worktree.c

   1 #include "git-compat-util.h"
   2 #include "alloc.h"
   3 #include "repository.h"
   4 #include "refs.h"
   5 #include "strbuf.h"
   6 #include "worktree.h"
   7 #include "dir.h"
   8 #include "wt-status.h"
   9 #include "config.h"
  10
  11 void free_worktrees(struct worktree **worktrees)
  12 {
  13         int i = 0;
  14
  15         for (i = 0; worktrees[i]; i++) {
  16                 free(worktrees[i]->path);
  17                 free(worktrees[i]->id);
  18                 free(worktrees[i]->head_ref);
  19                 free(worktrees[i]->lock_reason);
  20                 free(worktrees[i]->prune_reason);
  21                 free(worktrees[i]);
  22         }
  23         free (worktrees);
  24 }
  25
  26 /**
  27  * Update head_oid, head_ref and is_detached of the given worktree
  28  */
  29 static void add_head_info(struct worktree *wt)
  30 {
  31         int flags;
  32         const char *target;
  33
  34         target = refs_resolve_ref_unsafe(get_worktree_ref_store(wt),
  35                                          "HEAD",
  36                                          0,
  37                                          &wt->head_oid, &flags);
  38         if (!target)
  39                 return;
  40
  41         if (flags & REF_ISSYMREF)
  42                 wt->head_ref = xstrdup(target);
  43         else
  44                 wt->is_detached = 1;
  45 }
  46
  47 /**
  48  * get the main worktree
  49  */
  50 static struct worktree *get_main_worktree(void)
  51 {
  52         struct worktree *worktree = NULL;
  53         struct strbuf worktree_path = STRBUF_INIT;
  54
  55         strbuf_add_real_path(&worktree_path, get_git_common_dir());
  56         strbuf_strip_suffix(&worktree_path, "/.git");
  57
  58         CALLOC_ARRAY(worktree, 1);
  59         worktree->path = strbuf_detach(&worktree_path, NULL);
  60         /*
  61          * NEEDSWORK: If this function is called from a secondary worktree and
  62          * config.worktree is present, is_bare_repository_cfg will reflect the
  63          * contents of config.worktree, not the contents of the main worktree.
  64          * This means that worktree->is_bare may be set to 0 even if the main
  65          * worktree is configured to be bare.
  66          */
  67         worktree->is_bare = (is_bare_repository_cfg == 1) ||
  68                 is_bare_repository();
  69         add_head_info(worktree);
  70         return worktree;
  71 }
  72
  73 static struct worktree *get_linked_worktree(const char *id)
  74 {
  75         struct worktree *worktree = NULL;
  76         struct strbuf path = STRBUF_INIT;
  77         struct strbuf worktree_path = STRBUF_INIT;
  78
  79         if (!id)
  80                 die("Missing linked worktree name");
  81
  82         strbuf_git_common_path(&path, the_repository, "worktrees/%s/gitdir", id);
  83         if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
  84                 /* invalid gitdir file */
  85                 goto done;
  86         strbuf_rtrim(&worktree_path);
  87         strbuf_strip_suffix(&worktree_path, "/.git");
  88
  89         CALLOC_ARRAY(worktree, 1);
  90         worktree->path = strbuf_detach(&worktree_path, NULL);
  91         worktree->id = xstrdup(id);
  92         add_head_info(worktree);
  93
  94 done:
  95         strbuf_release(&path);
  96         strbuf_release(&worktree_path);
  97         return worktree;
  98 }
  99
 100 static void mark_current_worktree(struct worktree **worktrees)
 101 {
 102         char *git_dir = absolute_pathdup(get_git_dir());
 103         int i;
 104
 105         for (i = 0; worktrees[i]; i++) {
 106                 struct worktree *wt = worktrees[i];
 107                 const char *wt_git_dir = get_worktree_git_dir(wt);
 108
 109                 if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
 110                         wt->is_current = 1;
 111                         break;
 112                 }
 113         }
 114         free(git_dir);
 115 }
 116
 117 struct worktree **get_worktrees(void)
 118 {
 119         struct worktree **list = NULL;
 120         struct strbuf path = STRBUF_INIT;
 121         DIR *dir;
 122         struct dirent *d;
 123         int counter = 0, alloc = 2;
 124
 125         ALLOC_ARRAY(list, alloc);
 126
 127         list[counter++] = get_main_worktree();
 128
 129         strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
 130         dir = opendir(path.buf);
 131         strbuf_release(&path);
 132         if (dir) {
 133                 while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) {
 134                         struct worktree *linked = NULL;
 135
 136                         if ((linked = get_linked_worktree(d->d_name))) {
 137                                 ALLOC_GROW(list, counter + 1, alloc);
 138                                 list[counter++] = linked;
