xref: /netbsd-src/external/bsd/tmux/dist/window.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* $OpenBSD$ */
2 
3 /*
4  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/ioctl.h>
21 
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <fnmatch.h>
25 #include <signal.h>
26 #include <stdint.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <termios.h>
30 #include <time.h>
31 #include <unistd.h>
32 
33 #include "tmux.h"
34 
35 /*
36  * Each window is attached to a number of panes, each of which is a pty. This
37  * file contains code to handle them.
38  *
39  * A pane has two buffers attached, these are filled and emptied by the main
40  * server poll loop. Output data is received from pty's in screen format,
41  * translated and returned as a series of escape sequences and strings via
42  * input_parse (in input.c). Input data is received as key codes and written
43  * directly via input_key.
44  *
45  * Each pane also has a "virtual" screen (screen.c) which contains the current
46  * state and is redisplayed when the window is reattached to a client.
47  *
48  * Windows are stored directly on a global array and wrapped in any number of
49  * winlink structs to be linked onto local session RB trees. A reference count
50  * is maintained and a window removed from the global list and destroyed when
51  * it reaches zero.
52  */
53 
54 /* Global window list. */
55 struct windows windows;
56 
57 /* Global panes tree. */
58 struct window_pane_tree all_window_panes;
59 static u_int	next_window_pane_id;
60 static u_int	next_window_id;
61 static u_int	next_active_point;
62 
63 static void	window_destroy(struct window *);
64 
65 static struct window_pane *window_pane_create(struct window *, u_int, u_int,
66 		    u_int);
67 static void	window_pane_destroy(struct window_pane *);
68 
69 static void	window_pane_read_callback(struct bufferevent *, void *);
70 static void	window_pane_error_callback(struct bufferevent *, short, void *);
71 
72 static int	winlink_next_index(struct winlinks *, int);
73 
74 static struct window_pane *window_pane_choose_best(struct window_pane **,
75 		    u_int);
76 
77 RB_GENERATE(windows, window, entry, window_cmp);
78 RB_GENERATE(winlinks, winlink, entry, winlink_cmp);
79 RB_GENERATE(window_pane_tree, window_pane, tree_entry, window_pane_cmp);
80 
81 int
82 window_cmp(struct window *w1, struct window *w2)
83 {
84 	return (w1->id - w2->id);
85 }
86 
87 int
88 winlink_cmp(struct winlink *wl1, struct winlink *wl2)
89 {
90 	return (wl1->idx - wl2->idx);
91 }
92 
93 int
94 window_pane_cmp(struct window_pane *wp1, struct window_pane *wp2)
95 {
96 	return (wp1->id - wp2->id);
97 }
98 
99 struct winlink *
100 winlink_find_by_window(struct winlinks *wwl, struct window *w)
101 {
102 	struct winlink	*wl;
103 
104 	RB_FOREACH(wl, winlinks, wwl) {
105 		if (wl->window == w)
106 			return (wl);
107 	}
108 
109 	return (NULL);
110 }
111 
112 struct winlink *
113 winlink_find_by_index(struct winlinks *wwl, int idx)
114 {
115 	struct winlink	wl;
116 
117 	if (idx < 0)
118 		fatalx("bad index");
119 
120 	wl.idx = idx;
121 	return (RB_FIND(winlinks, wwl, &wl));
122 }
123 
124 struct winlink *
125 winlink_find_by_window_id(struct winlinks *wwl, u_int id)
126 {
127 	struct winlink *wl;
128 
129 	RB_FOREACH(wl, winlinks, wwl) {
130 		if (wl->window->id == id)
131 			return (wl);
132 	}
133 	return (NULL);
134 }
135 
136 static int
137 winlink_next_index(struct winlinks *wwl, int idx)
138 {
139 	int	i;
140 
141 	i = idx;
142 	do {
143 		if (winlink_find_by_index(wwl, i) == NULL)
144 			return (i);
145 		if (i == INT_MAX)
146 			i = 0;
147 		else
148 			i++;
149 	} while (i != idx);
150 	return (-1);
151 }
152 
153 u_int
154 winlink_count(struct winlinks *wwl)
155 {
156 	struct winlink	*wl;
157 	u_int		 n;
158 
159 	n = 0;
160 	RB_FOREACH(wl, winlinks, wwl)
161 		n++;
162 
163 	return (n);
164 }
165 
166 struct winlink *
167 winlink_add(struct winlinks *wwl, int idx)
168 {
169 	struct winlink	*wl;
170 
171 	if (idx < 0) {
172 		if ((idx = winlink_next_index(wwl, -idx - 1)) == -1)
173 			return (NULL);
174 	} else if (winlink_find_by_index(wwl, idx) != NULL)
175 		return (NULL);
176 
177 	wl = xcalloc(1, sizeof *wl);
178 	wl->idx = idx;
179 	RB_INSERT(winlinks, wwl, wl);
180 
181 	return (wl);
182 }
183 
184 void
185 winlink_set_window(struct winlink *wl, struct window *w)
186 {
187 	if (wl->window != NULL) {
188 		TAILQ_REMOVE(&wl->window->winlinks, wl, wentry);
189 		window_remove_ref(wl->window, __func__);
190 	}
191 	TAILQ_INSERT_TAIL(&w->winlinks, wl, wentry);
192 	wl->window = w;
193 	window_add_ref(w, __func__);
194 }
195 
196 void
197 winlink_remove(struct winlinks *wwl, struct winlink *wl)
198 {
199 	struct window	*w = wl->window;
200 
201 	if (w != NULL) {
202 		TAILQ_REMOVE(&w->winlinks, wl, wentry);
203 		window_remove_ref(w, __func__);
204 	}
205 
206 	RB_REMOVE(winlinks, wwl, wl);
207 	free(wl->status_text);
208 	free(wl);
209 }
210 
211 struct winlink *
212 winlink_next(struct winlink *wl)
213 {
214 	return (RB_NEXT(winlinks, wwl, wl));
215 }
216 
217 struct winlink *
218 winlink_previous(struct winlink *wl)
219 {
220 	return (RB_PREV(winlinks, wwl, wl));
221 }
222 
223 struct winlink *
224 winlink_next_by_number(struct winlink *wl, struct session *s, int n)
225 {
226 	for (; n > 0; n--) {
227 		if ((wl = RB_NEXT(winlinks, wwl, wl)) == NULL)
228 			wl = RB_MIN(winlinks, &s->windows);
229 	}
230 
231 	return (wl);
232 }
233 
234 struct winlink *
235 winlink_previous_by_number(struct winlink *wl, struct session *s, int n)
236 {
237 	for (; n > 0; n--) {
238 		if ((wl = RB_PREV(winlinks, wwl, wl)) == NULL)
239 			wl = RB_MAX(winlinks, &s->windows);
240 	}
