worktree.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "refs.h"
   4 #include "strbuf.h"
   5 #include "worktree.h"
   6 #include "dir.h"
   7 #include "wt-status.h"
   8 #include "config.h"
   9
  10 void free_worktrees(struct worktree **worktrees)
  11 {
  12         int i = 0;
  13
  14         for (i = 0; worktrees[i]; i++) {
  15                 free(worktrees[i]->path);
  16                 free(worktrees[i]->id);
  17                 free(worktrees[i]->head_ref);
  18                 free(worktrees[i]->lock_reason);
  19                 free(worktrees[i]->prune_reason);
  20                 free(worktrees[i]);
  21         }
  22         free (worktrees);
  23 }
  24
  25 /**
  26  * Update head_oid, head_ref and is_detached of the given worktree
  27  */
  28 static void add_head_info(struct worktree *wt)
  29 {
  30         int flags;
  31         const char *target;
  32
  33         target = refs_resolve_ref_unsafe(get_worktree_ref_store(wt),
  34                                          "HEAD",
  35                                          0,
  36                                          &wt->head_oid, &flags);
  37         if (!target)
  38                 return;
  39
  40         if (flags & REF_ISSYMREF)
  41                 wt->head_ref = xstrdup(target);
  42         else
  43                 wt->is_detached = 1;
  44 }
  45
  46 /**
  47  * get the main worktree
  48  */
  49 static struct worktree *get_main_worktree(void)
  50 {
  51         struct worktree *worktree = NULL;
  52         struct strbuf worktree_path = STRBUF_INIT;
  53
  54         strbuf_add_real_path(&worktree_path, get_git_common_dir());
  55         strbuf_strip_suffix(&worktree_path, "/.git");
  56
  57         CALLOC_ARRAY(worktree, 1);
  58         worktree->path = strbuf_detach(&worktree_path, NULL);
  59         /*
  60          * NEEDSWORK: If this function is called from a secondary worktree and
  61          * config.worktree is present, is_bare_repository_cfg will reflect the
  62          * contents of config.worktree, not the contents of the main worktree.
  63          * This means that worktree->is_bare may be set to 0 even if the main
  64          * worktree is configured to be bare.
  65          */
  66         worktree->is_bare = (is_bare_repository_cfg == 1) ||
  67                 is_bare_repository();
  68         add_head_info(worktree);
  69         return worktree;
  70 }
  71
  72 static struct worktree *get_linked_worktree(const char *id)
  73 {
  74         struct worktree *worktree = NULL;
  75         struct strbuf path = STRBUF_INIT;
  76         struct strbuf worktree_path = STRBUF_INIT;
  77
  78         if (!id)
  79                 die("Missing linked worktree name");
  80
  81         strbuf_git_common_path(&path, the_repository, "worktrees/%s/gitdir", id);
  82         if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
  83                 /* invalid gitdir file */
  84                 goto done;
  85         strbuf_rtrim(&worktree_path);
  86         strbuf_strip_suffix(&worktree_path, "/.git");
  87
  88         CALLOC_ARRAY(worktree, 1);
  89         worktree->path = strbuf_detach(&worktree_path, NULL);
  90         worktree->id = xstrdup(id);
  91         add_head_info(worktree);
  92
  93 done:
  94         strbuf_release(&path);
  95         strbuf_release(&worktree_path);
  96         return worktree;
  97 }
  98
  99 static void mark_current_worktree(struct worktree **worktrees)
 100 {
 101         char *git_dir = absolute_pathdup(get_git_dir());
 102         int i;
 103
 104         for (i = 0; worktrees[i]; i++) {
 105                 struct worktree *wt = worktrees[i];
 106                 const char *wt_git_dir = get_worktree_git_dir(wt);
 107
 108                 if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
 109                         wt->is_current = 1;
 110                         break;
 111                 }
 112         }
 113         free(git_dir);
 114 }
 115
 116 struct worktree **get_worktrees(void)
 117 {
 118         struct worktree **list = NULL;
 119         struct strbuf path = STRBUF_INIT;
 120         DIR *dir;
 121         struct dirent *d;
 122         int counter = 0, alloc = 2;
 123
 124         ALLOC_ARRAY(list, alloc);
 125
 126         list[counter++] = get_main_worktree();
 127
 128         strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
 129         dir = opendir(path.buf);
 130         strbuf_release(&path);
 131         if (dir) {
 132                 while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) {
 133                         struct worktree *linked = NULL;
 134
 135                         if ((linked = get_linked_worktree(d->d_name))) {
 136                                 ALLOC_GROW(list, counter + 1, alloc);
 137                                 list[counter++] = linked;
 138                         }