 139                         }
 140                 }
 141                 closedir(dir);
 142         }
 143         ALLOC_GROW(list, counter + 1, alloc);
 144         list[counter] = NULL;
 145
 146         mark_current_worktree(list);
 147         return list;
 148 }
 149
 150 const char *get_worktree_git_dir(const struct worktree *wt)
 151 {
 152         if (!wt)
 153                 return get_git_dir();
 154         else if (!wt->id)
 155                 return get_git_common_dir();
 156         else
 157                 return git_common_path("worktrees/%s", wt->id);
 158 }
 159
 160 static struct worktree *find_worktree_by_suffix(struct worktree **list,
 161                                                 const char *suffix)
 162 {
 163         struct worktree *found = NULL;
 164         int nr_found = 0, suffixlen;
 165
 166         suffixlen = strlen(suffix);
 167         if (!suffixlen)
 168                 return NULL;
 169
 170         for (; *list && nr_found < 2; list++) {
 171                 const char      *path    = (*list)->path;
 172                 int              pathlen = strlen(path);
 173                 int              start   = pathlen - suffixlen;
 174
 175                 /* suffix must start at directory boundary */
 176                 if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
 177                     !fspathcmp(suffix, path + start)) {
 178                         found = *list;
 179                         nr_found++;
 180                 }
 181         }
 182         return nr_found == 1 ? found : NULL;
 183 }
 184
 185 struct worktree *find_worktree(struct worktree **list,
 186                                const char *prefix,
 187                                const char *arg)
 188 {
 189         struct worktree *wt;
 190         char *to_free = NULL;
 191
 192         if ((wt = find_worktree_by_suffix(list, arg)))
 193                 return wt;
 194
 195         if (prefix)
 196                 arg = to_free = prefix_filename(prefix, arg);
 197         wt = find_worktree_by_path(list, arg);
 198         free(to_free);
 199         return wt;
 200 }
 201
 202 struct worktree *find_worktree_by_path(struct worktree **list, const char *p)
 203 {
 204         struct strbuf wt_path = STRBUF_INIT;
 205         char *path = real_pathdup(p, 0);
 206
 207         if (!path)
 208                 return NULL;
 209         for (; *list; list++) {
 210                 if (!strbuf_realpath(&wt_path, (*list)->path, 0))
 211                         continue;
 212
 213                 if (!fspathcmp(path, wt_path.buf))
 214                         break;
 215         }
 216         free(path);
 217         strbuf_release(&wt_path);
 218         return *list;
 219 }
 220
 221 int is_main_worktree(const struct worktree *wt)
 222 {
 223         return !wt->id;
 224 }
 225
 226 const char *worktree_lock_reason(struct worktree *wt)
 227 {
 228         if (is_main_worktree(wt))
 229                 return NULL;
 230
 231         if (!wt->lock_reason_valid) {
 232                 struct strbuf path = STRBUF_INIT;
 233
 234                 strbuf_addstr(&path, worktree_git_path(wt, "locked"));
 235                 if (file_exists(path.buf)) {
 236                         struct strbuf lock_reason = STRBUF_INIT;
 237                         if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
 238                                 die_errno(_("failed to read '%s'"), path.buf);
 239                         strbuf_trim(&lock_reason);
 240                         wt->lock_reason = strbuf_detach(&lock_reason, NULL);
 241                 } else
 242                         wt->lock_reason = NULL;
 243                 wt->lock_reason_valid = 1;
 244                 strbuf_release(&path);
 245         }
 246
 247         return wt->lock_reason;
 248 }
 249
 250 const char *worktree_prune_reason(struct worktree *wt, timestamp_t expire)
 251 {
 252         struct strbuf reason = STRBUF_INIT;
 253         char *path = NULL;
 254
 255         if (is_main_worktree(wt))
 256                 return NULL;
 257         if (wt->prune_reason_valid)
 258                 return wt->prune_reason;
 259
 260         if (should_prune_worktree(wt->id, &reason, &path, expire))
 261                 wt->prune_reason = strbuf_detach(&reason, NULL);
 262         wt->prune_reason_valid = 1;
 263
 264         strbuf_release(&reason);
 265         free(path);
 266         return wt->prune_reason;
 267 }
 268
 269 /* convenient wrapper to deal with NULL strbuf */
 270 __attribute__((format (printf, 2, 3)))
 271 static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
 272 {
 273         va_list params;
 274
 275         if (!buf)
 276                 return;
 277
 278         va_start(params, fmt);
 279         strbuf_vaddf(buf, fmt, params);
 280         va_end(params);
 281 }
 282
 283 int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
