp->fr_win->w_vsep_width;
3282 	else
3283 	{
3284 	    /* window: minimal width of the window plus separator column */
3285 	    m = p_wmw + topfrp->fr_win->w_vsep_width;
3286 	    /* Current window is minimal one column wide */
3287 	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
3288 		++m;
3289 	}
3290     }
3291     else if (topfrp->fr_layout == FR_COL)
3292     {
3293 	/* get the minimal width from each frame in this column */
3294 	m = 0;
3295 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3296 	{
3297 	    n = frame_minwidth(frp, next_curwin);
3298 	    if (n > m)
3299 		m = n;
3300 	}
3301     }
3302     else
3303     {
3304 	/* Add up the minimal widths for all frames in this row. */
3305 	m = 0;
3306 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3307 	    m += frame_minwidth(frp, next_curwin);
3308     }
3309 
3310     return m;
3311 }
3312 
3313 
3314 /*
3315  * Try to close all windows except current one.
3316  * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
3317  * used and the buffer was modified.
3318  *
3319  * Used by ":bdel" and ":only".
3320  */
3321     void
3322 close_others(
3323     int		message,
3324     int		forceit)	    /* always hide all other windows */
3325 {
3326     win_T	*wp;
3327     win_T	*nextwp;
3328     int		r;
3329 
3330     if (one_window())
3331     {
3332 	if (message && !autocmd_busy)
3333 	    MSG(_(m_onlyone));
3334 	return;
3335     }
3336 
3337     /* Be very careful here: autocommands may change the window layout. */
3338     for (wp = firstwin; win_valid(wp); wp = nextwp)
3339     {
3340 	nextwp = wp->w_next;
3341 	if (wp != curwin)		/* don't close current window */
3342 	{
3343 
3344 	    /* Check if it's allowed to abandon this window */
3345 	    r = can_abandon(wp->w_buffer, forceit);
3346 	    if (!win_valid(wp))		/* autocommands messed wp up */
3347 	    {
3348 		nextwp = firstwin;
3349 		continue;
3350 	    }
3351 	    if (!r)
3352 	    {
3353 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
3354 		if (message && (p_confirm || cmdmod.confirm) && p_write)
3355 		{
3356 		    dialog_changed(wp->w_buffer, FALSE);
3357 		    if (!win_valid(wp))		/* autocommands messed wp up */
3358 		    {
3359 			nextwp = firstwin;
3360 			continue;
3361 		    }
3362 		}
3363 		if (bufIsChanged(wp->w_buffer))
3364 #endif
3365 		    continue;
3366 	    }
3367 	    win_close(wp, !buf_hide(wp->w_buffer)
3368 					       && !bufIsChanged(wp->w_buffer));
3369 	}
3370     }
3371 
3372     if (message && !ONE_WINDOW)
3373 	EMSG(_("E445: Other window contains changes"));
3374 }
3375 
3376 /*
3377  * Init the current window "curwin".
3378  * Called when a new file is being edited.
3379  */
3380     void
3381 curwin_init(void)
3382 {
3383     win_init_empty(curwin);
3384 }
3385 
3386     void
3387 win_init_empty(win_T *wp)
3388 {
3389     redraw_win_later(wp, NOT_VALID);
3390     wp->w_lines_valid = 0;
3391     wp->w_cursor.lnum = 1;
3392     wp->w_curswant = wp->w_cursor.col = 0;
3393 #ifdef FEAT_VIRTUALEDIT
3394     wp->w_cursor.coladd = 0;
3395 #endif
3396     wp->w_pcmark.lnum = 1;	/* pcmark not cleared but set to line 1 */
3397     wp->w_pcmark.col = 0;
3398     wp->w_prev_pcmark.lnum = 0;
3399     wp->w_prev_pcmark.col = 0;
3400     wp->w_topline = 1;
3401 #ifdef FEAT_DIFF
3402     wp->w_topfill = 0;
3403 #endif
3404     wp->w_botline = 2;
3405 #ifdef FEAT_FKMAP
3406     if (wp->w_p_rl)
3407 	wp->w_farsi = W_CONV + W_R_L;
3408     else
3409 	wp->w_farsi = W_CONV;
3410 #endif
3411 #ifdef FEAT_SYN_HL
3412     wp->w_s = &wp->w_buffer->b_s;
3413 #endif
3414 }
3415 
3416 /*
3417  * Allocate the first window and put an empty buffer in it.
3418  * Called from main().
3419  * Return FAIL when something goes wrong (out of memory).
3420  */
3421     int
3422 win_alloc_first(void)
3423 {
3424     if (win_alloc_firstwin(NULL) == FAIL)
3425 	return FAIL;
3426 
3427     first_tabpage = alloc_tabpage();
3428     if (first_tabpage == NULL)
3429 	return FAIL;
3430     first_tabpage->tp_topframe = topframe;
3431     curtab = first_tabpage;
3432 
3433     return OK;
3434 }
3435 
3436 /*
3437  * Init "aucmd_win".  This can only be done after the first
3438  * window is fully initialized, thus it can't be in win_alloc_first().
3439  */
3440     void
3441 win_alloc_aucmd_win(void)
3442 {
3443     aucmd_win = win_alloc(NULL, TRUE);
3444     if (aucmd_win != NULL)
3445     {
3446 	win_init_some(aucmd_win, curwin);
3447 	RESET_BINDING(aucmd_win);
3448 	new_frame(aucmd_win);
3449     }
3450 }
3451 
3452 /*
3453  * Allocate the first window or the first window in a new tab page.
3454  * When "oldwin" is NULL create an empty buffer for it.
3455  * When "oldwin" is not NULL copy info from it to the new window.
3456  * Return FAIL when something goes wrong (out of memory).
3457  */
3458     static int
3459 win_alloc_firstwin(win_T *oldwin)
3460 {
3461     curwin = win_alloc(NULL, FALSE);
3462     if (oldwin == NULL)
3463     {
3464 	/* Very first window, need to create an empty buffer for it and
3465 	 * initialize from scratch. */
3466 	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
3467 	if (curwin == NULL || curbuf == NULL)
3468 	    return FAIL;
3469 	curwin->w_buffer = curbuf;
3470 #ifdef FEAT_SYN_HL
3471 	curwin->w_s = &(curbuf->b_s);
3472 #endif
3473 	curbuf->b_nwindows = 1;	/* there is one window */
3474 	curwin->w_alist = &global_alist;
3475 	curwin_init();		/* init current window */
3476     }
3477     else
3478     {
3479 	/* First window in new tab page, initialize it from "oldwin". */
3480 	win_init(curwin, oldwin, 0);
3481 
3482 	/* We don't want cursor- and scroll-binding in the first window. */
3483 	RESET_BINDING(curwin);
3484     }
3485 
3486     new_frame(curwin);
3487     if (curwin->w_frame == NULL)
3488 	return FAIL;
3489     topframe = curwin->w_frame;
3490     topframe->fr_width = Columns;
3491     topframe->fr_height = Rows - p_ch;
3492 
3493     return OK;
3494 }
3495 
3496 /*
3497  * Create a frame for window "wp".
3498  */
3499     static void
3500 new_frame(win_T *wp)
3501 {
3502     frame_T *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
3503 
3504     wp->w_frame = frp;
3505     if (frp != NULL)
3506     {
3507 	frp->fr_layout = FR_LEAF;
3508 	frp->fr_win = wp;
3509     }
3510 }
3511 
3512 /*
3513  * Initialize the window and frame size to the maximum.
3514  */
3515     void
3516 win_init_size(void)
3517 {
3518     firstwin->w_height = ROWS_AVAIL;
3519     topframe->fr_height = ROWS_AVAIL;
3520     firstwin->w_width = Columns;
3521     topframe->fr_width = Columns;
3522 }
3523 
3524 /*
3525  * Allocate a new tabpage_T and init the values.
3526  * Returns NULL when out of memory.
3527  */
3528     static tabpage_T *
3529 alloc_tabpage(void)
3530 {
3531     tabpage_T	*tp;
3532 # ifdef FEAT_GUI
3533     int		i;
3534 # endif
3535 
3536 
3537     tp = (tabpage_T *)alloc_clear((unsigned)sizeof(tabpage_T));
3538     if (tp == NULL)
3539 	return NULL;
3540 
3541 # ifdef FEAT_EVAL
3542     /* init t: variables */
3543     tp->tp_vars = dict_alloc();
3544     if (tp->tp_vars == NULL)
3545     {
3546 	vim_free(tp);
3547 	return NULL;
3548     }
3549     init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
3550 # endif
3551 
3552 # ifdef FEAT_GUI
3553     for (i = 0; i < 3; i++)
3554 	tp->tp_prev_which_scrollbars[i] = -1;
3555 # endif
3556 # ifdef FEAT_DIFF
3557     tp->tp_diff_invalid = TRUE;
3558 # endif
3559     tp->tp_ch_used = p_ch;
3560 
3561     return tp;
3562 }
3563 
3564     void
3565 free_tabpage(tabpage_T *tp)
3566 {
3567     int idx;
3568 
3569 # ifdef FEAT_DIFF
3570     diff_clear(tp);
3571 # endif
3572     for (idx = 0; idx < SNAP_COUNT; ++idx)
3573 	clear_snapshot(tp, idx);
3574 #ifdef FEAT_EVAL
3575     vars_clear(&tp->tp_vars->dv_hashtab);	/* free all t: variables */
3576     hash_init(&tp->tp_vars->dv_hashtab);
3577     unref_var_dict(tp->tp_vars);
3578 #endif
3579 
3580 #ifdef FEAT_PYTHON
3581     python_tabpage_free(tp);
3582 #endif
3583 
3584 #ifdef FEAT_PYTHON3
3585     python3_tabpage_free(tp);
3586 #endif
3587 
3588     vim_free(tp);
3589 }
3590 
3591 /*
3592  * Create a new Tab page with one window.
3593  * It will edit the current buffer, like after ":split".
3594  * When "after" is 0 put it just after the current Tab page.
3595  * Otherwise put it just before tab page "after".
3596  * Return FAIL or OK.
3597  */
3598     int
3599 win_new_tabpage(int after)
3600 {
3601     tabpage_T	*tp = curtab;
3602     tabpage_T	*newtp;
3603     int		n;
3604 
3605     newtp = alloc_tabpage();
3606     if (newtp == NULL)
3607 	return FAIL;
3608 
3609     /* Remember the current windows in this Tab page. */
3610     if (leave_tabpage(curbuf, TRUE) == FAIL)
3611     {
3612 	vim_free(newtp);
3613 	return FAIL;
3614     }
3615     curtab = newtp;
3616 
3617     /* Create a new empty window. */
3618     if (win_alloc_firstwin(tp->tp_curwin) == OK)
3619     {
3620 	/* Make the new Tab page the new topframe. */
3621 	if (after == 1)
3622 	{
3623 	    /* New tab page becomes the first one. */
3624 	    newtp->tp_next = first_tabpage;
3625 	    first_tabpage = newtp;
3626 	}
3627 	else
3628 	{
3629 	    if (after > 0)
3630 	    {
3631 		/* Put new tab page before tab page "after". */
3632 		n = 2;
3633 		for (tp = first_tabpage; tp->tp_next != NULL
3634 					       && n < after; tp = tp->tp_next)
3635 		    ++n;
3636 	    }
3637 	    newtp->tp_next = tp->tp_next;
3638 	    tp->tp_next = newtp;
3639 	}
3640 	win_init_size();
3641 	firstwin->w_winrow = tabline_height();
3642 	win_comp_scroll(curwin);
3643 
3644 	newtp->tp_topframe = topframe;
3645 	last_status(FALSE);
3646 
3647 #if defined(FEAT_GUI)
3648 	/* When 'guioptions' includes 'L' or 'R' may have to remove or add
3649 	 * scrollbars.  Have to update them anyway. */
3650 	gui_may_update_scrollbars();
3651 #endif
3652 
3653 	redraw_all_later(CLEAR);
3654 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
3655 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
3656 	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
3657 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3658 	return OK;
3659     }
3660 
3661     /* Failed, get back the previous Tab page */
3662     enter_tabpage(curtab, curbuf, TRUE, TRUE);
3663     return FAIL;
3664 }
3665 
3666 /*
3667  * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
3668  * like with ":split".
3669  * Returns OK if a new tab page was created, FAIL otherwise.
3670  */
3671     int
3672 may_open_tabpage(void)
3673 {
3674     int		n = (cmdmod.tab == 0) ? postponed_split_tab : cmdmod.tab;
3675 
3676     if (n != 0)
3677     {
3678 	cmdmod.tab = 0;	    /* reset it to avoid doing it twice */
3679 	postponed_split_tab = 0;
3680 	return win_new_tabpage(n);
3681     }
3682     return FAIL;
3683 }
3684 
3685 /*
3686  * Create up to "maxcount" tabpages with empty windows.
3687  * Returns the number of resulting tab pages.
3688  */
3689     int
3690 make_tabpages(int maxcount)
3691 {
3692     int		count = maxcount;
3693     int		todo;
3694 
3695     /* Limit to 'tabpagemax' tabs. */
3696     if (count > p_tpm)
3697 	count = p_tpm;
3698 
3699     /*
3700      * Don't execute autocommands while creating the tab pages.  Must do that
3701      * when putting the buffers in the windows.
3702      */
3703     block_autocmds();
3704 
3705     for (todo = count - 1; todo > 0; --todo)
3706 	if (win_new_tabpage(0) == FAIL)
3707 	    break;
3708 
3709     unblock_autocmds();
3710 
3711     /* return actual number of tab pages */
3712     return (count - todo);
3713 }
3714 
3715 /*
3716  * Return TRUE when "tpc" points to a valid tab page.
3717  */
3718     int
3719 valid_tabpage(tabpage_T *tpc)
3720 {
3721     tabpage_T	*tp;
3722 
3723     FOR_ALL_TABPAGES(tp)
3724 	if (tp == tpc)
3725 	    return TRUE;
3726     return FALSE;
3727 }
3728 
3729 /*
3730  * Return TRUE when "tpc" points to a valid tab page and at least one window is
3731  * valid.
3732  */
3733     int
3734 valid_tabpage_win(tabpage_T *tpc)
3735 {
3736     tabpage_T	*tp;
3737     win_T	*wp;
3738 
3739     FOR_ALL_TABPAGES(tp)
3740     {
3741 	if (tp == tpc)
3742 	{
3743 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
3744 	    {
3745 		if (win_valid_any_tab(wp))
3746 		    return TRUE;
3747 	    }
3748 	    return FALSE;
3749 	}
3750     }
3751     /* shouldn't happen */
3752     return FALSE;
3753 }
3754 
3755 /*
3756  * Close tabpage "tab", assuming it has no windows in it.
3757  * There must be another tabpage or this will crash.
3758  */
3759     void
3760 close_tabpage(tabpage_T *tab)
3761 {
3762     tabpage_T	*ptp;
3763 
3764     if (tab == first_tabpage)
3765     {
3766 	first_tabpage = tab->tp_next;
3767 	ptp = first_tabpage;
3768     }
3769     else
3770     {
3771 	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
3772 							    ptp = ptp->tp_next)
3773 	    ;
3774 	assert(ptp != NULL);
3775 	ptp->tp_next = tab->tp_next;
3776     }
3777 
3778     goto_tabpage_tp(ptp, FALSE, FALSE);
3779     free_tabpage(tab);
3780 }
3781 
3782 /*
3783  * Find tab page "n" (first one is 1).  Returns NULL when not found.