241 
242 	return (wl);
243 }
244 
245 void
246 winlink_stack_push(struct winlink_stack *stack, struct winlink *wl)
247 {
248 	if (wl == NULL)
249 		return;
250 
251 	winlink_stack_remove(stack, wl);
252 	TAILQ_INSERT_HEAD(stack, wl, sentry);
253 }
254 
255 void
256 winlink_stack_remove(struct winlink_stack *stack, struct winlink *wl)
257 {
258 	struct winlink	*wl2;
259 
260 	if (wl == NULL)
261 		return;
262 
263 	TAILQ_FOREACH(wl2, stack, sentry) {
264 		if (wl2 == wl) {
265 			TAILQ_REMOVE(stack, wl, sentry);
266 			return;
267 		}
268 	}
269 }
270 
271 struct window *
272 window_find_by_id_str(const char *s)
273 {
274 	const char	*errstr;
275 	u_int		 id;
276 
277 	if (*s != '@')
278 		return (NULL);
279 
280 	id = strtonum(s + 1, 0, UINT_MAX, &errstr);
281 	if (errstr != NULL)
282 		return (NULL);
283 	return (window_find_by_id(id));
284 }
285 
286 struct window *
287 window_find_by_id(u_int id)
288 {
289 	struct window	w;
290 
291 	w.id = id;
292 	return (RB_FIND(windows, &windows, &w));
293 }
294 
295 void
296 window_update_activity(struct window *w)
297 {
298 	gettimeofday(&w->activity_time, NULL);
299 	alerts_queue(w, WINDOW_ACTIVITY);
300 }
301 
302 struct window *
303 window_create(u_int sx, u_int sy)
304 {
305 	struct window	*w;
306 
307 	w = xcalloc(1, sizeof *w);
308 	w->name = NULL;
309 	w->flags = WINDOW_STYLECHANGED;
310 
311 	TAILQ_INIT(&w->panes);
312 	w->active = NULL;
313 
314 	w->lastlayout = -1;
315 	w->layout_root = NULL;
316 
317 	w->sx = sx;
318 	w->sy = sy;
319 
320 	w->options = options_create(global_w_options);
321 
322 	w->references = 0;
323 	TAILQ_INIT(&w->winlinks);
324 
325 	w->id = next_window_id++;
326 	RB_INSERT(windows, &windows, w);
327 
328 	window_update_activity(w);
329 
330 	return (w);
331 }
332 
333 struct window *
334 window_create_spawn(const char *name, int argc, char **argv, const char *path,
335     const char *shell, const char *cwd, struct environ *env,
336     struct termios *tio, u_int sx, u_int sy, u_int hlimit, char **cause)
337 {
338 	struct window		*w;
339 	struct window_pane	*wp;
340 
341 	w = window_create(sx, sy);
342 	wp = window_add_pane(w, NULL, 0, hlimit);
343 	layout_init(w, wp);
344 
345 	if (window_pane_spawn(wp, argc, argv, path, shell, cwd,
346 	    env, tio, cause) != 0) {
347 		window_destroy(w);
348 		return (NULL);
349 	}
350 
351 	w->active = TAILQ_FIRST(&w->panes);
352 	if (name != NULL) {
353 		w->name = xstrdup(name);
354 		options_set_number(w->options, "automatic-rename", 0);
355 	} else
356 		w->name = default_window_name(w);
357 
358 	notify_window("window-pane-changed", w);
359 
360 	return (w);
361 }
362 
363 static void
364 window_destroy(struct window *w)
365 {
366 	log_debug("window @%u destroyed (%d references)", w->id, w->references);
367 
368 	RB_REMOVE(windows, &windows, w);
369 
370 	if (w->layout_root != NULL)
371 		layout_free_cell(w->layout_root);
372 	if (w->saved_layout_root != NULL)
373 		layout_free_cell(w->saved_layout_root);
374 	free(w->old_layout);
375 
376 	if (event_initialized(&w->name_event))
377 		evtimer_del(&w->name_event);
378 
379 	if (event_initialized(&w->alerts_timer))
380 		evtimer_del(&w->alerts_timer);
381 
382 	options_free(w->options);
383 
384 	window_destroy_panes(w);
385 
386 	free(w->name);
387 	free(w);
388 }
389 
390 int
391 window_pane_destroy_ready(struct window_pane *wp)
392 {
393 	int	n;
394 
395 	if (wp->pipe_fd != -1) {
396 		if (EVBUFFER_LENGTH(wp->pipe_event->output) != 0)
397 			return (0);
398 		if (ioctl(wp->fd, FIONREAD, &n) != -1 && n > 0)
399 			return (0);
400 	}
401 
402 	if (~wp->flags & PANE_EXITED)
403 		return (0);
404 	return (1);
405 }
406 
407 void
408 window_add_ref(struct window *w, const char *from)
409 {
410 	w->references++;
411 	log_debug("%s: @%u %s, now %d", __func__, w->id, from, w->references);
412 }
413 
414 void
415 window_remove_ref(struct window *w, const char *from)
416 {
417 	w->references--;
418 	log_debug("%s: @%u %s, now %d", __func__, w->id, from, w->references);
419 
420 	if (w->references == 0)
421 		window_destroy(w);
422 }
423 
424 void
425 window_set_name(struct window *w, const char *new_name)
426 {
427 	free(w->name);
428 	utf8_stravis(&w->name, new_name, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
429 	notify_window("window-renamed", w);
430 }
431 
432 void
433 window_resize(struct window *w, u_int sx, u_int sy)
434 {
435 	w->sx = sx;
436 	w->sy = sy;
437 }
438 
439 int
440 window_has_pane(struct window *w, struct window_pane *wp)
441 {
442 	struct window_pane	*wp1;
443 
444 	TAILQ_FOREACH(wp1, &w->panes, entry) {
445 		if (wp1 == wp)
446 			return (1);
447 	}
448 	return (0);
449 }
450 
451 int
452 window_set_active_pane(struct window *w, struct window_pane *wp)
453 {
454 	log_debug("%s: pane %%%u (was %%%u)", __func__, wp->id, w->active->id);
455 	if (wp == w->active)
456 		return (0);
457 	w->last = w->active;
458 	w->active = wp;
459 	while (!window_pane_visible(w->active)) {
460 		w->active = TAILQ_PREV(w->active, window_panes, entry);
461 		if (w->active == NULL)
462 			w->active = TAILQ_LAST(&w->panes, window_panes);
463 		if (w->active == wp) {
464 			notify_window("window-pane-changed", w);
465 			return (1);
466 		}
467 	}
468 	w->active->active_point = next_active_point++;
469 	w->active->flags |= PANE_CHANGED;
470 	notify_window("window-pane-changed", w);
471 	return (1);
472 }
473 
474 void
475 window_redraw_active_switch(struct window *w, struct window_pane *wp)
476 {
477 	const struct grid_cell	*gc;
478 
479 	if (wp == w->active)
480 		return;
481 
482 	/*
483 	 * If window-style and window-active-style are the same, we don't need
484 	 * to redraw panes when switching active panes.
