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 <string.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <time.h>
  26
  27 #include "tmux.h"
  28
  29 struct sessions         sessions;
  30 u_int                   next_session_id;
  31 struct session_groups   session_groups = RB_INITIALIZER(&session_groups);
  32
  33 static void     session_free(int, short, void *);
  34
  35 static void     session_lock_timer(int, short, void *);
  36
  37 static struct winlink *session_next_alert(struct winlink *);
  38 static struct winlink *session_previous_alert(struct winlink *);
  39
  40 static void     session_group_remove(struct session *);
  41 static void     session_group_synchronize1(struct session *, struct session *);
  42
  43 int
  44 session_cmp(struct session *s1, struct session *s2)
  45 {
  46         return (strcmp(s1->name, s2->name));
  47 }
  48 RB_GENERATE(sessions, session, entry, session_cmp);
  49
  50 static int
  51 session_group_cmp(struct session_group *s1, struct session_group *s2)
  52 {
  53         return (strcmp(s1->name, s2->name));
  54 }
  55 RB_GENERATE_STATIC(session_groups, session_group, entry, session_group_cmp);
  56
  57 /*
  58  * Find if session is still alive. This is true if it is still on the global
  59  * sessions list.
  60  */
  61 int
  62 session_alive(struct session *s)
  63 {
  64         struct session *s_loop;
  65
  66         RB_FOREACH(s_loop, sessions, &sessions) {
  67                 if (s_loop == s)
  68                         return (1);
  69         }
  70         return (0);
  71 }
  72
  73 /* Find session by name. */
  74 struct session *
  75 session_find(const char *name)
  76 {
  77         struct session  s;
  78
  79         s.name = (char *) name;
  80         return (RB_FIND(sessions, &sessions, &s));
  81 }
  82
  83 /* Find session by id parsed from a string. */
  84 struct session *
  85 session_find_by_id_str(const char *s)
  86 {
  87         const char      *errstr;
  88         u_int            id;
  89
  90         if (*s != '$')
  91                 return (NULL);
  92
  93         id = strtonum(s + 1, 0, UINT_MAX, &errstr);
  94         if (errstr != NULL)
  95                 return (NULL);
  96         return (session_find_by_id(id));
  97 }
  98
  99 /* Find session by id. */
 100 struct session *
 101 session_find_by_id(u_int id)
 102 {
 103         struct session  *s;
 104
 105         RB_FOREACH(s, sessions, &sessions) {
 106                 if (s->id == id)
 107                         return (s);
 108         }
 109         return (NULL);
 110 }
 111
 112 /* Create a new session. */
 113 struct session *
 114 session_create(const char *prefix, const char *name, const char *cwd,
 115     struct environ *env, struct options *oo, struct termios *tio)
 116 {
 117         struct session  *s;
 118
 119         s = xcalloc(1, sizeof *s);
 120         s->references = 1;
 121         s->flags = 0;
 122
 123         s->cwd = xstrdup(cwd);
 124
 125         TAILQ_INIT(&s->lastw);
 126         RB_INIT(&s->windows);
 127
 128         s->environ = env;
 129         s->options = oo;
 130
 131         status_update_cache(s);
 132
 133         s->tio = NULL;
 134         if (tio != NULL) {
 135                 s->tio = xmalloc(sizeof *s->tio);
 136                 memcpy(s->tio, tio, sizeof *s->tio);
 137         }
 138
 139         if (name != NULL) {
 140                 s->name = xstrdup(name);
 141                 s->id = next_session_id++;
 142         } else {
 143                 do {
 144                         s->id = next_session_id++;
 145                         free(s->name);
 146                         if (prefix != NULL)
 147                                 xasprintf(&s->name, "%s-%u", prefix, s->id);
 148                         else
