xref: /vim-8.2.3635/src/window.c (revision 51ad4eaa)
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 if (cmdwin_type != 0) { EMSG(_(e_cmdwin)); break; }
103 #else
104 # define CHECK_CMDWIN
105 #endif
106 
107     switch (nchar)
108     {
109 /* split current window in two parts, horizontally */
110     case 'S':
111     case Ctrl_S:
112     case 's':
113 		CHECK_CMDWIN
114 		reset_VIsual_and_resel();	/* stop Visual mode */
115 #ifdef FEAT_QUICKFIX
116 		/* When splitting the quickfix window open a new buffer in it,
117 		 * don't replicate the quickfix buffer. */
118 		if (bt_quickfix(curbuf))
119 		    goto newwindow;
120 #endif
121 #ifdef FEAT_GUI
122 		need_mouse_correct = TRUE;
123 #endif
124 		(void)win_split((int)Prenum, 0);
125 		break;
126 
127 /* split current window in two parts, vertically */
128     case Ctrl_V:
129     case 'v':
130 		CHECK_CMDWIN
131 		reset_VIsual_and_resel();	/* stop Visual mode */
132 #ifdef FEAT_QUICKFIX
133 		/* When splitting the quickfix window open a new buffer in it,
134 		 * don't replicate the quickfix buffer. */
135 		if (bt_quickfix(curbuf))
136 		    goto newwindow;
137 #endif
138 #ifdef FEAT_GUI
139 		need_mouse_correct = TRUE;
140 #endif
141 		(void)win_split((int)Prenum, WSP_VERT);
142 		break;
143 
144 /* split current window and edit alternate file */
145     case Ctrl_HAT:
146     case '^':
147 		CHECK_CMDWIN
148 		reset_VIsual_and_resel();	/* stop Visual mode */
149 		cmd_with_count("split #", cbuf, sizeof(cbuf), Prenum);
150 		do_cmdline_cmd(cbuf);
151 		break;
152 
153 /* open new window */
154     case Ctrl_N:
155     case 'n':
156 		CHECK_CMDWIN
157 		reset_VIsual_and_resel();	/* stop Visual mode */
158 #ifdef FEAT_QUICKFIX
159 newwindow:
160 #endif
161 		if (Prenum)
162 		    /* window height */
163 		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
164 		else
165 		    cbuf[0] = NUL;
166 #if defined(FEAT_QUICKFIX)
167 		if (nchar == 'v' || nchar == Ctrl_V)
168 		    STRCAT(cbuf, "v");
169 #endif
170 		STRCAT(cbuf, "new");
171 		do_cmdline_cmd(cbuf);
172 		break;
173 
174 /* quit current window */
175     case Ctrl_Q:
176     case 'q':
177 		reset_VIsual_and_resel();	/* stop Visual mode */
178 		cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
179 		do_cmdline_cmd(cbuf);
180 		break;
181 
182 /* close current window */
183     case Ctrl_C:
184     case 'c':
185 		reset_VIsual_and_resel();	/* stop Visual mode */
186 		cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
187 		do_cmdline_cmd(cbuf);
188 		break;
189 
190 #if defined(FEAT_QUICKFIX)
191 /* close preview window */
192     case Ctrl_Z:
193     case 'z':
194 		CHECK_CMDWIN
195 		reset_VIsual_and_resel();	/* stop Visual mode */
196 		do_cmdline_cmd((char_u *)"pclose");
197 		break;
198 
199 /* cursor to preview window */
200     case 'P':
201 		FOR_ALL_WINDOWS(wp)
202 		    if (wp->w_p_pvw)
203 			break;
204 		if (wp == NULL)
205 		    EMSG(_("E441: There is no preview window"));
206 		else
207 		    win_goto(wp);
208 		break;
209 #endif
210 
211 /* close all but current window */
212     case Ctrl_O:
213     case 'o':
214 		CHECK_CMDWIN
215 		reset_VIsual_and_resel();	/* stop Visual mode */
216 		cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
217 		do_cmdline_cmd(cbuf);
218 		break;
219 
220 /* cursor to next window with wrap around */
221     case Ctrl_W:
222     case 'w':
223 /* cursor to previous window with wrap around */
224     case 'W':
225 		CHECK_CMDWIN
226 		if (ONE_WINDOW && Prenum != 1)	/* just one window */
227 		    beep_flush();
228 		else
229 		{
230 		    if (Prenum)			/* go to specified window */
231 		    {
232 			for (wp = firstwin; --Prenum > 0; )
233 			{
234 			    if (wp->w_next == NULL)
235 				break;
236 			    else
237 				wp = wp->w_next;
238 			}
239 		    }
240 		    else
241 		    {
242 			if (nchar == 'W')	    /* go to previous window */
243 			{
244 			    wp = curwin->w_prev;
245 			    if (wp == NULL)
246 				wp = lastwin;	    /* wrap around */
247 			}
248 			else			    /* go to next window */
249 			{
250 			    wp = curwin->w_next;
251 			    if (wp == NULL)
252 				wp = firstwin;	    /* wrap around */
253 			}
254 		    }
255 		    win_goto(wp);
256 		}
257 		break;
258 
259 /* cursor to window below */
260     case 'j':
261     case K_DOWN:
262     case Ctrl_J:
263 		CHECK_CMDWIN
264 		win_goto_ver(FALSE, Prenum1);
265 		break;
266 
267 /* cursor to window above */
268     case 'k':
269     case K_UP:
270     case Ctrl_K:
271 		CHECK_CMDWIN
272 		win_goto_ver(TRUE, Prenum1);
273 		break;
274 
275 /* cursor to left window */
276     case 'h':
277     case K_LEFT:
278     case Ctrl_H:
279     case K_BS:
280 		CHECK_CMDWIN
281 		win_goto_hor(TRUE, Prenum1);
282 		break;
283 
284 /* cursor to right window */
285     case 'l':
286     case K_RIGHT:
287     case Ctrl_L:
288 		CHECK_CMDWIN
289 		win_goto_hor(FALSE, Prenum1);
290 		break;
291 
292 /* move window to new tab page */
293     case 'T':
294 		if (one_window())
295 		    MSG(_(m_onlyone));
296 		else
297 		{
298 		    tabpage_T	*oldtab = curtab;
299 		    tabpage_T	*newtab;
300 
301 		    /* First create a new tab with the window, then go back to
302 		     * the old tab and close the window there. */
303 		    wp = curwin;
304 		    if (win_new_tabpage((int)Prenum) == OK
305 						     && valid_tabpage(oldtab))
306 		    {
307 			newtab = curtab;
308 			goto_tabpage_tp(oldtab, TRUE, TRUE);
309 			if (curwin == wp)
310 			    win_close(curwin, FALSE);
311 			if (valid_tabpage(newtab))
312 			    goto_tabpage_tp(newtab, TRUE, TRUE);
313 		    }
314 		}
315 		break;
316 
317 /* cursor to top-left window */
318     case 't':
319     case Ctrl_T:
320 		win_goto(firstwin);
321 		break;
322 
323 /* cursor to bottom-right window */
324     case 'b':
325     case Ctrl_B:
326 		win_goto(lastwin);
327 		break;
328 
329 /* cursor to last accessed (previous) window */
330     case 'p':
331     case Ctrl_P:
332 		if (!win_valid(prevwin))
333 		    beep_flush();
334 		else
335 		    win_goto(prevwin);
336 		break;
337 
338 /* exchange current and next window */
339     case 'x':
340     case Ctrl_X:
341 		CHECK_CMDWIN
342 		win_exchange(Prenum);
343 		break;
344 
345 /* rotate windows downwards */
346     case Ctrl_R:
347     case 'r':
348 		CHECK_CMDWIN
349 		reset_VIsual_and_resel();	/* stop Visual mode */
350 		win_rotate(FALSE, (int)Prenum1);    /* downwards */
351 		break;
352 
353 /* rotate windows upwards */
354     case 'R':
355 		CHECK_CMDWIN
356 		reset_VIsual_and_resel();	/* stop Visual mode */
357 		win_rotate(TRUE, (int)Prenum1);	    /* upwards */
358 		break;
359 
360 /* move window to the very top/bottom/left/right */
361     case 'K':
362     case 'J':
363     case 'H':
364     case 'L':
365 		CHECK_CMDWIN
366 		win_totop((int)Prenum,
367 			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
368 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
369 		break;
370 
371 /* make all windows the same height */
372     case '=':
373 #ifdef FEAT_GUI
374 		need_mouse_correct = TRUE;
375 #endif
376 		win_equal(NULL, FALSE, 'b');
377 		break;
378 
379 /* increase current window height */
380     case '+':
381 #ifdef FEAT_GUI
382 		need_mouse_correct = TRUE;
383 #endif
384 		win_setheight(curwin->w_height + (int)Prenum1);
385 		break;
386 
387 /* decrease current window height */
388     case '-':
389 #ifdef FEAT_GUI
390 		need_mouse_correct = TRUE;
391 #endif
392 		win_setheight(curwin->w_height - (int)Prenum1);
393 		break;
394 
395 /* set current window height */
396     case Ctrl__:
397     case '_':
398 #ifdef FEAT_GUI
399 		need_mouse_correct = TRUE;
400 #endif
401 		win_setheight(Prenum ? (int)Prenum : 9999);
402 		break;
403 
404 /* increase current window width */
405     case '>':
406 #ifdef FEAT_GUI
407 		need_mouse_correct = TRUE;
408 #endif
409 		win_setwidth(curwin->w_width + (int)Prenum1);
410 		break;
411 
412 /* decrease current window width */
413     case '<':
414 #ifdef FEAT_GUI
415 		need_mouse_correct = TRUE;
416 #endif
417 		win_setwidth(curwin->w_width - (int)Prenum1);
418 		break;
419 
420 /* set current window width */
421     case '|':
422 #ifdef FEAT_GUI
423 		need_mouse_correct = TRUE;
424 #endif
425 		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
426 		break;
427 
428 /* jump to tag and split window if tag exists (in preview window) */
429 #if defined(FEAT_QUICKFIX)
430     case '}':
431 		CHECK_CMDWIN
432 		if (Prenum)
433 		    g_do_tagpreview = Prenum;
434 		else
435 		    g_do_tagpreview = p_pvh;
436 #endif
437 		/* FALLTHROUGH */
438     case ']':
439     case Ctrl_RSB:
440 		CHECK_CMDWIN
441 		/* keep Visual mode, can select words to use as a tag */
442 		if (Prenum)
443 		    postponed_split = Prenum;
444 		else
445 		    postponed_split = -1;
446 #ifdef FEAT_QUICKFIX
447 		if (nchar != '}')
448 		    g_do_tagpreview = 0;
449 #endif
450 
451 		/* Execute the command right here, required when "wincmd ]"
452 		 * was used in a function. */
453 		do_nv_ident(Ctrl_RSB, NUL);
454 		break;
455 
456 #ifdef FEAT_SEARCHPATH
457 /* edit file name under cursor in a new window */
458     case 'f':
459     case 'F':
460     case Ctrl_F:
461 wingotofile:
462 		CHECK_CMDWIN
463 
464 		ptr = grab_file_name(Prenum1, &lnum);
465 		if (ptr != NULL)
466 		{
467 		    tabpage_T	*oldtab = curtab;
468 		    win_T	*oldwin = curwin;
469 # ifdef FEAT_GUI
470 		    need_mouse_correct = TRUE;
471 # endif
472 		    setpcmark();
473 		    if (win_split(0, 0) == OK)
474 		    {
475 			RESET_BINDING(curwin);
476 			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
477 						   ECMD_HIDE, NULL) == FAIL)
478 			{
479 			    /* Failed to open the file, close the window
480 			     * opened for it. */
481 			    win_close(curwin, FALSE);
482 			    goto_tabpage_win(oldtab, oldwin);
483 			}
484 			else if (nchar == 'F' && lnum >= 0)
485 			{
486 			    curwin->w_cursor.lnum = lnum;
487 			    check_cursor_lnum();
488 			    beginline(BL_SOL | BL_FIX);
489 			}
490 		    }
491 		    vim_free(ptr);
492 		}
493 		break;
494 #endif
495 
496 #ifdef FEAT_FIND_ID
497 /* Go to the first occurrence of the identifier under cursor along path in a
498  * new window -- webb
499  */
500     case 'i':			    /* Go to any match */
501     case Ctrl_I:
502 		type = FIND_ANY;
503 		/* FALLTHROUGH */
504     case 'd':			    /* Go to definition, using 'define' */
505     case Ctrl_D:
506 		CHECK_CMDWIN
507 		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
508 		    break;
509 		find_pattern_in_path(ptr, 0, len, TRUE,
510 			Prenum == 0 ? TRUE : FALSE, type,
511 			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
512 		curwin->w_set_curswant = TRUE;
513 		break;
514 #endif
515 
516     case K_KENTER:
517     case CAR:
518 #if defined(FEAT_QUICKFIX)
519 		/*
520 		 * In a quickfix window a <CR> jumps to the error under the
521 		 * cursor in a new window.
522 		 */
523 		if (bt_quickfix(curbuf))
524 		{
525 		    sprintf((char *)cbuf, "split +%ld%s",
526 				(long)curwin->w_cursor.lnum,
527 				(curwin->w_llist_ref == NULL) ? "cc" : "ll");
528 		    do_cmdline_cmd(cbuf);
529 		}
530 #endif
531 		break;
532 
533 
534 /* CTRL-W g  extended commands */
535     case 'g':
536     case Ctrl_G:
537 		CHECK_CMDWIN
538 #ifdef USE_ON_FLY_SCROLL
539 		dont_scroll = TRUE;		/* disallow scrolling here */
540 #endif
541 		++no_mapping;
542 		++allow_keys;   /* no mapping for xchar, but allow key codes */
543 		if (xchar == NUL)
544 		    xchar = plain_vgetc();
545 		LANGMAP_ADJUST(xchar, TRUE);
546 		--no_mapping;
547 		--allow_keys;
548 #ifdef FEAT_CMDL_INFO
549 		(void)add_to_showcmd(xchar);
550 #endif
551 		switch (xchar)
552 		{
553 #if defined(FEAT_QUICKFIX)
554 		    case '}':
555 			xchar = Ctrl_RSB;
556 			if (Prenum)
557 			    g_do_tagpreview = Prenum;
558 			else
559 			    g_do_tagpreview = p_pvh;
560 #endif
561 			/* FALLTHROUGH */
562 		    case ']':
563 		    case Ctrl_RSB:
564 			/* keep Visual mode, can select words to use as a tag */
565 			if (Prenum)
566 			    postponed_split = Prenum;
567 			else
568 			    postponed_split = -1;
569 
570 			/* Execute the command right here, required when
571 			 * "wincmd g}" was used in a function. */
572 			do_nv_ident('g', xchar);
573 			break;
574 
575 #ifdef FEAT_SEARCHPATH
576 		    case 'f':	    /* CTRL-W gf: "gf" in a new tab page */
577 		    case 'F':	    /* CTRL-W gF: "gF" in a new tab page */
578 			cmdmod.tab = tabpage_index(curtab) + 1;
579 			nchar = xchar;
580 			goto wingotofile;
581 #endif
582 		    default:
583 			beep_flush();
584 			break;
585 		}
586 		break;
587 
588     default:	beep_flush();
589 		break;
590     }
591 }
592 
593 /*
594  * Figure out the address type for ":wnncmd".
595  */
596     void
597 get_wincmd_addr_type(char_u *arg, exarg_T *eap)
598 {
599     switch (*arg)
600     {
601     case 'S':
602     case Ctrl_S:
603     case 's':
604     case Ctrl_N:
605     case 'n':
606     case 'j':
607     case Ctrl_J:
608     case 'k':
609     case Ctrl_K:
610     case 'T':
611     case Ctrl_R:
612     case 'r':
613     case 'R':
614     case 'K':
615     case 'J':
616     case '+':
617     case '-':
618     case Ctrl__:
619     case '_':
620     case '|':
621     case ']':
622     case Ctrl_RSB:
623     case 'g':
624     case Ctrl_G:
625     case Ctrl_V:
626     case 'v':
627     case 'h':
628     case Ctrl_H:
629     case 'l':
630     case Ctrl_L:
631     case 'H':
632     case 'L':
633     case '>':
634     case '<':
635 #if defined(FEAT_QUICKFIX)
636     case '}':
637 #endif
638 #ifdef FEAT_SEARCHPATH
639     case 'f':
640     case 'F':
641     case Ctrl_F:
642 #endif
643 #ifdef FEAT_FIND_ID
644     case 'i':
645     case Ctrl_I:
646     case 'd':
647     case Ctrl_D:
648 #endif
649 		/* window size or any count */
650 		eap->addr_type = ADDR_LINES;
651 		break;
652 
653     case Ctrl_HAT:
654     case '^':
655 		/* buffer number */
656 		eap->addr_type = ADDR_BUFFERS;
657 		break;
658 
659     case Ctrl_Q:
660     case 'q':
661     case Ctrl_C:
662     case 'c':
663     case Ctrl_O:
664     case 'o':
665     case Ctrl_W:
666     case 'w':
667     case 'W':
668     case 'x':
669     case Ctrl_X:
670 		/* window number */
671 		eap->addr_type = ADDR_WINDOWS;
672 		break;
673 
674 #if defined(FEAT_QUICKFIX)
675     case Ctrl_Z:
676     case 'z':
677     case 'P':
678 #endif
679     case 't':
680     case Ctrl_T:
681     case 'b':
682     case Ctrl_B:
683     case 'p':
684     case Ctrl_P:
685     case '=':
686     case CAR:
687 		/* no count */
688 		eap->addr_type = 0;
689 		break;
690     }
691 }
692 
693     static void
694 cmd_with_count(
695     char	*cmd,
696     char_u	*bufp,
697     size_t	bufsize,
698     long	Prenum)
699 {
700     size_t	len = STRLEN(cmd);
701 
702     STRCPY(bufp, cmd);
703     if (Prenum > 0)
704 	vim_snprintf((char *)bufp + len, bufsize - len, "%ld", Prenum);
705 }
706 
707 /*
708  * split the current window, implements CTRL-W s and :split
709  *
710  * "size" is the height or width for the new window, 0 to use half of current
711  * height or width.
712  *
713  * "flags":
714  * WSP_ROOM: require enough room for new window
715  * WSP_VERT: vertical split.
716  * WSP_TOP:  open window at the top-left of the shell (help window).
717  * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
718  * WSP_HELP: creating the help window, keep layout snapshot
719  *
720  * return FAIL for failure, OK otherwise
721  */
722     int
723 win_split(int size, int flags)
724 {
725     /* When the ":tab" modifier was used open a new tab page instead. */
726     if (may_open_tabpage() == OK)
727 	return OK;
728 
729     /* Add flags from ":vertical", ":topleft" and ":botright". */
730     flags |= cmdmod.split;
731     if ((flags & WSP_TOP) && (flags & WSP_BOT))
732     {
733 	EMSG(_("E442: Can't split topleft and botright at the same time"));
734 	return FAIL;
735     }
736 
737     /* When creating the help window make a snapshot of the window layout.
738      * Otherwise clear the snapshot, it's now invalid. */
739     if (flags & WSP_HELP)
740 	make_snapshot(SNAP_HELP_IDX);
741     else
742 	clear_snapshot(curtab, SNAP_HELP_IDX);
743 
744     return win_split_ins(size, flags, NULL, 0);
745 }
746 
747 /*
748  * When "new_wp" is NULL: split the current window in two.
749  * When "new_wp" is not NULL: insert this window at the far
750  * top/left/right/bottom.
751  * return FAIL for failure, OK otherwise
752  */
753     int
754 win_split_ins(
755     int		size,
756     int		flags,
757     win_T	*new_wp,
758     int		dir)
759 {
760     win_T	*wp = new_wp;
761     win_T	*oldwin;
762     int		new_size = size;
763     int		i;
764     int		need_status = 0;
765     int		do_equal = FALSE;
766     int		needed;
767     int		available;
768     int		oldwin_height = 0;
769     int		layout;
770     frame_T	*frp, *curfrp, *frp2, *prevfrp;
771     int		before;
772     int		minheight;
773     int		wmh1;
774 
775     if (flags & WSP_TOP)
776 	oldwin = firstwin;
777     else if (flags & WSP_BOT)
778 	oldwin = lastwin;
779     else
780 	oldwin = curwin;
781 
782     /* add a status line when p_ls == 1 and splitting the first window */
783     if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
784     {
785 	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
786 	{
787 	    EMSG(_(e_noroom));
788 	    return FAIL;
789 	}
790 	need_status = STATUS_HEIGHT;
791     }
792 
793 #ifdef FEAT_GUI
794     /* May be needed for the scrollbars that are going to change. */
795     if (gui.in_use)
796 	out_flush();
797 #endif
798 
799     if (flags & WSP_VERT)
800     {
801 	int	wmw1;
802 	int	minwidth;
803 
804 	layout = FR_ROW;
805 
806 	/*
807 	 * Check if we are able to split the current window and compute its
808 	 * width.
809 	 */
810 	/* Current window requires at least 1 space. */
811 	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
812 	needed = wmw1 + 1;
813 	if (flags & WSP_ROOM)
814 	    needed += p_wiw - wmw1;
815 	if (flags & (WSP_BOT | WSP_TOP))
816 	{
817 	    minwidth = frame_minwidth(topframe, NOWIN);
818 	    available = topframe->fr_width;
819 	    needed += minwidth;
820 	}
821 	else if (p_ea)
822 	{
823 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
824 	    prevfrp = oldwin->w_frame;
825 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
826 							frp = frp->fr_parent)
827 	    {
828 		if (frp->fr_layout == FR_ROW)
829 		    for (frp2 = frp->fr_child; frp2 != NULL;
830 							frp2 = frp2->fr_next)
831 			if (frp2 != prevfrp)
832 			    minwidth += frame_minwidth(frp2, NOWIN);
833 		prevfrp = frp;
834 	    }
835 	    available = topframe->fr_width;
836 	    needed += minwidth;
837 	}
838 	else
839 	{
840 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
841 	    available = oldwin->w_frame->fr_width;
842 	    needed += minwidth;
843 	}
844 	if (available < needed && new_wp == NULL)
845 	{
846 	    EMSG(_(e_noroom));
847 	    return FAIL;
848 	}
849 	if (new_size == 0)
850 	    new_size = oldwin->w_width / 2;
851 	if (new_size > available - minwidth - 1)
852 	    new_size = available - minwidth - 1;
853 	if (new_size < wmw1)
854 	    new_size = wmw1;
855 
856 	/* if it doesn't fit in the current window, need win_equal() */
857 	if (oldwin->w_width - new_size - 1 < p_wmw)
858 	    do_equal = TRUE;
859 
860 	/* We don't like to take lines for the new window from a
861 	 * 'winfixwidth' window.  Take them from a window to the left or right
862 	 * instead, if possible. Add one for the separator. */
863 	if (oldwin->w_p_wfw)
864 	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
865 
866 	/* Only make all windows the same width if one of them (except oldwin)
867 	 * is wider than one of the split windows. */
868 	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
869 	   && oldwin->w_frame->fr_parent != NULL)
870 	{
871 	    frp = oldwin->w_frame->fr_parent->fr_child;
872 	    while (frp != NULL)
873 	    {
874 		if (frp->fr_win != oldwin && frp->fr_win != NULL
875 			&& (frp->fr_win->w_width > new_size
876 			    || frp->fr_win->w_width > oldwin->w_width
877 							      - new_size - 1))
878 		{
879 		    do_equal = TRUE;
880 		    break;
881 		}
882 		frp = frp->fr_next;
883 	    }
884 	}
885     }
886     else
887     {
888 	layout = FR_COL;
889 
890 	/*
891 	 * Check if we are able to split the current window and compute its
892 	 * height.
893 	 */
894 	/* Current window requires at least 1 space. */
895 	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
896 	needed = wmh1 + STATUS_HEIGHT;
897 	if (flags & WSP_ROOM)
898 	    needed += p_wh - wmh1;
899 	if (flags & (WSP_BOT | WSP_TOP))
900 	{
901 	    minheight = frame_minheight(topframe, NOWIN) + need_status;
902 	    available = topframe->fr_height;
903 	    needed += minheight;
904 	}
905 	else if (p_ea)
906 	{
907 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
908 	    prevfrp = oldwin->w_frame;
909 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
910 							frp = frp->fr_parent)
911 	    {
912 		if (frp->fr_layout == FR_COL)
913 		    for (frp2 = frp->fr_child; frp2 != NULL;
914 							frp2 = frp2->fr_next)
915 			if (frp2 != prevfrp)
916 			    minheight += frame_minheight(frp2, NOWIN);
917 		prevfrp = frp;
918 	    }
919 	    available = topframe->fr_height;
920 	    needed += minheight;
921 	}
922 	else
923 	{
924 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
925 	    available = oldwin->w_frame->fr_height;
926 	    needed += minheight;
927 	}
928 	if (available < needed && new_wp == NULL)
929 	{
930 	    EMSG(_(e_noroom));
931 	    return FAIL;
932 	}
933 	oldwin_height = oldwin->w_height;
934 	if (need_status)
935 	{
936 	    oldwin->w_status_height = STATUS_HEIGHT;
937 	    oldwin_height -= STATUS_HEIGHT;
938 	}
939 	if (new_size == 0)
940 	    new_size = oldwin_height / 2;
941 	if (new_size > available - minheight - STATUS_HEIGHT)
942 	    new_size = available - minheight - STATUS_HEIGHT;
943 	if (new_size < wmh1)
944 	    new_size = wmh1;
945 
946 	/* if it doesn't fit in the current window, need win_equal() */
947 	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
948 	    do_equal = TRUE;
949 
950 	/* We don't like to take lines for the new window from a
951 	 * 'winfixheight' window.  Take them from a window above or below
952 	 * instead, if possible. */
953 	if (oldwin->w_p_wfh)
954 	{
955 	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
956 								      oldwin);
957 	    oldwin_height = oldwin->w_height;
958 	    if (need_status)
959 		oldwin_height -= STATUS_HEIGHT;
960 	}
961 
962 	/* Only make all windows the same height if one of them (except oldwin)
963 	 * is higher than one of the split windows. */
964 	if (!do_equal && p_ea && size == 0 && *p_ead != 'h'
965 	   && oldwin->w_frame->fr_parent != NULL)
966 	{
967 	    frp = oldwin->w_frame->fr_parent->fr_child;
968 	    while (frp != NULL)
969 	    {
970 		if (frp->fr_win != oldwin && frp->fr_win != NULL
971 			&& (frp->fr_win->w_height > new_size
972 			    || frp->fr_win->w_height > oldwin_height - new_size
973 							      - STATUS_HEIGHT))
974 		{
975 		    do_equal = TRUE;
976 		    break;
977 		}
978 		frp = frp->fr_next;
979 	    }
980 	}
981     }
982 
983     /*
984      * allocate new window structure and link it in the window list
985      */
986     if ((flags & WSP_TOP) == 0
987 	    && ((flags & WSP_BOT)
988 		|| (flags & WSP_BELOW)
989 		|| (!(flags & WSP_ABOVE)
990 		    && ( (flags & WSP_VERT) ? p_spr : p_sb))))
991     {
992 	/* new window below/right of current one */
993 	if (new_wp == NULL)
994 	    wp = win_alloc(oldwin, FALSE);
995 	else
996 	    win_append(oldwin, wp);
997     }
998     else
999     {
1000 	if (new_wp == NULL)
1001 	    wp = win_alloc(oldwin->w_prev, FALSE);
1002 	else
1003 	    win_append(oldwin->w_prev, wp);
1004     }
1005 
1006     if (new_wp == NULL)
1007     {
1008 	if (wp == NULL)
1009 	    return FAIL;
1010 
1011 	new_frame(wp);
1012 	if (wp->w_frame == NULL)
1013 	{
1014 	    win_free(wp, NULL);
1015 	    return FAIL;
1016 	}
1017 
1018 	/* make the contents of the new window the same as the current one */
1019 	win_init(wp, curwin, flags);
1020     }
1021 
1022     /*
1023      * Reorganise the tree of frames to insert the new window.
