git.oblomov.eu Git - git/blob - submodule.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "config.h"
   4 #include "submodule-config.h"
   5 #include "submodule.h"
   6 #include "dir.h"
   7 #include "diff.h"
   8 #include "commit.h"
   9 #include "revision.h"
  10 #include "run-command.h"
  11 #include "diffcore.h"
  12 #include "refs.h"
  13 #include "string-list.h"
  14 #include "sha1-array.h"
  15 #include "argv-array.h"
  16 #include "blob.h"
  17 #include "thread-utils.h"
  18 #include "quote.h"
  19 #include "remote.h"
  20 #include "worktree.h"
  21 #include "parse-options.h"
  22
  23 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
  24 static struct string_list changed_submodule_paths = STRING_LIST_INIT_DUP;
  25 static int initialized_fetch_ref_tips;
  26 static struct oid_array ref_tips_before_fetch;
  27 static struct oid_array ref_tips_after_fetch;
  28
  29 /*
  30  * Check if the .gitmodules file is unmerged. Parsing of the .gitmodules file
  31  * will be disabled because we can't guess what might be configured in
  32  * .gitmodules unless the user resolves the conflict.
  33  */
  34 int is_gitmodules_unmerged(const struct index_state *istate)
  35 {
  36         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  37         if (pos < 0) { /* .gitmodules not found or isn't merged */
  38                 pos = -1 - pos;
  39                 if (istate->cache_nr > pos) {  /* there is a .gitmodules */
  40                         const struct cache_entry *ce = istate->cache[pos];
  41                         if (ce_namelen(ce) == strlen(GITMODULES_FILE) &&
  42                             !strcmp(ce->name, GITMODULES_FILE))
  43                                 return 1;
  44                 }
  45         }
  46
  47         return 0;
  48 }
  49
  50 /*
  51  * Check if the .gitmodules file has unstaged modifications.  This must be
  52  * checked before allowing modifications to the .gitmodules file with the
  53  * intention to stage them later, because when continuing we would stage the
  54  * modifications the user didn't stage herself too. That might change in a
  55  * future version when we learn to stage the changes we do ourselves without
  56  * staging any previous modifications.
  57  */
  58 int is_staging_gitmodules_ok(const struct index_state *istate)
  59 {
  60         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  61
  62         if ((pos >= 0) && (pos < istate->cache_nr)) {
  63                 struct stat st;
  64                 if (lstat(GITMODULES_FILE, &st) == 0 &&
  65                     ce_match_stat(istate->cache[pos], &st, 0) & DATA_CHANGED)
  66                         return 0;
  67         }
  68
  69         return 1;
  70 }
  71
  72 /*
  73  * Try to update the "path" entry in the "submodule.<name>" section of the
  74  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
  75  * with the correct path=<oldpath> setting was found and we could update it.
  76  */
  77 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
  78 {
  79         struct strbuf entry = STRBUF_INIT;
  80         const struct submodule *submodule;
  81
  82         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
  83                 return -1;
  84
  85         if (is_gitmodules_unmerged(&the_index))
  86                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  87
  88         submodule = submodule_from_path(&null_oid, oldpath);
  89         if (!submodule || !submodule->name) {
  90                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
  91                 return -1;
  92         }
  93         strbuf_addstr(&entry, "submodule.");
  94         strbuf_addstr(&entry, submodule->name);
  95         strbuf_addstr(&entry, ".path");
  96         if (git_config_set_in_file_gently(GITMODULES_FILE, entry.buf, newpath) < 0) {
  97                 /* Maybe the user already did that, don't error out here */
  98                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
  99                 strbuf_release(&entry);
 100                 return -1;
 101         }
 102         strbuf_release(&entry);
 103         return 0;
 104 }
 105
 106 /*
 107  * Try to remove the "submodule.<name>" section from .gitmodules where the given
 108  * path is configured. Return 0 only if a .gitmodules file was found, a section
 109  * with the correct path=<path> setting was found and we could remove it.
 110  */
 111 int remove_path_from_gitmodules(const char *path)
 112 {
 113         struct strbuf sect = STRBUF_INIT;
 114         const struct submodule *submodule;
 115
 116         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
 117                 return -1;
 118
 119         if (is_gitmodules_unmerged(&the_index))
 120                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 121
 122         submodule = submodule_from_path(&null_oid, path);
 123         if (!submodule || !submodule->name) {
 124                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 125                 return -1;
 126         }
 127         strbuf_addstr(&sect, "submodule.");
 128         strbuf_addstr(&sect, submodule->name);
 129         if (git_config_rename_section_in_file(GITMODULES_FILE, sect.buf, NULL) < 0) {
 130                 /* Maybe the user already did that, don't error out here */
 131                 warning(_("Could not remove .gitmodules entry for %s"), path);
 132                 strbuf_release(&sect);
 133                 return -1;
 134         }
 135         strbuf_release(&sect);
 136         return 0;
 137 }
 138
 139 void stage_updated_gitmodules(void)
 140 {
 141         if (add_file_to_cache(GITMODULES_FILE, 0))
 142                 die(_("staging updated .gitmodules failed"));
 143 }
 144
 145 static int add_submodule_odb(const char *path)
 146 {
 147         struct strbuf objects_directory = STRBUF_INIT;
 148         int ret = 0;
 149
 150         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
 151         if (ret)
 152                 goto done;
 153         if (!is_directory(objects_directory.buf)) {
 154                 ret = -1;
 155                 goto done;
 156         }
 157         add_to_alternates_memory(objects_directory.buf);
 158 done:
 159         strbuf_release(&objects_directory);
 160         return ret;
 161 }
 162
 163 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 164                                              const char *path)
 165 {
 166         const struct submodule *submodule = submodule_from_path(&null_oid, path);
 167         if (submodule) {
 168                 const char *ignore;
 169                 char *key;
 170
 171                 key = xstrfmt("submodule.%s.ignore", submodule->name);
 172                 if (repo_config_get_string_const(the_repository, key, &ignore))
 173                         ignore = submodule->ignore;
 174                 free(key);
 175
 176                 if (ignore)
 177                         handle_ignore_submodules_arg(diffopt, ignore);
 178                 else if (is_gitmodules_unmerged(&the_index))
 179                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 180         }
 181 }
 182
 183 /* Cheap function that only determines if we're interested in submodules at all */
 184 int git_default_submodule_config(const char *var, const char *value, void *cb)
 185 {
 186         if (!strcmp(var, "submodule.recurse")) {
 187                 int v = git_config_bool(var, value) ?