 139                 }
 140                 closedir(dir);
 141         }
 142         ALLOC_GROW(list, counter + 1, alloc);
 143         list[counter] = NULL;
 144
 145         mark_current_worktree(list);
 146         return list;
 147 }
 148
 149 const char *get_worktree_git_dir(const struct worktree *wt)
 150 {
 151         if (!wt)
 152                 return get_git_dir();
 153         else if (!wt->id)
 154                 return get_git_common_dir();
 155         else
 156                 return git_common_path("worktrees/%s", wt->id);
 157 }
 158
 159 static struct worktree *find_worktree_by_suffix(struct worktree **list,
 160                                                 const char *suffix)
 161 {
 162         struct worktree *found = NULL;
 163         int nr_found = 0, suffixlen;
 164
 165         suffixlen = strlen(suffix);
 166         if (!suffixlen)
 167                 return NULL;
 168
 169         for (; *list && nr_found < 2; list++) {
 170                 const char      *path    = (*list)->path;
 171                 int              pathlen = strlen(path);
 172                 int              start   = pathlen - suffixlen;
 173
 174                 /* suffix must start at directory boundary */
 175                 if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
 176                     !fspathcmp(suffix, path + start)) {
 177                         found = *list;
 178                         nr_found++;
 179                 }
 180         }
 181         return nr_found == 1 ? found : NULL;
 182 }
 183
 184 struct worktree *find_worktree(struct worktree **list,
 185                                const char *prefix,
 186                                const char *arg)
 187 {
 188         struct worktree *wt;
 189         char *to_free = NULL;
 190
 191         if ((wt = find_worktree_by_suffix(list, arg)))
 192                 return wt;
 193
 194         if (prefix)
 195                 arg = to_free = prefix_filename(prefix, arg);
 196         wt = find_worktree_by_path(list, arg);
 197         free(to_free);
 198         return wt;
 199 }
 200
 201 struct worktree *find_worktree_by_path(struct worktree **list, const char *p)
 202 {
 203         struct strbuf wt_path = STRBUF_INIT;
 204         char *path = real_pathdup(p, 0);
 205
 206         if (!path)
 207                 return NULL;
 208         for (; *list; list++) {
 209                 if (!strbuf_realpath(&wt_path, (*list)->path, 0))
 210                         continue;
 211
 212                 if (!fspathcmp(path, wt_path.buf))
 213                         break;
 214         }
 215         free(path);
 216         strbuf_release(&wt_path);
 217         return *list;
 218 }
 219
 220 int is_main_worktree(const struct worktree *wt)
 221 {
 222         return !wt->id;
 223 }
 224
 225 const char *worktree_lock_reason(struct worktree *wt)
 226 {
 227         if (is_main_worktree(wt))
 228                 return NULL;
 229
 230         if (!wt->lock_reason_valid) {
 231                 struct strbuf path = STRBUF_INIT;
 232
 233                 strbuf_addstr(&path, worktree_git_path(wt, "locked"));
 234                 if (file_exists(path.buf)) {
 235                         struct strbuf lock_reason = STRBUF_INIT;
 236                         if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
 237                                 die_errno(_("failed to read '%s'"), path.buf);
 238                         strbuf_trim(&lock_reason);
 239                         wt->lock_reason = strbuf_detach(&lock_reason, NULL);
 240                 } else
 241                         wt->lock_reason = NULL;
 242                 wt->lock_reason_valid = 1;
 243                 strbuf_release(&path);
 244         }
 245
 246         return wt->lock_reason;
 247 }
 248
 249 const char *worktree_prune_reason(struct worktree *wt, timestamp_t expire)
 250 {
 251         struct strbuf reason = STRBUF_INIT;
 252         char *path = NULL;
 253
 254         if (is_main_worktree(wt))
 255                 return NULL;
 256         if (wt->prune_reason_valid)
 257                 return wt->prune_reason;
 258
 259         if (should_prune_worktree(wt->id, &reason, &path, expire))
 260                 wt->prune_reason = strbuf_detach(&reason, NULL);
 261         wt->prune_reason_valid = 1;
 262
 263         strbuf_release(&reason);
 264         free(path);
 265         return wt->prune_reason;
 266 }
 267
 268 /* convenient wrapper to deal with NULL strbuf */
 269 __attribute__((format (printf, 2, 3)))
 270 static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
 271 {
 272         va_list params;
 273
 274         if (!buf)
 275                 return;
 276
 277         va_start(params, fmt);
 278         strbuf_vaddf(buf, fmt, params);
 279         va_end(params);
 280 }
 281
 282 int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
