xref: /vim-8.2.3635/src/window.c (revision fa79be6b)
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 		CHECK_CMDWIN;
344 		if (one_window())
345 		    msg(_(m_onlyone));
346 		else
347 		{
348 		    tabpage_T	*oldtab = curtab;
349 		    tabpage_T	*newtab;
350 
351 		    // First create a new tab with the window, then go back to
352 		    // the old tab and close the window there.
353 		    wp = curwin;
354 		    if (win_new_tabpage((int)Prenum) == OK
355 						     && valid_tabpage(oldtab))
356 		    {
357 			newtab = curtab;
358 			goto_tabpage_tp(oldtab, TRUE, TRUE);
359 			if (curwin == wp)
360 			    win_close(curwin, FALSE);
361 			if (valid_tabpage(newtab))
362 			    goto_tabpage_tp(newtab, TRUE, TRUE);
363 		    }
364 		}
365 		break;
366 
367 // cursor to top-left window
368     case 't':
369     case Ctrl_T:
370 		win_goto(firstwin);
371 		break;
372 
373 // cursor to bottom-right window
374     case 'b':
375     case Ctrl_B:
376 		win_goto(lastwin);
377 		break;
378 
379 // cursor to last accessed (previous) window
380     case 'p':
381     case Ctrl_P:
382 		if (!win_valid(prevwin))
383 		    beep_flush();
384 		else
385 		    win_goto(prevwin);
386 		break;
387 
388 // exchange current and next window
389     case 'x':
390     case Ctrl_X:
391 		CHECK_CMDWIN;
392 		win_exchange(Prenum);
393 		break;
394 
395 // rotate windows downwards
396     case Ctrl_R:
397     case 'r':
398 		CHECK_CMDWIN;
399 		reset_VIsual_and_resel();	// stop Visual mode
400 		win_rotate(FALSE, (int)Prenum1);    // downwards
401 		break;
402 
403 // rotate windows upwards
404     case 'R':
405 		CHECK_CMDWIN;
406 		reset_VIsual_and_resel();	// stop Visual mode
407 		win_rotate(TRUE, (int)Prenum1);	    // upwards
408 		break;
409 
410 // move window to the very top/bottom/left/right
411     case 'K':
412     case 'J':
413     case 'H':
414     case 'L':
415 		CHECK_CMDWIN;
416 		win_totop((int)Prenum,
417 			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
418 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
419 		break;
420 
421 // make all windows the same height
422     case '=':
423 #ifdef FEAT_GUI
424 		need_mouse_correct = TRUE;
425 #endif
426 		win_equal(NULL, FALSE, 'b');
427 		break;
428 
429 // increase current window height
430     case '+':
431 #ifdef FEAT_GUI
432 		need_mouse_correct = TRUE;
433 #endif
434 		win_setheight(curwin->w_height + (int)Prenum1);
435 		break;
436 
437 // decrease current window height
438     case '-':
439 #ifdef FEAT_GUI
440 		need_mouse_correct = TRUE;
441 #endif
442 		win_setheight(curwin->w_height - (int)Prenum1);
443 		break;
444 
445 // set current window height
446     case Ctrl__:
447     case '_':
448 #ifdef FEAT_GUI
449 		need_mouse_correct = TRUE;
450 #endif
451 		win_setheight(Prenum ? (int)Prenum : 9999);
452 		break;
453 
454 // increase current window width
455     case '>':
456 #ifdef FEAT_GUI
457 		need_mouse_correct = TRUE;
458 #endif
459 		win_setwidth(curwin->w_width + (int)Prenum1);
460 		break;
461 
462 // decrease current window width
463     case '<':
464 #ifdef FEAT_GUI
465 		need_mouse_correct = TRUE;
466 #endif
467 		win_setwidth(curwin->w_width - (int)Prenum1);
468 		break;
469 
470 // set current window width
471     case '|':
472 #ifdef FEAT_GUI
473 		need_mouse_correct = TRUE;
474 #endif
475 		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
476 		break;
477 
478 // jump to tag and split window if tag exists (in preview window)
479 #if defined(FEAT_QUICKFIX)
480     case '}':
481 		CHECK_CMDWIN;
482 		if (Prenum)
483 		    g_do_tagpreview = Prenum;
484 		else
485 		    g_do_tagpreview = p_pvh;
486 #endif
487 		// FALLTHROUGH
488     case ']':
489     case Ctrl_RSB:
490 		CHECK_CMDWIN;
491 		// keep Visual mode, can select words to use as a tag
492 		if (Prenum)
493 		    postponed_split = Prenum;
494 		else
495 		    postponed_split = -1;
496 #ifdef FEAT_QUICKFIX
497 		if (nchar != '}')
498 		    g_do_tagpreview = 0;
499 #endif
500 
501 		// Execute the command right here, required when "wincmd ]"
502 		// was used in a function.
503 		do_nv_ident(Ctrl_RSB, NUL);
504 		break;
505 
506 #ifdef FEAT_SEARCHPATH
507 // edit file name under cursor in a new window
508     case 'f':
509     case 'F':
510     case Ctrl_F:
511 wingotofile:
512 		CHECK_CMDWIN;
513 
514 		ptr = grab_file_name(Prenum1, &lnum);
515 		if (ptr != NULL)
516 		{
517 		    tabpage_T	*oldtab = curtab;
518 		    win_T	*oldwin = curwin;
519 # ifdef FEAT_GUI
520 		    need_mouse_correct = TRUE;
521 # endif
522 		    setpcmark();
523 		    if (win_split(0, 0) == OK)
524 		    {
525 			RESET_BINDING(curwin);
526 			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
527 						   ECMD_HIDE, NULL) == FAIL)
528 			{
529 			    // Failed to open the file, close the window
530 			    // opened for it.
531 			    win_close(curwin, FALSE);
532 			    goto_tabpage_win(oldtab, oldwin);
533 			}
534 			else if (nchar == 'F' && lnum >= 0)
535 			{
536 			    curwin->w_cursor.lnum = lnum;
537 			    check_cursor_lnum();
538 			    beginline(BL_SOL | BL_FIX);
539 			}
540 		    }
541 		    vim_free(ptr);
542 		}
543 		break;
544 #endif
545 
546 #ifdef FEAT_FIND_ID
547 // Go to the first occurrence of the identifier under cursor along path in a
548 // new window -- webb
549     case 'i':			    // Go to any match
550     case Ctrl_I:
551 		type = FIND_ANY;
552 		// FALLTHROUGH
553     case 'd':			    // Go to definition, using 'define'
554     case Ctrl_D:
555 		CHECK_CMDWIN;
556 		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
557 		    break;
558 		find_pattern_in_path(ptr, 0, len, TRUE,
559 			Prenum == 0 ? TRUE : FALSE, type,
560 			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
561 		curwin->w_set_curswant = TRUE;
562 		break;
563 #endif
564 
565 // Quickfix window only: view the result under the cursor in a new split.
566 #if defined(FEAT_QUICKFIX)
567     case K_KENTER:
568     case CAR:
569 		if (bt_quickfix(curbuf))
570 		    qf_view_result(TRUE);
571 		break;
572 #endif
573 
574 // CTRL-W g  extended commands
575     case 'g':
576     case Ctrl_G:
577 		CHECK_CMDWIN;
578 #ifdef USE_ON_FLY_SCROLL
579 		dont_scroll = TRUE;		// disallow scrolling here
580 #endif
581 		++no_mapping;
582 		++allow_keys;   // no mapping for xchar, but allow key codes
583 		if (xchar == NUL)
584 		    xchar = plain_vgetc();
585 		LANGMAP_ADJUST(xchar, TRUE);
586 		--no_mapping;
587 		--allow_keys;
588 #ifdef FEAT_CMDL_INFO
589 		(void)add_to_showcmd(xchar);
590 #endif
591 		switch (xchar)
592 		{
593 #if defined(FEAT_QUICKFIX)
594 		    case '}':
595 			xchar = Ctrl_RSB;
596 			if (Prenum)
597 			    g_do_tagpreview = Prenum;
598 			else
599 			    g_do_tagpreview = p_pvh;
600 #endif
601 			// FALLTHROUGH
602 		    case ']':
603 		    case Ctrl_RSB:
604 			// keep Visual mode, can select words to use as a tag
605 			if (Prenum)
606 			    postponed_split = Prenum;
607 			else
608 			    postponed_split = -1;
609 
610 			// Execute the command right here, required when
611 			// "wincmd g}" was used in a function.
612 			do_nv_ident('g', xchar);
613 			break;
614 
615 #ifdef FEAT_SEARCHPATH
616 		    case 'f':	    // CTRL-W gf: "gf" in a new tab page
617 		    case 'F':	    // CTRL-W gF: "gF" in a new tab page
618 			cmdmod.tab = tabpage_index(curtab) + 1;
619 			nchar = xchar;
620 			goto wingotofile;
621 #endif
622 		    case 't':	    // CTRL-W gt: go to next tab page
623 			goto_tabpage((int)Prenum);
624 			break;
625 
626 		    case 'T':	    // CTRL-W gT: go to previous tab page
627 			goto_tabpage(-(int)Prenum1);
628 			break;
629 
630 		    case TAB:	    // CTRL-W g<Tab>: go to last used tab page
631 			if (goto_tabpage_lastused() == FAIL)
632 			    beep_flush();
633 			break;
634 
635 		    default:
636 			beep_flush();
637 			break;
638 		}
639 		break;
640 
641     default:	beep_flush();
642 		break;
643     }
644 }
645 
646 /*
647  * Figure out the address type for ":wincmd".
648  */
649     void
650 get_wincmd_addr_type(char_u *arg, exarg_T *eap)
651 {
652     switch (*arg)
653     {
654     case 'S':
655     case Ctrl_S:
656     case 's':
657     case Ctrl_N:
658     case 'n':
659     case 'j':
660     case Ctrl_J:
661     case 'k':
662     case Ctrl_K:
663     case 'T':
664     case Ctrl_R:
665     case 'r':
666     case 'R':
667     case 'K':
668     case 'J':
669     case '+':
670     case '-':
671     case Ctrl__:
672     case '_':
673     case '|':
674     case ']':
675     case Ctrl_RSB:
676     case 'g':
677     case Ctrl_G:
678     case Ctrl_V:
679     case 'v':
680     case 'h':
681     case Ctrl_H:
682     case 'l':
683     case Ctrl_L:
684     case 'H':
685     case 'L':
686     case '>':
687     case '<':
688 #if defined(FEAT_QUICKFIX)
689     case '}':
690 #endif
691 #ifdef FEAT_SEARCHPATH
692     case 'f':
693     case 'F':
694     case Ctrl_F:
695 #endif
696 #ifdef FEAT_FIND_ID
697     case 'i':
698     case Ctrl_I:
699     case 'd':
700     case Ctrl_D:
701 #endif
702 		// window size or any count
703 		eap->addr_type = ADDR_OTHER;
704 		break;
705 
706     case Ctrl_HAT:
707     case '^':
708 		// buffer number
709 		eap->addr_type = ADDR_BUFFERS;
710 		break;
711 
712     case Ctrl_Q:
713     case 'q':
714     case Ctrl_C:
715     case 'c':
716     case Ctrl_O:
717     case 'o':
718     case Ctrl_W:
719     case 'w':
720     case 'W':
721     case 'x':
722     case Ctrl_X:
723 		// window number
724 		eap->addr_type = ADDR_WINDOWS;
725 		break;
726 
727 #if defined(FEAT_QUICKFIX)
728     case Ctrl_Z:
729     case 'z':
730     case 'P':
731 #endif
732     case 't':
733     case Ctrl_T:
734     case 'b':
735     case Ctrl_B:
736     case 'p':
737     case Ctrl_P:
738     case '=':
739     case CAR:
740 		// no count
741 		eap->addr_type = ADDR_NONE;
742 		break;
743     }
744 }
745 
746     static void
747 cmd_with_count(
748     char	*cmd,
749     char_u	*bufp,
750     size_t	bufsize,
751     long	Prenum)
752 {
753     size_t	len = STRLEN(cmd);
754 
755     STRCPY(bufp, cmd);
756     if (Prenum > 0)
757 	vim_snprintf((char *)bufp + len, bufsize - len, "%ld", Prenum);
758 }
759 
760 /*
761  * If "split_disallowed" is set given an error and return FAIL.
762  * Otherwise return OK.
763  */
764     static int
765 check_split_disallowed()
766 {
767     if (split_disallowed > 0)
768     {
769 	emsg(_("E242: Can't split a window while closing another"));
770 	return FAIL;
771     }
772     return OK;
773 }
774 
775 /*
776  * split the current window, implements CTRL-W s and :split
777  *
778  * "size" is the height or width for the new window, 0 to use half of current
779  * height or width.
780  *
781  * "flags":
782  * WSP_ROOM: require enough room for new window
783  * WSP_VERT: vertical split.
784  * WSP_TOP:  open window at the top-left of the shell (help window).
785  * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
786  * WSP_HELP: creating the help window, keep layout snapshot
787  *
788  * return FAIL for failure, OK otherwise
789  */
790     int
791 win_split(int size, int flags)
792 {
793     if (ERROR_IF_ANY_POPUP_WINDOW)
794 	return FAIL;
795 
796     // When the ":tab" modifier was used open a new tab page instead.
797     if (may_open_tabpage() == OK)
798 	return OK;
799 
800     // Add flags from ":vertical", ":topleft" and ":botright".
801     flags |= cmdmod.split;
802     if ((flags & WSP_TOP) && (flags & WSP_BOT))
803     {
804 	emsg(_("E442: Can't split topleft and botright at the same time"));
805 	return FAIL;
806     }
807     if (check_split_disallowed() == FAIL)
808 	return FAIL;
809 
810     // When creating the help window make a snapshot of the window layout.
811     // Otherwise clear the snapshot, it's now invalid.
812     if (flags & WSP_HELP)
813 	make_snapshot(SNAP_HELP_IDX);
814     else
815 	clear_snapshot(curtab, SNAP_HELP_IDX);
816 
817     return win_split_ins(size, flags, NULL, 0);
818 }
819 
820 /*
821  * When "new_wp" is NULL: split the current window in two.
822  * When "new_wp" is not NULL: insert this window at the far
823  * top/left/right/bottom.
824  * return FAIL for failure, OK otherwise
825  */
826     int
827 win_split_ins(
828     int		size,
829     int		flags,
830     win_T	*new_wp,
831     int		dir)
832 {
833     win_T	*wp = new_wp;
834     win_T	*oldwin;
835     int		new_size = size;
836     int		i;
837     int		need_status = 0;
838     int		do_equal = FALSE;
839     int		needed;
840     int		available;
841     int		oldwin_height = 0;
842     int		layout;
843     frame_T	*frp, *curfrp, *frp2, *prevfrp;
844     int		before;
845     int		minheight;
846     int		wmh1;
847     int		did_set_fraction = FALSE;
848 
849     if (flags & WSP_TOP)
850 	oldwin = firstwin;
851     else if (flags & WSP_BOT)
852 	oldwin = lastwin;
853     else
854 	oldwin = curwin;
855 
856     // add a status line when p_ls == 1 and splitting the first window
857     if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
858     {
859 	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
860 	{
861 	    emsg(_(e_noroom));
862 	    return FAIL;
863 	}
864 	need_status = STATUS_HEIGHT;
865     }
866 
867 #ifdef FEAT_GUI
868     // May be needed for the scrollbars that are going to change.
869     if (gui.in_use)
870 	out_flush();
871 #endif
872 
873     if (flags & WSP_VERT)
874     {
875 	int	wmw1;
876 	int	minwidth;
877 
878 	layout = FR_ROW;
879 
880 	/*
881 	 * Check if we are able to split the current window and compute its
882 	 * width.
883 	 */
884 	// Current window requires at least 1 space.
885 	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
886 	needed = wmw1 + 1;
887 	if (flags & WSP_ROOM)
888 	    needed += p_wiw - wmw1;
889 	if (flags & (WSP_BOT | WSP_TOP))
890 	{
891 	    minwidth = frame_minwidth(topframe, NOWIN);
892 	    available = topframe->fr_width;
893 	    needed += minwidth;
894 	}
895 	else if (p_ea)
896 	{
897 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
898 	    prevfrp = oldwin->w_frame;
899 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
900 							frp = frp->fr_parent)
901 	    {
902 		if (frp->fr_layout == FR_ROW)
903 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
904 			if (frp2 != prevfrp)
905 			    minwidth += frame_minwidth(frp2, NOWIN);
906 		prevfrp = frp;
907 	    }
908 	    available = topframe->fr_width;
909 	    needed += minwidth;
910 	}
911 	else
912 	{
913 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
914 	    available = oldwin->w_frame->fr_width;
915 	    needed += minwidth;
916 	}
917 	if (available < needed && new_wp == NULL)
918 	{
919 	    emsg(_(e_noroom));
920 	    return FAIL;
921 	}
922 	if (new_size == 0)
923 	    new_size = oldwin->w_width / 2;
924 	if (new_size > available - minwidth - 1)
925 	    new_size = available - minwidth - 1;
926 	if (new_size < wmw1)
927 	    new_size = wmw1;
928 
929 	// if it doesn't fit in the current window, need win_equal()
930 	if (oldwin->w_width - new_size - 1 < p_wmw)
931 	    do_equal = TRUE;
932 
933 	// We don't like to take lines for the new window from a
934 	// 'winfixwidth' window.  Take them from a window to the left or right
935 	// instead, if possible. Add one for the separator.
936 	if (oldwin->w_p_wfw)
937 	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
938 
939 	// Only make all windows the same width if one of them (except oldwin)
940 	// is wider than one of the split windows.
941 	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
942 					 && oldwin->w_frame->fr_parent != NULL)
943 	{
944 	    frp = oldwin->w_frame->fr_parent->fr_child;
945 	    while (frp != NULL)
946 	    {
947 		if (frp->fr_win != oldwin && frp->fr_win != NULL
948 			&& (frp->fr_win->w_width > new_size
949 			    || frp->fr_win->w_width > oldwin->w_width
950 							      - new_size - 1))
951 		{
952 		    do_equal = TRUE;
953 		    break;
954 		}
955 		frp = frp->fr_next;
956 	    }
957 	}
958     }
959     else
960     {
961 	layout = FR_COL;
962 
963 	/*
964 	 * Check if we are able to split the current window and compute its
965 	 * height.
966 	 */
967 	// Current window requires at least 1 space.
968 	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
969 	needed = wmh1 + STATUS_HEIGHT;
970 	if (flags & WSP_ROOM)
971 	    needed += p_wh - wmh1;
972 	if (flags & (WSP_BOT | WSP_TOP))
973 	{
974 	    minheight = frame_minheight(topframe, NOWIN) + need_status;
975 	    available = topframe->fr_height;
976 	    needed += minheight;
977 	}
978 	else if (p_ea)
979 	{
980 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
981 	    prevfrp = oldwin->w_frame;
982 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
983 							frp = frp->fr_parent)
984 	    {
985 		if (frp->fr_layout == FR_COL)
986 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
987 			if (frp2 != prevfrp)
988 			    minheight += frame_minheight(frp2, NOWIN);
989 		prevfrp = frp;
990 	    }
991 	    available = topframe->fr_height;
992 	    needed += minheight;
993 	}
994 	else
995 	{
996 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
997 	    available = oldwin->w_frame->fr_height;
998 	    needed += minheight;
999 	}
1000 	if (available < needed && new_wp == NULL)
1001 	{
1002 	    emsg(_(e_noroom));
1003 	    return FAIL;
1004 	}
1005 	oldwin_height = oldwin->w_height;
1006 	if (need_status)
1007 	{
1008 	    oldwin->w_status_height = STATUS_HEIGHT;
1009 	    oldwin_height -= STATUS_HEIGHT;
1010 	}
1011 	if (new_size == 0)
1012 	    new_size = oldwin_height / 2;
1013 	if (new_size > available - minheight - STATUS_HEIGHT)
1014 	    new_size = available - minheight - STATUS_HEIGHT;
1015 	if (new_size < wmh1)
1016 	    new_size = wmh1;
1017 
1018 	// if it doesn't fit in the current window, need win_equal()
1019 	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
1020 	    do_equal = TRUE;
1021 
1022 	// We don't like to take lines for the new window from a
1023 	// 'winfixheight' window.  Take them from a window above or below
1024 	// instead, if possible.
1025 	if (oldwin->w_p_wfh)
1026 	{
1027 	    // Set w_fraction now so that the cursor keeps the same relative
1028 	    // vertical position using the old height.
1029 	    set_fraction(oldwin);
1030 	    did_set_fraction = TRUE;
1031 
1032 	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
1033 								      oldwin);
1034 	    oldwin_height = oldwin->w_height;
1035 	    if (need_status)
1036 		oldwin_height -= STATUS_HEIGHT;
1037 	}
1038 
1039 	// Only make all windows the same height if one of them (except oldwin)
1040 	// is higher than one of the split windows.
1041 	if (!do_equal && p_ea && size == 0 && *p_ead != 'h'
1042 	   && oldwin->w_frame->fr_parent != NULL)
1043 	{
1044 	    frp = oldwin->w_frame->fr_parent->fr_child;
1045 	    while (frp != NULL)
1046 	    {
1047 		if (frp->fr_win != oldwin && frp->fr_win != NULL
1048 			&& (frp->fr_win->w_height > new_size
1049 			    || frp->fr_win->w_height > oldwin_height - new_size
1050 							      - STATUS_HEIGHT))
1051 		{
1052 		    do_equal = TRUE;
1053 		    break;
1054 		}
1055 		frp = frp->fr_next;
1056 	    }
1057 	}
1058     }
1059 
1060     /*
1061      * allocate new window structure and link it in the window list
1062      */
1063     if ((flags & WSP_TOP) == 0
1064 	    && ((flags & WSP_BOT)
1065 		|| (flags & WSP_BELOW)
1066 		|| (!(flags & WSP_ABOVE)
1067 		    && ( (flags & WSP_VERT) ? p_spr : p_sb))))
1068     {
1069 	// new window below/right of current one
1070 	if (new_wp == NULL)
1071 	    wp = win_alloc(oldwin, FALSE);
1072 	else
1073 	    win_append(oldwin, wp);
1074     }
1075     else
1076     {
1077 	if (new_wp == NULL)
1078 	    wp = win_alloc(oldwin->w_prev, FALSE);
1079 	else
1080 	    win_append(oldwin->w_prev, wp);
1081     }
1082 
1083     if (new_wp == NULL)
1084     {
1085 	if (wp == NULL)
1086 	    return FAIL;
1087 
1088 	new_frame(wp);
1089 	if (wp->w_frame == NULL)
1090 	{
1091 	    win_free(wp, NULL);
1092 	    return FAIL;
1093 	}
1094 
1095 	// make the contents of the new window the same as the current one
1096 	win_init(wp, curwin, flags);
1097     }
1098 
1099     /*
1100      * Reorganise the tree of frames to insert the new window.
1101      */
1102     if (flags & (WSP_TOP | WSP_BOT))
1103     {
1104 	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
1105 	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
1106 	{
1107 	    curfrp = topframe->fr_child;
1108 	    if (flags & WSP_BOT)
1109 		while (curfrp->fr_next != NULL)
1110 		    curfrp = curfrp->fr_next;
1111 	}
1112 	else
1113 	    curfrp = topframe;
1114 	before = (flags & WSP_TOP);
1115     }
1116     else
1117     {
1118 	curfrp = oldwin->w_frame;
1119 	if (flags & WSP_BELOW)
1120 	    before = FALSE;
1121 	else if (flags & WSP_ABOVE)
1122 	    before = TRUE;
1123 	else if (flags & WSP_VERT)
1124 	    before = !p_spr;
1125 	else
1126 	    before = !p_sb;
1127     }
1128     if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
1129     {
1130 	// Need to create a new frame in the tree to make a branch.
1131 	frp = ALLOC_CLEAR_ONE(frame_T);
1132 	*frp = *curfrp;
1133 	curfrp->fr_layout = layout;
1134 	frp->fr_parent = curfrp;
1135 	frp->fr_next = NULL;
1136 	frp->fr_prev = NULL;
1137 	curfrp->fr_child = frp;
1138 	curfrp->fr_win = NULL;
1139 	curfrp = frp;
1140 	if (frp->fr_win != NULL)
1141 	    oldwin->w_frame = frp;
1142 	else
1143 	    FOR_ALL_FRAMES(frp, frp->fr_child)
1144 		frp->fr_parent = curfrp;
1145     }
1146 
1147     if (new_wp == NULL)
1148 	frp = wp->w_frame;
1149     else
1150 	frp = new_wp->w_frame;
1151     frp->fr_parent = curfrp->fr_parent;
1152 
1153     // Insert the new frame at the right place in the frame list.
1154     if (before)
1155 	frame_insert(curfrp, frp);
1156     else
1157 	frame_append(curfrp, frp);
1158 
1159     // Set w_fraction now so that the cursor keeps the same relative
1160     // vertical position.
