xref: /vim-8.2.3635/src/window.c (revision d7df2798)
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_POPUP_WINDOW)
126 	return;
127 
128 #ifdef FEAT_CMDWIN
129 # define CHECK_CMDWIN \
130     do { \
131 	if (cmdwin_type != 0) \
132 	{ \
133 	    emsg(_(e_cmdwin)); \
134 	    return; \
135 	} \
136     } while (0)
137 #else
138 # define CHECK_CMDWIN do { /**/ } while (0)
139 #endif
140 
141     Prenum1 = Prenum == 0 ? 1 : Prenum;
142 
143     switch (nchar)
144     {
145 // split current window in two parts, horizontally
146     case 'S':
147     case Ctrl_S:
148     case 's':
149 		CHECK_CMDWIN;
150 		reset_VIsual_and_resel();	// stop Visual mode
151 #ifdef FEAT_QUICKFIX
152 		// When splitting the quickfix window open a new buffer in it,
153 		// don't replicate the quickfix buffer.
154 		if (bt_quickfix(curbuf))
155 		    goto newwindow;
156 #endif
157 #ifdef FEAT_GUI
158 		need_mouse_correct = TRUE;
159 #endif
160 		(void)win_split((int)Prenum, 0);
161 		break;
162 
163 // split current window in two parts, vertically
164     case Ctrl_V:
165     case 'v':
166 		CHECK_CMDWIN;
167 		reset_VIsual_and_resel();	// stop Visual mode
168 #ifdef FEAT_QUICKFIX
169 		// When splitting the quickfix window open a new buffer in it,
170 		// don't replicate the quickfix buffer.
171 		if (bt_quickfix(curbuf))
172 		    goto newwindow;
173 #endif
174 #ifdef FEAT_GUI
175 		need_mouse_correct = TRUE;
176 #endif
177 		(void)win_split((int)Prenum, WSP_VERT);
178 		break;
179 
180 // split current window and edit alternate file
181     case Ctrl_HAT:
182     case '^':
183 		CHECK_CMDWIN;
184 		reset_VIsual_and_resel();	// stop Visual mode
185 
186 		if (buflist_findnr(Prenum == 0
187 					? curwin->w_alt_fnum : Prenum) == NULL)
188 		{
189 		    if (Prenum == 0)
190 			emsg(_(e_noalt));
191 		    else
192 			semsg(_("E92: Buffer %ld not found"), Prenum);
193 		    break;
194 		}
195 
196 		if (!curbuf_locked() && win_split(0, 0) == OK)
197 		    (void)buflist_getfile(
198 			    Prenum == 0 ? curwin->w_alt_fnum : Prenum,
199 			    (linenr_T)0, GETF_ALT, FALSE);
200 		break;
201 
202 // open new window
203     case Ctrl_N:
204     case 'n':
205 		CHECK_CMDWIN;
206 		reset_VIsual_and_resel();	// stop Visual mode
207 #ifdef FEAT_QUICKFIX
208 newwindow:
209 #endif
210 		if (Prenum)
211 		    // window height
212 		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
213 		else
214 		    cbuf[0] = NUL;
215 #if defined(FEAT_QUICKFIX)
216 		if (nchar == 'v' || nchar == Ctrl_V)
217 		    STRCAT(cbuf, "v");
218 #endif
219 		STRCAT(cbuf, "new");
220 		do_cmdline_cmd(cbuf);
221 		break;
222 
223 // quit current window
224     case Ctrl_Q:
225     case 'q':
226 		reset_VIsual_and_resel();	// stop Visual mode
227 		cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
228 		do_cmdline_cmd(cbuf);
229 		break;
230 
231 // close current window
232     case Ctrl_C:
233     case 'c':
234 		reset_VIsual_and_resel();	// stop Visual mode
235 		cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
236 		do_cmdline_cmd(cbuf);
237 		break;
238 
239 #if defined(FEAT_QUICKFIX)
240 // close preview window
241     case Ctrl_Z:
242     case 'z':
243 		CHECK_CMDWIN;
244 		reset_VIsual_and_resel();	// stop Visual mode
245 		do_cmdline_cmd((char_u *)"pclose");
246 		break;
247 
248 // cursor to preview window
249     case 'P':
250 		FOR_ALL_WINDOWS(wp)
251 		    if (wp->w_p_pvw)
252 			break;
253 		if (wp == NULL)
254 		    emsg(_("E441: There is no preview window"));
255 		else
256 		    win_goto(wp);
257 		break;
258 #endif
259 
260 // close all but current window
261     case Ctrl_O:
262     case 'o':
263 		CHECK_CMDWIN;
264 		reset_VIsual_and_resel();	// stop Visual mode
265 		cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
266 		do_cmdline_cmd(cbuf);
267 		break;
268 
269 // cursor to next window with wrap around
270     case Ctrl_W:
271     case 'w':
272 // cursor to previous window with wrap around
273     case 'W':
274 		CHECK_CMDWIN;
275 		if (ONE_WINDOW && Prenum != 1)	// just one window
276 		    beep_flush();
277 		else
278 		{
279 		    if (Prenum)			// go to specified window
280 		    {
281 			for (wp = firstwin; --Prenum > 0; )
282 			{
283 			    if (wp->w_next == NULL)
284 				break;
285 			    else
286 				wp = wp->w_next;
287 			}
288 		    }
289 		    else
290 		    {
291 			if (nchar == 'W')	    // go to previous window
292 			{
293 			    wp = curwin->w_prev;
294 			    if (wp == NULL)
295 				wp = lastwin;	    // wrap around
296 			}
297 			else			    // go to next window
298 			{
299 			    wp = curwin->w_next;
300 			    if (wp == NULL)
301 				wp = firstwin;	    // wrap around
302 			}
303 		    }
304 		    win_goto(wp);
305 		}
306 		break;
307 
308 // cursor to window below
309     case 'j':
310     case K_DOWN:
311     case Ctrl_J:
312 		CHECK_CMDWIN;
313 		win_goto_ver(FALSE, Prenum1);
314 		break;
315 
316 // cursor to window above
317     case 'k':
318     case K_UP:
319     case Ctrl_K:
320 		CHECK_CMDWIN;
321 		win_goto_ver(TRUE, Prenum1);
322 		break;
323 
324 // cursor to left window
325     case 'h':
326     case K_LEFT:
327     case Ctrl_H:
328     case K_BS:
329 		CHECK_CMDWIN;
330 		win_goto_hor(TRUE, Prenum1);
331 		break;
332 
333 // cursor to right window
334     case 'l':
335     case K_RIGHT:
336     case Ctrl_L:
337 		CHECK_CMDWIN;
338 		win_goto_hor(FALSE, Prenum1);
339 		break;
340 
341 // move window to new tab page
342     case 'T':
343 		if (one_window())
344 		    msg(_(m_onlyone));
345 		else
346 		{
347 		    tabpage_T	*oldtab = curtab;
348 		    tabpage_T	*newtab;
349 
350 		    // First create a new tab with the window, then go back to
351 		    // the old tab and close the window there.
352 		    wp = curwin;
353 		    if (win_new_tabpage((int)Prenum) == OK
354 						     && valid_tabpage(oldtab))
355 		    {
356 			newtab = curtab;
357 			goto_tabpage_tp(oldtab, TRUE, TRUE);
358 			if (curwin == wp)
359 			    win_close(curwin, FALSE);
360 			if (valid_tabpage(newtab))
361 			    goto_tabpage_tp(newtab, TRUE, TRUE);
362 		    }
363 		}
364 		break;
365 
366 // cursor to top-left window
367     case 't':
368     case Ctrl_T:
369 		win_goto(firstwin);
370 		break;
371 
372 // cursor to bottom-right window
373     case 'b':
374     case Ctrl_B:
375 		win_goto(lastwin);
376 		break;
377 
378 // cursor to last accessed (previous) window
379     case 'p':
380     case Ctrl_P:
381 		if (!win_valid(prevwin))
382 		    beep_flush();
383 		else
384 		    win_goto(prevwin);
385 		break;
386 
387 // exchange current and next window
388     case 'x':
389     case Ctrl_X:
390 		CHECK_CMDWIN;
391 		win_exchange(Prenum);
392 		break;
393 
394 // rotate windows downwards
395     case Ctrl_R:
396     case 'r':
397 		CHECK_CMDWIN;
398 		reset_VIsual_and_resel();	// stop Visual mode
399 		win_rotate(FALSE, (int)Prenum1);    // downwards
400 		break;
401 
402 // rotate windows upwards
403     case 'R':
404 		CHECK_CMDWIN;
405 		reset_VIsual_and_resel();	// stop Visual mode
406 		win_rotate(TRUE, (int)Prenum1);	    // upwards
407 		break;
408 
409 // move window to the very top/bottom/left/right
410     case 'K':
411     case 'J':
412     case 'H':
413     case 'L':
414 		CHECK_CMDWIN;
415 		win_totop((int)Prenum,
416 			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
417 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
418 		break;
419 
420 // make all windows the same height
421     case '=':
422 #ifdef FEAT_GUI
423 		need_mouse_correct = TRUE;
424 #endif
425 		win_equal(NULL, FALSE, 'b');
426 		break;
427 
428 // increase current window height
429     case '+':
430 #ifdef FEAT_GUI
431 		need_mouse_correct = TRUE;
432 #endif
433 		win_setheight(curwin->w_height + (int)Prenum1);
434 		break;
435 
436 // decrease current window height
437     case '-':
438 #ifdef FEAT_GUI
439 		need_mouse_correct = TRUE;
440 #endif
441 		win_setheight(curwin->w_height - (int)Prenum1);
442 		break;
443 
444 // set current window height
445     case Ctrl__:
446     case '_':
447 #ifdef FEAT_GUI
448 		need_mouse_correct = TRUE;
449 #endif
450 		win_setheight(Prenum ? (int)Prenum : 9999);
451 		break;
452 
453 // increase current window width
454     case '>':
455 #ifdef FEAT_GUI
456 		need_mouse_correct = TRUE;
457 #endif
458 		win_setwidth(curwin->w_width + (int)Prenum1);
459 		break;
460 
461 // decrease current window width
462     case '<':
463 #ifdef FEAT_GUI
464 		need_mouse_correct = TRUE;
465 #endif
466 		win_setwidth(curwin->w_width - (int)Prenum1);
467 		break;
468 
469 // set current window width
470     case '|':
471 #ifdef FEAT_GUI
472 		need_mouse_correct = TRUE;
473 #endif
474 		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
475 		break;
476 
477 // jump to tag and split window if tag exists (in preview window)
478 #if defined(FEAT_QUICKFIX)
479     case '}':
480 		CHECK_CMDWIN;
481 		if (Prenum)
482 		    g_do_tagpreview = Prenum;
483 		else
484 		    g_do_tagpreview = p_pvh;
485 #endif
486 		// FALLTHROUGH
487     case ']':
488     case Ctrl_RSB:
489 		CHECK_CMDWIN;
490 		// keep Visual mode, can select words to use as a tag
491 		if (Prenum)
492 		    postponed_split = Prenum;
493 		else
494 		    postponed_split = -1;
495 #ifdef FEAT_QUICKFIX
496 		if (nchar != '}')
497 		    g_do_tagpreview = 0;
498 #endif
499 
500 		// Execute the command right here, required when "wincmd ]"
501 		// was used in a function.
502 		do_nv_ident(Ctrl_RSB, NUL);
503 		break;
504 
505 #ifdef FEAT_SEARCHPATH
506 // edit file name under cursor in a new window
507     case 'f':
508     case 'F':
509     case Ctrl_F:
510 wingotofile:
511 		CHECK_CMDWIN;
512 
513 		ptr = grab_file_name(Prenum1, &lnum);
514 		if (ptr != NULL)
515 		{
516 		    tabpage_T	*oldtab = curtab;
517 		    win_T	*oldwin = curwin;
518 # ifdef FEAT_GUI
519 		    need_mouse_correct = TRUE;
520 # endif
521 		    setpcmark();
522 		    if (win_split(0, 0) == OK)
523 		    {
524 			RESET_BINDING(curwin);
525 			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
526 						   ECMD_HIDE, NULL) == FAIL)
527 			{
528 			    // Failed to open the file, close the window
529 			    // opened for it.
530 			    win_close(curwin, FALSE);
531 			    goto_tabpage_win(oldtab, oldwin);
532 			}
533 			else if (nchar == 'F' && lnum >= 0)
534 			{
535 			    curwin->w_cursor.lnum = lnum;
536 			    check_cursor_lnum();
537 			    beginline(BL_SOL | BL_FIX);
538 			}
539 		    }
540 		    vim_free(ptr);
541 		}
542 		break;
543 #endif
544 
545 #ifdef FEAT_FIND_ID
546 // Go to the first occurrence of the identifier under cursor along path in a
547 // new window -- webb
548     case 'i':			    // Go to any match
549     case Ctrl_I:
550 		type = FIND_ANY;
551 		// FALLTHROUGH
552     case 'd':			    // Go to definition, using 'define'
553     case Ctrl_D:
554 		CHECK_CMDWIN;
555 		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
556 		    break;
557 		find_pattern_in_path(ptr, 0, len, TRUE,
558 			Prenum == 0 ? TRUE : FALSE, type,
559 			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
560 		curwin->w_set_curswant = TRUE;
561 		break;
562 #endif
563 
564 // Quickfix window only: view the result under the cursor in a new split.
565 #if defined(FEAT_QUICKFIX)
566     case K_KENTER:
567     case CAR:
568 		if (bt_quickfix(curbuf))
569 		    qf_view_result(TRUE);
570 		break;
571 #endif
572 
573 // CTRL-W g  extended commands
574     case 'g':
575     case Ctrl_G:
576 		CHECK_CMDWIN;
577 #ifdef USE_ON_FLY_SCROLL
578 		dont_scroll = TRUE;		// disallow scrolling here
579 #endif
580 		++no_mapping;
581 		++allow_keys;   // no mapping for xchar, but allow key codes
582 		if (xchar == NUL)
583 		    xchar = plain_vgetc();
584 		LANGMAP_ADJUST(xchar, TRUE);
585 		--no_mapping;
586 		--allow_keys;
587 #ifdef FEAT_CMDL_INFO
588 		(void)add_to_showcmd(xchar);
589 #endif
590 		switch (xchar)
591 		{
592 #if defined(FEAT_QUICKFIX)
593 		    case '}':
594 			xchar = Ctrl_RSB;
595 			if (Prenum)
596 			    g_do_tagpreview = Prenum;
597 			else
598 			    g_do_tagpreview = p_pvh;
599 #endif
600 			// FALLTHROUGH
601 		    case ']':
602 		    case Ctrl_RSB:
603 			// keep Visual mode, can select words to use as a tag
604 			if (Prenum)
605 			    postponed_split = Prenum;
606 			else
607 			    postponed_split = -1;
608 
609 			// Execute the command right here, required when
610 			// "wincmd g}" was used in a function.
611 			do_nv_ident('g', xchar);
612 			break;
613 
614 #ifdef FEAT_SEARCHPATH
615 		    case 'f':	    // CTRL-W gf: "gf" in a new tab page
616 		    case 'F':	    // CTRL-W gF: "gF" in a new tab page
617 			cmdmod.tab = tabpage_index(curtab) + 1;
618 			nchar = xchar;
619 			goto wingotofile;
620 #endif
621 		    case 't':	    // CTRL-W gt: go to next tab page
622 			goto_tabpage((int)Prenum);
623 			break;
624 
625 		    case 'T':	    // CTRL-W gT: go to previous tab page
626 			goto_tabpage(-(int)Prenum1);
627 			break;
628 
629 		    default:
630 			beep_flush();
631 			break;
632 		}
633 		break;
634 
635     default:	beep_flush();
636 		break;
637     }
638 }
639 
640 /*
641  * Figure out the address type for ":wincmd".
642  */
643     void
644 get_wincmd_addr_type(char_u *arg, exarg_T *eap)
645 {
646     switch (*arg)
647     {
648     case 'S':
649     case Ctrl_S:
650     case 's':
651     case Ctrl_N:
652     case 'n':
653     case 'j':
654     case Ctrl_J:
655     case 'k':
656     case Ctrl_K:
657     case 'T':
658     case Ctrl_R:
659     case 'r':
660     case 'R':
661     case 'K':
662     case 'J':
663     case '+':
664     case '-':
665     case Ctrl__:
666     case '_':
667     case '|':
668     case ']':
669     case Ctrl_RSB:
670     case 'g':
671     case Ctrl_G:
672     case Ctrl_V:
673     case 'v':
674     case 'h':
675     case Ctrl_H:
676     case 'l':
677     case Ctrl_L:
678     case 'H':
679     case 'L':
680     case '>':
681     case '<':
682 #if defined(FEAT_QUICKFIX)
683     case '}':
684 #endif
685 #ifdef FEAT_SEARCHPATH
686     case 'f':
687     case 'F':
688     case Ctrl_F:
689 #endif
690 #ifdef FEAT_FIND_ID
691     case 'i':
692     case Ctrl_I:
693     case 'd':
694     case Ctrl_D:
695 #endif
696 		// window size or any count
697 		eap->addr_type = ADDR_OTHER;
698 		break;
699 
700     case Ctrl_HAT:
701     case '^':
702 		// buffer number
703 		eap->addr_type = ADDR_BUFFERS;
704 		break;
705 
706     case Ctrl_Q:
707     case 'q':
708     case Ctrl_C:
709     case 'c':
710     case Ctrl_O:
711     case 'o':
712     case Ctrl_W:
713     case 'w':
714     case 'W':
715     case 'x':
716     case Ctrl_X:
717 		// window number
718 		eap->addr_type = ADDR_WINDOWS;
719 		break;
720 
721 #if defined(FEAT_QUICKFIX)
722     case Ctrl_Z:
723     case 'z':
724     case 'P':
725 #endif
726     case 't':
727     case Ctrl_T:
728     case 'b':
729     case Ctrl_B:
730     case 'p':
731     case Ctrl_P:
732     case '=':
733     case CAR:
734 		// no count
735 		eap->addr_type = ADDR_NONE;
736 		break;
737     }
738 }
739 
740     static void
741 cmd_with_count(
742     char	*cmd,
743     char_u	*bufp,
744     size_t	bufsize,
745     long	Prenum)
746 {
747     size_t	len = STRLEN(cmd);
748 
749     STRCPY(bufp, cmd);
750     if (Prenum > 0)
751 	vim_snprintf((char *)bufp + len, bufsize - len, "%ld", Prenum);
752 }
753 
754 /*
755  * If "split_disallowed" is set given an error and return FAIL.
756  * Otherwise return OK.
757  */
758     static int
759 check_split_disallowed()
760 {
761     if (split_disallowed > 0)
762     {
763 	emsg(_("E242: Can't split a window while closing another"));
764 	return FAIL;
765     }
766     return OK;
767 }
768 
769 /*
770  * split the current window, implements CTRL-W s and :split
771  *
772  * "size" is the height or width for the new window, 0 to use half of current
773  * height or width.
774  *
775  * "flags":
776  * WSP_ROOM: require enough room for new window
777  * WSP_VERT: vertical split.
778  * WSP_TOP:  open window at the top-left of the shell (help window).
779  * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
780  * WSP_HELP: creating the help window, keep layout snapshot
781  *
782  * return FAIL for failure, OK otherwise
783  */
784     int
785 win_split(int size, int flags)
786 {
787     if (ERROR_IF_POPUP_WINDOW)
788 	return FAIL;
789 
790     // When the ":tab" modifier was used open a new tab page instead.
791     if (may_open_tabpage() == OK)
792 	return OK;
793 
794     // Add flags from ":vertical", ":topleft" and ":botright".
795     flags |= cmdmod.split;
796     if ((flags & WSP_TOP) && (flags & WSP_BOT))
797     {
798 	emsg(_("E442: Can't split topleft and botright at the same time"));
799 	return FAIL;
800     }
801     if (check_split_disallowed() == FAIL)
802 	return FAIL;
803 
804     // When creating the help window make a snapshot of the window layout.
805     // Otherwise clear the snapshot, it's now invalid.
806     if (flags & WSP_HELP)
807 	make_snapshot(SNAP_HELP_IDX);
808     else
809 	clear_snapshot(curtab, SNAP_HELP_IDX);
810 
811     return win_split_ins(size, flags, NULL, 0);
812 }
813 
814 /*
815  * When "new_wp" is NULL: split the current window in two.
816  * When "new_wp" is not NULL: insert this window at the far
817  * top/left/right/bottom.
818  * return FAIL for failure, OK otherwise
819  */
820     int
821 win_split_ins(
822     int		size,
823     int		flags,
824     win_T	*new_wp,
825     int		dir)
826 {
827     win_T	*wp = new_wp;
828     win_T	*oldwin;
829     int		new_size = size;
830     int		i;
831     int		need_status = 0;
832     int		do_equal = FALSE;
833     int		needed;
834     int		available;
835     int		oldwin_height = 0;
836     int		layout;
837     frame_T	*frp, *curfrp, *frp2, *prevfrp;
838     int		before;
839     int		minheight;
840     int		wmh1;
841     int		did_set_fraction = FALSE;
842 
843     if (flags & WSP_TOP)
844 	oldwin = firstwin;
845     else if (flags & WSP_BOT)
846 	oldwin = lastwin;
847     else
848 	oldwin = curwin;
849 
850     // add a status line when p_ls == 1 and splitting the first window
851     if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
852     {
853 	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
854 	{
855 	    emsg(_(e_noroom));
856 	    return FAIL;
857 	}
858 	need_status = STATUS_HEIGHT;
859     }
860 
861 #ifdef FEAT_GUI
862     // May be needed for the scrollbars that are going to change.
863     if (gui.in_use)
864 	out_flush();
865 #endif
866 
867     if (flags & WSP_VERT)
868     {
869 	int	wmw1;
870 	int	minwidth;
871 
872 	layout = FR_ROW;
873 
874 	/*
875 	 * Check if we are able to split the current window and compute its
876 	 * width.
877 	 */
878 	// Current window requires at least 1 space.
879 	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
880 	needed = wmw1 + 1;
881 	if (flags & WSP_ROOM)
882 	    needed += p_wiw - wmw1;
883 	if (flags & (WSP_BOT | WSP_TOP))
884 	{
885 	    minwidth = frame_minwidth(topframe, NOWIN);
886 	    available = topframe->fr_width;
887 	    needed += minwidth;
888 	}
889 	else if (p_ea)
890 	{
891 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
892 	    prevfrp = oldwin->w_frame;
893 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
894 							frp = frp->fr_parent)
895 	    {
896 		if (frp->fr_layout == FR_ROW)
897 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
898 			if (frp2 != prevfrp)
899 			    minwidth += frame_minwidth(frp2, NOWIN);
900 		prevfrp = frp;
901 	    }
902 	    available = topframe->fr_width;
903 	    needed += minwidth;
904 	}
905 	else
906 	{
907 	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
908 	    available = oldwin->w_frame->fr_width;
909 	    needed += minwidth;
910 	}
911 	if (available < needed && new_wp == NULL)
912 	{
913 	    emsg(_(e_noroom));
914 	    return FAIL;
915 	}
916 	if (new_size == 0)
917 	    new_size = oldwin->w_width / 2;
918 	if (new_size > available - minwidth - 1)
919 	    new_size = available - minwidth - 1;
920 	if (new_size < wmw1)
921 	    new_size = wmw1;
922 
923 	// if it doesn't fit in the current window, need win_equal()
924 	if (oldwin->w_width - new_size - 1 < p_wmw)
925 	    do_equal = TRUE;
926 
927 	// We don't like to take lines for the new window from a
928 	// 'winfixwidth' window.  Take them from a window to the left or right
929 	// instead, if possible. Add one for the separator.
930 	if (oldwin->w_p_wfw)
931 	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
932 
933 	// Only make all windows the same width if one of them (except oldwin)
934 	// is wider than one of the split windows.
935 	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
936 					 && oldwin->w_frame->fr_parent != NULL)
937 	{
938 	    frp = oldwin->w_frame->fr_parent->fr_child;
939 	    while (frp != NULL)
940 	    {
941 		if (frp->fr_win != oldwin && frp->fr_win != NULL
942 			&& (frp->fr_win->w_width > new_size
943 			    || frp->fr_win->w_width > oldwin->w_width
944 							      - new_size - 1))
945 		{
946 		    do_equal = TRUE;
947 		    break;
948 		}
949 		frp = frp->fr_next;
950 	    }
951 	}
952     }
953     else
954     {
955 	layout = FR_COL;
956 
957 	/*
958 	 * Check if we are able to split the current window and compute its
959 	 * height.
960 	 */
961 	// Current window requires at least 1 space.
962 	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
963 	needed = wmh1 + STATUS_HEIGHT;
964 	if (flags & WSP_ROOM)
965 	    needed += p_wh - wmh1;
966 	if (flags & (WSP_BOT | WSP_TOP))
967 	{
968 	    minheight = frame_minheight(topframe, NOWIN) + need_status;
969 	    available = topframe->fr_height;
970 	    needed += minheight;
971 	}
972 	else if (p_ea)
973 	{
974 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
975 	    prevfrp = oldwin->w_frame;
976 	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
977 							frp = frp->fr_parent)
978 	    {
979 		if (frp->fr_layout == FR_COL)
980 		    FOR_ALL_FRAMES(frp2, frp->fr_child)
981 			if (frp2 != prevfrp)
982 			    minheight += frame_minheight(frp2, NOWIN);
983 		prevfrp = frp;
984 	    }
985 	    available = topframe->fr_height;
986 	    needed += minheight;
987 	}
988 	else
989 	{
990 	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
991 	    available = oldwin->w_frame->fr_height;
992 	    needed += minheight;
993 	}
994 	if (available < needed && new_wp == NULL)
995 	{
996 	    emsg(_(e_noroom));
997 	    return FAIL;
998 	}
999 	oldwin_height = oldwin->w_height;
1000 	if (need_status)
1001 	{
1002 	    oldwin->w_status_height = STATUS_HEIGHT;
1003 	    oldwin_height -= STATUS_HEIGHT;
1004 	}
1005 	if (new_size == 0)
1006 	    new_size = oldwin_height / 2;
1007 	if (new_size > available - minheight - STATUS_HEIGHT)
1008 	    new_size = available - minheight - STATUS_HEIGHT;
1009 	if (new_size < wmh1)
1010 	    new_size = wmh1;
1011 
1012 	// if it doesn't fit in the current window, need win_equal()
1013 	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
1014 	    do_equal = TRUE;
1015 
1016 	// We don't like to take lines for the new window from a
1017 	// 'winfixheight' window.  Take them from a window above or below
1018 	// instead, if possible.