 283                       unsigned flags)
 284 {
 285         struct strbuf wt_path = STRBUF_INIT;
 286         struct strbuf realpath = STRBUF_INIT;
 287         char *path = NULL;
 288         int err, ret = -1;
 289
 290         strbuf_addf(&wt_path, "%s/.git", wt->path);
 291
 292         if (is_main_worktree(wt)) {
 293                 if (is_directory(wt_path.buf)) {
 294                         ret = 0;
 295                         goto done;
 296                 }
 297                 /*
 298                  * Main worktree using .git file to point to the
 299                  * repository would make it impossible to know where
 300                  * the actual worktree is if this function is executed
 301                  * from another worktree. No .git file support for now.
 302                  */
 303                 strbuf_addf_gently(errmsg,
 304                                    _("'%s' at main working tree is not the repository directory"),
 305                                    wt_path.buf);
 306                 goto done;
 307         }
 308
 309         /*
 310          * Make sure "gitdir" file points to a real .git file and that
 311          * file points back here.
 312          */
 313         if (!is_absolute_path(wt->path)) {
 314                 strbuf_addf_gently(errmsg,
 315                                    _("'%s' file does not contain absolute path to the working tree location"),
 316                                    git_common_path("worktrees/%s/gitdir", wt->id));
 317                 goto done;
 318         }
 319
 320         if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
 321             !file_exists(wt->path)) {
 322                 ret = 0;
 323                 goto done;
 324         }
 325
 326         if (!file_exists(wt_path.buf)) {
 327                 strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
 328                 goto done;
 329         }
 330
 331         path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
 332         if (!path) {
 333                 strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
 334                                    wt_path.buf, err);
 335                 goto done;
 336         }
 337
 338         strbuf_realpath(&realpath, git_common_path("worktrees/%s", wt->id), 1);
 339         ret = fspathcmp(path, realpath.buf);
 340
 341         if (ret)
 342                 strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
 343                                    wt->path, git_common_path("worktrees/%s", wt->id));
 344 done:
 345         free(path);
 346         strbuf_release(&wt_path);
 347         strbuf_release(&realpath);
 348         return ret;
 349 }
 350
 351 void update_worktree_location(struct worktree *wt, const char *path_)
 352 {
 353         struct strbuf path = STRBUF_INIT;
 354
 355         if (is_main_worktree(wt))
 356                 BUG("can't relocate main worktree");
 357
 358         strbuf_realpath(&path, path_, 1);
 359         if (fspathcmp(wt->path, path.buf)) {
 360                 write_file(git_common_path("worktrees/%s/gitdir", wt->id),
 361                            "%s/.git", path.buf);
 362                 free(wt->path);
 363                 wt->path = strbuf_detach(&path, NULL);
 364         }
 365         strbuf_release(&path);
 366 }
 367
 368 int is_worktree_being_rebased(const struct worktree *wt,
 369                               const char *target)
 370 {
 371         struct wt_status_state state;
 372         int found_rebase;
 373
 374         memset(&state, 0, sizeof(state));
 375         found_rebase = wt_status_check_rebase(wt, &state) &&
 376                        (state.rebase_in_progress ||
 377                         state.rebase_interactive_in_progress) &&
 378                        state.branch &&
 379                        skip_prefix(target, "refs/heads/", &target) &&
 380                        !strcmp(state.branch, target);
 381         wt_status_state_free_buffers(&state);
 382         return found_rebase;
 383 }
 384
 385 int is_worktree_being_bisected(const struct worktree *wt,
 386                                const char *target)
 387 {
 388         struct wt_status_state state;
 389         int found_bisect;
 390
 391         memset(&state, 0, sizeof(state));
 392         found_bisect = wt_status_check_bisect(wt, &state) &&
 393                        state.branch &&
 394                        skip_prefix(target, "refs/heads/", &target) &&
 395                        !strcmp(state.branch, target);
 396         wt_status_state_free_buffers(&state);
 397         return found_bisect;
 398 }
 399
 400 /*
 401  * note: this function should be able to detect shared symref even if
 402  * HEAD is temporarily detached (e.g. in the middle of rebase or
 403  * bisect). New commands that do similar things should update this
 404  * function as well.