 188                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 189                 config_update_recurse_submodules = v;
 190         }
 191         return 0;
 192 }
 193
 194 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 195                                                      const char *arg, int unset)
 196 {
 197         if (unset) {
 198                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 199                 return 0;
 200         }
 201         if (arg)
 202                 config_update_recurse_submodules =
 203                         parse_update_recurse_submodules_arg(opt->long_name,
 204                                                             arg);
 205         else
 206                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 207
 208         return 0;
 209 }
 210
 211 /*
 212  * Determine if a submodule has been initialized at a given 'path'
 213  */
 214 int is_submodule_active(struct repository *repo, const char *path)
 215 {
 216         int ret = 0;
 217         char *key = NULL;
 218         char *value = NULL;
 219         const struct string_list *sl;
 220         const struct submodule *module;
 221
 222         module = submodule_from_cache(repo, &null_oid, path);
 223
 224         /* early return if there isn't a path->module mapping */
 225         if (!module)
 226                 return 0;
 227
 228         /* submodule.<name>.active is set */
 229         key = xstrfmt("submodule.%s.active", module->name);
 230         if (!repo_config_get_bool(repo, key, &ret)) {
 231                 free(key);
 232                 return ret;
 233         }
 234         free(key);
 235
 236         /* submodule.active is set */
 237         sl = repo_config_get_value_multi(repo, "submodule.active");
 238         if (sl) {
 239                 struct pathspec ps;
 240                 struct argv_array args = ARGV_ARRAY_INIT;
 241                 const struct string_list_item *item;
 242
 243                 for_each_string_list_item(item, sl) {
 244                         argv_array_push(&args, item->string);
 245                 }
 246
 247                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 248                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
 249
 250                 argv_array_clear(&args);
 251                 clear_pathspec(&ps);
 252                 return ret;
 253         }
 254
 255         /* fallback to checking if the URL is set */
 256         key = xstrfmt("submodule.%s.url", module->name);
 257         ret = !repo_config_get_string(repo, key, &value);
 258
 259         free(value);
 260         free(key);
 261         return ret;
 262 }
 263
 264 int is_submodule_populated_gently(const char *path, int *return_error_code)
 265 {
 266         int ret = 0;
 267         char *gitdir = xstrfmt("%s/.git", path);
 268
 269         if (resolve_gitdir_gently(gitdir, return_error_code))
 270                 ret = 1;
 271
 272         free(gitdir);
 273         return ret;
 274 }
 275
 276 /*
 277  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 278  */
 279 void die_in_unpopulated_submodule(const struct index_state *istate,
 280                                   const char *prefix)
 281 {
 282         int i, prefixlen;
 283
 284         if (!prefix)
 285                 return;
 286
 287         prefixlen = strlen(prefix);
 288
 289         for (i = 0; i < istate->cache_nr; i++) {
 290                 struct cache_entry *ce = istate->cache[i];
 291                 int ce_len = ce_namelen(ce);
 292
 293                 if (!S_ISGITLINK(ce->ce_mode))
 294                         continue;
 295                 if (prefixlen <= ce_len)
 296                         continue;
 297                 if (strncmp(ce->name, prefix, ce_len))
 298                         continue;
 299                 if (prefix[ce_len] != '/')
 300                         continue;
 301
 302                 die(_("in unpopulated submodule '%s'"), ce->name);
 303         }
 304 }
 305
 306 /*
 307  * Dies if any paths in the provided pathspec descends into a submodule
 308  */
 309 void die_path_inside_submodule(const struct index_state *istate,
 310                                const struct pathspec *ps)
 311 {
 312         int i, j;
 313
 314         for (i = 0; i < istate->cache_nr; i++) {
 315                 struct cache_entry *ce = istate->cache[i];
 316                 int ce_len = ce_namelen(ce);
 317
 318                 if (!S_ISGITLINK(ce->ce_mode))
 319                         continue;
 320
 321                 for (j = 0; j < ps->nr ; j++) {
 322                         const struct pathspec_item *item = &ps->items[j];
 323
 324                         if (item->len <= ce_len)
 325                                 continue;
 326                         if (item->match[ce_len] != '/')
 327                                 continue;
 328                         if (strncmp(ce->name, item->match, ce_len))
 329                                 continue;
 330                         if (item->len == ce_len + 1)
 331                                 continue;
 332
 333                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 334                             item->original, ce_len, ce->name);
 335                 }
 336         }
 337 }
 338
 339 enum submodule_update_type parse_submodule_update_type(const char *value)
 340 {
 341         if (!strcmp(value, "none"))
 342                 return SM_UPDATE_NONE;
 343         else if (!strcmp(value, "checkout"))
 344                 return SM_UPDATE_CHECKOUT;
 345         else if (!strcmp(value, "rebase"))
 346                 return SM_UPDATE_REBASE;
 347         else if (!strcmp(value, "merge"))
 348                 return SM_UPDATE_MERGE;
 349         else if (*value == '!')
 350                 return SM_UPDATE_COMMAND;
 351         else
 352                 return SM_UPDATE_UNSPECIFIED;
 353 }
 354
 355 int parse_submodule_update_strategy(const char *value,
 356                 struct submodule_update_strategy *dst)
 357 {
 358         enum submodule_update_type type;
 359
 360         free((void*)dst->command);
 361         dst->command = NULL;
 362
 363         type = parse_submodule_update_type(value);
 364         if (type == SM_UPDATE_UNSPECIFIED)
 365                 return -1;
 366
 367         dst->type = type;
 368         if (type == SM_UPDATE_COMMAND)
 369                 dst->command = xstrdup(value + 1);
 370
 371         return 0;
 372 }
 373
 374 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 375 {
 376         struct strbuf sb = STRBUF_INIT;
 377         switch (s->type) {
 378         case SM_UPDATE_CHECKOUT:
 379                 return "checkout";
 380         case SM_UPDATE_MERGE:
 381                 return "merge";
 382         case SM_UPDATE_REBASE:
 383                 return "rebase";
 384         case SM_UPDATE_NONE:
 385                 return "none";
 386         case SM_UPDATE_UNSPECIFIED:
 387                 return NULL;
 388         case SM_UPDATE_COMMAND:
 389                 strbuf_addf(&sb, "!%s", s->command);
 390                 return strbuf_detach(&sb, NULL);
 391         }
 392         return NULL;
 393 }
 394
 395 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 396                                   const char *arg)
 397 {
 398         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 399         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 400         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 401
 402         if (!strcmp(arg, "all"))
 403                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 404         else if (!strcmp(arg, "untracked"))
 405                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 406         else if (!strcmp(arg, "dirty"))
 407                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 408         else if (strcmp(arg, "none"))
 409                 die("bad --ignore-submodules argument: %s", arg);
 410 }
 411
 412 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 413                 struct commit *left, struct commit *right,
 414                 struct commit_list *merge_bases)
 415 {
 416         struct commit_list *list;
 417
 418         init_revisions(rev, NULL);
 419         setup_revisions(0, NULL, rev, NULL);
 420         rev->left_right = 1;
 421         rev->first_parent_only = 1;
 422         left->object.flags |= SYMMETRIC_LEFT;
 423         add_pending_object(rev, &left->object, path);
 424         add_pending_object(rev, &right->object, path);
 425         for (list = merge_bases; list; list = list->next) {
 426                 list->item->object.flags |= UNINTERESTING;
 427                 add_pending_object(rev, &list->item->object,
 428                         oid_to_hex(&list->item->object.oid));
 429         }
 430         return prepare_revision_walk(rev);
 431 }
 432
 433 static void print_submodule_summary(struct rev_info *rev, struct diff_options *o)
 434 {
 435         static const char format[] = "  %m %s";
 436         struct strbuf sb = STRBUF_INIT;
 437         struct commit *commit;
 438
 439         while ((commit = get_revision(rev))) {
 440                 struct pretty_print_context ctx = {0};
 441                 ctx.date_mode = rev->date_mode;
 442                 ctx.output_encoding = get_log_output_encoding();
 443                 strbuf_setlen(&sb, 0);
 444                 format_commit_message(commit, format, &sb, &ctx);
 445                 strbuf_addch(&sb, '\n');
 446                 if (commit->object.flags & SYMMETRIC_LEFT)
 447                         diff_emit_submodule_del(o, sb.buf);
 448                 else
 449                         diff_emit_submodule_add(o, sb.buf);
 450         }
 451         strbuf_release(&sb);
 452 }
 453
 454 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 455 {
 456         const char * const *var;
 457
 458         for (var = local_repo_env; *var; var++) {
 459                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 460                         argv_array_push(out, *var);
 461         }
 462 }
 463
 464 void prepare_submodule_repo_env(struct argv_array *out)
 465 {
 466         prepare_submodule_repo_env_no_git_dir(out);
 467         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 468                          DEFAULT_GIT_DIR_ENVIRONMENT);
 469 }
 470
 471 /* Helper function to display the submodule header line prior to the full
 472  * summary output. If it can locate the submodule objects directory it will
 473  * attempt to lookup both the left and right commits and put them into the
 474  * left and right pointers.
 475  */
 476 static void show_submodule_header(struct diff_options *o, const char *path,
 477                 struct object_id *one, struct object_id *two,
 478                 unsigned dirty_submodule,
 479                 struct commit **left, struct commit **right,
 480                 struct commit_list **merge_bases)
 481 {
 482         const char *message = NULL;
 483         struct strbuf sb = STRBUF_INIT;
 484         int fast_forward = 0, fast_backward = 0;
 485
 486         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 487                 diff_emit_submodule_untracked(o, path);
 488
 489         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 490                 diff_emit_submodule_modified(o, path);
 491
 492         if (is_null_oid(one))
 493                 message = "(new submodule)";
 494         else if (is_null_oid(two))
 495                 message = "(submodule deleted)";
 496
 497         if (add_submodule_odb(path)) {
 498                 if (!message)
 499                         message = "(not initialized)";
 500                 goto output_header;
 501         }
 502
 503         /*
 504          * Attempt to lookup the commit references, and determine if this is
 505          * a fast forward or fast backwards update.