1019 	if (oldwin->w_p_wfh)
1020 	{
1021 	    // Set w_fraction now so that the cursor keeps the same relative
1022 	    // vertical position using the old height.
1023 	    set_fraction(oldwin);
1024 	    did_set_fraction = TRUE;
1025 
1026 	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
1027 								      oldwin);
1028 	    oldwin_height = oldwin->w_height;
1029 	    if (need_status)
1030 		oldwin_height -= STATUS_HEIGHT;
1031 	}
1032 
1033 	// Only make all windows the same height if one of them (except oldwin)
1034 	// is higher than one of the split windows.
1035 	if (!do_equal && p_ea && size == 0 && *p_ead != 'h'
1036 	   && oldwin->w_frame->fr_parent != NULL)
1037 	{
1038 	    frp = oldwin->w_frame->fr_parent->fr_child;
1039 	    while (frp != NULL)
1040 	    {
1041 		if (frp->fr_win != oldwin && frp->fr_win != NULL
1042 			&& (frp->fr_win->w_height > new_size
1043 			    || frp->fr_win->w_height > oldwin_height - new_size
1044 							      - STATUS_HEIGHT))
1045 		{
1046 		    do_equal = TRUE;
1047 		    break;
1048 		}
1049 		frp = frp->fr_next;
1050 	    }
1051 	}
1052     }
1053 
1054     /*
1055      * allocate new window structure and link it in the window list
1056      */
1057     if ((flags & WSP_TOP) == 0
1058 	    && ((flags & WSP_BOT)
1059 		|| (flags & WSP_BELOW)
1060 		|| (!(flags & WSP_ABOVE)
1061 		    && ( (flags & WSP_VERT) ? p_spr : p_sb))))
1062     {
1063 	// new window below/right of current one
1064 	if (new_wp == NULL)
1065 	    wp = win_alloc(oldwin, FALSE);
1066 	else
1067 	    win_append(oldwin, wp);
1068     }
1069     else
1070     {
1071 	if (new_wp == NULL)
1072 	    wp = win_alloc(oldwin->w_prev, FALSE);
1073 	else
1074 	    win_append(oldwin->w_prev, wp);
1075     }
1076 
1077     if (new_wp == NULL)
1078     {
1079 	if (wp == NULL)
1080 	    return FAIL;
1081 
1082 	new_frame(wp);
1083 	if (wp->w_frame == NULL)
1084 	{
1085 	    win_free(wp, NULL);
1086 	    return FAIL;
1087 	}
1088 
1089 	// make the contents of the new window the same as the current one
1090 	win_init(wp, curwin, flags);
1091     }
1092 
1093     /*
1094      * Reorganise the tree of frames to insert the new window.
1095      */
1096     if (flags & (WSP_TOP | WSP_BOT))
1097     {
1098 	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
1099 	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
1100 	{
1101 	    curfrp = topframe->fr_child;
1102 	    if (flags & WSP_BOT)
1103 		while (curfrp->fr_next != NULL)
1104 		    curfrp = curfrp->fr_next;
1105 	}
1106 	else
1107 	    curfrp = topframe;
1108 	before = (flags & WSP_TOP);
1109     }
1110     else
1111     {
1112 	curfrp = oldwin->w_frame;
1113 	if (flags & WSP_BELOW)
1114 	    before = FALSE;
1115 	else if (flags & WSP_ABOVE)
1116 	    before = TRUE;
1117 	else if (flags & WSP_VERT)
1118 	    before = !p_spr;
1119 	else
1120 	    before = !p_sb;
1121     }
1122     if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
1123     {
1124 	// Need to create a new frame in the tree to make a branch.
1125 	frp = ALLOC_CLEAR_ONE(frame_T);
1126 	*frp = *curfrp;
1127 	curfrp->fr_layout = layout;
1128 	frp->fr_parent = curfrp;
1129 	frp->fr_next = NULL;
1130 	frp->fr_prev = NULL;
1131 	curfrp->fr_child = frp;
1132 	curfrp->fr_win = NULL;
1133 	curfrp = frp;
1134 	if (frp->fr_win != NULL)
1135 	    oldwin->w_frame = frp;
1136 	else
1137 	    FOR_ALL_FRAMES(frp, frp->fr_child)
1138 		frp->fr_parent = curfrp;
1139     }
1140 
1141     if (new_wp == NULL)
1142 	frp = wp->w_frame;
1143     else
1144 	frp = new_wp->w_frame;
1145     frp->fr_parent = curfrp->fr_parent;
1146 
1147     // Insert the new frame at the right place in the frame list.
1148     if (before)
1149 	frame_insert(curfrp, frp);
1150     else
1151 	frame_append(curfrp, frp);
1152 
1153     // Set w_fraction now so that the cursor keeps the same relative
1154     // vertical position.
1155     if (!did_set_fraction)
1156 	set_fraction(oldwin);
1157     wp->w_fraction = oldwin->w_fraction;
1158 
1159     if (flags & WSP_VERT)
1160     {
1161 	wp->w_p_scr = curwin->w_p_scr;
1162 
1163 	if (need_status)
1164 	{
1165 	    win_new_height(oldwin, oldwin->w_height - 1);
1166 	    oldwin->w_status_height = need_status;
1167 	}
1168 	if (flags & (WSP_TOP | WSP_BOT))
1169 	{
1170 	    // set height and row of new window to full height
1171 	    wp->w_winrow = tabline_height();
1172 	    win_new_height(wp, curfrp->fr_height - (p_ls > 0)
1173 							  - WINBAR_HEIGHT(wp));
1174 	    wp->w_status_height = (p_ls > 0);
1175 	}
1176 	else
1177 	{
1178 	    // height and row of new window is same as current window
1179 	    wp->w_winrow = oldwin->w_winrow;
1180 	    win_new_height(wp, VISIBLE_HEIGHT(oldwin));
1181 	    wp->w_status_height = oldwin->w_status_height;
1182 	}
1183 	frp->fr_height = curfrp->fr_height;
1184 
1185 	// "new_size" of the current window goes to the new window, use
1186 	// one column for the vertical separator
1187 	win_new_width(wp, new_size);
1188 	if (before)
1189 	    wp->w_vsep_width = 1;
1190 	else
1191 	{
1192 	    wp->w_vsep_width = oldwin->w_vsep_width;
1193 	    oldwin->w_vsep_width = 1;
1194 	}
1195 	if (flags & (WSP_TOP | WSP_BOT))
1196 	{
1197 	    if (flags & WSP_BOT)
1198 		frame_add_vsep(curfrp);
1199 	    // Set width of neighbor frame
1200 	    frame_new_width(curfrp, curfrp->fr_width
1201 		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
1202 								       FALSE);
1203 	}
1204 	else
1205 	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
1206 	if (before)	// new window left of current one
1207 	{
1208 	    wp->w_wincol = oldwin->w_wincol;
1209 	    oldwin->w_wincol += new_size + 1;
1210 	}
1211 	else		// new window right of current one
1212 	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
1213 	frame_fix_width(oldwin);
1214 	frame_fix_width(wp);
1215     }
1216     else
1217     {
1218 	// width and column of new window is same as current window
1219 	if (flags & (WSP_TOP | WSP_BOT))
1220 	{
1221 	    wp->w_wincol = 0;
1222 	    win_new_width(wp, Columns);
1223 	    wp->w_vsep_width = 0;
1224 	}
1225 	else
1226 	{
1227 	    wp->w_wincol = oldwin->w_wincol;
1228 	    win_new_width(wp, oldwin->w_width);
1229 	    wp->w_vsep_width = oldwin->w_vsep_width;
1230 	}
1231 	frp->fr_width = curfrp->fr_width;
1232 
1233 	// "new_size" of the current window goes to the new window, use
1234 	// one row for the status line
1235 	win_new_height(wp, new_size);
1236 	if (flags & (WSP_TOP | WSP_BOT))
1237 	{
1238 	    int new_fr_height = curfrp->fr_height - new_size
1239 							  + WINBAR_HEIGHT(wp) ;
1240 
1241 	    if (!((flags & WSP_BOT) && p_ls == 0))
1242 		new_fr_height -= STATUS_HEIGHT;
1243 	    frame_new_height(curfrp, new_fr_height, flags & WSP_TOP, FALSE);
1244 	}
1245 	else
1246 	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
1247 	if (before)	// new window above current one
1248 	{
1249 	    wp->w_winrow = oldwin->w_winrow;
1250 	    wp->w_status_height = STATUS_HEIGHT;
1251 	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
1252 	}
1253 	else		// new window below current one
1254 	{
1255 	    wp->w_winrow = oldwin->w_winrow + VISIBLE_HEIGHT(oldwin)
1256 							       + STATUS_HEIGHT;
1257 	    wp->w_status_height = oldwin->w_status_height;
1258 	    if (!(flags & WSP_BOT))
1259 		oldwin->w_status_height = STATUS_HEIGHT;
1260 	}
1261 	if (flags & WSP_BOT)
1262 	    frame_add_statusline(curfrp);
1263 	frame_fix_height(wp);
1264 	frame_fix_height(oldwin);
1265     }
1266 
1267     if (flags & (WSP_TOP | WSP_BOT))
1268 	(void)win_comp_pos();
1269 
1270     /*
1271      * Both windows need redrawing
1272      */
1273     redraw_win_later(wp, NOT_VALID);
1274     wp->w_redr_status = TRUE;
1275     redraw_win_later(oldwin, NOT_VALID);
1276     oldwin->w_redr_status = TRUE;
1277 
1278     if (need_status)
1279     {
1280 	msg_row = Rows - 1;
1281 	msg_col = sc_col;
1282 	msg_clr_eos_force();	// Old command/ruler may still be there
1283 	comp_col();
1284 	msg_row = Rows - 1;
1285 	msg_col = 0;	// put position back at start of line
1286     }
1287 
1288     /*
1289      * equalize the window sizes.
1290      */
1291     if (do_equal || dir != 0)
1292 	win_equal(wp, TRUE,
1293 		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
1294 		: dir == 'h' ? 'b' : 'v');
1295 
1296     // Don't change the window height/width to 'winheight' / 'winwidth' if a
1297     // size was given.
1298     if (flags & WSP_VERT)
1299     {
1300 	i = p_wiw;
1301 	if (size != 0)
1302 	    p_wiw = size;
1303 
1304 # ifdef FEAT_GUI
1305 	// When 'guioptions' includes 'L' or 'R' may have to add scrollbars.
1306 	if (gui.in_use)
1307 	    gui_init_which_components(NULL);
1308 # endif
1309     }
1310     else
1311     {
1312 	i = p_wh;
1313 	if (size != 0)
1314 	    p_wh = size;
1315     }
1316 
1317 #ifdef FEAT_JUMPLIST
1318     // Keep same changelist position in new window.
1319     wp->w_changelistidx = oldwin->w_changelistidx;
1320 #endif
1321 
1322     /*
1323      * make the new window the current window
1324      */
1325     win_enter_ext(wp, FALSE, FALSE, TRUE, TRUE, TRUE);
1326     if (flags & WSP_VERT)
1327 	p_wiw = i;
1328     else
1329 	p_wh = i;
1330 
1331     return OK;
1332 }
1333 
1334 
1335 /*
1336  * Initialize window "newp" from window "oldp".
1337  * Used when splitting a window and when creating a new tab page.
1338  * The windows will both edit the same buffer.
1339  * WSP_NEWLOC may be specified in flags to prevent the location list from
1340  * being copied.
1341  */
1342     static void
1343 win_init(win_T *newp, win_T *oldp, int flags UNUSED)
1344 {
1345     int		i;
1346 
1347     newp->w_buffer = oldp->w_buffer;
1348 #ifdef FEAT_SYN_HL
1349     newp->w_s = &(oldp->w_buffer->b_s);
1350 #endif
1351     oldp->w_buffer->b_nwindows++;
1352     newp->w_cursor = oldp->w_cursor;
1353     newp->w_valid = 0;
1354     newp->w_curswant = oldp->w_curswant;
1355     newp->w_set_curswant = oldp->w_set_curswant;
1356     newp->w_topline = oldp->w_topline;
1357 #ifdef FEAT_DIFF
1358     newp->w_topfill = oldp->w_topfill;
1359 #endif
1360     newp->w_leftcol = oldp->w_leftcol;
1361     newp->w_pcmark = oldp->w_pcmark;
1362     newp->w_prev_pcmark = oldp->w_prev_pcmark;
1363     newp->w_alt_fnum = oldp->w_alt_fnum;
1364     newp->w_wrow = oldp->w_wrow;
1365     newp->w_fraction = oldp->w_fraction;
1366     newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
1367 #ifdef FEAT_JUMPLIST
1368     copy_jumplist(oldp, newp);
1369 #endif
1370 #ifdef FEAT_QUICKFIX
1371     if (flags & WSP_NEWLOC)
1372     {
1373 	// Don't copy the location list.
1374 	newp->w_llist = NULL;
1375 	newp->w_llist_ref = NULL;
1376     }
1377     else
1378 	copy_loclist_stack(oldp, newp);
1379 #endif
1380     newp->w_localdir = (oldp->w_localdir == NULL)
1381 				    ? NULL : vim_strsave(oldp->w_localdir);
1382 
1383     // copy tagstack and folds
1384     for (i = 0; i < oldp->w_tagstacklen; i++)
1385     {
1386 	taggy_T	*tag = &newp->w_tagstack[i];
1387 	*tag = oldp->w_tagstack[i];
1388 	if (tag->tagname != NULL)
1389 	    tag->tagname = vim_strsave(tag->tagname);
1390 	if (tag->user_data != NULL)
1391 	    tag->user_data = vim_strsave(tag->user_data);
1392     }
1393     newp->w_tagstackidx = oldp->w_tagstackidx;
1394     newp->w_tagstacklen = oldp->w_tagstacklen;
1395 #ifdef FEAT_FOLDING
1396     copyFoldingState(oldp, newp);
1397 #endif
1398 
1399     win_init_some(newp, oldp);
1400 
1401 #ifdef FEAT_SYN_HL
1402     check_colorcolumn(newp);
1403 #endif
1404 }
1405 
1406 /*
1407  * Initialize window "newp" from window "old".
1408  * Only the essential things are copied.
1409  */
1410     static void
1411 win_init_some(win_T *newp, win_T *oldp)
1412 {
1413     // Use the same argument list.
1414     newp->w_alist = oldp->w_alist;
1415     ++newp->w_alist->al_refcount;
1416     newp->w_arg_idx = oldp->w_arg_idx;
1417 
1418     // copy options from existing window
1419     win_copy_options(oldp, newp);
1420 }
1421 
1422 /*
1423  * Return TRUE if "win" is a global popup or a popup in the current tab page.
1424  */
1425     int
1426 win_valid_popup(win_T *win UNUSED)
1427 {
1428 #ifdef FEAT_PROP_POPUP
1429     win_T	*wp;
1430 
1431     for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
1432 	if (wp == win)
1433 	    return TRUE;
1434     for (wp = curtab->tp_first_popupwin; wp != NULL; wp = wp->w_next)
1435 	if (wp == win)
1436 	    return TRUE;
1437 #endif
1438     return FALSE;
1439 }
1440 
1441 /*
1442  * Check if "win" is a pointer to an existing window in the current tab page.
1443  */
1444     int
1445 win_valid(win_T *win)
1446 {
1447     win_T	*wp;
1448 
1449     if (win == NULL)
1450 	return FALSE;
1451     FOR_ALL_WINDOWS(wp)
1452 	if (wp == win)
1453 	    return TRUE;
1454     return win_valid_popup(win);
1455 }
1456 
1457 /*
1458  * Check if "win" is a pointer to an existing window in any tab page.
1459  */
1460     int
1461 win_valid_any_tab(win_T *win)
1462 {
1463     win_T	*wp;
1464     tabpage_T	*tp;
1465 
1466     if (win == NULL)
1467 	return FALSE;
1468     FOR_ALL_TABPAGES(tp)
1469     {
1470 	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
1471 	{
1472 	    if (wp == win)
1473 		return TRUE;
1474 	}
1475 #ifdef FEAT_PROP_POPUP
1476 	for (wp = tp->tp_first_popupwin; wp != NULL; wp = wp->w_next)
1477 	    if (wp == win)
1478 		return TRUE;
1479 #endif
1480     }
1481     return win_valid_popup(win);
1482 }
1483 
1484 /*
1485  * Return the number of windows.
1486  */
1487     int
1488 win_count(void)
1489 {
1490     win_T	*wp;
1491     int		count = 0;
1492 
1493     FOR_ALL_WINDOWS(wp)
1494 	++count;
1495     return count;
1496 }
1497 
1498 /*
1499  * Make "count" windows on the screen.
1500  * Return actual number of windows on the screen.
1501  * Must be called when there is just one window, filling the whole screen
1502  * (excluding the command line).
1503  */
1504     int
1505 make_windows(
1506     int		count,
1507     int		vertical UNUSED)  // split windows vertically if TRUE
1508 {
1509     int		maxcount;
1510     int		todo;
1511 
1512     if (vertical)
1513     {
1514 	// Each windows needs at least 'winminwidth' lines and a separator
1515 	// column.
1516 	maxcount = (curwin->w_width + curwin->w_vsep_width
1517 					     - (p_wiw - p_wmw)) / (p_wmw + 1);
1518     }
1519     else
1520     {
1521 	// Each window needs at least 'winminheight' lines and a status line.
1522 	maxcount = (VISIBLE_HEIGHT(curwin) + curwin->w_status_height
1523 				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
1524     }
1525 
1526     if (maxcount < 2)
1527 	maxcount = 2;
1528     if (count > maxcount)
1529 	count = maxcount;
1530 
1531     /*
1532      * add status line now, otherwise first window will be too big
1533      */
1534     if (count > 1)
1535 	last_status(TRUE);
1536 
1537     /*
1538      * Don't execute autocommands while creating the windows.  Must do that
1539      * when putting the buffers in the windows.
1540      */
1541     block_autocmds();
1542 
1543     // todo is number of windows left to create
1544     for (todo = count - 1; todo > 0; --todo)
1545 	if (vertical)
1546 	{
1547 	    if (win_split(curwin->w_width - (curwin->w_width - todo)
1548 			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
1549 		break;
1550 	}
1551 	else
1552 	{
1553 	    if (win_split(curwin->w_height - (curwin->w_height - todo
1554 			    * STATUS_HEIGHT) / (todo + 1)
1555 			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
1556 		break;
1557 	}
1558 
1559     unblock_autocmds();
1560 
1561     // return actual number of windows
1562     return (count - todo);
1563 }
1564 
1565 /*
1566  * Exchange current and next window
1567  */
1568     static void
1569 win_exchange(long Prenum)
1570 {
1571     frame_T	*frp;
1572     frame_T	*frp2;
1573     win_T	*wp;
1574     win_T	*wp2;
1575     int		temp;
1576 
1577     if (ERROR_IF_POPUP_WINDOW)
1578 	return;
1579     if (ONE_WINDOW)	    // just one window
1580     {
1581 	beep_flush();
1582 	return;
1583     }
1584 
1585 #ifdef FEAT_GUI
1586     need_mouse_correct = TRUE;
1587 #endif
1588 
1589     /*
1590      * find window to exchange with
1591      */
1592     if (Prenum)
1593     {
1594 	frp = curwin->w_frame->fr_parent->fr_child;
1595 	while (frp != NULL && --Prenum > 0)
1596 	    frp = frp->fr_next;
1597     }
1598     else if (curwin->w_frame->fr_next != NULL)	// Swap with next
1599 	frp = curwin->w_frame->fr_next;
1600     else    // Swap last window in row/col with previous
1601 	frp = curwin->w_frame->fr_prev;
1602 
1603     // We can only exchange a window with another window, not with a frame
1604     // containing windows.
1605     if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
1606 	return;
1607     wp = frp->fr_win;
1608 
1609 /*
1610  * 1. remove curwin from the list. Remember after which window it was in wp2
1611  * 2. insert curwin before wp in the list
1612  * if wp != wp2
1613  *    3. remove wp from the list
1614  *    4. insert wp after wp2
1615  * 5. exchange the status line height and vsep width.
1616  */
1617     wp2 = curwin->w_prev;
1618     frp2 = curwin->w_frame->fr_prev;
1619     if (wp->w_prev != curwin)
1620     {
1621 	win_remove(curwin, NULL);
1622 	frame_remove(curwin->w_frame);
1623 	win_append(wp->w_prev, curwin);
1624 	frame_insert(frp, curwin->w_frame);
1625     }
1626     if (wp != wp2)
1627     {
1628 	win_remove(wp, NULL);
1629 	frame_remove(wp->w_frame);
1630 	win_append(wp2, wp);
1631 	if (frp2 == NULL)
1632 	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
1633 	else
1634 	    frame_append(frp2, wp->w_frame);
1635     }
1636     temp = curwin->w_status_height;
1637     curwin->w_status_height = wp->w_status_height;
1638     wp->w_status_height = temp;
1639     temp = curwin->w_vsep_width;
1640     curwin->w_vsep_width = wp->w_vsep_width;
1641     wp->w_vsep_width = temp;
1642 
1643     // If the windows are not in the same frame, exchange the sizes to avoid
1644     // messing up the window layout.  Otherwise fix the frame sizes.
1645     if (curwin->w_frame->fr_parent != wp->w_frame->fr_parent)
1646     {
1647 	temp = curwin->w_height;
1648 	curwin->w_height = wp->w_height;
1649 	wp->w_height = temp;
1650 	temp = curwin->w_width;
1651 	curwin->w_width = wp->w_width;
1652 	wp->w_width = temp;
1653     }
1654     else
1655     {
1656 	frame_fix_height(curwin);
1657 	frame_fix_height(wp);
1658 	frame_fix_width(curwin);
1659 	frame_fix_width(wp);
1660     }
1661 
1662     (void)win_comp_pos();		// recompute window positions
1663 
1664     win_enter(wp, TRUE);
1665     redraw_all_later(NOT_VALID);
1666 }
1667 
1668 /*
1669  * rotate windows: if upwards TRUE the second window becomes the first one
1670  *		   if upwards FALSE the first window becomes the second one
1671  */
1672     static void
1673 win_rotate(int upwards, int count)
1674 {
1675     win_T	*wp1;
1676     win_T	*wp2;
1677     frame_T	*frp;
1678     int		n;
1679 
1680     if (ONE_WINDOW)		// nothing to do
1681     {
1682 	beep_flush();
1683 	return;
1684     }
1685 
1686 #ifdef FEAT_GUI
1687     need_mouse_correct = TRUE;
1688 #endif
1689 
1690     // Check if all frames in this row/col have one window.
1691     FOR_ALL_FRAMES(frp, curwin->w_frame->fr_parent->fr_child)
1692 	if (frp->fr_win == NULL)
1693 	{
1694 	    emsg(_("E443: Cannot rotate when another window is split"));
1695 	    return;
1696 	}
1697 
1698     while (count--)
1699     {
1700 	if (upwards)		// first window becomes last window
1701 	{
1702 	    // remove first window/frame from the list
1703 	    frp = curwin->w_frame->fr_parent->fr_child;
1704 	    wp1 = frp->fr_win;
1705 	    win_remove(wp1, NULL);
1706 	    frame_remove(frp);
1707 
1708 	    // find last frame and append removed window/frame after it
1709 	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
1710 		;
1711 	    win_append(frp->fr_win, wp1);
1712 	    frame_append(frp, wp1->w_frame);
1713 
1714 	    wp2 = frp->fr_win;		// previously last window
1715 	}
1716 	else			// last window becomes first window
1717 	{
1718 	    // find last window/frame in the list and remove it
1719 	    for (frp = curwin->w_frame; frp->fr_next != NULL;
1720 							   frp = frp->fr_next)
1721 		;
1722 	    wp1 = frp->fr_win;
1723 	    wp2 = wp1->w_prev;		    // will become last window
1724 	    win_remove(wp1, NULL);
1725 	    frame_remove(frp);
1726 
1727 	    // append the removed window/frame before the first in the list
1728 	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
1729 	    frame_insert(frp->fr_parent->fr_child, frp);
1730 	}
1731 
1732 	// exchange status height and vsep width of old and new last window
1733 	n = wp2->w_status_height;
1734 	wp2->w_status_height = wp1->w_status_height;
1735 	wp1->w_status_height = n;
1736 	frame_fix_height(wp1);
1737 	frame_fix_height(wp2);
1738 	n = wp2->w_vsep_width;
1739 	wp2->w_vsep_width = wp1->w_vsep_width;
1740 	wp1->w_vsep_width = n;
1741 	frame_fix_width(wp1);
1742 	frame_fix_width(wp2);
1743 
1744 	// recompute w_winrow and w_wincol for all windows
1745 	(void)win_comp_pos();
1746     }
1747 
1748     redraw_all_later(NOT_VALID);
1749 }
1750 
1751 /*
1752  * Move the current window to the very top/bottom/left/right of the screen.
1753  */
1754     static void
1755 win_totop(int size, int flags)
1756 {
1757     int		dir;
1758     int		height = curwin->w_height;
1759 
1760     if (ONE_WINDOW)
1761     {
1762 	beep_flush();
1763 	return;
1764     }
1765     if (check_split_disallowed() == FAIL)
1766 	return;
1767 
1768     // Remove the window and frame from the tree of frames.
1769     (void)winframe_remove(curwin, &dir, NULL);
1770     win_remove(curwin, NULL);
1771     last_status(FALSE);	    // may need to remove last status line
1772     (void)win_comp_pos();   // recompute window positions
1773 
1774     // Split a window on the desired side and put the window there.
1775     (void)win_split_ins(size, flags, curwin, dir);
1776     if (!(flags & WSP_VERT))
1777     {
1778 	win_setheight(height);
1779 	if (p_ea)
1780 	    win_equal(curwin, TRUE, 'v');
1781     }
1782 
1783 #if defined(FEAT_GUI)
1784     // When 'guioptions' includes 'L' or 'R' may have to remove or add
1785     // scrollbars.  Have to update them anyway.
1786     gui_may_update_scrollbars();
1787 #endif
1788 }
1789 
1790 /*
1791  * Move window "win1" to below/right of "win2" and make "win1" the current
1792  * window.  Only works within the same frame!
