session.c

   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/time.h>
  21
  22 #include <paths.h>
  23 #include <string.h>
  24 #include <stdlib.h>
  25 #include <unistd.h>
  26 #include <vis.h>
  27 #include <time.h>
  28
  29 #include "tmux.h"
  30
  31 struct sessions         sessions;
  32 u_int                   next_session_id;
  33 struct session_groups   session_groups = RB_INITIALIZER(&session_groups);
  34
  35 static void     session_free(int, short, void *);
  36
  37 static void     session_lock_timer(int, short, void *);
  38
  39 static struct winlink *session_next_alert(struct winlink *);
  40 static struct winlink *session_previous_alert(struct winlink *);
  41
  42 static void     session_group_remove(struct session *);
  43 static void     session_group_synchronize1(struct session *, struct session *);
  44
  45 int
  46 session_cmp(struct session *s1, struct session *s2)
  47 {
  48         return (strcmp(s1->name, s2->name));
  49 }
  50 RB_GENERATE(sessions, session, entry, session_cmp);
  51
  52 static int
  53 session_group_cmp(struct session_group *s1, struct session_group *s2)
  54 {
  55         return (strcmp(s1->name, s2->name));
  56 }
  57 RB_GENERATE_STATIC(session_groups, session_group, entry, session_group_cmp);
  58
  59 /*
  60  * Find if session is still alive. This is true if it is still on the global
  61  * sessions list.
  62  */
  63 int
  64 session_alive(struct session *s)
  65 {
  66         struct session *s_loop;
  67
  68         RB_FOREACH(s_loop, sessions, &sessions) {
  69                 if (s_loop == s)
  70                         return (1);
  71         }
  72         return (0);
  73 }
  74
  75 /* Find session by name. */
  76 struct session *
  77 session_find(const char *name)
  78 {
  79         struct session  s;
  80
  81         s.name = (char *) name;
  82         return (RB_FIND(sessions, &sessions, &s));
  83 }
  84
  85 /* Find session by id parsed from a string. */
  86 struct session *
  87 session_find_by_id_str(const char *s)
  88 {
  89         const char      *errstr;
  90         u_int            id;
  91
  92         if (*s != '$')
  93                 return (NULL);
  94
  95         id = strtonum(s + 1, 0, UINT_MAX, &errstr);
  96         if (errstr != NULL)
  97                 return (NULL);
  98         return (session_find_by_id(id));
  99 }
 100
 101 /* Find session by id. */
 102 struct session *
 103 session_find_by_id(u_int id)
 104 {
 105         struct session  *s;
 106
 107         RB_FOREACH(s, sessions, &sessions) {
 108                 if (s->id == id)
 109                         return (s);
 110         }
 111         return (NULL);
 112 }
 113
 114 /* Create a new session. */
 115 struct session *
 116 session_create(const char *prefix, const char *name, const char *cwd,
 117     struct environ *env, struct options *oo, struct termios *tio)
 118 {
 119         struct session  *s;
 120
 121         s = xcalloc(1, sizeof *s);
 122         s->references = 1;
 123         s->flags = 0;
 124
 125         s->cwd = xstrdup(cwd);
 126
 127         TAILQ_INIT(&s->lastw);
 128         RB_INIT(&s->windows);
 129
 130         s->environ = env;
 131         s->options = oo;
 132
 133         status_update_cache(s);
 134
 135         s->tio = NULL;
 136         if (tio != NULL) {
 137                 s->tio = xmalloc(sizeof *s->tio);
 138                 memcpy(s->tio, tio, sizeof *s->tio);
 139         }
 140