 506          */
 507         *left = lookup_commit_reference(one);
 508         *right = lookup_commit_reference(two);
 509
 510         /*
 511          * Warn about missing commits in the submodule project, but only if
 512          * they aren't null.
 513          */
 514         if ((!is_null_oid(one) && !*left) ||
 515              (!is_null_oid(two) && !*right))
 516                 message = "(commits not present)";
 517
 518         *merge_bases = get_merge_bases(*left, *right);
 519         if (*merge_bases) {
 520                 if ((*merge_bases)->item == *left)
 521                         fast_forward = 1;
 522                 else if ((*merge_bases)->item == *right)
 523                         fast_backward = 1;
 524         }
 525
 526         if (!oidcmp(one, two)) {
 527                 strbuf_release(&sb);
 528                 return;
 529         }
 530
 531 output_header:
 532         strbuf_addf(&sb, "Submodule %s ", path);
 533         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
 534         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 535         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
 536         if (message)
 537                 strbuf_addf(&sb, " %s\n", message);
 538         else
 539                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 540         diff_emit_submodule_header(o, sb.buf);
 541
 542         strbuf_release(&sb);
 543 }
 544
 545 void show_submodule_summary(struct diff_options *o, const char *path,
 546                 struct object_id *one, struct object_id *two,
 547                 unsigned dirty_submodule)
 548 {
 549         struct rev_info rev;
 550         struct commit *left = NULL, *right = NULL;
 551         struct commit_list *merge_bases = NULL;
 552
 553         show_submodule_header(o, path, one, two, dirty_submodule,
 554                               &left, &right, &merge_bases);
 555
 556         /*
 557          * If we don't have both a left and a right pointer, there is no
 558          * reason to try and display a summary. The header line should contain
 559          * all the information the user needs.
 560          */
 561         if (!left || !right)
 562                 goto out;
 563
 564         /* Treat revision walker failure the same as missing commits */
 565         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 566                 diff_emit_submodule_error(o, "(revision walker failed)\n");
 567                 goto out;
 568         }
 569
 570         print_submodule_summary(&rev, o);
 571
 572 out:
 573         if (merge_bases)
 574                 free_commit_list(merge_bases);
 575         clear_commit_marks(left, ~0);
 576         clear_commit_marks(right, ~0);
 577 }
 578
 579 void show_submodule_inline_diff(struct diff_options *o, const char *path,
 580                 struct object_id *one, struct object_id *two,
 581                 unsigned dirty_submodule)
 582 {
 583         const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
 584         struct commit *left = NULL, *right = NULL;
 585         struct commit_list *merge_bases = NULL;
 586         struct child_process cp = CHILD_PROCESS_INIT;
 587         struct strbuf sb = STRBUF_INIT;
 588
 589         show_submodule_header(o, path, one, two, dirty_submodule,
 590                               &left, &right, &merge_bases);
 591
 592         /* We need a valid left and right commit to display a difference */
 593         if (!(left || is_null_oid(one)) ||
 594             !(right || is_null_oid(two)))
 595                 goto done;
 596
 597         if (left)
 598                 old = one;
 599         if (right)
 600                 new = two;
 601
 602         cp.git_cmd = 1;
 603         cp.dir = path;
 604         cp.out = -1;
 605         cp.no_stdin = 1;
 606
 607         /* TODO: other options may need to be passed here. */
 608         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 609         argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 610                          "always" : "never");
 611
 612         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
 613                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 614                                  o->b_prefix, path);
 615                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 616                                  o->a_prefix, path);
 617         } else {
 618                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 619                                  o->a_prefix, path);
 620                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 621                                  o->b_prefix, path);
 622         }
 623         argv_array_push(&cp.args, oid_to_hex(old));
 624         /*
 625          * If the submodule has modified content, we will diff against the
 626          * work tree, under the assumption that the user has asked for the
 627          * diff format and wishes to actually see all differences even if they
 628          * haven't yet been committed to the submodule yet.
 629          */
 630         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 631                 argv_array_push(&cp.args, oid_to_hex(new));
 632
 633         prepare_submodule_repo_env(&cp.env_array);
 634         if (start_command(&cp))
 635                 diff_emit_submodule_error(o, "(diff failed)\n");
 636
 637         while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
 638                 diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
 639
 640         if (finish_command(&cp))
 641                 diff_emit_submodule_error(o, "(diff failed)\n");
 642
 643 done:
 644         strbuf_release(&sb);
 645         if (merge_bases)
 646                 free_commit_list(merge_bases);
 647         if (left)
 648                 clear_commit_marks(left, ~0);
 649         if (right)
 650                 clear_commit_marks(right, ~0);
 651 }
 652
 653 int should_update_submodules(void)
 654 {
 655         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 656 }
 657
 658 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 659 {
 660         if (!S_ISGITLINK(ce->ce_mode))
 661                 return NULL;
 662
 663         if (!should_update_submodules())
 664                 return NULL;
 665
 666         return submodule_from_path(&null_oid, ce->name);
 667 }
 668
 669 static struct oid_array *submodule_commits(struct string_list *submodules,
 670                                            const char *path)
 671 {
 672         struct string_list_item *item;
 673
 674         item = string_list_insert(submodules, path);
 675         if (item->util)
 676                 return (struct oid_array *) item->util;
 677
 678         /* NEEDSWORK: should we have oid_array_init()? */
 679         item->util = xcalloc(1, sizeof(struct oid_array));
 680         return (struct oid_array *) item->util;
 681 }
 682
 683 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 684                                           struct diff_options *options,
 685                                           void *data)
 686 {
 687         int i;
 688         struct string_list *changed = data;
 689
 690         for (i = 0; i < q->nr; i++) {
 691                 struct diff_filepair *p = q->queue[i];
 692                 struct oid_array *commits;
 693                 if (!S_ISGITLINK(p->two->mode))
 694                         continue;
 695
 696                 if (S_ISGITLINK(p->one->mode)) {
 697                         /*
 698                          * NEEDSWORK: We should honor the name configured in
 699                          * the .gitmodules file of the commit we are examining
 700                          * here to be able to correctly follow submodules
 701                          * being moved around.
 702                          */
 703                         commits = submodule_commits(changed, p->two->path);
 704                         oid_array_append(commits, &p->two->oid);
 705                 } else {
 706                         /* Submodule is new or was moved here */
 707                         /*
 708                          * NEEDSWORK: When the .git directories of submodules
 709                          * live inside the superprojects .git directory some
 710                          * day we should fetch new submodules directly into
 711                          * that location too when config or options request
 712                          * that so they can be checked out from there.
 713                          */
 714                         continue;
 715                 }
 716         }
 717 }
 718
 719 /*
 720  * Collect the paths of submodules in 'changed' which have changed based on
 721  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 722  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 723  * what the submodule pointers were updated to during the change.
 724  */
 725 static void collect_changed_submodules(struct string_list *changed,
 726                                        struct argv_array *argv)
 727 {
 728         struct rev_info rev;
 729         const struct commit *commit;
 730
 731         init_revisions(&rev, NULL);
 732         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 733         if (prepare_revision_walk(&rev))
 734                 die("revision walk setup failed");
 735
 736         while ((commit = get_revision(&rev))) {
 737                 struct rev_info diff_rev;
 738
 739                 init_revisions(&diff_rev, NULL);
 740                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 741                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 742                 diff_rev.diffopt.format_callback_data = changed;
 743                 diff_tree_combined_merge(commit, 1, &diff_rev);
 744         }
 745
 746         reset_revision_walk();
 747 }
 748
 749 static void free_submodules_oids(struct string_list *submodules)
 750 {
 751         struct string_list_item *item;
 752         for_each_string_list_item(item, submodules)
 753                 oid_array_clear((struct oid_array *) item->util);
 754         string_list_clear(submodules, 1);
 755 }
 756
 757 static int has_remote(const char *refname, const struct object_id *oid,
 758                       int flags, void *cb_data)
 759 {
 760         return 1;
 761 }
 762
 763 static int append_oid_to_argv(const struct object_id *oid, void *data)
 764 {
 765         struct argv_array *argv = data;
 766         argv_array_push(argv, oid_to_hex(oid));
 767         return 0;
 768 }
 769
 770 static int check_has_commit(const struct object_id *oid, void *data)
 771 {
 772         int *has_commit = data;
 773
 774         if (!lookup_commit_reference(oid))
 775                 *has_commit = 0;
 776
 777         return 0;
 778 }
 779
 780 static int submodule_has_commits(const char *path, struct oid_array *commits)
 781 {
 782         int has_commit = 1;
 783
 784         /*
 785          * Perform a cheap, but incorrect check for the existence of 'commits'.