1793  */
1794     void
1795 win_move_after(win_T *win1, win_T *win2)
1796 {
1797     int		height;
1798 
1799     // check if the arguments are reasonable
1800     if (win1 == win2)
1801 	return;
1802 
1803     // check if there is something to do
1804     if (win2->w_next != win1)
1805     {
1806 	if (win1->w_frame->fr_parent != win2->w_frame->fr_parent)
1807 	{
1808 	    iemsg("INTERNAL: trying to move a window into another frame");
1809 	    return;
1810 	}
1811 
1812 	// may need move the status line/vertical separator of the last window
1813 	//
1814 	if (win1 == lastwin)
1815 	{
1816 	    height = win1->w_prev->w_status_height;
1817 	    win1->w_prev->w_status_height = win1->w_status_height;
1818 	    win1->w_status_height = height;
1819 	    if (win1->w_prev->w_vsep_width == 1)
1820 	    {
1821 		// Remove the vertical separator from the last-but-one window,
1822 		// add it to the last window.  Adjust the frame widths.
1823 		win1->w_prev->w_vsep_width = 0;
1824 		win1->w_prev->w_frame->fr_width -= 1;
1825 		win1->w_vsep_width = 1;
1826 		win1->w_frame->fr_width += 1;
1827 	    }
1828 	}
1829 	else if (win2 == lastwin)
1830 	{
1831 	    height = win1->w_status_height;
1832 	    win1->w_status_height = win2->w_status_height;
1833 	    win2->w_status_height = height;
1834 	    if (win1->w_vsep_width == 1)
1835 	    {
1836 		// Remove the vertical separator from win1, add it to the last
1837 		// window, win2.  Adjust the frame widths.
1838 		win2->w_vsep_width = 1;
1839 		win2->w_frame->fr_width += 1;
1840 		win1->w_vsep_width = 0;
1841 		win1->w_frame->fr_width -= 1;
1842 	    }
1843 	}
1844 	win_remove(win1, NULL);
1845 	frame_remove(win1->w_frame);
1846 	win_append(win2, win1);
1847 	frame_append(win2->w_frame, win1->w_frame);
1848 
1849 	(void)win_comp_pos();	// recompute w_winrow for all windows
1850 	redraw_later(NOT_VALID);
1851     }
1852     win_enter(win1, FALSE);
1853 }
1854 
1855 /*
1856  * Make all windows the same height.
1857  * 'next_curwin' will soon be the current window, make sure it has enough
1858  * rows.
1859  */
1860     void
1861 win_equal(
1862     win_T	*next_curwin,	// pointer to current window to be or NULL
1863     int		current,	// do only frame with current window
1864     int		dir)		// 'v' for vertically, 'h' for horizontally,
1865 				// 'b' for both, 0 for using p_ead
1866 {
1867     if (dir == 0)
1868 	dir = *p_ead;
1869     win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
1870 		      topframe, dir, 0, tabline_height(),
1871 					   (int)Columns, topframe->fr_height);
1872 }
1873 
1874 /*
1875  * Set a frame to a new position and height, spreading the available room
1876  * equally over contained frames.
1877  * The window "next_curwin" (if not NULL) should at least get the size from
1878  * 'winheight' and 'winwidth' if possible.
1879  */
1880     static void
1881 win_equal_rec(
1882     win_T	*next_curwin,	// pointer to current window to be or NULL
1883     int		current,	// do only frame with current window
1884     frame_T	*topfr,		// frame to set size off
1885     int		dir,		// 'v', 'h' or 'b', see win_equal()
1886     int		col,		// horizontal position for frame
1887     int		row,		// vertical position for frame
1888     int		width,		// new width of frame
1889     int		height)		// new height of frame
1890 {
1891     int		n, m;
1892     int		extra_sep = 0;
1893     int		wincount, totwincount = 0;
1894     frame_T	*fr;
1895     int		next_curwin_size = 0;
1896     int		room = 0;
1897     int		new_size;
1898     int		has_next_curwin = 0;
1899     int		hnc;
1900 
1901     if (topfr->fr_layout == FR_LEAF)
1902     {
1903 	// Set the width/height of this frame.
1904 	// Redraw when size or position changes
1905 	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
1906 		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
1907 	   )
1908 	{
1909 	    topfr->fr_win->w_winrow = row;
1910 	    frame_new_height(topfr, height, FALSE, FALSE);
1911 	    topfr->fr_win->w_wincol = col;
1912 	    frame_new_width(topfr, width, FALSE, FALSE);
1913 	    redraw_all_later(NOT_VALID);
1914 	}
1915     }
1916     else if (topfr->fr_layout == FR_ROW)
1917     {
1918 	topfr->fr_width = width;
1919 	topfr->fr_height = height;
1920 
1921 	if (dir != 'v')			// equalize frame widths
1922 	{
1923 	    // Compute the maximum number of windows horizontally in this
1924 	    // frame.
1925 	    n = frame_minwidth(topfr, NOWIN);
1926 	    // add one for the rightmost window, it doesn't have a separator
1927 	    if (col + width == Columns)
1928 		extra_sep = 1;
1929 	    else
1930 		extra_sep = 0;
1931 	    totwincount = (n + extra_sep) / (p_wmw + 1);
1932 	    has_next_curwin = frame_has_win(topfr, next_curwin);
1933 
1934 	    /*
1935 	     * Compute width for "next_curwin" window and room available for
1936 	     * other windows.
1937 	     * "m" is the minimal width when counting p_wiw for "next_curwin".
1938 	     */
1939 	    m = frame_minwidth(topfr, next_curwin);
1940 	    room = width - m;
1941 	    if (room < 0)
1942 	    {
1943 		next_curwin_size = p_wiw + room;
1944 		room = 0;
1945 	    }
1946 	    else
1947 	    {
1948 		next_curwin_size = -1;
1949 		FOR_ALL_FRAMES(fr, topfr->fr_child)
1950 		{
1951 		    // If 'winfixwidth' set keep the window width if
1952 		    // possible.
1953 		    // Watch out for this window being the next_curwin.
1954 		    if (frame_fixed_width(fr))
1955 		    {
1956 			n = frame_minwidth(fr, NOWIN);
1957 			new_size = fr->fr_width;
1958 			if (frame_has_win(fr, next_curwin))
1959 			{
1960 			    room += p_wiw - p_wmw;
1961 			    next_curwin_size = 0;
1962 			    if (new_size < p_wiw)
1963 				new_size = p_wiw;
1964 			}
1965 			else
1966 			    // These windows don't use up room.
1967 			    totwincount -= (n + (fr->fr_next == NULL
1968 					      ? extra_sep : 0)) / (p_wmw + 1);
1969 			room -= new_size - n;
1970 			if (room < 0)
1971 			{
1972 			    new_size += room;
1973 			    room = 0;
1974 			}
1975 			fr->fr_newwidth = new_size;
1976 		    }
1977 		}
1978 		if (next_curwin_size == -1)
1979 		{
1980 		    if (!has_next_curwin)
1981 			next_curwin_size = 0;
1982 		    else if (totwincount > 1
1983 			    && (room + (totwincount - 2))
1984 						  / (totwincount - 1) > p_wiw)
1985 		    {
1986 			// Can make all windows wider than 'winwidth', spread
1987 			// the room equally.
1988 			next_curwin_size = (room + p_wiw
1989 					    + (totwincount - 1) * p_wmw
1990 					    + (totwincount - 1)) / totwincount;
1991 			room -= next_curwin_size - p_wiw;
1992 		    }
1993 		    else
1994 			next_curwin_size = p_wiw;
1995 		}
1996 	    }
1997 
1998 	    if (has_next_curwin)
1999 		--totwincount;		// don't count curwin
2000 	}
2001 
2002 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2003 	{
2004 	    wincount = 1;
2005 	    if (fr->fr_next == NULL)
2006 		// last frame gets all that remains (avoid roundoff error)
2007 		new_size = width;
2008 	    else if (dir == 'v')
2009 		new_size = fr->fr_width;
2010 	    else if (frame_fixed_width(fr))
2011 	    {
2012 		new_size = fr->fr_newwidth;
2013 		wincount = 0;	    // doesn't count as a sizeable window
2014 	    }
2015 	    else
2016 	    {
2017 		// Compute the maximum number of windows horiz. in "fr".
2018 		n = frame_minwidth(fr, NOWIN);
2019 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2020 								/ (p_wmw + 1);
2021 		m = frame_minwidth(fr, next_curwin);
2022 		if (has_next_curwin)
2023 		    hnc = frame_has_win(fr, next_curwin);
2024 		else
2025 		    hnc = FALSE;
2026 		if (hnc)	    // don't count next_curwin
2027 		    --wincount;
2028 		if (totwincount == 0)
2029 		    new_size = room;
2030 		else
2031 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2032 								/ totwincount;
2033 		if (hnc)	    // add next_curwin size
2034 		{
2035 		    next_curwin_size -= p_wiw - (m - n);
2036 		    new_size += next_curwin_size;
2037 		    room -= new_size - next_curwin_size;
2038 		}
2039 		else
2040 		    room -= new_size;
2041 		new_size += n;
2042 	    }
2043 
2044 	    // Skip frame that is full width when splitting or closing a
2045 	    // window, unless equalizing all frames.
2046 	    if (!current || dir != 'v' || topfr->fr_parent != NULL
2047 		    || (new_size != fr->fr_width)
2048 		    || frame_has_win(fr, next_curwin))
2049 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2050 							    new_size, height);
2051 	    col += new_size;
2052 	    width -= new_size;
2053 	    totwincount -= wincount;
2054 	}
2055     }
2056     else // topfr->fr_layout == FR_COL
2057     {
2058 	topfr->fr_width = width;
2059 	topfr->fr_height = height;
2060 
2061 	if (dir != 'h')			// equalize frame heights
2062 	{
2063 	    // Compute maximum number of windows vertically in this frame.
2064 	    n = frame_minheight(topfr, NOWIN);
2065 	    // add one for the bottom window if it doesn't have a statusline
2066 	    if (row + height == cmdline_row && p_ls == 0)
2067 		extra_sep = 1;
2068 	    else
2069 		extra_sep = 0;
2070 	    totwincount = (n + extra_sep) / (p_wmh + 1);
2071 	    has_next_curwin = frame_has_win(topfr, next_curwin);
2072 
2073 	    /*
2074 	     * Compute height for "next_curwin" window and room available for
2075 	     * other windows.
2076 	     * "m" is the minimal height when counting p_wh for "next_curwin".
2077 	     */
2078 	    m = frame_minheight(topfr, next_curwin);
2079 	    room = height - m;
2080 	    if (room < 0)
2081 	    {
2082 		// The room is less then 'winheight', use all space for the
2083 		// current window.
2084 		next_curwin_size = p_wh + room;
2085 		room = 0;
2086 	    }
2087 	    else
2088 	    {
2089 		next_curwin_size = -1;
2090 		FOR_ALL_FRAMES(fr, topfr->fr_child)
2091 		{
2092 		    // If 'winfixheight' set keep the window height if
2093 		    // possible.
2094 		    // Watch out for this window being the next_curwin.
2095 		    if (frame_fixed_height(fr))
2096 		    {
2097 			n = frame_minheight(fr, NOWIN);
2098 			new_size = fr->fr_height;
2099 			if (frame_has_win(fr, next_curwin))
2100 			{
2101 			    room += p_wh - p_wmh;
2102 			    next_curwin_size = 0;
2103 			    if (new_size < p_wh)
2104 				new_size = p_wh;
2105 			}
2106 			else
2107 			    // These windows don't use up room.
2108 			    totwincount -= (n + (fr->fr_next == NULL
2109 					      ? extra_sep : 0)) / (p_wmh + 1);
2110 			room -= new_size - n;
2111 			if (room < 0)
2112 			{
2113 			    new_size += room;
2114 			    room = 0;
2115 			}
2116 			fr->fr_newheight = new_size;
2117 		    }
2118 		}
2119 		if (next_curwin_size == -1)
2120 		{
2121 		    if (!has_next_curwin)
2122 			next_curwin_size = 0;
2123 		    else if (totwincount > 1
2124 			    && (room + (totwincount - 2))
2125 						   / (totwincount - 1) > p_wh)
2126 		    {
2127 			// can make all windows higher than 'winheight',
2128 			// spread the room equally.
2129 			next_curwin_size = (room + p_wh
2130 					   + (totwincount - 1) * p_wmh
2131 					   + (totwincount - 1)) / totwincount;
2132 			room -= next_curwin_size - p_wh;
2133 		    }
2134 		    else
2135 			next_curwin_size = p_wh;
2136 		}
2137 	    }
2138 
2139 	    if (has_next_curwin)
2140 		--totwincount;		// don't count curwin
2141 	}
2142 
2143 	FOR_ALL_FRAMES(fr, topfr->fr_child)
2144 	{
2145 	    wincount = 1;
2146 	    if (fr->fr_next == NULL)
2147 		// last frame gets all that remains (avoid roundoff error)
2148 		new_size = height;
2149 	    else if (dir == 'h')
2150 		new_size = fr->fr_height;
2151 	    else if (frame_fixed_height(fr))
2152 	    {
2153 		new_size = fr->fr_newheight;
2154 		wincount = 0;	    // doesn't count as a sizeable window
2155 	    }
2156 	    else
2157 	    {
2158 		// Compute the maximum number of windows vert. in "fr".
2159 		n = frame_minheight(fr, NOWIN);
2160 		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
2161 								/ (p_wmh + 1);
2162 		m = frame_minheight(fr, next_curwin);
2163 		if (has_next_curwin)
2164 		    hnc = frame_has_win(fr, next_curwin);
2165 		else
2166 		    hnc = FALSE;
2167 		if (hnc)	    // don't count next_curwin
2168 		    --wincount;
2169 		if (totwincount == 0)
2170 		    new_size = room;
2171 		else
2172 		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
2173 								/ totwincount;
2174 		if (hnc)	    // add next_curwin size
2175 		{
2176 		    next_curwin_size -= p_wh - (m - n);
2177 		    new_size += next_curwin_size;
2178 		    room -= new_size - next_curwin_size;
2179 		}
2180 		else
2181 		    room -= new_size;
2182 		new_size += n;
2183 	    }
2184 	    // Skip frame that is full width when splitting or closing a
2185 	    // window, unless equalizing all frames.
2186 	    if (!current || dir != 'h' || topfr->fr_parent != NULL
2187 		    || (new_size != fr->fr_height)
2188 		    || frame_has_win(fr, next_curwin))
2189 		win_equal_rec(next_curwin, current, fr, dir, col, row,
2190 							     width, new_size);
2191 	    row += new_size;
2192 	    height -= new_size;
2193 	    totwincount -= wincount;
2194 	}
2195     }
2196 }
2197 
2198 #ifdef FEAT_JOB_CHANNEL
2199     static void
2200 leaving_window(win_T *win)
2201 {
2202     // Only matters for a prompt window.
2203     if (!bt_prompt(win->w_buffer))
2204 	return;
2205 
2206     // When leaving a prompt window stop Insert mode and perhaps restart
2207     // it when entering that window again.
2208     win->w_buffer->b_prompt_insert = restart_edit;
2209     if (restart_edit != 0 && mode_displayed)
2210 	clear_cmdline = TRUE;		// unshow mode later
2211     restart_edit = NUL;
2212 
2213     // When leaving the window (or closing the window) was done from a
2214     // callback we need to break out of the Insert mode loop and restart Insert
2215     // mode when entering the window again.
2216     if (State & INSERT)
2217     {
2218 	stop_insert_mode = TRUE;
2219 	if (win->w_buffer->b_prompt_insert == NUL)
2220 	    win->w_buffer->b_prompt_insert = 'A';
2221     }
2222 }
2223 
2224     static void
2225 entering_window(win_T *win)
2226 {
2227     // Only matters for a prompt window.
2228     if (!bt_prompt(win->w_buffer))
2229 	return;
2230 
2231     // When switching to a prompt buffer that was in Insert mode, don't stop
2232     // Insert mode, it may have been set in leaving_window().
2233     if (win->w_buffer->b_prompt_insert != NUL)
2234 	stop_insert_mode = FALSE;
2235 
2236     // When entering the prompt window restart Insert mode if we were in Insert
2237     // mode when we left it.
2238     restart_edit = win->w_buffer->b_prompt_insert;
2239 }
2240 #endif
2241 
2242 /*
2243  * Close all windows for buffer "buf".
2244  */
2245     void
2246 close_windows(
2247     buf_T	*buf,
2248     int		keep_curwin)	    // don't close "curwin"
2249 {
2250     win_T	*wp;
2251     tabpage_T   *tp, *nexttp;
2252     int		h = tabline_height();
2253     int		count = tabpage_index(NULL);
2254 
2255     ++RedrawingDisabled;
2256 
2257     for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
2258     {
2259 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
2260 		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
2261 	{
2262 	    if (win_close(wp, FALSE) == FAIL)
2263 		// If closing the window fails give up, to avoid looping
2264 		// forever.
2265 		break;
2266 
2267 	    // Start all over, autocommands may change the window layout.
2268 	    wp = firstwin;
2269 	}
2270 	else
2271 	    wp = wp->w_next;
2272     }
2273 
2274     // Also check windows in other tab pages.
2275     for (tp = first_tabpage; tp != NULL; tp = nexttp)
2276     {
2277 	nexttp = tp->tp_next;
2278 	if (tp != curtab)
2279 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
2280 		if (wp->w_buffer == buf
2281 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
2282 		{
2283 		    win_close_othertab(wp, FALSE, tp);
2284 
2285 		    // Start all over, the tab page may be closed and
2286 		    // autocommands may change the window layout.
2287 		    nexttp = first_tabpage;
2288 		    break;
2289 		}
2290     }
2291 
2292     --RedrawingDisabled;
2293 
2294     if (count != tabpage_index(NULL))
2295 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2296 
2297     redraw_tabline = TRUE;
2298     if (h != tabline_height())
2299 	shell_new_rows();
2300 }
2301 
2302 /*
2303  * Return TRUE if the current window is the only window that exists (ignoring
2304  * "aucmd_win").
2305  * Returns FALSE if there is a window, possibly in another tab page.
2306  */
2307     static int
2308 last_window(void)
2309 {
2310     return (one_window() && first_tabpage->tp_next == NULL);
2311 }
2312 
2313 /*
2314  * Return TRUE if there is only one window other than "aucmd_win" in the
2315  * current tab page.
2316  */
2317     int
2318 one_window(void)
2319 {
2320     win_T	*wp;
2321     int		seen_one = FALSE;
2322 
2323     FOR_ALL_WINDOWS(wp)
2324     {
2325 	if (wp != aucmd_win)
2326 	{
2327 	    if (seen_one)
2328 		return FALSE;
2329 	    seen_one = TRUE;
2330 	}
2331     }
2332     return TRUE;
2333 }
2334 
2335 /*
2336  * Close the possibly last window in a tab page.
2337  * Returns TRUE when the window was closed already.
2338  */
2339     static int
2340 close_last_window_tabpage(
2341     win_T	*win,
2342     int		free_buf,
2343     tabpage_T   *prev_curtab)
2344 {
2345     if (ONE_WINDOW)
2346     {
2347 	buf_T	*old_curbuf = curbuf;
2348 
2349 	/*
2350 	 * Closing the last window in a tab page.  First go to another tab
2351 	 * page and then close the window and the tab page.  This avoids that
2352 	 * curwin and curtab are invalid while we are freeing memory, they may
2353 	 * be used in GUI events.
2354 	 * Don't trigger autocommands yet, they may use wrong values, so do
2355 	 * that below.
2356 	 */
2357 	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
2358 	redraw_tabline = TRUE;
2359 
2360 	// Safety check: Autocommands may have closed the window when jumping
2361 	// to the other tab page.
2362 	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
2363 	{
2364 	    int	    h = tabline_height();
2365 
2366 	    win_close_othertab(win, free_buf, prev_curtab);
2367 	    if (h != tabline_height())
2368 		shell_new_rows();
2369 	}
2370 #ifdef FEAT_JOB_CHANNEL
2371 	entering_window(curwin);
2372 #endif
2373 	// Since goto_tabpage_tp above did not trigger *Enter autocommands, do
2374 	// that now.
2375 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
2376 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
2377 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
2378 	if (old_curbuf != curbuf)
2379 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2380 	return TRUE;
2381     }
2382     return FALSE;
2383 }
2384 
2385 /*
2386  * Close the buffer of "win" and unload it if "action" is DOBUF_UNLOAD.
2387  * "action" can also be zero (do nothing) or DOBUF_WIPE.
2388  * "abort_if_last" is passed to close_buffer(): abort closing if all other
2389  * windows are closed.
2390  */
2391     static void
2392 win_close_buffer(win_T *win, int action, int abort_if_last)
2393 {
2394 #ifdef FEAT_SYN_HL
2395     // Free independent synblock before the buffer is freed.
2396     if (win->w_buffer != NULL)
2397 	reset_synblock(win);
2398 #endif
2399 
2400 #ifdef FEAT_QUICKFIX
2401     // When the quickfix/location list window is closed, unlist the buffer.
2402     if (win->w_buffer != NULL && bt_quickfix(win->w_buffer))
2403 	win->w_buffer->b_p_bl = FALSE;
2404 #endif
2405 
2406     // Close the link to the buffer.
2407     if (win->w_buffer != NULL)
2408     {
2409 	bufref_T    bufref;
2410 
2411 	set_bufref(&bufref, curbuf);
2412 	win->w_closing = TRUE;
2413 	close_buffer(win, win->w_buffer, action, abort_if_last, FALSE);
2414 	if (win_valid_any_tab(win))
2415 	    win->w_closing = FALSE;
2416 	// Make sure curbuf is valid. It can become invalid if 'bufhidden' is
2417 	// "wipe".
2418 	if (!bufref_valid(&bufref))
2419 	    curbuf = firstbuf;
2420     }
2421 }
2422 
2423 /*
2424  * Close window "win".  Only works for the current tab page.
2425  * If "free_buf" is TRUE related buffer may be unloaded.
2426  *
2427  * Called by :quit, :close, :xit, :wq and findtag().
2428  * Returns FAIL when the window was not closed.
2429  */
2430     int
2431 win_close(win_T *win, int free_buf)
2432 {
2433     win_T	*wp;
2434     int		other_buffer = FALSE;
2435     int		close_curwin = FALSE;
2436     int		dir;
2437     int		help_window = FALSE;
2438     tabpage_T   *prev_curtab = curtab;
2439     frame_T	*win_frame = win->w_frame->fr_parent;
2440 #ifdef FEAT_DIFF
2441     int		had_diffmode = win->w_p_diff;
2442 #endif
2443 
2444     if (ERROR_IF_POPUP_WINDOW)
2445 	return FAIL;
2446 
2447     if (last_window())
2448     {
2449 	emsg(_("E444: Cannot close last window"));
2450 	return FAIL;
2451     }
2452 
2453     if (win->w_closing || (win->w_buffer != NULL
2454 					       && win->w_buffer->b_locked > 0))
2455 	return FAIL; // window is already being closed
2456     if (win_unlisted(win))
2457     {
2458 	emsg(_("E813: Cannot close autocmd or popup window"));
2459 	return FAIL;
2460     }
2461     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
2462     {
2463 	emsg(_("E814: Cannot close window, only autocmd window would remain"));
2464 	return FAIL;
2465     }
2466 
2467     // When closing the last window in a tab page first go to another tab page
2468     // and then close the window and the tab page to avoid that curwin and
2469     // curtab are invalid while we are freeing memory.
2470     if (close_last_window_tabpage(win, free_buf, prev_curtab))
2471       return FAIL;
2472 
2473     // When closing the help window, try restoring a snapshot after closing
2474     // the window.  Otherwise clear the snapshot, it's now invalid.
2475     if (bt_help(win->w_buffer))
2476 	help_window = TRUE;
2477     else
2478 	clear_snapshot(curtab, SNAP_HELP_IDX);
2479 
2480     if (win == curwin)
2481     {
2482 #ifdef FEAT_JOB_CHANNEL
2483 	leaving_window(curwin);
2484 #endif
2485 	/*
2486 	 * Guess which window is going to be the new current window.
2487 	 * This may change because of the autocommands (sigh).
2488 	 */
2489 	wp = frame2win(win_altframe(win, NULL));
2490 
2491 	/*
2492 	 * Be careful: If autocommands delete the window or cause this window
2493 	 * to be the last one left, return now.
2494 	 */
2495 	if (wp->w_buffer != curbuf)
2496 	{
2497 	    other_buffer = TRUE;
2498 	    win->w_closing = TRUE;
2499 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
2500 	    if (!win_valid(win))
2501 		return FAIL;
2502 	    win->w_closing = FALSE;
2503 	    if (last_window())
2504 		return FAIL;
2505 	}
2506 	win->w_closing = TRUE;
2507 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
2508 	if (!win_valid(win))
2509 	    return FAIL;
2510 	win->w_closing = FALSE;
2511 	if (last_window())
2512 	    return FAIL;
2513 #ifdef FEAT_EVAL
2514 	// autocmds may abort script processing
2515 	if (aborting())
2516 	    return FAIL;
2517 #endif
2518     }
2519 
2520 #ifdef FEAT_GUI
2521     // Avoid trouble with scrollbars that are going to be deleted in
2522     // win_free().
2523     if (gui.in_use)
2524 	out_flush();
2525 #endif
2526 
2527 #ifdef FEAT_PROP_POPUP
2528     if (popup_win_closed(win) && !win_valid(win))
2529 	return FAIL;
2530 #endif
2531     win_close_buffer(win, free_buf ? DOBUF_UNLOAD : 0, TRUE);
2532 
2533     if (only_one_window() && win_valid(win) && win->w_buffer == NULL
2534 	    && (last_window() || curtab != prev_curtab
2535 		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
2536     {
2537 	// Autocommands have closed all windows, quit now.  Restore
2538 	// curwin->w_buffer, otherwise writing viminfo may fail.
2539 	if (curwin->w_buffer == NULL)
2540 	    curwin->w_buffer = curbuf;
2541 	getout(0);
2542     }
2543 
2544     // Autocommands may have moved to another tab page.
2545     if (curtab != prev_curtab && win_valid_any_tab(win)
2546 						      && win->w_buffer == NULL)
2547     {
2548 	// Need to close the window anyway, since the buffer is NULL.
2549 	win_close_othertab(win, FALSE, prev_curtab);
2550 	return FAIL;
2551     }
2552 
2553     // Autocommands may have closed the window already or closed the only
2554     // other window.
2555     if (!win_valid(win) || last_window()
2556 	    || close_last_window_tabpage(win, free_buf, prev_curtab))
2557 	return FAIL;
2558 
2559     // Now we are really going to close the window.  Disallow any autocommand
2560     // to split a window to avoid trouble.
2561     ++split_disallowed;
2562 
2563     // Free the memory used for the window and get the window that received
2564     // the screen space.
