xref: /vim-8.2.3635/src/window.c (revision 23beefed)
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 void trigger_winclosed(win_T *win);
23 static win_T *win_free_mem(win_T *win, int *dirp, tabpage_T *tp);
24 static frame_T *win_altframe(win_T *win, tabpage_T *tp);
25 static tabpage_T *alt_tabpage(void);
26 static win_T *frame2win(frame_T *frp);
27 static int frame_has_win(frame_T *frp, win_T *wp);
28 static void frame_new_height(frame_T *topfrp, int height, int topfirst, int wfh);
29 static int frame_fixed_height(frame_T *frp);
30 static int frame_fixed_width(frame_T *frp);
31 static void frame_add_statusline(frame_T *frp);
32 static void frame_new_width(frame_T *topfrp, int width, int leftfirst, int wfw);
33 static void frame_add_vsep(frame_T *frp);
34 static int frame_minwidth(frame_T *topfrp, win_T *next_curwin);
35 static void frame_fix_width(win_T *wp);
36 static int win_alloc_firstwin(win_T *oldwin);
37 static void new_frame(win_T *wp);
38 static tabpage_T *alloc_tabpage(void);
39 static int leave_tabpage(buf_T *new_curbuf, int trigger_leave_autocmds);
40 static void enter_tabpage(tabpage_T *tp, buf_T *old_curbuf, int trigger_enter_autocmds, int trigger_leave_autocmds);
41 static void frame_fix_height(win_T *wp);
42 static int frame_minheight(frame_T *topfrp, win_T *next_curwin);
43 static int may_open_tabpage(void);
44 static int win_enter_ext(win_T *wp, int flags);
45 static void win_free(win_T *wp, tabpage_T *tp);
46 static int win_unlisted(win_T *wp);
47 static void win_append(win_T *after, win_T *wp);
48 static void frame_append(frame_T *after, frame_T *frp);
49 static void frame_insert(frame_T *before, frame_T *frp);
50 static void frame_remove(frame_T *frp);
51 static void win_goto_ver(int up, long count);
52 static void win_goto_hor(int left, long count);
53 static void frame_add_height(frame_T *frp, int n);
54 static void last_status_rec(frame_T *fr, int statusline);
55 
56 static void make_snapshot_rec(frame_T *fr, frame_T **frp);
57 static void clear_snapshot(tabpage_T *tp, int idx);
58 static void clear_snapshot_rec(frame_T *fr);
59 static int check_snapshot_rec(frame_T *sn, frame_T *fr);
60 static win_T *restore_snapshot_rec(frame_T *sn, frame_T *fr);
61 
62 static int frame_check_height(frame_T *topfrp, int height);
63 static int frame_check_width(frame_T *topfrp, int width);
64 
65 static win_T *win_alloc(win_T *after, int hidden);
66 
67 #define NOWIN		(win_T *)-1	// non-existing window
68 
69 #define ROWS_AVAIL (Rows - p_ch - tabline_height())
70 
71 // flags for win_enter_ext()
72 #define WEE_UNDO_SYNC			0x01
73 #define WEE_CURWIN_INVALID		0x02
74 #define WEE_TRIGGER_NEW_AUTOCMDS	0x04
75 #define WEE_TRIGGER_ENTER_AUTOCMDS	0x08
76 #define WEE_TRIGGER_LEAVE_AUTOCMDS	0x10
77 #define WEE_ALLOW_PARSE_MESSAGES	0x20
78 
79 static char *m_onlyone = N_("Already only one window");
80 
81 // When non-zero splitting a window is forbidden.  Used to avoid that nasty
82 // autocommands mess up the window structure.
83 static int split_disallowed = 0;
84 
85 // #define WIN_DEBUG
86 #ifdef WIN_DEBUG
87 /*
88  * Call this method to log the current window layout.
89  */
90     static void
91 log_frame_layout(frame_T *frame)
92 {
93     ch_log(NULL, "layout %s, wi: %d, he: %d, wwi: %d, whe: %d, id: %d",
94 	    frame->fr_layout == FR_LEAF ? "LEAF"
95 				  : frame->fr_layout == FR_ROW ? "ROW" : "COL",
96 	    frame->fr_width,
97 	    frame->fr_height,
98 	    frame->fr_win == NULL ? -1 : frame->fr_win->w_width,
99 	    frame->fr_win == NULL ? -1 : frame->fr_win->w_height,
100 	    frame->fr_win == NULL ? -1 : frame->fr_win->w_id);
101     if (frame->fr_child != NULL)
102     {
103 	ch_log(NULL, "children");
104 	log_frame_layout(frame->fr_child);
105 	if (frame->fr_next != NULL)
106 	    ch_log(NULL, "END of children");
107     }
108     if (frame->fr_next != NULL)
109 	log_frame_layout(frame->fr_next);
110 }
111 #endif
112 
113 /*
114  * All CTRL-W window commands are handled here, called from normal_cmd().
115  */
116     void
117 do_window(
118     int		nchar,
119     long	Prenum,
120     int		xchar)	    // extra char from ":wincmd gx" or NUL
121 {
122     long	Prenum1;
123     win_T	*wp;
124 #if defined(FEAT_SEARCHPATH) || defined(FEAT_FIND_ID)
125     char_u	*ptr;
126     linenr_T    lnum = -1;
127 #endif
128 #ifdef FEAT_FIND_ID
129     int		type = FIND_DEFINE;
130     int		len;
131 #endif
132     char_u	cbuf[40];
133 
134     if (ERROR_IF_ANY_POPUP_WINDOW)
135 	return;
136 
137 #ifdef FEAT_CMDWIN
138 # define CHECK_CMDWIN \
139     do { \
140 	if (cmdwin_type != 0) \
141 	{ \
142 	    emsg(_(e_invalid_in_cmdline_window)); \
143 	    return; \
144 	} \
145     } while (0)
146 #else
147 # define CHECK_CMDWIN do { /**/ } while (0)
148 #endif
149 
150     Prenum1 = Prenum == 0 ? 1 : Prenum;
151 
152     switch (nchar)
153     {
154 // split current window in two parts, horizontally
155     case 'S':
156     case Ctrl_S:
157     case 's':
158 		CHECK_CMDWIN;
159 		reset_VIsual_and_resel();	// stop Visual mode
160 #ifdef FEAT_QUICKFIX
161 		// When splitting the quickfix window open a new buffer in it,
162 		// don't replicate the quickfix buffer.
163 		if (bt_quickfix(curbuf))
164 		    goto newwindow;
165 #endif
166 #ifdef FEAT_GUI
167 		need_mouse_correct = TRUE;
168 #endif
169 		(void)win_split((int)Prenum, 0);
170 		break;
171 
172 // split current window in two parts, vertically
173     case Ctrl_V:
174     case 'v':
175 		CHECK_CMDWIN;
176 		reset_VIsual_and_resel();	// stop Visual mode
177 #ifdef FEAT_QUICKFIX
178 		// When splitting the quickfix window open a new buffer in it,
179 		// don't replicate the quickfix buffer.
180 		if (bt_quickfix(curbuf))
181 		    goto newwindow;
182 #endif
183 #ifdef FEAT_GUI
184 		need_mouse_correct = TRUE;
185 #endif
186 		(void)win_split((int)Prenum, WSP_VERT);
187 		break;
188 
189 // split current window and edit alternate file
190     case Ctrl_HAT:
191     case '^':
192 		CHECK_CMDWIN;
193 		reset_VIsual_and_resel();	// stop Visual mode
194 
195 		if (buflist_findnr(Prenum == 0
196 					? curwin->w_alt_fnum : Prenum) == NULL)
197 		{
198 		    if (Prenum == 0)
199 			emsg(_(e_no_alternate_file));
200 		    else
201 			semsg(_("E92: Buffer %ld not found"), Prenum);
202 		    break;
203 		}
204 
205 		if (!curbuf_locked() && win_split(0, 0) == OK)
206 		    (void)buflist_getfile(
207 			    Prenum == 0 ? curwin->w_alt_fnum : Prenum,
208 			    (linenr_T)0, GETF_ALT, FALSE);
209 		break;
210 
211 // open new window
212     case Ctrl_N:
213     case 'n':
214 		CHECK_CMDWIN;
215 		reset_VIsual_and_resel();	// stop Visual mode
216 #ifdef FEAT_QUICKFIX
217 newwindow:
218 #endif
219 		if (Prenum)
220 		    // window height
221 		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
222 		else
223 		    cbuf[0] = NUL;
224 #if defined(FEAT_QUICKFIX)
225 		if (nchar == 'v' || nchar == Ctrl_V)
226 		    STRCAT(cbuf, "v");
227 #endif
228 		STRCAT(cbuf, "new");
229 		do_cmdline_cmd(cbuf);
230 		break;
231 
232 // quit current window
233     case Ctrl_Q:
234     case 'q':
235 		reset_VIsual_and_resel();	// stop Visual mode
236 		cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
237 		do_cmdline_cmd(cbuf);
238 		break;
239 
240 // close current window
241     case Ctrl_C:
242     case 'c':
243 		reset_VIsual_and_resel();	// stop Visual mode
244 		cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
245 		do_cmdline_cmd(cbuf);
246 		break;
247 
248 #if defined(FEAT_QUICKFIX)
249 // close preview window
250     case Ctrl_Z:
251     case 'z':
252 		CHECK_CMDWIN;
253 		reset_VIsual_and_resel();	// stop Visual mode
254 		do_cmdline_cmd((char_u *)"pclose");
255 		break;
256 
257 // cursor to preview window
258     case 'P':
259 		FOR_ALL_WINDOWS(wp)
260 		    if (wp->w_p_pvw)
261 			break;
262 		if (wp == NULL)
263 		    emsg(_("E441: There is no preview window"));
264 		else
265 		    win_goto(wp);
266 		break;
267 #endif
268 
269 // close all but current window
270     case Ctrl_O:
271     case 'o':
272 		CHECK_CMDWIN;
273 		reset_VIsual_and_resel();	// stop Visual mode
274 		cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
275 		do_cmdline_cmd(cbuf);
276 		break;
277 
278 // cursor to next window with wrap around
279     case Ctrl_W:
280     case 'w':
281 // cursor to previous window with wrap around
282     case 'W':
283 		CHECK_CMDWIN;
284 		if (ONE_WINDOW && Prenum != 1)	// just one window
285 		    beep_flush();
286 		else
287 		{
288 		    if (Prenum)			// go to specified window
289 		    {
290 			for (wp = firstwin; --Prenum > 0; )
291 			{
292 			    if (wp->w_next == NULL)
293 				break;
294 			    else
295 				wp = wp->w_next;
296 			}
297 		    }
298 		    else
299 		    {
300 			if (nchar == 'W')	    // go to previous window
301 			{
302 			    wp = curwin->w_prev;
303 			    if (wp == NULL)
304 				wp = lastwin;	    // wrap around
305 			}
306 			else			    // go to next window
307 			{
308 			    wp = curwin->w_next;
309 			    if (wp == NULL)
310 				wp = firstwin;	    // wrap around
311 			}
312 		    }
313 		    win_goto(wp);
314 		}
315 		break;
316 
317 // cursor to window below
318     case 'j':
319     case K_DOWN:
320     case Ctrl_J:
321 		CHECK_CMDWIN;
322 		win_goto_ver(FALSE, Prenum1);
323 		break;
324 
325 // cursor to window above
326     case 'k':
327     case K_UP:
328     case Ctrl_K:
329 		CHECK_CMDWIN;
330 		win_goto_ver(TRUE, Prenum1);
331 		break;
332 
333 // cursor to left window
334     case 'h':
335     case K_LEFT:
336     case Ctrl_H:
337     case K_BS:
338 		CHECK_CMDWIN;
339 		win_goto_hor(TRUE, Prenum1);
340 		break;
341 
342 // cursor to right window
343     case 'l':
344     case K_RIGHT:
345     case Ctrl_L:
346 		CHECK_CMDWIN;
347 		win_goto_hor(FALSE, Prenum1);
348 		break;
349 
350 // move window to new tab page
351     case 'T':
352 		CHECK_CMDWIN;
353 		if (one_window())
354 		    msg(_(m_onlyone));
355 		else
356 		{
357 		    tabpage_T	*oldtab = curtab;
358 		    tabpage_T	*newtab;
359 
360 		    // First create a new tab with the window, then go back to
361 		    // the old tab and close the window there.
362 		    wp = curwin;
363 		    if (win_new_tabpage((int)Prenum) == OK
364 						     && valid_tabpage(oldtab))
365 		    {
366 			newtab = curtab;
367 			goto_tabpage_tp(oldtab, TRUE, TRUE);
368 			if (curwin == wp)
369 			    win_close(curwin, FALSE);
370 			if (valid_tabpage(newtab))
371 			    goto_tabpage_tp(newtab, TRUE, TRUE);
372 		    }
373 		}
374 		break;
375 
376 // cursor to top-left window
377     case 't':
378     case Ctrl_T:
379 		win_goto(firstwin);
380 		break;
381 
382 // cursor to bottom-right window
383     case 'b':
384     case Ctrl_B:
385 		win_goto(lastwin);
386 		break;
387 
388 // cursor to last accessed (previous) window
389     case 'p':
390     case Ctrl_P:
391 		if (!win_valid(prevwin))
392 		    beep_flush();
393 		else
394 		    win_goto(prevwin);
395 		break;
396 
397 // exchange current and next window
398     case 'x':
399     case Ctrl_X:
400 		CHECK_CMDWIN;
401 		win_exchange(Prenum);
402 		break;
403 
404 // rotate windows downwards
405     case Ctrl_R:
406     case 'r':
407 		CHECK_CMDWIN;
408 		reset_VIsual_and_resel();	// stop Visual mode
409 		win_rotate(FALSE, (int)Prenum1);    // downwards
410 		break;
411 
412 // rotate windows upwards
413     case 'R':
414 		CHECK_CMDWIN;
415 		reset_VIsual_and_resel();	// stop Visual mode
416 		win_rotate(TRUE, (int)Prenum1);	    // upwards
417 		break;
418 
419 // move window to the very top/bottom/left/right
420     case 'K':
421     case 'J':
422     case 'H':
423     case 'L':
424 		CHECK_CMDWIN;
425 		win_totop((int)Prenum,
426 			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
427 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
428 		break;
429 
430 // make all windows the same height
431     case '=':
432 #ifdef FEAT_GUI
433 		need_mouse_correct = TRUE;
434 #endif
435 		win_equal(NULL, FALSE, 'b');
436 		break;
437 
438 // increase current window height
439     case '+':
440 #ifdef FEAT_GUI
441 		need_mouse_correct = TRUE;
442 #endif
443 		win_setheight(curwin->w_height + (int)Prenum1);
444 		break;
445 
446 // decrease current window height
447     case '-':
448 #ifdef FEAT_GUI
449 		need_mouse_correct = TRUE;
450 #endif
451 		win_setheight(curwin->w_height - (int)Prenum1);
452 		break;
453 
454 // set current window height
455     case Ctrl__:
456     case '_':
457 #ifdef FEAT_GUI
458 		need_mouse_correct = TRUE;
459 #endif
460 		win_setheight(Prenum ? (int)Prenum : 9999);
461 		break;
462 
463 // increase current window width
464     case '>':
465 #ifdef FEAT_GUI
466 		need_mouse_correct = TRUE;
467 #endif
468 		win_setwidth(curwin->w_width + (int)Prenum1);
469 		break;
470 
471 // decrease current window width
472     case '<':
473 #ifdef FEAT_GUI
474 		need_mouse_correct = TRUE;
475 #endif
476 		win_setwidth(curwin->w_width - (int)Prenum1);
477 		break;
478 
479 // set current window width
480     case '|':
481 #ifdef FEAT_GUI
482 		need_mouse_correct = TRUE;
483 #endif
484 		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
485 		break;
486 
487 // jump to tag and split window if tag exists (in preview window)
488 #if defined(FEAT_QUICKFIX)
489     case '}':
490 		CHECK_CMDWIN;
491 		if (Prenum)
492 		    g_do_tagpreview = Prenum;
493 		else
494 		    g_do_tagpreview = p_pvh;
495 #endif
496 		// FALLTHROUGH
497     case ']':
498     case Ctrl_RSB:
499 		CHECK_CMDWIN;
500 		// keep Visual mode, can select words to use as a tag
501 		if (Prenum)
502 		    postponed_split = Prenum;
503 		else
504 		    postponed_split = -1;
505 #ifdef FEAT_QUICKFIX
506 		if (nchar != '}')
507 		    g_do_tagpreview = 0;
508 #endif
509 
510 		// Execute the command right here, required when "wincmd ]"
511 		// was used in a function.
512 		do_nv_ident(Ctrl_RSB, NUL);
513 		break;
514 
515 #ifdef FEAT_SEARCHPATH
516 // edit file name under cursor in a new window
517     case 'f':
518     case 'F':
519     case Ctrl_F:
520 wingotofile:
521 		CHECK_CMDWIN;
522 
523 		ptr = grab_file_name(Prenum1, &lnum);
524 		if (ptr != NULL)
525 		{
526 		    tabpage_T	*oldtab = curtab;
527 		    win_T	*oldwin = curwin;
528 # ifdef FEAT_GUI
529 		    need_mouse_correct = TRUE;
530 # endif
531 		    setpcmark();
532 		    if (win_split(0, 0) == OK)
533 		    {
534 			RESET_BINDING(curwin);
535 			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
536 						   ECMD_HIDE, NULL) == FAIL)
537 			{
538 			    // Failed to open the file, close the window
539 			    // opened for it.
540 			    win_close(curwin, FALSE);
541 			    goto_tabpage_win(oldtab, oldwin);
542 			}
543 			else if (nchar == 'F' && lnum >= 0)
544 			{
545 			    curwin->w_cursor.lnum = lnum;
546 			    check_cursor_lnum();
547 			    beginline(BL_SOL | BL_FIX);
548 			}
549 		    }
550 		    vim_free(ptr);
551 		}
552 		break;
553 #endif
554 
555 #ifdef FEAT_FIND_ID
556 // Go to the first occurrence of the identifier under cursor along path in a
557 // new window -- webb
558     case 'i':			    // Go to any match
559     case Ctrl_I:
560 		type = FIND_ANY;
561 		// FALLTHROUGH
562     case 'd':			    // Go to definition, using 'define'
563     case Ctrl_D:
564 		CHECK_CMDWIN;
565 		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
566 		    break;
567 		find_pattern_in_path(ptr, 0, len, TRUE,
568 			Prenum == 0 ? TRUE : FALSE, type,
569 			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
570 		curwin->w_set_curswant = TRUE;
571 		break;
572 #endif
573 
574 // Quickfix window only: view the result under the cursor in a new split.
575 #if defined(FEAT_QUICKFIX)
576     case K_KENTER:
577     case CAR:
578 		if (bt_quickfix(curbuf))
579 		    qf_view_result(TRUE);
580 		break;
581 #endif
582 
583 // CTRL-W g  extended commands
584     case 'g':
585     case Ctrl_G:
586 		CHECK_CMDWIN;
587 #ifdef USE_ON_FLY_SCROLL
588 		dont_scroll = TRUE;		// disallow scrolling here
589 #endif
590 		++no_mapping;
591 		++allow_keys;   // no mapping for xchar, but allow key codes
592 		if (xchar == NUL)
593 		    xchar = plain_vgetc();
594 		LANGMAP_ADJUST(xchar, TRUE);
595 		--no_mapping;
596 		--allow_keys;
597 #ifdef FEAT_CMDL_INFO
598 		(void)add_to_showcmd(xchar);
599 #endif
600 		switch (xchar)
601 		{
602 #if defined(FEAT_QUICKFIX)
603 		    case '}':
604 			xchar = Ctrl_RSB;
605 			if (Prenum)
606 			    g_do_tagpreview = Prenum;
607 			else
608 			    g_do_tagpreview = p_pvh;
609 #endif
610 			// FALLTHROUGH
611 		    case ']':
612 		    case Ctrl_RSB:
613 			// keep Visual mode, can select words to use as a tag
614 			if (Prenum)
615 			    postponed_split = Prenum;
616 			else
617 			    postponed_split = -1;
618 
619 			// Execute the command right here, required when
620 			// "wincmd g}" was used in a function.
621 			do_nv_ident('g', xchar);
622 			break;
623 
624 #ifdef FEAT_SEARCHPATH
625 		    case 'f':	    // CTRL-W gf: "gf" in a new tab page
626 		    case 'F':	    // CTRL-W gF: "gF" in a new tab page
627 			cmdmod.cmod_tab = tabpage_index(curtab) + 1;
628 			nchar = xchar;
629 			goto wingotofile;
630 #endif
631 		    case 't':	    // CTRL-W gt: go to next tab page
632 			goto_tabpage((int)Prenum);
633 			break;
634 
635 		    case 'T':	    // CTRL-W gT: go to previous tab page
636 			goto_tabpage(-(int)Prenum1);
637 			break;
638 
639 		    case TAB:	    // CTRL-W g<Tab>: go to last used tab page
640 			if (goto_tabpage_lastused() == FAIL)
641 			    beep_flush();
642 			break;
643 
644 		    default:
645 			beep_flush();
646 			break;
647 		}
648 		break;
649 
650     default:	beep_flush();
651 		break;
652     }
653 }
654 
655 /*
656  * Figure out the address type for ":wincmd".
657  */
658     void
659 get_wincmd_addr_type(char_u *arg, exarg_T *eap)
660 {
661     switch (*arg)
662     {
663     case 'S':
664     case Ctrl_S:
665     case 's':
666     case Ctrl_N:
667     case 'n':
668     case 'j':
669     case Ctrl_J:
670     case 'k':
671     case Ctrl_K:
672     case 'T':
673     case Ctrl_R:
674     case 'r':
675     case 'R':
676     case 'K':
677     case 'J':
678     case '+':
679     case '-':
680     case Ctrl__:
681     case '_':
682     case '|':
683     case ']':
684     case Ctrl_RSB:
685     case 'g':
686     case Ctrl_G:
687     case Ctrl_V:
688     case 'v':
689     case 'h':
690     case Ctrl_H:
691     case 'l':
692     case Ctrl_L:
693     case 'H':
694     case 'L':
695     case '>':
696     case '<':
697 #if defined(FEAT_QUICKFIX)
698     case '}':
699 #endif
700 #ifdef FEAT_SEARCHPATH
701     case 'f':
702     case 'F':
703     case Ctrl_F:
704 #endif
705 #ifdef FEAT_FIND_ID
706     case 'i':
707     case Ctrl_I:
708     case 'd':
709     case Ctrl_D:
710 #endif
711 		// window size or any count
712 		eap->addr_type = ADDR_OTHER;
713 		break;
714 
715     case Ctrl_HAT:
716     case '^':
717 		// buffer number
718 		eap->addr_type = ADDR_BUFFERS;
719 		break;
720 
721     case Ctrl_Q:
722     case 'q':
723     case Ctrl_C:
724     case 'c':
725     case Ctrl_O:
726     case 'o':
727     case Ctrl_W:
728     case 'w':
729     case 'W':
730     case 'x':
731     case Ctrl_X:
732 		// window number
733 		eap->addr_type = ADDR_WINDOWS;
734 		break;
735 
736 #if defined(FEAT_QUICKFIX)
737     case Ctrl_Z:
738     case 'z':
739     case 'P':
740 #endif
741     case 't':
742     case Ctrl_T:
743     case 'b':
744     case Ctrl_B:
745     case 'p':
746     case Ctrl_P:
747     case '=':
748     case CAR:
749 		// no count
750 		eap->addr_type = ADDR_NONE;
751 		break;
752     }
753 }
754 
755     static void
756 cmd_with_count(
757     char	*cmd,
758     char_u	*bufp,
759     size_t	bufsize,
760     long	Prenum)
761 {
762     if (Prenum > 0)
763 	vim_snprintf((char *)bufp, bufsize, "%s %ld", cmd, Prenum);
764     else
765 	STRCPY(bufp, cmd);
766 }
767 
768 /*
769  * If "split_disallowed" is set given an error and return FAIL.
770  * Otherwise return OK.
771  */
772     static int
773 check_split_disallowed()
774 {
775     if (split_disallowed > 0)
776     {
777 	emsg(_("E242: Can't split a window while closing another"));
778 	return FAIL;
779     }
780     if (curwin->w_buffer->b_locked_split)
781     {
782 	emsg(_(e_cannot_split_window_when_closing_buffer));
783 	return FAIL;
784     }
785     return OK;
786 }
787 
788 /*
789  * split the current window, implements CTRL-W s and :split
790  *
791  * "size" is the height or width for the new window, 0 to use half of current
792  * height or width.
793  *
794  * "flags":
795  * WSP_ROOM: require enough room for new window
796  * WSP_VERT: vertical split.
797  * WSP_TOP:  open window at the top-left of the shell (help window).
798  * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
799  * WSP_HELP: creating the help window, keep layout snapshot
800  *
801  * return FAIL for failure, OK otherwise
802  */
803     int
804 win_split(int size, int flags)
805 {
806     if (ERROR_IF_ANY_POPUP_WINDOW)
807 	return FAIL;
808 
809     if (check_split_disallowed() == FAIL)
810 	return FAIL;
811 
812     // When the ":tab" modifier was used open a new tab page instead.
813     if (may_open_tabpage() == OK)
814 	return OK;
815 
816     // Add flags from ":vertical", ":topleft" and ":botright".
817     flags |= cmdmod.cmod_split;
818     if ((flags & WSP_TOP) && (flags & WSP_BOT))
819     {
820 	emsg(_("E442: Can't split topleft and botright at the same time"));
821 	return FAIL;
822     }
823 
824     // When creating the help window make a snapshot of the window layout.
825     // Otherwise clear the snapshot, it's now invalid.
826     if (flags & WSP_HELP)
827 	make_snapshot(SNAP_HELP_IDX);
828     else
829 	clear_snapshot(curtab, SNAP_HELP_IDX);
830 
831     return win_split_ins(size, flags, NULL, 0);
832 }
833 
834 /*
835  * When "new_wp" is NULL: split the current window in two.
836  * When "new_wp" is not NULL: insert this window at the far
837  * top/left/right/bottom.
838  * return FAIL for failure, OK otherwise
839  */
840     int
841 win_split_ins(
842     int		size,
843     int		flags,
844     win_T	*new_wp,
845     int		dir)
846 {
847     win_T	*wp = new_wp;
848     win_T	*oldwin;
849     int		new_size = size;
850     int		i;
851     int		need_status = 0;
852     int		do_equal = FALSE;
853     int		needed;
854     int		available;
855     int		oldwin_height = 0;
856     int		layout;
857     frame_T	*frp, *curfrp, *frp2, *prevfrp;
858     int		before;
859     int		minheight;
860     int		wmh1;
861     int		did_set_fraction = FALSE;
862 
863     if (flags & WSP_TOP)
864 	oldwin = firstwin;
865     else if (flags & WSP_BOT)
866 	oldwin = lastwin;
867     else
868 	oldwin = curwin;
869 
870     // add a status line when p_ls == 1 and splitting the first window
871     if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
872     {
873 	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
874 	{
875 	    emsg(_(e_not_enough_room));
876 	    return FAIL;
877 	}
878 	need_status = STATUS_HEIGHT;
879     }
880 
881 #ifdef FEAT_GUI
882     // May be needed for the scrollbars that are going to change.
883     if (gui.in_use)
884 	out_flush();
885 #endif
886 
887     if (flags & WSP_VERT)
888     {
889 	int	wmw1;
890 	int	minwidth;
891 
892 	layout = FR_ROW;
893 
894 	/*
895 	 * Check if we are able to split the current window and compute its
896 	 * width.
897 	 */
898 	// Current window requires at least 1 space.
