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 void load_submodule_cache(void)
 212 {
 213         if (config_update_recurse_submodules == RECURSE_SUBMODULES_OFF)
 214                 return;
 215
 216         gitmodules_config();
 217 }
 218
 219 void gitmodules_config(void)
 220 {
 221         repo_read_gitmodules(the_repository);
 222 }
 223
 224 /*
 225  * Determine if a submodule has been initialized at a given 'path'
 226  */
 227 int is_submodule_active(struct repository *repo, const char *path)
 228 {
 229         int ret = 0;
 230         char *key = NULL;
 231         char *value = NULL;
 232         const struct string_list *sl;
 233         const struct submodule *module;
 234
 235         module = submodule_from_cache(repo, &null_oid, path);
 236
 237         /* early return if there isn't a path->module mapping */
 238         if (!module)
 239                 return 0;
 240
 241         /* submodule.<name>.active is set */
 242         key = xstrfmt("submodule.%s.active", module->name);
 243         if (!repo_config_get_bool(repo, key, &ret)) {
 244                 free(key);
 245                 return ret;
 246         }
 247         free(key);
 248
 249         /* submodule.active is set */
 250         sl = repo_config_get_value_multi(repo, "submodule.active");
 251         if (sl) {
 252                 struct pathspec ps;
 253                 struct argv_array args = ARGV_ARRAY_INIT;
 254                 const struct string_list_item *item;
 255
 256                 for_each_string_list_item(item, sl) {
 257                         argv_array_push(&args, item->string);
 258                 }
 259
 260                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 261                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
 262
 263                 argv_array_clear(&args);
 264                 clear_pathspec(&ps);
 265                 return ret;
 266         }
 267
 268         /* fallback to checking if the URL is set */
 269         key = xstrfmt("submodule.%s.url", module->name);
 270         ret = !repo_config_get_string(repo, key, &value);
 271
 272         free(value);
 273         free(key);
 274         return ret;
 275 }
 276
 277 int is_submodule_populated_gently(const char *path, int *return_error_code)
 278 {
 279         int ret = 0;
 280         char *gitdir = xstrfmt("%s/.git", path);
 281
 282         if (resolve_gitdir_gently(gitdir, return_error_code))
 283                 ret = 1;
 284
 285         free(gitdir);
 286         return ret;
 287 }
 288
 289 /*
 290  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 291  */
 292 void die_in_unpopulated_submodule(const struct index_state *istate,
 293                                   const char *prefix)
 294 {
 295         int i, prefixlen;
 296
 297         if (!prefix)
 298                 return;
 299
 300         prefixlen = strlen(prefix);
 301
 302         for (i = 0; i < istate->cache_nr; i++) {
 303                 struct cache_entry *ce = istate->cache[i];
 304                 int ce_len = ce_namelen(ce);
 305
 306                 if (!S_ISGITLINK(ce->ce_mode))
 307                         continue;
 308                 if (prefixlen <= ce_len)
 309                         continue;
 310                 if (strncmp(ce->name, prefix, ce_len))
 311                         continue;
 312                 if (prefix[ce_len] != '/')
 313                         continue;
 314
 315                 die(_("in unpopulated submodule '%s'"), ce->name);
 316         }
 317 }
 318
 319 /*
 320  * Dies if any paths in the provided pathspec descends into a submodule
 321  */
 322 void die_path_inside_submodule(const struct index_state *istate,
 323                                const struct pathspec *ps)
 324 {
 325         int i, j;
 326
 327         for (i = 0; i < istate->cache_nr; i++) {
 328                 struct cache_entry *ce = istate->cache[i];
 329                 int ce_len = ce_namelen(ce);
 330
 331                 if (!S_ISGITLINK(ce->ce_mode))
 332                         continue;
 333
 334                 for (j = 0; j < ps->nr ; j++) {
 335                         const struct pathspec_item *item = &ps->items[j];
 336
 337                         if (item->len <= ce_len)
 338                                 continue;
 339                         if (item->match[ce_len] != '/')
 340                                 continue;
 341                         if (strncmp(ce->name, item->match, ce_len))
 342                                 continue;
 343                         if (item->len == ce_len + 1)
 344                                 continue;
 345
 346                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 347                             item->original, ce_len, ce->name);
 348                 }
 349         }
 350 }
 351
 352 enum submodule_update_type parse_submodule_update_type(const char *value)
 353 {
 354         if (!strcmp(value, "none"))
 355                 return SM_UPDATE_NONE;
 356         else if (!strcmp(value, "checkout"))
 357                 return SM_UPDATE_CHECKOUT;
 358         else if (!strcmp(value, "rebase"))
 359                 return SM_UPDATE_REBASE;
 360         else if (!strcmp(value, "merge"))
 361                 return SM_UPDATE_MERGE;
 362         else if (*value == '!')
 363                 return SM_UPDATE_COMMAND;
 364         else
 365                 return SM_UPDATE_UNSPECIFIED;
 366 }
 367
 368 int parse_submodule_update_strategy(const char *value,
 369                 struct submodule_update_strategy *dst)
 370 {
 371         enum submodule_update_type type;
 372
 373         free((void*)dst->command);
 374         dst->command = NULL;
 375
 376         type = parse_submodule_update_type(value);
 377         if (type == SM_UPDATE_UNSPECIFIED)
 378                 return -1;
 379
 380         dst->type = type;
 381         if (type == SM_UPDATE_COMMAND)
 382                 dst->command = xstrdup(value + 1);
 383
 384         return 0;
 385 }
 386
 387 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 388 {
 389         struct strbuf sb = STRBUF_INIT;
 390         switch (s->type) {
 391         case SM_UPDATE_CHECKOUT:
 392                 return "checkout";
 393         case SM_UPDATE_MERGE:
 394                 return "merge";
 395         case SM_UPDATE_REBASE:
 396                 return "rebase";
 397         case SM_UPDATE_NONE:
 398                 return "none";
 399         case SM_UPDATE_UNSPECIFIED:
 400                 return NULL;
 401         case SM_UPDATE_COMMAND:
 402                 strbuf_addf(&sb, "!%s", s->command);
 403                 return strbuf_detach(&sb, NULL);
 404         }
 405         return NULL;
 406 }
 407
 408 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 409                                   const char *arg)
 410 {
 411         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 412         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 413         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 414
 415         if (!strcmp(arg, "all"))
 416                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 417         else if (!strcmp(arg, "untracked"))
 418                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 419         else if (!strcmp(arg, "dirty"))
 420                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 421         else if (strcmp(arg, "none"))
 422                 die("bad --ignore-submodules argument: %s", arg);
 423 }
 424
 425 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 426                 struct commit *left, struct commit *right,
 427                 struct commit_list *merge_bases)
 428 {
 429         struct commit_list *list;
 430
 431         init_revisions(rev, NULL);
 432         setup_revisions(0, NULL, rev, NULL);
 433         rev->left_right = 1;
 434         rev->first_parent_only = 1;
 435         left->object.flags |= SYMMETRIC_LEFT;
 436         add_pending_object(rev, &left->object, path);
 437         add_pending_object(rev, &right->object, path);
 438         for (list = merge_bases; list; list = list->next) {
 439                 list->item->object.flags |= UNINTERESTING;
 440                 add_pending_object(rev, &list->item->object,
 441                         oid_to_hex(&list->item->object.oid));
 442         }
 443         return prepare_revision_walk(rev);
 444 }
 445
 446 static void print_submodule_summary(struct rev_info *rev, FILE *f,
 447                 const char *line_prefix,
 448                 const char *del, const char *add, const char *reset)
 449 {
 450         static const char format[] = "  %m %s";
 451         struct strbuf sb = STRBUF_INIT;
 452         struct commit *commit;
 453
 454         while ((commit = get_revision(rev))) {
 455                 struct pretty_print_context ctx = {0};
 456                 ctx.date_mode = rev->date_mode;
 457                 ctx.output_encoding = get_log_output_encoding();
 458                 strbuf_setlen(&sb, 0);
 459                 strbuf_addstr(&sb, line_prefix);
 460                 if (commit->object.flags & SYMMETRIC_LEFT) {
 461                         if (del)
 462                                 strbuf_addstr(&sb, del);
 463                 }
 464                 else if (add)
 465                         strbuf_addstr(&sb, add);
 466                 format_commit_message(commit, format, &sb, &ctx);
 467                 if (reset)
 468                         strbuf_addstr(&sb, reset);
 469                 strbuf_addch(&sb, '\n');
 470                 fprintf(f, "%s", sb.buf);
 471         }
 472         strbuf_release(&sb);
 473 }
 474
 475 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 476 {
 477         const char * const *var;
 478
 479         for (var = local_repo_env; *var; var++) {
 480                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 481                         argv_array_push(out, *var);
 482         }
 483 }
 484
 485 void prepare_submodule_repo_env(struct argv_array *out)
 486 {
 487         prepare_submodule_repo_env_no_git_dir(out);
 488         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 489                          DEFAULT_GIT_DIR_ENVIRONMENT);
 490 }
 491
 492 /* Helper function to display the submodule header line prior to the full
 493  * summary output. If it can locate the submodule objects directory it will
 494  * attempt to lookup both the left and right commits and put them into the
 495  * left and right pointers.