1161     if (!did_set_fraction)
1162 	set_fraction(oldwin);
1163     wp->w_fraction = oldwin->w_fraction;
1164 
1165     if (flags & WSP_VERT)
1166     {
1167 	wp->w_p_scr = curwin->w_p_scr;
1168 
1169 	if (need_status)
1170 	{
1171 	    win_new_height(oldwin, oldwin->w_height - 1);
1172 	    oldwin->w_status_height = need_status;
1173 	}
1174 	if (flags & (WSP_TOP | WSP_BOT))
1175 	{
1176 	    // set height and row of new window to full height
1177 	    wp->w_winrow = tabline_height();
1178 	    win_new_height(wp, curfrp->fr_height - (p_ls > 0)
1179 							  - WINBAR_HEIGHT(wp));
1180 	    wp->w_status_height = (p_ls > 0);
1181 	}
1182 	else
1183 	{
1184 	    // height and row of new window is same as current window
1185 	    wp->w_winrow = oldwin->w_winrow;
1186 	    win_new_height(wp, VISIBLE_HEIGHT(oldwin));
1187 	    wp->w_status_height = oldwin->w_status_height;
1188 	}
1189 	frp->fr_height = curfrp->fr_height;
1190 
1191 	// "new_size" of the current window goes to the new window, use
1192 	// one column for the vertical separator
1193 	win_new_width(wp, new_size);
1194 	if (before)
1195 	    wp->w_vsep_width = 1;
1196 	else
1197 	{
1198 	    wp->w_vsep_width = oldwin->w_vsep_width;
1199 	    oldwin->w_vsep_width = 1;
1200 	}
1201 	if (flags & (WSP_TOP | WSP_BOT))
1202 	{
1203 	    if (flags & WSP_BOT)
1204 		frame_add_vsep(curfrp);
1205 	    // Set width of neighbor frame
1206 	    frame_new_width(curfrp, curfrp->fr_width
1207 		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
1208 								       FALSE);
1209 	}
1210 	else
1211 	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
1212 	if (before)	// new window left of current one
1213 	{
1214 	    wp->w_wincol = oldwin->w_wincol;
1215 	    oldwin->w_wincol += new_size + 1;
1216 	}
1217 	else		// new window right of current one
1218 	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
1219 	frame_fix_width(oldwin);
1220 	frame_fix_width(wp);
1221     }
1222     else
1223     {
1224 	// width and column of new window is same as current window
1225 	if (flags & (WSP_TOP | WSP_BOT))
1226 	{
1227 	    wp->w_wincol = 0;
1228 	    win_new_width(wp, Columns);
1229 	    wp->w_vsep_width = 0;
1230 	}
1231 	else
1232 	{
1233 	    wp->w_wincol = oldwin->w_wincol;
1234 	    win_new_width(wp, oldwin->w_width);
1235 	    wp->w_vsep_width = oldwin->w_vsep_width;
1236 	}
1237 	frp->fr_width = curfrp->fr_width;
1238 
1239 	// "new_size" of the current window goes to the new window, use
1240 	// one row for the status line
1241 	win_new_height(wp, new_size);
1242 	if (flags & (WSP_TOP | WSP_BOT))
1243 	{
1244 	    int new_fr_height = curfrp->fr_height - new_size
1245 							  + WINBAR_HEIGHT(wp) ;
1246 
1247 	    if (!((flags & WSP_BOT) && p_ls == 0))
1248 		new_fr_height -= STATUS_HEIGHT;
1249 	    frame_new_height(curfrp, new_fr_height, flags & WSP_TOP, FALSE);
1250 	}
1251 	else
1252 	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
1253 	if (before)	// new window above current one
1254 	{
1255 	    wp->w_winrow = oldwin->w_winrow;
1256 	    wp->w_status_height = STATUS_HEIGHT;
1257 	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
1258 	}
1259 	else		// new window below current one
1260 	{
1261 	    wp->w_winrow = oldwin->w_winrow + VISIBLE_HEIGHT(oldwin)
1262 							       + STATUS_HEIGHT;
1263 	    wp->w_status_height = oldwin->w_status_height;
1264 	    if (!(flags & WSP_BOT))
1265 		oldwin->w_status_height = STATUS_HEIGHT;
1266 	}
1267 	if (flags & WSP_BOT)
1268 	    frame_add_statusline(curfrp);
1269 	frame_fix_height(wp);
1270 	frame_fix_height(oldwin);
1271     }
1272 
1273     if (flags & (WSP_TOP | WSP_BOT))
1274 	(void)win_comp_pos();
1275 
1276      // Both windows need redrawing.  Update all status lines, in case they
1277      // show something related to the window count or position.
1278     redraw_win_later(wp, NOT_VALID);
1279     redraw_win_later(oldwin, NOT_VALID);
1280     status_redraw_all();
1281 
1282     if (need_status)
1283     {
1284 	msg_row = Rows - 1;
1285 	msg_col = sc_col;
1286 	msg_clr_eos_force();	// Old command/ruler may still be there
1287 	comp_col();
1288 	msg_row = Rows - 1;
1289 	msg_col = 0;	// put position back at start of line
1290     }
1291 
1292     /*
1293      * equalize the window sizes.
1294      */
1295     if (do_equal || dir != 0)
1296 	win_equal(wp, TRUE,
1297 		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
1298 		: dir == 'h' ? 'b' : 'v');
1299 
1300     // Don't change the window height/width to 'winheight' / 'winwidth' if a
1301     // size was given.
1302     if (flags & WSP_VERT)
1303     {
1304 	i = p_wiw;
1305 	if (size != 0)
1306 	    p_wiw = size;
1307 
1308 # ifdef FEAT_GUI
1309 	// When 'guioptions' includes 'L' or 'R' may have to add scrollbars.
1310 	if (gui.in_use)
1311 	    gui_init_which_components(NULL);
1312 # endif
1313     }
1314     else
1315     {
1316 	i = p_wh;
1317 	if (size != 0)
1318 	    p_wh = size;
1319     }
1320 
1321 #ifdef FEAT_JUMPLIST
1322     // Keep same changelist position in new window.
1323     wp->w_changelistidx = oldwin->w_changelistidx;
1324 #endif
1325 
1326     /*
1327      * make the new window the current window
1328      */
1329     win_enter_ext(wp, FALSE, FALSE, TRUE, TRUE, TRUE);
1330     if (flags & WSP_VERT)
1331 	p_wiw = i;
1332     else
1333 	p_wh = i;
1334 
1335     return OK;
1336 }
1337 
1338 
1339 /*
1340  * Initialize window "newp" from window "oldp".
1341  * Used when splitting a window and when creating a new tab page.
1342  * The windows will both edit the same buffer.
1343  * WSP_NEWLOC may be specified in flags to prevent the location list from
1344  * being copied.
1345  */
1346     static void
1347 win_init(win_T *newp, win_T *oldp, int flags UNUSED)
1348 {
1349     int		i;
1350 
1351     newp->w_buffer = oldp->w_buffer;
1352 #ifdef FEAT_SYN_HL
1353     newp->w_s = &(oldp->w_buffer->b_s);
1354 #endif
1355     oldp->w_buffer->b_nwindows++;
1356     newp->w_cursor = oldp->w_cursor;
1357     newp->w_valid = 0;
1358     newp->w_curswant = oldp->w_curswant;
1359     newp->w_set_curswant = oldp->w_set_curswant;
1360     newp->w_topline = oldp->w_topline;
1361 #ifdef FEAT_DIFF
1362     newp->w_topfill = oldp->w_topfill;
1363 #endif
1364     newp->w_leftcol = oldp->w_leftcol;
1365     newp->w_pcmark = oldp->w_pcmark;
1366     newp->w_prev_pcmark = oldp->w_prev_pcmark;
1367     newp->w_alt_fnum = oldp->w_alt_fnum;
1368     newp->w_wrow = oldp->w_wrow;
1369     newp->w_fraction = oldp->w_fraction;
1370     newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
1371 #ifdef FEAT_JUMPLIST
1372     copy_jumplist(oldp, newp);
1373 #endif
1374 #ifdef FEAT_QUICKFIX
1375     if (flags & WSP_NEWLOC)
1376     {
1377 	// Don't copy the location list.
1378 	newp->w_llist = NULL;
1379 	newp->w_llist_ref = NULL;
1380     }
1381     else
1382 	copy_loclist_stack(oldp, newp);
1383 #endif
1384     newp->w_localdir = (oldp->w_localdir == NULL)
1385 				    ? NULL : vim_strsave(oldp->w_localdir);
1386     newp->w_prevdir = (oldp->w_prevdir == NULL)
1387 				    ? NULL : vim_strsave(oldp->w_prevdir);
1388 
1389     // copy tagstack and folds
1390     for (i = 0; i < oldp->w_tagstacklen; i++)
1391     {
1392 	taggy_T	*tag = &newp->w_tagstack[i];
1393 	*tag = oldp->w_tagstack[i];
1394 	if (tag->tagname != NULL)
1395 	    tag->tagname = vim_strsave(tag->tagname);
1396 	if (tag->user_data != NULL)
1397 	    tag->user_data = vim_strsave(tag->user_data);
1398     }
1399     newp->w_tagstackidx = oldp->w_tagstackidx;
1400     newp->w_tagstacklen = oldp->w_tagstacklen;
1401 #ifdef FEAT_FOLDING
1402     copyFoldingState(oldp, newp);
1403 #endif
1404 
1405     win_init_some(newp, oldp);
1406 
1407 #ifdef FEAT_SYN_HL
1408     check_colorcolumn(newp);
1409 #endif
1410 }
1411 
1412 /*
1413  * Initialize window "newp" from window "old".
1414  * Only the essential things are copied.
1415  */
1416     static void
1417 win_init_some(win_T *newp, win_T *oldp)
1418 {
1419     // Use the same argument list.
1420     newp->w_alist = oldp->w_alist;
1421     ++newp->w_alist->al_refcount;
1422     newp->w_arg_idx = oldp->w_arg_idx;
1423 
1424     // copy options from existing window
1425     win_copy_options(oldp, newp);
1426 }
1427 
1428 /*
1429  * Return TRUE if "win" is a global popup or a popup in the current tab page.
1430  */
1431     int
1432 win_valid_popup(win_T *win UNUSED)
1433 {
1434 #ifdef FEAT_PROP_POPUP
1435     win_T	*wp;
1436 
1437     FOR_ALL_POPUPWINS(wp)
1438 	if (wp == win)
1439 	    return TRUE;
1440     FOR_ALL_POPUPWINS_IN_TAB(curtab, wp)
1441 	if (wp == win)
1442 	    return TRUE;
1443 #endif
1444     return FALSE;
1445 }
1446 
1447 /*
1448  * Check if "win" is a pointer to an existing window in the current tab page.
1449  */
1450     int
1451 win_valid(win_T *win)
1452 {
1453     win_T	*wp;
1454 
1455     if (win == NULL)
1456 	return FALSE;
1457     FOR_ALL_WINDOWS(wp)
1458 	if (wp == win)
1459 	    return TRUE;
1460     return win_valid_popup(win);
1461 }
1462 
1463 /*
1464  * Check if "win" is a pointer to an existing window in any tab page.
1465  */
1466     int
1467 win_valid_any_tab(win_T *win)
1468 {
1469     win_T	*wp;
1470     tabpage_T	*tp;
1471 
1472     if (win == NULL)
1473 	return FALSE;
1474     FOR_ALL_TABPAGES(tp)
1475     {
1476 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
1477 	{
1478 	    if (wp == win)
1479 		return TRUE;
1480 	}
1481 #ifdef FEAT_PROP_POPUP
1482 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
1483 	    if (wp == win)
1484 		return TRUE;
1485 #endif
1486     }
1487     return win_valid_popup(win);
1488 }
1489 
1490 /*
1491  * Return the number of windows.
1492  */
1493     int
1494 win_count(void)
1495 {
1496     win_T	*wp;
1497     int		count = 0;
1498 
1499     FOR_ALL_WINDOWS(wp)
1500 	++count;
1501     return count;
1502 }
1503 
1504 /*
1505  * Make "count" windows on the screen.
1506  * Return actual number of windows on the screen.
1507  * Must be called when there is just one window, filling the whole screen
1508  * (excluding the command line).
1509  */
1510     int
1511 make_windows(
1512     int		count,
1513     int		vertical UNUSED)  // split windows vertically if TRUE
1514 {
1515     int		maxcount;
1516     int		todo;
1517 
1518     if (vertical)
1519     {
1520 	// Each windows needs at least 'winminwidth' lines and a separator
1521 	// column.
1522 	maxcount = (curwin->w_width + curwin->w_vsep_width
1523 					     - (p_wiw - p_wmw)) / (p_wmw + 1);
1524     }
1525     else
1526     {
1527 	// Each window needs at least 'winminheight' lines and a status line.
1528 	maxcount = (VISIBLE_HEIGHT(curwin) + curwin->w_status_height
1529 				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
1530     }
1531 
1532     if (maxcount < 2)
1533 	maxcount = 2;
1534     if (count > maxcount)
1535 	count = maxcount;
1536 
1537     /*
1538      * add status line now, otherwise first window will be too big
1539      */
1540     if (count > 1)
1541 	last_status(TRUE);
1542 
1543     /*
1544      * Don't execute autocommands while creating the windows.  Must do that
1545      * when putting the buffers in the windows.
1546      */
1547     block_autocmds();
1548 
1549     // todo is number of windows left to create
1550     for (todo = count - 1; todo > 0; --todo)
1551 	if (vertical)
1552 	{
1553 	    if (win_split(curwin->w_width - (curwin->w_width - todo)
1554 			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
1555 		break;
1556 	}
1557 	else
1558 	{
1559 	    if (win_split(curwin->w_height - (curwin->w_height - todo
1560 			    * STATUS_HEIGHT) / (todo + 1)
1561 			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
1562 		break;
1563 	}
1564 
1565     unblock_autocmds();
1566 
1567     // return actual number of windows
1568     return (count - todo);
1569 }
1570 
1571 /*
1572  * Exchange current and next window
1573  */
1574     static void
1575 win_exchange(long Prenum)
1576 {
1577     frame_T	*frp;
1578     frame_T	*frp2;
1579     win_T	*wp;
1580     win_T	*wp2;
1581     int		temp;
1582 
1583     if (ERROR_IF_ANY_POPUP_WINDOW)
1584 	return;
1585     if (ONE_WINDOW)	    // just one window
1586     {
1587 	beep_flush();
1588 	return;
1589     }
1590 
1591 #ifdef FEAT_GUI
1592     need_mouse_correct = TRUE;
1593 #endif
1594 
1595     /*
1596      * find window to exchange with
1597      */
1598     if (Prenum)
1599     {
1600 	frp = curwin->w_frame->fr_parent->fr_child;
1601 	while (frp != NULL && --Prenum > 0)
1602 	    frp = frp->fr_next;
1603     }
1604     else if (curwin->w_frame->fr_next != NULL)	// Swap with next
1605 	frp = curwin->w_frame->fr_next;
1606     else    // Swap last window in row/col with previous
1607 	frp = curwin->w_frame->fr_prev;
1608 
1609     // We can only exchange a window with another window, not with a frame
1610     // containing windows.
1611     if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
1612 	return;
1613     wp = frp->fr_win;
1614 
1615 /*
1616  * 1. remove curwin from the list. Remember after which window it was in wp2
1617  * 2. insert curwin before wp in the list
1618  * if wp != wp2
1619  *    3. remove wp from the list
1620  *    4. insert wp after wp2
1621  * 5. exchange the status line height and vsep width.
1622  */
1623     wp2 = curwin->w_prev;
1624     frp2 = curwin->w_frame->fr_prev;
1625     if (wp->w_prev != curwin)
1626     {
1627 	win_remove(curwin, NULL);
1628 	frame_remove(curwin->w_frame);
1629 	win_append(wp->w_prev, curwin);
1630 	frame_insert(frp, curwin->w_frame);
1631     }
1632     if (wp != wp2)
1633     {
1634 	win_remove(wp, NULL);
1635 	frame_remove(wp->w_frame);
1636 	win_append(wp2, wp);
1637 	if (frp2 == NULL)
1638 	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
1639 	else
1640 	    frame_append(frp2, wp->w_frame);
1641     }
1642     temp = curwin->w_status_height;
1643     curwin->w_status_height = wp->w_status_height;
1644     wp->w_status_height = temp;
1645     temp = curwin->w_vsep_width;
1646     curwin->w_vsep_width = wp->w_vsep_width;
1647     wp->w_vsep_width = temp;
1648 
1649     // If the windows are not in the same frame, exchange the sizes to avoid
1650     // messing up the window layout.  Otherwise fix the frame sizes.
1651     if (curwin->w_frame->fr_parent != wp->w_frame->fr_parent)
1652     {
1653 	temp = curwin->w_height;
1654 	curwin->w_height = wp->w_height;
1655 	wp->w_height = temp;
1656 	temp = curwin->w_width;
1657 	curwin->w_width = wp->w_width;
1658 	wp->w_width = temp;
1659     }
1660     else
1661     {
1662 	frame_fix_height(curwin);
1663 	frame_fix_height(wp);
1664 	frame_fix_width(curwin);
1665 	frame_fix_width(wp);
1666     }
1667 
1668     (void)win_comp_pos();		// recompute window positions
1669 
1670     win_enter(wp, TRUE);
1671     redraw_all_later(NOT_VALID);
1672 }
1673 
1674 /*
1675  * rotate windows: if upwards TRUE the second window becomes the first one
1676  *		   if upwards FALSE the first window becomes the second one
1677  */
1678     static void
1679 win_rotate(int upwards, int count)
1680 {
1681     win_T	*wp1;
1682     win_T	*wp2;
1683     frame_T	*frp;
1684     int		n;
1685 
1686     if (ONE_WINDOW)		// nothing to do
1687     {
1688 	beep_flush();
1689 	return;
1690     }
1691 
1692 #ifdef FEAT_GUI
1693     need_mouse_correct = TRUE;
1694 #endif
1695 
1696     // Check if all frames in this row/col have one window.
1697     FOR_ALL_FRAMES(frp, curwin->w_frame->fr_parent->fr_child)
1698 	if (frp->fr_win == NULL)
1699 	{
1700 	    emsg(_("E443: Cannot rotate when another window is split"));
1701 	    return;
1702 	}
1703 
1704     while (count--)
1705     {
1706 	if (upwards)		// first window becomes last window
1707 	{
1708 	    // remove first window/frame from the list
1709 	    frp = curwin->w_frame->fr_parent->fr_child;
1710 	    wp1 = frp->fr_win;
1711 	    win_remove(wp1, NULL);
1712 	    frame_remove(frp);
1713 
1714 	    // find last frame and append removed window/frame after it
1715 	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
1716 		;
1717 	    win_append(frp->fr_win, wp1);
1718 	    frame_append(frp, wp1->w_frame);
1719 
1720 	    wp2 = frp->fr_win;		// previously last window
1721 	}
1722 	else			// last window becomes first window
1723 	{
1724 	    // find last window/frame in the list and remove it
1725 	    for (frp = curwin->w_frame; frp->fr_next != NULL;
1726 							   frp = frp->fr_next)
1727 		;
1728 	    wp1 = frp->fr_win;
1729 	    wp2 = wp1->w_prev;		    // will become last window
1730 	    win_remove(wp1, NULL);
1731 	    frame_remove(frp);
1732 
1733 	    // append the removed window/frame before the first in the list
1734 	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
1735 	    frame_insert(frp->fr_parent->fr_child, frp);
1736 	}
1737 
1738 	// exchange status height and vsep width of old and new last window
1739 	n = wp2->w_status_height;
1740 	wp2->w_status_height = wp1->w_status_height;
1741 	wp1->w_status_height = n;
1742 	frame_fix_height(wp1);
1743 	frame_fix_height(wp2);
1744 	n = wp2->w_vsep_width;
1745 	wp2->w_vsep_width = wp1->w_vsep_width;
1746 	wp1->w_vsep_width = n;
1747 	frame_fix_width(wp1);
1748 	frame_fix_width(wp2);
1749 
1750 	// recompute w_winrow and w_wincol for all windows
1751 	(void)win_comp_pos();
1752     }
1753 
1754     redraw_all_later(NOT_VALID);
1755 }
1756 
1757 /*
1758  * Move the current window to the very top/bottom/left/right of the screen.
1759  */
1760     static void
1761 win_totop(int size, int flags)
1762 {
1763     int		dir;
1764     int		height = curwin->w_height;
1765 
1766     if (ONE_WINDOW)
1767     {
1768 	beep_flush();
1769 	return;
1770     }
1771     if (check_split_disallowed() == FAIL)
1772 	return;
1773 
1774     // Remove the window and frame from the tree of frames.
1775     (void)winframe_remove(curwin, &dir, NULL);
1776     win_remove(curwin, NULL);
1777     last_status(FALSE);	    // may need to remove last status line
1778     (void)win_comp_pos();   // recompute window positions
1779 
1780     // Split a window on the desired side and put the window there.
1781     (void)win_split_ins(size, flags, curwin, dir);
1782     if (!(flags & WSP_VERT))
1783     {
1784 	win_setheight(height);
1785 	if (p_ea)
1786 	    win_equal(curwin, TRUE, 'v');
1787     }
1788 
1789 #if defined(FEAT_GUI)
1790     // When 'guioptions' includes 'L' or 'R' may have to remove or add
1791     // scrollbars.  Have to update them anyway.
1792     gui_may_update_scrollbars();
1793 #endif
1794 }
1795 
1796 /*
1797  * Move window "win1" to below/right of "win2" and make "win1" the current
1798  * window.  Only works within the same frame!
1799  */
1800     void
1801 win_move_after(win_T *win1, win_T *win2)
1802 {
1803     int		height;
1804 
1805     // check if the arguments are reasonable
1806     if (win1 == win2)
1807 	return;
1808 
1809     // check if there is something to do
1810     if (win2->w_next != win1)
1811     {
1812 	if (win1->w_frame->fr_parent != win2->w_frame->fr_parent)
1813 	{
1814 	    iemsg("INTERNAL: trying to move a window into another frame");
1815 	    return;
1816 	}
1817 
1818 	// may need to move the status line/vertical separator of the last
1819 	// window
1820 	if (win1 == lastwin)
1821 	{
1822 	    height = win1->w_prev->w_status_height;
1823 	    win1->w_prev->w_status_height = win1->w_status_height;
1824 	    win1->w_status_height = height;
1825 	    if (win1->w_prev->w_vsep_width == 1)
1826 	    {
1827 		// Remove the vertical separator from the last-but-one window,
1828 		// add it to the last window.  Adjust the frame widths.
1829 		win1->w_prev->w_vsep_width = 0;
1830 		win1->w_prev->w_frame->fr_width -= 1;
1831 		win1->w_vsep_width = 1;
1832 		win1->w_frame->fr_width += 1;
1833 	    }
1834 	}
1835 	else if (win2 == lastwin)
1836 	{
1837 	    height = win1->w_status_height;
1838 	    win1->w_status_height = win2->w_status_height;
1839 	    win2->w_status_height = height;
1840 	    if (win1->w_vsep_width == 1)
1841 	    {
1842 		// Remove the vertical separator from win1, add it to the last
1843 		// window, win2.  Adjust the frame widths.
1844 		win2->w_vsep_width = 1;
1845 		win2->w_frame->fr_width += 1;
1846 		win1->w_vsep_width = 0;
1847 		win1->w_frame->fr_width -= 1;
1848 	    }
1849 	}
1850 	win_remove(win1, NULL);
1851 	frame_remove(win1->w_frame);
1852 	win_append(win2, win1);
1853 	frame_append(win2->w_frame, win1->w_frame);
1854 
1855 	(void)win_comp_pos();	// recompute w_winrow for all windows
1856 	redraw_later(NOT_VALID);
1857     }
1858     win_enter(win1, FALSE);
1859 }
1860 
1861 /*
1862  * Make all windows the same height.
1863  * 'next_curwin' will soon be the current window, make sure it has enough
1864  * rows.
1865  */
1866     void
1867 win_equal(
1868     win_T	*next_curwin,	// pointer to current window to be or NULL
1869     int		current,	// do only frame with current window
1870     int		dir)		// 'v' for vertically, 'h' for horizontally,
1871 				// 'b' for both, 0 for using p_ead
1872 {
1873     if (dir == 0)
1874 	dir = *p_ead;
1875     win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
1876 		      topframe, dir, 0, tabline_height(),
1877 					   (int)Columns, topframe->fr_height);
1878 }
1879 
1880 /*
1881  * Set a frame to a new position and height, spreading the available room
1882  * equally over contained frames.
1883  * The window "next_curwin" (if not NULL) should at least get the size from
1884  * 'winheight' and 'winwidth' if possible.
1885  */
1886     static void
1887 win_equal_rec(
1888     win_T	*next_curwin,	// pointer to current window to be or NULL
1889     int		current,	// do only frame with current window
1890     frame_T	*topfr,		// frame to set size off
1891     int		dir,		// 'v', 'h' or 'b', see win_equal()
1892     int		col,		// horizontal position for frame
1893     int		row,		// vertical position for frame
1894     int		width,		// new width of frame
1895     int		height)		// new height of frame
1896 {
1897     int		n, m;
1898     int		extra_sep = 0;
1899     int		wincount, totwincount = 0;
1900     frame_T	*fr;
1901     int		next_curwin_size = 0;
1902     int		room = 0;
1903     int		new_size;
1904     int		has_next_curwin = 0;
1905     int		hnc;
1906 
1907     if (topfr->fr_layout == FR_LEAF)
1908     {
1909 	// Set the width/height of this frame.
1910 	// Redraw when size or position changes
1911 	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
1912 		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
1913 	   )
1914 	{
1915 	    topfr->fr_win->w_winrow = row;
1916 	    frame_new_height(topfr, height, FALSE, FALSE);
1917 	    topfr->fr_win->w_wincol = col;
1918 	    frame_new_width(topfr, width, FALSE, FALSE);
1919 	    redraw_all_later(NOT_VALID);
1920 	}
1921     }
1922     else if (topfr->fr_layout == FR_ROW)
1923     {
1924 	topfr->fr_width = width;
1925 	topfr->fr_height = height;
1926 
1927 	if (dir != 'v')			// equalize frame widths
1928 	{
1929 	    // Compute the maximum number of windows horizontally in this
1930 	    // frame.
1931 	    n = frame_minwidth(topfr, NOWIN);
1932 	    // add one for the rightmost window, it doesn't have a separator
1933 	    if (col + width == Columns)
1934 		extra_sep = 1;
1935 	    else
1936 		extra_sep = 0;
1937 	    totwincount = (n + extra_sep) / (p_wmw + 1);
1938 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1939 
1940 	    /*
1941 	     * Compute width for "next_curwin" window and room available for
1942 	     * other windows.
1943 	     * "m" is the minimal width when counting p_wiw for "next_curwin".
1944 	     */
1945 	    m = frame_minwidth(topfr, next_curwin);
1946 	    room = width - m;
1947 	    if (room < 0)
1948 	    {
1949 		next_curwin_size = p_wiw + room;
1950 		room = 0;
1951 	    }
1952 	    else
1953 	    {
1954 		next_curwin_size = -1;
1955 		FOR_ALL_FRAMES(fr, topfr->fr_child)
1956 		{
1957 		    // If 'winfixwidth' set keep the window width if
1958 		    // possible.