899 	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
900 	needed = wmw1 + 1;
901 	if (flags & WSP_ROOM)
902 	    needed += p_wiw - wmw1;
903 	if (flags & (WSP_BOT | WSP_TOP))
904 	{
905 	    minwidth = frame_minwidth(topframe, NOWIN);
906 	    available = topframe->fr_width;
907 	    needed += minwidth;
908 	}
909 	else if (p_ea)
910 	{
911 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
912 	    prevfrp = oldwin->w_frame;
913 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
914 							frp = frp->fr_parent)
915 	    {
916 		if (frp->fr_layout == FR_ROW)
917 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
918 			if (frp2 != prevfrp)
919 			    minwidth += frame_minwidth(frp2, NOWIN);
920 		prevfrp = frp;
921 	    }
922 	    available = topframe->fr_width;
923 	    needed += minwidth;
924 	}
925 	else
926 	{
927 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
928 	    available = oldwin->w_frame->fr_width;
929 	    needed += minwidth;
930 	}
931 	if (available < needed && new_wp == NULL)
932 	{
933 	    emsg(_(e_not_enough_room));
934 	    return FAIL;
935 	}
936 	if (new_size == 0)
937 	    new_size = oldwin->w_width / 2;
938 	if (new_size > available - minwidth - 1)
939 	    new_size = available - minwidth - 1;
940 	if (new_size < wmw1)
941 	    new_size = wmw1;
942 
943 	// if it doesn't fit in the current window, need win_equal()
944 	if (oldwin->w_width - new_size - 1 < p_wmw)
945 	    do_equal = TRUE;
946 
947 	// We don't like to take lines for the new window from a
948 	// 'winfixwidth' window.  Take them from a window to the left or right
949 	// instead, if possible. Add one for the separator.
950 	if (oldwin->w_p_wfw)
951 	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
952 
953 	// Only make all windows the same width if one of them (except oldwin)
954 	// is wider than one of the split windows.
955 	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
956 					 && oldwin->w_frame->fr_parent != NULL)
957 	{
958 	    frp = oldwin->w_frame->fr_parent->fr_child;
959 	    while (frp != NULL)
960 	    {
961 		if (frp->fr_win != oldwin && frp->fr_win != NULL
962 			&& (frp->fr_win->w_width > new_size
963 			    || frp->fr_win->w_width > oldwin->w_width
964 							      - new_size - 1))
965 		{
966 		    do_equal = TRUE;
967 		    break;
968 		}
969 		frp = frp->fr_next;
970 	    }
971 	}
972     }
973     else
974     {
975 	layout = FR_COL;
976 
977 	/*
978 	 * Check if we are able to split the current window and compute its
979 	 * height.
980 	 */
981 	// Current window requires at least 1 space.
982 	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
983 	needed = wmh1 + STATUS_HEIGHT;
984 	if (flags & WSP_ROOM)
985 	    needed += p_wh - wmh1;
986 	if (flags & (WSP_BOT | WSP_TOP))
987 	{
988 	    minheight = frame_minheight(topframe, NOWIN) + need_status;
989 	    available = topframe->fr_height;
990 	    needed += minheight;
991 	}
992 	else if (p_ea)
993 	{
994 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
995 	    prevfrp = oldwin->w_frame;
996 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
997 							frp = frp->fr_parent)
998 	    {
999 		if (frp->fr_layout == FR_COL)
1000 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
1001 			if (frp2 != prevfrp)
1002 			    minheight += frame_minheight(frp2, NOWIN);
1003 		prevfrp = frp;
1004 	    }
1005 	    available = topframe->fr_height;
1006 	    needed += minheight;
1007 	}
1008 	else
1009 	{
1010 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
1011 	    available = oldwin->w_frame->fr_height;
1012 	    needed += minheight;
1013 	}
1014 	if (available < needed && new_wp == NULL)
1015 	{
1016 	    emsg(_(e_not_enough_room));
1017 	    return FAIL;
1018 	}
1019 	oldwin_height = oldwin->w_height;
1020 	if (need_status)
1021 	{
1022 	    oldwin->w_status_height = STATUS_HEIGHT;
1023 	    oldwin_height -= STATUS_HEIGHT;
1024 	}
1025 	if (new_size == 0)
1026 	    new_size = oldwin_height / 2;
1027 	if (new_size > available - minheight - STATUS_HEIGHT)
1028 	    new_size = available - minheight - STATUS_HEIGHT;
1029 	if (new_size < wmh1)
1030 	    new_size = wmh1;
1031 
1032 	// if it doesn't fit in the current window, need win_equal()
1033 	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
1034 	    do_equal = TRUE;
1035 
1036 	// We don't like to take lines for the new window from a
1037 	// 'winfixheight' window.  Take them from a window above or below
1038 	// instead, if possible.
1039 	if (oldwin->w_p_wfh)
1040 	{
1041 	    // Set w_fraction now so that the cursor keeps the same relative
1042 	    // vertical position using the old height.
1043 	    set_fraction(oldwin);
1044 	    did_set_fraction = TRUE;
1045 
1046 	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
1047 								      oldwin);
1048 	    oldwin_height = oldwin->w_height;
1049 	    if (need_status)
1050 		oldwin_height -= STATUS_HEIGHT;
1051 	}
1052 
1053 	// Only make all windows the same height if one of them (except oldwin)
1054 	// is higher than one of the split windows.
1055 	if (!do_equal && p_ea && size == 0 && *p_ead != 'h'
1056 	   && oldwin->w_frame->fr_parent != NULL)
1057 	{
1058 	    frp = oldwin->w_frame->fr_parent->fr_child;
1059 	    while (frp != NULL)
1060 	    {
1061 		if (frp->fr_win != oldwin && frp->fr_win != NULL
1062 			&& (frp->fr_win->w_height > new_size
1063 			    || frp->fr_win->w_height > oldwin_height - new_size
1064 							      - STATUS_HEIGHT))
1065 		{
1066 		    do_equal = TRUE;
1067 		    break;
1068 		}
1069 		frp = frp->fr_next;
1070 	    }
1071 	}
1072     }
1073 
1074     /*
1075      * allocate new window structure and link it in the window list
1076      */
1077     if ((flags & WSP_TOP) == 0
1078 	    && ((flags & WSP_BOT)
1079 		|| (flags & WSP_BELOW)
1080 		|| (!(flags & WSP_ABOVE)
1081 		    && ( (flags & WSP_VERT) ? p_spr : p_sb))))
1082     {
1083 	// new window below/right of current one
1084 	if (new_wp == NULL)
1085 	    wp = win_alloc(oldwin, FALSE);
1086 	else
1087 	    win_append(oldwin, wp);
1088     }
1089     else
1090     {
1091 	if (new_wp == NULL)
1092 	    wp = win_alloc(oldwin->w_prev, FALSE);
1093 	else
1094 	    win_append(oldwin->w_prev, wp);
1095     }
1096 
1097     if (new_wp == NULL)
1098     {
1099 	if (wp == NULL)
1100 	    return FAIL;
1101 
1102 	new_frame(wp);
1103 	if (wp->w_frame == NULL)
1104 	{
1105 	    win_free(wp, NULL);
1106 	    return FAIL;
1107 	}
1108 
1109 	// make the contents of the new window the same as the current one
1110 	win_init(wp, curwin, flags);
1111     }
1112 
1113     /*
1114      * Reorganise the tree of frames to insert the new window.
1115      */
1116     if (flags & (WSP_TOP | WSP_BOT))
1117     {
1118 	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
1119 	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
1120 	{
1121 	    curfrp = topframe->fr_child;
1122 	    if (flags & WSP_BOT)
1123 		while (curfrp->fr_next != NULL)
1124 		    curfrp = curfrp->fr_next;
1125 	}
1126 	else
1127 	    curfrp = topframe;
1128 	before = (flags & WSP_TOP);
1129     }
1130     else
1131     {
1132 	curfrp = oldwin->w_frame;
1133 	if (flags & WSP_BELOW)
1134 	    before = FALSE;
1135 	else if (flags & WSP_ABOVE)
1136 	    before = TRUE;
1137 	else if (flags & WSP_VERT)
1138 	    before = !p_spr;
1139 	else
1140 	    before = !p_sb;
1141     }
1142     if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
1143     {
1144 	// Need to create a new frame in the tree to make a branch.
1145 	frp = ALLOC_CLEAR_ONE(frame_T);
1146 	*frp = *curfrp;
1147 	curfrp->fr_layout = layout;
1148 	frp->fr_parent = curfrp;
1149 	frp->fr_next = NULL;
1150 	frp->fr_prev = NULL;
1151 	curfrp->fr_child = frp;
1152 	curfrp->fr_win = NULL;
1153 	curfrp = frp;
1154 	if (frp->fr_win != NULL)
1155 	    oldwin->w_frame = frp;
1156 	else
1157 	    FOR_ALL_FRAMES(frp, frp->fr_child)
1158 		frp->fr_parent = curfrp;
1159     }
1160 
1161     if (new_wp == NULL)
1162 	frp = wp->w_frame;
1163     else
1164 	frp = new_wp->w_frame;
1165     frp->fr_parent = curfrp->fr_parent;
1166 
1167     // Insert the new frame at the right place in the frame list.
1168     if (before)
1169 	frame_insert(curfrp, frp);
1170     else
1171 	frame_append(curfrp, frp);
1172 
1173     // Set w_fraction now so that the cursor keeps the same relative
1174     // vertical position.
1175     if (!did_set_fraction)
1176 	set_fraction(oldwin);
1177     wp->w_fraction = oldwin->w_fraction;
1178 
1179     if (flags & WSP_VERT)
1180     {
1181 	wp->w_p_scr = curwin->w_p_scr;
1182 
1183 	if (need_status)
1184 	{
1185 	    win_new_height(oldwin, oldwin->w_height - 1);
1186 	    oldwin->w_status_height = need_status;
1187 	}
1188 	if (flags & (WSP_TOP | WSP_BOT))
1189 	{
1190 	    // set height and row of new window to full height
1191 	    wp->w_winrow = tabline_height();
1192 	    win_new_height(wp, curfrp->fr_height - (p_ls > 0)
1193 							  - WINBAR_HEIGHT(wp));
1194 	    wp->w_status_height = (p_ls > 0);
1195 	}
1196 	else
1197 	{
1198 	    // height and row of new window is same as current window
1199 	    wp->w_winrow = oldwin->w_winrow;
1200 	    win_new_height(wp, VISIBLE_HEIGHT(oldwin));
1201 	    wp->w_status_height = oldwin->w_status_height;
1202 	}
1203 	frp->fr_height = curfrp->fr_height;
1204 
1205 	// "new_size" of the current window goes to the new window, use
1206 	// one column for the vertical separator
1207 	win_new_width(wp, new_size);
1208 	if (before)
1209 	    wp->w_vsep_width = 1;
1210 	else
1211 	{
1212 	    wp->w_vsep_width = oldwin->w_vsep_width;
1213 	    oldwin->w_vsep_width = 1;
1214 	}
1215 	if (flags & (WSP_TOP | WSP_BOT))
1216 	{
1217 	    if (flags & WSP_BOT)
1218 		frame_add_vsep(curfrp);
1219 	    // Set width of neighbor frame
1220 	    frame_new_width(curfrp, curfrp->fr_width
1221 		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
1222 								       FALSE);
1223 	}
1224 	else
1225 	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
1226 	if (before)	// new window left of current one
1227 	{
1228 	    wp->w_wincol = oldwin->w_wincol;
1229 	    oldwin->w_wincol += new_size + 1;
1230 	}
1231 	else		// new window right of current one
1232 	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
1233 	frame_fix_width(oldwin);
1234 	frame_fix_width(wp);
1235     }
1236     else
1237     {
1238 	// width and column of new window is same as current window
1239 	if (flags & (WSP_TOP | WSP_BOT))
1240 	{
1241 	    wp->w_wincol = 0;
1242 	    win_new_width(wp, Columns);
1243 	    wp->w_vsep_width = 0;
1244 	}
1245 	else
1246 	{
1247 	    wp->w_wincol = oldwin->w_wincol;
1248 	    win_new_width(wp, oldwin->w_width);
1249 	    wp->w_vsep_width = oldwin->w_vsep_width;
1250 	}
1251 	frp->fr_width = curfrp->fr_width;
1252 
1253 	// "new_size" of the current window goes to the new window, use
1254 	// one row for the status line
1255 	win_new_height(wp, new_size);
1256 	if (flags & (WSP_TOP | WSP_BOT))
1257 	{
1258 	    int new_fr_height = curfrp->fr_height - new_size
1259 							  + WINBAR_HEIGHT(wp) ;
1260 
1261 	    if (!((flags & WSP_BOT) && p_ls == 0))
1262 		new_fr_height -= STATUS_HEIGHT;
1263 	    frame_new_height(curfrp, new_fr_height, flags & WSP_TOP, FALSE);
1264 	}
1265 	else
1266 	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
1267 	if (before)	// new window above current one
1268 	{
1269 	    wp->w_winrow = oldwin->w_winrow;
1270 	    wp->w_status_height = STATUS_HEIGHT;
1271 	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
1272 	}
1273 	else		// new window below current one
1274 	{
1275 	    wp->w_winrow = oldwin->w_winrow + VISIBLE_HEIGHT(oldwin)
1276 							       + STATUS_HEIGHT;
1277 	    wp->w_status_height = oldwin->w_status_height;
1278 	    if (!(flags & WSP_BOT))
1279 		oldwin->w_status_height = STATUS_HEIGHT;
1280 	}
1281 	if (flags & WSP_BOT)
1282 	    frame_add_statusline(curfrp);
1283 	frame_fix_height(wp);
1284 	frame_fix_height(oldwin);
1285     }
1286 
1287     if (flags & (WSP_TOP | WSP_BOT))
1288 	(void)win_comp_pos();
1289 
1290      // Both windows need redrawing.  Update all status lines, in case they
1291      // show something related to the window count or position.
1292     redraw_win_later(wp, NOT_VALID);
1293     redraw_win_later(oldwin, NOT_VALID);
1294     status_redraw_all();
1295 
1296     if (need_status)
1297     {
1298 	msg_row = Rows - 1;
1299 	msg_col = sc_col;
1300 	msg_clr_eos_force();	// Old command/ruler may still be there
1301 	comp_col();
1302 	msg_row = Rows - 1;
1303 	msg_col = 0;	// put position back at start of line
1304     }
1305 
1306     /*
1307      * equalize the window sizes.
1308      */
1309     if (do_equal || dir != 0)
1310 	win_equal(wp, TRUE,
1311 		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
1312 		: dir == 'h' ? 'b' : 'v');
1313 
1314     // Don't change the window height/width to 'winheight' / 'winwidth' if a
1315     // size was given.
1316     if (flags & WSP_VERT)
1317     {
1318 	i = p_wiw;
1319 	if (size != 0)
1320 	    p_wiw = size;
1321 
1322 # ifdef FEAT_GUI
1323 	// When 'guioptions' includes 'L' or 'R' may have to add scrollbars.
1324 	if (gui.in_use)
1325 	    gui_init_which_components(NULL);
1326 # endif
1327     }
1328     else
1329     {
1330 	i = p_wh;
1331 	if (size != 0)
1332 	    p_wh = size;
1333     }
1334 
1335 #ifdef FEAT_JUMPLIST
1336     // Keep same changelist position in new window.
1337     wp->w_changelistidx = oldwin->w_changelistidx;
1338 #endif
1339 
1340     /*
1341      * make the new window the current window
1342      */
1343     (void)win_enter_ext(wp, WEE_TRIGGER_NEW_AUTOCMDS
1344 		    | WEE_TRIGGER_ENTER_AUTOCMDS | WEE_TRIGGER_LEAVE_AUTOCMDS);
1345     if (flags & WSP_VERT)
1346 	p_wiw = i;
1347     else
1348 	p_wh = i;
1349 
1350     return OK;
1351 }
1352 
1353 
1354 /*
1355  * Initialize window "newp" from window "oldp".
1356  * Used when splitting a window and when creating a new tab page.
1357  * The windows will both edit the same buffer.
1358  * WSP_NEWLOC may be specified in flags to prevent the location list from
1359  * being copied.
1360  */
1361     static void
1362 win_init(win_T *newp, win_T *oldp, int flags UNUSED)
1363 {
1364     int		i;
1365 
1366     newp->w_buffer = oldp->w_buffer;
1367 #ifdef FEAT_SYN_HL
1368     newp->w_s = &(oldp->w_buffer->b_s);
1369 #endif
1370     oldp->w_buffer->b_nwindows++;
1371     newp->w_cursor = oldp->w_cursor;
1372     newp->w_valid = 0;
1373     newp->w_curswant = oldp->w_curswant;
1374     newp->w_set_curswant = oldp->w_set_curswant;
1375     newp->w_topline = oldp->w_topline;
1376 #ifdef FEAT_DIFF
1377     newp->w_topfill = oldp->w_topfill;
1378 #endif
1379     newp->w_leftcol = oldp->w_leftcol;
1380     newp->w_pcmark = oldp->w_pcmark;
1381     newp->w_prev_pcmark = oldp->w_prev_pcmark;
1382     newp->w_alt_fnum = oldp->w_alt_fnum;
1383     newp->w_wrow = oldp->w_wrow;
1384     newp->w_fraction = oldp->w_fraction;
1385     newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
1386 #ifdef FEAT_JUMPLIST
1387     copy_jumplist(oldp, newp);
1388 #endif
1389 #ifdef FEAT_QUICKFIX
1390     if (flags & WSP_NEWLOC)
1391     {
1392 	// Don't copy the location list.
1393 	newp->w_llist = NULL;
1394 	newp->w_llist_ref = NULL;
1395     }
1396     else
1397 	copy_loclist_stack(oldp, newp);
1398 #endif
1399     newp->w_localdir = (oldp->w_localdir == NULL)
1400 				    ? NULL : vim_strsave(oldp->w_localdir);
1401     newp->w_prevdir = (oldp->w_prevdir == NULL)
1402 				    ? NULL : vim_strsave(oldp->w_prevdir);
1403 
1404     // copy tagstack and folds
1405     for (i = 0; i < oldp->w_tagstacklen; i++)
1406     {
1407 	taggy_T	*tag = &newp->w_tagstack[i];
1408 	*tag = oldp->w_tagstack[i];
1409 	if (tag->tagname != NULL)
1410 	    tag->tagname = vim_strsave(tag->tagname);
1411 	if (tag->user_data != NULL)
1412 	    tag->user_data = vim_strsave(tag->user_data);
1413     }
1414     newp->w_tagstackidx = oldp->w_tagstackidx;
1415     newp->w_tagstacklen = oldp->w_tagstacklen;
1416 #ifdef FEAT_FOLDING
1417     copyFoldingState(oldp, newp);
1418 #endif
1419 
1420     win_init_some(newp, oldp);
1421 
1422 #ifdef FEAT_SYN_HL
1423     check_colorcolumn(newp);
1424 #endif
1425 }
1426 
1427 /*
1428  * Initialize window "newp" from window "old".
1429  * Only the essential things are copied.
1430  */
1431     static void
1432 win_init_some(win_T *newp, win_T *oldp)
1433 {
1434     // Use the same argument list.
1435     newp->w_alist = oldp->w_alist;
1436     ++newp->w_alist->al_refcount;
1437     newp->w_arg_idx = oldp->w_arg_idx;
1438 
1439     // copy options from existing window
1440     win_copy_options(oldp, newp);
1441 }
1442 
1443 /*
1444  * Return TRUE if "win" is a global popup or a popup in the current tab page.
1445  */
1446     int
1447 win_valid_popup(win_T *win UNUSED)
1448 {
1449 #ifdef FEAT_PROP_POPUP
1450     win_T	*wp;
1451 
1452     FOR_ALL_POPUPWINS(wp)
1453 	if (wp == win)
1454 	    return TRUE;
1455     FOR_ALL_POPUPWINS_IN_TAB(curtab, wp)
1456 	if (wp == win)
1457 	    return TRUE;
1458 #endif
1459     return FALSE;
1460 }
1461 
1462 /*
1463  * Check if "win" is a pointer to an existing window in the current tab page.
1464  */
1465     int
1466 win_valid(win_T *win)
1467 {
1468     win_T	*wp;
1469 
1470     if (win == NULL)
1471 	return FALSE;
1472     FOR_ALL_WINDOWS(wp)
1473 	if (wp == win)
1474 	    return TRUE;
1475     return win_valid_popup(win);
1476 }
1477 
1478 /*
1479  * Find window "id" in the current tab page.
1480  * Also find popup windows.
1481  * Return NULL if not found.
1482  */
1483     win_T *
1484 win_find_by_id(int id)
1485 {
1486     win_T   *wp;
1487 
1488     FOR_ALL_WINDOWS(wp)
1489 	if (wp->w_id == id)
1490 	    return wp;
1491 #ifdef FEAT_PROP_POPUP
1492     FOR_ALL_POPUPWINS(wp)
1493 	if (wp->w_id == id)
1494 	    return wp;
1495     FOR_ALL_POPUPWINS_IN_TAB(curtab, wp)
1496 	if (wp->w_id == id)
1497 	    return wp;
1498 #endif
1499     return NULL;
1500 }
1501 
1502 /*
1503  * Check if "win" is a pointer to an existing window in any tab page.
1504  */
1505     int
1506 win_valid_any_tab(win_T *win)
1507 {
1508     win_T	*wp;
1509     tabpage_T	*tp;
1510 
1511     if (win == NULL)
1512 	return FALSE;
1513     FOR_ALL_TABPAGES(tp)
1514     {
1515 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
1516 	{
1517 	    if (wp == win)
1518 		return TRUE;
1519 	}
1520 #ifdef FEAT_PROP_POPUP
1521 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
1522 	    if (wp == win)
1523 		return TRUE;
1524 #endif
1525     }
1526     return win_valid_popup(win);
1527 }
1528 
1529 /*
1530  * Return the number of windows.
1531  */
1532     int
1533 win_count(void)
1534 {
1535     win_T	*wp;
1536     int		count = 0;
1537 
1538     FOR_ALL_WINDOWS(wp)
1539 	++count;
1540     return count;
1541 }
1542 
1543 /*
1544  * Make "count" windows on the screen.
1545  * Return actual number of windows on the screen.
1546  * Must be called when there is just one window, filling the whole screen
1547  * (excluding the command line).
1548  */
1549     int
1550 make_windows(
1551     int		count,
1552     int		vertical UNUSED)  // split windows vertically if TRUE
1553 {
1554     int		maxcount;
1555     int		todo;
1556 
1557     if (vertical)
1558     {
1559 	// Each windows needs at least 'winminwidth' lines and a separator
1560 	// column.
1561 	maxcount = (curwin->w_width + curwin->w_vsep_width
1562 					     - (p_wiw - p_wmw)) / (p_wmw + 1);
1563     }
1564     else
1565     {
1566 	// Each window needs at least 'winminheight' lines and a status line.
1567 	maxcount = (VISIBLE_HEIGHT(curwin) + curwin->w_status_height
1568 				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
1569     }
1570 
1571     if (maxcount < 2)
1572 	maxcount = 2;
1573     if (count > maxcount)
1574 	count = maxcount;
1575 
1576     /*
1577      * add status line now, otherwise first window will be too big
1578      */
1579     if (count > 1)
1580 	last_status(TRUE);
1581 
1582     /*
1583      * Don't execute autocommands while creating the windows.  Must do that
1584      * when putting the buffers in the windows.
1585      */
1586     block_autocmds();
1587 
1588     // todo is number of windows left to create
1589     for (todo = count - 1; todo > 0; --todo)
1590 	if (vertical)
1591 	{
1592 	    if (win_split(curwin->w_width - (curwin->w_width - todo)
1593 			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
1594 		break;
1595 	}
1596 	else
1597 	{
1598 	    if (win_split(curwin->w_height - (curwin->w_height - todo
1599 			    * STATUS_HEIGHT) / (todo + 1)
1600 			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
1601 		break;
1602 	}
1603 
1604     unblock_autocmds();
1605 
1606     // return actual number of windows
1607     return (count - todo);
1608 }
1609 
1610 /*
1611  * Exchange current and next window
1612  */
1613     static void
1614 win_exchange(long Prenum)
1615 {
1616     frame_T	*frp;
1617     frame_T	*frp2;
1618     win_T	*wp;
1619     win_T	*wp2;
1620     int		temp;
1621 
1622     if (ERROR_IF_ANY_POPUP_WINDOW)
1623 	return;
1624     if (ONE_WINDOW)	    // just one window
1625     {
1626 	beep_flush();
1627 	return;
1628     }
1629 
1630 #ifdef FEAT_GUI
1631     need_mouse_correct = TRUE;
1632 #endif
1633 
1634     /*
1635      * find window to exchange with
1636      */
1637     if (Prenum)
1638     {
1639 	frp = curwin->w_frame->fr_parent->fr_child;
1640 	while (frp != NULL && --Prenum > 0)
1641 	    frp = frp->fr_next;
1642     }
1643     else if (curwin->w_frame->fr_next != NULL)	// Swap with next
1644 	frp = curwin->w_frame->fr_next;
1645     else    // Swap last window in row/col with previous
1646 	frp = curwin->w_frame->fr_prev;
1647 
1648     // We can only exchange a window with another window, not with a frame
1649     // containing windows.
1650     if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
1651 	return;
1652     wp = frp->fr_win;
1653 
1654 /*
1655  * 1. remove curwin from the list. Remember after which window it was in wp2
1656  * 2. insert curwin before wp in the list
1657  * if wp != wp2
1658  *    3. remove wp from the list
1659  *    4. insert wp after wp2
1660  * 5. exchange the status line height and vsep width.
1661  */
1662     wp2 = curwin->w_prev;
1663     frp2 = curwin->w_frame->fr_prev;
1664     if (wp->w_prev != curwin)
1665     {
1666 	win_remove(curwin, NULL);
1667 	frame_remove(curwin->w_frame);
1668 	win_append(wp->w_prev, curwin);
1669 	frame_insert(frp, curwin->w_frame);
1670     }
1671     if (wp != wp2)
1672     {
1673 	win_remove(wp, NULL);
1674 	frame_remove(wp->w_frame);
1675 	win_append(wp2, wp);
1676 	if (frp2 == NULL)
1677 	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
1678 	else
1679 	    frame_append(frp2, wp->w_frame);
1680     }
1681     temp = curwin->w_status_height;
1682     curwin->w_status_height = wp->w_status_height;
1683     wp->w_status_height = temp;
1684     temp = curwin->w_vsep_width;
1685     curwin->w_vsep_width = wp->w_vsep_width;
1686     wp->w_vsep_width = temp;
1687 
1688     frame_fix_height(curwin);
1689     frame_fix_height(wp);
1690     frame_fix_width(curwin);
1691     frame_fix_width(wp);
1692 
1693     (void)win_comp_pos();		// recompute window positions
1694 
1695     win_enter(wp, TRUE);
1696     redraw_all_later(NOT_VALID);
1697 }
1698 
1699 /*
1700  * rotate windows: if upwards TRUE the second window becomes the first one
1701  *		   if upwards FALSE the first window becomes the second one
1702  */
1703     static void
1704 win_rotate(int upwards, int count)
1705 {
1706     win_T	*wp1;
1707     win_T	*wp2;
1708     frame_T	*frp;
1709     int		n;
1710 
1711     if (ONE_WINDOW)		// nothing to do
1712     {
1713 	beep_flush();
1714 	return;
1715     }
1716 
1717 #ifdef FEAT_GUI
1718     need_mouse_correct = TRUE;
1719 #endif
1720 
1721     // Check if all frames in this row/col have one window.
1722     FOR_ALL_FRAMES(frp, curwin->w_frame->fr_parent->fr_child)
1723 	if (frp->fr_win == NULL)
1724 	{
1725 	    emsg(_("E443: Cannot rotate when another window is split"));
1726 	    return;
1727 	}
1728 
1729     while (count--)
1730     {
1731 	if (upwards)		// first window becomes last window
1732 	{
1733 	    // remove first window/frame from the list
1734 	    frp = curwin->w_frame->fr_parent->fr_child;
1735 	    wp1 = frp->fr_win;
1736 	    win_remove(wp1, NULL);
1737 	    frame_remove(frp);
1738 
1739 	    // find last frame and append removed window/frame after it
1740 	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
1741 		;
1742 	    win_append(frp->fr_win, wp1);
1743 	    frame_append(frp, wp1->w_frame);
1744 
1745 	    wp2 = frp->fr_win;		// previously last window
1746 	}
1747 	else			// last window becomes first window
1748 	{
1749 	    // find last window/frame in the list and remove it
1750 	    for (frp = curwin->w_frame; frp->fr_next != NULL;
1751 							   frp = frp->fr_next)
1752 		;
1753 	    wp1 = frp->fr_win;
1754 	    wp2 = wp1->w_prev;		    // will become last window
1755 	    win_remove(wp1, NULL);
1756 	    frame_remove(frp);
1757 
1758 	    // append the removed window/frame before the first in the list
1759 	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
1760 	    frame_insert(frp->fr_parent->fr_child, frp);
1761 	}
1762 
1763 	// exchange status height and vsep width of old and new last window
1764 	n = wp2->w_status_height;
1765 	wp2->w_status_height = wp1->w_status_height;
1766 	wp1->w_status_height = n;
1767 	frame_fix_height(wp1);
1768 	frame_fix_height(wp2);
1769 	n = wp2->w_vsep_width;
1770 	wp2->w_vsep_width = wp1->w_vsep_width;
1771 	wp1->w_vsep_width = n;
1772 	frame_fix_width(wp1);
1773 	frame_fix_width(wp2);
1774 
1775 	// recompute w_winrow and w_wincol for all windows
1776 	(void)win_comp_pos();
1777     }
1778 
1779     redraw_all_later(NOT_VALID);
1780 }
1781 
1782 /*
1783  * Move the current window to the very top/bottom/left/right of the screen.