 284                       unsigned flags)
 285 {
 286         struct strbuf wt_path = STRBUF_INIT;
 287         struct strbuf realpath = STRBUF_INIT;
 288         char *path = NULL;
 289         int err, ret = -1;
 290
 291         strbuf_addf(&wt_path, "%s/.git", wt->path);
 292
 293         if (is_main_worktree(wt)) {
 294                 if (is_directory(wt_path.buf)) {
 295                         ret = 0;
 296                         goto done;
 297                 }
 298                 /*
 299                  * Main worktree using .git file to point to the
 300                  * repository would make it impossible to know where
 301                  * the actual worktree is if this function is executed
 302                  * from another worktree. No .git file support for now.
 303                  */
 304                 strbuf_addf_gently(errmsg,
 305                                    _("'%s' at main working tree is not the repository directory"),
 306                                    wt_path.buf);
 307                 goto done;
 308         }
 309
 310         /*
 311          * Make sure "gitdir" file points to a real .git file and that
 312          * file points back here.
 313          */
 314         if (!is_absolute_path(wt->path)) {
 315                 strbuf_addf_gently(errmsg,
 316                                    _("'%s' file does not contain absolute path to the working tree location"),
 317                                    git_common_path("worktrees/%s/gitdir", wt->id));
 318                 goto done;
 319         }
 320
 321         if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
 322             !file_exists(wt->path)) {
 323                 ret = 0;
 324                 goto done;
 325         }
 326
 327         if (!file_exists(wt_path.buf)) {
 328                 strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
 329                 goto done;
 330         }
 331
 332         path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
 333         if (!path) {
 334                 strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
 335                                    wt_path.buf, err);
 336                 goto done;
 337         }
 338
 339         strbuf_realpath(&realpath, git_common_path("worktrees/%s", wt->id), 1);
 340         ret = fspathcmp(path, realpath.buf);
 341
 342         if (ret)
 343                 strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
 344                                    wt->path, git_common_path("worktrees/%s", wt->id));
 345 done:
 346         free(path);
 347         strbuf_release(&wt_path);
 348         strbuf_release(&realpath);
 349         return ret;
 350 }
 351
 352 void update_worktree_location(struct worktree *wt, const char *path_)
 353 {
 354         struct strbuf path = STRBUF_INIT;
 355
 356         if (is_main_worktree(wt))
 357                 BUG("can't relocate main worktree");
 358
 359         strbuf_realpath(&path, path_, 1);
 360         if (fspathcmp(wt->path, path.buf)) {
 361                 write_file(git_common_path("worktrees/%s/gitdir", wt->id),
 362                            "%s/.git", path.buf);
 363                 free(wt->path);
 364                 wt->path = strbuf_detach(&path, NULL);
 365         }
 366         strbuf_release(&path);
 367 }
 368
 369 int is_worktree_being_rebased(const struct worktree *wt,
 370                               const char *target)
 371 {
 372         struct wt_status_state state;
 373         int found_rebase;
 374
 375         memset(&state, 0, sizeof(state));
 376         found_rebase = wt_status_check_rebase(wt, &state) &&
 377                        (state.rebase_in_progress ||
 378                         state.rebase_interactive_in_progress) &&
 379                        state.branch &&
 380                        skip_prefix(target, "refs/heads/", &target) &&
 381                        !strcmp(state.branch, target);
 382         wt_status_state_free_buffers(&state);
 383         return found_rebase;
 384 }
 385
 386 int is_worktree_being_bisected(const struct worktree *wt,
 387                                const char *target)
 388 {
 389         struct wt_status_state state;
 390         int found_bisect;
 391
 392         memset(&state, 0, sizeof(state));
 393         found_bisect = wt_status_check_bisect(wt, &state) &&
 394                        state.branch &&
 395                        skip_prefix(target, "refs/heads/", &target) &&
 396                        !strcmp(state.branch, target);
 397         wt_status_state_free_buffers(&state);
 398         return found_bisect;
 399 }
 400
 401 /*
 402  * note: this function should be able to detect shared symref even if
 403  * HEAD is temporarily detached (e.g. in the middle of rebase or
 404  * bisect). New commands that do similar things should update this
 405  * function as well.