 141         if (name != NULL) {
 142                 s->name = xstrdup(name);
 143                 s->id = next_session_id++;
 144         } else {
 145                 do {
 146                         s->id = next_session_id++;
 147                         free(s->name);
 148                         if (prefix != NULL)
 149                                 xasprintf(&s->name, "%s-%u", prefix, s->id);
 150                         else
 151                                 xasprintf(&s->name, "%u", s->id);
 152                 } while (RB_FIND(sessions, &sessions, s) != NULL);
 153         }
 154         RB_INSERT(sessions, &sessions, s);
 155
 156         log_debug("new session %s $%u", s->name, s->id);
 157
 158         if (gettimeofday(&s->creation_time, NULL) != 0)
 159                 fatal("gettimeofday failed");
 160         session_update_activity(s, &s->creation_time);
 161
 162         return (s);
 163 }
 164
 165 /* Add a reference to a session. */
 166 void
 167 session_add_ref(struct session *s, const char *from)
 168 {
 169         s->references++;
 170         log_debug("%s: %s %s, now %d", __func__, s->name, from, s->references);
 171 }
 172
 173 /* Remove a reference from a session. */
 174 void
 175 session_remove_ref(struct session *s, const char *from)
 176 {
 177         s->references--;
 178         log_debug("%s: %s %s, now %d", __func__, s->name, from, s->references);
 179
 180         if (s->references == 0)
 181                 event_once(-1, EV_TIMEOUT, session_free, s, NULL);
 182 }
 183
 184 /* Free session. */
 185 static void
 186 session_free(__unused int fd, __unused short events, void *arg)
 187 {
 188         struct session  *s = arg;
 189
 190         log_debug("session %s freed (%d references)", s->name, s->references);
 191
 192         if (s->references == 0) {
 193                 environ_free(s->environ);
 194                 options_free(s->options);
 195
 196                 free(s->name);
 197                 free(s);
 198         }
 199 }
 200
 201 /* Destroy a session. */
 202 void
 203 session_destroy(struct session *s, int notify, const char *from)
 204 {
 205         struct winlink  *wl;
 206
 207         log_debug("session %s destroyed (%s)", s->name, from);
 208
 209         if (s->curw == NULL)
 210                 return;
 211         s->curw = NULL;
 212
 213         RB_REMOVE(sessions, &sessions, s);
 214         if (notify)
 215                 notify_session("session-closed", s);
 216
 217         free(s->tio);
 218
 219         if (event_initialized(&s->lock_timer))
 220                 event_del(&s->lock_timer);
 221
 222         session_group_remove(s);
 223
 224         while (!TAILQ_EMPTY(&s->lastw))
 225                 winlink_stack_remove(&s->lastw, TAILQ_FIRST(&s->lastw));
 226         while (!RB_EMPTY(&s->windows)) {
 227                 wl = RB_ROOT(&s->windows);
 228                 notify_session_window("window-unlinked", s, wl->window);
 229                 winlink_remove(&s->windows, wl);
 230         }
 231
 232         free((void *)s->cwd);
 233
 234         session_remove_ref(s, __func__);
 235 }
 236
 237 /* Sanitize session name. */
 238 char *
 239 session_check_name(const char *name)
 240 {
 241         char    *copy, *cp, *new_name;
 242
 243         if (*name == '\0')
 244                 return (NULL);
 245         copy = xstrdup(name);
 246         for (cp = copy; *cp != '\0'; cp++) {
 247                 if (*cp == ':' || *cp == '.')