1784  */
1785     static void
1786 win_totop(int size, int flags)
1787 {
1788     int		dir;
1789     int		height = curwin->w_height;
1790 
1791     if (ONE_WINDOW)
1792     {
1793 	beep_flush();
1794 	return;
1795     }
1796     if (check_split_disallowed() == FAIL)
1797 	return;
1798 
1799     // Remove the window and frame from the tree of frames.
1800     (void)winframe_remove(curwin, &dir, NULL);
1801     win_remove(curwin, NULL);
1802     last_status(FALSE);	    // may need to remove last status line
1803     (void)win_comp_pos();   // recompute window positions
1804 
1805     // Split a window on the desired side and put the window there.
1806     (void)win_split_ins(size, flags, curwin, dir);
1807     if (!(flags & WSP_VERT))
1808     {
1809 	win_setheight(height);
1810 	if (p_ea)
1811 	    win_equal(curwin, TRUE, 'v');
1812     }
1813 
1814 #if defined(FEAT_GUI)
1815     // When 'guioptions' includes 'L' or 'R' may have to remove or add
1816     // scrollbars.  Have to update them anyway.
1817     gui_may_update_scrollbars();
1818 #endif
1819 }
1820 
1821 /*
1822  * Move window "win1" to below/right of "win2" and make "win1" the current
1823  * window.  Only works within the same frame!
1824  */
1825     void
1826 win_move_after(win_T *win1, win_T *win2)
1827 {
1828     int		height;
1829 
1830     // check if the arguments are reasonable
1831     if (win1 == win2)
1832 	return;
1833 
1834     // check if there is something to do
1835     if (win2->w_next != win1)
1836     {
1837 	if (win1->w_frame->fr_parent != win2->w_frame->fr_parent)
1838 	{
1839 	    iemsg("INTERNAL: trying to move a window into another frame");
1840 	    return;
1841 	}
1842 
1843 	// may need to move the status line/vertical separator of the last
1844 	// window
1845 	if (win1 == lastwin)
1846 	{
1847 	    height = win1->w_prev->w_status_height;
1848 	    win1->w_prev->w_status_height = win1->w_status_height;
1849 	    win1->w_status_height = height;
1850 	    if (win1->w_prev->w_vsep_width == 1)
1851 	    {
1852 		// Remove the vertical separator from the last-but-one window,
1853 		// add it to the last window.  Adjust the frame widths.
1854 		win1->w_prev->w_vsep_width = 0;
1855 		win1->w_prev->w_frame->fr_width -= 1;
1856 		win1->w_vsep_width = 1;
1857 		win1->w_frame->fr_width += 1;
1858 	    }
1859 	}
1860 	else if (win2 == lastwin)
1861 	{
1862 	    height = win1->w_status_height;
1863 	    win1->w_status_height = win2->w_status_height;
1864 	    win2->w_status_height = height;
1865 	    if (win1->w_vsep_width == 1)
1866 	    {
1867 		// Remove the vertical separator from win1, add it to the last
1868 		// window, win2.  Adjust the frame widths.
1869 		win2->w_vsep_width = 1;
1870 		win2->w_frame->fr_width += 1;
1871 		win1->w_vsep_width = 0;
1872 		win1->w_frame->fr_width -= 1;
1873 	    }
1874 	}
1875 	win_remove(win1, NULL);
1876 	frame_remove(win1->w_frame);
1877 	win_append(win2, win1);
1878 	frame_append(win2->w_frame, win1->w_frame);
1879 
1880 	(void)win_comp_pos();	// recompute w_winrow for all windows
1881 	redraw_later(NOT_VALID);
1882     }
1883     win_enter(win1, FALSE);
1884 }
1885 
1886 /*
1887  * Make all windows the same height.
1888  * 'next_curwin' will soon be the current window, make sure it has enough
1889  * rows.
1890  */
1891     void
1892 win_equal(
1893     win_T	*next_curwin,	// pointer to current window to be or NULL
1894     int		current,	// do only frame with current window
1895     int		dir)		// 'v' for vertically, 'h' for horizontally,
1896 				// 'b' for both, 0 for using p_ead
1897 {
1898     if (dir == 0)
1899 	dir = *p_ead;
1900     win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
1901 		      topframe, dir, 0, tabline_height(),
1902 					   (int)Columns, topframe->fr_height);
1903 }
1904 
1905 /*
1906  * Set a frame to a new position and height, spreading the available room
1907  * equally over contained frames.
1908  * The window "next_curwin" (if not NULL) should at least get the size from
1909  * 'winheight' and 'winwidth' if possible.
1910  */
1911     static void
1912 win_equal_rec(
1913     win_T	*next_curwin,	// pointer to current window to be or NULL
1914     int		current,	// do only frame with current window
1915     frame_T	*topfr,		// frame to set size off
1916     int		dir,		// 'v', 'h' or 'b', see win_equal()
1917     int		col,		// horizontal position for frame
1918     int		row,		// vertical position for frame
1919     int		width,		// new width of frame
1920     int		height)		// new height of frame
1921 {
1922     int		n, m;
1923     int		extra_sep = 0;
1924     int		wincount, totwincount = 0;
1925     frame_T	*fr;
1926     int		next_curwin_size = 0;
1927     int		room = 0;
1928     int		new_size;
1929     int		has_next_curwin = 0;
1930     int		hnc;
1931 
1932     if (topfr->fr_layout == FR_LEAF)
1933     {
1934 	// Set the width/height of this frame.
1935 	// Redraw when size or position changes
1936 	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
1937 		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
1938 	   )
1939 	{
1940 	    topfr->fr_win->w_winrow = row;
1941 	    frame_new_height(topfr, height, FALSE, FALSE);
1942 	    topfr->fr_win->w_wincol = col;
1943 	    frame_new_width(topfr, width, FALSE, FALSE);
1944 	    redraw_all_later(NOT_VALID);
1945 	}
1946     }
1947     else if (topfr->fr_layout == FR_ROW)
1948     {
1949 	topfr->fr_width = width;
1950 	topfr->fr_height = height;
1951 
1952 	if (dir != 'v')			// equalize frame widths
1953 	{
1954 	    // Compute the maximum number of windows horizontally in this
1955 	    // frame.
1956 	    n = frame_minwidth(topfr, NOWIN);
1957 	    // add one for the rightmost window, it doesn't have a separator
1958 	    if (col + width == Columns)
1959 		extra_sep = 1;
1960 	    else
1961 		extra_sep = 0;
1962 	    totwincount = (n + extra_sep) / (p_wmw + 1);
1963 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1964 
1965 	    /*
1966 	     * Compute width for "next_curwin" window and room available for
1967 	     * other windows.
1968 	     * "m" is the minimal width when counting p_wiw for "next_curwin".
1969 	     */
1970 	    m = frame_minwidth(topfr, next_curwin);
1971 	    room = width - m;
1972 	    if (room < 0)
1973 	    {
1974 		next_curwin_size = p_wiw + room;
1975 		room = 0;
1976 	    }
1977 	    else
1978 	    {
1979 		next_curwin_size = -1;
1980 		FOR_ALL_FRAMES(fr, topfr->fr_child)
1981 		{
1982 		    // If 'winfixwidth' set keep the window width if
1983 		    // possible.
1984 		    // Watch out for this window being the next_curwin.
1985 		    if (frame_fixed_width(fr))
1986 		    {
1987 			n = frame_minwidth(fr, NOWIN);
1988 			new_size = fr->fr_width;
1989 			if (frame_has_win(fr, next_curwin))
1990 			{
1991 			    room += p_wiw - p_wmw;
1992 			    next_curwin_size = 0;
1993 			    if (new_size < p_wiw)
1994 				new_size = p_wiw;
1995 			}
1996 			else
1997 			    // These windows don't use up room.
1998 			    totwincount -= (n + (fr->fr_next == NULL
1999 					      ? extra_sep : 0)) / (p_wmw + 1);
2000 			room -= new_size - n;
2001 			if (room < 0)
2002 			{
2003 			    new_size += room;
2004 			    room = 0;
2005 			}
2006 			fr->fr_newwidth = new_size;
2007 		    }
2008 		}
2009 		if (next_curwin_size == -1)
2010 		{
2011 		    if (!has_next_curwin)
2012 			next_curwin_size = 0;
2013 		    else if (totwincount > 1
2014 			    && (room + (totwincount - 2))
2015 						  / (totwincount - 1) > p_wiw)
2016 		    {
2017 			// Can make all windows wider than 'winwidth', spread
2018 			// the room equally.
2019 			next_curwin_size = (room + p_wiw
2020 					    + (totwincount - 1) * p_wmw
2021 					    + (totwincount - 1)) / totwincount;
2022 			room -= next_curwin_size - p_wiw;
2023 		    }
2024 		    else
2025 			next_curwin_size = p_wiw;
2026 		}
2027 	    }
2028 
2029 	    if (has_next_curwin)
2030 		--totwincount;		// don't count curwin
2031 	}
2032 
2033 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2034 	{
2035 	    wincount = 1;
2036 	    if (fr->fr_next == NULL)
2037 		// last frame gets all that remains (avoid roundoff error)
2038 		new_size = width;
2039 	    else if (dir == 'v')
2040 		new_size = fr->fr_width;
2041 	    else if (frame_fixed_width(fr))
2042 	    {
2043 		new_size = fr->fr_newwidth;
2044 		wincount = 0;	    // doesn't count as a sizeable window
2045 	    }
2046 	    else
2047 	    {
2048 		// Compute the maximum number of windows horiz. in "fr".
2049 		n = frame_minwidth(fr, NOWIN);
2050 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2051 								/ (p_wmw + 1);
2052 		m = frame_minwidth(fr, next_curwin);
2053 		if (has_next_curwin)
2054 		    hnc = frame_has_win(fr, next_curwin);
2055 		else
2056 		    hnc = FALSE;
2057 		if (hnc)	    // don't count next_curwin
2058 		    --wincount;
2059 		if (totwincount == 0)
2060 		    new_size = room;
2061 		else
2062 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2063 								/ totwincount;
2064 		if (hnc)	    // add next_curwin size
2065 		{
2066 		    next_curwin_size -= p_wiw - (m - n);
2067 		    new_size += next_curwin_size;
2068 		    room -= new_size - next_curwin_size;
2069 		}
2070 		else
2071 		    room -= new_size;
2072 		new_size += n;
2073 	    }
2074 
2075 	    // Skip frame that is full width when splitting or closing a
2076 	    // window, unless equalizing all frames.
2077 	    if (!current || dir != 'v' || topfr->fr_parent != NULL
2078 		    || (new_size != fr->fr_width)
2079 		    || frame_has_win(fr, next_curwin))
2080 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2081 							    new_size, height);
2082 	    col += new_size;
2083 	    width -= new_size;
2084 	    totwincount -= wincount;
2085 	}
2086     }
2087     else // topfr->fr_layout == FR_COL
2088     {
2089 	topfr->fr_width = width;
2090 	topfr->fr_height = height;
2091 
2092 	if (dir != 'h')			// equalize frame heights
2093 	{
2094 	    // Compute maximum number of windows vertically in this frame.
2095 	    n = frame_minheight(topfr, NOWIN);
2096 	    // add one for the bottom window if it doesn't have a statusline
2097 	    if (row + height == cmdline_row && p_ls == 0)
2098 		extra_sep = 1;
2099 	    else
2100 		extra_sep = 0;
2101 	    totwincount = (n + extra_sep) / (p_wmh + 1);
2102 	    has_next_curwin = frame_has_win(topfr, next_curwin);
2103 
2104 	    /*
2105 	     * Compute height for "next_curwin" window and room available for
2106 	     * other windows.
2107 	     * "m" is the minimal height when counting p_wh for "next_curwin".
2108 	     */
2109 	    m = frame_minheight(topfr, next_curwin);
2110 	    room = height - m;
2111 	    if (room < 0)
2112 	    {
2113 		// The room is less then 'winheight', use all space for the
2114 		// current window.
2115 		next_curwin_size = p_wh + room;
2116 		room = 0;
2117 	    }
2118 	    else
2119 	    {
2120 		next_curwin_size = -1;
2121 		FOR_ALL_FRAMES(fr, topfr->fr_child)
2122 		{
2123 		    // If 'winfixheight' set keep the window height if
2124 		    // possible.
2125 		    // Watch out for this window being the next_curwin.
2126 		    if (frame_fixed_height(fr))
2127 		    {
2128 			n = frame_minheight(fr, NOWIN);
2129 			new_size = fr->fr_height;
2130 			if (frame_has_win(fr, next_curwin))
2131 			{
2132 			    room += p_wh - p_wmh;
2133 			    next_curwin_size = 0;
2134 			    if (new_size < p_wh)
2135 				new_size = p_wh;
2136 			}
2137 			else
2138 			    // These windows don't use up room.
2139 			    totwincount -= (n + (fr->fr_next == NULL
2140 					      ? extra_sep : 0)) / (p_wmh + 1);
2141 			room -= new_size - n;
2142 			if (room < 0)
2143 			{
2144 			    new_size += room;
2145 			    room = 0;
2146 			}
2147 			fr->fr_newheight = new_size;
2148 		    }
2149 		}
2150 		if (next_curwin_size == -1)
2151 		{
2152 		    if (!has_next_curwin)
2153 			next_curwin_size = 0;
2154 		    else if (totwincount > 1
2155 			    && (room + (totwincount - 2))
2156 						   / (totwincount - 1) > p_wh)
2157 		    {
2158 			// can make all windows higher than 'winheight',
2159 			// spread the room equally.
2160 			next_curwin_size = (room + p_wh
2161 					   + (totwincount - 1) * p_wmh
2162 					   + (totwincount - 1)) / totwincount;
2163 			room -= next_curwin_size - p_wh;
2164 		    }
2165 		    else
2166 			next_curwin_size = p_wh;
2167 		}
2168 	    }
2169 
2170 	    if (has_next_curwin)
2171 		--totwincount;		// don't count curwin
2172 	}
2173 
2174 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2175 	{
2176 	    wincount = 1;
2177 	    if (fr->fr_next == NULL)
2178 		// last frame gets all that remains (avoid roundoff error)
2179 		new_size = height;
2180 	    else if (dir == 'h')
2181 		new_size = fr->fr_height;
2182 	    else if (frame_fixed_height(fr))
2183 	    {
2184 		new_size = fr->fr_newheight;
2185 		wincount = 0;	    // doesn't count as a sizeable window
2186 	    }
2187 	    else
2188 	    {
2189 		// Compute the maximum number of windows vert. in "fr".
2190 		n = frame_minheight(fr, NOWIN);
2191 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2192 								/ (p_wmh + 1);
2193 		m = frame_minheight(fr, next_curwin);
2194 		if (has_next_curwin)
2195 		    hnc = frame_has_win(fr, next_curwin);
2196 		else
2197 		    hnc = FALSE;
2198 		if (hnc)	    // don't count next_curwin
2199 		    --wincount;
2200 		if (totwincount == 0)
2201 		    new_size = room;
2202 		else
2203 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2204 								/ totwincount;
2205 		if (hnc)	    // add next_curwin size
2206 		{
2207 		    next_curwin_size -= p_wh - (m - n);
2208 		    new_size += next_curwin_size;
2209 		    room -= new_size - next_curwin_size;
2210 		}
2211 		else
2212 		    room -= new_size;
2213 		new_size += n;
2214 	    }
2215 	    // Skip frame that is full width when splitting or closing a
2216 	    // window, unless equalizing all frames.
2217 	    if (!current || dir != 'h' || topfr->fr_parent != NULL
2218 		    || (new_size != fr->fr_height)
2219 		    || frame_has_win(fr, next_curwin))
2220 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2221 							     width, new_size);
2222 	    row += new_size;
2223 	    height -= new_size;
2224 	    totwincount -= wincount;
2225 	}
2226     }
2227 }
2228 
2229 #ifdef FEAT_JOB_CHANNEL
2230     static void
2231 leaving_window(win_T *win)
2232 {
2233     // Only matters for a prompt window.
2234     if (!bt_prompt(win->w_buffer))
2235 	return;
2236 
2237     // When leaving a prompt window stop Insert mode and perhaps restart
2238     // it when entering that window again.
2239     win->w_buffer->b_prompt_insert = restart_edit;
2240     if (restart_edit != 0 && mode_displayed)
2241 	clear_cmdline = TRUE;		// unshow mode later
2242     restart_edit = NUL;
2243 
2244     // When leaving the window (or closing the window) was done from a
2245     // callback we need to break out of the Insert mode loop and restart Insert
2246     // mode when entering the window again.
2247     if (State & INSERT)
2248     {
2249 	stop_insert_mode = TRUE;
2250 	if (win->w_buffer->b_prompt_insert == NUL)
2251 	    win->w_buffer->b_prompt_insert = 'A';
2252     }
2253 }
2254 
2255     void
2256 entering_window(win_T *win)
2257 {
2258     // Only matters for a prompt window.
2259     if (!bt_prompt(win->w_buffer))
2260 	return;
2261 
2262     // When switching to a prompt buffer that was in Insert mode, don't stop
2263     // Insert mode, it may have been set in leaving_window().
2264     if (win->w_buffer->b_prompt_insert != NUL)
2265 	stop_insert_mode = FALSE;
2266 
2267     // When entering the prompt window restart Insert mode if we were in Insert
2268     // mode when we left it.
2269     restart_edit = win->w_buffer->b_prompt_insert;
2270 }
2271 #endif
2272 
2273 /*
2274  * Close all windows for buffer "buf".
2275  */
2276     void
2277 close_windows(
2278     buf_T	*buf,
2279     int		keep_curwin)	    // don't close "curwin"
2280 {
2281     win_T	*wp;
2282     tabpage_T   *tp, *nexttp;
2283     int		h = tabline_height();
2284     int		count = tabpage_index(NULL);
2285 
2286     ++RedrawingDisabled;
2287 
2288     for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
2289     {
2290 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
2291 		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
2292 	{
2293 	    if (win_close(wp, FALSE) == FAIL)
2294 		// If closing the window fails give up, to avoid looping
2295 		// forever.
2296 		break;
2297 
2298 	    // Start all over, autocommands may change the window layout.
2299 	    wp = firstwin;
2300 	}
2301 	else
2302 	    wp = wp->w_next;
2303     }
2304 
2305     // Also check windows in other tab pages.
2306     for (tp = first_tabpage; tp != NULL; tp = nexttp)
2307     {
2308 	nexttp = tp->tp_next;
2309 	if (tp != curtab)
2310 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
2311 		if (wp->w_buffer == buf
2312 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
2313 		{
2314 		    win_close_othertab(wp, FALSE, tp);
2315 
2316 		    // Start all over, the tab page may be closed and
2317 		    // autocommands may change the window layout.
2318 		    nexttp = first_tabpage;
2319 		    break;
2320 		}
2321     }
2322 
2323     --RedrawingDisabled;
2324 
2325     if (count != tabpage_index(NULL))
2326 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2327 
2328     redraw_tabline = TRUE;
2329     if (h != tabline_height())
2330 	shell_new_rows();
2331 }
2332 
2333 /*
2334  * Return TRUE if the current window is the only window that exists (ignoring
2335  * "aucmd_win").
2336  * Returns FALSE if there is a window, possibly in another tab page.
2337  */
2338     static int
2339 last_window(void)
2340 {
2341     return (one_window() && first_tabpage->tp_next == NULL);
2342 }
2343 
2344 /*
2345  * Return TRUE if there is only one window other than "aucmd_win" in the
2346  * current tab page.
2347  */
2348     int
2349 one_window(void)
2350 {
2351     win_T	*wp;
2352     int		seen_one = FALSE;
2353 
2354     FOR_ALL_WINDOWS(wp)
2355     {
2356 	if (wp != aucmd_win)
2357 	{
2358 	    if (seen_one)
2359 		return FALSE;
2360 	    seen_one = TRUE;
2361 	}
2362     }
2363     return TRUE;
2364 }
2365 
2366 /*
2367  * Close the possibly last window in a tab page.
2368  * Returns TRUE when the window was closed already.
2369  */
2370     static int
2371 close_last_window_tabpage(
2372     win_T	*win,
2373     int		free_buf,
2374     tabpage_T   *prev_curtab)
2375 {
2376     if (ONE_WINDOW)
2377     {
2378 	buf_T	*old_curbuf = curbuf;
2379 
2380 	/*
2381 	 * Closing the last window in a tab page.  First go to another tab
2382 	 * page and then close the window and the tab page.  This avoids that
2383 	 * curwin and curtab are invalid while we are freeing memory, they may
2384 	 * be used in GUI events.
2385 	 * Don't trigger autocommands yet, they may use wrong values, so do
2386 	 * that below.
2387 	 */
2388 	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
2389 	redraw_tabline = TRUE;
2390 
2391 	// Safety check: Autocommands may have closed the window when jumping
2392 	// to the other tab page.
2393 	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
2394 	{
2395 	    int	    h = tabline_height();
2396 
2397 	    win_close_othertab(win, free_buf, prev_curtab);
2398 	    if (h != tabline_height())
2399 		shell_new_rows();
2400 	}
2401 #ifdef FEAT_JOB_CHANNEL
2402 	entering_window(curwin);
2403 #endif
2404 	// Since goto_tabpage_tp above did not trigger *Enter autocommands, do
2405 	// that now.
2406 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2407 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
2408 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
2409 	if (old_curbuf != curbuf)
2410 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2411 	return TRUE;
2412     }
2413     return FALSE;
2414 }
2415 
2416 /*
2417  * Close the buffer of "win" and unload it if "action" is DOBUF_UNLOAD.
2418  * "action" can also be zero (do nothing) or DOBUF_WIPE.
2419  * "abort_if_last" is passed to close_buffer(): abort closing if all other
2420  * windows are closed.
2421  */
2422     static void
2423 win_close_buffer(win_T *win, int action, int abort_if_last)
2424 {
2425 #ifdef FEAT_SYN_HL
2426     // Free independent synblock before the buffer is freed.
2427     if (win->w_buffer != NULL)
2428 	reset_synblock(win);
2429 #endif
2430 
2431 #ifdef FEAT_QUICKFIX
2432     // When the quickfix/location list window is closed, unlist the buffer.
2433     if (win->w_buffer != NULL && bt_quickfix(win->w_buffer))
2434 	win->w_buffer->b_p_bl = FALSE;
2435 #endif
2436 
2437     // Close the link to the buffer.
2438     if (win->w_buffer != NULL)
2439     {
2440 	bufref_T    bufref;
2441 
2442 	set_bufref(&bufref, curbuf);
2443 	win->w_closing = TRUE;
2444 	close_buffer(win, win->w_buffer, action, abort_if_last, FALSE);
2445 	if (win_valid_any_tab(win))
2446 	    win->w_closing = FALSE;
2447 	// Make sure curbuf is valid. It can become invalid if 'bufhidden' is
2448 	// "wipe".
2449 	if (!bufref_valid(&bufref))
2450 	    curbuf = firstbuf;
2451     }
2452 }
2453 
2454 /*
2455  * Close window "win".  Only works for the current tab page.
2456  * If "free_buf" is TRUE related buffer may be unloaded.
2457  *
2458  * Called by :quit, :close, :xit, :wq and findtag().
2459  * Returns FAIL when the window was not closed.
2460  */
2461     int
2462 win_close(win_T *win, int free_buf)
2463 {
2464     win_T	*wp;
2465     int		other_buffer = FALSE;
2466     int		close_curwin = FALSE;
2467     int		dir;
2468     int		help_window = FALSE;
2469     tabpage_T   *prev_curtab = curtab;
2470     frame_T	*win_frame = win->w_frame->fr_parent;
2471 #ifdef FEAT_DIFF
2472     int		had_diffmode = win->w_p_diff;
2473 #endif
2474 #ifdef MESSAGE_QUEUE
2475     int		did_decrement = FALSE;
2476 #endif
2477 
2478 #if defined(FEAT_TERMINAL) && defined(FEAT_PROP_POPUP)
2479     // Can close a popup window with a terminal if the job has finished.
2480     if (may_close_term_popup() == OK)
2481 	return OK;
2482 #endif
2483     if (ERROR_IF_ANY_POPUP_WINDOW)
2484 	return FAIL;
2485 
2486     if (last_window())
2487     {
2488 	emsg(_("E444: Cannot close last window"));
2489 	return FAIL;
2490     }
2491 
2492     if (win->w_closing || (win->w_buffer != NULL
2493 					       && win->w_buffer->b_locked > 0))
2494 	return FAIL; // window is already being closed
2495     if (win_unlisted(win))
2496     {
2497 	emsg(_(e_autocmd_close));
2498 	return FAIL;
2499     }
2500     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
2501     {
2502 	emsg(_("E814: Cannot close window, only autocmd window would remain"));
2503 	return FAIL;
2504     }
2505 
2506     // When closing the last window in a tab page first go to another tab page
2507     // and then close the window and the tab page to avoid that curwin and
2508     // curtab are invalid while we are freeing memory.
2509     if (close_last_window_tabpage(win, free_buf, prev_curtab))
2510       return FAIL;
2511 
2512     // When closing the help window, try restoring a snapshot after closing
2513     // the window.  Otherwise clear the snapshot, it's now invalid.
2514     if (bt_help(win->w_buffer))
2515 	help_window = TRUE;
2516     else
2517 	clear_snapshot(curtab, SNAP_HELP_IDX);
2518 
2519     if (win == curwin)
2520     {
2521 #ifdef FEAT_JOB_CHANNEL
2522 	leaving_window(curwin);
2523 #endif
2524 	/*
2525 	 * Guess which window is going to be the new current window.
2526 	 * This may change because of the autocommands (sigh).
2527 	 */
2528 	wp = frame2win(win_altframe(win, NULL));
2529 
2530 	/*
2531 	 * Be careful: If autocommands delete the window or cause this window
2532 	 * to be the last one left, return now.
2533 	 */
2534 	if (wp->w_buffer != curbuf)
2535 	{
2536 	    other_buffer = TRUE;
2537 	    win->w_closing = TRUE;
2538 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
2539 	    if (!win_valid(win))
2540 		return FAIL;
2541 	    win->w_closing = FALSE;
2542 	    if (last_window())
2543 		return FAIL;
2544 	}
2545 	win->w_closing = TRUE;
2546 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
2547 	if (!win_valid(win))
2548 	    return FAIL;
2549 	win->w_closing = FALSE;
2550 	if (last_window())
2551 	    return FAIL;
2552 #ifdef FEAT_EVAL
2553 	// autocmds may abort script processing
2554 	if (aborting())
2555 	    return FAIL;
2556 #endif
2557     }
2558 
2559 #ifdef FEAT_GUI
2560     // Avoid trouble with scrollbars that are going to be deleted in
2561     // win_free().
2562     if (gui.in_use)
2563 	out_flush();
2564 #endif
2565 
2566 #ifdef FEAT_PROP_POPUP
2567     if (popup_win_closed(win) && !win_valid(win))
2568 	return FAIL;
2569 #endif
2570 
2571     // Trigger WinClosed just before starting to free window-related resources.
2572     trigger_winclosed(win);
2573     // autocmd may have freed the window already.
