xref: /vim-8.2.3635/src/window.c (revision 3b0ef8cf)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read a list of people who contributed.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 #include "vim.h"
11 
12 static void cmd_with_count(char *cmd, char_u *bufp, size_t bufsize, long Prenum);
13 static void win_init(win_T *newp, win_T *oldp, int flags);
14 static void win_init_some(win_T *newp, win_T *oldp);
15 static void frame_comp_pos(frame_T *topfrp, int *row, int *col);
16 static void frame_setheight(frame_T *curfrp, int height);
17 static void frame_setwidth(frame_T *curfrp, int width);
18 static void win_exchange(long);
19 static void win_rotate(int, int);
20 static void win_totop(int size, int flags);
21 static void win_equal_rec(win_T *next_curwin, int current, frame_T *topfr, int dir, int col, int row, int width, int height);
22 static win_T *win_free_mem(win_T *win, int *dirp, tabpage_T *tp);
23 static frame_T *win_altframe(win_T *win, tabpage_T *tp);
24 static tabpage_T *alt_tabpage(void);
25 static win_T *frame2win(frame_T *frp);
26 static int frame_has_win(frame_T *frp, win_T *wp);
27 static void frame_new_height(frame_T *topfrp, int height, int topfirst, int wfh);
28 static int frame_fixed_height(frame_T *frp);
29 static int frame_fixed_width(frame_T *frp);
30 static void frame_add_statusline(frame_T *frp);
31 static void frame_new_width(frame_T *topfrp, int width, int leftfirst, int wfw);
32 static void frame_add_vsep(frame_T *frp);
33 static int frame_minwidth(frame_T *topfrp, win_T *next_curwin);
34 static void frame_fix_width(win_T *wp);
35 static int win_alloc_firstwin(win_T *oldwin);
36 static void new_frame(win_T *wp);
37 static tabpage_T *alloc_tabpage(void);
38 static int leave_tabpage(buf_T *new_curbuf, int trigger_leave_autocmds);
39 static void enter_tabpage(tabpage_T *tp, buf_T *old_curbuf, int trigger_enter_autocmds, int trigger_leave_autocmds);
40 static void frame_fix_height(win_T *wp);
41 static int frame_minheight(frame_T *topfrp, win_T *next_curwin);
42 static int may_open_tabpage(void);
43 static void win_enter_ext(win_T *wp, int undo_sync, int no_curwin, int trigger_new_autocmds, int trigger_enter_autocmds, int trigger_leave_autocmds);
44 static void win_free(win_T *wp, tabpage_T *tp);
45 static int win_unlisted(win_T *wp);
46 static void win_append(win_T *after, win_T *wp);
47 static void frame_append(frame_T *after, frame_T *frp);
48 static void frame_insert(frame_T *before, frame_T *frp);
49 static void frame_remove(frame_T *frp);
50 static void win_goto_ver(int up, long count);
51 static void win_goto_hor(int left, long count);
52 static void frame_add_height(frame_T *frp, int n);
53 static void last_status_rec(frame_T *fr, int statusline);
54 
55 static void make_snapshot_rec(frame_T *fr, frame_T **frp);
56 static void clear_snapshot(tabpage_T *tp, int idx);
57 static void clear_snapshot_rec(frame_T *fr);
58 static int check_snapshot_rec(frame_T *sn, frame_T *fr);
59 static win_T *restore_snapshot_rec(frame_T *sn, frame_T *fr);
60 
61 static int frame_check_height(frame_T *topfrp, int height);
62 static int frame_check_width(frame_T *topfrp, int width);
63 
64 static win_T *win_alloc(win_T *after, int hidden);
65 
66 #define NOWIN		(win_T *)-1	// non-existing window
67 
68 #define ROWS_AVAIL (Rows - p_ch - tabline_height())
69 
70 static char *m_onlyone = N_("Already only one window");
71 
72 // When non-zero splitting a window is forbidden.  Used to avoid that nasty
73 // autocommands mess up the window structure.
74 static int split_disallowed = 0;
75 
76 // #define WIN_DEBUG
77 #ifdef WIN_DEBUG
78 /*
79  * Call this method to log the current window layout.
80  */
81     static void
82 log_frame_layout(frame_T *frame)
83 {
84     ch_log(NULL, "layout %s, wi: %d, he: %d, wwi: %d, whe: %d, id: %d",
85 	    frame->fr_layout == FR_LEAF ? "LEAF"
86 				  : frame->fr_layout == FR_ROW ? "ROW" : "COL",
87 	    frame->fr_width,
88 	    frame->fr_height,
89 	    frame->fr_win == NULL ? -1 : frame->fr_win->w_width,
90 	    frame->fr_win == NULL ? -1 : frame->fr_win->w_height,
91 	    frame->fr_win == NULL ? -1 : frame->fr_win->w_id);
92     if (frame->fr_child != NULL)
93     {
94 	ch_log(NULL, "children");
95 	log_frame_layout(frame->fr_child);
96 	if (frame->fr_next != NULL)
97 	    ch_log(NULL, "END of children");
98     }
99     if (frame->fr_next != NULL)
100 	log_frame_layout(frame->fr_next);
101 }
102 #endif
103 
104 /*
105  * All CTRL-W window commands are handled here, called from normal_cmd().
106  */
107     void
108 do_window(
109     int		nchar,
110     long	Prenum,
111     int		xchar)	    // extra char from ":wincmd gx" or NUL
112 {
113     long	Prenum1;
114     win_T	*wp;
115 #if defined(FEAT_SEARCHPATH) || defined(FEAT_FIND_ID)
116     char_u	*ptr;
117     linenr_T    lnum = -1;
118 #endif
119 #ifdef FEAT_FIND_ID
120     int		type = FIND_DEFINE;
121     int		len;
122 #endif
123     char_u	cbuf[40];
124 
125     if (ERROR_IF_ANY_POPUP_WINDOW)
126 	return;
127 
128 #ifdef FEAT_CMDWIN
129 # define CHECK_CMDWIN \
130     do { \
131 	if (cmdwin_type != 0) \
132 	{ \
133 	    emsg(_(e_cmdwin)); \
134 	    return; \
135 	} \
136     } while (0)
137 #else
138 # define CHECK_CMDWIN do { /**/ } while (0)
139 #endif
140 
141     Prenum1 = Prenum == 0 ? 1 : Prenum;
142 
143     switch (nchar)
144     {
145 // split current window in two parts, horizontally
146     case 'S':
147     case Ctrl_S:
148     case 's':
149 		CHECK_CMDWIN;
150 		reset_VIsual_and_resel();	// stop Visual mode
151 #ifdef FEAT_QUICKFIX
152 		// When splitting the quickfix window open a new buffer in it,
153 		// don't replicate the quickfix buffer.
154 		if (bt_quickfix(curbuf))
155 		    goto newwindow;
156 #endif
157 #ifdef FEAT_GUI
158 		need_mouse_correct = TRUE;
159 #endif
160 		(void)win_split((int)Prenum, 0);
161 		break;
162 
163 // split current window in two parts, vertically
164     case Ctrl_V:
165     case 'v':
166 		CHECK_CMDWIN;
167 		reset_VIsual_and_resel();	// stop Visual mode
168 #ifdef FEAT_QUICKFIX
169 		// When splitting the quickfix window open a new buffer in it,
170 		// don't replicate the quickfix buffer.
171 		if (bt_quickfix(curbuf))
172 		    goto newwindow;
173 #endif
174 #ifdef FEAT_GUI
175 		need_mouse_correct = TRUE;
176 #endif
177 		(void)win_split((int)Prenum, WSP_VERT);
178 		break;
179 
180 // split current window and edit alternate file
181     case Ctrl_HAT:
182     case '^':
183 		CHECK_CMDWIN;
184 		reset_VIsual_and_resel();	// stop Visual mode
185 
186 		if (buflist_findnr(Prenum == 0
187 					? curwin->w_alt_fnum : Prenum) == NULL)
188 		{
189 		    if (Prenum == 0)
190 			emsg(_(e_noalt));
191 		    else
192 			semsg(_("E92: Buffer %ld not found"), Prenum);
193 		    break;
194 		}
195 
196 		if (!curbuf_locked() && win_split(0, 0) == OK)
197 		    (void)buflist_getfile(
198 			    Prenum == 0 ? curwin->w_alt_fnum : Prenum,
199 			    (linenr_T)0, GETF_ALT, FALSE);
200 		break;
201 
202 // open new window
203     case Ctrl_N:
204     case 'n':
205 		CHECK_CMDWIN;
206 		reset_VIsual_and_resel();	// stop Visual mode
207 #ifdef FEAT_QUICKFIX
208 newwindow:
209 #endif
210 		if (Prenum)
211 		    // window height
212 		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
213 		else
214 		    cbuf[0] = NUL;
215 #if defined(FEAT_QUICKFIX)
216 		if (nchar == 'v' || nchar == Ctrl_V)
217 		    STRCAT(cbuf, "v");
218 #endif
219 		STRCAT(cbuf, "new");
220 		do_cmdline_cmd(cbuf);
221 		break;
222 
223 // quit current window
224     case Ctrl_Q:
225     case 'q':
226 		reset_VIsual_and_resel();	// stop Visual mode
227 		cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
228 		do_cmdline_cmd(cbuf);
229 		break;
230 
231 // close current window
232     case Ctrl_C:
233     case 'c':
234 		reset_VIsual_and_resel();	// stop Visual mode
235 		cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
236 		do_cmdline_cmd(cbuf);
237 		break;
238 
239 #if defined(FEAT_QUICKFIX)
240 // close preview window
241     case Ctrl_Z:
242     case 'z':
243 		CHECK_CMDWIN;
244 		reset_VIsual_and_resel();	// stop Visual mode
245 		do_cmdline_cmd((char_u *)"pclose");
246 		break;
247 
248 // cursor to preview window
249     case 'P':
250 		FOR_ALL_WINDOWS(wp)
251 		    if (wp->w_p_pvw)
252 			break;
253 		if (wp == NULL)
254 		    emsg(_("E441: There is no preview window"));
255 		else
256 		    win_goto(wp);
257 		break;
258 #endif
259 
260 // close all but current window
261     case Ctrl_O:
262     case 'o':
263 		CHECK_CMDWIN;
264 		reset_VIsual_and_resel();	// stop Visual mode
265 		cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
266 		do_cmdline_cmd(cbuf);
267 		break;
268 
269 // cursor to next window with wrap around
270     case Ctrl_W:
271     case 'w':
272 // cursor to previous window with wrap around
273     case 'W':
274 		CHECK_CMDWIN;
275 		if (ONE_WINDOW && Prenum != 1)	// just one window
276 		    beep_flush();
277 		else
278 		{
279 		    if (Prenum)			// go to specified window
280 		    {
281 			for (wp = firstwin; --Prenum > 0; )
282 			{
283 			    if (wp->w_next == NULL)
284 				break;
285 			    else
286 				wp = wp->w_next;
287 			}
288 		    }
289 		    else
290 		    {
291 			if (nchar == 'W')	    // go to previous window
292 			{
293 			    wp = curwin->w_prev;
294 			    if (wp == NULL)
295 				wp = lastwin;	    // wrap around
296 			}
297 			else			    // go to next window
298 			{
299 			    wp = curwin->w_next;
300 			    if (wp == NULL)
301 				wp = firstwin;	    // wrap around
302 			}
303 		    }
304 		    win_goto(wp);
305 		}
306 		break;
307 
308 // cursor to window below
309     case 'j':
310     case K_DOWN:
311     case Ctrl_J:
312 		CHECK_CMDWIN;
313 		win_goto_ver(FALSE, Prenum1);
314 		break;
315 
316 // cursor to window above
317     case 'k':
318     case K_UP:
319     case Ctrl_K:
320 		CHECK_CMDWIN;
321 		win_goto_ver(TRUE, Prenum1);
322 		break;
323 
324 // cursor to left window
325     case 'h':
326     case K_LEFT:
327     case Ctrl_H:
328     case K_BS:
329 		CHECK_CMDWIN;
330 		win_goto_hor(TRUE, Prenum1);
331 		break;
332 
333 // cursor to right window
334     case 'l':
335     case K_RIGHT:
336     case Ctrl_L:
337 		CHECK_CMDWIN;
338 		win_goto_hor(FALSE, Prenum1);
339 		break;
340 
341 // move window to new tab page
342     case 'T':
343 		if (one_window())
344 		    msg(_(m_onlyone));
345 		else
346 		{
347 		    tabpage_T	*oldtab = curtab;
348 		    tabpage_T	*newtab;
349 
350 		    // First create a new tab with the window, then go back to
351 		    // the old tab and close the window there.
352 		    wp = curwin;
353 		    if (win_new_tabpage((int)Prenum) == OK
354 						     && valid_tabpage(oldtab))
355 		    {
356 			newtab = curtab;
357 			goto_tabpage_tp(oldtab, TRUE, TRUE);
358 			if (curwin == wp)
359 			    win_close(curwin, FALSE);
360 			if (valid_tabpage(newtab))
361 			    goto_tabpage_tp(newtab, TRUE, TRUE);
362 		    }
363 		}
364 		break;
365 
366 // cursor to top-left window
367     case 't':
368     case Ctrl_T:
369 		win_goto(firstwin);
370 		break;
371 
372 // cursor to bottom-right window
373     case 'b':
374     case Ctrl_B:
375 		win_goto(lastwin);
376 		break;
377 
378 // cursor to last accessed (previous) window
379     case 'p':
380     case Ctrl_P:
381 		if (!win_valid(prevwin))
382 		    beep_flush();
383 		else
384 		    win_goto(prevwin);
385 		break;
386 
387 // exchange current and next window
388     case 'x':
389     case Ctrl_X:
390 		CHECK_CMDWIN;
391 		win_exchange(Prenum);
392 		break;
393 
394 // rotate windows downwards
395     case Ctrl_R:
396     case 'r':
397 		CHECK_CMDWIN;
398 		reset_VIsual_and_resel();	// stop Visual mode
399 		win_rotate(FALSE, (int)Prenum1);    // downwards
400 		break;
401 
402 // rotate windows upwards
403     case 'R':
404 		CHECK_CMDWIN;
405 		reset_VIsual_and_resel();	// stop Visual mode
406 		win_rotate(TRUE, (int)Prenum1);	    // upwards
407 		break;
408 
409 // move window to the very top/bottom/left/right
410     case 'K':
411     case 'J':
412     case 'H':
413     case 'L':
414 		CHECK_CMDWIN;
415 		win_totop((int)Prenum,
416 			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
417 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
418 		break;
419 
420 // make all windows the same height
421     case '=':
422 #ifdef FEAT_GUI
423 		need_mouse_correct = TRUE;
424 #endif
425 		win_equal(NULL, FALSE, 'b');
426 		break;
427 
428 // increase current window height
429     case '+':
430 #ifdef FEAT_GUI
431 		need_mouse_correct = TRUE;
432 #endif
433 		win_setheight(curwin->w_height + (int)Prenum1);
434 		break;
435 
436 // decrease current window height
437     case '-':
438 #ifdef FEAT_GUI
439 		need_mouse_correct = TRUE;
440 #endif
441 		win_setheight(curwin->w_height - (int)Prenum1);
442 		break;
443 
444 // set current window height
445     case Ctrl__:
446     case '_':
447 #ifdef FEAT_GUI
448 		need_mouse_correct = TRUE;
449 #endif
450 		win_setheight(Prenum ? (int)Prenum : 9999);
451 		break;
452 
453 // increase current window width
454     case '>':
455 #ifdef FEAT_GUI
456 		need_mouse_correct = TRUE;
457 #endif
458 		win_setwidth(curwin->w_width + (int)Prenum1);
459 		break;
460 
461 // decrease current window width
462     case '<':
463 #ifdef FEAT_GUI
464 		need_mouse_correct = TRUE;
465 #endif
466 		win_setwidth(curwin->w_width - (int)Prenum1);
467 		break;
468 
469 // set current window width
470     case '|':
471 #ifdef FEAT_GUI
472 		need_mouse_correct = TRUE;
473 #endif
474 		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
475 		break;
476 
477 // jump to tag and split window if tag exists (in preview window)
478 #if defined(FEAT_QUICKFIX)
479     case '}':
480 		CHECK_CMDWIN;
481 		if (Prenum)
482 		    g_do_tagpreview = Prenum;
483 		else
484 		    g_do_tagpreview = p_pvh;
485 #endif
486 		// FALLTHROUGH
487     case ']':
488     case Ctrl_RSB:
489 		CHECK_CMDWIN;
490 		// keep Visual mode, can select words to use as a tag
491 		if (Prenum)
492 		    postponed_split = Prenum;
493 		else
494 		    postponed_split = -1;
495 #ifdef FEAT_QUICKFIX
496 		if (nchar != '}')
497 		    g_do_tagpreview = 0;
498 #endif
499 
500 		// Execute the command right here, required when "wincmd ]"
501 		// was used in a function.
502 		do_nv_ident(Ctrl_RSB, NUL);
503 		break;
504 
505 #ifdef FEAT_SEARCHPATH
506 // edit file name under cursor in a new window
507     case 'f':
508     case 'F':
509     case Ctrl_F:
510 wingotofile:
511 		CHECK_CMDWIN;
512 
513 		ptr = grab_file_name(Prenum1, &lnum);
514 		if (ptr != NULL)
515 		{
516 		    tabpage_T	*oldtab = curtab;
517 		    win_T	*oldwin = curwin;
518 # ifdef FEAT_GUI
519 		    need_mouse_correct = TRUE;
520 # endif
521 		    setpcmark();
522 		    if (win_split(0, 0) == OK)
523 		    {
524 			RESET_BINDING(curwin);
525 			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
526 						   ECMD_HIDE, NULL) == FAIL)
527 			{
528 			    // Failed to open the file, close the window
529 			    // opened for it.
530 			    win_close(curwin, FALSE);
531 			    goto_tabpage_win(oldtab, oldwin);
532 			}
533 			else if (nchar == 'F' && lnum >= 0)
534 			{
535 			    curwin->w_cursor.lnum = lnum;
536 			    check_cursor_lnum();
537 			    beginline(BL_SOL | BL_FIX);
538 			}
539 		    }
540 		    vim_free(ptr);
541 		}
542 		break;
543 #endif
544 
545 #ifdef FEAT_FIND_ID
546 // Go to the first occurrence of the identifier under cursor along path in a
547 // new window -- webb
548     case 'i':			    // Go to any match
549     case Ctrl_I:
550 		type = FIND_ANY;
551 		// FALLTHROUGH
552     case 'd':			    // Go to definition, using 'define'
553     case Ctrl_D:
554 		CHECK_CMDWIN;
555 		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
556 		    break;
557 		find_pattern_in_path(ptr, 0, len, TRUE,
558 			Prenum == 0 ? TRUE : FALSE, type,
559 			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
560 		curwin->w_set_curswant = TRUE;
561 		break;
562 #endif
563 
564 // Quickfix window only: view the result under the cursor in a new split.
565 #if defined(FEAT_QUICKFIX)
566     case K_KENTER:
567     case CAR:
568 		if (bt_quickfix(curbuf))
569 		    qf_view_result(TRUE);
570 		break;
571 #endif
572 
573 // CTRL-W g  extended commands
574     case 'g':
575     case Ctrl_G:
576 		CHECK_CMDWIN;
577 #ifdef USE_ON_FLY_SCROLL
578 		dont_scroll = TRUE;		// disallow scrolling here
579 #endif
580 		++no_mapping;
581 		++allow_keys;   // no mapping for xchar, but allow key codes
582 		if (xchar == NUL)
583 		    xchar = plain_vgetc();
584 		LANGMAP_ADJUST(xchar, TRUE);
585 		--no_mapping;
586 		--allow_keys;
587 #ifdef FEAT_CMDL_INFO
588 		(void)add_to_showcmd(xchar);
589 #endif
590 		switch (xchar)
591 		{
592 #if defined(FEAT_QUICKFIX)
593 		    case '}':
594 			xchar = Ctrl_RSB;
595 			if (Prenum)
596 			    g_do_tagpreview = Prenum;
597 			else
598 			    g_do_tagpreview = p_pvh;
599 #endif
600 			// FALLTHROUGH
601 		    case ']':
602 		    case Ctrl_RSB:
603 			// keep Visual mode, can select words to use as a tag
604 			if (Prenum)
605 			    postponed_split = Prenum;
606 			else
607 			    postponed_split = -1;
608 
609 			// Execute the command right here, required when
610 			// "wincmd g}" was used in a function.
611 			do_nv_ident('g', xchar);
612 			break;
613 
614 #ifdef FEAT_SEARCHPATH
615 		    case 'f':	    // CTRL-W gf: "gf" in a new tab page
616 		    case 'F':	    // CTRL-W gF: "gF" in a new tab page
617 			cmdmod.tab = tabpage_index(curtab) + 1;
618 			nchar = xchar;
619 			goto wingotofile;
620 #endif
621 		    case 't':	    // CTRL-W gt: go to next tab page
622 			goto_tabpage((int)Prenum);
623 			break;
624 
625 		    case 'T':	    // CTRL-W gT: go to previous tab page
626 			goto_tabpage(-(int)Prenum1);
627 			break;
628 
629 		    default:
630 			beep_flush();
631 			break;
632 		}
633 		break;
634 
635     default:	beep_flush();
636 		break;
637     }
638 }
639 
640 /*
641  * Figure out the address type for ":wincmd".
642  */
643     void
644 get_wincmd_addr_type(char_u *arg, exarg_T *eap)
645 {
646     switch (*arg)
647     {
648     case 'S':
649     case Ctrl_S:
650     case 's':
651     case Ctrl_N:
652     case 'n':
653     case 'j':
654     case Ctrl_J:
655     case 'k':
656     case Ctrl_K:
657     case 'T':
658     case Ctrl_R:
659     case 'r':
660     case 'R':
661     case 'K':
662     case 'J':
663     case '+':
664     case '-':
665     case Ctrl__:
666     case '_':
667     case '|':
668     case ']':
669     case Ctrl_RSB:
670     case 'g':
671     case Ctrl_G:
672     case Ctrl_V:
673     case 'v':
674     case 'h':
675     case Ctrl_H:
676     case 'l':
677     case Ctrl_L:
678     case 'H':
679     case 'L':
680     case '>':
681     case '<':
682 #if defined(FEAT_QUICKFIX)
683     case '}':
684 #endif
685 #ifdef FEAT_SEARCHPATH
686     case 'f':
687     case 'F':
688     case Ctrl_F:
689 #endif
690 #ifdef FEAT_FIND_ID
691     case 'i':
692     case Ctrl_I:
693     case 'd':
694     case Ctrl_D:
695 #endif
696 		// window size or any count
697 		eap->addr_type = ADDR_OTHER;
698 		break;
699 
700     case Ctrl_HAT:
701     case '^':
702 		// buffer number
703 		eap->addr_type = ADDR_BUFFERS;
704 		break;
705 
706     case Ctrl_Q:
707     case 'q':
708     case Ctrl_C:
709     case 'c':
710     case Ctrl_O:
711     case 'o':
712     case Ctrl_W:
713     case 'w':
714     case 'W':
715     case 'x':
716     case Ctrl_X:
717 		// window number
718 		eap->addr_type = ADDR_WINDOWS;
719 		break;
720 
721 #if defined(FEAT_QUICKFIX)
722     case Ctrl_Z:
723     case 'z':
724     case 'P':
725 #endif
726     case 't':
727     case Ctrl_T:
728     case 'b':
729     case Ctrl_B:
730     case 'p':
731     case Ctrl_P:
732     case '=':
733     case CAR:
734 		// no count
735 		eap->addr_type = ADDR_NONE;
736 		break;
737     }
738 }
739 
740     static void
741 cmd_with_count(
742     char	*cmd,
743     char_u	*bufp,
744     size_t	bufsize,
745     long	Prenum)
746 {
747     size_t	len = STRLEN(cmd);
748 
749     STRCPY(bufp, cmd);
750     if (Prenum > 0)
751 	vim_snprintf((char *)bufp + len, bufsize - len, "%ld", Prenum);
752 }
753 
754 /*
755  * If "split_disallowed" is set given an error and return FAIL.
756  * Otherwise return OK.
757  */
758     static int
759 check_split_disallowed()
760 {
761     if (split_disallowed > 0)
762     {
763 	emsg(_("E242: Can't split a window while closing another"));
764 	return FAIL;
765     }
766     return OK;
767 }
768 
769 /*
770  * split the current window, implements CTRL-W s and :split
771  *
772  * "size" is the height or width for the new window, 0 to use half of current
773  * height or width.
774  *
775  * "flags":
776  * WSP_ROOM: require enough room for new window
777  * WSP_VERT: vertical split.
778  * WSP_TOP:  open window at the top-left of the shell (help window).
779  * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
780  * WSP_HELP: creating the help window, keep layout snapshot
781  *
782  * return FAIL for failure, OK otherwise
783  */
784     int
785 win_split(int size, int flags)
786 {
787     if (ERROR_IF_ANY_POPUP_WINDOW)
788 	return FAIL;
789 
790     // When the ":tab" modifier was used open a new tab page instead.
791     if (may_open_tabpage() == OK)
792 	return OK;
793 
794     // Add flags from ":vertical", ":topleft" and ":botright".
795     flags |= cmdmod.split;
796     if ((flags & WSP_TOP) && (flags & WSP_BOT))
797     {
798 	emsg(_("E442: Can't split topleft and botright at the same time"));
799 	return FAIL;
800     }
801     if (check_split_disallowed() == FAIL)
802 	return FAIL;
803 
804     // When creating the help window make a snapshot of the window layout.
805     // Otherwise clear the snapshot, it's now invalid.
806     if (flags & WSP_HELP)
807 	make_snapshot(SNAP_HELP_IDX);
808     else
809 	clear_snapshot(curtab, SNAP_HELP_IDX);
810 
811     return win_split_ins(size, flags, NULL, 0);
812 }
813 
814 /*
815  * When "new_wp" is NULL: split the current window in two.
816  * When "new_wp" is not NULL: insert this window at the far
817  * top/left/right/bottom.
818  * return FAIL for failure, OK otherwise
819  */
820     int
821 win_split_ins(
822     int		size,
823     int		flags,
824     win_T	*new_wp,
825     int		dir)
826 {
827     win_T	*wp = new_wp;
828     win_T	*oldwin;
829     int		new_size = size;
830     int		i;
831     int		need_status = 0;
832     int		do_equal = FALSE;
833     int		needed;
834     int		available;
835     int		oldwin_height = 0;
836     int		layout;
837     frame_T	*frp, *curfrp, *frp2, *prevfrp;
838     int		before;
839     int		minheight;
840     int		wmh1;
841     int		did_set_fraction = FALSE;
842 
843     if (flags & WSP_TOP)
844 	oldwin = firstwin;
845     else if (flags & WSP_BOT)
846 	oldwin = lastwin;
847     else
848 	oldwin = curwin;
849 
850     // add a status line when p_ls == 1 and splitting the first window
851     if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
852     {
853 	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
854 	{
855 	    emsg(_(e_noroom));
856 	    return FAIL;
857 	}
858 	need_status = STATUS_HEIGHT;
859     }
860 
861 #ifdef FEAT_GUI
862     // May be needed for the scrollbars that are going to change.
863     if (gui.in_use)
864 	out_flush();
865 #endif
866 
867     if (flags & WSP_VERT)
868     {
869 	int	wmw1;
870 	int	minwidth;
871 
872 	layout = FR_ROW;
873 
874 	/*
875 	 * Check if we are able to split the current window and compute its
876 	 * width.