 786          * This is done by adding the submodule's object store to the in-core
 787          * object store, and then querying for each commit's existence.  If we
 788          * do not have the commit object anywhere, there is no chance we have
 789          * it in the object store of the correct submodule and have it
 790          * reachable from a ref, so we can fail early without spawning rev-list
 791          * which is expensive.
 792          */
 793         if (add_submodule_odb(path))
 794                 return 0;
 795
 796         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 797
 798         if (has_commit) {
 799                 /*
 800                  * Even if the submodule is checked out and the commit is
 801                  * present, make sure it exists in the submodule's object store
 802                  * and that it is reachable from a ref.
 803                  */
 804                 struct child_process cp = CHILD_PROCESS_INIT;
 805                 struct strbuf out = STRBUF_INIT;
 806
 807                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 808                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 809                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 810
 811                 prepare_submodule_repo_env(&cp.env_array);
 812                 cp.git_cmd = 1;
 813                 cp.no_stdin = 1;
 814                 cp.dir = path;
 815
 816                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 817                         has_commit = 0;
 818
 819                 strbuf_release(&out);
 820         }
 821
 822         return has_commit;
 823 }
 824
 825 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
 826 {
 827         if (!submodule_has_commits(path, commits))
 828                 /*
 829                  * NOTE: We do consider it safe to return "no" here. The
 830                  * correct answer would be "We do not know" instead of
 831                  * "No push needed", but it is quite hard to change
 832                  * the submodule pointer without having the submodule
 833                  * around. If a user did however change the submodules
 834                  * without having the submodule around, this indicates
 835                  * an expert who knows what they are doing or a
 836                  * maintainer integrating work from other people. In
 837                  * both cases it should be safe to skip this check.
 838                  */
 839                 return 0;
 840
 841         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 842                 struct child_process cp = CHILD_PROCESS_INIT;
 843                 struct strbuf buf = STRBUF_INIT;
 844                 int needs_pushing = 0;
 845
 846                 argv_array_push(&cp.args, "rev-list");
 847                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 848                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 849
 850                 prepare_submodule_repo_env(&cp.env_array);
 851                 cp.git_cmd = 1;
 852                 cp.no_stdin = 1;
 853                 cp.out = -1;
 854                 cp.dir = path;
 855                 if (start_command(&cp))
 856                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 857                                         path);
 858                 if (strbuf_read(&buf, cp.out, 41))
 859                         needs_pushing = 1;
 860                 finish_command(&cp);
 861                 close(cp.out);
 862                 strbuf_release(&buf);
 863                 return needs_pushing;
 864         }
 865
 866         return 0;
 867 }
 868
 869 int find_unpushed_submodules(struct oid_array *commits,
 870                 const char *remotes_name, struct string_list *needs_pushing)
 871 {
 872         struct string_list submodules = STRING_LIST_INIT_DUP;
 873         struct string_list_item *submodule;
 874         struct argv_array argv = ARGV_ARRAY_INIT;
 875
 876         /* argv.argv[0] will be ignored by setup_revisions */
 877         argv_array_push(&argv, "find_unpushed_submodules");
 878         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
 879         argv_array_push(&argv, "--not");
 880         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
 881
 882         collect_changed_submodules(&submodules, &argv);
 883
 884         for_each_string_list_item(submodule, &submodules) {
 885                 struct oid_array *commits = submodule->util;
 886                 const char *path = submodule->string;
 887
 888                 if (submodule_needs_pushing(path, commits))
 889                         string_list_insert(needs_pushing, path);
 890         }
 891
 892         free_submodules_oids(&submodules);
 893         argv_array_clear(&argv);
 894
 895         return needs_pushing->nr;
 896 }
 897
 898 static int push_submodule(const char *path,
 899                           const struct remote *remote,
 900                           const char **refspec, int refspec_nr,
 901                           const struct string_list *push_options,
 902                           int dry_run)
 903 {
 904         if (add_submodule_odb(path))
 905                 return 1;
 906
 907         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 908                 struct child_process cp = CHILD_PROCESS_INIT;
 909                 argv_array_push(&cp.args, "push");
 910                 if (dry_run)
 911                         argv_array_push(&cp.args, "--dry-run");
 912
 913                 if (push_options && push_options->nr) {
 914                         const struct string_list_item *item;
 915                         for_each_string_list_item(item, push_options)
 916                                 argv_array_pushf(&cp.args, "--push-option=%s",
 917                                                  item->string);
 918                 }
 919
 920                 if (remote->origin != REMOTE_UNCONFIGURED) {
 921                         int i;
 922                         argv_array_push(&cp.args, remote->name);
 923                         for (i = 0; i < refspec_nr; i++)
 924                                 argv_array_push(&cp.args, refspec[i]);
 925                 }
 926
 927                 prepare_submodule_repo_env(&cp.env_array);
 928                 cp.git_cmd = 1;
 929                 cp.no_stdin = 1;
 930                 cp.dir = path;
 931                 if (run_command(&cp))
 932                         return 0;
 933                 close(cp.out);
 934         }
 935
 936         return 1;
 937 }
 938
 939 /*
 940  * Perform a check in the submodule to see if the remote and refspec work.
 941  * Die if the submodule can't be pushed.
 942  */
 943 static void submodule_push_check(const char *path, const char *head,
 944                                  const struct remote *remote,
 945                                  const char **refspec, int refspec_nr)
 946 {
 947         struct child_process cp = CHILD_PROCESS_INIT;
 948         int i;
 949
 950         argv_array_push(&cp.args, "submodule--helper");
 951         argv_array_push(&cp.args, "push-check");
 952         argv_array_push(&cp.args, head);
 953         argv_array_push(&cp.args, remote->name);
 954
 955         for (i = 0; i < refspec_nr; i++)
 956                 argv_array_push(&cp.args, refspec[i]);
 957
 958         prepare_submodule_repo_env(&cp.env_array);
 959         cp.git_cmd = 1;
 960         cp.no_stdin = 1;
 961         cp.no_stdout = 1;
 962         cp.dir = path;
 963
 964         /*
 965          * Simply indicate if 'submodule--helper push-check' failed.
 966          * More detailed error information will be provided by the
 967          * child process.
 968          */
 969         if (run_command(&cp))
 970                 die("process for submodule '%s' failed", path);
 971 }
 972
 973 int push_unpushed_submodules(struct oid_array *commits,
 974                              const struct remote *remote,
 975                              const char **refspec, int refspec_nr,
 976                              const struct string_list *push_options,
 977                              int dry_run)
 978 {
 979         int i, ret = 1;
 980         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
 981
 982         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
 983                 return 1;
 984
 985         /*
 986          * Verify that the remote and refspec can be propagated to all
 987          * submodules.  This check can be skipped if the remote and refspec
 988          * won't be propagated due to the remote being unconfigured (e.g. a URL
 989          * instead of a remote name).