1959 		    // Watch out for this window being the next_curwin.
1960 		    if (frame_fixed_width(fr))
1961 		    {
1962 			n = frame_minwidth(fr, NOWIN);
1963 			new_size = fr->fr_width;
1964 			if (frame_has_win(fr, next_curwin))
1965 			{
1966 			    room += p_wiw - p_wmw;
1967 			    next_curwin_size = 0;
1968 			    if (new_size < p_wiw)
1969 				new_size = p_wiw;
1970 			}
1971 			else
1972 			    // These windows don't use up room.
1973 			    totwincount -= (n + (fr->fr_next == NULL
1974 					      ? extra_sep : 0)) / (p_wmw + 1);
1975 			room -= new_size - n;
1976 			if (room < 0)
1977 			{
1978 			    new_size += room;
1979 			    room = 0;
1980 			}
1981 			fr->fr_newwidth = new_size;
1982 		    }
1983 		}
1984 		if (next_curwin_size == -1)
1985 		{
1986 		    if (!has_next_curwin)
1987 			next_curwin_size = 0;
1988 		    else if (totwincount > 1
1989 			    && (room + (totwincount - 2))
1990 						  / (totwincount - 1) > p_wiw)
1991 		    {
1992 			// Can make all windows wider than 'winwidth', spread
1993 			// the room equally.
1994 			next_curwin_size = (room + p_wiw
1995 					    + (totwincount - 1) * p_wmw
1996 					    + (totwincount - 1)) / totwincount;
1997 			room -= next_curwin_size - p_wiw;
1998 		    }
1999 		    else
2000 			next_curwin_size = p_wiw;
2001 		}
2002 	    }
2003 
2004 	    if (has_next_curwin)
2005 		--totwincount;		// don't count curwin
2006 	}
2007 
2008 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2009 	{
2010 	    wincount = 1;
2011 	    if (fr->fr_next == NULL)
2012 		// last frame gets all that remains (avoid roundoff error)
2013 		new_size = width;
2014 	    else if (dir == 'v')
2015 		new_size = fr->fr_width;
2016 	    else if (frame_fixed_width(fr))
2017 	    {
2018 		new_size = fr->fr_newwidth;
2019 		wincount = 0;	    // doesn't count as a sizeable window
2020 	    }
2021 	    else
2022 	    {
2023 		// Compute the maximum number of windows horiz. in "fr".
2024 		n = frame_minwidth(fr, NOWIN);
2025 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2026 								/ (p_wmw + 1);
2027 		m = frame_minwidth(fr, next_curwin);
2028 		if (has_next_curwin)
2029 		    hnc = frame_has_win(fr, next_curwin);
2030 		else
2031 		    hnc = FALSE;
2032 		if (hnc)	    // don't count next_curwin
2033 		    --wincount;
2034 		if (totwincount == 0)
2035 		    new_size = room;
2036 		else
2037 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2038 								/ totwincount;
2039 		if (hnc)	    // add next_curwin size
2040 		{
2041 		    next_curwin_size -= p_wiw - (m - n);
2042 		    new_size += next_curwin_size;
2043 		    room -= new_size - next_curwin_size;
2044 		}
2045 		else
2046 		    room -= new_size;
2047 		new_size += n;
2048 	    }
2049 
2050 	    // Skip frame that is full width when splitting or closing a
2051 	    // window, unless equalizing all frames.
2052 	    if (!current || dir != 'v' || topfr->fr_parent != NULL
2053 		    || (new_size != fr->fr_width)
2054 		    || frame_has_win(fr, next_curwin))
2055 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2056 							    new_size, height);
2057 	    col += new_size;
2058 	    width -= new_size;
2059 	    totwincount -= wincount;
2060 	}
2061     }
2062     else // topfr->fr_layout == FR_COL
2063     {
2064 	topfr->fr_width = width;
2065 	topfr->fr_height = height;
2066 
2067 	if (dir != 'h')			// equalize frame heights
2068 	{
2069 	    // Compute maximum number of windows vertically in this frame.
2070 	    n = frame_minheight(topfr, NOWIN);
2071 	    // add one for the bottom window if it doesn't have a statusline
2072 	    if (row + height == cmdline_row && p_ls == 0)
2073 		extra_sep = 1;
2074 	    else
2075 		extra_sep = 0;
2076 	    totwincount = (n + extra_sep) / (p_wmh + 1);
2077 	    has_next_curwin = frame_has_win(topfr, next_curwin);
2078 
2079 	    /*
2080 	     * Compute height for "next_curwin" window and room available for
2081 	     * other windows.
2082 	     * "m" is the minimal height when counting p_wh for "next_curwin".
2083 	     */
2084 	    m = frame_minheight(topfr, next_curwin);
2085 	    room = height - m;
2086 	    if (room < 0)
2087 	    {
2088 		// The room is less then 'winheight', use all space for the
2089 		// current window.
2090 		next_curwin_size = p_wh + room;
2091 		room = 0;
2092 	    }
2093 	    else
2094 	    {
2095 		next_curwin_size = -1;
2096 		FOR_ALL_FRAMES(fr, topfr->fr_child)
2097 		{
2098 		    // If 'winfixheight' set keep the window height if
2099 		    // possible.
2100 		    // Watch out for this window being the next_curwin.
2101 		    if (frame_fixed_height(fr))
2102 		    {
2103 			n = frame_minheight(fr, NOWIN);
2104 			new_size = fr->fr_height;
2105 			if (frame_has_win(fr, next_curwin))
2106 			{
2107 			    room += p_wh - p_wmh;
2108 			    next_curwin_size = 0;
2109 			    if (new_size < p_wh)
2110 				new_size = p_wh;
2111 			}
2112 			else
2113 			    // These windows don't use up room.
2114 			    totwincount -= (n + (fr->fr_next == NULL
2115 					      ? extra_sep : 0)) / (p_wmh + 1);
2116 			room -= new_size - n;
2117 			if (room < 0)
2118 			{
2119 			    new_size += room;
2120 			    room = 0;
2121 			}
2122 			fr->fr_newheight = new_size;
2123 		    }
2124 		}
2125 		if (next_curwin_size == -1)
2126 		{
2127 		    if (!has_next_curwin)
2128 			next_curwin_size = 0;
2129 		    else if (totwincount > 1
2130 			    && (room + (totwincount - 2))
2131 						   / (totwincount - 1) > p_wh)
2132 		    {
2133 			// can make all windows higher than 'winheight',
2134 			// spread the room equally.
2135 			next_curwin_size = (room + p_wh
2136 					   + (totwincount - 1) * p_wmh
2137 					   + (totwincount - 1)) / totwincount;
2138 			room -= next_curwin_size - p_wh;
2139 		    }
2140 		    else
2141 			next_curwin_size = p_wh;
2142 		}
2143 	    }
2144 
2145 	    if (has_next_curwin)
2146 		--totwincount;		// don't count curwin
2147 	}
2148 
2149 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2150 	{
2151 	    wincount = 1;
2152 	    if (fr->fr_next == NULL)
2153 		// last frame gets all that remains (avoid roundoff error)
2154 		new_size = height;
2155 	    else if (dir == 'h')
2156 		new_size = fr->fr_height;
2157 	    else if (frame_fixed_height(fr))
2158 	    {
2159 		new_size = fr->fr_newheight;
2160 		wincount = 0;	    // doesn't count as a sizeable window
2161 	    }
2162 	    else
2163 	    {
2164 		// Compute the maximum number of windows vert. in "fr".
2165 		n = frame_minheight(fr, NOWIN);
2166 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2167 								/ (p_wmh + 1);
2168 		m = frame_minheight(fr, next_curwin);
2169 		if (has_next_curwin)
2170 		    hnc = frame_has_win(fr, next_curwin);
2171 		else
2172 		    hnc = FALSE;
2173 		if (hnc)	    // don't count next_curwin
2174 		    --wincount;
2175 		if (totwincount == 0)
2176 		    new_size = room;
2177 		else
2178 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2179 								/ totwincount;
2180 		if (hnc)	    // add next_curwin size
2181 		{
2182 		    next_curwin_size -= p_wh - (m - n);
2183 		    new_size += next_curwin_size;
2184 		    room -= new_size - next_curwin_size;
2185 		}
2186 		else
2187 		    room -= new_size;
2188 		new_size += n;
2189 	    }
2190 	    // Skip frame that is full width when splitting or closing a
2191 	    // window, unless equalizing all frames.
2192 	    if (!current || dir != 'h' || topfr->fr_parent != NULL
2193 		    || (new_size != fr->fr_height)
2194 		    || frame_has_win(fr, next_curwin))
2195 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2196 							     width, new_size);
2197 	    row += new_size;
2198 	    height -= new_size;
2199 	    totwincount -= wincount;
2200 	}
2201     }
2202 }
2203 
2204 #ifdef FEAT_JOB_CHANNEL
2205     static void
2206 leaving_window(win_T *win)
2207 {
2208     // Only matters for a prompt window.
2209     if (!bt_prompt(win->w_buffer))
2210 	return;
2211 
2212     // When leaving a prompt window stop Insert mode and perhaps restart
2213     // it when entering that window again.
2214     win->w_buffer->b_prompt_insert = restart_edit;
2215     if (restart_edit != 0 && mode_displayed)
2216 	clear_cmdline = TRUE;		// unshow mode later
2217     restart_edit = NUL;
2218 
2219     // When leaving the window (or closing the window) was done from a
2220     // callback we need to break out of the Insert mode loop and restart Insert
2221     // mode when entering the window again.
2222     if (State & INSERT)
2223     {
2224 	stop_insert_mode = TRUE;
2225 	if (win->w_buffer->b_prompt_insert == NUL)
2226 	    win->w_buffer->b_prompt_insert = 'A';
2227     }
2228 }
2229 
2230     void
2231 entering_window(win_T *win)
2232 {
2233     // Only matters for a prompt window.
2234     if (!bt_prompt(win->w_buffer))
2235 	return;
2236 
2237     // When switching to a prompt buffer that was in Insert mode, don't stop
2238     // Insert mode, it may have been set in leaving_window().
2239     if (win->w_buffer->b_prompt_insert != NUL)
2240 	stop_insert_mode = FALSE;
2241 
2242     // When entering the prompt window restart Insert mode if we were in Insert
2243     // mode when we left it.
2244     restart_edit = win->w_buffer->b_prompt_insert;
2245 }
2246 #endif
2247 
2248 /*
2249  * Close all windows for buffer "buf".
2250  */
2251     void
2252 close_windows(
2253     buf_T	*buf,
2254     int		keep_curwin)	    // don't close "curwin"
2255 {
2256     win_T	*wp;
2257     tabpage_T   *tp, *nexttp;
2258     int		h = tabline_height();
2259     int		count = tabpage_index(NULL);
2260 
2261     ++RedrawingDisabled;
2262 
2263     for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
2264     {
2265 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
2266 		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
2267 	{
2268 	    if (win_close(wp, FALSE) == FAIL)
2269 		// If closing the window fails give up, to avoid looping
2270 		// forever.
2271 		break;
2272 
2273 	    // Start all over, autocommands may change the window layout.
2274 	    wp = firstwin;
2275 	}
2276 	else
2277 	    wp = wp->w_next;
2278     }
2279 
2280     // Also check windows in other tab pages.
2281     for (tp = first_tabpage; tp != NULL; tp = nexttp)
2282     {
2283 	nexttp = tp->tp_next;
2284 	if (tp != curtab)
2285 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
2286 		if (wp->w_buffer == buf
2287 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
2288 		{
2289 		    win_close_othertab(wp, FALSE, tp);
2290 
2291 		    // Start all over, the tab page may be closed and
2292 		    // autocommands may change the window layout.
2293 		    nexttp = first_tabpage;
2294 		    break;
2295 		}
2296     }
2297 
2298     --RedrawingDisabled;
2299 
2300     if (count != tabpage_index(NULL))
2301 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2302 
2303     redraw_tabline = TRUE;
2304     if (h != tabline_height())
2305 	shell_new_rows();
2306 }
2307 
2308 /*
2309  * Return TRUE if the current window is the only window that exists (ignoring
2310  * "aucmd_win").
2311  * Returns FALSE if there is a window, possibly in another tab page.
2312  */
2313     static int
2314 last_window(void)
2315 {
2316     return (one_window() && first_tabpage->tp_next == NULL);
2317 }
2318 
2319 /*
2320  * Return TRUE if there is only one window other than "aucmd_win" in the
2321  * current tab page.
2322  */
2323     int
2324 one_window(void)
2325 {
2326     win_T	*wp;
2327     int		seen_one = FALSE;
2328 
2329     FOR_ALL_WINDOWS(wp)
2330     {
2331 	if (wp != aucmd_win)
2332 	{
2333 	    if (seen_one)
2334 		return FALSE;
2335 	    seen_one = TRUE;
2336 	}
2337     }
2338     return TRUE;
2339 }
2340 
2341 /*
2342  * Close the possibly last window in a tab page.
2343  * Returns TRUE when the window was closed already.
2344  */
2345     static int
2346 close_last_window_tabpage(
2347     win_T	*win,
2348     int		free_buf,
2349     tabpage_T   *prev_curtab)
2350 {
2351     if (ONE_WINDOW)
2352     {
2353 	buf_T	*old_curbuf = curbuf;
2354 
2355 	/*
2356 	 * Closing the last window in a tab page.  First go to another tab
2357 	 * page and then close the window and the tab page.  This avoids that
2358 	 * curwin and curtab are invalid while we are freeing memory, they may
2359 	 * be used in GUI events.
2360 	 * Don't trigger autocommands yet, they may use wrong values, so do
2361 	 * that below.
2362 	 */
2363 	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
2364 	redraw_tabline = TRUE;
2365 
2366 	// Safety check: Autocommands may have closed the window when jumping
2367 	// to the other tab page.
2368 	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
2369 	{
2370 	    int	    h = tabline_height();
2371 
2372 	    win_close_othertab(win, free_buf, prev_curtab);
2373 	    if (h != tabline_height())
2374 		shell_new_rows();
2375 	}
2376 #ifdef FEAT_JOB_CHANNEL
2377 	entering_window(curwin);
2378 #endif
2379 	// Since goto_tabpage_tp above did not trigger *Enter autocommands, do
2380 	// that now.
2381 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2382 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
2383 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
2384 	if (old_curbuf != curbuf)
2385 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2386 	return TRUE;
2387     }
2388     return FALSE;
2389 }
2390 
2391 /*
2392  * Close the buffer of "win" and unload it if "action" is DOBUF_UNLOAD.
2393  * "action" can also be zero (do nothing) or DOBUF_WIPE.
2394  * "abort_if_last" is passed to close_buffer(): abort closing if all other
2395  * windows are closed.
2396  */
2397     static void
2398 win_close_buffer(win_T *win, int action, int abort_if_last)
2399 {
2400 #ifdef FEAT_SYN_HL
2401     // Free independent synblock before the buffer is freed.
2402     if (win->w_buffer != NULL)
2403 	reset_synblock(win);
2404 #endif
2405 
2406 #ifdef FEAT_QUICKFIX
2407     // When the quickfix/location list window is closed, unlist the buffer.
2408     if (win->w_buffer != NULL && bt_quickfix(win->w_buffer))
2409 	win->w_buffer->b_p_bl = FALSE;
2410 #endif
2411 
2412     // Close the link to the buffer.
2413     if (win->w_buffer != NULL)
2414     {
2415 	bufref_T    bufref;
2416 
2417 	set_bufref(&bufref, curbuf);
2418 	win->w_closing = TRUE;
2419 	close_buffer(win, win->w_buffer, action, abort_if_last, FALSE);
2420 	if (win_valid_any_tab(win))
2421 	    win->w_closing = FALSE;
2422 	// Make sure curbuf is valid. It can become invalid if 'bufhidden' is
2423 	// "wipe".
2424 	if (!bufref_valid(&bufref))
2425 	    curbuf = firstbuf;
2426     }
2427 }
2428 
2429 /*
2430  * Close window "win".  Only works for the current tab page.
2431  * If "free_buf" is TRUE related buffer may be unloaded.
2432  *
2433  * Called by :quit, :close, :xit, :wq and findtag().
2434  * Returns FAIL when the window was not closed.
2435  */
2436     int
2437 win_close(win_T *win, int free_buf)
2438 {
2439     win_T	*wp;
2440     int		other_buffer = FALSE;
2441     int		close_curwin = FALSE;
2442     int		dir;
2443     int		help_window = FALSE;
2444     tabpage_T   *prev_curtab = curtab;
2445     frame_T	*win_frame = win->w_frame->fr_parent;
2446 #ifdef FEAT_DIFF
2447     int		had_diffmode = win->w_p_diff;
2448 #endif
2449 
2450 #if defined(FEAT_TERMINAL) && defined(FEAT_PROP_POPUP)
2451     // Can close a popup window with a terminal if the job has finished.
2452     if (may_close_term_popup() == OK)
2453 	return OK;
2454 #endif
2455     if (ERROR_IF_ANY_POPUP_WINDOW)
2456 	return FAIL;
2457 
2458     if (last_window())
2459     {
2460 	emsg(_("E444: Cannot close last window"));
2461 	return FAIL;
2462     }
2463 
2464     if (win->w_closing || (win->w_buffer != NULL
2465 					       && win->w_buffer->b_locked > 0))
2466 	return FAIL; // window is already being closed
2467     if (win_unlisted(win))
2468     {
2469 	emsg(_(e_autocmd_close));
2470 	return FAIL;
2471     }
2472     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
2473     {
2474 	emsg(_("E814: Cannot close window, only autocmd window would remain"));
2475 	return FAIL;
2476     }
2477 
2478     // When closing the last window in a tab page first go to another tab page
2479     // and then close the window and the tab page to avoid that curwin and
2480     // curtab are invalid while we are freeing memory.
2481     if (close_last_window_tabpage(win, free_buf, prev_curtab))
2482       return FAIL;
2483 
2484     // When closing the help window, try restoring a snapshot after closing
2485     // the window.  Otherwise clear the snapshot, it's now invalid.
2486     if (bt_help(win->w_buffer))
2487 	help_window = TRUE;
2488     else
2489 	clear_snapshot(curtab, SNAP_HELP_IDX);
2490 
2491     if (win == curwin)
2492     {
2493 #ifdef FEAT_JOB_CHANNEL
2494 	leaving_window(curwin);
2495 #endif
2496 	/*
2497 	 * Guess which window is going to be the new current window.
2498 	 * This may change because of the autocommands (sigh).
2499 	 */
2500 	wp = frame2win(win_altframe(win, NULL));
2501 
2502 	/*
2503 	 * Be careful: If autocommands delete the window or cause this window
2504 	 * to be the last one left, return now.
2505 	 */
2506 	if (wp->w_buffer != curbuf)
2507 	{
2508 	    other_buffer = TRUE;
2509 	    win->w_closing = TRUE;
2510 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
2511 	    if (!win_valid(win))
2512 		return FAIL;
2513 	    win->w_closing = FALSE;
2514 	    if (last_window())
2515 		return FAIL;
2516 	}
2517 	win->w_closing = TRUE;
2518 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
2519 	if (!win_valid(win))
2520 	    return FAIL;
2521 	win->w_closing = FALSE;
2522 	if (last_window())
2523 	    return FAIL;
2524 #ifdef FEAT_EVAL
2525 	// autocmds may abort script processing
2526 	if (aborting())
2527 	    return FAIL;
2528 #endif
2529     }
2530 
2531 #ifdef FEAT_GUI
2532     // Avoid trouble with scrollbars that are going to be deleted in
2533     // win_free().
2534     if (gui.in_use)
2535 	out_flush();
2536 #endif
2537 
2538 #ifdef FEAT_PROP_POPUP
2539     if (popup_win_closed(win) && !win_valid(win))
2540 	return FAIL;
2541 #endif
2542     win_close_buffer(win, free_buf ? DOBUF_UNLOAD : 0, TRUE);
2543 
2544     if (only_one_window() && win_valid(win) && win->w_buffer == NULL
2545 	    && (last_window() || curtab != prev_curtab
2546 		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
2547     {
2548 	// Autocommands have closed all windows, quit now.  Restore
2549 	// curwin->w_buffer, otherwise writing viminfo may fail.
2550 	if (curwin->w_buffer == NULL)
2551 	    curwin->w_buffer = curbuf;
2552 	getout(0);
2553     }
2554 
2555     // Autocommands may have moved to another tab page.
2556     if (curtab != prev_curtab && win_valid_any_tab(win)
2557 						      && win->w_buffer == NULL)
2558     {
2559 	// Need to close the window anyway, since the buffer is NULL.
2560 	win_close_othertab(win, FALSE, prev_curtab);
2561 	return FAIL;
2562     }
2563 
2564     // Autocommands may have closed the window already or closed the only
2565     // other window.
2566     if (!win_valid(win) || last_window()
2567 	    || close_last_window_tabpage(win, free_buf, prev_curtab))
2568 	return FAIL;
2569 
2570     // Now we are really going to close the window.  Disallow any autocommand
2571     // to split a window to avoid trouble.
2572     ++split_disallowed;
2573 
2574     // Free the memory used for the window and get the window that received
2575     // the screen space.
2576     wp = win_free_mem(win, &dir, NULL);
2577 
2578     // Make sure curwin isn't invalid.  It can cause severe trouble when
2579     // printing an error message.  For win_equal() curbuf needs to be valid
2580     // too.
2581     if (win == curwin)
2582     {
2583 	curwin = wp;
2584 #ifdef FEAT_QUICKFIX
2585 	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
2586 	{
2587 	    /*
2588 	     * If the cursor goes to the preview or the quickfix window, try
2589 	     * finding another window to go to.
2590 	     */
2591 	    for (;;)
2592 	    {
2593 		if (wp->w_next == NULL)
2594 		    wp = firstwin;
2595 		else
2596 		    wp = wp->w_next;
2597 		if (wp == curwin)
2598 		    break;
2599 		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
2600 		{
2601 		    curwin = wp;
2602 		    break;
2603 		}
2604 	    }
2605 	}
2606 #endif
2607 	curbuf = curwin->w_buffer;
2608 	close_curwin = TRUE;
2609 
2610 	// The cursor position may be invalid if the buffer changed after last
2611 	// using the window.
2612 	check_cursor();
2613     }
2614     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
2615 	// If the frame of the closed window contains the new current window,
2616 	// only resize that frame.  Otherwise resize all windows.
2617 	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
2618     else
2619 	win_comp_pos();
2620     if (close_curwin)
2621     {
2622 	win_enter_ext(wp, FALSE, TRUE, FALSE, TRUE, TRUE);
2623 	if (other_buffer)
2624 	    // careful: after this wp and win may be invalid!
2625 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2626     }
2627 
2628     --split_disallowed;
2629 
2630     /*
2631      * If last window has a status line now and we don't want one,
2632      * remove the status line.
2633      */
2634     last_status(FALSE);
2635 
2636     // After closing the help window, try restoring the window layout from
2637     // before it was opened.
2638     if (help_window)
2639 	restore_snapshot(SNAP_HELP_IDX, close_curwin);
2640 
2641 #ifdef FEAT_DIFF
2642     // If the window had 'diff' set and now there is only one window left in
2643     // the tab page with 'diff' set, and "closeoff" is in 'diffopt', then
2644     // execute ":diffoff!".
2645     if (diffopt_closeoff() && had_diffmode && curtab == prev_curtab)
2646     {
2647 	int	diffcount = 0;
2648 	win_T	*dwin;
2649 
2650 	FOR_ALL_WINDOWS(dwin)
2651 	    if (dwin->w_p_diff)
2652 		++diffcount;
2653 	if (diffcount == 1)
2654 	    do_cmdline_cmd((char_u *)"diffoff!");
2655     }
2656 #endif
2657 
2658 #if defined(FEAT_GUI)
2659     // When 'guioptions' includes 'L' or 'R' may have to remove scrollbars.
2660     if (gui.in_use && !win_hasvertsplit())
2661 	gui_init_which_components(NULL);
2662 #endif
2663 
2664     redraw_all_later(NOT_VALID);
2665     return OK;
2666 }
2667 
2668 /*
2669  * Close window "win" in tab page "tp", which is not the current tab page.
2670  * This may be the last window in that tab page and result in closing the tab,
2671  * thus "tp" may become invalid!
2672  * Caller must check if buffer is hidden and whether the tabline needs to be
2673  * updated.
2674  */
2675     void
2676 win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
2677 {
2678     win_T	*wp;
2679     int		dir;
2680     tabpage_T   *ptp = NULL;
2681     int		free_tp = FALSE;
2682 
2683     // Get here with win->w_buffer == NULL when win_close() detects the tab
2684     // page changed.
2685     if (win->w_closing || (win->w_buffer != NULL
2686 					       && win->w_buffer->b_locked > 0))
2687 	return; // window is already being closed
2688 
2689     if (win->w_buffer != NULL)
2690 	// Close the link to the buffer.
2691 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0,
2692 								 FALSE, FALSE);
2693 
2694     // Careful: Autocommands may have closed the tab page or made it the
2695     // current tab page.
2696     for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
2697 	;
2698     if (ptp == NULL || tp == curtab)
2699 	return;
2700 
2701     // Autocommands may have closed the window already.
2702     for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
2703 	;
2704     if (wp == NULL)
2705 	return;
2706 
2707     // When closing the last window in a tab page remove the tab page.
2708     if (tp->tp_firstwin == tp->tp_lastwin)
2709     {
2710 	if (tp == first_tabpage)
2711 	    first_tabpage = tp->tp_next;
2712 	else
2713 	{
2714 	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
2715 							   ptp = ptp->tp_next)
2716 		;
2717 	    if (ptp == NULL)
2718 	    {
2719 		internal_error("win_close_othertab()");
2720 		return;
2721 	    }
2722 	    ptp->tp_next = tp->tp_next;
2723 	}
2724 	free_tp = TRUE;
2725     }
2726 
2727     // Free the memory used for the window.
2728     win_free_mem(win, &dir, tp);
2729 
2730     if (free_tp)
2731 	free_tabpage(tp);
2732 }
2733 
2734 /*
2735  * Free the memory used for a window.
2736  * Returns a pointer to the window that got the freed up space.