 149                                 xasprintf(&s->name, "%u", s->id);
 150                 } while (RB_FIND(sessions, &sessions, s) != NULL);
 151         }
 152         RB_INSERT(sessions, &sessions, s);
 153
 154         log_debug("new session %s $%u", s->name, s->id);
 155
 156         if (gettimeofday(&s->creation_time, NULL) != 0)
 157                 fatal("gettimeofday failed");
 158         session_update_activity(s, &s->creation_time);
 159
 160         return (s);
 161 }
 162
 163 /* Add a reference to a session. */
 164 void
 165 session_add_ref(struct session *s, const char *from)
 166 {
 167         s->references++;
 168         log_debug("%s: %s %s, now %d", __func__, s->name, from, s->references);
 169 }
 170
 171 /* Remove a reference from a session. */
 172 void
 173 session_remove_ref(struct session *s, const char *from)
 174 {
 175         s->references--;
 176         log_debug("%s: %s %s, now %d", __func__, s->name, from, s->references);
 177
 178         if (s->references == 0)
 179                 event_once(-1, EV_TIMEOUT, session_free, s, NULL);
 180 }
 181
 182 /* Free session. */
 183 static void
 184 session_free(__unused int fd, __unused short events, void *arg)
 185 {
 186         struct session  *s = arg;
 187
 188         log_debug("session %s freed (%d references)", s->name, s->references);
 189
 190         if (s->references == 0) {
 191                 environ_free(s->environ);
 192                 options_free(s->options);
 193
 194                 free(s->name);
 195                 free(s);
 196         }
 197 }
 198
 199 /* Destroy a session. */
 200 void
 201 session_destroy(struct session *s, int notify, const char *from)
 202 {
 203         struct winlink  *wl;
 204
 205         log_debug("session %s destroyed (%s)", s->name, from);
 206
 207         if (s->curw == NULL)
 208                 return;
 209         s->curw = NULL;
 210
 211         RB_REMOVE(sessions, &sessions, s);
 212         if (notify)
 213                 notify_session("session-closed", s);
 214
 215         free(s->tio);
 216
 217         if (event_initialized(&s->lock_timer))
 218                 event_del(&s->lock_timer);
 219
 220         session_group_remove(s);
 221
 222         while (!TAILQ_EMPTY(&s->lastw))
 223                 winlink_stack_remove(&s->lastw, TAILQ_FIRST(&s->lastw));
 224         while (!RB_EMPTY(&s->windows)) {
 225                 wl = RB_ROOT(&s->windows);
 226                 notify_session_window("window-unlinked", s, wl->window);
 227                 winlink_remove(&s->windows, wl);
 228         }
 229
 230         free((void *)s->cwd);
 231
 232         session_remove_ref(s, __func__);
 233 }
 234
 235 /* Sanitize session name. */
 236 char *
 237 session_check_name(const char *name)
 238 {
 239         char    *copy, *cp, *new_name;
 240
 241         if (*name == '\0')
 242                 return (NULL);
 243         copy = xstrdup(name);
 244         for (cp = copy; *cp != '\0'; cp++) {
 245                 if (*cp == ':' || *cp == '.')
 246                         *cp = '_';
 247         }
 248         utf8_stravis(&new_name, copy, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
 249         free(copy);
 250         return (new_name);
 251 }
 252
 253 /* Lock session if it has timed out. */
 254 static void
 255 session_lock_timer(__unused int fd, __unused short events, void *arg)
 256 {
 257         struct session  *s = arg;
 258
 259         if (s->attached == 0)
 260                 return;
 261
 262         log_debug("session %s locked, activity time %lld", s->name,
 263             (long long)s->activity_time.tv_sec);
 264
 265         server_lock_session(s);
 266         recalculate_sizes();
 267 }
 268
 269 /* Update activity time. */
 270 void
 271 session_update_activity(struct session *s, struct timeval *from)
 272 {
