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

   1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
   2
   3 #include "cache.h"
   4 #include "repository.h"
   5 #include "config.h"
   6 #include "submodule-config.h"
   7 #include "submodule.h"
   8 #include "dir.h"
   9 #include "diff.h"
  10 #include "commit.h"
  11 #include "revision.h"
  12 #include "run-command.h"
  13 #include "diffcore.h"
  14 #include "refs.h"
  15 #include "string-list.h"
  16 #include "sha1-array.h"
  17 #include "argv-array.h"
  18 #include "blob.h"
  19 #include "thread-utils.h"
  20 #include "quote.h"
  21 #include "remote.h"
  22 #include "worktree.h"
  23 #include "parse-options.h"
  24 #include "object-store.h"
  25
  26 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
  27 static struct string_list changed_submodule_names = STRING_LIST_INIT_DUP;
  28 static int initialized_fetch_ref_tips;
  29 static struct oid_array ref_tips_before_fetch;
  30 static struct oid_array ref_tips_after_fetch;
  31
  32 /*
  33  * Check if the .gitmodules file is unmerged. Parsing of the .gitmodules file
  34  * will be disabled because we can't guess what might be configured in
  35  * .gitmodules unless the user resolves the conflict.
  36  */
  37 int is_gitmodules_unmerged(const struct index_state *istate)
  38 {
  39         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  40         if (pos < 0) { /* .gitmodules not found or isn't merged */
  41                 pos = -1 - pos;
  42                 if (istate->cache_nr > pos) {  /* there is a .gitmodules */
  43                         const struct cache_entry *ce = istate->cache[pos];
  44                         if (ce_namelen(ce) == strlen(GITMODULES_FILE) &&
  45                             !strcmp(ce->name, GITMODULES_FILE))
  46                                 return 1;
  47                 }
  48         }
  49
  50         return 0;
  51 }
  52
  53 /*
  54  * Check if the .gitmodules file has unstaged modifications.  This must be
  55  * checked before allowing modifications to the .gitmodules file with the
  56  * intention to stage them later, because when continuing we would stage the
  57  * modifications the user didn't stage herself too. That might change in a
  58  * future version when we learn to stage the changes we do ourselves without
  59  * staging any previous modifications.
  60  */
  61 int is_staging_gitmodules_ok(struct index_state *istate)
  62 {
  63         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  64
  65         if ((pos >= 0) && (pos < istate->cache_nr)) {
  66                 struct stat st;
  67                 if (lstat(GITMODULES_FILE, &st) == 0 &&
  68                     ie_match_stat(istate, istate->cache[pos], &st,
  69                                   CE_MATCH_IGNORE_FSMONITOR) & DATA_CHANGED)
  70                         return 0;
  71         }
  72
  73         return 1;
  74 }
  75
  76 static int for_each_remote_ref_submodule(const char *submodule,
  77                                          each_ref_fn fn, void *cb_data)
  78 {
  79         return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
  80                                         fn, cb_data);
  81 }
  82
  83 /*
  84  * Try to update the "path" entry in the "submodule.<name>" section of the
  85  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
  86  * with the correct path=<oldpath> setting was found and we could update it.
  87  */
  88 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
  89 {
  90         struct strbuf entry = STRBUF_INIT;
  91         const struct submodule *submodule;
  92
  93         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
  94                 return -1;
  95
  96         if (is_gitmodules_unmerged(&the_index))
  97                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  98
  99         submodule = submodule_from_path(the_repository, &null_oid, oldpath);
 100         if (!submodule || !submodule->name) {
 101                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
 102                 return -1;
 103         }
 104         strbuf_addstr(&entry, "submodule.");
 105         strbuf_addstr(&entry, submodule->name);
 106         strbuf_addstr(&entry, ".path");
 107         if (git_config_set_in_file_gently(GITMODULES_FILE, entry.buf, newpath) < 0) {
 108                 /* Maybe the user already did that, don't error out here */
 109                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
 110                 strbuf_release(&entry);
 111                 return -1;
 112         }
 113         strbuf_release(&entry);
 114         return 0;
 115 }
 116
 117 /*
 118  * Try to remove the "submodule.<name>" section from .gitmodules where the given
 119  * path is configured. Return 0 only if a .gitmodules file was found, a section
 120  * with the correct path=<path> setting was found and we could remove it.