2737  */
2738     static win_T *
2739 win_free_mem(
2740     win_T	*win,
2741     int		*dirp,		// set to 'v' or 'h' for direction if 'ea'
2742     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2743 {
2744     frame_T	*frp;
2745     win_T	*wp;
2746     tabpage_T	*win_tp = tp == NULL ? curtab : tp;
2747 
2748     // Remove the window and its frame from the tree of frames.
2749     frp = win->w_frame;
2750     wp = winframe_remove(win, dirp, tp);
2751     vim_free(frp);
2752     win_free(win, tp);
2753 
2754     // When deleting the current window in the tab, select a new current
2755     // window.
2756     if (win == win_tp->tp_curwin)
2757 	win_tp->tp_curwin = wp;
2758 
2759     return wp;
2760 }
2761 
2762 #if defined(EXITFREE) || defined(PROTO)
2763     void
2764 win_free_all(void)
2765 {
2766     int		dummy;
2767 
2768     while (first_tabpage->tp_next != NULL)
2769 	tabpage_close(TRUE);
2770 
2771     if (aucmd_win != NULL)
2772     {
2773 	(void)win_free_mem(aucmd_win, &dummy, NULL);
2774 	aucmd_win = NULL;
2775     }
2776 
2777     while (firstwin != NULL)
2778 	(void)win_free_mem(firstwin, &dummy, NULL);
2779 
2780     // No window should be used after this. Set curwin to NULL to crash
2781     // instead of using freed memory.
2782     curwin = NULL;
2783 }
2784 #endif
2785 
2786 /*
2787  * Remove a window and its frame from the tree of frames.
2788  * Returns a pointer to the window that got the freed up space.
2789  */
2790     win_T *
2791 winframe_remove(
2792     win_T	*win,
2793     int		*dirp UNUSED,	// set to 'v' or 'h' for direction if 'ea'
2794     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2795 {
2796     frame_T	*frp, *frp2, *frp3;
2797     frame_T	*frp_close = win->w_frame;
2798     win_T	*wp;
2799 
2800     /*
2801      * If there is only one window there is nothing to remove.
2802      */
2803     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2804 	return NULL;
2805 
2806     /*
2807      * Remove the window from its frame.
2808      */
2809     frp2 = win_altframe(win, tp);
2810     wp = frame2win(frp2);
2811 
2812     // Remove this frame from the list of frames.
2813     frame_remove(frp_close);
2814 
2815     if (frp_close->fr_parent->fr_layout == FR_COL)
2816     {
2817 	// When 'winfixheight' is set, try to find another frame in the column
2818 	// (as close to the closed frame as possible) to distribute the height
2819 	// to.
2820 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
2821 	{
2822 	    frp = frp_close->fr_prev;
2823 	    frp3 = frp_close->fr_next;
2824 	    while (frp != NULL || frp3 != NULL)
2825 	    {
2826 		if (frp != NULL)
2827 		{
2828 		    if (!frame_fixed_height(frp))
2829 		    {
2830 			frp2 = frp;
2831 			wp = frame2win(frp2);
2832 			break;
2833 		    }
2834 		    frp = frp->fr_prev;
2835 		}
2836 		if (frp3 != NULL)
2837 		{
2838 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
2839 		    {
2840 			frp2 = frp3;
2841 			wp = frp3->fr_win;
2842 			break;
2843 		    }
2844 		    frp3 = frp3->fr_next;
2845 		}
2846 	    }
2847 	}
2848 	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
2849 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2850 	*dirp = 'v';
2851     }
2852     else
2853     {
2854 	// When 'winfixwidth' is set, try to find another frame in the column
2855 	// (as close to the closed frame as possible) to distribute the width
2856 	// to.
2857 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
2858 	{
2859 	    frp = frp_close->fr_prev;
2860 	    frp3 = frp_close->fr_next;
2861 	    while (frp != NULL || frp3 != NULL)
2862 	    {
2863 		if (frp != NULL)
2864 		{
2865 		    if (!frame_fixed_width(frp))
2866 		    {
2867 			frp2 = frp;
2868 			wp = frame2win(frp2);
2869 			break;
2870 		    }
2871 		    frp = frp->fr_prev;
2872 		}
2873 		if (frp3 != NULL)
2874 		{
2875 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
2876 		    {
2877 			frp2 = frp3;
2878 			wp = frp3->fr_win;
2879 			break;
2880 		    }
2881 		    frp3 = frp3->fr_next;
2882 		}
2883 	    }
2884 	}
2885 	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
2886 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2887 	*dirp = 'h';
2888     }
2889 
2890     // If rows/columns go to a window below/right its positions need to be
2891     // updated.  Can only be done after the sizes have been updated.
2892     if (frp2 == frp_close->fr_next)
2893     {
2894 	int row = win->w_winrow;
2895 	int col = win->w_wincol;
2896 
2897 	frame_comp_pos(frp2, &row, &col);
2898     }
2899 
2900     if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
2901     {
2902 	// There is no other frame in this list, move its info to the parent
2903 	// and remove it.
2904 	frp2->fr_parent->fr_layout = frp2->fr_layout;
2905 	frp2->fr_parent->fr_child = frp2->fr_child;
2906 	FOR_ALL_FRAMES(frp, frp2->fr_child)
2907 	    frp->fr_parent = frp2->fr_parent;
2908 	frp2->fr_parent->fr_win = frp2->fr_win;
2909 	if (frp2->fr_win != NULL)
2910 	    frp2->fr_win->w_frame = frp2->fr_parent;
2911 	frp = frp2->fr_parent;
2912 	if (topframe->fr_child == frp2)
2913 	    topframe->fr_child = frp;
2914 	vim_free(frp2);
2915 
2916 	frp2 = frp->fr_parent;
2917 	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
2918 	{
2919 	    // The frame above the parent has the same layout, have to merge
2920 	    // the frames into this list.
2921 	    if (frp2->fr_child == frp)
2922 		frp2->fr_child = frp->fr_child;
2923 	    frp->fr_child->fr_prev = frp->fr_prev;
2924 	    if (frp->fr_prev != NULL)
2925 		frp->fr_prev->fr_next = frp->fr_child;
2926 	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
2927 	    {
2928 		frp3->fr_parent = frp2;
2929 		if (frp3->fr_next == NULL)
2930 		{
2931 		    frp3->fr_next = frp->fr_next;
2932 		    if (frp->fr_next != NULL)
2933 			frp->fr_next->fr_prev = frp3;
2934 		    break;
2935 		}
2936 	    }
2937 	    if (topframe->fr_child == frp)
2938 		topframe->fr_child = frp2;
2939 	    vim_free(frp);
2940 	}
2941     }
2942 
2943     return wp;
2944 }
2945 
2946 /*
2947  * Return a pointer to the frame that will receive the empty screen space that
2948  * is left over after "win" is closed.
2949  *
2950  * If 'splitbelow' or 'splitright' is set, the space goes above or to the left
2951  * by default.  Otherwise, the free space goes below or to the right.  The
2952  * result is that opening a window and then immediately closing it will
2953  * preserve the initial window layout.  The 'wfh' and 'wfw' settings are
2954  * respected when possible.
2955  */
2956     static frame_T *
2957 win_altframe(
2958     win_T	*win,
2959     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2960 {
2961     frame_T	*frp;
2962     frame_T	*other_fr, *target_fr;
2963 
2964     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2965 	return alt_tabpage()->tp_curwin->w_frame;
2966 
2967     frp = win->w_frame;
2968 
2969     if (frp->fr_prev == NULL)
2970 	return frp->fr_next;
2971     if (frp->fr_next == NULL)
2972 	return frp->fr_prev;
2973 
2974     // By default the next window will get the space that was abandoned by this
2975     // window
2976     target_fr = frp->fr_next;
2977     other_fr  = frp->fr_prev;
2978 
2979     // If this is part of a column of windows and 'splitbelow' is true then the
2980     // previous window will get the space.
2981     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_COL && p_sb)
2982     {
2983 	target_fr = frp->fr_prev;
2984 	other_fr  = frp->fr_next;
2985     }
2986 
2987     // If this is part of a row of windows, and 'splitright' is true then the
2988     // previous window will get the space.
2989     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW && p_spr)
2990     {
2991 	target_fr = frp->fr_prev;
2992 	other_fr  = frp->fr_next;
2993     }
2994 
2995     // If 'wfh' or 'wfw' is set for the target and not for the alternate
2996     // window, reverse the selection.
2997     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
2998     {
2999 	if (frame_fixed_width(target_fr) && !frame_fixed_width(other_fr))
3000 	    target_fr = other_fr;
3001     }
3002     else
3003     {
3004 	if (frame_fixed_height(target_fr) && !frame_fixed_height(other_fr))
3005 	    target_fr = other_fr;
3006     }
3007 
3008     return target_fr;
3009 }
3010 
3011 /*
3012  * Return the tabpage that will be used if the current one is closed.
3013  */
3014     static tabpage_T *
3015 alt_tabpage(void)
3016 {
3017     tabpage_T	*tp;
3018 
3019     // Use the next tab page if possible.
3020     if (curtab->tp_next != NULL)
3021 	return curtab->tp_next;
3022 
3023     // Find the last but one tab page.
3024     for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
3025 	;
3026     return tp;
3027 }
3028 
3029 /*
3030  * Find the left-upper window in frame "frp".
3031  */
3032     static win_T *
3033 frame2win(frame_T *frp)
3034 {
3035     while (frp->fr_win == NULL)
3036 	frp = frp->fr_child;
3037     return frp->fr_win;
3038 }
3039 
3040 /*
3041  * Return TRUE if frame "frp" contains window "wp".
3042  */
3043     static int
3044 frame_has_win(frame_T *frp, win_T *wp)
3045 {
3046     frame_T	*p;
3047 
3048     if (frp->fr_layout == FR_LEAF)
3049 	return frp->fr_win == wp;
3050 
3051     FOR_ALL_FRAMES(p, frp->fr_child)
3052 	if (frame_has_win(p, wp))
3053 	    return TRUE;
3054     return FALSE;
3055 }
3056 
3057 /*
3058  * Set a new height for a frame.  Recursively sets the height for contained
3059  * frames and windows.  Caller must take care of positions.
3060  */
3061     static void
3062 frame_new_height(
3063     frame_T	*topfrp,
3064     int		height,
3065     int		topfirst,	// resize topmost contained frame first
3066     int		wfh)		// obey 'winfixheight' when there is a choice;
3067 				// may cause the height not to be set
3068 {
3069     frame_T	*frp;
3070     int		extra_lines;
3071     int		h;
3072 
3073     if (topfrp->fr_win != NULL)
3074     {
3075 	// Simple case: just one window.
3076 	win_new_height(topfrp->fr_win,
3077 				    height - topfrp->fr_win->w_status_height
3078 					      - WINBAR_HEIGHT(topfrp->fr_win));
3079     }
3080     else if (topfrp->fr_layout == FR_ROW)
3081     {
3082 	do
3083 	{
3084 	    // All frames in this row get the same new height.
3085 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3086 	    {
3087 		frame_new_height(frp, height, topfirst, wfh);
3088 		if (frp->fr_height > height)
3089 		{
3090 		    // Could not fit the windows, make the whole row higher.
3091 		    height = frp->fr_height;
3092 		    break;
3093 		}
3094 	    }
3095 	}
3096 	while (frp != NULL);
3097     }
3098     else    // fr_layout == FR_COL
3099     {
3100 	// Complicated case: Resize a column of frames.  Resize the bottom
3101 	// frame first, frames above that when needed.
3102 
3103 	frp = topfrp->fr_child;
3104 	if (wfh)
3105 	    // Advance past frames with one window with 'wfh' set.
3106 	    while (frame_fixed_height(frp))
3107 	    {
3108 		frp = frp->fr_next;
3109 		if (frp == NULL)
3110 		    return;	    // no frame without 'wfh', give up
3111 	    }
3112 	if (!topfirst)
3113 	{
3114 	    // Find the bottom frame of this column
3115 	    while (frp->fr_next != NULL)
3116 		frp = frp->fr_next;
3117 	    if (wfh)
3118 		// Advance back for frames with one window with 'wfh' set.
3119 		while (frame_fixed_height(frp))
3120 		    frp = frp->fr_prev;
3121 	}
3122 
3123 	extra_lines = height - topfrp->fr_height;
3124 	if (extra_lines < 0)
3125 	{
3126 	    // reduce height of contained frames, bottom or top frame first
3127 	    while (frp != NULL)
3128 	    {
3129 		h = frame_minheight(frp, NULL);
3130 		if (frp->fr_height + extra_lines < h)
3131 		{
3132 		    extra_lines += frp->fr_height - h;
3133 		    frame_new_height(frp, h, topfirst, wfh);
3134 		}
3135 		else
3136 		{
3137 		    frame_new_height(frp, frp->fr_height + extra_lines,
3138 							       topfirst, wfh);
3139 		    break;
3140 		}
3141 		if (topfirst)
3142 		{
3143 		    do
3144 			frp = frp->fr_next;
3145 		    while (wfh && frp != NULL && frame_fixed_height(frp));
3146 		}
3147 		else
3148 		{
3149 		    do
3150 			frp = frp->fr_prev;
3151 		    while (wfh && frp != NULL && frame_fixed_height(frp));
3152 		}
3153 		// Increase "height" if we could not reduce enough frames.
3154 		if (frp == NULL)
3155 		    height -= extra_lines;
3156 	    }
3157 	}
3158 	else if (extra_lines > 0)
3159 	{
3160 	    // increase height of bottom or top frame
3161 	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
3162 	}
3163     }
3164     topfrp->fr_height = height;
3165 }
3166 
3167 /*
3168  * Return TRUE if height of frame "frp" should not be changed because of
3169  * the 'winfixheight' option.
3170  */
3171     static int
3172 frame_fixed_height(frame_T *frp)
3173 {
3174     // frame with one window: fixed height if 'winfixheight' set.
3175     if (frp->fr_win != NULL)
3176 	return frp->fr_win->w_p_wfh;
3177 
3178     if (frp->fr_layout == FR_ROW)
3179     {
3180 	// The frame is fixed height if one of the frames in the row is fixed
3181 	// height.
3182 	FOR_ALL_FRAMES(frp, frp->fr_child)
3183 	    if (frame_fixed_height(frp))
3184 		return TRUE;
3185 	return FALSE;
3186     }
3187 
3188     // frp->fr_layout == FR_COL: The frame is fixed height if all of the
3189     // frames in the row are fixed height.
3190     FOR_ALL_FRAMES(frp, frp->fr_child)
3191 	if (!frame_fixed_height(frp))
3192 	    return FALSE;
3193     return TRUE;
3194 }
3195 
3196 /*
3197  * Return TRUE if width of frame "frp" should not be changed because of
3198  * the 'winfixwidth' option.
3199  */
3200     static int
3201 frame_fixed_width(frame_T *frp)
3202 {
3203     // frame with one window: fixed width if 'winfixwidth' set.
3204     if (frp->fr_win != NULL)
3205 	return frp->fr_win->w_p_wfw;
3206 
3207     if (frp->fr_layout == FR_COL)
3208     {
3209 	// The frame is fixed width if one of the frames in the row is fixed
3210 	// width.
3211 	FOR_ALL_FRAMES(frp, frp->fr_child)
3212 	    if (frame_fixed_width(frp))
3213 		return TRUE;
3214 	return FALSE;
3215     }
3216 
3217     // frp->fr_layout == FR_ROW: The frame is fixed width if all of the
3218     // frames in the row are fixed width.
3219     FOR_ALL_FRAMES(frp, frp->fr_child)
3220 	if (!frame_fixed_width(frp))
3221 	    return FALSE;
3222     return TRUE;
3223 }
3224 
3225 /*
3226  * Add a status line to windows at the bottom of "frp".
3227  * Note: Does not check if there is room!
3228  */
3229     static void
3230 frame_add_statusline(frame_T *frp)
3231 {
3232     win_T	*wp;
3233 
3234     if (frp->fr_layout == FR_LEAF)
3235     {
3236 	wp = frp->fr_win;
3237 	if (wp->w_status_height == 0)
3238 	{
3239 	    if (wp->w_height > 0)	// don't make it negative
3240 		--wp->w_height;
3241 	    wp->w_status_height = STATUS_HEIGHT;
3242 	}
3243     }
3244     else if (frp->fr_layout == FR_ROW)
3245     {
3246 	// Handle all the frames in the row.
3247 	FOR_ALL_FRAMES(frp, frp->fr_child)
3248 	    frame_add_statusline(frp);
3249     }
3250     else // frp->fr_layout == FR_COL
3251     {
3252 	// Only need to handle the last frame in the column.
3253 	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
3254 	    ;
3255 	frame_add_statusline(frp);
3256     }
3257 }
3258 
3259 /*
3260  * Set width of a frame.  Handles recursively going through contained frames.
3261  * May remove separator line for windows at the right side (for win_close()).
3262  */
3263     static void
3264 frame_new_width(
3265     frame_T	*topfrp,
3266     int		width,
3267     int		leftfirst,	// resize leftmost contained frame first
3268     int		wfw)		// obey 'winfixwidth' when there is a choice;
3269 				// may cause the width not to be set
3270 {
3271     frame_T	*frp;
3272     int		extra_cols;
3273     int		w;
3274     win_T	*wp;
3275 
3276     if (topfrp->fr_layout == FR_LEAF)
3277     {
3278 	// Simple case: just one window.
3279 	wp = topfrp->fr_win;
3280 	// Find out if there are any windows right of this one.
3281 	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
3282 	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
3283 		break;
3284 	if (frp->fr_parent == NULL)
3285 	    wp->w_vsep_width = 0;
3286 	win_new_width(wp, width - wp->w_vsep_width);
3287     }
3288     else if (topfrp->fr_layout == FR_COL)
3289     {
3290 	do
3291 	{
3292 	    // All frames in this column get the same new width.
3293 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3294 	    {
3295 		frame_new_width(frp, width, leftfirst, wfw);
3296 		if (frp->fr_width > width)
3297 		{
3298 		    // Could not fit the windows, make whole column wider.
3299 		    width = frp->fr_width;
3300 		    break;
3301 		}
3302 	    }
3303 	} while (frp != NULL);
3304     }
3305     else    // fr_layout == FR_ROW
3306     {
3307 	// Complicated case: Resize a row of frames.  Resize the rightmost
3308 	// frame first, frames left of it when needed.
3309 
3310 	frp = topfrp->fr_child;
3311 	if (wfw)
3312 	    // Advance past frames with one window with 'wfw' set.
3313 	    while (frame_fixed_width(frp))
3314 	    {
3315 		frp = frp->fr_next;
3316 		if (frp == NULL)
3317 		    return;	    // no frame without 'wfw', give up
3318 	    }
3319 	if (!leftfirst)
3320 	{
3321 	    // Find the rightmost frame of this row
3322 	    while (frp->fr_next != NULL)
3323 		frp = frp->fr_next;
3324 	    if (wfw)
3325 		// Advance back for frames with one window with 'wfw' set.
3326 		while (frame_fixed_width(frp))
3327 		    frp = frp->fr_prev;
3328 	}
3329 
3330 	extra_cols = width - topfrp->fr_width;
3331 	if (extra_cols < 0)
3332 	{
3333 	    // reduce frame width, rightmost frame first
3334 	    while (frp != NULL)
3335 	    {
3336 		w = frame_minwidth(frp, NULL);
3337 		if (frp->fr_width + extra_cols < w)
3338 		{
3339 		    extra_cols += frp->fr_width - w;
3340 		    frame_new_width(frp, w, leftfirst, wfw);
3341 		}
3342 		else
3343 		{
3344 		    frame_new_width(frp, frp->fr_width + extra_cols,
3345 							      leftfirst, wfw);
3346 		    break;
3347 		}
3348 		if (leftfirst)
3349 		{
3350 		    do
3351 			frp = frp->fr_next;
3352 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3353 		}
3354 		else
3355 		{
3356 		    do
3357 			frp = frp->fr_prev;
3358 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3359 		}
3360 		// Increase "width" if we could not reduce enough frames.
3361 		if (frp == NULL)
3362 		    width -= extra_cols;
3363 	    }
3364 	}
3365 	else if (extra_cols > 0)
3366 	{
3367 	    // increase width of rightmost frame
3368 	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
3369 	}
3370     }
3371     topfrp->fr_width = width;
3372 }
3373 
3374 /*
3375  * Add the vertical separator to windows at the right side of "frp".
3376  * Note: Does not check if there is room!
3377  */
3378     static void
3379 frame_add_vsep(frame_T *frp)
3380 {
3381     win_T	*wp;
3382 
3383     if (frp->fr_layout == FR_LEAF)
3384     {
3385 	wp = frp->fr_win;
3386 	if (wp->w_vsep_width == 0)
3387 	{
3388 	    if (wp->w_width > 0)	// don't make it negative
3389 		--wp->w_width;
3390 	    wp->w_vsep_width = 1;
3391 	}
3392     }
3393     else if (frp->fr_layout == FR_COL)
3394     {
3395 	// Handle all the frames in the column.
3396 	FOR_ALL_FRAMES(frp, frp->fr_child)
3397 	    frame_add_vsep(frp);
3398     }
3399     else // frp->fr_layout == FR_ROW
3400     {
3401 	// Only need to handle the last frame in the row.
3402 	frp = frp->fr_child;
3403 	while (frp->fr_next != NULL)
3404 	    frp = frp->fr_next;
3405 	frame_add_vsep(frp);
3406     }
3407 }
3408 
3409 /*
3410  * Set frame width from the window it contains.
3411  */
3412     static void
3413 frame_fix_width(win_T *wp)
3414 {
3415     wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
3416 }
3417 
3418 /*
3419  * Set frame height from the window it contains.
3420  */
3421     static void
3422 frame_fix_height(win_T *wp)
3423 {
3424     wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
3425 }
3426 
3427 /*
3428  * Compute the minimal height for frame "topfrp".
3429  * Uses the 'winminheight' option.
3430  * When "next_curwin" isn't NULL, use p_wh for this window.
3431  * When "next_curwin" is NOWIN, don't use at least one line for the current
3432  * window.
3433  */
3434     static int
3435 frame_minheight(frame_T *topfrp, win_T *next_curwin)
3436 {
3437     frame_T	*frp;
3438     int		m;
3439     int		n;
3440 
3441     if (topfrp->fr_win != NULL)
3442     {
3443 	if (topfrp->fr_win == next_curwin)
3444 	    m = p_wh + topfrp->fr_win->w_status_height;
3445 	else
3446 	{
3447 	    // window: minimal height of the window plus status line
3448 	    m = p_wmh + topfrp->fr_win->w_status_height;
3449 	    if (topfrp->fr_win == curwin && next_curwin == NULL)
3450 	    {
3451 		// Current window is minimal one line high and WinBar is
3452 		// visible.
3453 		if (p_wmh == 0)
3454 		    ++m;
3455 		m += WINBAR_HEIGHT(curwin);
3456 	    }
3457 	}
3458     }
3459     else if (topfrp->fr_layout == FR_ROW)
3460     {
3461 	// get the minimal height from each frame in this row
3462 	m = 0;
3463 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3464 	{
3465 	    n = frame_minheight(frp, next_curwin);
3466 	    if (n > m)
3467 		m = n;
3468 	}
3469     }
3470     else
3471     {
3472 	// Add up the minimal heights for all frames in this column.
3473 	m = 0;
3474 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3475 	    m += frame_minheight(frp, next_curwin);
3476     }
3477 
3478     return m;
3479 }
3480 
3481 /*
3482  * Compute the minimal width for frame "topfrp".
3483  * When "next_curwin" isn't NULL, use p_wiw for this window.
3484  * When "next_curwin" is NOWIN, don't use at least one column for the current
3485  * window.
3486  */
3487     static int
3488 frame_minwidth(
3489     frame_T	*topfrp,
3490     win_T	*next_curwin)	// use p_wh and p_wiw for next_curwin
3491 {
3492     frame_T	*frp;
3493     int		m, n;
3494 
3495     if (topfrp->fr_win != NULL)
3496     {
3497 	if (topfrp->fr_win == next_curwin)
3498 	    m = p_wiw + topfrp->fr_win->w_vsep_width;
3499 	else
3500 	{
3501 	    // window: minimal width of the window plus separator column
3502 	    m = p_wmw + topfrp->fr_win->w_vsep_width;
3503 	    // Current window is minimal one column wide
3504 	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
3505 		++m;
3506 	}
3507     }
3508     else if (topfrp->fr_layout == FR_COL)
3509     {
3510 	// get the minimal width from each frame in this column
3511 	m = 0;
3512 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3513 	{
3514 	    n = frame_minwidth(frp, next_curwin);
3515 	    if (n > m)
3516 		m = n;
3517 	}
3518     }
3519     else
3520     {
3521 	// Add up the minimal widths for all frames in this row.
3522 	m = 0;
3523 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3524 	    m += frame_minwidth(frp, next_curwin);
3525     }
3526 
3527     return m;
3528 }
3529 
3530 
3531 /*
3532  * Try to close all windows except current one.
3533  * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
3534  * used and the buffer was modified.
3535  *
3536  * Used by ":bdel" and ":only".
3537  */
3538     void
3539 close_others(
3540     int		message,
3541     int		forceit)	    // always hide all other windows
3542 {
3543     win_T	*wp;
3544     win_T	*nextwp;
3545     int		r;
3546 
3547     if (one_window())
3548     {
3549 	if (message && !autocmd_busy)
3550 	    msg(_(m_onlyone));
3551 	return;
3552     }
3553 
3554     // Be very careful here: autocommands may change the window layout.