1024      */
1025     if (flags & (WSP_TOP | WSP_BOT))
1026     {
1027 	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
1028 	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
1029 	{
1030 	    curfrp = topframe->fr_child;
1031 	    if (flags & WSP_BOT)
1032 		while (curfrp->fr_next != NULL)
1033 		    curfrp = curfrp->fr_next;
1034 	}
1035 	else
1036 	    curfrp = topframe;
1037 	before = (flags & WSP_TOP);
1038     }
1039     else
1040     {
1041 	curfrp = oldwin->w_frame;
1042 	if (flags & WSP_BELOW)
1043 	    before = FALSE;
1044 	else if (flags & WSP_ABOVE)
1045 	    before = TRUE;
1046 	else if (flags & WSP_VERT)
1047 	    before = !p_spr;
1048 	else
1049 	    before = !p_sb;
1050     }
1051     if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
1052     {
1053 	/* Need to create a new frame in the tree to make a branch. */
1054 	frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
1055 	*frp = *curfrp;
1056 	curfrp->fr_layout = layout;
1057 	frp->fr_parent = curfrp;
1058 	frp->fr_next = NULL;
1059 	frp->fr_prev = NULL;
1060 	curfrp->fr_child = frp;
1061 	curfrp->fr_win = NULL;
1062 	curfrp = frp;
1063 	if (frp->fr_win != NULL)
1064 	    oldwin->w_frame = frp;
1065 	else
1066 	    for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
1067 		frp->fr_parent = curfrp;
1068     }
1069 
1070     if (new_wp == NULL)
1071 	frp = wp->w_frame;
1072     else
1073 	frp = new_wp->w_frame;
1074     frp->fr_parent = curfrp->fr_parent;
1075 
1076     /* Insert the new frame at the right place in the frame list. */
1077     if (before)
1078 	frame_insert(curfrp, frp);
1079     else
1080 	frame_append(curfrp, frp);
1081 
1082     /* Set w_fraction now so that the cursor keeps the same relative
1083      * vertical position. */
1084     set_fraction(oldwin);
1085     wp->w_fraction = oldwin->w_fraction;
1086 
1087     if (flags & WSP_VERT)
1088     {
1089 	wp->w_p_scr = curwin->w_p_scr;
1090 
1091 	if (need_status)
1092 	{
1093 	    win_new_height(oldwin, oldwin->w_height - 1);
1094 	    oldwin->w_status_height = need_status;
1095 	}
1096 	if (flags & (WSP_TOP | WSP_BOT))
1097 	{
1098 	    /* set height and row of new window to full height */
1099 	    wp->w_winrow = tabline_height();
1100 	    win_new_height(wp, curfrp->fr_height - (p_ls > 0)
1101 							  - WINBAR_HEIGHT(wp));
1102 	    wp->w_status_height = (p_ls > 0);
1103 	}
1104 	else
1105 	{
1106 	    /* height and row of new window is same as current window */
1107 	    wp->w_winrow = oldwin->w_winrow;
1108 	    win_new_height(wp, VISIBLE_HEIGHT(oldwin));
1109 	    wp->w_status_height = oldwin->w_status_height;
1110 	}
1111 	frp->fr_height = curfrp->fr_height;
1112 
1113 	/* "new_size" of the current window goes to the new window, use
1114 	 * one column for the vertical separator */
1115 	win_new_width(wp, new_size);
1116 	if (before)
1117 	    wp->w_vsep_width = 1;
1118 	else
1119 	{
1120 	    wp->w_vsep_width = oldwin->w_vsep_width;
1121 	    oldwin->w_vsep_width = 1;
1122 	}
1123 	if (flags & (WSP_TOP | WSP_BOT))
1124 	{
1125 	    if (flags & WSP_BOT)
1126 		frame_add_vsep(curfrp);
1127 	    /* Set width of neighbor frame */
1128 	    frame_new_width(curfrp, curfrp->fr_width
1129 		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
1130 								       FALSE);
1131 	}
1132 	else
1133 	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
1134 	if (before)	/* new window left of current one */
1135 	{
1136 	    wp->w_wincol = oldwin->w_wincol;
1137 	    oldwin->w_wincol += new_size + 1;
1138 	}
1139 	else		/* new window right of current one */
1140 	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
1141 	frame_fix_width(oldwin);
1142 	frame_fix_width(wp);
1143     }
1144     else
1145     {
1146 	/* width and column of new window is same as current window */
1147 	if (flags & (WSP_TOP | WSP_BOT))
1148 	{
1149 	    wp->w_wincol = 0;
1150 	    win_new_width(wp, Columns);
1151 	    wp->w_vsep_width = 0;
1152 	}
1153 	else
1154 	{
1155 	    wp->w_wincol = oldwin->w_wincol;
1156 	    win_new_width(wp, oldwin->w_width);
1157 	    wp->w_vsep_width = oldwin->w_vsep_width;
1158 	}
1159 	frp->fr_width = curfrp->fr_width;
1160 
1161 	/* "new_size" of the current window goes to the new window, use
1162 	 * one row for the status line */
1163 	win_new_height(wp, new_size);
1164 	if (flags & (WSP_TOP | WSP_BOT))
1165 	{
1166 	    int new_fr_height = curfrp->fr_height - new_size
1167 							  + WINBAR_HEIGHT(wp) ;
1168 
1169 	    if (!((flags & WSP_BOT) && p_ls == 0))
1170 		new_fr_height -= STATUS_HEIGHT;
1171 	    frame_new_height(curfrp, new_fr_height, flags & WSP_TOP, FALSE);
1172 	}
1173 	else
1174 	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
1175 	if (before)	/* new window above current one */
1176 	{
1177 	    wp->w_winrow = oldwin->w_winrow;
1178 	    wp->w_status_height = STATUS_HEIGHT;
1179 	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
1180 	}
1181 	else		/* new window below current one */
1182 	{
1183 	    wp->w_winrow = oldwin->w_winrow + VISIBLE_HEIGHT(oldwin)
1184 							       + STATUS_HEIGHT;
1185 	    wp->w_status_height = oldwin->w_status_height;
1186 	    if (!(flags & WSP_BOT))
1187 		oldwin->w_status_height = STATUS_HEIGHT;
1188 	}
1189 	if (flags & WSP_BOT)
1190 	    frame_add_statusline(curfrp);
1191 	frame_fix_height(wp);
1192 	frame_fix_height(oldwin);
1193     }
1194 
1195     if (flags & (WSP_TOP | WSP_BOT))
1196 	(void)win_comp_pos();
1197 
1198     /*
1199      * Both windows need redrawing
1200      */
1201     redraw_win_later(wp, NOT_VALID);
1202     wp->w_redr_status = TRUE;
1203     redraw_win_later(oldwin, NOT_VALID);
1204     oldwin->w_redr_status = TRUE;
1205 
1206     if (need_status)
1207     {
1208 	msg_row = Rows - 1;
1209 	msg_col = sc_col;
1210 	msg_clr_eos_force();	/* Old command/ruler may still be there */
1211 	comp_col();
1212 	msg_row = Rows - 1;
1213 	msg_col = 0;	/* put position back at start of line */
1214     }
1215 
1216     /*
1217      * equalize the window sizes.
1218      */
1219     if (do_equal || dir != 0)
1220 	win_equal(wp, TRUE,
1221 		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
1222 		: dir == 'h' ? 'b' : 'v');
1223 
1224     /* Don't change the window height/width to 'winheight' / 'winwidth' if a
1225      * size was given. */
1226     if (flags & WSP_VERT)
1227     {
1228 	i = p_wiw;
1229 	if (size != 0)
1230 	    p_wiw = size;
1231 
1232 # ifdef FEAT_GUI
1233 	/* When 'guioptions' includes 'L' or 'R' may have to add scrollbars. */
1234 	if (gui.in_use)
1235 	    gui_init_which_components(NULL);
1236 # endif
1237     }
1238     else
1239     {
1240 	i = p_wh;
1241 	if (size != 0)
1242 	    p_wh = size;
1243     }
1244 
1245 #ifdef FEAT_JUMPLIST
1246     /* Keep same changelist position in new window. */
1247     wp->w_changelistidx = oldwin->w_changelistidx;
1248 #endif
1249 
1250     /*
1251      * make the new window the current window
1252      */
1253     win_enter_ext(wp, FALSE, FALSE, TRUE, TRUE, TRUE);
1254     if (flags & WSP_VERT)
1255 	p_wiw = i;
1256     else
1257 	p_wh = i;
1258 
1259     return OK;
1260 }
1261 
1262 
1263 /*
1264  * Initialize window "newp" from window "oldp".
1265  * Used when splitting a window and when creating a new tab page.
1266  * The windows will both edit the same buffer.
1267  * WSP_NEWLOC may be specified in flags to prevent the location list from
1268  * being copied.
1269  */
1270     static void
1271 win_init(win_T *newp, win_T *oldp, int flags UNUSED)
1272 {
1273     int		i;
1274 
1275     newp->w_buffer = oldp->w_buffer;
1276 #ifdef FEAT_SYN_HL
1277     newp->w_s = &(oldp->w_buffer->b_s);
1278 #endif
1279     oldp->w_buffer->b_nwindows++;
1280     newp->w_cursor = oldp->w_cursor;
1281     newp->w_valid = 0;
1282     newp->w_curswant = oldp->w_curswant;
1283     newp->w_set_curswant = oldp->w_set_curswant;
1284     newp->w_topline = oldp->w_topline;
1285 #ifdef FEAT_DIFF
1286     newp->w_topfill = oldp->w_topfill;
1287 #endif
1288     newp->w_leftcol = oldp->w_leftcol;
1289     newp->w_pcmark = oldp->w_pcmark;
1290     newp->w_prev_pcmark = oldp->w_prev_pcmark;
1291     newp->w_alt_fnum = oldp->w_alt_fnum;
1292     newp->w_wrow = oldp->w_wrow;
1293     newp->w_fraction = oldp->w_fraction;
1294     newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
1295 #ifdef FEAT_JUMPLIST
1296     copy_jumplist(oldp, newp);
1297 #endif
1298 #ifdef FEAT_QUICKFIX
1299     if (flags & WSP_NEWLOC)
1300     {
1301 	/* Don't copy the location list.  */
1302 	newp->w_llist = NULL;
1303 	newp->w_llist_ref = NULL;
1304     }
1305     else
1306 	copy_loclist(oldp, newp);
1307 #endif
1308     newp->w_localdir = (oldp->w_localdir == NULL)
1309 				    ? NULL : vim_strsave(oldp->w_localdir);
1310 
1311     /* copy tagstack and folds */
1312     for (i = 0; i < oldp->w_tagstacklen; i++)
1313     {
1314 	newp->w_tagstack[i] = oldp->w_tagstack[i];
1315 	if (newp->w_tagstack[i].tagname != NULL)
1316 	    newp->w_tagstack[i].tagname =
1317 				   vim_strsave(newp->w_tagstack[i].tagname);
1318     }
1319     newp->w_tagstackidx = oldp->w_tagstackidx;
1320     newp->w_tagstacklen = oldp->w_tagstacklen;
1321 #ifdef FEAT_FOLDING
1322     copyFoldingState(oldp, newp);
1323 #endif
1324 
1325     win_init_some(newp, oldp);
1326 
1327 #ifdef FEAT_SYN_HL
1328     check_colorcolumn(newp);
1329 #endif
1330 }
1331 
1332 /*
1333  * Initialize window "newp" from window "old".
1334  * Only the essential things are copied.
1335  */
1336     static void
1337 win_init_some(win_T *newp, win_T *oldp)
1338 {
1339     /* Use the same argument list. */
1340     newp->w_alist = oldp->w_alist;
1341     ++newp->w_alist->al_refcount;
1342     newp->w_arg_idx = oldp->w_arg_idx;
1343 
1344     /* copy options from existing window */
1345     win_copy_options(oldp, newp);
1346 }
1347 
1348 
1349 /*
1350  * Check if "win" is a pointer to an existing window in the current tab page.
1351  */
1352     int
1353 win_valid(win_T *win)
1354 {
1355     win_T	*wp;
1356 
1357     if (win == NULL)
1358 	return FALSE;
1359     FOR_ALL_WINDOWS(wp)
1360 	if (wp == win)
1361 	    return TRUE;
1362     return FALSE;
1363 }
1364 
1365 /*
1366  * Check if "win" is a pointer to an existing window in any tab page.
1367  */
1368     int
1369 win_valid_any_tab(win_T *win)
1370 {
1371     win_T	*wp;
1372     tabpage_T	*tp;
1373 
1374     if (win == NULL)
1375 	return FALSE;
1376     FOR_ALL_TABPAGES(tp)
1377     {
1378 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
1379 	{
1380 	    if (wp == win)
1381 		return TRUE;
1382 	}
1383     }
1384     return FALSE;
1385 }
1386 
1387 /*
1388  * Return the number of windows.
1389  */
1390     int
1391 win_count(void)
1392 {
1393     win_T	*wp;
1394     int		count = 0;
1395 
1396     FOR_ALL_WINDOWS(wp)
1397 	++count;
1398     return count;
1399 }
1400 
1401 /*
1402  * Make "count" windows on the screen.
1403  * Return actual number of windows on the screen.
1404  * Must be called when there is just one window, filling the whole screen
1405  * (excluding the command line).
1406  */
1407     int
1408 make_windows(
1409     int		count,
1410     int		vertical UNUSED)  /* split windows vertically if TRUE */
1411 {
1412     int		maxcount;
1413     int		todo;
1414 
1415     if (vertical)
1416     {
1417 	/* Each windows needs at least 'winminwidth' lines and a separator
1418 	 * column. */
1419 	maxcount = (curwin->w_width + curwin->w_vsep_width
1420 					     - (p_wiw - p_wmw)) / (p_wmw + 1);
1421     }
1422     else
1423     {
1424 	/* Each window needs at least 'winminheight' lines and a status line. */
1425 	maxcount = (VISIBLE_HEIGHT(curwin) + curwin->w_status_height
1426 				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
1427     }
1428 
1429     if (maxcount < 2)
1430 	maxcount = 2;
1431     if (count > maxcount)
1432 	count = maxcount;
1433 
1434     /*
1435      * add status line now, otherwise first window will be too big
1436      */
1437     if (count > 1)
1438 	last_status(TRUE);
1439 
1440     /*
1441      * Don't execute autocommands while creating the windows.  Must do that
1442      * when putting the buffers in the windows.
1443      */
1444     block_autocmds();
1445 
1446     /* todo is number of windows left to create */
1447     for (todo = count - 1; todo > 0; --todo)
1448 	if (vertical)
1449 	{
1450 	    if (win_split(curwin->w_width - (curwin->w_width - todo)
1451 			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
1452 		break;
1453 	}
1454 	else
1455 	{
1456 	    if (win_split(curwin->w_height - (curwin->w_height - todo
1457 			    * STATUS_HEIGHT) / (todo + 1)
1458 			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
1459 		break;
1460 	}
1461 
1462     unblock_autocmds();
1463 
1464     /* return actual number of windows */
1465     return (count - todo);
1466 }
1467 
1468 /*
1469  * Exchange current and next window
1470  */
1471     static void
1472 win_exchange(long Prenum)
1473 {
1474     frame_T	*frp;
1475     frame_T	*frp2;
1476     win_T	*wp;
1477     win_T	*wp2;
1478     int		temp;
1479 
1480     if (ONE_WINDOW)	    /* just one window */
1481     {
1482 	beep_flush();
1483 	return;
1484     }
1485 
1486 #ifdef FEAT_GUI
1487     need_mouse_correct = TRUE;
1488 #endif
1489 
1490     /*
1491      * find window to exchange with
1492      */
1493     if (Prenum)
1494     {
1495 	frp = curwin->w_frame->fr_parent->fr_child;
1496 	while (frp != NULL && --Prenum > 0)
1497 	    frp = frp->fr_next;
1498     }
1499     else if (curwin->w_frame->fr_next != NULL)	/* Swap with next */
1500 	frp = curwin->w_frame->fr_next;
1501     else    /* Swap last window in row/col with previous */
1502 	frp = curwin->w_frame->fr_prev;
1503 
1504     /* We can only exchange a window with another window, not with a frame
1505      * containing windows. */
1506     if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
1507 	return;
1508     wp = frp->fr_win;
1509 
1510 /*
1511  * 1. remove curwin from the list. Remember after which window it was in wp2
1512  * 2. insert curwin before wp in the list
1513  * if wp != wp2
1514  *    3. remove wp from the list
1515  *    4. insert wp after wp2
1516  * 5. exchange the status line height and vsep width.
1517  */
1518     wp2 = curwin->w_prev;
1519     frp2 = curwin->w_frame->fr_prev;
1520     if (wp->w_prev != curwin)
1521     {
1522 	win_remove(curwin, NULL);
1523 	frame_remove(curwin->w_frame);
1524 	win_append(wp->w_prev, curwin);
1525 	frame_insert(frp, curwin->w_frame);
1526     }
1527     if (wp != wp2)
1528     {
1529 	win_remove(wp, NULL);
1530 	frame_remove(wp->w_frame);
1531 	win_append(wp2, wp);
1532 	if (frp2 == NULL)
1533 	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
1534 	else
1535 	    frame_append(frp2, wp->w_frame);
1536     }
1537     temp = curwin->w_status_height;
1538     curwin->w_status_height = wp->w_status_height;
1539     wp->w_status_height = temp;
1540     temp = curwin->w_vsep_width;
1541     curwin->w_vsep_width = wp->w_vsep_width;
1542     wp->w_vsep_width = temp;
1543 
1544     /* If the windows are not in the same frame, exchange the sizes to avoid
1545      * messing up the window layout.  Otherwise fix the frame sizes. */
1546     if (curwin->w_frame->fr_parent != wp->w_frame->fr_parent)
1547     {
1548 	temp = curwin->w_height;
1549 	curwin->w_height = wp->w_height;
1550 	wp->w_height = temp;
1551 	temp = curwin->w_width;
1552 	curwin->w_width = wp->w_width;
1553 	wp->w_width = temp;
1554     }
1555     else
1556     {
1557 	frame_fix_height(curwin);
1558 	frame_fix_height(wp);
1559 	frame_fix_width(curwin);
1560 	frame_fix_width(wp);
1561     }
1562 
1563     (void)win_comp_pos();		/* recompute window positions */
1564 
1565     win_enter(wp, TRUE);
1566     redraw_later(CLEAR);
1567 }
1568 
1569 /*
1570  * rotate windows: if upwards TRUE the second window becomes the first one
1571  *		   if upwards FALSE the first window becomes the second one
1572  */
1573     static void
1574 win_rotate(int upwards, int count)
1575 {
1576     win_T	*wp1;
1577     win_T	*wp2;
1578     frame_T	*frp;
1579     int		n;
1580 
1581     if (ONE_WINDOW)		/* nothing to do */
1582     {
1583 	beep_flush();
1584 	return;
1585     }
1586 
1587 #ifdef FEAT_GUI
1588     need_mouse_correct = TRUE;
1589 #endif
1590 
1591     /* Check if all frames in this row/col have one window. */
1592     for (frp = curwin->w_frame->fr_parent->fr_child; frp != NULL;
1593 							   frp = frp->fr_next)
1594 	if (frp->fr_win == NULL)
1595 	{
1596 	    EMSG(_("E443: Cannot rotate when another window is split"));
1597 	    return;
1598 	}
1599 
1600     while (count--)
1601     {
1602 	if (upwards)		/* first window becomes last window */
1603 	{
1604 	    /* remove first window/frame from the list */
1605 	    frp = curwin->w_frame->fr_parent->fr_child;
1606 	    wp1 = frp->fr_win;
1607 	    win_remove(wp1, NULL);
1608 	    frame_remove(frp);
1609 
1610 	    /* find last frame and append removed window/frame after it */
1611 	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
1612 		;
1613 	    win_append(frp->fr_win, wp1);
1614 	    frame_append(frp, wp1->w_frame);
1615 
1616 	    wp2 = frp->fr_win;		/* previously last window */
1617 	}
1618 	else			/* last window becomes first window */
1619 	{
1620 	    /* find last window/frame in the list and remove it */
1621 	    for (frp = curwin->w_frame; frp->fr_next != NULL;
1622 							   frp = frp->fr_next)
1623 		;
1624 	    wp1 = frp->fr_win;
1625 	    wp2 = wp1->w_prev;		    /* will become last window */
1626 	    win_remove(wp1, NULL);
1627 	    frame_remove(frp);
1628 
1629 	    /* append the removed window/frame before the first in the list */
1630 	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
1631 	    frame_insert(frp->fr_parent->fr_child, frp);
1632 	}
1633 
1634 	/* exchange status height and vsep width of old and new last window */
1635 	n = wp2->w_status_height;
1636 	wp2->w_status_height = wp1->w_status_height;
1637 	wp1->w_status_height = n;
1638 	frame_fix_height(wp1);
1639 	frame_fix_height(wp2);
1640 	n = wp2->w_vsep_width;
1641 	wp2->w_vsep_width = wp1->w_vsep_width;
1642 	wp1->w_vsep_width = n;
1643 	frame_fix_width(wp1);
1644 	frame_fix_width(wp2);
1645 
1646 	/* recompute w_winrow and w_wincol for all windows */
1647 	(void)win_comp_pos();
1648     }
1649 
1650     redraw_later(CLEAR);
1651 }
1652 
1653 /*
1654  * Move the current window to the very top/bottom/left/right of the screen.
1655  */
1656     static void
1657 win_totop(int size, int flags)
1658 {
1659     int		dir;
1660     int		height = curwin->w_height;
1661 
1662     if (ONE_WINDOW)
1663     {
1664 	beep_flush();
1665 	return;
1666     }
1667 
1668     /* Remove the window and frame from the tree of frames. */
1669     (void)winframe_remove(curwin, &dir, NULL);
1670     win_remove(curwin, NULL);
1671     last_status(FALSE);	    /* may need to remove last status line */
1672     (void)win_comp_pos();   /* recompute window positions */
1673 
1674     /* Split a window on the desired side and put the window there. */
1675     (void)win_split_ins(size, flags, curwin, dir);
1676     if (!(flags & WSP_VERT))
1677     {
1678 	win_setheight(height);
1679 	if (p_ea)
1680 	    win_equal(curwin, TRUE, 'v');
1681     }
1682 
1683 #if defined(FEAT_GUI)
1684     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
1685      * scrollbars.  Have to update them anyway. */
1686     gui_may_update_scrollbars();
1687 #endif
1688 }
1689 
1690 /*
1691  * Move window "win1" to below/right of "win2" and make "win1" the current
1692  * window.  Only works within the same frame!
1693  */
1694     void
1695 win_move_after(win_T *win1, win_T *win2)
1696 {
1697     int		height;
1698 
1699     /* check if the arguments are reasonable */
1700     if (win1 == win2)
1701 	return;
1702 
1703     /* check if there is something to do */
1704     if (win2->w_next != win1)
1705     {
1706 	/* may need move the status line/vertical separator of the last window
1707 	 * */
1708 	if (win1 == lastwin)
1709 	{
1710 	    height = win1->w_prev->w_status_height;
1711 	    win1->w_prev->w_status_height = win1->w_status_height;
1712 	    win1->w_status_height = height;
1713 	    if (win1->w_prev->w_vsep_width == 1)
1714 	    {
1715 		/* Remove the vertical separator from the last-but-one window,
1716 		 * add it to the last window.  Adjust the frame widths. */
1717 		win1->w_prev->w_vsep_width = 0;
1718 		win1->w_prev->w_frame->fr_width -= 1;
1719 		win1->w_vsep_width = 1;
1720 		win1->w_frame->fr_width += 1;
1721 	    }
1722 	}
1723 	else if (win2 == lastwin)
1724 	{
1725 	    height = win1->w_status_height;
1726 	    win1->w_status_height = win2->w_status_height;
1727 	    win2->w_status_height = height;
1728 	    if (win1->w_vsep_width == 1)
1729 	    {
1730 		/* Remove the vertical separator from win1, add it to the last
1731 		 * window, win2.  Adjust the frame widths. */
1732 		win2->w_vsep_width = 1;
1733 		win2->w_frame->fr_width += 1;
1734 		win1->w_vsep_width = 0;
1735 		win1->w_frame->fr_width -= 1;
1736 	    }
1737 	}
1738 	win_remove(win1, NULL);
1739 	frame_remove(win1->w_frame);
1740 	win_append(win2, win1);
1741 	frame_append(win2->w_frame, win1->w_frame);
1742 
1743 	(void)win_comp_pos();	/* recompute w_winrow for all windows */
1744 	redraw_later(NOT_VALID);
1745     }
1746     win_enter(win1, FALSE);
1747 }
1748 
1749 /*
1750  * Make all windows the same height.
1751  * 'next_curwin' will soon be the current window, make sure it has enough
1752  * rows.
1753  */
1754     void
1755 win_equal(
1756     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1757     int		current,	/* do only frame with current window */
1758     int		dir)		/* 'v' for vertically, 'h' for horizontally,
1759 				   'b' for both, 0 for using p_ead */
1760 {
1761     if (dir == 0)
1762 	dir = *p_ead;
1763     win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
1764 		      topframe, dir, 0, tabline_height(),
1765 					   (int)Columns, topframe->fr_height);
1766 }
1767 
1768 /*
1769  * Set a frame to a new position and height, spreading the available room
1770  * equally over contained frames.
1771  * The window "next_curwin" (if not NULL) should at least get the size from
1772  * 'winheight' and 'winwidth' if possible.
1773  */
1774     static void
1775 win_equal_rec(
1776     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1777     int		current,	/* do only frame with current window */
1778     frame_T	*topfr,		/* frame to set size off */
1779     int		dir,		/* 'v', 'h' or 'b', see win_equal() */
1780     int		col,		/* horizontal position for frame */
1781     int		row,		/* vertical position for frame */
1782     int		width,		/* new width of frame */
1783     int		height)		/* new height of frame */
1784 {
1785     int		n, m;
1786     int		extra_sep = 0;
1787     int		wincount, totwincount = 0;
1788     frame_T	*fr;
1789     int		next_curwin_size = 0;
1790     int		room = 0;
1791     int		new_size;
1792     int		has_next_curwin = 0;
1793     int		hnc;
1794 
1795     if (topfr->fr_layout == FR_LEAF)
1796     {
1797 	/* Set the width/height of this frame.
1798 	 * Redraw when size or position changes */
1799 	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
1800 		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
1801 	   )
1802 	{
1803 	    topfr->fr_win->w_winrow = row;
1804 	    frame_new_height(topfr, height, FALSE, FALSE);
1805 	    topfr->fr_win->w_wincol = col;
1806 	    frame_new_width(topfr, width, FALSE, FALSE);
1807 	    redraw_all_later(CLEAR);
1808 	}
1809     }
1810     else if (topfr->fr_layout == FR_ROW)
1811     {
1812 	topfr->fr_width = width;
1813 	topfr->fr_height = height;
1814 
1815 	if (dir != 'v')			/* equalize frame widths */
1816 	{
1817 	    /* Compute the maximum number of windows horizontally in this
1818 	     * frame. */
1819 	    n = frame_minwidth(topfr, NOWIN);
1820 	    /* add one for the rightmost window, it doesn't have a separator */
1821 	    if (col + width == Columns)
1822 		extra_sep = 1;
1823 	    else
1824 		extra_sep = 0;
1825 	    totwincount = (n + extra_sep) / (p_wmw + 1);
1826 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1827 
1828 	    /*
1829 	     * Compute width for "next_curwin" window and room available for
1830 	     * other windows.
1831 	     * "m" is the minimal width when counting p_wiw for "next_curwin".