 273         struct timeval  *last = &s->last_activity_time;
 274         struct timeval   tv;
 275
 276         memcpy(last, &s->activity_time, sizeof *last);
 277         if (from == NULL)
 278                 gettimeofday(&s->activity_time, NULL);
 279         else
 280                 memcpy(&s->activity_time, from, sizeof s->activity_time);
 281
 282         log_debug("session $%u %s activity %lld.%06d (last %lld.%06d)", s->id,
 283             s->name, (long long)s->activity_time.tv_sec,
 284             (int)s->activity_time.tv_usec, (long long)last->tv_sec,
 285             (int)last->tv_usec);
 286
 287         if (evtimer_initialized(&s->lock_timer))
 288                 evtimer_del(&s->lock_timer);
 289         else
 290                 evtimer_set(&s->lock_timer, session_lock_timer, s);
 291
 292         if (s->attached != 0) {
 293                 timerclear(&tv);
 294                 tv.tv_sec = options_get_number(s->options, "lock-after-time");
 295                 if (tv.tv_sec != 0)
 296                         evtimer_add(&s->lock_timer, &tv);
 297         }
 298 }
 299
 300 /* Find the next usable session. */
 301 struct session *
 302 session_next_session(struct session *s)
 303 {
 304         struct session *s2;
 305
 306         if (RB_EMPTY(&sessions) || !session_alive(s))
 307                 return (NULL);
 308
 309         s2 = RB_NEXT(sessions, &sessions, s);
 310         if (s2 == NULL)
 311                 s2 = RB_MIN(sessions, &sessions);
 312         if (s2 == s)
 313                 return (NULL);
 314         return (s2);
 315 }
 316
 317 /* Find the previous usable session. */
 318 struct session *
 319 session_previous_session(struct session *s)
 320 {
 321         struct session *s2;
 322
 323         if (RB_EMPTY(&sessions) || !session_alive(s))
 324                 return (NULL);
 325
 326         s2 = RB_PREV(sessions, &sessions, s);
 327         if (s2 == NULL)
 328                 s2 = RB_MAX(sessions, &sessions);
 329         if (s2 == s)
 330                 return (NULL);
 331         return (s2);
 332 }
 333
 334 /* Attach a window to a session. */
 335 struct winlink *
 336 session_attach(struct session *s, struct window *w, int idx, char **cause)
 337 {
 338         struct winlink  *wl;
 339
 340         if ((wl = winlink_add(&s->windows, idx)) == NULL) {
 341                 xasprintf(cause, "index in use: %d", idx);
 342                 return (NULL);
 343         }
 344         wl->session = s;
 345         winlink_set_window(wl, w);
 346         notify_session_window("window-linked", s, w);
 347
 348         session_group_synchronize_from(s);
 349         return (wl);
 350 }
 351
 352 /* Detach a window from a session. */
 353 int
 354 session_detach(struct session *s, struct winlink *wl)
 355 {
 356         if (s->curw == wl &&
 357             session_last(s) != 0 &&
 358             session_previous(s, 0) != 0)
 359                 session_next(s, 0);
 360
 361         wl->flags &= ~WINLINK_ALERTFLAGS;
 362         notify_session_window("window-unlinked", s, wl->window);
 363         winlink_stack_remove(&s->lastw, wl);
 364         winlink_remove(&s->windows, wl);
 365
 366         session_group_synchronize_from(s);
 367
 368         if (RB_EMPTY(&s->windows))
 369                 return (1);
 370         return (0);
 371 }
 372
 373 /* Return if session has window. */
 374 int
 375 session_has(struct session *s, struct window *w)
 376 {
 377         struct winlink  *wl;
 378
 379         TAILQ_FOREACH(wl, &w->winlinks, wentry) {
 380                 if (wl->session == s)
 381                         return (1);
 382         }
 383         return (0);
 384 }
 385
 386 /*
 387  * Return 1 if a window is linked outside this session (not including session
 388  * groups). The window must be in this session!