3555     for (wp = firstwin; win_valid(wp); wp = nextwp)
3556     {
3557 	nextwp = wp->w_next;
3558 	if (wp != curwin)		// don't close current window
3559 	{
3560 
3561 	    // Check if it's allowed to abandon this window
3562 	    r = can_abandon(wp->w_buffer, forceit);
3563 	    if (!win_valid(wp))		// autocommands messed wp up
3564 	    {
3565 		nextwp = firstwin;
3566 		continue;
3567 	    }
3568 	    if (!r)
3569 	    {
3570 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
3571 		if (message && (p_confirm || cmdmod.confirm) && p_write)
3572 		{
3573 		    dialog_changed(wp->w_buffer, FALSE);
3574 		    if (!win_valid(wp))		// autocommands messed wp up
3575 		    {
3576 			nextwp = firstwin;
3577 			continue;
3578 		    }
3579 		}
3580 		if (bufIsChanged(wp->w_buffer))
3581 #endif
3582 		    continue;
3583 	    }
3584 	    win_close(wp, !buf_hide(wp->w_buffer)
3585 					       && !bufIsChanged(wp->w_buffer));
3586 	}
3587     }
3588 
3589     if (message && !ONE_WINDOW)
3590 	emsg(_("E445: Other window contains changes"));
3591 }
3592 
3593     static void
3594 win_init_empty(win_T *wp)
3595 {
3596     redraw_win_later(wp, NOT_VALID);
3597     wp->w_lines_valid = 0;
3598     wp->w_cursor.lnum = 1;
3599     wp->w_curswant = wp->w_cursor.col = 0;
3600     wp->w_cursor.coladd = 0;
3601     wp->w_pcmark.lnum = 1;	// pcmark not cleared but set to line 1
3602     wp->w_pcmark.col = 0;
3603     wp->w_prev_pcmark.lnum = 0;
3604     wp->w_prev_pcmark.col = 0;
3605     wp->w_topline = 1;
3606 #ifdef FEAT_DIFF
3607     wp->w_topfill = 0;
3608 #endif
3609     wp->w_botline = 2;
3610 #if defined(FEAT_SYN_HL) || defined(FEAT_SPELL)
3611     wp->w_s = &wp->w_buffer->b_s;
3612 #endif
3613 }
3614 
3615 /*
3616  * Init the current window "curwin".
3617  * Called when a new file is being edited.
3618  */
3619     void
3620 curwin_init(void)
3621 {
3622     win_init_empty(curwin);
3623 }
3624 
3625 /*
3626  * Allocate the first window and put an empty buffer in it.
3627  * Called from main().
3628  * Return FAIL when something goes wrong (out of memory).
3629  */
3630     int
3631 win_alloc_first(void)
3632 {
3633     if (win_alloc_firstwin(NULL) == FAIL)
3634 	return FAIL;
3635 
3636     first_tabpage = alloc_tabpage();
3637     if (first_tabpage == NULL)
3638 	return FAIL;
3639     first_tabpage->tp_topframe = topframe;
3640     curtab = first_tabpage;
3641     curtab->tp_firstwin = firstwin;
3642     curtab->tp_lastwin = lastwin;
3643     curtab->tp_curwin = curwin;
3644 
3645     return OK;
3646 }
3647 
3648 /*
3649  * Allocate and init a window that is not a regular window.
3650  * This can only be done after the first window is fully initialized, thus it
3651  * can't be in win_alloc_first().
3652  */
3653     win_T *
3654 win_alloc_popup_win(void)
3655 {
3656     win_T *wp;
3657 
3658     wp = win_alloc(NULL, TRUE);
3659     if (wp != NULL)
3660     {
3661 	// We need to initialize options with something, using the current
3662 	// window makes most sense.
3663 	win_init_some(wp, curwin);
3664 
3665 	RESET_BINDING(wp);
3666 	new_frame(wp);
3667     }
3668     return wp;
3669 }
3670 
3671 /*
3672  * Initialize window "wp" to display buffer "buf".
3673  */
3674     void
3675 win_init_popup_win(win_T *wp, buf_T *buf)
3676 {
3677     wp->w_buffer = buf;
3678     ++buf->b_nwindows;
3679     win_init_empty(wp); // set cursor and topline to safe values
3680 
3681     // Make sure w_localdir and globaldir are NULL to avoid a chdir() in
3682     // win_enter_ext().
3683     VIM_CLEAR(wp->w_localdir);
3684 }
3685 
3686 /*
3687  * Allocate the first window or the first window in a new tab page.
3688  * When "oldwin" is NULL create an empty buffer for it.
3689  * When "oldwin" is not NULL copy info from it to the new window.
3690  * Return FAIL when something goes wrong (out of memory).
3691  */
3692     static int
3693 win_alloc_firstwin(win_T *oldwin)
3694 {
3695     curwin = win_alloc(NULL, FALSE);
3696     if (oldwin == NULL)
3697     {
3698 	// Very first window, need to create an empty buffer for it and
3699 	// initialize from scratch.
3700 	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
3701 	if (curwin == NULL || curbuf == NULL)
3702 	    return FAIL;
3703 	curwin->w_buffer = curbuf;
3704 #ifdef FEAT_SYN_HL
3705 	curwin->w_s = &(curbuf->b_s);
3706 #endif
3707 	curbuf->b_nwindows = 1;	// there is one window
3708 	curwin->w_alist = &global_alist;
3709 	curwin_init();		// init current window
3710     }
3711     else
3712     {
3713 	// First window in new tab page, initialize it from "oldwin".
3714 	win_init(curwin, oldwin, 0);
3715 
3716 	// We don't want cursor- and scroll-binding in the first window.
3717 	RESET_BINDING(curwin);
3718     }
3719 
3720     new_frame(curwin);
3721     if (curwin->w_frame == NULL)
3722 	return FAIL;
3723     topframe = curwin->w_frame;
3724     topframe->fr_width = Columns;
3725     topframe->fr_height = Rows - p_ch;
3726 
3727     return OK;
3728 }
3729 
3730 /*
3731  * Create a frame for window "wp".
3732  */
3733     static void
3734 new_frame(win_T *wp)
3735 {
3736     frame_T *frp = ALLOC_CLEAR_ONE(frame_T);
3737 
3738     wp->w_frame = frp;
3739     if (frp != NULL)
3740     {
3741 	frp->fr_layout = FR_LEAF;
3742 	frp->fr_win = wp;
3743     }
3744 }
3745 
3746 /*
3747  * Initialize the window and frame size to the maximum.
3748  */
3749     void
3750 win_init_size(void)
3751 {
3752     firstwin->w_height = ROWS_AVAIL;
3753     topframe->fr_height = ROWS_AVAIL;
3754     firstwin->w_width = Columns;
3755     topframe->fr_width = Columns;
3756 }
3757 
3758 /*
3759  * Allocate a new tabpage_T and init the values.
3760  * Returns NULL when out of memory.
3761  */
3762     static tabpage_T *
3763 alloc_tabpage(void)
3764 {
3765     tabpage_T	*tp;
3766 # ifdef FEAT_GUI
3767     int		i;
3768 # endif
3769 
3770 
3771     tp = ALLOC_CLEAR_ONE(tabpage_T);
3772     if (tp == NULL)
3773 	return NULL;
3774 
3775 # ifdef FEAT_EVAL
3776     // init t: variables
3777     tp->tp_vars = dict_alloc();
3778     if (tp->tp_vars == NULL)
3779     {
3780 	vim_free(tp);
3781 	return NULL;
3782     }
3783     init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
3784 # endif
3785 
3786 # ifdef FEAT_GUI
3787     for (i = 0; i < 3; i++)
3788 	tp->tp_prev_which_scrollbars[i] = -1;
3789 # endif
3790 # ifdef FEAT_DIFF
3791     tp->tp_diff_invalid = TRUE;
3792 # endif
3793     tp->tp_ch_used = p_ch;
3794 
3795     return tp;
3796 }
3797 
3798     void
3799 free_tabpage(tabpage_T *tp)
3800 {
3801     int idx;
3802 
3803 # ifdef FEAT_DIFF
3804     diff_clear(tp);
3805 # endif
3806 # ifdef FEAT_PROP_POPUP
3807     while (tp->tp_first_popupwin != NULL)
3808 	popup_close_tabpage(tp, tp->tp_first_popupwin->w_id, TRUE);
3809 #endif
3810     for (idx = 0; idx < SNAP_COUNT; ++idx)
3811 	clear_snapshot(tp, idx);
3812 #ifdef FEAT_EVAL
3813     vars_clear(&tp->tp_vars->dv_hashtab);	// free all t: variables
3814     hash_init(&tp->tp_vars->dv_hashtab);
3815     unref_var_dict(tp->tp_vars);
3816 #endif
3817 
3818     if (tp == lastused_tabpage)
3819 	lastused_tabpage = NULL;
3820 
3821     vim_free(tp->tp_localdir);
3822     vim_free(tp->tp_prevdir);
3823 
3824 #ifdef FEAT_PYTHON
3825     python_tabpage_free(tp);
3826 #endif
3827 
3828 #ifdef FEAT_PYTHON3
3829     python3_tabpage_free(tp);
3830 #endif
3831 
3832     vim_free(tp);
3833 }
3834 
3835 /*
3836  * Create a new Tab page with one window.
3837  * It will edit the current buffer, like after ":split".
3838  * When "after" is 0 put it just after the current Tab page.
3839  * Otherwise put it just before tab page "after".
3840  * Return FAIL or OK.
3841  */
3842     int
3843 win_new_tabpage(int after)
3844 {
3845     tabpage_T	*tp = curtab;
3846     tabpage_T	*prev_tp = curtab;
3847     tabpage_T	*newtp;
3848     int		n;
3849 
3850     newtp = alloc_tabpage();
3851     if (newtp == NULL)
3852 	return FAIL;
3853 
3854     // Remember the current windows in this Tab page.
3855     if (leave_tabpage(curbuf, TRUE) == FAIL)
3856     {
3857 	vim_free(newtp);
3858 	return FAIL;
3859     }
3860     curtab = newtp;
3861 
3862     newtp->tp_localdir = (tp->tp_localdir == NULL)
3863 				    ? NULL : vim_strsave(tp->tp_localdir);
3864     // Create a new empty window.
3865     if (win_alloc_firstwin(tp->tp_curwin) == OK)
3866     {
3867 	// Make the new Tab page the new topframe.
3868 	if (after == 1)
3869 	{
3870 	    // New tab page becomes the first one.
3871 	    newtp->tp_next = first_tabpage;
3872 	    first_tabpage = newtp;
3873 	}
3874 	else
3875 	{
3876 	    if (after > 0)
3877 	    {
3878 		// Put new tab page before tab page "after".
3879 		n = 2;
3880 		for (tp = first_tabpage; tp->tp_next != NULL
3881 					       && n < after; tp = tp->tp_next)
3882 		    ++n;
3883 	    }
3884 	    newtp->tp_next = tp->tp_next;
3885 	    tp->tp_next = newtp;
3886 	}
3887 	newtp->tp_firstwin = newtp->tp_lastwin = newtp->tp_curwin = curwin;
3888 
3889 	win_init_size();
3890 	firstwin->w_winrow = tabline_height();
3891 	win_comp_scroll(curwin);
3892 
3893 	newtp->tp_topframe = topframe;
3894 	last_status(FALSE);
3895 
3896 	lastused_tabpage = prev_tp;
3897 
3898 #if defined(FEAT_GUI)
3899 	// When 'guioptions' includes 'L' or 'R' may have to remove or add
3900 	// scrollbars.  Have to update them anyway.
3901 	gui_may_update_scrollbars();
3902 #endif
3903 #ifdef FEAT_JOB_CHANNEL
3904 	entering_window(curwin);
3905 #endif
3906 
3907 	redraw_all_later(NOT_VALID);
3908 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
3909 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
3910 	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
3911 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3912 	return OK;
3913     }
3914 
3915     // Failed, get back the previous Tab page
3916     enter_tabpage(curtab, curbuf, TRUE, TRUE);
3917     return FAIL;
3918 }
3919 
3920 /*
3921  * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
3922  * like with ":split".
3923  * Returns OK if a new tab page was created, FAIL otherwise.
3924  */
3925     static int
3926 may_open_tabpage(void)
3927 {
3928     int		n = (cmdmod.tab == 0) ? postponed_split_tab : cmdmod.tab;
3929 
3930     if (n != 0)
3931     {
3932 	cmdmod.tab = 0;	    // reset it to avoid doing it twice
3933 	postponed_split_tab = 0;
3934 	return win_new_tabpage(n);
3935     }
3936     return FAIL;
3937 }
3938 
3939 /*
3940  * Create up to "maxcount" tabpages with empty windows.
3941  * Returns the number of resulting tab pages.
3942  */
3943     int
3944 make_tabpages(int maxcount)
3945 {
3946     int		count = maxcount;
3947     int		todo;
3948 
3949     // Limit to 'tabpagemax' tabs.
3950     if (count > p_tpm)
3951 	count = p_tpm;
3952 
3953     /*
3954      * Don't execute autocommands while creating the tab pages.  Must do that
3955      * when putting the buffers in the windows.
3956      */
3957     block_autocmds();
3958 
3959     for (todo = count - 1; todo > 0; --todo)
3960 	if (win_new_tabpage(0) == FAIL)
3961 	    break;
3962 
3963     unblock_autocmds();
3964 
3965     // return actual number of tab pages
3966     return (count - todo);
3967 }
3968 
3969 /*
3970  * Return TRUE when "tpc" points to a valid tab page.
3971  */
3972     int
3973 valid_tabpage(tabpage_T *tpc)
3974 {
3975     tabpage_T	*tp;
3976 
3977     FOR_ALL_TABPAGES(tp)
3978 	if (tp == tpc)
3979 	    return TRUE;
3980     return FALSE;
3981 }
3982 
3983 /*
3984  * Return TRUE when "tpc" points to a valid tab page and at least one window is
3985  * valid.
3986  */
3987     int
3988 valid_tabpage_win(tabpage_T *tpc)
3989 {
3990     tabpage_T	*tp;
3991     win_T	*wp;
3992 
3993     FOR_ALL_TABPAGES(tp)
3994     {
3995 	if (tp == tpc)
3996 	{
3997 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
3998 	    {
3999 		if (win_valid_any_tab(wp))
4000 		    return TRUE;
4001 	    }
4002 	    return FALSE;
4003 	}
4004     }
4005     // shouldn't happen
4006     return FALSE;
4007 }
4008 
4009 /*
4010  * Close tabpage "tab", assuming it has no windows in it.
4011  * There must be another tabpage or this will crash.
4012  */
4013     void
4014 close_tabpage(tabpage_T *tab)
4015 {
4016     tabpage_T	*ptp;
4017 
4018     if (tab == first_tabpage)
4019     {
4020 	first_tabpage = tab->tp_next;
4021 	ptp = first_tabpage;
4022     }
4023     else
4024     {
4025 	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
4026 							    ptp = ptp->tp_next)
4027 	    ;
4028 	assert(ptp != NULL);
4029 	ptp->tp_next = tab->tp_next;
4030     }
4031 
4032     goto_tabpage_tp(ptp, FALSE, FALSE);
4033     free_tabpage(tab);
4034 }
4035 
4036 /*
4037  * Find tab page "n" (first one is 1).  Returns NULL when not found.
4038  */
4039     tabpage_T *
4040 find_tabpage(int n)
4041 {
4042     tabpage_T	*tp;
4043     int		i = 1;
4044 
4045     if (n == 0)
4046 	return curtab;
4047 
4048     for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
4049 	++i;
4050     return tp;
4051 }
4052 
4053 /*
4054  * Get index of tab page "tp".  First one has index 1.
4055  * When not found returns number of tab pages plus one.
4056  */
4057     int
4058 tabpage_index(tabpage_T *ftp)
4059 {
4060     int		i = 1;
4061     tabpage_T	*tp;
4062 
4063     for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
4064 	++i;
4065     return i;
4066 }
4067 
4068 /*
4069  * Prepare for leaving the current tab page.
4070  * When autocommands change "curtab" we don't leave the tab page and return
4071  * FAIL.
4072  * Careful: When OK is returned need to get a new tab page very very soon!
4073  */
4074     static int
4075 leave_tabpage(
4076     buf_T	*new_curbuf UNUSED,    // what is going to be the new curbuf,
4077 				       // NULL if unknown
4078     int		trigger_leave_autocmds UNUSED)
4079 {
4080     tabpage_T	*tp = curtab;
4081 
4082 #ifdef FEAT_JOB_CHANNEL
4083     leaving_window(curwin);
4084 #endif
4085     reset_VIsual_and_resel();	// stop Visual mode
4086     if (trigger_leave_autocmds)
4087     {
4088 	if (new_curbuf != curbuf)
4089 	{
4090 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4091 	    if (curtab != tp)
4092 		return FAIL;
4093 	}
4094 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4095 	if (curtab != tp)
4096 	    return FAIL;
4097 	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
4098 	if (curtab != tp)
4099 	    return FAIL;
4100     }
4101 #if defined(FEAT_GUI)
4102     // Remove the scrollbars.  They may be added back later.
4103     if (gui.in_use)
4104 	gui_remove_scrollbars();
4105 #endif
4106     tp->tp_curwin = curwin;
4107     tp->tp_prevwin = prevwin;
4108     tp->tp_firstwin = firstwin;
4109     tp->tp_lastwin = lastwin;
4110     tp->tp_old_Rows = Rows;
4111     tp->tp_old_Columns = Columns;
4112     firstwin = NULL;
4113     lastwin = NULL;
4114     return OK;
4115 }
4116 
4117 /*
4118  * Start using tab page "tp".
4119  * Only to be used after leave_tabpage() or freeing the current tab page.
4120  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4121  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4122  */
4123     static void
4124 enter_tabpage(
4125     tabpage_T	*tp,
4126     buf_T	*old_curbuf UNUSED,
4127     int		trigger_enter_autocmds,
4128     int		trigger_leave_autocmds)
4129 {
4130     int		row;
4131     int		old_off = tp->tp_firstwin->w_winrow;
4132     win_T	*next_prevwin = tp->tp_prevwin;
4133     tabpage_T	*last_tab = curtab;
4134 
4135     curtab = tp;
4136     firstwin = tp->tp_firstwin;
4137     lastwin = tp->tp_lastwin;
4138     topframe = tp->tp_topframe;
4139 
4140     // We would like doing the TabEnter event first, but we don't have a
4141     // valid current window yet, which may break some commands.
4142     // This triggers autocommands, thus may make "tp" invalid.
4143     win_enter_ext(tp->tp_curwin, FALSE, TRUE, FALSE,
4144 			      trigger_enter_autocmds, trigger_leave_autocmds);
4145     prevwin = next_prevwin;
4146 
4147     last_status(FALSE);		// status line may appear or disappear
4148     row = win_comp_pos();	// recompute w_winrow for all windows
4149 #ifdef FEAT_DIFF
4150     diff_need_scrollbind = TRUE;
4151 #endif
4152 
4153     // The tabpage line may have appeared or disappeared, may need to resize
4154     // the frames for that.  When the Vim window was resized need to update
4155     // frame sizes too.  Use the stored value of p_ch, so that it can be
4156     // different for each tab page.
4157     if (p_ch != curtab->tp_ch_used)
4158 	clear_cmdline = TRUE;
4159     p_ch = curtab->tp_ch_used;
4160 
4161     // When cmdheight is changed in a tab page with '<C-w>-', cmdline_row is
4162     // changed but p_ch and tp_ch_used are not changed. Thus we also need to
4163     // check cmdline_row.
4164     if ((row < cmdline_row) && (cmdline_row <= Rows - p_ch))
4165 	clear_cmdline = TRUE;
4166 
4167     if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
4168 #ifdef FEAT_GUI_TABLINE
4169 			    && !gui_use_tabline()
4170 #endif
4171 		))
4172 	shell_new_rows();
4173     if (curtab->tp_old_Columns != Columns && starting == 0)
4174 	shell_new_columns();	// update window widths
4175 
4176     lastused_tabpage = last_tab;
4177 
4178 #if defined(FEAT_GUI)
4179     // When 'guioptions' includes 'L' or 'R' may have to remove or add
4180     // scrollbars.  Have to update them anyway.
4181     gui_may_update_scrollbars();
4182 #endif
4183 
4184     // Apply autocommands after updating the display, when 'rows' and
4185     // 'columns' have been set correctly.
4186     if (trigger_enter_autocmds)
4187     {
4188 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
4189 	if (old_curbuf != curbuf)
4190 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4191     }
4192 
4193     redraw_all_later(NOT_VALID);
4194 }
4195 
4196 /*
4197  * Go to tab page "n".  For ":tab N" and "Ngt".
4198  * When "n" is 9999 go to the last tab page.
4199  */
4200     void
4201 goto_tabpage(int n)
4202 {
4203     tabpage_T	*tp = NULL;  // shut up compiler
4204     tabpage_T	*ttp;
4205     int		i;
4206 
4207     if (text_locked())
4208     {
4209 	// Not allowed when editing the command line.
4210 	text_locked_msg();
4211 	return;
4212     }
4213 
4214     // If there is only one it can't work.
4215     if (first_tabpage->tp_next == NULL)
4216     {
4217 	if (n > 1)
4218 	    beep_flush();
4219 	return;
4220     }
4221 
4222     if (n == 0)
4223     {
4224 	// No count, go to next tab page, wrap around end.
4225 	if (curtab->tp_next == NULL)
4226 	    tp = first_tabpage;
4227 	else
4228 	    tp = curtab->tp_next;
4229     }
4230     else if (n < 0)
4231     {
4232 	// "gT": go to previous tab page, wrap around end.  "N gT" repeats
4233 	// this N times.
4234 	ttp = curtab;
4235 	for (i = n; i < 0; ++i)
4236 	{
4237 	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
4238 		    tp = tp->tp_next)
4239 		;
4240 	    ttp = tp;
4241 	}
4242     }
4243     else if (n == 9999)
4244     {
4245 	// Go to last tab page.
4246 	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
4247 	    ;
4248     }
4249     else
4250     {
4251 	// Go to tab page "n".
4252 	tp = find_tabpage(n);
4253 	if (tp == NULL)
4254 	{
4255 	    beep_flush();
4256 	    return;
4257 	}
4258     }
4259 
4260     goto_tabpage_tp(tp, TRUE, TRUE);
4261 
4262 #ifdef FEAT_GUI_TABLINE
4263     if (gui_use_tabline())
4264 	gui_mch_set_curtab(tabpage_index(curtab));
4265 #endif
4266 }
4267 
4268 /*
4269  * Go to tabpage "tp".
4270  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4271  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4272  * Note: doesn't update the GUI tab.
4273  */
4274     void
4275 goto_tabpage_tp(
4276     tabpage_T	*tp,
4277     int		trigger_enter_autocmds,
4278     int		trigger_leave_autocmds)
4279 {
4280     // Don't repeat a message in another tab page.
4281     set_keep_msg(NULL, 0);
4282 
4283     if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
4284 					trigger_leave_autocmds) == OK)
4285     {
4286 	if (valid_tabpage(tp))
4287 	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
4288 		    trigger_leave_autocmds);
4289 	else
4290 	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
4291 		    trigger_leave_autocmds);
4292     }
4293 }
4294 
4295 /*
4296  * Go to the last accessed tab page, if there is one.
4297  * Return OK or FAIL
4298  */
4299     int
4300 goto_tabpage_lastused(void)
4301 {
4302     if (valid_tabpage(lastused_tabpage))
4303     {
4304 	goto_tabpage_tp(lastused_tabpage, TRUE, TRUE);
4305 	return OK;
4306     }
4307     return FAIL;
4308 }
4309 
4310 /*
4311  * Enter window "wp" in tab page "tp".
4312  * Also updates the GUI tab.
4313  */
4314     void
4315 goto_tabpage_win(tabpage_T *tp, win_T *wp)
4316 {
4317     goto_tabpage_tp(tp, TRUE, TRUE);
4318     if (curtab == tp && win_valid(wp))
4319     {
4320 	win_enter(wp, TRUE);
4321 # ifdef FEAT_GUI_TABLINE
4322 	if (gui_use_tabline())
4323 	    gui_mch_set_curtab(tabpage_index(curtab));
4324 # endif
4325     }
4326 }
4327 
4328 /*
4329  * Move the current tab page to after tab page "nr".
4330  */
4331     void
4332 tabpage_move(int nr)
4333 {
4334     int		n = 1;
4335     tabpage_T	*tp, *tp_dst;
4336 
4337     if (first_tabpage->tp_next == NULL)
4338 	return;
4339 
4340     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
4341 	++n;
4342 
4343     if (tp == curtab || (nr > 0 && tp->tp_next != NULL
4344 						    && tp->tp_next == curtab))
4345 	return;
4346 
4347     tp_dst = tp;
4348 
4349     // Remove the current tab page from the list of tab pages.
4350     if (curtab == first_tabpage)
4351 	first_tabpage = curtab->tp_next;
4352     else
4353     {
4354 	FOR_ALL_TABPAGES(tp)
4355 	    if (tp->tp_next == curtab)
4356 		break;
4357 	if (tp == NULL)	// "cannot happen"
4358 	    return;
4359 	tp->tp_next = curtab->tp_next;
4360     }
4361 
4362     // Re-insert it at the specified position.
4363     if (nr <= 0)
4364     {
4365 	curtab->tp_next = first_tabpage;
4366 	first_tabpage = curtab;
4367     }
4368     else
4369     {
4370 	curtab->tp_next = tp_dst->tp_next;
4371 	tp_dst->tp_next = curtab;
4372     }
4373 
4374     // Need to redraw the tabline.  Tab page contents doesn't change.
4375     redraw_tabline = TRUE;
4376 }
4377 
4378 
4379 /*
4380  * Go to another window.
4381  * When jumping to another buffer, stop Visual mode.  Do this before
4382  * changing windows so we can yank the selection into the '*' register.
4383  * When jumping to another window on the same buffer, adjust its cursor
4384  * position to keep the same Visual area.
4385  */
4386     void
4387 win_goto(win_T *wp)
4388 {
4389 #ifdef FEAT_CONCEAL
4390     win_T	*owp = curwin;
4391 #endif
4392 
4393 #ifdef FEAT_PROP_POPUP
4394     if (ERROR_IF_ANY_POPUP_WINDOW)
4395 	return;
4396     if (popup_is_popup(wp))
4397     {
4398 	emsg(_("E366: Not allowed to enter a popup window"));
4399 	return;
4400     }
4401 #endif
4402     if (text_and_win_locked())
4403     {
4404 	beep_flush();
4405 	text_locked_msg();
4406 	return;
4407     }
4408     if (curbuf_locked())
4409 	return;
4410 
4411     if (wp->w_buffer != curbuf)
4412 	reset_VIsual_and_resel();
4413     else if (VIsual_active)
4414 	wp->w_cursor = curwin->w_cursor;
4415 
4416 #ifdef FEAT_GUI
4417     need_mouse_correct = TRUE;
4418 #endif
4419     win_enter(wp, TRUE);
4420 
4421 #ifdef FEAT_CONCEAL
4422     // Conceal cursor line in previous window, unconceal in current window.