 248                         *cp = '_';
 249         }
 250         utf8_stravis(&new_name, copy, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
 251         free(copy);
 252         return (new_name);
 253 }
 254
 255 /* Lock session if it has timed out. */
 256 static void
 257 session_lock_timer(__unused int fd, __unused short events, void *arg)
 258 {
 259         struct session  *s = arg;
 260
 261         if (s->attached == 0)
 262                 return;
 263
 264         log_debug("session %s locked, activity time %lld", s->name,
 265             (long long)s->activity_time.tv_sec);
 266
 267         server_lock_session(s);
 268         recalculate_sizes();
 269 }
 270
 271 /* Update activity time. */
 272 void
 273 session_update_activity(struct session *s, struct timeval *from)
 274 {
 275         struct timeval  *last = &s->last_activity_time;
 276         struct timeval   tv;
 277
 278         memcpy(last, &s->activity_time, sizeof *last);
 279         if (from == NULL)
 280                 gettimeofday(&s->activity_time, NULL);
 281         else
 282                 memcpy(&s->activity_time, from, sizeof s->activity_time);
 283
 284         log_debug("session $%u %s activity %lld.%06d (last %lld.%06d)", s->id,
 285             s->name, (long long)s->activity_time.tv_sec,
 286             (int)s->activity_time.tv_usec, (long long)last->tv_sec,
 287             (int)last->tv_usec);
 288
 289         if (evtimer_initialized(&s->lock_timer))
 290                 evtimer_del(&s->lock_timer);
 291         else
 292                 evtimer_set(&s->lock_timer, session_lock_timer, s);
 293
 294         if (s->attached != 0) {
 295                 timerclear(&tv);
 296                 tv.tv_sec = options_get_number(s->options, "lock-after-time");
 297                 if (tv.tv_sec != 0)
 298                         evtimer_add(&s->lock_timer, &tv);
 299         }
 300 }
 301
 302 /* Find the next usable session. */
 303 struct session *
 304 session_next_session(struct session *s)
 305 {
 306         struct session *s2;
 307
 308         if (RB_EMPTY(&sessions) || !session_alive(s))
 309                 return (NULL);
 310
 311         s2 = RB_NEXT(sessions, &sessions, s);
 312         if (s2 == NULL)
 313                 s2 = RB_MIN(sessions, &sessions);
 314         if (s2 == s)
 315                 return (NULL);
 316         return (s2);
 317 }
 318
 319 /* Find the previous usable session. */
 320 struct session *
 321 session_previous_session(struct session *s)
 322 {
 323         struct session *s2;
 324
 325         if (RB_EMPTY(&sessions) || !session_alive(s))
 326                 return (NULL);
 327
 328         s2 = RB_PREV(sessions, &sessions, s);
 329         if (s2 == NULL)
 330                 s2 = RB_MAX(sessions, &sessions);
 331         if (s2 == s)
 332                 return (NULL);
 333         return (s2);
 334 }
 335
 336 /* Attach a window to a session. */
 337 struct winlink *
 338 session_attach(struct session *s, struct window *w, int idx, char **cause)
 339 {
 340         struct winlink  *wl;
 341
 342         if ((wl = winlink_add(&s->windows, idx)) == NULL) {
 343                 xasprintf(cause, "index in use: %d", idx);
 344                 return (NULL);
 345         }
 346         wl->session = s;
 347         winlink_set_window(wl, w);
 348         notify_session_window("window-linked", s, w);
 349
 350         session_group_synchronize_from(s);
 351         return (wl);
 352 }
 353
 354 /* Detach a window from a session. */
 355 int
 356 session_detach(struct session *s, struct winlink *wl)
 357 {
 358         if (s->curw == wl &&
 359             session_last(s) != 0 &&
 360             session_previous(s, 0) != 0)
 361                 session_next(s, 0);
 362
 363         wl->flags &= ~WINLINK_ALERTFLAGS;
 364         notify_session_window("window-unlinked", s, wl->window);
 365         winlink_stack_remove(&s->lastw, wl);
 366         winlink_remove(&s->windows, wl);
 367
 368         session_group_synchronize_from(s);
 369
 370         if (RB_EMPTY(&s->windows)) {
 371                 session_destroy(s, 1, __func__);
 372                 return (1);
 373         }
 374         return (0);
 375 }
 376
 377 /* Return if session has window. */
 378 int
 379 session_has(struct session *s, struct window *w)
 380 {
 381         struct winlink  *wl;
 382
 383         TAILQ_FOREACH(wl, &w->winlinks, wentry) {
 384                 if (wl->session == s)
 385                         return (1);
 386         }
 387         return (0);
 388 }
 389
 390 /*
 391  * Return 1 if a window is linked outside this session (not including session
 392  * groups). The window must be in this session!