877 	 */
878 	// Current window requires at least 1 space.
879 	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
880 	needed = wmw1 + 1;
881 	if (flags & WSP_ROOM)
882 	    needed += p_wiw - wmw1;
883 	if (flags & (WSP_BOT | WSP_TOP))
884 	{
885 	    minwidth = frame_minwidth(topframe, NOWIN);
886 	    available = topframe->fr_width;
887 	    needed += minwidth;
888 	}
889 	else if (p_ea)
890 	{
891 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
892 	    prevfrp = oldwin->w_frame;
893 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
894 							frp = frp->fr_parent)
895 	    {
896 		if (frp->fr_layout == FR_ROW)
897 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
898 			if (frp2 != prevfrp)
899 			    minwidth += frame_minwidth(frp2, NOWIN);
900 		prevfrp = frp;
901 	    }
902 	    available = topframe->fr_width;
903 	    needed += minwidth;
904 	}
905 	else
906 	{
907 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
908 	    available = oldwin->w_frame->fr_width;
909 	    needed += minwidth;
910 	}
911 	if (available < needed && new_wp == NULL)
912 	{
913 	    emsg(_(e_noroom));
914 	    return FAIL;
915 	}
916 	if (new_size == 0)
917 	    new_size = oldwin->w_width / 2;
918 	if (new_size > available - minwidth - 1)
919 	    new_size = available - minwidth - 1;
920 	if (new_size < wmw1)
921 	    new_size = wmw1;
922 
923 	// if it doesn't fit in the current window, need win_equal()
924 	if (oldwin->w_width - new_size - 1 < p_wmw)
925 	    do_equal = TRUE;
926 
927 	// We don't like to take lines for the new window from a
928 	// 'winfixwidth' window.  Take them from a window to the left or right
929 	// instead, if possible. Add one for the separator.
930 	if (oldwin->w_p_wfw)
931 	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
932 
933 	// Only make all windows the same width if one of them (except oldwin)
934 	// is wider than one of the split windows.
935 	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
936 					 && oldwin->w_frame->fr_parent != NULL)
937 	{
938 	    frp = oldwin->w_frame->fr_parent->fr_child;
939 	    while (frp != NULL)
940 	    {
941 		if (frp->fr_win != oldwin && frp->fr_win != NULL
942 			&& (frp->fr_win->w_width > new_size
943 			    || frp->fr_win->w_width > oldwin->w_width
944 							      - new_size - 1))
945 		{
946 		    do_equal = TRUE;
947 		    break;
948 		}
949 		frp = frp->fr_next;
950 	    }
951 	}
952     }
953     else
954     {
955 	layout = FR_COL;
956 
957 	/*
958 	 * Check if we are able to split the current window and compute its
959 	 * height.
960 	 */
961 	// Current window requires at least 1 space.
962 	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
963 	needed = wmh1 + STATUS_HEIGHT;
964 	if (flags & WSP_ROOM)
965 	    needed += p_wh - wmh1;
966 	if (flags & (WSP_BOT | WSP_TOP))
967 	{
968 	    minheight = frame_minheight(topframe, NOWIN) + need_status;
969 	    available = topframe->fr_height;
970 	    needed += minheight;
971 	}
972 	else if (p_ea)
973 	{
974 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
975 	    prevfrp = oldwin->w_frame;
976 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
977 							frp = frp->fr_parent)
978 	    {
979 		if (frp->fr_layout == FR_COL)
980 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
981 			if (frp2 != prevfrp)
982 			    minheight += frame_minheight(frp2, NOWIN);
983 		prevfrp = frp;
984 	    }
985 	    available = topframe->fr_height;
986 	    needed += minheight;
987 	}
988 	else
989 	{
990 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
991 	    available = oldwin->w_frame->fr_height;
992 	    needed += minheight;
993 	}
994 	if (available < needed && new_wp == NULL)
995 	{
996 	    emsg(_(e_noroom));
997 	    return FAIL;
998 	}
999 	oldwin_height = oldwin->w_height;
1000 	if (need_status)
1001 	{
1002 	    oldwin->w_status_height = STATUS_HEIGHT;
1003 	    oldwin_height -= STATUS_HEIGHT;
1004 	}
1005 	if (new_size == 0)
1006 	    new_size = oldwin_height / 2;
1007 	if (new_size > available - minheight - STATUS_HEIGHT)
1008 	    new_size = available - minheight - STATUS_HEIGHT;
1009 	if (new_size < wmh1)
1010 	    new_size = wmh1;
1011 
1012 	// if it doesn't fit in the current window, need win_equal()
1013 	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
1014 	    do_equal = TRUE;
1015 
1016 	// We don't like to take lines for the new window from a
1017 	// 'winfixheight' window.  Take them from a window above or below
1018 	// instead, if possible.
1019 	if (oldwin->w_p_wfh)
1020 	{
1021 	    // Set w_fraction now so that the cursor keeps the same relative
1022 	    // vertical position using the old height.
1023 	    set_fraction(oldwin);
1024 	    did_set_fraction = TRUE;
1025 
1026 	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
1027 								      oldwin);
1028 	    oldwin_height = oldwin->w_height;
1029 	    if (need_status)
1030 		oldwin_height -= STATUS_HEIGHT;
1031 	}
1032 
1033 	// Only make all windows the same height if one of them (except oldwin)
1034 	// is higher than one of the split windows.
1035 	if (!do_equal && p_ea && size == 0 && *p_ead != 'h'
1036 	   && oldwin->w_frame->fr_parent != NULL)
1037 	{
1038 	    frp = oldwin->w_frame->fr_parent->fr_child;
1039 	    while (frp != NULL)
1040 	    {
1041 		if (frp->fr_win != oldwin && frp->fr_win != NULL
1042 			&& (frp->fr_win->w_height > new_size
1043 			    || frp->fr_win->w_height > oldwin_height - new_size
1044 							      - STATUS_HEIGHT))
1045 		{
1046 		    do_equal = TRUE;
1047 		    break;
1048 		}
1049 		frp = frp->fr_next;
1050 	    }
1051 	}
1052     }
1053 
1054     /*
1055      * allocate new window structure and link it in the window list
1056      */
1057     if ((flags & WSP_TOP) == 0
1058 	    && ((flags & WSP_BOT)
1059 		|| (flags & WSP_BELOW)
1060 		|| (!(flags & WSP_ABOVE)
1061 		    && ( (flags & WSP_VERT) ? p_spr : p_sb))))
1062     {
1063 	// new window below/right of current one
1064 	if (new_wp == NULL)
1065 	    wp = win_alloc(oldwin, FALSE);
1066 	else
1067 	    win_append(oldwin, wp);
1068     }
1069     else
1070     {
1071 	if (new_wp == NULL)
1072 	    wp = win_alloc(oldwin->w_prev, FALSE);
1073 	else
1074 	    win_append(oldwin->w_prev, wp);
1075     }
1076 
1077     if (new_wp == NULL)
1078     {
1079 	if (wp == NULL)
1080 	    return FAIL;
1081 
1082 	new_frame(wp);
1083 	if (wp->w_frame == NULL)
1084 	{
1085 	    win_free(wp, NULL);
1086 	    return FAIL;
1087 	}
1088 
1089 	// make the contents of the new window the same as the current one
1090 	win_init(wp, curwin, flags);
1091     }
1092 
1093     /*
1094      * Reorganise the tree of frames to insert the new window.
1095      */
1096     if (flags & (WSP_TOP | WSP_BOT))
1097     {
1098 	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
1099 	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
1100 	{
1101 	    curfrp = topframe->fr_child;
1102 	    if (flags & WSP_BOT)
1103 		while (curfrp->fr_next != NULL)
1104 		    curfrp = curfrp->fr_next;
1105 	}
1106 	else
1107 	    curfrp = topframe;
1108 	before = (flags & WSP_TOP);
1109     }
1110     else
1111     {
1112 	curfrp = oldwin->w_frame;
1113 	if (flags & WSP_BELOW)
1114 	    before = FALSE;
1115 	else if (flags & WSP_ABOVE)
1116 	    before = TRUE;
1117 	else if (flags & WSP_VERT)
1118 	    before = !p_spr;
1119 	else
1120 	    before = !p_sb;
1121     }
1122     if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
1123     {
1124 	// Need to create a new frame in the tree to make a branch.
1125 	frp = ALLOC_CLEAR_ONE(frame_T);
1126 	*frp = *curfrp;
1127 	curfrp->fr_layout = layout;
1128 	frp->fr_parent = curfrp;
1129 	frp->fr_next = NULL;
1130 	frp->fr_prev = NULL;
1131 	curfrp->fr_child = frp;
1132 	curfrp->fr_win = NULL;
1133 	curfrp = frp;
1134 	if (frp->fr_win != NULL)
1135 	    oldwin->w_frame = frp;
1136 	else
1137 	    FOR_ALL_FRAMES(frp, frp->fr_child)
1138 		frp->fr_parent = curfrp;
1139     }
1140 
1141     if (new_wp == NULL)
1142 	frp = wp->w_frame;
1143     else
1144 	frp = new_wp->w_frame;
1145     frp->fr_parent = curfrp->fr_parent;
1146 
1147     // Insert the new frame at the right place in the frame list.
1148     if (before)
1149 	frame_insert(curfrp, frp);
1150     else
1151 	frame_append(curfrp, frp);
1152 
1153     // Set w_fraction now so that the cursor keeps the same relative
1154     // vertical position.
1155     if (!did_set_fraction)
1156 	set_fraction(oldwin);
1157     wp->w_fraction = oldwin->w_fraction;
1158 
1159     if (flags & WSP_VERT)
1160     {
1161 	wp->w_p_scr = curwin->w_p_scr;
1162 
1163 	if (need_status)
1164 	{
1165 	    win_new_height(oldwin, oldwin->w_height - 1);
1166 	    oldwin->w_status_height = need_status;
1167 	}
1168 	if (flags & (WSP_TOP | WSP_BOT))
1169 	{
1170 	    // set height and row of new window to full height
1171 	    wp->w_winrow = tabline_height();
1172 	    win_new_height(wp, curfrp->fr_height - (p_ls > 0)
1173 							  - WINBAR_HEIGHT(wp));
1174 	    wp->w_status_height = (p_ls > 0);
1175 	}
1176 	else
1177 	{
1178 	    // height and row of new window is same as current window
1179 	    wp->w_winrow = oldwin->w_winrow;
1180 	    win_new_height(wp, VISIBLE_HEIGHT(oldwin));
1181 	    wp->w_status_height = oldwin->w_status_height;
1182 	}
1183 	frp->fr_height = curfrp->fr_height;
1184 
1185 	// "new_size" of the current window goes to the new window, use
1186 	// one column for the vertical separator
1187 	win_new_width(wp, new_size);
1188 	if (before)
1189 	    wp->w_vsep_width = 1;
1190 	else
1191 	{
1192 	    wp->w_vsep_width = oldwin->w_vsep_width;
1193 	    oldwin->w_vsep_width = 1;
1194 	}
1195 	if (flags & (WSP_TOP | WSP_BOT))
1196 	{
1197 	    if (flags & WSP_BOT)
1198 		frame_add_vsep(curfrp);
1199 	    // Set width of neighbor frame
1200 	    frame_new_width(curfrp, curfrp->fr_width
1201 		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
1202 								       FALSE);
1203 	}
1204 	else
1205 	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
1206 	if (before)	// new window left of current one
1207 	{
1208 	    wp->w_wincol = oldwin->w_wincol;
1209 	    oldwin->w_wincol += new_size + 1;
1210 	}
1211 	else		// new window right of current one
1212 	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
1213 	frame_fix_width(oldwin);
1214 	frame_fix_width(wp);
1215     }
1216     else
1217     {
1218 	// width and column of new window is same as current window
1219 	if (flags & (WSP_TOP | WSP_BOT))
1220 	{
1221 	    wp->w_wincol = 0;
1222 	    win_new_width(wp, Columns);
1223 	    wp->w_vsep_width = 0;
1224 	}
1225 	else
1226 	{
1227 	    wp->w_wincol = oldwin->w_wincol;
1228 	    win_new_width(wp, oldwin->w_width);
1229 	    wp->w_vsep_width = oldwin->w_vsep_width;
1230 	}
1231 	frp->fr_width = curfrp->fr_width;
1232 
1233 	// "new_size" of the current window goes to the new window, use
1234 	// one row for the status line
1235 	win_new_height(wp, new_size);
1236 	if (flags & (WSP_TOP | WSP_BOT))
1237 	{
1238 	    int new_fr_height = curfrp->fr_height - new_size
1239 							  + WINBAR_HEIGHT(wp) ;
1240 
1241 	    if (!((flags & WSP_BOT) && p_ls == 0))
1242 		new_fr_height -= STATUS_HEIGHT;
1243 	    frame_new_height(curfrp, new_fr_height, flags & WSP_TOP, FALSE);
1244 	}
1245 	else
1246 	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
1247 	if (before)	// new window above current one
1248 	{
1249 	    wp->w_winrow = oldwin->w_winrow;
1250 	    wp->w_status_height = STATUS_HEIGHT;
1251 	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
1252 	}
1253 	else		// new window below current one
1254 	{
1255 	    wp->w_winrow = oldwin->w_winrow + VISIBLE_HEIGHT(oldwin)
1256 							       + STATUS_HEIGHT;
1257 	    wp->w_status_height = oldwin->w_status_height;
1258 	    if (!(flags & WSP_BOT))
1259 		oldwin->w_status_height = STATUS_HEIGHT;
1260 	}
1261 	if (flags & WSP_BOT)
1262 	    frame_add_statusline(curfrp);
1263 	frame_fix_height(wp);
1264 	frame_fix_height(oldwin);
1265     }
1266 
1267     if (flags & (WSP_TOP | WSP_BOT))
1268 	(void)win_comp_pos();
1269 
1270     /*
1271      * Both windows need redrawing
1272      */
1273     redraw_win_later(wp, NOT_VALID);
1274     wp->w_redr_status = TRUE;
1275     redraw_win_later(oldwin, NOT_VALID);
1276     oldwin->w_redr_status = TRUE;
1277 
1278     if (need_status)
1279     {
1280 	msg_row = Rows - 1;
1281 	msg_col = sc_col;
1282 	msg_clr_eos_force();	// Old command/ruler may still be there
1283 	comp_col();
1284 	msg_row = Rows - 1;
1285 	msg_col = 0;	// put position back at start of line
1286     }
1287 
1288     /*
1289      * equalize the window sizes.
1290      */
1291     if (do_equal || dir != 0)
1292 	win_equal(wp, TRUE,
1293 		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
1294 		: dir == 'h' ? 'b' : 'v');
1295 
1296     // Don't change the window height/width to 'winheight' / 'winwidth' if a
1297     // size was given.
1298     if (flags & WSP_VERT)
1299     {
1300 	i = p_wiw;
1301 	if (size != 0)
1302 	    p_wiw = size;
1303 
1304 # ifdef FEAT_GUI
1305 	// When 'guioptions' includes 'L' or 'R' may have to add scrollbars.
1306 	if (gui.in_use)
1307 	    gui_init_which_components(NULL);
1308 # endif
1309     }
1310     else
1311     {
1312 	i = p_wh;
1313 	if (size != 0)
1314 	    p_wh = size;
1315     }
1316 
1317 #ifdef FEAT_JUMPLIST
1318     // Keep same changelist position in new window.
1319     wp->w_changelistidx = oldwin->w_changelistidx;
1320 #endif
1321 
1322     /*
1323      * make the new window the current window
1324      */
1325     win_enter_ext(wp, FALSE, FALSE, TRUE, TRUE, TRUE);
1326     if (flags & WSP_VERT)
1327 	p_wiw = i;
1328     else
1329 	p_wh = i;
1330 
1331     return OK;
1332 }
1333 
1334 
1335 /*
1336  * Initialize window "newp" from window "oldp".
1337  * Used when splitting a window and when creating a new tab page.
1338  * The windows will both edit the same buffer.
1339  * WSP_NEWLOC may be specified in flags to prevent the location list from
1340  * being copied.
1341  */
1342     static void
1343 win_init(win_T *newp, win_T *oldp, int flags UNUSED)
1344 {
1345     int		i;
1346 
1347     newp->w_buffer = oldp->w_buffer;
1348 #ifdef FEAT_SYN_HL
1349     newp->w_s = &(oldp->w_buffer->b_s);
1350 #endif
1351     oldp->w_buffer->b_nwindows++;
1352     newp->w_cursor = oldp->w_cursor;
1353     newp->w_valid = 0;
1354     newp->w_curswant = oldp->w_curswant;
1355     newp->w_set_curswant = oldp->w_set_curswant;
1356     newp->w_topline = oldp->w_topline;
1357 #ifdef FEAT_DIFF
1358     newp->w_topfill = oldp->w_topfill;
1359 #endif
1360     newp->w_leftcol = oldp->w_leftcol;
1361     newp->w_pcmark = oldp->w_pcmark;
1362     newp->w_prev_pcmark = oldp->w_prev_pcmark;
1363     newp->w_alt_fnum = oldp->w_alt_fnum;
1364     newp->w_wrow = oldp->w_wrow;
1365     newp->w_fraction = oldp->w_fraction;
1366     newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
1367 #ifdef FEAT_JUMPLIST
1368     copy_jumplist(oldp, newp);
1369 #endif
1370 #ifdef FEAT_QUICKFIX
1371     if (flags & WSP_NEWLOC)
1372     {
1373 	// Don't copy the location list.
1374 	newp->w_llist = NULL;
1375 	newp->w_llist_ref = NULL;
1376     }
1377     else
1378 	copy_loclist_stack(oldp, newp);
1379 #endif
1380     newp->w_localdir = (oldp->w_localdir == NULL)
1381 				    ? NULL : vim_strsave(oldp->w_localdir);
1382 
1383     // copy tagstack and folds
1384     for (i = 0; i < oldp->w_tagstacklen; i++)
1385     {
1386 	taggy_T	*tag = &newp->w_tagstack[i];
1387 	*tag = oldp->w_tagstack[i];
1388 	if (tag->tagname != NULL)
1389 	    tag->tagname = vim_strsave(tag->tagname);
1390 	if (tag->user_data != NULL)
1391 	    tag->user_data = vim_strsave(tag->user_data);
1392     }
1393     newp->w_tagstackidx = oldp->w_tagstackidx;
1394     newp->w_tagstacklen = oldp->w_tagstacklen;
1395 #ifdef FEAT_FOLDING
1396     copyFoldingState(oldp, newp);
1397 #endif
1398 
1399     win_init_some(newp, oldp);
1400 
1401 #ifdef FEAT_SYN_HL
1402     check_colorcolumn(newp);
1403 #endif
1404 }
1405 
1406 /*
1407  * Initialize window "newp" from window "old".
1408  * Only the essential things are copied.
1409  */
1410     static void
1411 win_init_some(win_T *newp, win_T *oldp)
1412 {
1413     // Use the same argument list.
1414     newp->w_alist = oldp->w_alist;
1415     ++newp->w_alist->al_refcount;
1416     newp->w_arg_idx = oldp->w_arg_idx;
1417 
1418     // copy options from existing window
1419     win_copy_options(oldp, newp);
1420 }
1421 
1422 /*
1423  * Return TRUE if "win" is a global popup or a popup in the current tab page.
1424  */
1425     int
1426 win_valid_popup(win_T *win UNUSED)
1427 {
1428 #ifdef FEAT_PROP_POPUP
1429     win_T	*wp;
1430 
1431     for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
1432 	if (wp == win)
1433 	    return TRUE;
1434     for (wp = curtab->tp_first_popupwin; wp != NULL; wp = wp->w_next)
1435 	if (wp == win)
1436 	    return TRUE;
1437 #endif
1438     return FALSE;
1439 }
1440 
1441 /*
1442  * Check if "win" is a pointer to an existing window in the current tab page.
1443  */
1444     int
1445 win_valid(win_T *win)
1446 {
1447     win_T	*wp;
1448 
1449     if (win == NULL)
1450 	return FALSE;
1451     FOR_ALL_WINDOWS(wp)
1452 	if (wp == win)
1453 	    return TRUE;
1454     return win_valid_popup(win);
1455 }
1456 
1457 /*
1458  * Check if "win" is a pointer to an existing window in any tab page.
1459  */
1460     int
1461 win_valid_any_tab(win_T *win)
1462 {
1463     win_T	*wp;
1464     tabpage_T	*tp;
1465 
1466     if (win == NULL)
1467 	return FALSE;
1468     FOR_ALL_TABPAGES(tp)
1469     {
1470 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
1471 	{
1472 	    if (wp == win)
1473 		return TRUE;
1474 	}
1475 #ifdef FEAT_PROP_POPUP
1476 	for (wp = tp->tp_first_popupwin; wp != NULL; wp = wp->w_next)
1477 	    if (wp == win)
1478 		return TRUE;
1479 #endif
1480     }
1481     return win_valid_popup(win);
1482 }
1483 
1484 /*
1485  * Return the number of windows.
1486  */
1487     int
1488 win_count(void)
1489 {
1490     win_T	*wp;
1491     int		count = 0;
1492 
1493     FOR_ALL_WINDOWS(wp)
1494 	++count;
1495     return count;
1496 }
1497 
1498 /*
1499  * Make "count" windows on the screen.
1500  * Return actual number of windows on the screen.
1501  * Must be called when there is just one window, filling the whole screen
1502  * (excluding the command line).
1503  */
1504     int
1505 make_windows(
1506     int		count,
1507     int		vertical UNUSED)  // split windows vertically if TRUE
1508 {
1509     int		maxcount;
1510     int		todo;
1511 
1512     if (vertical)
1513     {
1514 	// Each windows needs at least 'winminwidth' lines and a separator
1515 	// column.
1516 	maxcount = (curwin->w_width + curwin->w_vsep_width
1517 					     - (p_wiw - p_wmw)) / (p_wmw + 1);
1518     }
1519     else
1520     {
1521 	// Each window needs at least 'winminheight' lines and a status line.
1522 	maxcount = (VISIBLE_HEIGHT(curwin) + curwin->w_status_height
1523 				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
1524     }
1525 
1526     if (maxcount < 2)
1527 	maxcount = 2;
1528     if (count > maxcount)
1529 	count = maxcount;
1530 
1531     /*
1532      * add status line now, otherwise first window will be too big
1533      */
1534     if (count > 1)
1535 	last_status(TRUE);
1536 
1537     /*
1538      * Don't execute autocommands while creating the windows.  Must do that
1539      * when putting the buffers in the windows.
1540      */
1541     block_autocmds();
1542 
1543     // todo is number of windows left to create
1544     for (todo = count - 1; todo > 0; --todo)
1545 	if (vertical)
1546 	{
1547 	    if (win_split(curwin->w_width - (curwin->w_width - todo)
1548 			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
1549 		break;
1550 	}
1551 	else
1552 	{
1553 	    if (win_split(curwin->w_height - (curwin->w_height - todo
1554 			    * STATUS_HEIGHT) / (todo + 1)
1555 			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
1556 		break;
1557 	}
1558 
1559     unblock_autocmds();
1560 
1561     // return actual number of windows
1562     return (count - todo);
1563 }
1564 
1565 /*
1566  * Exchange current and next window
1567  */
1568     static void
1569 win_exchange(long Prenum)
1570 {
1571     frame_T	*frp;
1572     frame_T	*frp2;
1573     win_T	*wp;
1574     win_T	*wp2;
1575     int		temp;
1576 
1577     if (ERROR_IF_ANY_POPUP_WINDOW)
1578 	return;
1579     if (ONE_WINDOW)	    // just one window
1580     {
1581 	beep_flush();
1582 	return;
1583     }
1584 
1585 #ifdef FEAT_GUI
1586     need_mouse_correct = TRUE;
1587 #endif
1588 
1589     /*
1590      * find window to exchange with
1591      */
1592     if (Prenum)
1593     {
1594 	frp = curwin->w_frame->fr_parent->fr_child;
1595 	while (frp != NULL && --Prenum > 0)
1596 	    frp = frp->fr_next;
1597     }
1598     else if (curwin->w_frame->fr_next != NULL)	// Swap with next
1599 	frp = curwin->w_frame->fr_next;
1600     else    // Swap last window in row/col with previous
1601 	frp = curwin->w_frame->fr_prev;
1602 
1603     // We can only exchange a window with another window, not with a frame
1604     // containing windows.
1605     if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
1606 	return;
1607     wp = frp->fr_win;
1608 
1609 /*
1610  * 1. remove curwin from the list. Remember after which window it was in wp2
1611  * 2. insert curwin before wp in the list
1612  * if wp != wp2
1613  *    3. remove wp from the list
1614  *    4. insert wp after wp2
1615  * 5. exchange the status line height and vsep width.
1616  */
1617     wp2 = curwin->w_prev;
1618     frp2 = curwin->w_frame->fr_prev;
1619     if (wp->w_prev != curwin)
1620     {
1621 	win_remove(curwin, NULL);
1622 	frame_remove(curwin->w_frame);
1623 	win_append(wp->w_prev, curwin);
1624 	frame_insert(frp, curwin->w_frame);
1625     }
1626     if (wp != wp2)
1627     {
1628 	win_remove(wp, NULL);
1629 	frame_remove(wp->w_frame);
1630 	win_append(wp2, wp);
1631 	if (frp2 == NULL)
1632 	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
1633 	else
1634 	    frame_append(frp2, wp->w_frame);
1635     }
1636     temp = curwin->w_status_height;
1637     curwin->w_status_height = wp->w_status_height;
1638     wp->w_status_height = temp;
1639     temp = curwin->w_vsep_width;
1640     curwin->w_vsep_width = wp->w_vsep_width;
1641     wp->w_vsep_width = temp;
1642 
1643     // If the windows are not in the same frame, exchange the sizes to avoid
1644     // messing up the window layout.  Otherwise fix the frame sizes.
1645     if (curwin->w_frame->fr_parent != wp->w_frame->fr_parent)
1646     {
1647 	temp = curwin->w_height;
1648 	curwin->w_height = wp->w_height;
1649 	wp->w_height = temp;
1650 	temp = curwin->w_width;
1651 	curwin->w_width = wp->w_width;
1652 	wp->w_width = temp;
1653     }
1654     else
1655     {
1656 	frame_fix_height(curwin);
1657 	frame_fix_height(wp);
1658 	frame_fix_width(curwin);
1659 	frame_fix_width(wp);
1660     }
1661 
1662     (void)win_comp_pos();		// recompute window positions
1663 
1664     win_enter(wp, TRUE);
1665     redraw_all_later(NOT_VALID);
1666 }
1667 
1668 /*
1669  * rotate windows: if upwards TRUE the second window becomes the first one
1670  *		   if upwards FALSE the first window becomes the second one
1671  */
1672     static void
1673 win_rotate(int upwards, int count)
1674 {
1675     win_T	*wp1;
1676     win_T	*wp2;
1677     frame_T	*frp;
1678     int		n;
1679 
1680     if (ONE_WINDOW)		// nothing to do
1681     {
1682 	beep_flush();
1683 	return;
1684     }
1685 
1686 #ifdef FEAT_GUI
1687     need_mouse_correct = TRUE;
1688 #endif
1689 
1690     // Check if all frames in this row/col have one window.