1832 	     */
1833 	    m = frame_minwidth(topfr, next_curwin);
1834 	    room = width - m;
1835 	    if (room < 0)
1836 	    {
1837 		next_curwin_size = p_wiw + room;
1838 		room = 0;
1839 	    }
1840 	    else
1841 	    {
1842 		next_curwin_size = -1;
1843 		for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
1844 		{
1845 		    /* If 'winfixwidth' set keep the window width if
1846 		     * possible.
1847 		     * Watch out for this window being the next_curwin. */
1848 		    if (frame_fixed_width(fr))
1849 		    {
1850 			n = frame_minwidth(fr, NOWIN);
1851 			new_size = fr->fr_width;
1852 			if (frame_has_win(fr, next_curwin))
1853 			{
1854 			    room += p_wiw - p_wmw;
1855 			    next_curwin_size = 0;
1856 			    if (new_size < p_wiw)
1857 				new_size = p_wiw;
1858 			}
1859 			else
1860 			    /* These windows don't use up room. */
1861 			    totwincount -= (n + (fr->fr_next == NULL
1862 					      ? extra_sep : 0)) / (p_wmw + 1);
1863 			room -= new_size - n;
1864 			if (room < 0)
1865 			{
1866 			    new_size += room;
1867 			    room = 0;
1868 			}
1869 			fr->fr_newwidth = new_size;
1870 		    }
1871 		}
1872 		if (next_curwin_size == -1)
1873 		{
1874 		    if (!has_next_curwin)
1875 			next_curwin_size = 0;
1876 		    else if (totwincount > 1
1877 			    && (room + (totwincount - 2))
1878 						  / (totwincount - 1) > p_wiw)
1879 		    {
1880 			/* Can make all windows wider than 'winwidth', spread
1881 			 * the room equally. */
1882 			next_curwin_size = (room + p_wiw
1883 					    + (totwincount - 1) * p_wmw
1884 					    + (totwincount - 1)) / totwincount;
1885 			room -= next_curwin_size - p_wiw;
1886 		    }
1887 		    else
1888 			next_curwin_size = p_wiw;
1889 		}
1890 	    }
1891 
1892 	    if (has_next_curwin)
1893 		--totwincount;		/* don't count curwin */
1894 	}
1895 
1896 	for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
1897 	{
1898 	    wincount = 1;
1899 	    if (fr->fr_next == NULL)
1900 		/* last frame gets all that remains (avoid roundoff error) */
1901 		new_size = width;
1902 	    else if (dir == 'v')
1903 		new_size = fr->fr_width;
1904 	    else if (frame_fixed_width(fr))
1905 	    {
1906 		new_size = fr->fr_newwidth;
1907 		wincount = 0;	    /* doesn't count as a sizeable window */
1908 	    }
1909 	    else
1910 	    {
1911 		/* Compute the maximum number of windows horiz. in "fr". */
1912 		n = frame_minwidth(fr, NOWIN);
1913 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
1914 								/ (p_wmw + 1);
1915 		m = frame_minwidth(fr, next_curwin);
1916 		if (has_next_curwin)
1917 		    hnc = frame_has_win(fr, next_curwin);
1918 		else
1919 		    hnc = FALSE;
1920 		if (hnc)	    /* don't count next_curwin */
1921 		    --wincount;
1922 		if (totwincount == 0)
1923 		    new_size = room;
1924 		else
1925 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
1926 								/ totwincount;
1927 		if (hnc)	    /* add next_curwin size */
1928 		{
1929 		    next_curwin_size -= p_wiw - (m - n);
1930 		    new_size += next_curwin_size;
1931 		    room -= new_size - next_curwin_size;
1932 		}
1933 		else
1934 		    room -= new_size;
1935 		new_size += n;
1936 	    }
1937 
1938 	    /* Skip frame that is full width when splitting or closing a
1939 	     * window, unless equalizing all frames. */
1940 	    if (!current || dir != 'v' || topfr->fr_parent != NULL
1941 		    || (new_size != fr->fr_width)
1942 		    || frame_has_win(fr, next_curwin))
1943 		win_equal_rec(next_curwin, current, fr, dir, col, row,
1944 							    new_size, height);
1945 	    col += new_size;
1946 	    width -= new_size;
1947 	    totwincount -= wincount;
1948 	}
1949     }
1950     else /* topfr->fr_layout == FR_COL */
1951     {
1952 	topfr->fr_width = width;
1953 	topfr->fr_height = height;
1954 
1955 	if (dir != 'h')			/* equalize frame heights */
1956 	{
1957 	    /* Compute maximum number of windows vertically in this frame. */
1958 	    n = frame_minheight(topfr, NOWIN);
1959 	    /* add one for the bottom window if it doesn't have a statusline */
1960 	    if (row + height == cmdline_row && p_ls == 0)
1961 		extra_sep = 1;
1962 	    else
1963 		extra_sep = 0;
1964 	    totwincount = (n + extra_sep) / (p_wmh + 1);
1965 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1966 
1967 	    /*
1968 	     * Compute height for "next_curwin" window and room available for
1969 	     * other windows.
1970 	     * "m" is the minimal height when counting p_wh for "next_curwin".
1971 	     */
1972 	    m = frame_minheight(topfr, next_curwin);
1973 	    room = height - m;
1974 	    if (room < 0)
1975 	    {
1976 		/* The room is less then 'winheight', use all space for the
1977 		 * current window. */
1978 		next_curwin_size = p_wh + room;
1979 		room = 0;
1980 	    }
1981 	    else
1982 	    {
1983 		next_curwin_size = -1;
1984 		for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
1985 		{
1986 		    /* If 'winfixheight' set keep the window height if
1987 		     * possible.
1988 		     * Watch out for this window being the next_curwin. */
1989 		    if (frame_fixed_height(fr))
1990 		    {
1991 			n = frame_minheight(fr, NOWIN);
1992 			new_size = fr->fr_height;
1993 			if (frame_has_win(fr, next_curwin))
1994 			{
1995 			    room += p_wh - p_wmh;
1996 			    next_curwin_size = 0;
1997 			    if (new_size < p_wh)
1998 				new_size = p_wh;
1999 			}
2000 			else
2001 			    /* These windows don't use up room. */
2002 			    totwincount -= (n + (fr->fr_next == NULL
2003 					      ? extra_sep : 0)) / (p_wmh + 1);
2004 			room -= new_size - n;
2005 			if (room < 0)
2006 			{
2007 			    new_size += room;
2008 			    room = 0;
2009 			}
2010 			fr->fr_newheight = new_size;
2011 		    }
2012 		}
2013 		if (next_curwin_size == -1)
2014 		{
2015 		    if (!has_next_curwin)
2016 			next_curwin_size = 0;
2017 		    else if (totwincount > 1
2018 			    && (room + (totwincount - 2))
2019 						   / (totwincount - 1) > p_wh)
2020 		    {
2021 			/* can make all windows higher than 'winheight',
2022 			 * spread the room equally. */
2023 			next_curwin_size = (room + p_wh
2024 					   + (totwincount - 1) * p_wmh
2025 					   + (totwincount - 1)) / totwincount;
2026 			room -= next_curwin_size - p_wh;
2027 		    }
2028 		    else
2029 			next_curwin_size = p_wh;
2030 		}
2031 	    }
2032 
2033 	    if (has_next_curwin)
2034 		--totwincount;		/* don't count curwin */
2035 	}
2036 
2037 	for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
2038 	{
2039 	    wincount = 1;
2040 	    if (fr->fr_next == NULL)
2041 		/* last frame gets all that remains (avoid roundoff error) */
2042 		new_size = height;
2043 	    else if (dir == 'h')
2044 		new_size = fr->fr_height;
2045 	    else if (frame_fixed_height(fr))
2046 	    {
2047 		new_size = fr->fr_newheight;
2048 		wincount = 0;	    /* doesn't count as a sizeable window */
2049 	    }
2050 	    else
2051 	    {
2052 		/* Compute the maximum number of windows vert. in "fr". */
2053 		n = frame_minheight(fr, NOWIN);
2054 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2055 								/ (p_wmh + 1);
2056 		m = frame_minheight(fr, next_curwin);
2057 		if (has_next_curwin)
2058 		    hnc = frame_has_win(fr, next_curwin);
2059 		else
2060 		    hnc = FALSE;
2061 		if (hnc)	    /* don't count next_curwin */
2062 		    --wincount;
2063 		if (totwincount == 0)
2064 		    new_size = room;
2065 		else
2066 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2067 								/ totwincount;
2068 		if (hnc)	    /* add next_curwin size */
2069 		{
2070 		    next_curwin_size -= p_wh - (m - n);
2071 		    new_size += next_curwin_size;
2072 		    room -= new_size - next_curwin_size;
2073 		}
2074 		else
2075 		    room -= new_size;
2076 		new_size += n;
2077 	    }
2078 	    /* Skip frame that is full width when splitting or closing a
2079 	     * window, unless equalizing all frames. */
2080 	    if (!current || dir != 'h' || topfr->fr_parent != NULL
2081 		    || (new_size != fr->fr_height)
2082 		    || frame_has_win(fr, next_curwin))
2083 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2084 							     width, new_size);
2085 	    row += new_size;
2086 	    height -= new_size;
2087 	    totwincount -= wincount;
2088 	}
2089     }
2090 }
2091 
2092 /*
2093  * Close all windows for buffer "buf".
2094  */
2095     void
2096 close_windows(
2097     buf_T	*buf,
2098     int		keep_curwin)	    /* don't close "curwin" */
2099 {
2100     win_T	*wp;
2101     tabpage_T   *tp, *nexttp;
2102     int		h = tabline_height();
2103     int		count = tabpage_index(NULL);
2104 
2105     ++RedrawingDisabled;
2106 
2107     for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
2108     {
2109 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
2110 		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
2111 	{
2112 	    if (win_close(wp, FALSE) == FAIL)
2113 		/* If closing the window fails give up, to avoid looping
2114 		 * forever. */
2115 		break;
2116 
2117 	    /* Start all over, autocommands may change the window layout. */
2118 	    wp = firstwin;
2119 	}
2120 	else
2121 	    wp = wp->w_next;
2122     }
2123 
2124     /* Also check windows in other tab pages. */
2125     for (tp = first_tabpage; tp != NULL; tp = nexttp)
2126     {
2127 	nexttp = tp->tp_next;
2128 	if (tp != curtab)
2129 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
2130 		if (wp->w_buffer == buf
2131 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
2132 		{
2133 		    win_close_othertab(wp, FALSE, tp);
2134 
2135 		    /* Start all over, the tab page may be closed and
2136 		     * autocommands may change the window layout. */
2137 		    nexttp = first_tabpage;
2138 		    break;
2139 		}
2140     }
2141 
2142     --RedrawingDisabled;
2143 
2144     if (count != tabpage_index(NULL))
2145 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2146 
2147     redraw_tabline = TRUE;
2148     if (h != tabline_height())
2149 	shell_new_rows();
2150 }
2151 
2152 /*
2153  * Return TRUE if the current window is the only window that exists (ignoring
2154  * "aucmd_win").
2155  * Returns FALSE if there is a window, possibly in another tab page.
2156  */
2157     static int
2158 last_window(void)
2159 {
2160     return (one_window() && first_tabpage->tp_next == NULL);
2161 }
2162 
2163 /*
2164  * Return TRUE if there is only one window other than "aucmd_win" in the
2165  * current tab page.
2166  */
2167     int
2168 one_window(void)
2169 {
2170     win_T	*wp;
2171     int		seen_one = FALSE;
2172 
2173     FOR_ALL_WINDOWS(wp)
2174     {
2175 	if (wp != aucmd_win)
2176 	{
2177 	    if (seen_one)
2178 		return FALSE;
2179 	    seen_one = TRUE;
2180 	}
2181     }
2182     return TRUE;
2183 }
2184 
2185 /*
2186  * Close the possibly last window in a tab page.
2187  * Returns TRUE when the window was closed already.
2188  */
2189     static int
2190 close_last_window_tabpage(
2191     win_T	*win,
2192     int		free_buf,
2193     tabpage_T   *prev_curtab)
2194 {
2195     if (ONE_WINDOW)
2196     {
2197 	buf_T	*old_curbuf = curbuf;
2198 
2199 	/*
2200 	 * Closing the last window in a tab page.  First go to another tab
2201 	 * page and then close the window and the tab page.  This avoids that
2202 	 * curwin and curtab are invalid while we are freeing memory, they may
2203 	 * be used in GUI events.
2204 	 * Don't trigger autocommands yet, they may use wrong values, so do
2205 	 * that below.
2206 	 */
2207 	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
2208 	redraw_tabline = TRUE;
2209 
2210 	/* Safety check: Autocommands may have closed the window when jumping
2211 	 * to the other tab page. */
2212 	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
2213 	{
2214 	    int	    h = tabline_height();
2215 
2216 	    win_close_othertab(win, free_buf, prev_curtab);
2217 	    if (h != tabline_height())
2218 		shell_new_rows();
2219 	}
2220 	/* Since goto_tabpage_tp above did not trigger *Enter autocommands, do
2221 	 * that now. */
2222 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2223 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
2224 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
2225 	if (old_curbuf != curbuf)
2226 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2227 	return TRUE;
2228     }
2229     return FALSE;
2230 }
2231 
2232 /*
2233  * Close window "win".  Only works for the current tab page.
2234  * If "free_buf" is TRUE related buffer may be unloaded.
2235  *
2236  * Called by :quit, :close, :xit, :wq and findtag().
2237  * Returns FAIL when the window was not closed.
2238  */
2239     int
2240 win_close(win_T *win, int free_buf)
2241 {
2242     win_T	*wp;
2243     int		other_buffer = FALSE;
2244     int		close_curwin = FALSE;
2245     int		dir;
2246     int		help_window = FALSE;
2247     tabpage_T   *prev_curtab = curtab;
2248     frame_T	*win_frame = win->w_frame->fr_parent;
2249 
2250     if (last_window())
2251     {
2252 	EMSG(_("E444: Cannot close last window"));
2253 	return FAIL;
2254     }
2255 
2256     if (win->w_closing || (win->w_buffer != NULL
2257 					       && win->w_buffer->b_locked > 0))
2258 	return FAIL; /* window is already being closed */
2259     if (win == aucmd_win)
2260     {
2261 	EMSG(_("E813: Cannot close autocmd window"));
2262 	return FAIL;
2263     }
2264     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
2265     {
2266 	EMSG(_("E814: Cannot close window, only autocmd window would remain"));
2267 	return FAIL;
2268     }
2269 
2270     /* When closing the last window in a tab page first go to another tab page
2271      * and then close the window and the tab page to avoid that curwin and
2272      * curtab are invalid while we are freeing memory. */
2273     if (close_last_window_tabpage(win, free_buf, prev_curtab))
2274       return FAIL;
2275 
2276     /* When closing the help window, try restoring a snapshot after closing
2277      * the window.  Otherwise clear the snapshot, it's now invalid. */
2278     if (bt_help(win->w_buffer))
2279 	help_window = TRUE;
2280     else
2281 	clear_snapshot(curtab, SNAP_HELP_IDX);
2282 
2283     if (win == curwin)
2284     {
2285 	/*
2286 	 * Guess which window is going to be the new current window.
2287 	 * This may change because of the autocommands (sigh).
2288 	 */
2289 	wp = frame2win(win_altframe(win, NULL));
2290 
2291 	/*
2292 	 * Be careful: If autocommands delete the window or cause this window
2293 	 * to be the last one left, return now.
2294 	 */
2295 	if (wp->w_buffer != curbuf)
2296 	{
2297 	    other_buffer = TRUE;
2298 	    win->w_closing = TRUE;
2299 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
2300 	    if (!win_valid(win))
2301 		return FAIL;
2302 	    win->w_closing = FALSE;
2303 	    if (last_window())
2304 		return FAIL;
2305 	}
2306 	win->w_closing = TRUE;
2307 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
2308 	if (!win_valid(win))
2309 	    return FAIL;
2310 	win->w_closing = FALSE;
2311 	if (last_window())
2312 	    return FAIL;
2313 #ifdef FEAT_EVAL
2314 	/* autocmds may abort script processing */
2315 	if (aborting())
2316 	    return FAIL;
2317 #endif
2318     }
2319 
2320 #ifdef FEAT_GUI
2321     /* Avoid trouble with scrollbars that are going to be deleted in
2322      * win_free(). */
2323     if (gui.in_use)
2324 	out_flush();
2325 #endif
2326 
2327 #ifdef FEAT_SYN_HL
2328     /* Free independent synblock before the buffer is freed. */
2329     if (win->w_buffer != NULL)
2330 	reset_synblock(win);
2331 #endif
2332 
2333     /*
2334      * Close the link to the buffer.
2335      */
2336     if (win->w_buffer != NULL)
2337     {
2338 	bufref_T    bufref;
2339 
2340 	set_bufref(&bufref, curbuf);
2341 	win->w_closing = TRUE;
2342 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, TRUE);
2343 	if (win_valid_any_tab(win))
2344 	    win->w_closing = FALSE;
2345 	/* Make sure curbuf is valid. It can become invalid if 'bufhidden' is
2346 	 * "wipe". */
2347 	if (!bufref_valid(&bufref))
2348 	    curbuf = firstbuf;
2349     }
2350 
2351     if (only_one_window() && win_valid(win) && win->w_buffer == NULL
2352 	    && (last_window() || curtab != prev_curtab
2353 		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
2354     {
2355 	/* Autocommands have closed all windows, quit now.  Restore
2356 	 * curwin->w_buffer, otherwise writing viminfo may fail. */
2357 	if (curwin->w_buffer == NULL)
2358 	    curwin->w_buffer = curbuf;
2359 	getout(0);
2360     }
2361 
2362     /* Autocommands may have moved to another tab page. */
2363     if (curtab != prev_curtab && win_valid_any_tab(win)
2364 						      && win->w_buffer == NULL)
2365     {
2366 	/* Need to close the window anyway, since the buffer is NULL. */
2367 	win_close_othertab(win, FALSE, prev_curtab);
2368 	return FAIL;
2369     }
2370 
2371     /* Autocommands may have closed the window already or closed the only
2372      * other window. */
2373     if (!win_valid(win) || last_window()
2374 	    || close_last_window_tabpage(win, free_buf, prev_curtab))
2375 	return FAIL;
2376 
2377     /* Free the memory used for the window and get the window that received
2378      * the screen space. */
2379     wp = win_free_mem(win, &dir, NULL);
2380 
2381     /* Make sure curwin isn't invalid.  It can cause severe trouble when
2382      * printing an error message.  For win_equal() curbuf needs to be valid
2383      * too. */
2384     if (win == curwin)
2385     {
2386 	curwin = wp;
2387 #ifdef FEAT_QUICKFIX
2388 	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
2389 	{
2390 	    /*
2391 	     * If the cursor goes to the preview or the quickfix window, try
2392 	     * finding another window to go to.
2393 	     */
2394 	    for (;;)
2395 	    {
2396 		if (wp->w_next == NULL)
2397 		    wp = firstwin;
2398 		else
2399 		    wp = wp->w_next;
2400 		if (wp == curwin)
2401 		    break;
2402 		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
2403 		{
2404 		    curwin = wp;
2405 		    break;
2406 		}
2407 	    }
2408 	}
2409 #endif
2410 	curbuf = curwin->w_buffer;
2411 	close_curwin = TRUE;
2412 
2413 	/* The cursor position may be invalid if the buffer changed after last
2414 	 * using the window. */
2415 	check_cursor();
2416     }
2417     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
2418 	/* If the frame of the closed window contains the new current window,
2419 	 * only resize that frame.  Otherwise resize all windows. */
2420 	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
2421     else
2422 	win_comp_pos();
2423     if (close_curwin)
2424     {
2425 	win_enter_ext(wp, FALSE, TRUE, FALSE, TRUE, TRUE);
2426 	if (other_buffer)
2427 	    /* careful: after this wp and win may be invalid! */
2428 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2429     }
2430 
2431     /*
2432      * If last window has a status line now and we don't want one,
2433      * remove the status line.
2434      */
2435     last_status(FALSE);
2436 
2437     /* After closing the help window, try restoring the window layout from
2438      * before it was opened. */
2439     if (help_window)
2440 	restore_snapshot(SNAP_HELP_IDX, close_curwin);
2441 
2442 #if defined(FEAT_GUI)
2443     /* When 'guioptions' includes 'L' or 'R' may have to remove scrollbars. */
2444     if (gui.in_use && !win_hasvertsplit())
2445 	gui_init_which_components(NULL);
2446 #endif
2447 
2448     redraw_all_later(NOT_VALID);
2449     return OK;
2450 }
2451 
2452 /*
2453  * Close window "win" in tab page "tp", which is not the current tab page.
2454  * This may be the last window in that tab page and result in closing the tab,
2455  * thus "tp" may become invalid!
2456  * Caller must check if buffer is hidden and whether the tabline needs to be
2457  * updated.
2458  */
2459     void
2460 win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
2461 {
2462     win_T	*wp;
2463     int		dir;
2464     tabpage_T   *ptp = NULL;
2465     int		free_tp = FALSE;
2466 
2467     /* Get here with win->w_buffer == NULL when win_close() detects the tab
2468      * page changed. */
2469     if (win->w_closing || (win->w_buffer != NULL
2470 					       && win->w_buffer->b_locked > 0))
2471 	return; /* window is already being closed */
2472 
2473     if (win->w_buffer != NULL)
2474 	/* Close the link to the buffer. */
2475 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, FALSE);
2476 
2477     /* Careful: Autocommands may have closed the tab page or made it the
2478      * current tab page.  */
2479     for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
2480 	;
2481     if (ptp == NULL || tp == curtab)
2482 	return;
2483 
2484     /* Autocommands may have closed the window already. */
2485     for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
2486 	;
2487     if (wp == NULL)
2488 	return;
2489 
2490     /* When closing the last window in a tab page remove the tab page. */
2491     if (tp->tp_firstwin == tp->tp_lastwin)
2492     {
2493 	if (tp == first_tabpage)
2494 	    first_tabpage = tp->tp_next;
2495 	else
2496 	{
2497 	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
2498 							   ptp = ptp->tp_next)
2499 		;
2500 	    if (ptp == NULL)
2501 	    {
2502 		internal_error("win_close_othertab()");
2503 		return;
2504 	    }
2505 	    ptp->tp_next = tp->tp_next;
2506 	}
2507 	free_tp = TRUE;
2508     }
2509 
2510     /* Free the memory used for the window. */
2511     win_free_mem(win, &dir, tp);
2512 
2513     if (free_tp)
2514 	free_tabpage(tp);
2515 }
2516 
2517 /*
2518  * Free the memory used for a window.
2519  * Returns a pointer to the window that got the freed up space.
2520  */
2521     static win_T *
2522 win_free_mem(
2523     win_T	*win,
2524     int		*dirp,		/* set to 'v' or 'h' for direction if 'ea' */
2525     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2526 {
2527     frame_T	*frp;
2528     win_T	*wp;
2529 
2530     /* Remove the window and its frame from the tree of frames. */
2531     frp = win->w_frame;
2532     wp = winframe_remove(win, dirp, tp);
2533     vim_free(frp);
2534     win_free(win, tp);
2535 
2536     /* When deleting the current window of another tab page select a new
2537      * current window. */
2538     if (tp != NULL && win == tp->tp_curwin)
2539 	tp->tp_curwin = wp;
2540 
2541     return wp;
2542 }
2543 
2544 #if defined(EXITFREE) || defined(PROTO)
2545     void
2546 win_free_all(void)
2547 {
2548     int		dummy;
2549 
2550     while (first_tabpage->tp_next != NULL)
2551 	tabpage_close(TRUE);
2552 
2553     if (aucmd_win != NULL)
2554     {
2555 	(void)win_free_mem(aucmd_win, &dummy, NULL);
2556 	aucmd_win = NULL;
2557     }
2558 
2559     while (firstwin != NULL)
2560 	(void)win_free_mem(firstwin, &dummy, NULL);
2561 
2562     /* No window should be used after this. Set curwin to NULL to crash
2563      * instead of using freed memory. */
2564     curwin = NULL;
2565 }
2566 #endif
2567 
2568 /*
2569  * Remove a window and its frame from the tree of frames.
2570  * Returns a pointer to the window that got the freed up space.
2571  */
2572     win_T *
2573 winframe_remove(
2574     win_T	*win,
2575     int		*dirp UNUSED,	/* set to 'v' or 'h' for direction if 'ea' */
2576     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2577 {
2578     frame_T	*frp, *frp2, *frp3;
2579     frame_T	*frp_close = win->w_frame;
2580     win_T	*wp;
2581 
2582     /*
2583      * If there is only one window there is nothing to remove.
2584      */
2585     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2586 	return NULL;
2587 
2588     /*
2589      * Remove the window from its frame.
2590      */
2591     frp2 = win_altframe(win, tp);
2592     wp = frame2win(frp2);
2593 
2594     /* Remove this frame from the list of frames. */
2595     frame_remove(frp_close);
2596 
2597     if (frp_close->fr_parent->fr_layout == FR_COL)
2598     {
2599 	/* When 'winfixheight' is set, try to find another frame in the column
2600 	 * (as close to the closed frame as possible) to distribute the height
2601 	 * to. */
2602 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
2603 	{
2604 	    frp = frp_close->fr_prev;
2605 	    frp3 = frp_close->fr_next;
2606 	    while (frp != NULL || frp3 != NULL)
2607 	    {
2608 		if (frp != NULL)
2609 		{
2610 		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfh)
2611 		    {
2612 			frp2 = frp;
2613 			wp = frp->fr_win;
2614 			break;
2615 		    }
2616 		    frp = frp->fr_prev;
2617 		}
2618 		if (frp3 != NULL)
2619 		{
2620 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
2621 		    {
2622 			frp2 = frp3;
2623 			wp = frp3->fr_win;
2624 			break;
2625 		    }
2626 		    frp3 = frp3->fr_next;
2627 		}
2628 	    }
2629 	}
2630 	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
2631 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2632 	*dirp = 'v';
2633     }
2634     else
2635     {
2636 	/* When 'winfixwidth' is set, try to find another frame in the column
2637 	 * (as close to the closed frame as possible) to distribute the width
2638 	 * to. */
2639 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
2640 	{
2641 	    frp = frp_close->fr_prev;
2642 	    frp3 = frp_close->fr_next;
2643 	    while (frp != NULL || frp3 != NULL)
2644 	    {
2645 		if (frp != NULL)
2646 		{
2647 		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfw)
2648 		    {
2649 			frp2 = frp;
2650 			wp = frp->fr_win;
2651 			break;
2652 		    }
2653 		    frp = frp->fr_prev;
2654 		}
2655 		if (frp3 != NULL)
2656 		{
2657 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
2658 		    {
2659 			frp2 = frp3;
2660 			wp = frp3->fr_win;
2661 			break;
2662 		    }
2663 		    frp3 = frp3->fr_next;
2664 		}
2665 	    }
2666 	}
2667 	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
2668 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2669 	*dirp = 'h';
2670     }
2671 
2672     /* If rows/columns go to a window below/right its positions need to be
2673      * updated.  Can only be done after the sizes have been updated. */
2674     if (frp2 == frp_close->fr_next)
2675     {
2676 	int row = win->w_winrow;
2677 	int col = win->w_wincol;
2678 
2679 	frame_comp_pos(frp2, &row, &col);
2680     }
2681 
2682     if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
2683     {
2684 	/* There is no other frame in this list, move its info to the parent
2685 	 * and remove it. */
2686 	frp2->fr_parent->fr_layout = frp2->fr_layout;
2687 	frp2->fr_parent->fr_child = frp2->fr_child;
2688 	for (frp = frp2->fr_child; frp != NULL; frp = frp->fr_next)
2689 	    frp->fr_parent = frp2->fr_parent;
2690 	frp2->fr_parent->fr_win = frp2->fr_win;
2691 	if (frp2->fr_win != NULL)
2692 	    frp2->fr_win->w_frame = frp2->fr_parent;
2693 	frp = frp2->fr_parent;
2694 	if (topframe->fr_child == frp2)
2695 	    topframe->fr_child = frp;
2696 	vim_free(frp2);
2697 
2698 	frp2 = frp->fr_parent;
2699 	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
2700 	{
2701 	    /* The frame above the parent has the same layout, have to merge
2702 	     * the frames into this list. */
2703 	    if (frp2->fr_child == frp)
2704 		frp2->fr_child = frp->fr_child;
2705 	    frp->fr_child->fr_prev = frp->fr_prev;
2706 	    if (frp->fr_prev != NULL)
2707 		frp->fr_prev->fr_next = frp->fr_child;
2708 	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
2709 	    {
2710 		frp3->fr_parent = frp2;
2711 		if (frp3->fr_next == NULL)
2712 		{
2713 		    frp3->fr_next = frp->fr_next;
2714 		    if (frp->fr_next != NULL)
2715 			frp->fr_next->fr_prev = frp3;
2716 		    break;
2717 		}
2718 	    }
2719 	    if (topframe->fr_child == frp)
2720 		topframe->fr_child = frp2;
2721 	    vim_free(frp);
2722 	}
2723     }
2724 
2725     return wp;
2726 }
2727 
2728 /*
2729  * Find out which frame is going to get the freed up space when "win" is
2730  * closed.
