worktree.c

   1 #include "git-compat-util.h"
   2 #include "abspath.h"
   3 #include "alloc.h"
   4 #include "environment.h"
   5 #include "gettext.h"
   6 #include "path.h"
   7 #include "repository.h"
   8 #include "refs.h"
   9 #include "setup.h"
  10 #include "strbuf.h"
  11 #include "worktree.h"
  12 #include "dir.h"
  13 #include "wt-status.h"
  14 #include "config.h"
  15 #include "wrapper.h"
  16
  17 void free_worktrees(struct worktree **worktrees)
  18 {
  19         int i = 0;
  20
  21         for (i = 0; worktrees[i]; i++) {
  22                 free(worktrees[i]->path);
  23                 free(worktrees[i]->id);
  24                 free(worktrees[i]->head_ref);
  25                 free(worktrees[i]->lock_reason);
  26                 free(worktrees[i]->prune_reason);
  27                 free(worktrees[i]);
  28         }
  29         free (worktrees);
  30 }
  31
  32 /**
  33  * Update head_oid, head_ref and is_detached of the given worktree
  34  */
  35 static void add_head_info(struct worktree *wt)
  36 {
  37         int flags;
  38         const char *target;
  39
  40         target = refs_resolve_ref_unsafe(get_worktree_ref_store(wt),
  41                                          "HEAD",
  42                                          0,
  43                                          &wt->head_oid, &flags);
  44         if (!target)
  45                 return;
  46
  47         if (flags & REF_ISSYMREF)
  48                 wt->head_ref = xstrdup(target);
  49         else
  50                 wt->is_detached = 1;
  51 }
  52
  53 /**
  54  * get the main worktree
  55  */
  56 static struct worktree *get_main_worktree(void)
  57 {
  58         struct worktree *worktree = NULL;
  59         struct strbuf worktree_path = STRBUF_INIT;
  60
  61         strbuf_add_real_path(&worktree_path, get_git_common_dir());
  62         strbuf_strip_suffix(&worktree_path, "/.git");
  63
  64         CALLOC_ARRAY(worktree, 1);
  65         worktree->path = strbuf_detach(&worktree_path, NULL);
  66         /*
  67          * NEEDSWORK: If this function is called from a secondary worktree and
  68          * config.worktree is present, is_bare_repository_cfg will reflect the
  69          * contents of config.worktree, not the contents of the main worktree.
  70          * This means that worktree->is_bare may be set to 0 even if the main
  71          * worktree is configured to be bare.
  72          */
  73         worktree->is_bare = (is_bare_repository_cfg == 1) ||
  74                 is_bare_repository();
  75         add_head_info(worktree);
  76         return worktree;
  77 }
  78
  79 static struct worktree *get_linked_worktree(const char *id)
  80 {
  81         struct worktree *worktree = NULL;
  82         struct strbuf path = STRBUF_INIT;
  83         struct strbuf worktree_path = STRBUF_INIT;
  84
  85         if (!id)
  86                 die("Missing linked worktree name");
  87
  88         strbuf_git_common_path(&path, the_repository, "worktrees/%s/gitdir", id);
  89         if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
  90                 /* invalid gitdir file */
  91                 goto done;
  92         strbuf_rtrim(&worktree_path);
  93         strbuf_strip_suffix(&worktree_path, "/.git");
  94
  95         CALLOC_ARRAY(worktree, 1);
  96         worktree->path = strbuf_detach(&worktree_path, NULL);
  97         worktree->id = xstrdup(id);
  98         add_head_info(worktree);
  99
 100 done:
 101         strbuf_release(&path);
 102         strbuf_release(&worktree_path);
 103         return worktree;
 104 }
 105
 106 static void mark_current_worktree(struct worktree **worktrees)
 107 {
 108         char *git_dir = absolute_pathdup(get_git_dir());
 109         int i;
 110
 111         for (i = 0; worktrees[i]; i++) {
 112                 struct worktree *wt = worktrees[i];
 113                 const char *wt_git_dir = get_worktree_git_dir(wt);
 114
 115                 if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
 116                         wt->is_current = 1;
 117                         break;
 118                 }
 119         }
 120         free(git_dir);
 121 }
 122
 123 struct worktree **get_worktrees(void)
 124 {
 125         struct worktree **list = NULL;
 126         struct strbuf path = STRBUF_INIT;
 127         DIR *dir;
 128         struct dirent *d;
 129         int counter = 0, alloc = 2;
 130
 131         ALLOC_ARRAY(list, alloc);
 132
 133         list[counter++] = get_main_worktree();
 134
 135         strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
 136         dir = opendir(path.buf);
 137         strbuf_release(&path);
 138         if (dir) {
 139                 while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) {
 140                         struct worktree *linked = NULL;
 141
 142                         if ((linked = get_linked_worktree(d->d_name))) {