1691     FOR_ALL_FRAMES(frp, curwin->w_frame->fr_parent->fr_child)
1692 	if (frp->fr_win == NULL)
1693 	{
1694 	    emsg(_("E443: Cannot rotate when another window is split"));
1695 	    return;
1696 	}
1697 
1698     while (count--)
1699     {
1700 	if (upwards)		// first window becomes last window
1701 	{
1702 	    // remove first window/frame from the list
1703 	    frp = curwin->w_frame->fr_parent->fr_child;
1704 	    wp1 = frp->fr_win;
1705 	    win_remove(wp1, NULL);
1706 	    frame_remove(frp);
1707 
1708 	    // find last frame and append removed window/frame after it
1709 	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
1710 		;
1711 	    win_append(frp->fr_win, wp1);
1712 	    frame_append(frp, wp1->w_frame);
1713 
1714 	    wp2 = frp->fr_win;		// previously last window
1715 	}
1716 	else			// last window becomes first window
1717 	{
1718 	    // find last window/frame in the list and remove it
1719 	    for (frp = curwin->w_frame; frp->fr_next != NULL;
1720 							   frp = frp->fr_next)
1721 		;
1722 	    wp1 = frp->fr_win;
1723 	    wp2 = wp1->w_prev;		    // will become last window
1724 	    win_remove(wp1, NULL);
1725 	    frame_remove(frp);
1726 
1727 	    // append the removed window/frame before the first in the list
1728 	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
1729 	    frame_insert(frp->fr_parent->fr_child, frp);
1730 	}
1731 
1732 	// exchange status height and vsep width of old and new last window
1733 	n = wp2->w_status_height;
1734 	wp2->w_status_height = wp1->w_status_height;
1735 	wp1->w_status_height = n;
1736 	frame_fix_height(wp1);
1737 	frame_fix_height(wp2);
1738 	n = wp2->w_vsep_width;
1739 	wp2->w_vsep_width = wp1->w_vsep_width;
1740 	wp1->w_vsep_width = n;
1741 	frame_fix_width(wp1);
1742 	frame_fix_width(wp2);
1743 
1744 	// recompute w_winrow and w_wincol for all windows
1745 	(void)win_comp_pos();
1746     }
1747 
1748     redraw_all_later(NOT_VALID);
1749 }
1750 
1751 /*
1752  * Move the current window to the very top/bottom/left/right of the screen.
1753  */
1754     static void
1755 win_totop(int size, int flags)
1756 {
1757     int		dir;
1758     int		height = curwin->w_height;
1759 
1760     if (ONE_WINDOW)
1761     {
1762 	beep_flush();
1763 	return;
1764     }
1765     if (check_split_disallowed() == FAIL)
1766 	return;
1767 
1768     // Remove the window and frame from the tree of frames.
1769     (void)winframe_remove(curwin, &dir, NULL);
1770     win_remove(curwin, NULL);
1771     last_status(FALSE);	    // may need to remove last status line
1772     (void)win_comp_pos();   // recompute window positions
1773 
1774     // Split a window on the desired side and put the window there.
1775     (void)win_split_ins(size, flags, curwin, dir);
1776     if (!(flags & WSP_VERT))
1777     {
1778 	win_setheight(height);
1779 	if (p_ea)
1780 	    win_equal(curwin, TRUE, 'v');
1781     }
1782 
1783 #if defined(FEAT_GUI)
1784     // When 'guioptions' includes 'L' or 'R' may have to remove or add
1785     // scrollbars.  Have to update them anyway.
1786     gui_may_update_scrollbars();
1787 #endif
1788 }
1789 
1790 /*
1791  * Move window "win1" to below/right of "win2" and make "win1" the current
1792  * window.  Only works within the same frame!
1793  */
1794     void
1795 win_move_after(win_T *win1, win_T *win2)
1796 {
1797     int		height;
1798 
1799     // check if the arguments are reasonable
1800     if (win1 == win2)
1801 	return;
1802 
1803     // check if there is something to do
1804     if (win2->w_next != win1)
1805     {
1806 	if (win1->w_frame->fr_parent != win2->w_frame->fr_parent)
1807 	{
1808 	    iemsg("INTERNAL: trying to move a window into another frame");
1809 	    return;
1810 	}
1811 
1812 	// may need move the status line/vertical separator of the last window
1813 	//
1814 	if (win1 == lastwin)
1815 	{
1816 	    height = win1->w_prev->w_status_height;
1817 	    win1->w_prev->w_status_height = win1->w_status_height;
1818 	    win1->w_status_height = height;
1819 	    if (win1->w_prev->w_vsep_width == 1)
1820 	    {
1821 		// Remove the vertical separator from the last-but-one window,
1822 		// add it to the last window.  Adjust the frame widths.
1823 		win1->w_prev->w_vsep_width = 0;
1824 		win1->w_prev->w_frame->fr_width -= 1;
1825 		win1->w_vsep_width = 1;
1826 		win1->w_frame->fr_width += 1;
1827 	    }
1828 	}
1829 	else if (win2 == lastwin)
1830 	{
1831 	    height = win1->w_status_height;
1832 	    win1->w_status_height = win2->w_status_height;
1833 	    win2->w_status_height = height;
1834 	    if (win1->w_vsep_width == 1)
1835 	    {
1836 		// Remove the vertical separator from win1, add it to the last
1837 		// window, win2.  Adjust the frame widths.
1838 		win2->w_vsep_width = 1;
1839 		win2->w_frame->fr_width += 1;
1840 		win1->w_vsep_width = 0;
1841 		win1->w_frame->fr_width -= 1;
1842 	    }
1843 	}
1844 	win_remove(win1, NULL);
1845 	frame_remove(win1->w_frame);
1846 	win_append(win2, win1);
1847 	frame_append(win2->w_frame, win1->w_frame);
1848 
1849 	(void)win_comp_pos();	// recompute w_winrow for all windows
1850 	redraw_later(NOT_VALID);
1851     }
1852     win_enter(win1, FALSE);
1853 }
1854 
1855 /*
1856  * Make all windows the same height.
1857  * 'next_curwin' will soon be the current window, make sure it has enough
1858  * rows.
1859  */
1860     void
1861 win_equal(
1862     win_T	*next_curwin,	// pointer to current window to be or NULL
1863     int		current,	// do only frame with current window
1864     int		dir)		// 'v' for vertically, 'h' for horizontally,
1865 				// 'b' for both, 0 for using p_ead
1866 {
1867     if (dir == 0)
1868 	dir = *p_ead;
1869     win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
1870 		      topframe, dir, 0, tabline_height(),
1871 					   (int)Columns, topframe->fr_height);
1872 }
1873 
1874 /*
1875  * Set a frame to a new position and height, spreading the available room
1876  * equally over contained frames.
1877  * The window "next_curwin" (if not NULL) should at least get the size from
1878  * 'winheight' and 'winwidth' if possible.
1879  */
1880     static void
1881 win_equal_rec(
1882     win_T	*next_curwin,	// pointer to current window to be or NULL
1883     int		current,	// do only frame with current window
1884     frame_T	*topfr,		// frame to set size off
1885     int		dir,		// 'v', 'h' or 'b', see win_equal()
1886     int		col,		// horizontal position for frame
1887     int		row,		// vertical position for frame
1888     int		width,		// new width of frame
1889     int		height)		// new height of frame
1890 {
1891     int		n, m;
1892     int		extra_sep = 0;
1893     int		wincount, totwincount = 0;
1894     frame_T	*fr;
1895     int		next_curwin_size = 0;
1896     int		room = 0;
1897     int		new_size;
1898     int		has_next_curwin = 0;
1899     int		hnc;
1900 
1901     if (topfr->fr_layout == FR_LEAF)
1902     {
1903 	// Set the width/height of this frame.
1904 	// Redraw when size or position changes
1905 	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
1906 		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
1907 	   )
1908 	{
1909 	    topfr->fr_win->w_winrow = row;
1910 	    frame_new_height(topfr, height, FALSE, FALSE);
1911 	    topfr->fr_win->w_wincol = col;
1912 	    frame_new_width(topfr, width, FALSE, FALSE);
1913 	    redraw_all_later(NOT_VALID);
1914 	}
1915     }
1916     else if (topfr->fr_layout == FR_ROW)
1917     {
1918 	topfr->fr_width = width;
1919 	topfr->fr_height = height;
1920 
1921 	if (dir != 'v')			// equalize frame widths
1922 	{
1923 	    // Compute the maximum number of windows horizontally in this
1924 	    // frame.
1925 	    n = frame_minwidth(topfr, NOWIN);
1926 	    // add one for the rightmost window, it doesn't have a separator
1927 	    if (col + width == Columns)
1928 		extra_sep = 1;
1929 	    else
1930 		extra_sep = 0;
1931 	    totwincount = (n + extra_sep) / (p_wmw + 1);
1932 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1933 
1934 	    /*
1935 	     * Compute width for "next_curwin" window and room available for
1936 	     * other windows.
1937 	     * "m" is the minimal width when counting p_wiw for "next_curwin".
1938 	     */
1939 	    m = frame_minwidth(topfr, next_curwin);
1940 	    room = width - m;
1941 	    if (room < 0)
1942 	    {
1943 		next_curwin_size = p_wiw + room;
1944 		room = 0;
1945 	    }
1946 	    else
1947 	    {
1948 		next_curwin_size = -1;
1949 		FOR_ALL_FRAMES(fr, topfr->fr_child)
1950 		{
1951 		    // If 'winfixwidth' set keep the window width if
1952 		    // possible.
1953 		    // Watch out for this window being the next_curwin.
1954 		    if (frame_fixed_width(fr))
1955 		    {
1956 			n = frame_minwidth(fr, NOWIN);
1957 			new_size = fr->fr_width;
1958 			if (frame_has_win(fr, next_curwin))
1959 			{
1960 			    room += p_wiw - p_wmw;
1961 			    next_curwin_size = 0;
1962 			    if (new_size < p_wiw)
1963 				new_size = p_wiw;
1964 			}
1965 			else
1966 			    // These windows don't use up room.
1967 			    totwincount -= (n + (fr->fr_next == NULL
1968 					      ? extra_sep : 0)) / (p_wmw + 1);
1969 			room -= new_size - n;
1970 			if (room < 0)
1971 			{
1972 			    new_size += room;
1973 			    room = 0;
1974 			}
1975 			fr->fr_newwidth = new_size;
1976 		    }
1977 		}
1978 		if (next_curwin_size == -1)
1979 		{
1980 		    if (!has_next_curwin)
1981 			next_curwin_size = 0;
1982 		    else if (totwincount > 1
1983 			    && (room + (totwincount - 2))
1984 						  / (totwincount - 1) > p_wiw)
1985 		    {
1986 			// Can make all windows wider than 'winwidth', spread
1987 			// the room equally.
1988 			next_curwin_size = (room + p_wiw
1989 					    + (totwincount - 1) * p_wmw
1990 					    + (totwincount - 1)) / totwincount;
1991 			room -= next_curwin_size - p_wiw;
1992 		    }
1993 		    else
1994 			next_curwin_size = p_wiw;
1995 		}
1996 	    }
1997 
1998 	    if (has_next_curwin)
1999 		--totwincount;		// don't count curwin
2000 	}
2001 
2002 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2003 	{
2004 	    wincount = 1;
2005 	    if (fr->fr_next == NULL)
2006 		// last frame gets all that remains (avoid roundoff error)
2007 		new_size = width;
2008 	    else if (dir == 'v')
2009 		new_size = fr->fr_width;
2010 	    else if (frame_fixed_width(fr))
2011 	    {
2012 		new_size = fr->fr_newwidth;
2013 		wincount = 0;	    // doesn't count as a sizeable window
2014 	    }
2015 	    else
2016 	    {
2017 		// Compute the maximum number of windows horiz. in "fr".
2018 		n = frame_minwidth(fr, NOWIN);
2019 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2020 								/ (p_wmw + 1);
2021 		m = frame_minwidth(fr, next_curwin);
2022 		if (has_next_curwin)
2023 		    hnc = frame_has_win(fr, next_curwin);
2024 		else
2025 		    hnc = FALSE;
2026 		if (hnc)	    // don't count next_curwin
2027 		    --wincount;
2028 		if (totwincount == 0)
2029 		    new_size = room;
2030 		else
2031 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2032 								/ totwincount;
2033 		if (hnc)	    // add next_curwin size
2034 		{
2035 		    next_curwin_size -= p_wiw - (m - n);
2036 		    new_size += next_curwin_size;
2037 		    room -= new_size - next_curwin_size;
2038 		}
2039 		else
2040 		    room -= new_size;
2041 		new_size += n;
2042 	    }
2043 
2044 	    // Skip frame that is full width when splitting or closing a
2045 	    // window, unless equalizing all frames.
2046 	    if (!current || dir != 'v' || topfr->fr_parent != NULL
2047 		    || (new_size != fr->fr_width)
2048 		    || frame_has_win(fr, next_curwin))
2049 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2050 							    new_size, height);
2051 	    col += new_size;
2052 	    width -= new_size;
2053 	    totwincount -= wincount;
2054 	}
2055     }
2056     else // topfr->fr_layout == FR_COL
2057     {
2058 	topfr->fr_width = width;
2059 	topfr->fr_height = height;
2060 
2061 	if (dir != 'h')			// equalize frame heights
2062 	{
2063 	    // Compute maximum number of windows vertically in this frame.
2064 	    n = frame_minheight(topfr, NOWIN);
2065 	    // add one for the bottom window if it doesn't have a statusline
2066 	    if (row + height == cmdline_row && p_ls == 0)
2067 		extra_sep = 1;
2068 	    else
2069 		extra_sep = 0;
2070 	    totwincount = (n + extra_sep) / (p_wmh + 1);
2071 	    has_next_curwin = frame_has_win(topfr, next_curwin);
2072 
2073 	    /*
2074 	     * Compute height for "next_curwin" window and room available for
2075 	     * other windows.
2076 	     * "m" is the minimal height when counting p_wh for "next_curwin".
2077 	     */
2078 	    m = frame_minheight(topfr, next_curwin);
2079 	    room = height - m;
2080 	    if (room < 0)
2081 	    {
2082 		// The room is less then 'winheight', use all space for the
2083 		// current window.
2084 		next_curwin_size = p_wh + room;
2085 		room = 0;
2086 	    }
2087 	    else
2088 	    {
2089 		next_curwin_size = -1;
2090 		FOR_ALL_FRAMES(fr, topfr->fr_child)
2091 		{
2092 		    // If 'winfixheight' set keep the window height if
2093 		    // possible.
2094 		    // Watch out for this window being the next_curwin.
2095 		    if (frame_fixed_height(fr))
2096 		    {
2097 			n = frame_minheight(fr, NOWIN);
2098 			new_size = fr->fr_height;
2099 			if (frame_has_win(fr, next_curwin))
2100 			{
2101 			    room += p_wh - p_wmh;
2102 			    next_curwin_size = 0;
2103 			    if (new_size < p_wh)
2104 				new_size = p_wh;
2105 			}
2106 			else
2107 			    // These windows don't use up room.
2108 			    totwincount -= (n + (fr->fr_next == NULL
2109 					      ? extra_sep : 0)) / (p_wmh + 1);
2110 			room -= new_size - n;
2111 			if (room < 0)
2112 			{
2113 			    new_size += room;
2114 			    room = 0;
2115 			}
2116 			fr->fr_newheight = new_size;
2117 		    }
2118 		}
2119 		if (next_curwin_size == -1)
2120 		{
2121 		    if (!has_next_curwin)
2122 			next_curwin_size = 0;
2123 		    else if (totwincount > 1
2124 			    && (room + (totwincount - 2))
2125 						   / (totwincount - 1) > p_wh)
2126 		    {
2127 			// can make all windows higher than 'winheight',
2128 			// spread the room equally.
2129 			next_curwin_size = (room + p_wh
2130 					   + (totwincount - 1) * p_wmh
2131 					   + (totwincount - 1)) / totwincount;
2132 			room -= next_curwin_size - p_wh;
2133 		    }
2134 		    else
2135 			next_curwin_size = p_wh;
2136 		}
2137 	    }
2138 
2139 	    if (has_next_curwin)
2140 		--totwincount;		// don't count curwin
2141 	}
2142 
2143 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2144 	{
2145 	    wincount = 1;
2146 	    if (fr->fr_next == NULL)
2147 		// last frame gets all that remains (avoid roundoff error)
2148 		new_size = height;
2149 	    else if (dir == 'h')
2150 		new_size = fr->fr_height;
2151 	    else if (frame_fixed_height(fr))
2152 	    {
2153 		new_size = fr->fr_newheight;
2154 		wincount = 0;	    // doesn't count as a sizeable window
2155 	    }
2156 	    else
2157 	    {
2158 		// Compute the maximum number of windows vert. in "fr".
2159 		n = frame_minheight(fr, NOWIN);
2160 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2161 								/ (p_wmh + 1);
2162 		m = frame_minheight(fr, next_curwin);
2163 		if (has_next_curwin)
2164 		    hnc = frame_has_win(fr, next_curwin);
2165 		else
2166 		    hnc = FALSE;
2167 		if (hnc)	    // don't count next_curwin
2168 		    --wincount;
2169 		if (totwincount == 0)
2170 		    new_size = room;
2171 		else
2172 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2173 								/ totwincount;
2174 		if (hnc)	    // add next_curwin size
2175 		{
2176 		    next_curwin_size -= p_wh - (m - n);
2177 		    new_size += next_curwin_size;
2178 		    room -= new_size - next_curwin_size;
2179 		}
2180 		else
2181 		    room -= new_size;
2182 		new_size += n;
2183 	    }
2184 	    // Skip frame that is full width when splitting or closing a
2185 	    // window, unless equalizing all frames.
2186 	    if (!current || dir != 'h' || topfr->fr_parent != NULL
2187 		    || (new_size != fr->fr_height)
2188 		    || frame_has_win(fr, next_curwin))
2189 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2190 							     width, new_size);
2191 	    row += new_size;
2192 	    height -= new_size;
2193 	    totwincount -= wincount;
2194 	}
2195     }
2196 }
2197 
2198 #ifdef FEAT_JOB_CHANNEL
2199     static void
2200 leaving_window(win_T *win)
2201 {
2202     // Only matters for a prompt window.
2203     if (!bt_prompt(win->w_buffer))
2204 	return;
2205 
2206     // When leaving a prompt window stop Insert mode and perhaps restart
2207     // it when entering that window again.
2208     win->w_buffer->b_prompt_insert = restart_edit;
2209     if (restart_edit != 0 && mode_displayed)
2210 	clear_cmdline = TRUE;		// unshow mode later
2211     restart_edit = NUL;
2212 
2213     // When leaving the window (or closing the window) was done from a
2214     // callback we need to break out of the Insert mode loop and restart Insert
2215     // mode when entering the window again.
2216     if (State & INSERT)
2217     {
2218 	stop_insert_mode = TRUE;
2219 	if (win->w_buffer->b_prompt_insert == NUL)
2220 	    win->w_buffer->b_prompt_insert = 'A';
2221     }
2222 }
2223 
2224     static void
2225 entering_window(win_T *win)
2226 {
2227     // Only matters for a prompt window.
2228     if (!bt_prompt(win->w_buffer))
2229 	return;
2230 
2231     // When switching to a prompt buffer that was in Insert mode, don't stop
2232     // Insert mode, it may have been set in leaving_window().
2233     if (win->w_buffer->b_prompt_insert != NUL)
2234 	stop_insert_mode = FALSE;
2235 
2236     // When entering the prompt window restart Insert mode if we were in Insert
2237     // mode when we left it.
2238     restart_edit = win->w_buffer->b_prompt_insert;
2239 }
2240 #endif
2241 
2242 /*
2243  * Close all windows for buffer "buf".
2244  */
2245     void
2246 close_windows(
2247     buf_T	*buf,
2248     int		keep_curwin)	    // don't close "curwin"
2249 {
2250     win_T	*wp;
2251     tabpage_T   *tp, *nexttp;
2252     int		h = tabline_height();
2253     int		count = tabpage_index(NULL);
2254 
2255     ++RedrawingDisabled;
2256 
2257     for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
2258     {
2259 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
2260 		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
2261 	{
2262 	    if (win_close(wp, FALSE) == FAIL)
2263 		// If closing the window fails give up, to avoid looping
2264 		// forever.
2265 		break;
2266 
2267 	    // Start all over, autocommands may change the window layout.
2268 	    wp = firstwin;
2269 	}
2270 	else
2271 	    wp = wp->w_next;
2272     }
2273 
2274     // Also check windows in other tab pages.
2275     for (tp = first_tabpage; tp != NULL; tp = nexttp)
2276     {
2277 	nexttp = tp->tp_next;
2278 	if (tp != curtab)
2279 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
2280 		if (wp->w_buffer == buf
2281 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
2282 		{
2283 		    win_close_othertab(wp, FALSE, tp);
2284 
2285 		    // Start all over, the tab page may be closed and
2286 		    // autocommands may change the window layout.
2287 		    nexttp = first_tabpage;
2288 		    break;
2289 		}
2290     }
2291 
2292     --RedrawingDisabled;
2293 
2294     if (count != tabpage_index(NULL))
2295 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2296 
2297     redraw_tabline = TRUE;
2298     if (h != tabline_height())
2299 	shell_new_rows();
2300 }
2301 
2302 /*
2303  * Return TRUE if the current window is the only window that exists (ignoring
2304  * "aucmd_win").
2305  * Returns FALSE if there is a window, possibly in another tab page.
2306  */
2307     static int
2308 last_window(void)
2309 {
2310     return (one_window() && first_tabpage->tp_next == NULL);
2311 }
2312 
2313 /*
2314  * Return TRUE if there is only one window other than "aucmd_win" in the
2315  * current tab page.
2316  */
2317     int
2318 one_window(void)
2319 {
2320     win_T	*wp;
2321     int		seen_one = FALSE;
2322 
2323     FOR_ALL_WINDOWS(wp)
2324     {
2325 	if (wp != aucmd_win)
2326 	{
2327 	    if (seen_one)
2328 		return FALSE;
2329 	    seen_one = TRUE;
2330 	}
2331     }
2332     return TRUE;
2333 }
2334 
2335 /*
2336  * Close the possibly last window in a tab page.
2337  * Returns TRUE when the window was closed already.
2338  */
2339     static int
2340 close_last_window_tabpage(
2341     win_T	*win,
2342     int		free_buf,
2343     tabpage_T   *prev_curtab)
2344 {
2345     if (ONE_WINDOW)
2346     {
2347 	buf_T	*old_curbuf = curbuf;
2348 
2349 	/*
2350 	 * Closing the last window in a tab page.  First go to another tab
2351 	 * page and then close the window and the tab page.  This avoids that
2352 	 * curwin and curtab are invalid while we are freeing memory, they may
2353 	 * be used in GUI events.
2354 	 * Don't trigger autocommands yet, they may use wrong values, so do
2355 	 * that below.
2356 	 */
2357 	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
2358 	redraw_tabline = TRUE;
2359 
2360 	// Safety check: Autocommands may have closed the window when jumping
2361 	// to the other tab page.
2362 	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
2363 	{
2364 	    int	    h = tabline_height();
2365 
2366 	    win_close_othertab(win, free_buf, prev_curtab);
2367 	    if (h != tabline_height())
2368 		shell_new_rows();
2369 	}
2370 #ifdef FEAT_JOB_CHANNEL
2371 	entering_window(curwin);
2372 #endif
2373 	// Since goto_tabpage_tp above did not trigger *Enter autocommands, do
2374 	// that now.
2375 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2376 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
2377 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
2378 	if (old_curbuf != curbuf)
2379 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2380 	return TRUE;
2381     }
2382     return FALSE;
2383 }
2384 
2385 /*
2386  * Close the buffer of "win" and unload it if "action" is DOBUF_UNLOAD.
2387  * "action" can also be zero (do nothing) or DOBUF_WIPE.
2388  * "abort_if_last" is passed to close_buffer(): abort closing if all other
2389  * windows are closed.
2390  */
2391     static void
2392 win_close_buffer(win_T *win, int action, int abort_if_last)
2393 {
2394 #ifdef FEAT_SYN_HL
2395     // Free independent synblock before the buffer is freed.
2396     if (win->w_buffer != NULL)
2397 	reset_synblock(win);
2398 #endif
2399 
2400 #ifdef FEAT_QUICKFIX
2401     // When the quickfix/location list window is closed, unlist the buffer.
2402     if (win->w_buffer != NULL && bt_quickfix(win->w_buffer))
2403 	win->w_buffer->b_p_bl = FALSE;
2404 #endif
2405 
2406     // Close the link to the buffer.
2407     if (win->w_buffer != NULL)
2408     {
2409 	bufref_T    bufref;
2410 
2411 	set_bufref(&bufref, curbuf);
2412 	win->w_closing = TRUE;
2413 	close_buffer(win, win->w_buffer, action, abort_if_last, FALSE);
2414 	if (win_valid_any_tab(win))
2415 	    win->w_closing = FALSE;
2416 	// Make sure curbuf is valid. It can become invalid if 'bufhidden' is
2417 	// "wipe".
2418 	if (!bufref_valid(&bufref))
2419 	    curbuf = firstbuf;
2420     }
2421 }
2422 
2423 /*
2424  * Close window "win".  Only works for the current tab page.
2425  * If "free_buf" is TRUE related buffer may be unloaded.
2426  *
2427  * Called by :quit, :close, :xit, :wq and findtag().
2428  * Returns FAIL when the window was not closed.
2429  */
2430     int
2431 win_close(win_T *win, int free_buf)
2432 {
2433     win_T	*wp;
2434     int		other_buffer = FALSE;
2435     int		close_curwin = FALSE;
2436     int		dir;
2437     int		help_window = FALSE;
2438     tabpage_T   *prev_curtab = curtab;
2439     frame_T	*win_frame = win->w_frame->fr_parent;
2440 #ifdef FEAT_DIFF
2441     int		had_diffmode = win->w_p_diff;
2442 #endif
2443 
2444 #if defined(FEAT_TERMINAL) && defined(FEAT_PROP_POPUP)
2445     // Can close a popup window with a terminal if the job has finished.
2446     if (may_close_term_popup() == OK)
2447 	return OK;
2448 #endif
2449     if (ERROR_IF_ANY_POPUP_WINDOW)
2450 	return FAIL;
2451 
2452     if (last_window())
2453     {
2454 	emsg(_("E444: Cannot close last window"));
2455 	return FAIL;
2456     }
2457 
2458     if (win->w_closing || (win->w_buffer != NULL
2459 					       && win->w_buffer->b_locked > 0))
2460 	return FAIL; // window is already being closed
2461     if (win_unlisted(win))
2462     {
2463 	emsg(_("E813: Cannot close autocmd or popup window"));
2464 	return FAIL;
2465     }
2466     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
2467     {
2468 	emsg(_("E814: Cannot close window, only autocmd window would remain"));
2469 	return FAIL;
2470     }
2471 
2472     // When closing the last window in a tab page first go to another tab page
2473     // and then close the window and the tab page to avoid that curwin and
2474     // curtab are invalid while we are freeing memory.
2475     if (close_last_window_tabpage(win, free_buf, prev_curtab))
2476       return FAIL;
2477 
2478     // When closing the help window, try restoring a snapshot after closing
2479     // the window.  Otherwise clear the snapshot, it's now invalid.
2480     if (bt_help(win->w_buffer))
2481 	help_window = TRUE;
2482     else
2483 	clear_snapshot(curtab, SNAP_HELP_IDX);
2484 
2485     if (win == curwin)
2486     {
2487 #ifdef FEAT_JOB_CHANNEL
2488 	leaving_window(curwin);
2489 #endif
2490 	/*
2491 	 * Guess which window is going to be the new current window.