485 	 */
486 	gc = options_get_style(w->options, "window-active-style");
487 	if (style_equal(gc, options_get_style(w->options, "window-style")))
488 		return;
489 
490 	/*
491 	 * If the now active or inactive pane do not have a custom style or if
492 	 * the palette is different, they need to be redrawn.
493 	 */
494 	if (window_pane_get_palette(w->active, w->active->colgc.fg) != -1 ||
495 	    window_pane_get_palette(w->active, w->active->colgc.bg) != -1 ||
496 	    style_equal(&grid_default_cell, &w->active->colgc))
497 		w->active->flags |= PANE_REDRAW;
498 	if (window_pane_get_palette(wp, wp->colgc.fg) != -1 ||
499 	    window_pane_get_palette(wp, wp->colgc.bg) != -1 ||
500 	    style_equal(&grid_default_cell, &wp->colgc))
501 		wp->flags |= PANE_REDRAW;
502 }
503 
504 struct window_pane *
505 window_get_active_at(struct window *w, u_int x, u_int y)
506 {
507 	struct window_pane	*wp;
508 
509 	TAILQ_FOREACH(wp, &w->panes, entry) {
510 		if (!window_pane_visible(wp))
511 			continue;
512 		if (x < wp->xoff || x > wp->xoff + wp->sx)
513 			continue;
514 		if (y < wp->yoff || y > wp->yoff + wp->sy)
515 			continue;
516 		return (wp);
517 	}
518 	return (NULL);
519 }
520 
521 struct window_pane *
522 window_find_string(struct window *w, const char *s)
523 {
524 	u_int	x, y;
525 
526 	x = w->sx / 2;
527 	y = w->sy / 2;
528 
529 	if (strcasecmp(s, "top") == 0)
530 		y = 0;
531 	else if (strcasecmp(s, "bottom") == 0)
532 		y = w->sy - 1;
533 	else if (strcasecmp(s, "left") == 0)
534 		x = 0;
535 	else if (strcasecmp(s, "right") == 0)
536 		x = w->sx - 1;
537 	else if (strcasecmp(s, "top-left") == 0) {
538 		x = 0;
539 		y = 0;
540 	} else if (strcasecmp(s, "top-right") == 0) {
541 		x = w->sx - 1;
542 		y = 0;
543 	} else if (strcasecmp(s, "bottom-left") == 0) {
544 		x = 0;
545 		y = w->sy - 1;
546 	} else if (strcasecmp(s, "bottom-right") == 0) {
547 		x = w->sx - 1;
548 		y = w->sy - 1;
549 	} else
550 		return (NULL);
551 
552 	return (window_get_active_at(w, x, y));
553 }
554 
555 int
556 window_zoom(struct window_pane *wp)
557 {
558 	struct window		*w = wp->window;
559 	struct window_pane	*wp1;
560 
561 	if (w->flags & WINDOW_ZOOMED)
562 		return (-1);
563 
564 	if (!window_pane_visible(wp))
565 		return (-1);
566 
567 	if (window_count_panes(w) == 1)
568 		return (-1);
569 
570 	if (w->active != wp)
571 		window_set_active_pane(w, wp);
572 
573 	TAILQ_FOREACH(wp1, &w->panes, entry) {
574 		wp1->saved_layout_cell = wp1->layout_cell;
575 		wp1->layout_cell = NULL;
576 	}
577 
578 	w->saved_layout_root = w->layout_root;
579 	layout_init(w, wp);
580 	w->flags |= WINDOW_ZOOMED;
581 	notify_window("window-layout-changed", w);
582 
583 	return (0);
584 }
585 
586 int
587 window_unzoom(struct window *w)
588 {
589 	struct window_pane	*wp;
590 
591 	if (!(w->flags & WINDOW_ZOOMED))
592 		return (-1);
593 
594 	w->flags &= ~WINDOW_ZOOMED;
595 	layout_free(w);
596 	w->layout_root = w->saved_layout_root;
597 	w->saved_layout_root = NULL;
598 
599 	TAILQ_FOREACH(wp, &w->panes, entry) {
600 		wp->layout_cell = wp->saved_layout_cell;
601 		wp->saved_layout_cell = NULL;
602 	}
603 	layout_fix_panes(w, w->sx, w->sy);
604 	notify_window("window-layout-changed", w);
605 
606 	return (0);
607 }
608 
609 struct window_pane *
610 window_add_pane(struct window *w, struct window_pane *other, int before,
611     u_int hlimit)
612 {
613 	struct window_pane	*wp;
614 
615 	if (other == NULL)
616 		other = w->active;
617 
618 	wp = window_pane_create(w, w->sx, w->sy, hlimit);
619 	if (TAILQ_EMPTY(&w->panes)) {
620 		log_debug("%s: @%u at start", __func__, w->id);
621 		TAILQ_INSERT_HEAD(&w->panes, wp, entry);
622 	} else if (before) {
623 		log_debug("%s: @%u before %%%u", __func__, w->id, wp->id);
624 		TAILQ_INSERT_BEFORE(other, wp, entry);
625 	} else {
626 		log_debug("%s: @%u after %%%u", __func__, w->id, wp->id);
627 		TAILQ_INSERT_AFTER(&w->panes, other, wp, entry);
628 	}
629 	return (wp);
630 }
631 
632 void
633 window_lost_pane(struct window *w, struct window_pane *wp)
634 {
635 	log_debug("%s: @%u pane %%%u", __func__, w->id, wp->id);
636 
637 	if (wp == marked_pane.wp)
638 		server_clear_marked();
639 
640 	if (wp == w->active) {
641 		w->active = w->last;
642 		w->last = NULL;
643 		if (w->active == NULL) {
644 			w->active = TAILQ_PREV(wp, window_panes, entry);
645 			if (w->active == NULL)
646 				w->active = TAILQ_NEXT(wp, entry);
647 		}
648 		if (w->active != NULL) {
649 			w->active->flags |= PANE_CHANGED;
650 			notify_window("window-pane-changed", w);