 406  */
 407 int is_shared_symref(const struct worktree *wt, const char *symref,
 408                      const char *target)
 409 {
 410         const char *symref_target;
 411         struct ref_store *refs;
 412         int flags;
 413
 414         if (wt->is_bare)
 415                 return 0;
 416
 417         if (wt->is_detached && !strcmp(symref, "HEAD")) {
 418                 if (is_worktree_being_rebased(wt, target))
 419                         return 1;
 420                 if (is_worktree_being_bisected(wt, target))
 421                         return 1;
 422         }
 423
 424         refs = get_worktree_ref_store(wt);
 425         symref_target = refs_resolve_ref_unsafe(refs, symref, 0,
 426                                                 NULL, &flags);
 427         if ((flags & REF_ISSYMREF) &&
 428             symref_target && !strcmp(symref_target, target))
 429                 return 1;
 430
 431         return 0;
 432 }
 433
 434 const struct worktree *find_shared_symref(struct worktree **worktrees,
 435                                           const char *symref,
 436                                           const char *target)
 437 {
 438
 439         for (int i = 0; worktrees[i]; i++)
 440                 if (is_shared_symref(worktrees[i], symref, target))
 441                         return worktrees[i];
 442
 443         return NULL;
 444 }
 445
 446 int submodule_uses_worktrees(const char *path)
 447 {
 448         char *submodule_gitdir;
 449         struct strbuf sb = STRBUF_INIT, err = STRBUF_INIT;
 450         DIR *dir;
 451         struct dirent *d;
 452         int ret = 0;
 453         struct repository_format format = REPOSITORY_FORMAT_INIT;
 454
 455         submodule_gitdir = git_pathdup_submodule(path, "%s", "");
 456         if (!submodule_gitdir)
 457                 return 0;
 458
 459         /* The env would be set for the superproject. */
 460         get_common_dir_noenv(&sb, submodule_gitdir);
 461         free(submodule_gitdir);
 462
 463         strbuf_addstr(&sb, "/config");
 464         read_repository_format(&format, sb.buf);
 465         if (verify_repository_format(&format, &err)) {
 466                 strbuf_release(&err);
 467                 strbuf_release(&sb);
 468                 clear_repository_format(&format);
 469                 return 1;
 470         }
 471         clear_repository_format(&format);
 472         strbuf_release(&err);
 473
 474         /* Replace config by worktrees. */
 475         strbuf_setlen(&sb, sb.len - strlen("config"));
 476         strbuf_addstr(&sb, "worktrees");
 477
 478         /* See if there is any file inside the worktrees directory. */
 479         dir = opendir(sb.buf);
 480         strbuf_release(&sb);
 481
 482         if (!dir)
 483                 return 0;
 484
 485         d = readdir_skip_dot_and_dotdot(dir);
 486         if (d)
 487                 ret = 1;
 488         closedir(dir);
 489         return ret;
 490 }
 491
 492 void strbuf_worktree_ref(const struct worktree *wt,
 493                          struct strbuf *sb,
 494                          const char *refname)
 495 {
 496         if (parse_worktree_ref(refname, NULL, NULL, NULL) ==
 497                     REF_WORKTREE_CURRENT &&
 498             wt && !wt->is_current) {
 499                 if (is_main_worktree(wt))
 500                         strbuf_addstr(sb, "main-worktree/");
 501                 else
 502                         strbuf_addf(sb, "worktrees/%s/", wt->id);
 503         }
 504         strbuf_addstr(sb, refname);
 505 }
 506
 507 int other_head_refs(each_ref_fn fn, void *cb_data)
 508 {
 509         struct worktree **worktrees, **p;
 510         struct strbuf refname = STRBUF_INIT;
 511         int ret = 0;
 512
 513         worktrees = get_worktrees();
 514         for (p = worktrees; *p; p++) {
 515                 struct worktree *wt = *p;
 516                 struct object_id oid;
 517                 int flag;
 518
 519                 if (wt->is_current)
 520                         continue;
 521
 522                 strbuf_reset(&refname);
 523                 strbuf_worktree_ref(wt, &refname, "HEAD");
 524                 if (refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
 525                                             refname.buf,
 526                                             RESOLVE_REF_READING,
 527                                             &oid, &flag))
 528                         ret = fn(refname.buf, &oid, flag, cb_data);
 529                 if (ret)
 530                         break;
 531         }
 532         free_worktrees(worktrees);
 533         strbuf_release(&refname);
 534         return ret;
 535 }
 536
 537 /*
 538  * Repair worktree's /path/to/worktree/.git file if missing, corrupt, or not
 539  * pointing at <repo>/worktrees/<id>.