2492 	 * This may change because of the autocommands (sigh).
2493 	 */
2494 	wp = frame2win(win_altframe(win, NULL));
2495 
2496 	/*
2497 	 * Be careful: If autocommands delete the window or cause this window
2498 	 * to be the last one left, return now.
2499 	 */
2500 	if (wp->w_buffer != curbuf)
2501 	{
2502 	    other_buffer = TRUE;
2503 	    win->w_closing = TRUE;
2504 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
2505 	    if (!win_valid(win))
2506 		return FAIL;
2507 	    win->w_closing = FALSE;
2508 	    if (last_window())
2509 		return FAIL;
2510 	}
2511 	win->w_closing = TRUE;
2512 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
2513 	if (!win_valid(win))
2514 	    return FAIL;
2515 	win->w_closing = FALSE;
2516 	if (last_window())
2517 	    return FAIL;
2518 #ifdef FEAT_EVAL
2519 	// autocmds may abort script processing
2520 	if (aborting())
2521 	    return FAIL;
2522 #endif
2523     }
2524 
2525 #ifdef FEAT_GUI
2526     // Avoid trouble with scrollbars that are going to be deleted in
2527     // win_free().
2528     if (gui.in_use)
2529 	out_flush();
2530 #endif
2531 
2532 #ifdef FEAT_PROP_POPUP
2533     if (popup_win_closed(win) && !win_valid(win))
2534 	return FAIL;
2535 #endif
2536     win_close_buffer(win, free_buf ? DOBUF_UNLOAD : 0, TRUE);
2537 
2538     if (only_one_window() && win_valid(win) && win->w_buffer == NULL
2539 	    && (last_window() || curtab != prev_curtab
2540 		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
2541     {
2542 	// Autocommands have closed all windows, quit now.  Restore
2543 	// curwin->w_buffer, otherwise writing viminfo may fail.
2544 	if (curwin->w_buffer == NULL)
2545 	    curwin->w_buffer = curbuf;
2546 	getout(0);
2547     }
2548 
2549     // Autocommands may have moved to another tab page.
2550     if (curtab != prev_curtab && win_valid_any_tab(win)
2551 						      && win->w_buffer == NULL)
2552     {
2553 	// Need to close the window anyway, since the buffer is NULL.
2554 	win_close_othertab(win, FALSE, prev_curtab);
2555 	return FAIL;
2556     }
2557 
2558     // Autocommands may have closed the window already or closed the only
2559     // other window.
2560     if (!win_valid(win) || last_window()
2561 	    || close_last_window_tabpage(win, free_buf, prev_curtab))
2562 	return FAIL;
2563 
2564     // Now we are really going to close the window.  Disallow any autocommand
2565     // to split a window to avoid trouble.
2566     ++split_disallowed;
2567 
2568     // Free the memory used for the window and get the window that received
2569     // the screen space.
2570     wp = win_free_mem(win, &dir, NULL);
2571 
2572     // Make sure curwin isn't invalid.  It can cause severe trouble when
2573     // printing an error message.  For win_equal() curbuf needs to be valid
2574     // too.
2575     if (win == curwin)
2576     {
2577 	curwin = wp;
2578 #ifdef FEAT_QUICKFIX
2579 	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
2580 	{
2581 	    /*
2582 	     * If the cursor goes to the preview or the quickfix window, try
2583 	     * finding another window to go to.
2584 	     */
2585 	    for (;;)
2586 	    {
2587 		if (wp->w_next == NULL)
2588 		    wp = firstwin;
2589 		else
2590 		    wp = wp->w_next;
2591 		if (wp == curwin)
2592 		    break;
2593 		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
2594 		{
2595 		    curwin = wp;
2596 		    break;
2597 		}
2598 	    }
2599 	}
2600 #endif
2601 	curbuf = curwin->w_buffer;
2602 	close_curwin = TRUE;
2603 
2604 	// The cursor position may be invalid if the buffer changed after last
2605 	// using the window.
2606 	check_cursor();
2607     }
2608     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
2609 	// If the frame of the closed window contains the new current window,
2610 	// only resize that frame.  Otherwise resize all windows.
2611 	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
2612     else
2613 	win_comp_pos();
2614     if (close_curwin)
2615     {
2616 	win_enter_ext(wp, FALSE, TRUE, FALSE, TRUE, TRUE);
2617 	if (other_buffer)
2618 	    // careful: after this wp and win may be invalid!
2619 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2620     }
2621 
2622     --split_disallowed;
2623 
2624     /*
2625      * If last window has a status line now and we don't want one,
2626      * remove the status line.
2627      */
2628     last_status(FALSE);
2629 
2630     // After closing the help window, try restoring the window layout from
2631     // before it was opened.
2632     if (help_window)
2633 	restore_snapshot(SNAP_HELP_IDX, close_curwin);
2634 
2635 #ifdef FEAT_DIFF
2636     // If the window had 'diff' set and now there is only one window left in
2637     // the tab page with 'diff' set, and "closeoff" is in 'diffopt', then
2638     // execute ":diffoff!".
2639     if (diffopt_closeoff() && had_diffmode && curtab == prev_curtab)
2640     {
2641 	int	diffcount = 0;
2642 	win_T	*dwin;
2643 
2644 	FOR_ALL_WINDOWS(dwin)
2645 	    if (dwin->w_p_diff)
2646 		++diffcount;
2647 	if (diffcount == 1)
2648 	    do_cmdline_cmd((char_u *)"diffoff!");
2649     }
2650 #endif
2651 
2652 #if defined(FEAT_GUI)
2653     // When 'guioptions' includes 'L' or 'R' may have to remove scrollbars.
2654     if (gui.in_use && !win_hasvertsplit())
2655 	gui_init_which_components(NULL);
2656 #endif
2657 
2658     redraw_all_later(NOT_VALID);
2659     return OK;
2660 }
2661 
2662 /*
2663  * Close window "win" in tab page "tp", which is not the current tab page.
2664  * This may be the last window in that tab page and result in closing the tab,
2665  * thus "tp" may become invalid!
2666  * Caller must check if buffer is hidden and whether the tabline needs to be
2667  * updated.
2668  */
2669     void
2670 win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
2671 {
2672     win_T	*wp;
2673     int		dir;
2674     tabpage_T   *ptp = NULL;
2675     int		free_tp = FALSE;
2676 
2677     // Get here with win->w_buffer == NULL when win_close() detects the tab
2678     // page changed.
2679     if (win->w_closing || (win->w_buffer != NULL
2680 					       && win->w_buffer->b_locked > 0))
2681 	return; // window is already being closed
2682 
2683     if (win->w_buffer != NULL)
2684 	// Close the link to the buffer.
2685 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0,
2686 								 FALSE, FALSE);
2687 
2688     // Careful: Autocommands may have closed the tab page or made it the
2689     // current tab page.
2690     for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
2691 	;
2692     if (ptp == NULL || tp == curtab)
2693 	return;
2694 
2695     // Autocommands may have closed the window already.
2696     for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
2697 	;
2698     if (wp == NULL)
2699 	return;
2700 
2701     // When closing the last window in a tab page remove the tab page.
2702     if (tp->tp_firstwin == tp->tp_lastwin)
2703     {
2704 	if (tp == first_tabpage)
2705 	    first_tabpage = tp->tp_next;
2706 	else
2707 	{
2708 	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
2709 							   ptp = ptp->tp_next)
2710 		;
2711 	    if (ptp == NULL)
2712 	    {
2713 		internal_error("win_close_othertab()");
2714 		return;
2715 	    }
2716 	    ptp->tp_next = tp->tp_next;
2717 	}
2718 	free_tp = TRUE;
2719     }
2720 
2721     // Free the memory used for the window.
2722     win_free_mem(win, &dir, tp);
2723 
2724     if (free_tp)
2725 	free_tabpage(tp);
2726 }
2727 
2728 /*
2729  * Free the memory used for a window.
2730  * Returns a pointer to the window that got the freed up space.
2731  */
2732     static win_T *
2733 win_free_mem(
2734     win_T	*win,
2735     int		*dirp,		// set to 'v' or 'h' for direction if 'ea'
2736     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2737 {
2738     frame_T	*frp;
2739     win_T	*wp;
2740 
2741     // Remove the window and its frame from the tree of frames.
2742     frp = win->w_frame;
2743     wp = winframe_remove(win, dirp, tp);
2744     vim_free(frp);
2745     win_free(win, tp);
2746 
2747     // When deleting the current window of another tab page select a new
2748     // current window.
2749     if (tp != NULL && win == tp->tp_curwin)
2750 	tp->tp_curwin = wp;
2751 
2752     return wp;
2753 }
2754 
2755 #if defined(EXITFREE) || defined(PROTO)
2756     void
2757 win_free_all(void)
2758 {
2759     int		dummy;
2760 
2761     while (first_tabpage->tp_next != NULL)
2762 	tabpage_close(TRUE);
2763 
2764     if (aucmd_win != NULL)
2765     {
2766 	(void)win_free_mem(aucmd_win, &dummy, NULL);
2767 	aucmd_win = NULL;
2768     }
2769 # ifdef FEAT_PROP_POPUP
2770     close_all_popups();
2771 # endif
2772 
2773     while (firstwin != NULL)
2774 	(void)win_free_mem(firstwin, &dummy, NULL);
2775 
2776     // No window should be used after this. Set curwin to NULL to crash
2777     // instead of using freed memory.
2778     curwin = NULL;
2779 }
2780 #endif
2781 
2782 /*
2783  * Remove a window and its frame from the tree of frames.
2784  * Returns a pointer to the window that got the freed up space.
2785  */
2786     win_T *
2787 winframe_remove(
2788     win_T	*win,
2789     int		*dirp UNUSED,	// set to 'v' or 'h' for direction if 'ea'
2790     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2791 {
2792     frame_T	*frp, *frp2, *frp3;
2793     frame_T	*frp_close = win->w_frame;
2794     win_T	*wp;
2795 
2796     /*
2797      * If there is only one window there is nothing to remove.
2798      */
2799     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2800 	return NULL;
2801 
2802     /*
2803      * Remove the window from its frame.
2804      */
2805     frp2 = win_altframe(win, tp);
2806     wp = frame2win(frp2);
2807 
2808     // Remove this frame from the list of frames.
2809     frame_remove(frp_close);
2810 
2811     if (frp_close->fr_parent->fr_layout == FR_COL)
2812     {
2813 	// When 'winfixheight' is set, try to find another frame in the column
2814 	// (as close to the closed frame as possible) to distribute the height
2815 	// to.
2816 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
2817 	{
2818 	    frp = frp_close->fr_prev;
2819 	    frp3 = frp_close->fr_next;
2820 	    while (frp != NULL || frp3 != NULL)
2821 	    {
2822 		if (frp != NULL)
2823 		{
2824 		    if (!frame_fixed_height(frp))
2825 		    {
2826 			frp2 = frp;
2827 			wp = frame2win(frp2);
2828 			break;
2829 		    }
2830 		    frp = frp->fr_prev;
2831 		}
2832 		if (frp3 != NULL)
2833 		{
2834 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
2835 		    {
2836 			frp2 = frp3;
2837 			wp = frp3->fr_win;
2838 			break;
2839 		    }
2840 		    frp3 = frp3->fr_next;
2841 		}
2842 	    }
2843 	}
2844 	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
2845 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2846 	*dirp = 'v';
2847     }
2848     else
2849     {
2850 	// When 'winfixwidth' is set, try to find another frame in the column
2851 	// (as close to the closed frame as possible) to distribute the width
2852 	// to.
2853 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
2854 	{
2855 	    frp = frp_close->fr_prev;
2856 	    frp3 = frp_close->fr_next;
2857 	    while (frp != NULL || frp3 != NULL)
2858 	    {
2859 		if (frp != NULL)
2860 		{
2861 		    if (!frame_fixed_width(frp))
2862 		    {
2863 			frp2 = frp;
2864 			wp = frame2win(frp2);
2865 			break;
2866 		    }
2867 		    frp = frp->fr_prev;
2868 		}
2869 		if (frp3 != NULL)
2870 		{
2871 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
2872 		    {
2873 			frp2 = frp3;
2874 			wp = frp3->fr_win;
2875 			break;
2876 		    }
2877 		    frp3 = frp3->fr_next;
2878 		}
2879 	    }
2880 	}
2881 	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
2882 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2883 	*dirp = 'h';
2884     }
2885 
2886     // If rows/columns go to a window below/right its positions need to be
2887     // updated.  Can only be done after the sizes have been updated.
2888     if (frp2 == frp_close->fr_next)
2889     {
2890 	int row = win->w_winrow;
2891 	int col = win->w_wincol;
2892 
2893 	frame_comp_pos(frp2, &row, &col);
2894     }
2895 
2896     if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
2897     {
2898 	// There is no other frame in this list, move its info to the parent
2899 	// and remove it.
2900 	frp2->fr_parent->fr_layout = frp2->fr_layout;
2901 	frp2->fr_parent->fr_child = frp2->fr_child;
2902 	FOR_ALL_FRAMES(frp, frp2->fr_child)
2903 	    frp->fr_parent = frp2->fr_parent;
2904 	frp2->fr_parent->fr_win = frp2->fr_win;
2905 	if (frp2->fr_win != NULL)
2906 	    frp2->fr_win->w_frame = frp2->fr_parent;
2907 	frp = frp2->fr_parent;
2908 	if (topframe->fr_child == frp2)
2909 	    topframe->fr_child = frp;
2910 	vim_free(frp2);
2911 
2912 	frp2 = frp->fr_parent;
2913 	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
2914 	{
2915 	    // The frame above the parent has the same layout, have to merge
2916 	    // the frames into this list.
2917 	    if (frp2->fr_child == frp)
2918 		frp2->fr_child = frp->fr_child;
2919 	    frp->fr_child->fr_prev = frp->fr_prev;
2920 	    if (frp->fr_prev != NULL)
2921 		frp->fr_prev->fr_next = frp->fr_child;
2922 	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
2923 	    {
2924 		frp3->fr_parent = frp2;
2925 		if (frp3->fr_next == NULL)
2926 		{
2927 		    frp3->fr_next = frp->fr_next;
2928 		    if (frp->fr_next != NULL)
2929 			frp->fr_next->fr_prev = frp3;
2930 		    break;
2931 		}
2932 	    }
2933 	    if (topframe->fr_child == frp)
2934 		topframe->fr_child = frp2;
2935 	    vim_free(frp);
2936 	}
2937     }
2938 
2939     return wp;
2940 }
2941 
2942 /*
2943  * Return a pointer to the frame that will receive the empty screen space that
2944  * is left over after "win" is closed.
2945  *
2946  * If 'splitbelow' or 'splitright' is set, the space goes above or to the left
2947  * by default.  Otherwise, the free space goes below or to the right.  The
2948  * result is that opening a window and then immediately closing it will
2949  * preserve the initial window layout.  The 'wfh' and 'wfw' settings are
2950  * respected when possible.
2951  */
2952     static frame_T *
2953 win_altframe(
2954     win_T	*win,
2955     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2956 {
2957     frame_T	*frp;
2958     frame_T	*other_fr, *target_fr;
2959 
2960     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2961 	return alt_tabpage()->tp_curwin->w_frame;
2962 
2963     frp = win->w_frame;
2964 
2965     if (frp->fr_prev == NULL)
2966 	return frp->fr_next;
2967     if (frp->fr_next == NULL)
2968 	return frp->fr_prev;
2969 
2970     target_fr = frp->fr_next;
2971     other_fr  = frp->fr_prev;
2972     if (p_spr || p_sb)
2973     {
2974 	target_fr = frp->fr_prev;
2975 	other_fr  = frp->fr_next;
2976     }
2977 
2978     // If 'wfh' or 'wfw' is set for the target and not for the alternate
2979     // window, reverse the selection.
2980     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
2981     {
2982 	if (frame_fixed_width(target_fr) && !frame_fixed_width(other_fr))
2983 	    target_fr = other_fr;
2984     }
2985     else
2986     {
2987 	if (frame_fixed_height(target_fr) && !frame_fixed_height(other_fr))
2988 	    target_fr = other_fr;
2989     }
2990 
2991     return target_fr;
2992 }
2993 
2994 /*
2995  * Return the tabpage that will be used if the current one is closed.
2996  */
2997     static tabpage_T *
2998 alt_tabpage(void)
2999 {
3000     tabpage_T	*tp;
3001 
3002     // Use the next tab page if possible.
3003     if (curtab->tp_next != NULL)
3004 	return curtab->tp_next;
3005 
3006     // Find the last but one tab page.
3007     for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
3008 	;
3009     return tp;
3010 }
3011 
3012 /*
3013  * Find the left-upper window in frame "frp".
3014  */
3015     static win_T *
3016 frame2win(frame_T *frp)
3017 {
3018     while (frp->fr_win == NULL)
3019 	frp = frp->fr_child;
3020     return frp->fr_win;
3021 }
3022 
3023 /*
3024  * Return TRUE if frame "frp" contains window "wp".
3025  */
3026     static int
3027 frame_has_win(frame_T *frp, win_T *wp)
3028 {
3029     frame_T	*p;
3030 
3031     if (frp->fr_layout == FR_LEAF)
3032 	return frp->fr_win == wp;
3033 
3034     FOR_ALL_FRAMES(p, frp->fr_child)
3035 	if (frame_has_win(p, wp))
3036 	    return TRUE;
3037     return FALSE;
3038 }
3039 
3040 /*
3041  * Set a new height for a frame.  Recursively sets the height for contained
3042  * frames and windows.  Caller must take care of positions.
3043  */
3044     static void
3045 frame_new_height(
3046     frame_T	*topfrp,
3047     int		height,
3048     int		topfirst,	// resize topmost contained frame first
3049     int		wfh)		// obey 'winfixheight' when there is a choice;
3050 				// may cause the height not to be set
3051 {
3052     frame_T	*frp;
3053     int		extra_lines;
3054     int		h;
3055 
3056     if (topfrp->fr_win != NULL)
3057     {
3058 	// Simple case: just one window.
3059 	win_new_height(topfrp->fr_win,
3060 				    height - topfrp->fr_win->w_status_height
3061 					      - WINBAR_HEIGHT(topfrp->fr_win));
3062     }
3063     else if (topfrp->fr_layout == FR_ROW)
3064     {
3065 	do
3066 	{
3067 	    // All frames in this row get the same new height.
3068 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3069 	    {
3070 		frame_new_height(frp, height, topfirst, wfh);
3071 		if (frp->fr_height > height)
3072 		{
3073 		    // Could not fit the windows, make the whole row higher.
3074 		    height = frp->fr_height;
3075 		    break;
3076 		}
3077 	    }
3078 	}
3079 	while (frp != NULL);
3080     }
3081     else    // fr_layout == FR_COL
3082     {
3083 	// Complicated case: Resize a column of frames.  Resize the bottom
3084 	// frame first, frames above that when needed.
3085 
3086 	frp = topfrp->fr_child;
3087 	if (wfh)
3088 	    // Advance past frames with one window with 'wfh' set.
3089 	    while (frame_fixed_height(frp))
3090 	    {
3091 		frp = frp->fr_next;
3092 		if (frp == NULL)
3093 		    return;	    // no frame without 'wfh', give up
3094 	    }
3095 	if (!topfirst)
3096 	{
3097 	    // Find the bottom frame of this column
3098 	    while (frp->fr_next != NULL)
3099 		frp = frp->fr_next;
3100 	    if (wfh)
3101 		// Advance back for frames with one window with 'wfh' set.
3102 		while (frame_fixed_height(frp))
3103 		    frp = frp->fr_prev;
3104 	}
3105 
3106 	extra_lines = height - topfrp->fr_height;
3107 	if (extra_lines < 0)
3108 	{
3109 	    // reduce height of contained frames, bottom or top frame first
3110 	    while (frp != NULL)
3111 	    {
3112 		h = frame_minheight(frp, NULL);
3113 		if (frp->fr_height + extra_lines < h)
3114 		{
3115 		    extra_lines += frp->fr_height - h;
3116 		    frame_new_height(frp, h, topfirst, wfh);
3117 		}
3118 		else
3119 		{
3120 		    frame_new_height(frp, frp->fr_height + extra_lines,
3121 							       topfirst, wfh);
3122 		    break;
3123 		}
3124 		if (topfirst)
3125 		{
3126 		    do
3127 			frp = frp->fr_next;
3128 		    while (wfh && frp != NULL && frame_fixed_height(frp));
3129 		}
3130 		else
3131 		{
3132 		    do
3133 			frp = frp->fr_prev;
3134 		    while (wfh && frp != NULL && frame_fixed_height(frp));
3135 		}
3136 		// Increase "height" if we could not reduce enough frames.
3137 		if (frp == NULL)
3138 		    height -= extra_lines;
3139 	    }
3140 	}
3141 	else if (extra_lines > 0)
3142 	{
3143 	    // increase height of bottom or top frame
3144 	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
3145 	}
3146     }
3147     topfrp->fr_height = height;
3148 }
3149 
3150 /*
3151  * Return TRUE if height of frame "frp" should not be changed because of
3152  * the 'winfixheight' option.
3153  */
3154     static int
3155 frame_fixed_height(frame_T *frp)
3156 {
3157     // frame with one window: fixed height if 'winfixheight' set.
3158     if (frp->fr_win != NULL)
3159 	return frp->fr_win->w_p_wfh;
3160 
3161     if (frp->fr_layout == FR_ROW)
3162     {
3163 	// The frame is fixed height if one of the frames in the row is fixed
3164 	// height.
3165 	FOR_ALL_FRAMES(frp, frp->fr_child)
3166 	    if (frame_fixed_height(frp))
3167 		return TRUE;
3168 	return FALSE;
3169     }
3170 
3171     // frp->fr_layout == FR_COL: The frame is fixed height if all of the
3172     // frames in the row are fixed height.
3173     FOR_ALL_FRAMES(frp, frp->fr_child)
3174 	if (!frame_fixed_height(frp))
3175 	    return FALSE;
3176     return TRUE;
3177 }
3178 
3179 /*
3180  * Return TRUE if width of frame "frp" should not be changed because of
3181  * the 'winfixwidth' option.
3182  */
3183     static int
3184 frame_fixed_width(frame_T *frp)
3185 {
3186     // frame with one window: fixed width if 'winfixwidth' set.
3187     if (frp->fr_win != NULL)
3188 	return frp->fr_win->w_p_wfw;
3189 
3190     if (frp->fr_layout == FR_COL)
3191     {
3192 	// The frame is fixed width if one of the frames in the row is fixed
3193 	// width.
3194 	FOR_ALL_FRAMES(frp, frp->fr_child)
3195 	    if (frame_fixed_width(frp))
3196 		return TRUE;
3197 	return FALSE;
3198     }
3199 
3200     // frp->fr_layout == FR_ROW: The frame is fixed width if all of the
3201     // frames in the row are fixed width.
3202     FOR_ALL_FRAMES(frp, frp->fr_child)
3203 	if (!frame_fixed_width(frp))
3204 	    return FALSE;
3205     return TRUE;
3206 }
3207 
3208 /*
3209  * Add a status line to windows at the bottom of "frp".
3210  * Note: Does not check if there is room!
3211  */
3212     static void
3213 frame_add_statusline(frame_T *frp)
3214 {
3215     win_T	*wp;
3216 
3217     if (frp->fr_layout == FR_LEAF)
3218     {
3219 	wp = frp->fr_win;
3220 	if (wp->w_status_height == 0)
3221 	{
3222 	    if (wp->w_height > 0)	// don't make it negative
3223 		--wp->w_height;
3224 	    wp->w_status_height = STATUS_HEIGHT;
3225 	}
3226     }
3227     else if (frp->fr_layout == FR_ROW)
3228     {
3229 	// Handle all the frames in the row.
3230 	FOR_ALL_FRAMES(frp, frp->fr_child)
3231 	    frame_add_statusline(frp);
3232     }
3233     else // frp->fr_layout == FR_COL
3234     {
3235 	// Only need to handle the last frame in the column.
3236 	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
3237 	    ;
3238 	frame_add_statusline(frp);
3239     }
3240 }
3241 
3242 /*
3243  * Set width of a frame.  Handles recursively going through contained frames.
3244  * May remove separator line for windows at the right side (for win_close()).
3245  */
3246     static void
3247 frame_new_width(
3248     frame_T	*topfrp,
3249     int		width,
3250     int		leftfirst,	// resize leftmost contained frame first
3251     int		wfw)		// obey 'winfixwidth' when there is a choice;
3252 				// may cause the width not to be set
3253 {
3254     frame_T	*frp;
3255     int		extra_cols;
3256     int		w;
3257     win_T	*wp;
3258 
3259     if (topfrp->fr_layout == FR_LEAF)
3260     {
3261 	// Simple case: just one window.
3262 	wp = topfrp->fr_win;
3263 	// Find out if there are any windows right of this one.
3264 	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
3265 	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
3266 		break;
3267 	if (frp->fr_parent == NULL)
3268 	    wp->w_vsep_width = 0;
3269 	win_new_width(wp, width - wp->w_vsep_width);
3270     }
3271     else if (topfrp->fr_layout == FR_COL)
3272     {
3273 	do
3274 	{
3275 	    // All frames in this column get the same new width.
3276 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3277 	    {
3278 		frame_new_width(frp, width, leftfirst, wfw);
3279 		if (frp->fr_width > width)
3280 		{
3281 		    // Could not fit the windows, make whole column wider.
3282 		    width = frp->fr_width;
3283 		    break;
3284 		}
3285 	    }
3286 	} while (frp != NULL);
3287     }
3288     else    // fr_layout == FR_ROW
3289     {
3290 	// Complicated case: Resize a row of frames.  Resize the rightmost
3291 	// frame first, frames left of it when needed.
3292 
3293 	frp = topfrp->fr_child;
3294 	if (wfw)
3295 	    // Advance past frames with one window with 'wfw' set.
3296 	    while (frame_fixed_width(frp))
3297 	    {
3298 		frp = frp->fr_next;
3299 		if (frp == NULL)
3300 		    return;	    // no frame without 'wfw', give up
3301 	    }
3302 	if (!leftfirst)
3303 	{
3304 	    // Find the rightmost frame of this row
3305 	    while (frp->fr_next != NULL)
3306 		frp = frp->fr_next;
3307 	    if (wfw)
3308 		// Advance back for frames with one window with 'wfw' set.
3309 		while (frame_fixed_width(frp))
3310 		    frp = frp->fr_prev;
3311 	}
3312 
3313 	extra_cols = width - topfrp->fr_width;
3314 	if (extra_cols < 0)
3315 	{
3316 	    // reduce frame width, rightmost frame first
3317 	    while (frp != NULL)
3318 	    {
3319 		w = frame_minwidth(frp, NULL);
3320 		if (frp->fr_width + extra_cols < w)
3321 		{
3322 		    extra_cols += frp->fr_width - w;
3323 		    frame_new_width(frp, w, leftfirst, wfw);
3324 		}
3325 		else
3326 		{
3327 		    frame_new_width(frp, frp->fr_width + extra_cols,
3328 							      leftfirst, wfw);
3329 		    break;
3330 		}
3331 		if (leftfirst)
3332 		{
3333 		    do
3334 			frp = frp->fr_next;
3335 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3336 		}
3337 		else
3338 		{
3339 		    do
3340 			frp = frp->fr_prev;
3341 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3342 		}
3343 		// Increase "width" if we could not reduce enough frames.
