xref: /vim-8.2.3635/src/window.c (revision 577fadfc)
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 void cmd_with_count(char *cmd, char_u *bufp, size_t bufsize, long Prenum);
13 static void win_init(win_T *newp, win_T *oldp, int flags);
14 static void win_init_some(win_T *newp, win_T *oldp);
15 static void frame_comp_pos(frame_T *topfrp, int *row, int *col);
16 static void frame_setheight(frame_T *curfrp, int height);
17 static void frame_setwidth(frame_T *curfrp, int width);
18 static void win_exchange(long);
19 static void win_rotate(int, int);
20 static void win_totop(int size, int flags);
21 static void win_equal_rec(win_T *next_curwin, int current, frame_T *topfr, int dir, int col, int row, int width, int height);
22 static win_T *win_free_mem(win_T *win, int *dirp, tabpage_T *tp);
23 static frame_T *win_altframe(win_T *win, tabpage_T *tp);
24 static tabpage_T *alt_tabpage(void);
25 static win_T *frame2win(frame_T *frp);
26 static int frame_has_win(frame_T *frp, win_T *wp);
27 static void frame_new_height(frame_T *topfrp, int height, int topfirst, int wfh);
28 static int frame_fixed_height(frame_T *frp);
29 static int frame_fixed_width(frame_T *frp);
30 static void frame_add_statusline(frame_T *frp);
31 static void frame_new_width(frame_T *topfrp, int width, int leftfirst, int wfw);
32 static void frame_add_vsep(frame_T *frp);
33 static int frame_minwidth(frame_T *topfrp, win_T *next_curwin);
34 static void frame_fix_width(win_T *wp);
35 static int win_alloc_firstwin(win_T *oldwin);
36 static void new_frame(win_T *wp);
37 static tabpage_T *alloc_tabpage(void);
38 static int leave_tabpage(buf_T *new_curbuf, int trigger_leave_autocmds);
39 static void enter_tabpage(tabpage_T *tp, buf_T *old_curbuf, int trigger_enter_autocmds, int trigger_leave_autocmds);
40 static void frame_fix_height(win_T *wp);
41 static int frame_minheight(frame_T *topfrp, win_T *next_curwin);
42 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);
43 static void win_free(win_T *wp, tabpage_T *tp);
44 static void frame_append(frame_T *after, frame_T *frp);
45 static void frame_insert(frame_T *before, frame_T *frp);
46 static void frame_remove(frame_T *frp);
47 static void win_goto_ver(int up, long count);
48 static void win_goto_hor(int left, long count);
49 static void frame_add_height(frame_T *frp, int n);
50 static void last_status_rec(frame_T *fr, int statusline);
51 
52 static void make_snapshot_rec(frame_T *fr, frame_T **frp);
53 static void clear_snapshot(tabpage_T *tp, int idx);
54 static void clear_snapshot_rec(frame_T *fr);
55 static int check_snapshot_rec(frame_T *sn, frame_T *fr);
56 static win_T *restore_snapshot_rec(frame_T *sn, frame_T *fr);
57 
58 static int frame_check_height(frame_T *topfrp, int height);
59 static int frame_check_width(frame_T *topfrp, int width);
60 
61 static win_T *win_alloc(win_T *after, int hidden);
62 
63 #define NOWIN		(win_T *)-1	/* non-existing window */
64 
65 #define ROWS_AVAIL (Rows - p_ch - tabline_height())
66 
67 static char *m_onlyone = N_("Already only one window");
68 
69 /*
70  * All CTRL-W window commands are handled here, called from normal_cmd().
71  */
72     void
73 do_window(
74     int		nchar,
75     long	Prenum,
76     int		xchar)	    /* extra char from ":wincmd gx" or NUL */
77 {
78     long	Prenum1;
79     win_T	*wp;
80 #if defined(FEAT_SEARCHPATH) || defined(FEAT_FIND_ID)
81     char_u	*ptr;
82     linenr_T    lnum = -1;
83 #endif
84 #ifdef FEAT_FIND_ID
85     int		type = FIND_DEFINE;
86     int		len;
87 #endif
88     char_u	cbuf[40];
89 
90     Prenum1 = Prenum == 0 ? 1 : Prenum;
91 
92 #ifdef FEAT_CMDWIN
93 # define CHECK_CMDWIN \
94     do { \
95 	if (cmdwin_type != 0) \
96 	{ \
97 	    emsg(_(e_cmdwin)); \
98 	    return; \
99 	} \
100     } while (0)
101 #else
102 # define CHECK_CMDWIN do { /**/ } while (0)
103 #endif
104 
105     switch (nchar)
106     {
107 /* split current window in two parts, horizontally */
108     case 'S':
109     case Ctrl_S:
110     case 's':
111 		CHECK_CMDWIN;
112 		reset_VIsual_and_resel();	/* stop Visual mode */
113 #ifdef FEAT_QUICKFIX
114 		/* When splitting the quickfix window open a new buffer in it,
115 		 * don't replicate the quickfix buffer. */
116 		if (bt_quickfix(curbuf))
117 		    goto newwindow;
118 #endif
119 #ifdef FEAT_GUI
120 		need_mouse_correct = TRUE;
121 #endif
122 		(void)win_split((int)Prenum, 0);
123 		break;
124 
125 /* split current window in two parts, vertically */
126     case Ctrl_V:
127     case 'v':
128 		CHECK_CMDWIN;
129 		reset_VIsual_and_resel();	/* stop Visual mode */
130 #ifdef FEAT_QUICKFIX
131 		/* When splitting the quickfix window open a new buffer in it,
132 		 * don't replicate the quickfix buffer. */
133 		if (bt_quickfix(curbuf))
134 		    goto newwindow;
135 #endif
136 #ifdef FEAT_GUI
137 		need_mouse_correct = TRUE;
138 #endif
139 		(void)win_split((int)Prenum, WSP_VERT);
140 		break;
141 
142 /* split current window and edit alternate file */
143     case Ctrl_HAT:
144     case '^':
145 		CHECK_CMDWIN;
146 		reset_VIsual_and_resel();	/* stop Visual mode */
147 
148 		if (buflist_findnr(Prenum == 0
149 					? curwin->w_alt_fnum : Prenum) == NULL)
150 		{
151 		    if (Prenum == 0)
152 			emsg(_(e_noalt));
153 		    else
154 			semsg(_("E92: Buffer %ld not found"), Prenum);
155 		    break;
156 		}
157 
158 		if (!curbuf_locked() && win_split(0, 0) == OK)
159 		    (void)buflist_getfile(
160 			    Prenum == 0 ? curwin->w_alt_fnum : Prenum,
161 			    (linenr_T)0, GETF_ALT, FALSE);
162 		break;
163 
164 /* open new window */
165     case Ctrl_N:
166     case 'n':
167 		CHECK_CMDWIN;
168 		reset_VIsual_and_resel();	/* stop Visual mode */
169 #ifdef FEAT_QUICKFIX
170 newwindow:
171 #endif
172 		if (Prenum)
173 		    /* window height */
174 		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
175 		else
176 		    cbuf[0] = NUL;
177 #if defined(FEAT_QUICKFIX)
178 		if (nchar == 'v' || nchar == Ctrl_V)
179 		    STRCAT(cbuf, "v");
180 #endif
181 		STRCAT(cbuf, "new");
182 		do_cmdline_cmd(cbuf);
183 		break;
184 
185 /* quit current window */
186     case Ctrl_Q:
187     case 'q':
188 		reset_VIsual_and_resel();	/* stop Visual mode */
189 		cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
190 		do_cmdline_cmd(cbuf);
191 		break;
192 
193 /* close current window */
194     case Ctrl_C:
195     case 'c':
196 		reset_VIsual_and_resel();	/* stop Visual mode */
197 		cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
198 		do_cmdline_cmd(cbuf);
199 		break;
200 
201 #if defined(FEAT_QUICKFIX)
202 /* close preview window */
203     case Ctrl_Z:
204     case 'z':
205 		CHECK_CMDWIN;
206 		reset_VIsual_and_resel();	/* stop Visual mode */
207 		do_cmdline_cmd((char_u *)"pclose");
208 		break;
209 
210 /* cursor to preview window */
211     case 'P':
212 		FOR_ALL_WINDOWS(wp)
213 		    if (wp->w_p_pvw)
214 			break;
215 		if (wp == NULL)
216 		    emsg(_("E441: There is no preview window"));
217 		else
218 		    win_goto(wp);
219 		break;
220 #endif
221 
222 /* close all but current window */
223     case Ctrl_O:
224     case 'o':
225 		CHECK_CMDWIN;
226 		reset_VIsual_and_resel();	/* stop Visual mode */
227 		cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
228 		do_cmdline_cmd(cbuf);
229 		break;
230 
231 /* cursor to next window with wrap around */
232     case Ctrl_W:
233     case 'w':
234 /* cursor to previous window with wrap around */
235     case 'W':
236 		CHECK_CMDWIN;
237 		if (ONE_WINDOW && Prenum != 1)	/* just one window */
238 		    beep_flush();
239 		else
240 		{
241 		    if (Prenum)			/* go to specified window */
242 		    {
243 			for (wp = firstwin; --Prenum > 0; )
244 			{
245 			    if (wp->w_next == NULL)
246 				break;
247 			    else
248 				wp = wp->w_next;
249 			}
250 		    }
251 		    else
252 		    {
253 			if (nchar == 'W')	    /* go to previous window */
254 			{
255 			    wp = curwin->w_prev;
256 			    if (wp == NULL)
257 				wp = lastwin;	    /* wrap around */
258 			}
259 			else			    /* go to next window */
260 			{
261 			    wp = curwin->w_next;
262 			    if (wp == NULL)
263 				wp = firstwin;	    /* wrap around */
264 			}
265 		    }
266 		    win_goto(wp);
267 		}
268 		break;
269 
270 /* cursor to window below */
271     case 'j':
272     case K_DOWN:
273     case Ctrl_J:
274 		CHECK_CMDWIN;
275 		win_goto_ver(FALSE, Prenum1);
276 		break;
277 
278 /* cursor to window above */
279     case 'k':
280     case K_UP:
281     case Ctrl_K:
282 		CHECK_CMDWIN;
283 		win_goto_ver(TRUE, Prenum1);
284 		break;
285 
286 /* cursor to left window */
287     case 'h':
288     case K_LEFT:
289     case Ctrl_H:
290     case K_BS:
291 		CHECK_CMDWIN;
292 		win_goto_hor(TRUE, Prenum1);
293 		break;
294 
295 /* cursor to right window */
296     case 'l':
297     case K_RIGHT:
298     case Ctrl_L:
299 		CHECK_CMDWIN;
300 		win_goto_hor(FALSE, Prenum1);
301 		break;
302 
303 /* move window to new tab page */
304     case 'T':
305 		if (one_window())
306 		    msg(_(m_onlyone));
307 		else
308 		{
309 		    tabpage_T	*oldtab = curtab;
310 		    tabpage_T	*newtab;
311 
312 		    /* First create a new tab with the window, then go back to
313 		     * the old tab and close the window there. */
314 		    wp = curwin;
315 		    if (win_new_tabpage((int)Prenum) == OK
316 						     && valid_tabpage(oldtab))
317 		    {
318 			newtab = curtab;
319 			goto_tabpage_tp(oldtab, TRUE, TRUE);
320 			if (curwin == wp)
321 			    win_close(curwin, FALSE);
322 			if (valid_tabpage(newtab))
323 			    goto_tabpage_tp(newtab, TRUE, TRUE);
324 		    }
325 		}
326 		break;
327 
328 /* cursor to top-left window */
329     case 't':
330     case Ctrl_T:
331 		win_goto(firstwin);
332 		break;
333 
334 /* cursor to bottom-right window */
335     case 'b':
336     case Ctrl_B:
337 		win_goto(lastwin);
338 		break;
339 
340 /* cursor to last accessed (previous) window */
341     case 'p':
342     case Ctrl_P:
343 		if (!win_valid(prevwin))
344 		    beep_flush();
345 		else
346 		    win_goto(prevwin);
347 		break;
348 
349 /* exchange current and next window */
350     case 'x':
351     case Ctrl_X:
352 		CHECK_CMDWIN;
353 		win_exchange(Prenum);
354 		break;
355 
356 /* rotate windows downwards */
357     case Ctrl_R:
358     case 'r':
359 		CHECK_CMDWIN;
360 		reset_VIsual_and_resel();	/* stop Visual mode */
361 		win_rotate(FALSE, (int)Prenum1);    /* downwards */
362 		break;
363 
364 /* rotate windows upwards */
365     case 'R':
366 		CHECK_CMDWIN;
367 		reset_VIsual_and_resel();	/* stop Visual mode */
368 		win_rotate(TRUE, (int)Prenum1);	    /* upwards */
369 		break;
370 
371 /* move window to the very top/bottom/left/right */
372     case 'K':
373     case 'J':
374     case 'H':
375     case 'L':
376 		CHECK_CMDWIN;
377 		win_totop((int)Prenum,
378 			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
379 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
380 		break;
381 
382 /* make all windows the same height */
383     case '=':
384 #ifdef FEAT_GUI
385 		need_mouse_correct = TRUE;
386 #endif
387 		win_equal(NULL, FALSE, 'b');
388 		break;
389 
390 /* increase current window height */
391     case '+':
392 #ifdef FEAT_GUI
393 		need_mouse_correct = TRUE;
394 #endif
395 		win_setheight(curwin->w_height + (int)Prenum1);
396 		break;
397 
398 /* decrease current window height */
399     case '-':
400 #ifdef FEAT_GUI
401 		need_mouse_correct = TRUE;
402 #endif
403 		win_setheight(curwin->w_height - (int)Prenum1);
404 		break;
405 
406 /* set current window height */
407     case Ctrl__:
408     case '_':
409 #ifdef FEAT_GUI
410 		need_mouse_correct = TRUE;
411 #endif
412 		win_setheight(Prenum ? (int)Prenum : 9999);
413 		break;
414 
415 /* increase current window width */
416     case '>':
417 #ifdef FEAT_GUI
418 		need_mouse_correct = TRUE;
419 #endif
420 		win_setwidth(curwin->w_width + (int)Prenum1);
421 		break;
422 
423 /* decrease current window width */
424     case '<':
425 #ifdef FEAT_GUI
426 		need_mouse_correct = TRUE;
427 #endif
428 		win_setwidth(curwin->w_width - (int)Prenum1);
429 		break;
430 
431 /* set current window width */
432     case '|':
433 #ifdef FEAT_GUI
434 		need_mouse_correct = TRUE;
435 #endif
436 		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
437 		break;
438 
439 /* jump to tag and split window if tag exists (in preview window) */
440 #if defined(FEAT_QUICKFIX)
441     case '}':
442 		CHECK_CMDWIN;
443 		if (Prenum)
444 		    g_do_tagpreview = Prenum;
445 		else
446 		    g_do_tagpreview = p_pvh;
447 #endif
448 		/* FALLTHROUGH */
449     case ']':
450     case Ctrl_RSB:
451 		CHECK_CMDWIN;
452 		/* keep Visual mode, can select words to use as a tag */
453 		if (Prenum)
454 		    postponed_split = Prenum;
455 		else
456 		    postponed_split = -1;
457 #ifdef FEAT_QUICKFIX
458 		if (nchar != '}')
459 		    g_do_tagpreview = 0;
460 #endif
461 
462 		/* Execute the command right here, required when "wincmd ]"
463 		 * was used in a function. */
464 		do_nv_ident(Ctrl_RSB, NUL);
465 		break;
466 
467 #ifdef FEAT_SEARCHPATH
468 /* edit file name under cursor in a new window */
469     case 'f':
470     case 'F':
471     case Ctrl_F:
472 wingotofile:
473 		CHECK_CMDWIN;
474 
475 		ptr = grab_file_name(Prenum1, &lnum);
476 		if (ptr != NULL)
477 		{
478 		    tabpage_T	*oldtab = curtab;
479 		    win_T	*oldwin = curwin;
480 # ifdef FEAT_GUI
481 		    need_mouse_correct = TRUE;
482 # endif
483 		    setpcmark();
484 		    if (win_split(0, 0) == OK)
485 		    {
486 			RESET_BINDING(curwin);
487 			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
488 						   ECMD_HIDE, NULL) == FAIL)
489 			{
490 			    /* Failed to open the file, close the window
491 			     * opened for it. */
492 			    win_close(curwin, FALSE);
493 			    goto_tabpage_win(oldtab, oldwin);
494 			}
495 			else if (nchar == 'F' && lnum >= 0)
496 			{
497 			    curwin->w_cursor.lnum = lnum;
498 			    check_cursor_lnum();
499 			    beginline(BL_SOL | BL_FIX);
500 			}
501 		    }
502 		    vim_free(ptr);
503 		}
504 		break;
505 #endif
506 
507 #ifdef FEAT_FIND_ID
508 /* Go to the first occurrence of the identifier under cursor along path in a
509  * new window -- webb
510  */
511     case 'i':			    /* Go to any match */
512     case Ctrl_I:
513 		type = FIND_ANY;
514 		/* FALLTHROUGH */
515     case 'd':			    /* Go to definition, using 'define' */
516     case Ctrl_D:
517 		CHECK_CMDWIN;
518 		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
519 		    break;
520 		find_pattern_in_path(ptr, 0, len, TRUE,
521 			Prenum == 0 ? TRUE : FALSE, type,
522 			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
523 		curwin->w_set_curswant = TRUE;
524 		break;
525 #endif
526 
527 /* Quickfix window only: view the result under the cursor in a new split. */
528 #if defined(FEAT_QUICKFIX)
529     case K_KENTER:
530     case CAR:
531 		if (bt_quickfix(curbuf))
532 		    qf_view_result(TRUE);
533 		break;
534 #endif
535 
536 /* CTRL-W g  extended commands */
537     case 'g':
538     case Ctrl_G:
539 		CHECK_CMDWIN;
540 #ifdef USE_ON_FLY_SCROLL
541 		dont_scroll = TRUE;		/* disallow scrolling here */
542 #endif
543 		++no_mapping;
544 		++allow_keys;   /* no mapping for xchar, but allow key codes */
545 		if (xchar == NUL)
546 		    xchar = plain_vgetc();
547 		LANGMAP_ADJUST(xchar, TRUE);
548 		--no_mapping;
549 		--allow_keys;
550 #ifdef FEAT_CMDL_INFO
551 		(void)add_to_showcmd(xchar);
552 #endif
553 		switch (xchar)
554 		{
555 #if defined(FEAT_QUICKFIX)
556 		    case '}':
557 			xchar = Ctrl_RSB;
558 			if (Prenum)
559 			    g_do_tagpreview = Prenum;
560 			else
561 			    g_do_tagpreview = p_pvh;
562 #endif
563 			/* FALLTHROUGH */
564 		    case ']':
565 		    case Ctrl_RSB:
566 			/* keep Visual mode, can select words to use as a tag */
567 			if (Prenum)
568 			    postponed_split = Prenum;
569 			else
570 			    postponed_split = -1;
571 
572 			/* Execute the command right here, required when
573 			 * "wincmd g}" was used in a function. */
574 			do_nv_ident('g', xchar);
575 			break;
576 
577 #ifdef FEAT_SEARCHPATH
578 		    case 'f':	    /* CTRL-W gf: "gf" in a new tab page */
579 		    case 'F':	    /* CTRL-W gF: "gF" in a new tab page */
580 			cmdmod.tab = tabpage_index(curtab) + 1;
581 			nchar = xchar;
582 			goto wingotofile;
583 #endif
584 		    case 't':	    // CTRL-W gt: go to next tab page
585 			goto_tabpage((int)Prenum);
586 			break;
587 
588 		    case 'T':	    // CTRL-W gT: go to previous tab page
589 			goto_tabpage(-(int)Prenum1);
590 			break;
591 
592 		    default:
593 			beep_flush();
594 			break;
595 		}
596 		break;
597 
598     default:	beep_flush();
599 		break;
600     }
601 }
602 
603 /*
604  * Figure out the address type for ":wnncmd".
605  */
606     void
607 get_wincmd_addr_type(char_u *arg, exarg_T *eap)
608 {
609     switch (*arg)
610     {
611     case 'S':
612     case Ctrl_S:
613     case 's':
614     case Ctrl_N:
615     case 'n':
616     case 'j':
617     case Ctrl_J:
618     case 'k':
619     case Ctrl_K:
620     case 'T':
621     case Ctrl_R:
622     case 'r':
623     case 'R':
624     case 'K':
625     case 'J':
626     case '+':
627     case '-':
628     case Ctrl__:
629     case '_':
630     case '|':
631     case ']':
632     case Ctrl_RSB:
633     case 'g':
634     case Ctrl_G:
635     case Ctrl_V:
636     case 'v':
637     case 'h':
638     case Ctrl_H:
639     case 'l':
640     case Ctrl_L:
641     case 'H':
642     case 'L':
643     case '>':
644     case '<':
645 #if defined(FEAT_QUICKFIX)
646     case '}':
647 #endif
648 #ifdef FEAT_SEARCHPATH
649     case 'f':
650     case 'F':
651     case Ctrl_F:
652 #endif
653 #ifdef FEAT_FIND_ID
654     case 'i':
655     case Ctrl_I:
656     case 'd':
657     case Ctrl_D:
658 #endif
659 		/* window size or any count */
660 		eap->addr_type = ADDR_LINES;
661 		break;
662 
663     case Ctrl_HAT:
664     case '^':
665 		/* buffer number */
666 		eap->addr_type = ADDR_BUFFERS;
667 		break;
668 
669     case Ctrl_Q:
670     case 'q':
671     case Ctrl_C:
672     case 'c':
673     case Ctrl_O:
674     case 'o':
675     case Ctrl_W:
676     case 'w':
677     case 'W':
678     case 'x':
679     case Ctrl_X:
680 		/* window number */
681 		eap->addr_type = ADDR_WINDOWS;
682 		break;
683 
684 #if defined(FEAT_QUICKFIX)
685     case Ctrl_Z:
686     case 'z':
687     case 'P':
688 #endif
689     case 't':
690     case Ctrl_T:
691     case 'b':
692     case Ctrl_B:
693     case 'p':
694     case Ctrl_P:
695     case '=':
696     case CAR:
697 		/* no count */
698 		eap->addr_type = 0;
699 		break;
700     }
701 }
702 
703     static void
704 cmd_with_count(
705     char	*cmd,
706     char_u	*bufp,
707     size_t	bufsize,
708     long	Prenum)
709 {
710     size_t	len = STRLEN(cmd);
711 
712     STRCPY(bufp, cmd);
713     if (Prenum > 0)
714 	vim_snprintf((char *)bufp + len, bufsize - len, "%ld", Prenum);
715 }
716 
717 /*
718  * split the current window, implements CTRL-W s and :split
719  *
720  * "size" is the height or width for the new window, 0 to use half of current
721  * height or width.
722  *
723  * "flags":
724  * WSP_ROOM: require enough room for new window
725  * WSP_VERT: vertical split.
726  * WSP_TOP:  open window at the top-left of the shell (help window).
727  * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
728  * WSP_HELP: creating the help window, keep layout snapshot
729  *
730  * return FAIL for failure, OK otherwise
731  */
732     int
733 win_split(int size, int flags)
734 {
735     /* When the ":tab" modifier was used open a new tab page instead. */
736     if (may_open_tabpage() == OK)
737 	return OK;
738 
739     /* Add flags from ":vertical", ":topleft" and ":botright". */
740     flags |= cmdmod.split;
741     if ((flags & WSP_TOP) && (flags & WSP_BOT))
742     {
743 	emsg(_("E442: Can't split topleft and botright at the same time"));
744 	return FAIL;
745     }
746 
747     /* When creating the help window make a snapshot of the window layout.
748      * Otherwise clear the snapshot, it's now invalid. */
749     if (flags & WSP_HELP)
750 	make_snapshot(SNAP_HELP_IDX);
751     else
752 	clear_snapshot(curtab, SNAP_HELP_IDX);
753 
754     return win_split_ins(size, flags, NULL, 0);
755 }
756 
757 /*
758  * When "new_wp" is NULL: split the current window in two.
759  * When "new_wp" is not NULL: insert this window at the far
760  * top/left/right/bottom.
761  * return FAIL for failure, OK otherwise
762  */
763     int
764 win_split_ins(
765     int		size,
766     int		flags,
767     win_T	*new_wp,
768     int		dir)
769 {
770     win_T	*wp = new_wp;
771     win_T	*oldwin;
772     int		new_size = size;
773     int		i;
774     int		need_status = 0;
775     int		do_equal = FALSE;
776     int		needed;
777     int		available;
778     int		oldwin_height = 0;
779     int		layout;
780     frame_T	*frp, *curfrp, *frp2, *prevfrp;
781     int		before;
782     int		minheight;
783     int		wmh1;
784     int		did_set_fraction = FALSE;
785 
786     if (flags & WSP_TOP)
787 	oldwin = firstwin;
788     else if (flags & WSP_BOT)
789 	oldwin = lastwin;
790     else
791 	oldwin = curwin;
792 
793     /* add a status line when p_ls == 1 and splitting the first window */
794     if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
795     {
796 	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
797 	{
798 	    emsg(_(e_noroom));
799 	    return FAIL;
800 	}
801 	need_status = STATUS_HEIGHT;
802     }
803 
804 #ifdef FEAT_GUI
805     /* May be needed for the scrollbars that are going to change. */
806     if (gui.in_use)
807 	out_flush();
808 #endif
809 
810     if (flags & WSP_VERT)
811     {
812 	int	wmw1;
813 	int	minwidth;
814 
815 	layout = FR_ROW;
816 
817 	/*
818 	 * Check if we are able to split the current window and compute its
819 	 * width.
820 	 */
821 	/* Current window requires at least 1 space. */
822 	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
823 	needed = wmw1 + 1;
824 	if (flags & WSP_ROOM)
825 	    needed += p_wiw - wmw1;
826 	if (flags & (WSP_BOT | WSP_TOP))
827 	{
828 	    minwidth = frame_minwidth(topframe, NOWIN);
829 	    available = topframe->fr_width;
830 	    needed += minwidth;
831 	}
832 	else if (p_ea)
833 	{
834 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
835 	    prevfrp = oldwin->w_frame;
836 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
837 							frp = frp->fr_parent)
838 	    {
839 		if (frp->fr_layout == FR_ROW)
840 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
841 			if (frp2 != prevfrp)
842 			    minwidth += frame_minwidth(frp2, NOWIN);
843 		prevfrp = frp;
844 	    }
845 	    available = topframe->fr_width;
846 	    needed += minwidth;
847 	}
848 	else
849 	{
850 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
851 	    available = oldwin->w_frame->fr_width;
852 	    needed += minwidth;
853 	}
854 	if (available < needed && new_wp == NULL)
855 	{
856 	    emsg(_(e_noroom));
857 	    return FAIL;
858 	}
859 	if (new_size == 0)
860 	    new_size = oldwin->w_width / 2;
861 	if (new_size > available - minwidth - 1)
862 	    new_size = available - minwidth - 1;
863 	if (new_size < wmw1)
864 	    new_size = wmw1;
865 
866 	/* if it doesn't fit in the current window, need win_equal() */
867 	if (oldwin->w_width - new_size - 1 < p_wmw)
868 	    do_equal = TRUE;
869 
870 	/* We don't like to take lines for the new window from a
871 	 * 'winfixwidth' window.  Take them from a window to the left or right
872 	 * instead, if possible. Add one for the separator. */
873 	if (oldwin->w_p_wfw)
874 	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
875 
876 	/* Only make all windows the same width if one of them (except oldwin)
877 	 * is wider than one of the split windows. */
878 	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
879 	   && oldwin->w_frame->fr_parent != NULL)
880 	{
881 	    frp = oldwin->w_frame->fr_parent->fr_child;
882 	    while (frp != NULL)
883 	    {
884 		if (frp->fr_win != oldwin && frp->fr_win != NULL
885 			&& (frp->fr_win->w_width > new_size
886 			    || frp->fr_win->w_width > oldwin->w_width
887 							      - new_size - 1))
888 		{
889 		    do_equal = TRUE;
890 		    break;
891 		}
892 		frp = frp->fr_next;
893 	    }
894 	}
895     }
896     else
897     {
898 	layout = FR_COL;
899 
900 	/*
901 	 * Check if we are able to split the current window and compute its
902 	 * height.