 990          */
 991         if (remote->origin != REMOTE_UNCONFIGURED) {
 992                 char *head;
 993                 struct object_id head_oid;
 994
 995                 head = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
 996                 if (!head)
 997                         die(_("Failed to resolve HEAD as a valid ref."));
 998
 999                 for (i = 0; i < needs_pushing.nr; i++)
1000                         submodule_push_check(needs_pushing.items[i].string,
1001                                              head, remote,
1002                                              refspec, refspec_nr);
1003                 free(head);
1004         }
1005
1006         /* Actually push the submodules */
1007         for (i = 0; i < needs_pushing.nr; i++) {
1008                 const char *path = needs_pushing.items[i].string;
1009                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1010                 if (!push_submodule(path, remote, refspec, refspec_nr,
1011                                     push_options, dry_run)) {
1012                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1013                         ret = 0;
1014                 }
1015         }
1016
1017         string_list_clear(&needs_pushing, 0);
1018
1019         return ret;
1020 }
1021
1022 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1023                                int flags, void *data)
1024 {
1025         struct oid_array *array = data;
1026         oid_array_append(array, oid);
1027         return 0;
1028 }
1029
1030 void check_for_new_submodule_commits(struct object_id *oid)
1031 {
1032         if (!initialized_fetch_ref_tips) {
1033                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1034                 initialized_fetch_ref_tips = 1;
1035         }
1036
1037         oid_array_append(&ref_tips_after_fetch, oid);
1038 }
1039
1040 static void calculate_changed_submodule_paths(void)
1041 {
1042         struct argv_array argv = ARGV_ARRAY_INIT;
1043         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1044         const struct string_list_item *item;
1045
1046         /* No need to check if there are no submodules configured */
1047         if (!submodule_from_path(NULL, NULL))
1048                 return;
1049
1050         argv_array_push(&argv, "--"); /* argv[0] program name */
1051         oid_array_for_each_unique(&ref_tips_after_fetch,
1052                                    append_oid_to_argv, &argv);
1053         argv_array_push(&argv, "--not");
1054         oid_array_for_each_unique(&ref_tips_before_fetch,
1055                                    append_oid_to_argv, &argv);
1056
1057         /*
1058          * Collect all submodules (whether checked out or not) for which new
1059          * commits have been recorded upstream in "changed_submodule_paths".
1060          */
1061         collect_changed_submodules(&changed_submodules, &argv);
1062
1063         for_each_string_list_item(item, &changed_submodules) {
1064                 struct oid_array *commits = item->util;
1065                 const char *path = item->string;
1066
1067                 if (!submodule_has_commits(path, commits))
1068                         string_list_append(&changed_submodule_paths, path);
1069         }
1070
1071         free_submodules_oids(&changed_submodules);
1072         argv_array_clear(&argv);
1073         oid_array_clear(&ref_tips_before_fetch);
1074         oid_array_clear(&ref_tips_after_fetch);
1075         initialized_fetch_ref_tips = 0;
1076 }
1077
1078 int submodule_touches_in_range(struct object_id *excl_oid,
1079                                struct object_id *incl_oid)
1080 {
1081         struct string_list subs = STRING_LIST_INIT_DUP;
1082         struct argv_array args = ARGV_ARRAY_INIT;
1083         int ret;
1084
1085         /* No need to check if there are no submodules configured */
1086         if (!submodule_from_path(NULL, NULL))
1087                 return 0;
1088
1089         argv_array_push(&args, "--"); /* args[0] program name */
1090         argv_array_push(&args, oid_to_hex(incl_oid));
1091         argv_array_push(&args, "--not");
1092         argv_array_push(&args, oid_to_hex(excl_oid));
1093
1094         collect_changed_submodules(&subs, &args);
1095         ret = subs.nr;
1096
1097         argv_array_clear(&args);
1098
1099         free_submodules_oids(&subs);
1100         return ret;
1101 }
1102
1103 struct submodule_parallel_fetch {
1104         int count;
1105         struct argv_array args;
1106         const char *work_tree;
1107         const char *prefix;
1108         int command_line_option;
1109         int default_option;
1110         int quiet;
1111         int result;
1112 };
1113 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0}
1114
1115 static int get_next_submodule(struct child_process *cp,
1116                               struct strbuf *err, void *data, void **task_cb)
1117 {
1118         int ret = 0;
1119         struct submodule_parallel_fetch *spf = data;
1120
1121         for (; spf->count < active_nr; spf->count++) {
1122                 struct strbuf submodule_path = STRBUF_INIT;
1123                 struct strbuf submodule_git_dir = STRBUF_INIT;
1124                 struct strbuf submodule_prefix = STRBUF_INIT;
1125                 const struct cache_entry *ce = active_cache[spf->count];
1126                 const char *git_dir, *default_argv;
1127                 const struct submodule *submodule;
1128
1129                 if (!S_ISGITLINK(ce->ce_mode))
1130                         continue;
1131
1132                 submodule = submodule_from_path(&null_oid, ce->name);
1133
1134                 default_argv = "yes";
1135                 if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
1136                         int fetch_recurse = RECURSE_SUBMODULES_NONE;
1137
1138                         if (submodule) {
1139                                 char *key;
1140                                 const char *value;
1141
1142                                 fetch_recurse = submodule->fetch_recurse;
1143                                 key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1144                                 if (!repo_config_get_string_const(the_repository, key, &value)) {
1145                                         fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1146                                 }
1147                                 free(key);
1148                         }
1149
1150                         if (fetch_recurse != RECURSE_SUBMODULES_NONE) {
1151                                 if (fetch_recurse == RECURSE_SUBMODULES_OFF)
1152                                         continue;
1153                                 if (fetch_recurse == RECURSE_SUBMODULES_ON_DEMAND) {
1154                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1155                                                 continue;
1156                                         default_argv = "on-demand";
1157                                 }
1158                         } else {
1159                                 if (spf->default_option == RECURSE_SUBMODULES_OFF)
1160                                         continue;
1161                                 if (spf->default_option == RECURSE_SUBMODULES_ON_DEMAND) {
1162                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1163                                                 continue;
1164                                         default_argv = "on-demand";
1165                                 }
1166                         }
1167                 } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
1168                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1169                                 continue;
1170                         default_argv = "on-demand";
1171                 }
1172
1173                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1174                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1175                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1176                 git_dir = read_gitfile(submodule_git_dir.buf);
1177                 if (!git_dir)
1178                         git_dir = submodule_git_dir.buf;
1179                 if (is_directory(git_dir)) {
1180                         child_process_init(cp);
1181                         cp->dir = strbuf_detach(&submodule_path, NULL);
1182                         prepare_submodule_repo_env(&cp->env_array);
1183                         cp->git_cmd = 1;
1184                         if (!spf->quiet)
1185                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1186                                             spf->prefix, ce->name);
1187                         argv_array_init(&cp->args);
1188                         argv_array_pushv(&cp->args, spf->args.argv);
1189                         argv_array_push(&cp->args, default_argv);
1190                         argv_array_push(&cp->args, "--submodule-prefix");
1191                         argv_array_push(&cp->args, submodule_prefix.buf);
1192                         ret = 1;
1193                 }
1194                 strbuf_release(&submodule_path);
1195                 strbuf_release(&submodule_git_dir);
1196                 strbuf_release(&submodule_prefix);
1197                 if (ret) {
1198                         spf->count++;
1199                         return 1;
1200                 }
1201         }
1202         return 0;
1203 }
1204
1205 static int fetch_start_failure(struct strbuf *err,
1206                                void *cb, void *task_cb)
1207 {
1208         struct submodule_parallel_fetch *spf = cb;
1209
1210         spf->result = 1;
1211
1212         return 0;
1213 }
1214
1215 static int fetch_finish(int retvalue, struct strbuf *err,
1216                         void *cb, void *task_cb)
1217 {
1218         struct submodule_parallel_fetch *spf = cb;
1219
1220         if (retvalue)
1221                 spf->result = 1;
1222
1223         return 0;
1224 }
1225
1226 int fetch_populated_submodules(const struct argv_array *options,
1227                                const char *prefix, int command_line_option,
1228                                int default_option,
1229                                int quiet, int max_parallel_jobs)
1230 {
1231         int i;
1232         struct submodule_parallel_fetch spf = SPF_INIT;
1233
1234         spf.work_tree = get_git_work_tree();
1235         spf.command_line_option = command_line_option;
1236         spf.default_option = default_option;
1237         spf.quiet = quiet;
1238         spf.prefix = prefix;
1239
1240         if (!spf.work_tree)
1241                 goto out;
1242
1243         if (read_cache() < 0)
1244                 die("index file corrupt");
1245
1246         argv_array_push(&spf.args, "fetch");
1247         for (i = 0; i < options->argc; i++)
1248                 argv_array_push(&spf.args, options->argv[i]);
1249         argv_array_push(&spf.args, "--recurse-submodules-default");
1250         /* default value, "--submodule-prefix" and its value are added later */
1251
1252         calculate_changed_submodule_paths();
1253         run_processes_parallel(max_parallel_jobs,
1254                                get_next_submodule,
1255                                fetch_start_failure,
1256                                fetch_finish,
1257                                &spf);
1258
1259         argv_array_clear(&spf.args);
1260 out:
1261         string_list_clear(&changed_submodule_paths, 1);
1262         return spf.result;
1263 }
1264
1265 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1266 {
1267         struct child_process cp = CHILD_PROCESS_INIT;
1268         struct strbuf buf = STRBUF_INIT;
1269         FILE *fp;
1270         unsigned dirty_submodule = 0;
1271         const char *git_dir;
1272         int ignore_cp_exit_code = 0;
1273
1274         strbuf_addf(&buf, "%s/.git", path);
1275         git_dir = read_gitfile(buf.buf);
1276         if (!git_dir)
1277                 git_dir = buf.buf;
1278         if (!is_git_directory(git_dir)) {
1279                 if (is_directory(git_dir))
1280                         die(_("'%s' not recognized as a git repository"), git_dir);
1281                 strbuf_release(&buf);
1282                 /* The submodule is not checked out, so it is not modified */
1283                 return 0;
1284         }
1285         strbuf_reset(&buf);
1286
1287         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1288         if (ignore_untracked)
1289                 argv_array_push(&cp.args, "-uno");
1290
1291         prepare_submodule_repo_env(&cp.env_array);
1292         cp.git_cmd = 1;
1293         cp.no_stdin = 1;
1294         cp.out = -1;
1295         cp.dir = path;
1296         if (start_command(&cp))
1297                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1298
1299         fp = xfdopen(cp.out, "r");
1300         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1301                 /* regular untracked files */
1302                 if (buf.buf[0] == '?')