3344 		if (frp == NULL)
3345 		    width -= extra_cols;
3346 	    }
3347 	}
3348 	else if (extra_cols > 0)
3349 	{
3350 	    // increase width of rightmost frame
3351 	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
3352 	}
3353     }
3354     topfrp->fr_width = width;
3355 }
3356 
3357 /*
3358  * Add the vertical separator to windows at the right side of "frp".
3359  * Note: Does not check if there is room!
3360  */
3361     static void
3362 frame_add_vsep(frame_T *frp)
3363 {
3364     win_T	*wp;
3365 
3366     if (frp->fr_layout == FR_LEAF)
3367     {
3368 	wp = frp->fr_win;
3369 	if (wp->w_vsep_width == 0)
3370 	{
3371 	    if (wp->w_width > 0)	// don't make it negative
3372 		--wp->w_width;
3373 	    wp->w_vsep_width = 1;
3374 	}
3375     }
3376     else if (frp->fr_layout == FR_COL)
3377     {
3378 	// Handle all the frames in the column.
3379 	FOR_ALL_FRAMES(frp, frp->fr_child)
3380 	    frame_add_vsep(frp);
3381     }
3382     else // frp->fr_layout == FR_ROW
3383     {
3384 	// Only need to handle the last frame in the row.
3385 	frp = frp->fr_child;
3386 	while (frp->fr_next != NULL)
3387 	    frp = frp->fr_next;
3388 	frame_add_vsep(frp);
3389     }
3390 }
3391 
3392 /*
3393  * Set frame width from the window it contains.
3394  */
3395     static void
3396 frame_fix_width(win_T *wp)
3397 {
3398     wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
3399 }
3400 
3401 /*
3402  * Set frame height from the window it contains.
3403  */
3404     static void
3405 frame_fix_height(win_T *wp)
3406 {
3407     wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
3408 }
3409 
3410 /*
3411  * Compute the minimal height for frame "topfrp".
3412  * Uses the 'winminheight' option.
3413  * When "next_curwin" isn't NULL, use p_wh for this window.
3414  * When "next_curwin" is NOWIN, don't use at least one line for the current
3415  * window.
3416  */
3417     static int
3418 frame_minheight(frame_T *topfrp, win_T *next_curwin)
3419 {
3420     frame_T	*frp;
3421     int		m;
3422     int		n;
3423 
3424     if (topfrp->fr_win != NULL)
3425     {
3426 	if (topfrp->fr_win == next_curwin)
3427 	    m = p_wh + topfrp->fr_win->w_status_height;
3428 	else
3429 	{
3430 	    // window: minimal height of the window plus status line
3431 	    m = p_wmh + topfrp->fr_win->w_status_height;
3432 	    if (topfrp->fr_win == curwin && next_curwin == NULL)
3433 	    {
3434 		// Current window is minimal one line high and WinBar is
3435 		// visible.
3436 		if (p_wmh == 0)
3437 		    ++m;
3438 		m += WINBAR_HEIGHT(curwin);
3439 	    }
3440 	}
3441     }
3442     else if (topfrp->fr_layout == FR_ROW)
3443     {
3444 	// get the minimal height from each frame in this row
3445 	m = 0;
3446 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3447 	{
3448 	    n = frame_minheight(frp, next_curwin);
3449 	    if (n > m)
3450 		m = n;
3451 	}
3452     }
3453     else
3454     {
3455 	// Add up the minimal heights for all frames in this column.
3456 	m = 0;
3457 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3458 	    m += frame_minheight(frp, next_curwin);
3459     }
3460 
3461     return m;
3462 }
3463 
3464 /*
3465  * Compute the minimal width for frame "topfrp".
3466  * When "next_curwin" isn't NULL, use p_wiw for this window.
3467  * When "next_curwin" is NOWIN, don't use at least one column for the current
3468  * window.
3469  */
3470     static int
3471 frame_minwidth(
3472     frame_T	*topfrp,
3473     win_T	*next_curwin)	// use p_wh and p_wiw for next_curwin
3474 {
3475     frame_T	*frp;
3476     int		m, n;
3477 
3478     if (topfrp->fr_win != NULL)
3479     {
3480 	if (topfrp->fr_win == next_curwin)
3481 	    m = p_wiw + topfrp->fr_win->w_vsep_width;
3482 	else
3483 	{
3484 	    // window: minimal width of the window plus separator column
3485 	    m = p_wmw + topfrp->fr_win->w_vsep_width;
3486 	    // Current window is minimal one column wide
3487 	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
3488 		++m;
3489 	}
3490     }
3491     else if (topfrp->fr_layout == FR_COL)
3492     {
3493 	// get the minimal width from each frame in this column
3494 	m = 0;
3495 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3496 	{
3497 	    n = frame_minwidth(frp, next_curwin);
3498 	    if (n > m)
3499 		m = n;
3500 	}
3501     }
3502     else
3503     {
3504 	// Add up the minimal widths for all frames in this row.
3505 	m = 0;
3506 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3507 	    m += frame_minwidth(frp, next_curwin);
3508     }
3509 
3510     return m;
3511 }
3512 
3513 
3514 /*
3515  * Try to close all windows except current one.
3516  * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
3517  * used and the buffer was modified.
3518  *
3519  * Used by ":bdel" and ":only".
3520  */
3521     void
3522 close_others(
3523     int		message,
3524     int		forceit)	    // always hide all other windows
3525 {
3526     win_T	*wp;
3527     win_T	*nextwp;
3528     int		r;
3529 
3530     if (one_window())
3531     {
3532 	if (message && !autocmd_busy)
3533 	    msg(_(m_onlyone));
3534 	return;
3535     }
3536 
3537     // Be very careful here: autocommands may change the window layout.
3538     for (wp = firstwin; win_valid(wp); wp = nextwp)
3539     {
3540 	nextwp = wp->w_next;
3541 	if (wp != curwin)		// don't close current window
3542 	{
3543 
3544 	    // Check if it's allowed to abandon this window
3545 	    r = can_abandon(wp->w_buffer, forceit);
3546 	    if (!win_valid(wp))		// autocommands messed wp up
3547 	    {
3548 		nextwp = firstwin;
3549 		continue;
3550 	    }
3551 	    if (!r)
3552 	    {
3553 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
3554 		if (message && (p_confirm || cmdmod.confirm) && p_write)
3555 		{
3556 		    dialog_changed(wp->w_buffer, FALSE);
3557 		    if (!win_valid(wp))		// autocommands messed wp up
3558 		    {
3559 			nextwp = firstwin;
3560 			continue;
3561 		    }
3562 		}
3563 		if (bufIsChanged(wp->w_buffer))
3564 #endif
3565 		    continue;
3566 	    }
3567 	    win_close(wp, !buf_hide(wp->w_buffer)
3568 					       && !bufIsChanged(wp->w_buffer));
3569 	}
3570     }
3571 
3572     if (message && !ONE_WINDOW)
3573 	emsg(_("E445: Other window contains changes"));
3574 }
3575 
3576     static void
3577 win_init_empty(win_T *wp)
3578 {
3579     redraw_win_later(wp, NOT_VALID);
3580     wp->w_lines_valid = 0;
3581     wp->w_cursor.lnum = 1;
3582     wp->w_curswant = wp->w_cursor.col = 0;
3583     wp->w_cursor.coladd = 0;
3584     wp->w_pcmark.lnum = 1;	// pcmark not cleared but set to line 1
3585     wp->w_pcmark.col = 0;
3586     wp->w_prev_pcmark.lnum = 0;
3587     wp->w_prev_pcmark.col = 0;
3588     wp->w_topline = 1;
3589 #ifdef FEAT_DIFF
3590     wp->w_topfill = 0;
3591 #endif
3592     wp->w_botline = 2;
3593 #if defined(FEAT_SYN_HL) || defined(FEAT_SPELL)
3594     wp->w_s = &wp->w_buffer->b_s;
3595 #endif
3596 }
3597 
3598 /*
3599  * Init the current window "curwin".
3600  * Called when a new file is being edited.
3601  */
3602     void
3603 curwin_init(void)
3604 {
3605     win_init_empty(curwin);
3606 }
3607 
3608 /*
3609  * Allocate the first window and put an empty buffer in it.
3610  * Called from main().
3611  * Return FAIL when something goes wrong (out of memory).
3612  */
3613     int
3614 win_alloc_first(void)
3615 {
3616     if (win_alloc_firstwin(NULL) == FAIL)
3617 	return FAIL;
3618 
3619     first_tabpage = alloc_tabpage();
3620     if (first_tabpage == NULL)
3621 	return FAIL;
3622     first_tabpage->tp_topframe = topframe;
3623     curtab = first_tabpage;
3624     curtab->tp_firstwin = firstwin;
3625     curtab->tp_lastwin = lastwin;
3626     curtab->tp_curwin = curwin;
3627 
3628     return OK;
3629 }
3630 
3631 /*
3632  * Allocate and init a window that is not a regular window.
3633  * This can only be done after the first window is fully initialized, thus it
3634  * can't be in win_alloc_first().
3635  */
3636     win_T *
3637 win_alloc_popup_win(void)
3638 {
3639     win_T *wp;
3640 
3641     wp = win_alloc(NULL, TRUE);
3642     if (wp != NULL)
3643     {
3644 	// We need to initialize options with something, using the current
3645 	// window makes most sense.
3646 	win_init_some(wp, curwin);
3647 
3648 	RESET_BINDING(wp);
3649 	new_frame(wp);
3650     }
3651     return wp;
3652 }
3653 
3654 /*
3655  * Initialize window "wp" to display buffer "buf".
3656  */
3657     void
3658 win_init_popup_win(win_T *wp, buf_T *buf)
3659 {
3660     wp->w_buffer = buf;
3661     ++buf->b_nwindows;
3662     win_init_empty(wp); // set cursor and topline to safe values
3663 
3664     // Make sure w_localdir and globaldir are NULL to avoid a chdir() in
3665     // win_enter_ext().
3666     VIM_CLEAR(wp->w_localdir);
3667 }
3668 
3669 /*
3670  * Allocate the first window or the first window in a new tab page.
3671  * When "oldwin" is NULL create an empty buffer for it.
3672  * When "oldwin" is not NULL copy info from it to the new window.
3673  * Return FAIL when something goes wrong (out of memory).
3674  */
3675     static int
3676 win_alloc_firstwin(win_T *oldwin)
3677 {
3678     curwin = win_alloc(NULL, FALSE);
3679     if (oldwin == NULL)
3680     {
3681 	// Very first window, need to create an empty buffer for it and
3682 	// initialize from scratch.
3683 	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
3684 	if (curwin == NULL || curbuf == NULL)
3685 	    return FAIL;
3686 	curwin->w_buffer = curbuf;
3687 #ifdef FEAT_SYN_HL
3688 	curwin->w_s = &(curbuf->b_s);
3689 #endif
3690 	curbuf->b_nwindows = 1;	// there is one window
3691 	curwin->w_alist = &global_alist;
3692 	curwin_init();		// init current window
3693     }
3694     else
3695     {
3696 	// First window in new tab page, initialize it from "oldwin".
3697 	win_init(curwin, oldwin, 0);
3698 
3699 	// We don't want cursor- and scroll-binding in the first window.
3700 	RESET_BINDING(curwin);
3701     }
3702 
3703     new_frame(curwin);
3704     if (curwin->w_frame == NULL)
3705 	return FAIL;
3706     topframe = curwin->w_frame;
3707     topframe->fr_width = Columns;
3708     topframe->fr_height = Rows - p_ch;
3709 
3710     return OK;
3711 }
3712 
3713 /*
3714  * Create a frame for window "wp".
3715  */
3716     static void
3717 new_frame(win_T *wp)
3718 {
3719     frame_T *frp = ALLOC_CLEAR_ONE(frame_T);
3720 
3721     wp->w_frame = frp;
3722     if (frp != NULL)
3723     {
3724 	frp->fr_layout = FR_LEAF;
3725 	frp->fr_win = wp;
3726     }
3727 }
3728 
3729 /*
3730  * Initialize the window and frame size to the maximum.
3731  */
3732     void
3733 win_init_size(void)
3734 {
3735     firstwin->w_height = ROWS_AVAIL;
3736     topframe->fr_height = ROWS_AVAIL;
3737     firstwin->w_width = Columns;
3738     topframe->fr_width = Columns;
3739 }
3740 
3741 /*
3742  * Allocate a new tabpage_T and init the values.
3743  * Returns NULL when out of memory.
3744  */
3745     static tabpage_T *
3746 alloc_tabpage(void)
3747 {
3748     tabpage_T	*tp;
3749 # ifdef FEAT_GUI
3750     int		i;
3751 # endif
3752 
3753 
3754     tp = ALLOC_CLEAR_ONE(tabpage_T);
3755     if (tp == NULL)
3756 	return NULL;
3757 
3758 # ifdef FEAT_EVAL
3759     // init t: variables
3760     tp->tp_vars = dict_alloc();
3761     if (tp->tp_vars == NULL)
3762     {
3763 	vim_free(tp);
3764 	return NULL;
3765     }
3766     init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
3767 # endif
3768 
3769 # ifdef FEAT_GUI
3770     for (i = 0; i < 3; i++)
3771 	tp->tp_prev_which_scrollbars[i] = -1;
3772 # endif
3773 # ifdef FEAT_DIFF
3774     tp->tp_diff_invalid = TRUE;
3775 # endif
3776     tp->tp_ch_used = p_ch;
3777 
3778     return tp;
3779 }
3780 
3781     void
3782 free_tabpage(tabpage_T *tp)
3783 {
3784     int idx;
3785 
3786 # ifdef FEAT_DIFF
3787     diff_clear(tp);
3788 # endif
3789 # ifdef FEAT_PROP_POPUP
3790     while (tp->tp_first_popupwin != NULL)
3791 	popup_close_tabpage(tp, tp->tp_first_popupwin->w_id);
3792 #endif
3793     for (idx = 0; idx < SNAP_COUNT; ++idx)
3794 	clear_snapshot(tp, idx);
3795 #ifdef FEAT_EVAL
3796     vars_clear(&tp->tp_vars->dv_hashtab);	// free all t: variables
3797     hash_init(&tp->tp_vars->dv_hashtab);
3798     unref_var_dict(tp->tp_vars);
3799 #endif
3800 
3801     vim_free(tp->tp_localdir);
3802 
3803 #ifdef FEAT_PYTHON
3804     python_tabpage_free(tp);
3805 #endif
3806 
3807 #ifdef FEAT_PYTHON3
3808     python3_tabpage_free(tp);
3809 #endif
3810 
3811     vim_free(tp);
3812 }
3813 
3814 /*
3815  * Create a new Tab page with one window.
3816  * It will edit the current buffer, like after ":split".
3817  * When "after" is 0 put it just after the current Tab page.
3818  * Otherwise put it just before tab page "after".
3819  * Return FAIL or OK.
3820  */
3821     int
3822 win_new_tabpage(int after)
3823 {
3824     tabpage_T	*tp = curtab;
3825     tabpage_T	*newtp;
3826     int		n;
3827 
3828     newtp = alloc_tabpage();
3829     if (newtp == NULL)
3830 	return FAIL;
3831 
3832     // Remember the current windows in this Tab page.
3833     if (leave_tabpage(curbuf, TRUE) == FAIL)
3834     {
3835 	vim_free(newtp);
3836 	return FAIL;
3837     }
3838     curtab = newtp;
3839 
3840     newtp->tp_localdir = (tp->tp_localdir == NULL)
3841 				    ? NULL : vim_strsave(tp->tp_localdir);
3842     // Create a new empty window.
3843     if (win_alloc_firstwin(tp->tp_curwin) == OK)
3844     {
3845 	// Make the new Tab page the new topframe.
3846 	if (after == 1)
3847 	{
3848 	    // New tab page becomes the first one.
3849 	    newtp->tp_next = first_tabpage;
3850 	    first_tabpage = newtp;
3851 	}
3852 	else
3853 	{
3854 	    if (after > 0)
3855 	    {
3856 		// Put new tab page before tab page "after".
3857 		n = 2;
3858 		for (tp = first_tabpage; tp->tp_next != NULL
3859 					       && n < after; tp = tp->tp_next)
3860 		    ++n;
3861 	    }
3862 	    newtp->tp_next = tp->tp_next;
3863 	    tp->tp_next = newtp;
3864 	}
3865 	newtp->tp_firstwin = newtp->tp_lastwin = newtp->tp_curwin = curwin;
3866 
3867 	win_init_size();
3868 	firstwin->w_winrow = tabline_height();
3869 	win_comp_scroll(curwin);
3870 
3871 	newtp->tp_topframe = topframe;
3872 	last_status(FALSE);
3873 
3874 #if defined(FEAT_GUI)
3875 	// When 'guioptions' includes 'L' or 'R' may have to remove or add
3876 	// scrollbars.  Have to update them anyway.
3877 	gui_may_update_scrollbars();
3878 #endif
3879 #ifdef FEAT_JOB_CHANNEL
3880 	entering_window(curwin);
3881 #endif
3882 
3883 	redraw_all_later(NOT_VALID);
3884 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
3885 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
3886 	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
3887 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3888 	return OK;
3889     }
3890 
3891     // Failed, get back the previous Tab page
3892     enter_tabpage(curtab, curbuf, TRUE, TRUE);
3893     return FAIL;
3894 }
3895 
3896 /*
3897  * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
3898  * like with ":split".
3899  * Returns OK if a new tab page was created, FAIL otherwise.
3900  */
3901     static int
3902 may_open_tabpage(void)
3903 {
3904     int		n = (cmdmod.tab == 0) ? postponed_split_tab : cmdmod.tab;
3905 
3906     if (n != 0)
3907     {
3908 	cmdmod.tab = 0;	    // reset it to avoid doing it twice
3909 	postponed_split_tab = 0;
3910 	return win_new_tabpage(n);
3911     }
3912     return FAIL;
3913 }
3914 
3915 /*
3916  * Create up to "maxcount" tabpages with empty windows.
3917  * Returns the number of resulting tab pages.
3918  */
3919     int
3920 make_tabpages(int maxcount)
3921 {
3922     int		count = maxcount;
3923     int		todo;
3924 
3925     // Limit to 'tabpagemax' tabs.
3926     if (count > p_tpm)
3927 	count = p_tpm;
3928 
3929     /*
3930      * Don't execute autocommands while creating the tab pages.  Must do that
3931      * when putting the buffers in the windows.
3932      */
3933     block_autocmds();
3934 
3935     for (todo = count - 1; todo > 0; --todo)
3936 	if (win_new_tabpage(0) == FAIL)
3937 	    break;
3938 
3939     unblock_autocmds();
3940 
3941     // return actual number of tab pages
3942     return (count - todo);
3943 }
3944 
3945 /*
3946  * Return TRUE when "tpc" points to a valid tab page.
3947  */
3948     int
3949 valid_tabpage(tabpage_T *tpc)
3950 {
3951     tabpage_T	*tp;
3952 
3953     FOR_ALL_TABPAGES(tp)
3954 	if (tp == tpc)
3955 	    return TRUE;
3956     return FALSE;
3957 }
3958 
3959 /*
3960  * Return TRUE when "tpc" points to a valid tab page and at least one window is
3961  * valid.
3962  */
3963     int
3964 valid_tabpage_win(tabpage_T *tpc)
3965 {
3966     tabpage_T	*tp;
3967     win_T	*wp;
3968 
3969     FOR_ALL_TABPAGES(tp)
3970     {
3971 	if (tp == tpc)
3972 	{
3973 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
3974 	    {
3975 		if (win_valid_any_tab(wp))
3976 		    return TRUE;
3977 	    }
3978 	    return FALSE;
3979 	}
3980     }
3981     // shouldn't happen
3982     return FALSE;
3983 }
3984 
3985 /*
3986  * Close tabpage "tab", assuming it has no windows in it.
3987  * There must be another tabpage or this will crash.
3988  */
3989     void
3990 close_tabpage(tabpage_T *tab)
3991 {
3992     tabpage_T	*ptp;
3993 
3994     if (tab == first_tabpage)
3995     {
3996 	first_tabpage = tab->tp_next;
3997 	ptp = first_tabpage;
3998     }
3999     else
4000     {
4001 	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
4002 							    ptp = ptp->tp_next)
4003 	    ;
4004 	assert(ptp != NULL);
4005 	ptp->tp_next = tab->tp_next;
4006     }
4007 
4008     goto_tabpage_tp(ptp, FALSE, FALSE);
4009     free_tabpage(tab);
4010 }
4011 
4012 /*
4013  * Find tab page "n" (first one is 1).  Returns NULL when not found.
4014  */
4015     tabpage_T *
4016 find_tabpage(int n)
4017 {
4018     tabpage_T	*tp;
4019     int		i = 1;
4020 
4021     if (n == 0)
4022 	return curtab;
4023 
4024     for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
4025 	++i;
4026     return tp;
4027 }
4028 
4029 /*
4030  * Get index of tab page "tp".  First one has index 1.
4031  * When not found returns number of tab pages plus one.
4032  */
4033     int
4034 tabpage_index(tabpage_T *ftp)
4035 {
4036     int		i = 1;
4037     tabpage_T	*tp;
4038 
4039     for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
4040 	++i;
4041     return i;
4042 }
4043 
4044 /*
4045  * Prepare for leaving the current tab page.
4046  * When autocommands change "curtab" we don't leave the tab page and return
4047  * FAIL.
4048  * Careful: When OK is returned need to get a new tab page very very soon!
4049  */
4050     static int
4051 leave_tabpage(
4052     buf_T	*new_curbuf UNUSED,    // what is going to be the new curbuf,
4053 				       // NULL if unknown
4054     int		trigger_leave_autocmds UNUSED)
4055 {
4056     tabpage_T	*tp = curtab;
4057 
4058 #ifdef FEAT_JOB_CHANNEL
4059     leaving_window(curwin);
4060 #endif
4061     reset_VIsual_and_resel();	// stop Visual mode
4062     if (trigger_leave_autocmds)
4063     {
4064 	if (new_curbuf != curbuf)
4065 	{
4066 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4067 	    if (curtab != tp)
4068 		return FAIL;
4069 	}
4070 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4071 	if (curtab != tp)
4072 	    return FAIL;
4073 	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
4074 	if (curtab != tp)
4075 	    return FAIL;
4076     }
4077 #if defined(FEAT_GUI)
4078     // Remove the scrollbars.  They may be added back later.
4079     if (gui.in_use)
4080 	gui_remove_scrollbars();
4081 #endif
4082     tp->tp_curwin = curwin;
4083     tp->tp_prevwin = prevwin;
4084     tp->tp_firstwin = firstwin;
4085     tp->tp_lastwin = lastwin;
4086     tp->tp_old_Rows = Rows;
4087     tp->tp_old_Columns = Columns;
4088     firstwin = NULL;
4089     lastwin = NULL;
4090     return OK;
4091 }
4092 
4093 /*
4094  * Start using tab page "tp".
4095  * Only to be used after leave_tabpage() or freeing the current tab page.
4096  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4097  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4098  */
4099     static void
4100 enter_tabpage(
4101     tabpage_T	*tp,
4102     buf_T	*old_curbuf UNUSED,
4103     int		trigger_enter_autocmds,
4104     int		trigger_leave_autocmds)
4105 {
4106     int		row;
4107     int		old_off = tp->tp_firstwin->w_winrow;
4108     win_T	*next_prevwin = tp->tp_prevwin;
4109 
4110     curtab = tp;
4111     firstwin = tp->tp_firstwin;
4112     lastwin = tp->tp_lastwin;
4113     topframe = tp->tp_topframe;
4114 
4115     // We would like doing the TabEnter event first, but we don't have a
4116     // valid current window yet, which may break some commands.
4117     // This triggers autocommands, thus may make "tp" invalid.
4118     win_enter_ext(tp->tp_curwin, FALSE, TRUE, FALSE,
4119 			      trigger_enter_autocmds, trigger_leave_autocmds);
4120     prevwin = next_prevwin;
4121 
4122     last_status(FALSE);		// status line may appear or disappear
4123     row = win_comp_pos();	// recompute w_winrow for all windows
4124 #ifdef FEAT_DIFF
4125     diff_need_scrollbind = TRUE;
4126 #endif
4127 
4128     // The tabpage line may have appeared or disappeared, may need to resize
4129     // the frames for that.  When the Vim window was resized need to update
4130     // frame sizes too.  Use the stored value of p_ch, so that it can be
4131     // different for each tab page.
4132     if (p_ch != curtab->tp_ch_used)
4133 	clear_cmdline = TRUE;
4134     p_ch = curtab->tp_ch_used;
4135 
4136     // When cmdheight is changed in a tab page with '<C-w>-', cmdline_row is
4137     // changed but p_ch and tp_ch_used are not changed. Thus we also need to
4138     // check cmdline_row.
4139     if ((row < cmdline_row) && (cmdline_row <= Rows - p_ch))
4140 	clear_cmdline = TRUE;
4141 
4142     if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
4143 #ifdef FEAT_GUI_TABLINE
4144 			    && !gui_use_tabline()
4145 #endif
4146 		))
4147 	shell_new_rows();
4148     if (curtab->tp_old_Columns != Columns && starting == 0)
4149 	shell_new_columns();	// update window widths
4150 
4151 #if defined(FEAT_GUI)
4152     // When 'guioptions' includes 'L' or 'R' may have to remove or add
4153     // scrollbars.  Have to update them anyway.
4154     gui_may_update_scrollbars();
4155 #endif
4156 
4157     // Apply autocommands after updating the display, when 'rows' and
4158     // 'columns' have been set correctly.
4159     if (trigger_enter_autocmds)
4160     {
4161 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
4162 	if (old_curbuf != curbuf)
4163 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4164     }
4165 
4166     redraw_all_later(NOT_VALID);
4167 }
4168 
4169 /*
4170  * Go to tab page "n".  For ":tab N" and "Ngt".
4171  * When "n" is 9999 go to the last tab page.
4172  */
4173     void
4174 goto_tabpage(int n)
4175 {
4176     tabpage_T	*tp = NULL;  // shut up compiler
4177     tabpage_T	*ttp;
4178     int		i;
4179 
4180     if (text_locked())
4181     {
4182 	// Not allowed when editing the command line.
4183 	text_locked_msg();
4184 	return;
4185     }
4186 
4187     // If there is only one it can't work.
4188     if (first_tabpage->tp_next == NULL)
4189     {
4190 	if (n > 1)
4191 	    beep_flush();
4192 	return;
4193     }
4194 
4195     if (n == 0)
4196     {
4197 	// No count, go to next tab page, wrap around end.
4198 	if (curtab->tp_next == NULL)
4199 	    tp = first_tabpage;
4200 	else
4201 	    tp = curtab->tp_next;
4202     }
4203     else if (n < 0)
4204     {
4205 	// "gT": go to previous tab page, wrap around end.  "N gT" repeats
4206 	// this N times.
4207 	ttp = curtab;
4208 	for (i = n; i < 0; ++i)
4209 	{
4210 	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
4211 		    tp = tp->tp_next)
4212 		;
4213 	    ttp = tp;
4214 	}
4215     }
4216     else if (n == 9999)
4217     {
4218 	// Go to last tab page.
4219 	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
4220 	    ;
4221     }
4222     else
4223     {
4224 	// Go to tab page "n".