903 	 */
904 	/* Current window requires at least 1 space. */
905 	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
906 	needed = wmh1 + STATUS_HEIGHT;
907 	if (flags & WSP_ROOM)
908 	    needed += p_wh - wmh1;
909 	if (flags & (WSP_BOT | WSP_TOP))
910 	{
911 	    minheight = frame_minheight(topframe, NOWIN) + need_status;
912 	    available = topframe->fr_height;
913 	    needed += minheight;
914 	}
915 	else if (p_ea)
916 	{
917 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
918 	    prevfrp = oldwin->w_frame;
919 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
920 							frp = frp->fr_parent)
921 	    {
922 		if (frp->fr_layout == FR_COL)
923 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
924 			if (frp2 != prevfrp)
925 			    minheight += frame_minheight(frp2, NOWIN);
926 		prevfrp = frp;
927 	    }
928 	    available = topframe->fr_height;
929 	    needed += minheight;
930 	}
931 	else
932 	{
933 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
934 	    available = oldwin->w_frame->fr_height;
935 	    needed += minheight;
936 	}
937 	if (available < needed && new_wp == NULL)
938 	{
939 	    emsg(_(e_noroom));
940 	    return FAIL;
941 	}
942 	oldwin_height = oldwin->w_height;
943 	if (need_status)
944 	{
945 	    oldwin->w_status_height = STATUS_HEIGHT;
946 	    oldwin_height -= STATUS_HEIGHT;
947 	}
948 	if (new_size == 0)
949 	    new_size = oldwin_height / 2;
950 	if (new_size > available - minheight - STATUS_HEIGHT)
951 	    new_size = available - minheight - STATUS_HEIGHT;
952 	if (new_size < wmh1)
953 	    new_size = wmh1;
954 
955 	/* if it doesn't fit in the current window, need win_equal() */
956 	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
957 	    do_equal = TRUE;
958 
959 	/* We don't like to take lines for the new window from a
960 	 * 'winfixheight' window.  Take them from a window above or below
961 	 * instead, if possible. */
962 	if (oldwin->w_p_wfh)
963 	{
964 	    /* Set w_fraction now so that the cursor keeps the same relative
965 	     * vertical position using the old height. */
966 	    set_fraction(oldwin);
967 	    did_set_fraction = TRUE;
968 
969 	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
970 								      oldwin);
971 	    oldwin_height = oldwin->w_height;
972 	    if (need_status)
973 		oldwin_height -= STATUS_HEIGHT;
974 	}
975 
976 	/* Only make all windows the same height if one of them (except oldwin)
977 	 * is higher than one of the split windows. */
978 	if (!do_equal && p_ea && size == 0 && *p_ead != 'h'
979 	   && oldwin->w_frame->fr_parent != NULL)
980 	{
981 	    frp = oldwin->w_frame->fr_parent->fr_child;
982 	    while (frp != NULL)
983 	    {
984 		if (frp->fr_win != oldwin && frp->fr_win != NULL
985 			&& (frp->fr_win->w_height > new_size
986 			    || frp->fr_win->w_height > oldwin_height - new_size
987 							      - STATUS_HEIGHT))
988 		{
989 		    do_equal = TRUE;
990 		    break;
991 		}
992 		frp = frp->fr_next;
993 	    }
994 	}
995     }
996 
997     /*
998      * allocate new window structure and link it in the window list
999      */
1000     if ((flags & WSP_TOP) == 0
1001 	    && ((flags & WSP_BOT)
1002 		|| (flags & WSP_BELOW)
1003 		|| (!(flags & WSP_ABOVE)
1004 		    && ( (flags & WSP_VERT) ? p_spr : p_sb))))
1005     {
1006 	/* new window below/right of current one */
1007 	if (new_wp == NULL)
1008 	    wp = win_alloc(oldwin, FALSE);
1009 	else
1010 	    win_append(oldwin, wp);
1011     }
1012     else
1013     {
1014 	if (new_wp == NULL)
1015 	    wp = win_alloc(oldwin->w_prev, FALSE);
1016 	else
1017 	    win_append(oldwin->w_prev, wp);
1018     }
1019 
1020     if (new_wp == NULL)
1021     {
1022 	if (wp == NULL)
1023 	    return FAIL;
1024 
1025 	new_frame(wp);
1026 	if (wp->w_frame == NULL)
1027 	{
1028 	    win_free(wp, NULL);
1029 	    return FAIL;
1030 	}
1031 
1032 	/* make the contents of the new window the same as the current one */
1033 	win_init(wp, curwin, flags);
1034     }
1035 
1036     /*
1037      * Reorganise the tree of frames to insert the new window.
1038      */
1039     if (flags & (WSP_TOP | WSP_BOT))
1040     {
1041 	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
1042 	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
1043 	{
1044 	    curfrp = topframe->fr_child;
1045 	    if (flags & WSP_BOT)
1046 		while (curfrp->fr_next != NULL)
1047 		    curfrp = curfrp->fr_next;
1048 	}
1049 	else
1050 	    curfrp = topframe;
1051 	before = (flags & WSP_TOP);
1052     }
1053     else
1054     {
1055 	curfrp = oldwin->w_frame;
1056 	if (flags & WSP_BELOW)
1057 	    before = FALSE;
1058 	else if (flags & WSP_ABOVE)
1059 	    before = TRUE;
1060 	else if (flags & WSP_VERT)
1061 	    before = !p_spr;
1062 	else
1063 	    before = !p_sb;
1064     }
1065     if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
1066     {
1067 	/* Need to create a new frame in the tree to make a branch. */
1068 	frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
1069 	*frp = *curfrp;
1070 	curfrp->fr_layout = layout;
1071 	frp->fr_parent = curfrp;
1072 	frp->fr_next = NULL;
1073 	frp->fr_prev = NULL;
1074 	curfrp->fr_child = frp;
1075 	curfrp->fr_win = NULL;
1076 	curfrp = frp;
1077 	if (frp->fr_win != NULL)
1078 	    oldwin->w_frame = frp;
1079 	else
1080 	    FOR_ALL_FRAMES(frp, frp->fr_child)
1081 		frp->fr_parent = curfrp;
1082     }
1083 
1084     if (new_wp == NULL)
1085 	frp = wp->w_frame;
1086     else
1087 	frp = new_wp->w_frame;
1088     frp->fr_parent = curfrp->fr_parent;
1089 
1090     /* Insert the new frame at the right place in the frame list. */
1091     if (before)
1092 	frame_insert(curfrp, frp);
1093     else
1094 	frame_append(curfrp, frp);
1095 
1096     /* Set w_fraction now so that the cursor keeps the same relative
1097      * vertical position. */
1098     if (!did_set_fraction)
1099 	set_fraction(oldwin);
1100     wp->w_fraction = oldwin->w_fraction;
1101 
1102     if (flags & WSP_VERT)
1103     {
1104 	wp->w_p_scr = curwin->w_p_scr;
1105 
1106 	if (need_status)
1107 	{
1108 	    win_new_height(oldwin, oldwin->w_height - 1);
1109 	    oldwin->w_status_height = need_status;
1110 	}
1111 	if (flags & (WSP_TOP | WSP_BOT))
1112 	{
1113 	    /* set height and row of new window to full height */
1114 	    wp->w_winrow = tabline_height();
1115 	    win_new_height(wp, curfrp->fr_height - (p_ls > 0)
1116 							  - WINBAR_HEIGHT(wp));
1117 	    wp->w_status_height = (p_ls > 0);
1118 	}
1119 	else
1120 	{
1121 	    /* height and row of new window is same as current window */
1122 	    wp->w_winrow = oldwin->w_winrow;
1123 	    win_new_height(wp, VISIBLE_HEIGHT(oldwin));
1124 	    wp->w_status_height = oldwin->w_status_height;
1125 	}
1126 	frp->fr_height = curfrp->fr_height;
1127 
1128 	/* "new_size" of the current window goes to the new window, use
1129 	 * one column for the vertical separator */
1130 	win_new_width(wp, new_size);
1131 	if (before)
1132 	    wp->w_vsep_width = 1;
1133 	else
1134 	{
1135 	    wp->w_vsep_width = oldwin->w_vsep_width;
1136 	    oldwin->w_vsep_width = 1;
1137 	}
1138 	if (flags & (WSP_TOP | WSP_BOT))
1139 	{
1140 	    if (flags & WSP_BOT)
1141 		frame_add_vsep(curfrp);
1142 	    /* Set width of neighbor frame */
1143 	    frame_new_width(curfrp, curfrp->fr_width
1144 		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
1145 								       FALSE);
1146 	}
1147 	else
1148 	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
1149 	if (before)	/* new window left of current one */
1150 	{
1151 	    wp->w_wincol = oldwin->w_wincol;
1152 	    oldwin->w_wincol += new_size + 1;
1153 	}
1154 	else		/* new window right of current one */
1155 	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
1156 	frame_fix_width(oldwin);
1157 	frame_fix_width(wp);
1158     }
1159     else
1160     {
1161 	/* width and column of new window is same as current window */
1162 	if (flags & (WSP_TOP | WSP_BOT))
1163 	{
1164 	    wp->w_wincol = 0;
1165 	    win_new_width(wp, Columns);
1166 	    wp->w_vsep_width = 0;
1167 	}
1168 	else
1169 	{
1170 	    wp->w_wincol = oldwin->w_wincol;
1171 	    win_new_width(wp, oldwin->w_width);
1172 	    wp->w_vsep_width = oldwin->w_vsep_width;
1173 	}
1174 	frp->fr_width = curfrp->fr_width;
1175 
1176 	/* "new_size" of the current window goes to the new window, use
1177 	 * one row for the status line */
1178 	win_new_height(wp, new_size);
1179 	if (flags & (WSP_TOP | WSP_BOT))
1180 	{
1181 	    int new_fr_height = curfrp->fr_height - new_size
1182 							  + WINBAR_HEIGHT(wp) ;
1183 
1184 	    if (!((flags & WSP_BOT) && p_ls == 0))
1185 		new_fr_height -= STATUS_HEIGHT;
1186 	    frame_new_height(curfrp, new_fr_height, flags & WSP_TOP, FALSE);
1187 	}
1188 	else
1189 	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
1190 	if (before)	/* new window above current one */
1191 	{
1192 	    wp->w_winrow = oldwin->w_winrow;
1193 	    wp->w_status_height = STATUS_HEIGHT;
1194 	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
1195 	}
1196 	else		/* new window below current one */
1197 	{
1198 	    wp->w_winrow = oldwin->w_winrow + VISIBLE_HEIGHT(oldwin)
1199 							       + STATUS_HEIGHT;
1200 	    wp->w_status_height = oldwin->w_status_height;
1201 	    if (!(flags & WSP_BOT))
1202 		oldwin->w_status_height = STATUS_HEIGHT;
1203 	}
1204 	if (flags & WSP_BOT)
1205 	    frame_add_statusline(curfrp);
1206 	frame_fix_height(wp);
1207 	frame_fix_height(oldwin);
1208     }
1209 
1210     if (flags & (WSP_TOP | WSP_BOT))
1211 	(void)win_comp_pos();
1212 
1213     /*
1214      * Both windows need redrawing
1215      */
1216     redraw_win_later(wp, NOT_VALID);
1217     wp->w_redr_status = TRUE;
1218     redraw_win_later(oldwin, NOT_VALID);
1219     oldwin->w_redr_status = TRUE;
1220 
1221     if (need_status)
1222     {
1223 	msg_row = Rows - 1;
1224 	msg_col = sc_col;
1225 	msg_clr_eos_force();	/* Old command/ruler may still be there */
1226 	comp_col();
1227 	msg_row = Rows - 1;
1228 	msg_col = 0;	/* put position back at start of line */
1229     }
1230 
1231     /*
1232      * equalize the window sizes.
1233      */
1234     if (do_equal || dir != 0)
1235 	win_equal(wp, TRUE,
1236 		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
1237 		: dir == 'h' ? 'b' : 'v');
1238 
1239     /* Don't change the window height/width to 'winheight' / 'winwidth' if a
1240      * size was given. */
1241     if (flags & WSP_VERT)
1242     {
1243 	i = p_wiw;
1244 	if (size != 0)
1245 	    p_wiw = size;
1246 
1247 # ifdef FEAT_GUI
1248 	/* When 'guioptions' includes 'L' or 'R' may have to add scrollbars. */
1249 	if (gui.in_use)
1250 	    gui_init_which_components(NULL);
1251 # endif
1252     }
1253     else
1254     {
1255 	i = p_wh;
1256 	if (size != 0)
1257 	    p_wh = size;
1258     }
1259 
1260 #ifdef FEAT_JUMPLIST
1261     /* Keep same changelist position in new window. */
1262     wp->w_changelistidx = oldwin->w_changelistidx;
1263 #endif
1264 
1265     /*
1266      * make the new window the current window
1267      */
1268     win_enter_ext(wp, FALSE, FALSE, TRUE, TRUE, TRUE);
1269     if (flags & WSP_VERT)
1270 	p_wiw = i;
1271     else
1272 	p_wh = i;
1273 
1274     return OK;
1275 }
1276 
1277 
1278 /*
1279  * Initialize window "newp" from window "oldp".
1280  * Used when splitting a window and when creating a new tab page.
1281  * The windows will both edit the same buffer.
1282  * WSP_NEWLOC may be specified in flags to prevent the location list from
1283  * being copied.
1284  */
1285     static void
1286 win_init(win_T *newp, win_T *oldp, int flags UNUSED)
1287 {
1288     int		i;
1289 
1290     newp->w_buffer = oldp->w_buffer;
1291 #ifdef FEAT_SYN_HL
1292     newp->w_s = &(oldp->w_buffer->b_s);
1293 #endif
1294     oldp->w_buffer->b_nwindows++;
1295     newp->w_cursor = oldp->w_cursor;
1296     newp->w_valid = 0;
1297     newp->w_curswant = oldp->w_curswant;
1298     newp->w_set_curswant = oldp->w_set_curswant;
1299     newp->w_topline = oldp->w_topline;
1300 #ifdef FEAT_DIFF
1301     newp->w_topfill = oldp->w_topfill;
1302 #endif
1303     newp->w_leftcol = oldp->w_leftcol;
1304     newp->w_pcmark = oldp->w_pcmark;
1305     newp->w_prev_pcmark = oldp->w_prev_pcmark;
1306     newp->w_alt_fnum = oldp->w_alt_fnum;
1307     newp->w_wrow = oldp->w_wrow;
1308     newp->w_fraction = oldp->w_fraction;
1309     newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
1310 #ifdef FEAT_JUMPLIST
1311     copy_jumplist(oldp, newp);
1312 #endif
1313 #ifdef FEAT_QUICKFIX
1314     if (flags & WSP_NEWLOC)
1315     {
1316 	/* Don't copy the location list.  */
1317 	newp->w_llist = NULL;
1318 	newp->w_llist_ref = NULL;
1319     }
1320     else
1321 	copy_loclist_stack(oldp, newp);
1322 #endif
1323     newp->w_localdir = (oldp->w_localdir == NULL)
1324 				    ? NULL : vim_strsave(oldp->w_localdir);
1325 
1326     /* copy tagstack and folds */
1327     for (i = 0; i < oldp->w_tagstacklen; i++)
1328     {
1329 	newp->w_tagstack[i] = oldp->w_tagstack[i];
1330 	if (newp->w_tagstack[i].tagname != NULL)
1331 	    newp->w_tagstack[i].tagname =
1332 				   vim_strsave(newp->w_tagstack[i].tagname);
1333     }
1334     newp->w_tagstackidx = oldp->w_tagstackidx;
1335     newp->w_tagstacklen = oldp->w_tagstacklen;
1336 #ifdef FEAT_FOLDING
1337     copyFoldingState(oldp, newp);
1338 #endif
1339 
1340     win_init_some(newp, oldp);
1341 
1342 #ifdef FEAT_SYN_HL
1343     check_colorcolumn(newp);
1344 #endif
1345 }
1346 
1347 /*
1348  * Initialize window "newp" from window "old".
1349  * Only the essential things are copied.
1350  */
1351     static void
1352 win_init_some(win_T *newp, win_T *oldp)
1353 {
1354     /* Use the same argument list. */
1355     newp->w_alist = oldp->w_alist;
1356     ++newp->w_alist->al_refcount;
1357     newp->w_arg_idx = oldp->w_arg_idx;
1358 
1359     /* copy options from existing window */
1360     win_copy_options(oldp, newp);
1361 }
1362 
1363 
1364 /*
1365  * Check if "win" is a pointer to an existing window in the current tab page.
1366  */
1367     int
1368 win_valid(win_T *win)
1369 {
1370     win_T	*wp;
1371 
1372     if (win == NULL)
1373 	return FALSE;
1374     FOR_ALL_WINDOWS(wp)
1375 	if (wp == win)
1376 	    return TRUE;
1377     return FALSE;
1378 }
1379 
1380 /*
1381  * Check if "win" is a pointer to an existing window in any tab page.
1382  */
1383     int
1384 win_valid_any_tab(win_T *win)
1385 {
1386     win_T	*wp;
1387     tabpage_T	*tp;
1388 
1389     if (win == NULL)
1390 	return FALSE;
1391     FOR_ALL_TABPAGES(tp)
1392     {
1393 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
1394 	{
1395 	    if (wp == win)
1396 		return TRUE;
1397 	}
1398     }
1399     return FALSE;
1400 }
1401 
1402 /*
1403  * Return the number of windows.
1404  */
1405     int
1406 win_count(void)
1407 {
1408     win_T	*wp;
1409     int		count = 0;
1410 
1411     FOR_ALL_WINDOWS(wp)
1412 	++count;
1413     return count;
1414 }
1415 
1416 /*
1417  * Make "count" windows on the screen.
1418  * Return actual number of windows on the screen.
1419  * Must be called when there is just one window, filling the whole screen
1420  * (excluding the command line).
1421  */
1422     int
1423 make_windows(
1424     int		count,
1425     int		vertical UNUSED)  /* split windows vertically if TRUE */
1426 {
1427     int		maxcount;
1428     int		todo;
1429 
1430     if (vertical)
1431     {
1432 	/* Each windows needs at least 'winminwidth' lines and a separator
1433 	 * column. */
1434 	maxcount = (curwin->w_width + curwin->w_vsep_width
1435 					     - (p_wiw - p_wmw)) / (p_wmw + 1);
1436     }
1437     else
1438     {
1439 	/* Each window needs at least 'winminheight' lines and a status line. */
1440 	maxcount = (VISIBLE_HEIGHT(curwin) + curwin->w_status_height
1441 				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
1442     }
1443 
1444     if (maxcount < 2)
1445 	maxcount = 2;
1446     if (count > maxcount)
1447 	count = maxcount;
1448 
1449     /*
1450      * add status line now, otherwise first window will be too big
1451      */
1452     if (count > 1)
1453 	last_status(TRUE);
1454 
1455     /*
1456      * Don't execute autocommands while creating the windows.  Must do that
1457      * when putting the buffers in the windows.
1458      */
1459     block_autocmds();
1460 
1461     /* todo is number of windows left to create */
1462     for (todo = count - 1; todo > 0; --todo)
1463 	if (vertical)
1464 	{
1465 	    if (win_split(curwin->w_width - (curwin->w_width - todo)
1466 			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
1467 		break;
1468 	}
1469 	else
1470 	{
1471 	    if (win_split(curwin->w_height - (curwin->w_height - todo
1472 			    * STATUS_HEIGHT) / (todo + 1)
1473 			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
1474 		break;
1475 	}
1476 
1477     unblock_autocmds();
1478 
1479     /* return actual number of windows */
1480     return (count - todo);
1481 }
1482 
1483 /*
1484  * Exchange current and next window
1485  */
1486     static void
1487 win_exchange(long Prenum)
1488 {
1489     frame_T	*frp;
1490     frame_T	*frp2;
1491     win_T	*wp;
1492     win_T	*wp2;
1493     int		temp;
1494 
1495     if (ONE_WINDOW)	    /* just one window */
1496     {
1497 	beep_flush();
1498 	return;
1499     }
1500 
1501 #ifdef FEAT_GUI
1502     need_mouse_correct = TRUE;
1503 #endif
1504 
1505     /*
1506      * find window to exchange with
1507      */
1508     if (Prenum)
1509     {
1510 	frp = curwin->w_frame->fr_parent->fr_child;
1511 	while (frp != NULL && --Prenum > 0)
1512 	    frp = frp->fr_next;
1513     }
1514     else if (curwin->w_frame->fr_next != NULL)	/* Swap with next */
1515 	frp = curwin->w_frame->fr_next;
1516     else    /* Swap last window in row/col with previous */
1517 	frp = curwin->w_frame->fr_prev;
1518 
1519     /* We can only exchange a window with another window, not with a frame
1520      * containing windows. */
1521     if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
1522 	return;
1523     wp = frp->fr_win;
1524 
1525 /*
1526  * 1. remove curwin from the list. Remember after which window it was in wp2
1527  * 2. insert curwin before wp in the list
1528  * if wp != wp2
1529  *    3. remove wp from the list
1530  *    4. insert wp after wp2
1531  * 5. exchange the status line height and vsep width.
1532  */
1533     wp2 = curwin->w_prev;
1534     frp2 = curwin->w_frame->fr_prev;
1535     if (wp->w_prev != curwin)
1536     {
1537 	win_remove(curwin, NULL);
1538 	frame_remove(curwin->w_frame);
1539 	win_append(wp->w_prev, curwin);
1540 	frame_insert(frp, curwin->w_frame);
1541     }
1542     if (wp != wp2)
1543     {
1544 	win_remove(wp, NULL);
1545 	frame_remove(wp->w_frame);
1546 	win_append(wp2, wp);
1547 	if (frp2 == NULL)
1548 	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
1549 	else
1550 	    frame_append(frp2, wp->w_frame);
1551     }
1552     temp = curwin->w_status_height;
1553     curwin->w_status_height = wp->w_status_height;
1554     wp->w_status_height = temp;
1555     temp = curwin->w_vsep_width;
1556     curwin->w_vsep_width = wp->w_vsep_width;
1557     wp->w_vsep_width = temp;
1558 
1559     /* If the windows are not in the same frame, exchange the sizes to avoid
1560      * messing up the window layout.  Otherwise fix the frame sizes. */
1561     if (curwin->w_frame->fr_parent != wp->w_frame->fr_parent)
1562     {
1563 	temp = curwin->w_height;
1564 	curwin->w_height = wp->w_height;
1565 	wp->w_height = temp;
1566 	temp = curwin->w_width;
1567 	curwin->w_width = wp->w_width;
1568 	wp->w_width = temp;
1569     }
1570     else
1571     {
1572 	frame_fix_height(curwin);
1573 	frame_fix_height(wp);
1574 	frame_fix_width(curwin);
1575 	frame_fix_width(wp);
1576     }
1577 
1578     (void)win_comp_pos();		/* recompute window positions */
1579 
1580     win_enter(wp, TRUE);
1581     redraw_all_later(NOT_VALID);
1582 }
1583 
1584 /*
1585  * rotate windows: if upwards TRUE the second window becomes the first one
1586  *		   if upwards FALSE the first window becomes the second one
1587  */
1588     static void
1589 win_rotate(int upwards, int count)
1590 {
1591     win_T	*wp1;
1592     win_T	*wp2;
1593     frame_T	*frp;
1594     int		n;
1595 
1596     if (ONE_WINDOW)		/* nothing to do */
1597     {
1598 	beep_flush();
1599 	return;
1600     }
1601 
1602 #ifdef FEAT_GUI
1603     need_mouse_correct = TRUE;
1604 #endif
1605 
1606     /* Check if all frames in this row/col have one window. */
1607     FOR_ALL_FRAMES(frp, curwin->w_frame->fr_parent->fr_child)
1608 	if (frp->fr_win == NULL)
1609 	{
1610 	    emsg(_("E443: Cannot rotate when another window is split"));
1611 	    return;
1612 	}
1613 
1614     while (count--)
1615     {
1616 	if (upwards)		/* first window becomes last window */
1617 	{
1618 	    /* remove first window/frame from the list */
1619 	    frp = curwin->w_frame->fr_parent->fr_child;
1620 	    wp1 = frp->fr_win;
1621 	    win_remove(wp1, NULL);
1622 	    frame_remove(frp);
1623 
1624 	    /* find last frame and append removed window/frame after it */
1625 	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
1626 		;
1627 	    win_append(frp->fr_win, wp1);
1628 	    frame_append(frp, wp1->w_frame);
1629 
1630 	    wp2 = frp->fr_win;		/* previously last window */
1631 	}
1632 	else			/* last window becomes first window */
1633 	{
1634 	    /* find last window/frame in the list and remove it */
1635 	    for (frp = curwin->w_frame; frp->fr_next != NULL;
1636 							   frp = frp->fr_next)
1637 		;
1638 	    wp1 = frp->fr_win;
1639 	    wp2 = wp1->w_prev;		    /* will become last window */
1640 	    win_remove(wp1, NULL);
1641 	    frame_remove(frp);
1642 
1643 	    /* append the removed window/frame before the first in the list */
1644 	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
1645 	    frame_insert(frp->fr_parent->fr_child, frp);
1646 	}
1647 
1648 	/* exchange status height and vsep width of old and new last window */
1649 	n = wp2->w_status_height;
1650 	wp2->w_status_height = wp1->w_status_height;
1651 	wp1->w_status_height = n;
1652 	frame_fix_height(wp1);
1653 	frame_fix_height(wp2);
1654 	n = wp2->w_vsep_width;
1655 	wp2->w_vsep_width = wp1->w_vsep_width;
1656 	wp1->w_vsep_width = n;
1657 	frame_fix_width(wp1);
1658 	frame_fix_width(wp2);
1659 
1660 	/* recompute w_winrow and w_wincol for all windows */
1661 	(void)win_comp_pos();
1662     }
1663 
1664     redraw_all_later(NOT_VALID);
1665 }
1666 
1667 /*
1668  * Move the current window to the very top/bottom/left/right of the screen.
1669  */
1670     static void
1671 win_totop(int size, int flags)
1672 {
1673     int		dir;
1674     int		height = curwin->w_height;
1675 
1676     if (ONE_WINDOW)
1677     {
1678 	beep_flush();
1679 	return;
1680     }
1681 
1682     /* Remove the window and frame from the tree of frames. */
1683     (void)winframe_remove(curwin, &dir, NULL);
1684     win_remove(curwin, NULL);
1685     last_status(FALSE);	    /* may need to remove last status line */
1686     (void)win_comp_pos();   /* recompute window positions */
1687 
1688     /* Split a window on the desired side and put the window there. */
1689     (void)win_split_ins(size, flags, curwin, dir);
1690     if (!(flags & WSP_VERT))
1691     {
1692 	win_setheight(height);
1693 	if (p_ea)
1694 	    win_equal(curwin, TRUE, 'v');
1695     }
1696 
1697 #if defined(FEAT_GUI)
1698     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
1699      * scrollbars.  Have to update them anyway. */
1700     gui_may_update_scrollbars();
1701 #endif
1702 }
1703 
1704 /*
1705  * Move window "win1" to below/right of "win2" and make "win1" the current
1706  * window.  Only works within the same frame!