651 		}
652 	} else if (wp == w->last)
653 		w->last = NULL;
654 }
655 
656 void
657 window_remove_pane(struct window *w, struct window_pane *wp)
658 {
659 	window_lost_pane(w, wp);
660 
661 	TAILQ_REMOVE(&w->panes, wp, entry);
662 	window_pane_destroy(wp);
663 }
664 
665 struct window_pane *
666 window_pane_at_index(struct window *w, u_int idx)
667 {
668 	struct window_pane	*wp;
669 	u_int			 n;
670 
671 	n = options_get_number(w->options, "pane-base-index");
672 	TAILQ_FOREACH(wp, &w->panes, entry) {
673 		if (n == idx)
674 			return (wp);
675 		n++;
676 	}
677 	return (NULL);
678 }
679 
680 struct window_pane *
681 window_pane_next_by_number(struct window *w, struct window_pane *wp, u_int n)
682 {
683 	for (; n > 0; n--) {
684 		if ((wp = TAILQ_NEXT(wp, entry)) == NULL)
685 			wp = TAILQ_FIRST(&w->panes);
686 	}
687 
688 	return (wp);
689 }
690 
691 struct window_pane *
692 window_pane_previous_by_number(struct window *w, struct window_pane *wp,
693     u_int n)
694 {
695 	for (; n > 0; n--) {
696 		if ((wp = TAILQ_PREV(wp, window_panes, entry)) == NULL)
697 			wp = TAILQ_LAST(&w->panes, window_panes);
698 	}
699 
700 	return (wp);
701 }
702 
703 int
704 window_pane_index(struct window_pane *wp, u_int *i)
705 {
706 	struct window_pane	*wq;
707 	struct window		*w = wp->window;
708 
709 	*i = options_get_number(w->options, "pane-base-index");
710 	TAILQ_FOREACH(wq, &w->panes, entry) {
711 		if (wp == wq) {
712 			return (0);
713 		}
714 		(*i)++;
715 	}
716 
717 	return (-1);
718 }
719 
720 u_int
721 window_count_panes(struct window *w)
722 {
723 	struct window_pane	*wp;
724 	u_int			 n;
725 
726 	n = 0;
727 	TAILQ_FOREACH(wp, &w->panes, entry)
728 		n++;
729 	return (n);
730 }
731 
732 void
733 window_destroy_panes(struct window *w)
734 {
735 	struct window_pane	*wp;
736 
737 	while (!TAILQ_EMPTY(&w->panes)) {
738 		wp = TAILQ_FIRST(&w->panes);
739 		TAILQ_REMOVE(&w->panes, wp, entry);
740 		window_pane_destroy(wp);
741 	}
742 }
743 
744 const char *
745 window_printable_flags(struct winlink *wl)
746 {
747 	struct session	*s = wl->session;
748 	static char	 flags[32];
749 	int		 pos;
750 
751 	pos = 0;
752 	if (wl->flags & WINLINK_ACTIVITY)
753 		flags[pos++] = '#';
754 	if (wl->flags & WINLINK_BELL)
755 		flags[pos++] = '!';
756 	if (wl->flags & WINLINK_SILENCE)
757 		flags[pos++] = '~';
758 	if (wl == s->curw)
759 		flags[pos++] = '*';
760 	if (wl == TAILQ_FIRST(&s->lastw))
761 		flags[pos++] = '-';
762 	if (server_check_marked() && wl == marked_pane.wl)
763 		flags[pos++] = 'M';
764 	if (wl->window->flags & WINDOW_ZOOMED)
765 		flags[pos++] = 'Z';
766 	flags[pos] = '\0';
767 	return (flags);
768 }
769 
770 struct window_pane *
771 window_pane_find_by_id_str(const char *s)
772 {
773 	const char	*errstr;
774 	u_int		 id;
775 
776 	if (*s != '%')
777 		return (NULL);
778 
779 	id = strtonum(s + 1, 0, UINT_MAX, &errstr);
780 	if (errstr != NULL)
781 		return (NULL);
782 	return (window_pane_find_by_id(id));
783 }
784 
785 struct window_pane *
786 window_pane_find_by_id(u_int id)
787 {
788 	struct window_pane	wp;
789 
790 	wp.id = id;
791 	return (RB_FIND(window_pane_tree, &all_window_panes, &wp));
792 }
793 
794 static struct window_pane *
795 window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
796 {
797 	struct window_pane	*wp;
798 	char			 host[HOST_NAME_MAX + 1];
799 
800 	wp = xcalloc(1, sizeof *wp);
801 	wp->window = w;
802 
803 	wp->id = next_window_pane_id++;
804 	RB_INSERT(window_pane_tree, &all_window_panes, wp);
805 
806 	wp->argc = 0;
807 	wp->argv = NULL;
808 	wp->shell = NULL;
809 	wp->cwd = NULL;
810 
811 	wp->fd = -1;
812 	wp->event = NULL;
813 
814 	wp->mode = NULL;
815 	wp->modeprefix = 1;
816 
817 	wp->layout_cell = NULL;
818 
819 	wp->xoff = 0;
820 	wp->yoff = 0;
821 
822 	wp->sx = wp->osx = sx;
823 	wp->sy = wp->osx = sy;
824 
825 	wp->pipe_fd = -1;
826 	wp->pipe_off = 0;
827 	wp->pipe_event = NULL;
828 
829 	wp->saved_grid = NULL;
830 
831 	memcpy(&wp->colgc, &grid_default_cell, sizeof wp->colgc);
832 
833 	screen_init(&wp->base, sx, sy, hlimit);
834 	wp->screen = &wp->base;
835 
836 	screen_init(&wp->status_screen, 1, 1, 0);
837 
838 	if (gethostname(host, sizeof host) == 0)
839 		screen_set_title(&wp->base, host);
840 
841 	input_init(wp);
842 
843 	return (wp);
844 }
845 
846 static void
847 window_pane_destroy(struct window_pane *wp)
848 {
849 	window_pane_reset_mode(wp);
850 	free(wp->searchstr);
851 
852 	if (wp->fd != -1) {
853 #ifdef HAVE_UTEMPTER
854 		utempter_remove_record(wp->fd);
855 #endif