 405  */
 406 const struct worktree *find_shared_symref(struct worktree **worktrees,
 407                                           const char *symref,
 408                                           const char *target)
 409 {
 410         const struct worktree *existing = NULL;
 411         int i = 0;
 412
 413         for (i = 0; worktrees[i]; i++) {
 414                 struct worktree *wt = worktrees[i];
 415                 const char *symref_target;
 416                 struct ref_store *refs;
 417                 int flags;
 418
 419                 if (wt->is_bare)
 420                         continue;
 421
 422                 if (wt->is_detached && !strcmp(symref, "HEAD")) {
 423                         if (is_worktree_being_rebased(wt, target)) {
 424                                 existing = wt;
 425                                 break;
 426                         }
 427                         if (is_worktree_being_bisected(wt, target)) {
 428                                 existing = wt;
 429                                 break;
 430                         }
 431                 }
 432
 433                 refs = get_worktree_ref_store(wt);
 434                 symref_target = refs_resolve_ref_unsafe(refs, symref, 0,
 435                                                         NULL, &flags);
 436                 if ((flags & REF_ISSYMREF) &&
 437                     symref_target && !strcmp(symref_target, target)) {
 438                         existing = wt;
 439                         break;
 440                 }
 441         }
 442
 443         return existing;
 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 int parse_worktree_ref(const char *worktree_ref, const char **name,
 493                        int *name_length, const char **ref)
 494 {
 495         if (skip_prefix(worktree_ref, "main-worktree/", &worktree_ref)) {
 496                 if (!*worktree_ref)
 497                         return -1;
 498                 if (name)
 499                         *name = NULL;
 500                 if (name_length)
 501                         *name_length = 0;
 502                 if (ref)
 503                         *ref = worktree_ref;
 504                 return 0;
 505         }
 506         if (skip_prefix(worktree_ref, "worktrees/", &worktree_ref)) {
 507                 const char *slash = strchr(worktree_ref, '/');
 508
 509                 if (!slash || slash == worktree_ref || !slash[1])
 510                         return -1;
 511                 if (name)
 512                         *name = worktree_ref;
 513                 if (name_length)
 514                         *name_length = slash - worktree_ref;
 515                 if (ref)
 516                         *ref = slash + 1;
 517                 return 0;
 518         }
 519         return -1;
 520 }
 521
 522 void strbuf_worktree_ref(const struct worktree *wt,
 523                          struct strbuf *sb,
 524                          const char *refname)
 525 {
 526         switch (ref_type(refname)) {
 527         case REF_TYPE_PSEUDOREF:
 528         case REF_TYPE_PER_WORKTREE:
 529                 if (wt && !wt->is_current) {
 530                         if (is_main_worktree(wt))
 531                                 strbuf_addstr(sb, "main-worktree/");
 532                         else
 533                                 strbuf_addf(sb, "worktrees/%s/", wt->id);
 534                 }
 535                 break;
 536
 537         case REF_TYPE_MAIN_PSEUDOREF:
 538         case REF_TYPE_OTHER_PSEUDOREF:
 539                 break;
 540
 541         case REF_TYPE_NORMAL:
 542                 /*
 543                  * For shared refs, don't prefix worktrees/ or
 544                  * main-worktree/. It's not necessary and
 545                  * files-backend.c can't handle it anyway.