2731  * if 'splitbelow'/'splitleft' the space goes to the window above/left.
2732  * if 'nosplitbelow'/'nosplitleft' the space goes to the window below/right.
2733  * This makes opening a window and closing it immediately keep the same window
2734  * layout.
2735  */
2736     static frame_T *
2737 win_altframe(
2738     win_T	*win,
2739     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2740 {
2741     frame_T	*frp;
2742     int		b;
2743 
2744     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2745 	/* Last window in this tab page, will go to next tab page. */
2746 	return alt_tabpage()->tp_curwin->w_frame;
2747 
2748     frp = win->w_frame;
2749     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
2750 	b = p_spr;
2751     else
2752 	b = p_sb;
2753     if ((!b && frp->fr_next != NULL) || frp->fr_prev == NULL)
2754 	return frp->fr_next;
2755     return frp->fr_prev;
2756 }
2757 
2758 /*
2759  * Return the tabpage that will be used if the current one is closed.
2760  */
2761     static tabpage_T *
2762 alt_tabpage(void)
2763 {
2764     tabpage_T	*tp;
2765 
2766     /* Use the next tab page if possible. */
2767     if (curtab->tp_next != NULL)
2768 	return curtab->tp_next;
2769 
2770     /* Find the last but one tab page. */
2771     for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
2772 	;
2773     return tp;
2774 }
2775 
2776 /*
2777  * Find the left-upper window in frame "frp".
2778  */
2779     static win_T *
2780 frame2win(frame_T *frp)
2781 {
2782     while (frp->fr_win == NULL)
2783 	frp = frp->fr_child;
2784     return frp->fr_win;
2785 }
2786 
2787 /*
2788  * Return TRUE if frame "frp" contains window "wp".
2789  */
2790     static int
2791 frame_has_win(frame_T *frp, win_T *wp)
2792 {
2793     frame_T	*p;
2794 
2795     if (frp->fr_layout == FR_LEAF)
2796 	return frp->fr_win == wp;
2797 
2798     for (p = frp->fr_child; p != NULL; p = p->fr_next)
2799 	if (frame_has_win(p, wp))
2800 	    return TRUE;
2801     return FALSE;
2802 }
2803 
2804 /*
2805  * Set a new height for a frame.  Recursively sets the height for contained
2806  * frames and windows.  Caller must take care of positions.
2807  */
2808     static void
2809 frame_new_height(
2810     frame_T	*topfrp,
2811     int		height,
2812     int		topfirst,	/* resize topmost contained frame first */
2813     int		wfh)		/* obey 'winfixheight' when there is a choice;
2814 				   may cause the height not to be set */
2815 {
2816     frame_T	*frp;
2817     int		extra_lines;
2818     int		h;
2819 
2820     if (topfrp->fr_win != NULL)
2821     {
2822 	/* Simple case: just one window. */
2823 	win_new_height(topfrp->fr_win,
2824 				    height - topfrp->fr_win->w_status_height
2825 					      - WINBAR_HEIGHT(topfrp->fr_win));
2826     }
2827     else if (topfrp->fr_layout == FR_ROW)
2828     {
2829 	do
2830 	{
2831 	    /* All frames in this row get the same new height. */
2832 	    for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
2833 	    {
2834 		frame_new_height(frp, height, topfirst, wfh);
2835 		if (frp->fr_height > height)
2836 		{
2837 		    /* Could not fit the windows, make the whole row higher. */
2838 		    height = frp->fr_height;
2839 		    break;
2840 		}
2841 	    }
2842 	}
2843 	while (frp != NULL);
2844     }
2845     else    /* fr_layout == FR_COL */
2846     {
2847 	/* Complicated case: Resize a column of frames.  Resize the bottom
2848 	 * frame first, frames above that when needed. */
2849 
2850 	frp = topfrp->fr_child;
2851 	if (wfh)
2852 	    /* Advance past frames with one window with 'wfh' set. */
2853 	    while (frame_fixed_height(frp))
2854 	    {
2855 		frp = frp->fr_next;
2856 		if (frp == NULL)
2857 		    return;	    /* no frame without 'wfh', give up */
2858 	    }
2859 	if (!topfirst)
2860 	{
2861 	    /* Find the bottom frame of this column */
2862 	    while (frp->fr_next != NULL)
2863 		frp = frp->fr_next;
2864 	    if (wfh)
2865 		/* Advance back for frames with one window with 'wfh' set. */
2866 		while (frame_fixed_height(frp))
2867 		    frp = frp->fr_prev;
2868 	}
2869 
2870 	extra_lines = height - topfrp->fr_height;
2871 	if (extra_lines < 0)
2872 	{
2873 	    /* reduce height of contained frames, bottom or top frame first */
2874 	    while (frp != NULL)
2875 	    {
2876 		h = frame_minheight(frp, NULL);
2877 		if (frp->fr_height + extra_lines < h)
2878 		{
2879 		    extra_lines += frp->fr_height - h;
2880 		    frame_new_height(frp, h, topfirst, wfh);
2881 		}
2882 		else
2883 		{
2884 		    frame_new_height(frp, frp->fr_height + extra_lines,
2885 							       topfirst, wfh);
2886 		    break;
2887 		}
2888 		if (topfirst)
2889 		{
2890 		    do
2891 			frp = frp->fr_next;
2892 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2893 		}
2894 		else
2895 		{
2896 		    do
2897 			frp = frp->fr_prev;
2898 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2899 		}
2900 		/* Increase "height" if we could not reduce enough frames. */
2901 		if (frp == NULL)
2902 		    height -= extra_lines;
2903 	    }
2904 	}
2905 	else if (extra_lines > 0)
2906 	{
2907 	    /* increase height of bottom or top frame */
2908 	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
2909 	}
2910     }
2911     topfrp->fr_height = height;
2912 }
2913 
2914 /*
2915  * Return TRUE if height of frame "frp" should not be changed because of
2916  * the 'winfixheight' option.
2917  */
2918     static int
2919 frame_fixed_height(frame_T *frp)
2920 {
2921     /* frame with one window: fixed height if 'winfixheight' set. */
2922     if (frp->fr_win != NULL)
2923 	return frp->fr_win->w_p_wfh;
2924 
2925     if (frp->fr_layout == FR_ROW)
2926     {
2927 	/* The frame is fixed height if one of the frames in the row is fixed
2928 	 * height. */
2929 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
2930 	    if (frame_fixed_height(frp))
2931 		return TRUE;
2932 	return FALSE;
2933     }
2934 
2935     /* frp->fr_layout == FR_COL: The frame is fixed height if all of the
2936      * frames in the row are fixed height. */
2937     for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
2938 	if (!frame_fixed_height(frp))
2939 	    return FALSE;
2940     return TRUE;
2941 }
2942 
2943 /*
2944  * Return TRUE if width of frame "frp" should not be changed because of
2945  * the 'winfixwidth' option.
2946  */
2947     static int
2948 frame_fixed_width(frame_T *frp)
2949 {
2950     /* frame with one window: fixed width if 'winfixwidth' set. */
2951     if (frp->fr_win != NULL)
2952 	return frp->fr_win->w_p_wfw;
2953 
2954     if (frp->fr_layout == FR_COL)
2955     {
2956 	/* The frame is fixed width if one of the frames in the row is fixed
2957 	 * width. */
2958 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
2959 	    if (frame_fixed_width(frp))
2960 		return TRUE;
2961 	return FALSE;
2962     }
2963 
2964     /* frp->fr_layout == FR_ROW: The frame is fixed width if all of the
2965      * frames in the row are fixed width. */
2966     for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
2967 	if (!frame_fixed_width(frp))
2968 	    return FALSE;
2969     return TRUE;
2970 }
2971 
2972 /*
2973  * Add a status line to windows at the bottom of "frp".
2974  * Note: Does not check if there is room!
2975  */
2976     static void
2977 frame_add_statusline(frame_T *frp)
2978 {
2979     win_T	*wp;
2980 
2981     if (frp->fr_layout == FR_LEAF)
2982     {
2983 	wp = frp->fr_win;
2984 	if (wp->w_status_height == 0)
2985 	{
2986 	    if (wp->w_height > 0)	/* don't make it negative */
2987 		--wp->w_height;
2988 	    wp->w_status_height = STATUS_HEIGHT;
2989 	}
2990     }
2991     else if (frp->fr_layout == FR_ROW)
2992     {
2993 	/* Handle all the frames in the row. */
2994 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
2995 	    frame_add_statusline(frp);
2996     }
2997     else /* frp->fr_layout == FR_COL */
2998     {
2999 	/* Only need to handle the last frame in the column. */
3000 	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
3001 	    ;
3002 	frame_add_statusline(frp);
3003     }
3004 }
3005 
3006 /*
3007  * Set width of a frame.  Handles recursively going through contained frames.
3008  * May remove separator line for windows at the right side (for win_close()).
3009  */
3010     static void
3011 frame_new_width(
3012     frame_T	*topfrp,
3013     int		width,
3014     int		leftfirst,	/* resize leftmost contained frame first */
3015     int		wfw)		/* obey 'winfixwidth' when there is a choice;
3016 				   may cause the width not to be set */
3017 {
3018     frame_T	*frp;
3019     int		extra_cols;
3020     int		w;
3021     win_T	*wp;
3022 
3023     if (topfrp->fr_layout == FR_LEAF)
3024     {
3025 	/* Simple case: just one window. */
3026 	wp = topfrp->fr_win;
3027 	/* Find out if there are any windows right of this one. */
3028 	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
3029 	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
3030 		break;
3031 	if (frp->fr_parent == NULL)
3032 	    wp->w_vsep_width = 0;
3033 	win_new_width(wp, width - wp->w_vsep_width);
3034     }
3035     else if (topfrp->fr_layout == FR_COL)
3036     {
3037 	do
3038 	{
3039 	    /* All frames in this column get the same new width. */
3040 	    for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3041 	    {
3042 		frame_new_width(frp, width, leftfirst, wfw);
3043 		if (frp->fr_width > width)
3044 		{
3045 		    /* Could not fit the windows, make whole column wider. */
3046 		    width = frp->fr_width;
3047 		    break;
3048 		}
3049 	    }
3050 	} while (frp != NULL);
3051     }
3052     else    /* fr_layout == FR_ROW */
3053     {
3054 	/* Complicated case: Resize a row of frames.  Resize the rightmost
3055 	 * frame first, frames left of it when needed. */
3056 
3057 	frp = topfrp->fr_child;
3058 	if (wfw)
3059 	    /* Advance past frames with one window with 'wfw' set. */
3060 	    while (frame_fixed_width(frp))
3061 	    {
3062 		frp = frp->fr_next;
3063 		if (frp == NULL)
3064 		    return;	    /* no frame without 'wfw', give up */
3065 	    }
3066 	if (!leftfirst)
3067 	{
3068 	    /* Find the rightmost frame of this row */
3069 	    while (frp->fr_next != NULL)
3070 		frp = frp->fr_next;
3071 	    if (wfw)
3072 		/* Advance back for frames with one window with 'wfw' set. */
3073 		while (frame_fixed_width(frp))
3074 		    frp = frp->fr_prev;
3075 	}
3076 
3077 	extra_cols = width - topfrp->fr_width;
3078 	if (extra_cols < 0)
3079 	{
3080 	    /* reduce frame width, rightmost frame first */
3081 	    while (frp != NULL)
3082 	    {
3083 		w = frame_minwidth(frp, NULL);
3084 		if (frp->fr_width + extra_cols < w)
3085 		{
3086 		    extra_cols += frp->fr_width - w;
3087 		    frame_new_width(frp, w, leftfirst, wfw);
3088 		}
3089 		else
3090 		{
3091 		    frame_new_width(frp, frp->fr_width + extra_cols,
3092 							      leftfirst, wfw);
3093 		    break;
3094 		}
3095 		if (leftfirst)
3096 		{
3097 		    do
3098 			frp = frp->fr_next;
3099 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3100 		}
3101 		else
3102 		{
3103 		    do
3104 			frp = frp->fr_prev;
3105 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3106 		}
3107 		/* Increase "width" if we could not reduce enough frames. */
3108 		if (frp == NULL)
3109 		    width -= extra_cols;
3110 	    }
3111 	}
3112 	else if (extra_cols > 0)
3113 	{
3114 	    /* increase width of rightmost frame */
3115 	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
3116 	}
3117     }
3118     topfrp->fr_width = width;
3119 }
3120 
3121 /*
3122  * Add the vertical separator to windows at the right side of "frp".
3123  * Note: Does not check if there is room!
3124  */
3125     static void
3126 frame_add_vsep(frame_T *frp)
3127 {
3128     win_T	*wp;
3129 
3130     if (frp->fr_layout == FR_LEAF)
3131     {
3132 	wp = frp->fr_win;
3133 	if (wp->w_vsep_width == 0)
3134 	{
3135 	    if (wp->w_width > 0)	/* don't make it negative */
3136 		--wp->w_width;
3137 	    wp->w_vsep_width = 1;
3138 	}
3139     }
3140     else if (frp->fr_layout == FR_COL)
3141     {
3142 	/* Handle all the frames in the column. */
3143 	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
3144 	    frame_add_vsep(frp);
3145     }
3146     else /* frp->fr_layout == FR_ROW */
3147     {
3148 	/* Only need to handle the last frame in the row. */
3149 	frp = frp->fr_child;
3150 	while (frp->fr_next != NULL)
3151 	    frp = frp->fr_next;
3152 	frame_add_vsep(frp);
3153     }
3154 }
3155 
3156 /*
3157  * Set frame width from the window it contains.
3158  */
3159     static void
3160 frame_fix_width(win_T *wp)
3161 {
3162     wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
3163 }
3164 
3165 /*
3166  * Set frame height from the window it contains.
3167  */
3168     static void
3169 frame_fix_height(win_T *wp)
3170 {
3171     wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
3172 }
3173 
3174 /*
3175  * Compute the minimal height for frame "topfrp".
3176  * Uses the 'winminheight' option.
3177  * When "next_curwin" isn't NULL, use p_wh for this window.
3178  * When "next_curwin" is NOWIN, don't use at least one line for the current
3179  * window.
3180  */
3181     static int
3182 frame_minheight(frame_T *topfrp, win_T *next_curwin)
3183 {
3184     frame_T	*frp;
3185     int		m;
3186     int		n;
3187 
3188     if (topfrp->fr_win != NULL)
3189     {
3190 	if (topfrp->fr_win == next_curwin)
3191 	    m = p_wh + topfrp->fr_win->w_status_height;
3192 	else
3193 	{
3194 	    /* window: minimal height of the window plus status line */
3195 	    m = p_wmh + topfrp->fr_win->w_status_height;
3196 	    if (topfrp->fr_win == curwin && next_curwin == NULL)
3197 	    {
3198 		/* Current window is minimal one line high and WinBar is
3199 		 * visible. */
3200 		if (p_wmh == 0)
3201 		    ++m;
3202 		m += WINBAR_HEIGHT(curwin);
3203 	    }
3204 	}
3205     }
3206     else if (topfrp->fr_layout == FR_ROW)
3207     {
3208 	/* get the minimal height from each frame in this row */
3209 	m = 0;
3210 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3211 	{
3212 	    n = frame_minheight(frp, next_curwin);
3213 	    if (n > m)
3214 		m = n;
3215 	}
3216     }
3217     else
3218     {
3219 	/* Add up the minimal heights for all frames in this column. */
3220 	m = 0;
3221 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3222 	    m += frame_minheight(frp, next_curwin);
3223     }
3224 
3225     return m;
3226 }
3227 
3228 /*
3229  * Compute the minimal width for frame "topfrp".
3230  * When "next_curwin" isn't NULL, use p_wiw for this window.
3231  * When "next_curwin" is NOWIN, don't use at least one column for the current
3232  * window.
3233  */
3234     static int
3235 frame_minwidth(
3236     frame_T	*topfrp,
3237     win_T	*next_curwin)	/* use p_wh and p_wiw for next_curwin */
3238 {
3239     frame_T	*frp;
3240     int		m, n;
3241 
3242     if (topfrp->fr_win != NULL)
3243     {
3244 	if (topfrp->fr_win == next_curwin)
3245 	    m = p_wiw + topfrp->fr_win->w_vsep_width;
3246 	else
3247 	{
3248 	    /* window: minimal width of the window plus separator column */
3249 	    m = p_wmw + topfrp->fr_win->w_vsep_width;
3250 	    /* Current window is minimal one column wide */
3251 	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
3252 		++m;
3253 	}
3254     }
3255     else if (topfrp->fr_layout == FR_COL)
3256     {
3257 	/* get the minimal width from each frame in this column */
3258 	m = 0;
3259 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3260 	{
3261 	    n = frame_minwidth(frp, next_curwin);
3262 	    if (n > m)
3263 		m = n;
3264 	}
3265     }
3266     else
3267     {
3268 	/* Add up the minimal widths for all frames in this row. */
3269 	m = 0;
3270 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
3271 	    m += frame_minwidth(frp, next_curwin);
3272     }
3273 
3274     return m;
3275 }
3276 
3277 
3278 /*
3279  * Try to close all windows except current one.
3280  * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
3281  * used and the buffer was modified.
3282  *
3283  * Used by ":bdel" and ":only".
3284  */
3285     void
3286 close_others(
3287     int		message,
3288     int		forceit)	    /* always hide all other windows */
3289 {
3290     win_T	*wp;
3291     win_T	*nextwp;
3292     int		r;
3293 
3294     if (one_window())
3295     {
3296 	if (message && !autocmd_busy)
3297 	    MSG(_(m_onlyone));
3298 	return;
3299     }
3300 
3301     /* Be very careful here: autocommands may change the window layout. */
3302     for (wp = firstwin; win_valid(wp); wp = nextwp)
3303     {
3304 	nextwp = wp->w_next;
3305 	if (wp != curwin)		/* don't close current window */
3306 	{
3307 
3308 	    /* Check if it's allowed to abandon this window */
3309 	    r = can_abandon(wp->w_buffer, forceit);
3310 	    if (!win_valid(wp))		/* autocommands messed wp up */
3311 	    {
3312 		nextwp = firstwin;
3313 		continue;
3314 	    }
3315 	    if (!r)
3316 	    {
3317 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
3318 		if (message && (p_confirm || cmdmod.confirm) && p_write)
3319 		{
3320 		    dialog_changed(wp->w_buffer, FALSE);
3321 		    if (!win_valid(wp))		/* autocommands messed wp up */
3322 		    {
3323 			nextwp = firstwin;
3324 			continue;
3325 		    }
3326 		}
3327 		if (bufIsChanged(wp->w_buffer))
3328 #endif
3329 		    continue;
3330 	    }
3331 	    win_close(wp, !buf_hide(wp->w_buffer)
3332 					       && !bufIsChanged(wp->w_buffer));
3333 	}
3334     }
3335 
3336     if (message && !ONE_WINDOW)
3337 	EMSG(_("E445: Other window contains changes"));
3338 }
3339 
3340 /*
3341  * Init the current window "curwin".
3342  * Called when a new file is being edited.
3343  */
3344     void
3345 curwin_init(void)
3346 {
3347     win_init_empty(curwin);
3348 }
3349 
3350     void
3351 win_init_empty(win_T *wp)
3352 {
3353     redraw_win_later(wp, NOT_VALID);
3354     wp->w_lines_valid = 0;
3355     wp->w_cursor.lnum = 1;
3356     wp->w_curswant = wp->w_cursor.col = 0;
3357 #ifdef FEAT_VIRTUALEDIT
3358     wp->w_cursor.coladd = 0;
3359 #endif
3360     wp->w_pcmark.lnum = 1;	/* pcmark not cleared but set to line 1 */
3361     wp->w_pcmark.col = 0;
3362     wp->w_prev_pcmark.lnum = 0;
3363     wp->w_prev_pcmark.col = 0;
3364     wp->w_topline = 1;
3365 #ifdef FEAT_DIFF
3366     wp->w_topfill = 0;
3367 #endif
3368     wp->w_botline = 2;
3369 #ifdef FEAT_FKMAP
3370     if (wp->w_p_rl)
3371 	wp->w_farsi = W_CONV + W_R_L;
3372     else
3373 	wp->w_farsi = W_CONV;
3374 #endif
3375 #ifdef FEAT_SYN_HL
3376     wp->w_s = &wp->w_buffer->b_s;
3377 #endif
3378 }
3379 
3380 /*
3381  * Allocate the first window and put an empty buffer in it.
3382  * Called from main().
3383  * Return FAIL when something goes wrong (out of memory).
3384  */
3385     int
3386 win_alloc_first(void)
3387 {
3388     if (win_alloc_firstwin(NULL) == FAIL)
3389 	return FAIL;
3390 
3391     first_tabpage = alloc_tabpage();
3392     if (first_tabpage == NULL)
3393 	return FAIL;
3394     first_tabpage->tp_topframe = topframe;
3395     curtab = first_tabpage;
3396 
3397     return OK;
3398 }
3399 
3400 /*
3401  * Init "aucmd_win".  This can only be done after the first
3402  * window is fully initialized, thus it can't be in win_alloc_first().
3403  */
3404     void
3405 win_alloc_aucmd_win(void)
3406 {
3407     aucmd_win = win_alloc(NULL, TRUE);
3408     if (aucmd_win != NULL)
3409     {
3410 	win_init_some(aucmd_win, curwin);
3411 	RESET_BINDING(aucmd_win);
3412 	new_frame(aucmd_win);
3413     }
3414 }
3415 
3416 /*
3417  * Allocate the first window or the first window in a new tab page.
3418  * When "oldwin" is NULL create an empty buffer for it.
3419  * When "oldwin" is not NULL copy info from it to the new window.
3420  * Return FAIL when something goes wrong (out of memory).
3421  */
3422     static int
3423 win_alloc_firstwin(win_T *oldwin)
3424 {
3425     curwin = win_alloc(NULL, FALSE);
3426     if (oldwin == NULL)
3427     {
3428 	/* Very first window, need to create an empty buffer for it and
3429 	 * initialize from scratch. */
3430 	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
3431 	if (curwin == NULL || curbuf == NULL)
3432 	    return FAIL;
3433 	curwin->w_buffer = curbuf;
3434 #ifdef FEAT_SYN_HL
3435 	curwin->w_s = &(curbuf->b_s);
3436 #endif
3437 	curbuf->b_nwindows = 1;	/* there is one window */
3438 	curwin->w_alist = &global_alist;
3439 	curwin_init();		/* init current window */
3440     }
3441     else
3442     {
3443 	/* First window in new tab page, initialize it from "oldwin". */
3444 	win_init(curwin, oldwin, 0);
3445 
3446 	/* We don't want cursor- and scroll-binding in the first window. */
3447 	RESET_BINDING(curwin);
3448     }
3449 
3450     new_frame(curwin);
3451     if (curwin->w_frame == NULL)
3452 	return FAIL;
3453     topframe = curwin->w_frame;
3454     topframe->fr_width = Columns;
3455     topframe->fr_height = Rows - p_ch;
3456 
3457     return OK;
3458 }
3459 
3460 /*
3461  * Create a frame for window "wp".
3462  */
3463     static void
3464 new_frame(win_T *wp)
3465 {
3466     frame_T *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
3467 
3468     wp->w_frame = frp;
3469     if (frp != NULL)
3470     {
3471 	frp->fr_layout = FR_LEAF;
3472 	frp->fr_win = wp;
3473     }
3474 }
3475 
3476 /*
3477  * Initialize the window and frame size to the maximum.
3478  */
3479     void
3480 win_init_size(void)
3481 {
3482     firstwin->w_height = ROWS_AVAIL;
3483     topframe->fr_height = ROWS_AVAIL;
3484     firstwin->w_width = Columns;
3485     topframe->fr_width = Columns;
3486 }
3487 
3488 /*
3489  * Allocate a new tabpage_T and init the values.
3490  * Returns NULL when out of memory.
3491  */
3492     static tabpage_T *
3493 alloc_tabpage(void)
3494 {
3495     tabpage_T	*tp;
3496 # ifdef FEAT_GUI
3497     int		i;
3498 # endif
3499 
3500 
3501     tp = (tabpage_T *)alloc_clear((unsigned)sizeof(tabpage_T));
3502     if (tp == NULL)
3503 	return NULL;
3504 
3505 # ifdef FEAT_EVAL
3506     /* init t: variables */
3507     tp->tp_vars = dict_alloc();
3508     if (tp->tp_vars == NULL)
3509     {
3510 	vim_free(tp);
3511 	return NULL;
3512     }
3513     init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
3514 # endif
3515 
3516 # ifdef FEAT_GUI
3517     for (i = 0; i < 3; i++)
3518 	tp->tp_prev_which_scrollbars[i] = -1;
3519 # endif
3520 # ifdef FEAT_DIFF
3521     tp->tp_diff_invalid = TRUE;
3522 # endif
3523     tp->tp_ch_used = p_ch;
3524 
3525     return tp;
3526 }
3527 
3528     void
3529 free_tabpage(tabpage_T *tp)
3530 {
3531     int idx;
3532 
3533 # ifdef FEAT_DIFF
3534     diff_clear(tp);
3535 # endif
3536     for (idx = 0; idx < SNAP_COUNT; ++idx)
3537 	clear_snapshot(tp, idx);
3538 #ifdef FEAT_EVAL
3539     vars_clear(&tp->tp_vars->dv_hashtab);	/* free all t: variables */
3540     hash_init(&tp->tp_vars->dv_hashtab);
3541     unref_var_dict(tp->tp_vars);
3542 #endif
3543 
3544 #ifdef FEAT_PYTHON
3545     python_tabpage_free(tp);
3546 #endif
3547 
3548 #ifdef FEAT_PYTHON3
3549     python3_tabpage_free(tp);
3550 #endif
3551 
3552     vim_free(tp);
3553 }
3554 
3555 /*
3556  * Create a new Tab page with one window.
3557  * It will edit the current buffer, like after ":split".
3558  * When "after" is 0 put it just after the current Tab page.
3559  * Otherwise put it just before tab page "after".
3560  * Return FAIL or OK.