2565     wp = win_free_mem(win, &dir, NULL);
2566 
2567     // Make sure curwin isn't invalid.  It can cause severe trouble when
2568     // printing an error message.  For win_equal() curbuf needs to be valid
2569     // too.
2570     if (win == curwin)
2571     {
2572 	curwin = wp;
2573 #ifdef FEAT_QUICKFIX
2574 	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
2575 	{
2576 	    /*
2577 	     * If the cursor goes to the preview or the quickfix window, try
2578 	     * finding another window to go to.
2579 	     */
2580 	    for (;;)
2581 	    {
2582 		if (wp->w_next == NULL)
2583 		    wp = firstwin;
2584 		else
2585 		    wp = wp->w_next;
2586 		if (wp == curwin)
2587 		    break;
2588 		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
2589 		{
2590 		    curwin = wp;
2591 		    break;
2592 		}
2593 	    }
2594 	}
2595 #endif
2596 	curbuf = curwin->w_buffer;
2597 	close_curwin = TRUE;
2598 
2599 	// The cursor position may be invalid if the buffer changed after last
2600 	// using the window.
2601 	check_cursor();
2602     }
2603     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
2604 	// If the frame of the closed window contains the new current window,
2605 	// only resize that frame.  Otherwise resize all windows.
2606 	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
2607     else
2608 	win_comp_pos();
2609     if (close_curwin)
2610     {
2611 	win_enter_ext(wp, FALSE, TRUE, FALSE, TRUE, TRUE);
2612 	if (other_buffer)
2613 	    // careful: after this wp and win may be invalid!
2614 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
2615     }
2616 
2617     --split_disallowed;
2618 
2619     /*
2620      * If last window has a status line now and we don't want one,
2621      * remove the status line.
2622      */
2623     last_status(FALSE);
2624 
2625     // After closing the help window, try restoring the window layout from
2626     // before it was opened.
2627     if (help_window)
2628 	restore_snapshot(SNAP_HELP_IDX, close_curwin);
2629 
2630 #ifdef FEAT_DIFF
2631     // If the window had 'diff' set and now there is only one window left in
2632     // the tab page with 'diff' set, and "closeoff" is in 'diffopt', then
2633     // execute ":diffoff!".
2634     if (diffopt_closeoff() && had_diffmode && curtab == prev_curtab)
2635     {
2636 	int	diffcount = 0;
2637 	win_T	*dwin;
2638 
2639 	FOR_ALL_WINDOWS(dwin)
2640 	    if (dwin->w_p_diff)
2641 		++diffcount;
2642 	if (diffcount == 1)
2643 	    do_cmdline_cmd((char_u *)"diffoff!");
2644     }
2645 #endif
2646 
2647 #if defined(FEAT_GUI)
2648     // When 'guioptions' includes 'L' or 'R' may have to remove scrollbars.
2649     if (gui.in_use && !win_hasvertsplit())
2650 	gui_init_which_components(NULL);
2651 #endif
2652 
2653     redraw_all_later(NOT_VALID);
2654     return OK;
2655 }
2656 
2657 /*
2658  * Close window "win" in tab page "tp", which is not the current tab page.
2659  * This may be the last window in that tab page and result in closing the tab,
2660  * thus "tp" may become invalid!
2661  * Caller must check if buffer is hidden and whether the tabline needs to be
2662  * updated.
2663  */
2664     void
2665 win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
2666 {
2667     win_T	*wp;
2668     int		dir;
2669     tabpage_T   *ptp = NULL;
2670     int		free_tp = FALSE;
2671 
2672     // Get here with win->w_buffer == NULL when win_close() detects the tab
2673     // page changed.
2674     if (win->w_closing || (win->w_buffer != NULL
2675 					       && win->w_buffer->b_locked > 0))
2676 	return; // window is already being closed
2677 
2678     if (win->w_buffer != NULL)
2679 	// Close the link to the buffer.
2680 	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0,
2681 								 FALSE, FALSE);
2682 
2683     // Careful: Autocommands may have closed the tab page or made it the
2684     // current tab page.
2685     for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
2686 	;
2687     if (ptp == NULL || tp == curtab)
2688 	return;
2689 
2690     // Autocommands may have closed the window already.
2691     for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
2692 	;
2693     if (wp == NULL)
2694 	return;
2695 
2696     // When closing the last window in a tab page remove the tab page.
2697     if (tp->tp_firstwin == tp->tp_lastwin)
2698     {
2699 	if (tp == first_tabpage)
2700 	    first_tabpage = tp->tp_next;
2701 	else
2702 	{
2703 	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
2704 							   ptp = ptp->tp_next)
2705 		;
2706 	    if (ptp == NULL)
2707 	    {
2708 		internal_error("win_close_othertab()");
2709 		return;
2710 	    }
2711 	    ptp->tp_next = tp->tp_next;
2712 	}
2713 	free_tp = TRUE;
2714     }
2715 
2716     // Free the memory used for the window.
2717     win_free_mem(win, &dir, tp);
2718 
2719     if (free_tp)
2720 	free_tabpage(tp);
2721 }
2722 
2723 /*
2724  * Free the memory used for a window.
2725  * Returns a pointer to the window that got the freed up space.
2726  */
2727     static win_T *
2728 win_free_mem(
2729     win_T	*win,
2730     int		*dirp,		// set to 'v' or 'h' for direction if 'ea'
2731     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2732 {
2733     frame_T	*frp;
2734     win_T	*wp;
2735 
2736     // Remove the window and its frame from the tree of frames.
2737     frp = win->w_frame;
2738     wp = winframe_remove(win, dirp, tp);
2739     vim_free(frp);
2740     win_free(win, tp);
2741 
2742     // When deleting the current window of another tab page select a new
2743     // current window.
2744     if (tp != NULL && win == tp->tp_curwin)
2745 	tp->tp_curwin = wp;
2746 
2747     return wp;
2748 }
2749 
2750 #if defined(EXITFREE) || defined(PROTO)
2751     void
2752 win_free_all(void)
2753 {
2754     int		dummy;
2755 
2756     while (first_tabpage->tp_next != NULL)
2757 	tabpage_close(TRUE);
2758 
2759     if (aucmd_win != NULL)
2760     {
2761 	(void)win_free_mem(aucmd_win, &dummy, NULL);
2762 	aucmd_win = NULL;
2763     }
2764 # ifdef FEAT_PROP_POPUP
2765     close_all_popups();
2766 # endif
2767 
2768     while (firstwin != NULL)
2769 	(void)win_free_mem(firstwin, &dummy, NULL);
2770 
2771     // No window should be used after this. Set curwin to NULL to crash
2772     // instead of using freed memory.
2773     curwin = NULL;
2774 }
2775 #endif
2776 
2777 /*
2778  * Remove a window and its frame from the tree of frames.
2779  * Returns a pointer to the window that got the freed up space.
2780  */
2781     win_T *
2782 winframe_remove(
2783     win_T	*win,
2784     int		*dirp UNUSED,	// set to 'v' or 'h' for direction if 'ea'
2785     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2786 {
2787     frame_T	*frp, *frp2, *frp3;
2788     frame_T	*frp_close = win->w_frame;
2789     win_T	*wp;
2790 
2791     /*
2792      * If there is only one window there is nothing to remove.
2793      */
2794     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2795 	return NULL;
2796 
2797     /*
2798      * Remove the window from its frame.
2799      */
2800     frp2 = win_altframe(win, tp);
2801     wp = frame2win(frp2);
2802 
2803     // Remove this frame from the list of frames.
2804     frame_remove(frp_close);
2805 
2806     if (frp_close->fr_parent->fr_layout == FR_COL)
2807     {
2808 	// When 'winfixheight' is set, try to find another frame in the column
2809 	// (as close to the closed frame as possible) to distribute the height
2810 	// to.
2811 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
2812 	{
2813 	    frp = frp_close->fr_prev;
2814 	    frp3 = frp_close->fr_next;
2815 	    while (frp != NULL || frp3 != NULL)
2816 	    {
2817 		if (frp != NULL)
2818 		{
2819 		    if (!frame_fixed_height(frp))
2820 		    {
2821 			frp2 = frp;
2822 			wp = frame2win(frp2);
2823 			break;
2824 		    }
2825 		    frp = frp->fr_prev;
2826 		}
2827 		if (frp3 != NULL)
2828 		{
2829 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
2830 		    {
2831 			frp2 = frp3;
2832 			wp = frp3->fr_win;
2833 			break;
2834 		    }
2835 		    frp3 = frp3->fr_next;
2836 		}
2837 	    }
2838 	}
2839 	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
2840 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2841 	*dirp = 'v';
2842     }
2843     else
2844     {
2845 	// When 'winfixwidth' is set, try to find another frame in the column
2846 	// (as close to the closed frame as possible) to distribute the width
2847 	// to.
2848 	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
2849 	{
2850 	    frp = frp_close->fr_prev;
2851 	    frp3 = frp_close->fr_next;
2852 	    while (frp != NULL || frp3 != NULL)
2853 	    {
2854 		if (frp != NULL)
2855 		{
2856 		    if (!frame_fixed_width(frp))
2857 		    {
2858 			frp2 = frp;
2859 			wp = frame2win(frp2);
2860 			break;
2861 		    }
2862 		    frp = frp->fr_prev;
2863 		}
2864 		if (frp3 != NULL)
2865 		{
2866 		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
2867 		    {
2868 			frp2 = frp3;
2869 			wp = frp3->fr_win;
2870 			break;
2871 		    }
2872 		    frp3 = frp3->fr_next;
2873 		}
2874 	    }
2875 	}
2876 	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
2877 			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
2878 	*dirp = 'h';
2879     }
2880 
2881     // If rows/columns go to a window below/right its positions need to be
2882     // updated.  Can only be done after the sizes have been updated.
2883     if (frp2 == frp_close->fr_next)
2884     {
2885 	int row = win->w_winrow;
2886 	int col = win->w_wincol;
2887 
2888 	frame_comp_pos(frp2, &row, &col);
2889     }
2890 
2891     if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
2892     {
2893 	// There is no other frame in this list, move its info to the parent
2894 	// and remove it.
2895 	frp2->fr_parent->fr_layout = frp2->fr_layout;
2896 	frp2->fr_parent->fr_child = frp2->fr_child;
2897 	FOR_ALL_FRAMES(frp, frp2->fr_child)
2898 	    frp->fr_parent = frp2->fr_parent;
2899 	frp2->fr_parent->fr_win = frp2->fr_win;
2900 	if (frp2->fr_win != NULL)
2901 	    frp2->fr_win->w_frame = frp2->fr_parent;
2902 	frp = frp2->fr_parent;
2903 	if (topframe->fr_child == frp2)
2904 	    topframe->fr_child = frp;
2905 	vim_free(frp2);
2906 
2907 	frp2 = frp->fr_parent;
2908 	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
2909 	{
2910 	    // The frame above the parent has the same layout, have to merge
2911 	    // the frames into this list.
2912 	    if (frp2->fr_child == frp)
2913 		frp2->fr_child = frp->fr_child;
2914 	    frp->fr_child->fr_prev = frp->fr_prev;
2915 	    if (frp->fr_prev != NULL)
2916 		frp->fr_prev->fr_next = frp->fr_child;
2917 	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
2918 	    {
2919 		frp3->fr_parent = frp2;
2920 		if (frp3->fr_next == NULL)
2921 		{
2922 		    frp3->fr_next = frp->fr_next;
2923 		    if (frp->fr_next != NULL)
2924 			frp->fr_next->fr_prev = frp3;
2925 		    break;
2926 		}
2927 	    }
2928 	    if (topframe->fr_child == frp)
2929 		topframe->fr_child = frp2;
2930 	    vim_free(frp);
2931 	}
2932     }
2933 
2934     return wp;
2935 }
2936 
2937 /*
2938  * Return a pointer to the frame that will receive the empty screen space that
2939  * is left over after "win" is closed.
2940  *
2941  * If 'splitbelow' or 'splitright' is set, the space goes above or to the left
2942  * by default.  Otherwise, the free space goes below or to the right.  The
2943  * result is that opening a window and then immediately closing it will
2944  * preserve the initial window layout.  The 'wfh' and 'wfw' settings are
2945  * respected when possible.
2946  */
2947     static frame_T *
2948 win_altframe(
2949     win_T	*win,
2950     tabpage_T	*tp)		// tab page "win" is in, NULL for current
2951 {
2952     frame_T	*frp;
2953     frame_T	*other_fr, *target_fr;
2954 
2955     if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
2956 	return alt_tabpage()->tp_curwin->w_frame;
2957 
2958     frp = win->w_frame;
2959 
2960     if (frp->fr_prev == NULL)
2961 	return frp->fr_next;
2962     if (frp->fr_next == NULL)
2963 	return frp->fr_prev;
2964 
2965     target_fr = frp->fr_next;
2966     other_fr  = frp->fr_prev;
2967     if (p_spr || p_sb)
2968     {
2969 	target_fr = frp->fr_prev;
2970 	other_fr  = frp->fr_next;
2971     }
2972 
2973     // If 'wfh' or 'wfw' is set for the target and not for the alternate
2974     // window, reverse the selection.
2975     if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
2976     {
2977 	if (frame_fixed_width(target_fr) && !frame_fixed_width(other_fr))
2978 	    target_fr = other_fr;
2979     }
2980     else
2981     {
2982 	if (frame_fixed_height(target_fr) && !frame_fixed_height(other_fr))
2983 	    target_fr = other_fr;
2984     }
2985 
2986     return target_fr;
2987 }
2988 
2989 /*
2990  * Return the tabpage that will be used if the current one is closed.
2991  */
2992     static tabpage_T *
2993 alt_tabpage(void)
2994 {
2995     tabpage_T	*tp;
2996 
2997     // Use the next tab page if possible.
2998     if (curtab->tp_next != NULL)
2999 	return curtab->tp_next;
3000 
3001     // Find the last but one tab page.
3002     for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
3003 	;
3004     return tp;
3005 }
3006 
3007 /*
3008  * Find the left-upper window in frame "frp".
3009  */
3010     static win_T *
3011 frame2win(frame_T *frp)
3012 {
3013     while (frp->fr_win == NULL)
3014 	frp = frp->fr_child;
3015     return frp->fr_win;
3016 }
3017 
3018 /*
3019  * Return TRUE if frame "frp" contains window "wp".
3020  */
3021     static int
3022 frame_has_win(frame_T *frp, win_T *wp)
3023 {
3024     frame_T	*p;
3025 
3026     if (frp->fr_layout == FR_LEAF)
3027 	return frp->fr_win == wp;
3028 
3029     FOR_ALL_FRAMES(p, frp->fr_child)
3030 	if (frame_has_win(p, wp))
3031 	    return TRUE;
3032     return FALSE;
3033 }
3034 
3035 /*
3036  * Set a new height for a frame.  Recursively sets the height for contained
3037  * frames and windows.  Caller must take care of positions.
3038  */
3039     static void
3040 frame_new_height(
3041     frame_T	*topfrp,
3042     int		height,
3043     int		topfirst,	// resize topmost contained frame first
3044     int		wfh)		// obey 'winfixheight' when there is a choice;
3045 				// may cause the height not to be set
3046 {
3047     frame_T	*frp;
3048     int		extra_lines;
3049     int		h;
3050 
3051     if (topfrp->fr_win != NULL)
3052     {
3053 	// Simple case: just one window.
3054 	win_new_height(topfrp->fr_win,
3055 				    height - topfrp->fr_win->w_status_height
3056 					      - WINBAR_HEIGHT(topfrp->fr_win));
3057     }
3058     else if (topfrp->fr_layout == FR_ROW)
3059     {
3060 	do
3061 	{
3062 	    // All frames in this row get the same new height.
3063 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3064 	    {
3065 		frame_new_height(frp, height, topfirst, wfh);
3066 		if (frp->fr_height > height)
3067 		{
3068 		    // Could not fit the windows, make the whole row higher.
3069 		    height = frp->fr_height;
3070 		    break;
3071 		}
3072 	    }
3073 	}
3074 	while (frp != NULL);
3075     }
3076     else    // fr_layout == FR_COL
3077     {
3078 	// Complicated case: Resize a column of frames.  Resize the bottom
3079 	// frame first, frames above that when needed.
3080 
3081 	frp = topfrp->fr_child;
3082 	if (wfh)
3083 	    // Advance past frames with one window with 'wfh' set.
3084 	    while (frame_fixed_height(frp))
3085 	    {
3086 		frp = frp->fr_next;
3087 		if (frp == NULL)
3088 		    return;	    // no frame without 'wfh', give up
3089 	    }
3090 	if (!topfirst)
3091 	{
3092 	    // Find the bottom frame of this column
3093 	    while (frp->fr_next != NULL)
3094 		frp = frp->fr_next;
3095 	    if (wfh)
3096 		// Advance back for frames with one window with 'wfh' set.
3097 		while (frame_fixed_height(frp))
3098 		    frp = frp->fr_prev;
3099 	}
3100 
3101 	extra_lines = height - topfrp->fr_height;
3102 	if (extra_lines < 0)
3103 	{
3104 	    // reduce height of contained frames, bottom or top frame first
3105 	    while (frp != NULL)
3106 	    {
3107 		h = frame_minheight(frp, NULL);
3108 		if (frp->fr_height + extra_lines < h)
3109 		{
3110 		    extra_lines += frp->fr_height - h;
3111 		    frame_new_height(frp, h, topfirst, wfh);
3112 		}
3113 		else
3114 		{
3115 		    frame_new_height(frp, frp->fr_height + extra_lines,
3116 							       topfirst, wfh);
3117 		    break;
3118 		}
3119 		if (topfirst)
3120 		{
3121 		    do
3122 			frp = frp->fr_next;
3123 		    while (wfh && frp != NULL && frame_fixed_height(frp));
3124 		}
3125 		else
3126 		{
3127 		    do
3128 			frp = frp->fr_prev;
3129 		    while (wfh && frp != NULL && frame_fixed_height(frp));
3130 		}
3131 		// Increase "height" if we could not reduce enough frames.
3132 		if (frp == NULL)
3133 		    height -= extra_lines;
3134 	    }
3135 	}
3136 	else if (extra_lines > 0)
3137 	{
3138 	    // increase height of bottom or top frame
3139 	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
3140 	}
3141     }
3142     topfrp->fr_height = height;
3143 }
3144 
3145 /*
3146  * Return TRUE if height of frame "frp" should not be changed because of
3147  * the 'winfixheight' option.
3148  */
3149     static int
3150 frame_fixed_height(frame_T *frp)
3151 {
3152     // frame with one window: fixed height if 'winfixheight' set.
3153     if (frp->fr_win != NULL)
3154 	return frp->fr_win->w_p_wfh;
3155 
3156     if (frp->fr_layout == FR_ROW)
3157     {
3158 	// The frame is fixed height if one of the frames in the row is fixed
3159 	// height.
3160 	FOR_ALL_FRAMES(frp, frp->fr_child)
3161 	    if (frame_fixed_height(frp))
3162 		return TRUE;
3163 	return FALSE;
3164     }
3165 
3166     // frp->fr_layout == FR_COL: The frame is fixed height if all of the
3167     // frames in the row are fixed height.
3168     FOR_ALL_FRAMES(frp, frp->fr_child)
3169 	if (!frame_fixed_height(frp))
3170 	    return FALSE;
3171     return TRUE;
3172 }
3173 
3174 /*
3175  * Return TRUE if width of frame "frp" should not be changed because of
3176  * the 'winfixwidth' option.
3177  */
3178     static int
3179 frame_fixed_width(frame_T *frp)
3180 {
3181     // frame with one window: fixed width if 'winfixwidth' set.
3182     if (frp->fr_win != NULL)
3183 	return frp->fr_win->w_p_wfw;
3184 
3185     if (frp->fr_layout == FR_COL)
3186     {
3187 	// The frame is fixed width if one of the frames in the row is fixed
3188 	// width.
3189 	FOR_ALL_FRAMES(frp, frp->fr_child)
3190 	    if (frame_fixed_width(frp))
3191 		return TRUE;
3192 	return FALSE;
3193     }
3194 
3195     // frp->fr_layout == FR_ROW: The frame is fixed width if all of the
3196     // frames in the row are fixed width.
3197     FOR_ALL_FRAMES(frp, frp->fr_child)
3198 	if (!frame_fixed_width(frp))
3199 	    return FALSE;
3200     return TRUE;
3201 }
3202 
3203 /*
3204  * Add a status line to windows at the bottom of "frp".
3205  * Note: Does not check if there is room!
3206  */
3207     static void
3208 frame_add_statusline(frame_T *frp)
3209 {
3210     win_T	*wp;
3211 
3212     if (frp->fr_layout == FR_LEAF)
3213     {
3214 	wp = frp->fr_win;
3215 	if (wp->w_status_height == 0)
3216 	{
3217 	    if (wp->w_height > 0)	// don't make it negative
3218 		--wp->w_height;
3219 	    wp->w_status_height = STATUS_HEIGHT;
3220 	}
3221     }
3222     else if (frp->fr_layout == FR_ROW)
3223     {
3224 	// Handle all the frames in the row.
3225 	FOR_ALL_FRAMES(frp, frp->fr_child)
3226 	    frame_add_statusline(frp);
3227     }
3228     else // frp->fr_layout == FR_COL
3229     {
3230 	// Only need to handle the last frame in the column.
3231 	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
3232 	    ;
3233 	frame_add_statusline(frp);
3234     }
3235 }
3236 
3237 /*
3238  * Set width of a frame.  Handles recursively going through contained frames.
3239  * May remove separator line for windows at the right side (for win_close()).
3240  */
3241     static void
3242 frame_new_width(
3243     frame_T	*topfrp,
3244     int		width,
3245     int		leftfirst,	// resize leftmost contained frame first
3246     int		wfw)		// obey 'winfixwidth' when there is a choice;
3247 				// may cause the width not to be set
3248 {
3249     frame_T	*frp;
3250     int		extra_cols;
3251     int		w;
3252     win_T	*wp;
3253 
3254     if (topfrp->fr_layout == FR_LEAF)
3255     {
3256 	// Simple case: just one window.
3257 	wp = topfrp->fr_win;
3258 	// Find out if there are any windows right of this one.
3259 	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
3260 	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
3261 		break;
3262 	if (frp->fr_parent == NULL)
3263 	    wp->w_vsep_width = 0;
3264 	win_new_width(wp, width - wp->w_vsep_width);
3265     }
3266     else if (topfrp->fr_layout == FR_COL)
3267     {
3268 	do
3269 	{
3270 	    // All frames in this column get the same new width.
3271 	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
3272 	    {
3273 		frame_new_width(frp, width, leftfirst, wfw);
3274 		if (frp->fr_width > width)
3275 		{
3276 		    // Could not fit the windows, make whole column wider.
3277 		    width = frp->fr_width;
3278 		    break;
3279 		}
3280 	    }
3281 	} while (frp != NULL);
3282     }
3283     else    // fr_layout == FR_ROW
3284     {
3285 	// Complicated case: Resize a row of frames.  Resize the rightmost
3286 	// frame first, frames left of it when needed.
3287 
3288 	frp = topfrp->fr_child;
3289 	if (wfw)
3290 	    // Advance past frames with one window with 'wfw' set.
3291 	    while (frame_fixed_width(frp))
3292 	    {
3293 		frp = frp->fr_next;
3294 		if (frp == NULL)
3295 		    return;	    // no frame without 'wfw', give up
3296 	    }
3297 	if (!leftfirst)
3298 	{
3299 	    // Find the rightmost frame of this row
3300 	    while (frp->fr_next != NULL)
3301 		frp = frp->fr_next;
3302 	    if (wfw)
3303 		// Advance back for frames with one window with 'wfw' set.
3304 		while (frame_fixed_width(frp))
3305 		    frp = frp->fr_prev;
3306 	}
3307 
3308 	extra_cols = width - topfrp->fr_width;
3309 	if (extra_cols < 0)
3310 	{
3311 	    // reduce frame width, rightmost frame first
3312 	    while (frp != NULL)
3313 	    {
3314 		w = frame_minwidth(frp, NULL);
3315 		if (frp->fr_width + extra_cols < w)
3316 		{
3317 		    extra_cols += frp->fr_width - w;
3318 		    frame_new_width(frp, w, leftfirst, wfw);
3319 		}
3320 		else
3321 		{
3322 		    frame_new_width(frp, frp->fr_width + extra_cols,
3323 							      leftfirst, wfw);
3324 		    break;
3325 		}
3326 		if (leftfirst)
3327 		{
3328 		    do
3329 			frp = frp->fr_next;
3330 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3331 		}
3332 		else
3333 		{
3334 		    do
3335 			frp = frp->fr_prev;
3336 		    while (wfw && frp != NULL && frame_fixed_width(frp));
3337 		}
3338 		// Increase "width" if we could not reduce enough frames.
3339 		if (frp == NULL)
3340 		    width -= extra_cols;
3341 	    }
3342 	}
3343 	else if (extra_cols > 0)
3344 	{
3345 	    // increase width of rightmost frame
3346 	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
3347 	}
3348     }
3349     topfrp->fr_width = width;
3350 }
3351 
3352 /*
3353  * Add the vertical separator to windows at the right side of "frp".
3354  * Note: Does not check if there is room!
3355  */
3356     static void
3357 frame_add_vsep(frame_T *frp)
3358 {
3359     win_T	*wp;
3360 
3361     if (frp->fr_layout == FR_LEAF)
3362     {
3363 	wp = frp->fr_win;
3364 	if (wp->w_vsep_width == 0)
3365 	{
3366 	    if (wp->w_width > 0)	// don't make it negative
3367 		--wp->w_width;
3368 	    wp->w_vsep_width = 1;
3369 	}
3370     }
3371     else if (frp->fr_layout == FR_COL)
3372     {
3373 	// Handle all the frames in the column.
3374 	FOR_ALL_FRAMES(frp, frp->fr_child)
3375 	    frame_add_vsep(frp);
3376     }
3377     else // frp->fr_layout == FR_ROW
3378     {
3379 	// Only need to handle the last frame in the row.
3380 	frp = frp->fr_child;
3381 	while (frp->fr_next != NULL)
3382 	    frp = frp->fr_next;
3383 	frame_add_vsep(frp);
3384     }
3385 }
3386 
3387 /*
3388  * Set frame width from the window it contains.
3389  */
3390     static void
3391 frame_fix_width(win_T *wp)
3392 {
3393     wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
3394 }
3395 
3396 /*
3397  * Set frame height from the window it contains.
3398  */
3399     static void
3400 frame_fix_height(win_T *wp)
3401 {
3402     wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
3403 }
3404 
3405 /*
3406  * Compute the minimal height for frame "topfrp".
3407  * Uses the 'winminheight' option.