 143                                 ALLOC_GROW(list, counter + 1, alloc);
 144                                 list[counter++] = linked;
 145                         }
 146                 }
 147                 closedir(dir);
 148         }
 149         ALLOC_GROW(list, counter + 1, alloc);
 150         list[counter] = NULL;
 151
 152         mark_current_worktree(list);
 153         return list;
 154 }
 155
 156 const char *get_worktree_git_dir(const struct worktree *wt)
 157 {
 158         if (!wt)
 159                 return get_git_dir();
 160         else if (!wt->id)
 161                 return get_git_common_dir();
 162         else
 163                 return git_common_path("worktrees/%s", wt->id);
 164 }
 165
 166 static struct worktree *find_worktree_by_suffix(struct worktree **list,
 167                                                 const char *suffix)
 168 {
 169         struct worktree *found = NULL;
 170         int nr_found = 0, suffixlen;
 171
 172         suffixlen = strlen(suffix);
 173         if (!suffixlen)
 174                 return NULL;
 175
 176         for (; *list && nr_found < 2; list++) {
 177                 const char      *path    = (*list)->path;
 178                 int              pathlen = strlen(path);
 179                 int              start   = pathlen - suffixlen;
 180
 181                 /* suffix must start at directory boundary */
 182                 if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
 183                     !fspathcmp(suffix, path + start)) {
 184                         found = *list;
 185                         nr_found++;
 186                 }
 187         }
 188         return nr_found == 1 ? found : NULL;
 189 }
 190
 191 struct worktree *find_worktree(struct worktree **list,
 192                                const char *prefix,
 193                                const char *arg)
 194 {
 195         struct worktree *wt;
 196         char *to_free = NULL;
 197
 198         if ((wt = find_worktree_by_suffix(list, arg)))
 199                 return wt;
 200
 201         if (prefix)
 202                 arg = to_free = prefix_filename(prefix, arg);
 203         wt = find_worktree_by_path(list, arg);
 204         free(to_free);
 205         return wt;
 206 }
 207
 208 struct worktree *find_worktree_by_path(struct worktree **list, const char *p)
 209 {
 210         struct strbuf wt_path = STRBUF_INIT;
 211         char *path = real_pathdup(p, 0);
 212
 213         if (!path)
 214                 return NULL;
 215         for (; *list; list++) {
 216                 if (!strbuf_realpath(&wt_path, (*list)->path, 0))
 217                         continue;
 218
 219                 if (!fspathcmp(path, wt_path.buf))
 220                         break;
 221         }
 222         free(path);
 223         strbuf_release(&wt_path);
 224         return *list;
 225 }
 226
 227 int is_main_worktree(const struct worktree *wt)
 228 {
 229         return !wt->id;
 230 }
 231
 232 const char *worktree_lock_reason(struct worktree *wt)
 233 {
 234         if (is_main_worktree(wt))
 235                 return NULL;
 236
 237         if (!wt->lock_reason_valid) {
 238                 struct strbuf path = STRBUF_INIT;
 239
 240                 strbuf_addstr(&path, worktree_git_path(wt, "locked"));
 241                 if (file_exists(path.buf)) {
 242                         struct strbuf lock_reason = STRBUF_INIT;
 243                         if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
 244                                 die_errno(_("failed to read '%s'"), path.buf);
 245                         strbuf_trim(&lock_reason);
 246                         wt->lock_reason = strbuf_detach(&lock_reason, NULL);
 247                 } else
 248                         wt->lock_reason = NULL;
 249                 wt->lock_reason_valid = 1;
 250                 strbuf_release(&path);
 251         }
 252
 253         return wt->lock_reason;
 254 }
 255
 256 const char *worktree_prune_reason(struct worktree *wt, timestamp_t expire)
 257 {
 258         struct strbuf reason = STRBUF_INIT;
 259         char *path = NULL;
 260
 261         if (is_main_worktree(wt))
 262                 return NULL;
 263         if (wt->prune_reason_valid)
 264                 return wt->prune_reason;
 265
 266         if (should_prune_worktree(wt->id, &reason, &path, expire))
 267                 wt->prune_reason = strbuf_detach(&reason, NULL);
 268         wt->prune_reason_valid = 1;
 269
 270         strbuf_release(&reason);
 271         free(path);
 272         return wt->prune_reason;
 273 }
 274
 275 /* convenient wrapper to deal with NULL strbuf */
 276 __attribute__((format (printf, 2, 3)))
 277 static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
 278 {
 279         va_list params;
 280
 281         if (!buf)
 282                 return;
 283
 284         va_start(params, fmt);
 285         strbuf_vaddf(buf, fmt, params);
 286         va_end(params);
 287 }