3561  */
3562     int
3563 win_new_tabpage(int after)
3564 {
3565     tabpage_T	*tp = curtab;
3566     tabpage_T	*newtp;
3567     int		n;
3568 
3569     newtp = alloc_tabpage();
3570     if (newtp == NULL)
3571 	return FAIL;
3572 
3573     /* Remember the current windows in this Tab page. */
3574     if (leave_tabpage(curbuf, TRUE) == FAIL)
3575     {
3576 	vim_free(newtp);
3577 	return FAIL;
3578     }
3579     curtab = newtp;
3580 
3581     /* Create a new empty window. */
3582     if (win_alloc_firstwin(tp->tp_curwin) == OK)
3583     {
3584 	/* Make the new Tab page the new topframe. */
3585 	if (after == 1)
3586 	{
3587 	    /* New tab page becomes the first one. */
3588 	    newtp->tp_next = first_tabpage;
3589 	    first_tabpage = newtp;
3590 	}
3591 	else
3592 	{
3593 	    if (after > 0)
3594 	    {
3595 		/* Put new tab page before tab page "after". */
3596 		n = 2;
3597 		for (tp = first_tabpage; tp->tp_next != NULL
3598 					       && n < after; tp = tp->tp_next)
3599 		    ++n;
3600 	    }
3601 	    newtp->tp_next = tp->tp_next;
3602 	    tp->tp_next = newtp;
3603 	}
3604 	win_init_size();
3605 	firstwin->w_winrow = tabline_height();
3606 	win_comp_scroll(curwin);
3607 
3608 	newtp->tp_topframe = topframe;
3609 	last_status(FALSE);
3610 
3611 #if defined(FEAT_GUI)
3612 	/* When 'guioptions' includes 'L' or 'R' may have to remove or add
3613 	 * scrollbars.  Have to update them anyway. */
3614 	gui_may_update_scrollbars();
3615 #endif
3616 
3617 	redraw_all_later(CLEAR);
3618 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
3619 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
3620 	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
3621 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3622 	return OK;
3623     }
3624 
3625     /* Failed, get back the previous Tab page */
3626     enter_tabpage(curtab, curbuf, TRUE, TRUE);
3627     return FAIL;
3628 }
3629 
3630 /*
3631  * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
3632  * like with ":split".
3633  * Returns OK if a new tab page was created, FAIL otherwise.
3634  */
3635     int
3636 may_open_tabpage(void)
3637 {
3638     int		n = (cmdmod.tab == 0) ? postponed_split_tab : cmdmod.tab;
3639 
3640     if (n != 0)
3641     {
3642 	cmdmod.tab = 0;	    /* reset it to avoid doing it twice */
3643 	postponed_split_tab = 0;
3644 	return win_new_tabpage(n);
3645     }
3646     return FAIL;
3647 }
3648 
3649 /*
3650  * Create up to "maxcount" tabpages with empty windows.
3651  * Returns the number of resulting tab pages.
3652  */
3653     int
3654 make_tabpages(int maxcount)
3655 {
3656     int		count = maxcount;
3657     int		todo;
3658 
3659     /* Limit to 'tabpagemax' tabs. */
3660     if (count > p_tpm)
3661 	count = p_tpm;
3662 
3663     /*
3664      * Don't execute autocommands while creating the tab pages.  Must do that
3665      * when putting the buffers in the windows.
3666      */
3667     block_autocmds();
3668 
3669     for (todo = count - 1; todo > 0; --todo)
3670 	if (win_new_tabpage(0) == FAIL)
3671 	    break;
3672 
3673     unblock_autocmds();
3674 
3675     /* return actual number of tab pages */
3676     return (count - todo);
3677 }
3678 
3679 /*
3680  * Return TRUE when "tpc" points to a valid tab page.
3681  */
3682     int
3683 valid_tabpage(tabpage_T *tpc)
3684 {
3685     tabpage_T	*tp;
3686 
3687     FOR_ALL_TABPAGES(tp)
3688 	if (tp == tpc)
3689 	    return TRUE;
3690     return FALSE;
3691 }
3692 
3693 /*
3694  * Return TRUE when "tpc" points to a valid tab page and at least one window is
3695  * valid.
3696  */
3697     int
3698 valid_tabpage_win(tabpage_T *tpc)
3699 {
3700     tabpage_T	*tp;
3701     win_T	*wp;
3702 
3703     FOR_ALL_TABPAGES(tp)
3704     {
3705 	if (tp == tpc)
3706 	{
3707 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
3708 	    {
3709 		if (win_valid_any_tab(wp))
3710 		    return TRUE;
3711 	    }
3712 	    return FALSE;
3713 	}
3714     }
3715     /* shouldn't happen */
3716     return FALSE;
3717 }
3718 
3719 /*
3720  * Close tabpage "tab", assuming it has no windows in it.
3721  * There must be another tabpage or this will crash.
3722  */
3723     void
3724 close_tabpage(tabpage_T *tab)
3725 {
3726     tabpage_T	*ptp;
3727 
3728     if (tab == first_tabpage)
3729     {
3730 	first_tabpage = tab->tp_next;
3731 	ptp = first_tabpage;
3732     }
3733     else
3734     {
3735 	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
3736 							    ptp = ptp->tp_next)
3737 	    ;
3738 	assert(ptp != NULL);
3739 	ptp->tp_next = tab->tp_next;
3740     }
3741 
3742     goto_tabpage_tp(ptp, FALSE, FALSE);
3743     free_tabpage(tab);
3744 }
3745 
3746 /*
3747  * Find tab page "n" (first one is 1).  Returns NULL when not found.
3748  */
3749     tabpage_T *
3750 find_tabpage(int n)
3751 {
3752     tabpage_T	*tp;
3753     int		i = 1;
3754 
3755     for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
3756 	++i;
3757     return tp;
3758 }
3759 
3760 /*
3761  * Get index of tab page "tp".  First one has index 1.
3762  * When not found returns number of tab pages plus one.
3763  */
3764     int
3765 tabpage_index(tabpage_T *ftp)
3766 {
3767     int		i = 1;
3768     tabpage_T	*tp;
3769 
3770     for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
3771 	++i;
3772     return i;
3773 }
3774 
3775 /*
3776  * Prepare for leaving the current tab page.
3777  * When autocommands change "curtab" we don't leave the tab page and return
3778  * FAIL.
3779  * Careful: When OK is returned need to get a new tab page very very soon!
3780  */
3781     static int
3782 leave_tabpage(
3783     buf_T	*new_curbuf UNUSED,    /* what is going to be the new curbuf,
3784 				       NULL if unknown */
3785     int		trigger_leave_autocmds UNUSED)
3786 {
3787     tabpage_T	*tp = curtab;
3788 
3789     reset_VIsual_and_resel();	/* stop Visual mode */
3790     if (trigger_leave_autocmds)
3791     {
3792 	if (new_curbuf != curbuf)
3793 	{
3794 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
3795 	    if (curtab != tp)
3796 		return FAIL;
3797 	}
3798 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
3799 	if (curtab != tp)
3800 	    return FAIL;
3801 	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
3802 	if (curtab != tp)
3803 	    return FAIL;
3804     }
3805 #if defined(FEAT_GUI)
3806     /* Remove the scrollbars.  They may be added back later. */
3807     if (gui.in_use)
3808 	gui_remove_scrollbars();
3809 #endif
3810     tp->tp_curwin = curwin;
3811     tp->tp_prevwin = prevwin;
3812     tp->tp_firstwin = firstwin;
3813     tp->tp_lastwin = lastwin;
3814     tp->tp_old_Rows = Rows;
3815     tp->tp_old_Columns = Columns;
3816     firstwin = NULL;
3817     lastwin = NULL;
3818     return OK;
3819 }
3820 
3821 /*
3822  * Start using tab page "tp".
3823  * Only to be used after leave_tabpage() or freeing the current tab page.
3824  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
3825  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
3826  */
3827     static void
3828 enter_tabpage(
3829     tabpage_T	*tp,
3830     buf_T	*old_curbuf UNUSED,
3831     int		trigger_enter_autocmds,
3832     int		trigger_leave_autocmds)
3833 {
3834     int		old_off = tp->tp_firstwin->w_winrow;
3835     win_T	*next_prevwin = tp->tp_prevwin;
3836 
3837     curtab = tp;
3838     firstwin = tp->tp_firstwin;
3839     lastwin = tp->tp_lastwin;
3840     topframe = tp->tp_topframe;
3841 
3842     /* We would like doing the TabEnter event first, but we don't have a
3843      * valid current window yet, which may break some commands.
3844      * This triggers autocommands, thus may make "tp" invalid. */
3845     win_enter_ext(tp->tp_curwin, FALSE, TRUE, FALSE,
3846 			      trigger_enter_autocmds, trigger_leave_autocmds);
3847     prevwin = next_prevwin;
3848 
3849     last_status(FALSE);		/* status line may appear or disappear */
3850     (void)win_comp_pos();	/* recompute w_winrow for all windows */
3851     must_redraw = CLEAR;	/* need to redraw everything */
3852 #ifdef FEAT_DIFF
3853     diff_need_scrollbind = TRUE;
3854 #endif
3855 
3856     /* The tabpage line may have appeared or disappeared, may need to resize
3857      * the frames for that.  When the Vim window was resized need to update
3858      * frame sizes too.  Use the stored value of p_ch, so that it can be
3859      * different for each tab page. */
3860     p_ch = curtab->tp_ch_used;
3861     if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
3862 #ifdef FEAT_GUI_TABLINE
3863 			    && !gui_use_tabline()
3864 #endif
3865 		))
3866 	shell_new_rows();
3867     if (curtab->tp_old_Columns != Columns && starting == 0)
3868 	shell_new_columns();	/* update window widths */
3869 
3870 #if defined(FEAT_GUI)
3871     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
3872      * scrollbars.  Have to update them anyway. */
3873     gui_may_update_scrollbars();
3874 #endif
3875 
3876     /* Apply autocommands after updating the display, when 'rows' and
3877      * 'columns' have been set correctly. */
3878     if (trigger_enter_autocmds)
3879     {
3880 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3881 	if (old_curbuf != curbuf)
3882 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
3883     }
3884 
3885     redraw_all_later(CLEAR);
3886 }
3887 
3888 /*
3889  * Go to tab page "n".  For ":tab N" and "Ngt".
3890  * When "n" is 9999 go to the last tab page.
3891  */
3892     void
3893 goto_tabpage(int n)
3894 {
3895     tabpage_T	*tp;
3896     tabpage_T	*ttp;
3897     int		i;
3898 
3899     if (text_locked())
3900     {
3901 	/* Not allowed when editing the command line. */
3902 	text_locked_msg();
3903 	return;
3904     }
3905 
3906     /* If there is only one it can't work. */
3907     if (first_tabpage->tp_next == NULL)
3908     {
3909 	if (n > 1)
3910 	    beep_flush();
3911 	return;
3912     }
3913 
3914     if (n == 0)
3915     {
3916 	/* No count, go to next tab page, wrap around end. */
3917 	if (curtab->tp_next == NULL)
3918 	    tp = first_tabpage;
3919 	else
3920 	    tp = curtab->tp_next;
3921     }
3922     else if (n < 0)
3923     {
3924 	/* "gT": go to previous tab page, wrap around end.  "N gT" repeats
3925 	 * this N times. */
3926 	ttp = curtab;
3927 	for (i = n; i < 0; ++i)
3928 	{
3929 	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
3930 		    tp = tp->tp_next)
3931 		;
3932 	    ttp = tp;
3933 	}
3934     }
3935     else if (n == 9999)
3936     {
3937 	/* Go to last tab page. */
3938 	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
3939 	    ;
3940     }
3941     else
3942     {
3943 	/* Go to tab page "n". */
3944 	tp = find_tabpage(n);
3945 	if (tp == NULL)
3946 	{
3947 	    beep_flush();
3948 	    return;
3949 	}
3950     }
3951 
3952     goto_tabpage_tp(tp, TRUE, TRUE);
3953 
3954 #ifdef FEAT_GUI_TABLINE
3955     if (gui_use_tabline())
3956 	gui_mch_set_curtab(tabpage_index(curtab));
3957 #endif
3958 }
3959 
3960 /*
3961  * Go to tabpage "tp".
3962  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
3963  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
3964  * Note: doesn't update the GUI tab.
3965  */
3966     void
3967 goto_tabpage_tp(
3968     tabpage_T	*tp,
3969     int		trigger_enter_autocmds,
3970     int		trigger_leave_autocmds)
3971 {
3972     /* Don't repeat a message in another tab page. */
3973     set_keep_msg(NULL, 0);
3974 
3975     if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
3976 					trigger_leave_autocmds) == OK)
3977     {
3978 	if (valid_tabpage(tp))
3979 	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
3980 		    trigger_leave_autocmds);
3981 	else
3982 	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
3983 		    trigger_leave_autocmds);
3984     }
3985 }
3986 
3987 /*
3988  * Enter window "wp" in tab page "tp".
3989  * Also updates the GUI tab.
3990  */
3991     void
3992 goto_tabpage_win(tabpage_T *tp, win_T *wp)
3993 {
3994     goto_tabpage_tp(tp, TRUE, TRUE);
3995     if (curtab == tp && win_valid(wp))
3996     {
3997 	win_enter(wp, TRUE);
3998 # ifdef FEAT_GUI_TABLINE
3999 	if (gui_use_tabline())
4000 	    gui_mch_set_curtab(tabpage_index(curtab));
4001 # endif
4002     }
4003 }
4004 
4005 /*
4006  * Move the current tab page to after tab page "nr".
4007  */
4008     void
4009 tabpage_move(int nr)
4010 {
4011     int		n = 1;
4012     tabpage_T	*tp, *tp_dst;
4013 
4014     if (first_tabpage->tp_next == NULL)
4015 	return;
4016 
4017     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
4018 	++n;
4019 
4020     if (tp == curtab || (nr > 0 && tp->tp_next != NULL
4021 						    && tp->tp_next == curtab))
4022 	return;
4023 
4024     tp_dst = tp;
4025 
4026     /* Remove the current tab page from the list of tab pages. */
4027     if (curtab == first_tabpage)
4028 	first_tabpage = curtab->tp_next;
4029     else
4030     {
4031 	FOR_ALL_TABPAGES(tp)
4032 	    if (tp->tp_next == curtab)
4033 		break;
4034 	if (tp == NULL)	/* "cannot happen" */
4035 	    return;
4036 	tp->tp_next = curtab->tp_next;
4037     }
4038 
4039     /* Re-insert it at the specified position. */
4040     if (nr <= 0)
4041     {
4042 	curtab->tp_next = first_tabpage;
4043 	first_tabpage = curtab;
4044     }
4045     else
4046     {
4047 	curtab->tp_next = tp_dst->tp_next;
4048 	tp_dst->tp_next = curtab;
4049     }
4050 
4051     /* Need to redraw the tabline.  Tab page contents doesn't change. */
4052     redraw_tabline = TRUE;
4053 }
4054 
4055 
4056 /*
4057  * Go to another window.
4058  * When jumping to another buffer, stop Visual mode.  Do this before
4059  * changing windows so we can yank the selection into the '*' register.
4060  * When jumping to another window on the same buffer, adjust its cursor
4061  * position to keep the same Visual area.
4062  */
4063     void
4064 win_goto(win_T *wp)
4065 {
4066 #ifdef FEAT_CONCEAL
4067     win_T	*owp = curwin;
4068 #endif
4069 
4070     if (text_locked())
4071     {
4072 	beep_flush();
4073 	text_locked_msg();
4074 	return;
4075     }
4076     if (curbuf_locked())
4077 	return;
4078 
4079     if (wp->w_buffer != curbuf)
4080 	reset_VIsual_and_resel();
4081     else if (VIsual_active)
4082 	wp->w_cursor = curwin->w_cursor;
4083 
4084 #ifdef FEAT_GUI
4085     need_mouse_correct = TRUE;
4086 #endif
4087     win_enter(wp, TRUE);
4088 
4089 #ifdef FEAT_CONCEAL
4090     /* Conceal cursor line in previous window, unconceal in current window. */
4091     if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
4092 	update_single_line(owp, owp->w_cursor.lnum);
4093     if (curwin->w_p_cole > 0 && !msg_scrolled)
4094 	need_cursor_line_redraw = TRUE;
4095 #endif
4096 }
4097 
4098 #if defined(FEAT_PERL) || defined(PROTO)
4099 /*
4100  * Find window number "winnr" (counting top to bottom).
4101  */
4102     win_T *
4103 win_find_nr(int winnr)
4104 {
4105     win_T	*wp;
4106 
4107     FOR_ALL_WINDOWS(wp)
4108 	if (--winnr == 0)
4109 	    break;
4110     return wp;
4111 }
4112 #endif
4113 
4114 #if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
4115 /*
4116  * Find the tabpage for window "win".
4117  */
4118     tabpage_T *
4119 win_find_tabpage(win_T *win)
4120 {
4121     win_T	*wp;
4122     tabpage_T	*tp;
4123 
4124     FOR_ALL_TAB_WINDOWS(tp, wp)
4125 	    if (wp == win)
4126 		return tp;
4127     return NULL;
4128 }
4129 #endif
4130 
4131 /*
4132  * Move to window above or below "count" times.
4133  */
4134     static void
4135 win_goto_ver(
4136     int		up,		/* TRUE to go to win above */
4137     long	count)
4138 {
4139     frame_T	*fr;
4140     frame_T	*nfr;
4141     frame_T	*foundfr;
4142 
4143     foundfr = curwin->w_frame;
4144     while (count--)
4145     {
4146 	/*
4147 	 * First go upwards in the tree of frames until we find a upwards or
4148 	 * downwards neighbor.
4149 	 */
4150 	fr = foundfr;
4151 	for (;;)
4152 	{
4153 	    if (fr == topframe)
4154 		goto end;
4155 	    if (up)
4156 		nfr = fr->fr_prev;
4157 	    else
4158 		nfr = fr->fr_next;
4159 	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
4160 		break;
4161 	    fr = fr->fr_parent;
4162 	}
4163 
4164 	/*
4165 	 * Now go downwards to find the bottom or top frame in it.
4166 	 */
4167 	for (;;)
4168 	{
4169 	    if (nfr->fr_layout == FR_LEAF)
4170 	    {
4171 		foundfr = nfr;
4172 		break;
4173 	    }
4174 	    fr = nfr->fr_child;
4175 	    if (nfr->fr_layout == FR_ROW)
4176 	    {
4177 		/* Find the frame at the cursor row. */
4178 		while (fr->fr_next != NULL
4179 			&& frame2win(fr)->w_wincol + fr->fr_width
4180 					 <= curwin->w_wincol + curwin->w_wcol)
4181 		    fr = fr->fr_next;
4182 	    }
4183 	    if (nfr->fr_layout == FR_COL && up)
4184 		while (fr->fr_next != NULL)
4185 		    fr = fr->fr_next;
4186 	    nfr = fr;
4187 	}
4188     }
4189 end:
4190     if (foundfr != NULL)
4191 	win_goto(foundfr->fr_win);
4192 }
4193 
4194 /*
4195  * Move to left or right window.
4196  */
4197     static void
4198 win_goto_hor(
4199     int		left,		/* TRUE to go to left win */
4200     long	count)
4201 {
4202     frame_T	*fr;
4203     frame_T	*nfr;
4204     frame_T	*foundfr;
4205 
4206     foundfr = curwin->w_frame;
4207     while (count--)
4208     {
4209 	/*
4210 	 * First go upwards in the tree of frames until we find a left or
4211 	 * right neighbor.
4212 	 */
4213 	fr = foundfr;
4214 	for (;;)
4215 	{
4216 	    if (fr == topframe)
4217 		goto end;
4218 	    if (left)
4219 		nfr = fr->fr_prev;
4220 	    else
4221 		nfr = fr->fr_next;
4222 	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
4223 		break;
4224 	    fr = fr->fr_parent;
4225 	}
4226 
4227 	/*
4228 	 * Now go downwards to find the leftmost or rightmost frame in it.
4229 	 */
4230 	for (;;)
4231 	{
4232 	    if (nfr->fr_layout == FR_LEAF)
4233 	    {
4234 		foundfr = nfr;
4235 		break;
4236 	    }
4237 	    fr = nfr->fr_child;
4238 	    if (nfr->fr_layout == FR_COL)
4239 	    {
4240 		/* Find the frame at the cursor row. */
4241 		while (fr->fr_next != NULL
4242 			&& frame2win(fr)->w_winrow + fr->fr_height
4243 					 <= curwin->w_winrow + curwin->w_wrow)
4244 		    fr = fr->fr_next;
4245 	    }
4246 	    if (nfr->fr_layout == FR_ROW && left)
4247 		while (fr->fr_next != NULL)
4248 		    fr = fr->fr_next;
4249 	    nfr = fr;
4250 	}
4251     }
4252 end:
4253     if (foundfr != NULL)
4254 	win_goto(foundfr->fr_win);
4255 }
4256 
4257 /*
4258  * Make window "wp" the current window.
4259  */
4260     void
4261 win_enter(win_T *wp, int undo_sync)
4262 {
4263     win_enter_ext(wp, undo_sync, FALSE, FALSE, TRUE, TRUE);
4264 }
4265 
4266 /*
4267  * Make window wp the current window.
4268  * Can be called with "curwin_invalid" TRUE, which means that curwin has just
4269  * been closed and isn't valid.
4270  */
4271     static void
4272 win_enter_ext(
4273     win_T	*wp,
4274     int		undo_sync,
4275     int		curwin_invalid,
4276     int		trigger_new_autocmds UNUSED,
4277     int		trigger_enter_autocmds UNUSED,
4278     int		trigger_leave_autocmds UNUSED)
4279 {
4280     int		other_buffer = FALSE;
4281 
4282     if (wp == curwin && !curwin_invalid)	/* nothing to do */
4283 	return;
4284 
4285     if (!curwin_invalid && trigger_leave_autocmds)
4286     {
4287 	/*
4288 	 * Be careful: If autocommands delete the window, return now.
4289 	 */
4290 	if (wp->w_buffer != curbuf)
4291 	{
4292 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4293 	    other_buffer = TRUE;
4294 	    if (!win_valid(wp))
4295 		return;
4296 	}
4297 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4298 	if (!win_valid(wp))
4299 	    return;
4300 #ifdef FEAT_EVAL
4301 	/* autocmds may abort script processing */
4302 	if (aborting())
4303 	    return;
4304 #endif
4305     }
4306 
4307     /* sync undo before leaving the current buffer */
4308     if (undo_sync && curbuf != wp->w_buffer)
4309 	u_sync(FALSE);
4310 
4311     /* Might need to scroll the old window before switching, e.g., when the
4312      * cursor was moved. */
4313     update_topline();
4314 
4315     /* may have to copy the buffer options when 'cpo' contains 'S' */
4316     if (wp->w_buffer != curbuf)
4317 	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
4318     if (!curwin_invalid)
4319     {
4320 	prevwin = curwin;	/* remember for CTRL-W p */
4321 	curwin->w_redr_status = TRUE;
4322     }
4323     curwin = wp;
4324     curbuf = wp->w_buffer;
4325     check_cursor();
4326 #ifdef FEAT_VIRTUALEDIT
4327     if (!virtual_active())
4328 	curwin->w_cursor.coladd = 0;
4329 #endif
4330     changed_line_abv_curs();	/* assume cursor position needs updating */
4331 
4332     if (curwin->w_localdir != NULL)
4333     {
4334 	/* Window has a local directory: Save current directory as global
4335 	 * directory (unless that was done already) and change to the local
4336 	 * directory. */
4337 	if (globaldir == NULL)
4338 	{
4339 	    char_u	cwd[MAXPATHL];
4340 
4341 	    if (mch_dirname(cwd, MAXPATHL) == OK)
4342 		globaldir = vim_strsave(cwd);
4343 	}
4344 	if (mch_chdir((char *)curwin->w_localdir) == 0)
4345 	    shorten_fnames(TRUE);
4346     }
4347     else if (globaldir != NULL)
4348     {
4349 	/* Window doesn't have a local directory and we are not in the global
4350 	 * directory: Change to the global directory. */
4351 	ignored = mch_chdir((char *)globaldir);
4352 	VIM_CLEAR(globaldir);
4353 	shorten_fnames(TRUE);
4354     }
4355 
4356     if (trigger_new_autocmds)
4357 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
4358     if (trigger_enter_autocmds)
4359     {
4360 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
4361 	if (other_buffer)
4362 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4363     }
4364 
4365 #ifdef FEAT_TITLE
4366     maketitle();
4367 #endif
4368     curwin->w_redr_status = TRUE;
4369     redraw_tabline = TRUE;
4370     if (restart_edit)
4371 	redraw_later(VALID);	/* causes status line redraw */
4372 
4373     /* set window height to desired minimal value */
4374     if (curwin->w_height < p_wh && !curwin->w_p_wfh)
4375 	win_setheight((int)p_wh);
4376     else if (curwin->w_height == 0)
4377 	win_setheight(1);
4378 
4379     /* set window width to desired minimal value */
4380     if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
4381 	win_setwidth((int)p_wiw);
4382 
4383 #ifdef FEAT_MOUSE
4384     setmouse();			/* in case jumped to/from help buffer */
4385 #endif
4386 
4387     /* Change directories when the 'acd' option is set. */
4388     DO_AUTOCHDIR
4389 }
4390 
4391 
4392 /*
4393  * Jump to the first open window that contains buffer "buf", if one exists.
4394  * Returns a pointer to the window found, otherwise NULL.
4395  */
4396     win_T *
4397 buf_jump_open_win(buf_T *buf)
4398 {
4399     win_T	*wp = NULL;
4400 
4401     if (curwin->w_buffer == buf)
4402 	wp = curwin;
4403     else
4404 	FOR_ALL_WINDOWS(wp)
4405 	    if (wp->w_buffer == buf)
4406 		break;
4407     if (wp != NULL)
4408 	win_enter(wp, FALSE);
4409     return wp;
4410 }
4411 
4412 /*
4413  * Jump to the first open window in any tab page that contains buffer "buf",
4414  * if one exists.
4415  * Returns a pointer to the window found, otherwise NULL.
4416  */
4417     win_T *
4418 buf_jump_open_tab(buf_T *buf)
4419 {
4420     win_T	*wp = buf_jump_open_win(buf);
4421     tabpage_T	*tp;
4422 
4423     if (wp != NULL)
4424 	return wp;
4425 
4426     FOR_ALL_TABPAGES(tp)
4427 	if (tp != curtab)
4428 	{
4429 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
4430 		if (wp->w_buffer == buf)
4431 		    break;
4432 	    if (wp != NULL)
4433 	    {
4434 		goto_tabpage_win(tp, wp);
4435 		if (curwin != wp)
4436 		    wp = NULL;	/* something went wrong */
4437 		break;
4438 	    }
4439 	}
4440     return wp;
4441 }
4442 
4443 static int last_win_id = LOWEST_WIN_ID - 1;
4444 
4445 /*
4446  * Allocate a window structure and link it in the window list when "hidden" is
4447  * FALSE.
4448  */
4449     static win_T *
4450 win_alloc(win_T *after UNUSED, int hidden UNUSED)
4451 {
4452     win_T	*new_wp;
4453 
4454     /*
4455      * allocate window structure and linesizes arrays
4456      */
4457     new_wp = (win_T *)alloc_clear((unsigned)sizeof(win_T));
4458     if (new_wp == NULL)
4459 	return NULL;
4460 
4461     if (win_alloc_lines(new_wp) == FAIL)
4462     {
4463 	vim_free(new_wp);
4464 	return NULL;
4465     }
4466 
4467     new_wp->w_id = ++last_win_id;
4468 
4469 #ifdef FEAT_EVAL
4470     /* init w: variables */
4471     new_wp->w_vars = dict_alloc();
4472     if (new_wp->w_vars == NULL)
4473     {
4474 	win_free_lsize(new_wp);
4475 	vim_free(new_wp);
4476 	return NULL;
4477     }
4478     init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
4479 #endif
4480 
4481     /* Don't execute autocommands while the window is not properly
4482      * initialized yet.  gui_create_scrollbar() may trigger a FocusGained
4483      * event. */
4484     block_autocmds();
4485 
4486     /*
4487      * link the window in the window list
4488      */
4489     if (!hidden)
4490 	win_append(after, new_wp);
4491     new_wp->w_wincol = 0;
4492     new_wp->w_width = Columns;
4493 
4494     /* position the display and the cursor at the top of the file. */
4495     new_wp->w_topline = 1;
4496 #ifdef FEAT_DIFF
4497     new_wp->w_topfill = 0;
4498 #endif
4499     new_wp->w_botline = 2;
4500     new_wp->w_cursor.lnum = 1;
4501     new_wp->w_scbind_pos = 1;
4502 
4503     /* We won't calculate w_fraction until resizing the window */
4504     new_wp->w_fraction = 0;
4505     new_wp->w_prev_fraction_row = -1;
4506 
4507 #ifdef FEAT_GUI
4508     if (gui.in_use)
4509     {
4510 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
4511 		SBAR_LEFT, new_wp);
4512 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
4513 		SBAR_RIGHT, new_wp);
4514     }
4515 #endif
4516 #ifdef FEAT_FOLDING
4517     foldInitWin(new_wp);
4518 #endif
4519     unblock_autocmds();
4520 #ifdef FEAT_SEARCH_EXTRA
4521     new_wp->w_match_head = NULL;
4522     new_wp->w_next_match_id = 4;
4523 #endif
4524     return new_wp;
4525 }
4526 
4527 /*
4528  * Remove window 'wp' from the window list and free the structure.