 393  */
 394 int
 395 session_is_linked(struct session *s, struct window *w)
 396 {
 397         struct session_group    *sg;
 398
 399         if ((sg = session_group_contains(s)) != NULL)
 400                 return (w->references != session_group_count(sg));
 401         return (w->references != 1);
 402 }
 403
 404 static struct winlink *
 405 session_next_alert(struct winlink *wl)
 406 {
 407         while (wl != NULL) {
 408                 if (wl->flags & WINLINK_ALERTFLAGS)
 409                         break;
 410                 wl = winlink_next(wl);
 411         }
 412         return (wl);
 413 }
 414
 415 /* Move session to next window. */
 416 int
 417 session_next(struct session *s, int alert)
 418 {
 419         struct winlink  *wl;
 420
 421         if (s->curw == NULL)
 422                 return (-1);
 423
 424         wl = winlink_next(s->curw);
 425         if (alert)
 426                 wl = session_next_alert(wl);
 427         if (wl == NULL) {
 428                 wl = RB_MIN(winlinks, &s->windows);
 429                 if (alert && ((wl = session_next_alert(wl)) == NULL))
 430                         return (-1);
 431         }
 432         return (session_set_current(s, wl));
 433 }
 434
 435 static struct winlink *
 436 session_previous_alert(struct winlink *wl)
 437 {
 438         while (wl != NULL) {
 439                 if (wl->flags & WINLINK_ALERTFLAGS)
 440                         break;
 441                 wl = winlink_previous(wl);
 442         }
 443         return (wl);
 444 }
 445
 446 /* Move session to previous window. */
 447 int
 448 session_previous(struct session *s, int alert)
 449 {
 450         struct winlink  *wl;
 451
 452         if (s->curw == NULL)
 453                 return (-1);
 454
 455         wl = winlink_previous(s->curw);
 456         if (alert)
 457                 wl = session_previous_alert(wl);
 458         if (wl == NULL) {
 459                 wl = RB_MAX(winlinks, &s->windows);
 460                 if (alert && (wl = session_previous_alert(wl)) == NULL)
 461                         return (-1);
 462         }
 463         return (session_set_current(s, wl));
 464 }
 465
 466 /* Move session to specific window. */
 467 int
 468 session_select(struct session *s, int idx)
 469 {
 470         struct winlink  *wl;
 471
 472         wl = winlink_find_by_index(&s->windows, idx);
 473         return (session_set_current(s, wl));
 474 }
 475
 476 /* Move session to last used window. */
 477 int
 478 session_last(struct session *s)
 479 {
 480         struct winlink  *wl;
 481
 482         wl = TAILQ_FIRST(&s->lastw);
 483         if (wl == NULL)
 484                 return (-1);
 485         if (wl == s->curw)
 486                 return (1);
 487
 488         return (session_set_current(s, wl));
 489 }
 490
 491 /* Set current winlink to wl .*/
 492 int
 493 session_set_current(struct session *s, struct winlink *wl)
 494 {
 495         struct winlink  *old = s->curw;
 496
 497         if (wl == NULL)
 498                 return (-1);
 499         if (wl == s->curw)
 500                 return (1);
 501
 502         winlink_stack_remove(&s->lastw, wl);
 503         winlink_stack_push(&s->lastw, s->curw);
 504         s->curw = wl;
 505         if (options_get_number(global_options, "focus-events")) {
 506                 if (old != NULL)
 507                         window_update_focus(old->window);
 508                 window_update_focus(wl->window);
 509         }
 510         winlink_clear_flags(wl);
 511         window_update_activity(wl->window);
 512         tty_update_window_offset(wl->window);
 513         notify_session("session-window-changed", s);
 514         return (0);
 515 }
 516
 517 /* Find the session group containing a session. */
 518 struct session_group *
 519 session_group_contains(struct session *target)
 520 {
 521         struct session_group    *sg;