 288
 289 int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
 290                       unsigned flags)
 291 {
 292         struct strbuf wt_path = STRBUF_INIT;
 293         struct strbuf realpath = STRBUF_INIT;
 294         char *path = NULL;
 295         int err, ret = -1;
 296
 297         strbuf_addf(&wt_path, "%s/.git", wt->path);
 298
 299         if (is_main_worktree(wt)) {
 300                 if (is_directory(wt_path.buf)) {
 301                         ret = 0;
 302                         goto done;
 303                 }
 304                 /*
 305                  * Main worktree using .git file to point to the
 306                  * repository would make it impossible to know where
 307                  * the actual worktree is if this function is executed
 308                  * from another worktree. No .git file support for now.
 309                  */
 310                 strbuf_addf_gently(errmsg,
 311                                    _("'%s' at main working tree is not the repository directory"),
 312                                    wt_path.buf);
 313                 goto done;
 314         }
 315
 316         /*
 317          * Make sure "gitdir" file points to a real .git file and that
 318          * file points back here.
 319          */
 320         if (!is_absolute_path(wt->path)) {
 321                 strbuf_addf_gently(errmsg,
 322                                    _("'%s' file does not contain absolute path to the working tree location"),
 323                                    git_common_path("worktrees/%s/gitdir", wt->id));
 324                 goto done;
 325         }
 326
 327         if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
 328             !file_exists(wt->path)) {
 329                 ret = 0;
 330                 goto done;
 331         }
 332
 333         if (!file_exists(wt_path.buf)) {
 334                 strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
 335                 goto done;
 336         }
 337
 338         path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
 339         if (!path) {
 340                 strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
 341                                    wt_path.buf, err);
 342                 goto done;
 343         }
 344
 345         strbuf_realpath(&realpath, git_common_path("worktrees/%s", wt->id), 1);
 346         ret = fspathcmp(path, realpath.buf);
 347
 348         if (ret)
 349                 strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
 350                                    wt->path, git_common_path("worktrees/%s", wt->id));
 351 done:
 352         free(path);
 353         strbuf_release(&wt_path);
 354         strbuf_release(&realpath);
 355         return ret;
 356 }
 357
 358 void update_worktree_location(struct worktree *wt, const char *path_)
 359 {
 360         struct strbuf path = STRBUF_INIT;
 361
 362         if (is_main_worktree(wt))
 363                 BUG("can't relocate main worktree");
 364
 365         strbuf_realpath(&path, path_, 1);
 366         if (fspathcmp(wt->path, path.buf)) {
 367                 write_file(git_common_path("worktrees/%s/gitdir", wt->id),
 368                            "%s/.git", path.buf);
 369                 free(wt->path);
 370                 wt->path = strbuf_detach(&path, NULL);
 371         }
 372         strbuf_release(&path);
 373 }
 374
 375 int is_worktree_being_rebased(const struct worktree *wt,
 376                               const char *target)
 377 {
 378         struct wt_status_state state;
 379         int found_rebase;
 380
 381         memset(&state, 0, sizeof(state));
 382         found_rebase = wt_status_check_rebase(wt, &state) &&
 383                        (state.rebase_in_progress ||
 384                         state.rebase_interactive_in_progress) &&
 385                        state.branch &&
 386                        skip_prefix(target, "refs/heads/", &target) &&
 387                        !strcmp(state.branch, target);
 388         wt_status_state_free_buffers(&state);
 389         return found_rebase;
 390 }
 391
 392 int is_worktree_being_bisected(const struct worktree *wt,
 393                                const char *target)
 394 {
 395         struct wt_status_state state;
 396         int found_bisect;
 397
 398         memset(&state, 0, sizeof(state));
 399         found_bisect = wt_status_check_bisect(wt, &state) &&
 400                        state.branch &&
 401                        skip_prefix(target, "refs/heads/", &target) &&
 402                        !strcmp(state.branch, target);
 403         wt_status_state_free_buffers(&state);
 404         return found_bisect;
 405 }
 406
 407 /*
 408  * note: this function should be able to detect shared symref even if
 409  * HEAD is temporarily detached (e.g. in the middle of rebase or
 410  * bisect). New commands that do similar things should update this
 411  * function as well.