2574     if (!win_valid_any_tab(win))
2575 	return OK;
2576 
2577     win_close_buffer(win, free_buf ? DOBUF_UNLOAD : 0, TRUE);
2578 
2579     if (only_one_window() && win_valid(win) && win->w_buffer == NULL
2580 	    && (last_window() || curtab != prev_curtab
2581 		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
2582     {
2583 	// Autocommands have closed all windows, quit now.  Restore
2584 	// curwin->w_buffer, otherwise writing viminfo may fail.
2585 	if (curwin->w_buffer == NULL)
2586 	    curwin->w_buffer = curbuf;
2587 	getout(0);
2588     }
2589 
2590     // Autocommands may have moved to another tab page.
2591     if (curtab != prev_curtab && win_valid_any_tab(win)
2592 						      && win->w_buffer == NULL)
2593     {
2594 	// Need to close the window anyway, since the buffer is NULL.
2595 	win_close_othertab(win, FALSE, prev_curtab);
2596 	return FAIL;
2597     }
2598 
2599     // Autocommands may have closed the window already or closed the only
2600     // other window.
2601     if (!win_valid(win) || last_window()
2602 	    || close_last_window_tabpage(win, free_buf, prev_curtab))
2603 	return FAIL;
2604 
2605     // Now we are really going to close the window.  Disallow any autocommand
2606     // to split a window to avoid trouble.
2607     // Also bail out of parse_queued_messages() to avoid it tries to update the
2608     // screen.
2609     ++split_disallowed;
2610 #ifdef MESSAGE_QUEUE
2611     ++dont_parse_messages;
2612 #endif
2613 
2614     // Free the memory used for the window and get the window that received
2615     // the screen space.
2616     wp = win_free_mem(win, &dir, NULL);
2617 
2618     // Make sure curwin isn't invalid.  It can cause severe trouble when
2619     // printing an error message.  For win_equal() curbuf needs to be valid
2620     // too.
2621     if (win == curwin)
2622     {
2623 	curwin = wp;
2624 #ifdef FEAT_QUICKFIX
2625 	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
2626 	{
2627 	    /*
2628 	     * If the cursor goes to the preview or the quickfix window, try
2629 	     * finding another window to go to.
2630 	     */
2631 	    for (;;)
2632 	    {
2633 		if (wp->w_next == NULL)
2634 		    wp = firstwin;
2635 		else
2636 		    wp = wp->w_next;
2637 		if (wp == curwin)
2638 		    break;
2639 		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
2640 		{
2641 		    curwin = wp;
2642 		    break;
2643 		}
2644 	    }
2645 	}
2646 #endif
2647 	curbuf = curwin->w_buffer;
2648 	close_curwin = TRUE;
2649 
2650 	// The cursor position may be invalid if the buffer changed after last
2651 	// using the window.
2652 	check_cursor();
2653     }
2654     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
2655 	// If the frame of the closed window contains the new current window,
2656 	// only resize that frame.  Otherwise resize all windows.
2657 	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
2658     else
2659 	win_comp_pos();
2660     if (close_curwin)
2661     {
2662 	// Pass WEE_ALLOW_PARSE_MESSAGES to decrement dont_parse_messages
2663 	// before autocommands.
2664 #ifdef MESSAGE_QUEUE
2665 	did_decrement =
2666 #else
2667 	(void)
2668 #endif
2669 	    win_enter_ext(wp,
2670 		WEE_CURWIN_INVALID | WEE_TRIGGER_ENTER_AUTOCMDS
2671 		      | WEE_TRIGGER_LEAVE_AUTOCMDS | WEE_ALLOW_PARSE_MESSAGES);
2672 	if (other_buffer)
2673 	    // careful: after this wp and win may be invalid!
2674 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2675     }
2676 
2677     --split_disallowed;
2678 #ifdef MESSAGE_QUEUE
2679     if (!did_decrement)
2680 	--dont_parse_messages;
2681 #endif
2682 
2683     /*
2684      * If last window has a status line now and we don't want one,
2685      * remove the status line.
2686      */
2687     last_status(FALSE);
2688 
2689     // After closing the help window, try restoring the window layout from
2690     // before it was opened.
2691     if (help_window)
2692 	restore_snapshot(SNAP_HELP_IDX, close_curwin);
2693 
2694 #ifdef FEAT_DIFF
2695     // If the window had 'diff' set and now there is only one window left in
2696     // the tab page with 'diff' set, and "closeoff" is in 'diffopt', then
2697     // execute ":diffoff!".
2698     if (diffopt_closeoff() && had_diffmode && curtab == prev_curtab)
2699     {
2700 	int	diffcount = 0;
2701 	win_T	*dwin;
2702 
2703 	FOR_ALL_WINDOWS(dwin)
2704 	    if (dwin->w_p_diff)
2705 		++diffcount;
2706 	if (diffcount == 1)
2707 	    do_cmdline_cmd((char_u *)"diffoff!");
2708     }
2709 #endif
2710 
2711 #if defined(FEAT_GUI)
2712     // When 'guioptions' includes 'L' or 'R' may have to remove scrollbars.
2713     if (gui.in_use && !win_hasvertsplit())
2714 	gui_init_which_components(NULL);
2715 #endif
2716 
2717     redraw_all_later(NOT_VALID);
2718     return OK;
2719 }
2720 
2721     static void
2722 trigger_winclosed(win_T *win)
2723 {
2724     static int	recursive = FALSE;
2725     char_u	winid[NUMBUFLEN];
2726 
2727     if (recursive)
2728 	return;
2729     recursive = TRUE;
2730     vim_snprintf((char *)winid, sizeof(winid), "%i", win->w_id);
2731     apply_autocmds(EVENT_WINCLOSED, winid, winid, FALSE, win->w_buffer);
2732     recursive = FALSE;
2733 }
2734 
2735 /*
2736  * Close window "win" in tab page "tp", which is not the current tab page.
2737  * This may be the last window in that tab page and result in closing the tab,
2738  * thus "tp" may become invalid!
2739  * Caller must check if buffer is hidden and whether the tabline needs to be
2740  * updated.
2741  */
2742     void
2743 win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
2744 {
2745     win_T	*wp;
2746     int		dir;
2747     tabpage_T   *ptp = NULL;
2748     int		free_tp = FALSE;
2749 
2750     // Get here with win->w_buffer == NULL when win_close() detects the tab
2751     // page changed.
2752     if (win->w_closing || (win->w_buffer != NULL
2753 					       && win->w_buffer->b_locked > 0))
2754 	return; // window is already being closed
2755 
2756     // Trigger WinClosed just before starting to free window-related resources.
2757     trigger_winclosed(win);
2758     // autocmd may have freed the window already.
2759     if (!win_valid_any_tab(win))
2760 	return;
2761 
2762     if (win->w_buffer != NULL)
2763 	// Close the link to the buffer.
2764 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0,
2765 								 FALSE, FALSE);
2766 
2767     // Careful: Autocommands may have closed the tab page or made it the
2768     // current tab page.
2769     for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
2770 	;
2771     if (ptp == NULL || tp == curtab)
2772 	return;
2773 
2774     // Autocommands may have closed the window already.
2775     for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
2776 	;
2777     if (wp == NULL)
2778 	return;
2779 
2780     // When closing the last window in a tab page remove the tab page.
2781     if (tp->tp_firstwin == tp->tp_lastwin)
2782     {
2783 	if (tp == first_tabpage)
2784 	    first_tabpage = tp->tp_next;
2785 	else
2786 	{
2787 	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
2788 							   ptp = ptp->tp_next)
2789 		;
2790 	    if (ptp == NULL)
2791 	    {
2792 		internal_error("win_close_othertab()");
2793 		return;
2794 	    }
2795 	    ptp->tp_next = tp->tp_next;
2796 	}
2797 	free_tp = TRUE;
2798     }
2799 
2800     // Free the memory used for the window.
2801     win_free_mem(win, &dir, tp);
2802 
2803     if (free_tp)
2804 	free_tabpage(tp);
2805 }
2806 
2807 /*
2808  * Free the memory used for a window.
2809  * Returns a pointer to the window that got the freed up space.
2810  */
2811     static win_T *
2812 win_free_mem(
2813     win_T	*win,
2814     int		*dirp,		// set to 'v' or 'h' for direction if 'ea'
2815     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2816 {
2817     frame_T	*frp;
2818     win_T	*wp;
2819     tabpage_T	*win_tp = tp == NULL ? curtab : tp;
2820 
2821     // Remove the window and its frame from the tree of frames.
2822     frp = win->w_frame;
2823     wp = winframe_remove(win, dirp, tp);
2824     vim_free(frp);
2825     win_free(win, tp);
2826 
2827     // When deleting the current window in the tab, select a new current
2828     // window.
2829     if (win == win_tp->tp_curwin)
2830 	win_tp->tp_curwin = wp;
2831 
2832     return wp;
2833 }
2834 
2835 #if defined(EXITFREE) || defined(PROTO)
2836     void
2837 win_free_all(void)
2838 {
2839     int		dummy;
2840 
2841     while (first_tabpage->tp_next != NULL)
2842 	tabpage_close(TRUE);
2843 
2844     if (aucmd_win != NULL)
2845     {
2846 	(void)win_free_mem(aucmd_win, &dummy, NULL);
2847 	aucmd_win = NULL;
2848     }
2849 
2850     while (firstwin != NULL)
2851 	(void)win_free_mem(firstwin, &dummy, NULL);
2852 
2853     // No window should be used after this. Set curwin to NULL to crash
2854     // instead of using freed memory.
2855     curwin = NULL;
2856 }
2857 #endif
2858 
2859 /*
2860  * Remove a window and its frame from the tree of frames.
2861  * Returns a pointer to the window that got the freed up space.
2862  */
2863     win_T *
2864 winframe_remove(
2865     win_T	*win,
2866     int		*dirp UNUSED,	// set to 'v' or 'h' for direction if 'ea'
2867     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2868 {
2869     frame_T	*frp, *frp2, *frp3;
2870     frame_T	*frp_close = win->w_frame;
2871     win_T	*wp;
2872 
2873     /*
2874      * If there is only one window there is nothing to remove.
2875      */
2876     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2877 	return NULL;
2878 
2879     /*
2880      * Remove the window from its frame.
2881      */
2882     frp2 = win_altframe(win, tp);
2883     wp = frame2win(frp2);
2884 
2885     // Remove this frame from the list of frames.
2886     frame_remove(frp_close);
2887 
2888     if (frp_close->fr_parent->fr_layout == FR_COL)
2889     {
2890 	// When 'winfixheight' is set, try to find another frame in the column
2891 	// (as close to the closed frame as possible) to distribute the height
2892 	// to.
2893 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
2894 	{
2895 	    frp = frp_close->fr_prev;
2896 	    frp3 = frp_close->fr_next;
2897 	    while (frp != NULL || frp3 != NULL)
2898 	    {
2899 		if (frp != NULL)
2900 		{
2901 		    if (!frame_fixed_height(frp))
2902 		    {
2903 			frp2 = frp;
2904 			wp = frame2win(frp2);
2905 			break;
2906 		    }
2907 		    frp = frp->fr_prev;
2908 		}
2909 		if (frp3 != NULL)
2910 		{
2911 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
2912 		    {
2913 			frp2 = frp3;
2914 			wp = frp3->fr_win;
2915 			break;
2916 		    }
2917 		    frp3 = frp3->fr_next;
2918 		}
2919 	    }
2920 	}
2921 	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
2922 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2923 	*dirp = 'v';
2924     }
2925     else
2926     {
2927 	// When 'winfixwidth' is set, try to find another frame in the column
2928 	// (as close to the closed frame as possible) to distribute the width
2929 	// to.
2930 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
2931 	{
2932 	    frp = frp_close->fr_prev;
2933 	    frp3 = frp_close->fr_next;
2934 	    while (frp != NULL || frp3 != NULL)
2935 	    {
2936 		if (frp != NULL)
2937 		{
2938 		    if (!frame_fixed_width(frp))
2939 		    {
2940 			frp2 = frp;
2941 			wp = frame2win(frp2);
2942 			break;
2943 		    }
2944 		    frp = frp->fr_prev;
2945 		}
2946 		if (frp3 != NULL)
2947 		{
2948 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
2949 		    {
2950 			frp2 = frp3;
2951 			wp = frp3->fr_win;
2952 			break;
2953 		    }
2954 		    frp3 = frp3->fr_next;
2955 		}
2956 	    }
2957 	}
2958 	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
2959 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2960 	*dirp = 'h';
2961     }
2962 
2963     // If rows/columns go to a window below/right its positions need to be
2964     // updated.  Can only be done after the sizes have been updated.
2965     if (frp2 == frp_close->fr_next)
2966     {
2967 	int row = win->w_winrow;
2968 	int col = win->w_wincol;
2969 
2970 	frame_comp_pos(frp2, &row, &col);
2971     }
2972 
2973     if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
2974     {
2975 	// There is no other frame in this list, move its info to the parent
2976 	// and remove it.
2977 	frp2->fr_parent->fr_layout = frp2->fr_layout;
2978 	frp2->fr_parent->fr_child = frp2->fr_child;
2979 	FOR_ALL_FRAMES(frp, frp2->fr_child)
2980 	    frp->fr_parent = frp2->fr_parent;
2981 	frp2->fr_parent->fr_win = frp2->fr_win;
2982 	if (frp2->fr_win != NULL)
2983 	    frp2->fr_win->w_frame = frp2->fr_parent;
2984 	frp = frp2->fr_parent;
2985 	if (topframe->fr_child == frp2)
2986 	    topframe->fr_child = frp;
2987 	vim_free(frp2);
2988 
2989 	frp2 = frp->fr_parent;
2990 	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
2991 	{
2992 	    // The frame above the parent has the same layout, have to merge
2993 	    // the frames into this list.
2994 	    if (frp2->fr_child == frp)
2995 		frp2->fr_child = frp->fr_child;
2996 	    frp->fr_child->fr_prev = frp->fr_prev;
2997 	    if (frp->fr_prev != NULL)
2998 		frp->fr_prev->fr_next = frp->fr_child;
2999 	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
3000 	    {
3001 		frp3->fr_parent = frp2;
3002 		if (frp3->fr_next == NULL)
3003 		{
3004 		    frp3->fr_next = frp->fr_next;
3005 		    if (frp->fr_next != NULL)
3006 			frp->fr_next->fr_prev = frp3;
3007 		    break;
3008 		}
3009 	    }
3010 	    if (topframe->fr_child == frp)
3011 		topframe->fr_child = frp2;
3012 	    vim_free(frp);
3013 	}
3014     }
3015 
3016     return wp;
3017 }
3018 
3019 /*
3020  * Return a pointer to the frame that will receive the empty screen space that
3021  * is left over after "win" is closed.
3022  *
3023  * If 'splitbelow' or 'splitright' is set, the space goes above or to the left
3024  * by default.  Otherwise, the free space goes below or to the right.  The
3025  * result is that opening a window and then immediately closing it will
3026  * preserve the initial window layout.  The 'wfh' and 'wfw' settings are
3027  * respected when possible.
3028  */
3029     static frame_T *
3030 win_altframe(
3031     win_T	*win,
3032     tabpage_T	*tp)		// tab page "win" is in, NULL for current
3033 {
3034     frame_T	*frp;
3035     frame_T	*other_fr, *target_fr;
3036 
3037     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
3038 	return alt_tabpage()->tp_curwin->w_frame;
3039 
3040     frp = win->w_frame;
3041 
3042     if (frp->fr_prev == NULL)
3043 	return frp->fr_next;
3044     if (frp->fr_next == NULL)
3045 	return frp->fr_prev;
3046 
3047     // By default the next window will get the space that was abandoned by this
3048     // window
3049     target_fr = frp->fr_next;
3050     other_fr  = frp->fr_prev;
3051 
3052     // If this is part of a column of windows and 'splitbelow' is true then the
3053     // previous window will get the space.
3054     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_COL && p_sb)
3055     {
3056 	target_fr = frp->fr_prev;
3057 	other_fr  = frp->fr_next;
3058     }
3059 
3060     // If this is part of a row of windows, and 'splitright' is true then the
3061     // previous window will get the space.
3062     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW && p_spr)
3063     {
3064 	target_fr = frp->fr_prev;
3065 	other_fr  = frp->fr_next;
3066     }
3067 
3068     // If 'wfh' or 'wfw' is set for the target and not for the alternate
3069     // window, reverse the selection.
3070     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
3071     {
3072 	if (frame_fixed_width(target_fr) && !frame_fixed_width(other_fr))
3073 	    target_fr = other_fr;
3074     }
3075     else
3076     {
3077 	if (frame_fixed_height(target_fr) && !frame_fixed_height(other_fr))
3078 	    target_fr = other_fr;
3079     }
3080 
3081     return target_fr;
3082 }
3083 
3084 /*
3085  * Return the tabpage that will be used if the current one is closed.
3086  */
3087     static tabpage_T *
3088 alt_tabpage(void)
3089 {
3090     tabpage_T	*tp;
3091 
3092     // Use the next tab page if possible.
3093     if (curtab->tp_next != NULL)
3094 	return curtab->tp_next;
3095 
3096     // Find the last but one tab page.
3097     for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
3098 	;
3099     return tp;
3100 }
3101 
3102 /*
3103  * Find the left-upper window in frame "frp".
3104  */
3105     static win_T *
3106 frame2win(frame_T *frp)
3107 {
3108     while (frp->fr_win == NULL)
3109 	frp = frp->fr_child;
3110     return frp->fr_win;
3111 }
3112 
3113 /*
3114  * Return TRUE if frame "frp" contains window "wp".
3115  */
3116     static int
3117 frame_has_win(frame_T *frp, win_T *wp)
3118 {
3119     frame_T	*p;
3120 
3121     if (frp->fr_layout == FR_LEAF)
3122 	return frp->fr_win == wp;
3123 
3124     FOR_ALL_FRAMES(p, frp->fr_child)
3125 	if (frame_has_win(p, wp))
3126 	    return TRUE;
3127     return FALSE;
3128 }
3129 
3130 /*
3131  * Set a new height for a frame.  Recursively sets the height for contained
3132  * frames and windows.  Caller must take care of positions.
3133  */
3134     static void
3135 frame_new_height(
3136     frame_T	*topfrp,
3137     int		height,
3138     int		topfirst,	// resize topmost contained frame first
3139     int		wfh)		// obey 'winfixheight' when there is a choice;
3140 				// may cause the height not to be set
3141 {
3142     frame_T	*frp;
3143     int		extra_lines;
3144     int		h;
3145 
3146     if (topfrp->fr_win != NULL)
3147     {
3148 	// Simple case: just one window.
3149 	win_new_height(topfrp->fr_win,
3150 				    height - topfrp->fr_win->w_status_height
3151 					      - WINBAR_HEIGHT(topfrp->fr_win));
3152     }
3153     else if (topfrp->fr_layout == FR_ROW)
3154     {
3155 	do
3156 	{
3157 	    // All frames in this row get the same new height.
3158 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3159 	    {
3160 		frame_new_height(frp, height, topfirst, wfh);
3161 		if (frp->fr_height > height)
3162 		{
3163 		    // Could not fit the windows, make the whole row higher.
3164 		    height = frp->fr_height;
3165 		    break;
3166 		}
3167 	    }
3168 	}
3169 	while (frp != NULL);
3170     }
3171     else    // fr_layout == FR_COL
3172     {
3173 	// Complicated case: Resize a column of frames.  Resize the bottom
3174 	// frame first, frames above that when needed.
3175 
3176 	frp = topfrp->fr_child;
3177 	if (wfh)
3178 	    // Advance past frames with one window with 'wfh' set.
3179 	    while (frame_fixed_height(frp))
3180 	    {
3181 		frp = frp->fr_next;
3182 		if (frp == NULL)
3183 		    return;	    // no frame without 'wfh', give up
3184 	    }
3185 	if (!topfirst)
3186 	{
3187 	    // Find the bottom frame of this column
3188 	    while (frp->fr_next != NULL)
3189 		frp = frp->fr_next;
3190 	    if (wfh)
3191 		// Advance back for frames with one window with 'wfh' set.
3192 		while (frame_fixed_height(frp))
3193 		    frp = frp->fr_prev;
3194 	}
3195 
3196 	extra_lines = height - topfrp->fr_height;
3197 	if (extra_lines < 0)
3198 	{
3199 	    // reduce height of contained frames, bottom or top frame first
3200 	    while (frp != NULL)
3201 	    {
3202 		h = frame_minheight(frp, NULL);
3203 		if (frp->fr_height + extra_lines < h)
3204 		{
3205 		    extra_lines += frp->fr_height - h;
3206 		    frame_new_height(frp, h, topfirst, wfh);
3207 		}
3208 		else
3209 		{
3210 		    frame_new_height(frp, frp->fr_height + extra_lines,
3211 							       topfirst, wfh);
3212 		    break;
3213 		}
3214 		if (topfirst)
3215 		{
3216 		    do
3217 			frp = frp->fr_next;
3218 		    while (wfh && frp != NULL && frame_fixed_height(frp));
3219 		}
3220 		else
3221 		{
3222 		    do
3223 			frp = frp->fr_prev;
3224 		    while (wfh && frp != NULL && frame_fixed_height(frp));
3225 		}
3226 		// Increase "height" if we could not reduce enough frames.
3227 		if (frp == NULL)
3228 		    height -= extra_lines;
3229 	    }
3230 	}
3231 	else if (extra_lines > 0)
3232 	{
3233 	    // increase height of bottom or top frame
3234 	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
3235 	}
3236     }
3237     topfrp->fr_height = height;
3238 }
3239 
3240 /*
3241  * Return TRUE if height of frame "frp" should not be changed because of
3242  * the 'winfixheight' option.
3243  */
3244     static int
3245 frame_fixed_height(frame_T *frp)
3246 {
3247     // frame with one window: fixed height if 'winfixheight' set.
3248     if (frp->fr_win != NULL)
3249 	return frp->fr_win->w_p_wfh;
3250 
3251     if (frp->fr_layout == FR_ROW)
3252     {
3253 	// The frame is fixed height if one of the frames in the row is fixed
3254 	// height.
3255 	FOR_ALL_FRAMES(frp, frp->fr_child)
3256 	    if (frame_fixed_height(frp))
3257 		return TRUE;
3258 	return FALSE;
3259     }
3260 
3261     // frp->fr_layout == FR_COL: The frame is fixed height if all of the
3262     // frames in the row are fixed height.
3263     FOR_ALL_FRAMES(frp, frp->fr_child)
3264 	if (!frame_fixed_height(frp))
3265 	    return FALSE;
3266     return TRUE;
3267 }
3268 
3269 /*
3270  * Return TRUE if width of frame "frp" should not be changed because of
3271  * the 'winfixwidth' option.
3272  */
3273     static int
3274 frame_fixed_width(frame_T *frp)
3275 {
3276     // frame with one window: fixed width if 'winfixwidth' set.
3277     if (frp->fr_win != NULL)
3278 	return frp->fr_win->w_p_wfw;
3279 
3280     if (frp->fr_layout == FR_COL)
3281     {
3282 	// The frame is fixed width if one of the frames in the row is fixed
3283 	// width.
3284 	FOR_ALL_FRAMES(frp, frp->fr_child)
3285 	    if (frame_fixed_width(frp))
3286 		return TRUE;
3287 	return FALSE;
3288     }
3289 
3290     // frp->fr_layout == FR_ROW: The frame is fixed width if all of the
3291     // frames in the row are fixed width.
3292     FOR_ALL_FRAMES(frp, frp->fr_child)
3293 	if (!frame_fixed_width(frp))
3294 	    return FALSE;
3295     return TRUE;
3296 }
3297 
3298 /*
3299  * Add a status line to windows at the bottom of "frp".
3300  * Note: Does not check if there is room!
3301  */
3302     static void
3303 frame_add_statusline(frame_T *frp)
3304 {
3305     win_T	*wp;
3306 
3307     if (frp->fr_layout == FR_LEAF)
3308     {
3309 	wp = frp->fr_win;
3310 	if (wp->w_status_height == 0)
3311 	{
3312 	    if (wp->w_height > 0)	// don't make it negative
3313 		--wp->w_height;
3314 	    wp->w_status_height = STATUS_HEIGHT;
3315 	}
3316     }
3317     else if (frp->fr_layout == FR_ROW)
3318     {
3319 	// Handle all the frames in the row.
3320 	FOR_ALL_FRAMES(frp, frp->fr_child)
3321 	    frame_add_statusline(frp);
3322     }
3323     else // frp->fr_layout == FR_COL
3324     {
3325 	// Only need to handle the last frame in the column.
3326 	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
3327 	    ;
3328 	frame_add_statusline(frp);
3329     }
3330 }
3331 
3332 /*
3333  * Set width of a frame.  Handles recursively going through contained frames.
3334  * May remove separator line for windows at the right side (for win_close()).
3335  */
3336     static void
3337 frame_new_width(
3338     frame_T	*topfrp,
3339     int		width,
3340     int		leftfirst,	// resize leftmost contained frame first
3341     int		wfw)		// obey 'winfixwidth' when there is a choice;
3342 				// may cause the width not to be set
3343 {
3344     frame_T	*frp;
3345     int		extra_cols;
3346     int		w;
3347     win_T	*wp;
3348 
3349     if (topfrp->fr_layout == FR_LEAF)
3350     {
3351 	// Simple case: just one window.
3352 	wp = topfrp->fr_win;
3353 	// Find out if there are any windows right of this one.
3354 	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
3355 	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
3356 		break;
3357 	if (frp->fr_parent == NULL)
3358 	    wp->w_vsep_width = 0;
3359 	win_new_width(wp, width - wp->w_vsep_width);
3360     }
3361     else if (topfrp->fr_layout == FR_COL)
3362     {
3363 	do
3364 	{
3365 	    // All frames in this column get the same new width.
3366 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3367 	    {
3368 		frame_new_width(frp, width, leftfirst, wfw);
3369 		if (frp->fr_width > width)
3370 		{
3371 		    // Could not fit the windows, make whole column wider.
3372 		    width = frp->fr_width;
3373 		    break;
3374 		}
3375 	    }
3376 	} while (frp != NULL);
3377     }
3378     else    // fr_layout == FR_ROW
3379     {
3380 	// Complicated case: Resize a row of frames.  Resize the rightmost
3381 	// frame first, frames left of it when needed.
3382 
3383 	frp = topfrp->fr_child;
3384 	if (wfw)
3385 	    // Advance past frames with one window with 'wfw' set.
3386 	    while (frame_fixed_width(frp))
3387 	    {
3388 		frp = frp->fr_next;
3389 		if (frp == NULL)
3390 		    return;	    // no frame without 'wfw', give up
3391 	    }
3392 	if (!leftfirst)
3393 	{
3394 	    // Find the rightmost frame of this row
3395 	    while (frp->fr_next != NULL)
3396 		frp = frp->fr_next;
3397 	    if (wfw)
3398 		// Advance back for frames with one window with 'wfw' set.
3399 		while (frame_fixed_width(frp))
3400 		    frp = frp->fr_prev;
3401 	}
3402 
3403 	extra_cols = width - topfrp->fr_width;
3404 	if (extra_cols < 0)
3405 	{
3406 	    // reduce frame width, rightmost frame first
3407 	    while (frp != NULL)
3408 	    {
3409 		w = frame_minwidth(frp, NULL);
3410 		if (frp->fr_width + extra_cols < w)
3411 		{
3412 		    extra_cols += frp->fr_width - w;
3413 		    frame_new_width(frp, w, leftfirst, wfw);
3414 		}
3415 		else
3416 		{
3417 		    frame_new_width(frp, frp->fr_width + extra_cols,
3418 							      leftfirst, wfw);
3419 		    break;
3420 		}
3421 		if (leftfirst)
3422 		{
3423 		    do
3424 			frp = frp->fr_next;
3425 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3426 		}
3427 		else
3428 		{
3429 		    do
3430 			frp = frp->fr_prev;
3431 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3432 		}
3433 		// Increase "width" if we could not reduce enough frames.
3434 		if (frp == NULL)
3435 		    width -= extra_cols;
3436 	    }
3437 	}
3438 	else if (extra_cols > 0)
3439 	{
3440 	    // increase width of rightmost frame
3441 	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
3442 	}
3443     }
3444     topfrp->fr_width = width;
3445 }
3446 
3447 /*
3448  * Add the vertical separator to windows at the right side of "frp".