 496  */
 497 static void show_submodule_header(FILE *f, const char *path,
 498                 const char *line_prefix,
 499                 struct object_id *one, struct object_id *two,
 500                 unsigned dirty_submodule, const char *meta,
 501                 const char *reset,
 502                 struct commit **left, struct commit **right,
 503                 struct commit_list **merge_bases)
 504 {
 505         const char *message = NULL;
 506         struct strbuf sb = STRBUF_INIT;
 507         int fast_forward = 0, fast_backward = 0;
 508
 509         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 510                 fprintf(f, "%sSubmodule %s contains untracked content\n",
 511                         line_prefix, path);
 512         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 513                 fprintf(f, "%sSubmodule %s contains modified content\n",
 514                         line_prefix, path);
 515
 516         if (is_null_oid(one))
 517                 message = "(new submodule)";
 518         else if (is_null_oid(two))
 519                 message = "(submodule deleted)";
 520
 521         if (add_submodule_odb(path)) {
 522                 if (!message)
 523                         message = "(not initialized)";
 524                 goto output_header;
 525         }
 526
 527         /*
 528          * Attempt to lookup the commit references, and determine if this is
 529          * a fast forward or fast backwards update.
 530          */
 531         *left = lookup_commit_reference(one);
 532         *right = lookup_commit_reference(two);
 533
 534         /*
 535          * Warn about missing commits in the submodule project, but only if
 536          * they aren't null.
 537          */
 538         if ((!is_null_oid(one) && !*left) ||
 539              (!is_null_oid(two) && !*right))
 540                 message = "(commits not present)";
 541
 542         *merge_bases = get_merge_bases(*left, *right);
 543         if (*merge_bases) {
 544                 if ((*merge_bases)->item == *left)
 545                         fast_forward = 1;
 546                 else if ((*merge_bases)->item == *right)
 547                         fast_backward = 1;
 548         }
 549
 550         if (!oidcmp(one, two)) {
 551                 strbuf_release(&sb);
 552                 return;
 553         }
 554
 555 output_header:
 556         strbuf_addf(&sb, "%s%sSubmodule %s ", line_prefix, meta, path);
 557         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
 558         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 559         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
 560         if (message)
 561                 strbuf_addf(&sb, " %s%s\n", message, reset);
 562         else
 563                 strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
 564         fwrite(sb.buf, sb.len, 1, f);
 565
 566         strbuf_release(&sb);
 567 }
 568
 569 void show_submodule_summary(FILE *f, const char *path,
 570                 const char *line_prefix,
 571                 struct object_id *one, struct object_id *two,
 572                 unsigned dirty_submodule, const char *meta,
 573                 const char *del, const char *add, const char *reset)
 574 {
 575         struct rev_info rev;
 576         struct commit *left = NULL, *right = NULL;
 577         struct commit_list *merge_bases = NULL;
 578
 579         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
 580                               meta, reset, &left, &right, &merge_bases);
 581
 582         /*
 583          * If we don't have both a left and a right pointer, there is no
 584          * reason to try and display a summary. The header line should contain
 585          * all the information the user needs.
 586          */
 587         if (!left || !right)
 588                 goto out;
 589
 590         /* Treat revision walker failure the same as missing commits */
 591         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 592                 fprintf(f, "%s(revision walker failed)\n", line_prefix);
 593                 goto out;
 594         }
 595
 596         print_submodule_summary(&rev, f, line_prefix, del, add, reset);
 597
 598 out:
 599         if (merge_bases)
 600                 free_commit_list(merge_bases);
 601         clear_commit_marks(left, ~0);
 602         clear_commit_marks(right, ~0);
 603 }
 604
 605 void show_submodule_inline_diff(FILE *f, const char *path,
 606                 const char *line_prefix,
 607                 struct object_id *one, struct object_id *two,
 608                 unsigned dirty_submodule, const char *meta,
 609                 const char *del, const char *add, const char *reset,
 610                 const struct diff_options *o)
 611 {
 612         const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
 613         struct commit *left = NULL, *right = NULL;
 614         struct commit_list *merge_bases = NULL;
 615         struct strbuf submodule_dir = STRBUF_INIT;
 616         struct child_process cp = CHILD_PROCESS_INIT;
 617
 618         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
 619                               meta, reset, &left, &right, &merge_bases);
 620
 621         /* We need a valid left and right commit to display a difference */
 622         if (!(left || is_null_oid(one)) ||
 623             !(right || is_null_oid(two)))
 624                 goto done;
 625
 626         if (left)
 627                 old = one;
 628         if (right)
 629                 new = two;
 630
 631         fflush(f);
 632         cp.git_cmd = 1;
 633         cp.dir = path;
 634         cp.out = dup(fileno(f));
 635         cp.no_stdin = 1;
 636
 637         /* TODO: other options may need to be passed here. */
 638         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 639
 640         argv_array_pushf(&cp.args, "--line-prefix=%s", line_prefix);
 641         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
 642                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 643                                  o->b_prefix, path);
 644                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 645                                  o->a_prefix, path);
 646         } else {
 647                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 648                                  o->a_prefix, path);
 649                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 650                                  o->b_prefix, path);
 651         }
 652         argv_array_push(&cp.args, oid_to_hex(old));
 653         /*
 654          * If the submodule has modified content, we will diff against the
 655          * work tree, under the assumption that the user has asked for the
 656          * diff format and wishes to actually see all differences even if they
 657          * haven't yet been committed to the submodule yet.