1707  */
1708     void
1709 win_move_after(win_T *win1, win_T *win2)
1710 {
1711     int		height;
1712 
1713     /* check if the arguments are reasonable */
1714     if (win1 == win2)
1715 	return;
1716 
1717     /* check if there is something to do */
1718     if (win2->w_next != win1)
1719     {
1720 	/* may need move the status line/vertical separator of the last window
1721 	 * */
1722 	if (win1 == lastwin)
1723 	{
1724 	    height = win1->w_prev->w_status_height;
1725 	    win1->w_prev->w_status_height = win1->w_status_height;
1726 	    win1->w_status_height = height;
1727 	    if (win1->w_prev->w_vsep_width == 1)
1728 	    {
1729 		/* Remove the vertical separator from the last-but-one window,
1730 		 * add it to the last window.  Adjust the frame widths. */
1731 		win1->w_prev->w_vsep_width = 0;
1732 		win1->w_prev->w_frame->fr_width -= 1;
1733 		win1->w_vsep_width = 1;
1734 		win1->w_frame->fr_width += 1;
1735 	    }
1736 	}
1737 	else if (win2 == lastwin)
1738 	{
1739 	    height = win1->w_status_height;
1740 	    win1->w_status_height = win2->w_status_height;
1741 	    win2->w_status_height = height;
1742 	    if (win1->w_vsep_width == 1)
1743 	    {
1744 		/* Remove the vertical separator from win1, add it to the last
1745 		 * window, win2.  Adjust the frame widths. */
1746 		win2->w_vsep_width = 1;
1747 		win2->w_frame->fr_width += 1;
1748 		win1->w_vsep_width = 0;
1749 		win1->w_frame->fr_width -= 1;
1750 	    }
1751 	}
1752 	win_remove(win1, NULL);
1753 	frame_remove(win1->w_frame);
1754 	win_append(win2, win1);
1755 	frame_append(win2->w_frame, win1->w_frame);
1756 
1757 	(void)win_comp_pos();	/* recompute w_winrow for all windows */
1758 	redraw_later(NOT_VALID);
1759     }
1760     win_enter(win1, FALSE);
1761 }
1762 
1763 /*
1764  * Make all windows the same height.
1765  * 'next_curwin' will soon be the current window, make sure it has enough
1766  * rows.
1767  */
1768     void
1769 win_equal(
1770     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1771     int		current,	/* do only frame with current window */
1772     int		dir)		/* 'v' for vertically, 'h' for horizontally,
1773 				   'b' for both, 0 for using p_ead */
1774 {
1775     if (dir == 0)
1776 	dir = *p_ead;
1777     win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
1778 		      topframe, dir, 0, tabline_height(),
1779 					   (int)Columns, topframe->fr_height);
1780 }
1781 
1782 /*
1783  * Set a frame to a new position and height, spreading the available room
1784  * equally over contained frames.
1785  * The window "next_curwin" (if not NULL) should at least get the size from
1786  * 'winheight' and 'winwidth' if possible.
1787  */
1788     static void
1789 win_equal_rec(
1790     win_T	*next_curwin,	/* pointer to current window to be or NULL */
1791     int		current,	/* do only frame with current window */
1792     frame_T	*topfr,		/* frame to set size off */
1793     int		dir,		/* 'v', 'h' or 'b', see win_equal() */
1794     int		col,		/* horizontal position for frame */
1795     int		row,		/* vertical position for frame */
1796     int		width,		/* new width of frame */
1797     int		height)		/* new height of frame */
1798 {
1799     int		n, m;
1800     int		extra_sep = 0;
1801     int		wincount, totwincount = 0;
1802     frame_T	*fr;
1803     int		next_curwin_size = 0;
1804     int		room = 0;
1805     int		new_size;
1806     int		has_next_curwin = 0;
1807     int		hnc;
1808 
1809     if (topfr->fr_layout == FR_LEAF)
1810     {
1811 	/* Set the width/height of this frame.
1812 	 * Redraw when size or position changes */
1813 	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
1814 		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
1815 	   )
1816 	{
1817 	    topfr->fr_win->w_winrow = row;
1818 	    frame_new_height(topfr, height, FALSE, FALSE);
1819 	    topfr->fr_win->w_wincol = col;
1820 	    frame_new_width(topfr, width, FALSE, FALSE);
1821 	    redraw_all_later(NOT_VALID);
1822 	}
1823     }
1824     else if (topfr->fr_layout == FR_ROW)
1825     {
1826 	topfr->fr_width = width;
1827 	topfr->fr_height = height;
1828 
1829 	if (dir != 'v')			/* equalize frame widths */
1830 	{
1831 	    /* Compute the maximum number of windows horizontally in this
1832 	     * frame. */
1833 	    n = frame_minwidth(topfr, NOWIN);
1834 	    /* add one for the rightmost window, it doesn't have a separator */
1835 	    if (col + width == Columns)
1836 		extra_sep = 1;
1837 	    else
1838 		extra_sep = 0;
1839 	    totwincount = (n + extra_sep) / (p_wmw + 1);
1840 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1841 
1842 	    /*
1843 	     * Compute width for "next_curwin" window and room available for
1844 	     * other windows.
1845 	     * "m" is the minimal width when counting p_wiw for "next_curwin".
1846 	     */
1847 	    m = frame_minwidth(topfr, next_curwin);
1848 	    room = width - m;
1849 	    if (room < 0)
1850 	    {
1851 		next_curwin_size = p_wiw + room;
1852 		room = 0;
1853 	    }
1854 	    else
1855 	    {
1856 		next_curwin_size = -1;
1857 		FOR_ALL_FRAMES(fr, topfr->fr_child)
1858 		{
1859 		    /* If 'winfixwidth' set keep the window width if
1860 		     * possible.
1861 		     * Watch out for this window being the next_curwin. */
1862 		    if (frame_fixed_width(fr))
1863 		    {
1864 			n = frame_minwidth(fr, NOWIN);
1865 			new_size = fr->fr_width;
1866 			if (frame_has_win(fr, next_curwin))
1867 			{
1868 			    room += p_wiw - p_wmw;
1869 			    next_curwin_size = 0;
1870 			    if (new_size < p_wiw)
1871 				new_size = p_wiw;
1872 			}
1873 			else
1874 			    /* These windows don't use up room. */
1875 			    totwincount -= (n + (fr->fr_next == NULL
1876 					      ? extra_sep : 0)) / (p_wmw + 1);
1877 			room -= new_size - n;
1878 			if (room < 0)
1879 			{
1880 			    new_size += room;
1881 			    room = 0;
1882 			}
1883 			fr->fr_newwidth = new_size;
1884 		    }
1885 		}
1886 		if (next_curwin_size == -1)
1887 		{
1888 		    if (!has_next_curwin)
1889 			next_curwin_size = 0;
1890 		    else if (totwincount > 1
1891 			    && (room + (totwincount - 2))
1892 						  / (totwincount - 1) > p_wiw)
1893 		    {
1894 			/* Can make all windows wider than 'winwidth', spread
1895 			 * the room equally. */
1896 			next_curwin_size = (room + p_wiw
1897 					    + (totwincount - 1) * p_wmw
1898 					    + (totwincount - 1)) / totwincount;
1899 			room -= next_curwin_size - p_wiw;
1900 		    }
1901 		    else
1902 			next_curwin_size = p_wiw;
1903 		}
1904 	    }
1905 
1906 	    if (has_next_curwin)
1907 		--totwincount;		/* don't count curwin */
1908 	}
1909 
1910 	FOR_ALL_FRAMES(fr, topfr->fr_child)
1911 	{
1912 	    wincount = 1;
1913 	    if (fr->fr_next == NULL)
1914 		/* last frame gets all that remains (avoid roundoff error) */
1915 		new_size = width;
1916 	    else if (dir == 'v')
1917 		new_size = fr->fr_width;
1918 	    else if (frame_fixed_width(fr))
1919 	    {
1920 		new_size = fr->fr_newwidth;
1921 		wincount = 0;	    /* doesn't count as a sizeable window */
1922 	    }
1923 	    else
1924 	    {
1925 		/* Compute the maximum number of windows horiz. in "fr". */
1926 		n = frame_minwidth(fr, NOWIN);
1927 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
1928 								/ (p_wmw + 1);
1929 		m = frame_minwidth(fr, next_curwin);
1930 		if (has_next_curwin)
1931 		    hnc = frame_has_win(fr, next_curwin);
1932 		else
1933 		    hnc = FALSE;
1934 		if (hnc)	    /* don't count next_curwin */
1935 		    --wincount;
1936 		if (totwincount == 0)
1937 		    new_size = room;
1938 		else
1939 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
1940 								/ totwincount;
1941 		if (hnc)	    /* add next_curwin size */
1942 		{
1943 		    next_curwin_size -= p_wiw - (m - n);
1944 		    new_size += next_curwin_size;
1945 		    room -= new_size - next_curwin_size;
1946 		}
1947 		else
1948 		    room -= new_size;
1949 		new_size += n;
1950 	    }
1951 
1952 	    /* Skip frame that is full width when splitting or closing a
1953 	     * window, unless equalizing all frames. */
1954 	    if (!current || dir != 'v' || topfr->fr_parent != NULL
1955 		    || (new_size != fr->fr_width)
1956 		    || frame_has_win(fr, next_curwin))
1957 		win_equal_rec(next_curwin, current, fr, dir, col, row,
1958 							    new_size, height);
1959 	    col += new_size;
1960 	    width -= new_size;
1961 	    totwincount -= wincount;
1962 	}
1963     }
1964     else /* topfr->fr_layout == FR_COL */
1965     {
1966 	topfr->fr_width = width;
1967 	topfr->fr_height = height;
1968 
1969 	if (dir != 'h')			/* equalize frame heights */
1970 	{
1971 	    /* Compute maximum number of windows vertically in this frame. */
1972 	    n = frame_minheight(topfr, NOWIN);
1973 	    /* add one for the bottom window if it doesn't have a statusline */
1974 	    if (row + height == cmdline_row && p_ls == 0)
1975 		extra_sep = 1;
1976 	    else
1977 		extra_sep = 0;
1978 	    totwincount = (n + extra_sep) / (p_wmh + 1);
1979 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1980 
1981 	    /*
1982 	     * Compute height for "next_curwin" window and room available for
1983 	     * other windows.
1984 	     * "m" is the minimal height when counting p_wh for "next_curwin".
1985 	     */
1986 	    m = frame_minheight(topfr, next_curwin);
1987 	    room = height - m;
1988 	    if (room < 0)
1989 	    {
1990 		/* The room is less then 'winheight', use all space for the
1991 		 * current window. */
1992 		next_curwin_size = p_wh + room;
1993 		room = 0;
1994 	    }
1995 	    else
1996 	    {
1997 		next_curwin_size = -1;
1998 		FOR_ALL_FRAMES(fr, topfr->fr_child)
1999 		{
2000 		    /* If 'winfixheight' set keep the window height if
2001 		     * possible.
2002 		     * Watch out for this window being the next_curwin. */
2003 		    if (frame_fixed_height(fr))
2004 		    {
2005 			n = frame_minheight(fr, NOWIN);
2006 			new_size = fr->fr_height;
2007 			if (frame_has_win(fr, next_curwin))
2008 			{
2009 			    room += p_wh - p_wmh;
2010 			    next_curwin_size = 0;
2011 			    if (new_size < p_wh)
2012 				new_size = p_wh;
2013 			}
2014 			else
2015 			    /* These windows don't use up room. */
2016 			    totwincount -= (n + (fr->fr_next == NULL
2017 					      ? extra_sep : 0)) / (p_wmh + 1);
2018 			room -= new_size - n;
2019 			if (room < 0)
2020 			{
2021 			    new_size += room;
2022 			    room = 0;
2023 			}
2024 			fr->fr_newheight = new_size;
2025 		    }
2026 		}
2027 		if (next_curwin_size == -1)
2028 		{
2029 		    if (!has_next_curwin)
2030 			next_curwin_size = 0;
2031 		    else if (totwincount > 1
2032 			    && (room + (totwincount - 2))
2033 						   / (totwincount - 1) > p_wh)
2034 		    {
2035 			/* can make all windows higher than 'winheight',
2036 			 * spread the room equally. */
2037 			next_curwin_size = (room + p_wh
2038 					   + (totwincount - 1) * p_wmh
2039 					   + (totwincount - 1)) / totwincount;
2040 			room -= next_curwin_size - p_wh;
2041 		    }
2042 		    else
2043 			next_curwin_size = p_wh;
2044 		}
2045 	    }
2046 
2047 	    if (has_next_curwin)
2048 		--totwincount;		/* don't count curwin */
2049 	}
2050 
2051 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2052 	{
2053 	    wincount = 1;
2054 	    if (fr->fr_next == NULL)
2055 		/* last frame gets all that remains (avoid roundoff error) */
2056 		new_size = height;
2057 	    else if (dir == 'h')
2058 		new_size = fr->fr_height;
2059 	    else if (frame_fixed_height(fr))
2060 	    {
2061 		new_size = fr->fr_newheight;
2062 		wincount = 0;	    /* doesn't count as a sizeable window */
2063 	    }
2064 	    else
2065 	    {
2066 		/* Compute the maximum number of windows vert. in "fr". */
2067 		n = frame_minheight(fr, NOWIN);
2068 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2069 								/ (p_wmh + 1);
2070 		m = frame_minheight(fr, next_curwin);
2071 		if (has_next_curwin)
2072 		    hnc = frame_has_win(fr, next_curwin);
2073 		else
2074 		    hnc = FALSE;
2075 		if (hnc)	    /* don't count next_curwin */
2076 		    --wincount;
2077 		if (totwincount == 0)
2078 		    new_size = room;
2079 		else
2080 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2081 								/ totwincount;
2082 		if (hnc)	    /* add next_curwin size */
2083 		{
2084 		    next_curwin_size -= p_wh - (m - n);
2085 		    new_size += next_curwin_size;
2086 		    room -= new_size - next_curwin_size;
2087 		}
2088 		else
2089 		    room -= new_size;
2090 		new_size += n;
2091 	    }
2092 	    /* Skip frame that is full width when splitting or closing a
2093 	     * window, unless equalizing all frames. */
2094 	    if (!current || dir != 'h' || topfr->fr_parent != NULL
2095 		    || (new_size != fr->fr_height)
2096 		    || frame_has_win(fr, next_curwin))
2097 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2098 							     width, new_size);
2099 	    row += new_size;
2100 	    height -= new_size;
2101 	    totwincount -= wincount;
2102 	}
2103     }
2104 }
2105 
2106 #ifdef FEAT_JOB_CHANNEL
2107     static void
2108 leaving_window(win_T *win)
2109 {
2110     // Only matters for a prompt window.
2111     if (!bt_prompt(win->w_buffer))
2112 	return;
2113 
2114     // When leaving a prompt window stop Insert mode and perhaps restart
2115     // it when entering that window again.
2116     win->w_buffer->b_prompt_insert = restart_edit;
2117     if (restart_edit != 0 && mode_displayed)
2118 	clear_cmdline = TRUE;		/* unshow mode later */
2119     restart_edit = NUL;
2120 
2121     // When leaving the window (or closing the window) was done from a
2122     // callback we need to break out of the Insert mode loop and restart Insert
2123     // mode when entering the window again.
2124     if (State & INSERT)
2125     {
2126 	stop_insert_mode = TRUE;
2127 	if (win->w_buffer->b_prompt_insert == NUL)
2128 	    win->w_buffer->b_prompt_insert = 'A';
2129     }
2130 }
2131 
2132     static void
2133 entering_window(win_T *win)
2134 {
2135     // Only matters for a prompt window.
2136     if (!bt_prompt(win->w_buffer))
2137 	return;
2138 
2139     // When switching to a prompt buffer that was in Insert mode, don't stop
2140     // Insert mode, it may have been set in leaving_window().
2141     if (win->w_buffer->b_prompt_insert != NUL)
2142 	stop_insert_mode = FALSE;
2143 
2144     // When entering the prompt window restart Insert mode if we were in Insert
2145     // mode when we left it.
2146     restart_edit = win->w_buffer->b_prompt_insert;
2147 }
2148 #endif
2149 
2150 /*
2151  * Close all windows for buffer "buf".
2152  */
2153     void
2154 close_windows(
2155     buf_T	*buf,
2156     int		keep_curwin)	    /* don't close "curwin" */
2157 {
2158     win_T	*wp;
2159     tabpage_T   *tp, *nexttp;
2160     int		h = tabline_height();
2161     int		count = tabpage_index(NULL);
2162 
2163     ++RedrawingDisabled;
2164 
2165     for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
2166     {
2167 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
2168 		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
2169 	{
2170 	    if (win_close(wp, FALSE) == FAIL)
2171 		/* If closing the window fails give up, to avoid looping
2172 		 * forever. */
2173 		break;
2174 
2175 	    /* Start all over, autocommands may change the window layout. */
2176 	    wp = firstwin;
2177 	}
2178 	else
2179 	    wp = wp->w_next;
2180     }
2181 
2182     /* Also check windows in other tab pages. */
2183     for (tp = first_tabpage; tp != NULL; tp = nexttp)
2184     {
2185 	nexttp = tp->tp_next;
2186 	if (tp != curtab)
2187 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
2188 		if (wp->w_buffer == buf
2189 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
2190 		{
2191 		    win_close_othertab(wp, FALSE, tp);
2192 
2193 		    /* Start all over, the tab page may be closed and
2194 		     * autocommands may change the window layout. */
2195 		    nexttp = first_tabpage;
2196 		    break;
2197 		}
2198     }
2199 
2200     --RedrawingDisabled;
2201 
2202     if (count != tabpage_index(NULL))
2203 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2204 
2205     redraw_tabline = TRUE;
2206     if (h != tabline_height())
2207 	shell_new_rows();
2208 }
2209 
2210 /*
2211  * Return TRUE if the current window is the only window that exists (ignoring
2212  * "aucmd_win").
2213  * Returns FALSE if there is a window, possibly in another tab page.
2214  */
2215     static int
2216 last_window(void)
2217 {
2218     return (one_window() && first_tabpage->tp_next == NULL);
2219 }
2220 
2221 /*
2222  * Return TRUE if there is only one window other than "aucmd_win" in the
2223  * current tab page.
2224  */
2225     int
2226 one_window(void)
2227 {
2228     win_T	*wp;
2229     int		seen_one = FALSE;
2230 
2231     FOR_ALL_WINDOWS(wp)
2232     {
2233 	if (wp != aucmd_win)
2234 	{
2235 	    if (seen_one)
2236 		return FALSE;
2237 	    seen_one = TRUE;
2238 	}
2239     }
2240     return TRUE;
2241 }
2242 
2243 /*
2244  * Close the possibly last window in a tab page.
2245  * Returns TRUE when the window was closed already.
2246  */
2247     static int
2248 close_last_window_tabpage(
2249     win_T	*win,
2250     int		free_buf,
2251     tabpage_T   *prev_curtab)
2252 {
2253     if (ONE_WINDOW)
2254     {
2255 	buf_T	*old_curbuf = curbuf;
2256 
2257 	/*
2258 	 * Closing the last window in a tab page.  First go to another tab
2259 	 * page and then close the window and the tab page.  This avoids that
2260 	 * curwin and curtab are invalid while we are freeing memory, they may
2261 	 * be used in GUI events.
2262 	 * Don't trigger autocommands yet, they may use wrong values, so do
2263 	 * that below.
2264 	 */
2265 	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
2266 	redraw_tabline = TRUE;
2267 
2268 	/* Safety check: Autocommands may have closed the window when jumping
2269 	 * to the other tab page. */
2270 	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
2271 	{
2272 	    int	    h = tabline_height();
2273 
2274 	    win_close_othertab(win, free_buf, prev_curtab);
2275 	    if (h != tabline_height())
2276 		shell_new_rows();
2277 	}
2278 #ifdef FEAT_JOB_CHANNEL
2279 	entering_window(curwin);
2280 #endif
2281 	/* Since goto_tabpage_tp above did not trigger *Enter autocommands, do
2282 	 * that now. */
2283 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2284 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
2285 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
2286 	if (old_curbuf != curbuf)
2287 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2288 	return TRUE;
2289     }
2290     return FALSE;
2291 }
2292 
2293 /*
2294  * Close window "win".  Only works for the current tab page.
2295  * If "free_buf" is TRUE related buffer may be unloaded.
2296  *
2297  * Called by :quit, :close, :xit, :wq and findtag().
2298  * Returns FAIL when the window was not closed.
2299  */
2300     int
2301 win_close(win_T *win, int free_buf)
2302 {
2303     win_T	*wp;
2304     int		other_buffer = FALSE;
2305     int		close_curwin = FALSE;
2306     int		dir;
2307     int		help_window = FALSE;
2308     tabpage_T   *prev_curtab = curtab;
2309     frame_T	*win_frame = win->w_frame->fr_parent;
2310 
2311     if (last_window())
2312     {
2313 	emsg(_("E444: Cannot close last window"));
2314 	return FAIL;
2315     }
2316 
2317     if (win->w_closing || (win->w_buffer != NULL
2318 					       && win->w_buffer->b_locked > 0))
2319 	return FAIL; /* window is already being closed */
2320     if (win == aucmd_win)
2321     {
2322 	emsg(_("E813: Cannot close autocmd window"));
2323 	return FAIL;
2324     }
2325     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
2326     {
2327 	emsg(_("E814: Cannot close window, only autocmd window would remain"));
2328 	return FAIL;
2329     }
2330 
2331     /* When closing the last window in a tab page first go to another tab page
2332      * and then close the window and the tab page to avoid that curwin and
2333      * curtab are invalid while we are freeing memory. */
2334     if (close_last_window_tabpage(win, free_buf, prev_curtab))
2335       return FAIL;
2336 
2337     /* When closing the help window, try restoring a snapshot after closing
2338      * the window.  Otherwise clear the snapshot, it's now invalid. */
2339     if (bt_help(win->w_buffer))
2340 	help_window = TRUE;
2341     else
2342 	clear_snapshot(curtab, SNAP_HELP_IDX);
2343 
2344     if (win == curwin)
2345     {
2346 #ifdef FEAT_JOB_CHANNEL
2347 	leaving_window(curwin);
2348 #endif
2349 	/*
2350 	 * Guess which window is going to be the new current window.
2351 	 * This may change because of the autocommands (sigh).
2352 	 */
2353 	wp = frame2win(win_altframe(win, NULL));
2354 
2355 	/*
2356 	 * Be careful: If autocommands delete the window or cause this window
2357 	 * to be the last one left, return now.
2358 	 */
2359 	if (wp->w_buffer != curbuf)
2360 	{
2361 	    other_buffer = TRUE;
2362 	    win->w_closing = TRUE;
2363 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
2364 	    if (!win_valid(win))
2365 		return FAIL;
2366 	    win->w_closing = FALSE;
2367 	    if (last_window())
2368 		return FAIL;
2369 	}
2370 	win->w_closing = TRUE;
2371 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
2372 	if (!win_valid(win))
2373 	    return FAIL;
2374 	win->w_closing = FALSE;
2375 	if (last_window())
2376 	    return FAIL;
2377 #ifdef FEAT_EVAL
2378 	/* autocmds may abort script processing */
2379 	if (aborting())
2380 	    return FAIL;
2381 #endif
2382     }
2383 
2384 #ifdef FEAT_GUI
2385     // Avoid trouble with scrollbars that are going to be deleted in
2386     // win_free().
2387     if (gui.in_use)
2388 	out_flush();
2389 #endif
2390 
2391 #ifdef FEAT_SYN_HL
2392     // Free independent synblock before the buffer is freed.
2393     if (win->w_buffer != NULL)
2394 	reset_synblock(win);
2395 #endif
2396 
2397 #ifdef FEAT_QUICKFIX
2398     // When the quickfix/location list window is closed, unlist the buffer.
2399     if (win->w_buffer != NULL && bt_quickfix(win->w_buffer))
2400 	win->w_buffer->b_p_bl = FALSE;
2401 #endif
2402 
2403     /*
2404      * Close the link to the buffer.
2405      */
2406     if (win->w_buffer != NULL)
2407     {
2408 	bufref_T    bufref;
2409 
2410 	set_bufref(&bufref, curbuf);
2411 	win->w_closing = TRUE;
2412 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, TRUE);
2413 	if (win_valid_any_tab(win))
2414 	    win->w_closing = FALSE;
2415 	/* Make sure curbuf is valid. It can become invalid if 'bufhidden' is
2416 	 * "wipe". */
2417 	if (!bufref_valid(&bufref))
2418 	    curbuf = firstbuf;
2419     }
2420 
2421     if (only_one_window() && win_valid(win) && win->w_buffer == NULL
2422 	    && (last_window() || curtab != prev_curtab
2423 		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
2424     {
2425 	/* Autocommands have closed all windows, quit now.  Restore
2426 	 * curwin->w_buffer, otherwise writing viminfo may fail. */
2427 	if (curwin->w_buffer == NULL)
2428 	    curwin->w_buffer = curbuf;
2429 	getout(0);
2430     }
2431 
2432     /* Autocommands may have moved to another tab page. */
2433     if (curtab != prev_curtab && win_valid_any_tab(win)
2434 						      && win->w_buffer == NULL)
2435     {
2436 	/* Need to close the window anyway, since the buffer is NULL. */
2437 	win_close_othertab(win, FALSE, prev_curtab);
2438 	return FAIL;
2439     }
2440 
2441     /* Autocommands may have closed the window already or closed the only
2442      * other window. */
2443     if (!win_valid(win) || last_window()
2444 	    || close_last_window_tabpage(win, free_buf, prev_curtab))
2445 	return FAIL;
2446 
2447     /* Free the memory used for the window and get the window that received
2448      * the screen space. */
2449     wp = win_free_mem(win, &dir, NULL);
2450 
2451     /* Make sure curwin isn't invalid.  It can cause severe trouble when
2452      * printing an error message.  For win_equal() curbuf needs to be valid
2453      * too. */
2454     if (win == curwin)
2455     {
2456 	curwin = wp;
2457 #ifdef FEAT_QUICKFIX
2458 	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
2459 	{
2460 	    /*
2461 	     * If the cursor goes to the preview or the quickfix window, try
2462 	     * finding another window to go to.
2463 	     */
2464 	    for (;;)
2465 	    {
2466 		if (wp->w_next == NULL)
2467 		    wp = firstwin;
2468 		else
2469 		    wp = wp->w_next;
2470 		if (wp == curwin)
2471 		    break;
2472 		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
2473 		{
2474 		    curwin = wp;
2475 		    break;
2476 		}
2477 	    }
2478 	}
2479 #endif
2480 	curbuf = curwin->w_buffer;
2481 	close_curwin = TRUE;
2482 
2483 	/* The cursor position may be invalid if the buffer changed after last
2484 	 * using the window. */
2485 	check_cursor();
2486     }
2487     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
2488 	/* If the frame of the closed window contains the new current window,
2489 	 * only resize that frame.  Otherwise resize all windows. */
2490 	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
2491     else
2492 	win_comp_pos();
2493     if (close_curwin)
2494     {
2495 	win_enter_ext(wp, FALSE, TRUE, FALSE, TRUE, TRUE);
2496 	if (other_buffer)
2497 	    /* careful: after this wp and win may be invalid! */
2498 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2499     }
2500 
2501     /*
2502      * If last window has a status line now and we don't want one,
2503      * remove the status line.
2504      */
2505     last_status(FALSE);
2506 
2507     /* After closing the help window, try restoring the window layout from
2508      * before it was opened. */
2509     if (help_window)
2510 	restore_snapshot(SNAP_HELP_IDX, close_curwin);
2511 
2512 #if defined(FEAT_GUI)
2513     /* When 'guioptions' includes 'L' or 'R' may have to remove scrollbars. */
2514     if (gui.in_use && !win_hasvertsplit())
2515 	gui_init_which_components(NULL);
2516 #endif
2517 
2518     redraw_all_later(NOT_VALID);
2519     return OK;
2520 }
2521 
2522 /*
2523  * Close window "win" in tab page "tp", which is not the current tab page.
2524  * This may be the last window in that tab page and result in closing the tab,
2525  * thus "tp" may become invalid!
2526  * Caller must check if buffer is hidden and whether the tabline needs to be
2527  * updated.