 522         struct session          *s;
 523
 524         RB_FOREACH(sg, session_groups, &session_groups) {
 525                 TAILQ_FOREACH(s, &sg->sessions, gentry) {
 526                         if (s == target)
 527                                 return (sg);
 528                 }
 529         }
 530         return (NULL);
 531 }
 532
 533 /* Find session group by name. */
 534 struct session_group *
 535 session_group_find(const char *name)
 536 {
 537         struct session_group    sg;
 538
 539         sg.name = name;
 540         return (RB_FIND(session_groups, &session_groups, &sg));
 541 }
 542
 543 /* Create a new session group. */
 544 struct session_group *
 545 session_group_new(const char *name)
 546 {
 547         struct session_group    *sg;
 548
 549         if ((sg = session_group_find(name)) != NULL)
 550                 return (sg);
 551
 552         sg = xcalloc(1, sizeof *sg);
 553         sg->name = xstrdup(name);
 554         TAILQ_INIT(&sg->sessions);
 555
 556         RB_INSERT(session_groups, &session_groups, sg);
 557         return (sg);
 558 }
 559
 560 /* Add a session to a session group. */
 561 void
 562 session_group_add(struct session_group *sg, struct session *s)
 563 {
 564         if (session_group_contains(s) == NULL)
 565                 TAILQ_INSERT_TAIL(&sg->sessions, s, gentry);
 566 }
 567
 568 /* Remove a session from its group and destroy the group if empty. */
 569 static void
 570 session_group_remove(struct session *s)
 571 {
 572         struct session_group    *sg;
 573
 574         if ((sg = session_group_contains(s)) == NULL)
 575                 return;
 576         TAILQ_REMOVE(&sg->sessions, s, gentry);
 577         if (TAILQ_EMPTY(&sg->sessions)) {
 578                 RB_REMOVE(session_groups, &session_groups, sg);
 579                 free((void *)sg->name);
 580                 free(sg);
 581         }
 582 }
 583
 584 /* Count number of sessions in session group. */
 585 u_int
 586 session_group_count(struct session_group *sg)
 587 {
 588         struct session  *s;
 589         u_int            n;
 590
 591         n = 0;
 592         TAILQ_FOREACH(s, &sg->sessions, gentry)
 593                 n++;
 594         return (n);
 595 }
 596
 597 /* Count number of clients attached to sessions in session group. */
 598 u_int
 599 session_group_attached_count(struct session_group *sg)
 600 {
 601         struct session  *s;
 602         u_int            n;
 603
 604         n = 0;
 605         TAILQ_FOREACH(s, &sg->sessions, gentry)
 606                 n += s->attached;
 607         return (n);
 608 }
 609
 610 /* Synchronize a session to its session group. */
 611 void
 612 session_group_synchronize_to(struct session *s)
 613 {
 614         struct session_group    *sg;
 615         struct session          *target;
 616
 617         if ((sg = session_group_contains(s)) == NULL)
 618                 return;
 619
 620         target = NULL;
 621         TAILQ_FOREACH(target, &sg->sessions, gentry) {
 622                 if (target != s)
 623                         break;
 624         }
 625         if (target != NULL)
 626                 session_group_synchronize1(target, s);
 627 }
 628
 629 /* Synchronize a session group to a session. */
 630 void
 631 session_group_synchronize_from(struct session *target)
 632 {
 633         struct session_group    *sg;
 634         struct session          *s;
 635
 636         if ((sg = session_group_contains(target)) == NULL)
 637                 return;
 638
 639         TAILQ_FOREACH(s, &sg->sessions, gentry) {
 640                 if (s != target)
 641                         session_group_synchronize1(target, s);
 642         }
 643 }
 644
 645 /*
 646  * Synchronize a session with a target session. This means destroying all
 647  * winlinks then recreating them, then updating the current window, last window
 648  * stack and alerts.