 658          */
 659         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 660                 argv_array_push(&cp.args, oid_to_hex(new));
 661
 662         prepare_submodule_repo_env(&cp.env_array);
 663         if (run_command(&cp))
 664                 fprintf(f, "(diff failed)\n");
 665
 666 done:
 667         strbuf_release(&submodule_dir);
 668         if (merge_bases)
 669                 free_commit_list(merge_bases);
 670         if (left)
 671                 clear_commit_marks(left, ~0);
 672         if (right)
 673                 clear_commit_marks(right, ~0);
 674 }
 675
 676 int should_update_submodules(void)
 677 {
 678         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 679 }
 680
 681 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 682 {
 683         if (!S_ISGITLINK(ce->ce_mode))
 684                 return NULL;
 685
 686         if (!should_update_submodules())
 687                 return NULL;
 688
 689         return submodule_from_path(&null_oid, ce->name);
 690 }
 691
 692 static struct oid_array *submodule_commits(struct string_list *submodules,
 693                                            const char *path)
 694 {
 695         struct string_list_item *item;
 696
 697         item = string_list_insert(submodules, path);
 698         if (item->util)
 699                 return (struct oid_array *) item->util;
 700
 701         /* NEEDSWORK: should we have oid_array_init()? */
 702         item->util = xcalloc(1, sizeof(struct oid_array));
 703         return (struct oid_array *) item->util;
 704 }
 705
 706 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 707                                           struct diff_options *options,
 708                                           void *data)
 709 {
 710         int i;
 711         struct string_list *changed = data;
 712
 713         for (i = 0; i < q->nr; i++) {
 714                 struct diff_filepair *p = q->queue[i];
 715                 struct oid_array *commits;
 716                 if (!S_ISGITLINK(p->two->mode))
 717                         continue;
 718
 719                 if (S_ISGITLINK(p->one->mode)) {
 720                         /*
 721                          * NEEDSWORK: We should honor the name configured in
 722                          * the .gitmodules file of the commit we are examining
 723                          * here to be able to correctly follow submodules
 724                          * being moved around.
 725                          */
 726                         commits = submodule_commits(changed, p->two->path);
 727                         oid_array_append(commits, &p->two->oid);
 728                 } else {
 729                         /* Submodule is new or was moved here */
 730                         /*
 731                          * NEEDSWORK: When the .git directories of submodules
 732                          * live inside the superprojects .git directory some
 733                          * day we should fetch new submodules directly into
 734                          * that location too when config or options request
 735                          * that so they can be checked out from there.
 736                          */
 737                         continue;
 738                 }
 739         }
 740 }
 741
 742 /*
 743  * Collect the paths of submodules in 'changed' which have changed based on
 744  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 745  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 746  * what the submodule pointers were updated to during the change.
 747  */
 748 static void collect_changed_submodules(struct string_list *changed,
 749                                        struct argv_array *argv)
 750 {
 751         struct rev_info rev;
 752         const struct commit *commit;
 753
 754         init_revisions(&rev, NULL);
 755         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 756         if (prepare_revision_walk(&rev))
 757                 die("revision walk setup failed");
 758
 759         while ((commit = get_revision(&rev))) {
 760                 struct rev_info diff_rev;
 761
 762                 init_revisions(&diff_rev, NULL);
 763                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 764                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 765                 diff_rev.diffopt.format_callback_data = changed;
 766                 diff_tree_combined_merge(commit, 1, &diff_rev);
 767         }
 768
 769         reset_revision_walk();
 770 }
 771
 772 static void free_submodules_oids(struct string_list *submodules)
 773 {
 774         struct string_list_item *item;
 775         for_each_string_list_item(item, submodules)
 776                 oid_array_clear((struct oid_array *) item->util);
 777         string_list_clear(submodules, 1);
 778 }
 779
 780 static int has_remote(const char *refname, const struct object_id *oid,
 781                       int flags, void *cb_data)
 782 {
 783         return 1;
 784 }
 785
 786 static int append_oid_to_argv(const struct object_id *oid, void *data)
 787 {
 788         struct argv_array *argv = data;
 789         argv_array_push(argv, oid_to_hex(oid));
 790         return 0;
 791 }
 792
 793 static int check_has_commit(const struct object_id *oid, void *data)
 794 {
 795         int *has_commit = data;
 796
 797         if (!lookup_commit_reference(oid))
 798                 *has_commit = 0;
 799
 800         return 0;
 801 }
 802
 803 static int submodule_has_commits(const char *path, struct oid_array *commits)
 804 {
 805         int has_commit = 1;
 806
 807         /*
 808          * Perform a cheap, but incorrect check for the existence of 'commits'.
 809          * This is done by adding the submodule's object store to the in-core
 810          * object store, and then querying for each commit's existence.  If we
 811          * do not have the commit object anywhere, there is no chance we have
 812          * it in the object store of the correct submodule and have it
 813          * reachable from a ref, so we can fail early without spawning rev-list
 814          * which is expensive.
 815          */
 816         if (add_submodule_odb(path))
 817                 return 0;
 818
 819         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 820
 821         if (has_commit) {
 822                 /*
 823                  * Even if the submodule is checked out and the commit is
 824                  * present, make sure it exists in the submodule's object store
 825                  * and that it is reachable from a ref.
 826                  */
 827                 struct child_process cp = CHILD_PROCESS_INIT;
 828                 struct strbuf out = STRBUF_INIT;
 829
 830                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 831                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 832                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 833
 834                 prepare_submodule_repo_env(&cp.env_array);
 835                 cp.git_cmd = 1;
 836                 cp.no_stdin = 1;
 837                 cp.dir = path;
 838
 839                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 840                         has_commit = 0;
 841
 842                 strbuf_release(&out);
 843         }
 844
 845         return has_commit;
 846 }
 847
 848 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
 849 {
 850         if (!submodule_has_commits(path, commits))
 851                 /*
 852                  * NOTE: We do consider it safe to return "no" here. The
 853                  * correct answer would be "We do not know" instead of
 854                  * "No push needed", but it is quite hard to change
 855                  * the submodule pointer without having the submodule
 856                  * around. If a user did however change the submodules
 857                  * without having the submodule around, this indicates
 858                  * an expert who knows what they are doing or a
 859                  * maintainer integrating work from other people. In
 860                  * both cases it should be safe to skip this check.