3449  * Note: Does not check if there is room!
3450  */
3451     static void
3452 frame_add_vsep(frame_T *frp)
3453 {
3454     win_T	*wp;
3455 
3456     if (frp->fr_layout == FR_LEAF)
3457     {
3458 	wp = frp->fr_win;
3459 	if (wp->w_vsep_width == 0)
3460 	{
3461 	    if (wp->w_width > 0)	// don't make it negative
3462 		--wp->w_width;
3463 	    wp->w_vsep_width = 1;
3464 	}
3465     }
3466     else if (frp->fr_layout == FR_COL)
3467     {
3468 	// Handle all the frames in the column.
3469 	FOR_ALL_FRAMES(frp, frp->fr_child)
3470 	    frame_add_vsep(frp);
3471     }
3472     else // frp->fr_layout == FR_ROW
3473     {
3474 	// Only need to handle the last frame in the row.
3475 	frp = frp->fr_child;
3476 	while (frp->fr_next != NULL)
3477 	    frp = frp->fr_next;
3478 	frame_add_vsep(frp);
3479     }
3480 }
3481 
3482 /*
3483  * Set frame width from the window it contains.
3484  */
3485     static void
3486 frame_fix_width(win_T *wp)
3487 {
3488     wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
3489 }
3490 
3491 /*
3492  * Set frame height from the window it contains.
3493  */
3494     static void
3495 frame_fix_height(win_T *wp)
3496 {
3497     wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
3498 }
3499 
3500 /*
3501  * Compute the minimal height for frame "topfrp".
3502  * Uses the 'winminheight' option.
3503  * When "next_curwin" isn't NULL, use p_wh for this window.
3504  * When "next_curwin" is NOWIN, don't use at least one line for the current
3505  * window.
3506  */
3507     static int
3508 frame_minheight(frame_T *topfrp, win_T *next_curwin)
3509 {
3510     frame_T	*frp;
3511     int		m;
3512     int		n;
3513 
3514     if (topfrp->fr_win != NULL)
3515     {
3516 	if (topfrp->fr_win == next_curwin)
3517 	    m = p_wh + topfrp->fr_win->w_status_height;
3518 	else
3519 	{
3520 	    // window: minimal height of the window plus status line
3521 	    m = p_wmh + topfrp->fr_win->w_status_height;
3522 	    if (topfrp->fr_win == curwin && next_curwin == NULL)
3523 	    {
3524 		// Current window is minimal one line high and WinBar is
3525 		// visible.
3526 		if (p_wmh == 0)
3527 		    ++m;
3528 		m += WINBAR_HEIGHT(curwin);
3529 	    }
3530 	}
3531     }
3532     else if (topfrp->fr_layout == FR_ROW)
3533     {
3534 	// get the minimal height from each frame in this row
3535 	m = 0;
3536 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3537 	{
3538 	    n = frame_minheight(frp, next_curwin);
3539 	    if (n > m)
3540 		m = n;
3541 	}
3542     }
3543     else
3544     {
3545 	// Add up the minimal heights for all frames in this column.
3546 	m = 0;
3547 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3548 	    m += frame_minheight(frp, next_curwin);
3549     }
3550 
3551     return m;
3552 }
3553 
3554 /*
3555  * Compute the minimal width for frame "topfrp".
3556  * When "next_curwin" isn't NULL, use p_wiw for this window.
3557  * When "next_curwin" is NOWIN, don't use at least one column for the current
3558  * window.
3559  */
3560     static int
3561 frame_minwidth(
3562     frame_T	*topfrp,
3563     win_T	*next_curwin)	// use p_wh and p_wiw for next_curwin
3564 {
3565     frame_T	*frp;
3566     int		m, n;
3567 
3568     if (topfrp->fr_win != NULL)
3569     {
3570 	if (topfrp->fr_win == next_curwin)
3571 	    m = p_wiw + topfrp->fr_win->w_vsep_width;
3572 	else
3573 	{
3574 	    // window: minimal width of the window plus separator column
3575 	    m = p_wmw + topfrp->fr_win->w_vsep_width;
3576 	    // Current window is minimal one column wide
3577 	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
3578 		++m;
3579 	}
3580     }
3581     else if (topfrp->fr_layout == FR_COL)
3582     {
3583 	// get the minimal width from each frame in this column
3584 	m = 0;
3585 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3586 	{
3587 	    n = frame_minwidth(frp, next_curwin);
3588 	    if (n > m)
3589 		m = n;
3590 	}
3591     }
3592     else
3593     {
3594 	// Add up the minimal widths for all frames in this row.
3595 	m = 0;
3596 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3597 	    m += frame_minwidth(frp, next_curwin);
3598     }
3599 
3600     return m;
3601 }
3602 
3603 
3604 /*
3605  * Try to close all windows except current one.
3606  * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
3607  * used and the buffer was modified.
3608  *
3609  * Used by ":bdel" and ":only".
3610  */
3611     void
3612 close_others(
3613     int		message,
3614     int		forceit)	    // always hide all other windows
3615 {
3616     win_T	*wp;
3617     win_T	*nextwp;
3618     int		r;
3619 
3620     if (one_window())
3621     {
3622 	if (message && !autocmd_busy)
3623 	    msg(_(m_onlyone));
3624 	return;
3625     }
3626 
3627     // Be very careful here: autocommands may change the window layout.
3628     for (wp = firstwin; win_valid(wp); wp = nextwp)
3629     {
3630 	nextwp = wp->w_next;
3631 	if (wp != curwin)		// don't close current window
3632 	{
3633 
3634 	    // Check if it's allowed to abandon this window
3635 	    r = can_abandon(wp->w_buffer, forceit);
3636 	    if (!win_valid(wp))		// autocommands messed wp up
3637 	    {
3638 		nextwp = firstwin;
3639 		continue;
3640 	    }
3641 	    if (!r)
3642 	    {
3643 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
3644 		if (message && (p_confirm
3645 			     || (cmdmod.cmod_flags & CMOD_CONFIRM)) && p_write)
3646 		{
3647 		    dialog_changed(wp->w_buffer, FALSE);
3648 		    if (!win_valid(wp))		// autocommands messed wp up
3649 		    {
3650 			nextwp = firstwin;
3651 			continue;
3652 		    }
3653 		}
3654 		if (bufIsChanged(wp->w_buffer))
3655 #endif
3656 		    continue;
3657 	    }
3658 	    win_close(wp, !buf_hide(wp->w_buffer)
3659 					       && !bufIsChanged(wp->w_buffer));
3660 	}
3661     }
3662 
3663     if (message && !ONE_WINDOW)
3664 	emsg(_("E445: Other window contains changes"));
3665 }
3666 
3667     static void
3668 win_init_empty(win_T *wp)
3669 {
3670     redraw_win_later(wp, NOT_VALID);
3671     wp->w_lines_valid = 0;
3672     wp->w_cursor.lnum = 1;
3673     wp->w_curswant = wp->w_cursor.col = 0;
3674     wp->w_cursor.coladd = 0;
3675     wp->w_pcmark.lnum = 1;	// pcmark not cleared but set to line 1
3676     wp->w_pcmark.col = 0;
3677     wp->w_prev_pcmark.lnum = 0;
3678     wp->w_prev_pcmark.col = 0;
3679     wp->w_topline = 1;
3680 #ifdef FEAT_DIFF
3681     wp->w_topfill = 0;
3682 #endif
3683     wp->w_botline = 2;
3684 #if defined(FEAT_SYN_HL) || defined(FEAT_SPELL)
3685     wp->w_s = &wp->w_buffer->b_s;
3686 #endif
3687 }
3688 
3689 /*
3690  * Init the current window "curwin".
3691  * Called when a new file is being edited.
3692  */
3693     void
3694 curwin_init(void)
3695 {
3696     win_init_empty(curwin);
3697 }
3698 
3699 /*
3700  * Allocate the first window and put an empty buffer in it.
3701  * Called from main().
3702  * Return FAIL when something goes wrong (out of memory).
3703  */
3704     int
3705 win_alloc_first(void)
3706 {
3707     if (win_alloc_firstwin(NULL) == FAIL)
3708 	return FAIL;
3709 
3710     first_tabpage = alloc_tabpage();
3711     if (first_tabpage == NULL)
3712 	return FAIL;
3713     first_tabpage->tp_topframe = topframe;
3714     curtab = first_tabpage;
3715     curtab->tp_firstwin = firstwin;
3716     curtab->tp_lastwin = lastwin;
3717     curtab->tp_curwin = curwin;
3718 
3719     return OK;
3720 }
3721 
3722 /*
3723  * Allocate and init a window that is not a regular window.
3724  * This can only be done after the first window is fully initialized, thus it
3725  * can't be in win_alloc_first().
3726  */
3727     win_T *
3728 win_alloc_popup_win(void)
3729 {
3730     win_T *wp;
3731 
3732     wp = win_alloc(NULL, TRUE);
3733     if (wp != NULL)
3734     {
3735 	// We need to initialize options with something, using the current
3736 	// window makes most sense.
3737 	win_init_some(wp, curwin);
3738 
3739 	RESET_BINDING(wp);
3740 	new_frame(wp);
3741     }
3742     return wp;
3743 }
3744 
3745 /*
3746  * Initialize window "wp" to display buffer "buf".
3747  */
3748     void
3749 win_init_popup_win(win_T *wp, buf_T *buf)
3750 {
3751     wp->w_buffer = buf;
3752     ++buf->b_nwindows;
3753     win_init_empty(wp); // set cursor and topline to safe values
3754 
3755     // Make sure w_localdir and globaldir are NULL to avoid a chdir() in
3756     // win_enter_ext().
3757     VIM_CLEAR(wp->w_localdir);
3758 }
3759 
3760 /*
3761  * Allocate the first window or the first window in a new tab page.
3762  * When "oldwin" is NULL create an empty buffer for it.
3763  * When "oldwin" is not NULL copy info from it to the new window.
3764  * Return FAIL when something goes wrong (out of memory).
3765  */
3766     static int
3767 win_alloc_firstwin(win_T *oldwin)
3768 {
3769     curwin = win_alloc(NULL, FALSE);
3770     if (oldwin == NULL)
3771     {
3772 	// Very first window, need to create an empty buffer for it and
3773 	// initialize from scratch.
3774 	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
3775 	if (curwin == NULL || curbuf == NULL)
3776 	    return FAIL;
3777 	curwin->w_buffer = curbuf;
3778 #ifdef FEAT_SYN_HL
3779 	curwin->w_s = &(curbuf->b_s);
3780 #endif
3781 	curbuf->b_nwindows = 1;	// there is one window
3782 	curwin->w_alist = &global_alist;
3783 	curwin_init();		// init current window
3784     }
3785     else
3786     {
3787 	// First window in new tab page, initialize it from "oldwin".
3788 	win_init(curwin, oldwin, 0);
3789 
3790 	// We don't want cursor- and scroll-binding in the first window.
3791 	RESET_BINDING(curwin);
3792     }
3793 
3794     new_frame(curwin);
3795     if (curwin->w_frame == NULL)
3796 	return FAIL;
3797     topframe = curwin->w_frame;
3798     topframe->fr_width = Columns;
3799     topframe->fr_height = Rows - p_ch;
3800 
3801     return OK;
3802 }
3803 
3804 /*
3805  * Create a frame for window "wp".
3806  */
3807     static void
3808 new_frame(win_T *wp)
3809 {
3810     frame_T *frp = ALLOC_CLEAR_ONE(frame_T);
3811 
3812     wp->w_frame = frp;
3813     if (frp != NULL)
3814     {
3815 	frp->fr_layout = FR_LEAF;
3816 	frp->fr_win = wp;
3817     }
3818 }
3819 
3820 /*
3821  * Initialize the window and frame size to the maximum.
3822  */
3823     void
3824 win_init_size(void)
3825 {
3826     firstwin->w_height = ROWS_AVAIL;
3827     topframe->fr_height = ROWS_AVAIL;
3828     firstwin->w_width = Columns;
3829     topframe->fr_width = Columns;
3830 }
3831 
3832 /*
3833  * Allocate a new tabpage_T and init the values.
3834  * Returns NULL when out of memory.
3835  */
3836     static tabpage_T *
3837 alloc_tabpage(void)
3838 {
3839     tabpage_T	*tp;
3840 # ifdef FEAT_GUI
3841     int		i;
3842 # endif
3843 
3844 
3845     tp = ALLOC_CLEAR_ONE(tabpage_T);
3846     if (tp == NULL)
3847 	return NULL;
3848 
3849 # ifdef FEAT_EVAL
3850     // init t: variables
3851     tp->tp_vars = dict_alloc();
3852     if (tp->tp_vars == NULL)
3853     {
3854 	vim_free(tp);
3855 	return NULL;
3856     }
3857     init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
3858 # endif
3859 
3860 # ifdef FEAT_GUI
3861     for (i = 0; i < 3; i++)
3862 	tp->tp_prev_which_scrollbars[i] = -1;
3863 # endif
3864 # ifdef FEAT_DIFF
3865     tp->tp_diff_invalid = TRUE;
3866 # endif
3867     tp->tp_ch_used = p_ch;
3868 
3869     return tp;
3870 }
3871 
3872     void
3873 free_tabpage(tabpage_T *tp)
3874 {
3875     int idx;
3876 
3877 # ifdef FEAT_DIFF
3878     diff_clear(tp);
3879 # endif
3880 # ifdef FEAT_PROP_POPUP
3881     while (tp->tp_first_popupwin != NULL)
3882 	popup_close_tabpage(tp, tp->tp_first_popupwin->w_id, TRUE);
3883 #endif
3884     for (idx = 0; idx < SNAP_COUNT; ++idx)
3885 	clear_snapshot(tp, idx);
3886 #ifdef FEAT_EVAL
3887     vars_clear(&tp->tp_vars->dv_hashtab);	// free all t: variables
3888     hash_init(&tp->tp_vars->dv_hashtab);
3889     unref_var_dict(tp->tp_vars);
3890 #endif
3891 
3892     if (tp == lastused_tabpage)
3893 	lastused_tabpage = NULL;
3894 
3895     vim_free(tp->tp_localdir);
3896     vim_free(tp->tp_prevdir);
3897 
3898 #ifdef FEAT_PYTHON
3899     python_tabpage_free(tp);
3900 #endif
3901 
3902 #ifdef FEAT_PYTHON3
3903     python3_tabpage_free(tp);
3904 #endif
3905 
3906     vim_free(tp);
3907 }
3908 
3909 /*
3910  * Create a new Tab page with one window.
3911  * It will edit the current buffer, like after ":split".
3912  * When "after" is 0 put it just after the current Tab page.
3913  * Otherwise put it just before tab page "after".
3914  * Return FAIL or OK.
3915  */
3916     int
3917 win_new_tabpage(int after)
3918 {
3919     tabpage_T	*tp = curtab;
3920     tabpage_T	*prev_tp = curtab;
3921     tabpage_T	*newtp;
3922     int		n;
3923 
3924     newtp = alloc_tabpage();
3925     if (newtp == NULL)
3926 	return FAIL;
3927 
3928     // Remember the current windows in this Tab page.
3929     if (leave_tabpage(curbuf, TRUE) == FAIL)
3930     {
3931 	vim_free(newtp);
3932 	return FAIL;
3933     }
3934     curtab = newtp;
3935 
3936     newtp->tp_localdir = (tp->tp_localdir == NULL)
3937 				    ? NULL : vim_strsave(tp->tp_localdir);
3938     // Create a new empty window.
3939     if (win_alloc_firstwin(tp->tp_curwin) == OK)
3940     {
3941 	// Make the new Tab page the new topframe.
3942 	if (after == 1)
3943 	{
3944 	    // New tab page becomes the first one.
3945 	    newtp->tp_next = first_tabpage;
3946 	    first_tabpage = newtp;
3947 	}
3948 	else
3949 	{
3950 	    if (after > 0)
3951 	    {
3952 		// Put new tab page before tab page "after".
3953 		n = 2;
3954 		for (tp = first_tabpage; tp->tp_next != NULL
3955 					       && n < after; tp = tp->tp_next)
3956 		    ++n;
3957 	    }
3958 	    newtp->tp_next = tp->tp_next;
3959 	    tp->tp_next = newtp;
3960 	}
3961 	newtp->tp_firstwin = newtp->tp_lastwin = newtp->tp_curwin = curwin;
3962 
3963 	win_init_size();
3964 	firstwin->w_winrow = tabline_height();
3965 	win_comp_scroll(curwin);
3966 
3967 	newtp->tp_topframe = topframe;
3968 	last_status(FALSE);
3969 
3970 	lastused_tabpage = prev_tp;
3971 
3972 #if defined(FEAT_GUI)
3973 	// When 'guioptions' includes 'L' or 'R' may have to remove or add
3974 	// scrollbars.  Have to update them anyway.
3975 	gui_may_update_scrollbars();
3976 #endif
3977 #ifdef FEAT_JOB_CHANNEL
3978 	entering_window(curwin);
3979 #endif
3980 
3981 	redraw_all_later(NOT_VALID);
3982 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
3983 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
3984 	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
3985 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3986 	return OK;
3987     }
3988 
3989     // Failed, get back the previous Tab page
3990     enter_tabpage(curtab, curbuf, TRUE, TRUE);
3991     return FAIL;
3992 }
3993 
3994 /*
3995  * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
3996  * like with ":split".
3997  * Returns OK if a new tab page was created, FAIL otherwise.
3998  */
3999     static int
4000 may_open_tabpage(void)
4001 {
4002     int		n = (cmdmod.cmod_tab == 0)
4003 				       ? postponed_split_tab : cmdmod.cmod_tab;
4004 
4005     if (n != 0)
4006     {
4007 	cmdmod.cmod_tab = 0;	    // reset it to avoid doing it twice
4008 	postponed_split_tab = 0;
4009 	return win_new_tabpage(n);
4010     }
4011     return FAIL;
4012 }
4013 
4014 /*
4015  * Create up to "maxcount" tabpages with empty windows.
4016  * Returns the number of resulting tab pages.
4017  */
4018     int
4019 make_tabpages(int maxcount)
4020 {
4021     int		count = maxcount;
4022     int		todo;
4023 
4024     // Limit to 'tabpagemax' tabs.
4025     if (count > p_tpm)
4026 	count = p_tpm;
4027 
4028     /*
4029      * Don't execute autocommands while creating the tab pages.  Must do that
4030      * when putting the buffers in the windows.
4031      */
4032     block_autocmds();
4033 
4034     for (todo = count - 1; todo > 0; --todo)
4035 	if (win_new_tabpage(0) == FAIL)
4036 	    break;
4037 
4038     unblock_autocmds();
4039 
4040     // return actual number of tab pages
4041     return (count - todo);
4042 }
4043 
4044 /*
4045  * Return TRUE when "tpc" points to a valid tab page.
4046  */
4047     int
4048 valid_tabpage(tabpage_T *tpc)
4049 {
4050     tabpage_T	*tp;
4051 
4052     FOR_ALL_TABPAGES(tp)
4053 	if (tp == tpc)
4054 	    return TRUE;
4055     return FALSE;
4056 }
4057 
4058 /*
4059  * Return TRUE when "tpc" points to a valid tab page and at least one window is
4060  * valid.
4061  */
4062     int
4063 valid_tabpage_win(tabpage_T *tpc)
4064 {
4065     tabpage_T	*tp;
4066     win_T	*wp;
4067 
4068     FOR_ALL_TABPAGES(tp)
4069     {
4070 	if (tp == tpc)
4071 	{
4072 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
4073 	    {
4074 		if (win_valid_any_tab(wp))
4075 		    return TRUE;
4076 	    }
4077 	    return FALSE;
4078 	}
4079     }
4080     // shouldn't happen
4081     return FALSE;
4082 }
4083 
4084 /*
4085  * Close tabpage "tab", assuming it has no windows in it.
4086  * There must be another tabpage or this will crash.
4087  */
4088     void
4089 close_tabpage(tabpage_T *tab)
4090 {
4091     tabpage_T	*ptp;
4092 
4093     if (tab == first_tabpage)
4094     {
4095 	first_tabpage = tab->tp_next;
4096 	ptp = first_tabpage;
4097     }
4098     else
4099     {
4100 	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
4101 							    ptp = ptp->tp_next)
4102 	    ;
4103 	assert(ptp != NULL);
4104 	ptp->tp_next = tab->tp_next;
4105     }
4106 
4107     goto_tabpage_tp(ptp, FALSE, FALSE);
4108     free_tabpage(tab);
4109 }
4110 
4111 /*
4112  * Find tab page "n" (first one is 1).  Returns NULL when not found.
4113  */
4114     tabpage_T *
4115 find_tabpage(int n)
4116 {
4117     tabpage_T	*tp;
4118     int		i = 1;
4119 
4120     if (n == 0)
4121 	return curtab;
4122 
4123     for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
4124 	++i;
4125     return tp;
4126 }
4127 
4128 /*
4129  * Get index of tab page "tp".  First one has index 1.
4130  * When not found returns number of tab pages plus one.
4131  */
4132     int
4133 tabpage_index(tabpage_T *ftp)
4134 {
4135     int		i = 1;
4136     tabpage_T	*tp;
4137 
4138     for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
4139 	++i;
4140     return i;
4141 }
4142 
4143 /*
4144  * Prepare for leaving the current tab page.
4145  * When autocommands change "curtab" we don't leave the tab page and return
4146  * FAIL.
4147  * Careful: When OK is returned need to get a new tab page very very soon!
4148  */
4149     static int
4150 leave_tabpage(
4151     buf_T	*new_curbuf UNUSED,    // what is going to be the new curbuf,
4152 				       // NULL if unknown
4153     int		trigger_leave_autocmds UNUSED)
4154 {
4155     tabpage_T	*tp = curtab;
4156 
4157 #ifdef FEAT_JOB_CHANNEL
4158     leaving_window(curwin);
4159 #endif
4160     reset_VIsual_and_resel();	// stop Visual mode
4161     if (trigger_leave_autocmds)
4162     {
4163 	if (new_curbuf != curbuf)
4164 	{
4165 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4166 	    if (curtab != tp)
4167 		return FAIL;
4168 	}
4169 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4170 	if (curtab != tp)
4171 	    return FAIL;
4172 	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
4173 	if (curtab != tp)
4174 	    return FAIL;
4175     }
4176 #if defined(FEAT_GUI)
4177     // Remove the scrollbars.  They may be added back later.
4178     if (gui.in_use)
4179 	gui_remove_scrollbars();
4180 #endif
4181     tp->tp_curwin = curwin;
4182     tp->tp_prevwin = prevwin;
4183     tp->tp_firstwin = firstwin;
4184     tp->tp_lastwin = lastwin;
4185     tp->tp_old_Rows = Rows;
4186     tp->tp_old_Columns = Columns;
4187     firstwin = NULL;
4188     lastwin = NULL;
4189     return OK;
4190 }
4191 
4192 /*
4193  * Start using tab page "tp".
4194  * Only to be used after leave_tabpage() or freeing the current tab page.
4195  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4196  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4197  */
4198     static void
4199 enter_tabpage(
4200     tabpage_T	*tp,
4201     buf_T	*old_curbuf UNUSED,
4202     int		trigger_enter_autocmds,
4203     int		trigger_leave_autocmds)
4204 {
4205     int		row;
4206     int		old_off = tp->tp_firstwin->w_winrow;
4207     win_T	*next_prevwin = tp->tp_prevwin;
4208     tabpage_T	*last_tab = curtab;
4209 
4210     curtab = tp;
4211     firstwin = tp->tp_firstwin;
4212     lastwin = tp->tp_lastwin;
4213     topframe = tp->tp_topframe;
4214 
4215     // We would like doing the TabEnter event first, but we don't have a
4216     // valid current window yet, which may break some commands.
4217     // This triggers autocommands, thus may make "tp" invalid.
4218     (void)win_enter_ext(tp->tp_curwin, WEE_CURWIN_INVALID
4219 		  | (trigger_enter_autocmds ? WEE_TRIGGER_ENTER_AUTOCMDS : 0)
4220 		  | (trigger_leave_autocmds ? WEE_TRIGGER_LEAVE_AUTOCMDS : 0));
4221     prevwin = next_prevwin;
4222 
4223     last_status(FALSE);		// status line may appear or disappear
4224     row = win_comp_pos();	// recompute w_winrow for all windows
4225 #ifdef FEAT_DIFF
4226     diff_need_scrollbind = TRUE;
4227 #endif
4228 
4229     // The tabpage line may have appeared or disappeared, may need to resize
4230     // the frames for that.  When the Vim window was resized need to update
4231     // frame sizes too.  Use the stored value of p_ch, so that it can be
4232     // different for each tab page.
4233     if (p_ch != curtab->tp_ch_used)
4234 	clear_cmdline = TRUE;
4235     p_ch = curtab->tp_ch_used;
4236 
4237     // When cmdheight is changed in a tab page with '<C-w>-', cmdline_row is
4238     // changed but p_ch and tp_ch_used are not changed. Thus we also need to
4239     // check cmdline_row.
4240     if ((row < cmdline_row) && (cmdline_row <= Rows - p_ch))
4241 	clear_cmdline = TRUE;
4242 
4243     if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
4244 #ifdef FEAT_GUI_TABLINE
4245 			    && !gui_use_tabline()
4246 #endif
4247 		))
4248 	shell_new_rows();
4249     if (curtab->tp_old_Columns != Columns && starting == 0)
4250 	shell_new_columns();	// update window widths
4251 
4252     lastused_tabpage = last_tab;
4253 
4254 #if defined(FEAT_GUI)
4255     // When 'guioptions' includes 'L' or 'R' may have to remove or add
4256     // scrollbars.  Have to update them anyway.
4257     gui_may_update_scrollbars();
4258 #endif
4259 
4260     // Apply autocommands after updating the display, when 'rows' and
4261     // 'columns' have been set correctly.
4262     if (trigger_enter_autocmds)
4263     {
4264 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
4265 	if (old_curbuf != curbuf)
4266 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4267     }
4268 
4269     redraw_all_later(NOT_VALID);
4270 }
4271 
4272 /*
4273  * Go to tab page "n".  For ":tab N" and "Ngt".
4274  * When "n" is 9999 go to the last tab page.
4275  */
4276     void
4277 goto_tabpage(int n)
4278 {
4279     tabpage_T	*tp = NULL;  // shut up compiler
4280     tabpage_T	*ttp;
4281     int		i;
4282 
4283     if (text_locked())
4284     {
4285 	// Not allowed when editing the command line.
4286 	text_locked_msg();
4287 	return;
4288     }
4289 
4290     // If there is only one it can't work.
4291     if (first_tabpage->tp_next == NULL)
4292     {
4293 	if (n > 1)
4294 	    beep_flush();
4295 	return;
4296     }
4297 
4298     if (n == 0)
4299     {
4300 	// No count, go to next tab page, wrap around end.
4301 	if (curtab->tp_next == NULL)
4302 	    tp = first_tabpage;
4303 	else
4304 	    tp = curtab->tp_next;
4305     }
4306     else if (n < 0)
4307     {
4308 	// "gT": go to previous tab page, wrap around end.  "N gT" repeats
4309 	// this N times.
4310 	ttp = curtab;
4311 	for (i = n; i < 0; ++i)
4312 	{
4313 	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
4314 		    tp = tp->tp_next)
4315 		;
4316 	    ttp = tp;
4317 	}
4318     }
4319     else if (n == 9999)
4320     {
4321 	// Go to last tab page.
4322 	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
4323 	    ;
4324     }
4325     else
4326     {
4327 	// Go to tab page "n".
4328 	tp = find_tabpage(n);
4329 	if (tp == NULL)
4330 	{
4331 	    beep_flush();
4332 	    return;
4333 	}
4334     }
4335 
4336     goto_tabpage_tp(tp, TRUE, TRUE);
4337 
4338 #ifdef FEAT_GUI_TABLINE
4339     if (gui_use_tabline())
4340 	gui_mch_set_curtab(tabpage_index(curtab));
4341 #endif
4342 }
4343 
4344 /*
4345  * Go to tabpage "tp".