 389  */
 390 int
 391 session_is_linked(struct session *s, struct window *w)
 392 {
 393         struct session_group    *sg;
 394
 395         if ((sg = session_group_contains(s)) != NULL)
 396                 return (w->references != session_group_count(sg));
 397         return (w->references != 1);
 398 }
 399
 400 static struct winlink *
 401 session_next_alert(struct winlink *wl)
 402 {
 403         while (wl != NULL) {
 404                 if (wl->flags & WINLINK_ALERTFLAGS)
 405                         break;
 406                 wl = winlink_next(wl);
 407         }
 408         return (wl);
 409 }
 410
 411 /* Move session to next window. */
 412 int
 413 session_next(struct session *s, int alert)
 414 {
 415         struct winlink  *wl;
 416
 417         if (s->curw == NULL)
 418                 return (-1);
 419
 420         wl = winlink_next(s->curw);
 421         if (alert)
 422                 wl = session_next_alert(wl);
 423         if (wl == NULL) {
 424                 wl = RB_MIN(winlinks, &s->windows);
 425                 if (alert && ((wl = session_next_alert(wl)) == NULL))
 426                         return (-1);
 427         }
 428         return (session_set_current(s, wl));
 429 }
 430
 431 static struct winlink *
 432 session_previous_alert(struct winlink *wl)
 433 {
 434         while (wl != NULL) {
 435                 if (wl->flags & WINLINK_ALERTFLAGS)
 436                         break;
 437                 wl = winlink_previous(wl);
 438         }
 439         return (wl);
 440 }
 441
 442 /* Move session to previous window. */
 443 int
 444 session_previous(struct session *s, int alert)
 445 {
 446         struct winlink  *wl;
 447
 448         if (s->curw == NULL)
 449                 return (-1);
 450
 451         wl = winlink_previous(s->curw);
 452         if (alert)
 453                 wl = session_previous_alert(wl);
 454         if (wl == NULL) {
 455                 wl = RB_MAX(winlinks, &s->windows);
 456                 if (alert && (wl = session_previous_alert(wl)) == NULL)
 457                         return (-1);
 458         }
 459         return (session_set_current(s, wl));
 460 }
 461
 462 /* Move session to specific window. */
 463 int
 464 session_select(struct session *s, int idx)
 465 {
 466         struct winlink  *wl;
 467
 468         wl = winlink_find_by_index(&s->windows, idx);
 469         return (session_set_current(s, wl));
 470 }
 471
 472 /* Move session to last used window. */
 473 int
 474 session_last(struct session *s)
 475 {
 476         struct winlink  *wl;
 477
 478         wl = TAILQ_FIRST(&s->lastw);
 479         if (wl == NULL)
 480                 return (-1);
 481         if (wl == s->curw)
 482                 return (1);
 483
 484         return (session_set_current(s, wl));
 485 }
 486
 487 /* Set current winlink to wl .*/
 488 int
 489 session_set_current(struct session *s, struct winlink *wl)
 490 {
 491         struct winlink  *old = s->curw;
 492
 493         if (wl == NULL)
 494                 return (-1);
 495         if (wl == s->curw)
 496                 return (1);
 497
 498         winlink_stack_remove(&s->lastw, wl);
 499         winlink_stack_push(&s->lastw, s->curw);
 500         s->curw = wl;
 501         if (options_get_number(global_options, "focus-events")) {
 502                 if (old != NULL)
 503                         window_update_focus(old->window);
 504                 window_update_focus(wl->window);
 505         }
 506         winlink_clear_flags(wl);
 507         window_update_activity(wl->window);
 508         tty_update_window_offset(wl->window);
 509         notify_session("session-window-changed", s);
 510         return (0);
 511 }
 512
 513 /* Find the session group containing a session. */
 514 struct session_group *
 515 session_group_contains(struct session *target)
 516 {
 517         struct session_group    *sg;