 861                  */
 862                 return 0;
 863
 864         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 865                 struct child_process cp = CHILD_PROCESS_INIT;
 866                 struct strbuf buf = STRBUF_INIT;
 867                 int needs_pushing = 0;
 868
 869                 argv_array_push(&cp.args, "rev-list");
 870                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 871                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 872
 873                 prepare_submodule_repo_env(&cp.env_array);
 874                 cp.git_cmd = 1;
 875                 cp.no_stdin = 1;
 876                 cp.out = -1;
 877                 cp.dir = path;
 878                 if (start_command(&cp))
 879                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 880                                         path);
 881                 if (strbuf_read(&buf, cp.out, 41))
 882                         needs_pushing = 1;
 883                 finish_command(&cp);
 884                 close(cp.out);
 885                 strbuf_release(&buf);
 886                 return needs_pushing;
 887         }
 888
 889         return 0;
 890 }
 891
 892 int find_unpushed_submodules(struct oid_array *commits,
 893                 const char *remotes_name, struct string_list *needs_pushing)
 894 {
 895         struct string_list submodules = STRING_LIST_INIT_DUP;
 896         struct string_list_item *submodule;
 897         struct argv_array argv = ARGV_ARRAY_INIT;
 898
 899         /* argv.argv[0] will be ignored by setup_revisions */
 900         argv_array_push(&argv, "find_unpushed_submodules");
 901         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
 902         argv_array_push(&argv, "--not");
 903         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
 904
 905         collect_changed_submodules(&submodules, &argv);
 906
 907         for_each_string_list_item(submodule, &submodules) {
 908                 struct oid_array *commits = submodule->util;
 909                 const char *path = submodule->string;
 910
 911                 if (submodule_needs_pushing(path, commits))
 912                         string_list_insert(needs_pushing, path);
 913         }
 914
 915         free_submodules_oids(&submodules);
 916         argv_array_clear(&argv);
 917
 918         return needs_pushing->nr;
 919 }
 920
 921 static int push_submodule(const char *path,
 922                           const struct remote *remote,
 923                           const char **refspec, int refspec_nr,
 924                           const struct string_list *push_options,
 925                           int dry_run)
 926 {
 927         if (add_submodule_odb(path))
 928                 return 1;
 929
 930         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 931                 struct child_process cp = CHILD_PROCESS_INIT;
 932                 argv_array_push(&cp.args, "push");
 933                 if (dry_run)
 934                         argv_array_push(&cp.args, "--dry-run");
 935
 936                 if (push_options && push_options->nr) {
 937                         const struct string_list_item *item;
 938                         for_each_string_list_item(item, push_options)
 939                                 argv_array_pushf(&cp.args, "--push-option=%s",
 940                                                  item->string);
 941                 }
 942
 943                 if (remote->origin != REMOTE_UNCONFIGURED) {
 944                         int i;
 945                         argv_array_push(&cp.args, remote->name);
 946                         for (i = 0; i < refspec_nr; i++)
 947                                 argv_array_push(&cp.args, refspec[i]);
 948                 }
 949
 950                 prepare_submodule_repo_env(&cp.env_array);
 951                 cp.git_cmd = 1;
 952                 cp.no_stdin = 1;
 953                 cp.dir = path;
 954                 if (run_command(&cp))
 955                         return 0;
 956                 close(cp.out);
 957         }
 958
 959         return 1;
 960 }
 961
 962 /*
 963  * Perform a check in the submodule to see if the remote and refspec work.
 964  * Die if the submodule can't be pushed.
 965  */
 966 static void submodule_push_check(const char *path, const struct remote *remote,
 967                                  const char **refspec, int refspec_nr)
 968 {
 969         struct child_process cp = CHILD_PROCESS_INIT;
 970         int i;
 971
 972         argv_array_push(&cp.args, "submodule--helper");
 973         argv_array_push(&cp.args, "push-check");
 974         argv_array_push(&cp.args, remote->name);
 975
 976         for (i = 0; i < refspec_nr; i++)
 977                 argv_array_push(&cp.args, refspec[i]);
 978
 979         prepare_submodule_repo_env(&cp.env_array);
 980         cp.git_cmd = 1;
 981         cp.no_stdin = 1;
 982         cp.no_stdout = 1;
 983         cp.dir = path;
 984
 985         /*
 986          * Simply indicate if 'submodule--helper push-check' failed.
 987          * More detailed error information will be provided by the
 988          * child process.
 989          */
 990         if (run_command(&cp))
 991                 die("process for submodule '%s' failed", path);
 992 }
 993
 994 int push_unpushed_submodules(struct oid_array *commits,
 995                              const struct remote *remote,
 996                              const char **refspec, int refspec_nr,
 997                              const struct string_list *push_options,
 998                              int dry_run)
 999 {
1000         int i, ret = 1;
1001         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1002
1003         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1004                 return 1;
1005
1006         /*
1007          * Verify that the remote and refspec can be propagated to all
1008          * submodules.  This check can be skipped if the remote and refspec
1009          * won't be propagated due to the remote being unconfigured (e.g. a URL
1010          * instead of a remote name).
1011          */
1012         if (remote->origin != REMOTE_UNCONFIGURED)
1013                 for (i = 0; i < needs_pushing.nr; i++)
1014                         submodule_push_check(needs_pushing.items[i].string,
1015                                              remote, refspec, refspec_nr);
1016
1017         /* Actually push the submodules */
1018         for (i = 0; i < needs_pushing.nr; i++) {
1019                 const char *path = needs_pushing.items[i].string;
1020                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1021                 if (!push_submodule(path, remote, refspec, refspec_nr,
1022                                     push_options, dry_run)) {
1023                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1024                         ret = 0;
1025                 }
1026         }
1027
1028         string_list_clear(&needs_pushing, 0);
1029
1030         return ret;
1031 }
1032
1033 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1034                                int flags, void *data)
1035 {
1036         struct oid_array *array = data;
1037         oid_array_append(array, oid);
1038         return 0;
1039 }
1040
1041 void check_for_new_submodule_commits(struct object_id *oid)
1042 {
1043         if (!initialized_fetch_ref_tips) {
1044                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1045                 initialized_fetch_ref_tips = 1;
1046         }
1047
1048         oid_array_append(&ref_tips_after_fetch, oid);
1049 }
1050
1051 static void calculate_changed_submodule_paths(void)
1052 {
1053         struct argv_array argv = ARGV_ARRAY_INIT;
1054         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1055         const struct string_list_item *item;
1056
1057         /* No need to check if there are no submodules configured */
1058         if (!submodule_from_path(NULL, NULL))
1059                 return;
1060
1061         argv_array_push(&argv, "--"); /* argv[0] program name */
1062         oid_array_for_each_unique(&ref_tips_after_fetch,
1063                                    append_oid_to_argv, &argv);
1064         argv_array_push(&argv, "--not");
1065         oid_array_for_each_unique(&ref_tips_before_fetch,
1066                                    append_oid_to_argv, &argv);
1067
1068         /*
1069          * Collect all submodules (whether checked out or not) for which new
1070          * commits have been recorded upstream in "changed_submodule_paths".