4529  */
4530     static void
4531 win_free(
4532     win_T	*wp,
4533     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4534 {
4535     int		i;
4536     buf_T	*buf;
4537     wininfo_T	*wip;
4538 
4539 #ifdef FEAT_FOLDING
4540     clearFolding(wp);
4541 #endif
4542 
4543     /* reduce the reference count to the argument list. */
4544     alist_unlink(wp->w_alist);
4545 
4546     /* Don't execute autocommands while the window is halfway being deleted.
4547      * gui_mch_destroy_scrollbar() may trigger a FocusGained event. */
4548     block_autocmds();
4549 
4550 #ifdef FEAT_LUA
4551     lua_window_free(wp);
4552 #endif
4553 
4554 #ifdef FEAT_MZSCHEME
4555     mzscheme_window_free(wp);
4556 #endif
4557 
4558 #ifdef FEAT_PERL
4559     perl_win_free(wp);
4560 #endif
4561 
4562 #ifdef FEAT_PYTHON
4563     python_window_free(wp);
4564 #endif
4565 
4566 #ifdef FEAT_PYTHON3
4567     python3_window_free(wp);
4568 #endif
4569 
4570 #ifdef FEAT_TCL
4571     tcl_window_free(wp);
4572 #endif
4573 
4574 #ifdef FEAT_RUBY
4575     ruby_window_free(wp);
4576 #endif
4577 
4578     clear_winopt(&wp->w_onebuf_opt);
4579     clear_winopt(&wp->w_allbuf_opt);
4580 
4581 #ifdef FEAT_EVAL
4582     vars_clear(&wp->w_vars->dv_hashtab);	/* free all w: variables */
4583     hash_init(&wp->w_vars->dv_hashtab);
4584     unref_var_dict(wp->w_vars);
4585 #endif
4586 
4587     {
4588 	tabpage_T	*ttp;
4589 
4590 	if (prevwin == wp)
4591 	    prevwin = NULL;
4592 	FOR_ALL_TABPAGES(ttp)
4593 	    if (ttp->tp_prevwin == wp)
4594 		ttp->tp_prevwin = NULL;
4595     }
4596     win_free_lsize(wp);
4597 
4598     for (i = 0; i < wp->w_tagstacklen; ++i)
4599 	vim_free(wp->w_tagstack[i].tagname);
4600 
4601     vim_free(wp->w_localdir);
4602 
4603     /* Remove the window from the b_wininfo lists, it may happen that the
4604      * freed memory is re-used for another window. */
4605     FOR_ALL_BUFFERS(buf)
4606 	for (wip = buf->b_wininfo; wip != NULL; wip = wip->wi_next)
4607 	    if (wip->wi_win == wp)
4608 		wip->wi_win = NULL;
4609 
4610 #ifdef FEAT_SEARCH_EXTRA
4611     clear_matches(wp);
4612 #endif
4613 
4614 #ifdef FEAT_JUMPLIST
4615     free_jumplist(wp);
4616 #endif
4617 
4618 #ifdef FEAT_QUICKFIX
4619     qf_free_all(wp);
4620 #endif
4621 
4622 #ifdef FEAT_GUI
4623     if (gui.in_use)
4624     {
4625 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
4626 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
4627     }
4628 #endif /* FEAT_GUI */
4629 
4630 #ifdef FEAT_MENU
4631     remove_winbar(wp);
4632 #endif
4633 
4634 #ifdef FEAT_SYN_HL
4635     vim_free(wp->w_p_cc_cols);
4636 #endif
4637 
4638     if (wp != aucmd_win)
4639 	win_remove(wp, tp);
4640     if (autocmd_busy)
4641     {
4642 	wp->w_next = au_pending_free_win;
4643 	au_pending_free_win = wp;
4644     }
4645     else
4646 	vim_free(wp);
4647 
4648     unblock_autocmds();
4649 }
4650 
4651 /*
4652  * Append window "wp" in the window list after window "after".
4653  */
4654     void
4655 win_append(win_T *after, win_T *wp)
4656 {
4657     win_T	*before;
4658 
4659     if (after == NULL)	    /* after NULL is in front of the first */
4660 	before = firstwin;
4661     else
4662 	before = after->w_next;
4663 
4664     wp->w_next = before;
4665     wp->w_prev = after;
4666     if (after == NULL)
4667 	firstwin = wp;
4668     else
4669 	after->w_next = wp;
4670     if (before == NULL)
4671 	lastwin = wp;
4672     else
4673 	before->w_prev = wp;
4674 }
4675 
4676 /*
4677  * Remove a window from the window list.
4678  */
4679     void
4680 win_remove(
4681     win_T	*wp,
4682     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4683 {
4684     if (wp->w_prev != NULL)
4685 	wp->w_prev->w_next = wp->w_next;
4686     else if (tp == NULL)
4687 	firstwin = curtab->tp_firstwin = wp->w_next;
4688     else
4689 	tp->tp_firstwin = wp->w_next;
4690 
4691     if (wp->w_next != NULL)
4692 	wp->w_next->w_prev = wp->w_prev;
4693     else if (tp == NULL)
4694 	lastwin = curtab->tp_lastwin = wp->w_prev;
4695     else
4696 	tp->tp_lastwin = wp->w_prev;
4697 }
4698 
4699 /*
4700  * Append frame "frp" in a frame list after frame "after".
4701  */
4702     static void
4703 frame_append(frame_T *after, frame_T *frp)
4704 {
4705     frp->fr_next = after->fr_next;
4706     after->fr_next = frp;
4707     if (frp->fr_next != NULL)
4708 	frp->fr_next->fr_prev = frp;
4709     frp->fr_prev = after;
4710 }
4711 
4712 /*
4713  * Insert frame "frp" in a frame list before frame "before".
4714  */
4715     static void
4716 frame_insert(frame_T *before, frame_T *frp)
4717 {
4718     frp->fr_next = before;
4719     frp->fr_prev = before->fr_prev;
4720     before->fr_prev = frp;
4721     if (frp->fr_prev != NULL)
4722 	frp->fr_prev->fr_next = frp;
4723     else
4724 	frp->fr_parent->fr_child = frp;
4725 }
4726 
4727 /*
4728  * Remove a frame from a frame list.
4729  */
4730     static void
4731 frame_remove(frame_T *frp)
4732 {
4733     if (frp->fr_prev != NULL)
4734 	frp->fr_prev->fr_next = frp->fr_next;
4735     else
4736     {
4737 	frp->fr_parent->fr_child = frp->fr_next;
4738 	/* special case: topframe->fr_child == frp */
4739 	if (topframe->fr_child == frp)
4740 	    topframe->fr_child = frp->fr_next;
4741     }
4742     if (frp->fr_next != NULL)
4743 	frp->fr_next->fr_prev = frp->fr_prev;
4744 }
4745 
4746 /*
4747  * Allocate w_lines[] for window "wp".
4748  * Return FAIL for failure, OK for success.
4749  */
4750     int
4751 win_alloc_lines(win_T *wp)
4752 {
4753     wp->w_lines_valid = 0;
4754     wp->w_lines = (wline_T *)alloc_clear((unsigned)(Rows * sizeof(wline_T)));
4755     if (wp->w_lines == NULL)
4756 	return FAIL;
4757     return OK;
4758 }
4759 
4760 /*
4761  * free lsize arrays for a window
4762  */
4763     void
4764 win_free_lsize(win_T *wp)
4765 {
4766     /* TODO: why would wp be NULL here? */
4767     if (wp != NULL)
4768 	VIM_CLEAR(wp->w_lines);
4769 }
4770 
4771 /*
4772  * Called from win_new_shellsize() after Rows changed.
4773  * This only does the current tab page, others must be done when made active.
4774  */
4775     void
4776 shell_new_rows(void)
4777 {
4778     int		h = (int)ROWS_AVAIL;
4779 
4780     if (firstwin == NULL)	/* not initialized yet */
4781 	return;
4782     if (h < frame_minheight(topframe, NULL))
4783 	h = frame_minheight(topframe, NULL);
4784 
4785     /* First try setting the heights of windows with 'winfixheight'.  If
4786      * that doesn't result in the right height, forget about that option. */
4787     frame_new_height(topframe, h, FALSE, TRUE);
4788     if (!frame_check_height(topframe, h))
4789 	frame_new_height(topframe, h, FALSE, FALSE);
4790 
4791     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4792     compute_cmdrow();
4793     curtab->tp_ch_used = p_ch;
4794 
4795 #if 0
4796     /* Disabled: don't want making the screen smaller make a window larger. */
4797     if (p_ea)
4798 	win_equal(curwin, FALSE, 'v');
4799 #endif
4800 }
4801 
4802 /*
4803  * Called from win_new_shellsize() after Columns changed.
4804  */
4805     void
4806 shell_new_columns(void)
4807 {
4808     if (firstwin == NULL)	/* not initialized yet */
4809 	return;
4810 
4811     /* First try setting the widths of windows with 'winfixwidth'.  If that
4812      * doesn't result in the right width, forget about that option. */
4813     frame_new_width(topframe, (int)Columns, FALSE, TRUE);
4814     if (!frame_check_width(topframe, Columns))
4815 	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
4816 
4817     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4818 #if 0
4819     /* Disabled: don't want making the screen smaller make a window larger. */
4820     if (p_ea)
4821 	win_equal(curwin, FALSE, 'h');
4822 #endif
4823 }
4824 
4825 #if defined(FEAT_CMDWIN) || defined(PROTO)
4826 /*
4827  * Save the size of all windows in "gap".
4828  */
4829     void
4830 win_size_save(garray_T *gap)
4831 
4832 {
4833     win_T	*wp;
4834 
4835     ga_init2(gap, (int)sizeof(int), 1);
4836     if (ga_grow(gap, win_count() * 2) == OK)
4837 	FOR_ALL_WINDOWS(wp)
4838 	{
4839 	    ((int *)gap->ga_data)[gap->ga_len++] =
4840 					       wp->w_width + wp->w_vsep_width;
4841 	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
4842 	}
4843 }
4844 
4845 /*
4846  * Restore window sizes, but only if the number of windows is still the same.
4847  * Does not free the growarray.
4848  */
4849     void
4850 win_size_restore(garray_T *gap)
4851 {
4852     win_T	*wp;
4853     int		i, j;
4854 
4855     if (win_count() * 2 == gap->ga_len)
4856     {
4857 	/* The order matters, because frames contain other frames, but it's
4858 	 * difficult to get right. The easy way out is to do it twice. */
4859 	for (j = 0; j < 2; ++j)
4860 	{
4861 	    i = 0;
4862 	    FOR_ALL_WINDOWS(wp)
4863 	    {
4864 		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
4865 		win_setheight_win(((int *)gap->ga_data)[i++], wp);
4866 	    }
4867 	}
4868 	/* recompute the window positions */
4869 	(void)win_comp_pos();
4870     }
4871 }
4872 #endif /* FEAT_CMDWIN */
4873 
4874 /*
4875  * Update the position for all windows, using the width and height of the
4876  * frames.
4877  * Returns the row just after the last window.
4878  */
4879     int
4880 win_comp_pos(void)
4881 {
4882     int		row = tabline_height();
4883     int		col = 0;
4884 
4885     frame_comp_pos(topframe, &row, &col);
4886     return row;
4887 }
4888 
4889 /*
4890  * Update the position of the windows in frame "topfrp", using the width and
4891  * height of the frames.
4892  * "*row" and "*col" are the top-left position of the frame.  They are updated
4893  * to the bottom-right position plus one.
4894  */
4895     static void
4896 frame_comp_pos(frame_T *topfrp, int *row, int *col)
4897 {
4898     win_T	*wp;
4899     frame_T	*frp;
4900     int		startcol;
4901     int		startrow;
4902     int		h;
4903 
4904     wp = topfrp->fr_win;
4905     if (wp != NULL)
4906     {
4907 	if (wp->w_winrow != *row || wp->w_wincol != *col)
4908 	{
4909 	    /* position changed, redraw */
4910 	    wp->w_winrow = *row;
4911 	    wp->w_wincol = *col;
4912 	    redraw_win_later(wp, NOT_VALID);
4913 	    wp->w_redr_status = TRUE;
4914 	}
4915 	/* WinBar will not show if the window height is zero */
4916 	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
4917 	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
4918 	*col += wp->w_width + wp->w_vsep_width;
4919     }
4920     else
4921     {
4922 	startrow = *row;
4923 	startcol = *col;
4924 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
4925 	{
4926 	    if (topfrp->fr_layout == FR_ROW)
4927 		*row = startrow;	/* all frames are at the same row */
4928 	    else
4929 		*col = startcol;	/* all frames are at the same col */
4930 	    frame_comp_pos(frp, row, col);
4931 	}
4932     }
4933 }
4934 
4935 /*
4936  * Set current window height and take care of repositioning other windows to
4937  * fit around it.
4938  */
4939     void
4940 win_setheight(int height)
4941 {
4942     win_setheight_win(height, curwin);
4943 }
4944 
4945 /*
4946  * Set the window height of window "win" and take care of repositioning other
4947  * windows to fit around it.
4948  */
4949     void
4950 win_setheight_win(int height, win_T *win)
4951 {
4952     int		row;
4953 
4954     if (win == curwin)
4955     {
4956 	/* Always keep current window at least one line high, even when
4957 	 * 'winminheight' is zero. */
4958 	if (height < p_wmh)
4959 	    height = p_wmh;
4960 	if (height == 0)
4961 	    height = 1;
4962 	height += WINBAR_HEIGHT(curwin);
4963     }
4964 
4965     frame_setheight(win->w_frame, height + win->w_status_height);
4966 
4967     /* recompute the window positions */
4968     row = win_comp_pos();
4969 
4970     /*
4971      * If there is extra space created between the last window and the command
4972      * line, clear it.
4973      */
4974     if (full_screen && msg_scrolled == 0 && row < cmdline_row)
4975 	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
4976     cmdline_row = row;
4977     msg_row = row;
4978     msg_col = 0;
4979 
4980     redraw_all_later(NOT_VALID);
4981 }
4982 
4983 /*
4984  * Set the height of a frame to "height" and take care that all frames and
4985  * windows inside it are resized.  Also resize frames on the left and right if
4986  * the are in the same FR_ROW frame.
4987  *
4988  * Strategy:
4989  * If the frame is part of a FR_COL frame, try fitting the frame in that
4990  * frame.  If that doesn't work (the FR_COL frame is too small), recursively
4991  * go to containing frames to resize them and make room.
4992  * If the frame is part of a FR_ROW frame, all frames must be resized as well.
4993  * Check for the minimal height of the FR_ROW frame.
4994  * At the top level we can also use change the command line height.
4995  */
4996     static void
4997 frame_setheight(frame_T *curfrp, int height)
4998 {
4999     int		room;		/* total number of lines available */
5000     int		take;		/* number of lines taken from other windows */
5001     int		room_cmdline;	/* lines available from cmdline */
5002     int		run;
5003     frame_T	*frp;
5004     int		h;
5005     int		room_reserved;
5006 
5007     /* If the height already is the desired value, nothing to do. */
5008     if (curfrp->fr_height == height)
5009 	return;
5010 
5011     if (curfrp->fr_parent == NULL)
5012     {
5013 	/* topframe: can only change the command line */
5014 	if (height > ROWS_AVAIL)
5015 	    height = ROWS_AVAIL;
5016 	if (height > 0)
5017 	    frame_new_height(curfrp, height, FALSE, FALSE);
5018     }
5019     else if (curfrp->fr_parent->fr_layout == FR_ROW)
5020     {
5021 	/* Row of frames: Also need to resize frames left and right of this
5022 	 * one.  First check for the minimal height of these. */
5023 	h = frame_minheight(curfrp->fr_parent, NULL);
5024 	if (height < h)
5025 	    height = h;
5026 	frame_setheight(curfrp->fr_parent, height);
5027     }
5028     else
5029     {
5030 	/*
5031 	 * Column of frames: try to change only frames in this column.
5032 	 */
5033 	/*
5034 	 * Do this twice:
5035 	 * 1: compute room available, if it's not enough try resizing the
5036 	 *    containing frame.
5037 	 * 2: compute the room available and adjust the height to it.
5038 	 * Try not to reduce the height of a window with 'winfixheight' set.
5039 	 */
5040 	for (run = 1; run <= 2; ++run)
5041 	{
5042 	    room = 0;
5043 	    room_reserved = 0;
5044 	    for (frp = curfrp->fr_parent->fr_child; frp != NULL;
5045 							   frp = frp->fr_next)
5046 	    {
5047 		if (frp != curfrp
5048 			&& frp->fr_win != NULL
5049 			&& frp->fr_win->w_p_wfh)
5050 		    room_reserved += frp->fr_height;
5051 		room += frp->fr_height;
5052 		if (frp != curfrp)
5053 		    room -= frame_minheight(frp, NULL);
5054 	    }
5055 	    if (curfrp->fr_width != Columns)
5056 		room_cmdline = 0;
5057 	    else
5058 	    {
5059 		room_cmdline = Rows - p_ch - (lastwin->w_winrow
5060 						+ VISIBLE_HEIGHT(lastwin)
5061 						+ lastwin->w_status_height);
5062 		if (room_cmdline < 0)
5063 		    room_cmdline = 0;
5064 	    }
5065 
5066 	    if (height <= room + room_cmdline)
5067 		break;
5068 	    if (run == 2 || curfrp->fr_width == Columns)
5069 	    {
5070 		if (height > room + room_cmdline)
5071 		    height = room + room_cmdline;
5072 		break;
5073 	    }
5074 	    frame_setheight(curfrp->fr_parent, height
5075 		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
5076 	}
5077 
5078 	/*
5079 	 * Compute the number of lines we will take from others frames (can be
5080 	 * negative!).
5081 	 */
5082 	take = height - curfrp->fr_height;
5083 
5084 	/* If there is not enough room, also reduce the height of a window
5085 	 * with 'winfixheight' set. */
5086 	if (height > room + room_cmdline - room_reserved)
5087 	    room_reserved = room + room_cmdline - height;
5088 	/* If there is only a 'winfixheight' window and making the
5089 	 * window smaller, need to make the other window taller. */
5090 	if (take < 0 && room - curfrp->fr_height < room_reserved)
5091 	    room_reserved = 0;
5092 
5093 	if (take > 0 && room_cmdline > 0)
5094 	{
5095 	    /* use lines from cmdline first */
5096 	    if (take < room_cmdline)
5097 		room_cmdline = take;
5098 	    take -= room_cmdline;
5099 	    topframe->fr_height += room_cmdline;
5100 	}
5101 
5102 	/*
5103 	 * set the current frame to the new height
5104 	 */
5105 	frame_new_height(curfrp, height, FALSE, FALSE);
5106 
5107 	/*
5108 	 * First take lines from the frames after the current frame.  If
5109 	 * that is not enough, takes lines from frames above the current
5110 	 * frame.
5111 	 */
5112 	for (run = 0; run < 2; ++run)
5113 	{
5114 	    if (run == 0)
5115 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5116 	    else
5117 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5118 	    while (frp != NULL && take != 0)
5119 	    {
5120 		h = frame_minheight(frp, NULL);
5121 		if (room_reserved > 0
5122 			&& frp->fr_win != NULL
5123 			&& frp->fr_win->w_p_wfh)
5124 		{
5125 		    if (room_reserved >= frp->fr_height)
5126 			room_reserved -= frp->fr_height;
5127 		    else
5128 		    {
5129 			if (frp->fr_height - room_reserved > take)
5130 			    room_reserved = frp->fr_height - take;
5131 			take -= frp->fr_height - room_reserved;
5132 			frame_new_height(frp, room_reserved, FALSE, FALSE);
5133 			room_reserved = 0;
5134 		    }
5135 		}
5136 		else
5137 		{
5138 		    if (frp->fr_height - take < h)
5139 		    {
5140 			take -= frp->fr_height - h;
5141 			frame_new_height(frp, h, FALSE, FALSE);
5142 		    }
5143 		    else
5144 		    {
5145 			frame_new_height(frp, frp->fr_height - take,
5146 								FALSE, FALSE);
5147 			take = 0;
5148 		    }
5149 		}
5150 		if (run == 0)
5151 		    frp = frp->fr_next;
5152 		else
5153 		    frp = frp->fr_prev;
5154 	    }
5155 	}
5156     }
5157 }
5158 
5159 /*
5160  * Set current window width and take care of repositioning other windows to
5161  * fit around it.
5162  */
5163     void
5164 win_setwidth(int width)
5165 {
5166     win_setwidth_win(width, curwin);
5167 }
5168 
5169     void
5170 win_setwidth_win(int width, win_T *wp)
5171 {
5172     /* Always keep current window at least one column wide, even when
5173      * 'winminwidth' is zero. */
5174     if (wp == curwin)
5175     {
5176 	if (width < p_wmw)
5177 	    width = p_wmw;
5178 	if (width == 0)
5179 	    width = 1;
5180     }
5181 
5182     frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
5183 
5184     /* recompute the window positions */
5185     (void)win_comp_pos();
5186 
5187     redraw_all_later(NOT_VALID);
5188 }
5189 
5190 /*
5191  * Set the width of a frame to "width" and take care that all frames and
5192  * windows inside it are resized.  Also resize frames above and below if the
5193  * are in the same FR_ROW frame.
5194  *
5195  * Strategy is similar to frame_setheight().
5196  */
5197     static void
5198 frame_setwidth(frame_T *curfrp, int width)
5199 {
5200     int		room;		/* total number of lines available */
5201     int		take;		/* number of lines taken from other windows */
5202     int		run;
5203     frame_T	*frp;
5204     int		w;
5205     int		room_reserved;
5206 
5207     /* If the width already is the desired value, nothing to do. */
5208     if (curfrp->fr_width == width)
5209 	return;
5210 
5211     if (curfrp->fr_parent == NULL)
5212 	/* topframe: can't change width */
5213 	return;
5214 
5215     if (curfrp->fr_parent->fr_layout == FR_COL)
5216     {
5217 	/* Column of frames: Also need to resize frames above and below of
5218 	 * this one.  First check for the minimal width of these. */
5219 	w = frame_minwidth(curfrp->fr_parent, NULL);
5220 	if (width < w)
5221 	    width = w;
5222 	frame_setwidth(curfrp->fr_parent, width);
5223     }
5224     else
5225     {
5226 	/*
5227 	 * Row of frames: try to change only frames in this row.
5228 	 *
5229 	 * Do this twice:
5230 	 * 1: compute room available, if it's not enough try resizing the
5231 	 *    containing frame.
5232 	 * 2: compute the room available and adjust the width to it.
5233 	 */
5234 	for (run = 1; run <= 2; ++run)
5235 	{
5236 	    room = 0;
5237 	    room_reserved = 0;
5238 	    for (frp = curfrp->fr_parent->fr_child; frp != NULL;
5239 							   frp = frp->fr_next)
5240 	    {
5241 		if (frp != curfrp
5242 			&& frp->fr_win != NULL
5243 			&& frp->fr_win->w_p_wfw)
5244 		    room_reserved += frp->fr_width;
5245 		room += frp->fr_width;
5246 		if (frp != curfrp)
5247 		    room -= frame_minwidth(frp, NULL);
5248 	    }
5249 
5250 	    if (width <= room)
5251 		break;
5252 	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
5253 	    {
5254 		if (width > room)
5255 		    width = room;
5256 		break;
5257 	    }
5258 	    frame_setwidth(curfrp->fr_parent, width
5259 		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
5260 	}
5261 
5262 	/*
5263 	 * Compute the number of lines we will take from others frames (can be
5264 	 * negative!).
5265 	 */
5266 	take = width - curfrp->fr_width;
5267 
5268 	/* If there is not enough room, also reduce the width of a window
5269 	 * with 'winfixwidth' set. */
5270 	if (width > room - room_reserved)
5271 	    room_reserved = room - width;
5272 	/* If there is only a 'winfixwidth' window and making the
5273 	 * window smaller, need to make the other window narrower. */
5274 	if (take < 0 && room - curfrp->fr_width < room_reserved)
5275 	    room_reserved = 0;
5276 
5277 	/*
5278 	 * set the current frame to the new width
5279 	 */
5280 	frame_new_width(curfrp, width, FALSE, FALSE);
5281 
5282 	/*
5283 	 * First take lines from the frames right of the current frame.  If
5284 	 * that is not enough, takes lines from frames left of the current
5285 	 * frame.
5286 	 */
5287 	for (run = 0; run < 2; ++run)
5288 	{
5289 	    if (run == 0)
5290 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5291 	    else
5292 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5293 	    while (frp != NULL && take != 0)
5294 	    {
5295 		w = frame_minwidth(frp, NULL);
5296 		if (room_reserved > 0
5297 			&& frp->fr_win != NULL
5298 			&& frp->fr_win->w_p_wfw)
5299 		{
5300 		    if (room_reserved >= frp->fr_width)
5301 			room_reserved -= frp->fr_width;
5302 		    else
5303 		    {
5304 			if (frp->fr_width - room_reserved > take)
5305 			    room_reserved = frp->fr_width - take;
5306 			take -= frp->fr_width - room_reserved;
5307 			frame_new_width(frp, room_reserved, FALSE, FALSE);
5308 			room_reserved = 0;
5309 		    }
5310 		}
5311 		else
5312 		{
5313 		    if (frp->fr_width - take < w)
5314 		    {
5315 			take -= frp->fr_width - w;
5316 			frame_new_width(frp, w, FALSE, FALSE);
5317 		    }
5318 		    else
5319 		    {
5320 			frame_new_width(frp, frp->fr_width - take,
5321 								FALSE, FALSE);
5322 			take = 0;
5323 		    }
5324 		}
5325 		if (run == 0)
5326 		    frp = frp->fr_next;
5327 		else
5328 		    frp = frp->fr_prev;
5329 	    }
5330 	}
5331     }
5332 }
5333 
5334 /*
5335  * Check 'winminheight' for a valid value.
5336  */
5337     void
5338 win_setminheight(void)
5339 {
5340     int		room;
5341     int		first = TRUE;
5342     win_T	*wp;
5343 
5344     /* loop until there is a 'winminheight' that is possible */
5345     while (p_wmh > 0)
5346     {
5347 	/* TODO: handle vertical splits */
5348 	room = -p_wh;
5349 	FOR_ALL_WINDOWS(wp)
5350 	    room += VISIBLE_HEIGHT(wp) - p_wmh;
5351 	if (room >= 0)
5352 	    break;
5353 	--p_wmh;
5354 	if (first)
5355 	{
5356 	    EMSG(_(e_noroom));
5357 	    first = FALSE;
5358 	}
5359     }
5360 }
5361 
5362 #if defined(FEAT_MOUSE) || defined(PROTO)
5363 
5364 /*
5365  * Status line of dragwin is dragged "offset" lines down (negative is up).