3784  */
3785     tabpage_T *
3786 find_tabpage(int n)
3787 {
3788     tabpage_T	*tp;
3789     int		i = 1;
3790 
3791     for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
3792 	++i;
3793     return tp;
3794 }
3795 
3796 /*
3797  * Get index of tab page "tp".  First one has index 1.
3798  * When not found returns number of tab pages plus one.
3799  */
3800     int
3801 tabpage_index(tabpage_T *ftp)
3802 {
3803     int		i = 1;
3804     tabpage_T	*tp;
3805 
3806     for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
3807 	++i;
3808     return i;
3809 }
3810 
3811 /*
3812  * Prepare for leaving the current tab page.
3813  * When autocommands change "curtab" we don't leave the tab page and return
3814  * FAIL.
3815  * Careful: When OK is returned need to get a new tab page very very soon!
3816  */
3817     static int
3818 leave_tabpage(
3819     buf_T	*new_curbuf UNUSED,    /* what is going to be the new curbuf,
3820 				       NULL if unknown */
3821     int		trigger_leave_autocmds UNUSED)
3822 {
3823     tabpage_T	*tp = curtab;
3824 
3825     reset_VIsual_and_resel();	/* stop Visual mode */
3826     if (trigger_leave_autocmds)
3827     {
3828 	if (new_curbuf != curbuf)
3829 	{
3830 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
3831 	    if (curtab != tp)
3832 		return FAIL;
3833 	}
3834 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
3835 	if (curtab != tp)
3836 	    return FAIL;
3837 	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
3838 	if (curtab != tp)
3839 	    return FAIL;
3840     }
3841 #if defined(FEAT_GUI)
3842     /* Remove the scrollbars.  They may be added back later. */
3843     if (gui.in_use)
3844 	gui_remove_scrollbars();
3845 #endif
3846     tp->tp_curwin = curwin;
3847     tp->tp_prevwin = prevwin;
3848     tp->tp_firstwin = firstwin;
3849     tp->tp_lastwin = lastwin;
3850     tp->tp_old_Rows = Rows;
3851     tp->tp_old_Columns = Columns;
3852     firstwin = NULL;
3853     lastwin = NULL;
3854     return OK;
3855 }
3856 
3857 /*
3858  * Start using tab page "tp".
3859  * Only to be used after leave_tabpage() or freeing the current tab page.
3860  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
3861  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
3862  */
3863     static void
3864 enter_tabpage(
3865     tabpage_T	*tp,
3866     buf_T	*old_curbuf UNUSED,
3867     int		trigger_enter_autocmds,
3868     int		trigger_leave_autocmds)
3869 {
3870     int		old_off = tp->tp_firstwin->w_winrow;
3871     win_T	*next_prevwin = tp->tp_prevwin;
3872 
3873     curtab = tp;
3874     firstwin = tp->tp_firstwin;
3875     lastwin = tp->tp_lastwin;
3876     topframe = tp->tp_topframe;
3877 
3878     /* We would like doing the TabEnter event first, but we don't have a
3879      * valid current window yet, which may break some commands.
3880      * This triggers autocommands, thus may make "tp" invalid. */
3881     win_enter_ext(tp->tp_curwin, FALSE, TRUE, FALSE,
3882 			      trigger_enter_autocmds, trigger_leave_autocmds);
3883     prevwin = next_prevwin;
3884 
3885     last_status(FALSE);		/* status line may appear or disappear */
3886     (void)win_comp_pos();	/* recompute w_winrow for all windows */
3887     must_redraw = CLEAR;	/* need to redraw everything */
3888 #ifdef FEAT_DIFF
3889     diff_need_scrollbind = TRUE;
3890 #endif
3891 
3892     /* The tabpage line may have appeared or disappeared, may need to resize
3893      * the frames for that.  When the Vim window was resized need to update
3894      * frame sizes too.  Use the stored value of p_ch, so that it can be
3895      * different for each tab page. */
3896     p_ch = curtab->tp_ch_used;
3897     if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
3898 #ifdef FEAT_GUI_TABLINE
3899 			    && !gui_use_tabline()
3900 #endif
3901 		))
3902 	shell_new_rows();
3903     if (curtab->tp_old_Columns != Columns && starting == 0)
3904 	shell_new_columns();	/* update window widths */
3905 
3906 #if defined(FEAT_GUI)
3907     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
3908      * scrollbars.  Have to update them anyway. */
3909     gui_may_update_scrollbars();
3910 #endif
3911 
3912     /* Apply autocommands after updating the display, when 'rows' and
3913      * 'columns' have been set correctly. */
3914     if (trigger_enter_autocmds)
3915     {
3916 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3917 	if (old_curbuf != curbuf)
3918 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
3919     }
3920 
3921     redraw_all_later(CLEAR);
3922 }
3923 
3924 /*
3925  * Go to tab page "n".  For ":tab N" and "Ngt".
3926  * When "n" is 9999 go to the last tab page.
3927  */
3928     void
3929 goto_tabpage(int n)
3930 {
3931     tabpage_T	*tp;
3932     tabpage_T	*ttp;
3933     int		i;
3934 
3935     if (text_locked())
3936     {
3937 	/* Not allowed when editing the command line. */
3938 	text_locked_msg();
3939 	return;
3940     }
3941 
3942     /* If there is only one it can't work. */
3943     if (first_tabpage->tp_next == NULL)
3944     {
3945 	if (n > 1)
3946 	    beep_flush();
3947 	return;
3948     }
3949 
3950     if (n == 0)
3951     {
3952 	/* No count, go to next tab page, wrap around end. */
3953 	if (curtab->tp_next == NULL)
3954 	    tp = first_tabpage;
3955 	else
3956 	    tp = curtab->tp_next;
3957     }
3958     else if (n < 0)
3959     {
3960 	/* "gT": go to previous tab page, wrap around end.  "N gT" repeats
3961 	 * this N times. */
3962 	ttp = curtab;
3963 	for (i = n; i < 0; ++i)
3964 	{
3965 	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
3966 		    tp = tp->tp_next)
3967 		;
3968 	    ttp = tp;
3969 	}
3970     }
3971     else if (n == 9999)
3972     {
3973 	/* Go to last tab page. */
3974 	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
3975 	    ;
3976     }
3977     else
3978     {
3979 	/* Go to tab page "n". */
3980 	tp = find_tabpage(n);
3981 	if (tp == NULL)
3982 	{
3983 	    beep_flush();
3984 	    return;
3985 	}
3986     }
3987 
3988     goto_tabpage_tp(tp, TRUE, TRUE);
3989 
3990 #ifdef FEAT_GUI_TABLINE
3991     if (gui_use_tabline())
3992 	gui_mch_set_curtab(tabpage_index(curtab));
3993 #endif
3994 }
3995 
3996 /*
3997  * Go to tabpage "tp".
3998  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
3999  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4000  * Note: doesn't update the GUI tab.
4001  */
4002     void
4003 goto_tabpage_tp(
4004     tabpage_T	*tp,
4005     int		trigger_enter_autocmds,
4006     int		trigger_leave_autocmds)
4007 {
4008     /* Don't repeat a message in another tab page. */
4009     set_keep_msg(NULL, 0);
4010 
4011     if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
4012 					trigger_leave_autocmds) == OK)
4013     {
4014 	if (valid_tabpage(tp))
4015 	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
4016 		    trigger_leave_autocmds);
4017 	else
4018 	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
4019 		    trigger_leave_autocmds);
4020     }
4021 }
4022 
4023 /*
4024  * Enter window "wp" in tab page "tp".
4025  * Also updates the GUI tab.
4026  */
4027     void
4028 goto_tabpage_win(tabpage_T *tp, win_T *wp)
4029 {
4030     goto_tabpage_tp(tp, TRUE, TRUE);
4031     if (curtab == tp && win_valid(wp))
4032     {
4033 	win_enter(wp, TRUE);
4034 # ifdef FEAT_GUI_TABLINE
4035 	if (gui_use_tabline())
4036 	    gui_mch_set_curtab(tabpage_index(curtab));
4037 # endif
4038     }
4039 }
4040 
4041 /*
4042  * Move the current tab page to after tab page "nr".
4043  */
4044     void
4045 tabpage_move(int nr)
4046 {
4047     int		n = 1;
4048     tabpage_T	*tp, *tp_dst;
4049 
4050     if (first_tabpage->tp_next == NULL)
4051 	return;
4052 
4053     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
4054 	++n;
4055 
4056     if (tp == curtab || (nr > 0 && tp->tp_next != NULL
4057 						    && tp->tp_next == curtab))
4058 	return;
4059 
4060     tp_dst = tp;
4061 
4062     /* Remove the current tab page from the list of tab pages. */
4063     if (curtab == first_tabpage)
4064 	first_tabpage = curtab->tp_next;
4065     else
4066     {
4067 	FOR_ALL_TABPAGES(tp)
4068 	    if (tp->tp_next == curtab)
4069 		break;
4070 	if (tp == NULL)	/* "cannot happen" */
4071 	    return;
4072 	tp->tp_next = curtab->tp_next;
4073     }
4074 
4075     /* Re-insert it at the specified position. */
4076     if (nr <= 0)
4077     {
4078 	curtab->tp_next = first_tabpage;
4079 	first_tabpage = curtab;
4080     }
4081     else
4082     {
4083 	curtab->tp_next = tp_dst->tp_next;
4084 	tp_dst->tp_next = curtab;
4085     }
4086 
4087     /* Need to redraw the tabline.  Tab page contents doesn't change. */
4088     redraw_tabline = TRUE;
4089 }
4090 
4091 
4092 /*
4093  * Go to another window.
4094  * When jumping to another buffer, stop Visual mode.  Do this before
4095  * changing windows so we can yank the selection into the '*' register.
4096  * When jumping to another window on the same buffer, adjust its cursor
4097  * position to keep the same Visual area.
4098  */
4099     void
4100 win_goto(win_T *wp)
4101 {
4102 #ifdef FEAT_CONCEAL
4103     win_T	*owp = curwin;
4104 #endif
4105 
4106     if (text_locked())
4107     {
4108 	beep_flush();
4109 	text_locked_msg();
4110 	return;
4111     }
4112     if (curbuf_locked())
4113 	return;
4114 
4115     if (wp->w_buffer != curbuf)
4116 	reset_VIsual_and_resel();
4117     else if (VIsual_active)
4118 	wp->w_cursor = curwin->w_cursor;
4119 
4120 #ifdef FEAT_GUI
4121     need_mouse_correct = TRUE;
4122 #endif
4123     win_enter(wp, TRUE);
4124 
4125 #ifdef FEAT_CONCEAL
4126     /* Conceal cursor line in previous window, unconceal in current window. */
4127     if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
4128 	update_single_line(owp, owp->w_cursor.lnum);
4129     if (curwin->w_p_cole > 0 && !msg_scrolled)
4130 	need_cursor_line_redraw = TRUE;
4131 #endif
4132 }
4133 
4134 #if defined(FEAT_PERL) || defined(PROTO)
4135 /*
4136  * Find window number "winnr" (counting top to bottom).
4137  */
4138     win_T *
4139 win_find_nr(int winnr)
4140 {
4141     win_T	*wp;
4142 
4143     FOR_ALL_WINDOWS(wp)
4144 	if (--winnr == 0)
4145 	    break;
4146     return wp;
4147 }
4148 #endif
4149 
4150 #if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
4151 /*
4152  * Find the tabpage for window "win".
4153  */
4154     tabpage_T *
4155 win_find_tabpage(win_T *win)
4156 {
4157     win_T	*wp;
4158     tabpage_T	*tp;
4159 
4160     FOR_ALL_TAB_WINDOWS(tp, wp)
4161 	    if (wp == win)
4162 		return tp;
4163     return NULL;
4164 }
4165 #endif
4166 
4167 /*
4168  * Move to window above or below "count" times.
4169  */
4170     static void
4171 win_goto_ver(
4172     int		up,		/* TRUE to go to win above */
4173     long	count)
4174 {
4175     frame_T	*fr;
4176     frame_T	*nfr;
4177     frame_T	*foundfr;
4178 
4179     foundfr = curwin->w_frame;
4180     while (count--)
4181     {
4182 	/*
4183 	 * First go upwards in the tree of frames until we find a upwards or
4184 	 * downwards neighbor.
4185 	 */
4186 	fr = foundfr;
4187 	for (;;)
4188 	{
4189 	    if (fr == topframe)
4190 		goto end;
4191 	    if (up)
4192 		nfr = fr->fr_prev;
4193 	    else
4194 		nfr = fr->fr_next;
4195 	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
4196 		break;
4197 	    fr = fr->fr_parent;
4198 	}
4199 
4200 	/*
4201 	 * Now go downwards to find the bottom or top frame in it.
4202 	 */
4203 	for (;;)
4204 	{
4205 	    if (nfr->fr_layout == FR_LEAF)
4206 	    {
4207 		foundfr = nfr;
4208 		break;
4209 	    }
4210 	    fr = nfr->fr_child;
4211 	    if (nfr->fr_layout == FR_ROW)
4212 	    {
4213 		/* Find the frame at the cursor row. */
4214 		while (fr->fr_next != NULL
4215 			&& frame2win(fr)->w_wincol + fr->fr_width
4216 					 <= curwin->w_wincol + curwin->w_wcol)
4217 		    fr = fr->fr_next;
4218 	    }
4219 	    if (nfr->fr_layout == FR_COL && up)
4220 		while (fr->fr_next != NULL)
4221 		    fr = fr->fr_next;
4222 	    nfr = fr;
4223 	}
4224     }
4225 end:
4226     if (foundfr != NULL)
4227 	win_goto(foundfr->fr_win);
4228 }
4229 
4230 /*
4231  * Move to left or right window.
4232  */
4233     static void
4234 win_goto_hor(
4235     int		left,		/* TRUE to go to left win */
4236     long	count)
4237 {
4238     frame_T	*fr;
4239     frame_T	*nfr;
4240     frame_T	*foundfr;
4241 
4242     foundfr = curwin->w_frame;
4243     while (count--)
4244     {
4245 	/*
4246 	 * First go upwards in the tree of frames until we find a left or
4247 	 * right neighbor.
4248 	 */
4249 	fr = foundfr;
4250 	for (;;)
4251 	{
4252 	    if (fr == topframe)
4253 		goto end;
4254 	    if (left)
4255 		nfr = fr->fr_prev;
4256 	    else
4257 		nfr = fr->fr_next;
4258 	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
4259 		break;
4260 	    fr = fr->fr_parent;
4261 	}
4262 
4263 	/*
4264 	 * Now go downwards to find the leftmost or rightmost frame in it.
4265 	 */
4266 	for (;;)
4267 	{
4268 	    if (nfr->fr_layout == FR_LEAF)
4269 	    {
4270 		foundfr = nfr;
4271 		break;
4272 	    }
4273 	    fr = nfr->fr_child;
4274 	    if (nfr->fr_layout == FR_COL)
4275 	    {
4276 		/* Find the frame at the cursor row. */
4277 		while (fr->fr_next != NULL
4278 			&& frame2win(fr)->w_winrow + fr->fr_height
4279 					 <= curwin->w_winrow + curwin->w_wrow)
4280 		    fr = fr->fr_next;
4281 	    }
4282 	    if (nfr->fr_layout == FR_ROW && left)
4283 		while (fr->fr_next != NULL)
4284 		    fr = fr->fr_next;
4285 	    nfr = fr;
4286 	}
4287     }
4288 end:
4289     if (foundfr != NULL)
4290 	win_goto(foundfr->fr_win);
4291 }
4292 
4293 /*
4294  * Make window "wp" the current window.