1071          */
1072         collect_changed_submodules(&changed_submodules, &argv);
1073
1074         for_each_string_list_item(item, &changed_submodules) {
1075                 struct oid_array *commits = item->util;
1076                 const char *path = item->string;
1077
1078                 if (!submodule_has_commits(path, commits))
1079                         string_list_append(&changed_submodule_paths, path);
1080         }
1081
1082         free_submodules_oids(&changed_submodules);
1083         argv_array_clear(&argv);
1084         oid_array_clear(&ref_tips_before_fetch);
1085         oid_array_clear(&ref_tips_after_fetch);
1086         initialized_fetch_ref_tips = 0;
1087 }
1088
1089 int submodule_touches_in_range(struct object_id *excl_oid,
1090                                struct object_id *incl_oid)
1091 {
1092         struct string_list subs = STRING_LIST_INIT_DUP;
1093         struct argv_array args = ARGV_ARRAY_INIT;
1094         int ret;
1095
1096         gitmodules_config();
1097         /* No need to check if there are no submodules configured */
1098         if (!submodule_from_path(NULL, NULL))
1099                 return 0;
1100
1101         argv_array_push(&args, "--"); /* args[0] program name */
1102         argv_array_push(&args, oid_to_hex(incl_oid));
1103         argv_array_push(&args, "--not");
1104         argv_array_push(&args, oid_to_hex(excl_oid));
1105
1106         collect_changed_submodules(&subs, &args);
1107         ret = subs.nr;
1108
1109         argv_array_clear(&args);
1110
1111         free_submodules_oids(&subs);
1112         return ret;
1113 }
1114
1115 struct submodule_parallel_fetch {
1116         int count;
1117         struct argv_array args;
1118         const char *work_tree;
1119         const char *prefix;
1120         int command_line_option;
1121         int default_option;
1122         int quiet;
1123         int result;
1124 };
1125 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0}
1126
1127 static int get_next_submodule(struct child_process *cp,
1128                               struct strbuf *err, void *data, void **task_cb)
1129 {
1130         int ret = 0;
1131         struct submodule_parallel_fetch *spf = data;
1132
1133         for (; spf->count < active_nr; spf->count++) {
1134                 struct strbuf submodule_path = STRBUF_INIT;
1135                 struct strbuf submodule_git_dir = STRBUF_INIT;
1136                 struct strbuf submodule_prefix = STRBUF_INIT;
1137                 const struct cache_entry *ce = active_cache[spf->count];
1138                 const char *git_dir, *default_argv;
1139                 const struct submodule *submodule;
1140
1141                 if (!S_ISGITLINK(ce->ce_mode))
1142                         continue;
1143
1144                 submodule = submodule_from_path(&null_oid, ce->name);
1145
1146                 default_argv = "yes";
1147                 if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
1148                         int fetch_recurse = RECURSE_SUBMODULES_NONE;
1149
1150                         if (submodule) {
1151                                 char *key;
1152                                 const char *value;
1153
1154                                 fetch_recurse = submodule->fetch_recurse;
1155                                 key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1156                                 if (!repo_config_get_string_const(the_repository, key, &value)) {
1157                                         fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1158                                 }
1159                                 free(key);
1160                         }
1161
1162                         if (fetch_recurse != RECURSE_SUBMODULES_NONE) {
1163                                 if (fetch_recurse == RECURSE_SUBMODULES_OFF)
1164                                         continue;
1165                                 if (fetch_recurse == RECURSE_SUBMODULES_ON_DEMAND) {
1166                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1167                                                 continue;
1168                                         default_argv = "on-demand";
1169                                 }
1170                         } else {
1171                                 if (spf->default_option == RECURSE_SUBMODULES_OFF)
1172                                         continue;
1173                                 if (spf->default_option == RECURSE_SUBMODULES_ON_DEMAND) {
1174                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1175                                                 continue;
1176                                         default_argv = "on-demand";
1177                                 }
1178                         }
1179                 } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
1180                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1181                                 continue;
1182                         default_argv = "on-demand";
1183                 }
1184
1185                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1186                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1187                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1188                 git_dir = read_gitfile(submodule_git_dir.buf);
1189                 if (!git_dir)
1190                         git_dir = submodule_git_dir.buf;
1191                 if (is_directory(git_dir)) {
1192                         child_process_init(cp);
1193                         cp->dir = strbuf_detach(&submodule_path, NULL);
1194                         prepare_submodule_repo_env(&cp->env_array);
1195                         cp->git_cmd = 1;
1196                         if (!spf->quiet)
1197                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1198                                             spf->prefix, ce->name);
1199                         argv_array_init(&cp->args);
1200                         argv_array_pushv(&cp->args, spf->args.argv);
1201                         argv_array_push(&cp->args, default_argv);
1202                         argv_array_push(&cp->args, "--submodule-prefix");
1203                         argv_array_push(&cp->args, submodule_prefix.buf);
1204                         ret = 1;
1205                 }
1206                 strbuf_release(&submodule_path);
1207                 strbuf_release(&submodule_git_dir);
1208                 strbuf_release(&submodule_prefix);
1209                 if (ret) {
1210                         spf->count++;
1211                         return 1;
1212                 }
1213         }
1214         return 0;
1215 }
1216
1217 static int fetch_start_failure(struct strbuf *err,
1218                                void *cb, void *task_cb)
1219 {
1220         struct submodule_parallel_fetch *spf = cb;
1221
1222         spf->result = 1;
1223
1224         return 0;
1225 }
1226
1227 static int fetch_finish(int retvalue, struct strbuf *err,
1228                         void *cb, void *task_cb)
1229 {
1230         struct submodule_parallel_fetch *spf = cb;
1231
1232         if (retvalue)
1233                 spf->result = 1;
1234
1235         return 0;
1236 }
1237
1238 int fetch_populated_submodules(const struct argv_array *options,
1239                                const char *prefix, int command_line_option,
1240                                int default_option,
1241                                int quiet, int max_parallel_jobs)
1242 {
1243         int i;
1244         struct submodule_parallel_fetch spf = SPF_INIT;
1245
1246         spf.work_tree = get_git_work_tree();
1247         spf.command_line_option = command_line_option;
1248         spf.default_option = default_option;
1249         spf.quiet = quiet;
1250         spf.prefix = prefix;
1251
1252         if (!spf.work_tree)
1253                 goto out;
1254
1255         if (read_cache() < 0)
1256                 die("index file corrupt");
1257
1258         argv_array_push(&spf.args, "fetch");
1259         for (i = 0; i < options->argc; i++)
1260                 argv_array_push(&spf.args, options->argv[i]);
1261         argv_array_push(&spf.args, "--recurse-submodules-default");
1262         /* default value, "--submodule-prefix" and its value are added later */
1263
1264         calculate_changed_submodule_paths();
1265         run_processes_parallel(max_parallel_jobs,
1266                                get_next_submodule,
1267                                fetch_start_failure,
1268                                fetch_finish,
1269                                &spf);
1270
1271         argv_array_clear(&spf.args);
1272 out:
1273         string_list_clear(&changed_submodule_paths, 1);
1274         return spf.result;
1275 }
1276
1277 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1278 {
1279         struct child_process cp = CHILD_PROCESS_INIT;
1280         struct strbuf buf = STRBUF_INIT;
1281         FILE *fp;
1282         unsigned dirty_submodule = 0;
1283         const char *git_dir;
1284         int ignore_cp_exit_code = 0;
1285
1286         strbuf_addf(&buf, "%s/.git", path);
1287         git_dir = read_gitfile(buf.buf);
1288         if (!git_dir)
1289                 git_dir = buf.buf;
1290         if (!is_git_directory(git_dir)) {
1291                 if (is_directory(git_dir))
1292                         die(_("'%s' not recognized as a git repository"), git_dir);
1293                 strbuf_release(&buf);
1294                 /* The submodule is not checked out, so it is not modified */
1295                 return 0;
1296         }
1297         strbuf_reset(&buf);
1298
1299         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1300         if (ignore_untracked)
1301                 argv_array_push(&cp.args, "-uno");
1302
1303         prepare_submodule_repo_env(&cp.env_array);
1304         cp.git_cmd = 1;
1305         cp.no_stdin = 1;
1306         cp.out = -1;
1307         cp.dir = path;
1308         if (start_command(&cp))
1309                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1310
1311         fp = xfdopen(cp.out, "r");
1312         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1313                 /* regular untracked files */
1314                 if (buf.buf[0] == '?')