4423     if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
4424 	redrawWinline(owp, owp->w_cursor.lnum);
4425     if (curwin->w_p_cole > 0 && !msg_scrolled)
4426 	need_cursor_line_redraw = TRUE;
4427 #endif
4428 }
4429 
4430 #if defined(FEAT_PERL) || defined(PROTO)
4431 /*
4432  * Find window number "winnr" (counting top to bottom).
4433  */
4434     win_T *
4435 win_find_nr(int winnr)
4436 {
4437     win_T	*wp;
4438 
4439     FOR_ALL_WINDOWS(wp)
4440 	if (--winnr == 0)
4441 	    break;
4442     return wp;
4443 }
4444 #endif
4445 
4446 #if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
4447 /*
4448  * Find the tabpage for window "win".
4449  */
4450     tabpage_T *
4451 win_find_tabpage(win_T *win)
4452 {
4453     win_T	*wp;
4454     tabpage_T	*tp;
4455 
4456     FOR_ALL_TAB_WINDOWS(tp, wp)
4457 	    if (wp == win)
4458 		return tp;
4459     return NULL;
4460 }
4461 #endif
4462 
4463 /*
4464  * Get the above or below neighbor window of the specified window.
4465  *   up - TRUE for the above neighbor
4466  *   count - nth neighbor window
4467  * Returns the specified window if the neighbor is not found.
4468  */
4469     win_T *
4470 win_vert_neighbor(tabpage_T *tp, win_T *wp, int up, long count)
4471 {
4472     frame_T	*fr;
4473     frame_T	*nfr;
4474     frame_T	*foundfr;
4475 
4476 #ifdef FEAT_PROP_POPUP
4477     if (popup_is_popup(wp))
4478 	// popups don't have neighbors.
4479 	return NULL;
4480 #endif
4481     foundfr = wp->w_frame;
4482     while (count--)
4483     {
4484 	/*
4485 	 * First go upwards in the tree of frames until we find a upwards or
4486 	 * downwards neighbor.
4487 	 */
4488 	fr = foundfr;
4489 	for (;;)
4490 	{
4491 	    if (fr == tp->tp_topframe)
4492 		goto end;
4493 	    if (up)
4494 		nfr = fr->fr_prev;
4495 	    else
4496 		nfr = fr->fr_next;
4497 	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
4498 		break;
4499 	    fr = fr->fr_parent;
4500 	}
4501 
4502 	/*
4503 	 * Now go downwards to find the bottom or top frame in it.
4504 	 */
4505 	for (;;)
4506 	{
4507 	    if (nfr->fr_layout == FR_LEAF)
4508 	    {
4509 		foundfr = nfr;
4510 		break;
4511 	    }
4512 	    fr = nfr->fr_child;
4513 	    if (nfr->fr_layout == FR_ROW)
4514 	    {
4515 		// Find the frame at the cursor row.
4516 		while (fr->fr_next != NULL
4517 			&& frame2win(fr)->w_wincol + fr->fr_width
4518 					 <= wp->w_wincol + wp->w_wcol)
4519 		    fr = fr->fr_next;
4520 	    }
4521 	    if (nfr->fr_layout == FR_COL && up)
4522 		while (fr->fr_next != NULL)
4523 		    fr = fr->fr_next;
4524 	    nfr = fr;
4525 	}
4526     }
4527 end:
4528     return foundfr != NULL ? foundfr->fr_win : NULL;
4529 }
4530 
4531 /*
4532  * Move to window above or below "count" times.
4533  */
4534     static void
4535 win_goto_ver(
4536     int		up,		// TRUE to go to win above
4537     long	count)
4538 {
4539     win_T	*win;
4540 
4541 #ifdef FEAT_PROP_POPUP
4542     if (ERROR_IF_TERM_POPUP_WINDOW)
4543 	return;
4544 #endif
4545     win = win_vert_neighbor(curtab, curwin, up, count);
4546     if (win != NULL)
4547 	win_goto(win);
4548 }
4549 
4550 /*
4551  * Get the left or right neighbor window of the specified window.
4552  *   left - TRUE for the left neighbor
4553  *   count - nth neighbor window
4554  * Returns the specified window if the neighbor is not found.
4555  */
4556     win_T *
4557 win_horz_neighbor(tabpage_T *tp, win_T *wp, int left, long count)
4558 {
4559     frame_T	*fr;
4560     frame_T	*nfr;
4561     frame_T	*foundfr;
4562 
4563 #ifdef FEAT_PROP_POPUP
4564     if (popup_is_popup(wp))
4565 	// popups don't have neighbors.
4566 	return NULL;
4567 #endif
4568     foundfr = wp->w_frame;
4569     while (count--)
4570     {
4571 	/*
4572 	 * First go upwards in the tree of frames until we find a left or
4573 	 * right neighbor.
4574 	 */
4575 	fr = foundfr;
4576 	for (;;)
4577 	{
4578 	    if (fr == tp->tp_topframe)
4579 		goto end;
4580 	    if (left)
4581 		nfr = fr->fr_prev;
4582 	    else
4583 		nfr = fr->fr_next;
4584 	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
4585 		break;
4586 	    fr = fr->fr_parent;
4587 	}
4588 
4589 	/*
4590 	 * Now go downwards to find the leftmost or rightmost frame in it.
4591 	 */
4592 	for (;;)
4593 	{
4594 	    if (nfr->fr_layout == FR_LEAF)
4595 	    {
4596 		foundfr = nfr;
4597 		break;
4598 	    }
4599 	    fr = nfr->fr_child;
4600 	    if (nfr->fr_layout == FR_COL)
4601 	    {
4602 		// Find the frame at the cursor row.
4603 		while (fr->fr_next != NULL
4604 			&& frame2win(fr)->w_winrow + fr->fr_height
4605 					 <= wp->w_winrow + wp->w_wrow)
4606 		    fr = fr->fr_next;
4607 	    }
4608 	    if (nfr->fr_layout == FR_ROW && left)
4609 		while (fr->fr_next != NULL)
4610 		    fr = fr->fr_next;
4611 	    nfr = fr;
4612 	}
4613     }
4614 end:
4615     return foundfr != NULL ? foundfr->fr_win : NULL;
4616 }
4617 
4618 /*
4619  * Move to left or right window.
4620  */
4621     static void
4622 win_goto_hor(
4623     int		left,		// TRUE to go to left win
4624     long	count)
4625 {
4626     win_T	*win;
4627 
4628 #ifdef FEAT_PROP_POPUP
4629     if (ERROR_IF_TERM_POPUP_WINDOW)
4630 	return;
4631 #endif
4632     win = win_horz_neighbor(curtab, curwin, left, count);
4633     if (win != NULL)
4634 	win_goto(win);
4635 }
4636 
4637 /*
4638  * Make window "wp" the current window.
4639  */
4640     void
4641 win_enter(win_T *wp, int undo_sync)
4642 {
4643     win_enter_ext(wp, undo_sync, FALSE, FALSE, TRUE, TRUE);
4644 }
4645 
4646 /*
4647  * Make window wp the current window.
4648  * Can be called with "curwin_invalid" TRUE, which means that curwin has just
4649  * been closed and isn't valid.
4650  */
4651     static void
4652 win_enter_ext(
4653     win_T	*wp,
4654     int		undo_sync,
4655     int		curwin_invalid,
4656     int		trigger_new_autocmds,
4657     int		trigger_enter_autocmds,
4658     int		trigger_leave_autocmds)
4659 {
4660     int		other_buffer = FALSE;
4661 
4662     if (wp == curwin && !curwin_invalid)	// nothing to do
4663 	return;
4664 
4665 #ifdef FEAT_JOB_CHANNEL
4666     if (!curwin_invalid)
4667 	leaving_window(curwin);
4668 #endif
4669 
4670     if (!curwin_invalid && trigger_leave_autocmds)
4671     {
4672 	/*
4673 	 * Be careful: If autocommands delete the window, return now.
4674 	 */
4675 	if (wp->w_buffer != curbuf)
4676 	{
4677 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4678 	    other_buffer = TRUE;
4679 	    if (!win_valid(wp))
4680 		return;
4681 	}
4682 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4683 	if (!win_valid(wp))
4684 	    return;
4685 #ifdef FEAT_EVAL
4686 	// autocmds may abort script processing
4687 	if (aborting())
4688 	    return;
4689 #endif
4690     }
4691 
4692     // sync undo before leaving the current buffer
4693     if (undo_sync && curbuf != wp->w_buffer)
4694 	u_sync(FALSE);
4695 
4696     // Might need to scroll the old window before switching, e.g., when the
4697     // cursor was moved.
4698     update_topline();
4699 
4700     // may have to copy the buffer options when 'cpo' contains 'S'
4701     if (wp->w_buffer != curbuf)
4702 	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
4703     if (!curwin_invalid)
4704     {
4705 	prevwin = curwin;	// remember for CTRL-W p
4706 	curwin->w_redr_status = TRUE;
4707     }
4708     curwin = wp;
4709     curbuf = wp->w_buffer;
4710     check_cursor();
4711     if (!virtual_active())
4712 	curwin->w_cursor.coladd = 0;
4713     changed_line_abv_curs();	// assume cursor position needs updating
4714 
4715     if (curwin->w_localdir != NULL || curtab->tp_localdir != NULL)
4716     {
4717 	char_u	*dirname;
4718 
4719 	// Window or tab has a local directory: Save current directory as
4720 	// global directory (unless that was done already) and change to the
4721 	// local directory.
4722 	if (globaldir == NULL)
4723 	{
4724 	    char_u	cwd[MAXPATHL];
4725 
4726 	    if (mch_dirname(cwd, MAXPATHL) == OK)
4727 		globaldir = vim_strsave(cwd);
4728 	}
4729 	if (curwin->w_localdir != NULL)
4730 	    dirname = curwin->w_localdir;
4731 	else
4732 	    dirname = curtab->tp_localdir;
4733 
4734 	if (mch_chdir((char *)dirname) == 0)
4735 	    shorten_fnames(TRUE);
4736     }
4737     else if (globaldir != NULL)
4738     {
4739 	// Window doesn't have a local directory and we are not in the global
4740 	// directory: Change to the global directory.
4741 	vim_ignored = mch_chdir((char *)globaldir);
4742 	VIM_CLEAR(globaldir);
4743 	shorten_fnames(TRUE);
4744     }
4745 
4746 #ifdef FEAT_JOB_CHANNEL
4747     entering_window(curwin);
4748 #endif
4749     // Careful: autocommands may close the window and make "wp" invalid
4750     if (trigger_new_autocmds)
4751 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
4752     if (trigger_enter_autocmds)
4753     {
4754 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
4755 	if (other_buffer)
4756 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4757     }
4758 
4759 #ifdef FEAT_TITLE
4760     maketitle();
4761 #endif
4762     curwin->w_redr_status = TRUE;
4763 #ifdef FEAT_TERMINAL
4764     if (bt_terminal(curwin->w_buffer))
4765 	// terminal is likely in another mode
4766 	redraw_mode = TRUE;
4767 #endif
4768     redraw_tabline = TRUE;
4769     if (restart_edit)
4770 	redraw_later(VALID);	// causes status line redraw
4771 
4772     // set window height to desired minimal value
4773     if (curwin->w_height < p_wh && !curwin->w_p_wfh
4774 #ifdef FEAT_PROP_POPUP
4775 	    && !popup_is_popup(curwin)
4776 #endif
4777 	    )
4778 	win_setheight((int)p_wh);
4779     else if (curwin->w_height == 0)
4780 	win_setheight(1);
4781 
4782     // set window width to desired minimal value
4783     if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
4784 	win_setwidth((int)p_wiw);
4785 
4786     setmouse();			// in case jumped to/from help buffer
4787 
4788     // Change directories when the 'acd' option is set.
4789     DO_AUTOCHDIR;
4790 }
4791 
4792 
4793 /*
4794  * Jump to the first open window that contains buffer "buf", if one exists.
4795  * Returns a pointer to the window found, otherwise NULL.
4796  */
4797     win_T *
4798 buf_jump_open_win(buf_T *buf)
4799 {
4800     win_T	*wp = NULL;
4801 
4802     if (curwin->w_buffer == buf)
4803 	wp = curwin;
4804     else
4805 	FOR_ALL_WINDOWS(wp)
4806 	    if (wp->w_buffer == buf)
4807 		break;
4808     if (wp != NULL)
4809 	win_enter(wp, FALSE);
4810     return wp;
4811 }
4812 
4813 /*
4814  * Jump to the first open window in any tab page that contains buffer "buf",
4815  * if one exists.
4816  * Returns a pointer to the window found, otherwise NULL.
4817  */
4818     win_T *
4819 buf_jump_open_tab(buf_T *buf)
4820 {
4821     win_T	*wp = buf_jump_open_win(buf);
4822     tabpage_T	*tp;
4823 
4824     if (wp != NULL)
4825 	return wp;
4826 
4827     FOR_ALL_TABPAGES(tp)
4828 	if (tp != curtab)
4829 	{
4830 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
4831 		if (wp->w_buffer == buf)
4832 		    break;
4833 	    if (wp != NULL)
4834 	    {
4835 		goto_tabpage_win(tp, wp);
4836 		if (curwin != wp)
4837 		    wp = NULL;	// something went wrong
4838 		break;
4839 	    }
4840 	}
4841     return wp;
4842 }
4843 
4844 static int last_win_id = LOWEST_WIN_ID - 1;
4845 
4846 /*
4847  * Allocate a window structure and link it in the window list when "hidden" is
4848  * FALSE.
4849  */
4850     static win_T *
4851 win_alloc(win_T *after UNUSED, int hidden UNUSED)
4852 {
4853     win_T	*new_wp;
4854 
4855     /*
4856      * allocate window structure and linesizes arrays
4857      */
4858     new_wp = ALLOC_CLEAR_ONE(win_T);
4859     if (new_wp == NULL)
4860 	return NULL;
4861 
4862     if (win_alloc_lines(new_wp) == FAIL)
4863     {
4864 	vim_free(new_wp);
4865 	return NULL;
4866     }
4867 
4868     new_wp->w_id = ++last_win_id;
4869 
4870 #ifdef FEAT_EVAL
4871     // init w: variables
4872     new_wp->w_vars = dict_alloc();
4873     if (new_wp->w_vars == NULL)
4874     {
4875 	win_free_lsize(new_wp);
4876 	vim_free(new_wp);
4877 	return NULL;
4878     }
4879     init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
4880 #endif
4881 
4882     // Don't execute autocommands while the window is not properly
4883     // initialized yet.  gui_create_scrollbar() may trigger a FocusGained
4884     // event.
4885     block_autocmds();
4886 
4887     /*
4888      * link the window in the window list
4889      */
4890     if (!hidden)
4891 	win_append(after, new_wp);
4892     new_wp->w_wincol = 0;
4893     new_wp->w_width = Columns;
4894 
4895     // position the display and the cursor at the top of the file.
4896     new_wp->w_topline = 1;
4897 #ifdef FEAT_DIFF
4898     new_wp->w_topfill = 0;
4899 #endif
4900     new_wp->w_botline = 2;
4901     new_wp->w_cursor.lnum = 1;
4902     new_wp->w_scbind_pos = 1;
4903 
4904     // use global option value for global-local options
4905     new_wp->w_p_so = -1;
4906     new_wp->w_p_siso = -1;
4907 
4908     // We won't calculate w_fraction until resizing the window
4909     new_wp->w_fraction = 0;
4910     new_wp->w_prev_fraction_row = -1;
4911 
4912 #ifdef FEAT_GUI
4913     if (gui.in_use)
4914     {
4915 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
4916 		SBAR_LEFT, new_wp);
4917 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
4918 		SBAR_RIGHT, new_wp);
4919     }
4920 #endif
4921 #ifdef FEAT_FOLDING
4922     foldInitWin(new_wp);
4923 #endif
4924     unblock_autocmds();
4925 #ifdef FEAT_SEARCH_EXTRA
4926     new_wp->w_match_head = NULL;
4927     new_wp->w_next_match_id = 4;
4928 #endif
4929     return new_wp;
4930 }
4931 
4932 /*
4933  * Remove window 'wp' from the window list and free the structure.
4934  */
4935     static void
4936 win_free(
4937     win_T	*wp,
4938     tabpage_T	*tp)		// tab page "win" is in, NULL for current
4939 {
4940     int		i;
4941     buf_T	*buf;
4942     wininfo_T	*wip;
4943 
4944 #ifdef FEAT_FOLDING
4945     clearFolding(wp);
4946 #endif
4947 
4948     // reduce the reference count to the argument list.
4949     alist_unlink(wp->w_alist);
4950 
4951     // Don't execute autocommands while the window is halfway being deleted.
4952     // gui_mch_destroy_scrollbar() may trigger a FocusGained event.
4953     block_autocmds();
4954 
4955 #ifdef FEAT_LUA
4956     lua_window_free(wp);
4957 #endif
4958 
4959 #ifdef FEAT_MZSCHEME
4960     mzscheme_window_free(wp);
4961 #endif
4962 
4963 #ifdef FEAT_PERL
4964     perl_win_free(wp);
4965 #endif
4966 
4967 #ifdef FEAT_PYTHON
4968     python_window_free(wp);
4969 #endif
4970 
4971 #ifdef FEAT_PYTHON3
4972     python3_window_free(wp);
4973 #endif
4974 
4975 #ifdef FEAT_TCL
4976     tcl_window_free(wp);
4977 #endif
4978 
4979 #ifdef FEAT_RUBY
4980     ruby_window_free(wp);
4981 #endif
4982 
4983     clear_winopt(&wp->w_onebuf_opt);
4984     clear_winopt(&wp->w_allbuf_opt);
4985 
4986 #ifdef FEAT_EVAL
4987     vars_clear(&wp->w_vars->dv_hashtab);	// free all w: variables
4988     hash_init(&wp->w_vars->dv_hashtab);
4989     unref_var_dict(wp->w_vars);
4990 #endif
4991 
4992     {
4993 	tabpage_T	*ttp;
4994 
4995 	if (prevwin == wp)
4996 	    prevwin = NULL;
4997 	FOR_ALL_TABPAGES(ttp)
4998 	    if (ttp->tp_prevwin == wp)
4999 		ttp->tp_prevwin = NULL;
5000     }
5001     win_free_lsize(wp);
5002 
5003     for (i = 0; i < wp->w_tagstacklen; ++i)
5004     {
5005 	vim_free(wp->w_tagstack[i].tagname);
5006 	vim_free(wp->w_tagstack[i].user_data);
5007     }
5008     vim_free(wp->w_localdir);
5009     vim_free(wp->w_prevdir);
5010 
5011     // Remove the window from the b_wininfo lists, it may happen that the
5012     // freed memory is re-used for another window.
5013     FOR_ALL_BUFFERS(buf)
5014 	FOR_ALL_BUF_WININFO(buf, wip)
5015 	    if (wip->wi_win == wp)
5016 		wip->wi_win = NULL;
5017 
5018 #ifdef FEAT_SEARCH_EXTRA
5019     clear_matches(wp);
5020 #endif
5021 
5022 #ifdef FEAT_JUMPLIST
5023     free_jumplist(wp);
5024 #endif
5025 
5026 #ifdef FEAT_QUICKFIX
5027     qf_free_all(wp);
5028 #endif
5029 
5030 #ifdef FEAT_GUI
5031     if (gui.in_use)
5032     {
5033 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
5034 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
5035     }
5036 #endif // FEAT_GUI
5037 
5038 #ifdef FEAT_MENU
5039     remove_winbar(wp);
5040 #endif
5041 #ifdef FEAT_PROP_POPUP
5042     free_callback(&wp->w_close_cb);
5043     free_callback(&wp->w_filter_cb);
5044     for (i = 0; i < 4; ++i)
5045 	VIM_CLEAR(wp->w_border_highlight[i]);
5046     vim_free(wp->w_scrollbar_highlight);
5047     vim_free(wp->w_thumb_highlight);
5048     vim_free(wp->w_popup_title);
5049     list_unref(wp->w_popup_mask);
5050     vim_free(wp->w_popup_mask_cells);
5051 #endif
5052 
5053 #ifdef FEAT_SYN_HL
5054     vim_free(wp->w_p_cc_cols);
5055 #endif
5056 
5057     if (win_valid_any_tab(wp))
5058 	win_remove(wp, tp);
5059     if (autocmd_busy)
5060     {
5061 	wp->w_next = au_pending_free_win;
5062 	au_pending_free_win = wp;
5063     }
5064     else
5065 	vim_free(wp);
5066 
5067     unblock_autocmds();
5068 }
5069 
5070 /*
5071  * Return TRUE if "wp" is not in the list of windows: the autocmd window or a
5072  * popup window.
5073  */
5074     static int
5075 win_unlisted(win_T *wp)
5076 {
5077     return wp == aucmd_win || WIN_IS_POPUP(wp);
5078 }
5079 
5080 #if defined(FEAT_PROP_POPUP) || defined(PROTO)
5081 /*
5082  * Free a popup window.  This does not take the window out of the window list
5083  * and assumes there is only one toplevel frame, no split.
5084  */
5085     void
5086 win_free_popup(win_T *win)
5087 {
5088     if (bt_popup(win->w_buffer))
5089 	win_close_buffer(win, DOBUF_WIPE_REUSE, FALSE);
5090     else
5091 	close_buffer(win, win->w_buffer, 0, FALSE, FALSE);
5092 # if defined(FEAT_TIMERS)
5093     if (win->w_popup_timer != NULL)
5094 	stop_timer(win->w_popup_timer);
5095 # endif
5096     vim_free(win->w_frame);
5097     win_free(win, NULL);
5098 }
5099 #endif
5100 
5101 /*
5102  * Append window "wp" in the window list after window "after".
5103  */
5104     static void
5105 win_append(win_T *after, win_T *wp)
5106 {
5107     win_T	*before;
5108 
5109     if (after == NULL)	    // after NULL is in front of the first
5110 	before = firstwin;
5111     else
5112 	before = after->w_next;
5113 
5114     wp->w_next = before;
5115     wp->w_prev = after;
5116     if (after == NULL)
5117 	firstwin = wp;
5118     else
5119 	after->w_next = wp;
5120     if (before == NULL)
5121 	lastwin = wp;
5122     else
5123 	before->w_prev = wp;
5124 }
5125 
5126 /*
5127  * Remove a window from the window list.
5128  */
5129     void
5130 win_remove(
5131     win_T	*wp,
5132     tabpage_T	*tp)		// tab page "win" is in, NULL for current
5133 {
5134     if (wp->w_prev != NULL)
5135 	wp->w_prev->w_next = wp->w_next;
5136     else if (tp == NULL)
5137 	firstwin = curtab->tp_firstwin = wp->w_next;
5138     else
5139 	tp->tp_firstwin = wp->w_next;
5140 
5141     if (wp->w_next != NULL)
5142 	wp->w_next->w_prev = wp->w_prev;
5143     else if (tp == NULL)
5144 	lastwin = curtab->tp_lastwin = wp->w_prev;
5145     else
5146 	tp->tp_lastwin = wp->w_prev;
5147 }
5148 
5149 /*
5150  * Append frame "frp" in a frame list after frame "after".
5151  */
5152     static void
5153 frame_append(frame_T *after, frame_T *frp)
5154 {
5155     frp->fr_next = after->fr_next;
5156     after->fr_next = frp;
5157     if (frp->fr_next != NULL)
5158 	frp->fr_next->fr_prev = frp;
5159     frp->fr_prev = after;
5160 }
5161 
5162 /*
5163  * Insert frame "frp" in a frame list before frame "before".
5164  */
5165     static void
5166 frame_insert(frame_T *before, frame_T *frp)
5167 {
5168     frp->fr_next = before;
5169     frp->fr_prev = before->fr_prev;
5170     before->fr_prev = frp;
5171     if (frp->fr_prev != NULL)
5172 	frp->fr_prev->fr_next = frp;
5173     else
5174 	frp->fr_parent->fr_child = frp;
5175 }
5176 
5177 /*
5178  * Remove a frame from a frame list.
5179  */
5180     static void
5181 frame_remove(frame_T *frp)
5182 {
5183     if (frp->fr_prev != NULL)
5184 	frp->fr_prev->fr_next = frp->fr_next;
5185     else
5186     {
5187 	frp->fr_parent->fr_child = frp->fr_next;
5188 	// special case: topframe->fr_child == frp
5189 	if (topframe->fr_child == frp)
5190 	    topframe->fr_child = frp->fr_next;
5191     }
5192     if (frp->fr_next != NULL)
5193 	frp->fr_next->fr_prev = frp->fr_prev;
5194 }
5195 
5196 /*
5197  * Allocate w_lines[] for window "wp".
5198  * Return FAIL for failure, OK for success.
5199  */
5200     int
5201 win_alloc_lines(win_T *wp)
5202 {
5203     wp->w_lines_valid = 0;
5204     wp->w_lines = ALLOC_CLEAR_MULT(wline_T, Rows );
5205     if (wp->w_lines == NULL)
5206 	return FAIL;
5207     return OK;
5208 }
5209 
5210 /*
5211  * free lsize arrays for a window
5212  */
5213     void
5214 win_free_lsize(win_T *wp)
5215 {
5216     // TODO: why would wp be NULL here?
5217     if (wp != NULL)
5218 	VIM_CLEAR(wp->w_lines);
5219 }
5220 
5221 /*
5222  * Called from win_new_shellsize() after Rows changed.
5223  * This only does the current tab page, others must be done when made active.
5224  */
5225     void
5226 shell_new_rows(void)
5227 {
5228     int		h = (int)ROWS_AVAIL;
5229 
5230     if (firstwin == NULL)	// not initialized yet
5231 	return;
5232     if (h < frame_minheight(topframe, NULL))
5233 	h = frame_minheight(topframe, NULL);
5234 
5235     // First try setting the heights of windows with 'winfixheight'.  If
5236     // that doesn't result in the right height, forget about that option.