 540  */
 541 static void repair_gitfile(struct worktree *wt,
 542                            worktree_repair_fn fn, void *cb_data)
 543 {
 544         struct strbuf dotgit = STRBUF_INIT;
 545         struct strbuf repo = STRBUF_INIT;
 546         char *backlink;
 547         const char *repair = NULL;
 548         int err;
 549
 550         /* missing worktree can't be repaired */
 551         if (!file_exists(wt->path))
 552                 return;
 553
 554         if (!is_directory(wt->path)) {
 555                 fn(1, wt->path, _("not a directory"), cb_data);
 556                 return;
 557         }
 558
 559         strbuf_realpath(&repo, git_common_path("worktrees/%s", wt->id), 1);
 560         strbuf_addf(&dotgit, "%s/.git", wt->path);
 561         backlink = xstrdup_or_null(read_gitfile_gently(dotgit.buf, &err));
 562
 563         if (err == READ_GITFILE_ERR_NOT_A_FILE)
 564                 fn(1, wt->path, _(".git is not a file"), cb_data);
 565         else if (err)
 566                 repair = _(".git file broken");
 567         else if (fspathcmp(backlink, repo.buf))
 568                 repair = _(".git file incorrect");
 569
 570         if (repair) {
 571                 fn(0, wt->path, repair, cb_data);
 572                 write_file(dotgit.buf, "gitdir: %s", repo.buf);
 573         }
 574
 575         free(backlink);
 576         strbuf_release(&repo);
 577         strbuf_release(&dotgit);
 578 }
 579
 580 static void repair_noop(int iserr, const char *path, const char *msg,
 581                         void *cb_data)
 582 {
 583         /* nothing */
 584 }
 585
 586 void repair_worktrees(worktree_repair_fn fn, void *cb_data)
 587 {
 588         struct worktree **worktrees = get_worktrees();
 589         struct worktree **wt = worktrees + 1; /* +1 skips main worktree */
 590
 591         if (!fn)
 592                 fn = repair_noop;
 593         for (; *wt; wt++)
 594                 repair_gitfile(*wt, fn, cb_data);
 595         free_worktrees(worktrees);
 596 }
 597
 598 static int is_main_worktree_path(const char *path)
 599 {
 600         struct strbuf target = STRBUF_INIT;
 601         struct strbuf maindir = STRBUF_INIT;
 602         int cmp;
 603
 604         strbuf_add_real_path(&target, path);
 605         strbuf_strip_suffix(&target, "/.git");
 606         strbuf_add_real_path(&maindir, get_git_common_dir());
 607         strbuf_strip_suffix(&maindir, "/.git");
 608         cmp = fspathcmp(maindir.buf, target.buf);
 609
 610         strbuf_release(&maindir);
 611         strbuf_release(&target);
 612         return !cmp;
 613 }
 614
 615 /*
 616  * If both the main worktree and linked worktree have been moved, then the
 617  * gitfile /path/to/worktree/.git won't point into the repository, thus we
 618  * won't know which <repo>/worktrees/<id>/gitdir to repair. However, we may
 619  * be able to infer the gitdir by manually reading /path/to/worktree/.git,
 620  * extracting the <id>, and checking if <repo>/worktrees/<id> exists.