 518         struct session          *s;
 519
 520         RB_FOREACH(sg, session_groups, &session_groups) {
 521                 TAILQ_FOREACH(s, &sg->sessions, gentry) {
 522                         if (s == target)
 523                                 return (sg);
 524                 }
 525         }
 526         return (NULL);
 527 }
 528
 529 /* Find session group by name. */
 530 struct session_group *
 531 session_group_find(const char *name)
 532 {
 533         struct session_group    sg;
 534
 535         sg.name = name;
 536         return (RB_FIND(session_groups, &session_groups, &sg));
 537 }
 538
 539 /* Create a new session group. */
 540 struct session_group *
 541 session_group_new(const char *name)
 542 {
 543         struct session_group    *sg;
 544
 545         if ((sg = session_group_find(name)) != NULL)
 546                 return (sg);
 547
 548         sg = xcalloc(1, sizeof *sg);
 549         sg->name = xstrdup(name);
 550         TAILQ_INIT(&sg->sessions);
 551
 552         RB_INSERT(session_groups, &session_groups, sg);
 553         return (sg);
 554 }
 555
 556 /* Add a session to a session group. */
 557 void
 558 session_group_add(struct session_group *sg, struct session *s)
 559 {
 560         if (session_group_contains(s) == NULL)
 561                 TAILQ_INSERT_TAIL(&sg->sessions, s, gentry);
 562 }
 563
 564 /* Remove a session from its group and destroy the group if empty. */
 565 static void
 566 session_group_remove(struct session *s)
 567 {
 568         struct session_group    *sg;
 569
 570         if ((sg = session_group_contains(s)) == NULL)
 571                 return;
 572         TAILQ_REMOVE(&sg->sessions, s, gentry);
 573         if (TAILQ_EMPTY(&sg->sessions)) {
 574                 RB_REMOVE(session_groups, &session_groups, sg);
 575                 free((void *)sg->name);
 576                 free(sg);
 577         }
 578 }
 579
 580 /* Count number of sessions in session group. */
 581 u_int
 582 session_group_count(struct session_group *sg)
 583 {
 584         struct session  *s;
 585         u_int            n;
 586
 587         n = 0;
 588         TAILQ_FOREACH(s, &sg->sessions, gentry)
 589                 n++;
 590         return (n);
 591 }
 592
 593 /* Count number of clients attached to sessions in session group. */
 594 u_int
 595 session_group_attached_count(struct session_group *sg)
 596 {
 597         struct session  *s;
 598         u_int            n;
 599
 600         n = 0;
 601         TAILQ_FOREACH(s, &sg->sessions, gentry)
 602                 n += s->attached;
 603         return (n);
 604 }
 605
 606 /* Synchronize a session to its session group. */
 607 void
 608 session_group_synchronize_to(struct session *s)
 609 {
 610         struct session_group    *sg;
 611         struct session          *target;
 612
 613         if ((sg = session_group_contains(s)) == NULL)
 614                 return;
 615
 616         target = NULL;
 617         TAILQ_FOREACH(target, &sg->sessions, gentry) {
 618                 if (target != s)
 619                         break;
 620         }
 621         if (target != NULL)
 622                 session_group_synchronize1(target, s);
 623 }
 624
 625 /* Synchronize a session group to a session. */
 626 void
 627 session_group_synchronize_from(struct session *target)
 628 {
 629         struct session_group    *sg;
 630         struct session          *s;
 631
 632         if ((sg = session_group_contains(target)) == NULL)
 633                 return;
 634
 635         TAILQ_FOREACH(s, &sg->sessions, gentry) {
 636                 if (s != target)
 637                         session_group_synchronize1(target, s);
 638         }
 639 }
 640
 641 /*
 642  * Synchronize a session with a target session. This means destroying all
 643  * winlinks then recreating them, then updating the current window, last window
 644  * stack and alerts.