4295  */
4296     void
4297 win_enter(win_T *wp, int undo_sync)
4298 {
4299     win_enter_ext(wp, undo_sync, FALSE, FALSE, TRUE, TRUE);
4300 }
4301 
4302 /*
4303  * Make window wp the current window.
4304  * Can be called with "curwin_invalid" TRUE, which means that curwin has just
4305  * been closed and isn't valid.
4306  */
4307     static void
4308 win_enter_ext(
4309     win_T	*wp,
4310     int		undo_sync,
4311     int		curwin_invalid,
4312     int		trigger_new_autocmds,
4313     int		trigger_enter_autocmds,
4314     int		trigger_leave_autocmds)
4315 {
4316     int		other_buffer = FALSE;
4317 
4318     if (wp == curwin && !curwin_invalid)	/* nothing to do */
4319 	return;
4320 
4321     if (!curwin_invalid && trigger_leave_autocmds)
4322     {
4323 	/*
4324 	 * Be careful: If autocommands delete the window, return now.
4325 	 */
4326 	if (wp->w_buffer != curbuf)
4327 	{
4328 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4329 	    other_buffer = TRUE;
4330 	    if (!win_valid(wp))
4331 		return;
4332 	}
4333 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4334 	if (!win_valid(wp))
4335 	    return;
4336 #ifdef FEAT_EVAL
4337 	/* autocmds may abort script processing */
4338 	if (aborting())
4339 	    return;
4340 #endif
4341     }
4342 
4343     /* sync undo before leaving the current buffer */
4344     if (undo_sync && curbuf != wp->w_buffer)
4345 	u_sync(FALSE);
4346 
4347     /* Might need to scroll the old window before switching, e.g., when the
4348      * cursor was moved. */
4349     update_topline();
4350 
4351     /* may have to copy the buffer options when 'cpo' contains 'S' */
4352     if (wp->w_buffer != curbuf)
4353 	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
4354     if (!curwin_invalid)
4355     {
4356 	prevwin = curwin;	/* remember for CTRL-W p */
4357 	curwin->w_redr_status = TRUE;
4358     }
4359     curwin = wp;
4360     curbuf = wp->w_buffer;
4361     check_cursor();
4362 #ifdef FEAT_VIRTUALEDIT
4363     if (!virtual_active())
4364 	curwin->w_cursor.coladd = 0;
4365 #endif
4366     changed_line_abv_curs();	/* assume cursor position needs updating */
4367 
4368     if (curwin->w_localdir != NULL)
4369     {
4370 	/* Window has a local directory: Save current directory as global
4371 	 * directory (unless that was done already) and change to the local
4372 	 * directory. */
4373 	if (globaldir == NULL)
4374 	{
4375 	    char_u	cwd[MAXPATHL];
4376 
4377 	    if (mch_dirname(cwd, MAXPATHL) == OK)
4378 		globaldir = vim_strsave(cwd);
4379 	}
4380 	if (mch_chdir((char *)curwin->w_localdir) == 0)
4381 	    shorten_fnames(TRUE);
4382     }
4383     else if (globaldir != NULL)
4384     {
4385 	/* Window doesn't have a local directory and we are not in the global
4386 	 * directory: Change to the global directory. */
4387 	ignored = mch_chdir((char *)globaldir);
4388 	VIM_CLEAR(globaldir);
4389 	shorten_fnames(TRUE);
4390     }
4391 
4392     if (trigger_new_autocmds)
4393 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
4394     if (trigger_enter_autocmds)
4395     {
4396 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
4397 	if (other_buffer)
4398 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4399     }
4400 
4401 #ifdef FEAT_TITLE
4402     maketitle();
4403 #endif
4404     curwin->w_redr_status = TRUE;
4405     redraw_tabline = TRUE;
4406     if (restart_edit)
4407 	redraw_later(VALID);	/* causes status line redraw */
4408 
4409     /* set window height to desired minimal value */
4410     if (curwin->w_height < p_wh && !curwin->w_p_wfh)
4411 	win_setheight((int)p_wh);
4412     else if (curwin->w_height == 0)
4413 	win_setheight(1);
4414 
4415     /* set window width to desired minimal value */
4416     if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
4417 	win_setwidth((int)p_wiw);
4418 
4419 #ifdef FEAT_MOUSE
4420     setmouse();			/* in case jumped to/from help buffer */
4421 #endif
4422 
4423     /* Change directories when the 'acd' option is set. */
4424     DO_AUTOCHDIR;
4425 }
4426 
4427 
4428 /*
4429  * Jump to the first open window that contains buffer "buf", if one exists.
4430  * Returns a pointer to the window found, otherwise NULL.
4431  */
4432     win_T *
4433 buf_jump_open_win(buf_T *buf)
4434 {
4435     win_T	*wp = NULL;
4436 
4437     if (curwin->w_buffer == buf)
4438 	wp = curwin;
4439     else
4440 	FOR_ALL_WINDOWS(wp)
4441 	    if (wp->w_buffer == buf)
4442 		break;
4443     if (wp != NULL)
4444 	win_enter(wp, FALSE);
4445     return wp;
4446 }
4447 
4448 /*
4449  * Jump to the first open window in any tab page that contains buffer "buf",
4450  * if one exists.
4451  * Returns a pointer to the window found, otherwise NULL.
4452  */
4453     win_T *
4454 buf_jump_open_tab(buf_T *buf)
4455 {
4456     win_T	*wp = buf_jump_open_win(buf);
4457     tabpage_T	*tp;
4458 
4459     if (wp != NULL)
4460 	return wp;
4461 
4462     FOR_ALL_TABPAGES(tp)
4463 	if (tp != curtab)
4464 	{
4465 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
4466 		if (wp->w_buffer == buf)
4467 		    break;
4468 	    if (wp != NULL)
4469 	    {
4470 		goto_tabpage_win(tp, wp);
4471 		if (curwin != wp)
4472 		    wp = NULL;	/* something went wrong */
4473 		break;
4474 	    }
4475 	}
4476     return wp;
4477 }
4478 
4479 static int last_win_id = LOWEST_WIN_ID - 1;
4480 
4481 /*
4482  * Allocate a window structure and link it in the window list when "hidden" is
4483  * FALSE.
4484  */
4485     static win_T *
4486 win_alloc(win_T *after UNUSED, int hidden UNUSED)
4487 {
4488     win_T	*new_wp;
4489 
4490     /*
4491      * allocate window structure and linesizes arrays
4492      */
4493     new_wp = (win_T *)alloc_clear((unsigned)sizeof(win_T));
4494     if (new_wp == NULL)
4495 	return NULL;
4496 
4497     if (win_alloc_lines(new_wp) == FAIL)
4498     {
4499 	vim_free(new_wp);
4500 	return NULL;
4501     }
4502 
4503     new_wp->w_id = ++last_win_id;
4504 
4505 #ifdef FEAT_EVAL
4506     /* init w: variables */
4507     new_wp->w_vars = dict_alloc();
4508     if (new_wp->w_vars == NULL)
4509     {
4510 	win_free_lsize(new_wp);
4511 	vim_free(new_wp);
4512 	return NULL;
4513     }
4514     init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
4515 #endif
4516 
4517     /* Don't execute autocommands while the window is not properly
4518      * initialized yet.  gui_create_scrollbar() may trigger a FocusGained
4519      * event. */
4520     block_autocmds();
4521 
4522     /*
4523      * link the window in the window list
4524      */
4525     if (!hidden)
4526 	win_append(after, new_wp);
4527     new_wp->w_wincol = 0;
4528     new_wp->w_width = Columns;
4529 
4530     /* position the display and the cursor at the top of the file. */
4531     new_wp->w_topline = 1;
4532 #ifdef FEAT_DIFF
4533     new_wp->w_topfill = 0;
4534 #endif
4535     new_wp->w_botline = 2;
4536     new_wp->w_cursor.lnum = 1;
4537     new_wp->w_scbind_pos = 1;
4538 
4539     /* We won't calculate w_fraction until resizing the window */
4540     new_wp->w_fraction = 0;
4541     new_wp->w_prev_fraction_row = -1;
4542 
4543 #ifdef FEAT_GUI
4544     if (gui.in_use)
4545     {
4546 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
4547 		SBAR_LEFT, new_wp);
4548 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
4549 		SBAR_RIGHT, new_wp);
4550     }
4551 #endif
4552 #ifdef FEAT_FOLDING
4553     foldInitWin(new_wp);
4554 #endif
4555     unblock_autocmds();
4556 #ifdef FEAT_SEARCH_EXTRA
4557     new_wp->w_match_head = NULL;
4558     new_wp->w_next_match_id = 4;
4559 #endif
4560     return new_wp;
4561 }
4562 
4563 /*
4564  * Remove window 'wp' from the window list and free the structure.
4565  */
4566     static void
4567 win_free(
4568     win_T	*wp,
4569     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4570 {
4571     int		i;
4572     buf_T	*buf;
4573     wininfo_T	*wip;
4574 
4575 #ifdef FEAT_FOLDING
4576     clearFolding(wp);
4577 #endif
4578 
4579     /* reduce the reference count to the argument list. */
4580     alist_unlink(wp->w_alist);
4581 
4582     /* Don't execute autocommands while the window is halfway being deleted.
4583      * gui_mch_destroy_scrollbar() may trigger a FocusGained event. */
4584     block_autocmds();
4585 
4586 #ifdef FEAT_LUA
4587     lua_window_free(wp);
4588 #endif
4589 
4590 #ifdef FEAT_MZSCHEME
4591     mzscheme_window_free(wp);
4592 #endif
4593 
4594 #ifdef FEAT_PERL
4595     perl_win_free(wp);
4596 #endif
4597 
4598 #ifdef FEAT_PYTHON
4599     python_window_free(wp);
4600 #endif
4601 
4602 #ifdef FEAT_PYTHON3
4603     python3_window_free(wp);
4604 #endif
4605 
4606 #ifdef FEAT_TCL
4607     tcl_window_free(wp);
4608 #endif
4609 
4610 #ifdef FEAT_RUBY
4611     ruby_window_free(wp);
4612 #endif
4613 
4614     clear_winopt(&wp->w_onebuf_opt);
4615     clear_winopt(&wp->w_allbuf_opt);
4616 
4617 #ifdef FEAT_EVAL
4618     vars_clear(&wp->w_vars->dv_hashtab);	/* free all w: variables */
4619     hash_init(&wp->w_vars->dv_hashtab);
4620     unref_var_dict(wp->w_vars);
4621 #endif
4622 
4623     {
4624 	tabpage_T	*ttp;
4625 
4626 	if (prevwin == wp)
4627 	    prevwin = NULL;
4628 	FOR_ALL_TABPAGES(ttp)
4629 	    if (ttp->tp_prevwin == wp)
4630 		ttp->tp_prevwin = NULL;
4631     }
4632     win_free_lsize(wp);
4633 
4634     for (i = 0; i < wp->w_tagstacklen; ++i)
4635 	vim_free(wp->w_tagstack[i].tagname);
4636 
4637     vim_free(wp->w_localdir);
4638 
4639     /* Remove the window from the b_wininfo lists, it may happen that the
4640      * freed memory is re-used for another window. */
4641     FOR_ALL_BUFFERS(buf)
4642 	for (wip = buf->b_wininfo; wip != NULL; wip = wip->wi_next)
4643 	    if (wip->wi_win == wp)
4644 		wip->wi_win = NULL;
4645 
4646 #ifdef FEAT_SEARCH_EXTRA
4647     clear_matches(wp);
4648 #endif
4649 
4650 #ifdef FEAT_JUMPLIST
4651     free_jumplist(wp);
4652 #endif
4653 
4654 #ifdef FEAT_QUICKFIX
4655     qf_free_all(wp);
4656 #endif
4657 
4658 #ifdef FEAT_GUI
4659     if (gui.in_use)
4660     {
4661 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
4662 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
4663     }
4664 #endif /* FEAT_GUI */
4665 
4666 #ifdef FEAT_MENU
4667     remove_winbar(wp);
4668 #endif
4669 
4670 #ifdef FEAT_SYN_HL
4671     vim_free(wp->w_p_cc_cols);
4672 #endif
4673 
4674     if (wp != aucmd_win)
4675 	win_remove(wp, tp);
4676     if (autocmd_busy)
4677     {
4678 	wp->w_next = au_pending_free_win;
4679 	au_pending_free_win = wp;
4680     }
4681     else
4682 	vim_free(wp);
4683 
4684     unblock_autocmds();
4685 }
4686 
4687 /*
4688  * Append window "wp" in the window list after window "after".
4689  */
4690     void
4691 win_append(win_T *after, win_T *wp)
4692 {
4693     win_T	*before;
4694 
4695     if (after == NULL)	    /* after NULL is in front of the first */
4696 	before = firstwin;
4697     else
4698 	before = after->w_next;
4699 
4700     wp->w_next = before;
4701     wp->w_prev = after;
4702     if (after == NULL)
4703 	firstwin = wp;
4704     else
4705 	after->w_next = wp;
4706     if (before == NULL)
4707 	lastwin = wp;
4708     else
4709 	before->w_prev = wp;
4710 }
4711 
4712 /*
4713  * Remove a window from the window list.
4714  */
4715     void
4716 win_remove(
4717     win_T	*wp,
4718     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4719 {
4720     if (wp->w_prev != NULL)
4721 	wp->w_prev->w_next = wp->w_next;
4722     else if (tp == NULL)
4723 	firstwin = curtab->tp_firstwin = wp->w_next;
4724     else
4725 	tp->tp_firstwin = wp->w_next;
4726 
4727     if (wp->w_next != NULL)
4728 	wp->w_next->w_prev = wp->w_prev;
4729     else if (tp == NULL)
4730 	lastwin = curtab->tp_lastwin = wp->w_prev;
4731     else
4732 	tp->tp_lastwin = wp->w_prev;
4733 }
4734 
4735 /*
4736  * Append frame "frp" in a frame list after frame "after".
4737  */
4738     static void
4739 frame_append(frame_T *after, frame_T *frp)
4740 {
4741     frp->fr_next = after->fr_next;
4742     after->fr_next = frp;
4743     if (frp->fr_next != NULL)
4744 	frp->fr_next->fr_prev = frp;
4745     frp->fr_prev = after;
4746 }
4747 
4748 /*
4749  * Insert frame "frp" in a frame list before frame "before".
4750  */
4751     static void
4752 frame_insert(frame_T *before, frame_T *frp)
4753 {
4754     frp->fr_next = before;
4755     frp->fr_prev = before->fr_prev;
4756     before->fr_prev = frp;
4757     if (frp->fr_prev != NULL)
4758 	frp->fr_prev->fr_next = frp;
4759     else
4760 	frp->fr_parent->fr_child = frp;
4761 }
4762 
4763 /*
4764  * Remove a frame from a frame list.
4765  */
4766     static void
4767 frame_remove(frame_T *frp)
4768 {
4769     if (frp->fr_prev != NULL)
4770 	frp->fr_prev->fr_next = frp->fr_next;
4771     else
4772     {
4773 	frp->fr_parent->fr_child = frp->fr_next;
4774 	/* special case: topframe->fr_child == frp */
4775 	if (topframe->fr_child == frp)
4776 	    topframe->fr_child = frp->fr_next;
4777     }
4778     if (frp->fr_next != NULL)
4779 	frp->fr_next->fr_prev = frp->fr_prev;
4780 }
4781 
4782 /*
4783  * Allocate w_lines[] for window "wp".