2528  */
2529     void
2530 win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
2531 {
2532     win_T	*wp;
2533     int		dir;
2534     tabpage_T   *ptp = NULL;
2535     int		free_tp = FALSE;
2536 
2537     /* Get here with win->w_buffer == NULL when win_close() detects the tab
2538      * page changed. */
2539     if (win->w_closing || (win->w_buffer != NULL
2540 					       && win->w_buffer->b_locked > 0))
2541 	return; /* window is already being closed */
2542 
2543     if (win->w_buffer != NULL)
2544 	/* Close the link to the buffer. */
2545 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, FALSE);
2546 
2547     /* Careful: Autocommands may have closed the tab page or made it the
2548      * current tab page.  */
2549     for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
2550 	;
2551     if (ptp == NULL || tp == curtab)
2552 	return;
2553 
2554     /* Autocommands may have closed the window already. */
2555     for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
2556 	;
2557     if (wp == NULL)
2558 	return;
2559 
2560     /* When closing the last window in a tab page remove the tab page. */
2561     if (tp->tp_firstwin == tp->tp_lastwin)
2562     {
2563 	if (tp == first_tabpage)
2564 	    first_tabpage = tp->tp_next;
2565 	else
2566 	{
2567 	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
2568 							   ptp = ptp->tp_next)
2569 		;
2570 	    if (ptp == NULL)
2571 	    {
2572 		internal_error("win_close_othertab()");
2573 		return;
2574 	    }
2575 	    ptp->tp_next = tp->tp_next;
2576 	}
2577 	free_tp = TRUE;
2578     }
2579 
2580     /* Free the memory used for the window. */
2581     win_free_mem(win, &dir, tp);
2582 
2583     if (free_tp)
2584 	free_tabpage(tp);
2585 }
2586 
2587 /*
2588  * Free the memory used for a window.
2589  * Returns a pointer to the window that got the freed up space.
2590  */
2591     static win_T *
2592 win_free_mem(
2593     win_T	*win,
2594     int		*dirp,		/* set to 'v' or 'h' for direction if 'ea' */
2595     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2596 {
2597     frame_T	*frp;
2598     win_T	*wp;
2599 
2600     /* Remove the window and its frame from the tree of frames. */
2601     frp = win->w_frame;
2602     wp = winframe_remove(win, dirp, tp);
2603     vim_free(frp);
2604     win_free(win, tp);
2605 
2606     /* When deleting the current window of another tab page select a new
2607      * current window. */
2608     if (tp != NULL && win == tp->tp_curwin)
2609 	tp->tp_curwin = wp;
2610 
2611     return wp;
2612 }
2613 
2614 #if defined(EXITFREE) || defined(PROTO)
2615     void
2616 win_free_all(void)
2617 {
2618     int		dummy;
2619 
2620     while (first_tabpage->tp_next != NULL)
2621 	tabpage_close(TRUE);
2622 
2623     if (aucmd_win != NULL)
2624     {
2625 	(void)win_free_mem(aucmd_win, &dummy, NULL);
2626 	aucmd_win = NULL;
2627     }
2628 
2629     while (firstwin != NULL)
2630 	(void)win_free_mem(firstwin, &dummy, NULL);
2631 
2632     /* No window should be used after this. Set curwin to NULL to crash
2633      * instead of using freed memory. */
2634     curwin = NULL;
2635 }
2636 #endif
2637 
2638 /*
2639  * Remove a window and its frame from the tree of frames.
2640  * Returns a pointer to the window that got the freed up space.
2641  */
2642     win_T *
2643 winframe_remove(
2644     win_T	*win,
2645     int		*dirp UNUSED,	/* set to 'v' or 'h' for direction if 'ea' */
2646     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2647 {
2648     frame_T	*frp, *frp2, *frp3;
2649     frame_T	*frp_close = win->w_frame;
2650     win_T	*wp;
2651 
2652     /*
2653      * If there is only one window there is nothing to remove.
2654      */
2655     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2656 	return NULL;
2657 
2658     /*
2659      * Remove the window from its frame.
2660      */
2661     frp2 = win_altframe(win, tp);
2662     wp = frame2win(frp2);
2663 
2664     /* Remove this frame from the list of frames. */
2665     frame_remove(frp_close);
2666 
2667     if (frp_close->fr_parent->fr_layout == FR_COL)
2668     {
2669 	/* When 'winfixheight' is set, try to find another frame in the column
2670 	 * (as close to the closed frame as possible) to distribute the height
2671 	 * to. */
2672 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
2673 	{
2674 	    frp = frp_close->fr_prev;
2675 	    frp3 = frp_close->fr_next;
2676 	    while (frp != NULL || frp3 != NULL)
2677 	    {
2678 		if (frp != NULL)
2679 		{
2680 		    if (!frame_fixed_height(frp))
2681 		    {
2682 			frp2 = frp;
2683 			wp = frame2win(frp2);
2684 			break;
2685 		    }
2686 		    frp = frp->fr_prev;
2687 		}
2688 		if (frp3 != NULL)
2689 		{
2690 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
2691 		    {
2692 			frp2 = frp3;
2693 			wp = frp3->fr_win;
2694 			break;
2695 		    }
2696 		    frp3 = frp3->fr_next;
2697 		}
2698 	    }
2699 	}
2700 	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
2701 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2702 	*dirp = 'v';
2703     }
2704     else
2705     {
2706 	/* When 'winfixwidth' is set, try to find another frame in the column
2707 	 * (as close to the closed frame as possible) to distribute the width
2708 	 * to. */
2709 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
2710 	{
2711 	    frp = frp_close->fr_prev;
2712 	    frp3 = frp_close->fr_next;
2713 	    while (frp != NULL || frp3 != NULL)
2714 	    {
2715 		if (frp != NULL)
2716 		{
2717 		    if (!frame_fixed_width(frp))
2718 		    {
2719 			frp2 = frp;
2720 			wp = frame2win(frp2);
2721 			break;
2722 		    }
2723 		    frp = frp->fr_prev;
2724 		}
2725 		if (frp3 != NULL)
2726 		{
2727 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
2728 		    {
2729 			frp2 = frp3;
2730 			wp = frp3->fr_win;
2731 			break;
2732 		    }
2733 		    frp3 = frp3->fr_next;
2734 		}
2735 	    }
2736 	}
2737 	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
2738 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2739 	*dirp = 'h';
2740     }
2741 
2742     /* If rows/columns go to a window below/right its positions need to be
2743      * updated.  Can only be done after the sizes have been updated. */
2744     if (frp2 == frp_close->fr_next)
2745     {
2746 	int row = win->w_winrow;
2747 	int col = win->w_wincol;
2748 
2749 	frame_comp_pos(frp2, &row, &col);
2750     }
2751 
2752     if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
2753     {
2754 	/* There is no other frame in this list, move its info to the parent
2755 	 * and remove it. */
2756 	frp2->fr_parent->fr_layout = frp2->fr_layout;
2757 	frp2->fr_parent->fr_child = frp2->fr_child;
2758 	FOR_ALL_FRAMES(frp, frp2->fr_child)
2759 	    frp->fr_parent = frp2->fr_parent;
2760 	frp2->fr_parent->fr_win = frp2->fr_win;
2761 	if (frp2->fr_win != NULL)
2762 	    frp2->fr_win->w_frame = frp2->fr_parent;
2763 	frp = frp2->fr_parent;
2764 	if (topframe->fr_child == frp2)
2765 	    topframe->fr_child = frp;
2766 	vim_free(frp2);
2767 
2768 	frp2 = frp->fr_parent;
2769 	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
2770 	{
2771 	    /* The frame above the parent has the same layout, have to merge
2772 	     * the frames into this list. */
2773 	    if (frp2->fr_child == frp)
2774 		frp2->fr_child = frp->fr_child;
2775 	    frp->fr_child->fr_prev = frp->fr_prev;
2776 	    if (frp->fr_prev != NULL)
2777 		frp->fr_prev->fr_next = frp->fr_child;
2778 	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
2779 	    {
2780 		frp3->fr_parent = frp2;
2781 		if (frp3->fr_next == NULL)
2782 		{
2783 		    frp3->fr_next = frp->fr_next;
2784 		    if (frp->fr_next != NULL)
2785 			frp->fr_next->fr_prev = frp3;
2786 		    break;
2787 		}
2788 	    }
2789 	    if (topframe->fr_child == frp)
2790 		topframe->fr_child = frp2;
2791 	    vim_free(frp);
2792 	}
2793     }
2794 
2795     return wp;
2796 }
2797 
2798 /*
2799  * Return a pointer to the frame that will receive the empty screen space that
2800  * is left over after "win" is closed.
2801  *
2802  * If 'splitbelow' or 'splitright' is set, the space goes above or to the left
2803  * by default.  Otherwise, the free space goes below or to the right.  The
2804  * result is that opening a window and then immediately closing it will
2805  * preserve the initial window layout.  The 'wfh' and 'wfw' settings are
2806  * respected when possible.
2807  */
2808     static frame_T *
2809 win_altframe(
2810     win_T	*win,
2811     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
2812 {
2813     frame_T	*frp;
2814     frame_T	*other_fr, *target_fr;
2815 
2816     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2817 	return alt_tabpage()->tp_curwin->w_frame;
2818 
2819     frp = win->w_frame;
2820 
2821     if (frp->fr_prev == NULL)
2822 	return frp->fr_next;
2823     if (frp->fr_next == NULL)
2824 	return frp->fr_prev;
2825 
2826     target_fr = frp->fr_next;
2827     other_fr  = frp->fr_prev;
2828     if (p_spr || p_sb)
2829     {
2830 	target_fr = frp->fr_prev;
2831 	other_fr  = frp->fr_next;
2832     }
2833 
2834     /* If 'wfh' or 'wfw' is set for the target and not for the alternate
2835      * window, reverse the selection. */
2836     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
2837     {
2838 	if (frame_fixed_width(target_fr) && !frame_fixed_width(other_fr))
2839 	    target_fr = other_fr;
2840     }
2841     else
2842     {
2843 	if (frame_fixed_height(target_fr) && !frame_fixed_height(other_fr))
2844 	    target_fr = other_fr;
2845     }
2846 
2847     return target_fr;
2848 }
2849 
2850 /*
2851  * Return the tabpage that will be used if the current one is closed.
2852  */
2853     static tabpage_T *
2854 alt_tabpage(void)
2855 {
2856     tabpage_T	*tp;
2857 
2858     /* Use the next tab page if possible. */
2859     if (curtab->tp_next != NULL)
2860 	return curtab->tp_next;
2861 
2862     /* Find the last but one tab page. */
2863     for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
2864 	;
2865     return tp;
2866 }
2867 
2868 /*
2869  * Find the left-upper window in frame "frp".
2870  */
2871     static win_T *
2872 frame2win(frame_T *frp)
2873 {
2874     while (frp->fr_win == NULL)
2875 	frp = frp->fr_child;
2876     return frp->fr_win;
2877 }
2878 
2879 /*
2880  * Return TRUE if frame "frp" contains window "wp".
2881  */
2882     static int
2883 frame_has_win(frame_T *frp, win_T *wp)
2884 {
2885     frame_T	*p;
2886 
2887     if (frp->fr_layout == FR_LEAF)
2888 	return frp->fr_win == wp;
2889 
2890     FOR_ALL_FRAMES(p, frp->fr_child)
2891 	if (frame_has_win(p, wp))
2892 	    return TRUE;
2893     return FALSE;
2894 }
2895 
2896 /*
2897  * Set a new height for a frame.  Recursively sets the height for contained
2898  * frames and windows.  Caller must take care of positions.
2899  */
2900     static void
2901 frame_new_height(
2902     frame_T	*topfrp,
2903     int		height,
2904     int		topfirst,	/* resize topmost contained frame first */
2905     int		wfh)		/* obey 'winfixheight' when there is a choice;
2906 				   may cause the height not to be set */
2907 {
2908     frame_T	*frp;
2909     int		extra_lines;
2910     int		h;
2911 
2912     if (topfrp->fr_win != NULL)
2913     {
2914 	/* Simple case: just one window. */
2915 	win_new_height(topfrp->fr_win,
2916 				    height - topfrp->fr_win->w_status_height
2917 					      - WINBAR_HEIGHT(topfrp->fr_win));
2918     }
2919     else if (topfrp->fr_layout == FR_ROW)
2920     {
2921 	do
2922 	{
2923 	    /* All frames in this row get the same new height. */
2924 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
2925 	    {
2926 		frame_new_height(frp, height, topfirst, wfh);
2927 		if (frp->fr_height > height)
2928 		{
2929 		    /* Could not fit the windows, make the whole row higher. */
2930 		    height = frp->fr_height;
2931 		    break;
2932 		}
2933 	    }
2934 	}
2935 	while (frp != NULL);
2936     }
2937     else    /* fr_layout == FR_COL */
2938     {
2939 	/* Complicated case: Resize a column of frames.  Resize the bottom
2940 	 * frame first, frames above that when needed. */
2941 
2942 	frp = topfrp->fr_child;
2943 	if (wfh)
2944 	    /* Advance past frames with one window with 'wfh' set. */
2945 	    while (frame_fixed_height(frp))
2946 	    {
2947 		frp = frp->fr_next;
2948 		if (frp == NULL)
2949 		    return;	    /* no frame without 'wfh', give up */
2950 	    }
2951 	if (!topfirst)
2952 	{
2953 	    /* Find the bottom frame of this column */
2954 	    while (frp->fr_next != NULL)
2955 		frp = frp->fr_next;
2956 	    if (wfh)
2957 		/* Advance back for frames with one window with 'wfh' set. */
2958 		while (frame_fixed_height(frp))
2959 		    frp = frp->fr_prev;
2960 	}
2961 
2962 	extra_lines = height - topfrp->fr_height;
2963 	if (extra_lines < 0)
2964 	{
2965 	    /* reduce height of contained frames, bottom or top frame first */
2966 	    while (frp != NULL)
2967 	    {
2968 		h = frame_minheight(frp, NULL);
2969 		if (frp->fr_height + extra_lines < h)
2970 		{
2971 		    extra_lines += frp->fr_height - h;
2972 		    frame_new_height(frp, h, topfirst, wfh);
2973 		}
2974 		else
2975 		{
2976 		    frame_new_height(frp, frp->fr_height + extra_lines,
2977 							       topfirst, wfh);
2978 		    break;
2979 		}
2980 		if (topfirst)
2981 		{
2982 		    do
2983 			frp = frp->fr_next;
2984 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2985 		}
2986 		else
2987 		{
2988 		    do
2989 			frp = frp->fr_prev;
2990 		    while (wfh && frp != NULL && frame_fixed_height(frp));
2991 		}
2992 		/* Increase "height" if we could not reduce enough frames. */
2993 		if (frp == NULL)
2994 		    height -= extra_lines;
2995 	    }
2996 	}
2997 	else if (extra_lines > 0)
2998 	{
2999 	    /* increase height of bottom or top frame */
3000 	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
3001 	}
3002     }
3003     topfrp->fr_height = height;
3004 }
3005 
3006 /*
3007  * Return TRUE if height of frame "frp" should not be changed because of
3008  * the 'winfixheight' option.
3009  */
3010     static int
3011 frame_fixed_height(frame_T *frp)
3012 {
3013     /* frame with one window: fixed height if 'winfixheight' set. */
3014     if (frp->fr_win != NULL)
3015 	return frp->fr_win->w_p_wfh;
3016 
3017     if (frp->fr_layout == FR_ROW)
3018     {
3019 	/* The frame is fixed height if one of the frames in the row is fixed
3020 	 * height. */
3021 	FOR_ALL_FRAMES(frp, frp->fr_child)
3022 	    if (frame_fixed_height(frp))
3023 		return TRUE;
3024 	return FALSE;
3025     }
3026 
3027     /* frp->fr_layout == FR_COL: The frame is fixed height if all of the
3028      * frames in the row are fixed height. */
3029     FOR_ALL_FRAMES(frp, frp->fr_child)
3030 	if (!frame_fixed_height(frp))
3031 	    return FALSE;
3032     return TRUE;
3033 }
3034 
3035 /*
3036  * Return TRUE if width of frame "frp" should not be changed because of
3037  * the 'winfixwidth' option.
3038  */
3039     static int
3040 frame_fixed_width(frame_T *frp)
3041 {
3042     /* frame with one window: fixed width if 'winfixwidth' set. */
3043     if (frp->fr_win != NULL)
3044 	return frp->fr_win->w_p_wfw;
3045 
3046     if (frp->fr_layout == FR_COL)
3047     {
3048 	/* The frame is fixed width if one of the frames in the row is fixed
3049 	 * width. */
3050 	FOR_ALL_FRAMES(frp, frp->fr_child)
3051 	    if (frame_fixed_width(frp))
3052 		return TRUE;
3053 	return FALSE;
3054     }
3055 
3056     /* frp->fr_layout == FR_ROW: The frame is fixed width if all of the
3057      * frames in the row are fixed width. */
3058     FOR_ALL_FRAMES(frp, frp->fr_child)
3059 	if (!frame_fixed_width(frp))
3060 	    return FALSE;
3061     return TRUE;
3062 }
3063 
3064 /*
3065  * Add a status line to windows at the bottom of "frp".
3066  * Note: Does not check if there is room!
3067  */
3068     static void
3069 frame_add_statusline(frame_T *frp)
3070 {
3071     win_T	*wp;
3072 
3073     if (frp->fr_layout == FR_LEAF)
3074     {
3075 	wp = frp->fr_win;
3076 	if (wp->w_status_height == 0)
3077 	{
3078 	    if (wp->w_height > 0)	/* don't make it negative */
3079 		--wp->w_height;
3080 	    wp->w_status_height = STATUS_HEIGHT;
3081 	}
3082     }
3083     else if (frp->fr_layout == FR_ROW)
3084     {
3085 	/* Handle all the frames in the row. */
3086 	FOR_ALL_FRAMES(frp, frp->fr_child)
3087 	    frame_add_statusline(frp);
3088     }
3089     else /* frp->fr_layout == FR_COL */
3090     {
3091 	/* Only need to handle the last frame in the column. */
3092 	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
3093 	    ;
3094 	frame_add_statusline(frp);
3095     }
3096 }
3097 
3098 /*
3099  * Set width of a frame.  Handles recursively going through contained frames.
3100  * May remove separator line for windows at the right side (for win_close()).
3101  */
3102     static void
3103 frame_new_width(
3104     frame_T	*topfrp,
3105     int		width,
3106     int		leftfirst,	/* resize leftmost contained frame first */
3107     int		wfw)		/* obey 'winfixwidth' when there is a choice;
3108 				   may cause the width not to be set */
3109 {
3110     frame_T	*frp;
3111     int		extra_cols;
3112     int		w;
3113     win_T	*wp;
3114 
3115     if (topfrp->fr_layout == FR_LEAF)
3116     {
3117 	/* Simple case: just one window. */
3118 	wp = topfrp->fr_win;
3119 	/* Find out if there are any windows right of this one. */
3120 	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
3121 	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
3122 		break;
3123 	if (frp->fr_parent == NULL)
3124 	    wp->w_vsep_width = 0;
3125 	win_new_width(wp, width - wp->w_vsep_width);
3126     }
3127     else if (topfrp->fr_layout == FR_COL)
3128     {
3129 	do
3130 	{
3131 	    /* All frames in this column get the same new width. */
3132 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3133 	    {
3134 		frame_new_width(frp, width, leftfirst, wfw);
3135 		if (frp->fr_width > width)
3136 		{
3137 		    /* Could not fit the windows, make whole column wider. */
3138 		    width = frp->fr_width;
3139 		    break;
3140 		}
3141 	    }
3142 	} while (frp != NULL);
3143     }
3144     else    /* fr_layout == FR_ROW */
3145     {
3146 	/* Complicated case: Resize a row of frames.  Resize the rightmost
3147 	 * frame first, frames left of it when needed. */
3148 
3149 	frp = topfrp->fr_child;
3150 	if (wfw)
3151 	    /* Advance past frames with one window with 'wfw' set. */
3152 	    while (frame_fixed_width(frp))
3153 	    {
3154 		frp = frp->fr_next;
3155 		if (frp == NULL)
3156 		    return;	    /* no frame without 'wfw', give up */
3157 	    }
3158 	if (!leftfirst)
3159 	{
3160 	    /* Find the rightmost frame of this row */
3161 	    while (frp->fr_next != NULL)
3162 		frp = frp->fr_next;
3163 	    if (wfw)
3164 		/* Advance back for frames with one window with 'wfw' set. */
3165 		while (frame_fixed_width(frp))
3166 		    frp = frp->fr_prev;
3167 	}
3168 
3169 	extra_cols = width - topfrp->fr_width;
3170 	if (extra_cols < 0)
3171 	{
3172 	    /* reduce frame width, rightmost frame first */
3173 	    while (frp != NULL)
3174 	    {
3175 		w = frame_minwidth(frp, NULL);
3176 		if (frp->fr_width + extra_cols < w)
3177 		{
3178 		    extra_cols += frp->fr_width - w;
3179 		    frame_new_width(frp, w, leftfirst, wfw);
3180 		}
3181 		else
3182 		{
3183 		    frame_new_width(frp, frp->fr_width + extra_cols,
3184 							      leftfirst, wfw);
3185 		    break;
3186 		}
3187 		if (leftfirst)
3188 		{
3189 		    do
3190 			frp = frp->fr_next;
3191 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3192 		}
3193 		else
3194 		{
3195 		    do
3196 			frp = frp->fr_prev;
3197 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3198 		}
3199 		/* Increase "width" if we could not reduce enough frames. */
3200 		if (frp == NULL)
3201 		    width -= extra_cols;
3202 	    }
3203 	}
3204 	else if (extra_cols > 0)
3205 	{
3206 	    /* increase width of rightmost frame */
3207 	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
3208 	}
3209     }
3210     topfrp->fr_width = width;
3211 }
3212 
3213 /*
3214  * Add the vertical separator to windows at the right side of "frp".
3215  * Note: Does not check if there is room!
3216  */
3217     static void
3218 frame_add_vsep(frame_T *frp)
3219 {
3220     win_T	*wp;
3221 
3222     if (frp->fr_layout == FR_LEAF)
3223     {
3224 	wp = frp->fr_win;
3225 	if (wp->w_vsep_width == 0)
3226 	{
3227 	    if (wp->w_width > 0)	/* don't make it negative */
3228 		--wp->w_width;
3229 	    wp->w_vsep_width = 1;
3230 	}
3231     }
3232     else if (frp->fr_layout == FR_COL)
3233     {
3234 	/* Handle all the frames in the column. */
3235 	FOR_ALL_FRAMES(frp, frp->fr_child)
3236 	    frame_add_vsep(frp);
3237     }
3238     else /* frp->fr_layout == FR_ROW */
3239     {
3240 	/* Only need to handle the last frame in the row. */
3241 	frp = frp->fr_child;
3242 	while (frp->fr_next != NULL)
3243 	    frp = frp->fr_next;
3244 	frame_add_vsep(frp);
3245     }
3246 }
3247 
3248 /*
3249  * Set frame width from the window it contains.
3250  */
3251     static void
3252 frame_fix_width(win_T *wp)
3253 {
3254     wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
3255 }
3256 
3257 /*
3258  * Set frame height from the window it contains.
3259  */
3260     static void
3261 frame_fix_height(win_T *wp)
3262 {
3263     wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
3264 }
3265 
3266 /*
3267  * Compute the minimal height for frame "topfrp".
3268  * Uses the 'winminheight' option.
3269  * When "next_curwin" isn't NULL, use p_wh for this window.
3270  * When "next_curwin" is NOWIN, don't use at least one line for the current
3271  * window.
3272  */
3273     static int
3274 frame_minheight(frame_T *topfrp, win_T *next_curwin)
3275 {
3276     frame_T	*frp;
3277     int		m;
3278     int		n;
3279 
3280     if (topfrp->fr_win != NULL)
3281     {
3282 	if (topfrp->fr_win == next_curwin)
3283 	    m = p_wh + topfrp->fr_win->w_status_height;
3284 	else
3285 	{
3286 	    /* window: minimal height of the window plus status line */
3287 	    m = p_wmh + topfrp->fr_win->w_status_height;
3288 	    if (topfrp->fr_win == curwin && next_curwin == NULL)
3289 	    {
3290 		/* Current window is minimal one line high and WinBar is
3291 		 * visible. */
3292 		if (p_wmh == 0)
3293 		    ++m;
3294 		m += WINBAR_HEIGHT(curwin);
3295 	    }
3296 	}
3297     }
3298     else if (topfrp->fr_layout == FR_ROW)
3299     {
3300 	/* get the minimal height from each frame in this row */
3301 	m = 0;
3302 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3303 	{
3304 	    n = frame_minheight(frp, next_curwin);
3305 	    if (n > m)
3306 		m = n;
3307 	}
3308     }
3309     else
3310     {
3311 	/* Add up the minimal heights for all frames in this column. */
3312 	m = 0;
3313 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3314 	    m += frame_minheight(frp, next_curwin);
3315     }
3316 
3317     return m;
3318 }
3319 
3320 /*
3321  * Compute the minimal width for frame "topfrp".
3322  * When "next_curwin" isn't NULL, use p_wiw for this window.
3323  * When "next_curwin" is NOWIN, don't use at least one column for the current
3324  * window.
3325  */
3326     static int
3327 frame_minwidth(
3328     frame_T	*topfrp,
3329     win_T	*next_curwin)	/* use p_wh and p_wiw for next_curwin */
3330 {
3331     frame_T	*frp;
3332     int		m, n;
3333 
3334     if (topfrp->fr_win != NULL)
3335     {
3336 	if (topfrp->fr_win == next_curwin)
3337 	    m = p_wiw + topfrp->fr_win->w_vsep_width;
3338 	else
3339 	{
3340 	    /* window: minimal width of the window plus separator column */
3341 	    m = p_wmw + topfrp->fr_win->w_vsep_width;
3342 	    /* Current window is minimal one column wide */
3343 	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
3344 		++m;
3345 	}
3346     }
3347     else if (topfrp->fr_layout == FR_COL)
3348     {
3349 	/* get the minimal width from each frame in this column */
3350 	m = 0;
3351 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3352 	{
3353 	    n = frame_minwidth(frp, next_curwin);
3354 	    if (n > m)
3355 		m = n;
3356 	}
3357     }
3358     else
3359     {
3360 	/* Add up the minimal widths for all frames in this row. */
3361 	m = 0;
3362 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3363 	    m += frame_minwidth(frp, next_curwin);
3364     }
3365 
3366     return m;
3367 }
3368 
3369 
3370 /*
3371  * Try to close all windows except current one.
3372  * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
3373  * used and the buffer was modified.
3374  *
3375  * Used by ":bdel" and ":only".
3376  */
3377     void
3378 close_others(
3379     int		message,
3380     int		forceit)	    /* always hide all other windows */
3381 {
3382     win_T	*wp;
3383     win_T	*nextwp;
3384     int		r;
3385 
3386     if (one_window())
3387     {
3388 	if (message && !autocmd_busy)
3389 	    msg(_(m_onlyone));
3390 	return;
3391     }
3392 
3393     /* Be very careful here: autocommands may change the window layout. */
3394     for (wp = firstwin; win_valid(wp); wp = nextwp)
3395     {
3396 	nextwp = wp->w_next;
3397 	if (wp != curwin)		/* don't close current window */
3398 	{
3399 
3400 	    /* Check if it's allowed to abandon this window */
3401 	    r = can_abandon(wp->w_buffer, forceit);
3402 	    if (!win_valid(wp))		/* autocommands messed wp up */
3403 	    {
3404 		nextwp = firstwin;
3405 		continue;
3406 	    }
3407 	    if (!r)
3408 	    {
3409 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
3410 		if (message && (p_confirm || cmdmod.confirm) && p_write)
3411 		{
3412 		    dialog_changed(wp->w_buffer, FALSE);
3413 		    if (!win_valid(wp))		/* autocommands messed wp up */
3414 		    {
3415 			nextwp = firstwin;
3416 			continue;
3417 		    }
3418 		}
3419 		if (bufIsChanged(wp->w_buffer))
3420 #endif
3421 		    continue;
3422 	    }
3423 	    win_close(wp, !buf_hide(wp->w_buffer)
3424 					       && !bufIsChanged(wp->w_buffer));
3425 	}
3426     }
3427 
3428     if (message && !ONE_WINDOW)
3429 	emsg(_("E445: Other window contains changes"));
3430 }
3431 
3432 /*
3433  * Init the current window "curwin".