 645  */
 646 static void
 647 session_group_synchronize1(struct session *target, struct session *s)
 648 {
 649         struct winlinks          old_windows, *ww;
 650         struct winlink_stack     old_lastw;
 651         struct winlink          *wl, *wl2;
 652
 653         /* Don't do anything if the session is empty (it'll be destroyed). */
 654         ww = &target->windows;
 655         if (RB_EMPTY(ww))
 656                 return;
 657
 658         /* If the current window has vanished, move to the next now. */
 659         if (s->curw != NULL &&
 660             winlink_find_by_index(ww, s->curw->idx) == NULL &&
 661             session_last(s) != 0 && session_previous(s, 0) != 0)
 662                 session_next(s, 0);
 663
 664         /* Save the old pointer and reset it. */
 665         memcpy(&old_windows, &s->windows, sizeof old_windows);
 666         RB_INIT(&s->windows);
 667
 668         /* Link all the windows from the target. */
 669         RB_FOREACH(wl, winlinks, ww) {
 670                 wl2 = winlink_add(&s->windows, wl->idx);
 671                 wl2->session = s;
 672                 winlink_set_window(wl2, wl->window);
 673                 notify_session_window("window-linked", s, wl2->window);
 674                 wl2->flags |= wl->flags & WINLINK_ALERTFLAGS;
 675         }
 676
 677         /* Fix up the current window. */
 678         if (s->curw != NULL)
 679                 s->curw = winlink_find_by_index(&s->windows, s->curw->idx);
 680         else
 681                 s->curw = winlink_find_by_index(&s->windows, target->curw->idx);
 682
 683         /* Fix up the last window stack. */
 684         memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
 685         TAILQ_INIT(&s->lastw);
 686         TAILQ_FOREACH(wl, &old_lastw, sentry) {
 687                 wl2 = winlink_find_by_index(&s->windows, wl->idx);
 688                 if (wl2 != NULL) {
 689                         TAILQ_INSERT_TAIL(&s->lastw, wl2, sentry);
 690                         wl2->flags |= WINLINK_VISITED;
 691                 }
 692         }
 693
 694         /* Then free the old winlinks list. */
 695         while (!RB_EMPTY(&old_windows)) {
 696                 wl = RB_ROOT(&old_windows);
 697                 wl2 = winlink_find_by_window_id(&s->windows, wl->window->id);
 698                 if (wl2 == NULL)
 699                         notify_session_window("window-unlinked", s, wl->window);
 700                 winlink_remove(&old_windows, wl);
 701         }
 702 }
 703
 704 /* Renumber the windows across winlinks attached to a specific session. */
 705 void
 706 session_renumber_windows(struct session *s)
 707 {
 708         struct winlink          *wl, *wl1, *wl_new;
 709         struct winlinks          old_wins;
 710         struct winlink_stack     old_lastw;
 711         int                      new_idx, new_curw_idx, marked_idx = -1;
 712
 713         /* Save and replace old window list. */
 714         memcpy(&old_wins, &s->windows, sizeof old_wins);
 715         RB_INIT(&s->windows);
 716
 717         /* Start renumbering from the base-index if it's set. */
 718         new_idx = options_get_number(s->options, "base-index");
 719         new_curw_idx = 0;
 720
 721         /* Go through the winlinks and assign new indexes. */
 722         RB_FOREACH(wl, winlinks, &old_wins) {
 723                 wl_new = winlink_add(&s->windows, new_idx);
 724                 wl_new->session = s;
 725                 winlink_set_window(wl_new, wl->window);
 726                 wl_new->flags |= wl->flags & WINLINK_ALERTFLAGS;
 727
 728                 if (wl == marked_pane.wl)
 729                         marked_idx = wl_new->idx;
 730                 if (wl == s->curw)
 731                         new_curw_idx = wl_new->idx;
 732
 733                 new_idx++;
 734         }
 735
 736         /* Fix the stack of last windows now. */
 737         memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
 738         TAILQ_INIT(&s->lastw);
 739         TAILQ_FOREACH(wl, &old_lastw, sentry) {
 740                 wl->flags &= ~WINLINK_VISITED;
 741                 wl_new = winlink_find_by_window(&s->windows, wl->window);
 742                 if (wl_new != NULL) {
 743                         TAILQ_INSERT_TAIL(&s->lastw, wl_new, sentry);
 744                         wl_new->flags |= WINLINK_VISITED;
 745                 }
 746         }
 747
 748         /* Set the current window. */
 749         if (marked_idx != -1) {
 750                 marked_pane.wl = winlink_find_by_index(&s->windows, marked_idx);
 751                 if (marked_pane.wl == NULL)
 752                         server_clear_marked();
 753         }
 754         s->curw = winlink_find_by_index(&s->windows, new_curw_idx);
 755
 756         /* Free the old winlinks (reducing window references too). */
 757         RB_FOREACH_SAFE(wl, winlinks, &old_wins, wl1)
 758                 winlink_remove(&old_wins, wl);
 759 }