856 		bufferevent_free(wp->event);
857 		close(wp->fd);
858 	}
859 
860 	input_free(wp);
861 
862 	screen_free(&wp->base);
863 	if (wp->saved_grid != NULL)
864 		grid_destroy(wp->saved_grid);
865 
866 	if (wp->pipe_fd != -1) {
867 		bufferevent_free(wp->pipe_event);
868 		close(wp->pipe_fd);
869 	}
870 
871 	if (event_initialized(&wp->resize_timer))
872 		event_del(&wp->resize_timer);
873 
874 	RB_REMOVE(window_pane_tree, &all_window_panes, wp);
875 
876 	free(__UNCONST(wp->cwd));
877 	free(wp->shell);
878 	cmd_free_argv(wp->argc, wp->argv);
879 	free(wp->palette);
880 	free(wp);
881 }
882 
883 int
884 window_pane_spawn(struct window_pane *wp, int argc, char **argv,
885     const char *path, const char *shell, const char *cwd, struct environ *env,
886     struct termios *tio, char **cause)
887 {
888 	struct winsize	 ws;
889 	char		*argv0, *cmd, **argvp;
890 	const char	*ptr, *first, *home;
891 	struct termios	 tio2;
892 #ifdef HAVE_UTEMPTER
893 	char		 s[32];
894 #endif
895 	int		 i;
896 	sigset_t	 set, oldset;
897 
898 	if (wp->fd != -1) {
899 		bufferevent_free(wp->event);
900 		close(wp->fd);
901 	}
902 	if (argc > 0) {
903 		cmd_free_argv(wp->argc, wp->argv);
904 		wp->argc = argc;
905 		wp->argv = cmd_copy_argv(argc, argv);
906 	}
907 	if (shell != NULL) {
908 		free(wp->shell);
909 		wp->shell = xstrdup(shell);
910 	}
911 	if (cwd != NULL) {
912 		free(__UNCONST(wp->cwd));
913 		wp->cwd = xstrdup(cwd);
914 	}
915 
916 	cmd = cmd_stringify_argv(wp->argc, wp->argv);
917 	log_debug("spawn: %s -- %s", wp->shell, cmd);
918 	for (i = 0; i < wp->argc; i++)
919 		log_debug("spawn: argv[%d] = %s", i, wp->argv[i]);
920 	environ_log(env, "spawn: ");
921 
922 	memset(&ws, 0, sizeof ws);
923 	ws.ws_col = screen_size_x(&wp->base);
924 	ws.ws_row = screen_size_y(&wp->base);
925 
926 	sigfillset(&set);
927 	sigprocmask(SIG_BLOCK, &set, &oldset);
928 	switch (wp->pid = fdforkpty(ptm_fd, &wp->fd, wp->tty, NULL, &ws)) {
929 	case -1:
930 		wp->fd = -1;
931 
932 		xasprintf(cause, "%s: %s", cmd, strerror(errno));
933 		free(cmd);
934 
935 		sigprocmask(SIG_SETMASK, &oldset, NULL);
936 		return (-1);
937 	case 0:
938 		proc_clear_signals(server_proc, 1);
939 		sigprocmask(SIG_SETMASK, &oldset, NULL);
940 
941 		if (chdir(wp->cwd) != 0) {
942 			if ((home = find_home()) == NULL || chdir(home) != 0)
943 				chdir("/");
944 		}
945 
946 		if (tcgetattr(STDIN_FILENO, &tio2) != 0)
947 			fatal("tcgetattr failed");
948 		if (tio != NULL)
949 			memcpy(tio2.c_cc, tio->c_cc, sizeof tio2.c_cc);
950 		tio2.c_cc[VERASE] = '\177';
951 #ifdef IUTF8
952 		tio2.c_iflag |= IUTF8;
953 #endif
954 		if (tcsetattr(STDIN_FILENO, TCSANOW, &tio2) != 0)
955 			fatal("tcgetattr failed");
956 
957 		log_close();
958 		closefrom(STDERR_FILENO + 1);
959 
960 		if (path != NULL)
961 			environ_set(env, "PATH", "%s", path);
962 		environ_set(env, "TMUX_PANE", "%%%u", wp->id);
963 		environ_push(env);
964 
965 		setenv("SHELL", wp->shell, 1);
966 		ptr = strrchr(wp->shell, '/');
967 
968 		/*
969 		 * If given one argument, assume it should be passed to sh -c;
970 		 * with more than one argument, use execvp(). If there is no
971 		 * arguments, create a login shell.
972 		 */
973 		if (wp->argc > 0) {
974 			if (wp->argc != 1) {
975 				/* Copy to ensure argv ends in NULL. */
976 				argvp = cmd_copy_argv(wp->argc, wp->argv);
977 				execvp(argvp[0], argvp);
978 				fatal("execvp failed");
979 			}
980 			first = wp->argv[0];
981 
982 			if (ptr != NULL && *(ptr + 1) != '\0')
983 				xasprintf(&argv0, "%s", ptr + 1);
984 			else
985 				xasprintf(&argv0, "%s", wp->shell);
986 			execl(wp->shell, argv0, "-c", first, (char *)NULL);
987 			fatal("execl failed");
988 		}
989 		if (ptr != NULL && *(ptr + 1) != '\0')
990 			xasprintf(&argv0, "-%s", ptr + 1);
991 		else
992 			xasprintf(&argv0, "-%s", wp->shell);
993 		execl(wp->shell, argv0, (char *)NULL);
994 		fatal("execl failed");
995 	}
996 
997 #ifdef HAVE_UTEMPTER
998 	xsnprintf(s, sizeof s, "tmux(%lu).%%%u", (long) getpid(), wp->id);
999 	utempter_add_record(wp->fd, s);
1000 	kill(getpid(), SIGCHLD);
1001 #endif
1002 
1003 	sigprocmask(SIG_SETMASK, &oldset, NULL);
1004 	setblocking(wp->fd, 0);
1005 
1006 	wp->event = bufferevent_new(wp->fd, window_pane_read_callback, NULL,
1007 	    window_pane_error_callback, wp);
1008 
1009 	bufferevent_setwatermark(wp->event, EV_READ, 0, READ_SIZE);
1010 	bufferevent_enable(wp->event, EV_READ|EV_WRITE);
1011 
1012 	free(cmd);
1013 	return (0);
1014 }
1015 
1016 static void
1017 window_pane_read_callback(__unused struct bufferevent *bufev, void *data)