5237     frame_new_height(topframe, h, FALSE, TRUE);
5238     if (!frame_check_height(topframe, h))
5239 	frame_new_height(topframe, h, FALSE, FALSE);
5240 
5241     (void)win_comp_pos();		// recompute w_winrow and w_wincol
5242     compute_cmdrow();
5243     curtab->tp_ch_used = p_ch;
5244 
5245 #if 0
5246     // Disabled: don't want making the screen smaller make a window larger.
5247     if (p_ea)
5248 	win_equal(curwin, FALSE, 'v');
5249 #endif
5250 }
5251 
5252 /*
5253  * Called from win_new_shellsize() after Columns changed.
5254  */
5255     void
5256 shell_new_columns(void)
5257 {
5258     if (firstwin == NULL)	// not initialized yet
5259 	return;
5260 
5261     // First try setting the widths of windows with 'winfixwidth'.  If that
5262     // doesn't result in the right width, forget about that option.
5263     frame_new_width(topframe, (int)Columns, FALSE, TRUE);
5264     if (!frame_check_width(topframe, Columns))
5265 	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
5266 
5267     (void)win_comp_pos();		// recompute w_winrow and w_wincol
5268 #if 0
5269     // Disabled: don't want making the screen smaller make a window larger.
5270     if (p_ea)
5271 	win_equal(curwin, FALSE, 'h');
5272 #endif
5273 }
5274 
5275 #if defined(FEAT_CMDWIN) || defined(PROTO)
5276 /*
5277  * Save the size of all windows in "gap".
5278  */
5279     void
5280 win_size_save(garray_T *gap)
5281 
5282 {
5283     win_T	*wp;
5284 
5285     ga_init2(gap, (int)sizeof(int), 1);
5286     if (ga_grow(gap, win_count() * 2 + 1) == OK)
5287     {
5288 	// first entry is value of 'lines'
5289 	((int *)gap->ga_data)[gap->ga_len++] = Rows;
5290 
5291 	FOR_ALL_WINDOWS(wp)
5292 	{
5293 	    ((int *)gap->ga_data)[gap->ga_len++] =
5294 					       wp->w_width + wp->w_vsep_width;
5295 	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
5296 	}
5297     }
5298 }
5299 
5300 /*
5301  * Restore window sizes, but only if the number of windows is still the same
5302  * and 'lines' didn't change.
5303  * Does not free the growarray.
5304  */
5305     void
5306 win_size_restore(garray_T *gap)
5307 {
5308     win_T	*wp;
5309     int		i, j;
5310 
5311     if (win_count() * 2 + 1 == gap->ga_len
5312 	    && ((int *)gap->ga_data)[0] == Rows)
5313     {
5314 	// The order matters, because frames contain other frames, but it's
5315 	// difficult to get right. The easy way out is to do it twice.
5316 	for (j = 0; j < 2; ++j)
5317 	{
5318 	    i = 1;
5319 	    FOR_ALL_WINDOWS(wp)
5320 	    {
5321 		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
5322 		win_setheight_win(((int *)gap->ga_data)[i++], wp);
5323 	    }
5324 	}
5325 	// recompute the window positions
5326 	(void)win_comp_pos();
5327     }
5328 }
5329 #endif // FEAT_CMDWIN
5330 
5331 /*
5332  * Update the position for all windows, using the width and height of the
5333  * frames.
5334  * Returns the row just after the last window.
5335  */
5336     int
5337 win_comp_pos(void)
5338 {
5339     int		row = tabline_height();
5340     int		col = 0;
5341 
5342     frame_comp_pos(topframe, &row, &col);
5343     return row;
5344 }
5345 
5346 /*
5347  * Update the position of the windows in frame "topfrp", using the width and
5348  * height of the frames.
5349  * "*row" and "*col" are the top-left position of the frame.  They are updated
5350  * to the bottom-right position plus one.
5351  */
5352     static void
5353 frame_comp_pos(frame_T *topfrp, int *row, int *col)
5354 {
5355     win_T	*wp;
5356     frame_T	*frp;
5357     int		startcol;
5358     int		startrow;
5359     int		h;
5360 
5361     wp = topfrp->fr_win;
5362     if (wp != NULL)
5363     {
5364 	if (wp->w_winrow != *row || wp->w_wincol != *col)
5365 	{
5366 	    // position changed, redraw
5367 	    wp->w_winrow = *row;
5368 	    wp->w_wincol = *col;
5369 	    redraw_win_later(wp, NOT_VALID);
5370 	    wp->w_redr_status = TRUE;
5371 	}
5372 	// WinBar will not show if the window height is zero
5373 	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
5374 	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
5375 	*col += wp->w_width + wp->w_vsep_width;
5376     }
5377     else
5378     {
5379 	startrow = *row;
5380 	startcol = *col;
5381 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
5382 	{
5383 	    if (topfrp->fr_layout == FR_ROW)
5384 		*row = startrow;	// all frames are at the same row
5385 	    else
5386 		*col = startcol;	// all frames are at the same col
5387 	    frame_comp_pos(frp, row, col);
5388 	}
5389     }
5390 }
5391 
5392 /*
5393  * Set current window height and take care of repositioning other windows to
5394  * fit around it.
5395  */
5396     void
5397 win_setheight(int height)
5398 {
5399     win_setheight_win(height, curwin);
5400 }
5401 
5402 /*
5403  * Set the window height of window "win" and take care of repositioning other
5404  * windows to fit around it.
5405  */
5406     void
5407 win_setheight_win(int height, win_T *win)
5408 {
5409     int		row;
5410 
5411     if (win == curwin)
5412     {
5413 	// Always keep current window at least one line high, even when
5414 	// 'winminheight' is zero.
5415 	if (height < p_wmh)
5416 	    height = p_wmh;
5417 	if (height == 0)
5418 	    height = 1;
5419 	height += WINBAR_HEIGHT(curwin);
5420     }
5421 
5422     frame_setheight(win->w_frame, height + win->w_status_height);
5423 
5424     // recompute the window positions
5425     row = win_comp_pos();
5426 
5427     /*
5428      * If there is extra space created between the last window and the command
5429      * line, clear it.
5430      */
5431     if (full_screen && msg_scrolled == 0 && row < cmdline_row)
5432 	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5433     cmdline_row = row;
5434     msg_row = row;
5435     msg_col = 0;
5436 
5437     redraw_all_later(NOT_VALID);
5438 }
5439 
5440 /*
5441  * Set the height of a frame to "height" and take care that all frames and
5442  * windows inside it are resized.  Also resize frames on the left and right if
5443  * the are in the same FR_ROW frame.
5444  *
5445  * Strategy:
5446  * If the frame is part of a FR_COL frame, try fitting the frame in that
5447  * frame.  If that doesn't work (the FR_COL frame is too small), recursively
5448  * go to containing frames to resize them and make room.
5449  * If the frame is part of a FR_ROW frame, all frames must be resized as well.
5450  * Check for the minimal height of the FR_ROW frame.
5451  * At the top level we can also use change the command line height.
5452  */
5453     static void
5454 frame_setheight(frame_T *curfrp, int height)
5455 {
5456     int		room;		// total number of lines available
5457     int		take;		// number of lines taken from other windows
5458     int		room_cmdline;	// lines available from cmdline
5459     int		run;
5460     frame_T	*frp;
5461     int		h;
5462     int		room_reserved;
5463 
5464     // If the height already is the desired value, nothing to do.
5465     if (curfrp->fr_height == height)
5466 	return;
5467 
5468     if (curfrp->fr_parent == NULL)
5469     {
5470 	// topframe: can only change the command line
5471 	if (height > ROWS_AVAIL)
5472 	    height = ROWS_AVAIL;
5473 	if (height > 0)
5474 	    frame_new_height(curfrp, height, FALSE, FALSE);
5475     }
5476     else if (curfrp->fr_parent->fr_layout == FR_ROW)
5477     {
5478 	// Row of frames: Also need to resize frames left and right of this
5479 	// one.  First check for the minimal height of these.
5480 	h = frame_minheight(curfrp->fr_parent, NULL);
5481 	if (height < h)
5482 	    height = h;
5483 	frame_setheight(curfrp->fr_parent, height);
5484     }
5485     else
5486     {
5487 	/*
5488 	 * Column of frames: try to change only frames in this column.
5489 	 */
5490 	/*
5491 	 * Do this twice:
5492 	 * 1: compute room available, if it's not enough try resizing the
5493 	 *    containing frame.
5494 	 * 2: compute the room available and adjust the height to it.
5495 	 * Try not to reduce the height of a window with 'winfixheight' set.
5496 	 */
5497 	for (run = 1; run <= 2; ++run)
5498 	{
5499 	    room = 0;
5500 	    room_reserved = 0;
5501 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5502 	    {
5503 		if (frp != curfrp
5504 			&& frp->fr_win != NULL
5505 			&& frp->fr_win->w_p_wfh)
5506 		    room_reserved += frp->fr_height;
5507 		room += frp->fr_height;
5508 		if (frp != curfrp)
5509 		    room -= frame_minheight(frp, NULL);
5510 	    }
5511 	    if (curfrp->fr_width != Columns)
5512 		room_cmdline = 0;
5513 	    else
5514 	    {
5515 		room_cmdline = Rows - p_ch - (lastwin->w_winrow
5516 						+ VISIBLE_HEIGHT(lastwin)
5517 						+ lastwin->w_status_height);
5518 		if (room_cmdline < 0)
5519 		    room_cmdline = 0;
5520 	    }
5521 
5522 	    if (height <= room + room_cmdline)
5523 		break;
5524 	    if (run == 2 || curfrp->fr_width == Columns)
5525 	    {
5526 		if (height > room + room_cmdline)
5527 		    height = room + room_cmdline;
5528 		break;
5529 	    }
5530 	    frame_setheight(curfrp->fr_parent, height
5531 		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
5532 	}
5533 
5534 	/*
5535 	 * Compute the number of lines we will take from others frames (can be
5536 	 * negative!).
5537 	 */
5538 	take = height - curfrp->fr_height;
5539 
5540 	// If there is not enough room, also reduce the height of a window
5541 	// with 'winfixheight' set.
5542 	if (height > room + room_cmdline - room_reserved)
5543 	    room_reserved = room + room_cmdline - height;
5544 	// If there is only a 'winfixheight' window and making the
5545 	// window smaller, need to make the other window taller.
5546 	if (take < 0 && room - curfrp->fr_height < room_reserved)
5547 	    room_reserved = 0;
5548 
5549 	if (take > 0 && room_cmdline > 0)
5550 	{
5551 	    // use lines from cmdline first
5552 	    if (take < room_cmdline)
5553 		room_cmdline = take;
5554 	    take -= room_cmdline;
5555 	    topframe->fr_height += room_cmdline;
5556 	}
5557 
5558 	/*
5559 	 * set the current frame to the new height
5560 	 */
5561 	frame_new_height(curfrp, height, FALSE, FALSE);
5562 
5563 	/*
5564 	 * First take lines from the frames after the current frame.  If
5565 	 * that is not enough, takes lines from frames above the current
5566 	 * frame.
5567 	 */
5568 	for (run = 0; run < 2; ++run)
5569 	{
5570 	    if (run == 0)
5571 		frp = curfrp->fr_next;	// 1st run: start with next window
5572 	    else
5573 		frp = curfrp->fr_prev;	// 2nd run: start with prev window
5574 	    while (frp != NULL && take != 0)
5575 	    {
5576 		h = frame_minheight(frp, NULL);
5577 		if (room_reserved > 0
5578 			&& frp->fr_win != NULL
5579 			&& frp->fr_win->w_p_wfh)
5580 		{
5581 		    if (room_reserved >= frp->fr_height)
5582 			room_reserved -= frp->fr_height;
5583 		    else
5584 		    {
5585 			if (frp->fr_height - room_reserved > take)
5586 			    room_reserved = frp->fr_height - take;
5587 			take -= frp->fr_height - room_reserved;
5588 			frame_new_height(frp, room_reserved, FALSE, FALSE);
5589 			room_reserved = 0;
5590 		    }
5591 		}
5592 		else
5593 		{
5594 		    if (frp->fr_height - take < h)
5595 		    {
5596 			take -= frp->fr_height - h;
5597 			frame_new_height(frp, h, FALSE, FALSE);
5598 		    }
5599 		    else
5600 		    {
5601 			frame_new_height(frp, frp->fr_height - take,
5602 								FALSE, FALSE);
5603 			take = 0;
5604 		    }
5605 		}
5606 		if (run == 0)
5607 		    frp = frp->fr_next;
5608 		else
5609 		    frp = frp->fr_prev;
5610 	    }
5611 	}
5612     }
5613 }
5614 
5615 /*
5616  * Set current window width and take care of repositioning other windows to
5617  * fit around it.
5618  */
5619     void
5620 win_setwidth(int width)
5621 {
5622     win_setwidth_win(width, curwin);
5623 }
5624 
5625     void
5626 win_setwidth_win(int width, win_T *wp)
5627 {
5628     // Always keep current window at least one column wide, even when
5629     // 'winminwidth' is zero.
5630     if (wp == curwin)
5631     {
5632 	if (width < p_wmw)
5633 	    width = p_wmw;
5634 	if (width == 0)
5635 	    width = 1;
5636     }
5637 
5638     frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
5639 
5640     // recompute the window positions
5641     (void)win_comp_pos();
5642 
5643     redraw_all_later(NOT_VALID);
5644 }
5645 
5646 /*
5647  * Set the width of a frame to "width" and take care that all frames and
5648  * windows inside it are resized.  Also resize frames above and below if the
5649  * are in the same FR_ROW frame.
5650  *
5651  * Strategy is similar to frame_setheight().
5652  */
5653     static void
5654 frame_setwidth(frame_T *curfrp, int width)
5655 {
5656     int		room;		// total number of lines available
5657     int		take;		// number of lines taken from other windows
5658     int		run;
5659     frame_T	*frp;
5660     int		w;
5661     int		room_reserved;
5662 
5663     // If the width already is the desired value, nothing to do.
5664     if (curfrp->fr_width == width)
5665 	return;
5666 
5667     if (curfrp->fr_parent == NULL)
5668 	// topframe: can't change width
5669 	return;
5670 
5671     if (curfrp->fr_parent->fr_layout == FR_COL)
5672     {
5673 	// Column of frames: Also need to resize frames above and below of
5674 	// this one.  First check for the minimal width of these.
5675 	w = frame_minwidth(curfrp->fr_parent, NULL);
5676 	if (width < w)
5677 	    width = w;
5678 	frame_setwidth(curfrp->fr_parent, width);
5679     }
5680     else
5681     {
5682 	/*
5683 	 * Row of frames: try to change only frames in this row.
5684 	 *
5685 	 * Do this twice:
5686 	 * 1: compute room available, if it's not enough try resizing the
5687 	 *    containing frame.
5688 	 * 2: compute the room available and adjust the width to it.
5689 	 */
5690 	for (run = 1; run <= 2; ++run)
5691 	{
5692 	    room = 0;
5693 	    room_reserved = 0;
5694 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5695 	    {
5696 		if (frp != curfrp
5697 			&& frp->fr_win != NULL
5698 			&& frp->fr_win->w_p_wfw)
5699 		    room_reserved += frp->fr_width;
5700 		room += frp->fr_width;
5701 		if (frp != curfrp)
5702 		    room -= frame_minwidth(frp, NULL);
5703 	    }
5704 
5705 	    if (width <= room)
5706 		break;
5707 	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
5708 	    {
5709 		if (width > room)
5710 		    width = room;
5711 		break;
5712 	    }
5713 	    frame_setwidth(curfrp->fr_parent, width
5714 		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
5715 	}
5716 
5717 	/*
5718 	 * Compute the number of lines we will take from others frames (can be
5719 	 * negative!).
5720 	 */
5721 	take = width - curfrp->fr_width;
5722 
5723 	// If there is not enough room, also reduce the width of a window
5724 	// with 'winfixwidth' set.
5725 	if (width > room - room_reserved)
5726 	    room_reserved = room - width;
5727 	// If there is only a 'winfixwidth' window and making the
5728 	// window smaller, need to make the other window narrower.
5729 	if (take < 0 && room - curfrp->fr_width < room_reserved)
5730 	    room_reserved = 0;
5731 
5732 	/*
5733 	 * set the current frame to the new width
5734 	 */
5735 	frame_new_width(curfrp, width, FALSE, FALSE);
5736 
5737 	/*
5738 	 * First take lines from the frames right of the current frame.  If
5739 	 * that is not enough, takes lines from frames left of the current
5740 	 * frame.
5741 	 */
5742 	for (run = 0; run < 2; ++run)
5743 	{
5744 	    if (run == 0)
5745 		frp = curfrp->fr_next;	// 1st run: start with next window
5746 	    else
5747 		frp = curfrp->fr_prev;	// 2nd run: start with prev window
5748 	    while (frp != NULL && take != 0)
5749 	    {
5750 		w = frame_minwidth(frp, NULL);
5751 		if (room_reserved > 0
5752 			&& frp->fr_win != NULL
5753 			&& frp->fr_win->w_p_wfw)
5754 		{
5755 		    if (room_reserved >= frp->fr_width)
5756 			room_reserved -= frp->fr_width;
5757 		    else
5758 		    {
5759 			if (frp->fr_width - room_reserved > take)
5760 			    room_reserved = frp->fr_width - take;
5761 			take -= frp->fr_width - room_reserved;
5762 			frame_new_width(frp, room_reserved, FALSE, FALSE);
5763 			room_reserved = 0;
5764 		    }
5765 		}
5766 		else
5767 		{
5768 		    if (frp->fr_width - take < w)
5769 		    {
5770 			take -= frp->fr_width - w;
5771 			frame_new_width(frp, w, FALSE, FALSE);
5772 		    }
5773 		    else
5774 		    {
5775 			frame_new_width(frp, frp->fr_width - take,
5776 								FALSE, FALSE);
5777 			take = 0;
5778 		    }
5779 		}
5780 		if (run == 0)
5781 		    frp = frp->fr_next;
5782 		else
5783 		    frp = frp->fr_prev;
5784 	    }
5785 	}
5786     }
5787 }
5788 
5789 /*
5790  * Check 'winminheight' for a valid value and reduce it if needed.
5791  */
5792     void
5793 win_setminheight(void)
5794 {
5795     int		room;
5796     int		needed;
5797     int		first = TRUE;
5798 
5799     // loop until there is a 'winminheight' that is possible
5800     while (p_wmh > 0)
5801     {
5802 	room = Rows - p_ch;
5803 	needed = frame_minheight(topframe, NULL);
5804 	if (room >= needed)
5805 	    break;
5806 	--p_wmh;
5807 	if (first)
5808 	{
5809 	    emsg(_(e_noroom));
5810 	    first = FALSE;
5811 	}
5812     }
5813 }
5814 
5815 /*
5816  * Check 'winminwidth' for a valid value and reduce it if needed.
5817  */
5818     void
5819 win_setminwidth(void)
5820 {
5821     int		room;
5822     int		needed;
5823     int		first = TRUE;
5824 
5825     // loop until there is a 'winminheight' that is possible
5826     while (p_wmw > 0)
5827     {
5828 	room = Columns;
5829 	needed = frame_minwidth(topframe, NULL);
5830 	if (room >= needed)
5831 	    break;
5832 	--p_wmw;
5833 	if (first)
5834 	{
5835 	    emsg(_(e_noroom));
5836 	    first = FALSE;
5837 	}
5838     }
5839 }
5840 
5841 /*
5842  * Status line of dragwin is dragged "offset" lines down (negative is up).
5843  */
5844     void
5845 win_drag_status_line(win_T *dragwin, int offset)
5846 {
5847     frame_T	*curfr;
5848     frame_T	*fr;
5849     int		room;
5850     int		row;
5851     int		up;	// if TRUE, drag status line up, otherwise down
5852     int		n;
5853 
5854     fr = dragwin->w_frame;
5855     curfr = fr;
5856     if (fr != topframe)		// more than one window
5857     {
5858 	fr = fr->fr_parent;
5859 	// When the parent frame is not a column of frames, its parent should
5860 	// be.
5861 	if (fr->fr_layout != FR_COL)
5862 	{
5863 	    curfr = fr;
5864 	    if (fr != topframe)	// only a row of windows, may drag statusline
5865 		fr = fr->fr_parent;
5866 	}
5867     }
5868 
5869     // If this is the last frame in a column, may want to resize the parent
5870     // frame instead (go two up to skip a row of frames).
5871     while (curfr != topframe && curfr->fr_next == NULL)
5872     {
5873 	if (fr != topframe)
5874 	    fr = fr->fr_parent;
5875 	curfr = fr;
5876 	if (fr != topframe)
5877 	    fr = fr->fr_parent;
5878     }
5879 
5880     if (offset < 0) // drag up
5881     {
5882 	up = TRUE;
5883 	offset = -offset;
5884 	// sum up the room of the current frame and above it
5885 	if (fr == curfr)
5886 	{
5887 	    // only one window
5888 	    room = fr->fr_height - frame_minheight(fr, NULL);
5889 	}
5890 	else
5891 	{
5892 	    room = 0;
5893 	    for (fr = fr->fr_child; ; fr = fr->fr_next)
5894 	    {
5895 		room += fr->fr_height - frame_minheight(fr, NULL);
5896 		if (fr == curfr)
5897 		    break;
5898 	    }
5899 	}
5900 	fr = curfr->fr_next;		// put fr at frame that grows
5901     }
5902     else    // drag down
5903     {
5904 	up = FALSE;
5905 	/*
5906 	 * Only dragging the last status line can reduce p_ch.
5907 	 */
5908 	room = Rows - cmdline_row;
5909 	if (curfr->fr_next == NULL)
5910 	    room -= 1;
5911 	else
5912 	    room -= p_ch;
5913 	if (room < 0)
5914 	    room = 0;
5915 	// sum up the room of frames below of the current one
5916 	FOR_ALL_FRAMES(fr, curfr->fr_next)
5917 	    room += fr->fr_height - frame_minheight(fr, NULL);
5918 	fr = curfr;			// put fr at window that grows
5919     }
5920 
5921     if (room < offset)		// Not enough room
5922 	offset = room;		// Move as far as we can
5923     if (offset <= 0)
5924 	return;
5925 
5926     /*
5927      * Grow frame fr by "offset" lines.
5928      * Doesn't happen when dragging the last status line up.
5929      */
5930     if (fr != NULL)
5931 	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
5932 
5933     if (up)
5934 	fr = curfr;		// current frame gets smaller
5935     else
5936 	fr = curfr->fr_next;	// next frame gets smaller
5937 
5938     /*
5939      * Now make the other frames smaller.
5940      */
5941     while (fr != NULL && offset > 0)
5942     {
5943 	n = frame_minheight(fr, NULL);
5944 	if (fr->fr_height - offset <= n)
5945 	{
5946 	    offset -= fr->fr_height - n;
5947 	    frame_new_height(fr, n, !up, FALSE);
5948 	}
5949 	else
5950 	{
5951 	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
5952 	    break;
5953 	}
5954 	if (up)
5955 	    fr = fr->fr_prev;
5956 	else
5957 	    fr = fr->fr_next;
5958     }
5959     row = win_comp_pos();
5960     screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5961     cmdline_row = row;
5962     p_ch = Rows - cmdline_row;
5963     if (p_ch < 1)
5964 	p_ch = 1;
5965     curtab->tp_ch_used = p_ch;
5966     redraw_all_later(SOME_VALID);
5967     showmode();
5968 }
5969 
5970 /*
5971  * Separator line of dragwin is dragged "offset" lines right (negative is left).
5972  */
5973     void
5974 win_drag_vsep_line(win_T *dragwin, int offset)
5975 {
5976     frame_T	*curfr;
5977     frame_T	*fr;
5978     int		room;
5979     int		left;	// if TRUE, drag separator line left, otherwise right
5980     int		n;
5981 
5982     fr = dragwin->w_frame;
5983     if (fr == topframe)		// only one window (cannot happen?)
5984 	return;
5985     curfr = fr;
5986     fr = fr->fr_parent;
5987     // When the parent frame is not a row of frames, its parent should be.
5988     if (fr->fr_layout != FR_ROW)
5989     {
5990 	if (fr == topframe)	// only a column of windows (cannot happen?)
5991 	    return;
5992 	curfr = fr;
5993 	fr = fr->fr_parent;
5994     }
5995 
5996     // If this is the last frame in a row, may want to resize a parent
5997     // frame instead.
5998     while (curfr->fr_next == NULL)
5999     {
6000 	if (fr == topframe)
6001 	    break;
6002 	curfr = fr;
6003 	fr = fr->fr_parent;
6004 	if (fr != topframe)
6005 	{
6006 	    curfr = fr;
6007 	    fr = fr->fr_parent;
6008 	}
6009     }
6010 
6011     if (offset < 0) // drag left
6012     {
6013 	left = TRUE;
6014 	offset = -offset;
6015 	// sum up the room of the current frame and left of it
6016 	room = 0;
6017 	for (fr = fr->fr_child; ; fr = fr->fr_next)
6018 	{
6019 	    room += fr->fr_width - frame_minwidth(fr, NULL);
6020 	    if (fr == curfr)
6021 		break;
6022 	}
6023 	fr = curfr->fr_next;		// put fr at frame that grows
6024     }
6025     else    // drag right
6026     {
6027 	left = FALSE;
6028 	// sum up the room of frames right of the current one
6029 	room = 0;
6030 	FOR_ALL_FRAMES(fr, curfr->fr_next)
6031 	    room += fr->fr_width - frame_minwidth(fr, NULL);
6032 	fr = curfr;			// put fr at window that grows
6033     }
6034 
6035     if (room < offset)		// Not enough room
6036 	offset = room;		// Move as far as we can
6037     if (offset <= 0)		// No room at all, quit.
6038 	return;
6039     if (fr == NULL)
6040 	return;			// Safety check, should not happen.