4784  * Return FAIL for failure, OK for success.
4785  */
4786     int
4787 win_alloc_lines(win_T *wp)
4788 {
4789     wp->w_lines_valid = 0;
4790     wp->w_lines = (wline_T *)alloc_clear((unsigned)(Rows * sizeof(wline_T)));
4791     if (wp->w_lines == NULL)
4792 	return FAIL;
4793     return OK;
4794 }
4795 
4796 /*
4797  * free lsize arrays for a window
4798  */
4799     void
4800 win_free_lsize(win_T *wp)
4801 {
4802     /* TODO: why would wp be NULL here? */
4803     if (wp != NULL)
4804 	VIM_CLEAR(wp->w_lines);
4805 }
4806 
4807 /*
4808  * Called from win_new_shellsize() after Rows changed.
4809  * This only does the current tab page, others must be done when made active.
4810  */
4811     void
4812 shell_new_rows(void)
4813 {
4814     int		h = (int)ROWS_AVAIL;
4815 
4816     if (firstwin == NULL)	/* not initialized yet */
4817 	return;
4818     if (h < frame_minheight(topframe, NULL))
4819 	h = frame_minheight(topframe, NULL);
4820 
4821     /* First try setting the heights of windows with 'winfixheight'.  If
4822      * that doesn't result in the right height, forget about that option. */
4823     frame_new_height(topframe, h, FALSE, TRUE);
4824     if (!frame_check_height(topframe, h))
4825 	frame_new_height(topframe, h, FALSE, FALSE);
4826 
4827     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4828     compute_cmdrow();
4829     curtab->tp_ch_used = p_ch;
4830 
4831 #if 0
4832     /* Disabled: don't want making the screen smaller make a window larger. */
4833     if (p_ea)
4834 	win_equal(curwin, FALSE, 'v');
4835 #endif
4836 }
4837 
4838 /*
4839  * Called from win_new_shellsize() after Columns changed.
4840  */
4841     void
4842 shell_new_columns(void)
4843 {
4844     if (firstwin == NULL)	/* not initialized yet */
4845 	return;
4846 
4847     /* First try setting the widths of windows with 'winfixwidth'.  If that
4848      * doesn't result in the right width, forget about that option. */
4849     frame_new_width(topframe, (int)Columns, FALSE, TRUE);
4850     if (!frame_check_width(topframe, Columns))
4851 	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
4852 
4853     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4854 #if 0
4855     /* Disabled: don't want making the screen smaller make a window larger. */
4856     if (p_ea)
4857 	win_equal(curwin, FALSE, 'h');
4858 #endif
4859 }
4860 
4861 #if defined(FEAT_CMDWIN) || defined(PROTO)
4862 /*
4863  * Save the size of all windows in "gap".
4864  */
4865     void
4866 win_size_save(garray_T *gap)
4867 
4868 {
4869     win_T	*wp;
4870 
4871     ga_init2(gap, (int)sizeof(int), 1);
4872     if (ga_grow(gap, win_count() * 2) == OK)
4873 	FOR_ALL_WINDOWS(wp)
4874 	{
4875 	    ((int *)gap->ga_data)[gap->ga_len++] =
4876 					       wp->w_width + wp->w_vsep_width;
4877 	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
4878 	}
4879 }
4880 
4881 /*
4882  * Restore window sizes, but only if the number of windows is still the same.
4883  * Does not free the growarray.
4884  */
4885     void
4886 win_size_restore(garray_T *gap)
4887 {
4888     win_T	*wp;
4889     int		i, j;
4890 
4891     if (win_count() * 2 == gap->ga_len)
4892     {
4893 	/* The order matters, because frames contain other frames, but it's
4894 	 * difficult to get right. The easy way out is to do it twice. */
4895 	for (j = 0; j < 2; ++j)
4896 	{
4897 	    i = 0;
4898 	    FOR_ALL_WINDOWS(wp)
4899 	    {
4900 		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
4901 		win_setheight_win(((int *)gap->ga_data)[i++], wp);
4902 	    }
4903 	}
4904 	/* recompute the window positions */
4905 	(void)win_comp_pos();
4906     }
4907 }
4908 #endif /* FEAT_CMDWIN */
4909 
4910 /*
4911  * Update the position for all windows, using the width and height of the
4912  * frames.
4913  * Returns the row just after the last window.
4914  */
4915     int
4916 win_comp_pos(void)
4917 {
4918     int		row = tabline_height();
4919     int		col = 0;
4920 
4921     frame_comp_pos(topframe, &row, &col);
4922     return row;
4923 }
4924 
4925 /*
4926  * Update the position of the windows in frame "topfrp", using the width and
4927  * height of the frames.
4928  * "*row" and "*col" are the top-left position of the frame.  They are updated
4929  * to the bottom-right position plus one.
4930  */
4931     static void
4932 frame_comp_pos(frame_T *topfrp, int *row, int *col)
4933 {
4934     win_T	*wp;
4935     frame_T	*frp;
4936     int		startcol;
4937     int		startrow;
4938     int		h;
4939 
4940     wp = topfrp->fr_win;
4941     if (wp != NULL)
4942     {
4943 	if (wp->w_winrow != *row || wp->w_wincol != *col)
4944 	{
4945 	    /* position changed, redraw */
4946 	    wp->w_winrow = *row;
4947 	    wp->w_wincol = *col;
4948 	    redraw_win_later(wp, NOT_VALID);
4949 	    wp->w_redr_status = TRUE;
4950 	}
4951 	/* WinBar will not show if the window height is zero */
4952 	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
4953 	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
4954 	*col += wp->w_width + wp->w_vsep_width;
4955     }
4956     else
4957     {
4958 	startrow = *row;
4959 	startcol = *col;
4960 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
4961 	{
4962 	    if (topfrp->fr_layout == FR_ROW)
4963 		*row = startrow;	/* all frames are at the same row */
4964 	    else
4965 		*col = startcol;	/* all frames are at the same col */
4966 	    frame_comp_pos(frp, row, col);
4967 	}
4968     }
4969 }
4970 
4971 /*
4972  * Set current window height and take care of repositioning other windows to
4973  * fit around it.
4974  */
4975     void
4976 win_setheight(int height)
4977 {
4978     win_setheight_win(height, curwin);
4979 }
4980 
4981 /*
4982  * Set the window height of window "win" and take care of repositioning other
4983  * windows to fit around it.
4984  */
4985     void
4986 win_setheight_win(int height, win_T *win)
4987 {
4988     int		row;
4989 
4990     if (win == curwin)
4991     {
4992 	/* Always keep current window at least one line high, even when
4993 	 * 'winminheight' is zero. */
4994 	if (height < p_wmh)
4995 	    height = p_wmh;
4996 	if (height == 0)
4997 	    height = 1;
4998 	height += WINBAR_HEIGHT(curwin);
4999     }
5000 
5001     frame_setheight(win->w_frame, height + win->w_status_height);
5002 
5003     /* recompute the window positions */
5004     row = win_comp_pos();
5005 
5006     /*
5007      * If there is extra space created between the last window and the command
5008      * line, clear it.
5009      */
5010     if (full_screen && msg_scrolled == 0 && row < cmdline_row)
5011 	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5012     cmdline_row = row;
5013     msg_row = row;
5014     msg_col = 0;
5015 
5016     redraw_all_later(NOT_VALID);
5017 }
5018 
5019 /*
5020  * Set the height of a frame to "height" and take care that all frames and
5021  * windows inside it are resized.  Also resize frames on the left and right if
5022  * the are in the same FR_ROW frame.
5023  *
5024  * Strategy:
5025  * If the frame is part of a FR_COL frame, try fitting the frame in that
5026  * frame.  If that doesn't work (the FR_COL frame is too small), recursively
5027  * go to containing frames to resize them and make room.
5028  * If the frame is part of a FR_ROW frame, all frames must be resized as well.
5029  * Check for the minimal height of the FR_ROW frame.
5030  * At the top level we can also use change the command line height.
5031  */
5032     static void
5033 frame_setheight(frame_T *curfrp, int height)
5034 {
5035     int		room;		/* total number of lines available */
5036     int		take;		/* number of lines taken from other windows */
5037     int		room_cmdline;	/* lines available from cmdline */
5038     int		run;
5039     frame_T	*frp;
5040     int		h;
5041     int		room_reserved;
5042 
5043     /* If the height already is the desired value, nothing to do. */
5044     if (curfrp->fr_height == height)
5045 	return;
5046 
5047     if (curfrp->fr_parent == NULL)
5048     {
5049 	/* topframe: can only change the command line */
5050 	if (height > ROWS_AVAIL)
5051 	    height = ROWS_AVAIL;
5052 	if (height > 0)
5053 	    frame_new_height(curfrp, height, FALSE, FALSE);
5054     }
5055     else if (curfrp->fr_parent->fr_layout == FR_ROW)
5056     {
5057 	/* Row of frames: Also need to resize frames left and right of this
5058 	 * one.  First check for the minimal height of these. */
5059 	h = frame_minheight(curfrp->fr_parent, NULL);
5060 	if (height < h)
5061 	    height = h;
5062 	frame_setheight(curfrp->fr_parent, height);
5063     }
5064     else
5065     {
5066 	/*
5067 	 * Column of frames: try to change only frames in this column.
5068 	 */
5069 	/*
5070 	 * Do this twice:
5071 	 * 1: compute room available, if it's not enough try resizing the
5072 	 *    containing frame.
5073 	 * 2: compute the room available and adjust the height to it.
5074 	 * Try not to reduce the height of a window with 'winfixheight' set.
5075 	 */
5076 	for (run = 1; run <= 2; ++run)
5077 	{
5078 	    room = 0;
5079 	    room_reserved = 0;
5080 	    for (frp = curfrp->fr_parent->fr_child; frp != NULL;
5081 							   frp = frp->fr_next)
5082 	    {
5083 		if (frp != curfrp
5084 			&& frp->fr_win != NULL
5085 			&& frp->fr_win->w_p_wfh)
5086 		    room_reserved += frp->fr_height;
5087 		room += frp->fr_height;
5088 		if (frp != curfrp)
5089 		    room -= frame_minheight(frp, NULL);
5090 	    }
5091 	    if (curfrp->fr_width != Columns)
5092 		room_cmdline = 0;
5093 	    else
5094 	    {
5095 		room_cmdline = Rows - p_ch - (lastwin->w_winrow
5096 						+ VISIBLE_HEIGHT(lastwin)
5097 						+ lastwin->w_status_height);
5098 		if (room_cmdline < 0)
5099 		    room_cmdline = 0;
5100 	    }
5101 
5102 	    if (height <= room + room_cmdline)
5103 		break;
5104 	    if (run == 2 || curfrp->fr_width == Columns)
5105 	    {
5106 		if (height > room + room_cmdline)
5107 		    height = room + room_cmdline;
5108 		break;
5109 	    }
5110 	    frame_setheight(curfrp->fr_parent, height
5111 		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
5112 	}
5113 
5114 	/*
5115 	 * Compute the number of lines we will take from others frames (can be
5116 	 * negative!).
5117 	 */
5118 	take = height - curfrp->fr_height;
5119 
5120 	/* If there is not enough room, also reduce the height of a window
5121 	 * with 'winfixheight' set. */
5122 	if (height > room + room_cmdline - room_reserved)
5123 	    room_reserved = room + room_cmdline - height;
5124 	/* If there is only a 'winfixheight' window and making the
5125 	 * window smaller, need to make the other window taller. */
5126 	if (take < 0 && room - curfrp->fr_height < room_reserved)
5127 	    room_reserved = 0;
5128 
5129 	if (take > 0 && room_cmdline > 0)
5130 	{
5131 	    /* use lines from cmdline first */
5132 	    if (take < room_cmdline)
5133 		room_cmdline = take;
5134 	    take -= room_cmdline;
5135 	    topframe->fr_height += room_cmdline;
5136 	}
5137 
5138 	/*
5139 	 * set the current frame to the new height
5140 	 */
5141 	frame_new_height(curfrp, height, FALSE, FALSE);
5142 
5143 	/*
5144 	 * First take lines from the frames after the current frame.  If
5145 	 * that is not enough, takes lines from frames above the current
5146 	 * frame.
5147 	 */
5148 	for (run = 0; run < 2; ++run)
5149 	{
5150 	    if (run == 0)
5151 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5152 	    else
5153 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5154 	    while (frp != NULL && take != 0)
5155 	    {
5156 		h = frame_minheight(frp, NULL);
5157 		if (room_reserved > 0
5158 			&& frp->fr_win != NULL
5159 			&& frp->fr_win->w_p_wfh)
5160 		{
5161 		    if (room_reserved >= frp->fr_height)
5162 			room_reserved -= frp->fr_height;
5163 		    else
5164 		    {
5165 			if (frp->fr_height - room_reserved > take)
5166 			    room_reserved = frp->fr_height - take;
5167 			take -= frp->fr_height - room_reserved;
5168 			frame_new_height(frp, room_reserved, FALSE, FALSE);
5169 			room_reserved = 0;
5170 		    }
5171 		}
5172 		else
5173 		{
5174 		    if (frp->fr_height - take < h)
5175 		    {
5176 			take -= frp->fr_height - h;
5177 			frame_new_height(frp, h, FALSE, FALSE);
5178 		    }
5179 		    else
5180 		    {
5181 			frame_new_height(frp, frp->fr_height - take,
5182 								FALSE, FALSE);
5183 			take = 0;
5184 		    }
5185 		}
5186 		if (run == 0)
5187 		    frp = frp->fr_next;
5188 		else
5189 		    frp = frp->fr_prev;
5190 	    }
5191 	}
5192     }
5193 }
5194 
5195 /*
5196  * Set current window width and take care of repositioning other windows to
5197  * fit around it.
5198  */
5199     void
5200 win_setwidth(int width)
5201 {
5202     win_setwidth_win(width, curwin);
5203 }
5204 
5205     void
5206 win_setwidth_win(int width, win_T *wp)
5207 {
5208     /* Always keep current window at least one column wide, even when
5209      * 'winminwidth' is zero. */
5210     if (wp == curwin)
5211     {
5212 	if (width < p_wmw)
5213 	    width = p_wmw;
5214 	if (width == 0)
5215 	    width = 1;
5216     }
5217 
5218     frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
5219 
5220     /* recompute the window positions */
5221     (void)win_comp_pos();
5222 
5223     redraw_all_later(NOT_VALID);
5224 }
5225 
5226 /*
5227  * Set the width of a frame to "width" and take care that all frames and
5228  * windows inside it are resized.  Also resize frames above and below if the
5229  * are in the same FR_ROW frame.
5230  *
5231  * Strategy is similar to frame_setheight().