5366  */
5367     void
5368 win_drag_status_line(win_T *dragwin, int offset)
5369 {
5370     frame_T	*curfr;
5371     frame_T	*fr;
5372     int		room;
5373     int		row;
5374     int		up;	/* if TRUE, drag status line up, otherwise down */
5375     int		n;
5376 
5377     fr = dragwin->w_frame;
5378     curfr = fr;
5379     if (fr != topframe)		/* more than one window */
5380     {
5381 	fr = fr->fr_parent;
5382 	/* When the parent frame is not a column of frames, its parent should
5383 	 * be. */
5384 	if (fr->fr_layout != FR_COL)
5385 	{
5386 	    curfr = fr;
5387 	    if (fr != topframe)	/* only a row of windows, may drag statusline */
5388 		fr = fr->fr_parent;
5389 	}
5390     }
5391 
5392     /* If this is the last frame in a column, may want to resize the parent
5393      * frame instead (go two up to skip a row of frames). */
5394     while (curfr != topframe && curfr->fr_next == NULL)
5395     {
5396 	if (fr != topframe)
5397 	    fr = fr->fr_parent;
5398 	curfr = fr;
5399 	if (fr != topframe)
5400 	    fr = fr->fr_parent;
5401     }
5402 
5403     if (offset < 0) /* drag up */
5404     {
5405 	up = TRUE;
5406 	offset = -offset;
5407 	/* sum up the room of the current frame and above it */
5408 	if (fr == curfr)
5409 	{
5410 	    /* only one window */
5411 	    room = fr->fr_height - frame_minheight(fr, NULL);
5412 	}
5413 	else
5414 	{
5415 	    room = 0;
5416 	    for (fr = fr->fr_child; ; fr = fr->fr_next)
5417 	    {
5418 		room += fr->fr_height - frame_minheight(fr, NULL);
5419 		if (fr == curfr)
5420 		    break;
5421 	    }
5422 	}
5423 	fr = curfr->fr_next;		/* put fr at frame that grows */
5424     }
5425     else    /* drag down */
5426     {
5427 	up = FALSE;
5428 	/*
5429 	 * Only dragging the last status line can reduce p_ch.
5430 	 */
5431 	room = Rows - cmdline_row;
5432 	if (curfr->fr_next == NULL)
5433 	    room -= 1;
5434 	else
5435 	    room -= p_ch;
5436 	if (room < 0)
5437 	    room = 0;
5438 	/* sum up the room of frames below of the current one */
5439 	for (fr = curfr->fr_next; fr != NULL; fr = fr->fr_next)
5440 	    room += fr->fr_height - frame_minheight(fr, NULL);
5441 	fr = curfr;			/* put fr at window that grows */
5442     }
5443 
5444     if (room < offset)		/* Not enough room */
5445 	offset = room;		/* Move as far as we can */
5446     if (offset <= 0)
5447 	return;
5448 
5449     /*
5450      * Grow frame fr by "offset" lines.
5451      * Doesn't happen when dragging the last status line up.
5452      */
5453     if (fr != NULL)
5454 	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
5455 
5456     if (up)
5457 	fr = curfr;		/* current frame gets smaller */
5458     else
5459 	fr = curfr->fr_next;	/* next frame gets smaller */
5460 
5461     /*
5462      * Now make the other frames smaller.
5463      */
5464     while (fr != NULL && offset > 0)
5465     {
5466 	n = frame_minheight(fr, NULL);
5467 	if (fr->fr_height - offset <= n)
5468 	{
5469 	    offset -= fr->fr_height - n;
5470 	    frame_new_height(fr, n, !up, FALSE);
5471 	}
5472 	else
5473 	{
5474 	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
5475 	    break;
5476 	}
5477 	if (up)
5478 	    fr = fr->fr_prev;
5479 	else
5480 	    fr = fr->fr_next;
5481     }
5482     row = win_comp_pos();
5483     screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5484     cmdline_row = row;
5485     p_ch = Rows - cmdline_row;
5486     if (p_ch < 1)
5487 	p_ch = 1;
5488     curtab->tp_ch_used = p_ch;
5489     redraw_all_later(SOME_VALID);
5490     showmode();
5491 }
5492 
5493 /*
5494  * Separator line of dragwin is dragged "offset" lines right (negative is left).
5495  */
5496     void
5497 win_drag_vsep_line(win_T *dragwin, int offset)
5498 {
5499     frame_T	*curfr;
5500     frame_T	*fr;
5501     int		room;
5502     int		left;	/* if TRUE, drag separator line left, otherwise right */
5503     int		n;
5504 
5505     fr = dragwin->w_frame;
5506     if (fr == topframe)		/* only one window (cannot happen?) */
5507 	return;
5508     curfr = fr;
5509     fr = fr->fr_parent;
5510     /* When the parent frame is not a row of frames, its parent should be. */
5511     if (fr->fr_layout != FR_ROW)
5512     {
5513 	if (fr == topframe)	/* only a column of windows (cannot happen?) */
5514 	    return;
5515 	curfr = fr;
5516 	fr = fr->fr_parent;
5517     }
5518 
5519     /* If this is the last frame in a row, may want to resize a parent
5520      * frame instead. */
5521     while (curfr->fr_next == NULL)
5522     {
5523 	if (fr == topframe)
5524 	    break;
5525 	curfr = fr;
5526 	fr = fr->fr_parent;
5527 	if (fr != topframe)
5528 	{
5529 	    curfr = fr;
5530 	    fr = fr->fr_parent;
5531 	}
5532     }
5533 
5534     if (offset < 0) /* drag left */
5535     {
5536 	left = TRUE;
5537 	offset = -offset;
5538 	/* sum up the room of the current frame and left of it */
5539 	room = 0;
5540 	for (fr = fr->fr_child; ; fr = fr->fr_next)
5541 	{
5542 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5543 	    if (fr == curfr)
5544 		break;
5545 	}
5546 	fr = curfr->fr_next;		/* put fr at frame that grows */
5547     }
5548     else    /* drag right */
5549     {
5550 	left = FALSE;
5551 	/* sum up the room of frames right of the current one */
5552 	room = 0;
5553 	for (fr = curfr->fr_next; fr != NULL; fr = fr->fr_next)
5554 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5555 	fr = curfr;			/* put fr at window that grows */
5556     }
5557 
5558     if (room < offset)		/* Not enough room */
5559 	offset = room;		/* Move as far as we can */
5560     if (offset <= 0)		/* No room at all, quit. */
5561 	return;
5562     if (fr == NULL)
5563 	return;			/* Safety check, should not happen. */
5564 
5565     /* grow frame fr by offset lines */
5566     frame_new_width(fr, fr->fr_width + offset, left, FALSE);
5567 
5568     /* shrink other frames: current and at the left or at the right */
5569     if (left)
5570 	fr = curfr;		/* current frame gets smaller */
5571     else
5572 	fr = curfr->fr_next;	/* next frame gets smaller */
5573 
5574     while (fr != NULL && offset > 0)
5575     {
5576 	n = frame_minwidth(fr, NULL);
5577 	if (fr->fr_width - offset <= n)
5578 	{
5579 	    offset -= fr->fr_width - n;
5580 	    frame_new_width(fr, n, !left, FALSE);
5581 	}
5582 	else
5583 	{
5584 	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
5585 	    break;
5586 	}
5587 	if (left)
5588 	    fr = fr->fr_prev;
5589 	else
5590 	    fr = fr->fr_next;
5591     }
5592     (void)win_comp_pos();
5593     redraw_all_later(NOT_VALID);
5594 }
5595 #endif /* FEAT_MOUSE */
5596 
5597 #define FRACTION_MULT	16384L
5598 
5599 /*
5600  * Set wp->w_fraction for the current w_wrow and w_height.
5601  * Has no effect when the window is less than two lines.
5602  */
5603     void
5604 set_fraction(win_T *wp)
5605 {
5606     if (wp->w_height > 1)
5607 	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
5608 				    + wp->w_height / 2) / (long)wp->w_height;
5609 }
5610 
5611 /*
5612  * Set the height of a window.
5613  * "height" excludes any window toolbar.
5614  * This takes care of the things inside the window, not what happens to the
5615  * window position, the frame or to other windows.
5616  */
5617     void
5618 win_new_height(win_T *wp, int height)
5619 {
5620     int		prev_height = wp->w_height;
5621 
5622     /* Don't want a negative height.  Happens when splitting a tiny window.
5623      * Will equalize heights soon to fix it. */
5624     if (height < 0)
5625 	height = 0;
5626     if (wp->w_height == height)
5627 	return;	    /* nothing to do */
5628 
5629     if (wp->w_height > 0)
5630     {
5631 	if (wp == curwin)
5632 	    /* w_wrow needs to be valid. When setting 'laststatus' this may
5633 	     * call win_new_height() recursively. */
5634 	    validate_cursor();
5635 	if (wp->w_height != prev_height)
5636 	    return;  /* Recursive call already changed the size, bail out here
5637 			to avoid the following to mess things up. */
5638 	if (wp->w_wrow != wp->w_prev_fraction_row)
5639 	    set_fraction(wp);
5640     }
5641 
5642     wp->w_height = height;
5643     wp->w_skipcol = 0;
5644 
5645     /* There is no point in adjusting the scroll position when exiting.  Some
5646      * values might be invalid. */
5647     if (!exiting)
5648 	scroll_to_fraction(wp, prev_height);
5649 }
5650 
5651     void
5652 scroll_to_fraction(win_T *wp, int prev_height)
5653 {
5654     linenr_T	lnum;
5655     int		sline, line_size;
5656     int		height = wp->w_height;
5657 
5658     /* Don't change w_topline when height is zero.  Don't set w_topline when
5659      * 'scrollbind' is set and this isn't the current window. */
5660     if (height > 0 && (!wp->w_p_scb || wp == curwin))
5661     {
5662 	/*
5663 	 * Find a value for w_topline that shows the cursor at the same
5664 	 * relative position in the window as before (more or less).
5665 	 */
5666 	lnum = wp->w_cursor.lnum;
5667 	if (lnum < 1)		/* can happen when starting up */
5668 	    lnum = 1;
5669 	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L
5670 					 + FRACTION_MULT / 2) / FRACTION_MULT;
5671 	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
5672 	sline = wp->w_wrow - line_size;
5673 
5674 	if (sline >= 0)
5675 	{
5676 	    /* Make sure the whole cursor line is visible, if possible. */
5677 	    int rows = plines_win(wp, lnum, FALSE);
5678 
5679 	    if (sline > wp->w_height - rows)
5680 	    {
5681 		sline = wp->w_height - rows;
5682 		wp->w_wrow -= rows - line_size;
5683 	    }
5684 	}
5685 
5686 	if (sline < 0)
5687 	{
5688 	    /*
5689 	     * Cursor line would go off top of screen if w_wrow was this high.
5690 	     * Make cursor line the first line in the window.  If not enough
5691 	     * room use w_skipcol;
5692 	     */
5693 	    wp->w_wrow = line_size;
5694 	    if (wp->w_wrow >= wp->w_height
5695 				       && (wp->w_width - win_col_off(wp)) > 0)
5696 	    {
5697 		wp->w_skipcol += wp->w_width - win_col_off(wp);
5698 		--wp->w_wrow;
5699 		while (wp->w_wrow >= wp->w_height)
5700 		{
5701 		    wp->w_skipcol += wp->w_width - win_col_off(wp)
5702 							   + win_col_off2(wp);
5703 		    --wp->w_wrow;
5704 		}
5705 	    }
5706 	    set_topline(wp, lnum);
5707 	}
5708 	else if (sline > 0)
5709 	{
5710 	    while (sline > 0 && lnum > 1)
5711 	    {
5712 #ifdef FEAT_FOLDING
5713 		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
5714 		if (lnum == 1)
5715 		{
5716 		    /* first line in buffer is folded */
5717 		    line_size = 1;
5718 		    --sline;
5719 		    break;
5720 		}
5721 #endif
5722 		--lnum;
5723 #ifdef FEAT_DIFF
5724 		if (lnum == wp->w_topline)
5725 		    line_size = plines_win_nofill(wp, lnum, TRUE)
5726 							      + wp->w_topfill;
5727 		else
5728 #endif
5729 		    line_size = plines_win(wp, lnum, TRUE);
5730 		sline -= line_size;
5731 	    }
5732 
5733 	    if (sline < 0)
5734 	    {
5735 		/*
5736 		 * Line we want at top would go off top of screen.  Use next
5737 		 * line instead.
5738 		 */
5739 #ifdef FEAT_FOLDING
5740 		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
5741 #endif
5742 		lnum++;
5743 		wp->w_wrow -= line_size + sline;
5744 	    }
5745 	    else if (sline > 0)
5746 	    {
5747 		/* First line of file reached, use that as topline. */
5748 		lnum = 1;
5749 		wp->w_wrow -= sline;
5750 	    }
5751 
5752 	    set_topline(wp, lnum);
5753 	}
5754     }
5755 
5756     if (wp == curwin)
5757     {
5758 	if (p_so)
5759 	    update_topline();
5760 	curs_columns(FALSE);	/* validate w_wrow */
5761     }
5762     if (prev_height > 0)
5763 	wp->w_prev_fraction_row = wp->w_wrow;
5764 
5765     win_comp_scroll(wp);
5766     redraw_win_later(wp, SOME_VALID);
5767     wp->w_redr_status = TRUE;
5768     invalidate_botline_win(wp);
5769 }
5770 
5771 /*
5772  * Set the width of a window.
5773  */
5774     void
5775 win_new_width(win_T *wp, int width)
5776 {
5777     wp->w_width = width;
5778     wp->w_lines_valid = 0;
5779     changed_line_abv_curs_win(wp);
5780     invalidate_botline_win(wp);
5781     if (wp == curwin)
5782     {
5783 	update_topline();
5784 	curs_columns(TRUE);	/* validate w_wrow */
5785     }
5786     redraw_win_later(wp, NOT_VALID);
5787     wp->w_redr_status = TRUE;
5788 }
5789 
5790     void
5791 win_comp_scroll(win_T *wp)
5792 {
5793     wp->w_p_scr = ((unsigned)wp->w_height >> 1);
5794     if (wp->w_p_scr == 0)
5795 	wp->w_p_scr = 1;
5796 }
5797 
5798 /*
5799  * command_height: called whenever p_ch has been changed
5800  */
5801     void
5802 command_height(void)
5803 {
5804     int		h;
5805     frame_T	*frp;
5806     int		old_p_ch = curtab->tp_ch_used;
5807 
5808     /* Use the value of p_ch that we remembered.  This is needed for when the
5809      * GUI starts up, we can't be sure in what order things happen.  And when
5810      * p_ch was changed in another tab page. */
5811     curtab->tp_ch_used = p_ch;
5812 
5813     /* Find bottom frame with width of screen. */
5814     frp = lastwin->w_frame;
5815     while (frp->fr_width != Columns && frp->fr_parent != NULL)
5816 	frp = frp->fr_parent;
5817 
5818     /* Avoid changing the height of a window with 'winfixheight' set. */
5819     while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
5820 						      && frp->fr_win->w_p_wfh)
5821 	frp = frp->fr_prev;
5822 
5823     if (starting != NO_SCREEN)
5824     {
5825 	cmdline_row = Rows - p_ch;
5826 
5827 	if (p_ch > old_p_ch)		    /* p_ch got bigger */
5828 	{
5829 	    while (p_ch > old_p_ch)
5830 	    {
5831 		if (frp == NULL)
5832 		{
5833 		    EMSG(_(e_noroom));
5834 		    p_ch = old_p_ch;
5835 		    curtab->tp_ch_used = p_ch;
5836 		    cmdline_row = Rows - p_ch;
5837 		    break;
5838 		}
5839 		h = frp->fr_height - frame_minheight(frp, NULL);
5840 		if (h > p_ch - old_p_ch)
5841 		    h = p_ch - old_p_ch;
5842 		old_p_ch += h;
5843 		frame_add_height(frp, -h);
5844 		frp = frp->fr_prev;
5845 	    }
5846 
5847 	    /* Recompute window positions. */
5848 	    (void)win_comp_pos();
5849 
5850 	    /* clear the lines added to cmdline */
5851 	    if (full_screen)
5852 		screen_fill((int)(cmdline_row), (int)Rows, 0,
5853 						   (int)Columns, ' ', ' ', 0);
5854 	    msg_row = cmdline_row;
5855 	    redraw_cmdline = TRUE;
5856 	    return;
5857 	}
5858 
5859 	if (msg_row < cmdline_row)
5860 	    msg_row = cmdline_row;
5861 	redraw_cmdline = TRUE;
5862     }
5863     frame_add_height(frp, (int)(old_p_ch - p_ch));
5864 
5865     /* Recompute window positions. */
5866     if (frp != lastwin->w_frame)
5867 	(void)win_comp_pos();
5868 }
5869 
5870 /*
5871  * Resize frame "frp" to be "n" lines higher (negative for less high).
5872  * Also resize the frames it is contained in.
5873  */
5874     static void
5875 frame_add_height(frame_T *frp, int n)
5876 {
5877     frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
5878     for (;;)
5879     {
5880 	frp = frp->fr_parent;
5881 	if (frp == NULL)
5882 	    break;
5883 	frp->fr_height += n;
5884     }
5885 }
5886 
5887 /*
5888  * Add or remove a status line for the bottom window(s), according to the
5889  * value of 'laststatus'.
5890  */
5891     void
5892 last_status(
5893     int		morewin)	/* pretend there are two or more windows */
5894 {
5895     /* Don't make a difference between horizontal or vertical split. */
5896     last_status_rec(topframe, (p_ls == 2
5897 			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
5898 }
5899 
5900     static void
5901 last_status_rec(frame_T *fr, int statusline)
5902 {
5903     frame_T	*fp;
5904     win_T	*wp;
5905 
5906     if (fr->fr_layout == FR_LEAF)
5907     {
5908 	wp = fr->fr_win;
5909 	if (wp->w_status_height != 0 && !statusline)
5910 	{
5911 	    /* remove status line */
5912 	    win_new_height(wp, wp->w_height + 1);
5913 	    wp->w_status_height = 0;
5914 	    comp_col();
5915 	}
5916 	else if (wp->w_status_height == 0 && statusline)
5917 	{
5918 	    /* Find a frame to take a line from. */
5919 	    fp = fr;
5920 	    while (fp->fr_height <= frame_minheight(fp, NULL))
5921 	    {
5922 		if (fp == topframe)
5923 		{
5924 		    EMSG(_(e_noroom));
5925 		    return;
5926 		}
5927 		/* In a column of frames: go to frame above.  If already at
5928 		 * the top or in a row of frames: go to parent. */
5929 		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
5930 		    fp = fp->fr_prev;
5931 		else
5932 		    fp = fp->fr_parent;
5933 	    }
5934 	    wp->w_status_height = 1;
5935 	    if (fp != fr)
5936 	    {
5937 		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
5938 		frame_fix_height(wp);
5939 		(void)win_comp_pos();
5940 	    }
5941 	    else
5942 		win_new_height(wp, wp->w_height - 1);
5943 	    comp_col();
5944 	    redraw_all_later(SOME_VALID);
5945 	}
5946     }
5947     else if (fr->fr_layout == FR_ROW)
5948     {
5949 	/* vertically split windows, set status line for each one */
5950 	for (fp = fr->fr_child; fp != NULL; fp = fp->fr_next)
5951 	    last_status_rec(fp, statusline);
5952     }
5953     else
5954     {
5955 	/* horizontally split window, set status line for last one */
5956 	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
5957 	    ;
5958 	last_status_rec(fp, statusline);
5959     }
5960 }
5961 
5962 /*
5963  * Return the number of lines used by the tab page line.
5964  */
5965     int
5966 tabline_height(void)
5967 {
5968 #ifdef FEAT_GUI_TABLINE
5969     /* When the GUI has the tabline then this always returns zero. */
5970     if (gui_use_tabline())
5971 	return 0;
5972 #endif
5973     switch (p_stal)
5974     {
5975 	case 0: return 0;
5976 	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
5977     }
5978     return 1;
5979 }
5980 
5981 #if defined(FEAT_SEARCHPATH) || defined(PROTO)
5982 /*
5983  * Get the file name at the cursor.
5984  * If Visual mode is active, use the selected text if it's in one line.
5985  * Returns the name in allocated memory, NULL for failure.
5986  */
5987     char_u *
5988 grab_file_name(long count, linenr_T *file_lnum)
5989 {
5990     int options = FNAME_MESS|FNAME_EXP|FNAME_REL|FNAME_UNESC;
5991 
5992     if (VIsual_active)
5993     {
5994 	int	len;
5995 	char_u	*ptr;
5996 
5997 	if (get_visual_text(NULL, &ptr, &len) == FAIL)
5998 	    return NULL;
5999 	return find_file_name_in_path(ptr, len, options,
6000 						     count, curbuf->b_ffname);
6001     }
6002     return file_name_at_cursor(options | FNAME_HYP, count, file_lnum);
6003 }
6004 
6005 /*
6006  * Return the file name under or after the cursor.
6007  *
6008  * The 'path' option is searched if the file name is not absolute.
6009  * The string returned has been alloc'ed and should be freed by the caller.
6010  * NULL is returned if the file name or file is not found.
6011  *
6012  * options:
6013  * FNAME_MESS	    give error messages
6014  * FNAME_EXP	    expand to path
6015  * FNAME_HYP	    check for hypertext link
6016  * FNAME_INCL	    apply "includeexpr"
6017  */
6018     char_u *
6019 file_name_at_cursor(int options, long count, linenr_T *file_lnum)
6020 {
6021     return file_name_in_line(ml_get_curline(),
6022 		      curwin->w_cursor.col, options, count, curbuf->b_ffname,
6023 		      file_lnum);
6024 }
6025 
6026 /*
6027  * Return the name of the file under or after ptr[col].
6028  * Otherwise like file_name_at_cursor().
6029  */
6030     char_u *
6031 file_name_in_line(
6032     char_u	*line,
6033     int		col,
6034     int		options,
6035     long	count,
6036     char_u	*rel_fname,	/* file we are searching relative to */
6037     linenr_T	*file_lnum)	/* line number after the file name */
6038 {
6039     char_u	*ptr;
6040     int		len;
6041     int		in_type = TRUE;
6042     int		is_url = FALSE;
6043 
6044     /*
6045      * search forward for what could be the start of a file name
6046      */
6047     ptr = line + col;
6048     while (*ptr != NUL && !vim_isfilec(*ptr))
6049 	MB_PTR_ADV(ptr);
6050     if (*ptr == NUL)		/* nothing found */
6051     {
6052 	if (options & FNAME_MESS)
6053 	    EMSG(_("E446: No file name under cursor"));
6054 	return NULL;
6055     }
6056 
6057     /*
6058      * Search backward for first char of the file name.
6059      * Go one char back to ":" before "//" even when ':' is not in 'isfname'.
6060      */
6061     while (ptr > line)
6062     {
6063 #ifdef FEAT_MBYTE
6064 	if (has_mbyte && (len = (*mb_head_off)(line, ptr - 1)) > 0)
6065 	    ptr -= len + 1;
6066 	else
6067 #endif
6068 	if (vim_isfilec(ptr[-1])
6069 		|| ((options & FNAME_HYP) && path_is_url(ptr - 1)))
6070 	    --ptr;
6071 	else
6072 	    break;
6073     }
6074 
6075     /*
6076      * Search forward for the last char of the file name.
6077      * Also allow "://" when ':' is not in 'isfname'.
6078      */
6079     len = 0;
6080     while (vim_isfilec(ptr[len]) || (ptr[len] == '\\' && ptr[len + 1] == ' ')
6081 			 || ((options & FNAME_HYP) && path_is_url(ptr + len))
6082 			 || (is_url && vim_strchr((char_u *)"?&=", ptr[len]) != NULL))
6083     {
6084 	/* After type:// we also include ?, & and = as valid characters, so that
6085 	 * http://google.com?q=this&that=ok works. */
6086 	if ((ptr[len] >= 'A' && ptr[len] <= 'Z') || (ptr[len] >= 'a' && ptr[len] <= 'z'))
6087 	{
6088 	    if (in_type && path_is_url(ptr + len + 1))
6089 		is_url = TRUE;
6090 	}
6091 	else
6092 	    in_type = FALSE;
6093 
6094 	if (ptr[len] == '\\')
6095 	    /* Skip over the "\" in "\ ". */
6096 	    ++len;
6097 #ifdef FEAT_MBYTE
6098 	if (has_mbyte)
6099 	    len += (*mb_ptr2len)(ptr + len);
6100 	else
6101 #endif
6102 	    ++len;
6103     }
6104 
6105     /*
6106      * If there is trailing punctuation, remove it.
6107      * But don't remove "..", could be a directory name.
6108      */
6109     if (len > 2 && vim_strchr((char_u *)".,:;!", ptr[len - 1]) != NULL
6110 						       && ptr[len - 2] != '.')
6111 	--len;
6112 
6113     if (file_lnum != NULL)
6114     {
6115 	char_u *p;
6116 
6117 	/* Get the number after the file name and a separator character */
6118 	p = ptr + len;
6119 	p = skipwhite(p);
6120 	if (*p != NUL)
6121 	{
6122 	    if (!isdigit(*p))
6123 		++p;		    /* skip the separator */
6124 	    p = skipwhite(p);
6125 	    if (isdigit(*p))
6126 		*file_lnum = (int)getdigits(&p);
6127 	}
6128     }
6129 
6130     return find_file_name_in_path(ptr, len, options, count, rel_fname);
6131 }
6132 
6133 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6134 static char_u *eval_includeexpr(char_u *ptr, int len);
6135 
6136     static char_u *
6137 eval_includeexpr(char_u *ptr, int len)
6138 {
6139     char_u	*res;
6140 
6141     set_vim_var_string(VV_FNAME, ptr, len);
6142     res = eval_to_string_safe(curbuf->b_p_inex, NULL,
6143 		      was_set_insecurely((char_u *)"includeexpr", OPT_LOCAL));
6144     set_vim_var_string(VV_FNAME, NULL, 0);
6145     return res;
6146 }
6147 #endif
6148 
6149 /*
6150  * Return the name of the file ptr[len] in 'path'.
6151  * Otherwise like file_name_at_cursor().
6152  */
6153     char_u *
6154 find_file_name_in_path(
6155     char_u	*ptr,
6156     int		len,
6157     int		options,
6158     long	count,
6159     char_u	*rel_fname)	/* file we are searching relative to */
6160 {
6161     char_u	*file_name;
6162     int		c;
6163 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6164     char_u	*tofree = NULL;
6165 
6166     if ((options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
6167     {
6168 	tofree = eval_includeexpr(ptr, len);
6169 	if (tofree != NULL)
6170 	{
6171 	    ptr = tofree;
6172 	    len = (int)STRLEN(ptr);
6173 	}
6174     }
6175 # endif
6176 
6177     if (options & FNAME_EXP)
6178     {
6179 	file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
6180 							     TRUE, rel_fname);
6181 
6182 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6183 	/*
6184 	 * If the file could not be found in a normal way, try applying
6185 	 * 'includeexpr' (unless done already).
6186 	 */
6187 	if (file_name == NULL
6188 		&& !(options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
6189 	{
6190 	    tofree = eval_includeexpr(ptr, len);
6191 	    if (tofree != NULL)
6192 	    {
6193 		ptr = tofree;
6194 		len = (int)STRLEN(ptr);
6195 		file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
6196 							     TRUE, rel_fname);
6197 	    }
6198 	}
6199 # endif
6200 	if (file_name == NULL && (options & FNAME_MESS))
6201 	{
6202 	    c = ptr[len];
6203 	    ptr[len] = NUL;
6204 	    EMSG2(_("E447: Can't find file \"%s\" in path"), ptr);
6205 	    ptr[len] = c;
6206 	}
6207 
6208 	/* Repeat finding the file "count" times.  This matters when it
6209 	 * appears several times in the path. */
6210 	while (file_name != NULL && --count > 0)
6211 	{
6212 	    vim_free(file_name);
6213 	    file_name = find_file_in_path(ptr, len, options, FALSE, rel_fname);
6214 	}
6215     }
6216     else
6217 	file_name = vim_strnsave(ptr, len);
6218 
6219 # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
6220     vim_free(tofree);
6221 # endif
6222 
6223     return file_name;
6224 }
6225 #endif /* FEAT_SEARCHPATH */
6226 
6227 /*
6228  * Check if the "://" of a URL is at the pointer, return URL_SLASH.