4346  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4347  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4348  * Note: doesn't update the GUI tab.
4349  */
4350     void
4351 goto_tabpage_tp(
4352     tabpage_T	*tp,
4353     int		trigger_enter_autocmds,
4354     int		trigger_leave_autocmds)
4355 {
4356     // Don't repeat a message in another tab page.
4357     set_keep_msg(NULL, 0);
4358 
4359     if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
4360 					trigger_leave_autocmds) == OK)
4361     {
4362 	if (valid_tabpage(tp))
4363 	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
4364 		    trigger_leave_autocmds);
4365 	else
4366 	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
4367 		    trigger_leave_autocmds);
4368     }
4369 }
4370 
4371 /*
4372  * Go to the last accessed tab page, if there is one.
4373  * Return OK or FAIL
4374  */
4375     int
4376 goto_tabpage_lastused(void)
4377 {
4378     if (valid_tabpage(lastused_tabpage))
4379     {
4380 	goto_tabpage_tp(lastused_tabpage, TRUE, TRUE);
4381 	return OK;
4382     }
4383     return FAIL;
4384 }
4385 
4386 /*
4387  * Enter window "wp" in tab page "tp".
4388  * Also updates the GUI tab.
4389  */
4390     void
4391 goto_tabpage_win(tabpage_T *tp, win_T *wp)
4392 {
4393     goto_tabpage_tp(tp, TRUE, TRUE);
4394     if (curtab == tp && win_valid(wp))
4395     {
4396 	win_enter(wp, TRUE);
4397 # ifdef FEAT_GUI_TABLINE
4398 	if (gui_use_tabline())
4399 	    gui_mch_set_curtab(tabpage_index(curtab));
4400 # endif
4401     }
4402 }
4403 
4404 /*
4405  * Move the current tab page to after tab page "nr".
4406  */
4407     void
4408 tabpage_move(int nr)
4409 {
4410     int		n = 1;
4411     tabpage_T	*tp, *tp_dst;
4412 
4413     if (first_tabpage->tp_next == NULL)
4414 	return;
4415 
4416     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
4417 	++n;
4418 
4419     if (tp == curtab || (nr > 0 && tp->tp_next != NULL
4420 						    && tp->tp_next == curtab))
4421 	return;
4422 
4423     tp_dst = tp;
4424 
4425     // Remove the current tab page from the list of tab pages.
4426     if (curtab == first_tabpage)
4427 	first_tabpage = curtab->tp_next;
4428     else
4429     {
4430 	FOR_ALL_TABPAGES(tp)
4431 	    if (tp->tp_next == curtab)
4432 		break;
4433 	if (tp == NULL)	// "cannot happen"
4434 	    return;
4435 	tp->tp_next = curtab->tp_next;
4436     }
4437 
4438     // Re-insert it at the specified position.
4439     if (nr <= 0)
4440     {
4441 	curtab->tp_next = first_tabpage;
4442 	first_tabpage = curtab;
4443     }
4444     else
4445     {
4446 	curtab->tp_next = tp_dst->tp_next;
4447 	tp_dst->tp_next = curtab;
4448     }
4449 
4450     // Need to redraw the tabline.  Tab page contents doesn't change.
4451     redraw_tabline = TRUE;
4452 }
4453 
4454 
4455 /*
4456  * Go to another window.
4457  * When jumping to another buffer, stop Visual mode.  Do this before
4458  * changing windows so we can yank the selection into the '*' register.
4459  * When jumping to another window on the same buffer, adjust its cursor
4460  * position to keep the same Visual area.
4461  */
4462     void
4463 win_goto(win_T *wp)
4464 {
4465 #ifdef FEAT_CONCEAL
4466     win_T	*owp = curwin;
4467 #endif
4468 
4469 #ifdef FEAT_PROP_POPUP
4470     if (ERROR_IF_ANY_POPUP_WINDOW)
4471 	return;
4472     if (popup_is_popup(wp))
4473     {
4474 	emsg(_("E366: Not allowed to enter a popup window"));
4475 	return;
4476     }
4477 #endif
4478     if (text_and_win_locked())
4479     {
4480 	beep_flush();
4481 	text_locked_msg();
4482 	return;
4483     }
4484     if (curbuf_locked())
4485 	return;
4486 
4487     if (wp->w_buffer != curbuf)
4488 	reset_VIsual_and_resel();
4489     else if (VIsual_active)
4490 	wp->w_cursor = curwin->w_cursor;
4491 
4492 #ifdef FEAT_GUI
4493     need_mouse_correct = TRUE;
4494 #endif
4495     win_enter(wp, TRUE);
4496 
4497 #ifdef FEAT_CONCEAL
4498     // Conceal cursor line in previous window, unconceal in current window.
4499     if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
4500 	redrawWinline(owp, owp->w_cursor.lnum);
4501     if (curwin->w_p_cole > 0 && !msg_scrolled)
4502 	need_cursor_line_redraw = TRUE;
4503 #endif
4504 }
4505 
4506 #if defined(FEAT_PERL) || defined(PROTO)
4507 /*
4508  * Find window number "winnr" (counting top to bottom).
4509  */
4510     win_T *
4511 win_find_nr(int winnr)
4512 {
4513     win_T	*wp;
4514 
4515     FOR_ALL_WINDOWS(wp)
4516 	if (--winnr == 0)
4517 	    break;
4518     return wp;
4519 }
4520 #endif
4521 
4522 #if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
4523 /*
4524  * Find the tabpage for window "win".
4525  */
4526     tabpage_T *
4527 win_find_tabpage(win_T *win)
4528 {
4529     win_T	*wp;
4530     tabpage_T	*tp;
4531 
4532     FOR_ALL_TAB_WINDOWS(tp, wp)
4533 	    if (wp == win)
4534 		return tp;
4535     return NULL;
4536 }
4537 #endif
4538 
4539 /*
4540  * Get the above or below neighbor window of the specified window.
4541  *   up - TRUE for the above neighbor
4542  *   count - nth neighbor window
4543  * Returns the specified window if the neighbor is not found.
4544  */
4545     win_T *
4546 win_vert_neighbor(tabpage_T *tp, win_T *wp, int up, long count)
4547 {
4548     frame_T	*fr;
4549     frame_T	*nfr;
4550     frame_T	*foundfr;
4551 
4552 #ifdef FEAT_PROP_POPUP
4553     if (popup_is_popup(wp))
4554 	// popups don't have neighbors.
4555 	return NULL;
4556 #endif
4557     foundfr = wp->w_frame;
4558     while (count--)
4559     {
4560 	/*
4561 	 * First go upwards in the tree of frames until we find a upwards or
4562 	 * downwards neighbor.
4563 	 */
4564 	fr = foundfr;
4565 	for (;;)
4566 	{
4567 	    if (fr == tp->tp_topframe)
4568 		goto end;
4569 	    if (up)
4570 		nfr = fr->fr_prev;
4571 	    else
4572 		nfr = fr->fr_next;
4573 	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
4574 		break;
4575 	    fr = fr->fr_parent;
4576 	}
4577 
4578 	/*
4579 	 * Now go downwards to find the bottom or top frame in it.
4580 	 */
4581 	for (;;)
4582 	{
4583 	    if (nfr->fr_layout == FR_LEAF)
4584 	    {
4585 		foundfr = nfr;
4586 		break;
4587 	    }
4588 	    fr = nfr->fr_child;
4589 	    if (nfr->fr_layout == FR_ROW)
4590 	    {
4591 		// Find the frame at the cursor row.
4592 		while (fr->fr_next != NULL
4593 			&& frame2win(fr)->w_wincol + fr->fr_width
4594 					 <= wp->w_wincol + wp->w_wcol)
4595 		    fr = fr->fr_next;
4596 	    }
4597 	    if (nfr->fr_layout == FR_COL && up)
4598 		while (fr->fr_next != NULL)
4599 		    fr = fr->fr_next;
4600 	    nfr = fr;
4601 	}
4602     }
4603 end:
4604     return foundfr != NULL ? foundfr->fr_win : NULL;
4605 }
4606 
4607 /*
4608  * Move to window above or below "count" times.
4609  */
4610     static void
4611 win_goto_ver(
4612     int		up,		// TRUE to go to win above
4613     long	count)
4614 {
4615     win_T	*win;
4616 
4617 #ifdef FEAT_PROP_POPUP
4618     if (ERROR_IF_TERM_POPUP_WINDOW)
4619 	return;
4620 #endif
4621     win = win_vert_neighbor(curtab, curwin, up, count);
4622     if (win != NULL)
4623 	win_goto(win);
4624 }
4625 
4626 /*
4627  * Get the left or right neighbor window of the specified window.
4628  *   left - TRUE for the left neighbor
4629  *   count - nth neighbor window
4630  * Returns the specified window if the neighbor is not found.
4631  */
4632     win_T *
4633 win_horz_neighbor(tabpage_T *tp, win_T *wp, int left, long count)
4634 {
4635     frame_T	*fr;
4636     frame_T	*nfr;
4637     frame_T	*foundfr;
4638 
4639 #ifdef FEAT_PROP_POPUP
4640     if (popup_is_popup(wp))
4641 	// popups don't have neighbors.
4642 	return NULL;
4643 #endif
4644     foundfr = wp->w_frame;
4645     while (count--)
4646     {
4647 	/*
4648 	 * First go upwards in the tree of frames until we find a left or
4649 	 * right neighbor.
4650 	 */
4651 	fr = foundfr;
4652 	for (;;)
4653 	{
4654 	    if (fr == tp->tp_topframe)
4655 		goto end;
4656 	    if (left)
4657 		nfr = fr->fr_prev;
4658 	    else
4659 		nfr = fr->fr_next;
4660 	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
4661 		break;
4662 	    fr = fr->fr_parent;
4663 	}
4664 
4665 	/*
4666 	 * Now go downwards to find the leftmost or rightmost frame in it.
4667 	 */
4668 	for (;;)
4669 	{
4670 	    if (nfr->fr_layout == FR_LEAF)
4671 	    {
4672 		foundfr = nfr;
4673 		break;
4674 	    }
4675 	    fr = nfr->fr_child;
4676 	    if (nfr->fr_layout == FR_COL)
4677 	    {
4678 		// Find the frame at the cursor row.
4679 		while (fr->fr_next != NULL
4680 			&& frame2win(fr)->w_winrow + fr->fr_height
4681 					 <= wp->w_winrow + wp->w_wrow)
4682 		    fr = fr->fr_next;
4683 	    }
4684 	    if (nfr->fr_layout == FR_ROW && left)
4685 		while (fr->fr_next != NULL)
4686 		    fr = fr->fr_next;
4687 	    nfr = fr;
4688 	}
4689     }
4690 end:
4691     return foundfr != NULL ? foundfr->fr_win : NULL;
4692 }
4693 
4694 /*
4695  * Move to left or right window.
4696  */
4697     static void
4698 win_goto_hor(
4699     int		left,		// TRUE to go to left win
4700     long	count)
4701 {
4702     win_T	*win;
4703 
4704 #ifdef FEAT_PROP_POPUP
4705     if (ERROR_IF_TERM_POPUP_WINDOW)
4706 	return;
4707 #endif
4708     win = win_horz_neighbor(curtab, curwin, left, count);
4709     if (win != NULL)
4710 	win_goto(win);
4711 }
4712 
4713 /*
4714  * Make window "wp" the current window.
4715  */
4716     void
4717 win_enter(win_T *wp, int undo_sync)
4718 {
4719     (void)win_enter_ext(wp, (undo_sync ? WEE_UNDO_SYNC : 0)
4720 		    | WEE_TRIGGER_ENTER_AUTOCMDS | WEE_TRIGGER_LEAVE_AUTOCMDS);
4721 }
4722 
4723 /*
4724  * Make window "wp" the current window.
4725  * Can be called with "flags" containing WEE_CURWIN_INVALID, which means that
4726  * curwin has just been closed and isn't valid.
4727  * Returns TRUE when dont_parse_messages was decremented.
4728  */
4729     static int
4730 win_enter_ext(win_T *wp, int flags)
4731 {
4732     int		other_buffer = FALSE;
4733     int		curwin_invalid = (flags & WEE_CURWIN_INVALID);
4734     int		did_decrement = FALSE;
4735 
4736     if (wp == curwin && !curwin_invalid)	// nothing to do
4737 	return FALSE;
4738 
4739 #ifdef FEAT_JOB_CHANNEL
4740     if (!curwin_invalid)
4741 	leaving_window(curwin);
4742 #endif
4743 
4744     if (!curwin_invalid && (flags & WEE_TRIGGER_LEAVE_AUTOCMDS))
4745     {
4746 	/*
4747 	 * Be careful: If autocommands delete the window, return now.
4748 	 */
4749 	if (wp->w_buffer != curbuf)
4750 	{
4751 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4752 	    other_buffer = TRUE;
4753 	    if (!win_valid(wp))
4754 		return FALSE;
4755 	}
4756 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4757 	if (!win_valid(wp))
4758 	    return FALSE;
4759 #ifdef FEAT_EVAL
4760 	// autocmds may abort script processing
4761 	if (aborting())
4762 	    return FALSE;
4763 #endif
4764     }
4765 
4766     // sync undo before leaving the current buffer
4767     if ((flags & WEE_UNDO_SYNC) && curbuf != wp->w_buffer)
4768 	u_sync(FALSE);
4769 
4770     // Might need to scroll the old window before switching, e.g., when the
4771     // cursor was moved.
4772     update_topline();
4773 
4774     // may have to copy the buffer options when 'cpo' contains 'S'
4775     if (wp->w_buffer != curbuf)
4776 	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
4777     if (!curwin_invalid)
4778     {
4779 	prevwin = curwin;	// remember for CTRL-W p
4780 	curwin->w_redr_status = TRUE;
4781     }
4782     curwin = wp;
4783     curbuf = wp->w_buffer;
4784     check_cursor();
4785     if (!virtual_active())
4786 	curwin->w_cursor.coladd = 0;
4787     changed_line_abv_curs();	// assume cursor position needs updating
4788 
4789     // Now it is OK to parse messages again, which may be needed in
4790     // autocommands.
4791 #ifdef MESSAGE_QUEUE
4792     if (flags & WEE_ALLOW_PARSE_MESSAGES)
4793     {
4794 	--dont_parse_messages;
4795 	did_decrement = TRUE;
4796     }
4797 #endif
4798 
4799     if (curwin->w_localdir != NULL || curtab->tp_localdir != NULL)
4800     {
4801 	char_u	*dirname;
4802 
4803 	// Window or tab has a local directory: Save current directory as
4804 	// global directory (unless that was done already) and change to the
4805 	// local directory.
4806 	if (globaldir == NULL)
4807 	{
4808 	    char_u	cwd[MAXPATHL];
4809 
4810 	    if (mch_dirname(cwd, MAXPATHL) == OK)
4811 		globaldir = vim_strsave(cwd);
4812 	}
4813 	if (curwin->w_localdir != NULL)
4814 	    dirname = curwin->w_localdir;
4815 	else
4816 	    dirname = curtab->tp_localdir;
4817 
4818 	if (mch_chdir((char *)dirname) == 0)
4819 	    shorten_fnames(TRUE);
4820     }
4821     else if (globaldir != NULL)
4822     {
4823 	// Window doesn't have a local directory and we are not in the global
4824 	// directory: Change to the global directory.
4825 	vim_ignored = mch_chdir((char *)globaldir);
4826 	VIM_CLEAR(globaldir);
4827 	shorten_fnames(TRUE);
4828     }
4829 
4830 #ifdef FEAT_JOB_CHANNEL
4831     entering_window(curwin);
4832 #endif
4833     // Careful: autocommands may close the window and make "wp" invalid
4834     if (flags & WEE_TRIGGER_NEW_AUTOCMDS)
4835 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
4836     if (flags & WEE_TRIGGER_ENTER_AUTOCMDS)
4837     {
4838 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
4839 	if (other_buffer)
4840 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4841     }
4842 
4843 #ifdef FEAT_TITLE
4844     maketitle();
4845 #endif
4846     curwin->w_redr_status = TRUE;
4847 #ifdef FEAT_TERMINAL
4848     if (bt_terminal(curwin->w_buffer))
4849 	// terminal is likely in another mode
4850 	redraw_mode = TRUE;
4851 #endif
4852     redraw_tabline = TRUE;
4853     if (restart_edit)
4854 	redraw_later(VALID);	// causes status line redraw
4855 
4856     // set window height to desired minimal value
4857     if (curwin->w_height < p_wh && !curwin->w_p_wfh
4858 #ifdef FEAT_PROP_POPUP
4859 	    && !popup_is_popup(curwin)
4860 #endif
4861 	    )
4862 	win_setheight((int)p_wh);
4863     else if (curwin->w_height == 0)
4864 	win_setheight(1);
4865 
4866     // set window width to desired minimal value
4867     if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
4868 	win_setwidth((int)p_wiw);
4869 
4870     setmouse();			// in case jumped to/from help buffer
4871 
4872     // Change directories when the 'acd' option is set.
4873     DO_AUTOCHDIR;
4874 
4875     return did_decrement;
4876 }
4877 
4878 
4879 /*
4880  * Jump to the first open window that contains buffer "buf", if one exists.
4881  * Returns a pointer to the window found, otherwise NULL.
4882  */
4883     win_T *
4884 buf_jump_open_win(buf_T *buf)
4885 {
4886     win_T	*wp = NULL;
4887 
4888     if (curwin->w_buffer == buf)
4889 	wp = curwin;
4890     else
4891 	FOR_ALL_WINDOWS(wp)
4892 	    if (wp->w_buffer == buf)
4893 		break;
4894     if (wp != NULL)
4895 	win_enter(wp, FALSE);
4896     return wp;
4897 }
4898 
4899 /*
4900  * Jump to the first open window in any tab page that contains buffer "buf",
4901  * if one exists.
4902  * Returns a pointer to the window found, otherwise NULL.
4903  */
4904     win_T *
4905 buf_jump_open_tab(buf_T *buf)
4906 {
4907     win_T	*wp = buf_jump_open_win(buf);
4908     tabpage_T	*tp;
4909 
4910     if (wp != NULL)
4911 	return wp;
4912 
4913     FOR_ALL_TABPAGES(tp)
4914 	if (tp != curtab)
4915 	{
4916 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
4917 		if (wp->w_buffer == buf)
4918 		    break;
4919 	    if (wp != NULL)
4920 	    {
4921 		goto_tabpage_win(tp, wp);
4922 		if (curwin != wp)
4923 		    wp = NULL;	// something went wrong
4924 		break;
4925 	    }
4926 	}
4927     return wp;
4928 }
4929 
4930 static int last_win_id = LOWEST_WIN_ID - 1;
4931 
4932 /*
4933  * Allocate a window structure and link it in the window list when "hidden" is
4934  * FALSE.
4935  */
4936     static win_T *
4937 win_alloc(win_T *after UNUSED, int hidden UNUSED)
4938 {
4939     win_T	*new_wp;
4940 
4941     /*
4942      * allocate window structure and linesizes arrays
4943      */
4944     new_wp = ALLOC_CLEAR_ONE(win_T);
4945     if (new_wp == NULL)
4946 	return NULL;
4947 
4948     if (win_alloc_lines(new_wp) == FAIL)
4949     {
4950 	vim_free(new_wp);
4951 	return NULL;
4952     }
4953 
4954     new_wp->w_id = ++last_win_id;
4955 
4956 #ifdef FEAT_EVAL
4957     // init w: variables
4958     new_wp->w_vars = dict_alloc();
4959     if (new_wp->w_vars == NULL)
4960     {
4961 	win_free_lsize(new_wp);
4962 	vim_free(new_wp);
4963 	return NULL;
4964     }
4965     init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
4966 #endif
4967 
4968     // Don't execute autocommands while the window is not properly
4969     // initialized yet.  gui_create_scrollbar() may trigger a FocusGained
4970     // event.
4971     block_autocmds();
4972 
4973     /*
4974      * link the window in the window list
4975      */
4976     if (!hidden)
4977 	win_append(after, new_wp);
4978     new_wp->w_wincol = 0;
4979     new_wp->w_width = Columns;
4980 
4981     // position the display and the cursor at the top of the file.
4982     new_wp->w_topline = 1;
4983 #ifdef FEAT_DIFF
4984     new_wp->w_topfill = 0;
4985 #endif
4986     new_wp->w_botline = 2;
4987     new_wp->w_cursor.lnum = 1;
4988     new_wp->w_scbind_pos = 1;
4989 
4990     // use global option value for global-local options
4991     new_wp->w_p_so = -1;
4992     new_wp->w_p_siso = -1;
4993 
4994     // We won't calculate w_fraction until resizing the window
4995     new_wp->w_fraction = 0;
4996     new_wp->w_prev_fraction_row = -1;
4997 
4998 #ifdef FEAT_GUI
4999     if (gui.in_use)
5000     {
5001 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
5002 		SBAR_LEFT, new_wp);
5003 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
5004 		SBAR_RIGHT, new_wp);
5005     }
5006 #endif
5007 #ifdef FEAT_FOLDING
5008     foldInitWin(new_wp);
5009 #endif
5010     unblock_autocmds();
5011 #ifdef FEAT_SEARCH_EXTRA
5012     new_wp->w_match_head = NULL;
5013     new_wp->w_next_match_id = 4;
5014 #endif
5015     return new_wp;
5016 }
5017 
5018 /*
5019  * Remove window 'wp' from the window list and free the structure.
5020  */
5021     static void
5022 win_free(
5023     win_T	*wp,
5024     tabpage_T	*tp)		// tab page "win" is in, NULL for current
5025 {
5026     int		i;
5027     buf_T	*buf;
5028     wininfo_T	*wip;
5029 
5030 #ifdef FEAT_FOLDING
5031     clearFolding(wp);
5032 #endif
5033 
5034     // reduce the reference count to the argument list.
5035     alist_unlink(wp->w_alist);
5036 
5037     // Don't execute autocommands while the window is halfway being deleted.
5038     // gui_mch_destroy_scrollbar() may trigger a FocusGained event.
5039     block_autocmds();
5040 
5041 #ifdef FEAT_LUA
5042     lua_window_free(wp);
5043 #endif
5044 
5045 #ifdef FEAT_MZSCHEME
5046     mzscheme_window_free(wp);
5047 #endif
5048 
5049 #ifdef FEAT_PERL
5050     perl_win_free(wp);
5051 #endif
5052 
5053 #ifdef FEAT_PYTHON
5054     python_window_free(wp);
5055 #endif
5056 
5057 #ifdef FEAT_PYTHON3
5058     python3_window_free(wp);
5059 #endif
5060 
5061 #ifdef FEAT_TCL
5062     tcl_window_free(wp);
5063 #endif
5064 
5065 #ifdef FEAT_RUBY
5066     ruby_window_free(wp);
5067 #endif
5068 
5069     clear_winopt(&wp->w_onebuf_opt);
5070     clear_winopt(&wp->w_allbuf_opt);
5071 
5072     vim_free(wp->w_lcs_chars.multispace);
5073 
5074 #ifdef FEAT_EVAL
5075     vars_clear(&wp->w_vars->dv_hashtab);	// free all w: variables
5076     hash_init(&wp->w_vars->dv_hashtab);
5077     unref_var_dict(wp->w_vars);
5078 #endif
5079 
5080     {
5081 	tabpage_T	*ttp;
5082 
5083 	if (prevwin == wp)
5084 	    prevwin = NULL;
5085 	FOR_ALL_TABPAGES(ttp)
5086 	    if (ttp->tp_prevwin == wp)
5087 		ttp->tp_prevwin = NULL;
5088     }
5089     win_free_lsize(wp);
5090 
5091     for (i = 0; i < wp->w_tagstacklen; ++i)
5092     {
5093 	vim_free(wp->w_tagstack[i].tagname);
5094 	vim_free(wp->w_tagstack[i].user_data);
5095     }
5096     vim_free(wp->w_localdir);
5097     vim_free(wp->w_prevdir);
5098 
5099     // Remove the window from the b_wininfo lists, it may happen that the
5100     // freed memory is re-used for another window.
5101     FOR_ALL_BUFFERS(buf)
5102 	FOR_ALL_BUF_WININFO(buf, wip)
5103 	    if (wip->wi_win == wp)
5104 	    {
5105 		wininfo_T	*wip2;
5106 
5107 		// If there already is an entry with "wi_win" set to NULL it
5108 		// must be removed, it would never be used.
5109 		// Skip "wip" itself, otherwise Coverity complains.
5110 		for (wip2 = buf->b_wininfo; wip2 != NULL; wip2 = wip2->wi_next)
5111 		    if (wip2 != wip && wip2->wi_win == NULL)
5112 		    {
5113 			if (wip2->wi_next != NULL)
5114 			    wip2->wi_next->wi_prev = wip2->wi_prev;
5115 			if (wip2->wi_prev == NULL)
5116 			    buf->b_wininfo = wip2->wi_next;
5117 			else
5118 			    wip2->wi_prev->wi_next = wip2->wi_next;
5119 			free_wininfo(wip2);
5120 			break;
5121 		    }
5122 
5123 		wip->wi_win = NULL;
5124 	    }
5125 
5126 #ifdef FEAT_SEARCH_EXTRA
5127     clear_matches(wp);
5128 #endif
5129 
5130 #ifdef FEAT_JUMPLIST
5131     free_jumplist(wp);
5132 #endif
5133 
5134 #ifdef FEAT_QUICKFIX
5135     qf_free_all(wp);
5136 #endif
5137 
5138 #ifdef FEAT_GUI
5139     if (gui.in_use)
5140     {
5141 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
5142 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
5143     }
5144 #endif // FEAT_GUI
5145 
5146 #ifdef FEAT_MENU
5147     remove_winbar(wp);
5148 #endif
5149 #ifdef FEAT_PROP_POPUP
5150     free_callback(&wp->w_close_cb);
5151     free_callback(&wp->w_filter_cb);
5152     for (i = 0; i < 4; ++i)
5153 	VIM_CLEAR(wp->w_border_highlight[i]);
5154     vim_free(wp->w_scrollbar_highlight);
5155     vim_free(wp->w_thumb_highlight);
5156     vim_free(wp->w_popup_title);
5157     list_unref(wp->w_popup_mask);
5158     vim_free(wp->w_popup_mask_cells);
5159 #endif
5160 
5161 #ifdef FEAT_SYN_HL
5162     vim_free(wp->w_p_cc_cols);
5163 #endif
5164 
5165     if (win_valid_any_tab(wp))
5166 	win_remove(wp, tp);
5167     if (autocmd_busy)
5168     {
5169 	wp->w_next = au_pending_free_win;
5170 	au_pending_free_win = wp;
5171     }
5172     else
5173 	vim_free(wp);
5174 
5175     unblock_autocmds();
5176 }
5177 
5178 /*
5179  * Return TRUE if "wp" is not in the list of windows: the autocmd window or a
5180  * popup window.
5181  */
5182     static int
5183 win_unlisted(win_T *wp)
5184 {
5185     return wp == aucmd_win || WIN_IS_POPUP(wp);
5186 }
5187 
5188 #if defined(FEAT_PROP_POPUP) || defined(PROTO)
5189 /*
5190  * Free a popup window.  This does not take the window out of the window list
5191  * and assumes there is only one toplevel frame, no split.
5192  */
5193     void
5194 win_free_popup(win_T *win)
5195 {
5196     if (bt_popup(win->w_buffer))
5197 	win_close_buffer(win, DOBUF_WIPE_REUSE, FALSE);
5198     else
5199 	close_buffer(win, win->w_buffer, 0, FALSE, FALSE);
5200 # if defined(FEAT_TIMERS)
5201     if (win->w_popup_timer != NULL)
5202 	stop_timer(win->w_popup_timer);
5203 # endif
5204     vim_free(win->w_frame);
5205     win_free(win, NULL);
5206 }
5207 #endif
5208 
5209 /*
5210  * Append window "wp" in the window list after window "after".
5211  */
5212     static void
5213 win_append(win_T *after, win_T *wp)
5214 {
5215     win_T	*before;
5216 
5217     if (after == NULL)	    // after NULL is in front of the first
5218 	before = firstwin;
5219     else
5220 	before = after->w_next;
5221 
5222     wp->w_next = before;
5223     wp->w_prev = after;
5224     if (after == NULL)
5225 	firstwin = wp;
5226     else
5227 	after->w_next = wp;
5228     if (before == NULL)
5229 	lastwin = wp;
5230     else
5231 	before->w_prev = wp;
5232 }
5233 
5234 /*
5235  * Remove a window from the window list.