6041 
6042     // grow frame fr by offset lines
6043     frame_new_width(fr, fr->fr_width + offset, left, FALSE);
6044 
6045     // shrink other frames: current and at the left or at the right
6046     if (left)
6047 	fr = curfr;		// current frame gets smaller
6048     else
6049 	fr = curfr->fr_next;	// next frame gets smaller
6050 
6051     while (fr != NULL && offset > 0)
6052     {
6053 	n = frame_minwidth(fr, NULL);
6054 	if (fr->fr_width - offset <= n)
6055 	{
6056 	    offset -= fr->fr_width - n;
6057 	    frame_new_width(fr, n, !left, FALSE);
6058 	}
6059 	else
6060 	{
6061 	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
6062 	    break;
6063 	}
6064 	if (left)
6065 	    fr = fr->fr_prev;
6066 	else
6067 	    fr = fr->fr_next;
6068     }
6069     (void)win_comp_pos();
6070     redraw_all_later(NOT_VALID);
6071 }
6072 
6073 #define FRACTION_MULT	16384L
6074 
6075 /*
6076  * Set wp->w_fraction for the current w_wrow and w_height.
6077  * Has no effect when the window is less than two lines.
6078  */
6079     void
6080 set_fraction(win_T *wp)
6081 {
6082     if (wp->w_height > 1)
6083 	// When cursor is in the first line the percentage is computed as if
6084 	// it's halfway that line.  Thus with two lines it is 25%, with three
6085 	// lines 17%, etc.  Similarly for the last line: 75%, 83%, etc.
6086 	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
6087 				     + FRACTION_MULT / 2) / (long)wp->w_height;
6088 }
6089 
6090 /*
6091  * Set the height of a window.
6092  * "height" excludes any window toolbar.
6093  * This takes care of the things inside the window, not what happens to the
6094  * window position, the frame or to other windows.
6095  */
6096     void
6097 win_new_height(win_T *wp, int height)
6098 {
6099     int		prev_height = wp->w_height;
6100 
6101     // Don't want a negative height.  Happens when splitting a tiny window.
6102     // Will equalize heights soon to fix it.
6103     if (height < 0)
6104 	height = 0;
6105     if (wp->w_height == height)
6106 	return;	    // nothing to do
6107 
6108     if (wp->w_height > 0)
6109     {
6110 	if (wp == curwin)
6111 	    // w_wrow needs to be valid. When setting 'laststatus' this may
6112 	    // call win_new_height() recursively.
6113 	    validate_cursor();
6114 	if (wp->w_height != prev_height)
6115 	    return;  // Recursive call already changed the size, bail out here
6116 		     //	to avoid the following to mess things up.
6117 	if (wp->w_wrow != wp->w_prev_fraction_row)
6118 	    set_fraction(wp);
6119     }
6120 
6121     wp->w_height = height;
6122     wp->w_skipcol = 0;
6123 
6124     // There is no point in adjusting the scroll position when exiting.  Some
6125     // values might be invalid.
6126     if (!exiting)
6127 	scroll_to_fraction(wp, prev_height);
6128 }
6129 
6130     void
6131 scroll_to_fraction(win_T *wp, int prev_height)
6132 {
6133     linenr_T	lnum;
6134     int		sline, line_size;
6135     int		height = wp->w_height;
6136 
6137     // Don't change w_topline in any of these cases:
6138     // - window height is 0
6139     // - 'scrollbind' is set and this isn't the current window
6140     // - window height is sufficient to display the whole buffer and first line
6141     //   is visible.
6142     if (height > 0
6143         && (!wp->w_p_scb || wp == curwin)
6144         && (height < wp->w_buffer->b_ml.ml_line_count || wp->w_topline > 1))
6145     {
6146 	/*
6147 	 * Find a value for w_topline that shows the cursor at the same
6148 	 * relative position in the window as before (more or less).
6149 	 */
6150 	lnum = wp->w_cursor.lnum;
6151 	if (lnum < 1)		// can happen when starting up
6152 	    lnum = 1;
6153 	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L)
6154 							       / FRACTION_MULT;
6155 	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
6156 	sline = wp->w_wrow - line_size;
6157 
6158 	if (sline >= 0)
6159 	{
6160 	    // Make sure the whole cursor line is visible, if possible.
6161 	    int rows = plines_win(wp, lnum, FALSE);
6162 
6163 	    if (sline > wp->w_height - rows)
6164 	    {
6165 		sline = wp->w_height - rows;
6166 		wp->w_wrow -= rows - line_size;
6167 	    }
6168 	}
6169 
6170 	if (sline < 0)
6171 	{
6172 	    /*
6173 	     * Cursor line would go off top of screen if w_wrow was this high.
6174 	     * Make cursor line the first line in the window.  If not enough
6175 	     * room use w_skipcol;
6176 	     */
6177 	    wp->w_wrow = line_size;
6178 	    if (wp->w_wrow >= wp->w_height
6179 				       && (wp->w_width - win_col_off(wp)) > 0)
6180 	    {
6181 		wp->w_skipcol += wp->w_width - win_col_off(wp);
6182 		--wp->w_wrow;
6183 		while (wp->w_wrow >= wp->w_height)
6184 		{
6185 		    wp->w_skipcol += wp->w_width - win_col_off(wp)
6186 							   + win_col_off2(wp);
6187 		    --wp->w_wrow;
6188 		}
6189 	    }
6190 	}
6191 	else if (sline > 0)
6192 	{
6193 	    while (sline > 0 && lnum > 1)
6194 	    {
6195 #ifdef FEAT_FOLDING
6196 		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
6197 		if (lnum == 1)
6198 		{
6199 		    // first line in buffer is folded
6200 		    line_size = 1;
6201 		    --sline;
6202 		    break;
6203 		}
6204 #endif
6205 		--lnum;
6206 #ifdef FEAT_DIFF
6207 		if (lnum == wp->w_topline)
6208 		    line_size = plines_win_nofill(wp, lnum, TRUE)
6209 							      + wp->w_topfill;
6210 		else
6211 #endif
6212 		    line_size = plines_win(wp, lnum, TRUE);
6213 		sline -= line_size;
6214 	    }
6215 
6216 	    if (sline < 0)
6217 	    {
6218 		/*
6219 		 * Line we want at top would go off top of screen.  Use next
6220 		 * line instead.
6221 		 */
6222 #ifdef FEAT_FOLDING
6223 		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
6224 #endif
6225 		lnum++;
6226 		wp->w_wrow -= line_size + sline;
6227 	    }
6228 	    else if (sline > 0)
6229 	    {
6230 		// First line of file reached, use that as topline.
6231 		lnum = 1;
6232 		wp->w_wrow -= sline;
6233 	    }
6234 	}
6235 	set_topline(wp, lnum);
6236     }
6237 
6238     if (wp == curwin)
6239     {
6240 	if (get_scrolloff_value())
6241 	    update_topline();
6242 	curs_columns(FALSE);	// validate w_wrow
6243     }
6244     if (prev_height > 0)
6245 	wp->w_prev_fraction_row = wp->w_wrow;
6246 
6247     win_comp_scroll(wp);
6248     redraw_win_later(wp, SOME_VALID);
6249     wp->w_redr_status = TRUE;
6250     invalidate_botline_win(wp);
6251 }
6252 
6253 /*
6254  * Set the width of a window.
6255  */
6256     void
6257 win_new_width(win_T *wp, int width)
6258 {
6259     wp->w_width = width;
6260     wp->w_lines_valid = 0;
6261     changed_line_abv_curs_win(wp);
6262     invalidate_botline_win(wp);
6263     if (wp == curwin)
6264     {
6265 	update_topline();
6266 	curs_columns(TRUE);	// validate w_wrow
6267     }
6268     redraw_win_later(wp, NOT_VALID);
6269     wp->w_redr_status = TRUE;
6270 }
6271 
6272     void
6273 win_comp_scroll(win_T *wp)
6274 {
6275     wp->w_p_scr = ((unsigned)wp->w_height >> 1);
6276     if (wp->w_p_scr == 0)
6277 	wp->w_p_scr = 1;
6278 }
6279 
6280 /*
6281  * command_height: called whenever p_ch has been changed
6282  */
6283     void
6284 command_height(void)
6285 {
6286     int		h;
6287     frame_T	*frp;
6288     int		old_p_ch = curtab->tp_ch_used;
6289 
6290     // Use the value of p_ch that we remembered.  This is needed for when the
6291     // GUI starts up, we can't be sure in what order things happen.  And when
6292     // p_ch was changed in another tab page.
6293     curtab->tp_ch_used = p_ch;
6294 
6295     // Find bottom frame with width of screen.
6296     frp = lastwin->w_frame;
6297     while (frp->fr_width != Columns && frp->fr_parent != NULL)
6298 	frp = frp->fr_parent;
6299 
6300     // Avoid changing the height of a window with 'winfixheight' set.
6301     while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
6302 						      && frp->fr_win->w_p_wfh)
6303 	frp = frp->fr_prev;
6304 
6305     if (starting != NO_SCREEN)
6306     {
6307 	cmdline_row = Rows - p_ch;
6308 
6309 	if (p_ch > old_p_ch)		    // p_ch got bigger
6310 	{
6311 	    while (p_ch > old_p_ch)
6312 	    {
6313 		if (frp == NULL)
6314 		{
6315 		    emsg(_(e_noroom));
6316 		    p_ch = old_p_ch;
6317 		    curtab->tp_ch_used = p_ch;
6318 		    cmdline_row = Rows - p_ch;
6319 		    break;
6320 		}
6321 		h = frp->fr_height - frame_minheight(frp, NULL);
6322 		if (h > p_ch - old_p_ch)
6323 		    h = p_ch - old_p_ch;
6324 		old_p_ch += h;
6325 		frame_add_height(frp, -h);
6326 		frp = frp->fr_prev;
6327 	    }
6328 
6329 	    // Recompute window positions.
6330 	    (void)win_comp_pos();
6331 
6332 	    // clear the lines added to cmdline
6333 	    if (full_screen)
6334 		screen_fill((int)(cmdline_row), (int)Rows, 0,
6335 						   (int)Columns, ' ', ' ', 0);
6336 	    msg_row = cmdline_row;
6337 	    redraw_cmdline = TRUE;
6338 	    return;
6339 	}
6340 
6341 	if (msg_row < cmdline_row)
6342 	    msg_row = cmdline_row;
6343 	redraw_cmdline = TRUE;
6344     }
6345     frame_add_height(frp, (int)(old_p_ch - p_ch));
6346 
6347     // Recompute window positions.
6348     if (frp != lastwin->w_frame)
6349 	(void)win_comp_pos();
6350 }
6351 
6352 /*
6353  * Resize frame "frp" to be "n" lines higher (negative for less high).
6354  * Also resize the frames it is contained in.
6355  */
6356     static void
6357 frame_add_height(frame_T *frp, int n)
6358 {
6359     frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
6360     for (;;)
6361     {
6362 	frp = frp->fr_parent;
6363 	if (frp == NULL)
6364 	    break;
6365 	frp->fr_height += n;
6366     }
6367 }
6368 
6369 /*
6370  * Add or remove a status line for the bottom window(s), according to the
6371  * value of 'laststatus'.
6372  */
6373     void
6374 last_status(
6375     int		morewin)	// pretend there are two or more windows
6376 {
6377     // Don't make a difference between horizontal or vertical split.
6378     last_status_rec(topframe, (p_ls == 2
6379 			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
6380 }
6381 
6382     static void
6383 last_status_rec(frame_T *fr, int statusline)
6384 {
6385     frame_T	*fp;
6386     win_T	*wp;
6387 
6388     if (fr->fr_layout == FR_LEAF)
6389     {
6390 	wp = fr->fr_win;
6391 	if (wp->w_status_height != 0 && !statusline)
6392 	{
6393 	    // remove status line
6394 	    win_new_height(wp, wp->w_height + 1);
6395 	    wp->w_status_height = 0;
6396 	    comp_col();
6397 	}
6398 	else if (wp->w_status_height == 0 && statusline)
6399 	{
6400 	    // Find a frame to take a line from.
6401 	    fp = fr;
6402 	    while (fp->fr_height <= frame_minheight(fp, NULL))
6403 	    {
6404 		if (fp == topframe)
6405 		{
6406 		    emsg(_(e_noroom));
6407 		    return;
6408 		}
6409 		// In a column of frames: go to frame above.  If already at
6410 		// the top or in a row of frames: go to parent.
6411 		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
6412 		    fp = fp->fr_prev;
6413 		else
6414 		    fp = fp->fr_parent;
6415 	    }
6416 	    wp->w_status_height = 1;
6417 	    if (fp != fr)
6418 	    {
6419 		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
6420 		frame_fix_height(wp);
6421 		(void)win_comp_pos();
6422 	    }
6423 	    else
6424 		win_new_height(wp, wp->w_height - 1);
6425 	    comp_col();
6426 	    redraw_all_later(SOME_VALID);
6427 	}
6428     }
6429     else if (fr->fr_layout == FR_ROW)
6430     {
6431 	// vertically split windows, set status line for each one
6432 	FOR_ALL_FRAMES(fp, fr->fr_child)
6433 	    last_status_rec(fp, statusline);
6434     }
6435     else
6436     {
6437 	// horizontally split window, set status line for last one
6438 	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
6439 	    ;
6440 	last_status_rec(fp, statusline);
6441     }
6442 }
6443 
6444 /*
6445  * Return the number of lines used by the tab page line.
6446  */
6447     int
6448 tabline_height(void)
6449 {
6450 #ifdef FEAT_GUI_TABLINE
6451     // When the GUI has the tabline then this always returns zero.
6452     if (gui_use_tabline())
6453 	return 0;
6454 #endif
6455     switch (p_stal)
6456     {
6457 	case 0: return 0;
6458 	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
6459     }
6460     return 1;
6461 }
6462 
6463 /*
6464  * Return the minimal number of rows that is needed on the screen to display
6465  * the current number of windows.
6466  */
6467     int
6468 min_rows(void)
6469 {
6470     int		total;
6471     tabpage_T	*tp;
6472     int		n;
6473 
6474     if (firstwin == NULL)	// not initialized yet
6475 	return MIN_LINES;
6476 
6477     total = 0;
6478     FOR_ALL_TABPAGES(tp)
6479     {
6480 	n = frame_minheight(tp->tp_topframe, NULL);
6481 	if (total < n)
6482 	    total = n;
6483     }
6484     total += tabline_height();
6485     total += 1;		// count the room for the command line
6486     return total;
6487 }
6488 
6489 /*
6490  * Return TRUE if there is only one window and only one tab page, not
6491  * counting a help or preview window, unless it is the current window.
6492  * Does not count unlisted windows.
6493  */
6494     int
6495 only_one_window(void)
6496 {
6497     int		count = 0;
6498     win_T	*wp;
6499 
6500 #if defined(FEAT_PROP_POPUP)
6501     // If the current window is a popup then there always is another window.
6502     if (popup_is_popup(curwin))
6503 	return FALSE;
6504 #endif
6505 
6506     // If there is another tab page there always is another window.
6507     if (first_tabpage->tp_next != NULL)
6508 	return FALSE;
6509 
6510     FOR_ALL_WINDOWS(wp)
6511 	if (wp->w_buffer != NULL
6512 		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
6513 # ifdef FEAT_QUICKFIX
6514 		    || wp->w_p_pvw
6515 # endif
6516 	     ) || wp == curwin) && wp != aucmd_win)
6517 	    ++count;
6518     return (count <= 1);
6519 }
6520 
6521 /*
6522  * Correct the cursor line number in other windows.  Used after changing the
6523  * current buffer, and before applying autocommands.
6524  * When "do_curwin" is TRUE, also check current window.
6525  */
6526     void
6527 check_lnums(int do_curwin)
6528 {
6529     win_T	*wp;
6530     tabpage_T	*tp;
6531 
6532     FOR_ALL_TAB_WINDOWS(tp, wp)
6533 	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
6534 	{
6535 	    // save the original cursor position and topline
6536 	    wp->w_save_cursor.w_cursor_save = wp->w_cursor;
6537 	    wp->w_save_cursor.w_topline_save = wp->w_topline;
6538 
6539 	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
6540 		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
6541 	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
6542 		wp->w_topline = curbuf->b_ml.ml_line_count;
6543 
6544 	    // save the corrected cursor position and topline
6545 	    wp->w_save_cursor.w_cursor_corr = wp->w_cursor;
6546 	    wp->w_save_cursor.w_topline_corr = wp->w_topline;
6547 	}
6548 }
6549 
6550 /*
6551  * Reset cursor and topline to its stored values from check_lnums().
6552  * check_lnums() must have been called first!
6553  */
6554     void
6555 reset_lnums()
6556 {
6557     win_T	*wp;
6558     tabpage_T	*tp;
6559 
6560     FOR_ALL_TAB_WINDOWS(tp, wp)
6561 	if (wp->w_buffer == curbuf)
6562 	{
6563 	    // Restore the value if the autocommand didn't change it.
6564 	    if (EQUAL_POS(wp->w_save_cursor.w_cursor_corr, wp->w_cursor))
6565 		wp->w_cursor = wp->w_save_cursor.w_cursor_save;
6566 	    if (wp->w_save_cursor.w_topline_corr == wp->w_topline)
6567 		wp->w_topline = wp->w_save_cursor.w_topline_save;
6568 	}
6569 }
6570 
6571 /*
6572  * A snapshot of the window sizes, to restore them after closing the help
6573  * window.
6574  * Only these fields are used:
6575  * fr_layout
6576  * fr_width
6577  * fr_height
6578  * fr_next
6579  * fr_child
6580  * fr_win (only valid for the old curwin, NULL otherwise)
6581  */
6582 
6583 /*
6584  * Create a snapshot of the current frame sizes.
6585  */
6586     void
6587 make_snapshot(int idx)
6588 {
6589     clear_snapshot(curtab, idx);
6590     make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
6591 }
6592 
6593     static void
6594 make_snapshot_rec(frame_T *fr, frame_T **frp)
6595 {
6596     *frp = ALLOC_CLEAR_ONE(frame_T);
6597     if (*frp == NULL)
6598 	return;
6599     (*frp)->fr_layout = fr->fr_layout;
6600     (*frp)->fr_width = fr->fr_width;
6601     (*frp)->fr_height = fr->fr_height;
6602     if (fr->fr_next != NULL)
6603 	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
6604     if (fr->fr_child != NULL)
6605 	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
6606     if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
6607 	(*frp)->fr_win = curwin;
6608 }
6609 
6610 /*
6611  * Remove any existing snapshot.
6612  */
6613     static void
6614 clear_snapshot(tabpage_T *tp, int idx)
6615 {
6616     clear_snapshot_rec(tp->tp_snapshot[idx]);
6617     tp->tp_snapshot[idx] = NULL;
6618 }
6619 
6620     static void
6621 clear_snapshot_rec(frame_T *fr)
6622 {
6623     if (fr != NULL)
6624     {
6625 	clear_snapshot_rec(fr->fr_next);
6626 	clear_snapshot_rec(fr->fr_child);
6627 	vim_free(fr);
6628     }
6629 }
6630 
6631 /*
6632  * Restore a previously created snapshot, if there is any.
6633  * This is only done if the screen size didn't change and the window layout is
6634  * still the same.
6635  */
6636     void
6637 restore_snapshot(
6638     int		idx,
6639     int		close_curwin)	    // closing current window
6640 {
6641     win_T	*wp;
6642 
6643     if (curtab->tp_snapshot[idx] != NULL
6644 	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
6645 	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
6646 	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
6647     {
6648 	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
6649 	win_comp_pos();
6650 	if (wp != NULL && close_curwin)
6651 	    win_goto(wp);
6652 	redraw_all_later(NOT_VALID);
6653     }
6654     clear_snapshot(curtab, idx);
6655 }
6656 
6657 /*
6658  * Check if frames "sn" and "fr" have the same layout, same following frames
6659  * and same children.  And the window pointer is valid.
6660  */
6661     static int
6662 check_snapshot_rec(frame_T *sn, frame_T *fr)
6663 {
6664     if (sn->fr_layout != fr->fr_layout
6665 	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
6666 	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
6667 	    || (sn->fr_next != NULL
6668 		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
6669 	    || (sn->fr_child != NULL
6670 		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
6671 	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
6672 	return FAIL;
6673     return OK;
6674 }
6675 
6676 /*
6677  * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
6678  * following frames and children.
6679  * Returns a pointer to the old current window, or NULL.
6680  */
6681     static win_T *
6682 restore_snapshot_rec(frame_T *sn, frame_T *fr)
6683 {
6684     win_T	*wp = NULL;
6685     win_T	*wp2;
6686 
6687     fr->fr_height = sn->fr_height;
6688     fr->fr_width = sn->fr_width;
6689     if (fr->fr_layout == FR_LEAF)
6690     {
6691 	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
6692 	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
6693 	wp = sn->fr_win;
6694     }
6695     if (sn->fr_next != NULL)
6696     {
6697 	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
6698 	if (wp2 != NULL)
6699 	    wp = wp2;
6700     }
6701     if (sn->fr_child != NULL)
6702     {
6703 	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
6704 	if (wp2 != NULL)
6705 	    wp = wp2;
6706     }
6707     return wp;
6708 }
6709 
6710 #if defined(FEAT_GUI) || defined(PROTO)
6711 /*
6712  * Return TRUE if there is any vertically split window.
6713  */
6714     int
6715 win_hasvertsplit(void)
6716 {
6717     frame_T	*fr;
6718 
6719     if (topframe->fr_layout == FR_ROW)
6720 	return TRUE;
6721 
6722     if (topframe->fr_layout == FR_COL)
6723 	FOR_ALL_FRAMES(fr, topframe->fr_child)
6724 	    if (fr->fr_layout == FR_ROW)
6725 		return TRUE;
6726 
6727     return FALSE;
6728 }
6729 #endif
6730 
6731 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
6732     int
6733 get_win_number(win_T *wp, win_T *first_win)
6734 {
6735     int		i = 1;
6736     win_T	*w;
6737 
6738     for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
6739 	++i;
6740 
6741     if (w == NULL)
6742 	return 0;
6743     else
6744 	return i;
6745 }
6746 
6747     int
6748 get_tab_number(tabpage_T *tp UNUSED)
6749 {
6750     int		i = 1;
6751     tabpage_T	*t;
6752 
6753     for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
6754 	++i;
6755 
6756     if (t == NULL)
6757 	return 0;
6758     else
6759 	return i;
6760 }
6761 #endif
6762 
6763 /*
6764  * Return TRUE if "topfrp" and its children are at the right height.
6765  */
6766     static int
6767 frame_check_height(frame_T *topfrp, int height)
6768 {
6769     frame_T *frp;
6770 
6771     if (topfrp->fr_height != height)
6772 	return FALSE;
6773 
6774     if (topfrp->fr_layout == FR_ROW)
6775 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6776 	    if (frp->fr_height != height)
6777 		return FALSE;
6778 
6779     return TRUE;
6780 }
6781 
6782 /*
6783  * Return TRUE if "topfrp" and its children are at the right width.
6784  */
6785     static int
6786 frame_check_width(frame_T *topfrp, int width)
6787 {
6788     frame_T *frp;
6789 
6790     if (topfrp->fr_width != width)
6791 	return FALSE;
6792 
6793     if (topfrp->fr_layout == FR_COL)
6794 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6795 	    if (frp->fr_width != width)
6796 		return FALSE;
6797 
6798     return TRUE;
6799 }
6800 
6801 #if defined(FEAT_SYN_HL) || defined(PROTO)
6802 /*
6803  * Simple int comparison function for use with qsort()
6804  */
6805     static int
6806 int_cmp(const void *a, const void *b)
6807 {
6808     return *(const int *)a - *(const int *)b;
6809 }
6810 
6811 /*
6812  * Handle setting 'colorcolumn' or 'textwidth' in window "wp".
6813  * Returns error message, NULL if it's OK.
6814  */
6815     char *
6816 check_colorcolumn(win_T *wp)
6817 {
6818     char_u	*s;
6819     int		col;
6820     int		count = 0;
6821     int		color_cols[256];
6822     int		i;
6823     int		j = 0;
6824 
6825     if (wp->w_buffer == NULL)
6826 	return NULL;  // buffer was closed
6827 
6828     for (s = wp->w_p_cc; *s != NUL && count < 255;)
6829     {
6830 	if (*s == '-' || *s == '+')
6831 	{
6832 	    // -N and +N: add to 'textwidth'
6833 	    col = (*s == '-') ? -1 : 1;
6834 	    ++s;
6835 	    if (!VIM_ISDIGIT(*s))
6836 		return e_invarg;
6837 	    col = col * getdigits(&s);
6838 	    if (wp->w_buffer->b_p_tw == 0)
6839 		goto skip;  // 'textwidth' not set, skip this item
6840 	    col += wp->w_buffer->b_p_tw;
6841 	    if (col < 0)
6842 		goto skip;
6843 	}
6844 	else if (VIM_ISDIGIT(*s))
6845 	    col = getdigits(&s);
6846 	else
6847 	    return e_invarg;
6848 	color_cols[count++] = col - 1;  // 1-based to 0-based
6849 skip:
6850 	if (*s == NUL)
6851 	    break;
6852 	if (*s != ',')
6853 	    return e_invarg;
6854 	if (*++s == NUL)
6855 	    return e_invarg;  // illegal trailing comma as in "set cc=80,"
6856     }
6857 
6858     vim_free(wp->w_p_cc_cols);
6859     if (count == 0)
6860 	wp->w_p_cc_cols = NULL;
6861     else
6862     {
6863 	wp->w_p_cc_cols = ALLOC_MULT(int, count + 1);
6864 	if (wp->w_p_cc_cols != NULL)
6865 	{
6866 	    // sort the columns for faster usage on screen redraw inside
6867 	    // win_line()
6868 	    qsort(color_cols, count, sizeof(int), int_cmp);
6869 
6870 	    for (i = 0; i < count; ++i)
6871 		// skip duplicates
6872 		if (j == 0 || wp->w_p_cc_cols[j - 1] != color_cols[i])
6873 		    wp->w_p_cc_cols[j++] = color_cols[i];
6874 	    wp->w_p_cc_cols[j] = -1;  // end marker
6875 	}
6876     }
6877 
6878     return NULL;  // no error
6879 }
6880 #endif
6881