3434  * Called when a new file is being edited.
3435  */
3436     void
3437 curwin_init(void)
3438 {
3439     win_init_empty(curwin);
3440 }
3441 
3442     void
3443 win_init_empty(win_T *wp)
3444 {
3445     redraw_win_later(wp, NOT_VALID);
3446     wp->w_lines_valid = 0;
3447     wp->w_cursor.lnum = 1;
3448     wp->w_curswant = wp->w_cursor.col = 0;
3449     wp->w_cursor.coladd = 0;
3450     wp->w_pcmark.lnum = 1;	/* pcmark not cleared but set to line 1 */
3451     wp->w_pcmark.col = 0;
3452     wp->w_prev_pcmark.lnum = 0;
3453     wp->w_prev_pcmark.col = 0;
3454     wp->w_topline = 1;
3455 #ifdef FEAT_DIFF
3456     wp->w_topfill = 0;
3457 #endif
3458     wp->w_botline = 2;
3459 #ifdef FEAT_SYN_HL
3460     wp->w_s = &wp->w_buffer->b_s;
3461 #endif
3462 }
3463 
3464 /*
3465  * Allocate the first window and put an empty buffer in it.
3466  * Called from main().
3467  * Return FAIL when something goes wrong (out of memory).
3468  */
3469     int
3470 win_alloc_first(void)
3471 {
3472     if (win_alloc_firstwin(NULL) == FAIL)
3473 	return FAIL;
3474 
3475     first_tabpage = alloc_tabpage();
3476     if (first_tabpage == NULL)
3477 	return FAIL;
3478     first_tabpage->tp_topframe = topframe;
3479     curtab = first_tabpage;
3480 
3481     return OK;
3482 }
3483 
3484 /*
3485  * Init "aucmd_win".  This can only be done after the first
3486  * window is fully initialized, thus it can't be in win_alloc_first().
3487  */
3488     void
3489 win_alloc_aucmd_win(void)
3490 {
3491     aucmd_win = win_alloc(NULL, TRUE);
3492     if (aucmd_win != NULL)
3493     {
3494 	win_init_some(aucmd_win, curwin);
3495 	RESET_BINDING(aucmd_win);
3496 	new_frame(aucmd_win);
3497     }
3498 }
3499 
3500 /*
3501  * Allocate the first window or the first window in a new tab page.
3502  * When "oldwin" is NULL create an empty buffer for it.
3503  * When "oldwin" is not NULL copy info from it to the new window.
3504  * Return FAIL when something goes wrong (out of memory).
3505  */
3506     static int
3507 win_alloc_firstwin(win_T *oldwin)
3508 {
3509     curwin = win_alloc(NULL, FALSE);
3510     if (oldwin == NULL)
3511     {
3512 	/* Very first window, need to create an empty buffer for it and
3513 	 * initialize from scratch. */
3514 	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
3515 	if (curwin == NULL || curbuf == NULL)
3516 	    return FAIL;
3517 	curwin->w_buffer = curbuf;
3518 #ifdef FEAT_SYN_HL
3519 	curwin->w_s = &(curbuf->b_s);
3520 #endif
3521 	curbuf->b_nwindows = 1;	/* there is one window */
3522 	curwin->w_alist = &global_alist;
3523 	curwin_init();		/* init current window */
3524     }
3525     else
3526     {
3527 	/* First window in new tab page, initialize it from "oldwin". */
3528 	win_init(curwin, oldwin, 0);
3529 
3530 	/* We don't want cursor- and scroll-binding in the first window. */
3531 	RESET_BINDING(curwin);
3532     }
3533 
3534     new_frame(curwin);
3535     if (curwin->w_frame == NULL)
3536 	return FAIL;
3537     topframe = curwin->w_frame;
3538     topframe->fr_width = Columns;
3539     topframe->fr_height = Rows - p_ch;
3540 
3541     return OK;
3542 }
3543 
3544 /*
3545  * Create a frame for window "wp".
3546  */
3547     static void
3548 new_frame(win_T *wp)
3549 {
3550     frame_T *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
3551 
3552     wp->w_frame = frp;
3553     if (frp != NULL)
3554     {
3555 	frp->fr_layout = FR_LEAF;
3556 	frp->fr_win = wp;
3557     }
3558 }
3559 
3560 /*
3561  * Initialize the window and frame size to the maximum.
3562  */
3563     void
3564 win_init_size(void)
3565 {
3566     firstwin->w_height = ROWS_AVAIL;
3567     topframe->fr_height = ROWS_AVAIL;
3568     firstwin->w_width = Columns;
3569     topframe->fr_width = Columns;
3570 }
3571 
3572 /*
3573  * Allocate a new tabpage_T and init the values.
3574  * Returns NULL when out of memory.
3575  */
3576     static tabpage_T *
3577 alloc_tabpage(void)
3578 {
3579     tabpage_T	*tp;
3580 # ifdef FEAT_GUI
3581     int		i;
3582 # endif
3583 
3584 
3585     tp = (tabpage_T *)alloc_clear((unsigned)sizeof(tabpage_T));
3586     if (tp == NULL)
3587 	return NULL;
3588 
3589 # ifdef FEAT_EVAL
3590     /* init t: variables */
3591     tp->tp_vars = dict_alloc();
3592     if (tp->tp_vars == NULL)
3593     {
3594 	vim_free(tp);
3595 	return NULL;
3596     }
3597     init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
3598 # endif
3599 
3600 # ifdef FEAT_GUI
3601     for (i = 0; i < 3; i++)
3602 	tp->tp_prev_which_scrollbars[i] = -1;
3603 # endif
3604 # ifdef FEAT_DIFF
3605     tp->tp_diff_invalid = TRUE;
3606 # endif
3607     tp->tp_ch_used = p_ch;
3608 
3609     return tp;
3610 }
3611 
3612     void
3613 free_tabpage(tabpage_T *tp)
3614 {
3615     int idx;
3616 
3617 # ifdef FEAT_DIFF
3618     diff_clear(tp);
3619 # endif
3620     for (idx = 0; idx < SNAP_COUNT; ++idx)
3621 	clear_snapshot(tp, idx);
3622 #ifdef FEAT_EVAL
3623     vars_clear(&tp->tp_vars->dv_hashtab);	/* free all t: variables */
3624     hash_init(&tp->tp_vars->dv_hashtab);
3625     unref_var_dict(tp->tp_vars);
3626 #endif
3627 
3628 #ifdef FEAT_PYTHON
3629     python_tabpage_free(tp);
3630 #endif
3631 
3632 #ifdef FEAT_PYTHON3
3633     python3_tabpage_free(tp);
3634 #endif
3635 
3636     vim_free(tp);
3637 }
3638 
3639 /*
3640  * Create a new Tab page with one window.
3641  * It will edit the current buffer, like after ":split".
3642  * When "after" is 0 put it just after the current Tab page.
3643  * Otherwise put it just before tab page "after".
3644  * Return FAIL or OK.
3645  */
3646     int
3647 win_new_tabpage(int after)
3648 {
3649     tabpage_T	*tp = curtab;
3650     tabpage_T	*newtp;
3651     int		n;
3652 
3653     newtp = alloc_tabpage();
3654     if (newtp == NULL)
3655 	return FAIL;
3656 
3657     /* Remember the current windows in this Tab page. */
3658     if (leave_tabpage(curbuf, TRUE) == FAIL)
3659     {
3660 	vim_free(newtp);
3661 	return FAIL;
3662     }
3663     curtab = newtp;
3664 
3665     /* Create a new empty window. */
3666     if (win_alloc_firstwin(tp->tp_curwin) == OK)
3667     {
3668 	/* Make the new Tab page the new topframe. */
3669 	if (after == 1)
3670 	{
3671 	    /* New tab page becomes the first one. */
3672 	    newtp->tp_next = first_tabpage;
3673 	    first_tabpage = newtp;
3674 	}
3675 	else
3676 	{
3677 	    if (after > 0)
3678 	    {
3679 		/* Put new tab page before tab page "after". */
3680 		n = 2;
3681 		for (tp = first_tabpage; tp->tp_next != NULL
3682 					       && n < after; tp = tp->tp_next)
3683 		    ++n;
3684 	    }
3685 	    newtp->tp_next = tp->tp_next;
3686 	    tp->tp_next = newtp;
3687 	}
3688 	win_init_size();
3689 	firstwin->w_winrow = tabline_height();
3690 	win_comp_scroll(curwin);
3691 
3692 	newtp->tp_topframe = topframe;
3693 	last_status(FALSE);
3694 
3695 #if defined(FEAT_GUI)
3696 	/* When 'guioptions' includes 'L' or 'R' may have to remove or add
3697 	 * scrollbars.  Have to update them anyway. */
3698 	gui_may_update_scrollbars();
3699 #endif
3700 #ifdef FEAT_JOB_CHANNEL
3701 	entering_window(curwin);
3702 #endif
3703 
3704 	redraw_all_later(NOT_VALID);
3705 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
3706 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
3707 	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
3708 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3709 	return OK;
3710     }
3711 
3712     /* Failed, get back the previous Tab page */
3713     enter_tabpage(curtab, curbuf, TRUE, TRUE);
3714     return FAIL;
3715 }
3716 
3717 /*
3718  * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
3719  * like with ":split".
3720  * Returns OK if a new tab page was created, FAIL otherwise.
3721  */
3722     int
3723 may_open_tabpage(void)
3724 {
3725     int		n = (cmdmod.tab == 0) ? postponed_split_tab : cmdmod.tab;
3726 
3727     if (n != 0)
3728     {
3729 	cmdmod.tab = 0;	    /* reset it to avoid doing it twice */
3730 	postponed_split_tab = 0;
3731 	return win_new_tabpage(n);
3732     }
3733     return FAIL;
3734 }
3735 
3736 /*
3737  * Create up to "maxcount" tabpages with empty windows.
3738  * Returns the number of resulting tab pages.
3739  */
3740     int
3741 make_tabpages(int maxcount)
3742 {
3743     int		count = maxcount;
3744     int		todo;
3745 
3746     /* Limit to 'tabpagemax' tabs. */
3747     if (count > p_tpm)
3748 	count = p_tpm;
3749 
3750     /*
3751      * Don't execute autocommands while creating the tab pages.  Must do that
3752      * when putting the buffers in the windows.
3753      */
3754     block_autocmds();
3755 
3756     for (todo = count - 1; todo > 0; --todo)
3757 	if (win_new_tabpage(0) == FAIL)
3758 	    break;
3759 
3760     unblock_autocmds();
3761 
3762     /* return actual number of tab pages */
3763     return (count - todo);
3764 }
3765 
3766 /*
3767  * Return TRUE when "tpc" points to a valid tab page.
3768  */
3769     int
3770 valid_tabpage(tabpage_T *tpc)
3771 {
3772     tabpage_T	*tp;
3773 
3774     FOR_ALL_TABPAGES(tp)
3775 	if (tp == tpc)
3776 	    return TRUE;
3777     return FALSE;
3778 }
3779 
3780 /*
3781  * Return TRUE when "tpc" points to a valid tab page and at least one window is
3782  * valid.
3783  */
3784     int
3785 valid_tabpage_win(tabpage_T *tpc)
3786 {
3787     tabpage_T	*tp;
3788     win_T	*wp;
3789 
3790     FOR_ALL_TABPAGES(tp)
3791     {
3792 	if (tp == tpc)
3793 	{
3794 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
3795 	    {
3796 		if (win_valid_any_tab(wp))
3797 		    return TRUE;
3798 	    }
3799 	    return FALSE;
3800 	}
3801     }
3802     /* shouldn't happen */
3803     return FALSE;
3804 }
3805 
3806 /*
3807  * Close tabpage "tab", assuming it has no windows in it.
3808  * There must be another tabpage or this will crash.
3809  */
3810     void
3811 close_tabpage(tabpage_T *tab)
3812 {
3813     tabpage_T	*ptp;
3814 
3815     if (tab == first_tabpage)
3816     {
3817 	first_tabpage = tab->tp_next;
3818 	ptp = first_tabpage;
3819     }
3820     else
3821     {
3822 	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
3823 							    ptp = ptp->tp_next)
3824 	    ;
3825 	assert(ptp != NULL);
3826 	ptp->tp_next = tab->tp_next;
3827     }
3828 
3829     goto_tabpage_tp(ptp, FALSE, FALSE);
3830     free_tabpage(tab);
3831 }
3832 
3833 /*
3834  * Find tab page "n" (first one is 1).  Returns NULL when not found.
3835  */
3836     tabpage_T *
3837 find_tabpage(int n)
3838 {
3839     tabpage_T	*tp;
3840     int		i = 1;
3841 
3842     for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
3843 	++i;
3844     return tp;
3845 }
3846 
3847 /*
3848  * Get index of tab page "tp".  First one has index 1.
3849  * When not found returns number of tab pages plus one.
3850  */
3851     int
3852 tabpage_index(tabpage_T *ftp)
3853 {
3854     int		i = 1;
3855     tabpage_T	*tp;
3856 
3857     for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
3858 	++i;
3859     return i;
3860 }
3861 
3862 /*
3863  * Prepare for leaving the current tab page.
3864  * When autocommands change "curtab" we don't leave the tab page and return
3865  * FAIL.
3866  * Careful: When OK is returned need to get a new tab page very very soon!
3867  */
3868     static int
3869 leave_tabpage(
3870     buf_T	*new_curbuf UNUSED,    /* what is going to be the new curbuf,
3871 				       NULL if unknown */
3872     int		trigger_leave_autocmds UNUSED)
3873 {
3874     tabpage_T	*tp = curtab;
3875 
3876 #ifdef FEAT_JOB_CHANNEL
3877     leaving_window(curwin);
3878 #endif
3879     reset_VIsual_and_resel();	/* stop Visual mode */
3880     if (trigger_leave_autocmds)
3881     {
3882 	if (new_curbuf != curbuf)
3883 	{
3884 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
3885 	    if (curtab != tp)
3886 		return FAIL;
3887 	}
3888 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
3889 	if (curtab != tp)
3890 	    return FAIL;
3891 	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
3892 	if (curtab != tp)
3893 	    return FAIL;
3894     }
3895 #if defined(FEAT_GUI)
3896     /* Remove the scrollbars.  They may be added back later. */
3897     if (gui.in_use)
3898 	gui_remove_scrollbars();
3899 #endif
3900     tp->tp_curwin = curwin;
3901     tp->tp_prevwin = prevwin;
3902     tp->tp_firstwin = firstwin;
3903     tp->tp_lastwin = lastwin;
3904     tp->tp_old_Rows = Rows;
3905     tp->tp_old_Columns = Columns;
3906     firstwin = NULL;
3907     lastwin = NULL;
3908     return OK;
3909 }
3910 
3911 /*
3912  * Start using tab page "tp".
3913  * Only to be used after leave_tabpage() or freeing the current tab page.
3914  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
3915  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
3916  */
3917     static void
3918 enter_tabpage(
3919     tabpage_T	*tp,
3920     buf_T	*old_curbuf UNUSED,
3921     int		trigger_enter_autocmds,
3922     int		trigger_leave_autocmds)
3923 {
3924     int		old_off = tp->tp_firstwin->w_winrow;
3925     win_T	*next_prevwin = tp->tp_prevwin;
3926 
3927     curtab = tp;
3928     firstwin = tp->tp_firstwin;
3929     lastwin = tp->tp_lastwin;
3930     topframe = tp->tp_topframe;
3931 
3932     /* We would like doing the TabEnter event first, but we don't have a
3933      * valid current window yet, which may break some commands.
3934      * This triggers autocommands, thus may make "tp" invalid. */
3935     win_enter_ext(tp->tp_curwin, FALSE, TRUE, FALSE,
3936 			      trigger_enter_autocmds, trigger_leave_autocmds);
3937     prevwin = next_prevwin;
3938 
3939     last_status(FALSE);		/* status line may appear or disappear */
3940     (void)win_comp_pos();	/* recompute w_winrow for all windows */
3941 #ifdef FEAT_DIFF
3942     diff_need_scrollbind = TRUE;
3943 #endif
3944 
3945     /* The tabpage line may have appeared or disappeared, may need to resize
3946      * the frames for that.  When the Vim window was resized need to update
3947      * frame sizes too.  Use the stored value of p_ch, so that it can be
3948      * different for each tab page. */
3949     p_ch = curtab->tp_ch_used;
3950     if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
3951 #ifdef FEAT_GUI_TABLINE
3952 			    && !gui_use_tabline()
3953 #endif
3954 		))
3955 	shell_new_rows();
3956     if (curtab->tp_old_Columns != Columns && starting == 0)
3957 	shell_new_columns();	/* update window widths */
3958 
3959 #if defined(FEAT_GUI)
3960     /* When 'guioptions' includes 'L' or 'R' may have to remove or add
3961      * scrollbars.  Have to update them anyway. */
3962     gui_may_update_scrollbars();
3963 #endif
3964 
3965     /* Apply autocommands after updating the display, when 'rows' and
3966      * 'columns' have been set correctly. */
3967     if (trigger_enter_autocmds)
3968     {
3969 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3970 	if (old_curbuf != curbuf)
3971 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
3972     }
3973 
3974     redraw_all_later(NOT_VALID);
3975 }
3976 
3977 /*
3978  * Go to tab page "n".  For ":tab N" and "Ngt".
3979  * When "n" is 9999 go to the last tab page.
3980  */
3981     void
3982 goto_tabpage(int n)
3983 {
3984     tabpage_T	*tp;
3985     tabpage_T	*ttp;
3986     int		i;
3987 
3988     if (text_locked())
3989     {
3990 	/* Not allowed when editing the command line. */
3991 	text_locked_msg();
3992 	return;
3993     }
3994 
3995     /* If there is only one it can't work. */
3996     if (first_tabpage->tp_next == NULL)
3997     {
3998 	if (n > 1)
3999 	    beep_flush();
4000 	return;
4001     }
4002 
4003     if (n == 0)
4004     {
4005 	/* No count, go to next tab page, wrap around end. */
4006 	if (curtab->tp_next == NULL)
4007 	    tp = first_tabpage;
4008 	else
4009 	    tp = curtab->tp_next;
4010     }
4011     else if (n < 0)
4012     {
4013 	/* "gT": go to previous tab page, wrap around end.  "N gT" repeats
4014 	 * this N times. */
4015 	ttp = curtab;
4016 	for (i = n; i < 0; ++i)
4017 	{
4018 	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
4019 		    tp = tp->tp_next)
4020 		;
4021 	    ttp = tp;
4022 	}
4023     }
4024     else if (n == 9999)
4025     {
4026 	/* Go to last tab page. */
4027 	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
4028 	    ;
4029     }
4030     else
4031     {
4032 	/* Go to tab page "n". */
4033 	tp = find_tabpage(n);
4034 	if (tp == NULL)
4035 	{
4036 	    beep_flush();
4037 	    return;
4038 	}
4039     }
4040 
4041     goto_tabpage_tp(tp, TRUE, TRUE);
4042 
4043 #ifdef FEAT_GUI_TABLINE
4044     if (gui_use_tabline())
4045 	gui_mch_set_curtab(tabpage_index(curtab));
4046 #endif
4047 }
4048 
4049 /*
4050  * Go to tabpage "tp".
4051  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4052  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4053  * Note: doesn't update the GUI tab.
4054  */
4055     void
4056 goto_tabpage_tp(
4057     tabpage_T	*tp,
4058     int		trigger_enter_autocmds,
4059     int		trigger_leave_autocmds)
4060 {
4061     /* Don't repeat a message in another tab page. */
4062     set_keep_msg(NULL, 0);
4063 
4064     if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
4065 					trigger_leave_autocmds) == OK)
4066     {
4067 	if (valid_tabpage(tp))
4068 	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
4069 		    trigger_leave_autocmds);
4070 	else
4071 	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
4072 		    trigger_leave_autocmds);
4073     }
4074 }
4075 
4076 /*
4077  * Enter window "wp" in tab page "tp".
4078  * Also updates the GUI tab.
4079  */
4080     void
4081 goto_tabpage_win(tabpage_T *tp, win_T *wp)
4082 {
4083     goto_tabpage_tp(tp, TRUE, TRUE);
4084     if (curtab == tp && win_valid(wp))
4085     {
4086 	win_enter(wp, TRUE);
4087 # ifdef FEAT_GUI_TABLINE
4088 	if (gui_use_tabline())
4089 	    gui_mch_set_curtab(tabpage_index(curtab));
4090 # endif
4091     }
4092 }
4093 
4094 /*
4095  * Move the current tab page to after tab page "nr".
4096  */
4097     void
4098 tabpage_move(int nr)
4099 {
4100     int		n = 1;
4101     tabpage_T	*tp, *tp_dst;
4102 
4103     if (first_tabpage->tp_next == NULL)
4104 	return;
4105 
4106     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
4107 	++n;
4108 
4109     if (tp == curtab || (nr > 0 && tp->tp_next != NULL
4110 						    && tp->tp_next == curtab))
4111 	return;
4112 
4113     tp_dst = tp;
4114 
4115     /* Remove the current tab page from the list of tab pages. */
4116     if (curtab == first_tabpage)
4117 	first_tabpage = curtab->tp_next;
4118     else
4119     {
4120 	FOR_ALL_TABPAGES(tp)
4121 	    if (tp->tp_next == curtab)
4122 		break;
4123 	if (tp == NULL)	/* "cannot happen" */
4124 	    return;
4125 	tp->tp_next = curtab->tp_next;
4126     }
4127 
4128     /* Re-insert it at the specified position. */
4129     if (nr <= 0)
4130     {
4131 	curtab->tp_next = first_tabpage;
4132 	first_tabpage = curtab;
4133     }
4134     else
4135     {
4136 	curtab->tp_next = tp_dst->tp_next;
4137 	tp_dst->tp_next = curtab;
4138     }
4139 
4140     /* Need to redraw the tabline.  Tab page contents doesn't change. */
4141     redraw_tabline = TRUE;
4142 }
4143 
4144 
4145 /*
4146  * Go to another window.
4147  * When jumping to another buffer, stop Visual mode.  Do this before
4148  * changing windows so we can yank the selection into the '*' register.
4149  * When jumping to another window on the same buffer, adjust its cursor
4150  * position to keep the same Visual area.
4151  */
4152     void
4153 win_goto(win_T *wp)
4154 {
4155 #ifdef FEAT_CONCEAL
4156     win_T	*owp = curwin;
4157 #endif
4158 
4159     if (text_locked())
4160     {
4161 	beep_flush();
4162 	text_locked_msg();
4163 	return;
4164     }
4165     if (curbuf_locked())
4166 	return;
4167 
4168     if (wp->w_buffer != curbuf)
4169 	reset_VIsual_and_resel();
4170     else if (VIsual_active)
4171 	wp->w_cursor = curwin->w_cursor;
4172 
4173 #ifdef FEAT_GUI
4174     need_mouse_correct = TRUE;
4175 #endif
4176     win_enter(wp, TRUE);
4177 
4178 #ifdef FEAT_CONCEAL
4179     // Conceal cursor line in previous window, unconceal in current window.
4180     if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
4181 	redrawWinline(owp, owp->w_cursor.lnum);
4182     if (curwin->w_p_cole > 0 && !msg_scrolled)
4183 	need_cursor_line_redraw = TRUE;
4184 #endif
4185 }
4186 
4187 #if defined(FEAT_PERL) || defined(PROTO)
4188 /*
4189  * Find window number "winnr" (counting top to bottom).
4190  */
4191     win_T *
4192 win_find_nr(int winnr)
4193 {
4194     win_T	*wp;
4195 
4196     FOR_ALL_WINDOWS(wp)
4197 	if (--winnr == 0)
4198 	    break;
4199     return wp;
4200 }
4201 #endif
4202 
4203 #if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
4204 /*
4205  * Find the tabpage for window "win".
4206  */
4207     tabpage_T *
4208 win_find_tabpage(win_T *win)
4209 {
4210     win_T	*wp;
4211     tabpage_T	*tp;
4212 
4213     FOR_ALL_TAB_WINDOWS(tp, wp)
4214 	    if (wp == win)
4215 		return tp;
4216     return NULL;
4217 }
4218 #endif
4219 
4220 /*
4221  * Move to window above or below "count" times.
4222  */
4223     static void
4224 win_goto_ver(
4225     int		up,		/* TRUE to go to win above */
4226     long	count)
4227 {
4228     frame_T	*fr;
4229     frame_T	*nfr;
4230     frame_T	*foundfr;
4231 
4232     foundfr = curwin->w_frame;
4233     while (count--)
4234     {
4235 	/*
4236 	 * First go upwards in the tree of frames until we find a upwards or
4237 	 * downwards neighbor.
4238 	 */
4239 	fr = foundfr;
4240 	for (;;)
4241 	{
4242 	    if (fr == topframe)
4243 		goto end;
4244 	    if (up)
4245 		nfr = fr->fr_prev;
4246 	    else
4247 		nfr = fr->fr_next;
4248 	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
4249 		break;
4250 	    fr = fr->fr_parent;
4251 	}
4252 
4253 	/*
4254 	 * Now go downwards to find the bottom or top frame in it.
4255 	 */
4256 	for (;;)
4257 	{
4258 	    if (nfr->fr_layout == FR_LEAF)
4259 	    {
4260 		foundfr = nfr;
4261 		break;
4262 	    }
4263 	    fr = nfr->fr_child;
4264 	    if (nfr->fr_layout == FR_ROW)
4265 	    {
4266 		/* Find the frame at the cursor row. */
4267 		while (fr->fr_next != NULL
4268 			&& frame2win(fr)->w_wincol + fr->fr_width
4269 					 <= curwin->w_wincol + curwin->w_wcol)
4270 		    fr = fr->fr_next;
4271 	    }
4272 	    if (nfr->fr_layout == FR_COL && up)
4273 		while (fr->fr_next != NULL)
4274 		    fr = fr->fr_next;
4275 	    nfr = fr;
4276 	}
4277     }
4278 end:
4279     if (foundfr != NULL)
4280 	win_goto(foundfr->fr_win);
4281 }
4282 
4283 /*
4284  * Move to left or right window.
4285  */
4286     static void
4287 win_goto_hor(
4288     int		left,		/* TRUE to go to left win */
4289     long	count)
4290 {
4291     frame_T	*fr;
4292     frame_T	*nfr;
4293     frame_T	*foundfr;
4294 
4295     foundfr = curwin->w_frame;
4296     while (count--)
4297     {
4298 	/*
4299 	 * First go upwards in the tree of frames until we find a left or
4300 	 * right neighbor.
4301 	 */
4302 	fr = foundfr;
4303 	for (;;)
4304 	{
4305 	    if (fr == topframe)
4306 		goto end;
4307 	    if (left)
4308 		nfr = fr->fr_prev;
4309 	    else
4310 		nfr = fr->fr_next;
4311 	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
4312 		break;
4313 	    fr = fr->fr_parent;
4314 	}
4315 
4316 	/*
4317 	 * Now go downwards to find the leftmost or rightmost frame in it.