1315                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1316
1317                 if (buf.buf[0] == 'u' ||
1318                     buf.buf[0] == '1' ||
1319                     buf.buf[0] == '2') {
1320                         /* T = line type, XY = status, SSSS = submodule state */
1321                         if (buf.len < strlen("T XY SSSS"))
1322                                 die("BUG: invalid status --porcelain=2 line %s",
1323                                     buf.buf);
1324
1325                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1326                                 /* nested untracked file */
1327                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1328
1329                         if (buf.buf[0] == 'u' ||
1330                             buf.buf[0] == '2' ||
1331                             memcmp(buf.buf + 5, "S..U", 4))
1332                                 /* other change */
1333                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1334                 }
1335
1336                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1337                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1338                      ignore_untracked)) {
1339                         /*
1340                          * We're not interested in any further information from
1341                          * the child any more, neither output nor its exit code.
1342                          */
1343                         ignore_cp_exit_code = 1;
1344                         break;
1345                 }
1346         }
1347         fclose(fp);
1348
1349         if (finish_command(&cp) && !ignore_cp_exit_code)
1350                 die("'git status --porcelain=2' failed in submodule %s", path);
1351
1352         strbuf_release(&buf);
1353         return dirty_submodule;
1354 }
1355
1356 int submodule_uses_gitfile(const char *path)
1357 {
1358         struct child_process cp = CHILD_PROCESS_INIT;
1359         const char *argv[] = {
1360                 "submodule",
1361                 "foreach",
1362                 "--quiet",
1363                 "--recursive",
1364                 "test -f .git",
1365                 NULL,
1366         };
1367         struct strbuf buf = STRBUF_INIT;
1368         const char *git_dir;
1369
1370         strbuf_addf(&buf, "%s/.git", path);
1371         git_dir = read_gitfile(buf.buf);
1372         if (!git_dir) {
1373                 strbuf_release(&buf);
1374                 return 0;
1375         }
1376         strbuf_release(&buf);
1377
1378         /* Now test that all nested submodules use a gitfile too */
1379         cp.argv = argv;
1380         prepare_submodule_repo_env(&cp.env_array);
1381         cp.git_cmd = 1;
1382         cp.no_stdin = 1;
1383         cp.no_stderr = 1;
1384         cp.no_stdout = 1;
1385         cp.dir = path;
1386         if (run_command(&cp))
1387                 return 0;
1388
1389         return 1;
1390 }
1391
1392 /*
1393  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1394  * when doing so.
1395  *
1396  * Return 1 if we'd lose data, return 0 if the removal is fine,
1397  * and negative values for errors.
1398  */
1399 int bad_to_remove_submodule(const char *path, unsigned flags)
1400 {
1401         ssize_t len;
1402         struct child_process cp = CHILD_PROCESS_INIT;
1403         struct strbuf buf = STRBUF_INIT;
1404         int ret = 0;
1405
1406         if (!file_exists(path) || is_empty_dir(path))
1407                 return 0;
1408
1409         if (!submodule_uses_gitfile(path))
1410                 return 1;
1411
1412         argv_array_pushl(&cp.args, "status", "--porcelain",
1413                                    "--ignore-submodules=none", NULL);
1414
1415         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1416                 argv_array_push(&cp.args, "-uno");
1417         else
1418                 argv_array_push(&cp.args, "-uall");
1419
1420         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1421                 argv_array_push(&cp.args, "--ignored");
1422
1423         prepare_submodule_repo_env(&cp.env_array);
1424         cp.git_cmd = 1;
1425         cp.no_stdin = 1;
1426         cp.out = -1;
1427         cp.dir = path;
1428         if (start_command(&cp)) {
1429                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1430                         die(_("could not start 'git status' in submodule '%s'"),
1431                                 path);
1432                 ret = -1;
1433                 goto out;
1434         }
1435
1436         len = strbuf_read(&buf, cp.out, 1024);
1437         if (len > 2)
1438                 ret = 1;
1439         close(cp.out);
1440
1441         if (finish_command(&cp)) {
1442                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1443                         die(_("could not run 'git status' in submodule '%s'"),
1444                                 path);
1445                 ret = -1;
1446         }
1447 out:
1448         strbuf_release(&buf);
1449         return ret;
1450 }
1451
1452 static const char *get_super_prefix_or_empty(void)
1453 {
1454         const char *s = get_super_prefix();
1455         if (!s)
1456                 s = "";
1457         return s;
1458 }
1459
1460 static int submodule_has_dirty_index(const struct submodule *sub)
1461 {
1462         struct child_process cp = CHILD_PROCESS_INIT;
1463
1464         prepare_submodule_repo_env(&cp.env_array);
1465
1466         cp.git_cmd = 1;
1467         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1468                                    "--cached", "HEAD", NULL);
1469         cp.no_stdin = 1;
1470         cp.no_stdout = 1;
1471         cp.dir = sub->path;
1472         if (start_command(&cp))
1473                 die("could not recurse into submodule '%s'", sub->path);
1474
1475         return finish_command(&cp);
1476 }
1477
1478 static void submodule_reset_index(const char *path)
1479 {
1480         struct child_process cp = CHILD_PROCESS_INIT;
1481         prepare_submodule_repo_env(&cp.env_array);
1482
1483         cp.git_cmd = 1;
1484         cp.no_stdin = 1;
1485         cp.dir = path;
1486
1487         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1488                                    get_super_prefix_or_empty(), path);
1489         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1490
1491         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1492
1493         if (run_command(&cp))
1494                 die("could not reset submodule index");
1495 }
1496
1497 /**
1498  * Moves a submodule at a given path from a given head to another new head.
1499  * For edge cases (a submodule coming into existence or removing a submodule)
1500  * pass NULL for old or new respectively.
1501  */
1502 int submodule_move_head(const char *path,
1503                          const char *old,
1504                          const char *new,
1505                          unsigned flags)
1506 {
1507         int ret = 0;
1508         struct child_process cp = CHILD_PROCESS_INIT;
1509         const struct submodule *sub;
1510         int *error_code_ptr, error_code;
1511
1512         if (!is_submodule_active(the_repository, path))
1513                 return 0;
1514
1515         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1516                 /*
1517                  * Pass non NULL pointer to is_submodule_populated_gently
1518                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1519                  * to fixup the submodule in the force case later.