 412  */
 413 int is_shared_symref(const struct worktree *wt, const char *symref,
 414                      const char *target)
 415 {
 416         const char *symref_target;
 417         struct ref_store *refs;
 418         int flags;
 419
 420         if (wt->is_bare)
 421                 return 0;
 422
 423         if (wt->is_detached && !strcmp(symref, "HEAD")) {
 424                 if (is_worktree_being_rebased(wt, target))
 425                         return 1;
 426                 if (is_worktree_being_bisected(wt, target))
 427                         return 1;
 428         }
 429
 430         refs = get_worktree_ref_store(wt);
 431         symref_target = refs_resolve_ref_unsafe(refs, symref, 0,
 432                                                 NULL, &flags);
 433         if ((flags & REF_ISSYMREF) &&
 434             symref_target && !strcmp(symref_target, target))
 435                 return 1;
 436
 437         return 0;
 438 }
 439
 440 const struct worktree *find_shared_symref(struct worktree **worktrees,
 441                                           const char *symref,
 442                                           const char *target)
 443 {
 444
 445         for (int i = 0; worktrees[i]; i++)
 446                 if (is_shared_symref(worktrees[i], symref, target))
 447                         return worktrees[i];
 448
 449         return NULL;
 450 }
 451
 452 int submodule_uses_worktrees(const char *path)
 453 {
 454         char *submodule_gitdir;
 455         struct strbuf sb = STRBUF_INIT, err = STRBUF_INIT;
 456         DIR *dir;
 457         struct dirent *d;
 458         int ret = 0;
 459         struct repository_format format = REPOSITORY_FORMAT_INIT;
 460
 461         submodule_gitdir = git_pathdup_submodule(path, "%s", "");
 462         if (!submodule_gitdir)
 463                 return 0;
 464
 465         /* The env would be set for the superproject. */
 466         get_common_dir_noenv(&sb, submodule_gitdir);
 467         free(submodule_gitdir);
 468
 469         strbuf_addstr(&sb, "/config");
 470         read_repository_format(&format, sb.buf);
 471         if (verify_repository_format(&format, &err)) {
 472                 strbuf_release(&err);
 473                 strbuf_release(&sb);
 474                 clear_repository_format(&format);
 475                 return 1;
 476         }
 477         clear_repository_format(&format);
 478         strbuf_release(&err);
 479
 480         /* Replace config by worktrees. */
 481         strbuf_setlen(&sb, sb.len - strlen("config"));
 482         strbuf_addstr(&sb, "worktrees");
 483
 484         /* See if there is any file inside the worktrees directory. */
 485         dir = opendir(sb.buf);
 486         strbuf_release(&sb);
 487
 488         if (!dir)
 489                 return 0;
 490
 491         d = readdir_skip_dot_and_dotdot(dir);
 492         if (d)
 493                 ret = 1;
 494         closedir(dir);
 495         return ret;
 496 }
 497
 498 void strbuf_worktree_ref(const struct worktree *wt,
 499                          struct strbuf *sb,
 500                          const char *refname)
 501 {
 502         if (parse_worktree_ref(refname, NULL, NULL, NULL) ==
 503                     REF_WORKTREE_CURRENT &&
 504             wt && !wt->is_current) {
 505                 if (is_main_worktree(wt))
 506                         strbuf_addstr(sb, "main-worktree/");
 507                 else
 508                         strbuf_addf(sb, "worktrees/%s/", wt->id);
 509         }
 510         strbuf_addstr(sb, refname);
 511 }
 512
 513 int other_head_refs(each_ref_fn fn, void *cb_data)
 514 {
 515         struct worktree **worktrees, **p;
 516         struct strbuf refname = STRBUF_INIT;
 517         int ret = 0;
 518
 519         worktrees = get_worktrees();
 520         for (p = worktrees; *p; p++) {
 521                 struct worktree *wt = *p;
 522                 struct object_id oid;
 523                 int flag;
 524
 525                 if (wt->is_current)
 526                         continue;
 527
 528                 strbuf_reset(&refname);
 529                 strbuf_worktree_ref(wt, &refname, "HEAD");
 530                 if (refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
 531                                             refname.buf,
 532                                             RESOLVE_REF_READING,
 533                                             &oid, &flag))
 534                         ret = fn(refname.buf, &oid, flag, cb_data);
 535                 if (ret)
 536                         break;
 537         }
 538         free_worktrees(worktrees);
 539         strbuf_release(&refname);
 540         return ret;
 541 }
 542
 543 /*
 544  * Repair worktree's /path/to/worktree/.git file if missing, corrupt, or not
 545  * pointing at <repo>/worktrees/<id>.