1018 {
1019 	struct window_pane	*wp = data;
1020 	struct evbuffer		*evb = wp->event->input;
1021 	size_t			 size = EVBUFFER_LENGTH(evb);
1022 	char			*new_data;
1023 	size_t			 new_size;
1024 
1025 
1026 	new_size = size - wp->pipe_off;
1027 	if (wp->pipe_fd != -1 && new_size > 0) {
1028 		new_data = (char *)EVBUFFER_DATA(evb) + wp->pipe_off;
1029 		bufferevent_write(wp->pipe_event, new_data, new_size);
1030 	}
1031 
1032 	log_debug("%%%u has %zu bytes", wp->id, size);
1033 	input_parse(wp);
1034 
1035 	wp->pipe_off = EVBUFFER_LENGTH(evb);
1036 }
1037 
1038 static void
1039 window_pane_error_callback(__unused struct bufferevent *bufev,
1040     __unused short what, void *data)
1041 {
1042 	struct window_pane *wp = data;
1043 
1044 	log_debug("%%%u error", wp->id);
1045 	wp->flags |= PANE_EXITED;
1046 
1047 	if (window_pane_destroy_ready(wp))
1048 		server_destroy_pane(wp, 1);
1049 }
1050 
1051 void
1052 window_pane_resize(struct window_pane *wp, u_int sx, u_int sy)
1053 {
1054 	if (sx == wp->sx && sy == wp->sy)
1055 		return;
1056 	wp->sx = sx;
1057 	wp->sy = sy;
1058 
1059 	screen_resize(&wp->base, sx, sy, wp->saved_grid == NULL);
1060 	if (wp->mode != NULL)
1061 		wp->mode->resize(wp, sx, sy);
1062 
1063 	wp->flags |= PANE_RESIZE;
1064 }
1065 
1066 /*
1067  * Enter alternative screen mode. A copy of the visible screen is saved and the
1068  * history is not updated
1069  */
1070 void
1071 window_pane_alternate_on(struct window_pane *wp, struct grid_cell *gc,
1072     int cursor)
1073 {
1074 	struct screen	*s = &wp->base;
1075 	u_int		 sx, sy;
1076 
1077 	if (wp->saved_grid != NULL)
1078 		return;
1079 	if (!options_get_number(wp->window->options, "alternate-screen"))
1080 		return;
1081 	sx = screen_size_x(s);
1082 	sy = screen_size_y(s);
1083 
1084 	wp->saved_grid = grid_create(sx, sy, 0);
1085 	grid_duplicate_lines(wp->saved_grid, 0, s->grid, screen_hsize(s), sy);
1086 	if (cursor) {
1087 		wp->saved_cx = s->cx;
1088 		wp->saved_cy = s->cy;
1089 	}
1090 	memcpy(&wp->saved_cell, gc, sizeof wp->saved_cell);
1091 
1092 	grid_view_clear(s->grid, 0, 0, sx, sy, 8);
1093 
1094 	wp->base.grid->flags &= ~GRID_HISTORY;
1095 
1096 	wp->flags |= PANE_REDRAW;
1097 }
1098 
1099 /* Exit alternate screen mode and restore the copied grid. */
1100 void
1101 window_pane_alternate_off(struct window_pane *wp, struct grid_cell *gc,
1102     int cursor)
1103 {
1104 	struct screen	*s = &wp->base;
1105 	u_int		 sx, sy;
1106 
1107 	if (wp->saved_grid == NULL)
1108 		return;
1109 	if (!options_get_number(wp->window->options, "alternate-screen"))
1110 		return;
1111 	sx = screen_size_x(s);
1112 	sy = screen_size_y(s);
1113 
1114 	/*
1115 	 * If the current size is bigger, temporarily resize to the old size
1116 	 * before copying back.
1117 	 */
1118 	if (sy > wp->saved_grid->sy)
1119 		screen_resize(s, sx, wp->saved_grid->sy, 1);
1120 
1121 	/* Restore the grid, cursor position and cell. */
1122 	grid_duplicate_lines(s->grid, screen_hsize(s), wp->saved_grid, 0, sy);
1123 	if (cursor)
1124 		s->cx = wp->saved_cx;
1125 	if (s->cx > screen_size_x(s) - 1)
1126 		s->cx = screen_size_x(s) - 1;
1127 	if (cursor)
1128 		s->cy = wp->saved_cy;
1129 	if (s->cy > screen_size_y(s) - 1)
1130 		s->cy = screen_size_y(s) - 1;
1131 	memcpy(gc, &wp->saved_cell, sizeof *gc);
1132 
1133 	/*
1134 	 * Turn history back on (so resize can use it) and then resize back to
1135 	 * the current size.
1136 	 */
1137 	wp->base.grid->flags |= GRID_HISTORY;
1138 	if (sy > wp->saved_grid->sy || sx != wp->saved_grid->sx)
1139 		screen_resize(s, sx, sy, 1);
1140 
1141 	grid_destroy(wp->saved_grid);
1142 	wp->saved_grid = NULL;
1143 
1144 	wp->flags |= PANE_REDRAW;
1145 }
1146 
1147 void
1148 window_pane_set_palette(struct window_pane *wp, u_int n, int colour)
1149 {
1150 	if (n > 0xff)
1151 		return;
1152 
1153 	if (wp->palette == NULL)
1154 		wp->palette = xcalloc(0x100, sizeof *wp->palette);
1155 
1156 	wp->palette[n] = colour;
1157 	wp->flags |= PANE_REDRAW;
1158 }
1159 
1160 void
1161 window_pane_unset_palette(struct window_pane *wp, u_int n)
1162 {
1163 	if (n > 0xff || wp->palette == NULL)
1164 		return;
1165 
1166 	wp->palette[n] = 0;
1167 	wp->flags |= PANE_REDRAW;
1168 }
1169 
1170 void
1171 window_pane_reset_palette(struct window_pane *wp)
1172 {
1173 	if (wp->palette == NULL)
1174 		return;
1175 
1176 	free(wp->palette);
1177 	wp->palette = NULL;
1178 	wp->flags |= PANE_REDRAW;
1179 }
1180 
1181 int
1182 window_pane_get_palette(const struct window_pane *wp, int c)