1520                  */
1521                 error_code_ptr = &error_code;
1522         else
1523                 error_code_ptr = NULL;
1524
1525         if (old && !is_submodule_populated_gently(path, error_code_ptr))
1526                 return 0;
1527
1528         sub = submodule_from_path(&null_oid, path);
1529
1530         if (!sub)
1531                 die("BUG: could not get submodule information for '%s'", path);
1532
1533         if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1534                 /* Check if the submodule has a dirty index. */
1535                 if (submodule_has_dirty_index(sub))
1536                         return error(_("submodule '%s' has dirty index"), path);
1537         }
1538
1539         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1540                 if (old) {
1541                         if (!submodule_uses_gitfile(path))
1542                                 absorb_git_dir_into_superproject("", path,
1543                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1544                 } else {
1545                         char *gitdir = xstrfmt("%s/modules/%s",
1546                                     get_git_common_dir(), sub->name);
1547                         connect_work_tree_and_git_dir(path, gitdir);
1548                         free(gitdir);
1549
1550                         /* make sure the index is clean as well */
1551                         submodule_reset_index(path);
1552                 }
1553
1554                 if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1555                         char *gitdir = xstrfmt("%s/modules/%s",
1556                                     get_git_common_dir(), sub->name);
1557                         connect_work_tree_and_git_dir(path, gitdir);
1558                         free(gitdir);
1559                 }
1560         }
1561
1562         prepare_submodule_repo_env(&cp.env_array);
1563
1564         cp.git_cmd = 1;
1565         cp.no_stdin = 1;
1566         cp.dir = path;
1567
1568         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1569                         get_super_prefix_or_empty(), path);
1570         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1571
1572         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1573                 argv_array_push(&cp.args, "-n");
1574         else
1575                 argv_array_push(&cp.args, "-u");
1576
1577         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1578                 argv_array_push(&cp.args, "--reset");
1579         else
1580                 argv_array_push(&cp.args, "-m");
1581
1582         argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1583         argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1584
1585         if (run_command(&cp)) {
1586                 ret = -1;
1587                 goto out;
1588         }
1589
1590         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1591                 if (new) {
1592                         child_process_init(&cp);
1593                         /* also set the HEAD accordingly */
1594                         cp.git_cmd = 1;
1595                         cp.no_stdin = 1;
1596                         cp.dir = path;
1597
1598                         prepare_submodule_repo_env(&cp.env_array);
1599                         argv_array_pushl(&cp.args, "update-ref", "HEAD", new, NULL);
1600
1601                         if (run_command(&cp)) {
1602                                 ret = -1;
1603                                 goto out;
1604                         }
1605                 } else {
1606                         struct strbuf sb = STRBUF_INIT;
1607
1608                         strbuf_addf(&sb, "%s/.git", path);
1609                         unlink_or_warn(sb.buf);
1610                         strbuf_release(&sb);
1611
1612                         if (is_empty_dir(path))
1613                                 rmdir_or_warn(path);
1614                 }
1615         }
1616 out:
1617         return ret;
1618 }
1619
1620 static int find_first_merges(struct object_array *result, const char *path,
1621                 struct commit *a, struct commit *b)
1622 {
1623         int i, j;
1624         struct object_array merges = OBJECT_ARRAY_INIT;
1625         struct commit *commit;
1626         int contains_another;
1627
1628         char merged_revision[42];
1629         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1630                                    "--all", merged_revision, NULL };
1631         struct rev_info revs;
1632         struct setup_revision_opt rev_opts;
1633
1634         memset(result, 0, sizeof(struct object_array));
1635         memset(&rev_opts, 0, sizeof(rev_opts));
1636
1637         /* get all revisions that merge commit a */
1638         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1639                         oid_to_hex(&a->object.oid));
1640         init_revisions(&revs, NULL);
1641         rev_opts.submodule = path;
1642         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1643
1644         /* save all revisions from the above list that contain b */
1645         if (prepare_revision_walk(&revs))
1646                 die("revision walk setup failed");
1647         while ((commit = get_revision(&revs)) != NULL) {
1648                 struct object *o = &(commit->object);
1649                 if (in_merge_bases(b, commit))
1650                         add_object_array(o, NULL, &merges);
1651         }
1652         reset_revision_walk();
1653
1654         /* Now we've got all merges that contain a and b. Prune all
1655          * merges that contain another found merge and save them in
1656          * result.
1657          */
1658         for (i = 0; i < merges.nr; i++) {
1659                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1660
1661                 contains_another = 0;
1662                 for (j = 0; j < merges.nr; j++) {
1663                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1664                         if (i != j && in_merge_bases(m2, m1)) {
1665                                 contains_another = 1;
1666                                 break;
1667                         }
1668                 }
1669
1670                 if (!contains_another)
1671                         add_object_array(merges.objects[i].item, NULL, result);
1672         }
1673
1674         free(merges.objects);
1675         return result->nr;
1676 }
1677
1678 static void print_commit(struct commit *commit)
1679 {
1680         struct strbuf sb = STRBUF_INIT;
1681         struct pretty_print_context ctx = {0};
1682         ctx.date_mode.type = DATE_NORMAL;
1683         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1684         fprintf(stderr, "%s\n", sb.buf);
1685         strbuf_release(&sb);
1686 }
1687
1688 #define MERGE_WARNING(path, msg) \
1689         warning("Failed to merge submodule %s (%s)", path, msg);
1690
1691 int merge_submodule(struct object_id *result, const char *path,
1692                     const struct object_id *base, const struct object_id *a,
1693                     const struct object_id *b, int search)
1694 {
1695         struct commit *commit_base, *commit_a, *commit_b;
1696         int parent_count;
1697         struct object_array merges;
1698
1699         int i;
1700
1701         /* store a in result in case we fail */
1702         oidcpy(result, a);
1703
1704         /* we can not handle deletion conflicts */
1705         if (is_null_oid(base))
1706                 return 0;
1707         if (is_null_oid(a))
1708                 return 0;
1709         if (is_null_oid(b))
1710                 return 0;
1711
1712         if (add_submodule_odb(path)) {
1713                 MERGE_WARNING(path, "not checked out");
1714                 return 0;
1715         }
1716
1717         if (!(commit_base = lookup_commit_reference(base)) ||
1718             !(commit_a = lookup_commit_reference(a)) ||
1719             !(commit_b = lookup_commit_reference(b))) {
1720                 MERGE_WARNING(path, "commits not present");
1721                 return 0;
1722         }
1723
1724         /* check whether both changes are forward */
1725         if (!in_merge_bases(commit_base, commit_a) ||
1726             !in_merge_bases(commit_base, commit_b)) {
1727                 MERGE_WARNING(path, "commits don't follow merge-base");
1728                 return 0;
1729         }
1730
1731         /* Case #1: a is contained in b or vice versa */
1732         if (in_merge_bases(commit_a, commit_b)) {
1733                 oidcpy(result, b);
1734                 return 1;
1735         }
1736         if (in_merge_bases(commit_b, commit_a)) {
1737                 oidcpy(result, a);
1738                 return 1;
1739         }
1740
1741         /*
1742          * Case #2: There are one or more merges that contain a and b in
1743          * the submodule. If there is only one, then present it as a
1744          * suggestion to the user, but leave it marked unmerged so the
1745          * user needs to confirm the resolution.
1746          */
1747
1748         /* Skip the search if makes no sense to the calling context.  */
1749         if (!search)
1750                 return 0;
1751
1752         /* find commit which merges them */
1753         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1754         switch (parent_count) {
1755         case 0:
1756                 MERGE_WARNING(path, "merge following commits not found");
1757                 break;
1758
1759         case 1:
1760                 MERGE_WARNING(path, "not fast-forward");
1761                 fprintf(stderr, "Found a possible merge resolution "
1762                                 "for the submodule:\n");
1763                 print_commit((struct commit *) merges.objects[0].item);
1764                 fprintf(stderr,
1765                         "If this is correct simply add it to the index "
1766                         "for example\n"
1767                         "by using:\n\n"
1768                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1769                         "which will accept this suggestion.\n",
1770                         oid_to_hex(&merges.objects[0].item->oid), path);
1771                 break;
1772
1773         default:
1774                 MERGE_WARNING(path, "multiple merges found");
1775                 for (i = 0; i < merges.nr; i++)
1776                         print_commit((struct commit *) merges.objects[i].item);
1777         }
1778
1779         free(merges.objects);
1780         return 0;
1781 }
1782
1783 /*
1784  * Embeds a single submodules git directory into the superprojects git dir,
1785  * non recursively.