 546  */
 547 static void repair_gitfile(struct worktree *wt,
 548                            worktree_repair_fn fn, void *cb_data)
 549 {
 550         struct strbuf dotgit = STRBUF_INIT;
 551         struct strbuf repo = STRBUF_INIT;
 552         char *backlink;
 553         const char *repair = NULL;
 554         int err;
 555
 556         /* missing worktree can't be repaired */
 557         if (!file_exists(wt->path))
 558                 return;
 559
 560         if (!is_directory(wt->path)) {
 561                 fn(1, wt->path, _("not a directory"), cb_data);
 562                 return;
 563         }
 564
 565         strbuf_realpath(&repo, git_common_path("worktrees/%s", wt->id), 1);
 566         strbuf_addf(&dotgit, "%s/.git", wt->path);
 567         backlink = xstrdup_or_null(read_gitfile_gently(dotgit.buf, &err));
 568
 569         if (err == READ_GITFILE_ERR_NOT_A_FILE)
 570                 fn(1, wt->path, _(".git is not a file"), cb_data);
 571         else if (err)
 572                 repair = _(".git file broken");
 573         else if (fspathcmp(backlink, repo.buf))
 574                 repair = _(".git file incorrect");
 575
 576         if (repair) {
 577                 fn(0, wt->path, repair, cb_data);
 578                 write_file(dotgit.buf, "gitdir: %s", repo.buf);
 579         }
 580
 581         free(backlink);
 582         strbuf_release(&repo);
 583         strbuf_release(&dotgit);
 584 }
 585
 586 static void repair_noop(int iserr, const char *path, const char *msg,
 587                         void *cb_data)
 588 {
 589         /* nothing */
 590 }
 591
 592 void repair_worktrees(worktree_repair_fn fn, void *cb_data)
 593 {
 594         struct worktree **worktrees = get_worktrees();
 595         struct worktree **wt = worktrees + 1; /* +1 skips main worktree */
 596
 597         if (!fn)
 598                 fn = repair_noop;
 599         for (; *wt; wt++)
 600                 repair_gitfile(*wt, fn, cb_data);
 601         free_worktrees(worktrees);
 602 }
 603
 604 static int is_main_worktree_path(const char *path)
 605 {
 606         struct strbuf target = STRBUF_INIT;
 607         struct strbuf maindir = STRBUF_INIT;
 608         int cmp;
 609
 610         strbuf_add_real_path(&target, path);
 611         strbuf_strip_suffix(&target, "/.git");
 612         strbuf_add_real_path(&maindir, get_git_common_dir());
 613         strbuf_strip_suffix(&maindir, "/.git");
 614         cmp = fspathcmp(maindir.buf, target.buf);
 615
 616         strbuf_release(&maindir);
 617         strbuf_release(&target);
 618         return !cmp;
 619 }
 620
 621 /*
 622  * If both the main worktree and linked worktree have been moved, then the
 623  * gitfile /path/to/worktree/.git won't point into the repository, thus we
 624  * won't know which <repo>/worktrees/<id>/gitdir to repair. However, we may
 625  * be able to infer the gitdir by manually reading /path/to/worktree/.git,
 626  * extracting the <id>, and checking if <repo>/worktrees/<id> exists.