5232  */
5233     static void
5234 frame_setwidth(frame_T *curfrp, int width)
5235 {
5236     int		room;		/* total number of lines available */
5237     int		take;		/* number of lines taken from other windows */
5238     int		run;
5239     frame_T	*frp;
5240     int		w;
5241     int		room_reserved;
5242 
5243     /* If the width already is the desired value, nothing to do. */
5244     if (curfrp->fr_width == width)
5245 	return;
5246 
5247     if (curfrp->fr_parent == NULL)
5248 	/* topframe: can't change width */
5249 	return;
5250 
5251     if (curfrp->fr_parent->fr_layout == FR_COL)
5252     {
5253 	/* Column of frames: Also need to resize frames above and below of
5254 	 * this one.  First check for the minimal width of these. */
5255 	w = frame_minwidth(curfrp->fr_parent, NULL);
5256 	if (width < w)
5257 	    width = w;
5258 	frame_setwidth(curfrp->fr_parent, width);
5259     }
5260     else
5261     {
5262 	/*
5263 	 * Row of frames: try to change only frames in this row.
5264 	 *
5265 	 * Do this twice:
5266 	 * 1: compute room available, if it's not enough try resizing the
5267 	 *    containing frame.
5268 	 * 2: compute the room available and adjust the width to it.
5269 	 */
5270 	for (run = 1; run <= 2; ++run)
5271 	{
5272 	    room = 0;
5273 	    room_reserved = 0;
5274 	    for (frp = curfrp->fr_parent->fr_child; frp != NULL;
5275 							   frp = frp->fr_next)
5276 	    {
5277 		if (frp != curfrp
5278 			&& frp->fr_win != NULL
5279 			&& frp->fr_win->w_p_wfw)
5280 		    room_reserved += frp->fr_width;
5281 		room += frp->fr_width;
5282 		if (frp != curfrp)
5283 		    room -= frame_minwidth(frp, NULL);
5284 	    }
5285 
5286 	    if (width <= room)
5287 		break;
5288 	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
5289 	    {
5290 		if (width > room)
5291 		    width = room;
5292 		break;
5293 	    }
5294 	    frame_setwidth(curfrp->fr_parent, width
5295 		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
5296 	}
5297 
5298 	/*
5299 	 * Compute the number of lines we will take from others frames (can be
5300 	 * negative!).
5301 	 */
5302 	take = width - curfrp->fr_width;
5303 
5304 	/* If there is not enough room, also reduce the width of a window
5305 	 * with 'winfixwidth' set. */
5306 	if (width > room - room_reserved)
5307 	    room_reserved = room - width;
5308 	/* If there is only a 'winfixwidth' window and making the
5309 	 * window smaller, need to make the other window narrower. */
5310 	if (take < 0 && room - curfrp->fr_width < room_reserved)
5311 	    room_reserved = 0;
5312 
5313 	/*
5314 	 * set the current frame to the new width
5315 	 */
5316 	frame_new_width(curfrp, width, FALSE, FALSE);
5317 
5318 	/*
5319 	 * First take lines from the frames right of the current frame.  If
5320 	 * that is not enough, takes lines from frames left of the current
5321 	 * frame.
5322 	 */
5323 	for (run = 0; run < 2; ++run)
5324 	{
5325 	    if (run == 0)
5326 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5327 	    else
5328 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5329 	    while (frp != NULL && take != 0)
5330 	    {
5331 		w = frame_minwidth(frp, NULL);
5332 		if (room_reserved > 0
5333 			&& frp->fr_win != NULL
5334 			&& frp->fr_win->w_p_wfw)
5335 		{
5336 		    if (room_reserved >= frp->fr_width)
5337 			room_reserved -= frp->fr_width;
5338 		    else
5339 		    {
5340 			if (frp->fr_width - room_reserved > take)
5341 			    room_reserved = frp->fr_width - take;
5342 			take -= frp->fr_width - room_reserved;
5343 			frame_new_width(frp, room_reserved, FALSE, FALSE);
5344 			room_reserved = 0;
5345 		    }
5346 		}
5347 		else
5348 		{
5349 		    if (frp->fr_width - take < w)
5350 		    {
5351 			take -= frp->fr_width - w;
5352 			frame_new_width(frp, w, FALSE, FALSE);
5353 		    }
5354 		    else
5355 		    {
5356 			frame_new_width(frp, frp->fr_width - take,
5357 								FALSE, FALSE);
5358 			take = 0;
5359 		    }
5360 		}
5361 		if (run == 0)
5362 		    frp = frp->fr_next;
5363 		else
5364 		    frp = frp->fr_prev;
5365 	    }
5366 	}
5367     }
5368 }
5369 
5370 /*
5371  * Check 'winminheight' for a valid value.
5372  */
5373     void
5374 win_setminheight(void)
5375 {
5376     int		room;
5377     int		first = TRUE;
5378     win_T	*wp;
5379 
5380     /* loop until there is a 'winminheight' that is possible */
5381     while (p_wmh > 0)
5382     {
5383 	/* TODO: handle vertical splits */
5384 	room = -p_wh;
5385 	FOR_ALL_WINDOWS(wp)
5386 	    room += VISIBLE_HEIGHT(wp) - p_wmh;
5387 	if (room >= 0)
5388 	    break;
5389 	--p_wmh;
5390 	if (first)
5391 	{
5392 	    EMSG(_(e_noroom));
5393 	    first = FALSE;
5394 	}
5395     }
5396 }
5397 
5398 #if defined(FEAT_MOUSE) || defined(PROTO)
5399 
5400 /*
5401  * Status line of dragwin is dragged "offset" lines down (negative is up).
5402  */
5403     void
5404 win_drag_status_line(win_T *dragwin, int offset)
5405 {
5406     frame_T	*curfr;
5407     frame_T	*fr;
5408     int		room;
5409     int		row;
5410     int		up;	/* if TRUE, drag status line up, otherwise down */
5411     int		n;
5412 
5413     fr = dragwin->w_frame;
5414     curfr = fr;
5415     if (fr != topframe)		/* more than one window */
5416     {
5417 	fr = fr->fr_parent;
5418 	/* When the parent frame is not a column of frames, its parent should
5419 	 * be. */
5420 	if (fr->fr_layout != FR_COL)
5421 	{
5422 	    curfr = fr;
5423 	    if (fr != topframe)	/* only a row of windows, may drag statusline */
5424 		fr = fr->fr_parent;
5425 	}
5426     }
5427 
5428     /* If this is the last frame in a column, may want to resize the parent
5429      * frame instead (go two up to skip a row of frames). */
5430     while (curfr != topframe && curfr->fr_next == NULL)
5431     {
5432 	if (fr != topframe)
5433 	    fr = fr->fr_parent;
5434 	curfr = fr;
5435 	if (fr != topframe)
5436 	    fr = fr->fr_parent;
5437     }
5438 
5439     if (offset < 0) /* drag up */
5440     {
5441 	up = TRUE;
5442 	offset = -offset;
5443 	/* sum up the room of the current frame and above it */
5444 	if (fr == curfr)
5445 	{
5446 	    /* only one window */
5447 	    room = fr->fr_height - frame_minheight(fr, NULL);
5448 	}
5449 	else
5450 	{
5451 	    room = 0;
5452 	    for (fr = fr->fr_child; ; fr = fr->fr_next)
5453 	    {
5454 		room += fr->fr_height - frame_minheight(fr, NULL);
5455 		if (fr == curfr)
5456 		    break;
5457 	    }
5458 	}
5459 	fr = curfr->fr_next;		/* put fr at frame that grows */
5460     }
5461     else    /* drag down */
5462     {
5463 	up = FALSE;
5464 	/*
5465 	 * Only dragging the last status line can reduce p_ch.
5466 	 */
5467 	room = Rows - cmdline_row;
5468 	if (curfr->fr_next == NULL)
5469 	    room -= 1;
5470 	else
5471 	    room -= p_ch;
5472 	if (room < 0)
5473 	    room = 0;
5474 	/* sum up the room of frames below of the current one */
5475 	for (fr = curfr->fr_next; fr != NULL; fr = fr->fr_next)
5476 	    room += fr->fr_height - frame_minheight(fr, NULL);
5477 	fr = curfr;			/* put fr at window that grows */
5478     }
5479 
5480     if (room < offset)		/* Not enough room */
5481 	offset = room;		/* Move as far as we can */
5482     if (offset <= 0)
5483 	return;
5484 
5485     /*
5486      * Grow frame fr by "offset" lines.
5487      * Doesn't happen when dragging the last status line up.
5488      */
5489     if (fr != NULL)
5490 	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
5491 
5492     if (up)
5493 	fr = curfr;		/* current frame gets smaller */
5494     else
5495 	fr = curfr->fr_next;	/* next frame gets smaller */
5496 
5497     /*
5498      * Now make the other frames smaller.
5499      */
5500     while (fr != NULL && offset > 0)
5501     {
5502 	n = frame_minheight(fr, NULL);
5503 	if (fr->fr_height - offset <= n)
5504 	{
5505 	    offset -= fr->fr_height - n;
5506 	    frame_new_height(fr, n, !up, FALSE);
5507 	}
5508 	else
5509 	{
5510 	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
5511 	    break;
5512 	}
5513 	if (up)
5514 	    fr = fr->fr_prev;
5515 	else
5516 	    fr = fr->fr_next;
5517     }
5518     row = win_comp_pos();
5519     screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5520     cmdline_row = row;
5521     p_ch = Rows - cmdline_row;
5522     if (p_ch < 1)
5523 	p_ch = 1;
5524     curtab->tp_ch_used = p_ch;
5525     redraw_all_later(SOME_VALID);
5526     showmode();
5527 }
5528 
5529 /*
5530  * Separator line of dragwin is dragged "offset" lines right (negative is left).
5531  */
5532     void
5533 win_drag_vsep_line(win_T *dragwin, int offset)
5534 {
5535     frame_T	*curfr;
5536     frame_T	*fr;
5537     int		room;
5538     int		left;	/* if TRUE, drag separator line left, otherwise right */
5539     int		n;
5540 
5541     fr = dragwin->w_frame;
5542     if (fr == topframe)		/* only one window (cannot happen?) */
5543 	return;
5544     curfr = fr;
5545     fr = fr->fr_parent;
5546     /* When the parent frame is not a row of frames, its parent should be. */
5547     if (fr->fr_layout != FR_ROW)
5548     {
5549 	if (fr == topframe)	/* only a column of windows (cannot happen?) */
5550 	    return;
5551 	curfr = fr;
5552 	fr = fr->fr_parent;
5553     }
5554 
5555     /* If this is the last frame in a row, may want to resize a parent
5556      * frame instead. */
5557     while (curfr->fr_next == NULL)
5558     {
5559 	if (fr == topframe)
5560 	    break;
5561 	curfr = fr;
5562 	fr = fr->fr_parent;
5563 	if (fr != topframe)
5564 	{
5565 	    curfr = fr;
5566 	    fr = fr->fr_parent;
5567 	}
5568     }
5569 
5570     if (offset < 0) /* drag left */
5571     {
5572 	left = TRUE;
5573 	offset = -offset;
5574 	/* sum up the room of the current frame and left of it */
5575 	room = 0;
5576 	for (fr = fr->fr_child; ; fr = fr->fr_next)
5577 	{
5578 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5579 	    if (fr == curfr)
5580 		break;
5581 	}
5582 	fr = curfr->fr_next;		/* put fr at frame that grows */
5583     }
5584     else    /* drag right */
5585     {
5586 	left = FALSE;
5587 	/* sum up the room of frames right of the current one */
5588 	room = 0;
5589 	for (fr = curfr->fr_next; fr != NULL; fr = fr->fr_next)
5590 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5591 	fr = curfr;			/* put fr at window that grows */
5592     }
5593 
5594     if (room < offset)		/* Not enough room */
5595 	offset = room;		/* Move as far as we can */
5596     if (offset <= 0)		/* No room at all, quit. */
5597 	return;
5598     if (fr == NULL)
5599 	return;			/* Safety check, should not happen. */
5600 
5601     /* grow frame fr by offset lines */
5602     frame_new_width(fr, fr->fr_width + offset, left, FALSE);
5603 
5604     /* shrink other frames: current and at the left or at the right */
5605     if (left)
5606 	fr = curfr;		/* current frame gets smaller */
5607     else
5608 	fr = curfr->fr_next;	/* next frame gets smaller */
5609 
5610     while (fr != NULL && offset > 0)
5611     {
5612 	n = frame_minwidth(fr, NULL);
5613 	if (fr->fr_width - offset <= n)
5614 	{
5615 	    offset -= fr->fr_width - n;
5616 	    frame_new_width(fr, n, !left, FALSE);
5617 	}
5618 	else
5619 	{
5620 	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
5621 	    break;
5622 	}
5623 	if (left)
5624 	    fr = fr->fr_prev;
5625 	else
5626 	    fr = fr->fr_next;
5627     }
5628     (void)win_comp_pos();
5629     redraw_all_later(NOT_VALID);
5630 }
5631 #endif /* FEAT_MOUSE */
5632 
5633 #define FRACTION_MULT	16384L
5634 
5635 /*
5636  * Set wp->w_fraction for the current w_wrow and w_height.
5637  * Has no effect when the window is less than two lines.
5638  */
5639     void
5640 set_fraction(win_T *wp)
5641 {
5642     if (wp->w_height > 1)
5643 	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
5644 				    + wp->w_height / 2) / (long)wp->w_height;
5645 }
5646 
5647 /*
5648  * Set the height of a window.
5649  * "height" excludes any window toolbar.
5650  * This takes care of the things inside the window, not what happens to the
5651  * window position, the frame or to other windows.
5652  */
5653     void
5654 win_new_height(win_T *wp, int height)
5655 {
5656     int		prev_height = wp->w_height;
5657 
5658     /* Don't want a negative height.  Happens when splitting a tiny window.
5659      * Will equalize heights soon to fix it. */
5660     if (height < 0)
5661 	height = 0;
5662     if (wp->w_height == height)
5663 	return;	    /* nothing to do */
5664 
5665     if (wp->w_height > 0)
5666     {
5667 	if (wp == curwin)
5668 	    /* w_wrow needs to be valid. When setting 'laststatus' this may
5669 	     * call win_new_height() recursively. */
5670 	    validate_cursor();
5671 	if (wp->w_height != prev_height)
5672 	    return;  /* Recursive call already changed the size, bail out here
5673 			to avoid the following to mess things up. */
5674 	if (wp->w_wrow != wp->w_prev_fraction_row)
5675 	    set_fraction(wp);
5676     }
5677 
5678     wp->w_height = height;
5679     wp->w_skipcol = 0;
5680 
5681     /* There is no point in adjusting the scroll position when exiting.  Some
5682      * values might be invalid. */
5683     if (!exiting)
5684 	scroll_to_fraction(wp, prev_height);
5685 }
5686 
5687     void
5688 scroll_to_fraction(win_T *wp, int prev_height)
5689 {
5690     linenr_T	lnum;
5691     int		sline, line_size;
5692     int		height = wp->w_height;
5693 
5694     /* Don't change w_topline when height is zero.  Don't set w_topline when
5695      * 'scrollbind' is set and this isn't the current window. */
5696     if (height > 0 && (!wp->w_p_scb || wp == curwin))
5697     {
5698 	/*
5699 	 * Find a value for w_topline that shows the cursor at the same
5700 	 * relative position in the window as before (more or less).
5701 	 */
5702 	lnum = wp->w_cursor.lnum;
5703 	if (lnum < 1)		/* can happen when starting up */
5704 	    lnum = 1;
5705 	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L
5706 					 + FRACTION_MULT / 2) / FRACTION_MULT;
5707 	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
5708 	sline = wp->w_wrow - line_size;
5709 
5710 	if (sline >= 0)
5711 	{
5712 	    /* Make sure the whole cursor line is visible, if possible. */
5713 	    int rows = plines_win(wp, lnum, FALSE);
5714 
5715 	    if (sline > wp->w_height - rows)
5716 	    {
5717 		sline = wp->w_height - rows;
5718 		wp->w_wrow -= rows - line_size;
5719 	    }
5720 	}
5721 
5722 	if (sline < 0)
5723 	{
5724 	    /*
5725 	     * Cursor line would go off top of screen if w_wrow was this high.