 121  */
 122 int remove_path_from_gitmodules(const char *path)
 123 {
 124         struct strbuf sect = STRBUF_INIT;
 125         const struct submodule *submodule;
 126
 127         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
 128                 return -1;
 129
 130         if (is_gitmodules_unmerged(&the_index))
 131                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 132
 133         submodule = submodule_from_path(the_repository, &null_oid, path);
 134         if (!submodule || !submodule->name) {
 135                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 136                 return -1;
 137         }
 138         strbuf_addstr(&sect, "submodule.");
 139         strbuf_addstr(&sect, submodule->name);
 140         if (git_config_rename_section_in_file(GITMODULES_FILE, sect.buf, NULL) < 0) {
 141                 /* Maybe the user already did that, don't error out here */
 142                 warning(_("Could not remove .gitmodules entry for %s"), path);
 143                 strbuf_release(&sect);
 144                 return -1;
 145         }
 146         strbuf_release(&sect);
 147         return 0;
 148 }
 149
 150 void stage_updated_gitmodules(struct index_state *istate)
 151 {
 152         if (add_file_to_index(istate, GITMODULES_FILE, 0))
 153                 die(_("staging updated .gitmodules failed"));
 154 }
 155
 156 static int add_submodule_odb(const char *path)
 157 {
 158         struct strbuf objects_directory = STRBUF_INIT;
 159         int ret = 0;
 160
 161         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
 162         if (ret)
 163                 goto done;
 164         if (!is_directory(objects_directory.buf)) {
 165                 ret = -1;
 166                 goto done;
 167         }
 168         add_to_alternates_memory(objects_directory.buf);
 169 done:
 170         strbuf_release(&objects_directory);
 171         return ret;
 172 }
 173
 174 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 175                                              const char *path)
 176 {
 177         const struct submodule *submodule = submodule_from_path(the_repository,
 178                                                                 &null_oid, path);
 179         if (submodule) {
 180                 const char *ignore;
 181                 char *key;
 182
 183                 key = xstrfmt("submodule.%s.ignore", submodule->name);
 184                 if (repo_config_get_string_const(the_repository, key, &ignore))
 185                         ignore = submodule->ignore;
 186                 free(key);
 187
 188                 if (ignore)
 189                         handle_ignore_submodules_arg(diffopt, ignore);
 190                 else if (is_gitmodules_unmerged(&the_index))
 191                         diffopt->flags.ignore_submodules = 1;
 192         }
 193 }
 194
 195 /* Cheap function that only determines if we're interested in submodules at all */
 196 int git_default_submodule_config(const char *var, const char *value, void *cb)
 197 {
 198         if (!strcmp(var, "submodule.recurse")) {
 199                 int v = git_config_bool(var, value) ?
 200                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 201                 config_update_recurse_submodules = v;
 202         }
 203         return 0;
 204 }
 205
 206 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 207                                                      const char *arg, int unset)
 208 {
 209         if (unset) {
 210                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 211                 return 0;
 212         }
 213         if (arg)
 214                 config_update_recurse_submodules =
 215                         parse_update_recurse_submodules_arg(opt->long_name,
 216                                                             arg);
 217         else
 218                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 219
 220         return 0;
 221 }
 222
 223 /*
 224  * Determine if a submodule has been initialized at a given 'path'
 225  */
 226 int is_submodule_active(struct repository *repo, const char *path)
 227 {
 228         int ret = 0;
 229         char *key = NULL;
 230         char *value = NULL;
 231         const struct string_list *sl;
 232         const struct submodule *module;
 233
 234         module = submodule_from_path(repo, &null_oid, path);
 235
 236         /* early return if there isn't a path->module mapping */
 237         if (!module)
 238                 return 0;
 239
 240         /* submodule.<name>.active is set */
 241         key = xstrfmt("submodule.%s.active", module->name);
 242         if (!repo_config_get_bool(repo, key, &ret)) {
 243                 free(key);
 244                 return ret;
 245         }
 246         free(key);
 247
 248         /* submodule.active is set */
 249         sl = repo_config_get_value_multi(repo, "submodule.active");
 250         if (sl) {
 251                 struct pathspec ps;
 252                 struct argv_array args = ARGV_ARRAY_INIT;
 253                 const struct string_list_item *item;
 254
 255                 for_each_string_list_item(item, sl) {
 256                         argv_array_push(&args, item->string);
 257                 }
 258