 649  */
 650 static void
 651 session_group_synchronize1(struct session *target, struct session *s)
 652 {
 653         struct winlinks          old_windows, *ww;
 654         struct winlink_stack     old_lastw;
 655         struct winlink          *wl, *wl2;
 656
 657         /* Don't do anything if the session is empty (it'll be destroyed). */
 658         ww = &target->windows;
 659         if (RB_EMPTY(ww))
 660                 return;
 661
 662         /* If the current window has vanished, move to the next now. */
 663         if (s->curw != NULL &&
 664             winlink_find_by_index(ww, s->curw->idx) == NULL &&
 665             session_last(s) != 0 && session_previous(s, 0) != 0)
 666                 session_next(s, 0);
 667
 668         /* Save the old pointer and reset it. */
 669         memcpy(&old_windows, &s->windows, sizeof old_windows);
 670         RB_INIT(&s->windows);
 671
 672         /* Link all the windows from the target. */
 673         RB_FOREACH(wl, winlinks, ww) {
 674                 wl2 = winlink_add(&s->windows, wl->idx);
 675                 wl2->session = s;
 676                 winlink_set_window(wl2, wl->window);
 677                 notify_session_window("window-linked", s, wl2->window);
 678                 wl2->flags |= wl->flags & WINLINK_ALERTFLAGS;
 679         }
 680
 681         /* Fix up the current window. */
 682         if (s->curw != NULL)
 683                 s->curw = winlink_find_by_index(&s->windows, s->curw->idx);
 684         else
 685                 s->curw = winlink_find_by_index(&s->windows, target->curw->idx);
 686
 687         /* Fix up the last window stack. */
 688         memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
 689         TAILQ_INIT(&s->lastw);
 690         TAILQ_FOREACH(wl, &old_lastw, sentry) {
 691                 wl2 = winlink_find_by_index(&s->windows, wl->idx);
 692                 if (wl2 != NULL)
 693                         TAILQ_INSERT_TAIL(&s->lastw, wl2, sentry);
 694         }
 695
 696         /* Then free the old winlinks list. */
 697         while (!RB_EMPTY(&old_windows)) {
 698                 wl = RB_ROOT(&old_windows);
 699                 wl2 = winlink_find_by_window_id(&s->windows, wl->window->id);
 700                 if (wl2 == NULL)
 701                         notify_session_window("window-unlinked", s, wl->window);
 702                 winlink_remove(&old_windows, wl);
 703         }
 704 }
 705
 706 /* Renumber the windows across winlinks attached to a specific session. */
 707 void
 708 session_renumber_windows(struct session *s)
 709 {
 710         struct winlink          *wl, *wl1, *wl_new;
 711         struct winlinks          old_wins;
 712         struct winlink_stack     old_lastw;
 713         int                      new_idx, new_curw_idx, marked_idx = -1;
 714
 715         /* Save and replace old window list. */
 716         memcpy(&old_wins, &s->windows, sizeof old_wins);
 717         RB_INIT(&s->windows);
 718
 719         /* Start renumbering from the base-index if it's set. */
 720         new_idx = options_get_number(s->options, "base-index");
 721         new_curw_idx = 0;
 722
 723         /* Go through the winlinks and assign new indexes. */
 724         RB_FOREACH(wl, winlinks, &old_wins) {
 725                 wl_new = winlink_add(&s->windows, new_idx);
 726                 wl_new->session = s;
 727                 winlink_set_window(wl_new, wl->window);
 728                 wl_new->flags |= wl->flags & WINLINK_ALERTFLAGS;
 729
 730                 if (wl == marked_pane.wl)
 731                         marked_idx = wl_new->idx;
 732                 if (wl == s->curw)
 733                         new_curw_idx = wl_new->idx;
 734
 735                 new_idx++;
 736         }
 737
 738         /* Fix the stack of last windows now. */
 739         memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
 740         TAILQ_INIT(&s->lastw);
 741         TAILQ_FOREACH(wl, &old_lastw, sentry) {
 742                 wl_new = winlink_find_by_window(&s->windows, wl->window);
 743                 if (wl_new != NULL)
 744                         TAILQ_INSERT_TAIL(&s->lastw, wl_new, sentry);
 745         }
 746
 747         /* Set the current window. */
 748         if (marked_idx != -1) {
 749                 marked_pane.wl = winlink_find_by_index(&s->windows, marked_idx);
 750                 if (marked_pane.wl == NULL)
 751                         server_clear_marked();
 752         }
 753         s->curw = winlink_find_by_index(&s->windows, new_curw_idx);
 754
 755         /* Free the old winlinks (reducing window references too). */
 756         RB_FOREACH_SAFE(wl, winlinks, &old_wins, wl1)
 757                 winlink_remove(&old_wins, wl);
 758 }