 627  */
 628 static char *infer_backlink(const char *gitfile)
 629 {
 630         struct strbuf actual = STRBUF_INIT;
 631         struct strbuf inferred = STRBUF_INIT;
 632         const char *id;
 633
 634         if (strbuf_read_file(&actual, gitfile, 0) < 0)
 635                 goto error;
 636         if (!starts_with(actual.buf, "gitdir:"))
 637                 goto error;
 638         if (!(id = find_last_dir_sep(actual.buf)))
 639                 goto error;
 640         strbuf_trim(&actual);
 641         id++; /* advance past '/' to point at <id> */
 642         if (!*id)
 643                 goto error;
 644         strbuf_git_common_path(&inferred, the_repository, "worktrees/%s", id);
 645         if (!is_directory(inferred.buf))
 646                 goto error;
 647
 648         strbuf_release(&actual);
 649         return strbuf_detach(&inferred, NULL);
 650
 651 error:
 652         strbuf_release(&actual);
 653         strbuf_release(&inferred);
 654         return NULL;
 655 }
 656
 657 /*
 658  * Repair <repo>/worktrees/<id>/gitdir if missing, corrupt, or not pointing at
 659  * the worktree's path.
 660  */
 661 void repair_worktree_at_path(const char *path,
 662                              worktree_repair_fn fn, void *cb_data)
 663 {
 664         struct strbuf dotgit = STRBUF_INIT;
 665         struct strbuf realdotgit = STRBUF_INIT;
 666         struct strbuf gitdir = STRBUF_INIT;
 667         struct strbuf olddotgit = STRBUF_INIT;
 668         char *backlink = NULL;
 669         const char *repair = NULL;
 670         int err;
 671
 672         if (!fn)
 673                 fn = repair_noop;
 674
 675         if (is_main_worktree_path(path))
 676                 goto done;
 677
 678         strbuf_addf(&dotgit, "%s/.git", path);
 679         if (!strbuf_realpath(&realdotgit, dotgit.buf, 0)) {
 680                 fn(1, path, _("not a valid path"), cb_data);
 681                 goto done;
 682         }
 683
 684         backlink = xstrdup_or_null(read_gitfile_gently(realdotgit.buf, &err));
 685         if (err == READ_GITFILE_ERR_NOT_A_FILE) {
 686                 fn(1, realdotgit.buf, _("unable to locate repository; .git is not a file"), cb_data);
 687                 goto done;
 688         } else if (err == READ_GITFILE_ERR_NOT_A_REPO) {
 689                 if (!(backlink = infer_backlink(realdotgit.buf))) {
 690                         fn(1, realdotgit.buf, _("unable to locate repository; .git file does not reference a repository"), cb_data);
 691                         goto done;
 692                 }
 693         } else if (err) {
 694                 fn(1, realdotgit.buf, _("unable to locate repository; .git file broken"), cb_data);
 695                 goto done;
 696         }
 697
 698         strbuf_addf(&gitdir, "%s/gitdir", backlink);
 699         if (strbuf_read_file(&olddotgit, gitdir.buf, 0) < 0)
 700                 repair = _("gitdir unreadable");
 701         else {
 702                 strbuf_rtrim(&olddotgit);
 703                 if (fspathcmp(olddotgit.buf, realdotgit.buf))
 704                         repair = _("gitdir incorrect");
 705         }
 706
 707         if (repair) {
 708                 fn(0, gitdir.buf, repair, cb_data);
 709                 write_file(gitdir.buf, "%s", realdotgit.buf);
 710         }
 711 done:
 712         free(backlink);
 713         strbuf_release(&olddotgit);
 714         strbuf_release(&gitdir);
 715         strbuf_release(&realdotgit);
 716         strbuf_release(&dotgit);
 717 }
 718
 719 int should_prune_worktree(const char *id, struct strbuf *reason, char **wtpath, timestamp_t expire)
 720 {
 721         struct stat st;
 722         char *path;
 723         int fd;
 724         size_t len;
 725         ssize_t read_result;
 726
 727         *wtpath = NULL;
 728         if (!is_directory(git_path("worktrees/%s", id))) {
 729                 strbuf_addstr(reason, _("not a valid directory"));
 730                 return 1;
 731         }
 732         if (file_exists(git_path("worktrees/%s/locked", id)))
 733                 return 0;
 734         if (stat(git_path("worktrees/%s/gitdir", id), &st)) {
 735                 strbuf_addstr(reason, _("gitdir file does not exist"));
 736                 return 1;
 737         }
 738         fd = open(git_path("worktrees/%s/gitdir", id), O_RDONLY);
 739         if (fd < 0) {
 740                 strbuf_addf(reason, _("unable to read gitdir file (%s)"),
 741                             strerror(errno));
 742                 return 1;
 743         }
 744         len = xsize_t(st.st_size);
 745         path = xmallocz(len);
 746
 747         read_result = read_in_full(fd, path, len);