1303                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1304
1305                 if (buf.buf[0] == 'u' ||
1306                     buf.buf[0] == '1' ||
1307                     buf.buf[0] == '2') {
1308                         /* T = line type, XY = status, SSSS = submodule state */
1309                         if (buf.len < strlen("T XY SSSS"))
1310                                 die("BUG: invalid status --porcelain=2 line %s",
1311                                     buf.buf);
1312
1313                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1314                                 /* nested untracked file */
1315                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1316
1317                         if (buf.buf[0] == 'u' ||
1318                             buf.buf[0] == '2' ||
1319                             memcmp(buf.buf + 5, "S..U", 4))
1320                                 /* other change */
1321                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1322                 }
1323
1324                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1325                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1326                      ignore_untracked)) {
1327                         /*
1328                          * We're not interested in any further information from
1329                          * the child any more, neither output nor its exit code.
1330                          */
1331                         ignore_cp_exit_code = 1;
1332                         break;
1333                 }
1334         }
1335         fclose(fp);
1336
1337         if (finish_command(&cp) && !ignore_cp_exit_code)
1338                 die("'git status --porcelain=2' failed in submodule %s", path);
1339
1340         strbuf_release(&buf);
1341         return dirty_submodule;
1342 }
1343
1344 int submodule_uses_gitfile(const char *path)
1345 {
1346         struct child_process cp = CHILD_PROCESS_INIT;
1347         const char *argv[] = {
1348                 "submodule",
1349                 "foreach",
1350                 "--quiet",
1351                 "--recursive",
1352                 "test -f .git",
1353                 NULL,
1354         };
1355         struct strbuf buf = STRBUF_INIT;
1356         const char *git_dir;
1357
1358         strbuf_addf(&buf, "%s/.git", path);
1359         git_dir = read_gitfile(buf.buf);
1360         if (!git_dir) {
1361                 strbuf_release(&buf);
1362                 return 0;
1363         }
1364         strbuf_release(&buf);
1365
1366         /* Now test that all nested submodules use a gitfile too */
1367         cp.argv = argv;
1368         prepare_submodule_repo_env(&cp.env_array);
1369         cp.git_cmd = 1;
1370         cp.no_stdin = 1;
1371         cp.no_stderr = 1;
1372         cp.no_stdout = 1;
1373         cp.dir = path;
1374         if (run_command(&cp))
1375                 return 0;
1376
1377         return 1;
1378 }
1379
1380 /*
1381  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1382  * when doing so.
1383  *
1384  * Return 1 if we'd lose data, return 0 if the removal is fine,
1385  * and negative values for errors.
1386  */
1387 int bad_to_remove_submodule(const char *path, unsigned flags)
1388 {
1389         ssize_t len;
1390         struct child_process cp = CHILD_PROCESS_INIT;
1391         struct strbuf buf = STRBUF_INIT;
1392         int ret = 0;
1393
1394         if (!file_exists(path) || is_empty_dir(path))
1395                 return 0;
1396
1397         if (!submodule_uses_gitfile(path))
1398                 return 1;
1399
1400         argv_array_pushl(&cp.args, "status", "--porcelain",
1401                                    "--ignore-submodules=none", NULL);
1402
1403         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1404                 argv_array_push(&cp.args, "-uno");
1405         else
1406                 argv_array_push(&cp.args, "-uall");
1407
1408         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1409                 argv_array_push(&cp.args, "--ignored");
1410
1411         prepare_submodule_repo_env(&cp.env_array);
1412         cp.git_cmd = 1;
1413         cp.no_stdin = 1;
1414         cp.out = -1;
1415         cp.dir = path;
1416         if (start_command(&cp)) {
1417                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1418                         die(_("could not start 'git status' in submodule '%s'"),
1419                                 path);
1420                 ret = -1;
1421                 goto out;
1422         }
1423
1424         len = strbuf_read(&buf, cp.out, 1024);
1425         if (len > 2)
1426                 ret = 1;
1427         close(cp.out);
1428
1429         if (finish_command(&cp)) {
1430                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1431                         die(_("could not run 'git status' in submodule '%s'"),
1432                                 path);
1433                 ret = -1;
1434         }
1435 out:
1436         strbuf_release(&buf);
1437         return ret;
1438 }
1439
1440 static const char *get_super_prefix_or_empty(void)
1441 {
1442         const char *s = get_super_prefix();
1443         if (!s)
1444                 s = "";
1445         return s;
1446 }
1447
1448 static int submodule_has_dirty_index(const struct submodule *sub)
1449 {
1450         struct child_process cp = CHILD_PROCESS_INIT;
1451
1452         prepare_submodule_repo_env(&cp.env_array);
1453
1454         cp.git_cmd = 1;
1455         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1456                                    "--cached", "HEAD", NULL);
1457         cp.no_stdin = 1;
1458         cp.no_stdout = 1;
1459         cp.dir = sub->path;
1460         if (start_command(&cp))
1461                 die("could not recurse into submodule '%s'", sub->path);
1462
1463         return finish_command(&cp);
1464 }
1465
1466 static void submodule_reset_index(const char *path)
1467 {
1468         struct child_process cp = CHILD_PROCESS_INIT;
1469         prepare_submodule_repo_env(&cp.env_array);
1470
1471         cp.git_cmd = 1;
1472         cp.no_stdin = 1;
1473         cp.dir = path;
1474
1475         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1476                                    get_super_prefix_or_empty(), path);
1477         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1478
1479         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1480
1481         if (run_command(&cp))
1482                 die("could not reset submodule index");
1483 }
1484
1485 /**
1486  * Moves a submodule at a given path from a given head to another new head.
1487  * For edge cases (a submodule coming into existence or removing a submodule)
1488  * pass NULL for old or new respectively.
1489  */
1490 int submodule_move_head(const char *path,
1491                          const char *old,
1492                          const char *new,
1493                          unsigned flags)
1494 {
1495         int ret = 0;
1496         struct child_process cp = CHILD_PROCESS_INIT;
1497         const struct submodule *sub;
1498         int *error_code_ptr, error_code;
1499
1500         if (!is_submodule_active(the_repository, path))
1501                 return 0;
1502
1503         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1504                 /*
1505                  * Pass non NULL pointer to is_submodule_populated_gently
1506                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1507                  * to fixup the submodule in the force case later.