5726 	     * Make cursor line the first line in the window.  If not enough
5727 	     * room use w_skipcol;
5728 	     */
5729 	    wp->w_wrow = line_size;
5730 	    if (wp->w_wrow >= wp->w_height
5731 				       && (wp->w_width - win_col_off(wp)) > 0)
5732 	    {
5733 		wp->w_skipcol += wp->w_width - win_col_off(wp);
5734 		--wp->w_wrow;
5735 		while (wp->w_wrow >= wp->w_height)
5736 		{
5737 		    wp->w_skipcol += wp->w_width - win_col_off(wp)
5738 							   + win_col_off2(wp);
5739 		    --wp->w_wrow;
5740 		}
5741 	    }
5742 	    set_topline(wp, lnum);
5743 	}
5744 	else if (sline > 0)
5745 	{
5746 	    while (sline > 0 && lnum > 1)
5747 	    {
5748 #ifdef FEAT_FOLDING
5749 		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
5750 		if (lnum == 1)
5751 		{
5752 		    /* first line in buffer is folded */
5753 		    line_size = 1;
5754 		    --sline;
5755 		    break;
5756 		}
5757 #endif
5758 		--lnum;
5759 #ifdef FEAT_DIFF
5760 		if (lnum == wp->w_topline)
5761 		    line_size = plines_win_nofill(wp, lnum, TRUE)
5762 							      + wp->w_topfill;
5763 		else
5764 #endif
5765 		    line_size = plines_win(wp, lnum, TRUE);
5766 		sline -= line_size;
5767 	    }
5768 
5769 	    if (sline < 0)
5770 	    {
5771 		/*
5772 		 * Line we want at top would go off top of screen.  Use next
5773 		 * line instead.
5774 		 */
5775 #ifdef FEAT_FOLDING
5776 		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
5777 #endif
5778 		lnum++;
5779 		wp->w_wrow -= line_size + sline;
5780 	    }
5781 	    else if (sline > 0)
5782 	    {
5783 		/* First line of file reached, use that as topline. */
5784 		lnum = 1;
5785 		wp->w_wrow -= sline;
5786 	    }
5787 
5788 	    set_topline(wp, lnum);
5789 	}
5790     }
5791 
5792     if (wp == curwin)
5793     {
5794 	if (p_so)
5795 	    update_topline();
5796 	curs_columns(FALSE);	/* validate w_wrow */
5797     }
5798     if (prev_height > 0)
5799 	wp->w_prev_fraction_row = wp->w_wrow;
5800 
5801     win_comp_scroll(wp);
5802     redraw_win_later(wp, SOME_VALID);
5803     wp->w_redr_status = TRUE;
5804     invalidate_botline_win(wp);
5805 }
5806 
5807 /*
5808  * Set the width of a window.
5809  */
5810     void
5811 win_new_width(win_T *wp, int width)
5812 {
5813     wp->w_width = width;
5814     wp->w_lines_valid = 0;
5815     changed_line_abv_curs_win(wp);
5816     invalidate_botline_win(wp);
5817     if (wp == curwin)
5818     {
5819 	update_topline();
5820 	curs_columns(TRUE);	/* validate w_wrow */
5821     }
5822     redraw_win_later(wp, NOT_VALID);
5823     wp->w_redr_status = TRUE;
5824 }
5825 
5826     void
5827 win_comp_scroll(win_T *wp)
5828 {
5829     wp->w_p_scr = ((unsigned)wp->w_height >> 1);
5830     if (wp->w_p_scr == 0)
5831 	wp->w_p_scr = 1;
5832 }
5833 
5834 /*
5835  * command_height: called whenever p_ch has been changed
5836  */
5837     void
5838 command_height(void)
5839 {
5840     int		h;
5841     frame_T	*frp;
5842     int		old_p_ch = curtab->tp_ch_used;
5843 
5844     /* Use the value of p_ch that we remembered.  This is needed for when the
5845      * GUI starts up, we can't be sure in what order things happen.  And when
5846      * p_ch was changed in another tab page. */
5847     curtab->tp_ch_used = p_ch;
5848 
5849     /* Find bottom frame with width of screen. */
5850     frp = lastwin->w_frame;
5851     while (frp->fr_width != Columns && frp->fr_parent != NULL)
5852 	frp = frp->fr_parent;
5853 
5854     /* Avoid changing the height of a window with 'winfixheight' set. */
5855     while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
5856 						      && frp->fr_win->w_p_wfh)
5857 	frp = frp->fr_prev;
5858 
5859     if (starting != NO_SCREEN)
5860     {
5861 	cmdline_row = Rows - p_ch;
5862 
5863 	if (p_ch > old_p_ch)		    /* p_ch got bigger */
5864 	{
5865 	    while (p_ch > old_p_ch)
5866 	    {
5867 		if (frp == NULL)
5868 		{
5869 		    EMSG(_(e_noroom));
5870 		    p_ch = old_p_ch;
5871 		    curtab->tp_ch_used = p_ch;
5872 		    cmdline_row = Rows - p_ch;
5873 		    break;
5874 		}
5875 		h = frp->fr_height - frame_minheight(frp, NULL);
5876 		if (h > p_ch - old_p_ch)
5877 		    h = p_ch - old_p_ch;
5878 		old_p_ch += h;
5879 		frame_add_height(frp, -h);
5880 		frp = frp->fr_prev;
5881 	    }
5882 
5883 	    /* Recompute window positions. */
5884 	    (void)win_comp_pos();
5885 
5886 	    /* clear the lines added to cmdline */
5887 	    if (full_screen)
5888 		screen_fill((int)(cmdline_row), (int)Rows, 0,
5889 						   (int)Columns, ' ', ' ', 0);
5890 	    msg_row = cmdline_row;
5891 	    redraw_cmdline = TRUE;
5892 	    return;
5893 	}
5894 
5895 	if (msg_row < cmdline_row)
5896 	    msg_row = cmdline_row;
5897 	redraw_cmdline = TRUE;
5898     }
5899     frame_add_height(frp, (int)(old_p_ch - p_ch));
5900 
5901     /* Recompute window positions. */
5902     if (frp != lastwin->w_frame)
5903 	(void)win_comp_pos();
5904 }
5905 
5906 /*
5907  * Resize frame "frp" to be "n" lines higher (negative for less high).
5908  * Also resize the frames it is contained in.
5909  */
5910     static void
5911 frame_add_height(frame_T *frp, int n)
5912 {
5913     frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
5914     for (;;)
5915     {
5916 	frp = frp->fr_parent;
5917 	if (frp == NULL)
5918 	    break;
5919 	frp->fr_height += n;
5920     }
5921 }
5922 
5923 /*
5924  * Add or remove a status line for the bottom window(s), according to the
5925  * value of 'laststatus'.
5926  */
5927     void
5928 last_status(
5929     int		morewin)	/* pretend there are two or more windows */
5930 {
5931     /* Don't make a difference between horizontal or vertical split. */
5932     last_status_rec(topframe, (p_ls == 2
5933 			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
5934 }
5935 
5936     static void
5937 last_status_rec(frame_T *fr, int statusline)
5938 {
5939     frame_T	*fp;
5940     win_T	*wp;
5941 
5942     if (fr->fr_layout == FR_LEAF)
5943     {
5944 	wp = fr->fr_win;
5945 	if (wp->w_status_height != 0 && !statusline)
5946 	{
5947 	    /* remove status line */
5948 	    win_new_height(wp, wp->w_height + 1);
5949 	    wp->w_status_height = 0;
5950 	    comp_col();
5951 	}
5952 	else if (wp->w_status_height == 0 && statusline)
5953 	{
5954 	    /* Find a frame to take a line from. */
5955 	    fp = fr;
5956 	    while (fp->fr_height <= frame_minheight(fp, NULL))
5957 	    {
5958 		if (fp == topframe)
5959 		{
5960 		    EMSG(_(e_noroom));
5961 		    return;
5962 		}
5963 		/* In a column of frames: go to frame above.  If already at
5964 		 * the top or in a row of frames: go to parent. */
5965 		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
5966 		    fp = fp->fr_prev;
5967 		else
5968 		    fp = fp->fr_parent;
5969 	    }
5970 	    wp->w_status_height = 1;
5971 	    if (fp != fr)
5972 	    {
5973 		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
5974 		frame_fix_height(wp);
5975 		(void)win_comp_pos();
5976 	    }
5977 	    else
5978 		win_new_height(wp, wp->w_height - 1);
5979 	    comp_col();
5980 	    redraw_all_later(SOME_VALID);
5981 	}
5982     }
5983     else if (fr->fr_layout == FR_ROW)
5984     {
5985 	/* vertically split windows, set status line for each one */
5986 	for (fp = fr->fr_child; fp != NULL; fp = fp->fr_next)
5987 	    last_status_rec(fp, statusline);
5988     }
5989     else
5990     {
5991 	/* horizontally split window, set status line for last one */
5992 	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
5993 	    ;
5994 	last_status_rec(fp, statusline);
5995     }
5996 }
5997 
5998 /*
5999  * Return the number of lines used by the tab page line.
6000  */
6001     int
6002 tabline_height(void)
6003 {
6004 #ifdef FEAT_GUI_TABLINE
6005     /* When the GUI has the tabline then this always returns zero. */
6006     if (gui_use_tabline())
6007 	return 0;
6008 #endif
6009     switch (p_stal)
6010     {
6011 	case 0: return 0;
6012 	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
6013     }
6014     return 1;
6015 }
6016 
6017 #if defined(FEAT_SEARCHPATH) || defined(PROTO)
6018 /*
6019  * Get the file name at the cursor.
6020  * If Visual mode is active, use the selected text if it's in one line.
6021  * Returns the name in allocated memory, NULL for failure.
6022  */
6023     char_u *
6024 grab_file_name(long count, linenr_T *file_lnum)
6025 {
6026     int options = FNAME_MESS|FNAME_EXP|FNAME_REL|FNAME_UNESC;
6027 
6028     if (VIsual_active)
6029     {
6030 	int	len;
6031 	char_u	*ptr;
6032 
6033 	if (get_visual_text(NULL, &ptr, &len) == FAIL)
6034 	    return NULL;
6035 	return find_file_name_in_path(ptr, len, options,
6036 						     count, curbuf->b_ffname);
6037     }
6038     return file_name_at_cursor(options | FNAME_HYP, count, file_lnum);
6039 }
6040 
6041 /*
6042  * Return the file name under or after the cursor.
6043  *
6044  * The 'path' option is searched if the file name is not absolute.
6045  * The string returned has been alloc'ed and should be freed by the caller.
6046  * NULL is returned if the file name or file is not found.
6047  *
6048  * options:
6049  * FNAME_MESS	    give error messages
6050  * FNAME_EXP	    expand to path
6051  * FNAME_HYP	    check for hypertext link
6052  * FNAME_INCL	    apply "includeexpr"
6053  */
6054     char_u *
6055 file_name_at_cursor(int options, long count, linenr_T *file_lnum)
6056 {
6057     return file_name_in_line(ml_get_curline(),
6058 		      curwin->w_cursor.col, options, count, curbuf->b_ffname,
6059 		      file_lnum);
6060 }
6061 
6062 /*
6063  * Return the name of the file under or after ptr[col].
6064  * Otherwise like file_name_at_cursor().
6065  */
6066     char_u *
6067 file_name_in_line(
6068     char_u	*line,
6069     int		col,
6070     int		options,
6071     long	count,
6072     char_u	*rel_fname,	/* file we are searching relative to */
6073     linenr_T	*file_lnum)	/* line number after the file name */
6074 {
6075     char_u	*ptr;
6076     int		len;
6077     int		in_type = TRUE;
6078     int		is_url = FALSE;
6079 
6080     /*
6081      * search forward for what could be the start of a file name
6082      */
6083     ptr = line + col;
6084     while (*ptr != NUL && !vim_isfilec(*ptr))
6085 	MB_PTR_ADV(ptr);
6086     if (*ptr == NUL)		/* nothing found */
6087     {
6088 	if (options & FNAME_MESS)
6089 	    EMSG(_("E446: No file name under cursor"));
6090 	return NULL;
6091     }
6092 
6093     /*
6094      * Search backward for first char of the file name.
6095      * Go one char back to ":" before "//" even when ':' is not in 'isfname'.
6096      */
6097     while (ptr > line)
6098     {
6099 #ifdef FEAT_MBYTE
6100 	if (has_mbyte && (len = (*mb_head_off)(line, ptr - 1)) > 0)
6101 	    ptr -= len + 1;
6102 	else
6103 #endif
6104 	if (vim_isfilec(ptr[-1])
6105 		|| ((options & FNAME_HYP) && path_is_url(ptr - 1)))
6106 	    --ptr;
6107 	else
6108 	    break;
6109     }
6110 
6111     /*
6112      * Search forward for the last char of the file name.
6113      * Also allow "://" when ':' is not in 'isfname'.
6114      */
6115     len = 0;
6116     while (vim_isfilec(ptr[len]) || (ptr[len] == '\\' && ptr[len + 1] == ' ')
6117 			 || ((options & FNAME_HYP) && path_is_url(ptr + len))
6118 			 || (is_url && vim_strchr((char_u *)"?&=", ptr[len]) != NULL))
6119     {
6120 	/* After type:// we also include ?, & and = as valid characters, so that
6121 	 * http://google.com?q=this&that=ok works. */
6122 	if ((ptr[len] >= 'A' && ptr[len] <= 'Z') || (ptr[len] >= 'a' && ptr[len] <= 'z'))
6123 	{
6124 	    if (in_type && path_is_url(ptr + len + 1))
6125 		is_url = TRUE;
6126 	}
6127 	else
6128 	    in_type = FALSE;
6129 
6130 	if (ptr[len] == '\\')
6131 	    /* Skip over the "\" in "\ ". */
6132 	    ++len;
6133 #ifdef FEAT_MBYTE
6134 	if (has_mbyte)
6135 	    len += (*mb_ptr2len)(ptr + len);
6136 	else
6137 #endif
6138 	    ++len;
6139     }
6140 
6141     /*
6142      * If there is trailing punctuation, remove it.
6143      * But don't remove "..", could be a directory name.
6144      */
6145     if (len > 2 && vim_strchr((char_u *)".,:;!", ptr[len - 1]) != NULL
6146 						       && ptr[len - 2] != '.')
6147 	--len;
6148 
6149     if (file_lnum != NULL)
6150     {
6151 	char_u *p;
6152 
6153 	/* Get the number after the file name and a separator character */
6154 	p = ptr + len;
6155 	p = skipwhite(p);
6156 	if (*p != NUL)
6157 	{
6158 	    if (!isdigit(*p))
6159 		++p;		    /* skip the separator */
6160 	    p = skipwhite(p);
6161 	    if (isdigit(*p))
6162 		*file_lnum = (int)getdigits(&p);
6163 	}
6164     }
6165 
6166     return find_file_name_in_path(ptr, len, options, count, rel_fname);
6167 }
6168 
6169 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6170 static char_u *eval_includeexpr(char_u *ptr, int len);
6171 
6172     static char_u *
6173 eval_includeexpr(char_u *ptr, int len)
6174 {
6175     char_u	*res;
6176 
6177     set_vim_var_string(VV_FNAME, ptr, len);
6178     res = eval_to_string_safe(curbuf->b_p_inex, NULL,
6179 		      was_set_insecurely((char_u *)"includeexpr", OPT_LOCAL));
6180     set_vim_var_string(VV_FNAME, NULL, 0);
6181     return res;
6182 }
6183 #endif
6184 
6185 /*
6186  * Return the name of the file ptr[len] in 'path'.