5236  */
5237     void
5238 win_remove(
5239     win_T	*wp,
5240     tabpage_T	*tp)		// tab page "win" is in, NULL for current
5241 {
5242     if (wp->w_prev != NULL)
5243 	wp->w_prev->w_next = wp->w_next;
5244     else if (tp == NULL)
5245 	firstwin = curtab->tp_firstwin = wp->w_next;
5246     else
5247 	tp->tp_firstwin = wp->w_next;
5248 
5249     if (wp->w_next != NULL)
5250 	wp->w_next->w_prev = wp->w_prev;
5251     else if (tp == NULL)
5252 	lastwin = curtab->tp_lastwin = wp->w_prev;
5253     else
5254 	tp->tp_lastwin = wp->w_prev;
5255 }
5256 
5257 /*
5258  * Append frame "frp" in a frame list after frame "after".
5259  */
5260     static void
5261 frame_append(frame_T *after, frame_T *frp)
5262 {
5263     frp->fr_next = after->fr_next;
5264     after->fr_next = frp;
5265     if (frp->fr_next != NULL)
5266 	frp->fr_next->fr_prev = frp;
5267     frp->fr_prev = after;
5268 }
5269 
5270 /*
5271  * Insert frame "frp" in a frame list before frame "before".
5272  */
5273     static void
5274 frame_insert(frame_T *before, frame_T *frp)
5275 {
5276     frp->fr_next = before;
5277     frp->fr_prev = before->fr_prev;
5278     before->fr_prev = frp;
5279     if (frp->fr_prev != NULL)
5280 	frp->fr_prev->fr_next = frp;
5281     else
5282 	frp->fr_parent->fr_child = frp;
5283 }
5284 
5285 /*
5286  * Remove a frame from a frame list.
5287  */
5288     static void
5289 frame_remove(frame_T *frp)
5290 {
5291     if (frp->fr_prev != NULL)
5292 	frp->fr_prev->fr_next = frp->fr_next;
5293     else
5294 	frp->fr_parent->fr_child = frp->fr_next;
5295     if (frp->fr_next != NULL)
5296 	frp->fr_next->fr_prev = frp->fr_prev;
5297 }
5298 
5299 /*
5300  * Allocate w_lines[] for window "wp".
5301  * Return FAIL for failure, OK for success.
5302  */
5303     int
5304 win_alloc_lines(win_T *wp)
5305 {
5306     wp->w_lines_valid = 0;
5307     wp->w_lines = ALLOC_CLEAR_MULT(wline_T, Rows );
5308     if (wp->w_lines == NULL)
5309 	return FAIL;
5310     return OK;
5311 }
5312 
5313 /*
5314  * free lsize arrays for a window
5315  */
5316     void
5317 win_free_lsize(win_T *wp)
5318 {
5319     // TODO: why would wp be NULL here?
5320     if (wp != NULL)
5321 	VIM_CLEAR(wp->w_lines);
5322 }
5323 
5324 /*
5325  * Called from win_new_shellsize() after Rows changed.
5326  * This only does the current tab page, others must be done when made active.
5327  */
5328     void
5329 shell_new_rows(void)
5330 {
5331     int		h = (int)ROWS_AVAIL;
5332 
5333     if (firstwin == NULL)	// not initialized yet
5334 	return;
5335     if (h < frame_minheight(topframe, NULL))
5336 	h = frame_minheight(topframe, NULL);
5337 
5338     // First try setting the heights of windows with 'winfixheight'.  If
5339     // that doesn't result in the right height, forget about that option.
5340     frame_new_height(topframe, h, FALSE, TRUE);
5341     if (!frame_check_height(topframe, h))
5342 	frame_new_height(topframe, h, FALSE, FALSE);
5343 
5344     (void)win_comp_pos();		// recompute w_winrow and w_wincol
5345     compute_cmdrow();
5346     curtab->tp_ch_used = p_ch;
5347 
5348 #if 0
5349     // Disabled: don't want making the screen smaller make a window larger.
5350     if (p_ea)
5351 	win_equal(curwin, FALSE, 'v');
5352 #endif
5353 }
5354 
5355 /*
5356  * Called from win_new_shellsize() after Columns changed.
5357  */
5358     void
5359 shell_new_columns(void)
5360 {
5361     if (firstwin == NULL)	// not initialized yet
5362 	return;
5363 
5364     // First try setting the widths of windows with 'winfixwidth'.  If that
5365     // doesn't result in the right width, forget about that option.
5366     frame_new_width(topframe, (int)Columns, FALSE, TRUE);
5367     if (!frame_check_width(topframe, Columns))
5368 	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
5369 
5370     (void)win_comp_pos();		// recompute w_winrow and w_wincol
5371 #if 0
5372     // Disabled: don't want making the screen smaller make a window larger.
5373     if (p_ea)
5374 	win_equal(curwin, FALSE, 'h');
5375 #endif
5376 }
5377 
5378 #if defined(FEAT_CMDWIN) || defined(PROTO)
5379 /*
5380  * Save the size of all windows in "gap".
5381  */
5382     void
5383 win_size_save(garray_T *gap)
5384 
5385 {
5386     win_T	*wp;
5387 
5388     ga_init2(gap, (int)sizeof(int), 1);
5389     if (ga_grow(gap, win_count() * 2 + 1) == OK)
5390     {
5391 	// first entry is value of 'lines'
5392 	((int *)gap->ga_data)[gap->ga_len++] = Rows;
5393 
5394 	FOR_ALL_WINDOWS(wp)
5395 	{
5396 	    ((int *)gap->ga_data)[gap->ga_len++] =
5397 					       wp->w_width + wp->w_vsep_width;
5398 	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
5399 	}
5400     }
5401 }
5402 
5403 /*
5404  * Restore window sizes, but only if the number of windows is still the same
5405  * and 'lines' didn't change.
5406  * Does not free the growarray.
5407  */
5408     void
5409 win_size_restore(garray_T *gap)
5410 {
5411     win_T	*wp;
5412     int		i, j;
5413 
5414     if (win_count() * 2 + 1 == gap->ga_len
5415 	    && ((int *)gap->ga_data)[0] == Rows)
5416     {
5417 	// The order matters, because frames contain other frames, but it's
5418 	// difficult to get right. The easy way out is to do it twice.
5419 	for (j = 0; j < 2; ++j)
5420 	{
5421 	    i = 1;
5422 	    FOR_ALL_WINDOWS(wp)
5423 	    {
5424 		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
5425 		win_setheight_win(((int *)gap->ga_data)[i++], wp);
5426 	    }
5427 	}
5428 	// recompute the window positions
5429 	(void)win_comp_pos();
5430     }
5431 }
5432 #endif // FEAT_CMDWIN
5433 
5434 /*
5435  * Update the position for all windows, using the width and height of the
5436  * frames.
5437  * Returns the row just after the last window.
5438  */
5439     int
5440 win_comp_pos(void)
5441 {
5442     int		row = tabline_height();
5443     int		col = 0;
5444 
5445     frame_comp_pos(topframe, &row, &col);
5446     return row;
5447 }
5448 
5449 /*
5450  * Update the position of the windows in frame "topfrp", using the width and
5451  * height of the frames.
5452  * "*row" and "*col" are the top-left position of the frame.  They are updated
5453  * to the bottom-right position plus one.
5454  */
5455     static void
5456 frame_comp_pos(frame_T *topfrp, int *row, int *col)
5457 {
5458     win_T	*wp;
5459     frame_T	*frp;
5460     int		startcol;
5461     int		startrow;
5462     int		h;
5463 
5464     wp = topfrp->fr_win;
5465     if (wp != NULL)
5466     {
5467 	if (wp->w_winrow != *row || wp->w_wincol != *col)
5468 	{
5469 	    // position changed, redraw
5470 	    wp->w_winrow = *row;
5471 	    wp->w_wincol = *col;
5472 	    redraw_win_later(wp, NOT_VALID);
5473 	    wp->w_redr_status = TRUE;
5474 	}
5475 	// WinBar will not show if the window height is zero
5476 	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
5477 	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
5478 	*col += wp->w_width + wp->w_vsep_width;
5479     }
5480     else
5481     {
5482 	startrow = *row;
5483 	startcol = *col;
5484 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
5485 	{
5486 	    if (topfrp->fr_layout == FR_ROW)
5487 		*row = startrow;	// all frames are at the same row
5488 	    else
5489 		*col = startcol;	// all frames are at the same col
5490 	    frame_comp_pos(frp, row, col);
5491 	}
5492     }
5493 }
5494 
5495 /*
5496  * Set current window height and take care of repositioning other windows to
5497  * fit around it.
5498  */
5499     void
5500 win_setheight(int height)
5501 {
5502     win_setheight_win(height, curwin);
5503 }
5504 
5505 /*
5506  * Set the window height of window "win" and take care of repositioning other
5507  * windows to fit around it.
5508  */
5509     void
5510 win_setheight_win(int height, win_T *win)
5511 {
5512     int		row;
5513 
5514     if (win == curwin)
5515     {
5516 	// Always keep current window at least one line high, even when
5517 	// 'winminheight' is zero.
5518 	if (height < p_wmh)
5519 	    height = p_wmh;
5520 	if (height == 0)
5521 	    height = 1;
5522 	height += WINBAR_HEIGHT(curwin);
5523     }
5524 
5525     frame_setheight(win->w_frame, height + win->w_status_height);
5526 
5527     // recompute the window positions
5528     row = win_comp_pos();
5529 
5530     /*
5531      * If there is extra space created between the last window and the command
5532      * line, clear it.
5533      */
5534     if (full_screen && msg_scrolled == 0 && row < cmdline_row)
5535 	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5536     cmdline_row = row;
5537     msg_row = row;
5538     msg_col = 0;
5539 
5540     redraw_all_later(NOT_VALID);
5541 }
5542 
5543 /*
5544  * Set the height of a frame to "height" and take care that all frames and
5545  * windows inside it are resized.  Also resize frames on the left and right if
5546  * the are in the same FR_ROW frame.
5547  *
5548  * Strategy:
5549  * If the frame is part of a FR_COL frame, try fitting the frame in that
5550  * frame.  If that doesn't work (the FR_COL frame is too small), recursively
5551  * go to containing frames to resize them and make room.
5552  * If the frame is part of a FR_ROW frame, all frames must be resized as well.
5553  * Check for the minimal height of the FR_ROW frame.
5554  * At the top level we can also use change the command line height.
5555  */
5556     static void
5557 frame_setheight(frame_T *curfrp, int height)
5558 {
5559     int		room;		// total number of lines available
5560     int		take;		// number of lines taken from other windows
5561     int		room_cmdline;	// lines available from cmdline
5562     int		run;
5563     frame_T	*frp;
5564     int		h;
5565     int		room_reserved;
5566 
5567     // If the height already is the desired value, nothing to do.
5568     if (curfrp->fr_height == height)
5569 	return;
5570 
5571     if (curfrp->fr_parent == NULL)
5572     {
5573 	// topframe: can only change the command line
5574 	if (height > ROWS_AVAIL)
5575 	    height = ROWS_AVAIL;
5576 	if (height > 0)
5577 	    frame_new_height(curfrp, height, FALSE, FALSE);
5578     }
5579     else if (curfrp->fr_parent->fr_layout == FR_ROW)
5580     {
5581 	// Row of frames: Also need to resize frames left and right of this
5582 	// one.  First check for the minimal height of these.
5583 	h = frame_minheight(curfrp->fr_parent, NULL);
5584 	if (height < h)
5585 	    height = h;
5586 	frame_setheight(curfrp->fr_parent, height);
5587     }
5588     else
5589     {
5590 	/*
5591 	 * Column of frames: try to change only frames in this column.
5592 	 */
5593 	/*
5594 	 * Do this twice:
5595 	 * 1: compute room available, if it's not enough try resizing the
5596 	 *    containing frame.
5597 	 * 2: compute the room available and adjust the height to it.
5598 	 * Try not to reduce the height of a window with 'winfixheight' set.
5599 	 */
5600 	for (run = 1; run <= 2; ++run)
5601 	{
5602 	    room = 0;
5603 	    room_reserved = 0;
5604 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5605 	    {
5606 		if (frp != curfrp
5607 			&& frp->fr_win != NULL
5608 			&& frp->fr_win->w_p_wfh)
5609 		    room_reserved += frp->fr_height;
5610 		room += frp->fr_height;
5611 		if (frp != curfrp)
5612 		    room -= frame_minheight(frp, NULL);
5613 	    }
5614 	    if (curfrp->fr_width != Columns)
5615 		room_cmdline = 0;
5616 	    else
5617 	    {
5618 		room_cmdline = Rows - p_ch - (lastwin->w_winrow
5619 						+ VISIBLE_HEIGHT(lastwin)
5620 						+ lastwin->w_status_height);
5621 		if (room_cmdline < 0)
5622 		    room_cmdline = 0;
5623 	    }
5624 
5625 	    if (height <= room + room_cmdline)
5626 		break;
5627 	    if (run == 2 || curfrp->fr_width == Columns)
5628 	    {
5629 		if (height > room + room_cmdline)
5630 		    height = room + room_cmdline;
5631 		break;
5632 	    }
5633 	    frame_setheight(curfrp->fr_parent, height
5634 		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
5635 	}
5636 
5637 	/*
5638 	 * Compute the number of lines we will take from others frames (can be
5639 	 * negative!).
5640 	 */
5641 	take = height - curfrp->fr_height;
5642 
5643 	// If there is not enough room, also reduce the height of a window
5644 	// with 'winfixheight' set.
5645 	if (height > room + room_cmdline - room_reserved)
5646 	    room_reserved = room + room_cmdline - height;
5647 	// If there is only a 'winfixheight' window and making the
5648 	// window smaller, need to make the other window taller.
5649 	if (take < 0 && room - curfrp->fr_height < room_reserved)
5650 	    room_reserved = 0;
5651 
5652 	if (take > 0 && room_cmdline > 0)
5653 	{
5654 	    // use lines from cmdline first
5655 	    if (take < room_cmdline)
5656 		room_cmdline = take;
5657 	    take -= room_cmdline;
5658 	    topframe->fr_height += room_cmdline;
5659 	}
5660 
5661 	/*
5662 	 * set the current frame to the new height
5663 	 */
5664 	frame_new_height(curfrp, height, FALSE, FALSE);
5665 
5666 	/*
5667 	 * First take lines from the frames after the current frame.  If
5668 	 * that is not enough, takes lines from frames above the current
5669 	 * frame.
5670 	 */
5671 	for (run = 0; run < 2; ++run)
5672 	{
5673 	    if (run == 0)
5674 		frp = curfrp->fr_next;	// 1st run: start with next window
5675 	    else
5676 		frp = curfrp->fr_prev;	// 2nd run: start with prev window
5677 	    while (frp != NULL && take != 0)
5678 	    {
5679 		h = frame_minheight(frp, NULL);
5680 		if (room_reserved > 0
5681 			&& frp->fr_win != NULL
5682 			&& frp->fr_win->w_p_wfh)
5683 		{
5684 		    if (room_reserved >= frp->fr_height)
5685 			room_reserved -= frp->fr_height;
5686 		    else
5687 		    {
5688 			if (frp->fr_height - room_reserved > take)
5689 			    room_reserved = frp->fr_height - take;
5690 			take -= frp->fr_height - room_reserved;
5691 			frame_new_height(frp, room_reserved, FALSE, FALSE);
5692 			room_reserved = 0;
5693 		    }
5694 		}
5695 		else
5696 		{
5697 		    if (frp->fr_height - take < h)
5698 		    {
5699 			take -= frp->fr_height - h;
5700 			frame_new_height(frp, h, FALSE, FALSE);
5701 		    }
5702 		    else
5703 		    {
5704 			frame_new_height(frp, frp->fr_height - take,
5705 								FALSE, FALSE);
5706 			take = 0;
5707 		    }
5708 		}
5709 		if (run == 0)
5710 		    frp = frp->fr_next;
5711 		else
5712 		    frp = frp->fr_prev;
5713 	    }
5714 	}
5715     }
5716 }
5717 
5718 /*
5719  * Set current window width and take care of repositioning other windows to
5720  * fit around it.
5721  */
5722     void
5723 win_setwidth(int width)
5724 {
5725     win_setwidth_win(width, curwin);
5726 }
5727 
5728     void
5729 win_setwidth_win(int width, win_T *wp)
5730 {
5731     // Always keep current window at least one column wide, even when
5732     // 'winminwidth' is zero.
5733     if (wp == curwin)
5734     {
5735 	if (width < p_wmw)
5736 	    width = p_wmw;
5737 	if (width == 0)
5738 	    width = 1;
5739     }
5740     else if (width < 0)
5741 	width = 0;
5742 
5743     frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
5744 
5745     // recompute the window positions
5746     (void)win_comp_pos();
5747 
5748     redraw_all_later(NOT_VALID);
5749 }
5750 
5751 /*
5752  * Set the width of a frame to "width" and take care that all frames and
5753  * windows inside it are resized.  Also resize frames above and below if the
5754  * are in the same FR_ROW frame.
5755  *
5756  * Strategy is similar to frame_setheight().
5757  */
5758     static void
5759 frame_setwidth(frame_T *curfrp, int width)
5760 {
5761     int		room;		// total number of lines available
5762     int		take;		// number of lines taken from other windows
5763     int		run;
5764     frame_T	*frp;
5765     int		w;
5766     int		room_reserved;
5767 
5768     // If the width already is the desired value, nothing to do.
5769     if (curfrp->fr_width == width)
5770 	return;
5771 
5772     if (curfrp->fr_parent == NULL)
5773 	// topframe: can't change width
5774 	return;
5775 
5776     if (curfrp->fr_parent->fr_layout == FR_COL)
5777     {
5778 	// Column of frames: Also need to resize frames above and below of
5779 	// this one.  First check for the minimal width of these.
5780 	w = frame_minwidth(curfrp->fr_parent, NULL);
5781 	if (width < w)
5782 	    width = w;
5783 	frame_setwidth(curfrp->fr_parent, width);
5784     }
5785     else
5786     {
5787 	/*
5788 	 * Row of frames: try to change only frames in this row.
5789 	 *
5790 	 * Do this twice:
5791 	 * 1: compute room available, if it's not enough try resizing the
5792 	 *    containing frame.
5793 	 * 2: compute the room available and adjust the width to it.
5794 	 */
5795 	for (run = 1; run <= 2; ++run)
5796 	{
5797 	    room = 0;
5798 	    room_reserved = 0;
5799 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5800 	    {
5801 		if (frp != curfrp
5802 			&& frp->fr_win != NULL
5803 			&& frp->fr_win->w_p_wfw)
5804 		    room_reserved += frp->fr_width;
5805 		room += frp->fr_width;
5806 		if (frp != curfrp)
5807 		    room -= frame_minwidth(frp, NULL);
5808 	    }
5809 
5810 	    if (width <= room)
5811 		break;
5812 	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
5813 	    {
5814 		if (width > room)
5815 		    width = room;
5816 		break;
5817 	    }
5818 	    frame_setwidth(curfrp->fr_parent, width
5819 		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
5820 	}
5821 
5822 	/*
5823 	 * Compute the number of lines we will take from others frames (can be
5824 	 * negative!).
5825 	 */
5826 	take = width - curfrp->fr_width;
5827 
5828 	// If there is not enough room, also reduce the width of a window
5829 	// with 'winfixwidth' set.
5830 	if (width > room - room_reserved)
5831 	    room_reserved = room - width;
5832 	// If there is only a 'winfixwidth' window and making the
5833 	// window smaller, need to make the other window narrower.
5834 	if (take < 0 && room - curfrp->fr_width < room_reserved)
5835 	    room_reserved = 0;
5836 
5837 	/*
5838 	 * set the current frame to the new width
5839 	 */
5840 	frame_new_width(curfrp, width, FALSE, FALSE);
5841 
5842 	/*
5843 	 * First take lines from the frames right of the current frame.  If
5844 	 * that is not enough, takes lines from frames left of the current
5845 	 * frame.
5846 	 */
5847 	for (run = 0; run < 2; ++run)
5848 	{
5849 	    if (run == 0)
5850 		frp = curfrp->fr_next;	// 1st run: start with next window
5851 	    else
5852 		frp = curfrp->fr_prev;	// 2nd run: start with prev window
5853 	    while (frp != NULL && take != 0)
5854 	    {
5855 		w = frame_minwidth(frp, NULL);
5856 		if (room_reserved > 0
5857 			&& frp->fr_win != NULL
5858 			&& frp->fr_win->w_p_wfw)
5859 		{
5860 		    if (room_reserved >= frp->fr_width)
5861 			room_reserved -= frp->fr_width;
5862 		    else
5863 		    {
5864 			if (frp->fr_width - room_reserved > take)
5865 			    room_reserved = frp->fr_width - take;
5866 			take -= frp->fr_width - room_reserved;
5867 			frame_new_width(frp, room_reserved, FALSE, FALSE);
5868 			room_reserved = 0;
5869 		    }
5870 		}
5871 		else
5872 		{
5873 		    if (frp->fr_width - take < w)
5874 		    {
5875 			take -= frp->fr_width - w;
5876 			frame_new_width(frp, w, FALSE, FALSE);
5877 		    }
5878 		    else
5879 		    {
5880 			frame_new_width(frp, frp->fr_width - take,
5881 								FALSE, FALSE);
5882 			take = 0;
5883 		    }
5884 		}
5885 		if (run == 0)
5886 		    frp = frp->fr_next;
5887 		else
5888 		    frp = frp->fr_prev;
5889 	    }
5890 	}
5891     }
5892 }
5893 
5894 /*
5895  * Check 'winminheight' for a valid value and reduce it if needed.
5896  */
5897     void
5898 win_setminheight(void)
5899 {
5900     int		room;
5901     int		needed;
5902     int		first = TRUE;
5903 
5904     // loop until there is a 'winminheight' that is possible
5905     while (p_wmh > 0)
5906     {
5907 	room = Rows - p_ch;
5908 	needed = min_rows() - 1;  // 1 was added for the cmdline
5909 	if (room >= needed)
5910 	    break;
5911 	--p_wmh;
5912 	if (first)
5913 	{
5914 	    emsg(_(e_not_enough_room));
5915 	    first = FALSE;
5916 	}
5917     }
5918 }
5919 
5920 /*
5921  * Check 'winminwidth' for a valid value and reduce it if needed.
5922  */
5923     void
5924 win_setminwidth(void)
5925 {
5926     int		room;
5927     int		needed;
5928     int		first = TRUE;
5929 
5930     // loop until there is a 'winminheight' that is possible
5931     while (p_wmw > 0)
5932     {
5933 	room = Columns;
5934 	needed = frame_minwidth(topframe, NULL);
5935 	if (room >= needed)
5936 	    break;
5937 	--p_wmw;
5938 	if (first)
5939 	{
5940 	    emsg(_(e_not_enough_room));
5941 	    first = FALSE;
5942 	}
5943     }
5944 }
5945 
5946 /*
5947  * Status line of dragwin is dragged "offset" lines down (negative is up).
5948  */
5949     void
5950 win_drag_status_line(win_T *dragwin, int offset)
5951 {
5952     frame_T	*curfr;
5953     frame_T	*fr;
5954     int		room;
5955     int		row;
5956     int		up;	// if TRUE, drag status line up, otherwise down
5957     int		n;
5958 
5959     fr = dragwin->w_frame;
5960     curfr = fr;
5961     if (fr != topframe)		// more than one window
5962     {
5963 	fr = fr->fr_parent;
5964 	// When the parent frame is not a column of frames, its parent should
5965 	// be.
5966 	if (fr->fr_layout != FR_COL)
5967 	{
5968 	    curfr = fr;
5969 	    if (fr != topframe)	// only a row of windows, may drag statusline
5970 		fr = fr->fr_parent;
5971 	}
5972     }
5973 
5974     // If this is the last frame in a column, may want to resize the parent
5975     // frame instead (go two up to skip a row of frames).
5976     while (curfr != topframe && curfr->fr_next == NULL)
5977     {
5978 	if (fr != topframe)
5979 	    fr = fr->fr_parent;
5980 	curfr = fr;
5981 	if (fr != topframe)
5982 	    fr = fr->fr_parent;
5983     }
5984 
5985     if (offset < 0) // drag up
5986     {
5987 	up = TRUE;
5988 	offset = -offset;
5989 	// sum up the room of the current frame and above it
5990 	if (fr == curfr)
5991 	{
5992 	    // only one window
5993 	    room = fr->fr_height - frame_minheight(fr, NULL);
5994 	}
5995 	else
5996 	{
5997 	    room = 0;
5998 	    for (fr = fr->fr_child; ; fr = fr->fr_next)
5999 	    {
6000 		room += fr->fr_height - frame_minheight(fr, NULL);
6001 		if (fr == curfr)
6002 		    break;
6003 	    }
6004 	}
6005 	fr = curfr->fr_next;		// put fr at frame that grows
6006     }
6007     else    // drag down
6008     {
6009 	up = FALSE;
6010 	/*
6011 	 * Only dragging the last status line can reduce p_ch.
6012 	 */
6013 	room = Rows - cmdline_row;
6014 	if (curfr->fr_next == NULL)
6015 	    room -= 1;
6016 	else
6017 	    room -= p_ch;
6018 	if (room < 0)
6019 	    room = 0;
6020 	// sum up the room of frames below of the current one
6021 	FOR_ALL_FRAMES(fr, curfr->fr_next)
6022 	    room += fr->fr_height - frame_minheight(fr, NULL);
6023 	fr = curfr;			// put fr at window that grows
6024     }
6025 
6026     if (room < offset)		// Not enough room
6027 	offset = room;		// Move as far as we can
6028     if (offset <= 0)
6029 	return;
6030 
6031     /*
6032      * Grow frame fr by "offset" lines.
6033      * Doesn't happen when dragging the last status line up.
6034      */
6035     if (fr != NULL)
6036 	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
6037 
6038     if (up)
6039 	fr = curfr;		// current frame gets smaller
6040     else
6041 	fr = curfr->fr_next;	// next frame gets smaller
6042 
6043     /*
6044      * Now make the other frames smaller.
6045      */
6046     while (fr != NULL && offset > 0)
6047     {
6048 	n = frame_minheight(fr, NULL);
6049 	if (fr->fr_height - offset <= n)
6050 	{
6051 	    offset -= fr->fr_height - n;
6052 	    frame_new_height(fr, n, !up, FALSE);
6053 	}
6054 	else
6055 	{
6056 	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
6057 	    break;
6058 	}
6059 	if (up)
6060 	    fr = fr->fr_prev;
6061 	else
6062 	    fr = fr->fr_next;
6063     }
6064     row = win_comp_pos();
6065     screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
6066     cmdline_row = row;
6067     p_ch = Rows - cmdline_row;
6068     if (p_ch < 1)
6069 	p_ch = 1;
6070     curtab->tp_ch_used = p_ch;
6071     redraw_all_later(SOME_VALID);
6072     showmode();
6073 }
6074 
6075 /*
6076  * Separator line of dragwin is dragged "offset" lines right (negative is left).
6077  */
6078     void
6079 win_drag_vsep_line(win_T *dragwin, int offset)
6080 {
6081     frame_T	*curfr;
6082     frame_T	*fr;
6083     int		room;
6084     int		left;	// if TRUE, drag separator line left, otherwise right
6085     int		n;
6086 
6087     fr = dragwin->w_frame;
6088     if (fr == topframe)		// only one window (cannot happen?)
6089 	return;
6090     curfr = fr;
6091     fr = fr->fr_parent;
6092     // When the parent frame is not a row of frames, its parent should be.
6093     if (fr->fr_layout != FR_ROW)
6094     {
6095 	if (fr == topframe)	// only a column of windows (cannot happen?)
6096 	    return;
6097 	curfr = fr;
6098 	fr = fr->fr_parent;
6099     }
6100 
6101     // If this is the last frame in a row, may want to resize a parent
6102     // frame instead.