1183 {
1184 	int	new;
1185 
1186 	if (wp == NULL || wp->palette == NULL)
1187 		return (-1);
1188 
1189 	new = -1;
1190 	if (c < 8)
1191 		new = wp->palette[c];
1192 	else if (c >= 90 && c <= 97)
1193 		new = wp->palette[8 + c - 90];
1194 	else if (c & COLOUR_FLAG_256)
1195 		new = wp->palette[c & ~COLOUR_FLAG_256];
1196 	if (new == 0)
1197 		return (-1);
1198 	return (new);
1199 }
1200 
1201 static void
1202 window_pane_mode_timer(__unused int fd, __unused short events, void *arg)
1203 {
1204 	struct window_pane	*wp = arg;
1205 	struct timeval		 tv = { .tv_sec = 10 };
1206 	int			 n = 0;
1207 
1208 	evtimer_del(&wp->modetimer);
1209 	evtimer_add(&wp->modetimer, &tv);
1210 
1211 	log_debug("%%%u in mode: last=%ld", wp->id, (long)wp->modelast);
1212 
1213 	if (wp->modelast < time(NULL) - WINDOW_MODE_TIMEOUT) {
1214 		if (ioctl(wp->fd, FIONREAD, &n) == -1 || n > 0)
1215 			window_pane_reset_mode(wp);
1216 	}
1217 }
1218 
1219 int
1220 window_pane_set_mode(struct window_pane *wp, const struct window_mode *mode,
1221     struct cmd_find_state *fs, struct args *args)
1222 {
1223 	struct screen	*s;
1224 	struct timeval	 tv = { .tv_sec = 10 };
1225 
1226 	if (wp->mode != NULL)
1227 		return (1);
1228 	wp->mode = mode;
1229 
1230 	wp->modelast = time(NULL);
1231 	evtimer_set(&wp->modetimer, window_pane_mode_timer, wp);
1232 	evtimer_add(&wp->modetimer, &tv);
1233 
1234 	if ((s = wp->mode->init(wp, fs, args)) != NULL)
1235 		wp->screen = s;
1236 	wp->flags |= (PANE_REDRAW|PANE_CHANGED);
1237 
1238 	server_status_window(wp->window);
1239 	notify_pane("pane-mode-changed", wp);
1240 	return (0);
1241 }
1242 
1243 void
1244 window_pane_reset_mode(struct window_pane *wp)
1245 {
1246 	if (wp->mode == NULL)
1247 		return;
1248 
1249 	evtimer_del(&wp->modetimer);
1250 
1251 	wp->mode->free(wp);
1252 	wp->mode = NULL;
1253 	wp->modeprefix = 1;
1254 
1255 	wp->screen = &wp->base;
1256 	wp->flags |= (PANE_REDRAW|PANE_CHANGED);
1257 
1258 	server_status_window(wp->window);
1259 	notify_pane("pane-mode-changed", wp);
1260 }
1261 
1262 void
1263 window_pane_key(struct window_pane *wp, struct client *c, struct session *s,
1264     key_code key, struct mouse_event *m)
1265 {
1266 	struct window_pane	*wp2;
1267 
1268 	if (KEYC_IS_MOUSE(key) && m == NULL)
1269 		return;
1270 
1271 	if (wp->mode != NULL) {
1272 		wp->modelast = time(NULL);
1273 		if (wp->mode->key != NULL)
1274 			wp->mode->key(wp, c, s, (key & ~KEYC_XTERM), m);
1275 		return;
1276 	}
1277 
1278 	if (wp->fd == -1 || wp->flags & PANE_INPUTOFF)
1279 		return;
1280 
1281 	input_key(wp, key, m);
1282 
1283 	if (KEYC_IS_MOUSE(key))
1284 		return;
1285 	if (options_get_number(wp->window->options, "synchronize-panes")) {
1286 		TAILQ_FOREACH(wp2, &wp->window->panes, entry) {
1287 			if (wp2 == wp || wp2->mode != NULL)
1288 				continue;
1289 			if (wp2->fd == -1 || wp2->flags & PANE_INPUTOFF)
1290 				continue;
1291 			if (window_pane_visible(wp2))
1292 				input_key(wp2, key, NULL);
1293 		}
1294 	}
1295 }
1296 
1297 int
1298 window_pane_visible(struct window_pane *wp)
1299 {
1300 	struct window	*w = wp->window;
1301 
1302 	if (wp->layout_cell == NULL)
1303 		return (0);
1304 
1305 	if (wp->xoff >= w->sx || wp->yoff >= w->sy)
1306 		return (0);
1307 	if (wp->xoff + wp->sx > w->sx || wp->yoff + wp->sy > w->sy)
1308 		return (0);
1309 	return (1);
1310 }
1311 
1312 u_int
1313 window_pane_search(struct window_pane *wp, const char *searchstr)
1314 {
1315 	struct screen	*s = &wp->base;
1316 	char		*newsearchstr, *line;
1317 	u_int		 i;
1318 
1319 	xasprintf(&newsearchstr, "*%s*", searchstr);
1320 
1321 	for (i = 0; i < screen_size_y(s); i++) {
1322 		line = grid_view_string_cells(s->grid, 0, i, screen_size_x(s));
1323 		if (fnmatch(newsearchstr, line, 0) == 0) {
1324 			free(line);
1325 			break;
1326 		}
1327 		free(line);
1328 	}
1329 
1330 	free(newsearchstr);
1331 	if (i == screen_size_y(s))
1332 		return (0);
1333 	return (i + 1);
1334 }
1335 
1336 /* Get MRU pane from a list. */
1337 static struct window_pane *
1338 window_pane_choose_best(struct window_pane **list, u_int size)
1339 {
1340 	struct window_pane	*next, *best;
1341 	u_int			 i;
1342 
1343 	if (size == 0)
1344 		return (NULL);
1345 
1346 	best = list[0];
1347 	for (i = 1; i < size; i++) {
1348 		next = list[i];
1349 		if (next->active_point > best->active_point)
1350 			best = next;
1351 	}
1352 	return (best);
1353 }
1354 
1355 /*
1356  * Find the pane directly above another. We build a list of those adjacent to
1357  * top edge and then choose the best.