4225 	tp = find_tabpage(n);
4226 	if (tp == NULL)
4227 	{
4228 	    beep_flush();
4229 	    return;
4230 	}
4231     }
4232 
4233     goto_tabpage_tp(tp, TRUE, TRUE);
4234 
4235 #ifdef FEAT_GUI_TABLINE
4236     if (gui_use_tabline())
4237 	gui_mch_set_curtab(tabpage_index(curtab));
4238 #endif
4239 }
4240 
4241 /*
4242  * Go to tabpage "tp".
4243  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4244  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4245  * Note: doesn't update the GUI tab.
4246  */
4247     void
4248 goto_tabpage_tp(
4249     tabpage_T	*tp,
4250     int		trigger_enter_autocmds,
4251     int		trigger_leave_autocmds)
4252 {
4253     // Don't repeat a message in another tab page.
4254     set_keep_msg(NULL, 0);
4255 
4256     if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
4257 					trigger_leave_autocmds) == OK)
4258     {
4259 	if (valid_tabpage(tp))
4260 	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
4261 		    trigger_leave_autocmds);
4262 	else
4263 	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
4264 		    trigger_leave_autocmds);
4265     }
4266 }
4267 
4268 /*
4269  * Enter window "wp" in tab page "tp".
4270  * Also updates the GUI tab.
4271  */
4272     void
4273 goto_tabpage_win(tabpage_T *tp, win_T *wp)
4274 {
4275     goto_tabpage_tp(tp, TRUE, TRUE);
4276     if (curtab == tp && win_valid(wp))
4277     {
4278 	win_enter(wp, TRUE);
4279 # ifdef FEAT_GUI_TABLINE
4280 	if (gui_use_tabline())
4281 	    gui_mch_set_curtab(tabpage_index(curtab));
4282 # endif
4283     }
4284 }
4285 
4286 /*
4287  * Move the current tab page to after tab page "nr".
4288  */
4289     void
4290 tabpage_move(int nr)
4291 {
4292     int		n = 1;
4293     tabpage_T	*tp, *tp_dst;
4294 
4295     if (first_tabpage->tp_next == NULL)
4296 	return;
4297 
4298     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
4299 	++n;
4300 
4301     if (tp == curtab || (nr > 0 && tp->tp_next != NULL
4302 						    && tp->tp_next == curtab))
4303 	return;
4304 
4305     tp_dst = tp;
4306 
4307     // Remove the current tab page from the list of tab pages.
4308     if (curtab == first_tabpage)
4309 	first_tabpage = curtab->tp_next;
4310     else
4311     {
4312 	FOR_ALL_TABPAGES(tp)
4313 	    if (tp->tp_next == curtab)
4314 		break;
4315 	if (tp == NULL)	// "cannot happen"
4316 	    return;
4317 	tp->tp_next = curtab->tp_next;
4318     }
4319 
4320     // Re-insert it at the specified position.
4321     if (nr <= 0)
4322     {
4323 	curtab->tp_next = first_tabpage;
4324 	first_tabpage = curtab;
4325     }
4326     else
4327     {
4328 	curtab->tp_next = tp_dst->tp_next;
4329 	tp_dst->tp_next = curtab;
4330     }
4331 
4332     // Need to redraw the tabline.  Tab page contents doesn't change.
4333     redraw_tabline = TRUE;
4334 }
4335 
4336 
4337 /*
4338  * Go to another window.
4339  * When jumping to another buffer, stop Visual mode.  Do this before
4340  * changing windows so we can yank the selection into the '*' register.
4341  * When jumping to another window on the same buffer, adjust its cursor
4342  * position to keep the same Visual area.
4343  */
4344     void
4345 win_goto(win_T *wp)
4346 {
4347 #ifdef FEAT_CONCEAL
4348     win_T	*owp = curwin;
4349 #endif
4350 
4351 #ifdef FEAT_PROP_POPUP
4352     if (ERROR_IF_ANY_POPUP_WINDOW)
4353 	return;
4354     if (popup_is_popup(wp))
4355     {
4356 	emsg(_("E366: Not allowed to enter a popup window"));
4357 	return;
4358     }
4359 #endif
4360     if (text_locked())
4361     {
4362 	beep_flush();
4363 	text_locked_msg();
4364 	return;
4365     }
4366     if (curbuf_locked())
4367 	return;
4368 
4369     if (wp->w_buffer != curbuf)
4370 	reset_VIsual_and_resel();
4371     else if (VIsual_active)
4372 	wp->w_cursor = curwin->w_cursor;
4373 
4374 #ifdef FEAT_GUI
4375     need_mouse_correct = TRUE;
4376 #endif
4377     win_enter(wp, TRUE);
4378 
4379 #ifdef FEAT_CONCEAL
4380     // Conceal cursor line in previous window, unconceal in current window.
4381     if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
4382 	redrawWinline(owp, owp->w_cursor.lnum);
4383     if (curwin->w_p_cole > 0 && !msg_scrolled)
4384 	need_cursor_line_redraw = TRUE;
4385 #endif
4386 }
4387 
4388 #if defined(FEAT_PERL) || defined(PROTO)
4389 /*
4390  * Find window number "winnr" (counting top to bottom).
4391  */
4392     win_T *
4393 win_find_nr(int winnr)
4394 {
4395     win_T	*wp;
4396 
4397     FOR_ALL_WINDOWS(wp)
4398 	if (--winnr == 0)
4399 	    break;
4400     return wp;
4401 }
4402 #endif
4403 
4404 #if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
4405 /*
4406  * Find the tabpage for window "win".
4407  */
4408     tabpage_T *
4409 win_find_tabpage(win_T *win)
4410 {
4411     win_T	*wp;
4412     tabpage_T	*tp;
4413 
4414     FOR_ALL_TAB_WINDOWS(tp, wp)
4415 	    if (wp == win)
4416 		return tp;
4417     return NULL;
4418 }
4419 #endif
4420 
4421 /*
4422  * Get the above or below neighbor window of the specified window.
4423  *   up - TRUE for the above neighbor
4424  *   count - nth neighbor window
4425  * Returns the specified window if the neighbor is not found.
4426  */
4427     win_T *
4428 win_vert_neighbor(tabpage_T *tp, win_T *wp, int up, long count)
4429 {
4430     frame_T	*fr;
4431     frame_T	*nfr;
4432     frame_T	*foundfr;
4433 
4434 #ifdef FEAT_PROP_POPUP
4435     if (popup_is_popup(wp))
4436 	// popups don't have neighbors.
4437 	return NULL;
4438 #endif
4439     foundfr = wp->w_frame;
4440     while (count--)
4441     {
4442 	/*
4443 	 * First go upwards in the tree of frames until we find a upwards or
4444 	 * downwards neighbor.
4445 	 */
4446 	fr = foundfr;
4447 	for (;;)
4448 	{
4449 	    if (fr == tp->tp_topframe)
4450 		goto end;
4451 	    if (up)
4452 		nfr = fr->fr_prev;
4453 	    else
4454 		nfr = fr->fr_next;
4455 	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
4456 		break;
4457 	    fr = fr->fr_parent;
4458 	}
4459 
4460 	/*
4461 	 * Now go downwards to find the bottom or top frame in it.
4462 	 */
4463 	for (;;)
4464 	{
4465 	    if (nfr->fr_layout == FR_LEAF)
4466 	    {
4467 		foundfr = nfr;
4468 		break;
4469 	    }
4470 	    fr = nfr->fr_child;
4471 	    if (nfr->fr_layout == FR_ROW)
4472 	    {
4473 		// Find the frame at the cursor row.
4474 		while (fr->fr_next != NULL
4475 			&& frame2win(fr)->w_wincol + fr->fr_width
4476 					 <= wp->w_wincol + wp->w_wcol)
4477 		    fr = fr->fr_next;
4478 	    }
4479 	    if (nfr->fr_layout == FR_COL && up)
4480 		while (fr->fr_next != NULL)
4481 		    fr = fr->fr_next;
4482 	    nfr = fr;
4483 	}
4484     }
4485 end:
4486     return foundfr != NULL ? foundfr->fr_win : NULL;
4487 }
4488 
4489 /*
4490  * Move to window above or below "count" times.
4491  */
4492     static void
4493 win_goto_ver(
4494     int		up,		// TRUE to go to win above
4495     long	count)
4496 {
4497     win_T	*win;
4498 
4499 #ifdef FEAT_PROP_POPUP
4500     if (ERROR_IF_TERM_POPUP_WINDOW)
4501 	return;
4502 #endif
4503     win = win_vert_neighbor(curtab, curwin, up, count);
4504     if (win != NULL)
4505 	win_goto(win);
4506 }
4507 
4508 /*
4509  * Get the left or right neighbor window of the specified window.
4510  *   left - TRUE for the left neighbor
4511  *   count - nth neighbor window
4512  * Returns the specified window if the neighbor is not found.
4513  */
4514     win_T *
4515 win_horz_neighbor(tabpage_T *tp, win_T *wp, int left, long count)
4516 {
4517     frame_T	*fr;
4518     frame_T	*nfr;
4519     frame_T	*foundfr;
4520 
4521 #ifdef FEAT_PROP_POPUP
4522     if (popup_is_popup(wp))
4523 	// popups don't have neighbors.
4524 	return NULL;
4525 #endif
4526     foundfr = wp->w_frame;
4527     while (count--)
4528     {
4529 	/*
4530 	 * First go upwards in the tree of frames until we find a left or
4531 	 * right neighbor.
4532 	 */
4533 	fr = foundfr;
4534 	for (;;)
4535 	{
4536 	    if (fr == tp->tp_topframe)
4537 		goto end;
4538 	    if (left)
4539 		nfr = fr->fr_prev;
4540 	    else
4541 		nfr = fr->fr_next;
4542 	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
4543 		break;
4544 	    fr = fr->fr_parent;
4545 	}
4546 
4547 	/*
4548 	 * Now go downwards to find the leftmost or rightmost frame in it.
4549 	 */
4550 	for (;;)
4551 	{
4552 	    if (nfr->fr_layout == FR_LEAF)
4553 	    {
4554 		foundfr = nfr;
4555 		break;
4556 	    }
4557 	    fr = nfr->fr_child;
4558 	    if (nfr->fr_layout == FR_COL)
4559 	    {
4560 		// Find the frame at the cursor row.
4561 		while (fr->fr_next != NULL
4562 			&& frame2win(fr)->w_winrow + fr->fr_height
4563 					 <= wp->w_winrow + wp->w_wrow)
4564 		    fr = fr->fr_next;
4565 	    }
4566 	    if (nfr->fr_layout == FR_ROW && left)
4567 		while (fr->fr_next != NULL)
4568 		    fr = fr->fr_next;
4569 	    nfr = fr;
4570 	}
4571     }
4572 end:
4573     return foundfr != NULL ? foundfr->fr_win : NULL;
4574 }
4575 
4576 /*
4577  * Move to left or right window.
4578  */
4579     static void
4580 win_goto_hor(
4581     int		left,		// TRUE to go to left win
4582     long	count)
4583 {
4584     win_T	*win;
4585 
4586 #ifdef FEAT_PROP_POPUP
4587     if (ERROR_IF_TERM_POPUP_WINDOW)
4588 	return;
4589 #endif
4590     win = win_horz_neighbor(curtab, curwin, left, count);
4591     if (win != NULL)
4592 	win_goto(win);
4593 }
4594 
4595 /*
4596  * Make window "wp" the current window.
4597  */
4598     void
4599 win_enter(win_T *wp, int undo_sync)
4600 {
4601     win_enter_ext(wp, undo_sync, FALSE, FALSE, TRUE, TRUE);
4602 }
4603 
4604 /*
4605  * Make window wp the current window.
4606  * Can be called with "curwin_invalid" TRUE, which means that curwin has just
4607  * been closed and isn't valid.
4608  */
4609     static void
4610 win_enter_ext(
4611     win_T	*wp,
4612     int		undo_sync,
4613     int		curwin_invalid,
4614     int		trigger_new_autocmds,
4615     int		trigger_enter_autocmds,
4616     int		trigger_leave_autocmds)
4617 {
4618     int		other_buffer = FALSE;
4619 
4620     if (wp == curwin && !curwin_invalid)	// nothing to do
4621 	return;
4622 
4623 #ifdef FEAT_JOB_CHANNEL
4624     if (!curwin_invalid)
4625 	leaving_window(curwin);
4626 #endif
4627 
4628     if (!curwin_invalid && trigger_leave_autocmds)
4629     {
4630 	/*
4631 	 * Be careful: If autocommands delete the window, return now.
4632 	 */
4633 	if (wp->w_buffer != curbuf)
4634 	{
4635 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4636 	    other_buffer = TRUE;
4637 	    if (!win_valid(wp))
4638 		return;
4639 	}
4640 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4641 	if (!win_valid(wp))
4642 	    return;
4643 #ifdef FEAT_EVAL
4644 	// autocmds may abort script processing
4645 	if (aborting())
4646 	    return;
4647 #endif
4648     }
4649 
4650     // sync undo before leaving the current buffer
4651     if (undo_sync && curbuf != wp->w_buffer)
4652 	u_sync(FALSE);
4653 
4654     // Might need to scroll the old window before switching, e.g., when the
4655     // cursor was moved.
4656     update_topline();
4657 
4658     // may have to copy the buffer options when 'cpo' contains 'S'
4659     if (wp->w_buffer != curbuf)
4660 	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
4661     if (!curwin_invalid)
4662     {
4663 	prevwin = curwin;	// remember for CTRL-W p
4664 	curwin->w_redr_status = TRUE;
4665     }
4666     curwin = wp;
4667     curbuf = wp->w_buffer;
4668     check_cursor();
4669     if (!virtual_active())
4670 	curwin->w_cursor.coladd = 0;
4671     changed_line_abv_curs();	// assume cursor position needs updating
4672 
4673     if (curwin->w_localdir != NULL || curtab->tp_localdir != NULL)
4674     {
4675 	char_u	*dirname;
4676 
4677 	// Window or tab has a local directory: Save current directory as
4678 	// global directory (unless that was done already) and change to the
4679 	// local directory.
4680 	if (globaldir == NULL)
4681 	{
4682 	    char_u	cwd[MAXPATHL];
4683 
4684 	    if (mch_dirname(cwd, MAXPATHL) == OK)
4685 		globaldir = vim_strsave(cwd);
4686 	}
4687 	if (curwin->w_localdir != NULL)
4688 	    dirname = curwin->w_localdir;
4689 	else
4690 	    dirname = curtab->tp_localdir;
4691 
4692 	if (mch_chdir((char *)dirname) == 0)
4693 	    shorten_fnames(TRUE);
4694     }
4695     else if (globaldir != NULL)
4696     {
4697 	// Window doesn't have a local directory and we are not in the global
4698 	// directory: Change to the global directory.
4699 	vim_ignored = mch_chdir((char *)globaldir);
4700 	VIM_CLEAR(globaldir);
4701 	shorten_fnames(TRUE);
4702     }
4703 
4704 #ifdef FEAT_JOB_CHANNEL
4705     entering_window(curwin);
4706 #endif
4707     // Careful: autocommands may close the window and make "wp" invalid
4708     if (trigger_new_autocmds)
4709 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
4710     if (trigger_enter_autocmds)
4711     {
4712 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
4713 	if (other_buffer)
4714 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4715     }
4716 
4717 #ifdef FEAT_TITLE
4718     maketitle();
4719 #endif
4720     curwin->w_redr_status = TRUE;
4721 #ifdef FEAT_TERMINAL
4722     if (bt_terminal(curwin->w_buffer))
4723 	// terminal is likely in another mode
4724 	redraw_mode = TRUE;
4725 #endif
4726     redraw_tabline = TRUE;
4727     if (restart_edit)
4728 	redraw_later(VALID);	// causes status line redraw
4729 
4730     // set window height to desired minimal value
4731     if (curwin->w_height < p_wh && !curwin->w_p_wfh
4732 #ifdef FEAT_PROP_POPUP
4733 	    && !popup_is_popup(curwin)
4734 #endif
4735 	    )
4736 	win_setheight((int)p_wh);
4737     else if (curwin->w_height == 0)
4738 	win_setheight(1);
4739 
4740     // set window width to desired minimal value
4741     if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
4742 	win_setwidth((int)p_wiw);
4743 
4744     setmouse();			// in case jumped to/from help buffer
4745 
4746     // Change directories when the 'acd' option is set.
4747     DO_AUTOCHDIR;
4748 }
4749 
4750 
4751 /*
4752  * Jump to the first open window that contains buffer "buf", if one exists.
4753  * Returns a pointer to the window found, otherwise NULL.
4754  */
4755     win_T *
4756 buf_jump_open_win(buf_T *buf)
4757 {
4758     win_T	*wp = NULL;
4759 
4760     if (curwin->w_buffer == buf)
4761 	wp = curwin;
4762     else
4763 	FOR_ALL_WINDOWS(wp)
4764 	    if (wp->w_buffer == buf)
4765 		break;
4766     if (wp != NULL)
4767 	win_enter(wp, FALSE);
4768     return wp;
4769 }
4770 
4771 /*
4772  * Jump to the first open window in any tab page that contains buffer "buf",
4773  * if one exists.
4774  * Returns a pointer to the window found, otherwise NULL.
4775  */
4776     win_T *
4777 buf_jump_open_tab(buf_T *buf)
4778 {
4779     win_T	*wp = buf_jump_open_win(buf);
4780     tabpage_T	*tp;
4781 
4782     if (wp != NULL)
4783 	return wp;
4784 
4785     FOR_ALL_TABPAGES(tp)
4786 	if (tp != curtab)
4787 	{
4788 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
4789 		if (wp->w_buffer == buf)
4790 		    break;
4791 	    if (wp != NULL)
4792 	    {
4793 		goto_tabpage_win(tp, wp);
4794 		if (curwin != wp)
4795 		    wp = NULL;	// something went wrong
4796 		break;
4797 	    }
4798 	}
4799     return wp;
4800 }
4801 
4802 static int last_win_id = LOWEST_WIN_ID - 1;
4803 
4804 /*
4805  * Allocate a window structure and link it in the window list when "hidden" is
4806  * FALSE.
4807  */
4808     static win_T *
4809 win_alloc(win_T *after UNUSED, int hidden UNUSED)
4810 {
4811     win_T	*new_wp;
4812 
4813     /*
4814      * allocate window structure and linesizes arrays
4815      */
4816     new_wp = ALLOC_CLEAR_ONE(win_T);
4817     if (new_wp == NULL)
4818 	return NULL;
4819 
4820     if (win_alloc_lines(new_wp) == FAIL)
4821     {
4822 	vim_free(new_wp);
4823 	return NULL;
4824     }
4825 
4826     new_wp->w_id = ++last_win_id;
4827 
4828 #ifdef FEAT_EVAL
4829     // init w: variables
4830     new_wp->w_vars = dict_alloc();
4831     if (new_wp->w_vars == NULL)
4832     {
4833 	win_free_lsize(new_wp);
4834 	vim_free(new_wp);
4835 	return NULL;
4836     }
4837     init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
4838 #endif
4839 
4840     // Don't execute autocommands while the window is not properly
4841     // initialized yet.  gui_create_scrollbar() may trigger a FocusGained
4842     // event.
4843     block_autocmds();
4844 
4845     /*
4846      * link the window in the window list
4847      */
4848     if (!hidden)
4849 	win_append(after, new_wp);
4850     new_wp->w_wincol = 0;
4851     new_wp->w_width = Columns;
4852 
4853     // position the display and the cursor at the top of the file.
4854     new_wp->w_topline = 1;
4855 #ifdef FEAT_DIFF
4856     new_wp->w_topfill = 0;
4857 #endif
4858     new_wp->w_botline = 2;
4859     new_wp->w_cursor.lnum = 1;
4860     new_wp->w_scbind_pos = 1;
4861 
4862     // use global option value for global-local options
4863     new_wp->w_p_so = -1;
4864     new_wp->w_p_siso = -1;
4865 
4866     // We won't calculate w_fraction until resizing the window
4867     new_wp->w_fraction = 0;
4868     new_wp->w_prev_fraction_row = -1;
4869 
4870 #ifdef FEAT_GUI
4871     if (gui.in_use)
4872     {
4873 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
4874 		SBAR_LEFT, new_wp);
4875 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
4876 		SBAR_RIGHT, new_wp);
4877     }
4878 #endif
4879 #ifdef FEAT_FOLDING
4880     foldInitWin(new_wp);
4881 #endif
4882     unblock_autocmds();
4883 #ifdef FEAT_SEARCH_EXTRA
4884     new_wp->w_match_head = NULL;
4885     new_wp->w_next_match_id = 4;
4886 #endif
4887     return new_wp;
4888 }
4889 
4890 /*
4891  * Remove window 'wp' from the window list and free the structure.
4892  */
4893     static void
4894 win_free(
4895     win_T	*wp,
4896     tabpage_T	*tp)		// tab page "win" is in, NULL for current
4897 {
4898     int		i;
4899     buf_T	*buf;
4900     wininfo_T	*wip;
4901 
4902 #ifdef FEAT_FOLDING
4903     clearFolding(wp);
4904 #endif
4905 
4906     // reduce the reference count to the argument list.
4907     alist_unlink(wp->w_alist);
4908 
4909     // Don't execute autocommands while the window is halfway being deleted.
4910     // gui_mch_destroy_scrollbar() may trigger a FocusGained event.
4911     block_autocmds();
4912 
4913 #ifdef FEAT_LUA
4914     lua_window_free(wp);
4915 #endif
4916 
4917 #ifdef FEAT_MZSCHEME
4918     mzscheme_window_free(wp);
4919 #endif
4920 
4921 #ifdef FEAT_PERL
4922     perl_win_free(wp);
4923 #endif
4924 
4925 #ifdef FEAT_PYTHON
4926     python_window_free(wp);
4927 #endif
4928 
4929 #ifdef FEAT_PYTHON3
4930     python3_window_free(wp);
4931 #endif
4932 
4933 #ifdef FEAT_TCL
4934     tcl_window_free(wp);
4935 #endif
4936 
4937 #ifdef FEAT_RUBY
4938     ruby_window_free(wp);
4939 #endif
4940 
4941     clear_winopt(&wp->w_onebuf_opt);
4942     clear_winopt(&wp->w_allbuf_opt);
4943 
4944 #ifdef FEAT_EVAL
4945     vars_clear(&wp->w_vars->dv_hashtab);	// free all w: variables
4946     hash_init(&wp->w_vars->dv_hashtab);
4947     unref_var_dict(wp->w_vars);
4948 #endif
4949 
4950     {
4951 	tabpage_T	*ttp;
4952 
4953 	if (prevwin == wp)
4954 	    prevwin = NULL;
4955 	FOR_ALL_TABPAGES(ttp)
4956 	    if (ttp->tp_prevwin == wp)
4957 		ttp->tp_prevwin = NULL;
4958     }
4959     win_free_lsize(wp);
4960 
4961     for (i = 0; i < wp->w_tagstacklen; ++i)
4962     {
4963 	vim_free(wp->w_tagstack[i].tagname);
4964 	vim_free(wp->w_tagstack[i].user_data);
4965     }
4966     vim_free(wp->w_localdir);
4967 
4968     // Remove the window from the b_wininfo lists, it may happen that the
4969     // freed memory is re-used for another window.
4970     FOR_ALL_BUFFERS(buf)
4971 	for (wip = buf->b_wininfo; wip != NULL; wip = wip->wi_next)
4972 	    if (wip->wi_win == wp)
4973 		wip->wi_win = NULL;
4974 
4975 #ifdef FEAT_SEARCH_EXTRA
4976     clear_matches(wp);
4977 #endif
4978 
4979 #ifdef FEAT_JUMPLIST
4980     free_jumplist(wp);
4981 #endif
4982 
4983 #ifdef FEAT_QUICKFIX
4984     qf_free_all(wp);
4985 #endif
4986 
4987 #ifdef FEAT_GUI
4988     if (gui.in_use)
4989     {
4990 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
4991 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
4992     }
4993 #endif // FEAT_GUI
4994 
4995 #ifdef FEAT_MENU
4996     remove_winbar(wp);
4997 #endif
4998 #ifdef FEAT_PROP_POPUP
4999     free_callback(&wp->w_close_cb);
5000     free_callback(&wp->w_filter_cb);
5001     for (i = 0; i < 4; ++i)
5002 	VIM_CLEAR(wp->w_border_highlight[i]);
5003     vim_free(wp->w_scrollbar_highlight);
5004     vim_free(wp->w_thumb_highlight);
5005     vim_free(wp->w_popup_title);
5006     list_unref(wp->w_popup_mask);
5007     vim_free(wp->w_popup_mask_cells);
5008 #endif
5009 
5010 #ifdef FEAT_SYN_HL
5011     vim_free(wp->w_p_cc_cols);
5012 #endif
5013 
5014     if (win_valid_any_tab(wp))
5015 	win_remove(wp, tp);
5016     if (autocmd_busy)
5017     {
5018 	wp->w_next = au_pending_free_win;
5019 	au_pending_free_win = wp;
5020     }
5021     else
5022 	vim_free(wp);
5023 
5024     unblock_autocmds();
5025 }
5026 
5027 /*
5028  * Return TRUE if "wp" is not in the list of windows: the autocmd window or a
5029  * popup window.
5030  */
5031     static int
5032 win_unlisted(win_T *wp)
5033 {
5034     return wp == aucmd_win || WIN_IS_POPUP(wp);
5035 }
5036 
5037 #if defined(FEAT_PROP_POPUP) || defined(PROTO)
5038 /*
5039  * Free a popup window.  This does not take the window out of the window list
5040  * and assumes there is only one toplevel frame, no split.
5041  */
5042     void
5043 win_free_popup(win_T *win)
5044 {
5045     if (bt_popup(win->w_buffer))
5046 	win_close_buffer(win, DOBUF_WIPE_REUSE, FALSE);
5047     else
5048 	close_buffer(win, win->w_buffer, 0, FALSE, FALSE);
5049 # if defined(FEAT_TIMERS)
5050     if (win->w_popup_timer != NULL)
5051 	stop_timer(win->w_popup_timer);
5052 # endif
5053     vim_free(win->w_frame);
5054     win_free(win, NULL);
5055 }
5056 #endif
5057 
5058 /*
5059  * Append window "wp" in the window list after window "after".
5060  */
5061     static void
5062 win_append(win_T *after, win_T *wp)
5063 {
5064     win_T	*before;
5065 
5066     if (after == NULL)	    // after NULL is in front of the first
5067 	before = firstwin;
5068     else
5069 	before = after->w_next;
5070 
5071     wp->w_next = before;
5072     wp->w_prev = after;
5073     if (after == NULL)
5074 	firstwin = wp;
5075     else
5076 	after->w_next = wp;
5077     if (before == NULL)
5078 	lastwin = wp;
5079     else
5080 	before->w_prev = wp;
5081 }
5082 
5083 /*
5084  * Remove a window from the window list.
5085  */
5086     void
5087 win_remove(
5088     win_T	*wp,
5089     tabpage_T	*tp)		// tab page "win" is in, NULL for current
5090 {
5091     if (wp->w_prev != NULL)
5092 	wp->w_prev->w_next = wp->w_next;
5093     else if (tp == NULL)
5094 	firstwin = curtab->tp_firstwin = wp->w_next;
5095     else
5096 	tp->tp_firstwin = wp->w_next;
5097 
5098     if (wp->w_next != NULL)
5099 	wp->w_next->w_prev = wp->w_prev;
5100     else if (tp == NULL)
5101 	lastwin = curtab->tp_lastwin = wp->w_prev;
5102     else
5103 	tp->tp_lastwin = wp->w_prev;
5104 }
5105 
5106 /*
5107  * Append frame "frp" in a frame list after frame "after".