 621  */
 622 static char *infer_backlink(const char *gitfile)
 623 {
 624         struct strbuf actual = STRBUF_INIT;
 625         struct strbuf inferred = STRBUF_INIT;
 626         const char *id;
 627
 628         if (strbuf_read_file(&actual, gitfile, 0) < 0)
 629                 goto error;
 630         if (!starts_with(actual.buf, "gitdir:"))
 631                 goto error;
 632         if (!(id = find_last_dir_sep(actual.buf)))
 633                 goto error;
 634         strbuf_trim(&actual);
 635         id++; /* advance past '/' to point at <id> */
 636         if (!*id)
 637                 goto error;
 638         strbuf_git_common_path(&inferred, the_repository, "worktrees/%s", id);
 639         if (!is_directory(inferred.buf))
 640                 goto error;
 641
 642         strbuf_release(&actual);
 643         return strbuf_detach(&inferred, NULL);
 644
 645 error:
 646         strbuf_release(&actual);
 647         strbuf_release(&inferred);
 648         return NULL;
 649 }
 650
 651 /*
 652  * Repair <repo>/worktrees/<id>/gitdir if missing, corrupt, or not pointing at
 653  * the worktree's path.
 654  */
 655 void repair_worktree_at_path(const char *path,
 656                              worktree_repair_fn fn, void *cb_data)
 657 {
 658         struct strbuf dotgit = STRBUF_INIT;
 659         struct strbuf realdotgit = STRBUF_INIT;
 660         struct strbuf gitdir = STRBUF_INIT;
 661         struct strbuf olddotgit = STRBUF_INIT;
 662         char *backlink = NULL;
 663         const char *repair = NULL;
 664         int err;
 665
 666         if (!fn)
 667                 fn = repair_noop;
 668
 669         if (is_main_worktree_path(path))
 670                 goto done;
 671
 672         strbuf_addf(&dotgit, "%s/.git", path);
 673         if (!strbuf_realpath(&realdotgit, dotgit.buf, 0)) {
 674                 fn(1, path, _("not a valid path"), cb_data);
 675                 goto done;
 676         }
 677
 678         backlink = xstrdup_or_null(read_gitfile_gently(realdotgit.buf, &err));
 679         if (err == READ_GITFILE_ERR_NOT_A_FILE) {
 680                 fn(1, realdotgit.buf, _("unable to locate repository; .git is not a file"), cb_data);
 681                 goto done;
 682         } else if (err == READ_GITFILE_ERR_NOT_A_REPO) {
 683                 if (!(backlink = infer_backlink(realdotgit.buf))) {
 684                         fn(1, realdotgit.buf, _("unable to locate repository; .git file does not reference a repository"), cb_data);
 685                         goto done;
 686                 }
 687         } else if (err) {
 688                 fn(1, realdotgit.buf, _("unable to locate repository; .git file broken"), cb_data);
 689                 goto done;
 690         }
 691
 692         strbuf_addf(&gitdir, "%s/gitdir", backlink);
 693         if (strbuf_read_file(&olddotgit, gitdir.buf, 0) < 0)
 694                 repair = _("gitdir unreadable");
 695         else {
 696                 strbuf_rtrim(&olddotgit);
 697                 if (fspathcmp(olddotgit.buf, realdotgit.buf))
 698                         repair = _("gitdir incorrect");
 699         }
 700
 701         if (repair) {
 702                 fn(0, gitdir.buf, repair, cb_data);
 703                 write_file(gitdir.buf, "%s", realdotgit.buf);
 704         }
 705 done:
 706         free(backlink);
 707         strbuf_release(&olddotgit);
 708         strbuf_release(&gitdir);
 709         strbuf_release(&realdotgit);
 710         strbuf_release(&dotgit);
 711 }
 712
 713 int should_prune_worktree(const char *id, struct strbuf *reason, char **wtpath, timestamp_t expire)
 714 {
 715         struct stat st;
 716         char *path;
 717         int fd;
 718         size_t len;
 719         ssize_t read_result;
 720
 721         *wtpath = NULL;
 722         if (!is_directory(git_path("worktrees/%s", id))) {
 723                 strbuf_addstr(reason, _("not a valid directory"));
 724                 return 1;
 725         }
 726         if (file_exists(git_path("worktrees/%s/locked", id)))
 727                 return 0;
 728         if (stat(git_path("worktrees/%s/gitdir", id), &st)) {
 729                 strbuf_addstr(reason, _("gitdir file does not exist"));
 730                 return 1;
 731         }
 732         fd = open(git_path("worktrees/%s/gitdir", id), O_RDONLY);
 733         if (fd < 0) {
 734                 strbuf_addf(reason, _("unable to read gitdir file (%s)"),
 735                             strerror(errno));
 736                 return 1;
 737         }
 738         len = xsize_t(st.st_size);
 739         path = xmallocz(len);
 740
 741         read_result = read_in_full(fd, path, len);