6187  * Otherwise like file_name_at_cursor().
6188  */
6189     char_u *
6190 find_file_name_in_path(
6191     char_u	*ptr,
6192     int		len,
6193     int		options,
6194     long	count,
6195     char_u	*rel_fname)	/* file we are searching relative to */
6196 {
6197     char_u	*file_name;
6198     int		c;
6199 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6200     char_u	*tofree = NULL;
6201 
6202     if ((options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
6203     {
6204 	tofree = eval_includeexpr(ptr, len);
6205 	if (tofree != NULL)
6206 	{
6207 	    ptr = tofree;
6208 	    len = (int)STRLEN(ptr);
6209 	}
6210     }
6211 # endif
6212 
6213     if (options & FNAME_EXP)
6214     {
6215 	file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
6216 							     TRUE, rel_fname);
6217 
6218 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6219 	/*
6220 	 * If the file could not be found in a normal way, try applying
6221 	 * 'includeexpr' (unless done already).
6222 	 */
6223 	if (file_name == NULL
6224 		&& !(options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
6225 	{
6226 	    tofree = eval_includeexpr(ptr, len);
6227 	    if (tofree != NULL)
6228 	    {
6229 		ptr = tofree;
6230 		len = (int)STRLEN(ptr);
6231 		file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
6232 							     TRUE, rel_fname);
6233 	    }
6234 	}
6235 # endif
6236 	if (file_name == NULL && (options & FNAME_MESS))
6237 	{
6238 	    c = ptr[len];
6239 	    ptr[len] = NUL;
6240 	    EMSG2(_("E447: Can't find file \"%s\" in path"), ptr);
6241 	    ptr[len] = c;
6242 	}
6243 
6244 	/* Repeat finding the file "count" times.  This matters when it
6245 	 * appears several times in the path. */
6246 	while (file_name != NULL && --count > 0)
6247 	{
6248 	    vim_free(file_name);
6249 	    file_name = find_file_in_path(ptr, len, options, FALSE, rel_fname);
6250 	}
6251     }
6252     else
6253 	file_name = vim_strnsave(ptr, len);
6254 
6255 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6256     vim_free(tofree);
6257 # endif
6258 
6259     return file_name;
6260 }
6261 #endif /* FEAT_SEARCHPATH */
6262 
6263 /*
6264  * Check if the "://" of a URL is at the pointer, return URL_SLASH.
6265  * Also check for ":\\", which MS Internet Explorer accepts, return
6266  * URL_BACKSLASH.
6267  */
6268     static int
6269 path_is_url(char_u *p)
6270 {
6271     if (STRNCMP(p, "://", (size_t)3) == 0)
6272 	return URL_SLASH;
6273     else if (STRNCMP(p, ":\\\\", (size_t)3) == 0)
6274 	return URL_BACKSLASH;
6275     return 0;
6276 }
6277 
6278 /*
6279  * Check if "fname" starts with "name://".  Return URL_SLASH if it does.
6280  * Return URL_BACKSLASH for "name:\\".
6281  * Return zero otherwise.
6282  */
6283     int
6284 path_with_url(char_u *fname)
6285 {
6286     char_u *p;
6287 
6288     for (p = fname; isalpha(*p); ++p)
6289 	;
6290     return path_is_url(p);
6291 }
6292 
6293 /*
6294  * Return TRUE if "name" is a full (absolute) path name or URL.
6295  */
6296     int
6297 vim_isAbsName(char_u *name)
6298 {
6299     return (path_with_url(name) != 0 || mch_isFullName(name));
6300 }
6301 
6302 /*
6303  * Get absolute file name into buffer "buf[len]".
6304  *
6305  * return FAIL for failure, OK otherwise
6306  */
6307     int
6308 vim_FullName(
6309     char_u	*fname,
6310     char_u	*buf,
6311     int		len,
6312     int		force)	    /* force expansion even when already absolute */
6313 {
6314     int		retval = OK;
6315     int		url;
6316 
6317     *buf = NUL;
6318     if (fname == NULL)
6319 	return FAIL;
6320 
6321     url = path_with_url(fname);
6322     if (!url)
6323 	retval = mch_FullName(fname, buf, len, force);
6324     if (url || retval == FAIL)
6325     {
6326 	/* something failed; use the file name (truncate when too long) */
6327 	vim_strncpy(buf, fname, len - 1);
6328     }
6329 #if defined(MSWIN)
6330     slash_adjust(buf);
6331 #endif
6332     return retval;
6333 }
6334 
6335 /*
6336  * Return the minimal number of rows that is needed on the screen to display
6337  * the current number of windows.
6338  */
6339     int
6340 min_rows(void)
6341 {
6342     int		total;
6343     tabpage_T	*tp;
6344     int		n;
6345 
6346     if (firstwin == NULL)	/* not initialized yet */
6347 	return MIN_LINES;
6348 
6349     total = 0;
6350     FOR_ALL_TABPAGES(tp)
6351     {
6352 	n = frame_minheight(tp->tp_topframe, NULL);
6353 	if (total < n)
6354 	    total = n;
6355     }
6356     total += tabline_height();
6357     total += 1;		/* count the room for the command line */
6358     return total;
6359 }
6360 
6361 /*
6362  * Return TRUE if there is only one window (in the current tab page), not
6363  * counting a help or preview window, unless it is the current window.
6364  * Does not count "aucmd_win".
6365  */
6366     int
6367 only_one_window(void)
6368 {
6369     int		count = 0;
6370     win_T	*wp;
6371 
6372     /* If there is another tab page there always is another window. */
6373     if (first_tabpage->tp_next != NULL)
6374 	return FALSE;
6375 
6376     FOR_ALL_WINDOWS(wp)
6377 	if (wp->w_buffer != NULL
6378 		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
6379 # ifdef FEAT_QUICKFIX
6380 		    || wp->w_p_pvw
6381 # endif
6382 	     ) || wp == curwin) && wp != aucmd_win)
6383 	    ++count;
6384     return (count <= 1);
6385 }
6386 
6387 /*
6388  * Correct the cursor line number in other windows.  Used after changing the
6389  * current buffer, and before applying autocommands.
6390  * When "do_curwin" is TRUE, also check current window.
6391  */
6392     void
6393 check_lnums(int do_curwin)
6394 {
6395     win_T	*wp;
6396     tabpage_T	*tp;
6397 
6398     FOR_ALL_TAB_WINDOWS(tp, wp)
6399 	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
6400 	{
6401 	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
6402 		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
6403 	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
6404 		wp->w_topline = curbuf->b_ml.ml_line_count;
6405 	}
6406 }
6407 
6408 /*
6409  * A snapshot of the window sizes, to restore them after closing the help
6410  * window.
6411  * Only these fields are used:
6412  * fr_layout
6413  * fr_width
6414  * fr_height
6415  * fr_next
6416  * fr_child
6417  * fr_win (only valid for the old curwin, NULL otherwise)
6418  */
6419 
6420 /*
6421  * Create a snapshot of the current frame sizes.
6422  */
6423     void
6424 make_snapshot(int idx)
6425 {
6426     clear_snapshot(curtab, idx);
6427     make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
6428 }
6429 
6430     static void
6431 make_snapshot_rec(frame_T *fr, frame_T **frp)
6432 {
6433     *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
6434     if (*frp == NULL)
6435 	return;
6436     (*frp)->fr_layout = fr->fr_layout;
6437     (*frp)->fr_width = fr->fr_width;
6438     (*frp)->fr_height = fr->fr_height;
6439     if (fr->fr_next != NULL)
6440 	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
6441     if (fr->fr_child != NULL)
6442 	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
6443     if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
6444 	(*frp)->fr_win = curwin;
6445 }
6446 
6447 /*
6448  * Remove any existing snapshot.
6449  */
6450     static void
6451 clear_snapshot(tabpage_T *tp, int idx)
6452 {
6453     clear_snapshot_rec(tp->tp_snapshot[idx]);
6454     tp->tp_snapshot[idx] = NULL;
6455 }
6456 
6457     static void
6458 clear_snapshot_rec(frame_T *fr)
6459 {
6460     if (fr != NULL)
6461     {
6462 	clear_snapshot_rec(fr->fr_next);
6463 	clear_snapshot_rec(fr->fr_child);
6464 	vim_free(fr);
6465     }
6466 }
6467 
6468 /*
6469  * Restore a previously created snapshot, if there is any.
6470  * This is only done if the screen size didn't change and the window layout is
6471  * still the same.
6472  */
6473     void
6474 restore_snapshot(
6475     int		idx,
6476     int		close_curwin)	    /* closing current window */
6477 {
6478     win_T	*wp;
6479 
6480     if (curtab->tp_snapshot[idx] != NULL
6481 	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
6482 	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
6483 	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
6484     {
6485 	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
6486 	win_comp_pos();
6487 	if (wp != NULL && close_curwin)
6488 	    win_goto(wp);
6489 	redraw_all_later(CLEAR);
6490     }
6491     clear_snapshot(curtab, idx);
6492 }
6493 
6494 /*
6495  * Check if frames "sn" and "fr" have the same layout, same following frames
6496  * and same children.  And the window pointer is valid.
6497  */
6498     static int
6499 check_snapshot_rec(frame_T *sn, frame_T *fr)
6500 {
6501     if (sn->fr_layout != fr->fr_layout
6502 	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
6503 	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
6504 	    || (sn->fr_next != NULL
6505 		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
6506 	    || (sn->fr_child != NULL
6507 		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
6508 	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
6509 	return FAIL;
6510     return OK;
6511 }
6512 
6513 /*
6514  * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
6515  * following frames and children.
6516  * Returns a pointer to the old current window, or NULL.
6517  */
6518     static win_T *
6519 restore_snapshot_rec(frame_T *sn, frame_T *fr)
6520 {
6521     win_T	*wp = NULL;
6522     win_T	*wp2;
6523 
6524     fr->fr_height = sn->fr_height;
6525     fr->fr_width = sn->fr_width;
6526     if (fr->fr_layout == FR_LEAF)
6527     {
6528 	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
6529 	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
6530 	wp = sn->fr_win;
6531     }
6532     if (sn->fr_next != NULL)
6533     {
6534 	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
6535 	if (wp2 != NULL)
6536 	    wp = wp2;
6537     }
6538     if (sn->fr_child != NULL)
6539     {
6540 	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
6541 	if (wp2 != NULL)
6542 	    wp = wp2;
6543     }
6544     return wp;
6545 }
6546 
6547 #if defined(FEAT_EVAL) || defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \
6548 	|| defined(PROTO)
6549 /*
6550  * Set "win" to be the curwin and "tp" to be the current tab page.
6551  * restore_win() MUST be called to undo, also when FAIL is returned.
6552  * No autocommands will be executed until restore_win() is called.
6553  * When "no_display" is TRUE the display won't be affected, no redraw is
6554  * triggered, another tabpage access is limited.
6555  * Returns FAIL if switching to "win" failed.
6556  */
6557     int
6558 switch_win(
6559     win_T	**save_curwin,
6560     tabpage_T	**save_curtab,
6561     win_T	*win,
6562     tabpage_T	*tp,
6563     int		no_display)
6564 {
6565     block_autocmds();
6566     *save_curwin = curwin;
6567     if (tp != NULL)
6568     {
6569 	*save_curtab = curtab;
6570 	if (no_display)
6571 	{
6572 	    curtab->tp_firstwin = firstwin;
6573 	    curtab->tp_lastwin = lastwin;
6574 	    curtab = tp;
6575 	    firstwin = curtab->tp_firstwin;
6576 	    lastwin = curtab->tp_lastwin;
6577 	}
6578 	else
6579 	    goto_tabpage_tp(tp, FALSE, FALSE);
6580     }
6581     if (!win_valid(win))
6582 	return FAIL;
6583     curwin = win;
6584     curbuf = curwin->w_buffer;
6585     return OK;
6586 }
6587 
6588 /*
6589  * Restore current tabpage and window saved by switch_win(), if still valid.
6590  * When "no_display" is TRUE the display won't be affected, no redraw is
6591  * triggered.
6592  */
6593     void
6594 restore_win(
6595     win_T	*save_curwin UNUSED,
6596     tabpage_T	*save_curtab UNUSED,
6597     int		no_display UNUSED)
6598 {
6599     if (save_curtab != NULL && valid_tabpage(save_curtab))
6600     {
6601 	if (no_display)
6602 	{
6603 	    curtab->tp_firstwin = firstwin;
6604 	    curtab->tp_lastwin = lastwin;
6605 	    curtab = save_curtab;
6606 	    firstwin = curtab->tp_firstwin;
6607 	    lastwin = curtab->tp_lastwin;
6608 	}
6609 	else
6610 	    goto_tabpage_tp(save_curtab, FALSE, FALSE);
6611     }
6612     if (win_valid(save_curwin))
6613     {
6614 	curwin = save_curwin;
6615 	curbuf = curwin->w_buffer;
6616     }
6617     unblock_autocmds();
6618 }
6619 
6620 /*
6621  * Make "buf" the current buffer.  restore_buffer() MUST be called to undo.
6622  * No autocommands will be executed.  Use aucmd_prepbuf() if there are any.
6623  */
6624     void
6625 switch_buffer(bufref_T *save_curbuf, buf_T *buf)
6626 {
6627     block_autocmds();
6628     set_bufref(save_curbuf, curbuf);
6629     --curbuf->b_nwindows;
6630     curbuf = buf;
6631     curwin->w_buffer = buf;
6632     ++curbuf->b_nwindows;
6633 }
6634 
6635 /*
6636  * Restore the current buffer after using switch_buffer().
6637  */
6638     void
6639 restore_buffer(bufref_T *save_curbuf)
6640 {
6641     unblock_autocmds();
6642     /* Check for valid buffer, just in case. */
6643     if (bufref_valid(save_curbuf))
6644     {
6645 	--curbuf->b_nwindows;
6646 	curwin->w_buffer = save_curbuf->br_buf;
6647 	curbuf = save_curbuf->br_buf;
6648 	++curbuf->b_nwindows;
6649     }
6650 }
6651 #endif
6652 
6653 #if defined(FEAT_GUI) || defined(PROTO)
6654 /*
6655  * Return TRUE if there is any vertically split window.
6656  */
6657     int
6658 win_hasvertsplit(void)
6659 {
6660     frame_T	*fr;
6661 
6662     if (topframe->fr_layout == FR_ROW)
6663 	return TRUE;
6664 
6665     if (topframe->fr_layout == FR_COL)
6666 	for (fr = topframe->fr_child; fr != NULL; fr = fr->fr_next)
6667 	    if (fr->fr_layout == FR_ROW)
6668 		return TRUE;
6669 
6670     return FALSE;
6671 }
6672 #endif
6673 
6674 #if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
6675 /*
6676  * Add match to the match list of window 'wp'.  The pattern 'pat' will be
6677  * highlighted with the group 'grp' with priority 'prio'.
6678  * Optionally, a desired ID 'id' can be specified (greater than or equal to 1).