5108  */
5109     static void
5110 frame_append(frame_T *after, frame_T *frp)
5111 {
5112     frp->fr_next = after->fr_next;
5113     after->fr_next = frp;
5114     if (frp->fr_next != NULL)
5115 	frp->fr_next->fr_prev = frp;
5116     frp->fr_prev = after;
5117 }
5118 
5119 /*
5120  * Insert frame "frp" in a frame list before frame "before".
5121  */
5122     static void
5123 frame_insert(frame_T *before, frame_T *frp)
5124 {
5125     frp->fr_next = before;
5126     frp->fr_prev = before->fr_prev;
5127     before->fr_prev = frp;
5128     if (frp->fr_prev != NULL)
5129 	frp->fr_prev->fr_next = frp;
5130     else
5131 	frp->fr_parent->fr_child = frp;
5132 }
5133 
5134 /*
5135  * Remove a frame from a frame list.
5136  */
5137     static void
5138 frame_remove(frame_T *frp)
5139 {
5140     if (frp->fr_prev != NULL)
5141 	frp->fr_prev->fr_next = frp->fr_next;
5142     else
5143     {
5144 	frp->fr_parent->fr_child = frp->fr_next;
5145 	// special case: topframe->fr_child == frp
5146 	if (topframe->fr_child == frp)
5147 	    topframe->fr_child = frp->fr_next;
5148     }
5149     if (frp->fr_next != NULL)
5150 	frp->fr_next->fr_prev = frp->fr_prev;
5151 }
5152 
5153 /*
5154  * Allocate w_lines[] for window "wp".
5155  * Return FAIL for failure, OK for success.
5156  */
5157     int
5158 win_alloc_lines(win_T *wp)
5159 {
5160     wp->w_lines_valid = 0;
5161     wp->w_lines = ALLOC_CLEAR_MULT(wline_T, Rows );
5162     if (wp->w_lines == NULL)
5163 	return FAIL;
5164     return OK;
5165 }
5166 
5167 /*
5168  * free lsize arrays for a window
5169  */
5170     void
5171 win_free_lsize(win_T *wp)
5172 {
5173     // TODO: why would wp be NULL here?
5174     if (wp != NULL)
5175 	VIM_CLEAR(wp->w_lines);
5176 }
5177 
5178 /*
5179  * Called from win_new_shellsize() after Rows changed.
5180  * This only does the current tab page, others must be done when made active.
5181  */
5182     void
5183 shell_new_rows(void)
5184 {
5185     int		h = (int)ROWS_AVAIL;
5186 
5187     if (firstwin == NULL)	// not initialized yet
5188 	return;
5189     if (h < frame_minheight(topframe, NULL))
5190 	h = frame_minheight(topframe, NULL);
5191 
5192     // First try setting the heights of windows with 'winfixheight'.  If
5193     // that doesn't result in the right height, forget about that option.
5194     frame_new_height(topframe, h, FALSE, TRUE);
5195     if (!frame_check_height(topframe, h))
5196 	frame_new_height(topframe, h, FALSE, FALSE);
5197 
5198     (void)win_comp_pos();		// recompute w_winrow and w_wincol
5199     compute_cmdrow();
5200     curtab->tp_ch_used = p_ch;
5201 
5202 #if 0
5203     // Disabled: don't want making the screen smaller make a window larger.
5204     if (p_ea)
5205 	win_equal(curwin, FALSE, 'v');
5206 #endif
5207 }
5208 
5209 /*
5210  * Called from win_new_shellsize() after Columns changed.
5211  */
5212     void
5213 shell_new_columns(void)
5214 {
5215     if (firstwin == NULL)	// not initialized yet
5216 	return;
5217 
5218     // First try setting the widths of windows with 'winfixwidth'.  If that
5219     // doesn't result in the right width, forget about that option.
5220     frame_new_width(topframe, (int)Columns, FALSE, TRUE);
5221     if (!frame_check_width(topframe, Columns))
5222 	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
5223 
5224     (void)win_comp_pos();		// recompute w_winrow and w_wincol
5225 #if 0
5226     // Disabled: don't want making the screen smaller make a window larger.
5227     if (p_ea)
5228 	win_equal(curwin, FALSE, 'h');
5229 #endif
5230 }
5231 
5232 #if defined(FEAT_CMDWIN) || defined(PROTO)
5233 /*
5234  * Save the size of all windows in "gap".
5235  */
5236     void
5237 win_size_save(garray_T *gap)
5238 
5239 {
5240     win_T	*wp;
5241 
5242     ga_init2(gap, (int)sizeof(int), 1);
5243     if (ga_grow(gap, win_count() * 2 + 1) == OK)
5244     {
5245 	// first entry is value of 'lines'
5246 	((int *)gap->ga_data)[gap->ga_len++] = Rows;
5247 
5248 	FOR_ALL_WINDOWS(wp)
5249 	{
5250 	    ((int *)gap->ga_data)[gap->ga_len++] =
5251 					       wp->w_width + wp->w_vsep_width;
5252 	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
5253 	}
5254     }
5255 }
5256 
5257 /*
5258  * Restore window sizes, but only if the number of windows is still the same
5259  * and 'lines' didn't change.
5260  * Does not free the growarray.
5261  */
5262     void
5263 win_size_restore(garray_T *gap)
5264 {
5265     win_T	*wp;
5266     int		i, j;
5267 
5268     if (win_count() * 2 + 1 == gap->ga_len
5269 	    && ((int *)gap->ga_data)[0] == Rows)
5270     {
5271 	// The order matters, because frames contain other frames, but it's
5272 	// difficult to get right. The easy way out is to do it twice.
5273 	for (j = 0; j < 2; ++j)
5274 	{
5275 	    i = 1;
5276 	    FOR_ALL_WINDOWS(wp)
5277 	    {
5278 		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
5279 		win_setheight_win(((int *)gap->ga_data)[i++], wp);
5280 	    }
5281 	}
5282 	// recompute the window positions
5283 	(void)win_comp_pos();
5284     }
5285 }
5286 #endif // FEAT_CMDWIN
5287 
5288 /*
5289  * Update the position for all windows, using the width and height of the
5290  * frames.
5291  * Returns the row just after the last window.
5292  */
5293     int
5294 win_comp_pos(void)
5295 {
5296     int		row = tabline_height();
5297     int		col = 0;
5298 
5299     frame_comp_pos(topframe, &row, &col);
5300     return row;
5301 }
5302 
5303 /*
5304  * Update the position of the windows in frame "topfrp", using the width and
5305  * height of the frames.
5306  * "*row" and "*col" are the top-left position of the frame.  They are updated
5307  * to the bottom-right position plus one.
5308  */
5309     static void
5310 frame_comp_pos(frame_T *topfrp, int *row, int *col)
5311 {
5312     win_T	*wp;
5313     frame_T	*frp;
5314     int		startcol;
5315     int		startrow;
5316     int		h;
5317 
5318     wp = topfrp->fr_win;
5319     if (wp != NULL)
5320     {
5321 	if (wp->w_winrow != *row || wp->w_wincol != *col)
5322 	{
5323 	    // position changed, redraw
5324 	    wp->w_winrow = *row;
5325 	    wp->w_wincol = *col;
5326 	    redraw_win_later(wp, NOT_VALID);
5327 	    wp->w_redr_status = TRUE;
5328 	}
5329 	// WinBar will not show if the window height is zero
5330 	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
5331 	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
5332 	*col += wp->w_width + wp->w_vsep_width;
5333     }
5334     else
5335     {
5336 	startrow = *row;
5337 	startcol = *col;
5338 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
5339 	{
5340 	    if (topfrp->fr_layout == FR_ROW)
5341 		*row = startrow;	// all frames are at the same row
5342 	    else
5343 		*col = startcol;	// all frames are at the same col
5344 	    frame_comp_pos(frp, row, col);
5345 	}
5346     }
5347 }
5348 
5349 /*
5350  * Set current window height and take care of repositioning other windows to
5351  * fit around it.
5352  */
5353     void
5354 win_setheight(int height)
5355 {
5356     win_setheight_win(height, curwin);
5357 }
5358 
5359 /*
5360  * Set the window height of window "win" and take care of repositioning other
5361  * windows to fit around it.
5362  */
5363     void
5364 win_setheight_win(int height, win_T *win)
5365 {
5366     int		row;
5367 
5368     if (win == curwin)
5369     {
5370 	// Always keep current window at least one line high, even when
5371 	// 'winminheight' is zero.
5372 	if (height < p_wmh)
5373 	    height = p_wmh;
5374 	if (height == 0)
5375 	    height = 1;
5376 	height += WINBAR_HEIGHT(curwin);
5377     }
5378 
5379     frame_setheight(win->w_frame, height + win->w_status_height);
5380 
5381     // recompute the window positions
5382     row = win_comp_pos();
5383 
5384     /*
5385      * If there is extra space created between the last window and the command
5386      * line, clear it.
5387      */
5388     if (full_screen && msg_scrolled == 0 && row < cmdline_row)
5389 	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5390     cmdline_row = row;
5391     msg_row = row;
5392     msg_col = 0;
5393 
5394     redraw_all_later(NOT_VALID);
5395 }
5396 
5397 /*
5398  * Set the height of a frame to "height" and take care that all frames and
5399  * windows inside it are resized.  Also resize frames on the left and right if
5400  * the are in the same FR_ROW frame.
5401  *
5402  * Strategy:
5403  * If the frame is part of a FR_COL frame, try fitting the frame in that
5404  * frame.  If that doesn't work (the FR_COL frame is too small), recursively
5405  * go to containing frames to resize them and make room.
5406  * If the frame is part of a FR_ROW frame, all frames must be resized as well.
5407  * Check for the minimal height of the FR_ROW frame.
5408  * At the top level we can also use change the command line height.
5409  */
5410     static void
5411 frame_setheight(frame_T *curfrp, int height)
5412 {
5413     int		room;		// total number of lines available
5414     int		take;		// number of lines taken from other windows
5415     int		room_cmdline;	// lines available from cmdline
5416     int		run;
5417     frame_T	*frp;
5418     int		h;
5419     int		room_reserved;
5420 
5421     // If the height already is the desired value, nothing to do.
5422     if (curfrp->fr_height == height)
5423 	return;
5424 
5425     if (curfrp->fr_parent == NULL)
5426     {
5427 	// topframe: can only change the command line
5428 	if (height > ROWS_AVAIL)
5429 	    height = ROWS_AVAIL;
5430 	if (height > 0)
5431 	    frame_new_height(curfrp, height, FALSE, FALSE);
5432     }
5433     else if (curfrp->fr_parent->fr_layout == FR_ROW)
5434     {
5435 	// Row of frames: Also need to resize frames left and right of this
5436 	// one.  First check for the minimal height of these.
5437 	h = frame_minheight(curfrp->fr_parent, NULL);
5438 	if (height < h)
5439 	    height = h;
5440 	frame_setheight(curfrp->fr_parent, height);
5441     }
5442     else
5443     {
5444 	/*
5445 	 * Column of frames: try to change only frames in this column.
5446 	 */
5447 	/*
5448 	 * Do this twice:
5449 	 * 1: compute room available, if it's not enough try resizing the
5450 	 *    containing frame.
5451 	 * 2: compute the room available and adjust the height to it.
5452 	 * Try not to reduce the height of a window with 'winfixheight' set.
5453 	 */
5454 	for (run = 1; run <= 2; ++run)
5455 	{
5456 	    room = 0;
5457 	    room_reserved = 0;
5458 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5459 	    {
5460 		if (frp != curfrp
5461 			&& frp->fr_win != NULL
5462 			&& frp->fr_win->w_p_wfh)
5463 		    room_reserved += frp->fr_height;
5464 		room += frp->fr_height;
5465 		if (frp != curfrp)
5466 		    room -= frame_minheight(frp, NULL);
5467 	    }
5468 	    if (curfrp->fr_width != Columns)
5469 		room_cmdline = 0;
5470 	    else
5471 	    {
5472 		room_cmdline = Rows - p_ch - (lastwin->w_winrow
5473 						+ VISIBLE_HEIGHT(lastwin)
5474 						+ lastwin->w_status_height);
5475 		if (room_cmdline < 0)
5476 		    room_cmdline = 0;
5477 	    }
5478 
5479 	    if (height <= room + room_cmdline)
5480 		break;
5481 	    if (run == 2 || curfrp->fr_width == Columns)
5482 	    {
5483 		if (height > room + room_cmdline)
5484 		    height = room + room_cmdline;
5485 		break;
5486 	    }
5487 	    frame_setheight(curfrp->fr_parent, height
5488 		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
5489 	}
5490 
5491 	/*
5492 	 * Compute the number of lines we will take from others frames (can be
5493 	 * negative!).
5494 	 */
5495 	take = height - curfrp->fr_height;
5496 
5497 	// If there is not enough room, also reduce the height of a window
5498 	// with 'winfixheight' set.
5499 	if (height > room + room_cmdline - room_reserved)
5500 	    room_reserved = room + room_cmdline - height;
5501 	// If there is only a 'winfixheight' window and making the
5502 	// window smaller, need to make the other window taller.
5503 	if (take < 0 && room - curfrp->fr_height < room_reserved)
5504 	    room_reserved = 0;
5505 
5506 	if (take > 0 && room_cmdline > 0)
5507 	{
5508 	    // use lines from cmdline first
5509 	    if (take < room_cmdline)
5510 		room_cmdline = take;
5511 	    take -= room_cmdline;
5512 	    topframe->fr_height += room_cmdline;
5513 	}
5514 
5515 	/*
5516 	 * set the current frame to the new height
5517 	 */
5518 	frame_new_height(curfrp, height, FALSE, FALSE);
5519 
5520 	/*
5521 	 * First take lines from the frames after the current frame.  If
5522 	 * that is not enough, takes lines from frames above the current
5523 	 * frame.
5524 	 */
5525 	for (run = 0; run < 2; ++run)
5526 	{
5527 	    if (run == 0)
5528 		frp = curfrp->fr_next;	// 1st run: start with next window
5529 	    else
5530 		frp = curfrp->fr_prev;	// 2nd run: start with prev window
5531 	    while (frp != NULL && take != 0)
5532 	    {
5533 		h = frame_minheight(frp, NULL);
5534 		if (room_reserved > 0
5535 			&& frp->fr_win != NULL
5536 			&& frp->fr_win->w_p_wfh)
5537 		{
5538 		    if (room_reserved >= frp->fr_height)
5539 			room_reserved -= frp->fr_height;
5540 		    else
5541 		    {
5542 			if (frp->fr_height - room_reserved > take)
5543 			    room_reserved = frp->fr_height - take;
5544 			take -= frp->fr_height - room_reserved;
5545 			frame_new_height(frp, room_reserved, FALSE, FALSE);
5546 			room_reserved = 0;
5547 		    }
5548 		}
5549 		else
5550 		{
5551 		    if (frp->fr_height - take < h)
5552 		    {
5553 			take -= frp->fr_height - h;
5554 			frame_new_height(frp, h, FALSE, FALSE);
5555 		    }
5556 		    else
5557 		    {
5558 			frame_new_height(frp, frp->fr_height - take,
5559 								FALSE, FALSE);
5560 			take = 0;
5561 		    }
5562 		}
5563 		if (run == 0)
5564 		    frp = frp->fr_next;
5565 		else
5566 		    frp = frp->fr_prev;
5567 	    }
5568 	}
5569     }
5570 }
5571 
5572 /*
5573  * Set current window width and take care of repositioning other windows to
5574  * fit around it.
5575  */
5576     void
5577 win_setwidth(int width)
5578 {
5579     win_setwidth_win(width, curwin);
5580 }
5581 
5582     void
5583 win_setwidth_win(int width, win_T *wp)
5584 {
5585     // Always keep current window at least one column wide, even when
5586     // 'winminwidth' is zero.
5587     if (wp == curwin)
5588     {
5589 	if (width < p_wmw)
5590 	    width = p_wmw;
5591 	if (width == 0)
5592 	    width = 1;
5593     }
5594 
5595     frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
5596 
5597     // recompute the window positions
5598     (void)win_comp_pos();
5599 
5600     redraw_all_later(NOT_VALID);
5601 }
5602 
5603 /*
5604  * Set the width of a frame to "width" and take care that all frames and
5605  * windows inside it are resized.  Also resize frames above and below if the
5606  * are in the same FR_ROW frame.
5607  *
5608  * Strategy is similar to frame_setheight().
5609  */
5610     static void
5611 frame_setwidth(frame_T *curfrp, int width)
5612 {
5613     int		room;		// total number of lines available
5614     int		take;		// number of lines taken from other windows
5615     int		run;
5616     frame_T	*frp;
5617     int		w;
5618     int		room_reserved;
5619 
5620     // If the width already is the desired value, nothing to do.
5621     if (curfrp->fr_width == width)
5622 	return;
5623 
5624     if (curfrp->fr_parent == NULL)
5625 	// topframe: can't change width
5626 	return;
5627 
5628     if (curfrp->fr_parent->fr_layout == FR_COL)
5629     {
5630 	// Column of frames: Also need to resize frames above and below of
5631 	// this one.  First check for the minimal width of these.
5632 	w = frame_minwidth(curfrp->fr_parent, NULL);
5633 	if (width < w)
5634 	    width = w;
5635 	frame_setwidth(curfrp->fr_parent, width);
5636     }
5637     else
5638     {
5639 	/*
5640 	 * Row of frames: try to change only frames in this row.
5641 	 *
5642 	 * Do this twice:
5643 	 * 1: compute room available, if it's not enough try resizing the
5644 	 *    containing frame.
5645 	 * 2: compute the room available and adjust the width to it.
5646 	 */
5647 	for (run = 1; run <= 2; ++run)
5648 	{
5649 	    room = 0;
5650 	    room_reserved = 0;
5651 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5652 	    {
5653 		if (frp != curfrp
5654 			&& frp->fr_win != NULL
5655 			&& frp->fr_win->w_p_wfw)
5656 		    room_reserved += frp->fr_width;
5657 		room += frp->fr_width;
5658 		if (frp != curfrp)
5659 		    room -= frame_minwidth(frp, NULL);
5660 	    }
5661 
5662 	    if (width <= room)
5663 		break;
5664 	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
5665 	    {
5666 		if (width > room)
5667 		    width = room;
5668 		break;
5669 	    }
5670 	    frame_setwidth(curfrp->fr_parent, width
5671 		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
5672 	}
5673 
5674 	/*
5675 	 * Compute the number of lines we will take from others frames (can be
5676 	 * negative!).
5677 	 */
5678 	take = width - curfrp->fr_width;
5679 
5680 	// If there is not enough room, also reduce the width of a window
5681 	// with 'winfixwidth' set.
5682 	if (width > room - room_reserved)
5683 	    room_reserved = room - width;
5684 	// If there is only a 'winfixwidth' window and making the
5685 	// window smaller, need to make the other window narrower.
5686 	if (take < 0 && room - curfrp->fr_width < room_reserved)
5687 	    room_reserved = 0;
5688 
5689 	/*
5690 	 * set the current frame to the new width
5691 	 */
5692 	frame_new_width(curfrp, width, FALSE, FALSE);
5693 
5694 	/*
5695 	 * First take lines from the frames right of the current frame.  If
5696 	 * that is not enough, takes lines from frames left of the current
5697 	 * frame.
5698 	 */
5699 	for (run = 0; run < 2; ++run)
5700 	{
5701 	    if (run == 0)
5702 		frp = curfrp->fr_next;	// 1st run: start with next window
5703 	    else
5704 		frp = curfrp->fr_prev;	// 2nd run: start with prev window
5705 	    while (frp != NULL && take != 0)
5706 	    {
5707 		w = frame_minwidth(frp, NULL);
5708 		if (room_reserved > 0
5709 			&& frp->fr_win != NULL
5710 			&& frp->fr_win->w_p_wfw)
5711 		{
5712 		    if (room_reserved >= frp->fr_width)
5713 			room_reserved -= frp->fr_width;
5714 		    else
5715 		    {
5716 			if (frp->fr_width - room_reserved > take)
5717 			    room_reserved = frp->fr_width - take;
5718 			take -= frp->fr_width - room_reserved;
5719 			frame_new_width(frp, room_reserved, FALSE, FALSE);
5720 			room_reserved = 0;
5721 		    }
5722 		}
5723 		else
5724 		{
5725 		    if (frp->fr_width - take < w)
5726 		    {
5727 			take -= frp->fr_width - w;
5728 			frame_new_width(frp, w, FALSE, FALSE);
5729 		    }
5730 		    else
5731 		    {
5732 			frame_new_width(frp, frp->fr_width - take,
5733 								FALSE, FALSE);
5734 			take = 0;
5735 		    }
5736 		}
5737 		if (run == 0)
5738 		    frp = frp->fr_next;
5739 		else
5740 		    frp = frp->fr_prev;
5741 	    }
5742 	}
5743     }
5744 }
5745 
5746 /*
5747  * Check 'winminheight' for a valid value and reduce it if needed.
5748  */
5749     void
5750 win_setminheight(void)
5751 {
5752     int		room;
5753     int		needed;
5754     int		first = TRUE;
5755 
5756     // loop until there is a 'winminheight' that is possible
5757     while (p_wmh > 0)
5758     {
5759 	room = Rows - p_ch;
5760 	needed = frame_minheight(topframe, NULL);
5761 	if (room >= needed)
5762 	    break;
5763 	--p_wmh;
5764 	if (first)
5765 	{
5766 	    emsg(_(e_noroom));
5767 	    first = FALSE;
5768 	}
5769     }
5770 }
5771 
5772 /*
5773  * Check 'winminwidth' for a valid value and reduce it if needed.
5774  */
5775     void
5776 win_setminwidth(void)
5777 {
5778     int		room;
5779     int		needed;
5780     int		first = TRUE;
5781 
5782     // loop until there is a 'winminheight' that is possible
5783     while (p_wmw > 0)
5784     {
5785 	room = Columns;
5786 	needed = frame_minwidth(topframe, NULL);
5787 	if (room >= needed)
5788 	    break;
5789 	--p_wmw;
5790 	if (first)
5791 	{
5792 	    emsg(_(e_noroom));
5793 	    first = FALSE;
5794 	}
5795     }
5796 }
5797 
5798 /*
5799  * Status line of dragwin is dragged "offset" lines down (negative is up).
5800  */
5801     void
5802 win_drag_status_line(win_T *dragwin, int offset)
5803 {
5804     frame_T	*curfr;
5805     frame_T	*fr;
5806     int		room;
5807     int		row;
5808     int		up;	// if TRUE, drag status line up, otherwise down
5809     int		n;
5810 
5811     fr = dragwin->w_frame;
5812     curfr = fr;
5813     if (fr != topframe)		// more than one window
5814     {
5815 	fr = fr->fr_parent;
5816 	// When the parent frame is not a column of frames, its parent should
5817 	// be.
5818 	if (fr->fr_layout != FR_COL)
5819 	{
5820 	    curfr = fr;
5821 	    if (fr != topframe)	// only a row of windows, may drag statusline
5822 		fr = fr->fr_parent;
5823 	}
5824     }
5825 
5826     // If this is the last frame in a column, may want to resize the parent
5827     // frame instead (go two up to skip a row of frames).
5828     while (curfr != topframe && curfr->fr_next == NULL)
5829     {
5830 	if (fr != topframe)
5831 	    fr = fr->fr_parent;
5832 	curfr = fr;
5833 	if (fr != topframe)
5834 	    fr = fr->fr_parent;
5835     }
5836 
5837     if (offset < 0) // drag up
5838     {
5839 	up = TRUE;
5840 	offset = -offset;
5841 	// sum up the room of the current frame and above it
5842 	if (fr == curfr)
5843 	{
5844 	    // only one window
5845 	    room = fr->fr_height - frame_minheight(fr, NULL);
5846 	}
5847 	else
5848 	{
5849 	    room = 0;
5850 	    for (fr = fr->fr_child; ; fr = fr->fr_next)
5851 	    {
5852 		room += fr->fr_height - frame_minheight(fr, NULL);
5853 		if (fr == curfr)
5854 		    break;
5855 	    }
5856 	}
5857 	fr = curfr->fr_next;		// put fr at frame that grows
5858     }
5859     else    // drag down
5860     {
5861 	up = FALSE;
5862 	/*
5863 	 * Only dragging the last status line can reduce p_ch.
5864 	 */
5865 	room = Rows - cmdline_row;
5866 	if (curfr->fr_next == NULL)
5867 	    room -= 1;
5868 	else
5869 	    room -= p_ch;
5870 	if (room < 0)
5871 	    room = 0;
5872 	// sum up the room of frames below of the current one
5873 	FOR_ALL_FRAMES(fr, curfr->fr_next)
5874 	    room += fr->fr_height - frame_minheight(fr, NULL);
5875 	fr = curfr;			// put fr at window that grows
5876     }
5877 
5878     if (room < offset)		// Not enough room
5879 	offset = room;		// Move as far as we can
5880     if (offset <= 0)
5881 	return;
5882 
5883     /*
5884      * Grow frame fr by "offset" lines.
5885      * Doesn't happen when dragging the last status line up.
5886      */
5887     if (fr != NULL)
5888 	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
5889 
5890     if (up)
5891 	fr = curfr;		// current frame gets smaller
5892     else
5893 	fr = curfr->fr_next;	// next frame gets smaller
5894 
5895     /*
5896      * Now make the other frames smaller.
5897      */
5898     while (fr != NULL && offset > 0)
5899     {
5900 	n = frame_minheight(fr, NULL);
5901 	if (fr->fr_height - offset <= n)
5902 	{
5903 	    offset -= fr->fr_height - n;
5904 	    frame_new_height(fr, n, !up, FALSE);
5905 	}
5906 	else
5907 	{
5908 	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
5909 	    break;
5910 	}
5911 	if (up)
5912 	    fr = fr->fr_prev;
5913 	else
5914 	    fr = fr->fr_next;
5915     }
5916     row = win_comp_pos();
5917     screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5918     cmdline_row = row;
5919     p_ch = Rows - cmdline_row;
5920     if (p_ch < 1)
5921 	p_ch = 1;
5922     curtab->tp_ch_used = p_ch;
5923     redraw_all_later(SOME_VALID);
5924     showmode();
5925 }
5926 
5927 /*
5928  * Separator line of dragwin is dragged "offset" lines right (negative is left).
5929  */
5930     void
5931 win_drag_vsep_line(win_T *dragwin, int offset)
5932 {
5933     frame_T	*curfr;
5934     frame_T	*fr;
5935     int		room;
5936     int		left;	// if TRUE, drag separator line left, otherwise right
5937     int		n;
5938 
5939     fr = dragwin->w_frame;
5940     if (fr == topframe)		// only one window (cannot happen?)
5941 	return;
5942     curfr = fr;
5943     fr = fr->fr_parent;
5944     // When the parent frame is not a row of frames, its parent should be.
5945     if (fr->fr_layout != FR_ROW)
5946     {
5947 	if (fr == topframe)	// only a column of windows (cannot happen?)
5948 	    return;
5949 	curfr = fr;
5950 	fr = fr->fr_parent;
5951     }
5952 
5953     // If this is the last frame in a row, may want to resize a parent
5954     // frame instead.