6103     while (curfr->fr_next == NULL)
6104     {
6105 	if (fr == topframe)
6106 	    break;
6107 	curfr = fr;
6108 	fr = fr->fr_parent;
6109 	if (fr != topframe)
6110 	{
6111 	    curfr = fr;
6112 	    fr = fr->fr_parent;
6113 	}
6114     }
6115 
6116     if (offset < 0) // drag left
6117     {
6118 	left = TRUE;
6119 	offset = -offset;
6120 	// sum up the room of the current frame and left of it
6121 	room = 0;
6122 	for (fr = fr->fr_child; ; fr = fr->fr_next)
6123 	{
6124 	    room += fr->fr_width - frame_minwidth(fr, NULL);
6125 	    if (fr == curfr)
6126 		break;
6127 	}
6128 	fr = curfr->fr_next;		// put fr at frame that grows
6129     }
6130     else    // drag right
6131     {
6132 	left = FALSE;
6133 	// sum up the room of frames right of the current one
6134 	room = 0;
6135 	FOR_ALL_FRAMES(fr, curfr->fr_next)
6136 	    room += fr->fr_width - frame_minwidth(fr, NULL);
6137 	fr = curfr;			// put fr at window that grows
6138     }
6139 
6140     if (room < offset)		// Not enough room
6141 	offset = room;		// Move as far as we can
6142     if (offset <= 0)		// No room at all, quit.
6143 	return;
6144     if (fr == NULL)
6145 	return;			// Safety check, should not happen.
6146 
6147     // grow frame fr by offset lines
6148     frame_new_width(fr, fr->fr_width + offset, left, FALSE);
6149 
6150     // shrink other frames: current and at the left or at the right
6151     if (left)
6152 	fr = curfr;		// current frame gets smaller
6153     else
6154 	fr = curfr->fr_next;	// next frame gets smaller
6155 
6156     while (fr != NULL && offset > 0)
6157     {
6158 	n = frame_minwidth(fr, NULL);
6159 	if (fr->fr_width - offset <= n)
6160 	{
6161 	    offset -= fr->fr_width - n;
6162 	    frame_new_width(fr, n, !left, FALSE);
6163 	}
6164 	else
6165 	{
6166 	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
6167 	    break;
6168 	}
6169 	if (left)
6170 	    fr = fr->fr_prev;
6171 	else
6172 	    fr = fr->fr_next;
6173     }
6174     (void)win_comp_pos();
6175     redraw_all_later(NOT_VALID);
6176 }
6177 
6178 #define FRACTION_MULT	16384L
6179 
6180 /*
6181  * Set wp->w_fraction for the current w_wrow and w_height.
6182  * Has no effect when the window is less than two lines.
6183  */
6184     void
6185 set_fraction(win_T *wp)
6186 {
6187     if (wp->w_height > 1)
6188 	// When cursor is in the first line the percentage is computed as if
6189 	// it's halfway that line.  Thus with two lines it is 25%, with three
6190 	// lines 17%, etc.  Similarly for the last line: 75%, 83%, etc.
6191 	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
6192 				     + FRACTION_MULT / 2) / (long)wp->w_height;
6193 }
6194 
6195 /*
6196  * Set the height of a window.
6197  * "height" excludes any window toolbar.
6198  * This takes care of the things inside the window, not what happens to the
6199  * window position, the frame or to other windows.
6200  */
6201     void
6202 win_new_height(win_T *wp, int height)
6203 {
6204     int		prev_height = wp->w_height;
6205 
6206     // Don't want a negative height.  Happens when splitting a tiny window.
6207     // Will equalize heights soon to fix it.
6208     if (height < 0)
6209 	height = 0;
6210     if (wp->w_height == height)
6211 	return;	    // nothing to do
6212 
6213     if (wp->w_height > 0)
6214     {
6215 	if (wp == curwin)
6216 	    // w_wrow needs to be valid. When setting 'laststatus' this may
6217 	    // call win_new_height() recursively.
6218 	    validate_cursor();
6219 	if (wp->w_height != prev_height)
6220 	    return;  // Recursive call already changed the size, bail out here
6221 		     //	to avoid the following to mess things up.
6222 	if (wp->w_wrow != wp->w_prev_fraction_row)
6223 	    set_fraction(wp);
6224     }
6225 
6226     wp->w_height = height;
6227     wp->w_skipcol = 0;
6228 
6229     // There is no point in adjusting the scroll position when exiting.  Some
6230     // values might be invalid.
6231     if (!exiting)
6232 	scroll_to_fraction(wp, prev_height);
6233 }
6234 
6235     void
6236 scroll_to_fraction(win_T *wp, int prev_height)
6237 {
6238     linenr_T	lnum;
6239     int		sline, line_size;
6240     int		height = wp->w_height;
6241 
6242     // Don't change w_topline in any of these cases:
6243     // - window height is 0
6244     // - 'scrollbind' is set and this isn't the current window
6245     // - window height is sufficient to display the whole buffer and first line
6246     //   is visible.
6247     if (height > 0
6248         && (!wp->w_p_scb || wp == curwin)
6249         && (height < wp->w_buffer->b_ml.ml_line_count || wp->w_topline > 1))
6250     {
6251 	/*
6252 	 * Find a value for w_topline that shows the cursor at the same
6253 	 * relative position in the window as before (more or less).
6254 	 */
6255 	lnum = wp->w_cursor.lnum;
6256 	if (lnum < 1)		// can happen when starting up
6257 	    lnum = 1;
6258 	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L)
6259 							       / FRACTION_MULT;
6260 	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
6261 	sline = wp->w_wrow - line_size;
6262 
6263 	if (sline >= 0)
6264 	{
6265 	    // Make sure the whole cursor line is visible, if possible.
6266 	    int rows = plines_win(wp, lnum, FALSE);
6267 
6268 	    if (sline > wp->w_height - rows)
6269 	    {
6270 		sline = wp->w_height - rows;
6271 		wp->w_wrow -= rows - line_size;
6272 	    }
6273 	}
6274 
6275 	if (sline < 0)
6276 	{
6277 	    /*
6278 	     * Cursor line would go off top of screen if w_wrow was this high.
6279 	     * Make cursor line the first line in the window.  If not enough
6280 	     * room use w_skipcol;
6281 	     */
6282 	    wp->w_wrow = line_size;
6283 	    if (wp->w_wrow >= wp->w_height
6284 				       && (wp->w_width - win_col_off(wp)) > 0)
6285 	    {
6286 		wp->w_skipcol += wp->w_width - win_col_off(wp);
6287 		--wp->w_wrow;
6288 		while (wp->w_wrow >= wp->w_height)
6289 		{
6290 		    wp->w_skipcol += wp->w_width - win_col_off(wp)
6291 							   + win_col_off2(wp);
6292 		    --wp->w_wrow;
6293 		}
6294 	    }
6295 	}
6296 	else if (sline > 0)
6297 	{
6298 	    while (sline > 0 && lnum > 1)
6299 	    {
6300 #ifdef FEAT_FOLDING
6301 		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
6302 		if (lnum == 1)
6303 		{
6304 		    // first line in buffer is folded
6305 		    line_size = 1;
6306 		    --sline;
6307 		    break;
6308 		}
6309 #endif
6310 		--lnum;
6311 #ifdef FEAT_DIFF
6312 		if (lnum == wp->w_topline)
6313 		    line_size = plines_win_nofill(wp, lnum, TRUE)
6314 							      + wp->w_topfill;
6315 		else
6316 #endif
6317 		    line_size = plines_win(wp, lnum, TRUE);
6318 		sline -= line_size;
6319 	    }
6320 
6321 	    if (sline < 0)
6322 	    {
6323 		/*
6324 		 * Line we want at top would go off top of screen.  Use next
6325 		 * line instead.
6326 		 */
6327 #ifdef FEAT_FOLDING
6328 		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
6329 #endif
6330 		lnum++;
6331 		wp->w_wrow -= line_size + sline;
6332 	    }
6333 	    else if (sline > 0)
6334 	    {
6335 		// First line of file reached, use that as topline.
6336 		lnum = 1;
6337 		wp->w_wrow -= sline;
6338 	    }
6339 	}
6340 	set_topline(wp, lnum);
6341     }
6342 
6343     if (wp == curwin)
6344     {
6345 	if (get_scrolloff_value())
6346 	    update_topline();
6347 	curs_columns(FALSE);	// validate w_wrow
6348     }
6349     if (prev_height > 0)
6350 	wp->w_prev_fraction_row = wp->w_wrow;
6351 
6352     win_comp_scroll(wp);
6353     redraw_win_later(wp, SOME_VALID);
6354     wp->w_redr_status = TRUE;
6355     invalidate_botline_win(wp);
6356 }
6357 
6358 /*
6359  * Set the width of a window.
6360  */
6361     void
6362 win_new_width(win_T *wp, int width)
6363 {
6364     wp->w_width = width;
6365     wp->w_lines_valid = 0;
6366     changed_line_abv_curs_win(wp);
6367     invalidate_botline_win(wp);
6368     if (wp == curwin)
6369     {
6370 	update_topline();
6371 	curs_columns(TRUE);	// validate w_wrow
6372     }
6373     redraw_win_later(wp, NOT_VALID);
6374     wp->w_redr_status = TRUE;
6375 }
6376 
6377     void
6378 win_comp_scroll(win_T *wp)
6379 {
6380 #if defined(FEAT_EVAL)
6381     int old_w_p_scr = wp->w_p_scr;
6382 #endif
6383 
6384     wp->w_p_scr = ((unsigned)wp->w_height >> 1);
6385     if (wp->w_p_scr == 0)
6386 	wp->w_p_scr = 1;
6387 #if defined(FEAT_EVAL)
6388     if (wp->w_p_scr != old_w_p_scr)
6389     {
6390 	// Used by "verbose set scroll".
6391 	wp->w_p_script_ctx[WV_SCROLL].sc_sid = SID_WINLAYOUT;
6392 	wp->w_p_script_ctx[WV_SCROLL].sc_lnum = 0;
6393     }
6394 #endif
6395 }
6396 
6397 /*
6398  * command_height: called whenever p_ch has been changed
6399  */
6400     void
6401 command_height(void)
6402 {
6403     int		h;
6404     frame_T	*frp;
6405     int		old_p_ch = curtab->tp_ch_used;
6406 
6407     // Use the value of p_ch that we remembered.  This is needed for when the
6408     // GUI starts up, we can't be sure in what order things happen.  And when
6409     // p_ch was changed in another tab page.
6410     curtab->tp_ch_used = p_ch;
6411 
6412     // Find bottom frame with width of screen.
6413     frp = lastwin->w_frame;
6414     while (frp->fr_width != Columns && frp->fr_parent != NULL)
6415 	frp = frp->fr_parent;
6416 
6417     // Avoid changing the height of a window with 'winfixheight' set.
6418     while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
6419 						      && frp->fr_win->w_p_wfh)
6420 	frp = frp->fr_prev;
6421 
6422     if (starting != NO_SCREEN)
6423     {
6424 	cmdline_row = Rows - p_ch;
6425 
6426 	if (p_ch > old_p_ch)		    // p_ch got bigger
6427 	{
6428 	    while (p_ch > old_p_ch)
6429 	    {
6430 		if (frp == NULL)
6431 		{
6432 		    emsg(_(e_not_enough_room));
6433 		    p_ch = old_p_ch;
6434 		    curtab->tp_ch_used = p_ch;
6435 		    cmdline_row = Rows - p_ch;
6436 		    break;
6437 		}
6438 		h = frp->fr_height - frame_minheight(frp, NULL);
6439 		if (h > p_ch - old_p_ch)
6440 		    h = p_ch - old_p_ch;
6441 		old_p_ch += h;
6442 		frame_add_height(frp, -h);
6443 		frp = frp->fr_prev;
6444 	    }
6445 
6446 	    // Recompute window positions.
6447 	    (void)win_comp_pos();
6448 
6449 	    // clear the lines added to cmdline
6450 	    if (full_screen)
6451 		screen_fill((int)(cmdline_row), (int)Rows, 0,
6452 						   (int)Columns, ' ', ' ', 0);
6453 	    msg_row = cmdline_row;
6454 	    redraw_cmdline = TRUE;
6455 	    return;
6456 	}
6457 
6458 	if (msg_row < cmdline_row)
6459 	    msg_row = cmdline_row;
6460 	redraw_cmdline = TRUE;
6461     }
6462     frame_add_height(frp, (int)(old_p_ch - p_ch));
6463 
6464     // Recompute window positions.
6465     if (frp != lastwin->w_frame)
6466 	(void)win_comp_pos();
6467 }
6468 
6469 /*
6470  * Resize frame "frp" to be "n" lines higher (negative for less high).
6471  * Also resize the frames it is contained in.
6472  */
6473     static void
6474 frame_add_height(frame_T *frp, int n)
6475 {
6476     frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
6477     for (;;)
6478     {
6479 	frp = frp->fr_parent;
6480 	if (frp == NULL)
6481 	    break;
6482 	frp->fr_height += n;
6483     }
6484 }
6485 
6486 /*
6487  * Add or remove a status line for the bottom window(s), according to the
6488  * value of 'laststatus'.
6489  */
6490     void
6491 last_status(
6492     int		morewin)	// pretend there are two or more windows
6493 {
6494     // Don't make a difference between horizontal or vertical split.
6495     last_status_rec(topframe, (p_ls == 2
6496 			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
6497 }
6498 
6499     static void
6500 last_status_rec(frame_T *fr, int statusline)
6501 {
6502     frame_T	*fp;
6503     win_T	*wp;
6504 
6505     if (fr->fr_layout == FR_LEAF)
6506     {
6507 	wp = fr->fr_win;
6508 	if (wp->w_status_height != 0 && !statusline)
6509 	{
6510 	    // remove status line
6511 	    win_new_height(wp, wp->w_height + 1);
6512 	    wp->w_status_height = 0;
6513 	    comp_col();
6514 	}
6515 	else if (wp->w_status_height == 0 && statusline)
6516 	{
6517 	    // Find a frame to take a line from.
6518 	    fp = fr;
6519 	    while (fp->fr_height <= frame_minheight(fp, NULL))
6520 	    {
6521 		if (fp == topframe)
6522 		{
6523 		    emsg(_(e_not_enough_room));
6524 		    return;
6525 		}
6526 		// In a column of frames: go to frame above.  If already at
6527 		// the top or in a row of frames: go to parent.
6528 		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
6529 		    fp = fp->fr_prev;
6530 		else
6531 		    fp = fp->fr_parent;
6532 	    }
6533 	    wp->w_status_height = 1;
6534 	    if (fp != fr)
6535 	    {
6536 		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
6537 		frame_fix_height(wp);
6538 		(void)win_comp_pos();
6539 	    }
6540 	    else
6541 		win_new_height(wp, wp->w_height - 1);
6542 	    comp_col();
6543 	    redraw_all_later(SOME_VALID);
6544 	}
6545     }
6546     else if (fr->fr_layout == FR_ROW)
6547     {
6548 	// vertically split windows, set status line for each one
6549 	FOR_ALL_FRAMES(fp, fr->fr_child)
6550 	    last_status_rec(fp, statusline);
6551     }
6552     else
6553     {
6554 	// horizontally split window, set status line for last one
6555 	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
6556 	    ;
6557 	last_status_rec(fp, statusline);
6558     }
6559 }
6560 
6561 /*
6562  * Return the number of lines used by the tab page line.
6563  */
6564     int
6565 tabline_height(void)
6566 {
6567 #ifdef FEAT_GUI_TABLINE
6568     // When the GUI has the tabline then this always returns zero.
6569     if (gui_use_tabline())
6570 	return 0;
6571 #endif
6572     switch (p_stal)
6573     {
6574 	case 0: return 0;
6575 	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
6576     }
6577     return 1;
6578 }
6579 
6580 /*
6581  * Return the minimal number of rows that is needed on the screen to display
6582  * the current number of windows.
6583  */
6584     int
6585 min_rows(void)
6586 {
6587     int		total;
6588     tabpage_T	*tp;
6589     int		n;
6590 
6591     if (firstwin == NULL)	// not initialized yet
6592 	return MIN_LINES;
6593 
6594     total = 0;
6595     FOR_ALL_TABPAGES(tp)
6596     {
6597 	n = frame_minheight(tp->tp_topframe, NULL);
6598 	if (total < n)
6599 	    total = n;
6600     }
6601     total += tabline_height();
6602     total += 1;		// count the room for the command line
6603     return total;
6604 }
6605 
6606 /*
6607  * Return TRUE if there is only one window and only one tab page, not
6608  * counting a help or preview window, unless it is the current window.
6609  * Does not count unlisted windows.
6610  */
6611     int
6612 only_one_window(void)
6613 {
6614     int		count = 0;
6615     win_T	*wp;
6616 
6617 #if defined(FEAT_PROP_POPUP)
6618     // If the current window is a popup then there always is another window.
6619     if (popup_is_popup(curwin))
6620 	return FALSE;
6621 #endif
6622 
6623     // If there is another tab page there always is another window.
6624     if (first_tabpage->tp_next != NULL)
6625 	return FALSE;
6626 
6627     FOR_ALL_WINDOWS(wp)
6628 	if (wp->w_buffer != NULL
6629 		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
6630 # ifdef FEAT_QUICKFIX
6631 		    || wp->w_p_pvw
6632 # endif
6633 	     ) || wp == curwin) && wp != aucmd_win)
6634 	    ++count;
6635     return (count <= 1);
6636 }
6637 
6638 /*
6639  * Correct the cursor line number in other windows.  Used after changing the
6640  * current buffer, and before applying autocommands.
6641  * When "do_curwin" is TRUE, also check current window.
6642  */
6643     void
6644 check_lnums(int do_curwin)
6645 {
6646     win_T	*wp;
6647     tabpage_T	*tp;
6648 
6649     FOR_ALL_TAB_WINDOWS(tp, wp)
6650 	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
6651 	{
6652 	    // save the original cursor position and topline
6653 	    wp->w_save_cursor.w_cursor_save = wp->w_cursor;
6654 	    wp->w_save_cursor.w_topline_save = wp->w_topline;
6655 
6656 	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
6657 		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
6658 	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
6659 		wp->w_topline = curbuf->b_ml.ml_line_count;
6660 
6661 	    // save the corrected cursor position and topline
6662 	    wp->w_save_cursor.w_cursor_corr = wp->w_cursor;
6663 	    wp->w_save_cursor.w_topline_corr = wp->w_topline;
6664 	}
6665 }
6666 
6667 /*
6668  * Reset cursor and topline to its stored values from check_lnums().
6669  * check_lnums() must have been called first!
6670  */
6671     void
6672 reset_lnums()
6673 {
6674     win_T	*wp;
6675     tabpage_T	*tp;
6676 
6677     FOR_ALL_TAB_WINDOWS(tp, wp)
6678 	if (wp->w_buffer == curbuf)
6679 	{
6680 	    // Restore the value if the autocommand didn't change it.
6681 	    if (EQUAL_POS(wp->w_save_cursor.w_cursor_corr, wp->w_cursor))
6682 		wp->w_cursor = wp->w_save_cursor.w_cursor_save;
6683 	    if (wp->w_save_cursor.w_topline_corr == wp->w_topline)
6684 		wp->w_topline = wp->w_save_cursor.w_topline_save;
6685 	}
6686 }
6687 
6688 /*
6689  * A snapshot of the window sizes, to restore them after closing the help
6690  * window.
6691  * Only these fields are used:
6692  * fr_layout
6693  * fr_width
6694  * fr_height
6695  * fr_next
6696  * fr_child
6697  * fr_win (only valid for the old curwin, NULL otherwise)
6698  */
6699 
6700 /*
6701  * Create a snapshot of the current frame sizes.
6702  */
6703     void
6704 make_snapshot(int idx)
6705 {
6706     clear_snapshot(curtab, idx);
6707     make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
6708 }
6709 
6710     static void
6711 make_snapshot_rec(frame_T *fr, frame_T **frp)
6712 {
6713     *frp = ALLOC_CLEAR_ONE(frame_T);
6714     if (*frp == NULL)
6715 	return;
6716     (*frp)->fr_layout = fr->fr_layout;
6717     (*frp)->fr_width = fr->fr_width;
6718     (*frp)->fr_height = fr->fr_height;
6719     if (fr->fr_next != NULL)
6720 	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
6721     if (fr->fr_child != NULL)
6722 	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
6723     if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
6724 	(*frp)->fr_win = curwin;
6725 }
6726 
6727 /*
6728  * Remove any existing snapshot.
6729  */
6730     static void
6731 clear_snapshot(tabpage_T *tp, int idx)
6732 {
6733     clear_snapshot_rec(tp->tp_snapshot[idx]);
6734     tp->tp_snapshot[idx] = NULL;
6735 }
6736 
6737     static void
6738 clear_snapshot_rec(frame_T *fr)
6739 {
6740     if (fr != NULL)
6741     {
6742 	clear_snapshot_rec(fr->fr_next);
6743 	clear_snapshot_rec(fr->fr_child);
6744 	vim_free(fr);
6745     }
6746 }
6747 
6748 /*
6749  * Restore a previously created snapshot, if there is any.
6750  * This is only done if the screen size didn't change and the window layout is
6751  * still the same.
6752  */
6753     void
6754 restore_snapshot(
6755     int		idx,
6756     int		close_curwin)	    // closing current window
6757 {
6758     win_T	*wp;
6759 
6760     if (curtab->tp_snapshot[idx] != NULL
6761 	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
6762 	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
6763 	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
6764     {
6765 	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
6766 	win_comp_pos();
6767 	if (wp != NULL && close_curwin)
6768 	    win_goto(wp);
6769 	redraw_all_later(NOT_VALID);
6770     }
6771     clear_snapshot(curtab, idx);
6772 }
6773 
6774 /*
6775  * Check if frames "sn" and "fr" have the same layout, same following frames
6776  * and same children.  And the window pointer is valid.
6777  */
6778     static int
6779 check_snapshot_rec(frame_T *sn, frame_T *fr)
6780 {
6781     if (sn->fr_layout != fr->fr_layout
6782 	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
6783 	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
6784 	    || (sn->fr_next != NULL
6785 		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
6786 	    || (sn->fr_child != NULL
6787 		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
6788 	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
6789 	return FAIL;
6790     return OK;
6791 }
6792 
6793 /*
6794  * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
6795  * following frames and children.
6796  * Returns a pointer to the old current window, or NULL.
6797  */
6798     static win_T *
6799 restore_snapshot_rec(frame_T *sn, frame_T *fr)
6800 {
6801     win_T	*wp = NULL;
6802     win_T	*wp2;
6803 
6804     fr->fr_height = sn->fr_height;
6805     fr->fr_width = sn->fr_width;
6806     if (fr->fr_layout == FR_LEAF)
6807     {
6808 	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
6809 	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
6810 	wp = sn->fr_win;
6811     }
6812     if (sn->fr_next != NULL)
6813     {
6814 	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
6815 	if (wp2 != NULL)
6816 	    wp = wp2;
6817     }
6818     if (sn->fr_child != NULL)
6819     {
6820 	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
6821 	if (wp2 != NULL)
6822 	    wp = wp2;
6823     }
6824     return wp;
6825 }
6826 
6827 #if defined(FEAT_GUI) || defined(PROTO)
6828 /*
6829  * Return TRUE if there is any vertically split window.
6830  */
6831     int
6832 win_hasvertsplit(void)
6833 {
6834     frame_T	*fr;
6835 
6836     if (topframe->fr_layout == FR_ROW)
6837 	return TRUE;
6838 
6839     if (topframe->fr_layout == FR_COL)
6840 	FOR_ALL_FRAMES(fr, topframe->fr_child)
6841 	    if (fr->fr_layout == FR_ROW)
6842 		return TRUE;
6843 
6844     return FALSE;
6845 }
6846 #endif
6847 
6848 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
6849     int
6850 get_win_number(win_T *wp, win_T *first_win)
6851 {
6852     int		i = 1;
6853     win_T	*w;
6854 
6855     for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
6856 	++i;
6857 
6858     if (w == NULL)
6859 	return 0;
6860     else
6861 	return i;
6862 }
6863 
6864     int
6865 get_tab_number(tabpage_T *tp UNUSED)
6866 {
6867     int		i = 1;
6868     tabpage_T	*t;
6869 
6870     for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
6871 	++i;
6872 
6873     if (t == NULL)
6874 	return 0;
6875     else
6876 	return i;
6877 }
6878 #endif
6879 
6880 /*
6881  * Return TRUE if "topfrp" and its children are at the right height.
6882  */
6883     static int
6884 frame_check_height(frame_T *topfrp, int height)
6885 {
6886     frame_T *frp;
6887 
6888     if (topfrp->fr_height != height)
6889 	return FALSE;
6890 
6891     if (topfrp->fr_layout == FR_ROW)
6892 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6893 	    if (frp->fr_height != height)
6894 		return FALSE;
6895 
6896     return TRUE;
6897 }
6898 
6899 /*
6900  * Return TRUE if "topfrp" and its children are at the right width.
6901  */
6902     static int
6903 frame_check_width(frame_T *topfrp, int width)
6904 {
6905     frame_T *frp;
6906 
6907     if (topfrp->fr_width != width)
6908 	return FALSE;
6909 
6910     if (topfrp->fr_layout == FR_COL)
6911 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6912 	    if (frp->fr_width != width)
6913 		return FALSE;
6914 
6915     return TRUE;
6916 }
6917 
6918 #if defined(FEAT_SYN_HL) || defined(PROTO)
6919 /*
6920  * Simple int comparison function for use with qsort()
6921  */
6922     static int
6923 int_cmp(const void *a, const void *b)
6924 {
6925     return *(const int *)a - *(const int *)b;
6926 }
6927 
6928 /*
6929  * Handle setting 'colorcolumn' or 'textwidth' in window "wp".
6930  * Returns error message, NULL if it's OK.
6931  */
6932     char *
6933 check_colorcolumn(win_T *wp)
6934 {
6935     char_u	*s;
6936     int		col;
6937     int		count = 0;
6938     int		color_cols[256];
6939     int		i;
6940     int		j = 0;
6941 
6942     if (wp->w_buffer == NULL)
6943 	return NULL;  // buffer was closed
6944 
6945     for (s = wp->w_p_cc; *s != NUL && count < 255;)
6946     {
6947 	if (*s == '-' || *s == '+')
6948 	{
6949 	    // -N and +N: add to 'textwidth'
6950 	    col = (*s == '-') ? -1 : 1;
6951 	    ++s;
6952 	    if (!VIM_ISDIGIT(*s))
6953 		return e_invarg;
6954 	    col = col * getdigits(&s);
6955 	    if (wp->w_buffer->b_p_tw == 0)
6956 		goto skip;  // 'textwidth' not set, skip this item
6957 	    col += wp->w_buffer->b_p_tw;
6958 	    if (col < 0)
6959 		goto skip;
6960 	}
6961 	else if (VIM_ISDIGIT(*s))
6962 	    col = getdigits(&s);
6963 	else
6964 	    return e_invarg;
6965 	color_cols[count++] = col - 1;  // 1-based to 0-based
6966 skip:
6967 	if (*s == NUL)
6968 	    break;
6969 	if (*s != ',')
6970 	    return e_invarg;
6971 	if (*++s == NUL)
6972 	    return e_invarg;  // illegal trailing comma as in "set cc=80,"
6973     }
6974 
6975     vim_free(wp->w_p_cc_cols);
6976     if (count == 0)
6977 	wp->w_p_cc_cols = NULL;
6978     else
6979     {
6980 	wp->w_p_cc_cols = ALLOC_MULT(int, count + 1);
6981 	if (wp->w_p_cc_cols != NULL)
6982 	{
6983 	    // sort the columns for faster usage on screen redraw inside
6984 	    // win_line()
6985 	    qsort(color_cols, count, sizeof(int), int_cmp);
6986 
6987 	    for (i = 0; i < count; ++i)
6988 		// skip duplicates
6989 		if (j == 0 || wp->w_p_cc_cols[j - 1] != color_cols[i])
6990 		    wp->w_p_cc_cols[j++] = color_cols[i];
6991 	    wp->w_p_cc_cols[j] = -1;  // end marker
6992 	}
6993     }
6994 
6995     return NULL;  // no error
6996 }
6997 #endif
6998