6679  * If no particular ID is desired, -1 must be specified for 'id'.
6680  * Return ID of added match, -1 on failure.
6681  */
6682     int
6683 match_add(
6684     win_T	*wp,
6685     char_u	*grp,
6686     char_u	*pat,
6687     int		prio,
6688     int		id,
6689     list_T	*pos_list,
6690     char_u      *conceal_char UNUSED) /* pointer to conceal replacement char */
6691 {
6692     matchitem_T	*cur;
6693     matchitem_T	*prev;
6694     matchitem_T	*m;
6695     int		hlg_id;
6696     regprog_T	*regprog = NULL;
6697     int		rtype = SOME_VALID;
6698 
6699     if (*grp == NUL || (pat != NULL && *pat == NUL))
6700 	return -1;
6701     if (id < -1 || id == 0)
6702     {
6703 	EMSGN(_("E799: Invalid ID: %ld (must be greater than or equal to 1)"), id);
6704 	return -1;
6705     }
6706     if (id != -1)
6707     {
6708 	cur = wp->w_match_head;
6709 	while (cur != NULL)
6710 	{
6711 	    if (cur->id == id)
6712 	    {
6713 		EMSGN(_("E801: ID already taken: %ld"), id);
6714 		return -1;
6715 	    }
6716 	    cur = cur->next;
6717 	}
6718     }
6719     if ((hlg_id = syn_namen2id(grp, (int)STRLEN(grp))) == 0)
6720     {
6721 	EMSG2(_(e_nogroup), grp);
6722 	return -1;
6723     }
6724     if (pat != NULL && (regprog = vim_regcomp(pat, RE_MAGIC)) == NULL)
6725     {
6726 	EMSG2(_(e_invarg2), pat);
6727 	return -1;
6728     }
6729 
6730     /* Find available match ID. */
6731     while (id == -1)
6732     {
6733 	cur = wp->w_match_head;
6734 	while (cur != NULL && cur->id != wp->w_next_match_id)
6735 	    cur = cur->next;
6736 	if (cur == NULL)
6737 	    id = wp->w_next_match_id;
6738 	wp->w_next_match_id++;
6739     }
6740 
6741     /* Build new match. */
6742     m = (matchitem_T *)alloc_clear(sizeof(matchitem_T));
6743     m->id = id;
6744     m->priority = prio;
6745     m->pattern = pat == NULL ? NULL : vim_strsave(pat);
6746     m->hlg_id = hlg_id;
6747     m->match.regprog = regprog;
6748     m->match.rmm_ic = FALSE;
6749     m->match.rmm_maxcol = 0;
6750 # if defined(FEAT_CONCEAL) && defined(FEAT_MBYTE)
6751     m->conceal_char = 0;
6752     if (conceal_char != NULL)
6753 	m->conceal_char = (*mb_ptr2char)(conceal_char);
6754 # endif
6755 
6756     /* Set up position matches */
6757     if (pos_list != NULL)
6758     {
6759 	linenr_T	toplnum = 0;
6760 	linenr_T	botlnum = 0;
6761 	listitem_T	*li;
6762 	int		i;
6763 
6764 	for (i = 0, li = pos_list->lv_first; li != NULL && i < MAXPOSMATCH;
6765 							i++, li = li->li_next)
6766 	{
6767 	    linenr_T	lnum = 0;
6768 	    colnr_T	col = 0;
6769 	    int		len = 1;
6770 	    list_T	*subl;
6771 	    listitem_T	*subli;
6772 	    int		error = FALSE;
6773 
6774 	    if (li->li_tv.v_type == VAR_LIST)
6775 	    {
6776 		subl = li->li_tv.vval.v_list;
6777 		if (subl == NULL)
6778 		    goto fail;
6779 		subli = subl->lv_first;
6780 		if (subli == NULL)
6781 		    goto fail;
6782 		lnum = get_tv_number_chk(&subli->li_tv, &error);
6783 		if (error == TRUE)
6784 		    goto fail;
6785 		if (lnum == 0)
6786 		{
6787 		    --i;
6788 		    continue;
6789 		}
6790 		m->pos.pos[i].lnum = lnum;
6791 		subli = subli->li_next;
6792 		if (subli != NULL)
6793 		{
6794 		    col = get_tv_number_chk(&subli->li_tv, &error);
6795 		    if (error == TRUE)
6796 			goto fail;
6797 		    subli = subli->li_next;
6798 		    if (subli != NULL)
6799 		    {
6800 			len = get_tv_number_chk(&subli->li_tv, &error);
6801 			if (error == TRUE)
6802 			    goto fail;
6803 		    }
6804 		}
6805 		m->pos.pos[i].col = col;
6806 		m->pos.pos[i].len = len;
6807 	    }
6808 	    else if (li->li_tv.v_type == VAR_NUMBER)
6809 	    {
6810 		if (li->li_tv.vval.v_number == 0)
6811 		{
6812 		    --i;
6813 		    continue;
6814 		}
6815 		m->pos.pos[i].lnum = li->li_tv.vval.v_number;
6816 		m->pos.pos[i].col = 0;
6817 		m->pos.pos[i].len = 0;
6818 	    }
6819 	    else
6820 	    {
6821 		EMSG(_("List or number required"));
6822 		goto fail;
6823 	    }
6824 	    if (toplnum == 0 || lnum < toplnum)
6825 		toplnum = lnum;
6826 	    if (botlnum == 0 || lnum >= botlnum)
6827 		botlnum = lnum + 1;
6828 	}
6829 
6830 	/* Calculate top and bottom lines for redrawing area */
6831 	if (toplnum != 0)
6832 	{
6833 	    if (wp->w_buffer->b_mod_set)
6834 	    {
6835 		if (wp->w_buffer->b_mod_top > toplnum)
6836 		    wp->w_buffer->b_mod_top = toplnum;
6837 		if (wp->w_buffer->b_mod_bot < botlnum)
6838 		    wp->w_buffer->b_mod_bot = botlnum;
6839 	    }
6840 	    else
6841 	    {
6842 		wp->w_buffer->b_mod_set = TRUE;
6843 		wp->w_buffer->b_mod_top = toplnum;
6844 		wp->w_buffer->b_mod_bot = botlnum;
6845 		wp->w_buffer->b_mod_xlines = 0;
6846 	    }
6847 	    m->pos.toplnum = toplnum;
6848 	    m->pos.botlnum = botlnum;
6849 	    rtype = VALID;
6850 	}
6851     }
6852 
6853     /* Insert new match.  The match list is in ascending order with regard to
6854      * the match priorities. */
6855     cur = wp->w_match_head;
6856     prev = cur;
6857     while (cur != NULL && prio >= cur->priority)
6858     {
6859 	prev = cur;
6860 	cur = cur->next;
6861     }
6862     if (cur == prev)
6863 	wp->w_match_head = m;
6864     else
6865 	prev->next = m;
6866     m->next = cur;
6867 
6868     redraw_later(rtype);
6869     return id;
6870 
6871 fail:
6872     vim_free(m);
6873     return -1;
6874 }
6875 
6876 /*
6877  * Delete match with ID 'id' in the match list of window 'wp'.
6878  * Print error messages if 'perr' is TRUE.
6879  */
6880     int
6881 match_delete(win_T *wp, int id, int perr)
6882 {
6883     matchitem_T	*cur = wp->w_match_head;
6884     matchitem_T	*prev = cur;
6885     int		rtype = SOME_VALID;
6886 
6887     if (id < 1)
6888     {
6889 	if (perr == TRUE)
6890 	    EMSGN(_("E802: Invalid ID: %ld (must be greater than or equal to 1)"),
6891 									  id);
6892 	return -1;
6893     }
6894     while (cur != NULL && cur->id != id)
6895     {
6896 	prev = cur;
6897 	cur = cur->next;
6898     }
6899     if (cur == NULL)
6900     {
6901 	if (perr == TRUE)
6902 	    EMSGN(_("E803: ID not found: %ld"), id);
6903 	return -1;
6904     }
6905     if (cur == prev)
6906 	wp->w_match_head = cur->next;
6907     else
6908 	prev->next = cur->next;
6909     vim_regfree(cur->match.regprog);
6910     vim_free(cur->pattern);
6911     if (cur->pos.toplnum != 0)
6912     {
6913 	if (wp->w_buffer->b_mod_set)
6914 	{
6915 	    if (wp->w_buffer->b_mod_top > cur->pos.toplnum)
6916 		wp->w_buffer->b_mod_top = cur->pos.toplnum;
6917 	    if (wp->w_buffer->b_mod_bot < cur->pos.botlnum)
6918 		wp->w_buffer->b_mod_bot = cur->pos.botlnum;
6919 	}
6920 	else
6921 	{
6922 	    wp->w_buffer->b_mod_set = TRUE;
6923 	    wp->w_buffer->b_mod_top = cur->pos.toplnum;
6924 	    wp->w_buffer->b_mod_bot = cur->pos.botlnum;
6925 	    wp->w_buffer->b_mod_xlines = 0;
6926 	}
6927 	rtype = VALID;
6928     }
6929     vim_free(cur);
6930     redraw_later(rtype);
6931     return 0;
6932 }
6933 
6934 /*
6935  * Delete all matches in the match list of window 'wp'.
6936  */
6937     void
6938 clear_matches(win_T *wp)
6939 {
6940     matchitem_T *m;
6941 
6942     while (wp->w_match_head != NULL)
6943     {
6944 	m = wp->w_match_head->next;
6945 	vim_regfree(wp->w_match_head->match.regprog);
6946 	vim_free(wp->w_match_head->pattern);
6947 	vim_free(wp->w_match_head);
6948 	wp->w_match_head = m;
6949     }
6950     redraw_later(SOME_VALID);
6951 }
6952 
6953 /*
6954  * Get match from ID 'id' in window 'wp'.
6955  * Return NULL if match not found.
6956  */
6957     matchitem_T *
6958 get_match(win_T *wp, int id)
6959 {
6960     matchitem_T *cur = wp->w_match_head;
6961 
6962     while (cur != NULL && cur->id != id)
6963 	cur = cur->next;
6964     return cur;
6965 }
6966 #endif
6967 
6968 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
6969     int
6970 get_win_number(win_T *wp, win_T *first_win)
6971 {
6972     int		i = 1;
6973     win_T	*w;
6974 
6975     for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
6976 	++i;
6977 
6978     if (w == NULL)
6979 	return 0;
6980     else
6981 	return i;
6982 }
6983 
6984     int
6985 get_tab_number(tabpage_T *tp UNUSED)
6986 {
6987     int		i = 1;
6988     tabpage_T	*t;
6989 
6990     for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
6991 	++i;
6992 
6993     if (t == NULL)
6994 	return 0;
6995     else
6996 	return i;
6997 }
6998 #endif
6999 
7000 /*
7001  * Return TRUE if "topfrp" and its children are at the right height.
7002  */
7003     static int
7004 frame_check_height(frame_T *topfrp, int height)
7005 {
7006     frame_T *frp;
7007 
7008     if (topfrp->fr_height != height)
7009 	return FALSE;
7010 
7011     if (topfrp->fr_layout == FR_ROW)
7012 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
7013 	    if (frp->fr_height != height)
7014 		return FALSE;
7015 
7016     return TRUE;
7017 }
7018 
7019 /*
7020  * Return TRUE if "topfrp" and its children are at the right width.
7021  */
7022     static int
7023 frame_check_width(frame_T *topfrp, int width)
7024 {
7025     frame_T *frp;
7026 
7027     if (topfrp->fr_width != width)
7028 	return FALSE;
7029 
7030     if (topfrp->fr_layout == FR_COL)
7031 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
7032 	    if (frp->fr_width != width)
7033 		return FALSE;
7034 
7035     return TRUE;
7036 }
7037 
7038 #if defined(FEAT_EVAL) || defined(PROTO)
7039     int
7040 win_getid(typval_T *argvars)
7041 {
7042     int	    winnr;
7043     win_T   *wp;
7044 
7045     if (argvars[0].v_type == VAR_UNKNOWN)
7046 	return curwin->w_id;
7047     winnr = get_tv_number(&argvars[0]);
7048     if (winnr > 0)
7049     {
7050 	if (argvars[1].v_type == VAR_UNKNOWN)
7051 	    wp = firstwin;
7052 	else
7053 	{
7054 	    tabpage_T	*tp;
7055 	    int		tabnr = get_tv_number(&argvars[1]);
7056 
7057 	    FOR_ALL_TABPAGES(tp)
7058 		if (--tabnr == 0)
7059 		    break;
7060 	    if (tp == NULL)
7061 		return -1;
7062 	    if (tp == curtab)
7063 		wp = firstwin;
7064 	    else
7065 		wp = tp->tp_firstwin;
7066 	}
7067 	for ( ; wp != NULL; wp = wp->w_next)
7068 	    if (--winnr == 0)
7069 		return wp->w_id;
7070     }
7071     return 0;
7072 }
7073 
7074     int
7075 win_gotoid(typval_T *argvars)
7076 {
7077     win_T	*wp;
7078     tabpage_T   *tp;
7079     int		id = get_tv_number(&argvars[0]);
7080 
7081     FOR_ALL_TAB_WINDOWS(tp, wp)
7082 	    if (wp->w_id == id)
7083 	    {
7084 		goto_tabpage_win(tp, wp);
7085 		return 1;
7086 	    }
7087     return 0;
7088 }
7089 
7090     void
7091 win_id2tabwin(typval_T *argvars, list_T *list)
7092 {
7093     win_T	*wp;
7094     tabpage_T   *tp;
7095     int		winnr = 1;
7096     int		tabnr = 1;
7097     int		id = get_tv_number(&argvars[0]);
7098 
7099     FOR_ALL_TABPAGES(tp)
7100     {
7101 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
7102 	{
7103 	    if (wp->w_id == id)
7104 	    {
7105 		list_append_number(list, tabnr);
7106 		list_append_number(list, winnr);
7107 		return;
7108 	    }
7109 	    ++winnr;
7110 	}
7111 	++tabnr;
7112 	winnr = 1;
7113     }
7114     list_append_number(list, 0);
7115     list_append_number(list, 0);
7116 }
7117 
7118     win_T *
7119 win_id2wp(typval_T *argvars)
7120 {
7121     win_T	*wp;
7122     tabpage_T   *tp;
7123     int		id = get_tv_number(&argvars[0]);
7124 
7125     FOR_ALL_TAB_WINDOWS(tp, wp)
7126 	if (wp->w_id == id)
7127 	    return wp;
7128 
7129     return NULL;
7130 }
7131 
7132     int
7133 win_id2win(typval_T *argvars)
7134 {
7135     win_T   *wp;
7136     int	    nr = 1;
7137     int	    id = get_tv_number(&argvars[0]);
7138 
7139     FOR_ALL_WINDOWS(wp)
7140     {
7141 	if (wp->w_id == id)
7142 	    return nr;
7143 	++nr;
7144     }
7145     return 0;
7146 }
7147 
7148     void
7149 win_findbuf(typval_T *argvars, list_T *list)
7150 {
7151     win_T	*wp;
7152     tabpage_T   *tp;
7153     int		bufnr = get_tv_number(&argvars[0]);
7154 
7155     FOR_ALL_TAB_WINDOWS(tp, wp)
7156 	    if (wp->w_buffer->b_fnum == bufnr)
7157 		list_append_number(list, wp->w_id);
7158 }
7159 
7160 #endif
7161