1358  */
1359 struct window_pane *
1360 window_pane_find_up(struct window_pane *wp)
1361 {
1362 	struct window_pane	*next, *best, **list;
1363 	u_int			 edge, left, right, end, size;
1364 	int			 status, found;
1365 
1366 	if (wp == NULL || !window_pane_visible(wp))
1367 		return (NULL);
1368 	status = options_get_number(wp->window->options, "pane-border-status");
1369 
1370 	list = NULL;
1371 	size = 0;
1372 
1373 	edge = wp->yoff;
1374 	if (edge == (status == 1 ? 1 : 0))
1375 		edge = wp->window->sy + 1 - (status == 2 ? 1 : 0);
1376 
1377 	left = wp->xoff;
1378 	right = wp->xoff + wp->sx;
1379 
1380 	TAILQ_FOREACH(next, &wp->window->panes, entry) {
1381 		if (next == wp || !window_pane_visible(next))
1382 			continue;
1383 		if (next->yoff + next->sy + 1 != edge)
1384 			continue;
1385 		end = next->xoff + next->sx - 1;
1386 
1387 		found = 0;
1388 		if (next->xoff < left && end > right)
1389 			found = 1;
1390 		else if (next->xoff >= left && next->xoff <= right)
1391 			found = 1;
1392 		else if (end >= left && end <= right)
1393 			found = 1;
1394 		if (!found)
1395 			continue;
1396 		list = xreallocarray(list, size + 1, sizeof *list);
1397 		list[size++] = next;
1398 	}
1399 
1400 	best = window_pane_choose_best(list, size);
1401 	free(list);
1402 	return (best);
1403 }
1404 
1405 /* Find the pane directly below another. */
1406 struct window_pane *
1407 window_pane_find_down(struct window_pane *wp)
1408 {
1409 	struct window_pane	*next, *best, **list;
1410 	u_int			 edge, left, right, end, size;
1411 	int			 status, found;
1412 
1413 	if (wp == NULL || !window_pane_visible(wp))
1414 		return (NULL);
1415 	status = options_get_number(wp->window->options, "pane-border-status");
1416 
1417 	list = NULL;
1418 	size = 0;
1419 
1420 	edge = wp->yoff + wp->sy + 1;
1421 	if (edge >= wp->window->sy - (status == 2 ? 1 : 0))
1422 		edge = (status == 1 ? 1 : 0);
1423 
1424 	left = wp->xoff;
1425 	right = wp->xoff + wp->sx;
1426 
1427 	TAILQ_FOREACH(next, &wp->window->panes, entry) {
1428 		if (next == wp || !window_pane_visible(next))
1429 			continue;
1430 		if (next->yoff != edge)
1431 			continue;
1432 		end = next->xoff + next->sx - 1;
1433 
1434 		found = 0;
1435 		if (next->xoff < left && end > right)
1436 			found = 1;
1437 		else if (next->xoff >= left && next->xoff <= right)
1438 			found = 1;
1439 		else if (end >= left && end <= right)
1440 			found = 1;
1441 		if (!found)
1442 			continue;
1443 		list = xreallocarray(list, size + 1, sizeof *list);
1444 		list[size++] = next;
1445 	}
1446 
1447 	best = window_pane_choose_best(list, size);
1448 	free(list);
1449 	return (best);
1450 }
1451 
1452 /* Find the pane directly to the left of another. */
1453 struct window_pane *
1454 window_pane_find_left(struct window_pane *wp)
1455 {
1456 	struct window_pane	*next, *best, **list;
1457 	u_int			 edge, top, bottom, end, size;
1458 	int			 found;
1459 
1460 	if (wp == NULL || !window_pane_visible(wp))
1461 		return (NULL);
1462 
1463 	list = NULL;
1464 	size = 0;
1465 
1466 	edge = wp->xoff;
1467 	if (edge == 0)
1468 		edge = wp->window->sx + 1;
1469 
1470 	top = wp->yoff;
1471 	bottom = wp->yoff + wp->sy;
1472 
1473 	TAILQ_FOREACH(next, &wp->window->panes, entry) {
1474 		if (next == wp || !window_pane_visible(next))
1475 			continue;
1476 		if (next->xoff + next->sx + 1 != edge)
1477 			continue;
1478 		end = next->yoff + next->sy - 1;
1479 
1480 		found = 0;
1481 		if (next->yoff < top && end > bottom)
1482 			found = 1;
1483 		else if (next->yoff >= top && next->yoff <= bottom)
1484 			found = 1;
1485 		else if (end >= top && end <= bottom)
1486 			found = 1;
1487 		if (!found)
1488 			continue;
1489 		list = xreallocarray(list, size + 1, sizeof *list);
1490 		list[size++] = next;
1491 	}
1492 
1493 	best = window_pane_choose_best(list, size);
1494 	free(list);
1495 	return (best);
1496 }
1497 
1498 /* Find the pane directly to the right of another. */
1499 struct window_pane *
1500 window_pane_find_right(struct window_pane *wp)
1501 {
1502 	struct window_pane	*next, *best, **list;
1503 	u_int			 edge, top, bottom, end, size;
1504 	int			 found;
1505 
1506 	if (wp == NULL || !window_pane_visible(wp))
1507 		return (NULL);
1508 
1509 	list = NULL;
1510 	size = 0;
1511 
1512 	edge = wp->xoff + wp->sx + 1;
1513 	if (edge >= wp->window->sx)
1514 		edge = 0;
1515 
1516 	top = wp->yoff;
1517 	bottom = wp->yoff + wp->sy;
1518 
1519 	TAILQ_FOREACH(next, &wp->window->panes, entry) {
1520 		if (next == wp || !window_pane_visible(next))
1521 			continue;
1522 		if (next->xoff != edge)
1523 			continue;
1524 		end = next->yoff + next->sy - 1;
1525 
1526 		found = 0;
1527 		if (next->yoff < top && end > bottom)
1528 			found = 1;
1529 		else if (next->yoff >= top && next->yoff <= bottom)
1530 			found = 1;
1531 		else if (end >= top && end <= bottom)
1532 			found = 1;
1533 		if (!found)
1534 			continue;
1535 		list = xreallocarray(list, size + 1, sizeof *list);
1536 		list[size++] = next;
1537 	}
1538 
1539 	best = window_pane_choose_best(list, size);
1540 	free(list);
1541 	return (best);
1542 }
1543 
1544 /* Clear alert flags for a winlink */
1545 void
1546 winlink_clear_flags(struct winlink *wl)
1547 {
1548 	struct winlink	*loop;
1549 
1550 	wl->window->flags &= ~WINDOW_ALERTFLAGS;
1551 	TAILQ_FOREACH(loop, &wl->window->winlinks, wentry) {
1552 		if ((loop->flags & WINLINK_ALERTFLAGS) != 0) {
1553 			loop->flags &= ~WINLINK_ALERTFLAGS;
1554 			server_status_session(loop->session);
1555 		}
1556 	}
1557 }
1558 
1559 /* Shuffle window indexes up. */
1560 int
1561 winlink_shuffle_up(struct session *s, struct winlink *wl)
1562 {
1563 	int	 idx, last;
1564 
1565 	idx = wl->idx + 1;
1566 
1567 	/* Find the next free index. */
1568 	for (last = idx; last < INT_MAX; last++) {
1569 		if (winlink_find_by_index(&s->windows, last) == NULL)
1570 			break;
1571 	}
1572 	if (last == INT_MAX)
1573 		return (-1);
1574 
1575 	/* Move everything from last - 1 to idx up a bit. */
1576 	for (; last > idx; last--) {
1577 		wl = winlink_find_by_index(&s->windows, last - 1);
1578 		server_link_window(s, wl, s, last, 0, 0, NULL);
1579 		server_unlink_window(s, wl);
1580 	}
1581 
1582 	return (idx);
1583 }
1584