6229  * Also check for ":\\", which MS Internet Explorer accepts, return
6230  * URL_BACKSLASH.
6231  */
6232     static int
6233 path_is_url(char_u *p)
6234 {
6235     if (STRNCMP(p, "://", (size_t)3) == 0)
6236 	return URL_SLASH;
6237     else if (STRNCMP(p, ":\\\\", (size_t)3) == 0)
6238 	return URL_BACKSLASH;
6239     return 0;
6240 }
6241 
6242 /*
6243  * Check if "fname" starts with "name://".  Return URL_SLASH if it does.
6244  * Return URL_BACKSLASH for "name:\\".
6245  * Return zero otherwise.
6246  */
6247     int
6248 path_with_url(char_u *fname)
6249 {
6250     char_u *p;
6251 
6252     for (p = fname; isalpha(*p); ++p)
6253 	;
6254     return path_is_url(p);
6255 }
6256 
6257 /*
6258  * Return TRUE if "name" is a full (absolute) path name or URL.
6259  */
6260     int
6261 vim_isAbsName(char_u *name)
6262 {
6263     return (path_with_url(name) != 0 || mch_isFullName(name));
6264 }
6265 
6266 /*
6267  * Get absolute file name into buffer "buf[len]".
6268  *
6269  * return FAIL for failure, OK otherwise
6270  */
6271     int
6272 vim_FullName(
6273     char_u	*fname,
6274     char_u	*buf,
6275     int		len,
6276     int		force)	    /* force expansion even when already absolute */
6277 {
6278     int		retval = OK;
6279     int		url;
6280 
6281     *buf = NUL;
6282     if (fname == NULL)
6283 	return FAIL;
6284 
6285     url = path_with_url(fname);
6286     if (!url)
6287 	retval = mch_FullName(fname, buf, len, force);
6288     if (url || retval == FAIL)
6289     {
6290 	/* something failed; use the file name (truncate when too long) */
6291 	vim_strncpy(buf, fname, len - 1);
6292     }
6293 #if defined(MSWIN)
6294     slash_adjust(buf);
6295 #endif
6296     return retval;
6297 }
6298 
6299 /*
6300  * Return the minimal number of rows that is needed on the screen to display
6301  * the current number of windows.
6302  */
6303     int
6304 min_rows(void)
6305 {
6306     int		total;
6307     tabpage_T	*tp;
6308     int		n;
6309 
6310     if (firstwin == NULL)	/* not initialized yet */
6311 	return MIN_LINES;
6312 
6313     total = 0;
6314     FOR_ALL_TABPAGES(tp)
6315     {
6316 	n = frame_minheight(tp->tp_topframe, NULL);
6317 	if (total < n)
6318 	    total = n;
6319     }
6320     total += tabline_height();
6321     total += 1;		/* count the room for the command line */
6322     return total;
6323 }
6324 
6325 /*
6326  * Return TRUE if there is only one window (in the current tab page), not
6327  * counting a help or preview window, unless it is the current window.
6328  * Does not count "aucmd_win".
6329  */
6330     int
6331 only_one_window(void)
6332 {
6333     int		count = 0;
6334     win_T	*wp;
6335 
6336     /* If there is another tab page there always is another window. */
6337     if (first_tabpage->tp_next != NULL)
6338 	return FALSE;
6339 
6340     FOR_ALL_WINDOWS(wp)
6341 	if (wp->w_buffer != NULL
6342 		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
6343 # ifdef FEAT_QUICKFIX
6344 		    || wp->w_p_pvw
6345 # endif
6346 	     ) || wp == curwin) && wp != aucmd_win)
6347 	    ++count;
6348     return (count <= 1);
6349 }
6350 
6351 /*
6352  * Correct the cursor line number in other windows.  Used after changing the
6353  * current buffer, and before applying autocommands.
6354  * When "do_curwin" is TRUE, also check current window.
6355  */
6356     void
6357 check_lnums(int do_curwin)
6358 {
6359     win_T	*wp;
6360     tabpage_T	*tp;
6361 
6362     FOR_ALL_TAB_WINDOWS(tp, wp)
6363 	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
6364 	{
6365 	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
6366 		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
6367 	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
6368 		wp->w_topline = curbuf->b_ml.ml_line_count;
6369 	}
6370 }
6371 
6372 /*
6373  * A snapshot of the window sizes, to restore them after closing the help
6374  * window.
6375  * Only these fields are used:
6376  * fr_layout
6377  * fr_width
6378  * fr_height
6379  * fr_next
6380  * fr_child
6381  * fr_win (only valid for the old curwin, NULL otherwise)
6382  */
6383 
6384 /*
6385  * Create a snapshot of the current frame sizes.
6386  */
6387     void
6388 make_snapshot(int idx)
6389 {
6390     clear_snapshot(curtab, idx);
6391     make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
6392 }
6393 
6394     static void
6395 make_snapshot_rec(frame_T *fr, frame_T **frp)
6396 {
6397     *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
6398     if (*frp == NULL)
6399 	return;
6400     (*frp)->fr_layout = fr->fr_layout;
6401     (*frp)->fr_width = fr->fr_width;
6402     (*frp)->fr_height = fr->fr_height;
6403     if (fr->fr_next != NULL)
6404 	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
6405     if (fr->fr_child != NULL)
6406 	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
6407     if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
6408 	(*frp)->fr_win = curwin;
6409 }
6410 
6411 /*
6412  * Remove any existing snapshot.
6413  */
6414     static void
6415 clear_snapshot(tabpage_T *tp, int idx)
6416 {
6417     clear_snapshot_rec(tp->tp_snapshot[idx]);
6418     tp->tp_snapshot[idx] = NULL;
6419 }
6420 
6421     static void
6422 clear_snapshot_rec(frame_T *fr)
6423 {
6424     if (fr != NULL)
6425     {
6426 	clear_snapshot_rec(fr->fr_next);
6427 	clear_snapshot_rec(fr->fr_child);
6428 	vim_free(fr);
6429     }
6430 }
6431 
6432 /*
6433  * Restore a previously created snapshot, if there is any.
6434  * This is only done if the screen size didn't change and the window layout is
6435  * still the same.
6436  */
6437     void
6438 restore_snapshot(
6439     int		idx,
6440     int		close_curwin)	    /* closing current window */
6441 {
6442     win_T	*wp;
6443 
6444     if (curtab->tp_snapshot[idx] != NULL
6445 	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
6446 	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
6447 	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
6448     {
6449 	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
6450 	win_comp_pos();
6451 	if (wp != NULL && close_curwin)
6452 	    win_goto(wp);
6453 	redraw_all_later(CLEAR);
6454     }
6455     clear_snapshot(curtab, idx);
6456 }
6457 
6458 /*
6459  * Check if frames "sn" and "fr" have the same layout, same following frames
6460  * and same children.  And the window pointer is valid.
6461  */
6462     static int
6463 check_snapshot_rec(frame_T *sn, frame_T *fr)
6464 {
6465     if (sn->fr_layout != fr->fr_layout
6466 	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
6467 	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
6468 	    || (sn->fr_next != NULL
6469 		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
6470 	    || (sn->fr_child != NULL
6471 		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
6472 	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
6473 	return FAIL;
6474     return OK;
6475 }
6476 
6477 /*
6478  * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
6479  * following frames and children.
6480  * Returns a pointer to the old current window, or NULL.
6481  */
6482     static win_T *
6483 restore_snapshot_rec(frame_T *sn, frame_T *fr)
6484 {
6485     win_T	*wp = NULL;
6486     win_T	*wp2;
6487 
6488     fr->fr_height = sn->fr_height;
6489     fr->fr_width = sn->fr_width;
6490     if (fr->fr_layout == FR_LEAF)
6491     {
6492 	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
6493 	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
6494 	wp = sn->fr_win;
6495     }
6496     if (sn->fr_next != NULL)
6497     {
6498 	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
6499 	if (wp2 != NULL)
6500 	    wp = wp2;
6501     }
6502     if (sn->fr_child != NULL)
6503     {
6504 	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
6505 	if (wp2 != NULL)
6506 	    wp = wp2;
6507     }
6508     return wp;
6509 }
6510 
6511 #if defined(FEAT_EVAL) || defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \
6512 	|| defined(PROTO)
6513 /*
6514  * Set "win" to be the curwin and "tp" to be the current tab page.
6515  * restore_win() MUST be called to undo, also when FAIL is returned.
6516  * No autocommands will be executed until restore_win() is called.
6517  * When "no_display" is TRUE the display won't be affected, no redraw is
6518  * triggered, another tabpage access is limited.
6519  * Returns FAIL if switching to "win" failed.
6520  */
6521     int
6522 switch_win(
6523     win_T	**save_curwin,
6524     tabpage_T	**save_curtab,
6525     win_T	*win,
6526     tabpage_T	*tp,
6527     int		no_display)
6528 {
6529     block_autocmds();
6530     *save_curwin = curwin;
6531     if (tp != NULL)
6532     {
6533 	*save_curtab = curtab;
6534 	if (no_display)
6535 	{
6536 	    curtab->tp_firstwin = firstwin;
6537 	    curtab->tp_lastwin = lastwin;
6538 	    curtab = tp;
6539 	    firstwin = curtab->tp_firstwin;
6540 	    lastwin = curtab->tp_lastwin;
6541 	}
6542 	else
6543 	    goto_tabpage_tp(tp, FALSE, FALSE);
6544     }
6545     if (!win_valid(win))
6546 	return FAIL;
6547     curwin = win;
6548     curbuf = curwin->w_buffer;
6549     return OK;
6550 }
6551 
6552 /*
6553  * Restore current tabpage and window saved by switch_win(), if still valid.
6554  * When "no_display" is TRUE the display won't be affected, no redraw is
6555  * triggered.
6556  */
6557     void
6558 restore_win(
6559     win_T	*save_curwin UNUSED,
6560     tabpage_T	*save_curtab UNUSED,
6561     int		no_display UNUSED)
6562 {
6563     if (save_curtab != NULL && valid_tabpage(save_curtab))
6564     {
6565 	if (no_display)
6566 	{
6567 	    curtab->tp_firstwin = firstwin;
6568 	    curtab->tp_lastwin = lastwin;
6569 	    curtab = save_curtab;
6570 	    firstwin = curtab->tp_firstwin;
6571 	    lastwin = curtab->tp_lastwin;
6572 	}
6573 	else
6574 	    goto_tabpage_tp(save_curtab, FALSE, FALSE);
6575     }
6576     if (win_valid(save_curwin))
6577     {
6578 	curwin = save_curwin;
6579 	curbuf = curwin->w_buffer;
6580     }
6581     unblock_autocmds();
6582 }
6583 
6584 /*
6585  * Make "buf" the current buffer.  restore_buffer() MUST be called to undo.
6586  * No autocommands will be executed.  Use aucmd_prepbuf() if there are any.
6587  */
6588     void
6589 switch_buffer(bufref_T *save_curbuf, buf_T *buf)
6590 {
6591     block_autocmds();
6592     set_bufref(save_curbuf, curbuf);
6593     --curbuf->b_nwindows;
6594     curbuf = buf;
6595     curwin->w_buffer = buf;
6596     ++curbuf->b_nwindows;
6597 }
6598 
6599 /*
6600  * Restore the current buffer after using switch_buffer().
6601  */
6602     void
6603 restore_buffer(bufref_T *save_curbuf)
6604 {
6605     unblock_autocmds();
6606     /* Check for valid buffer, just in case. */
6607     if (bufref_valid(save_curbuf))
6608     {
6609 	--curbuf->b_nwindows;
6610 	curwin->w_buffer = save_curbuf->br_buf;
6611 	curbuf = save_curbuf->br_buf;
6612 	++curbuf->b_nwindows;
6613     }
6614 }
6615 #endif
6616 
6617 #if defined(FEAT_GUI) || defined(PROTO)
6618 /*
6619  * Return TRUE if there is any vertically split window.
6620  */
6621     int
6622 win_hasvertsplit(void)
6623 {
6624     frame_T	*fr;
6625 
6626     if (topframe->fr_layout == FR_ROW)
6627 	return TRUE;
6628 
6629     if (topframe->fr_layout == FR_COL)
6630 	for (fr = topframe->fr_child; fr != NULL; fr = fr->fr_next)
6631 	    if (fr->fr_layout == FR_ROW)
6632 		return TRUE;
6633 
6634     return FALSE;
6635 }
6636 #endif
6637 
6638 #if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
6639 /*
6640  * Add match to the match list of window 'wp'.  The pattern 'pat' will be
6641  * highlighted with the group 'grp' with priority 'prio'.
6642  * Optionally, a desired ID 'id' can be specified (greater than or equal to 1).
6643  * If no particular ID is desired, -1 must be specified for 'id'.
6644  * Return ID of added match, -1 on failure.
6645  */
6646     int
6647 match_add(
6648     win_T	*wp,
6649     char_u	*grp,
6650     char_u	*pat,
6651     int		prio,
6652     int		id,
6653     list_T	*pos_list,
6654     char_u      *conceal_char UNUSED) /* pointer to conceal replacement char */
6655 {
6656     matchitem_T	*cur;
6657     matchitem_T	*prev;
6658     matchitem_T	*m;
6659     int		hlg_id;
6660     regprog_T	*regprog = NULL;
6661     int		rtype = SOME_VALID;
6662 
6663     if (*grp == NUL || (pat != NULL && *pat == NUL))
6664 	return -1;
6665     if (id < -1 || id == 0)
6666     {
6667 	EMSGN(_("E799: Invalid ID: %ld (must be greater than or equal to 1)"), id);
6668 	return -1;
6669     }
6670     if (id != -1)
6671     {
6672 	cur = wp->w_match_head;
6673 	while (cur != NULL)
6674 	{
6675 	    if (cur->id == id)
6676 	    {
6677 		EMSGN(_("E801: ID already taken: %ld"), id);
6678 		return -1;
6679 	    }
6680 	    cur = cur->next;
6681 	}
6682     }
6683     if ((hlg_id = syn_namen2id(grp, (int)STRLEN(grp))) == 0)
6684     {
6685 	EMSG2(_(e_nogroup), grp);
6686 	return -1;
6687     }
6688     if (pat != NULL && (regprog = vim_regcomp(pat, RE_MAGIC)) == NULL)
6689     {
6690 	EMSG2(_(e_invarg2), pat);
6691 	return -1;
6692     }
6693 
6694     /* Find available match ID. */
6695     while (id == -1)
6696     {
6697 	cur = wp->w_match_head;
6698 	while (cur != NULL && cur->id != wp->w_next_match_id)
6699 	    cur = cur->next;
6700 	if (cur == NULL)
6701 	    id = wp->w_next_match_id;
6702 	wp->w_next_match_id++;
6703     }
6704 
6705     /* Build new match. */
6706     m = (matchitem_T *)alloc_clear(sizeof(matchitem_T));
6707     m->id = id;
6708     m->priority = prio;
6709     m->pattern = pat == NULL ? NULL : vim_strsave(pat);
6710     m->hlg_id = hlg_id;
6711     m->match.regprog = regprog;
6712     m->match.rmm_ic = FALSE;
6713     m->match.rmm_maxcol = 0;
6714 # if defined(FEAT_CONCEAL) && defined(FEAT_MBYTE)
6715     m->conceal_char = 0;
6716     if (conceal_char != NULL)
6717 	m->conceal_char = (*mb_ptr2char)(conceal_char);
6718 # endif
6719 
6720     /* Set up position matches */
6721     if (pos_list != NULL)
6722     {
6723 	linenr_T	toplnum = 0;
6724 	linenr_T	botlnum = 0;
6725 	listitem_T	*li;
6726 	int		i;
6727 
6728 	for (i = 0, li = pos_list->lv_first; li != NULL && i < MAXPOSMATCH;
6729 							i++, li = li->li_next)
6730 	{
6731 	    linenr_T	lnum = 0;
6732 	    colnr_T	col = 0;
6733 	    int		len = 1;
6734 	    list_T	*subl;
6735 	    listitem_T	*subli;
6736 	    int		error = FALSE;
6737 
6738 	    if (li->li_tv.v_type == VAR_LIST)
6739 	    {
6740 		subl = li->li_tv.vval.v_list;
6741 		if (subl == NULL)
6742 		    goto fail;
6743 		subli = subl->lv_first;
6744 		if (subli == NULL)
6745 		    goto fail;
6746 		lnum = get_tv_number_chk(&subli->li_tv, &error);
6747 		if (error == TRUE)
6748 		    goto fail;
6749 		if (lnum == 0)
6750 		{
6751 		    --i;
6752 		    continue;
6753 		}
6754 		m->pos.pos[i].lnum = lnum;
6755 		subli = subli->li_next;
6756 		if (subli != NULL)
6757 		{
6758 		    col = get_tv_number_chk(&subli->li_tv, &error);
6759 		    if (error == TRUE)
6760 			goto fail;
6761 		    subli = subli->li_next;
6762 		    if (subli != NULL)
6763 		    {
6764 			len = get_tv_number_chk(&subli->li_tv, &error);
6765 			if (error == TRUE)
6766 			    goto fail;
6767 		    }
6768 		}
6769 		m->pos.pos[i].col = col;
6770 		m->pos.pos[i].len = len;
6771 	    }
6772 	    else if (li->li_tv.v_type == VAR_NUMBER)
6773 	    {
6774 		if (li->li_tv.vval.v_number == 0)
6775 		{
6776 		    --i;
6777 		    continue;
6778 		}
6779 		m->pos.pos[i].lnum = li->li_tv.vval.v_number;
6780 		m->pos.pos[i].col = 0;
6781 		m->pos.pos[i].len = 0;
6782 	    }
6783 	    else
6784 	    {
6785 		EMSG(_("List or number required"));
6786 		goto fail;
6787 	    }
6788 	    if (toplnum == 0 || lnum < toplnum)
6789 		toplnum = lnum;
6790 	    if (botlnum == 0 || lnum >= botlnum)
6791 		botlnum = lnum + 1;
6792 	}
6793 
6794 	/* Calculate top and bottom lines for redrawing area */
6795 	if (toplnum != 0)
6796 	{
6797 	    if (wp->w_buffer->b_mod_set)
6798 	    {
6799 		if (wp->w_buffer->b_mod_top > toplnum)
6800 		    wp->w_buffer->b_mod_top = toplnum;
6801 		if (wp->w_buffer->b_mod_bot < botlnum)
6802 		    wp->w_buffer->b_mod_bot = botlnum;
6803 	    }
6804 	    else
6805 	    {
6806 		wp->w_buffer->b_mod_set = TRUE;
6807 		wp->w_buffer->b_mod_top = toplnum;
6808 		wp->w_buffer->b_mod_bot = botlnum;
6809 		wp->w_buffer->b_mod_xlines = 0;
6810 	    }
6811 	    m->pos.toplnum = toplnum;
6812 	    m->pos.botlnum = botlnum;
6813 	    rtype = VALID;
6814 	}
6815     }
6816 
6817     /* Insert new match.  The match list is in ascending order with regard to
6818      * the match priorities. */
6819     cur = wp->w_match_head;
6820     prev = cur;
6821     while (cur != NULL && prio >= cur->priority)
6822     {
6823 	prev = cur;
6824 	cur = cur->next;
6825     }
6826     if (cur == prev)
6827 	wp->w_match_head = m;
6828     else
6829 	prev->next = m;
6830     m->next = cur;
6831 
6832     redraw_later(rtype);
6833     return id;
6834 
6835 fail:
6836     vim_free(m);
6837     return -1;
6838 }
6839 
6840 /*
6841  * Delete match with ID 'id' in the match list of window 'wp'.
6842  * Print error messages if 'perr' is TRUE.
6843  */
6844     int
6845 match_delete(win_T *wp, int id, int perr)
6846 {
6847     matchitem_T	*cur = wp->w_match_head;
6848     matchitem_T	*prev = cur;
6849     int		rtype = SOME_VALID;
6850 
6851     if (id < 1)
6852     {
6853 	if (perr == TRUE)
6854 	    EMSGN(_("E802: Invalid ID: %ld (must be greater than or equal to 1)"),
6855 									  id);
6856 	return -1;
6857     }
6858     while (cur != NULL && cur->id != id)
6859     {
6860 	prev = cur;
6861 	cur = cur->next;
6862     }
6863     if (cur == NULL)
6864     {
6865 	if (perr == TRUE)
6866 	    EMSGN(_("E803: ID not found: %ld"), id);
6867 	return -1;
6868     }
6869     if (cur == prev)
6870 	wp->w_match_head = cur->next;
6871     else
6872 	prev->next = cur->next;
6873     vim_regfree(cur->match.regprog);
6874     vim_free(cur->pattern);
6875     if (cur->pos.toplnum != 0)
6876     {
6877 	if (wp->w_buffer->b_mod_set)
6878 	{
6879 	    if (wp->w_buffer->b_mod_top > cur->pos.toplnum)
6880 		wp->w_buffer->b_mod_top = cur->pos.toplnum;
6881 	    if (wp->w_buffer->b_mod_bot < cur->pos.botlnum)
6882 		wp->w_buffer->b_mod_bot = cur->pos.botlnum;
6883 	}
6884 	else
6885 	{
6886 	    wp->w_buffer->b_mod_set = TRUE;
6887 	    wp->w_buffer->b_mod_top = cur->pos.toplnum;
6888 	    wp->w_buffer->b_mod_bot = cur->pos.botlnum;
6889 	    wp->w_buffer->b_mod_xlines = 0;
6890 	}
6891 	rtype = VALID;
6892     }
6893     vim_free(cur);
6894     redraw_later(rtype);
6895     return 0;
6896 }
6897 
6898 /*
6899  * Delete all matches in the match list of window 'wp'.
6900  */
6901     void
6902 clear_matches(win_T *wp)
6903 {
6904     matchitem_T *m;
6905 
6906     while (wp->w_match_head != NULL)
6907     {
6908 	m = wp->w_match_head->next;
6909 	vim_regfree(wp->w_match_head->match.regprog);
6910 	vim_free(wp->w_match_head->pattern);
6911 	vim_free(wp->w_match_head);
6912 	wp->w_match_head = m;
6913     }
6914     redraw_later(SOME_VALID);
6915 }
6916 
6917 /*
6918  * Get match from ID 'id' in window 'wp'.
6919  * Return NULL if match not found.
6920  */
6921     matchitem_T *
6922 get_match(win_T *wp, int id)
6923 {
6924     matchitem_T *cur = wp->w_match_head;
6925 
6926     while (cur != NULL && cur->id != id)
6927 	cur = cur->next;
6928     return cur;
6929 }
6930 #endif
6931 
6932 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
6933     int
6934 get_win_number(win_T *wp, win_T *first_win)
6935 {
6936     int		i = 1;
6937     win_T	*w;
6938 
6939     for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
6940 	++i;
6941 
6942     if (w == NULL)
6943 	return 0;
6944     else
6945 	return i;
6946 }
6947 
6948     int
6949 get_tab_number(tabpage_T *tp UNUSED)
6950 {
6951     int		i = 1;
6952     tabpage_T	*t;
6953 
6954     for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
6955 	++i;
6956 
6957     if (t == NULL)
6958 	return 0;
6959     else
6960 	return i;
6961 }
6962 #endif
6963 
6964 /*
6965  * Return TRUE if "topfrp" and its children are at the right height.
6966  */
6967     static int
6968 frame_check_height(frame_T *topfrp, int height)
6969 {
6970     frame_T *frp;
6971 
6972     if (topfrp->fr_height != height)
6973 	return FALSE;
6974 
6975     if (topfrp->fr_layout == FR_ROW)
6976 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
6977 	    if (frp->fr_height != height)
6978 		return FALSE;
6979 
6980     return TRUE;
6981 }
6982 
6983 /*
6984  * Return TRUE if "topfrp" and its children are at the right width.
6985  */
6986     static int
6987 frame_check_width(frame_T *topfrp, int width)
6988 {
6989     frame_T *frp;
6990 
6991     if (topfrp->fr_width != width)
6992 	return FALSE;
6993 
6994     if (topfrp->fr_layout == FR_COL)
6995 	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
6996 	    if (frp->fr_width != width)
6997 		return FALSE;
6998 
6999     return TRUE;
7000 }
7001 
7002 #if defined(FEAT_EVAL) || defined(PROTO)
7003     int
7004 win_getid(typval_T *argvars)
7005 {
7006     int	    winnr;
7007     win_T   *wp;
7008 
7009     if (argvars[0].v_type == VAR_UNKNOWN)
7010 	return curwin->w_id;
7011     winnr = get_tv_number(&argvars[0]);
7012     if (winnr > 0)
7013     {
7014 	if (argvars[1].v_type == VAR_UNKNOWN)
7015 	    wp = firstwin;
7016 	else
7017 	{
7018 	    tabpage_T	*tp;
7019 	    int		tabnr = get_tv_number(&argvars[1]);
7020 
7021 	    FOR_ALL_TABPAGES(tp)
7022 		if (--tabnr == 0)
7023 		    break;
7024 	    if (tp == NULL)
7025 		return -1;
7026 	    if (tp == curtab)
7027 		wp = firstwin;
7028 	    else
7029 		wp = tp->tp_firstwin;
7030 	}
7031 	for ( ; wp != NULL; wp = wp->w_next)
7032 	    if (--winnr == 0)
7033 		return wp->w_id;
7034     }
7035     return 0;
7036 }
7037 
7038     int
7039 win_gotoid(typval_T *argvars)
7040 {
7041     win_T	*wp;
7042     tabpage_T   *tp;
7043     int		id = get_tv_number(&argvars[0]);
7044 
7045     FOR_ALL_TAB_WINDOWS(tp, wp)
7046 	    if (wp->w_id == id)
7047 	    {
7048 		goto_tabpage_win(tp, wp);
7049 		return 1;
7050 	    }
7051     return 0;
7052 }
7053 
7054     void
7055 win_id2tabwin(typval_T *argvars, list_T *list)
7056 {
7057     win_T	*wp;
7058     tabpage_T   *tp;
7059     int		winnr = 1;
7060     int		tabnr = 1;
7061     int		id = get_tv_number(&argvars[0]);
7062 
7063     FOR_ALL_TABPAGES(tp)
7064     {
7065 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
7066 	{
7067 	    if (wp->w_id == id)
7068 	    {
7069 		list_append_number(list, tabnr);
7070 		list_append_number(list, winnr);
7071 		return;
7072 	    }
7073 	    ++winnr;
7074 	}
7075 	++tabnr;
7076 	winnr = 1;
7077     }
7078     list_append_number(list, 0);
7079     list_append_number(list, 0);
7080 }
7081 
7082     win_T *
7083 win_id2wp(typval_T *argvars)
7084 {
7085     win_T	*wp;
7086     tabpage_T   *tp;
7087     int		id = get_tv_number(&argvars[0]);
7088 
7089     FOR_ALL_TAB_WINDOWS(tp, wp)
7090 	if (wp->w_id == id)
7091 	    return wp;
7092 
7093     return NULL;
7094 }
7095 
7096     int
7097 win_id2win(typval_T *argvars)
7098 {
7099     win_T   *wp;
7100     int	    nr = 1;
7101     int	    id = get_tv_number(&argvars[0]);
7102 
7103     FOR_ALL_WINDOWS(wp)
7104     {
7105 	if (wp->w_id == id)
7106 	    return nr;
7107 	++nr;
7108     }
7109     return 0;
7110 }
7111 
7112     void
7113 win_findbuf(typval_T *argvars, list_T *list)
7114 {
7115     win_T	*wp;
7116     tabpage_T   *tp;
7117     int		bufnr = get_tv_number(&argvars[0]);
7118 
7119     FOR_ALL_TAB_WINDOWS(tp, wp)
7120 	    if (wp->w_buffer->b_fnum == bufnr)
7121 		list_append_number(list, wp->w_id);
7122 }
7123 
7124 #endif
7125