 742         if (read_result < 0) {
 743                 strbuf_addf(reason, _("unable to read gitdir file (%s)"),
 744                             strerror(errno));
 745                 close(fd);
 746                 free(path);
 747                 return 1;
 748         }
 749         close(fd);
 750
 751         if (read_result != len) {
 752                 strbuf_addf(reason,
 753                             _("short read (expected %"PRIuMAX" bytes, read %"PRIuMAX")"),
 754                             (uintmax_t)len, (uintmax_t)read_result);
 755                 free(path);
 756                 return 1;
 757         }
 758         while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
 759                 len--;
 760         if (!len) {
 761                 strbuf_addstr(reason, _("invalid gitdir file"));
 762                 free(path);
 763                 return 1;
 764         }
 765         path[len] = '\0';
 766         if (!file_exists(path)) {
 767                 if (stat(git_path("worktrees/%s/index", id), &st) ||
 768                     st.st_mtime <= expire) {
 769                         strbuf_addstr(reason, _("gitdir file points to non-existent location"));
 770                         free(path);
 771                         return 1;
 772                 } else {
 773                         *wtpath = path;
 774                         return 0;
 775                 }
 776         }
 777         *wtpath = path;
 778         return 0;
 779 }
 780
 781 static int move_config_setting(const char *key, const char *value,
 782                                const char *from_file, const char *to_file)
 783 {
 784         if (git_config_set_in_file_gently(to_file, key, value))
 785                 return error(_("unable to set %s in '%s'"), key, to_file);
 786         if (git_config_set_in_file_gently(from_file, key, NULL))
 787                 return error(_("unable to unset %s in '%s'"), key, from_file);
 788         return 0;
 789 }
 790
 791 int init_worktree_config(struct repository *r)
 792 {
 793         int res = 0;
 794         int bare = 0;
 795         struct config_set cs = { { 0 } };
 796         const char *core_worktree;
 797         char *common_config_file;
 798         char *main_worktree_file;
 799
 800         /*
 801          * If the extension is already enabled, then we can skip the
 802          * upgrade process.
 803          */
 804         if (repository_format_worktree_config)
 805                 return 0;
 806         if ((res = git_config_set_gently("extensions.worktreeConfig", "true")))
 807                 return error(_("failed to set extensions.worktreeConfig setting"));
 808
 809         common_config_file = xstrfmt("%s/config", r->commondir);
 810         main_worktree_file = xstrfmt("%s/config.worktree", r->commondir);
 811
 812         git_configset_init(&cs);
 813         git_configset_add_file(&cs, common_config_file);
 814
 815         /*
 816          * If core.bare is true in the common config file, then we need to
 817          * move it to the main worktree's config file or it will break all
 818          * worktrees. If it is false, then leave it in place because it
 819          * _could_ be negating a global core.bare=true.
 820          */
 821         if (!git_configset_get_bool(&cs, "core.bare", &bare) && bare) {
 822                 if ((res = move_config_setting("core.bare", "true",
 823                                                common_config_file,
 824                                                main_worktree_file)))
 825                         goto cleanup;
 826         }
 827         /*
 828          * If core.worktree is set, then the main worktree is located
 829          * somewhere different than the parent of the common Git dir.
 830          * Relocate that value to avoid breaking all worktrees with this
 831          * upgrade to worktree config.
 832          */
 833         if (!git_configset_get_value(&cs, "core.worktree", &core_worktree)) {
 834                 if ((res = move_config_setting("core.worktree", core_worktree,
 835                                                common_config_file,
 836                                                main_worktree_file)))
 837                         goto cleanup;
 838         }
 839
 840         /*
 841          * Ensure that we use worktree config for the remaining lifetime
 842          * of the current process.
 843          */
 844         repository_format_worktree_config = 1;
 845
 846 cleanup:
 847         git_configset_clear(&cs);
 848         free(common_config_file);
 849         free(main_worktree_file);
 850         return res;
 851 }