 546                  */
 547                 break;
 548         }
 549         strbuf_addstr(sb, refname);
 550 }
 551
 552 int other_head_refs(each_ref_fn fn, void *cb_data)
 553 {
 554         struct worktree **worktrees, **p;
 555         struct strbuf refname = STRBUF_INIT;
 556         int ret = 0;
 557
 558         worktrees = get_worktrees();
 559         for (p = worktrees; *p; p++) {
 560                 struct worktree *wt = *p;
 561                 struct object_id oid;
 562                 int flag;
 563
 564                 if (wt->is_current)
 565                         continue;
 566
 567                 strbuf_reset(&refname);
 568                 strbuf_worktree_ref(wt, &refname, "HEAD");
 569                 if (refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
 570                                             refname.buf,
 571                                             RESOLVE_REF_READING,
 572                                             &oid, &flag))
 573                         ret = fn(refname.buf, &oid, flag, cb_data);
 574                 if (ret)
 575                         break;
 576         }
 577         free_worktrees(worktrees);
 578         strbuf_release(&refname);
 579         return ret;
 580 }
 581
 582 /*
 583  * Repair worktree's /path/to/worktree/.git file if missing, corrupt, or not
 584  * pointing at <repo>/worktrees/<id>.
 585  */
 586 static void repair_gitfile(struct worktree *wt,
 587                            worktree_repair_fn fn, void *cb_data)
 588 {
 589         struct strbuf dotgit = STRBUF_INIT;
 590         struct strbuf repo = STRBUF_INIT;
 591         char *backlink;
 592         const char *repair = NULL;
 593         int err;
 594
 595         /* missing worktree can't be repaired */
 596         if (!file_exists(wt->path))
 597                 return;
 598
 599         if (!is_directory(wt->path)) {
 600                 fn(1, wt->path, _("not a directory"), cb_data);
 601                 return;
 602         }
 603
 604         strbuf_realpath(&repo, git_common_path("worktrees/%s", wt->id), 1);
 605         strbuf_addf(&dotgit, "%s/.git", wt->path);
 606         backlink = xstrdup_or_null(read_gitfile_gently(dotgit.buf, &err));
 607
 608         if (err == READ_GITFILE_ERR_NOT_A_FILE)
 609                 fn(1, wt->path, _(".git is not a file"), cb_data);
 610         else if (err)
 611                 repair = _(".git file broken");
 612         else if (fspathcmp(backlink, repo.buf))
 613                 repair = _(".git file incorrect");
 614
 615         if (repair) {
 616                 fn(0, wt->path, repair, cb_data);
 617                 write_file(dotgit.buf, "gitdir: %s", repo.buf);
 618         }
 619
 620         free(backlink);
 621         strbuf_release(&repo);
 622         strbuf_release(&dotgit);
 623 }
 624
 625 static void repair_noop(int iserr, const char *path, const char *msg,
 626                         void *cb_data)
 627 {
 628         /* nothing */
 629 }
 630
 631 void repair_worktrees(worktree_repair_fn fn, void *cb_data)
 632 {
 633         struct worktree **worktrees = get_worktrees();
 634         struct worktree **wt = worktrees + 1; /* +1 skips main worktree */
 635
 636         if (!fn)
 637                 fn = repair_noop;
 638         for (; *wt; wt++)
 639                 repair_gitfile(*wt, fn, cb_data);
 640         free_worktrees(worktrees);
 641 }
 642
 643 static int is_main_worktree_path(const char *path)
 644 {
 645         struct strbuf target = STRBUF_INIT;
 646         struct strbuf maindir = STRBUF_INIT;
 647         int cmp;
 648
 649         strbuf_add_real_path(&target, path);
 650         strbuf_strip_suffix(&target, "/.git");
 651         strbuf_add_real_path(&maindir, get_git_common_dir());
 652         strbuf_strip_suffix(&maindir, "/.git");
 653         cmp = fspathcmp(maindir.buf, target.buf);
 654
 655         strbuf_release(&maindir);
 656         strbuf_release(&target);
 657         return !cmp;
 658 }
 659
 660 /*
 661  * If both the main worktree and linked worktree have been moved, then the
 662  * gitfile /path/to/worktree/.git won't point into the repository, thus we
 663  * won't know which <repo>/worktrees/<id>/gitdir to repair. However, we may
 664  * be able to infer the gitdir by manually reading /path/to/worktree/.git,
 665  * extracting the <id>, and checking if <repo>/worktrees/<id> exists.