5955     while (curfr->fr_next == NULL)
5956     {
5957 	if (fr == topframe)
5958 	    break;
5959 	curfr = fr;
5960 	fr = fr->fr_parent;
5961 	if (fr != topframe)
5962 	{
5963 	    curfr = fr;
5964 	    fr = fr->fr_parent;
5965 	}
5966     }
5967 
5968     if (offset < 0) // drag left
5969     {
5970 	left = TRUE;
5971 	offset = -offset;
5972 	// sum up the room of the current frame and left of it
5973 	room = 0;
5974 	for (fr = fr->fr_child; ; fr = fr->fr_next)
5975 	{
5976 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5977 	    if (fr == curfr)
5978 		break;
5979 	}
5980 	fr = curfr->fr_next;		// put fr at frame that grows
5981     }
5982     else    // drag right
5983     {
5984 	left = FALSE;
5985 	// sum up the room of frames right of the current one
5986 	room = 0;
5987 	FOR_ALL_FRAMES(fr, curfr->fr_next)
5988 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5989 	fr = curfr;			// put fr at window that grows
5990     }
5991 
5992     if (room < offset)		// Not enough room
5993 	offset = room;		// Move as far as we can
5994     if (offset <= 0)		// No room at all, quit.
5995 	return;
5996     if (fr == NULL)
5997 	return;			// Safety check, should not happen.
5998 
5999     // grow frame fr by offset lines
6000     frame_new_width(fr, fr->fr_width + offset, left, FALSE);
6001 
6002     // shrink other frames: current and at the left or at the right
6003     if (left)
6004 	fr = curfr;		// current frame gets smaller
6005     else
6006 	fr = curfr->fr_next;	// next frame gets smaller
6007 
6008     while (fr != NULL && offset > 0)
6009     {
6010 	n = frame_minwidth(fr, NULL);
6011 	if (fr->fr_width - offset <= n)
6012 	{
6013 	    offset -= fr->fr_width - n;
6014 	    frame_new_width(fr, n, !left, FALSE);
6015 	}
6016 	else
6017 	{
6018 	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
6019 	    break;
6020 	}
6021 	if (left)
6022 	    fr = fr->fr_prev;
6023 	else
6024 	    fr = fr->fr_next;
6025     }
6026     (void)win_comp_pos();
6027     redraw_all_later(NOT_VALID);
6028 }
6029 
6030 #define FRACTION_MULT	16384L
6031 
6032 /*
6033  * Set wp->w_fraction for the current w_wrow and w_height.
6034  * Has no effect when the window is less than two lines.
6035  */
6036     void
6037 set_fraction(win_T *wp)
6038 {
6039     if (wp->w_height > 1)
6040 	// When cursor is in the first line the percentage is computed as if
6041 	// it's halfway that line.  Thus with two lines it is 25%, with three
6042 	// lines 17%, etc.  Similarly for the last line: 75%, 83%, etc.
6043 	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
6044 				     + FRACTION_MULT / 2) / (long)wp->w_height;
6045 }
6046 
6047 /*
6048  * Set the height of a window.
6049  * "height" excludes any window toolbar.
6050  * This takes care of the things inside the window, not what happens to the
6051  * window position, the frame or to other windows.
6052  */
6053     void
6054 win_new_height(win_T *wp, int height)
6055 {
6056     int		prev_height = wp->w_height;
6057 
6058     // Don't want a negative height.  Happens when splitting a tiny window.
6059     // Will equalize heights soon to fix it.
6060     if (height < 0)
6061 	height = 0;
6062     if (wp->w_height == height)
6063 	return;	    // nothing to do
6064 
6065     if (wp->w_height > 0)
6066     {
6067 	if (wp == curwin)
6068 	    // w_wrow needs to be valid. When setting 'laststatus' this may
6069 	    // call win_new_height() recursively.
6070 	    validate_cursor();
6071 	if (wp->w_height != prev_height)
6072 	    return;  // Recursive call already changed the size, bail out here
6073 		     //	to avoid the following to mess things up.
6074 	if (wp->w_wrow != wp->w_prev_fraction_row)
6075 	    set_fraction(wp);
6076     }
6077 
6078     wp->w_height = height;
6079     wp->w_skipcol = 0;
6080 
6081     // There is no point in adjusting the scroll position when exiting.  Some
6082     // values might be invalid.
6083     if (!exiting)
6084 	scroll_to_fraction(wp, prev_height);
6085 }
6086 
6087     void
6088 scroll_to_fraction(win_T *wp, int prev_height)
6089 {
6090     linenr_T	lnum;
6091     int		sline, line_size;
6092     int		height = wp->w_height;
6093 
6094     // Don't change w_topline in any of these cases:
6095     // - window height is 0
6096     // - 'scrollbind' is set and this isn't the current window
6097     // - window height is sufficient to display the whole buffer and first line
6098     //   is visible.
6099     if (height > 0
6100         && (!wp->w_p_scb || wp == curwin)
6101         && (height < wp->w_buffer->b_ml.ml_line_count || wp->w_topline > 1))
6102     {
6103 	/*
6104 	 * Find a value for w_topline that shows the cursor at the same
6105 	 * relative position in the window as before (more or less).
6106 	 */
6107 	lnum = wp->w_cursor.lnum;
6108 	if (lnum < 1)		// can happen when starting up
6109 	    lnum = 1;
6110 	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L)
6111 							       / FRACTION_MULT;
6112 	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
6113 	sline = wp->w_wrow - line_size;
6114 
6115 	if (sline >= 0)
6116 	{
6117 	    // Make sure the whole cursor line is visible, if possible.
6118 	    int rows = plines_win(wp, lnum, FALSE);
6119 
6120 	    if (sline > wp->w_height - rows)
6121 	    {
6122 		sline = wp->w_height - rows;
6123 		wp->w_wrow -= rows - line_size;
6124 	    }
6125 	}
6126 
6127 	if (sline < 0)
6128 	{
6129 	    /*
6130 	     * Cursor line would go off top of screen if w_wrow was this high.
6131 	     * Make cursor line the first line in the window.  If not enough
6132 	     * room use w_skipcol;
6133 	     */
6134 	    wp->w_wrow = line_size;
6135 	    if (wp->w_wrow >= wp->w_height
6136 				       && (wp->w_width - win_col_off(wp)) > 0)
6137 	    {
6138 		wp->w_skipcol += wp->w_width - win_col_off(wp);
6139 		--wp->w_wrow;
6140 		while (wp->w_wrow >= wp->w_height)
6141 		{
6142 		    wp->w_skipcol += wp->w_width - win_col_off(wp)
6143 							   + win_col_off2(wp);
6144 		    --wp->w_wrow;
6145 		}
6146 	    }
6147 	}
6148 	else if (sline > 0)
6149 	{
6150 	    while (sline > 0 && lnum > 1)
6151 	    {
6152 #ifdef FEAT_FOLDING
6153 		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
6154 		if (lnum == 1)
6155 		{
6156 		    // first line in buffer is folded
6157 		    line_size = 1;
6158 		    --sline;
6159 		    break;
6160 		}
6161 #endif
6162 		--lnum;
6163 #ifdef FEAT_DIFF
6164 		if (lnum == wp->w_topline)
6165 		    line_size = plines_win_nofill(wp, lnum, TRUE)
6166 							      + wp->w_topfill;
6167 		else
6168 #endif
6169 		    line_size = plines_win(wp, lnum, TRUE);
6170 		sline -= line_size;
6171 	    }
6172 
6173 	    if (sline < 0)
6174 	    {
6175 		/*
6176 		 * Line we want at top would go off top of screen.  Use next
6177 		 * line instead.
6178 		 */
6179 #ifdef FEAT_FOLDING
6180 		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
6181 #endif
6182 		lnum++;
6183 		wp->w_wrow -= line_size + sline;
6184 	    }
6185 	    else if (sline > 0)
6186 	    {
6187 		// First line of file reached, use that as topline.
6188 		lnum = 1;
6189 		wp->w_wrow -= sline;
6190 	    }
6191 	}
6192 	set_topline(wp, lnum);
6193     }
6194 
6195     if (wp == curwin)
6196     {
6197 	if (get_scrolloff_value())
6198 	    update_topline();
6199 	curs_columns(FALSE);	// validate w_wrow
6200     }
6201     if (prev_height > 0)
6202 	wp->w_prev_fraction_row = wp->w_wrow;
6203 
6204     win_comp_scroll(wp);
6205     redraw_win_later(wp, SOME_VALID);
6206     wp->w_redr_status = TRUE;
6207     invalidate_botline_win(wp);
6208 }
6209 
6210 /*
6211  * Set the width of a window.
6212  */
6213     void
6214 win_new_width(win_T *wp, int width)
6215 {
6216     wp->w_width = width;
6217     wp->w_lines_valid = 0;
6218     changed_line_abv_curs_win(wp);
6219     invalidate_botline_win(wp);
6220     if (wp == curwin)
6221     {
6222 	update_topline();
6223 	curs_columns(TRUE);	// validate w_wrow
6224     }
6225     redraw_win_later(wp, NOT_VALID);
6226     wp->w_redr_status = TRUE;
6227 }
6228 
6229     void
6230 win_comp_scroll(win_T *wp)
6231 {
6232     wp->w_p_scr = ((unsigned)wp->w_height >> 1);
6233     if (wp->w_p_scr == 0)
6234 	wp->w_p_scr = 1;
6235 }
6236 
6237 /*
6238  * command_height: called whenever p_ch has been changed
6239  */
6240     void
6241 command_height(void)
6242 {
6243     int		h;
6244     frame_T	*frp;
6245     int		old_p_ch = curtab->tp_ch_used;
6246 
6247     // Use the value of p_ch that we remembered.  This is needed for when the
6248     // GUI starts up, we can't be sure in what order things happen.  And when
6249     // p_ch was changed in another tab page.
6250     curtab->tp_ch_used = p_ch;
6251 
6252     // Find bottom frame with width of screen.
6253     frp = lastwin->w_frame;
6254     while (frp->fr_width != Columns && frp->fr_parent != NULL)
6255 	frp = frp->fr_parent;
6256 
6257     // Avoid changing the height of a window with 'winfixheight' set.
6258     while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
6259 						      && frp->fr_win->w_p_wfh)
6260 	frp = frp->fr_prev;
6261 
6262     if (starting != NO_SCREEN)
6263     {
6264 	cmdline_row = Rows - p_ch;
6265 
6266 	if (p_ch > old_p_ch)		    // p_ch got bigger
6267 	{
6268 	    while (p_ch > old_p_ch)
6269 	    {
6270 		if (frp == NULL)
6271 		{
6272 		    emsg(_(e_noroom));
6273 		    p_ch = old_p_ch;
6274 		    curtab->tp_ch_used = p_ch;
6275 		    cmdline_row = Rows - p_ch;
6276 		    break;
6277 		}
6278 		h = frp->fr_height - frame_minheight(frp, NULL);
6279 		if (h > p_ch - old_p_ch)
6280 		    h = p_ch - old_p_ch;
6281 		old_p_ch += h;
6282 		frame_add_height(frp, -h);
6283 		frp = frp->fr_prev;
6284 	    }
6285 
6286 	    // Recompute window positions.
6287 	    (void)win_comp_pos();
6288 
6289 	    // clear the lines added to cmdline
6290 	    if (full_screen)
6291 		screen_fill((int)(cmdline_row), (int)Rows, 0,
6292 						   (int)Columns, ' ', ' ', 0);
6293 	    msg_row = cmdline_row;
6294 	    redraw_cmdline = TRUE;
6295 	    return;
6296 	}
6297 
6298 	if (msg_row < cmdline_row)
6299 	    msg_row = cmdline_row;
6300 	redraw_cmdline = TRUE;
6301     }
6302     frame_add_height(frp, (int)(old_p_ch - p_ch));
6303 
6304     // Recompute window positions.
6305     if (frp != lastwin->w_frame)
6306 	(void)win_comp_pos();
6307 }
6308 
6309 /*
6310  * Resize frame "frp" to be "n" lines higher (negative for less high).
6311  * Also resize the frames it is contained in.
6312  */
6313     static void
6314 frame_add_height(frame_T *frp, int n)
6315 {
6316     frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
6317     for (;;)
6318     {
6319 	frp = frp->fr_parent;
6320 	if (frp == NULL)
6321 	    break;
6322 	frp->fr_height += n;
6323     }
6324 }
6325 
6326 /*
6327  * Add or remove a status line for the bottom window(s), according to the
6328  * value of 'laststatus'.
6329  */
6330     void
6331 last_status(
6332     int		morewin)	// pretend there are two or more windows
6333 {
6334     // Don't make a difference between horizontal or vertical split.
6335     last_status_rec(topframe, (p_ls == 2
6336 			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
6337 }
6338 
6339     static void
6340 last_status_rec(frame_T *fr, int statusline)
6341 {
6342     frame_T	*fp;
6343     win_T	*wp;
6344 
6345     if (fr->fr_layout == FR_LEAF)
6346     {
6347 	wp = fr->fr_win;
6348 	if (wp->w_status_height != 0 && !statusline)
6349 	{
6350 	    // remove status line
6351 	    win_new_height(wp, wp->w_height + 1);
6352 	    wp->w_status_height = 0;
6353 	    comp_col();
6354 	}
6355 	else if (wp->w_status_height == 0 && statusline)
6356 	{
6357 	    // Find a frame to take a line from.
6358 	    fp = fr;
6359 	    while (fp->fr_height <= frame_minheight(fp, NULL))
6360 	    {
6361 		if (fp == topframe)
6362 		{
6363 		    emsg(_(e_noroom));
6364 		    return;
6365 		}
6366 		// In a column of frames: go to frame above.  If already at
6367 		// the top or in a row of frames: go to parent.
6368 		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
6369 		    fp = fp->fr_prev;
6370 		else
6371 		    fp = fp->fr_parent;
6372 	    }
6373 	    wp->w_status_height = 1;
6374 	    if (fp != fr)
6375 	    {
6376 		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
6377 		frame_fix_height(wp);
6378 		(void)win_comp_pos();
6379 	    }
6380 	    else
6381 		win_new_height(wp, wp->w_height - 1);
6382 	    comp_col();
6383 	    redraw_all_later(SOME_VALID);
6384 	}
6385     }
6386     else if (fr->fr_layout == FR_ROW)
6387     {
6388 	// vertically split windows, set status line for each one
6389 	FOR_ALL_FRAMES(fp, fr->fr_child)
6390 	    last_status_rec(fp, statusline);
6391     }
6392     else
6393     {
6394 	// horizontally split window, set status line for last one
6395 	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
6396 	    ;
6397 	last_status_rec(fp, statusline);
6398     }
6399 }
6400 
6401 /*
6402  * Return the number of lines used by the tab page line.
6403  */
6404     int
6405 tabline_height(void)
6406 {
6407 #ifdef FEAT_GUI_TABLINE
6408     // When the GUI has the tabline then this always returns zero.
6409     if (gui_use_tabline())
6410 	return 0;
6411 #endif
6412     switch (p_stal)
6413     {
6414 	case 0: return 0;
6415 	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
6416     }
6417     return 1;
6418 }
6419 
6420 /*
6421  * Return the minimal number of rows that is needed on the screen to display
6422  * the current number of windows.
6423  */
6424     int
6425 min_rows(void)
6426 {
6427     int		total;
6428     tabpage_T	*tp;
6429     int		n;
6430 
6431     if (firstwin == NULL)	// not initialized yet
6432 	return MIN_LINES;
6433 
6434     total = 0;
6435     FOR_ALL_TABPAGES(tp)
6436     {
6437 	n = frame_minheight(tp->tp_topframe, NULL);
6438 	if (total < n)
6439 	    total = n;
6440     }
6441     total += tabline_height();
6442     total += 1;		// count the room for the command line
6443     return total;
6444 }
6445 
6446 /*
6447  * Return TRUE if there is only one window and only one tab page, not
6448  * counting a help or preview window, unless it is the current window.
6449  * Does not count unlisted windows.
6450  */
6451     int
6452 only_one_window(void)
6453 {
6454     int		count = 0;
6455     win_T	*wp;
6456 
6457 #if defined(FEAT_PROP_POPUP)
6458     // If the current window is a popup then there always is another window.
6459     if (popup_is_popup(curwin))
6460 	return FALSE;
6461 #endif
6462 
6463     // If there is another tab page there always is another window.
6464     if (first_tabpage->tp_next != NULL)
6465 	return FALSE;
6466 
6467     FOR_ALL_WINDOWS(wp)
6468 	if (wp->w_buffer != NULL
6469 		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
6470 # ifdef FEAT_QUICKFIX
6471 		    || wp->w_p_pvw
6472 # endif
6473 	     ) || wp == curwin) && wp != aucmd_win)
6474 	    ++count;
6475     return (count <= 1);
6476 }
6477 
6478 /*
6479  * Correct the cursor line number in other windows.  Used after changing the
6480  * current buffer, and before applying autocommands.
6481  * When "do_curwin" is TRUE, also check current window.
6482  */
6483     void
6484 check_lnums(int do_curwin)
6485 {
6486     win_T	*wp;
6487     tabpage_T	*tp;
6488 
6489     FOR_ALL_TAB_WINDOWS(tp, wp)
6490 	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
6491 	{
6492 	    // save the original cursor position and topline
6493 	    wp->w_save_cursor.w_cursor_save = wp->w_cursor;
6494 	    wp->w_save_cursor.w_topline_save = wp->w_topline;
6495 
6496 	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
6497 		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
6498 	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
6499 		wp->w_topline = curbuf->b_ml.ml_line_count;
6500 
6501 	    // save the corrected cursor position and topline
6502 	    wp->w_save_cursor.w_cursor_corr = wp->w_cursor;
6503 	    wp->w_save_cursor.w_topline_corr = wp->w_topline;
6504 	}
6505 }
6506 
6507 /*
6508  * Reset cursor and topline to its stored values from check_lnums().
6509  * check_lnums() must have been called first!
6510  */
6511     void
6512 reset_lnums()
6513 {
6514     win_T	*wp;
6515     tabpage_T	*tp;
6516 
6517     FOR_ALL_TAB_WINDOWS(tp, wp)
6518 	if (wp->w_buffer == curbuf)
6519 	{
6520 	    // Restore the value if the autocommand didn't change it.
6521 	    if (EQUAL_POS(wp->w_save_cursor.w_cursor_corr, wp->w_cursor))
6522 		wp->w_cursor = wp->w_save_cursor.w_cursor_save;
6523 	    if (wp->w_save_cursor.w_topline_corr == wp->w_topline)
6524 		wp->w_topline = wp->w_save_cursor.w_topline_save;
6525 	}
6526 }
6527 
6528 /*
6529  * A snapshot of the window sizes, to restore them after closing the help
6530  * window.
6531  * Only these fields are used:
6532  * fr_layout
6533  * fr_width
6534  * fr_height
6535  * fr_next
6536  * fr_child
6537  * fr_win (only valid for the old curwin, NULL otherwise)
6538  */
6539 
6540 /*
6541  * Create a snapshot of the current frame sizes.
6542  */
6543     void
6544 make_snapshot(int idx)
6545 {
6546     clear_snapshot(curtab, idx);
6547     make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
6548 }
6549 
6550     static void
6551 make_snapshot_rec(frame_T *fr, frame_T **frp)
6552 {
6553     *frp = ALLOC_CLEAR_ONE(frame_T);
6554     if (*frp == NULL)
6555 	return;
6556     (*frp)->fr_layout = fr->fr_layout;
6557     (*frp)->fr_width = fr->fr_width;
6558     (*frp)->fr_height = fr->fr_height;
6559     if (fr->fr_next != NULL)
6560 	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
6561     if (fr->fr_child != NULL)
6562 	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
6563     if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
6564 	(*frp)->fr_win = curwin;
6565 }
6566 
6567 /*
6568  * Remove any existing snapshot.
6569  */
6570     static void
6571 clear_snapshot(tabpage_T *tp, int idx)
6572 {
6573     clear_snapshot_rec(tp->tp_snapshot[idx]);
6574     tp->tp_snapshot[idx] = NULL;
6575 }
6576 
6577     static void
6578 clear_snapshot_rec(frame_T *fr)
6579 {
6580     if (fr != NULL)
6581     {
6582 	clear_snapshot_rec(fr->fr_next);
6583 	clear_snapshot_rec(fr->fr_child);
6584 	vim_free(fr);
6585     }
6586 }
6587 
6588 /*
6589  * Restore a previously created snapshot, if there is any.
6590  * This is only done if the screen size didn't change and the window layout is
6591  * still the same.
6592  */
6593     void
6594 restore_snapshot(
6595     int		idx,
6596     int		close_curwin)	    // closing current window
6597 {
6598     win_T	*wp;
6599 
6600     if (curtab->tp_snapshot[idx] != NULL
6601 	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
6602 	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
6603 	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
6604     {
6605 	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
6606 	win_comp_pos();
6607 	if (wp != NULL && close_curwin)
6608 	    win_goto(wp);
6609 	redraw_all_later(NOT_VALID);
6610     }
6611     clear_snapshot(curtab, idx);
6612 }
6613 
6614 /*
6615  * Check if frames "sn" and "fr" have the same layout, same following frames
6616  * and same children.  And the window pointer is valid.
6617  */
6618     static int
6619 check_snapshot_rec(frame_T *sn, frame_T *fr)
6620 {
6621     if (sn->fr_layout != fr->fr_layout
6622 	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
6623 	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
6624 	    || (sn->fr_next != NULL
6625 		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
6626 	    || (sn->fr_child != NULL
6627 		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
6628 	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
6629 	return FAIL;
6630     return OK;
6631 }
6632 
6633 /*
6634  * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
6635  * following frames and children.
6636  * Returns a pointer to the old current window, or NULL.
6637  */
6638     static win_T *
6639 restore_snapshot_rec(frame_T *sn, frame_T *fr)
6640 {
6641     win_T	*wp = NULL;
6642     win_T	*wp2;
6643 
6644     fr->fr_height = sn->fr_height;
6645     fr->fr_width = sn->fr_width;
6646     if (fr->fr_layout == FR_LEAF)
6647     {
6648 	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
6649 	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
6650 	wp = sn->fr_win;
6651     }
6652     if (sn->fr_next != NULL)
6653     {
6654 	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
6655 	if (wp2 != NULL)
6656 	    wp = wp2;
6657     }
6658     if (sn->fr_child != NULL)
6659     {
6660 	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
6661 	if (wp2 != NULL)
6662 	    wp = wp2;
6663     }
6664     return wp;
6665 }
6666 
6667 #if defined(FEAT_GUI) || defined(PROTO)
6668 /*
6669  * Return TRUE if there is any vertically split window.
6670  */
6671     int
6672 win_hasvertsplit(void)
6673 {
6674     frame_T	*fr;
6675 
6676     if (topframe->fr_layout == FR_ROW)
6677 	return TRUE;
6678 
6679     if (topframe->fr_layout == FR_COL)
6680 	FOR_ALL_FRAMES(fr, topframe->fr_child)
6681 	    if (fr->fr_layout == FR_ROW)
6682 		return TRUE;
6683 
6684     return FALSE;
6685 }
6686 #endif
6687 
6688 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
6689     int
6690 get_win_number(win_T *wp, win_T *first_win)
6691 {
6692     int		i = 1;
6693     win_T	*w;
6694 
6695     for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
6696 	++i;
6697 
6698     if (w == NULL)
6699 	return 0;
6700     else
6701 	return i;
6702 }
6703 
6704     int
6705 get_tab_number(tabpage_T *tp UNUSED)
6706 {
6707     int		i = 1;
6708     tabpage_T	*t;
6709 
6710     for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
6711 	++i;
6712 
6713     if (t == NULL)
6714 	return 0;
6715     else
6716 	return i;
6717 }
6718 #endif
6719 
6720 /*
6721  * Return TRUE if "topfrp" and its children are at the right height.
6722  */
6723     static int
6724 frame_check_height(frame_T *topfrp, int height)
6725 {
6726     frame_T *frp;
6727 
6728     if (topfrp->fr_height != height)
6729 	return FALSE;
6730 
6731     if (topfrp->fr_layout == FR_ROW)
6732 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6733 	    if (frp->fr_height != height)
6734 		return FALSE;
6735 
6736     return TRUE;
6737 }
6738 
6739 /*
6740  * Return TRUE if "topfrp" and its children are at the right width.
6741  */
6742     static int
6743 frame_check_width(frame_T *topfrp, int width)
6744 {
6745     frame_T *frp;
6746 
6747     if (topfrp->fr_width != width)
6748 	return FALSE;
6749 
6750     if (topfrp->fr_layout == FR_COL)
6751 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6752 	    if (frp->fr_width != width)
6753 		return FALSE;
6754 
6755     return TRUE;
6756 }
6757 
6758 #if defined(FEAT_SYN_HL) || defined(PROTO)
6759 /*
6760  * Simple int comparison function for use with qsort()
6761  */
6762     static int
6763 int_cmp(const void *a, const void *b)
6764 {
6765     return *(const int *)a - *(const int *)b;
6766 }
6767 
6768 /*
6769  * Handle setting 'colorcolumn' or 'textwidth' in window "wp".
6770  * Returns error message, NULL if it's OK.
6771  */
6772     char *
6773 check_colorcolumn(win_T *wp)
6774 {
6775     char_u	*s;
6776     int		col;
6777     int		count = 0;
6778     int		color_cols[256];
6779     int		i;
6780     int		j = 0;
6781 
6782     if (wp->w_buffer == NULL)
6783 	return NULL;  // buffer was closed
6784 
6785     for (s = wp->w_p_cc; *s != NUL && count < 255;)
6786     {
6787 	if (*s == '-' || *s == '+')
6788 	{
6789 	    // -N and +N: add to 'textwidth'
6790 	    col = (*s == '-') ? -1 : 1;
6791 	    ++s;
6792 	    if (!VIM_ISDIGIT(*s))
6793 		return e_invarg;
6794 	    col = col * getdigits(&s);
6795 	    if (wp->w_buffer->b_p_tw == 0)
6796 		goto skip;  // 'textwidth' not set, skip this item
6797 	    col += wp->w_buffer->b_p_tw;
6798 	    if (col < 0)
6799 		goto skip;
6800 	}
6801 	else if (VIM_ISDIGIT(*s))
6802 	    col = getdigits(&s);
6803 	else
6804 	    return e_invarg;
6805 	color_cols[count++] = col - 1;  // 1-based to 0-based
6806 skip:
6807 	if (*s == NUL)
6808 	    break;
6809 	if (*s != ',')
6810 	    return e_invarg;
6811 	if (*++s == NUL)
6812 	    return e_invarg;  // illegal trailing comma as in "set cc=80,"
6813     }
6814 
6815     vim_free(wp->w_p_cc_cols);
6816     if (count == 0)
6817 	wp->w_p_cc_cols = NULL;
6818     else
6819     {
6820 	wp->w_p_cc_cols = ALLOC_MULT(int, count + 1);
6821 	if (wp->w_p_cc_cols != NULL)
6822 	{
6823 	    // sort the columns for faster usage on screen redraw inside
6824 	    // win_line()
6825 	    qsort(color_cols, count, sizeof(int), int_cmp);
6826 
6827 	    for (i = 0; i < count; ++i)
6828 		// skip duplicates
6829 		if (j == 0 || wp->w_p_cc_cols[j - 1] != color_cols[i])
6830 		    wp->w_p_cc_cols[j++] = color_cols[i];
6831 	    wp->w_p_cc_cols[j] = -1;  // end marker
6832 	}
6833     }
6834 
6835     return NULL;  // no error
6836 }
6837 #endif
6838