1508                  */
1509                 error_code_ptr = &error_code;
1510         else
1511                 error_code_ptr = NULL;
1512
1513         if (old && !is_submodule_populated_gently(path, error_code_ptr))
1514                 return 0;
1515
1516         sub = submodule_from_path(&null_oid, path);
1517
1518         if (!sub)
1519                 die("BUG: could not get submodule information for '%s'", path);
1520
1521         if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1522                 /* Check if the submodule has a dirty index. */
1523                 if (submodule_has_dirty_index(sub))
1524                         return error(_("submodule '%s' has dirty index"), path);
1525         }
1526
1527         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1528                 if (old) {
1529                         if (!submodule_uses_gitfile(path))
1530                                 absorb_git_dir_into_superproject("", path,
1531                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1532                 } else {
1533                         char *gitdir = xstrfmt("%s/modules/%s",
1534                                     get_git_common_dir(), sub->name);
1535                         connect_work_tree_and_git_dir(path, gitdir);
1536                         free(gitdir);
1537
1538                         /* make sure the index is clean as well */
1539                         submodule_reset_index(path);
1540                 }
1541
1542                 if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1543                         char *gitdir = xstrfmt("%s/modules/%s",
1544                                     get_git_common_dir(), sub->name);
1545                         connect_work_tree_and_git_dir(path, gitdir);
1546                         free(gitdir);
1547                 }
1548         }
1549
1550         prepare_submodule_repo_env(&cp.env_array);
1551
1552         cp.git_cmd = 1;
1553         cp.no_stdin = 1;
1554         cp.dir = path;
1555
1556         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1557                         get_super_prefix_or_empty(), path);
1558         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1559
1560         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1561                 argv_array_push(&cp.args, "-n");
1562         else
1563                 argv_array_push(&cp.args, "-u");
1564
1565         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1566                 argv_array_push(&cp.args, "--reset");
1567         else
1568                 argv_array_push(&cp.args, "-m");
1569
1570         argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1571         argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1572
1573         if (run_command(&cp)) {
1574                 ret = -1;
1575                 goto out;
1576         }
1577
1578         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1579                 if (new) {
1580                         child_process_init(&cp);
1581                         /* also set the HEAD accordingly */
1582                         cp.git_cmd = 1;
1583                         cp.no_stdin = 1;
1584                         cp.dir = path;
1585
1586                         prepare_submodule_repo_env(&cp.env_array);
1587                         argv_array_pushl(&cp.args, "update-ref", "HEAD", new, NULL);
1588
1589                         if (run_command(&cp)) {
1590                                 ret = -1;
1591                                 goto out;
1592                         }
1593                 } else {
1594                         struct strbuf sb = STRBUF_INIT;
1595
1596                         strbuf_addf(&sb, "%s/.git", path);
1597                         unlink_or_warn(sb.buf);
1598                         strbuf_release(&sb);
1599
1600                         if (is_empty_dir(path))
1601                                 rmdir_or_warn(path);
1602                 }
1603         }
1604 out:
1605         return ret;
1606 }
1607
1608 static int find_first_merges(struct object_array *result, const char *path,
1609                 struct commit *a, struct commit *b)
1610 {
1611         int i, j;
1612         struct object_array merges = OBJECT_ARRAY_INIT;
1613         struct commit *commit;
1614         int contains_another;
1615
1616         char merged_revision[42];
1617         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1618                                    "--all", merged_revision, NULL };
1619         struct rev_info revs;
1620         struct setup_revision_opt rev_opts;
1621
1622         memset(result, 0, sizeof(struct object_array));
1623         memset(&rev_opts, 0, sizeof(rev_opts));
1624
1625         /* get all revisions that merge commit a */
1626         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1627                         oid_to_hex(&a->object.oid));
1628         init_revisions(&revs, NULL);
1629         rev_opts.submodule = path;
1630         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1631
1632         /* save all revisions from the above list that contain b */
1633         if (prepare_revision_walk(&revs))
1634                 die("revision walk setup failed");
1635         while ((commit = get_revision(&revs)) != NULL) {
1636                 struct object *o = &(commit->object);
1637                 if (in_merge_bases(b, commit))
1638                         add_object_array(o, NULL, &merges);
1639         }
1640         reset_revision_walk();
1641
1642         /* Now we've got all merges that contain a and b. Prune all
1643          * merges that contain another found merge and save them in
1644          * result.
1645          */
1646         for (i = 0; i < merges.nr; i++) {
1647                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1648
1649                 contains_another = 0;
1650                 for (j = 0; j < merges.nr; j++) {
1651                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1652                         if (i != j && in_merge_bases(m2, m1)) {
1653                                 contains_another = 1;
1654                                 break;
1655                         }
1656                 }
1657
1658                 if (!contains_another)
1659                         add_object_array(merges.objects[i].item, NULL, result);
1660         }
1661
1662         free(merges.objects);
1663         return result->nr;
1664 }
1665
1666 static void print_commit(struct commit *commit)
1667 {
1668         struct strbuf sb = STRBUF_INIT;
1669         struct pretty_print_context ctx = {0};
1670         ctx.date_mode.type = DATE_NORMAL;
1671         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1672         fprintf(stderr, "%s\n", sb.buf);
1673         strbuf_release(&sb);
1674 }
1675
1676 #define MERGE_WARNING(path, msg) \
1677         warning("Failed to merge submodule %s (%s)", path, msg);
1678
1679 int merge_submodule(struct object_id *result, const char *path,
1680                     const struct object_id *base, const struct object_id *a,
1681                     const struct object_id *b, int search)
1682 {
1683         struct commit *commit_base, *commit_a, *commit_b;
1684         int parent_count;
1685         struct object_array merges;
1686
1687         int i;
1688
1689         /* store a in result in case we fail */
1690         oidcpy(result, a);
1691
1692         /* we can not handle deletion conflicts */
1693         if (is_null_oid(base))
1694                 return 0;
1695         if (is_null_oid(a))
1696                 return 0;
1697         if (is_null_oid(b))
1698                 return 0;
1699
1700         if (add_submodule_odb(path)) {
1701                 MERGE_WARNING(path, "not checked out");
1702                 return 0;
1703         }
1704
1705         if (!(commit_base = lookup_commit_reference(base)) ||
1706             !(commit_a = lookup_commit_reference(a)) ||
1707             !(commit_b = lookup_commit_reference(b))) {
1708                 MERGE_WARNING(path, "commits not present");
1709                 return 0;
1710         }
1711
1712         /* check whether both changes are forward */
1713         if (!in_merge_bases(commit_base, commit_a) ||
1714             !in_merge_bases(commit_base, commit_b)) {
1715                 MERGE_WARNING(path, "commits don't follow merge-base");
1716                 return 0;
1717         }
1718
1719         /* Case #1: a is contained in b or vice versa */
1720         if (in_merge_bases(commit_a, commit_b)) {
1721                 oidcpy(result, b);
1722                 return 1;
1723         }
1724         if (in_merge_bases(commit_b, commit_a)) {
1725                 oidcpy(result, a);
1726                 return 1;
1727         }
1728
1729         /*
1730          * Case #2: There are one or more merges that contain a and b in
1731          * the submodule. If there is only one, then present it as a
1732          * suggestion to the user, but leave it marked unmerged so the
1733          * user needs to confirm the resolution.