 666  */
 667 static char *infer_backlink(const char *gitfile)
 668 {
 669         struct strbuf actual = STRBUF_INIT;
 670         struct strbuf inferred = STRBUF_INIT;
 671         const char *id;
 672
 673         if (strbuf_read_file(&actual, gitfile, 0) < 0)
 674                 goto error;
 675         if (!starts_with(actual.buf, "gitdir:"))
 676                 goto error;
 677         if (!(id = find_last_dir_sep(actual.buf)))
 678                 goto error;
 679         strbuf_trim(&actual);
 680         id++; /* advance past '/' to point at <id> */
 681         if (!*id)
 682                 goto error;
 683         strbuf_git_common_path(&inferred, the_repository, "worktrees/%s", id);
 684         if (!is_directory(inferred.buf))
 685                 goto error;
 686
 687         strbuf_release(&actual);
 688         return strbuf_detach(&inferred, NULL);
 689
 690 error:
 691         strbuf_release(&actual);
 692         strbuf_release(&inferred);
 693         return NULL;
 694 }
 695
 696 /*
 697  * Repair <repo>/worktrees/<id>/gitdir if missing, corrupt, or not pointing at
 698  * the worktree's path.
 699  */
 700 void repair_worktree_at_path(const char *path,
 701                              worktree_repair_fn fn, void *cb_data)
 702 {
 703         struct strbuf dotgit = STRBUF_INIT;
 704         struct strbuf realdotgit = STRBUF_INIT;
 705         struct strbuf gitdir = STRBUF_INIT;
 706         struct strbuf olddotgit = STRBUF_INIT;
 707         char *backlink = NULL;
 708         const char *repair = NULL;
 709         int err;
 710
 711         if (!fn)
 712                 fn = repair_noop;
 713
 714         if (is_main_worktree_path(path))
 715                 goto done;
 716
 717         strbuf_addf(&dotgit, "%s/.git", path);
 718         if (!strbuf_realpath(&realdotgit, dotgit.buf, 0)) {
 719                 fn(1, path, _("not a valid path"), cb_data);
 720                 goto done;
 721         }
 722
 723         backlink = xstrdup_or_null(read_gitfile_gently(realdotgit.buf, &err));
 724         if (err == READ_GITFILE_ERR_NOT_A_FILE) {
 725                 fn(1, realdotgit.buf, _("unable to locate repository; .git is not a file"), cb_data);
 726                 goto done;
 727         } else if (err == READ_GITFILE_ERR_NOT_A_REPO) {
 728                 if (!(backlink = infer_backlink(realdotgit.buf))) {
 729                         fn(1, realdotgit.buf, _("unable to locate repository; .git file does not reference a repository"), cb_data);
 730                         goto done;
 731                 }
 732         } else if (err) {
 733                 fn(1, realdotgit.buf, _("unable to locate repository; .git file broken"), cb_data);
 734                 goto done;
 735         }
 736
 737         strbuf_addf(&gitdir, "%s/gitdir", backlink);
 738         if (strbuf_read_file(&olddotgit, gitdir.buf, 0) < 0)
 739                 repair = _("gitdir unreadable");
 740         else {
 741                 strbuf_rtrim(&olddotgit);
 742                 if (fspathcmp(olddotgit.buf, realdotgit.buf))
 743                         repair = _("gitdir incorrect");
 744         }
 745
 746         if (repair) {
 747                 fn(0, gitdir.buf, repair, cb_data);
 748                 write_file(gitdir.buf, "%s", realdotgit.buf);
 749         }
 750 done:
 751         free(backlink);
 752         strbuf_release(&olddotgit);
 753         strbuf_release(&gitdir);
 754         strbuf_release(&realdotgit);
 755         strbuf_release(&dotgit);
 756 }
 757
 758 int should_prune_worktree(const char *id, struct strbuf *reason, char **wtpath, timestamp_t expire)
 759 {
 760         struct stat st;
 761         char *path;
 762         int fd;
 763         size_t len;
 764         ssize_t read_result;
 765
 766         *wtpath = NULL;
 767         if (!is_directory(git_path("worktrees/%s", id))) {
 768                 strbuf_addstr(reason, _("not a valid directory"));
 769                 return 1;
 770         }
 771         if (file_exists(git_path("worktrees/%s/locked", id)))
 772                 return 0;
 773         if (stat(git_path("worktrees/%s/gitdir", id), &st)) {
 774                 strbuf_addstr(reason, _("gitdir file does not exist"));
 775                 return 1;
 776         }
 777         fd = open(git_path("worktrees/%s/gitdir", id), O_RDONLY);
 778         if (fd < 0) {
 779                 strbuf_addf(reason, _("unable to read gitdir file (%s)"),
 780                             strerror(errno));
 781                 return 1;
 782         }
 783         len = xsize_t(st.st_size);
 784         path = xmallocz(len);
 785
 786         read_result = read_in_full(fd, path, len);