4318 	 */
4319 	for (;;)
4320 	{
4321 	    if (nfr->fr_layout == FR_LEAF)
4322 	    {
4323 		foundfr = nfr;
4324 		break;
4325 	    }
4326 	    fr = nfr->fr_child;
4327 	    if (nfr->fr_layout == FR_COL)
4328 	    {
4329 		/* Find the frame at the cursor row. */
4330 		while (fr->fr_next != NULL
4331 			&& frame2win(fr)->w_winrow + fr->fr_height
4332 					 <= curwin->w_winrow + curwin->w_wrow)
4333 		    fr = fr->fr_next;
4334 	    }
4335 	    if (nfr->fr_layout == FR_ROW && left)
4336 		while (fr->fr_next != NULL)
4337 		    fr = fr->fr_next;
4338 	    nfr = fr;
4339 	}
4340     }
4341 end:
4342     if (foundfr != NULL)
4343 	win_goto(foundfr->fr_win);
4344 }
4345 
4346 /*
4347  * Make window "wp" the current window.
4348  */
4349     void
4350 win_enter(win_T *wp, int undo_sync)
4351 {
4352     win_enter_ext(wp, undo_sync, FALSE, FALSE, TRUE, TRUE);
4353 }
4354 
4355 /*
4356  * Make window wp the current window.
4357  * Can be called with "curwin_invalid" TRUE, which means that curwin has just
4358  * been closed and isn't valid.
4359  */
4360     static void
4361 win_enter_ext(
4362     win_T	*wp,
4363     int		undo_sync,
4364     int		curwin_invalid,
4365     int		trigger_new_autocmds,
4366     int		trigger_enter_autocmds,
4367     int		trigger_leave_autocmds)
4368 {
4369     int		other_buffer = FALSE;
4370 
4371     if (wp == curwin && !curwin_invalid)	/* nothing to do */
4372 	return;
4373 
4374 #ifdef FEAT_JOB_CHANNEL
4375     if (!curwin_invalid)
4376 	leaving_window(curwin);
4377 #endif
4378 
4379     if (!curwin_invalid && trigger_leave_autocmds)
4380     {
4381 	/*
4382 	 * Be careful: If autocommands delete the window, return now.
4383 	 */
4384 	if (wp->w_buffer != curbuf)
4385 	{
4386 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4387 	    other_buffer = TRUE;
4388 	    if (!win_valid(wp))
4389 		return;
4390 	}
4391 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4392 	if (!win_valid(wp))
4393 	    return;
4394 #ifdef FEAT_EVAL
4395 	/* autocmds may abort script processing */
4396 	if (aborting())
4397 	    return;
4398 #endif
4399     }
4400 
4401     /* sync undo before leaving the current buffer */
4402     if (undo_sync && curbuf != wp->w_buffer)
4403 	u_sync(FALSE);
4404 
4405     /* Might need to scroll the old window before switching, e.g., when the
4406      * cursor was moved. */
4407     update_topline();
4408 
4409     /* may have to copy the buffer options when 'cpo' contains 'S' */
4410     if (wp->w_buffer != curbuf)
4411 	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
4412     if (!curwin_invalid)
4413     {
4414 	prevwin = curwin;	/* remember for CTRL-W p */
4415 	curwin->w_redr_status = TRUE;
4416     }
4417     curwin = wp;
4418     curbuf = wp->w_buffer;
4419     check_cursor();
4420     if (!virtual_active())
4421 	curwin->w_cursor.coladd = 0;
4422     changed_line_abv_curs();	/* assume cursor position needs updating */
4423 
4424     if (curwin->w_localdir != NULL)
4425     {
4426 	/* Window has a local directory: Save current directory as global
4427 	 * directory (unless that was done already) and change to the local
4428 	 * directory. */
4429 	if (globaldir == NULL)
4430 	{
4431 	    char_u	cwd[MAXPATHL];
4432 
4433 	    if (mch_dirname(cwd, MAXPATHL) == OK)
4434 		globaldir = vim_strsave(cwd);
4435 	}
4436 	if (mch_chdir((char *)curwin->w_localdir) == 0)
4437 	    shorten_fnames(TRUE);
4438     }
4439     else if (globaldir != NULL)
4440     {
4441 	/* Window doesn't have a local directory and we are not in the global
4442 	 * directory: Change to the global directory. */
4443 	vim_ignored = mch_chdir((char *)globaldir);
4444 	VIM_CLEAR(globaldir);
4445 	shorten_fnames(TRUE);
4446     }
4447 
4448 #ifdef FEAT_JOB_CHANNEL
4449     entering_window(curwin);
4450 #endif
4451     if (trigger_new_autocmds)
4452 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
4453     if (trigger_enter_autocmds)
4454     {
4455 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
4456 	if (other_buffer)
4457 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4458     }
4459 
4460 #ifdef FEAT_TITLE
4461     maketitle();
4462 #endif
4463     curwin->w_redr_status = TRUE;
4464     redraw_tabline = TRUE;
4465     if (restart_edit)
4466 	redraw_later(VALID);	/* causes status line redraw */
4467 
4468     /* set window height to desired minimal value */
4469     if (curwin->w_height < p_wh && !curwin->w_p_wfh)
4470 	win_setheight((int)p_wh);
4471     else if (curwin->w_height == 0)
4472 	win_setheight(1);
4473 
4474     /* set window width to desired minimal value */
4475     if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
4476 	win_setwidth((int)p_wiw);
4477 
4478 #ifdef FEAT_MOUSE
4479     setmouse();			/* in case jumped to/from help buffer */
4480 #endif
4481 
4482     /* Change directories when the 'acd' option is set. */
4483     DO_AUTOCHDIR;
4484 }
4485 
4486 
4487 /*
4488  * Jump to the first open window that contains buffer "buf", if one exists.
4489  * Returns a pointer to the window found, otherwise NULL.
4490  */
4491     win_T *
4492 buf_jump_open_win(buf_T *buf)
4493 {
4494     win_T	*wp = NULL;
4495 
4496     if (curwin->w_buffer == buf)
4497 	wp = curwin;
4498     else
4499 	FOR_ALL_WINDOWS(wp)
4500 	    if (wp->w_buffer == buf)
4501 		break;
4502     if (wp != NULL)
4503 	win_enter(wp, FALSE);
4504     return wp;
4505 }
4506 
4507 /*
4508  * Jump to the first open window in any tab page that contains buffer "buf",
4509  * if one exists.
4510  * Returns a pointer to the window found, otherwise NULL.
4511  */
4512     win_T *
4513 buf_jump_open_tab(buf_T *buf)
4514 {
4515     win_T	*wp = buf_jump_open_win(buf);
4516     tabpage_T	*tp;
4517 
4518     if (wp != NULL)
4519 	return wp;
4520 
4521     FOR_ALL_TABPAGES(tp)
4522 	if (tp != curtab)
4523 	{
4524 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
4525 		if (wp->w_buffer == buf)
4526 		    break;
4527 	    if (wp != NULL)
4528 	    {
4529 		goto_tabpage_win(tp, wp);
4530 		if (curwin != wp)
4531 		    wp = NULL;	/* something went wrong */
4532 		break;
4533 	    }
4534 	}
4535     return wp;
4536 }
4537 
4538 static int last_win_id = LOWEST_WIN_ID - 1;
4539 
4540 /*
4541  * Allocate a window structure and link it in the window list when "hidden" is
4542  * FALSE.
4543  */
4544     static win_T *
4545 win_alloc(win_T *after UNUSED, int hidden UNUSED)
4546 {
4547     win_T	*new_wp;
4548 
4549     /*
4550      * allocate window structure and linesizes arrays
4551      */
4552     new_wp = (win_T *)alloc_clear((unsigned)sizeof(win_T));
4553     if (new_wp == NULL)
4554 	return NULL;
4555 
4556     if (win_alloc_lines(new_wp) == FAIL)
4557     {
4558 	vim_free(new_wp);
4559 	return NULL;
4560     }
4561 
4562     new_wp->w_id = ++last_win_id;
4563 
4564 #ifdef FEAT_EVAL
4565     /* init w: variables */
4566     new_wp->w_vars = dict_alloc();
4567     if (new_wp->w_vars == NULL)
4568     {
4569 	win_free_lsize(new_wp);
4570 	vim_free(new_wp);
4571 	return NULL;
4572     }
4573     init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
4574 #endif
4575 
4576     /* Don't execute autocommands while the window is not properly
4577      * initialized yet.  gui_create_scrollbar() may trigger a FocusGained
4578      * event. */
4579     block_autocmds();
4580 
4581     /*
4582      * link the window in the window list
4583      */
4584     if (!hidden)
4585 	win_append(after, new_wp);
4586     new_wp->w_wincol = 0;
4587     new_wp->w_width = Columns;
4588 
4589     /* position the display and the cursor at the top of the file. */
4590     new_wp->w_topline = 1;
4591 #ifdef FEAT_DIFF
4592     new_wp->w_topfill = 0;
4593 #endif
4594     new_wp->w_botline = 2;
4595     new_wp->w_cursor.lnum = 1;
4596     new_wp->w_scbind_pos = 1;
4597 
4598     // use global option value for global-local options
4599     new_wp->w_p_so = -1;
4600     new_wp->w_p_siso = -1;
4601 
4602     /* We won't calculate w_fraction until resizing the window */
4603     new_wp->w_fraction = 0;
4604     new_wp->w_prev_fraction_row = -1;
4605 
4606 #ifdef FEAT_GUI
4607     if (gui.in_use)
4608     {
4609 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
4610 		SBAR_LEFT, new_wp);
4611 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
4612 		SBAR_RIGHT, new_wp);
4613     }
4614 #endif
4615 #ifdef FEAT_FOLDING
4616     foldInitWin(new_wp);
4617 #endif
4618     unblock_autocmds();
4619 #ifdef FEAT_SEARCH_EXTRA
4620     new_wp->w_match_head = NULL;
4621     new_wp->w_next_match_id = 4;
4622 #endif
4623     return new_wp;
4624 }
4625 
4626 /*
4627  * Remove window 'wp' from the window list and free the structure.
4628  */
4629     static void
4630 win_free(
4631     win_T	*wp,
4632     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4633 {
4634     int		i;
4635     buf_T	*buf;
4636     wininfo_T	*wip;
4637 
4638 #ifdef FEAT_FOLDING
4639     clearFolding(wp);
4640 #endif
4641 
4642     /* reduce the reference count to the argument list. */
4643     alist_unlink(wp->w_alist);
4644 
4645     /* Don't execute autocommands while the window is halfway being deleted.
4646      * gui_mch_destroy_scrollbar() may trigger a FocusGained event. */
4647     block_autocmds();
4648 
4649 #ifdef FEAT_LUA
4650     lua_window_free(wp);
4651 #endif
4652 
4653 #ifdef FEAT_MZSCHEME
4654     mzscheme_window_free(wp);
4655 #endif
4656 
4657 #ifdef FEAT_PERL
4658     perl_win_free(wp);
4659 #endif
4660 
4661 #ifdef FEAT_PYTHON
4662     python_window_free(wp);
4663 #endif
4664 
4665 #ifdef FEAT_PYTHON3
4666     python3_window_free(wp);
4667 #endif
4668 
4669 #ifdef FEAT_TCL
4670     tcl_window_free(wp);
4671 #endif
4672 
4673 #ifdef FEAT_RUBY
4674     ruby_window_free(wp);
4675 #endif
4676 
4677     clear_winopt(&wp->w_onebuf_opt);
4678     clear_winopt(&wp->w_allbuf_opt);
4679 
4680 #ifdef FEAT_EVAL
4681     vars_clear(&wp->w_vars->dv_hashtab);	/* free all w: variables */
4682     hash_init(&wp->w_vars->dv_hashtab);
4683     unref_var_dict(wp->w_vars);
4684 #endif
4685 
4686     {
4687 	tabpage_T	*ttp;
4688 
4689 	if (prevwin == wp)
4690 	    prevwin = NULL;
4691 	FOR_ALL_TABPAGES(ttp)
4692 	    if (ttp->tp_prevwin == wp)
4693 		ttp->tp_prevwin = NULL;
4694     }
4695     win_free_lsize(wp);
4696 
4697     for (i = 0; i < wp->w_tagstacklen; ++i)
4698 	vim_free(wp->w_tagstack[i].tagname);
4699 
4700     vim_free(wp->w_localdir);
4701 
4702     /* Remove the window from the b_wininfo lists, it may happen that the
4703      * freed memory is re-used for another window. */
4704     FOR_ALL_BUFFERS(buf)
4705 	for (wip = buf->b_wininfo; wip != NULL; wip = wip->wi_next)
4706 	    if (wip->wi_win == wp)
4707 		wip->wi_win = NULL;
4708 
4709 #ifdef FEAT_SEARCH_EXTRA
4710     clear_matches(wp);
4711 #endif
4712 
4713 #ifdef FEAT_JUMPLIST
4714     free_jumplist(wp);
4715 #endif
4716 
4717 #ifdef FEAT_QUICKFIX
4718     qf_free_all(wp);
4719 #endif
4720 
4721 #ifdef FEAT_GUI
4722     if (gui.in_use)
4723     {
4724 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
4725 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
4726     }
4727 #endif /* FEAT_GUI */
4728 
4729 #ifdef FEAT_MENU
4730     remove_winbar(wp);
4731 #endif
4732 
4733 #ifdef FEAT_SYN_HL
4734     vim_free(wp->w_p_cc_cols);
4735 #endif
4736 
4737     if (wp != aucmd_win)
4738 	win_remove(wp, tp);
4739     if (autocmd_busy)
4740     {
4741 	wp->w_next = au_pending_free_win;
4742 	au_pending_free_win = wp;
4743     }
4744     else
4745 	vim_free(wp);
4746 
4747     unblock_autocmds();
4748 }
4749 
4750 /*
4751  * Append window "wp" in the window list after window "after".
4752  */
4753     void
4754 win_append(win_T *after, win_T *wp)
4755 {
4756     win_T	*before;
4757 
4758     if (after == NULL)	    /* after NULL is in front of the first */
4759 	before = firstwin;
4760     else
4761 	before = after->w_next;
4762 
4763     wp->w_next = before;
4764     wp->w_prev = after;
4765     if (after == NULL)
4766 	firstwin = wp;
4767     else
4768 	after->w_next = wp;
4769     if (before == NULL)
4770 	lastwin = wp;
4771     else
4772 	before->w_prev = wp;
4773 }
4774 
4775 /*
4776  * Remove a window from the window list.
4777  */
4778     void
4779 win_remove(
4780     win_T	*wp,
4781     tabpage_T	*tp)		/* tab page "win" is in, NULL for current */
4782 {
4783     if (wp->w_prev != NULL)
4784 	wp->w_prev->w_next = wp->w_next;
4785     else if (tp == NULL)
4786 	firstwin = curtab->tp_firstwin = wp->w_next;
4787     else
4788 	tp->tp_firstwin = wp->w_next;
4789 
4790     if (wp->w_next != NULL)
4791 	wp->w_next->w_prev = wp->w_prev;
4792     else if (tp == NULL)
4793 	lastwin = curtab->tp_lastwin = wp->w_prev;
4794     else
4795 	tp->tp_lastwin = wp->w_prev;
4796 }
4797 
4798 /*
4799  * Append frame "frp" in a frame list after frame "after".
4800  */
4801     static void
4802 frame_append(frame_T *after, frame_T *frp)
4803 {
4804     frp->fr_next = after->fr_next;
4805     after->fr_next = frp;
4806     if (frp->fr_next != NULL)
4807 	frp->fr_next->fr_prev = frp;
4808     frp->fr_prev = after;
4809 }
4810 
4811 /*
4812  * Insert frame "frp" in a frame list before frame "before".
4813  */
4814     static void
4815 frame_insert(frame_T *before, frame_T *frp)
4816 {
4817     frp->fr_next = before;
4818     frp->fr_prev = before->fr_prev;
4819     before->fr_prev = frp;
4820     if (frp->fr_prev != NULL)
4821 	frp->fr_prev->fr_next = frp;
4822     else
4823 	frp->fr_parent->fr_child = frp;
4824 }
4825 
4826 /*
4827  * Remove a frame from a frame list.
4828  */
4829     static void
4830 frame_remove(frame_T *frp)
4831 {
4832     if (frp->fr_prev != NULL)
4833 	frp->fr_prev->fr_next = frp->fr_next;
4834     else
4835     {
4836 	frp->fr_parent->fr_child = frp->fr_next;
4837 	/* special case: topframe->fr_child == frp */
4838 	if (topframe->fr_child == frp)
4839 	    topframe->fr_child = frp->fr_next;
4840     }
4841     if (frp->fr_next != NULL)
4842 	frp->fr_next->fr_prev = frp->fr_prev;
4843 }
4844 
4845 /*
4846  * Allocate w_lines[] for window "wp".
4847  * Return FAIL for failure, OK for success.
4848  */
4849     int
4850 win_alloc_lines(win_T *wp)
4851 {
4852     wp->w_lines_valid = 0;
4853     wp->w_lines = (wline_T *)alloc_clear((unsigned)(Rows * sizeof(wline_T)));
4854     if (wp->w_lines == NULL)
4855 	return FAIL;
4856     return OK;
4857 }
4858 
4859 /*
4860  * free lsize arrays for a window
4861  */
4862     void
4863 win_free_lsize(win_T *wp)
4864 {
4865     /* TODO: why would wp be NULL here? */
4866     if (wp != NULL)
4867 	VIM_CLEAR(wp->w_lines);
4868 }
4869 
4870 /*
4871  * Called from win_new_shellsize() after Rows changed.
4872  * This only does the current tab page, others must be done when made active.
4873  */
4874     void
4875 shell_new_rows(void)
4876 {
4877     int		h = (int)ROWS_AVAIL;
4878 
4879     if (firstwin == NULL)	/* not initialized yet */
4880 	return;
4881     if (h < frame_minheight(topframe, NULL))
4882 	h = frame_minheight(topframe, NULL);
4883 
4884     /* First try setting the heights of windows with 'winfixheight'.  If
4885      * that doesn't result in the right height, forget about that option. */
4886     frame_new_height(topframe, h, FALSE, TRUE);
4887     if (!frame_check_height(topframe, h))
4888 	frame_new_height(topframe, h, FALSE, FALSE);
4889 
4890     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4891     compute_cmdrow();
4892     curtab->tp_ch_used = p_ch;
4893 
4894 #if 0
4895     /* Disabled: don't want making the screen smaller make a window larger. */
4896     if (p_ea)
4897 	win_equal(curwin, FALSE, 'v');
4898 #endif
4899 }
4900 
4901 /*
4902  * Called from win_new_shellsize() after Columns changed.
4903  */
4904     void
4905 shell_new_columns(void)
4906 {
4907     if (firstwin == NULL)	/* not initialized yet */
4908 	return;
4909 
4910     /* First try setting the widths of windows with 'winfixwidth'.  If that
4911      * doesn't result in the right width, forget about that option. */
4912     frame_new_width(topframe, (int)Columns, FALSE, TRUE);
4913     if (!frame_check_width(topframe, Columns))
4914 	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
4915 
4916     (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
4917 #if 0
4918     /* Disabled: don't want making the screen smaller make a window larger. */
4919     if (p_ea)
4920 	win_equal(curwin, FALSE, 'h');
4921 #endif
4922 }
4923 
4924 #if defined(FEAT_CMDWIN) || defined(PROTO)
4925 /*
4926  * Save the size of all windows in "gap".
4927  */
4928     void
4929 win_size_save(garray_T *gap)
4930 
4931 {
4932     win_T	*wp;
4933 
4934     ga_init2(gap, (int)sizeof(int), 1);
4935     if (ga_grow(gap, win_count() * 2) == OK)
4936 	FOR_ALL_WINDOWS(wp)
4937 	{
4938 	    ((int *)gap->ga_data)[gap->ga_len++] =
4939 					       wp->w_width + wp->w_vsep_width;
4940 	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
4941 	}
4942 }
4943 
4944 /*
4945  * Restore window sizes, but only if the number of windows is still the same.
4946  * Does not free the growarray.
4947  */
4948     void
4949 win_size_restore(garray_T *gap)
4950 {
4951     win_T	*wp;
4952     int		i, j;
4953 
4954     if (win_count() * 2 == gap->ga_len)
4955     {
4956 	/* The order matters, because frames contain other frames, but it's
4957 	 * difficult to get right. The easy way out is to do it twice. */
4958 	for (j = 0; j < 2; ++j)
4959 	{
4960 	    i = 0;
4961 	    FOR_ALL_WINDOWS(wp)
4962 	    {
4963 		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
4964 		win_setheight_win(((int *)gap->ga_data)[i++], wp);
4965 	    }
4966 	}
4967 	/* recompute the window positions */
4968 	(void)win_comp_pos();
4969     }
4970 }
4971 #endif /* FEAT_CMDWIN */
4972 
4973 /*
4974  * Update the position for all windows, using the width and height of the
4975  * frames.
4976  * Returns the row just after the last window.
4977  */
4978     int
4979 win_comp_pos(void)
4980 {
4981     int		row = tabline_height();
4982     int		col = 0;
4983 
4984     frame_comp_pos(topframe, &row, &col);
4985     return row;
4986 }
4987 
4988 /*
4989  * Update the position of the windows in frame "topfrp", using the width and
4990  * height of the frames.
4991  * "*row" and "*col" are the top-left position of the frame.  They are updated
4992  * to the bottom-right position plus one.
4993  */
4994     static void
4995 frame_comp_pos(frame_T *topfrp, int *row, int *col)
4996 {
4997     win_T	*wp;
4998     frame_T	*frp;
4999     int		startcol;
5000     int		startrow;
5001     int		h;
5002 
5003     wp = topfrp->fr_win;
5004     if (wp != NULL)
5005     {
5006 	if (wp->w_winrow != *row || wp->w_wincol != *col)
5007 	{
5008 	    /* position changed, redraw */
5009 	    wp->w_winrow = *row;
5010 	    wp->w_wincol = *col;
5011 	    redraw_win_later(wp, NOT_VALID);
5012 	    wp->w_redr_status = TRUE;
5013 	}
5014 	/* WinBar will not show if the window height is zero */
5015 	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
5016 	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
5017 	*col += wp->w_width + wp->w_vsep_width;
5018     }
5019     else
5020     {
5021 	startrow = *row;
5022 	startcol = *col;
5023 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
5024 	{
5025 	    if (topfrp->fr_layout == FR_ROW)
5026 		*row = startrow;	/* all frames are at the same row */
5027 	    else
5028 		*col = startcol;	/* all frames are at the same col */
5029 	    frame_comp_pos(frp, row, col);
5030 	}
5031     }
5032 }
5033 
5034 /*
5035  * Set current window height and take care of repositioning other windows to
5036  * fit around it.
5037  */
5038     void
5039 win_setheight(int height)
5040 {
5041     win_setheight_win(height, curwin);
5042 }
5043 
5044 /*
5045  * Set the window height of window "win" and take care of repositioning other
5046  * windows to fit around it.
5047  */
5048     void
5049 win_setheight_win(int height, win_T *win)
5050 {
5051     int		row;
5052 
5053     if (win == curwin)
5054     {
5055 	/* Always keep current window at least one line high, even when
5056 	 * 'winminheight' is zero. */
5057 	if (height < p_wmh)
5058 	    height = p_wmh;
5059 	if (height == 0)
5060 	    height = 1;
5061 	height += WINBAR_HEIGHT(curwin);
5062     }
5063 
5064     frame_setheight(win->w_frame, height + win->w_status_height);
5065 
5066     /* recompute the window positions */
5067     row = win_comp_pos();
5068 
5069     /*
5070      * If there is extra space created between the last window and the command
5071      * line, clear it.
5072      */
5073     if (full_screen && msg_scrolled == 0 && row < cmdline_row)
5074 	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5075     cmdline_row = row;
5076     msg_row = row;
5077     msg_col = 0;
5078 
5079     redraw_all_later(NOT_VALID);
5080 }
5081 
5082 /*
5083  * Set the height of a frame to "height" and take care that all frames and
5084  * windows inside it are resized.  Also resize frames on the left and right if
5085  * the are in the same FR_ROW frame.
5086  *
5087  * Strategy:
5088  * If the frame is part of a FR_COL frame, try fitting the frame in that
5089  * frame.  If that doesn't work (the FR_COL frame is too small), recursively
5090  * go to containing frames to resize them and make room.
5091  * If the frame is part of a FR_ROW frame, all frames must be resized as well.
5092  * Check for the minimal height of the FR_ROW frame.
5093  * At the top level we can also use change the command line height.
5094  */
5095     static void
5096 frame_setheight(frame_T *curfrp, int height)
5097 {
5098     int		room;		/* total number of lines available */
5099     int		take;		/* number of lines taken from other windows */
5100     int		room_cmdline;	/* lines available from cmdline */
5101     int		run;
5102     frame_T	*frp;
5103     int		h;
5104     int		room_reserved;
5105 
5106     /* If the height already is the desired value, nothing to do. */
5107     if (curfrp->fr_height == height)
5108 	return;
5109 
5110     if (curfrp->fr_parent == NULL)
5111     {
5112 	/* topframe: can only change the command line */
5113 	if (height > ROWS_AVAIL)
5114 	    height = ROWS_AVAIL;
5115 	if (height > 0)
5116 	    frame_new_height(curfrp, height, FALSE, FALSE);
5117     }
5118     else if (curfrp->fr_parent->fr_layout == FR_ROW)
5119     {
5120 	/* Row of frames: Also need to resize frames left and right of this
5121 	 * one.  First check for the minimal height of these. */
5122 	h = frame_minheight(curfrp->fr_parent, NULL);
5123 	if (height < h)
5124 	    height = h;
5125 	frame_setheight(curfrp->fr_parent, height);
5126     }
5127     else
5128     {
5129 	/*
5130 	 * Column of frames: try to change only frames in this column.
5131 	 */
5132 	/*
5133 	 * Do this twice:
5134 	 * 1: compute room available, if it's not enough try resizing the
5135 	 *    containing frame.
5136 	 * 2: compute the room available and adjust the height to it.
5137 	 * Try not to reduce the height of a window with 'winfixheight' set.
5138 	 */
5139 	for (run = 1; run <= 2; ++run)
5140 	{
5141 	    room = 0;
5142 	    room_reserved = 0;
5143 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5144 	    {
5145 		if (frp != curfrp
5146 			&& frp->fr_win != NULL
5147 			&& frp->fr_win->w_p_wfh)
5148 		    room_reserved += frp->fr_height;
5149 		room += frp->fr_height;
5150 		if (frp != curfrp)
5151 		    room -= frame_minheight(frp, NULL);
5152 	    }
5153 	    if (curfrp->fr_width != Columns)
5154 		room_cmdline = 0;
5155 	    else
5156 	    {
5157 		room_cmdline = Rows - p_ch - (lastwin->w_winrow
5158 						+ VISIBLE_HEIGHT(lastwin)
5159 						+ lastwin->w_status_height);
5160 		if (room_cmdline < 0)
5161 		    room_cmdline = 0;
5162 	    }
5163 
5164 	    if (height <= room + room_cmdline)
5165 		break;
5166 	    if (run == 2 || curfrp->fr_width == Columns)
5167 	    {
5168 		if (height > room + room_cmdline)
5169 		    height = room + room_cmdline;
5170 		break;
5171 	    }
5172 	    frame_setheight(curfrp->fr_parent, height
5173 		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
5174 	}
5175 
5176 	/*
5177 	 * Compute the number of lines we will take from others frames (can be
5178 	 * negative!).
5179 	 */
5180 	take = height - curfrp->fr_height;
5181 
5182 	/* If there is not enough room, also reduce the height of a window
5183 	 * with 'winfixheight' set. */
5184 	if (height > room + room_cmdline - room_reserved)
5185 	    room_reserved = room + room_cmdline - height;
5186 	/* If there is only a 'winfixheight' window and making the
5187 	 * window smaller, need to make the other window taller. */
5188 	if (take < 0 && room - curfrp->fr_height < room_reserved)
5189 	    room_reserved = 0;
5190 
5191 	if (take > 0 && room_cmdline > 0)
5192 	{
5193 	    /* use lines from cmdline first */
5194 	    if (take < room_cmdline)
5195 		room_cmdline = take;
5196 	    take -= room_cmdline;
5197 	    topframe->fr_height += room_cmdline;
5198 	}
5199 
5200 	/*
5201 	 * set the current frame to the new height
5202 	 */
5203 	frame_new_height(curfrp, height, FALSE, FALSE);
5204 
5205 	/*
5206 	 * First take lines from the frames after the current frame.  If
5207 	 * that is not enough, takes lines from frames above the current
5208 	 * frame.