3408  * When "next_curwin" isn't NULL, use p_wh for this window.
3409  * When "next_curwin" is NOWIN, don't use at least one line for the current
3410  * window.
3411  */
3412     static int
3413 frame_minheight(frame_T *topfrp, win_T *next_curwin)
3414 {
3415     frame_T	*frp;
3416     int		m;
3417     int		n;
3418 
3419     if (topfrp->fr_win != NULL)
3420     {
3421 	if (topfrp->fr_win == next_curwin)
3422 	    m = p_wh + topfrp->fr_win->w_status_height;
3423 	else
3424 	{
3425 	    // window: minimal height of the window plus status line
3426 	    m = p_wmh + topfrp->fr_win->w_status_height;
3427 	    if (topfrp->fr_win == curwin && next_curwin == NULL)
3428 	    {
3429 		// Current window is minimal one line high and WinBar is
3430 		// visible.
3431 		if (p_wmh == 0)
3432 		    ++m;
3433 		m += WINBAR_HEIGHT(curwin);
3434 	    }
3435 	}
3436     }
3437     else if (topfrp->fr_layout == FR_ROW)
3438     {
3439 	// get the minimal height from each frame in this row
3440 	m = 0;
3441 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3442 	{
3443 	    n = frame_minheight(frp, next_curwin);
3444 	    if (n > m)
3445 		m = n;
3446 	}
3447     }
3448     else
3449     {
3450 	// Add up the minimal heights for all frames in this column.
3451 	m = 0;
3452 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3453 	    m += frame_minheight(frp, next_curwin);
3454     }
3455 
3456     return m;
3457 }
3458 
3459 /*
3460  * Compute the minimal width for frame "topfrp".
3461  * When "next_curwin" isn't NULL, use p_wiw for this window.
3462  * When "next_curwin" is NOWIN, don't use at least one column for the current
3463  * window.
3464  */
3465     static int
3466 frame_minwidth(
3467     frame_T	*topfrp,
3468     win_T	*next_curwin)	// use p_wh and p_wiw for next_curwin
3469 {
3470     frame_T	*frp;
3471     int		m, n;
3472 
3473     if (topfrp->fr_win != NULL)
3474     {
3475 	if (topfrp->fr_win == next_curwin)
3476 	    m = p_wiw + topfrp->fr_win->w_vsep_width;
3477 	else
3478 	{
3479 	    // window: minimal width of the window plus separator column
3480 	    m = p_wmw + topfrp->fr_win->w_vsep_width;
3481 	    // Current window is minimal one column wide
3482 	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
3483 		++m;
3484 	}
3485     }
3486     else if (topfrp->fr_layout == FR_COL)
3487     {
3488 	// get the minimal width from each frame in this column
3489 	m = 0;
3490 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3491 	{
3492 	    n = frame_minwidth(frp, next_curwin);
3493 	    if (n > m)
3494 		m = n;
3495 	}
3496     }
3497     else
3498     {
3499 	// Add up the minimal widths for all frames in this row.
3500 	m = 0;
3501 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
3502 	    m += frame_minwidth(frp, next_curwin);
3503     }
3504 
3505     return m;
3506 }
3507 
3508 
3509 /*
3510  * Try to close all windows except current one.
3511  * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
3512  * used and the buffer was modified.
3513  *
3514  * Used by ":bdel" and ":only".
3515  */
3516     void
3517 close_others(
3518     int		message,
3519     int		forceit)	    // always hide all other windows
3520 {
3521     win_T	*wp;
3522     win_T	*nextwp;
3523     int		r;
3524 
3525     if (one_window())
3526     {
3527 	if (message && !autocmd_busy)
3528 	    msg(_(m_onlyone));
3529 	return;
3530     }
3531 
3532     // Be very careful here: autocommands may change the window layout.
3533     for (wp = firstwin; win_valid(wp); wp = nextwp)
3534     {
3535 	nextwp = wp->w_next;
3536 	if (wp != curwin)		// don't close current window
3537 	{
3538 
3539 	    // Check if it's allowed to abandon this window
3540 	    r = can_abandon(wp->w_buffer, forceit);
3541 	    if (!win_valid(wp))		// autocommands messed wp up
3542 	    {
3543 		nextwp = firstwin;
3544 		continue;
3545 	    }
3546 	    if (!r)
3547 	    {
3548 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
3549 		if (message && (p_confirm || cmdmod.confirm) && p_write)
3550 		{
3551 		    dialog_changed(wp->w_buffer, FALSE);
3552 		    if (!win_valid(wp))		// autocommands messed wp up
3553 		    {
3554 			nextwp = firstwin;
3555 			continue;
3556 		    }
3557 		}
3558 		if (bufIsChanged(wp->w_buffer))
3559 #endif
3560 		    continue;
3561 	    }
3562 	    win_close(wp, !buf_hide(wp->w_buffer)
3563 					       && !bufIsChanged(wp->w_buffer));
3564 	}
3565     }
3566 
3567     if (message && !ONE_WINDOW)
3568 	emsg(_("E445: Other window contains changes"));
3569 }
3570 
3571     static void
3572 win_init_empty(win_T *wp)
3573 {
3574     redraw_win_later(wp, NOT_VALID);
3575     wp->w_lines_valid = 0;
3576     wp->w_cursor.lnum = 1;
3577     wp->w_curswant = wp->w_cursor.col = 0;
3578     wp->w_cursor.coladd = 0;
3579     wp->w_pcmark.lnum = 1;	// pcmark not cleared but set to line 1
3580     wp->w_pcmark.col = 0;
3581     wp->w_prev_pcmark.lnum = 0;
3582     wp->w_prev_pcmark.col = 0;
3583     wp->w_topline = 1;
3584 #ifdef FEAT_DIFF
3585     wp->w_topfill = 0;
3586 #endif
3587     wp->w_botline = 2;
3588 #if defined(FEAT_SYN_HL) || defined(FEAT_SPELL)
3589     wp->w_s = &wp->w_buffer->b_s;
3590 #endif
3591 }
3592 
3593 /*
3594  * Init the current window "curwin".
3595  * Called when a new file is being edited.
3596  */
3597     void
3598 curwin_init(void)
3599 {
3600     win_init_empty(curwin);
3601 }
3602 
3603 /*
3604  * Allocate the first window and put an empty buffer in it.
3605  * Called from main().
3606  * Return FAIL when something goes wrong (out of memory).
3607  */
3608     int
3609 win_alloc_first(void)
3610 {
3611     if (win_alloc_firstwin(NULL) == FAIL)
3612 	return FAIL;
3613 
3614     first_tabpage = alloc_tabpage();
3615     if (first_tabpage == NULL)
3616 	return FAIL;
3617     first_tabpage->tp_topframe = topframe;
3618     curtab = first_tabpage;
3619 
3620     return OK;
3621 }
3622 
3623 /*
3624  * Allocate and init a window that is not a regular window.
3625  * This can only be done after the first window is fully initialized, thus it
3626  * can't be in win_alloc_first().
3627  */
3628     win_T *
3629 win_alloc_popup_win(void)
3630 {
3631     win_T *wp;
3632 
3633     wp = win_alloc(NULL, TRUE);
3634     if (wp != NULL)
3635     {
3636 	// We need to initialize options with something, using the current
3637 	// window makes most sense.
3638 	win_init_some(wp, curwin);
3639 
3640 	RESET_BINDING(wp);
3641 	new_frame(wp);
3642     }
3643     return wp;
3644 }
3645 
3646 /*
3647  * Initialize window "wp" to display buffer "buf".
3648  */
3649     void
3650 win_init_popup_win(win_T *wp, buf_T *buf)
3651 {
3652     wp->w_buffer = buf;
3653     ++buf->b_nwindows;
3654     win_init_empty(wp); // set cursor and topline to safe values
3655 
3656     // Make sure w_localdir and globaldir are NULL to avoid a chdir() in
3657     // win_enter_ext().
3658     VIM_CLEAR(wp->w_localdir);
3659 }
3660 
3661 /*
3662  * Allocate the first window or the first window in a new tab page.
3663  * When "oldwin" is NULL create an empty buffer for it.
3664  * When "oldwin" is not NULL copy info from it to the new window.
3665  * Return FAIL when something goes wrong (out of memory).
3666  */
3667     static int
3668 win_alloc_firstwin(win_T *oldwin)
3669 {
3670     curwin = win_alloc(NULL, FALSE);
3671     if (oldwin == NULL)
3672     {
3673 	// Very first window, need to create an empty buffer for it and
3674 	// initialize from scratch.
3675 	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
3676 	if (curwin == NULL || curbuf == NULL)
3677 	    return FAIL;
3678 	curwin->w_buffer = curbuf;
3679 #ifdef FEAT_SYN_HL
3680 	curwin->w_s = &(curbuf->b_s);
3681 #endif
3682 	curbuf->b_nwindows = 1;	// there is one window
3683 	curwin->w_alist = &global_alist;
3684 	curwin_init();		// init current window
3685     }
3686     else
3687     {
3688 	// First window in new tab page, initialize it from "oldwin".
3689 	win_init(curwin, oldwin, 0);
3690 
3691 	// We don't want cursor- and scroll-binding in the first window.
3692 	RESET_BINDING(curwin);
3693     }
3694 
3695     new_frame(curwin);
3696     if (curwin->w_frame == NULL)
3697 	return FAIL;
3698     topframe = curwin->w_frame;
3699     topframe->fr_width = Columns;
3700     topframe->fr_height = Rows - p_ch;
3701 
3702     return OK;
3703 }
3704 
3705 /*
3706  * Create a frame for window "wp".
3707  */
3708     static void
3709 new_frame(win_T *wp)
3710 {
3711     frame_T *frp = ALLOC_CLEAR_ONE(frame_T);
3712 
3713     wp->w_frame = frp;
3714     if (frp != NULL)
3715     {
3716 	frp->fr_layout = FR_LEAF;
3717 	frp->fr_win = wp;
3718     }
3719 }
3720 
3721 /*
3722  * Initialize the window and frame size to the maximum.
3723  */
3724     void
3725 win_init_size(void)
3726 {
3727     firstwin->w_height = ROWS_AVAIL;
3728     topframe->fr_height = ROWS_AVAIL;
3729     firstwin->w_width = Columns;
3730     topframe->fr_width = Columns;
3731 }
3732 
3733 /*
3734  * Allocate a new tabpage_T and init the values.
3735  * Returns NULL when out of memory.
3736  */
3737     static tabpage_T *
3738 alloc_tabpage(void)
3739 {
3740     tabpage_T	*tp;
3741 # ifdef FEAT_GUI
3742     int		i;
3743 # endif
3744 
3745 
3746     tp = ALLOC_CLEAR_ONE(tabpage_T);
3747     if (tp == NULL)
3748 	return NULL;
3749 
3750 # ifdef FEAT_EVAL
3751     // init t: variables
3752     tp->tp_vars = dict_alloc();
3753     if (tp->tp_vars == NULL)
3754     {
3755 	vim_free(tp);
3756 	return NULL;
3757     }
3758     init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
3759 # endif
3760 
3761 # ifdef FEAT_GUI
3762     for (i = 0; i < 3; i++)
3763 	tp->tp_prev_which_scrollbars[i] = -1;
3764 # endif
3765 # ifdef FEAT_DIFF
3766     tp->tp_diff_invalid = TRUE;
3767 # endif
3768     tp->tp_ch_used = p_ch;
3769 
3770     return tp;
3771 }
3772 
3773     void
3774 free_tabpage(tabpage_T *tp)
3775 {
3776     int idx;
3777 
3778 # ifdef FEAT_DIFF
3779     diff_clear(tp);
3780 # endif
3781 # ifdef FEAT_PROP_POPUP
3782     while (tp->tp_first_popupwin != NULL)
3783 	popup_close_tabpage(tp, tp->tp_first_popupwin->w_id);
3784 #endif
3785     for (idx = 0; idx < SNAP_COUNT; ++idx)
3786 	clear_snapshot(tp, idx);
3787 #ifdef FEAT_EVAL
3788     vars_clear(&tp->tp_vars->dv_hashtab);	// free all t: variables
3789     hash_init(&tp->tp_vars->dv_hashtab);
3790     unref_var_dict(tp->tp_vars);
3791 #endif
3792 
3793     vim_free(tp->tp_localdir);
3794 
3795 #ifdef FEAT_PYTHON
3796     python_tabpage_free(tp);
3797 #endif
3798 
3799 #ifdef FEAT_PYTHON3
3800     python3_tabpage_free(tp);
3801 #endif
3802 
3803     vim_free(tp);
3804 }
3805 
3806 /*
3807  * Create a new Tab page with one window.
3808  * It will edit the current buffer, like after ":split".
3809  * When "after" is 0 put it just after the current Tab page.
3810  * Otherwise put it just before tab page "after".
3811  * Return FAIL or OK.
3812  */
3813     int
3814 win_new_tabpage(int after)
3815 {
3816     tabpage_T	*tp = curtab;
3817     tabpage_T	*newtp;
3818     int		n;
3819 
3820     newtp = alloc_tabpage();
3821     if (newtp == NULL)
3822 	return FAIL;
3823 
3824     // Remember the current windows in this Tab page.
3825     if (leave_tabpage(curbuf, TRUE) == FAIL)
3826     {
3827 	vim_free(newtp);
3828 	return FAIL;
3829     }
3830     curtab = newtp;
3831 
3832     newtp->tp_localdir = (tp->tp_localdir == NULL)
3833 				    ? NULL : vim_strsave(tp->tp_localdir);
3834     // Create a new empty window.
3835     if (win_alloc_firstwin(tp->tp_curwin) == OK)
3836     {
3837 	// Make the new Tab page the new topframe.
3838 	if (after == 1)
3839 	{
3840 	    // New tab page becomes the first one.
3841 	    newtp->tp_next = first_tabpage;
3842 	    first_tabpage = newtp;
3843 	}
3844 	else
3845 	{
3846 	    if (after > 0)
3847 	    {
3848 		// Put new tab page before tab page "after".
3849 		n = 2;
3850 		for (tp = first_tabpage; tp->tp_next != NULL
3851 					       && n < after; tp = tp->tp_next)
3852 		    ++n;
3853 	    }
3854 	    newtp->tp_next = tp->tp_next;
3855 	    tp->tp_next = newtp;
3856 	}
3857 	win_init_size();
3858 	firstwin->w_winrow = tabline_height();
3859 	win_comp_scroll(curwin);
3860 
3861 	newtp->tp_topframe = topframe;
3862 	last_status(FALSE);
3863 
3864 #if defined(FEAT_GUI)
3865 	// When 'guioptions' includes 'L' or 'R' may have to remove or add
3866 	// scrollbars.  Have to update them anyway.
3867 	gui_may_update_scrollbars();
3868 #endif
3869 #ifdef FEAT_JOB_CHANNEL
3870 	entering_window(curwin);
3871 #endif
3872 
3873 	redraw_all_later(NOT_VALID);
3874 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
3875 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
3876 	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
3877 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
3878 	return OK;
3879     }
3880 
3881     // Failed, get back the previous Tab page
3882     enter_tabpage(curtab, curbuf, TRUE, TRUE);
3883     return FAIL;
3884 }
3885 
3886 /*
3887  * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
3888  * like with ":split".
3889  * Returns OK if a new tab page was created, FAIL otherwise.
3890  */
3891     static int
3892 may_open_tabpage(void)
3893 {
3894     int		n = (cmdmod.tab == 0) ? postponed_split_tab : cmdmod.tab;
3895 
3896     if (n != 0)
3897     {
3898 	cmdmod.tab = 0;	    // reset it to avoid doing it twice
3899 	postponed_split_tab = 0;
3900 	return win_new_tabpage(n);
3901     }
3902     return FAIL;
3903 }
3904 
3905 /*
3906  * Create up to "maxcount" tabpages with empty windows.
3907  * Returns the number of resulting tab pages.
3908  */
3909     int
3910 make_tabpages(int maxcount)
3911 {
3912     int		count = maxcount;
3913     int		todo;
3914 
3915     // Limit to 'tabpagemax' tabs.
3916     if (count > p_tpm)
3917 	count = p_tpm;
3918 
3919     /*
3920      * Don't execute autocommands while creating the tab pages.  Must do that
3921      * when putting the buffers in the windows.
3922      */
3923     block_autocmds();
3924 
3925     for (todo = count - 1; todo > 0; --todo)
3926 	if (win_new_tabpage(0) == FAIL)
3927 	    break;
3928 
3929     unblock_autocmds();
3930 
3931     // return actual number of tab pages
3932     return (count - todo);
3933 }
3934 
3935 /*
3936  * Return TRUE when "tpc" points to a valid tab page.
3937  */
3938     int
3939 valid_tabpage(tabpage_T *tpc)
3940 {
3941     tabpage_T	*tp;
3942 
3943     FOR_ALL_TABPAGES(tp)
3944 	if (tp == tpc)
3945 	    return TRUE;
3946     return FALSE;
3947 }
3948 
3949 /*
3950  * Return TRUE when "tpc" points to a valid tab page and at least one window is
3951  * valid.
3952  */
3953     int
3954 valid_tabpage_win(tabpage_T *tpc)
3955 {
3956     tabpage_T	*tp;
3957     win_T	*wp;
3958 
3959     FOR_ALL_TABPAGES(tp)
3960     {
3961 	if (tp == tpc)
3962 	{
3963 	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
3964 	    {
3965 		if (win_valid_any_tab(wp))
3966 		    return TRUE;
3967 	    }
3968 	    return FALSE;
3969 	}
3970     }
3971     // shouldn't happen
3972     return FALSE;
3973 }
3974 
3975 /*
3976  * Close tabpage "tab", assuming it has no windows in it.
3977  * There must be another tabpage or this will crash.
3978  */
3979     void
3980 close_tabpage(tabpage_T *tab)
3981 {
3982     tabpage_T	*ptp;
3983 
3984     if (tab == first_tabpage)
3985     {
3986 	first_tabpage = tab->tp_next;
3987 	ptp = first_tabpage;
3988     }
3989     else
3990     {
3991 	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
3992 							    ptp = ptp->tp_next)
3993 	    ;
3994 	assert(ptp != NULL);
3995 	ptp->tp_next = tab->tp_next;
3996     }
3997 
3998     goto_tabpage_tp(ptp, FALSE, FALSE);
3999     free_tabpage(tab);
4000 }
4001 
4002 /*
4003  * Find tab page "n" (first one is 1).  Returns NULL when not found.
4004  */
4005     tabpage_T *
4006 find_tabpage(int n)
4007 {
4008     tabpage_T	*tp;
4009     int		i = 1;
4010 
4011     if (n == 0)
4012 	return curtab;
4013 
4014     for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
4015 	++i;
4016     return tp;
4017 }
4018 
4019 /*
4020  * Get index of tab page "tp".  First one has index 1.
4021  * When not found returns number of tab pages plus one.
4022  */
4023     int
4024 tabpage_index(tabpage_T *ftp)
4025 {
4026     int		i = 1;
4027     tabpage_T	*tp;
4028 
4029     for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
4030 	++i;
4031     return i;
4032 }
4033 
4034 /*
4035  * Prepare for leaving the current tab page.
4036  * When autocommands change "curtab" we don't leave the tab page and return
4037  * FAIL.
4038  * Careful: When OK is returned need to get a new tab page very very soon!
4039  */
4040     static int
4041 leave_tabpage(
4042     buf_T	*new_curbuf UNUSED,    // what is going to be the new curbuf,
4043 				       // NULL if unknown
4044     int		trigger_leave_autocmds UNUSED)
4045 {
4046     tabpage_T	*tp = curtab;
4047 
4048 #ifdef FEAT_JOB_CHANNEL
4049     leaving_window(curwin);
4050 #endif
4051     reset_VIsual_and_resel();	// stop Visual mode
4052     if (trigger_leave_autocmds)
4053     {
4054 	if (new_curbuf != curbuf)
4055 	{
4056 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4057 	    if (curtab != tp)
4058 		return FAIL;
4059 	}
4060 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4061 	if (curtab != tp)
4062 	    return FAIL;
4063 	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
4064 	if (curtab != tp)
4065 	    return FAIL;
4066     }
4067 #if defined(FEAT_GUI)
4068     // Remove the scrollbars.  They may be added back later.
4069     if (gui.in_use)
4070 	gui_remove_scrollbars();
4071 #endif
4072     tp->tp_curwin = curwin;
4073     tp->tp_prevwin = prevwin;
4074     tp->tp_firstwin = firstwin;
4075     tp->tp_lastwin = lastwin;
4076     tp->tp_old_Rows = Rows;
4077     tp->tp_old_Columns = Columns;
4078     firstwin = NULL;
4079     lastwin = NULL;
4080     return OK;
4081 }
4082 
4083 /*
4084  * Start using tab page "tp".
4085  * Only to be used after leave_tabpage() or freeing the current tab page.
4086  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4087  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4088  */
4089     static void
4090 enter_tabpage(
4091     tabpage_T	*tp,
4092     buf_T	*old_curbuf UNUSED,
4093     int		trigger_enter_autocmds,
4094     int		trigger_leave_autocmds)
4095 {
4096     int		old_off = tp->tp_firstwin->w_winrow;
4097     win_T	*next_prevwin = tp->tp_prevwin;
4098 
4099     curtab = tp;
4100     firstwin = tp->tp_firstwin;
4101     lastwin = tp->tp_lastwin;
4102     topframe = tp->tp_topframe;
4103 
4104     // We would like doing the TabEnter event first, but we don't have a
4105     // valid current window yet, which may break some commands.
4106     // This triggers autocommands, thus may make "tp" invalid.
4107     win_enter_ext(tp->tp_curwin, FALSE, TRUE, FALSE,
4108 			      trigger_enter_autocmds, trigger_leave_autocmds);
4109     prevwin = next_prevwin;
4110 
4111     last_status(FALSE);		// status line may appear or disappear
4112     (void)win_comp_pos();	// recompute w_winrow for all windows
4113 #ifdef FEAT_DIFF
4114     diff_need_scrollbind = TRUE;
4115 #endif
4116 
4117     // The tabpage line may have appeared or disappeared, may need to resize
4118     // the frames for that.  When the Vim window was resized need to update
4119     // frame sizes too.  Use the stored value of p_ch, so that it can be
4120     // different for each tab page.
4121     if (p_ch != curtab->tp_ch_used)
4122 	clear_cmdline = TRUE;
4123     p_ch = curtab->tp_ch_used;
4124     if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
4125 #ifdef FEAT_GUI_TABLINE
4126 			    && !gui_use_tabline()
4127 #endif
4128 		))
4129 	shell_new_rows();
4130     if (curtab->tp_old_Columns != Columns && starting == 0)
4131 	shell_new_columns();	// update window widths
4132 
4133 #if defined(FEAT_GUI)
4134     // When 'guioptions' includes 'L' or 'R' may have to remove or add
4135     // scrollbars.  Have to update them anyway.
4136     gui_may_update_scrollbars();
4137 #endif
4138 
4139     // Apply autocommands after updating the display, when 'rows' and
4140     // 'columns' have been set correctly.
4141     if (trigger_enter_autocmds)
4142     {
4143 	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
4144 	if (old_curbuf != curbuf)
4145 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4146     }
4147 
4148     redraw_all_later(NOT_VALID);
4149 }
4150 
4151 /*
4152  * Go to tab page "n".  For ":tab N" and "Ngt".
4153  * When "n" is 9999 go to the last tab page.
4154  */
4155     void
4156 goto_tabpage(int n)
4157 {
4158     tabpage_T	*tp = NULL;  // shut up compiler
4159     tabpage_T	*ttp;
4160     int		i;
4161 
4162     if (text_locked())
4163     {
4164 	// Not allowed when editing the command line.
4165 	text_locked_msg();
4166 	return;
4167     }
4168 
4169     // If there is only one it can't work.
4170     if (first_tabpage->tp_next == NULL)
4171     {
4172 	if (n > 1)
4173 	    beep_flush();
4174 	return;
4175     }
4176 
4177     if (n == 0)
4178     {
4179 	// No count, go to next tab page, wrap around end.
4180 	if (curtab->tp_next == NULL)
4181 	    tp = first_tabpage;
4182 	else
4183 	    tp = curtab->tp_next;
4184     }
4185     else if (n < 0)
4186     {
4187 	// "gT": go to previous tab page, wrap around end.  "N gT" repeats
4188 	// this N times.
4189 	ttp = curtab;
4190 	for (i = n; i < 0; ++i)
4191 	{
4192 	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
4193 		    tp = tp->tp_next)
4194 		;
4195 	    ttp = tp;
4196 	}
4197     }
4198     else if (n == 9999)
4199     {
4200 	// Go to last tab page.
4201 	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
4202 	    ;
4203     }
4204     else
4205     {
4206 	// Go to tab page "n".
4207 	tp = find_tabpage(n);
4208 	if (tp == NULL)
4209 	{
4210 	    beep_flush();
4211 	    return;
4212 	}
4213     }
4214 
4215     goto_tabpage_tp(tp, TRUE, TRUE);
4216 
4217 #ifdef FEAT_GUI_TABLINE
4218     if (gui_use_tabline())
4219 	gui_mch_set_curtab(tabpage_index(curtab));
4220 #endif
4221 }
4222 
4223 /*
4224  * Go to tabpage "tp".
4225  * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
4226  * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
4227  * Note: doesn't update the GUI tab.
4228  */
4229     void
4230 goto_tabpage_tp(
4231     tabpage_T	*tp,
4232     int		trigger_enter_autocmds,
4233     int		trigger_leave_autocmds)
4234 {
4235     // Don't repeat a message in another tab page.
4236     set_keep_msg(NULL, 0);
4237 
4238     if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
4239 					trigger_leave_autocmds) == OK)
4240     {
4241 	if (valid_tabpage(tp))
4242 	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
4243 		    trigger_leave_autocmds);
4244 	else
4245 	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
4246 		    trigger_leave_autocmds);
4247     }
4248 }
4249 
4250 /*
4251  * Enter window "wp" in tab page "tp".
4252  * Also updates the GUI tab.
4253  */
4254     void
4255 goto_tabpage_win(tabpage_T *tp, win_T *wp)
4256 {
4257     goto_tabpage_tp(tp, TRUE, TRUE);
4258     if (curtab == tp && win_valid(wp))
4259     {
4260 	win_enter(wp, TRUE);
4261 # ifdef FEAT_GUI_TABLINE
4262 	if (gui_use_tabline())
4263 	    gui_mch_set_curtab(tabpage_index(curtab));
4264 # endif
4265     }
4266 }
4267 
4268 /*
4269  * Move the current tab page to after tab page "nr".