 787         if (read_result < 0) {
 788                 strbuf_addf(reason, _("unable to read gitdir file (%s)"),
 789                             strerror(errno));
 790                 close(fd);
 791                 free(path);
 792                 return 1;
 793         }
 794         close(fd);
 795
 796         if (read_result != len) {
 797                 strbuf_addf(reason,
 798                             _("short read (expected %"PRIuMAX" bytes, read %"PRIuMAX")"),
 799                             (uintmax_t)len, (uintmax_t)read_result);
 800                 free(path);
 801                 return 1;
 802         }
 803         while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
 804                 len--;
 805         if (!len) {
 806                 strbuf_addstr(reason, _("invalid gitdir file"));
 807                 free(path);
 808                 return 1;
 809         }
 810         path[len] = '\0';
 811         if (!file_exists(path)) {
 812                 if (stat(git_path("worktrees/%s/index", id), &st) ||
 813                     st.st_mtime <= expire) {
 814                         strbuf_addstr(reason, _("gitdir file points to non-existent location"));
 815                         free(path);
 816                         return 1;
 817                 } else {
 818                         *wtpath = path;
 819                         return 0;
 820                 }
 821         }
 822         *wtpath = path;
 823         return 0;
 824 }
 825
 826 static int move_config_setting(const char *key, const char *value,
 827                                const char *from_file, const char *to_file)
 828 {
 829         if (git_config_set_in_file_gently(to_file, key, value))
 830                 return error(_("unable to set %s in '%s'"), key, to_file);
 831         if (git_config_set_in_file_gently(from_file, key, NULL))
 832                 return error(_("unable to unset %s in '%s'"), key, from_file);
 833         return 0;
 834 }
 835
 836 int init_worktree_config(struct repository *r)
 837 {
 838         int res = 0;
 839         int bare = 0;
 840         struct config_set cs = { { 0 } };
 841         const char *core_worktree;
 842         char *common_config_file;
 843         char *main_worktree_file;
 844
 845         /*
 846          * If the extension is already enabled, then we can skip the
 847          * upgrade process.
 848          */
 849         if (repository_format_worktree_config)
 850                 return 0;
 851         if ((res = git_config_set_gently("extensions.worktreeConfig", "true")))
 852                 return error(_("failed to set extensions.worktreeConfig setting"));
 853
 854         common_config_file = xstrfmt("%s/config", r->commondir);
 855         main_worktree_file = xstrfmt("%s/config.worktree", r->commondir);
 856
 857         git_configset_init(&cs);
 858         git_configset_add_file(&cs, common_config_file);
 859
 860         /*
 861          * If core.bare is true in the common config file, then we need to
 862          * move it to the main worktree's config file or it will break all
 863          * worktrees. If it is false, then leave it in place because it
 864          * _could_ be negating a global core.bare=true.
 865          */
 866         if (!git_configset_get_bool(&cs, "core.bare", &bare) && bare) {
 867                 if ((res = move_config_setting("core.bare", "true",
 868                                                common_config_file,
 869                                                main_worktree_file)))
 870                         goto cleanup;
 871         }
 872         /*
 873          * If core.worktree is set, then the main worktree is located
 874          * somewhere different than the parent of the common Git dir.
 875          * Relocate that value to avoid breaking all worktrees with this
 876          * upgrade to worktree config.
 877          */
 878         if (!git_configset_get_value(&cs, "core.worktree", &core_worktree)) {
 879                 if ((res = move_config_setting("core.worktree", core_worktree,
 880                                                common_config_file,
 881                                                main_worktree_file)))
 882                         goto cleanup;
 883         }
 884
 885         /*
 886          * Ensure that we use worktree config for the remaining lifetime
 887          * of the current process.
 888          */
 889         repository_format_worktree_config = 1;
 890
 891 cleanup:
 892         git_configset_clear(&cs);
 893         free(common_config_file);
 894         free(main_worktree_file);
 895         return res;
 896 }