 748         if (read_result < 0) {
 749                 strbuf_addf(reason, _("unable to read gitdir file (%s)"),
 750                             strerror(errno));
 751                 close(fd);
 752                 free(path);
 753                 return 1;
 754         }
 755         close(fd);
 756
 757         if (read_result != len) {
 758                 strbuf_addf(reason,
 759                             _("short read (expected %"PRIuMAX" bytes, read %"PRIuMAX")"),
 760                             (uintmax_t)len, (uintmax_t)read_result);
 761                 free(path);
 762                 return 1;
 763         }
 764         while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
 765                 len--;
 766         if (!len) {
 767                 strbuf_addstr(reason, _("invalid gitdir file"));
 768                 free(path);
 769                 return 1;
 770         }
 771         path[len] = '\0';
 772         if (!file_exists(path)) {
 773                 if (stat(git_path("worktrees/%s/index", id), &st) ||
 774                     st.st_mtime <= expire) {
 775                         strbuf_addstr(reason, _("gitdir file points to non-existent location"));
 776                         free(path);
 777                         return 1;
 778                 } else {
 779                         *wtpath = path;
 780                         return 0;
 781                 }
 782         }
 783         *wtpath = path;
 784         return 0;
 785 }
 786
 787 static int move_config_setting(const char *key, const char *value,
 788                                const char *from_file, const char *to_file)
 789 {
 790         if (git_config_set_in_file_gently(to_file, key, value))
 791                 return error(_("unable to set %s in '%s'"), key, to_file);
 792         if (git_config_set_in_file_gently(from_file, key, NULL))
 793                 return error(_("unable to unset %s in '%s'"), key, from_file);
 794         return 0;
 795 }
 796
 797 int init_worktree_config(struct repository *r)
 798 {
 799         int res = 0;
 800         int bare = 0;
 801         struct config_set cs = { { 0 } };
 802         const char *core_worktree;
 803         char *common_config_file;
 804         char *main_worktree_file;
 805
 806         /*
 807          * If the extension is already enabled, then we can skip the
 808          * upgrade process.
 809          */
 810         if (r->repository_format_worktree_config)
 811                 return 0;
 812         if ((res = git_config_set_gently("extensions.worktreeConfig", "true")))
 813                 return error(_("failed to set extensions.worktreeConfig setting"));
 814
 815         common_config_file = xstrfmt("%s/config", r->commondir);
 816         main_worktree_file = xstrfmt("%s/config.worktree", r->commondir);
 817
 818         git_configset_init(&cs);
 819         git_configset_add_file(&cs, common_config_file);
 820
 821         /*
 822          * If core.bare is true in the common config file, then we need to
 823          * move it to the main worktree's config file or it will break all
 824          * worktrees. If it is false, then leave it in place because it
 825          * _could_ be negating a global core.bare=true.
 826          */
 827         if (!git_configset_get_bool(&cs, "core.bare", &bare) && bare) {
 828                 if ((res = move_config_setting("core.bare", "true",
 829                                                common_config_file,
 830                                                main_worktree_file)))
 831                         goto cleanup;
 832         }
 833         /*
 834          * If core.worktree is set, then the main worktree is located
 835          * somewhere different than the parent of the common Git dir.
 836          * Relocate that value to avoid breaking all worktrees with this
 837          * upgrade to worktree config.
 838          */
 839         if (!git_configset_get_value(&cs, "core.worktree", &core_worktree, NULL)) {
 840                 if ((res = move_config_setting("core.worktree", core_worktree,
 841                                                common_config_file,
 842                                                main_worktree_file)))
 843                         goto cleanup;
 844         }
 845
 846         /*
 847          * Ensure that we use worktree config for the remaining lifetime
 848          * of the current process.
 849          */
 850         r->repository_format_worktree_config = 1;
 851
 852 cleanup:
 853         git_configset_clear(&cs);
 854         free(common_config_file);
 855         free(main_worktree_file);
 856         return res;
 857 }