4270  */
4271     void
4272 tabpage_move(int nr)
4273 {
4274     int		n = 1;
4275     tabpage_T	*tp, *tp_dst;
4276 
4277     if (first_tabpage->tp_next == NULL)
4278 	return;
4279 
4280     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
4281 	++n;
4282 
4283     if (tp == curtab || (nr > 0 && tp->tp_next != NULL
4284 						    && tp->tp_next == curtab))
4285 	return;
4286 
4287     tp_dst = tp;
4288 
4289     // Remove the current tab page from the list of tab pages.
4290     if (curtab == first_tabpage)
4291 	first_tabpage = curtab->tp_next;
4292     else
4293     {
4294 	FOR_ALL_TABPAGES(tp)
4295 	    if (tp->tp_next == curtab)
4296 		break;
4297 	if (tp == NULL)	// "cannot happen"
4298 	    return;
4299 	tp->tp_next = curtab->tp_next;
4300     }
4301 
4302     // Re-insert it at the specified position.
4303     if (nr <= 0)
4304     {
4305 	curtab->tp_next = first_tabpage;
4306 	first_tabpage = curtab;
4307     }
4308     else
4309     {
4310 	curtab->tp_next = tp_dst->tp_next;
4311 	tp_dst->tp_next = curtab;
4312     }
4313 
4314     // Need to redraw the tabline.  Tab page contents doesn't change.
4315     redraw_tabline = TRUE;
4316 }
4317 
4318 
4319 /*
4320  * Go to another window.
4321  * When jumping to another buffer, stop Visual mode.  Do this before
4322  * changing windows so we can yank the selection into the '*' register.
4323  * When jumping to another window on the same buffer, adjust its cursor
4324  * position to keep the same Visual area.
4325  */
4326     void
4327 win_goto(win_T *wp)
4328 {
4329 #ifdef FEAT_CONCEAL
4330     win_T	*owp = curwin;
4331 #endif
4332 
4333     if (ERROR_IF_POPUP_WINDOW)
4334 	return;
4335     if (text_locked())
4336     {
4337 	beep_flush();
4338 	text_locked_msg();
4339 	return;
4340     }
4341     if (curbuf_locked())
4342 	return;
4343 
4344     if (wp->w_buffer != curbuf)
4345 	reset_VIsual_and_resel();
4346     else if (VIsual_active)
4347 	wp->w_cursor = curwin->w_cursor;
4348 
4349 #ifdef FEAT_GUI
4350     need_mouse_correct = TRUE;
4351 #endif
4352     win_enter(wp, TRUE);
4353 
4354 #ifdef FEAT_CONCEAL
4355     // Conceal cursor line in previous window, unconceal in current window.
4356     if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
4357 	redrawWinline(owp, owp->w_cursor.lnum);
4358     if (curwin->w_p_cole > 0 && !msg_scrolled)
4359 	need_cursor_line_redraw = TRUE;
4360 #endif
4361 }
4362 
4363 #if defined(FEAT_PERL) || defined(PROTO)
4364 /*
4365  * Find window number "winnr" (counting top to bottom).
4366  */
4367     win_T *
4368 win_find_nr(int winnr)
4369 {
4370     win_T	*wp;
4371 
4372     FOR_ALL_WINDOWS(wp)
4373 	if (--winnr == 0)
4374 	    break;
4375     return wp;
4376 }
4377 #endif
4378 
4379 #if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
4380 /*
4381  * Find the tabpage for window "win".
4382  */
4383     tabpage_T *
4384 win_find_tabpage(win_T *win)
4385 {
4386     win_T	*wp;
4387     tabpage_T	*tp;
4388 
4389     FOR_ALL_TAB_WINDOWS(tp, wp)
4390 	    if (wp == win)
4391 		return tp;
4392     return NULL;
4393 }
4394 #endif
4395 
4396 /*
4397  * Get the above or below neighbor window of the specified window.
4398  *   up - TRUE for the above neighbor
4399  *   count - nth neighbor window
4400  * Returns the specified window if the neighbor is not found.
4401  */
4402     win_T *
4403 win_vert_neighbor(tabpage_T *tp, win_T *wp, int up, long count)
4404 {
4405     frame_T	*fr;
4406     frame_T	*nfr;
4407     frame_T	*foundfr;
4408 
4409     foundfr = wp->w_frame;
4410     while (count--)
4411     {
4412 	/*
4413 	 * First go upwards in the tree of frames until we find a upwards or
4414 	 * downwards neighbor.
4415 	 */
4416 	fr = foundfr;
4417 	for (;;)
4418 	{
4419 	    if (fr == tp->tp_topframe)
4420 		goto end;
4421 	    if (up)
4422 		nfr = fr->fr_prev;
4423 	    else
4424 		nfr = fr->fr_next;
4425 	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
4426 		break;
4427 	    fr = fr->fr_parent;
4428 	}
4429 
4430 	/*
4431 	 * Now go downwards to find the bottom or top frame in it.
4432 	 */
4433 	for (;;)
4434 	{
4435 	    if (nfr->fr_layout == FR_LEAF)
4436 	    {
4437 		foundfr = nfr;
4438 		break;
4439 	    }
4440 	    fr = nfr->fr_child;
4441 	    if (nfr->fr_layout == FR_ROW)
4442 	    {
4443 		// Find the frame at the cursor row.
4444 		while (fr->fr_next != NULL
4445 			&& frame2win(fr)->w_wincol + fr->fr_width
4446 					 <= wp->w_wincol + wp->w_wcol)
4447 		    fr = fr->fr_next;
4448 	    }
4449 	    if (nfr->fr_layout == FR_COL && up)
4450 		while (fr->fr_next != NULL)
4451 		    fr = fr->fr_next;
4452 	    nfr = fr;
4453 	}
4454     }
4455 end:
4456     return foundfr != NULL ? foundfr->fr_win : NULL;
4457 }
4458 
4459 /*
4460  * Move to window above or below "count" times.
4461  */
4462     static void
4463 win_goto_ver(
4464     int		up,		// TRUE to go to win above
4465     long	count)
4466 {
4467     win_T	*win;
4468 
4469     win = win_vert_neighbor(curtab, curwin, up, count);
4470     if (win != NULL)
4471 	win_goto(win);
4472 }
4473 
4474 /*
4475  * Get the left or right neighbor window of the specified window.
4476  *   left - TRUE for the left neighbor
4477  *   count - nth neighbor window
4478  * Returns the specified window if the neighbor is not found.
4479  */
4480     win_T *
4481 win_horz_neighbor(tabpage_T *tp, win_T *wp, int left, long count)
4482 {
4483     frame_T	*fr;
4484     frame_T	*nfr;
4485     frame_T	*foundfr;
4486 
4487     foundfr = wp->w_frame;
4488     while (count--)
4489     {
4490 	/*
4491 	 * First go upwards in the tree of frames until we find a left or
4492 	 * right neighbor.
4493 	 */
4494 	fr = foundfr;
4495 	for (;;)
4496 	{
4497 	    if (fr == tp->tp_topframe)
4498 		goto end;
4499 	    if (left)
4500 		nfr = fr->fr_prev;
4501 	    else
4502 		nfr = fr->fr_next;
4503 	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
4504 		break;
4505 	    fr = fr->fr_parent;
4506 	}
4507 
4508 	/*
4509 	 * Now go downwards to find the leftmost or rightmost frame in it.
4510 	 */
4511 	for (;;)
4512 	{
4513 	    if (nfr->fr_layout == FR_LEAF)
4514 	    {
4515 		foundfr = nfr;
4516 		break;
4517 	    }
4518 	    fr = nfr->fr_child;
4519 	    if (nfr->fr_layout == FR_COL)
4520 	    {
4521 		// Find the frame at the cursor row.
4522 		while (fr->fr_next != NULL
4523 			&& frame2win(fr)->w_winrow + fr->fr_height
4524 					 <= wp->w_winrow + wp->w_wrow)
4525 		    fr = fr->fr_next;
4526 	    }
4527 	    if (nfr->fr_layout == FR_ROW && left)
4528 		while (fr->fr_next != NULL)
4529 		    fr = fr->fr_next;
4530 	    nfr = fr;
4531 	}
4532     }
4533 end:
4534     return foundfr != NULL ? foundfr->fr_win : NULL;
4535 }
4536 
4537 /*
4538  * Move to left or right window.
4539  */
4540     static void
4541 win_goto_hor(
4542     int		left,		// TRUE to go to left win
4543     long	count)
4544 {
4545     win_T	*win;
4546 
4547     win = win_horz_neighbor(curtab, curwin, left, count);
4548     if (win != NULL)
4549 	win_goto(win);
4550 }
4551 
4552 /*
4553  * Make window "wp" the current window.
4554  */
4555     void
4556 win_enter(win_T *wp, int undo_sync)
4557 {
4558     win_enter_ext(wp, undo_sync, FALSE, FALSE, TRUE, TRUE);
4559 }
4560 
4561 /*
4562  * Make window wp the current window.
4563  * Can be called with "curwin_invalid" TRUE, which means that curwin has just
4564  * been closed and isn't valid.
4565  */
4566     static void
4567 win_enter_ext(
4568     win_T	*wp,
4569     int		undo_sync,
4570     int		curwin_invalid,
4571     int		trigger_new_autocmds,
4572     int		trigger_enter_autocmds,
4573     int		trigger_leave_autocmds)
4574 {
4575     int		other_buffer = FALSE;
4576 
4577     if (wp == curwin && !curwin_invalid)	// nothing to do
4578 	return;
4579 
4580 #ifdef FEAT_JOB_CHANNEL
4581     if (!curwin_invalid)
4582 	leaving_window(curwin);
4583 #endif
4584 
4585     if (!curwin_invalid && trigger_leave_autocmds)
4586     {
4587 	/*
4588 	 * Be careful: If autocommands delete the window, return now.
4589 	 */
4590 	if (wp->w_buffer != curbuf)
4591 	{
4592 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
4593 	    other_buffer = TRUE;
4594 	    if (!win_valid(wp))
4595 		return;
4596 	}
4597 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
4598 	if (!win_valid(wp))
4599 	    return;
4600 #ifdef FEAT_EVAL
4601 	// autocmds may abort script processing
4602 	if (aborting())
4603 	    return;
4604 #endif
4605     }
4606 
4607     // sync undo before leaving the current buffer
4608     if (undo_sync && curbuf != wp->w_buffer)
4609 	u_sync(FALSE);
4610 
4611     // Might need to scroll the old window before switching, e.g., when the
4612     // cursor was moved.
4613     update_topline();
4614 
4615     // may have to copy the buffer options when 'cpo' contains 'S'
4616     if (wp->w_buffer != curbuf)
4617 	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
4618     if (!curwin_invalid)
4619     {
4620 	prevwin = curwin;	// remember for CTRL-W p
4621 	curwin->w_redr_status = TRUE;
4622     }
4623     curwin = wp;
4624     curbuf = wp->w_buffer;
4625     check_cursor();
4626     if (!virtual_active())
4627 	curwin->w_cursor.coladd = 0;
4628     changed_line_abv_curs();	// assume cursor position needs updating
4629 
4630     if (curwin->w_localdir != NULL || curtab->tp_localdir != NULL)
4631     {
4632 	char_u	*dirname;
4633 
4634 	// Window or tab has a local directory: Save current directory as
4635 	// global directory (unless that was done already) and change to the
4636 	// local directory.
4637 	if (globaldir == NULL)
4638 	{
4639 	    char_u	cwd[MAXPATHL];
4640 
4641 	    if (mch_dirname(cwd, MAXPATHL) == OK)
4642 		globaldir = vim_strsave(cwd);
4643 	}
4644 	if (curwin->w_localdir != NULL)
4645 	    dirname = curwin->w_localdir;
4646 	else
4647 	    dirname = curtab->tp_localdir;
4648 
4649 	if (mch_chdir((char *)dirname) == 0)
4650 	    shorten_fnames(TRUE);
4651     }
4652     else if (globaldir != NULL)
4653     {
4654 	// Window doesn't have a local directory and we are not in the global
4655 	// directory: Change to the global directory.
4656 	vim_ignored = mch_chdir((char *)globaldir);
4657 	VIM_CLEAR(globaldir);
4658 	shorten_fnames(TRUE);
4659     }
4660 
4661 #ifdef FEAT_JOB_CHANNEL
4662     entering_window(curwin);
4663 #endif
4664     // Careful: autocommands may close the window and make "wp" invalid
4665     if (trigger_new_autocmds)
4666 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
4667     if (trigger_enter_autocmds)
4668     {
4669 	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
4670 	if (other_buffer)
4671 	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
4672     }
4673 
4674 #ifdef FEAT_TITLE
4675     maketitle();
4676 #endif
4677     curwin->w_redr_status = TRUE;
4678 #ifdef FEAT_TERMINAL
4679     if (bt_terminal(curwin->w_buffer))
4680 	// terminal is likely in another mode
4681 	redraw_mode = TRUE;
4682 #endif
4683     redraw_tabline = TRUE;
4684     if (restart_edit)
4685 	redraw_later(VALID);	// causes status line redraw
4686 
4687     // set window height to desired minimal value
4688     if (curwin->w_height < p_wh && !curwin->w_p_wfh
4689 #ifdef FEAT_PROP_POPUP
4690 	    && !popup_is_popup(curwin)
4691 #endif
4692 	    )
4693 	win_setheight((int)p_wh);
4694     else if (curwin->w_height == 0)
4695 	win_setheight(1);
4696 
4697     // set window width to desired minimal value
4698     if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
4699 	win_setwidth((int)p_wiw);
4700 
4701     setmouse();			// in case jumped to/from help buffer
4702 
4703     // Change directories when the 'acd' option is set.
4704     DO_AUTOCHDIR;
4705 }
4706 
4707 
4708 /*
4709  * Jump to the first open window that contains buffer "buf", if one exists.
4710  * Returns a pointer to the window found, otherwise NULL.
4711  */
4712     win_T *
4713 buf_jump_open_win(buf_T *buf)
4714 {
4715     win_T	*wp = NULL;
4716 
4717     if (curwin->w_buffer == buf)
4718 	wp = curwin;
4719     else
4720 	FOR_ALL_WINDOWS(wp)
4721 	    if (wp->w_buffer == buf)
4722 		break;
4723     if (wp != NULL)
4724 	win_enter(wp, FALSE);
4725     return wp;
4726 }
4727 
4728 /*
4729  * Jump to the first open window in any tab page that contains buffer "buf",
4730  * if one exists.
4731  * Returns a pointer to the window found, otherwise NULL.
4732  */
4733     win_T *
4734 buf_jump_open_tab(buf_T *buf)
4735 {
4736     win_T	*wp = buf_jump_open_win(buf);
4737     tabpage_T	*tp;
4738 
4739     if (wp != NULL)
4740 	return wp;
4741 
4742     FOR_ALL_TABPAGES(tp)
4743 	if (tp != curtab)
4744 	{
4745 	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
4746 		if (wp->w_buffer == buf)
4747 		    break;
4748 	    if (wp != NULL)
4749 	    {
4750 		goto_tabpage_win(tp, wp);
4751 		if (curwin != wp)
4752 		    wp = NULL;	// something went wrong
4753 		break;
4754 	    }
4755 	}
4756     return wp;
4757 }
4758 
4759 static int last_win_id = LOWEST_WIN_ID - 1;
4760 
4761 /*
4762  * Allocate a window structure and link it in the window list when "hidden" is
4763  * FALSE.
4764  */
4765     static win_T *
4766 win_alloc(win_T *after UNUSED, int hidden UNUSED)
4767 {
4768     win_T	*new_wp;
4769 
4770     /*
4771      * allocate window structure and linesizes arrays
4772      */
4773     new_wp = ALLOC_CLEAR_ONE(win_T);
4774     if (new_wp == NULL)
4775 	return NULL;
4776 
4777     if (win_alloc_lines(new_wp) == FAIL)
4778     {
4779 	vim_free(new_wp);
4780 	return NULL;
4781     }
4782 
4783     new_wp->w_id = ++last_win_id;
4784 
4785 #ifdef FEAT_EVAL
4786     // init w: variables
4787     new_wp->w_vars = dict_alloc();
4788     if (new_wp->w_vars == NULL)
4789     {
4790 	win_free_lsize(new_wp);
4791 	vim_free(new_wp);
4792 	return NULL;
4793     }
4794     init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
4795 #endif
4796 
4797     // Don't execute autocommands while the window is not properly
4798     // initialized yet.  gui_create_scrollbar() may trigger a FocusGained
4799     // event.
4800     block_autocmds();
4801 
4802     /*
4803      * link the window in the window list
4804      */
4805     if (!hidden)
4806 	win_append(after, new_wp);
4807     new_wp->w_wincol = 0;
4808     new_wp->w_width = Columns;
4809 
4810     // position the display and the cursor at the top of the file.
4811     new_wp->w_topline = 1;
4812 #ifdef FEAT_DIFF
4813     new_wp->w_topfill = 0;
4814 #endif
4815     new_wp->w_botline = 2;
4816     new_wp->w_cursor.lnum = 1;
4817     new_wp->w_scbind_pos = 1;
4818 
4819     // use global option value for global-local options
4820     new_wp->w_p_so = -1;
4821     new_wp->w_p_siso = -1;
4822 
4823     // We won't calculate w_fraction until resizing the window
4824     new_wp->w_fraction = 0;
4825     new_wp->w_prev_fraction_row = -1;
4826 
4827 #ifdef FEAT_GUI
4828     if (gui.in_use)
4829     {
4830 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
4831 		SBAR_LEFT, new_wp);
4832 	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
4833 		SBAR_RIGHT, new_wp);
4834     }
4835 #endif
4836 #ifdef FEAT_FOLDING
4837     foldInitWin(new_wp);
4838 #endif
4839     unblock_autocmds();
4840 #ifdef FEAT_SEARCH_EXTRA
4841     new_wp->w_match_head = NULL;
4842     new_wp->w_next_match_id = 4;
4843 #endif
4844     return new_wp;
4845 }
4846 
4847 /*
4848  * Remove window 'wp' from the window list and free the structure.
4849  */
4850     static void
4851 win_free(
4852     win_T	*wp,
4853     tabpage_T	*tp)		// tab page "win" is in, NULL for current
4854 {
4855     int		i;
4856     buf_T	*buf;
4857     wininfo_T	*wip;
4858 
4859 #ifdef FEAT_FOLDING
4860     clearFolding(wp);
4861 #endif
4862 
4863     // reduce the reference count to the argument list.
4864     alist_unlink(wp->w_alist);
4865 
4866     // Don't execute autocommands while the window is halfway being deleted.
4867     // gui_mch_destroy_scrollbar() may trigger a FocusGained event.
4868     block_autocmds();
4869 
4870 #ifdef FEAT_LUA
4871     lua_window_free(wp);
4872 #endif
4873 
4874 #ifdef FEAT_MZSCHEME
4875     mzscheme_window_free(wp);
4876 #endif
4877 
4878 #ifdef FEAT_PERL
4879     perl_win_free(wp);
4880 #endif
4881 
4882 #ifdef FEAT_PYTHON
4883     python_window_free(wp);
4884 #endif
4885 
4886 #ifdef FEAT_PYTHON3
4887     python3_window_free(wp);
4888 #endif
4889 
4890 #ifdef FEAT_TCL
4891     tcl_window_free(wp);
4892 #endif
4893 
4894 #ifdef FEAT_RUBY
4895     ruby_window_free(wp);
4896 #endif
4897 
4898     clear_winopt(&wp->w_onebuf_opt);
4899     clear_winopt(&wp->w_allbuf_opt);
4900 
4901 #ifdef FEAT_EVAL
4902     vars_clear(&wp->w_vars->dv_hashtab);	// free all w: variables
4903     hash_init(&wp->w_vars->dv_hashtab);
4904     unref_var_dict(wp->w_vars);
4905 #endif
4906 
4907     {
4908 	tabpage_T	*ttp;
4909 
4910 	if (prevwin == wp)
4911 	    prevwin = NULL;
4912 	FOR_ALL_TABPAGES(ttp)
4913 	    if (ttp->tp_prevwin == wp)
4914 		ttp->tp_prevwin = NULL;
4915     }
4916     win_free_lsize(wp);
4917 
4918     for (i = 0; i < wp->w_tagstacklen; ++i)
4919     {
4920 	vim_free(wp->w_tagstack[i].tagname);
4921 	vim_free(wp->w_tagstack[i].user_data);
4922     }
4923     vim_free(wp->w_localdir);
4924 
4925     // Remove the window from the b_wininfo lists, it may happen that the
4926     // freed memory is re-used for another window.
4927     FOR_ALL_BUFFERS(buf)
4928 	for (wip = buf->b_wininfo; wip != NULL; wip = wip->wi_next)
4929 	    if (wip->wi_win == wp)
4930 		wip->wi_win = NULL;
4931 
4932 #ifdef FEAT_SEARCH_EXTRA
4933     clear_matches(wp);
4934 #endif
4935 
4936 #ifdef FEAT_JUMPLIST
4937     free_jumplist(wp);
4938 #endif
4939 
4940 #ifdef FEAT_QUICKFIX
4941     qf_free_all(wp);
4942 #endif
4943 
4944 #ifdef FEAT_GUI
4945     if (gui.in_use)
4946     {
4947 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
4948 	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
4949     }
4950 #endif // FEAT_GUI
4951 
4952 #ifdef FEAT_MENU
4953     remove_winbar(wp);
4954 #endif
4955 #ifdef FEAT_PROP_POPUP
4956     free_callback(&wp->w_close_cb);
4957     free_callback(&wp->w_filter_cb);
4958     for (i = 0; i < 4; ++i)
4959 	VIM_CLEAR(wp->w_border_highlight[i]);
4960     vim_free(wp->w_scrollbar_highlight);
4961     vim_free(wp->w_thumb_highlight);
4962     vim_free(wp->w_popup_title);
4963     list_unref(wp->w_popup_mask);
4964     vim_free(wp->w_popup_mask_cells);
4965 #endif
4966 
4967 #ifdef FEAT_SYN_HL
4968     vim_free(wp->w_p_cc_cols);
4969 #endif
4970 
4971     if (win_valid_any_tab(wp))
4972 	win_remove(wp, tp);
4973     if (autocmd_busy)
4974     {
4975 	wp->w_next = au_pending_free_win;
4976 	au_pending_free_win = wp;
4977     }
4978     else
4979 	vim_free(wp);
4980 
4981     unblock_autocmds();
4982 }
4983 
4984 /*
4985  * Return TRUE if "wp" is not in the list of windows: the autocmd window or a
4986  * popup window.
4987  */
4988     static int
4989 win_unlisted(win_T *wp)
4990 {
4991     return wp == aucmd_win || WIN_IS_POPUP(wp);
4992 }
4993 
4994 #if defined(FEAT_PROP_POPUP) || defined(PROTO)
4995 /*
4996  * Free a popup window.  This does not take the window out of the window list
4997  * and assumes there is only one toplevel frame, no split.
4998  */
4999     void
5000 win_free_popup(win_T *win)
5001 {
5002     if (bt_popup(win->w_buffer))
5003 	win_close_buffer(win, DOBUF_WIPE_REUSE, FALSE);
5004     else
5005 	close_buffer(win, win->w_buffer, 0, FALSE, FALSE);
5006 # if defined(FEAT_TIMERS)
5007     if (win->w_popup_timer != NULL)
5008 	stop_timer(win->w_popup_timer);
5009 # endif
5010     vim_free(win->w_frame);
5011     win_free(win, NULL);
5012 }
5013 #endif
5014 
5015 /*
5016  * Append window "wp" in the window list after window "after".
5017  */
5018     static void
5019 win_append(win_T *after, win_T *wp)
5020 {
5021     win_T	*before;
5022 
5023     if (after == NULL)	    // after NULL is in front of the first
5024 	before = firstwin;
5025     else
5026 	before = after->w_next;
5027 
5028     wp->w_next = before;
5029     wp->w_prev = after;
5030     if (after == NULL)
5031 	firstwin = wp;
5032     else
5033 	after->w_next = wp;
5034     if (before == NULL)
5035 	lastwin = wp;
5036     else
5037 	before->w_prev = wp;
5038 }
5039 
5040 /*
5041  * Remove a window from the window list.
5042  */
5043     void
5044 win_remove(
5045     win_T	*wp,
5046     tabpage_T	*tp)		// tab page "win" is in, NULL for current
5047 {
5048     if (wp->w_prev != NULL)
5049 	wp->w_prev->w_next = wp->w_next;
5050     else if (tp == NULL)
5051 	firstwin = curtab->tp_firstwin = wp->w_next;
5052     else
5053 	tp->tp_firstwin = wp->w_next;
5054 
5055     if (wp->w_next != NULL)
5056 	wp->w_next->w_prev = wp->w_prev;
5057     else if (tp == NULL)
5058 	lastwin = curtab->tp_lastwin = wp->w_prev;
5059     else
5060 	tp->tp_lastwin = wp->w_prev;
5061 }
5062 
5063 /*
5064  * Append frame "frp" in a frame list after frame "after".
5065  */
5066     static void
5067 frame_append(frame_T *after, frame_T *frp)
5068 {
5069     frp->fr_next = after->fr_next;
5070     after->fr_next = frp;
5071     if (frp->fr_next != NULL)
5072 	frp->fr_next->fr_prev = frp;
5073     frp->fr_prev = after;
5074 }
5075 
5076 /*
5077  * Insert frame "frp" in a frame list before frame "before".
5078  */
5079     static void
5080 frame_insert(frame_T *before, frame_T *frp)
5081 {
5082     frp->fr_next = before;
5083     frp->fr_prev = before->fr_prev;
5084     before->fr_prev = frp;
5085     if (frp->fr_prev != NULL)
5086 	frp->fr_prev->fr_next = frp;
5087     else
5088 	frp->fr_parent->fr_child = frp;
5089 }
5090 
5091 /*
5092  * Remove a frame from a frame list.
5093  */
5094     static void
5095 frame_remove(frame_T *frp)
5096 {
5097     if (frp->fr_prev != NULL)
5098 	frp->fr_prev->fr_next = frp->fr_next;
5099     else
5100     {
5101 	frp->fr_parent->fr_child = frp->fr_next;
5102 	// special case: topframe->fr_child == frp
5103 	if (topframe->fr_child == frp)
5104 	    topframe->fr_child = frp->fr_next;
5105     }
5106     if (frp->fr_next != NULL)
5107 	frp->fr_next->fr_prev = frp->fr_prev;
5108 }
5109 
5110 /*
5111  * Allocate w_lines[] for window "wp".