1786  */
1787 static void relocate_single_git_dir_into_superproject(const char *prefix,
1788                                                       const char *path)
1789 {
1790         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1791         const char *new_git_dir;
1792         const struct submodule *sub;
1793
1794         if (submodule_uses_worktrees(path))
1795                 die(_("relocate_gitdir for submodule '%s' with "
1796                       "more than one worktree not supported"), path);
1797
1798         old_git_dir = xstrfmt("%s/.git", path);
1799         if (read_gitfile(old_git_dir))
1800                 /* If it is an actual gitfile, it doesn't need migration. */
1801                 return;
1802
1803         real_old_git_dir = real_pathdup(old_git_dir, 1);
1804
1805         sub = submodule_from_path(&null_oid, path);
1806         if (!sub)
1807                 die(_("could not lookup name for submodule '%s'"), path);
1808
1809         new_git_dir = git_path("modules/%s", sub->name);
1810         if (safe_create_leading_directories_const(new_git_dir) < 0)
1811                 die(_("could not create directory '%s'"), new_git_dir);
1812         real_new_git_dir = real_pathdup(new_git_dir, 1);
1813
1814         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1815                 get_super_prefix_or_empty(), path,
1816                 real_old_git_dir, real_new_git_dir);
1817
1818         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1819
1820         free(old_git_dir);
1821         free(real_old_git_dir);
1822         free(real_new_git_dir);
1823 }
1824
1825 /*
1826  * Migrate the git directory of the submodule given by path from
1827  * having its git directory within the working tree to the git dir nested
1828  * in its superprojects git dir under modules/.
1829  */
1830 void absorb_git_dir_into_superproject(const char *prefix,
1831                                       const char *path,
1832                                       unsigned flags)
1833 {
1834         int err_code;
1835         const char *sub_git_dir;
1836         struct strbuf gitdir = STRBUF_INIT;
1837         strbuf_addf(&gitdir, "%s/.git", path);
1838         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1839
1840         /* Not populated? */
1841         if (!sub_git_dir) {
1842                 const struct submodule *sub;
1843
1844                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1845                         /* unpopulated as expected */
1846                         strbuf_release(&gitdir);
1847                         return;
1848                 }
1849
1850                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1851                         /* We don't know what broke here. */
1852                         read_gitfile_error_die(err_code, path, NULL);
1853
1854                 /*
1855                 * Maybe populated, but no git directory was found?
1856                 * This can happen if the superproject is a submodule
1857                 * itself and was just absorbed. The absorption of the
1858                 * superproject did not rewrite the git file links yet,
1859                 * fix it now.
1860                 */
1861                 sub = submodule_from_path(&null_oid, path);
1862                 if (!sub)
1863                         die(_("could not lookup name for submodule '%s'"), path);
1864                 connect_work_tree_and_git_dir(path,
1865                         git_path("modules/%s", sub->name));
1866         } else {
1867                 /* Is it already absorbed into the superprojects git dir? */
1868                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1869                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1870
1871                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1872                         relocate_single_git_dir_into_superproject(prefix, path);
1873
1874                 free(real_sub_git_dir);
1875                 free(real_common_git_dir);
1876         }
1877         strbuf_release(&gitdir);
1878
1879         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1880                 struct child_process cp = CHILD_PROCESS_INIT;
1881                 struct strbuf sb = STRBUF_INIT;
1882
1883                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1884                         die("BUG: we don't know how to pass the flags down?");
1885
1886                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1887                 strbuf_addstr(&sb, path);
1888                 strbuf_addch(&sb, '/');
1889
1890                 cp.dir = path;
1891                 cp.git_cmd = 1;
1892                 cp.no_stdin = 1;
1893                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1894                                            "submodule--helper",
1895                                            "absorb-git-dirs", NULL);
1896                 prepare_submodule_repo_env(&cp.env_array);
1897                 if (run_command(&cp))
1898                         die(_("could not recurse into submodule '%s'"), path);
1899
1900                 strbuf_release(&sb);
1901         }
1902 }
1903
1904 const char *get_superproject_working_tree(void)
1905 {
1906         struct child_process cp = CHILD_PROCESS_INIT;
1907         struct strbuf sb = STRBUF_INIT;
1908         const char *one_up = real_path_if_valid("../");
1909         const char *cwd = xgetcwd();
1910         const char *ret = NULL;
1911         const char *subpath;
1912         int code;
1913         ssize_t len;
1914
1915         if (!is_inside_work_tree())
1916                 /*
1917                  * FIXME:
1918                  * We might have a superproject, but it is harder
1919                  * to determine.
1920                  */
1921                 return NULL;
1922
1923         if (!one_up)
1924                 return NULL;
1925
1926         subpath = relative_path(cwd, one_up, &sb);
1927
1928         prepare_submodule_repo_env(&cp.env_array);
1929         argv_array_pop(&cp.env_array);
1930
1931         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
1932                         "ls-files", "-z", "--stage", "--full-name", "--",
1933                         subpath, NULL);
1934         strbuf_reset(&sb);
1935
1936         cp.no_stdin = 1;
1937         cp.no_stderr = 1;
1938         cp.out = -1;
1939         cp.git_cmd = 1;
1940
1941         if (start_command(&cp))
1942                 die(_("could not start ls-files in .."));
1943
1944         len = strbuf_read(&sb, cp.out, PATH_MAX);
1945         close(cp.out);
1946
1947         if (starts_with(sb.buf, "160000")) {
1948                 int super_sub_len;
1949                 int cwd_len = strlen(cwd);
1950                 char *super_sub, *super_wt;
1951
1952                 /*
1953                  * There is a superproject having this repo as a submodule.
1954                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
1955                  * We're only interested in the name after the tab.
1956                  */
1957                 super_sub = strchr(sb.buf, '\t') + 1;
1958                 super_sub_len = sb.buf + sb.len - super_sub - 1;
1959
1960                 if (super_sub_len > cwd_len ||
1961                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
1962                         die (_("BUG: returned path string doesn't match cwd?"));
1963
1964                 super_wt = xstrdup(cwd);
1965                 super_wt[cwd_len - super_sub_len] = '\0';
1966
1967                 ret = real_path(super_wt);
1968                 free(super_wt);
1969         }
1970         strbuf_release(&sb);
1971
1972         code = finish_command(&cp);
1973
1974         if (code == 128)
1975                 /* '../' is not a git repository */
1976                 return NULL;
1977         if (code == 0 && len == 0)
1978                 /* There is an unrelated git repository at '../' */
1979                 return NULL;
1980         if (code)
1981                 die(_("ls-tree returned unexpected return code %d"), code);
1982
1983         return ret;
1984 }
1985
1986 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
1987 {
1988         const struct submodule *sub;
1989         const char *git_dir;
1990         int ret = 0;
1991
1992         strbuf_reset(buf);
1993         strbuf_addstr(buf, submodule);
1994         strbuf_complete(buf, '/');
1995         strbuf_addstr(buf, ".git");
1996
1997         git_dir = read_gitfile(buf->buf);
1998         if (git_dir) {
1999                 strbuf_reset(buf);
2000                 strbuf_addstr(buf, git_dir);
2001         }
2002         if (!is_git_directory(buf->buf)) {
2003                 gitmodules_config();
2004                 sub = submodule_from_path(&null_oid, submodule);
2005                 if (!sub) {
2006                         ret = -1;
2007                         goto cleanup;
2008                 }
2009                 strbuf_reset(buf);
2010                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2011         }
2012
2013 cleanup:
2014         return ret;
2015 }