5209 	 */
5210 	for (run = 0; run < 2; ++run)
5211 	{
5212 	    if (run == 0)
5213 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5214 	    else
5215 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5216 	    while (frp != NULL && take != 0)
5217 	    {
5218 		h = frame_minheight(frp, NULL);
5219 		if (room_reserved > 0
5220 			&& frp->fr_win != NULL
5221 			&& frp->fr_win->w_p_wfh)
5222 		{
5223 		    if (room_reserved >= frp->fr_height)
5224 			room_reserved -= frp->fr_height;
5225 		    else
5226 		    {
5227 			if (frp->fr_height - room_reserved > take)
5228 			    room_reserved = frp->fr_height - take;
5229 			take -= frp->fr_height - room_reserved;
5230 			frame_new_height(frp, room_reserved, FALSE, FALSE);
5231 			room_reserved = 0;
5232 		    }
5233 		}
5234 		else
5235 		{
5236 		    if (frp->fr_height - take < h)
5237 		    {
5238 			take -= frp->fr_height - h;
5239 			frame_new_height(frp, h, FALSE, FALSE);
5240 		    }
5241 		    else
5242 		    {
5243 			frame_new_height(frp, frp->fr_height - take,
5244 								FALSE, FALSE);
5245 			take = 0;
5246 		    }
5247 		}
5248 		if (run == 0)
5249 		    frp = frp->fr_next;
5250 		else
5251 		    frp = frp->fr_prev;
5252 	    }
5253 	}
5254     }
5255 }
5256 
5257 /*
5258  * Set current window width and take care of repositioning other windows to
5259  * fit around it.
5260  */
5261     void
5262 win_setwidth(int width)
5263 {
5264     win_setwidth_win(width, curwin);
5265 }
5266 
5267     void
5268 win_setwidth_win(int width, win_T *wp)
5269 {
5270     /* Always keep current window at least one column wide, even when
5271      * 'winminwidth' is zero. */
5272     if (wp == curwin)
5273     {
5274 	if (width < p_wmw)
5275 	    width = p_wmw;
5276 	if (width == 0)
5277 	    width = 1;
5278     }
5279 
5280     frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
5281 
5282     /* recompute the window positions */
5283     (void)win_comp_pos();
5284 
5285     redraw_all_later(NOT_VALID);
5286 }
5287 
5288 /*
5289  * Set the width of a frame to "width" and take care that all frames and
5290  * windows inside it are resized.  Also resize frames above and below if the
5291  * are in the same FR_ROW frame.
5292  *
5293  * Strategy is similar to frame_setheight().
5294  */
5295     static void
5296 frame_setwidth(frame_T *curfrp, int width)
5297 {
5298     int		room;		/* total number of lines available */
5299     int		take;		/* number of lines taken from other windows */
5300     int		run;
5301     frame_T	*frp;
5302     int		w;
5303     int		room_reserved;
5304 
5305     /* If the width already is the desired value, nothing to do. */
5306     if (curfrp->fr_width == width)
5307 	return;
5308 
5309     if (curfrp->fr_parent == NULL)
5310 	/* topframe: can't change width */
5311 	return;
5312 
5313     if (curfrp->fr_parent->fr_layout == FR_COL)
5314     {
5315 	/* Column of frames: Also need to resize frames above and below of
5316 	 * this one.  First check for the minimal width of these. */
5317 	w = frame_minwidth(curfrp->fr_parent, NULL);
5318 	if (width < w)
5319 	    width = w;
5320 	frame_setwidth(curfrp->fr_parent, width);
5321     }
5322     else
5323     {
5324 	/*
5325 	 * Row of frames: try to change only frames in this row.
5326 	 *
5327 	 * Do this twice:
5328 	 * 1: compute room available, if it's not enough try resizing the
5329 	 *    containing frame.
5330 	 * 2: compute the room available and adjust the width to it.
5331 	 */
5332 	for (run = 1; run <= 2; ++run)
5333 	{
5334 	    room = 0;
5335 	    room_reserved = 0;
5336 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5337 	    {
5338 		if (frp != curfrp
5339 			&& frp->fr_win != NULL
5340 			&& frp->fr_win->w_p_wfw)
5341 		    room_reserved += frp->fr_width;
5342 		room += frp->fr_width;
5343 		if (frp != curfrp)
5344 		    room -= frame_minwidth(frp, NULL);
5345 	    }
5346 
5347 	    if (width <= room)
5348 		break;
5349 	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
5350 	    {
5351 		if (width > room)
5352 		    width = room;
5353 		break;
5354 	    }
5355 	    frame_setwidth(curfrp->fr_parent, width
5356 		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
5357 	}
5358 
5359 	/*
5360 	 * Compute the number of lines we will take from others frames (can be
5361 	 * negative!).
5362 	 */
5363 	take = width - curfrp->fr_width;
5364 
5365 	/* If there is not enough room, also reduce the width of a window
5366 	 * with 'winfixwidth' set. */
5367 	if (width > room - room_reserved)
5368 	    room_reserved = room - width;
5369 	/* If there is only a 'winfixwidth' window and making the
5370 	 * window smaller, need to make the other window narrower. */
5371 	if (take < 0 && room - curfrp->fr_width < room_reserved)
5372 	    room_reserved = 0;
5373 
5374 	/*
5375 	 * set the current frame to the new width
5376 	 */
5377 	frame_new_width(curfrp, width, FALSE, FALSE);
5378 
5379 	/*
5380 	 * First take lines from the frames right of the current frame.  If
5381 	 * that is not enough, takes lines from frames left of the current
5382 	 * frame.
5383 	 */
5384 	for (run = 0; run < 2; ++run)
5385 	{
5386 	    if (run == 0)
5387 		frp = curfrp->fr_next;	/* 1st run: start with next window */
5388 	    else
5389 		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
5390 	    while (frp != NULL && take != 0)
5391 	    {
5392 		w = frame_minwidth(frp, NULL);
5393 		if (room_reserved > 0
5394 			&& frp->fr_win != NULL
5395 			&& frp->fr_win->w_p_wfw)
5396 		{
5397 		    if (room_reserved >= frp->fr_width)
5398 			room_reserved -= frp->fr_width;
5399 		    else
5400 		    {
5401 			if (frp->fr_width - room_reserved > take)
5402 			    room_reserved = frp->fr_width - take;
5403 			take -= frp->fr_width - room_reserved;
5404 			frame_new_width(frp, room_reserved, FALSE, FALSE);
5405 			room_reserved = 0;
5406 		    }
5407 		}
5408 		else
5409 		{
5410 		    if (frp->fr_width - take < w)
5411 		    {
5412 			take -= frp->fr_width - w;
5413 			frame_new_width(frp, w, FALSE, FALSE);
5414 		    }
5415 		    else
5416 		    {
5417 			frame_new_width(frp, frp->fr_width - take,
5418 								FALSE, FALSE);
5419 			take = 0;
5420 		    }
5421 		}
5422 		if (run == 0)
5423 		    frp = frp->fr_next;
5424 		else
5425 		    frp = frp->fr_prev;
5426 	    }
5427 	}
5428     }
5429 }
5430 
5431 /*
5432  * Check 'winminheight' for a valid value and reduce it if needed.
5433  */
5434     void
5435 win_setminheight(void)
5436 {
5437     int		room;
5438     int		needed;
5439     int		first = TRUE;
5440 
5441     // loop until there is a 'winminheight' that is possible
5442     while (p_wmh > 0)
5443     {
5444 	room = Rows - p_ch;
5445 	needed = frame_minheight(topframe, NULL);
5446 	if (room >= needed)
5447 	    break;
5448 	--p_wmh;
5449 	if (first)
5450 	{
5451 	    emsg(_(e_noroom));
5452 	    first = FALSE;
5453 	}
5454     }
5455 }
5456 
5457 /*
5458  * Check 'winminwidth' for a valid value and reduce it if needed.
5459  */
5460     void
5461 win_setminwidth(void)
5462 {
5463     int		room;
5464     int		needed;
5465     int		first = TRUE;
5466 
5467     // loop until there is a 'winminheight' that is possible
5468     while (p_wmw > 0)
5469     {
5470 	room = Columns;
5471 	needed = frame_minwidth(topframe, NULL);
5472 	if (room >= needed)
5473 	    break;
5474 	--p_wmw;
5475 	if (first)
5476 	{
5477 	    emsg(_(e_noroom));
5478 	    first = FALSE;
5479 	}
5480     }
5481 }
5482 
5483 #if defined(FEAT_MOUSE) || defined(PROTO)
5484 
5485 /*
5486  * Status line of dragwin is dragged "offset" lines down (negative is up).
5487  */
5488     void
5489 win_drag_status_line(win_T *dragwin, int offset)
5490 {
5491     frame_T	*curfr;
5492     frame_T	*fr;
5493     int		room;
5494     int		row;
5495     int		up;	/* if TRUE, drag status line up, otherwise down */
5496     int		n;
5497 
5498     fr = dragwin->w_frame;
5499     curfr = fr;
5500     if (fr != topframe)		/* more than one window */
5501     {
5502 	fr = fr->fr_parent;
5503 	/* When the parent frame is not a column of frames, its parent should
5504 	 * be. */
5505 	if (fr->fr_layout != FR_COL)
5506 	{
5507 	    curfr = fr;
5508 	    if (fr != topframe)	/* only a row of windows, may drag statusline */
5509 		fr = fr->fr_parent;
5510 	}
5511     }
5512 
5513     /* If this is the last frame in a column, may want to resize the parent
5514      * frame instead (go two up to skip a row of frames). */
5515     while (curfr != topframe && curfr->fr_next == NULL)
5516     {
5517 	if (fr != topframe)
5518 	    fr = fr->fr_parent;
5519 	curfr = fr;
5520 	if (fr != topframe)
5521 	    fr = fr->fr_parent;
5522     }
5523 
5524     if (offset < 0) /* drag up */
5525     {
5526 	up = TRUE;
5527 	offset = -offset;
5528 	/* sum up the room of the current frame and above it */
5529 	if (fr == curfr)
5530 	{
5531 	    /* only one window */
5532 	    room = fr->fr_height - frame_minheight(fr, NULL);
5533 	}
5534 	else
5535 	{
5536 	    room = 0;
5537 	    for (fr = fr->fr_child; ; fr = fr->fr_next)
5538 	    {
5539 		room += fr->fr_height - frame_minheight(fr, NULL);
5540 		if (fr == curfr)
5541 		    break;
5542 	    }
5543 	}
5544 	fr = curfr->fr_next;		/* put fr at frame that grows */
5545     }
5546     else    /* drag down */
5547     {
5548 	up = FALSE;
5549 	/*
5550 	 * Only dragging the last status line can reduce p_ch.
5551 	 */
5552 	room = Rows - cmdline_row;
5553 	if (curfr->fr_next == NULL)
5554 	    room -= 1;
5555 	else
5556 	    room -= p_ch;
5557 	if (room < 0)
5558 	    room = 0;
5559 	/* sum up the room of frames below of the current one */
5560 	FOR_ALL_FRAMES(fr, curfr->fr_next)
5561 	    room += fr->fr_height - frame_minheight(fr, NULL);
5562 	fr = curfr;			/* put fr at window that grows */
5563     }
5564 
5565     if (room < offset)		/* Not enough room */
5566 	offset = room;		/* Move as far as we can */
5567     if (offset <= 0)
5568 	return;
5569 
5570     /*
5571      * Grow frame fr by "offset" lines.
5572      * Doesn't happen when dragging the last status line up.
5573      */
5574     if (fr != NULL)
5575 	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
5576 
5577     if (up)
5578 	fr = curfr;		/* current frame gets smaller */
5579     else
5580 	fr = curfr->fr_next;	/* next frame gets smaller */
5581 
5582     /*
5583      * Now make the other frames smaller.
5584      */
5585     while (fr != NULL && offset > 0)
5586     {
5587 	n = frame_minheight(fr, NULL);
5588 	if (fr->fr_height - offset <= n)
5589 	{
5590 	    offset -= fr->fr_height - n;
5591 	    frame_new_height(fr, n, !up, FALSE);
5592 	}
5593 	else
5594 	{
5595 	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
5596 	    break;
5597 	}
5598 	if (up)
5599 	    fr = fr->fr_prev;
5600 	else
5601 	    fr = fr->fr_next;
5602     }
5603     row = win_comp_pos();
5604     screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5605     cmdline_row = row;
5606     p_ch = Rows - cmdline_row;
5607     if (p_ch < 1)
5608 	p_ch = 1;
5609     curtab->tp_ch_used = p_ch;
5610     redraw_all_later(SOME_VALID);
5611     showmode();
5612 }
5613 
5614 /*
5615  * Separator line of dragwin is dragged "offset" lines right (negative is left).
5616  */
5617     void
5618 win_drag_vsep_line(win_T *dragwin, int offset)
5619 {
5620     frame_T	*curfr;
5621     frame_T	*fr;
5622     int		room;
5623     int		left;	/* if TRUE, drag separator line left, otherwise right */
5624     int		n;
5625 
5626     fr = dragwin->w_frame;
5627     if (fr == topframe)		/* only one window (cannot happen?) */
5628 	return;
5629     curfr = fr;
5630     fr = fr->fr_parent;
5631     /* When the parent frame is not a row of frames, its parent should be. */
5632     if (fr->fr_layout != FR_ROW)
5633     {
5634 	if (fr == topframe)	/* only a column of windows (cannot happen?) */
5635 	    return;
5636 	curfr = fr;
5637 	fr = fr->fr_parent;
5638     }
5639 
5640     /* If this is the last frame in a row, may want to resize a parent
5641      * frame instead. */
5642     while (curfr->fr_next == NULL)
5643     {
5644 	if (fr == topframe)
5645 	    break;
5646 	curfr = fr;
5647 	fr = fr->fr_parent;
5648 	if (fr != topframe)
5649 	{
5650 	    curfr = fr;
5651 	    fr = fr->fr_parent;
5652 	}
5653     }
5654 
5655     if (offset < 0) /* drag left */
5656     {
5657 	left = TRUE;
5658 	offset = -offset;
5659 	/* sum up the room of the current frame and left of it */
5660 	room = 0;
5661 	for (fr = fr->fr_child; ; fr = fr->fr_next)
5662 	{
5663 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5664 	    if (fr == curfr)
5665 		break;
5666 	}
5667 	fr = curfr->fr_next;		/* put fr at frame that grows */
5668     }
5669     else    /* drag right */
5670     {
5671 	left = FALSE;
5672 	/* sum up the room of frames right of the current one */
5673 	room = 0;
5674 	FOR_ALL_FRAMES(fr, curfr->fr_next)
5675 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5676 	fr = curfr;			/* put fr at window that grows */
5677     }
5678 
5679     if (room < offset)		/* Not enough room */
5680 	offset = room;		/* Move as far as we can */
5681     if (offset <= 0)		/* No room at all, quit. */
5682 	return;
5683     if (fr == NULL)
5684 	return;			/* Safety check, should not happen. */
5685 
5686     /* grow frame fr by offset lines */
5687     frame_new_width(fr, fr->fr_width + offset, left, FALSE);
5688 
5689     /* shrink other frames: current and at the left or at the right */
5690     if (left)
5691 	fr = curfr;		/* current frame gets smaller */
5692     else
5693 	fr = curfr->fr_next;	/* next frame gets smaller */
5694 
5695     while (fr != NULL && offset > 0)
5696     {
5697 	n = frame_minwidth(fr, NULL);
5698 	if (fr->fr_width - offset <= n)
5699 	{
5700 	    offset -= fr->fr_width - n;
5701 	    frame_new_width(fr, n, !left, FALSE);
5702 	}
5703 	else
5704 	{
5705 	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
5706 	    break;
5707 	}
5708 	if (left)
5709 	    fr = fr->fr_prev;
5710 	else
5711 	    fr = fr->fr_next;
5712     }
5713     (void)win_comp_pos();
5714     redraw_all_later(NOT_VALID);
5715 }
5716 #endif /* FEAT_MOUSE */
5717 
5718 #define FRACTION_MULT	16384L
5719 
5720 /*
5721  * Set wp->w_fraction for the current w_wrow and w_height.
5722  * Has no effect when the window is less than two lines.
5723  */
5724     void
5725 set_fraction(win_T *wp)
5726 {
5727     if (wp->w_height > 1)
5728 	// When cursor is in the first line the percentage is computed as if
5729 	// it's halfway that line.  Thus with two lines it is 25%, with three
5730 	// lines 17%, etc.  Similarly for the last line: 75%, 83%, etc.
5731 	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
5732 				     + FRACTION_MULT / 2) / (long)wp->w_height;
5733 }
5734 
5735 /*
5736  * Set the height of a window.
5737  * "height" excludes any window toolbar.
5738  * This takes care of the things inside the window, not what happens to the
5739  * window position, the frame or to other windows.
5740  */
5741     void
5742 win_new_height(win_T *wp, int height)
5743 {
5744     int		prev_height = wp->w_height;
5745 
5746     /* Don't want a negative height.  Happens when splitting a tiny window.
5747      * Will equalize heights soon to fix it. */
5748     if (height < 0)
5749 	height = 0;
5750     if (wp->w_height == height)
5751 	return;	    /* nothing to do */
5752 
5753     if (wp->w_height > 0)
5754     {
5755 	if (wp == curwin)
5756 	    /* w_wrow needs to be valid. When setting 'laststatus' this may
5757 	     * call win_new_height() recursively. */
5758 	    validate_cursor();
5759 	if (wp->w_height != prev_height)
5760 	    return;  /* Recursive call already changed the size, bail out here
5761 			to avoid the following to mess things up. */
5762 	if (wp->w_wrow != wp->w_prev_fraction_row)
5763 	    set_fraction(wp);
5764     }
5765 
5766     wp->w_height = height;
5767     wp->w_skipcol = 0;
5768 
5769     /* There is no point in adjusting the scroll position when exiting.  Some
5770      * values might be invalid. */
5771     if (!exiting)
5772 	scroll_to_fraction(wp, prev_height);
5773 }
5774 
5775     void
5776 scroll_to_fraction(win_T *wp, int prev_height)
5777 {
5778     linenr_T	lnum;
5779     int		sline, line_size;
5780     int		height = wp->w_height;
5781 
5782     // Don't change w_topline when height is zero.  Don't set w_topline when
5783     // 'scrollbind' is set and this isn't the current window.
5784     if (height > 0 && (!wp->w_p_scb || wp == curwin))
5785     {
5786 	/*
5787 	 * Find a value for w_topline that shows the cursor at the same
5788 	 * relative position in the window as before (more or less).
5789 	 */
5790 	lnum = wp->w_cursor.lnum;
5791 	if (lnum < 1)		/* can happen when starting up */
5792 	    lnum = 1;
5793 	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L)
5794 							       / FRACTION_MULT;
5795 	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
5796 	sline = wp->w_wrow - line_size;
5797 
5798 	if (sline >= 0)
5799 	{
5800 	    /* Make sure the whole cursor line is visible, if possible. */
5801 	    int rows = plines_win(wp, lnum, FALSE);
5802 
5803 	    if (sline > wp->w_height - rows)
5804 	    {
5805 		sline = wp->w_height - rows;
5806 		wp->w_wrow -= rows - line_size;
5807 	    }
5808 	}
5809 
5810 	if (sline < 0)
5811 	{
5812 	    /*
5813 	     * Cursor line would go off top of screen if w_wrow was this high.
5814 	     * Make cursor line the first line in the window.  If not enough
5815 	     * room use w_skipcol;
5816 	     */
5817 	    wp->w_wrow = line_size;
5818 	    if (wp->w_wrow >= wp->w_height
5819 				       && (wp->w_width - win_col_off(wp)) > 0)
5820 	    {
5821 		wp->w_skipcol += wp->w_width - win_col_off(wp);
5822 		--wp->w_wrow;
5823 		while (wp->w_wrow >= wp->w_height)
5824 		{
5825 		    wp->w_skipcol += wp->w_width - win_col_off(wp)
5826 							   + win_col_off2(wp);
5827 		    --wp->w_wrow;
5828 		}
5829 	    }
5830 	}
5831 	else if (sline > 0)
5832 	{
5833 	    while (sline > 0 && lnum > 1)
5834 	    {
5835 #ifdef FEAT_FOLDING
5836 		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
5837 		if (lnum == 1)
5838 		{
5839 		    /* first line in buffer is folded */
5840 		    line_size = 1;
5841 		    --sline;
5842 		    break;
5843 		}
5844 #endif
5845 		--lnum;
5846 #ifdef FEAT_DIFF
5847 		if (lnum == wp->w_topline)
5848 		    line_size = plines_win_nofill(wp, lnum, TRUE)
5849 							      + wp->w_topfill;
5850 		else
5851 #endif
5852 		    line_size = plines_win(wp, lnum, TRUE);
5853 		sline -= line_size;
5854 	    }
5855 
5856 	    if (sline < 0)
5857 	    {
5858 		/*
5859 		 * Line we want at top would go off top of screen.  Use next
5860 		 * line instead.
5861 		 */
5862 #ifdef FEAT_FOLDING
5863 		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
5864 #endif
5865 		lnum++;
5866 		wp->w_wrow -= line_size + sline;
5867 	    }
5868 	    else if (sline > 0)
5869 	    {
5870 		// First line of file reached, use that as topline.
5871 		lnum = 1;
5872 		wp->w_wrow -= sline;
5873 	    }
5874 	}
5875 	set_topline(wp, lnum);
5876     }
5877 
5878     if (wp == curwin)
5879     {
5880 	if (get_scrolloff_value())
5881 	    update_topline();
5882 	curs_columns(FALSE);	/* validate w_wrow */
5883     }
5884     if (prev_height > 0)
5885 	wp->w_prev_fraction_row = wp->w_wrow;
5886 
5887     win_comp_scroll(wp);
5888     redraw_win_later(wp, SOME_VALID);
5889     wp->w_redr_status = TRUE;
5890     invalidate_botline_win(wp);
5891 }
5892 
5893 /*
5894  * Set the width of a window.
5895  */
5896     void
5897 win_new_width(win_T *wp, int width)
5898 {
5899     wp->w_width = width;
5900     wp->w_lines_valid = 0;
5901     changed_line_abv_curs_win(wp);
5902     invalidate_botline_win(wp);
5903     if (wp == curwin)
5904     {
5905 	update_topline();
5906 	curs_columns(TRUE);	/* validate w_wrow */
5907     }
5908     redraw_win_later(wp, NOT_VALID);
5909     wp->w_redr_status = TRUE;
5910 }
5911 
5912     void
5913 win_comp_scroll(win_T *wp)
5914 {
5915     wp->w_p_scr = ((unsigned)wp->w_height >> 1);
5916     if (wp->w_p_scr == 0)
5917 	wp->w_p_scr = 1;
5918 }
5919 
5920 /*
5921  * command_height: called whenever p_ch has been changed
5922  */
5923     void
5924 command_height(void)
5925 {
5926     int		h;
5927     frame_T	*frp;
5928     int		old_p_ch = curtab->tp_ch_used;
5929 
5930     /* Use the value of p_ch that we remembered.  This is needed for when the
5931      * GUI starts up, we can't be sure in what order things happen.  And when
5932      * p_ch was changed in another tab page. */
5933     curtab->tp_ch_used = p_ch;
5934 
5935     /* Find bottom frame with width of screen. */
5936     frp = lastwin->w_frame;
5937     while (frp->fr_width != Columns && frp->fr_parent != NULL)
5938 	frp = frp->fr_parent;
5939 
5940     /* Avoid changing the height of a window with 'winfixheight' set. */
5941     while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
5942 						      && frp->fr_win->w_p_wfh)
5943 	frp = frp->fr_prev;
5944 
5945     if (starting != NO_SCREEN)
5946     {
5947 	cmdline_row = Rows - p_ch;
5948 
5949 	if (p_ch > old_p_ch)		    /* p_ch got bigger */
5950 	{
5951 	    while (p_ch > old_p_ch)
5952 	    {
5953 		if (frp == NULL)
5954 		{
5955 		    emsg(_(e_noroom));
5956 		    p_ch = old_p_ch;
5957 		    curtab->tp_ch_used = p_ch;
5958 		    cmdline_row = Rows - p_ch;
5959 		    break;
5960 		}
5961 		h = frp->fr_height - frame_minheight(frp, NULL);
5962 		if (h > p_ch - old_p_ch)
5963 		    h = p_ch - old_p_ch;
5964 		old_p_ch += h;
5965 		frame_add_height(frp, -h);
5966 		frp = frp->fr_prev;
5967 	    }
5968 
5969 	    /* Recompute window positions. */
5970 	    (void)win_comp_pos();
5971 
5972 	    /* clear the lines added to cmdline */
5973 	    if (full_screen)
5974 		screen_fill((int)(cmdline_row), (int)Rows, 0,
5975 						   (int)Columns, ' ', ' ', 0);
5976 	    msg_row = cmdline_row;
5977 	    redraw_cmdline = TRUE;
5978 	    return;
5979 	}
5980 
5981 	if (msg_row < cmdline_row)
5982 	    msg_row = cmdline_row;
5983 	redraw_cmdline = TRUE;
5984     }
5985     frame_add_height(frp, (int)(old_p_ch - p_ch));
5986 
5987     /* Recompute window positions. */
5988     if (frp != lastwin->w_frame)
5989 	(void)win_comp_pos();
5990 }
5991 
5992 /*
5993  * Resize frame "frp" to be "n" lines higher (negative for less high).
5994  * Also resize the frames it is contained in.
5995  */
5996     static void
5997 frame_add_height(frame_T *frp, int n)
5998 {
5999     frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
6000     for (;;)
6001     {
6002 	frp = frp->fr_parent;
6003 	if (frp == NULL)
6004 	    break;
6005 	frp->fr_height += n;
6006     }
6007 }
6008 
6009 /*
6010  * Add or remove a status line for the bottom window(s), according to the
6011  * value of 'laststatus'.
6012  */
6013     void
6014 last_status(
6015     int		morewin)	/* pretend there are two or more windows */
6016 {
6017     /* Don't make a difference between horizontal or vertical split. */
6018     last_status_rec(topframe, (p_ls == 2
6019 			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
6020 }
6021 
6022     static void
6023 last_status_rec(frame_T *fr, int statusline)
6024 {
6025     frame_T	*fp;
6026     win_T	*wp;
6027 
6028     if (fr->fr_layout == FR_LEAF)
6029     {
6030 	wp = fr->fr_win;
6031 	if (wp->w_status_height != 0 && !statusline)
6032 	{
6033 	    /* remove status line */
6034 	    win_new_height(wp, wp->w_height + 1);
6035 	    wp->w_status_height = 0;
6036 	    comp_col();
6037 	}
6038 	else if (wp->w_status_height == 0 && statusline)
6039 	{
6040 	    /* Find a frame to take a line from. */
6041 	    fp = fr;
6042 	    while (fp->fr_height <= frame_minheight(fp, NULL))
6043 	    {
6044 		if (fp == topframe)
6045 		{
6046 		    emsg(_(e_noroom));
6047 		    return;
6048 		}
6049 		/* In a column of frames: go to frame above.  If already at
6050 		 * the top or in a row of frames: go to parent. */
6051 		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
6052 		    fp = fp->fr_prev;
6053 		else
6054 		    fp = fp->fr_parent;
6055 	    }
6056 	    wp->w_status_height = 1;
6057 	    if (fp != fr)
6058 	    {
6059 		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
6060 		frame_fix_height(wp);
6061 		(void)win_comp_pos();
6062 	    }
6063 	    else
6064 		win_new_height(wp, wp->w_height - 1);
6065 	    comp_col();
6066 	    redraw_all_later(SOME_VALID);
6067 	}
6068     }
6069     else if (fr->fr_layout == FR_ROW)
6070     {
6071 	/* vertically split windows, set status line for each one */
6072 	FOR_ALL_FRAMES(fp, fr->fr_child)
6073 	    last_status_rec(fp, statusline);
6074     }
6075     else
6076     {
6077 	/* horizontally split window, set status line for last one */
6078 	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
6079 	    ;
6080 	last_status_rec(fp, statusline);
6081     }
6082 }
6083 
6084 /*
6085  * Return the number of lines used by the tab page line.