5112  * Return FAIL for failure, OK for success.
5113  */
5114     int
5115 win_alloc_lines(win_T *wp)
5116 {
5117     wp->w_lines_valid = 0;
5118     wp->w_lines = ALLOC_CLEAR_MULT(wline_T, Rows );
5119     if (wp->w_lines == NULL)
5120 	return FAIL;
5121     return OK;
5122 }
5123 
5124 /*
5125  * free lsize arrays for a window
5126  */
5127     void
5128 win_free_lsize(win_T *wp)
5129 {
5130     // TODO: why would wp be NULL here?
5131     if (wp != NULL)
5132 	VIM_CLEAR(wp->w_lines);
5133 }
5134 
5135 /*
5136  * Called from win_new_shellsize() after Rows changed.
5137  * This only does the current tab page, others must be done when made active.
5138  */
5139     void
5140 shell_new_rows(void)
5141 {
5142     int		h = (int)ROWS_AVAIL;
5143 
5144     if (firstwin == NULL)	// not initialized yet
5145 	return;
5146     if (h < frame_minheight(topframe, NULL))
5147 	h = frame_minheight(topframe, NULL);
5148 
5149     // First try setting the heights of windows with 'winfixheight'.  If
5150     // that doesn't result in the right height, forget about that option.
5151     frame_new_height(topframe, h, FALSE, TRUE);
5152     if (!frame_check_height(topframe, h))
5153 	frame_new_height(topframe, h, FALSE, FALSE);
5154 
5155     (void)win_comp_pos();		// recompute w_winrow and w_wincol
5156     compute_cmdrow();
5157     curtab->tp_ch_used = p_ch;
5158 
5159 #if 0
5160     // Disabled: don't want making the screen smaller make a window larger.
5161     if (p_ea)
5162 	win_equal(curwin, FALSE, 'v');
5163 #endif
5164 }
5165 
5166 /*
5167  * Called from win_new_shellsize() after Columns changed.
5168  */
5169     void
5170 shell_new_columns(void)
5171 {
5172     if (firstwin == NULL)	// not initialized yet
5173 	return;
5174 
5175     // First try setting the widths of windows with 'winfixwidth'.  If that
5176     // doesn't result in the right width, forget about that option.
5177     frame_new_width(topframe, (int)Columns, FALSE, TRUE);
5178     if (!frame_check_width(topframe, Columns))
5179 	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
5180 
5181     (void)win_comp_pos();		// recompute w_winrow and w_wincol
5182 #if 0
5183     // Disabled: don't want making the screen smaller make a window larger.
5184     if (p_ea)
5185 	win_equal(curwin, FALSE, 'h');
5186 #endif
5187 }
5188 
5189 #if defined(FEAT_CMDWIN) || defined(PROTO)
5190 /*
5191  * Save the size of all windows in "gap".
5192  */
5193     void
5194 win_size_save(garray_T *gap)
5195 
5196 {
5197     win_T	*wp;
5198 
5199     ga_init2(gap, (int)sizeof(int), 1);
5200     if (ga_grow(gap, win_count() * 2 + 1) == OK)
5201     {
5202 	// first entry is value of 'lines'
5203 	((int *)gap->ga_data)[gap->ga_len++] = Rows;
5204 
5205 	FOR_ALL_WINDOWS(wp)
5206 	{
5207 	    ((int *)gap->ga_data)[gap->ga_len++] =
5208 					       wp->w_width + wp->w_vsep_width;
5209 	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
5210 	}
5211     }
5212 }
5213 
5214 /*
5215  * Restore window sizes, but only if the number of windows is still the same
5216  * and 'lines' didn't change.
5217  * Does not free the growarray.
5218  */
5219     void
5220 win_size_restore(garray_T *gap)
5221 {
5222     win_T	*wp;
5223     int		i, j;
5224 
5225     if (win_count() * 2 + 1 == gap->ga_len
5226 	    && ((int *)gap->ga_data)[0] == Rows)
5227     {
5228 	// The order matters, because frames contain other frames, but it's
5229 	// difficult to get right. The easy way out is to do it twice.
5230 	for (j = 0; j < 2; ++j)
5231 	{
5232 	    i = 1;
5233 	    FOR_ALL_WINDOWS(wp)
5234 	    {
5235 		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
5236 		win_setheight_win(((int *)gap->ga_data)[i++], wp);
5237 	    }
5238 	}
5239 	// recompute the window positions
5240 	(void)win_comp_pos();
5241     }
5242 }
5243 #endif // FEAT_CMDWIN
5244 
5245 /*
5246  * Update the position for all windows, using the width and height of the
5247  * frames.
5248  * Returns the row just after the last window.
5249  */
5250     int
5251 win_comp_pos(void)
5252 {
5253     int		row = tabline_height();
5254     int		col = 0;
5255 
5256     frame_comp_pos(topframe, &row, &col);
5257     return row;
5258 }
5259 
5260 /*
5261  * Update the position of the windows in frame "topfrp", using the width and
5262  * height of the frames.
5263  * "*row" and "*col" are the top-left position of the frame.  They are updated
5264  * to the bottom-right position plus one.
5265  */
5266     static void
5267 frame_comp_pos(frame_T *topfrp, int *row, int *col)
5268 {
5269     win_T	*wp;
5270     frame_T	*frp;
5271     int		startcol;
5272     int		startrow;
5273     int		h;
5274 
5275     wp = topfrp->fr_win;
5276     if (wp != NULL)
5277     {
5278 	if (wp->w_winrow != *row || wp->w_wincol != *col)
5279 	{
5280 	    // position changed, redraw
5281 	    wp->w_winrow = *row;
5282 	    wp->w_wincol = *col;
5283 	    redraw_win_later(wp, NOT_VALID);
5284 	    wp->w_redr_status = TRUE;
5285 	}
5286 	// WinBar will not show if the window height is zero
5287 	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
5288 	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
5289 	*col += wp->w_width + wp->w_vsep_width;
5290     }
5291     else
5292     {
5293 	startrow = *row;
5294 	startcol = *col;
5295 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
5296 	{
5297 	    if (topfrp->fr_layout == FR_ROW)
5298 		*row = startrow;	// all frames are at the same row
5299 	    else
5300 		*col = startcol;	// all frames are at the same col
5301 	    frame_comp_pos(frp, row, col);
5302 	}
5303     }
5304 }
5305 
5306 /*
5307  * Set current window height and take care of repositioning other windows to
5308  * fit around it.
5309  */
5310     void
5311 win_setheight(int height)
5312 {
5313     win_setheight_win(height, curwin);
5314 }
5315 
5316 /*
5317  * Set the window height of window "win" and take care of repositioning other
5318  * windows to fit around it.
5319  */
5320     void
5321 win_setheight_win(int height, win_T *win)
5322 {
5323     int		row;
5324 
5325     if (win == curwin)
5326     {
5327 	// Always keep current window at least one line high, even when
5328 	// 'winminheight' is zero.
5329 	if (height < p_wmh)
5330 	    height = p_wmh;
5331 	if (height == 0)
5332 	    height = 1;
5333 	height += WINBAR_HEIGHT(curwin);
5334     }
5335 
5336     frame_setheight(win->w_frame, height + win->w_status_height);
5337 
5338     // recompute the window positions
5339     row = win_comp_pos();
5340 
5341     /*
5342      * If there is extra space created between the last window and the command
5343      * line, clear it.
5344      */
5345     if (full_screen && msg_scrolled == 0 && row < cmdline_row)
5346 	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5347     cmdline_row = row;
5348     msg_row = row;
5349     msg_col = 0;
5350 
5351     redraw_all_later(NOT_VALID);
5352 }
5353 
5354 /*
5355  * Set the height of a frame to "height" and take care that all frames and
5356  * windows inside it are resized.  Also resize frames on the left and right if
5357  * the are in the same FR_ROW frame.
5358  *
5359  * Strategy:
5360  * If the frame is part of a FR_COL frame, try fitting the frame in that
5361  * frame.  If that doesn't work (the FR_COL frame is too small), recursively
5362  * go to containing frames to resize them and make room.
5363  * If the frame is part of a FR_ROW frame, all frames must be resized as well.
5364  * Check for the minimal height of the FR_ROW frame.
5365  * At the top level we can also use change the command line height.
5366  */
5367     static void
5368 frame_setheight(frame_T *curfrp, int height)
5369 {
5370     int		room;		// total number of lines available
5371     int		take;		// number of lines taken from other windows
5372     int		room_cmdline;	// lines available from cmdline
5373     int		run;
5374     frame_T	*frp;
5375     int		h;
5376     int		room_reserved;
5377 
5378     // If the height already is the desired value, nothing to do.
5379     if (curfrp->fr_height == height)
5380 	return;
5381 
5382     if (curfrp->fr_parent == NULL)
5383     {
5384 	// topframe: can only change the command line
5385 	if (height > ROWS_AVAIL)
5386 	    height = ROWS_AVAIL;
5387 	if (height > 0)
5388 	    frame_new_height(curfrp, height, FALSE, FALSE);
5389     }
5390     else if (curfrp->fr_parent->fr_layout == FR_ROW)
5391     {
5392 	// Row of frames: Also need to resize frames left and right of this
5393 	// one.  First check for the minimal height of these.
5394 	h = frame_minheight(curfrp->fr_parent, NULL);
5395 	if (height < h)
5396 	    height = h;
5397 	frame_setheight(curfrp->fr_parent, height);
5398     }
5399     else
5400     {
5401 	/*
5402 	 * Column of frames: try to change only frames in this column.
5403 	 */
5404 	/*
5405 	 * Do this twice:
5406 	 * 1: compute room available, if it's not enough try resizing the
5407 	 *    containing frame.
5408 	 * 2: compute the room available and adjust the height to it.
5409 	 * Try not to reduce the height of a window with 'winfixheight' set.
5410 	 */
5411 	for (run = 1; run <= 2; ++run)
5412 	{
5413 	    room = 0;
5414 	    room_reserved = 0;
5415 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5416 	    {
5417 		if (frp != curfrp
5418 			&& frp->fr_win != NULL
5419 			&& frp->fr_win->w_p_wfh)
5420 		    room_reserved += frp->fr_height;
5421 		room += frp->fr_height;
5422 		if (frp != curfrp)
5423 		    room -= frame_minheight(frp, NULL);
5424 	    }
5425 	    if (curfrp->fr_width != Columns)
5426 		room_cmdline = 0;
5427 	    else
5428 	    {
5429 		room_cmdline = Rows - p_ch - (lastwin->w_winrow
5430 						+ VISIBLE_HEIGHT(lastwin)
5431 						+ lastwin->w_status_height);
5432 		if (room_cmdline < 0)
5433 		    room_cmdline = 0;
5434 	    }
5435 
5436 	    if (height <= room + room_cmdline)
5437 		break;
5438 	    if (run == 2 || curfrp->fr_width == Columns)
5439 	    {
5440 		if (height > room + room_cmdline)
5441 		    height = room + room_cmdline;
5442 		break;
5443 	    }
5444 	    frame_setheight(curfrp->fr_parent, height
5445 		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
5446 	}
5447 
5448 	/*
5449 	 * Compute the number of lines we will take from others frames (can be
5450 	 * negative!).
5451 	 */
5452 	take = height - curfrp->fr_height;
5453 
5454 	// If there is not enough room, also reduce the height of a window
5455 	// with 'winfixheight' set.
5456 	if (height > room + room_cmdline - room_reserved)
5457 	    room_reserved = room + room_cmdline - height;
5458 	// If there is only a 'winfixheight' window and making the
5459 	// window smaller, need to make the other window taller.
5460 	if (take < 0 && room - curfrp->fr_height < room_reserved)
5461 	    room_reserved = 0;
5462 
5463 	if (take > 0 && room_cmdline > 0)
5464 	{
5465 	    // use lines from cmdline first
5466 	    if (take < room_cmdline)
5467 		room_cmdline = take;
5468 	    take -= room_cmdline;
5469 	    topframe->fr_height += room_cmdline;
5470 	}
5471 
5472 	/*
5473 	 * set the current frame to the new height
5474 	 */
5475 	frame_new_height(curfrp, height, FALSE, FALSE);
5476 
5477 	/*
5478 	 * First take lines from the frames after the current frame.  If
5479 	 * that is not enough, takes lines from frames above the current
5480 	 * frame.
5481 	 */
5482 	for (run = 0; run < 2; ++run)
5483 	{
5484 	    if (run == 0)
5485 		frp = curfrp->fr_next;	// 1st run: start with next window
5486 	    else
5487 		frp = curfrp->fr_prev;	// 2nd run: start with prev window
5488 	    while (frp != NULL && take != 0)
5489 	    {
5490 		h = frame_minheight(frp, NULL);
5491 		if (room_reserved > 0
5492 			&& frp->fr_win != NULL
5493 			&& frp->fr_win->w_p_wfh)
5494 		{
5495 		    if (room_reserved >= frp->fr_height)
5496 			room_reserved -= frp->fr_height;
5497 		    else
5498 		    {
5499 			if (frp->fr_height - room_reserved > take)
5500 			    room_reserved = frp->fr_height - take;
5501 			take -= frp->fr_height - room_reserved;
5502 			frame_new_height(frp, room_reserved, FALSE, FALSE);
5503 			room_reserved = 0;
5504 		    }
5505 		}
5506 		else
5507 		{
5508 		    if (frp->fr_height - take < h)
5509 		    {
5510 			take -= frp->fr_height - h;
5511 			frame_new_height(frp, h, FALSE, FALSE);
5512 		    }
5513 		    else
5514 		    {
5515 			frame_new_height(frp, frp->fr_height - take,
5516 								FALSE, FALSE);
5517 			take = 0;
5518 		    }
5519 		}
5520 		if (run == 0)
5521 		    frp = frp->fr_next;
5522 		else
5523 		    frp = frp->fr_prev;
5524 	    }
5525 	}
5526     }
5527 }
5528 
5529 /*
5530  * Set current window width and take care of repositioning other windows to
5531  * fit around it.
5532  */
5533     void
5534 win_setwidth(int width)
5535 {
5536     win_setwidth_win(width, curwin);
5537 }
5538 
5539     void
5540 win_setwidth_win(int width, win_T *wp)
5541 {
5542     // Always keep current window at least one column wide, even when
5543     // 'winminwidth' is zero.
5544     if (wp == curwin)
5545     {
5546 	if (width < p_wmw)
5547 	    width = p_wmw;
5548 	if (width == 0)
5549 	    width = 1;
5550     }
5551 
5552     frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
5553 
5554     // recompute the window positions
5555     (void)win_comp_pos();
5556 
5557     redraw_all_later(NOT_VALID);
5558 }
5559 
5560 /*
5561  * Set the width of a frame to "width" and take care that all frames and
5562  * windows inside it are resized.  Also resize frames above and below if the
5563  * are in the same FR_ROW frame.
5564  *
5565  * Strategy is similar to frame_setheight().
5566  */
5567     static void
5568 frame_setwidth(frame_T *curfrp, int width)
5569 {
5570     int		room;		// total number of lines available
5571     int		take;		// number of lines taken from other windows
5572     int		run;
5573     frame_T	*frp;
5574     int		w;
5575     int		room_reserved;
5576 
5577     // If the width already is the desired value, nothing to do.
5578     if (curfrp->fr_width == width)
5579 	return;
5580 
5581     if (curfrp->fr_parent == NULL)
5582 	// topframe: can't change width
5583 	return;
5584 
5585     if (curfrp->fr_parent->fr_layout == FR_COL)
5586     {
5587 	// Column of frames: Also need to resize frames above and below of
5588 	// this one.  First check for the minimal width of these.
5589 	w = frame_minwidth(curfrp->fr_parent, NULL);
5590 	if (width < w)
5591 	    width = w;
5592 	frame_setwidth(curfrp->fr_parent, width);
5593     }
5594     else
5595     {
5596 	/*
5597 	 * Row of frames: try to change only frames in this row.
5598 	 *
5599 	 * Do this twice:
5600 	 * 1: compute room available, if it's not enough try resizing the
5601 	 *    containing frame.
5602 	 * 2: compute the room available and adjust the width to it.
5603 	 */
5604 	for (run = 1; run <= 2; ++run)
5605 	{
5606 	    room = 0;
5607 	    room_reserved = 0;
5608 	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
5609 	    {
5610 		if (frp != curfrp
5611 			&& frp->fr_win != NULL
5612 			&& frp->fr_win->w_p_wfw)
5613 		    room_reserved += frp->fr_width;
5614 		room += frp->fr_width;
5615 		if (frp != curfrp)
5616 		    room -= frame_minwidth(frp, NULL);
5617 	    }
5618 
5619 	    if (width <= room)
5620 		break;
5621 	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
5622 	    {
5623 		if (width > room)
5624 		    width = room;
5625 		break;
5626 	    }
5627 	    frame_setwidth(curfrp->fr_parent, width
5628 		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
5629 	}
5630 
5631 	/*
5632 	 * Compute the number of lines we will take from others frames (can be
5633 	 * negative!).
5634 	 */
5635 	take = width - curfrp->fr_width;
5636 
5637 	// If there is not enough room, also reduce the width of a window
5638 	// with 'winfixwidth' set.
5639 	if (width > room - room_reserved)
5640 	    room_reserved = room - width;
5641 	// If there is only a 'winfixwidth' window and making the
5642 	// window smaller, need to make the other window narrower.
5643 	if (take < 0 && room - curfrp->fr_width < room_reserved)
5644 	    room_reserved = 0;
5645 
5646 	/*
5647 	 * set the current frame to the new width
5648 	 */
5649 	frame_new_width(curfrp, width, FALSE, FALSE);
5650 
5651 	/*
5652 	 * First take lines from the frames right of the current frame.  If
5653 	 * that is not enough, takes lines from frames left of the current
5654 	 * frame.
5655 	 */
5656 	for (run = 0; run < 2; ++run)
5657 	{
5658 	    if (run == 0)
5659 		frp = curfrp->fr_next;	// 1st run: start with next window
5660 	    else
5661 		frp = curfrp->fr_prev;	// 2nd run: start with prev window
5662 	    while (frp != NULL && take != 0)
5663 	    {
5664 		w = frame_minwidth(frp, NULL);
5665 		if (room_reserved > 0
5666 			&& frp->fr_win != NULL
5667 			&& frp->fr_win->w_p_wfw)
5668 		{
5669 		    if (room_reserved >= frp->fr_width)
5670 			room_reserved -= frp->fr_width;
5671 		    else
5672 		    {
5673 			if (frp->fr_width - room_reserved > take)
5674 			    room_reserved = frp->fr_width - take;
5675 			take -= frp->fr_width - room_reserved;
5676 			frame_new_width(frp, room_reserved, FALSE, FALSE);
5677 			room_reserved = 0;
5678 		    }
5679 		}
5680 		else
5681 		{
5682 		    if (frp->fr_width - take < w)
5683 		    {
5684 			take -= frp->fr_width - w;
5685 			frame_new_width(frp, w, FALSE, FALSE);
5686 		    }
5687 		    else
5688 		    {
5689 			frame_new_width(frp, frp->fr_width - take,
5690 								FALSE, FALSE);
5691 			take = 0;
5692 		    }
5693 		}
5694 		if (run == 0)
5695 		    frp = frp->fr_next;
5696 		else
5697 		    frp = frp->fr_prev;
5698 	    }
5699 	}
5700     }
5701 }
5702 
5703 /*
5704  * Check 'winminheight' for a valid value and reduce it if needed.
5705  */
5706     void
5707 win_setminheight(void)
5708 {
5709     int		room;
5710     int		needed;
5711     int		first = TRUE;
5712 
5713     // loop until there is a 'winminheight' that is possible
5714     while (p_wmh > 0)
5715     {
5716 	room = Rows - p_ch;
5717 	needed = frame_minheight(topframe, NULL);
5718 	if (room >= needed)
5719 	    break;
5720 	--p_wmh;
5721 	if (first)
5722 	{
5723 	    emsg(_(e_noroom));
5724 	    first = FALSE;
5725 	}
5726     }
5727 }
5728 
5729 /*
5730  * Check 'winminwidth' for a valid value and reduce it if needed.
5731  */
5732     void
5733 win_setminwidth(void)
5734 {
5735     int		room;
5736     int		needed;
5737     int		first = TRUE;
5738 
5739     // loop until there is a 'winminheight' that is possible
5740     while (p_wmw > 0)
5741     {
5742 	room = Columns;
5743 	needed = frame_minwidth(topframe, NULL);
5744 	if (room >= needed)
5745 	    break;
5746 	--p_wmw;
5747 	if (first)
5748 	{
5749 	    emsg(_(e_noroom));
5750 	    first = FALSE;
5751 	}
5752     }
5753 }
5754 
5755 /*
5756  * Status line of dragwin is dragged "offset" lines down (negative is up).
5757  */
5758     void
5759 win_drag_status_line(win_T *dragwin, int offset)
5760 {
5761     frame_T	*curfr;
5762     frame_T	*fr;
5763     int		room;
5764     int		row;
5765     int		up;	// if TRUE, drag status line up, otherwise down
5766     int		n;
5767 
5768     fr = dragwin->w_frame;
5769     curfr = fr;
5770     if (fr != topframe)		// more than one window
5771     {
5772 	fr = fr->fr_parent;
5773 	// When the parent frame is not a column of frames, its parent should
5774 	// be.
5775 	if (fr->fr_layout != FR_COL)
5776 	{
5777 	    curfr = fr;
5778 	    if (fr != topframe)	// only a row of windows, may drag statusline
5779 		fr = fr->fr_parent;
5780 	}
5781     }
5782 
5783     // If this is the last frame in a column, may want to resize the parent
5784     // frame instead (go two up to skip a row of frames).
5785     while (curfr != topframe && curfr->fr_next == NULL)
5786     {
5787 	if (fr != topframe)
5788 	    fr = fr->fr_parent;
5789 	curfr = fr;
5790 	if (fr != topframe)
5791 	    fr = fr->fr_parent;
5792     }
5793 
5794     if (offset < 0) // drag up
5795     {
5796 	up = TRUE;
5797 	offset = -offset;
5798 	// sum up the room of the current frame and above it
5799 	if (fr == curfr)
5800 	{
5801 	    // only one window
5802 	    room = fr->fr_height - frame_minheight(fr, NULL);
5803 	}
5804 	else
5805 	{
5806 	    room = 0;
5807 	    for (fr = fr->fr_child; ; fr = fr->fr_next)
5808 	    {
5809 		room += fr->fr_height - frame_minheight(fr, NULL);
5810 		if (fr == curfr)
5811 		    break;
5812 	    }
5813 	}
5814 	fr = curfr->fr_next;		// put fr at frame that grows
5815     }
5816     else    // drag down
5817     {
5818 	up = FALSE;
5819 	/*
5820 	 * Only dragging the last status line can reduce p_ch.
5821 	 */
5822 	room = Rows - cmdline_row;
5823 	if (curfr->fr_next == NULL)
5824 	    room -= 1;
5825 	else
5826 	    room -= p_ch;
5827 	if (room < 0)
5828 	    room = 0;
5829 	// sum up the room of frames below of the current one
5830 	FOR_ALL_FRAMES(fr, curfr->fr_next)
5831 	    room += fr->fr_height - frame_minheight(fr, NULL);
5832 	fr = curfr;			// put fr at window that grows
5833     }
5834 
5835     if (room < offset)		// Not enough room
5836 	offset = room;		// Move as far as we can
5837     if (offset <= 0)
5838 	return;
5839 
5840     /*
5841      * Grow frame fr by "offset" lines.
5842      * Doesn't happen when dragging the last status line up.
5843      */
5844     if (fr != NULL)
5845 	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
5846 
5847     if (up)
5848 	fr = curfr;		// current frame gets smaller
5849     else
5850 	fr = curfr->fr_next;	// next frame gets smaller
5851 
5852     /*
5853      * Now make the other frames smaller.
5854      */
5855     while (fr != NULL && offset > 0)
5856     {
5857 	n = frame_minheight(fr, NULL);
5858 	if (fr->fr_height - offset <= n)
5859 	{
5860 	    offset -= fr->fr_height - n;
5861 	    frame_new_height(fr, n, !up, FALSE);
5862 	}
5863 	else
5864 	{
5865 	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
5866 	    break;
5867 	}
5868 	if (up)
5869 	    fr = fr->fr_prev;
5870 	else
5871 	    fr = fr->fr_next;
5872     }
5873     row = win_comp_pos();
5874     screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
5875     cmdline_row = row;
5876     p_ch = Rows - cmdline_row;
5877     if (p_ch < 1)
5878 	p_ch = 1;
5879     curtab->tp_ch_used = p_ch;
5880     redraw_all_later(SOME_VALID);
5881     showmode();
5882 }
5883 
5884 /*
5885  * Separator line of dragwin is dragged "offset" lines right (negative is left).
5886  */
5887     void
5888 win_drag_vsep_line(win_T *dragwin, int offset)
5889 {
5890     frame_T	*curfr;
5891     frame_T	*fr;
5892     int		room;
5893     int		left;	// if TRUE, drag separator line left, otherwise right
5894     int		n;
5895 
5896     fr = dragwin->w_frame;
5897     if (fr == topframe)		// only one window (cannot happen?)
5898 	return;
5899     curfr = fr;
5900     fr = fr->fr_parent;
5901     // When the parent frame is not a row of frames, its parent should be.
5902     if (fr->fr_layout != FR_ROW)
5903     {
5904 	if (fr == topframe)	// only a column of windows (cannot happen?)
5905 	    return;
5906 	curfr = fr;
5907 	fr = fr->fr_parent;
5908     }
5909 
5910     // If this is the last frame in a row, may want to resize a parent
5911     // frame instead.
5912     while (curfr->fr_next == NULL)
5913     {
5914 	if (fr == topframe)
5915 	    break;
5916 	curfr = fr;
5917 	fr = fr->fr_parent;
5918 	if (fr != topframe)
5919 	{
5920 	    curfr = fr;
5921 	    fr = fr->fr_parent;
5922 	}
5923     }
5924 
5925     if (offset < 0) // drag left
5926     {
5927 	left = TRUE;
5928 	offset = -offset;
5929 	// sum up the room of the current frame and left of it
5930 	room = 0;
5931 	for (fr = fr->fr_child; ; fr = fr->fr_next)
5932 	{
5933 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5934 	    if (fr == curfr)
5935 		break;
5936 	}
5937 	fr = curfr->fr_next;		// put fr at frame that grows
5938     }
5939     else    // drag right
5940     {
5941 	left = FALSE;
5942 	// sum up the room of frames right of the current one
5943 	room = 0;
5944 	FOR_ALL_FRAMES(fr, curfr->fr_next)
5945 	    room += fr->fr_width - frame_minwidth(fr, NULL);
5946 	fr = curfr;			// put fr at window that grows
5947     }
5948 
5949     if (room < offset)		// Not enough room
5950 	offset = room;		// Move as far as we can
5951     if (offset <= 0)		// No room at all, quit.