1734          */
1735
1736         /* Skip the search if makes no sense to the calling context.  */
1737         if (!search)
1738                 return 0;
1739
1740         /* find commit which merges them */
1741         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1742         switch (parent_count) {
1743         case 0:
1744                 MERGE_WARNING(path, "merge following commits not found");
1745                 break;
1746
1747         case 1:
1748                 MERGE_WARNING(path, "not fast-forward");
1749                 fprintf(stderr, "Found a possible merge resolution "
1750                                 "for the submodule:\n");
1751                 print_commit((struct commit *) merges.objects[0].item);
1752                 fprintf(stderr,
1753                         "If this is correct simply add it to the index "
1754                         "for example\n"
1755                         "by using:\n\n"
1756                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1757                         "which will accept this suggestion.\n",
1758                         oid_to_hex(&merges.objects[0].item->oid), path);
1759                 break;
1760
1761         default:
1762                 MERGE_WARNING(path, "multiple merges found");
1763                 for (i = 0; i < merges.nr; i++)
1764                         print_commit((struct commit *) merges.objects[i].item);
1765         }
1766
1767         free(merges.objects);
1768         return 0;
1769 }
1770
1771 /*
1772  * Embeds a single submodules git directory into the superprojects git dir,
1773  * non recursively.
1774  */
1775 static void relocate_single_git_dir_into_superproject(const char *prefix,
1776                                                       const char *path)
1777 {
1778         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1779         const char *new_git_dir;
1780         const struct submodule *sub;
1781
1782         if (submodule_uses_worktrees(path))
1783                 die(_("relocate_gitdir for submodule '%s' with "
1784                       "more than one worktree not supported"), path);
1785
1786         old_git_dir = xstrfmt("%s/.git", path);
1787         if (read_gitfile(old_git_dir))
1788                 /* If it is an actual gitfile, it doesn't need migration. */
1789                 return;
1790
1791         real_old_git_dir = real_pathdup(old_git_dir, 1);
1792
1793         sub = submodule_from_path(&null_oid, path);
1794         if (!sub)
1795                 die(_("could not lookup name for submodule '%s'"), path);
1796
1797         new_git_dir = git_path("modules/%s", sub->name);
1798         if (safe_create_leading_directories_const(new_git_dir) < 0)
1799                 die(_("could not create directory '%s'"), new_git_dir);
1800         real_new_git_dir = real_pathdup(new_git_dir, 1);
1801
1802         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1803                 get_super_prefix_or_empty(), path,
1804                 real_old_git_dir, real_new_git_dir);
1805
1806         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1807
1808         free(old_git_dir);
1809         free(real_old_git_dir);
1810         free(real_new_git_dir);
1811 }
1812
1813 /*
1814  * Migrate the git directory of the submodule given by path from
1815  * having its git directory within the working tree to the git dir nested
1816  * in its superprojects git dir under modules/.
1817  */
1818 void absorb_git_dir_into_superproject(const char *prefix,
1819                                       const char *path,
1820                                       unsigned flags)
1821 {
1822         int err_code;
1823         const char *sub_git_dir;
1824         struct strbuf gitdir = STRBUF_INIT;
1825         strbuf_addf(&gitdir, "%s/.git", path);
1826         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1827
1828         /* Not populated? */
1829         if (!sub_git_dir) {
1830                 const struct submodule *sub;
1831
1832                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1833                         /* unpopulated as expected */
1834                         strbuf_release(&gitdir);
1835                         return;
1836                 }
1837
1838                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1839                         /* We don't know what broke here. */
1840                         read_gitfile_error_die(err_code, path, NULL);
1841
1842                 /*
1843                 * Maybe populated, but no git directory was found?
1844                 * This can happen if the superproject is a submodule
1845                 * itself and was just absorbed. The absorption of the
1846                 * superproject did not rewrite the git file links yet,
1847                 * fix it now.
1848                 */
1849                 sub = submodule_from_path(&null_oid, path);
1850                 if (!sub)
1851                         die(_("could not lookup name for submodule '%s'"), path);
1852                 connect_work_tree_and_git_dir(path,
1853                         git_path("modules/%s", sub->name));
1854         } else {
1855                 /* Is it already absorbed into the superprojects git dir? */
1856                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1857                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1858
1859                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1860                         relocate_single_git_dir_into_superproject(prefix, path);
1861
1862                 free(real_sub_git_dir);
1863                 free(real_common_git_dir);
1864         }
1865         strbuf_release(&gitdir);
1866
1867         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1868                 struct child_process cp = CHILD_PROCESS_INIT;
1869                 struct strbuf sb = STRBUF_INIT;
1870
1871                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1872                         die("BUG: we don't know how to pass the flags down?");
1873
1874                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1875                 strbuf_addstr(&sb, path);
1876                 strbuf_addch(&sb, '/');
1877
1878                 cp.dir = path;
1879                 cp.git_cmd = 1;
1880                 cp.no_stdin = 1;
1881                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1882                                            "submodule--helper",
1883                                            "absorb-git-dirs", NULL);
1884                 prepare_submodule_repo_env(&cp.env_array);
1885                 if (run_command(&cp))
1886                         die(_("could not recurse into submodule '%s'"), path);
1887
1888                 strbuf_release(&sb);
1889         }
1890 }
1891
1892 const char *get_superproject_working_tree(void)
1893 {
1894         struct child_process cp = CHILD_PROCESS_INIT;
1895         struct strbuf sb = STRBUF_INIT;
1896         const char *one_up = real_path_if_valid("../");
1897         const char *cwd = xgetcwd();
1898         const char *ret = NULL;
1899         const char *subpath;
1900         int code;
1901         ssize_t len;
1902
1903         if (!is_inside_work_tree())
1904                 /*
1905                  * FIXME:
1906                  * We might have a superproject, but it is harder
1907                  * to determine.
1908                  */
1909                 return NULL;
1910
1911         if (!one_up)
1912                 return NULL;
1913
1914         subpath = relative_path(cwd, one_up, &sb);
1915
1916         prepare_submodule_repo_env(&cp.env_array);
1917         argv_array_pop(&cp.env_array);
1918
1919         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
1920                         "ls-files", "-z", "--stage", "--full-name", "--",
1921                         subpath, NULL);
1922         strbuf_reset(&sb);
1923
1924         cp.no_stdin = 1;
1925         cp.no_stderr = 1;
1926         cp.out = -1;
1927         cp.git_cmd = 1;
1928
1929         if (start_command(&cp))
1930                 die(_("could not start ls-files in .."));
1931
1932         len = strbuf_read(&sb, cp.out, PATH_MAX);
1933         close(cp.out);
1934
1935         if (starts_with(sb.buf, "160000")) {
1936                 int super_sub_len;
1937                 int cwd_len = strlen(cwd);
1938                 char *super_sub, *super_wt;
1939
1940                 /*
1941                  * There is a superproject having this repo as a submodule.
1942                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
1943                  * We're only interested in the name after the tab.
1944                  */
1945                 super_sub = strchr(sb.buf, '\t') + 1;
1946                 super_sub_len = sb.buf + sb.len - super_sub - 1;
1947
1948                 if (super_sub_len > cwd_len ||
1949                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
1950                         die (_("BUG: returned path string doesn't match cwd?"));
1951
1952                 super_wt = xstrdup(cwd);
1953                 super_wt[cwd_len - super_sub_len] = '\0';
1954
1955                 ret = real_path(super_wt);
1956                 free(super_wt);
1957         }
1958         strbuf_release(&sb);
1959
1960         code = finish_command(&cp);
1961
1962         if (code == 128)
1963                 /* '../' is not a git repository */
1964                 return NULL;
1965         if (code == 0 && len == 0)
1966                 /* There is an unrelated git repository at '../' */
1967                 return NULL;
1968         if (code)
1969                 die(_("ls-tree returned unexpected return code %d"), code);
1970
1971         return ret;
1972 }
1973
1974 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
1975 {
1976         const struct submodule *sub;
1977         const char *git_dir;
1978         int ret = 0;
1979
1980         strbuf_reset(buf);
1981         strbuf_addstr(buf, submodule);
1982         strbuf_complete(buf, '/');
1983         strbuf_addstr(buf, ".git");
1984
1985         git_dir = read_gitfile(buf->buf);
1986         if (git_dir) {
1987                 strbuf_reset(buf);
1988                 strbuf_addstr(buf, git_dir);
1989         }
1990         if (!is_git_directory(buf->buf)) {
1991                 sub = submodule_from_path(&null_oid, submodule);
1992                 if (!sub) {
1993                         ret = -1;
1994                         goto cleanup;
1995                 }
1996                 strbuf_reset(buf);
1997                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
1998         }
1999
2000 cleanup:
2001         return ret;
2002 }