6086  */
6087     int
6088 tabline_height(void)
6089 {
6090 #ifdef FEAT_GUI_TABLINE
6091     /* When the GUI has the tabline then this always returns zero. */
6092     if (gui_use_tabline())
6093 	return 0;
6094 #endif
6095     switch (p_stal)
6096     {
6097 	case 0: return 0;
6098 	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
6099     }
6100     return 1;
6101 }
6102 
6103 /*
6104  * Return the minimal number of rows that is needed on the screen to display
6105  * the current number of windows.
6106  */
6107     int
6108 min_rows(void)
6109 {
6110     int		total;
6111     tabpage_T	*tp;
6112     int		n;
6113 
6114     if (firstwin == NULL)	/* not initialized yet */
6115 	return MIN_LINES;
6116 
6117     total = 0;
6118     FOR_ALL_TABPAGES(tp)
6119     {
6120 	n = frame_minheight(tp->tp_topframe, NULL);
6121 	if (total < n)
6122 	    total = n;
6123     }
6124     total += tabline_height();
6125     total += 1;		/* count the room for the command line */
6126     return total;
6127 }
6128 
6129 /*
6130  * Return TRUE if there is only one window (in the current tab page), not
6131  * counting a help or preview window, unless it is the current window.
6132  * Does not count "aucmd_win".
6133  */
6134     int
6135 only_one_window(void)
6136 {
6137     int		count = 0;
6138     win_T	*wp;
6139 
6140     /* If there is another tab page there always is another window. */
6141     if (first_tabpage->tp_next != NULL)
6142 	return FALSE;
6143 
6144     FOR_ALL_WINDOWS(wp)
6145 	if (wp->w_buffer != NULL
6146 		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
6147 # ifdef FEAT_QUICKFIX
6148 		    || wp->w_p_pvw
6149 # endif
6150 	     ) || wp == curwin) && wp != aucmd_win)
6151 	    ++count;
6152     return (count <= 1);
6153 }
6154 
6155 /*
6156  * Correct the cursor line number in other windows.  Used after changing the
6157  * current buffer, and before applying autocommands.
6158  * When "do_curwin" is TRUE, also check current window.
6159  */
6160     void
6161 check_lnums(int do_curwin)
6162 {
6163     win_T	*wp;
6164     tabpage_T	*tp;
6165 
6166     FOR_ALL_TAB_WINDOWS(tp, wp)
6167 	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
6168 	{
6169 	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
6170 		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
6171 	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
6172 		wp->w_topline = curbuf->b_ml.ml_line_count;
6173 	}
6174 }
6175 
6176 /*
6177  * A snapshot of the window sizes, to restore them after closing the help
6178  * window.
6179  * Only these fields are used:
6180  * fr_layout
6181  * fr_width
6182  * fr_height
6183  * fr_next
6184  * fr_child
6185  * fr_win (only valid for the old curwin, NULL otherwise)
6186  */
6187 
6188 /*
6189  * Create a snapshot of the current frame sizes.
6190  */
6191     void
6192 make_snapshot(int idx)
6193 {
6194     clear_snapshot(curtab, idx);
6195     make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
6196 }
6197 
6198     static void
6199 make_snapshot_rec(frame_T *fr, frame_T **frp)
6200 {
6201     *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
6202     if (*frp == NULL)
6203 	return;
6204     (*frp)->fr_layout = fr->fr_layout;
6205     (*frp)->fr_width = fr->fr_width;
6206     (*frp)->fr_height = fr->fr_height;
6207     if (fr->fr_next != NULL)
6208 	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
6209     if (fr->fr_child != NULL)
6210 	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
6211     if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
6212 	(*frp)->fr_win = curwin;
6213 }
6214 
6215 /*
6216  * Remove any existing snapshot.
6217  */
6218     static void
6219 clear_snapshot(tabpage_T *tp, int idx)
6220 {
6221     clear_snapshot_rec(tp->tp_snapshot[idx]);
6222     tp->tp_snapshot[idx] = NULL;
6223 }
6224 
6225     static void
6226 clear_snapshot_rec(frame_T *fr)
6227 {
6228     if (fr != NULL)
6229     {
6230 	clear_snapshot_rec(fr->fr_next);
6231 	clear_snapshot_rec(fr->fr_child);
6232 	vim_free(fr);
6233     }
6234 }
6235 
6236 /*
6237  * Restore a previously created snapshot, if there is any.
6238  * This is only done if the screen size didn't change and the window layout is
6239  * still the same.
6240  */
6241     void
6242 restore_snapshot(
6243     int		idx,
6244     int		close_curwin)	    /* closing current window */
6245 {
6246     win_T	*wp;
6247 
6248     if (curtab->tp_snapshot[idx] != NULL
6249 	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
6250 	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
6251 	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
6252     {
6253 	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
6254 	win_comp_pos();
6255 	if (wp != NULL && close_curwin)
6256 	    win_goto(wp);
6257 	redraw_all_later(NOT_VALID);
6258     }
6259     clear_snapshot(curtab, idx);
6260 }
6261 
6262 /*
6263  * Check if frames "sn" and "fr" have the same layout, same following frames
6264  * and same children.  And the window pointer is valid.
6265  */
6266     static int
6267 check_snapshot_rec(frame_T *sn, frame_T *fr)
6268 {
6269     if (sn->fr_layout != fr->fr_layout
6270 	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
6271 	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
6272 	    || (sn->fr_next != NULL
6273 		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
6274 	    || (sn->fr_child != NULL
6275 		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
6276 	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
6277 	return FAIL;
6278     return OK;
6279 }
6280 
6281 /*
6282  * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
6283  * following frames and children.
6284  * Returns a pointer to the old current window, or NULL.
6285  */
6286     static win_T *
6287 restore_snapshot_rec(frame_T *sn, frame_T *fr)
6288 {
6289     win_T	*wp = NULL;
6290     win_T	*wp2;
6291 
6292     fr->fr_height = sn->fr_height;
6293     fr->fr_width = sn->fr_width;
6294     if (fr->fr_layout == FR_LEAF)
6295     {
6296 	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
6297 	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
6298 	wp = sn->fr_win;
6299     }
6300     if (sn->fr_next != NULL)
6301     {
6302 	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
6303 	if (wp2 != NULL)
6304 	    wp = wp2;
6305     }
6306     if (sn->fr_child != NULL)
6307     {
6308 	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
6309 	if (wp2 != NULL)
6310 	    wp = wp2;
6311     }
6312     return wp;
6313 }
6314 
6315 #if defined(FEAT_EVAL) || defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \
6316 	|| defined(PROTO)
6317 /*
6318  * Set "win" to be the curwin and "tp" to be the current tab page.
6319  * restore_win() MUST be called to undo, also when FAIL is returned.
6320  * No autocommands will be executed until restore_win() is called.
6321  * When "no_display" is TRUE the display won't be affected, no redraw is
6322  * triggered, another tabpage access is limited.
6323  * Returns FAIL if switching to "win" failed.
6324  */
6325     int
6326 switch_win(
6327     win_T	**save_curwin,
6328     tabpage_T	**save_curtab,
6329     win_T	*win,
6330     tabpage_T	*tp,
6331     int		no_display)
6332 {
6333     block_autocmds();
6334     *save_curwin = curwin;
6335     if (tp != NULL)
6336     {
6337 	*save_curtab = curtab;
6338 	if (no_display)
6339 	{
6340 	    curtab->tp_firstwin = firstwin;
6341 	    curtab->tp_lastwin = lastwin;
6342 	    curtab = tp;
6343 	    firstwin = curtab->tp_firstwin;
6344 	    lastwin = curtab->tp_lastwin;
6345 	}
6346 	else
6347 	    goto_tabpage_tp(tp, FALSE, FALSE);
6348     }
6349     if (!win_valid(win))
6350 	return FAIL;
6351     curwin = win;
6352     curbuf = curwin->w_buffer;
6353     return OK;
6354 }
6355 
6356 /*
6357  * Restore current tabpage and window saved by switch_win(), if still valid.
6358  * When "no_display" is TRUE the display won't be affected, no redraw is
6359  * triggered.
6360  */
6361     void
6362 restore_win(
6363     win_T	*save_curwin UNUSED,
6364     tabpage_T	*save_curtab UNUSED,
6365     int		no_display UNUSED)
6366 {
6367     if (save_curtab != NULL && valid_tabpage(save_curtab))
6368     {
6369 	if (no_display)
6370 	{
6371 	    curtab->tp_firstwin = firstwin;
6372 	    curtab->tp_lastwin = lastwin;
6373 	    curtab = save_curtab;
6374 	    firstwin = curtab->tp_firstwin;
6375 	    lastwin = curtab->tp_lastwin;
6376 	}
6377 	else
6378 	    goto_tabpage_tp(save_curtab, FALSE, FALSE);
6379     }
6380     if (win_valid(save_curwin))
6381     {
6382 	curwin = save_curwin;
6383 	curbuf = curwin->w_buffer;
6384     }
6385     unblock_autocmds();
6386 }
6387 
6388 /*
6389  * Make "buf" the current buffer.  restore_buffer() MUST be called to undo.
6390  * No autocommands will be executed.  Use aucmd_prepbuf() if there are any.
6391  */
6392     void
6393 switch_buffer(bufref_T *save_curbuf, buf_T *buf)
6394 {
6395     block_autocmds();
6396     set_bufref(save_curbuf, curbuf);
6397     --curbuf->b_nwindows;
6398     curbuf = buf;
6399     curwin->w_buffer = buf;
6400     ++curbuf->b_nwindows;
6401 }
6402 
6403 /*
6404  * Restore the current buffer after using switch_buffer().
6405  */
6406     void
6407 restore_buffer(bufref_T *save_curbuf)
6408 {
6409     unblock_autocmds();
6410     /* Check for valid buffer, just in case. */
6411     if (bufref_valid(save_curbuf))
6412     {
6413 	--curbuf->b_nwindows;
6414 	curwin->w_buffer = save_curbuf->br_buf;
6415 	curbuf = save_curbuf->br_buf;
6416 	++curbuf->b_nwindows;
6417     }
6418 }
6419 #endif
6420 
6421 #if defined(FEAT_GUI) || defined(PROTO)
6422 /*
6423  * Return TRUE if there is any vertically split window.
6424  */
6425     int
6426 win_hasvertsplit(void)
6427 {
6428     frame_T	*fr;
6429 
6430     if (topframe->fr_layout == FR_ROW)
6431 	return TRUE;
6432 
6433     if (topframe->fr_layout == FR_COL)
6434 	FOR_ALL_FRAMES(fr, topframe->fr_child)
6435 	    if (fr->fr_layout == FR_ROW)
6436 		return TRUE;
6437 
6438     return FALSE;
6439 }
6440 #endif
6441 
6442 #if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
6443 /*
6444  * Add match to the match list of window 'wp'.  The pattern 'pat' will be
6445  * highlighted with the group 'grp' with priority 'prio'.
6446  * Optionally, a desired ID 'id' can be specified (greater than or equal to 1).
6447  * If no particular ID is desired, -1 must be specified for 'id'.
6448  * Return ID of added match, -1 on failure.
6449  */
6450     int
6451 match_add(
6452     win_T	*wp,
6453     char_u	*grp,
6454     char_u	*pat,
6455     int		prio,
6456     int		id,
6457     list_T	*pos_list,
6458     char_u      *conceal_char UNUSED) /* pointer to conceal replacement char */
6459 {
6460     matchitem_T	*cur;
6461     matchitem_T	*prev;
6462     matchitem_T	*m;
6463     int		hlg_id;
6464     regprog_T	*regprog = NULL;
6465     int		rtype = SOME_VALID;
6466 
6467     if (*grp == NUL || (pat != NULL && *pat == NUL))
6468 	return -1;
6469     if (id < -1 || id == 0)
6470     {
6471 	semsg(_("E799: Invalid ID: %d (must be greater than or equal to 1)"), id);
6472 	return -1;
6473     }
6474     if (id != -1)
6475     {
6476 	cur = wp->w_match_head;
6477 	while (cur != NULL)
6478 	{
6479 	    if (cur->id == id)
6480 	    {
6481 		semsg(_("E801: ID already taken: %d"), id);
6482 		return -1;
6483 	    }
6484 	    cur = cur->next;
6485 	}
6486     }
6487     if ((hlg_id = syn_namen2id(grp, (int)STRLEN(grp))) == 0)
6488     {
6489 	semsg(_(e_nogroup), grp);
6490 	return -1;
6491     }
6492     if (pat != NULL && (regprog = vim_regcomp(pat, RE_MAGIC)) == NULL)
6493     {
6494 	semsg(_(e_invarg2), pat);
6495 	return -1;
6496     }
6497 
6498     /* Find available match ID. */
6499     while (id == -1)
6500     {
6501 	cur = wp->w_match_head;
6502 	while (cur != NULL && cur->id != wp->w_next_match_id)
6503 	    cur = cur->next;
6504 	if (cur == NULL)
6505 	    id = wp->w_next_match_id;
6506 	wp->w_next_match_id++;
6507     }
6508 
6509     /* Build new match. */
6510     m = (matchitem_T *)alloc_clear(sizeof(matchitem_T));
6511     m->id = id;
6512     m->priority = prio;
6513     m->pattern = pat == NULL ? NULL : vim_strsave(pat);
6514     m->hlg_id = hlg_id;
6515     m->match.regprog = regprog;
6516     m->match.rmm_ic = FALSE;
6517     m->match.rmm_maxcol = 0;
6518 # if defined(FEAT_CONCEAL)
6519     m->conceal_char = 0;
6520     if (conceal_char != NULL)
6521 	m->conceal_char = (*mb_ptr2char)(conceal_char);
6522 # endif
6523 
6524     /* Set up position matches */
6525     if (pos_list != NULL)
6526     {
6527 	linenr_T	toplnum = 0;
6528 	linenr_T	botlnum = 0;
6529 	listitem_T	*li;
6530 	int		i;
6531 
6532 	for (i = 0, li = pos_list->lv_first; li != NULL && i < MAXPOSMATCH;
6533 							i++, li = li->li_next)
6534 	{
6535 	    linenr_T	lnum = 0;
6536 	    colnr_T	col = 0;
6537 	    int		len = 1;
6538 	    list_T	*subl;
6539 	    listitem_T	*subli;
6540 	    int		error = FALSE;
6541 
6542 	    if (li->li_tv.v_type == VAR_LIST)
6543 	    {
6544 		subl = li->li_tv.vval.v_list;
6545 		if (subl == NULL)
6546 		    goto fail;
6547 		subli = subl->lv_first;
6548 		if (subli == NULL)
6549 		    goto fail;
6550 		lnum = tv_get_number_chk(&subli->li_tv, &error);
6551 		if (error == TRUE)
6552 		    goto fail;
6553 		if (lnum == 0)
6554 		{
6555 		    --i;
6556 		    continue;
6557 		}
6558 		m->pos.pos[i].lnum = lnum;
6559 		subli = subli->li_next;
6560 		if (subli != NULL)
6561 		{
6562 		    col = tv_get_number_chk(&subli->li_tv, &error);
6563 		    if (error == TRUE)
6564 			goto fail;
6565 		    subli = subli->li_next;
6566 		    if (subli != NULL)
6567 		    {
6568 			len = tv_get_number_chk(&subli->li_tv, &error);
6569 			if (error == TRUE)
6570 			    goto fail;
6571 		    }
6572 		}
6573 		m->pos.pos[i].col = col;
6574 		m->pos.pos[i].len = len;
6575 	    }
6576 	    else if (li->li_tv.v_type == VAR_NUMBER)
6577 	    {
6578 		if (li->li_tv.vval.v_number == 0)
6579 		{
6580 		    --i;
6581 		    continue;
6582 		}
6583 		m->pos.pos[i].lnum = li->li_tv.vval.v_number;
6584 		m->pos.pos[i].col = 0;
6585 		m->pos.pos[i].len = 0;
6586 	    }
6587 	    else
6588 	    {
6589 		emsg(_("List or number required"));
6590 		goto fail;
6591 	    }
6592 	    if (toplnum == 0 || lnum < toplnum)
6593 		toplnum = lnum;
6594 	    if (botlnum == 0 || lnum >= botlnum)
6595 		botlnum = lnum + 1;
6596 	}
6597 
6598 	/* Calculate top and bottom lines for redrawing area */
6599 	if (toplnum != 0)
6600 	{
6601 	    if (wp->w_buffer->b_mod_set)
6602 	    {
6603 		if (wp->w_buffer->b_mod_top > toplnum)
6604 		    wp->w_buffer->b_mod_top = toplnum;
6605 		if (wp->w_buffer->b_mod_bot < botlnum)
6606 		    wp->w_buffer->b_mod_bot = botlnum;
6607 	    }
6608 	    else
6609 	    {
6610 		wp->w_buffer->b_mod_set = TRUE;
6611 		wp->w_buffer->b_mod_top = toplnum;
6612 		wp->w_buffer->b_mod_bot = botlnum;
6613 		wp->w_buffer->b_mod_xlines = 0;
6614 	    }
6615 	    m->pos.toplnum = toplnum;
6616 	    m->pos.botlnum = botlnum;
6617 	    rtype = VALID;
6618 	}
6619     }
6620 
6621     /* Insert new match.  The match list is in ascending order with regard to
6622      * the match priorities. */
6623     cur = wp->w_match_head;
6624     prev = cur;
6625     while (cur != NULL && prio >= cur->priority)
6626     {
6627 	prev = cur;
6628 	cur = cur->next;
6629     }
6630     if (cur == prev)
6631 	wp->w_match_head = m;
6632     else
6633 	prev->next = m;
6634     m->next = cur;
6635 
6636     redraw_later(rtype);
6637     return id;
6638 
6639 fail:
6640     vim_free(m);
6641     return -1;
6642 }
6643 
6644 /*
6645  * Delete match with ID 'id' in the match list of window 'wp'.
6646  * Print error messages if 'perr' is TRUE.
6647  */
6648     int
6649 match_delete(win_T *wp, int id, int perr)
6650 {
6651     matchitem_T	*cur = wp->w_match_head;
6652     matchitem_T	*prev = cur;
6653     int		rtype = SOME_VALID;
6654 
6655     if (id < 1)
6656     {
6657 	if (perr == TRUE)
6658 	    semsg(_("E802: Invalid ID: %d (must be greater than or equal to 1)"),
6659 									  id);
6660 	return -1;
6661     }
6662     while (cur != NULL && cur->id != id)
6663     {
6664 	prev = cur;
6665 	cur = cur->next;
6666     }
6667     if (cur == NULL)
6668     {
6669 	if (perr == TRUE)
6670 	    semsg(_("E803: ID not found: %d"), id);
6671 	return -1;
6672     }
6673     if (cur == prev)
6674 	wp->w_match_head = cur->next;
6675     else
6676 	prev->next = cur->next;
6677     vim_regfree(cur->match.regprog);
6678     vim_free(cur->pattern);
6679     if (cur->pos.toplnum != 0)
6680     {
6681 	if (wp->w_buffer->b_mod_set)
6682 	{
6683 	    if (wp->w_buffer->b_mod_top > cur->pos.toplnum)
6684 		wp->w_buffer->b_mod_top = cur->pos.toplnum;
6685 	    if (wp->w_buffer->b_mod_bot < cur->pos.botlnum)
6686 		wp->w_buffer->b_mod_bot = cur->pos.botlnum;
6687 	}
6688 	else
6689 	{
6690 	    wp->w_buffer->b_mod_set = TRUE;
6691 	    wp->w_buffer->b_mod_top = cur->pos.toplnum;
6692 	    wp->w_buffer->b_mod_bot = cur->pos.botlnum;
6693 	    wp->w_buffer->b_mod_xlines = 0;
6694 	}
6695 	rtype = VALID;
6696     }
6697     vim_free(cur);
6698     redraw_later(rtype);
6699     return 0;
6700 }
6701 
6702 /*
6703  * Delete all matches in the match list of window 'wp'.
6704  */
6705     void
6706 clear_matches(win_T *wp)
6707 {
6708     matchitem_T *m;
6709 
6710     while (wp->w_match_head != NULL)
6711     {
6712 	m = wp->w_match_head->next;
6713 	vim_regfree(wp->w_match_head->match.regprog);
6714 	vim_free(wp->w_match_head->pattern);
6715 	vim_free(wp->w_match_head);
6716 	wp->w_match_head = m;
6717     }
6718     redraw_later(SOME_VALID);
6719 }
6720 
6721 /*
6722  * Get match from ID 'id' in window 'wp'.
6723  * Return NULL if match not found.
6724  */
6725     matchitem_T *
6726 get_match(win_T *wp, int id)
6727 {
6728     matchitem_T *cur = wp->w_match_head;
6729 
6730     while (cur != NULL && cur->id != id)
6731 	cur = cur->next;
6732     return cur;
6733 }
6734 #endif
6735 
6736 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
6737     int
6738 get_win_number(win_T *wp, win_T *first_win)
6739 {
6740     int		i = 1;
6741     win_T	*w;
6742 
6743     for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
6744 	++i;
6745 
6746     if (w == NULL)
6747 	return 0;
6748     else
6749 	return i;
6750 }
6751 
6752     int
6753 get_tab_number(tabpage_T *tp UNUSED)
6754 {
6755     int		i = 1;
6756     tabpage_T	*t;
6757 
6758     for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
6759 	++i;
6760 
6761     if (t == NULL)
6762 	return 0;
6763     else
6764 	return i;
6765 }
6766 #endif
6767 
6768 /*
6769  * Return TRUE if "topfrp" and its children are at the right height.
6770  */
6771     static int
6772 frame_check_height(frame_T *topfrp, int height)
6773 {
6774     frame_T *frp;
6775 
6776     if (topfrp->fr_height != height)
6777 	return FALSE;
6778 
6779     if (topfrp->fr_layout == FR_ROW)
6780 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6781 	    if (frp->fr_height != height)
6782 		return FALSE;
6783 
6784     return TRUE;
6785 }
6786 
6787 /*
6788  * Return TRUE if "topfrp" and its children are at the right width.
6789  */
6790     static int
6791 frame_check_width(frame_T *topfrp, int width)
6792 {
6793     frame_T *frp;
6794 
6795     if (topfrp->fr_width != width)
6796 	return FALSE;
6797 
6798     if (topfrp->fr_layout == FR_COL)
6799 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6800 	    if (frp->fr_width != width)
6801 		return FALSE;
6802 
6803     return TRUE;
6804 }
6805 
6806 #if defined(FEAT_EVAL) || defined(PROTO)
6807     int
6808 win_getid(typval_T *argvars)
6809 {
6810     int	    winnr;
6811     win_T   *wp;
6812 
6813     if (argvars[0].v_type == VAR_UNKNOWN)
6814 	return curwin->w_id;
6815     winnr = tv_get_number(&argvars[0]);
6816     if (winnr > 0)
6817     {
6818 	if (argvars[1].v_type == VAR_UNKNOWN)
6819 	    wp = firstwin;
6820 	else
6821 	{
6822 	    tabpage_T	*tp;
6823 	    int		tabnr = tv_get_number(&argvars[1]);
6824 
6825 	    FOR_ALL_TABPAGES(tp)
6826 		if (--tabnr == 0)
6827 		    break;
6828 	    if (tp == NULL)
6829 		return -1;
6830 	    if (tp == curtab)
6831 		wp = firstwin;
6832 	    else
6833 		wp = tp->tp_firstwin;
6834 	}
6835 	for ( ; wp != NULL; wp = wp->w_next)
6836 	    if (--winnr == 0)
6837 		return wp->w_id;
6838     }
6839     return 0;
6840 }
6841 
6842     int
6843 win_gotoid(typval_T *argvars)
6844 {
6845     win_T	*wp;
6846     tabpage_T   *tp;
6847     int		id = tv_get_number(&argvars[0]);
6848 
6849     FOR_ALL_TAB_WINDOWS(tp, wp)
6850 	    if (wp->w_id == id)
6851 	    {
6852 		goto_tabpage_win(tp, wp);
6853 		return 1;
6854 	    }
6855     return 0;
6856 }
6857 
6858     void
6859 win_id2tabwin(typval_T *argvars, list_T *list)
6860 {
6861     win_T	*wp;
6862     tabpage_T   *tp;
6863     int		winnr = 1;
6864     int		tabnr = 1;
6865     int		id = tv_get_number(&argvars[0]);
6866 
6867     FOR_ALL_TABPAGES(tp)
6868     {
6869 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
6870 	{
6871 	    if (wp->w_id == id)
6872 	    {
6873 		list_append_number(list, tabnr);
6874 		list_append_number(list, winnr);
6875 		return;
6876 	    }
6877 	    ++winnr;
6878 	}
6879 	++tabnr;
6880 	winnr = 1;
6881     }
6882     list_append_number(list, 0);
6883     list_append_number(list, 0);
6884 }
6885 
6886     win_T *
6887 win_id2wp(int id)
6888 {
6889     win_T	*wp;
6890     tabpage_T   *tp;
6891 
6892     FOR_ALL_TAB_WINDOWS(tp, wp)
6893 	if (wp->w_id == id)
6894 	    return wp;
6895 
6896     return NULL;
6897 }
6898 
6899     int
6900 win_id2win(typval_T *argvars)
6901 {
6902     win_T   *wp;
6903     int	    nr = 1;
6904     int	    id = tv_get_number(&argvars[0]);
6905 
6906     FOR_ALL_WINDOWS(wp)
6907     {
6908 	if (wp->w_id == id)
6909 	    return nr;
6910 	++nr;
6911     }
6912     return 0;
6913 }
6914 
6915     void
6916 win_findbuf(typval_T *argvars, list_T *list)
6917 {
6918     win_T	*wp;
6919     tabpage_T   *tp;
6920     int		bufnr = tv_get_number(&argvars[0]);
6921 
6922     FOR_ALL_TAB_WINDOWS(tp, wp)
6923 	    if (wp->w_buffer->b_fnum == bufnr)
6924 		list_append_number(list, wp->w_id);
6925 }
6926 
6927 /*
6928  * Get the layout of the given tab page for winlayout().
6929  */
6930     void
6931 get_framelayout(frame_T *fr, list_T *l, int outer)
6932 {
6933     frame_T	*child;
6934     list_T	*fr_list;
6935     list_T	*win_list;
6936 
6937     if (fr == NULL)
6938 	return;
6939 
6940     if (outer)
6941 	// outermost call from f_winlayout()
6942 	fr_list = l;
6943     else
6944     {
6945 	fr_list = list_alloc();
6946 	if (fr_list == NULL)
6947 	    return;
6948 	list_append_list(l, fr_list);
6949     }
6950 
6951     if (fr->fr_layout == FR_LEAF)
6952     {
6953 	if (fr->fr_win != NULL)
6954 	{
6955 	    list_append_string(fr_list, (char_u *)"leaf", -1);
6956 	    list_append_number(fr_list, fr->fr_win->w_id);
6957 	}
6958     }
6959     else
6960     {
6961 	list_append_string(fr_list,
6962 	     fr->fr_layout == FR_ROW ?  (char_u *)"row" : (char_u *)"col", -1);
6963 
6964 	win_list = list_alloc();
6965 	if (win_list == NULL)
6966 	    return;
6967 	list_append_list(fr_list, win_list);
6968 	child = fr->fr_child;
6969 	while (child != NULL)
6970 	{
6971 	    get_framelayout(child, win_list, FALSE);
6972 	    child = child->fr_next;
6973 	}
6974     }
6975 }
6976 #endif
6977