5952 	return;
5953     if (fr == NULL)
5954 	return;			// Safety check, should not happen.
5955 
5956     // grow frame fr by offset lines
5957     frame_new_width(fr, fr->fr_width + offset, left, FALSE);
5958 
5959     // shrink other frames: current and at the left or at the right
5960     if (left)
5961 	fr = curfr;		// current frame gets smaller
5962     else
5963 	fr = curfr->fr_next;	// next frame gets smaller
5964 
5965     while (fr != NULL && offset > 0)
5966     {
5967 	n = frame_minwidth(fr, NULL);
5968 	if (fr->fr_width - offset <= n)
5969 	{
5970 	    offset -= fr->fr_width - n;
5971 	    frame_new_width(fr, n, !left, FALSE);
5972 	}
5973 	else
5974 	{
5975 	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
5976 	    break;
5977 	}
5978 	if (left)
5979 	    fr = fr->fr_prev;
5980 	else
5981 	    fr = fr->fr_next;
5982     }
5983     (void)win_comp_pos();
5984     redraw_all_later(NOT_VALID);
5985 }
5986 
5987 #define FRACTION_MULT	16384L
5988 
5989 /*
5990  * Set wp->w_fraction for the current w_wrow and w_height.
5991  * Has no effect when the window is less than two lines.
5992  */
5993     void
5994 set_fraction(win_T *wp)
5995 {
5996     if (wp->w_height > 1)
5997 	// When cursor is in the first line the percentage is computed as if
5998 	// it's halfway that line.  Thus with two lines it is 25%, with three
5999 	// lines 17%, etc.  Similarly for the last line: 75%, 83%, etc.
6000 	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
6001 				     + FRACTION_MULT / 2) / (long)wp->w_height;
6002 }
6003 
6004 /*
6005  * Set the height of a window.
6006  * "height" excludes any window toolbar.
6007  * This takes care of the things inside the window, not what happens to the
6008  * window position, the frame or to other windows.
6009  */
6010     void
6011 win_new_height(win_T *wp, int height)
6012 {
6013     int		prev_height = wp->w_height;
6014 
6015     // Don't want a negative height.  Happens when splitting a tiny window.
6016     // Will equalize heights soon to fix it.
6017     if (height < 0)
6018 	height = 0;
6019     if (wp->w_height == height)
6020 	return;	    // nothing to do
6021 
6022     if (wp->w_height > 0)
6023     {
6024 	if (wp == curwin)
6025 	    // w_wrow needs to be valid. When setting 'laststatus' this may
6026 	    // call win_new_height() recursively.
6027 	    validate_cursor();
6028 	if (wp->w_height != prev_height)
6029 	    return;  // Recursive call already changed the size, bail out here
6030 		     //	to avoid the following to mess things up.
6031 	if (wp->w_wrow != wp->w_prev_fraction_row)
6032 	    set_fraction(wp);
6033     }
6034 
6035     wp->w_height = height;
6036     wp->w_skipcol = 0;
6037 
6038     // There is no point in adjusting the scroll position when exiting.  Some
6039     // values might be invalid.
6040     if (!exiting)
6041 	scroll_to_fraction(wp, prev_height);
6042 }
6043 
6044     void
6045 scroll_to_fraction(win_T *wp, int prev_height)
6046 {
6047     linenr_T	lnum;
6048     int		sline, line_size;
6049     int		height = wp->w_height;
6050 
6051     // Don't change w_topline in any of these cases:
6052     // - window height is 0
6053     // - 'scrollbind' is set and this isn't the current window
6054     // - window height is sufficient to display the whole buffer and first line
6055     //   is visible.
6056     if (height > 0
6057         && (!wp->w_p_scb || wp == curwin)
6058         && (height < wp->w_buffer->b_ml.ml_line_count || wp->w_topline > 1))
6059     {
6060 	/*
6061 	 * Find a value for w_topline that shows the cursor at the same
6062 	 * relative position in the window as before (more or less).
6063 	 */
6064 	lnum = wp->w_cursor.lnum;
6065 	if (lnum < 1)		// can happen when starting up
6066 	    lnum = 1;
6067 	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L)
6068 							       / FRACTION_MULT;
6069 	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
6070 	sline = wp->w_wrow - line_size;
6071 
6072 	if (sline >= 0)
6073 	{
6074 	    // Make sure the whole cursor line is visible, if possible.
6075 	    int rows = plines_win(wp, lnum, FALSE);
6076 
6077 	    if (sline > wp->w_height - rows)
6078 	    {
6079 		sline = wp->w_height - rows;
6080 		wp->w_wrow -= rows - line_size;
6081 	    }
6082 	}
6083 
6084 	if (sline < 0)
6085 	{
6086 	    /*
6087 	     * Cursor line would go off top of screen if w_wrow was this high.
6088 	     * Make cursor line the first line in the window.  If not enough
6089 	     * room use w_skipcol;
6090 	     */
6091 	    wp->w_wrow = line_size;
6092 	    if (wp->w_wrow >= wp->w_height
6093 				       && (wp->w_width - win_col_off(wp)) > 0)
6094 	    {
6095 		wp->w_skipcol += wp->w_width - win_col_off(wp);
6096 		--wp->w_wrow;
6097 		while (wp->w_wrow >= wp->w_height)
6098 		{
6099 		    wp->w_skipcol += wp->w_width - win_col_off(wp)
6100 							   + win_col_off2(wp);
6101 		    --wp->w_wrow;
6102 		}
6103 	    }
6104 	}
6105 	else if (sline > 0)
6106 	{
6107 	    while (sline > 0 && lnum > 1)
6108 	    {
6109 #ifdef FEAT_FOLDING
6110 		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
6111 		if (lnum == 1)
6112 		{
6113 		    // first line in buffer is folded
6114 		    line_size = 1;
6115 		    --sline;
6116 		    break;
6117 		}
6118 #endif
6119 		--lnum;
6120 #ifdef FEAT_DIFF
6121 		if (lnum == wp->w_topline)
6122 		    line_size = plines_win_nofill(wp, lnum, TRUE)
6123 							      + wp->w_topfill;
6124 		else
6125 #endif
6126 		    line_size = plines_win(wp, lnum, TRUE);
6127 		sline -= line_size;
6128 	    }
6129 
6130 	    if (sline < 0)
6131 	    {
6132 		/*
6133 		 * Line we want at top would go off top of screen.  Use next
6134 		 * line instead.
6135 		 */
6136 #ifdef FEAT_FOLDING
6137 		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
6138 #endif
6139 		lnum++;
6140 		wp->w_wrow -= line_size + sline;
6141 	    }
6142 	    else if (sline > 0)
6143 	    {
6144 		// First line of file reached, use that as topline.
6145 		lnum = 1;
6146 		wp->w_wrow -= sline;
6147 	    }
6148 	}
6149 	set_topline(wp, lnum);
6150     }
6151 
6152     if (wp == curwin)
6153     {
6154 	if (get_scrolloff_value())
6155 	    update_topline();
6156 	curs_columns(FALSE);	// validate w_wrow
6157     }
6158     if (prev_height > 0)
6159 	wp->w_prev_fraction_row = wp->w_wrow;
6160 
6161     win_comp_scroll(wp);
6162     redraw_win_later(wp, SOME_VALID);
6163     wp->w_redr_status = TRUE;
6164     invalidate_botline_win(wp);
6165 }
6166 
6167 /*
6168  * Set the width of a window.
6169  */
6170     void
6171 win_new_width(win_T *wp, int width)
6172 {
6173     wp->w_width = width;
6174     wp->w_lines_valid = 0;
6175     changed_line_abv_curs_win(wp);
6176     invalidate_botline_win(wp);
6177     if (wp == curwin)
6178     {
6179 	update_topline();
6180 	curs_columns(TRUE);	// validate w_wrow
6181     }
6182     redraw_win_later(wp, NOT_VALID);
6183     wp->w_redr_status = TRUE;
6184 }
6185 
6186     void
6187 win_comp_scroll(win_T *wp)
6188 {
6189     wp->w_p_scr = ((unsigned)wp->w_height >> 1);
6190     if (wp->w_p_scr == 0)
6191 	wp->w_p_scr = 1;
6192 }
6193 
6194 /*
6195  * command_height: called whenever p_ch has been changed
6196  */
6197     void
6198 command_height(void)
6199 {
6200     int		h;
6201     frame_T	*frp;
6202     int		old_p_ch = curtab->tp_ch_used;
6203 
6204     // Use the value of p_ch that we remembered.  This is needed for when the
6205     // GUI starts up, we can't be sure in what order things happen.  And when
6206     // p_ch was changed in another tab page.
6207     curtab->tp_ch_used = p_ch;
6208 
6209     // Find bottom frame with width of screen.
6210     frp = lastwin->w_frame;
6211     while (frp->fr_width != Columns && frp->fr_parent != NULL)
6212 	frp = frp->fr_parent;
6213 
6214     // Avoid changing the height of a window with 'winfixheight' set.
6215     while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
6216 						      && frp->fr_win->w_p_wfh)
6217 	frp = frp->fr_prev;
6218 
6219     if (starting != NO_SCREEN)
6220     {
6221 	cmdline_row = Rows - p_ch;
6222 
6223 	if (p_ch > old_p_ch)		    // p_ch got bigger
6224 	{
6225 	    while (p_ch > old_p_ch)
6226 	    {
6227 		if (frp == NULL)
6228 		{
6229 		    emsg(_(e_noroom));
6230 		    p_ch = old_p_ch;
6231 		    curtab->tp_ch_used = p_ch;
6232 		    cmdline_row = Rows - p_ch;
6233 		    break;
6234 		}
6235 		h = frp->fr_height - frame_minheight(frp, NULL);
6236 		if (h > p_ch - old_p_ch)
6237 		    h = p_ch - old_p_ch;
6238 		old_p_ch += h;
6239 		frame_add_height(frp, -h);
6240 		frp = frp->fr_prev;
6241 	    }
6242 
6243 	    // Recompute window positions.
6244 	    (void)win_comp_pos();
6245 
6246 	    // clear the lines added to cmdline
6247 	    if (full_screen)
6248 		screen_fill((int)(cmdline_row), (int)Rows, 0,
6249 						   (int)Columns, ' ', ' ', 0);
6250 	    msg_row = cmdline_row;
6251 	    redraw_cmdline = TRUE;
6252 	    return;
6253 	}
6254 
6255 	if (msg_row < cmdline_row)
6256 	    msg_row = cmdline_row;
6257 	redraw_cmdline = TRUE;
6258     }
6259     frame_add_height(frp, (int)(old_p_ch - p_ch));
6260 
6261     // Recompute window positions.
6262     if (frp != lastwin->w_frame)
6263 	(void)win_comp_pos();
6264 }
6265 
6266 /*
6267  * Resize frame "frp" to be "n" lines higher (negative for less high).
6268  * Also resize the frames it is contained in.
6269  */
6270     static void
6271 frame_add_height(frame_T *frp, int n)
6272 {
6273     frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
6274     for (;;)
6275     {
6276 	frp = frp->fr_parent;
6277 	if (frp == NULL)
6278 	    break;
6279 	frp->fr_height += n;
6280     }
6281 }
6282 
6283 /*
6284  * Add or remove a status line for the bottom window(s), according to the
6285  * value of 'laststatus'.
6286  */
6287     void
6288 last_status(
6289     int		morewin)	// pretend there are two or more windows
6290 {
6291     // Don't make a difference between horizontal or vertical split.
6292     last_status_rec(topframe, (p_ls == 2
6293 			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
6294 }
6295 
6296     static void
6297 last_status_rec(frame_T *fr, int statusline)
6298 {
6299     frame_T	*fp;
6300     win_T	*wp;
6301 
6302     if (fr->fr_layout == FR_LEAF)
6303     {
6304 	wp = fr->fr_win;
6305 	if (wp->w_status_height != 0 && !statusline)
6306 	{
6307 	    // remove status line
6308 	    win_new_height(wp, wp->w_height + 1);
6309 	    wp->w_status_height = 0;
6310 	    comp_col();
6311 	}
6312 	else if (wp->w_status_height == 0 && statusline)
6313 	{
6314 	    // Find a frame to take a line from.
6315 	    fp = fr;
6316 	    while (fp->fr_height <= frame_minheight(fp, NULL))
6317 	    {
6318 		if (fp == topframe)
6319 		{
6320 		    emsg(_(e_noroom));
6321 		    return;
6322 		}
6323 		// In a column of frames: go to frame above.  If already at
6324 		// the top or in a row of frames: go to parent.
6325 		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
6326 		    fp = fp->fr_prev;
6327 		else
6328 		    fp = fp->fr_parent;
6329 	    }
6330 	    wp->w_status_height = 1;
6331 	    if (fp != fr)
6332 	    {
6333 		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
6334 		frame_fix_height(wp);
6335 		(void)win_comp_pos();
6336 	    }
6337 	    else
6338 		win_new_height(wp, wp->w_height - 1);
6339 	    comp_col();
6340 	    redraw_all_later(SOME_VALID);
6341 	}
6342     }
6343     else if (fr->fr_layout == FR_ROW)
6344     {
6345 	// vertically split windows, set status line for each one
6346 	FOR_ALL_FRAMES(fp, fr->fr_child)
6347 	    last_status_rec(fp, statusline);
6348     }
6349     else
6350     {
6351 	// horizontally split window, set status line for last one
6352 	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
6353 	    ;
6354 	last_status_rec(fp, statusline);
6355     }
6356 }
6357 
6358 /*
6359  * Return the number of lines used by the tab page line.
6360  */
6361     int
6362 tabline_height(void)
6363 {
6364 #ifdef FEAT_GUI_TABLINE
6365     // When the GUI has the tabline then this always returns zero.
6366     if (gui_use_tabline())
6367 	return 0;
6368 #endif
6369     switch (p_stal)
6370     {
6371 	case 0: return 0;
6372 	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
6373     }
6374     return 1;
6375 }
6376 
6377 /*
6378  * Return the minimal number of rows that is needed on the screen to display
6379  * the current number of windows.
6380  */
6381     int
6382 min_rows(void)
6383 {
6384     int		total;
6385     tabpage_T	*tp;
6386     int		n;
6387 
6388     if (firstwin == NULL)	// not initialized yet
6389 	return MIN_LINES;
6390 
6391     total = 0;
6392     FOR_ALL_TABPAGES(tp)
6393     {
6394 	n = frame_minheight(tp->tp_topframe, NULL);
6395 	if (total < n)
6396 	    total = n;
6397     }
6398     total += tabline_height();
6399     total += 1;		// count the room for the command line
6400     return total;
6401 }
6402 
6403 /*
6404  * Return TRUE if there is only one window and only one tab page, not
6405  * counting a help or preview window, unless it is the current window.
6406  * Does not count unlisted windows.
6407  */
6408     int
6409 only_one_window(void)
6410 {
6411     int		count = 0;
6412     win_T	*wp;
6413 
6414     // If there is another tab page there always is another window.
6415     if (first_tabpage->tp_next != NULL)
6416 	return FALSE;
6417 
6418     FOR_ALL_WINDOWS(wp)
6419 	if (wp->w_buffer != NULL
6420 		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
6421 # ifdef FEAT_QUICKFIX
6422 		    || wp->w_p_pvw
6423 # endif
6424 	     ) || wp == curwin) && wp != aucmd_win)
6425 	    ++count;
6426     return (count <= 1);
6427 }
6428 
6429 /*
6430  * Correct the cursor line number in other windows.  Used after changing the
6431  * current buffer, and before applying autocommands.
6432  * When "do_curwin" is TRUE, also check current window.
6433  */
6434     void
6435 check_lnums(int do_curwin)
6436 {
6437     win_T	*wp;
6438     tabpage_T	*tp;
6439 
6440     FOR_ALL_TAB_WINDOWS(tp, wp)
6441 	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
6442 	{
6443 	    // save the original cursor position and topline
6444 	    wp->w_save_cursor.w_cursor_save = wp->w_cursor;
6445 	    wp->w_save_cursor.w_topline_save = wp->w_topline;
6446 
6447 	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
6448 		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
6449 	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
6450 		wp->w_topline = curbuf->b_ml.ml_line_count;
6451 
6452 	    // save the corrected cursor position and topline
6453 	    wp->w_save_cursor.w_cursor_corr = wp->w_cursor;
6454 	    wp->w_save_cursor.w_topline_corr = wp->w_topline;
6455 	}
6456 }
6457 
6458 /*
6459  * Reset cursor and topline to its stored values from check_lnums().
6460  * check_lnums() must have been called first!
6461  */
6462     void
6463 reset_lnums()
6464 {
6465     win_T	*wp;
6466     tabpage_T	*tp;
6467 
6468     FOR_ALL_TAB_WINDOWS(tp, wp)
6469 	if (wp->w_buffer == curbuf)
6470 	{
6471 	    // Restore the value if the autocommand didn't change it.
6472 	    if (EQUAL_POS(wp->w_save_cursor.w_cursor_corr, wp->w_cursor))
6473 		wp->w_cursor = wp->w_save_cursor.w_cursor_save;
6474 	    if (wp->w_save_cursor.w_topline_corr == wp->w_topline)
6475 		wp->w_topline = wp->w_save_cursor.w_topline_save;
6476 	}
6477 }
6478 
6479 /*
6480  * A snapshot of the window sizes, to restore them after closing the help
6481  * window.
6482  * Only these fields are used:
6483  * fr_layout
6484  * fr_width
6485  * fr_height
6486  * fr_next
6487  * fr_child
6488  * fr_win (only valid for the old curwin, NULL otherwise)
6489  */
6490 
6491 /*
6492  * Create a snapshot of the current frame sizes.
6493  */
6494     void
6495 make_snapshot(int idx)
6496 {
6497     clear_snapshot(curtab, idx);
6498     make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
6499 }
6500 
6501     static void
6502 make_snapshot_rec(frame_T *fr, frame_T **frp)
6503 {
6504     *frp = ALLOC_CLEAR_ONE(frame_T);
6505     if (*frp == NULL)
6506 	return;
6507     (*frp)->fr_layout = fr->fr_layout;
6508     (*frp)->fr_width = fr->fr_width;
6509     (*frp)->fr_height = fr->fr_height;
6510     if (fr->fr_next != NULL)
6511 	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
6512     if (fr->fr_child != NULL)
6513 	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
6514     if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
6515 	(*frp)->fr_win = curwin;
6516 }
6517 
6518 /*
6519  * Remove any existing snapshot.
6520  */
6521     static void
6522 clear_snapshot(tabpage_T *tp, int idx)
6523 {
6524     clear_snapshot_rec(tp->tp_snapshot[idx]);
6525     tp->tp_snapshot[idx] = NULL;
6526 }
6527 
6528     static void
6529 clear_snapshot_rec(frame_T *fr)
6530 {
6531     if (fr != NULL)
6532     {
6533 	clear_snapshot_rec(fr->fr_next);
6534 	clear_snapshot_rec(fr->fr_child);
6535 	vim_free(fr);
6536     }
6537 }
6538 
6539 /*
6540  * Restore a previously created snapshot, if there is any.
6541  * This is only done if the screen size didn't change and the window layout is
6542  * still the same.
6543  */
6544     void
6545 restore_snapshot(
6546     int		idx,
6547     int		close_curwin)	    // closing current window
6548 {
6549     win_T	*wp;
6550 
6551     if (curtab->tp_snapshot[idx] != NULL
6552 	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
6553 	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
6554 	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
6555     {
6556 	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
6557 	win_comp_pos();
6558 	if (wp != NULL && close_curwin)
6559 	    win_goto(wp);
6560 	redraw_all_later(NOT_VALID);
6561     }
6562     clear_snapshot(curtab, idx);
6563 }
6564 
6565 /*
6566  * Check if frames "sn" and "fr" have the same layout, same following frames
6567  * and same children.  And the window pointer is valid.
6568  */
6569     static int
6570 check_snapshot_rec(frame_T *sn, frame_T *fr)
6571 {
6572     if (sn->fr_layout != fr->fr_layout
6573 	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
6574 	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
6575 	    || (sn->fr_next != NULL
6576 		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
6577 	    || (sn->fr_child != NULL
6578 		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
6579 	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
6580 	return FAIL;
6581     return OK;
6582 }
6583 
6584 /*
6585  * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
6586  * following frames and children.
6587  * Returns a pointer to the old current window, or NULL.
6588  */
6589     static win_T *
6590 restore_snapshot_rec(frame_T *sn, frame_T *fr)
6591 {
6592     win_T	*wp = NULL;
6593     win_T	*wp2;
6594 
6595     fr->fr_height = sn->fr_height;
6596     fr->fr_width = sn->fr_width;
6597     if (fr->fr_layout == FR_LEAF)
6598     {
6599 	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
6600 	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
6601 	wp = sn->fr_win;
6602     }
6603     if (sn->fr_next != NULL)
6604     {
6605 	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
6606 	if (wp2 != NULL)
6607 	    wp = wp2;
6608     }
6609     if (sn->fr_child != NULL)
6610     {
6611 	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
6612 	if (wp2 != NULL)
6613 	    wp = wp2;
6614     }
6615     return wp;
6616 }
6617 
6618 #if defined(FEAT_GUI) || defined(PROTO)
6619 /*
6620  * Return TRUE if there is any vertically split window.
6621  */
6622     int
6623 win_hasvertsplit(void)
6624 {
6625     frame_T	*fr;
6626 
6627     if (topframe->fr_layout == FR_ROW)
6628 	return TRUE;
6629 
6630     if (topframe->fr_layout == FR_COL)
6631 	FOR_ALL_FRAMES(fr, topframe->fr_child)
6632 	    if (fr->fr_layout == FR_ROW)
6633 		return TRUE;
6634 
6635     return FALSE;
6636 }
6637 #endif
6638 
6639 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
6640     int
6641 get_win_number(win_T *wp, win_T *first_win)
6642 {
6643     int		i = 1;
6644     win_T	*w;
6645 
6646     for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
6647 	++i;
6648 
6649     if (w == NULL)
6650 	return 0;
6651     else
6652 	return i;
6653 }
6654 
6655     int
6656 get_tab_number(tabpage_T *tp UNUSED)
6657 {
6658     int		i = 1;
6659     tabpage_T	*t;
6660 
6661     for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
6662 	++i;
6663 
6664     if (t == NULL)
6665 	return 0;
6666     else
6667 	return i;
6668 }
6669 #endif
6670 
6671 /*
6672  * Return TRUE if "topfrp" and its children are at the right height.
6673  */
6674     static int
6675 frame_check_height(frame_T *topfrp, int height)
6676 {
6677     frame_T *frp;
6678 
6679     if (topfrp->fr_height != height)
6680 	return FALSE;
6681 
6682     if (topfrp->fr_layout == FR_ROW)
6683 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6684 	    if (frp->fr_height != height)
6685 		return FALSE;
6686 
6687     return TRUE;
6688 }
6689 
6690 /*
6691  * Return TRUE if "topfrp" and its children are at the right width.
6692  */
6693     static int
6694 frame_check_width(frame_T *topfrp, int width)
6695 {
6696     frame_T *frp;
6697 
6698     if (topfrp->fr_width != width)
6699 	return FALSE;
6700 
6701     if (topfrp->fr_layout == FR_COL)
6702 	FOR_ALL_FRAMES(frp, topfrp->fr_child)
6703 	    if (frp->fr_width != width)
6704 		return FALSE;
6705 
6706     return TRUE;
6707 }
6708 
6709 #if defined(FEAT_SYN_HL) || defined(PROTO)
6710 /*
6711  * Simple int comparison function for use with qsort()
6712  */
6713     static int
6714 int_cmp(const void *a, const void *b)
6715 {
6716     return *(const int *)a - *(const int *)b;
6717 }
6718 
6719 /*
6720  * Handle setting 'colorcolumn' or 'textwidth' in window "wp".
6721  * Returns error message, NULL if it's OK.
6722  */
6723     char *
6724 check_colorcolumn(win_T *wp)
6725 {
6726     char_u	*s;
6727     int		col;
6728     int		count = 0;
6729     int		color_cols[256];
6730     int		i;
6731     int		j = 0;
6732 
6733     if (wp->w_buffer == NULL)
6734 	return NULL;  // buffer was closed
6735 
6736     for (s = wp->w_p_cc; *s != NUL && count < 255;)
6737     {
6738 	if (*s == '-' || *s == '+')
6739 	{
6740 	    // -N and +N: add to 'textwidth'
6741 	    col = (*s == '-') ? -1 : 1;
6742 	    ++s;
6743 	    if (!VIM_ISDIGIT(*s))
6744 		return e_invarg;
6745 	    col = col * getdigits(&s);
6746 	    if (wp->w_buffer->b_p_tw == 0)
6747 		goto skip;  // 'textwidth' not set, skip this item
6748 	    col += wp->w_buffer->b_p_tw;
6749 	    if (col < 0)
6750 		goto skip;
6751 	}
6752 	else if (VIM_ISDIGIT(*s))
6753 	    col = getdigits(&s);
6754 	else
6755 	    return e_invarg;
6756 	color_cols[count++] = col - 1;  // 1-based to 0-based
6757 skip:
6758 	if (*s == NUL)
6759 	    break;
6760 	if (*s != ',')
6761 	    return e_invarg;
6762 	if (*++s == NUL)
6763 	    return e_invarg;  // illegal trailing comma as in "set cc=80,"
6764     }
6765 
6766     vim_free(wp->w_p_cc_cols);
6767     if (count == 0)
6768 	wp->w_p_cc_cols = NULL;
6769     else
6770     {
6771 	wp->w_p_cc_cols = ALLOC_MULT(int, count + 1);
6772 	if (wp->w_p_cc_cols != NULL)
6773 	{
6774 	    // sort the columns for faster usage on screen redraw inside
6775 	    // win_line()
6776 	    qsort(color_cols, count, sizeof(int), int_cmp);
6777 
6778 	    for (i = 0; i < count; ++i)
6779 		// skip duplicates
6780 		if (j == 0 || wp->w_p_cc_cols[j - 1] != color_cols[i])
6781 		    wp->w_p_cc_cols[j++] = color_cols[i];
6782 	    wp->w_p_cc_cols[j] = -1;  // end marker
6783 	}
6784     }
6785 
6786     return NULL;  // no error
6787 }
6788 #endif
6789