 259                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 260                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
 261
 262                 argv_array_clear(&args);
 263                 clear_pathspec(&ps);
 264                 return ret;
 265         }
 266
 267         /* fallback to checking if the URL is set */
 268         key = xstrfmt("submodule.%s.url", module->name);
 269         ret = !repo_config_get_string(repo, key, &value);
 270
 271         free(value);
 272         free(key);
 273         return ret;
 274 }
 275
 276 int is_submodule_populated_gently(const char *path, int *return_error_code)
 277 {
 278         int ret = 0;
 279         char *gitdir = xstrfmt("%s/.git", path);
 280
 281         if (resolve_gitdir_gently(gitdir, return_error_code))
 282                 ret = 1;
 283
 284         free(gitdir);
 285         return ret;
 286 }
 287
 288 /*
 289  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 290  */
 291 void die_in_unpopulated_submodule(const struct index_state *istate,
 292                                   const char *prefix)
 293 {
 294         int i, prefixlen;
 295
 296         if (!prefix)
 297                 return;
 298
 299         prefixlen = strlen(prefix);
 300
 301         for (i = 0; i < istate->cache_nr; i++) {
 302                 struct cache_entry *ce = istate->cache[i];
 303                 int ce_len = ce_namelen(ce);
 304
 305                 if (!S_ISGITLINK(ce->ce_mode))
 306                         continue;
 307                 if (prefixlen <= ce_len)
 308                         continue;
 309                 if (strncmp(ce->name, prefix, ce_len))
 310                         continue;
 311                 if (prefix[ce_len] != '/')
 312                         continue;
 313
 314                 die(_("in unpopulated submodule '%s'"), ce->name);
 315         }
 316 }
 317
 318 /*
 319  * Dies if any paths in the provided pathspec descends into a submodule
 320  */
 321 void die_path_inside_submodule(const struct index_state *istate,
 322                                const struct pathspec *ps)
 323 {
 324         int i, j;
 325
 326         for (i = 0; i < istate->cache_nr; i++) {
 327                 struct cache_entry *ce = istate->cache[i];
 328                 int ce_len = ce_namelen(ce);
 329
 330                 if (!S_ISGITLINK(ce->ce_mode))
 331                         continue;
 332
 333                 for (j = 0; j < ps->nr ; j++) {
 334                         const struct pathspec_item *item = &ps->items[j];
 335
 336                         if (item->len <= ce_len)
 337                                 continue;
 338                         if (item->match[ce_len] != '/')
 339                                 continue;
 340                         if (strncmp(ce->name, item->match, ce_len))
 341                                 continue;
 342                         if (item->len == ce_len + 1)
 343                                 continue;
 344
 345                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 346                             item->original, ce_len, ce->name);
 347                 }
 348         }
 349 }
 350
 351 enum submodule_update_type parse_submodule_update_type(const char *value)
 352 {
 353         if (!strcmp(value, "none"))
 354                 return SM_UPDATE_NONE;
 355         else if (!strcmp(value, "checkout"))
 356                 return SM_UPDATE_CHECKOUT;
 357         else if (!strcmp(value, "rebase"))
 358                 return SM_UPDATE_REBASE;
 359         else if (!strcmp(value, "merge"))
 360                 return SM_UPDATE_MERGE;
 361         else if (*value == '!')
 362                 return SM_UPDATE_COMMAND;
 363         else
 364                 return SM_UPDATE_UNSPECIFIED;
 365 }
 366
 367 int parse_submodule_update_strategy(const char *value,
 368                 struct submodule_update_strategy *dst)
 369 {
 370         enum submodule_update_type type;
 371
 372         free((void*)dst->command);
 373         dst->command = NULL;
 374
 375         type = parse_submodule_update_type(value);
 376         if (type == SM_UPDATE_UNSPECIFIED)
 377                 return -1;
 378
 379         dst->type = type;
 380         if (type == SM_UPDATE_COMMAND)
 381                 dst->command = xstrdup(value + 1);
 382
 383         return 0;
 384 }
 385
 386 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 387 {
 388         struct strbuf sb = STRBUF_INIT;
 389         switch (s->type) {
 390         case SM_UPDATE_CHECKOUT:
 391                 return "checkout";
 392         case SM_UPDATE_MERGE:
 393                 return "merge";
 394         case SM_UPDATE_REBASE:
 395                 return "rebase";
 396         case SM_UPDATE_NONE:
 397                 return "none";
 398         case SM_UPDATE_UNSPECIFIED:
 399                 return NULL;
 400         case SM_UPDATE_COMMAND:
 401                 strbuf_addf(&sb, "!%s", s->command);
 402                 return strbuf_detach(&sb, NULL);
 403         }
 404         return NULL;
 405 }
 406
 407 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 408                                   const char *arg)
 409 {
 410         diffopt->flags.ignore_submodules = 0;
 411         diffopt->flags.ignore_untracked_in_submodules = 0;
 412         diffopt->flags.ignore_dirty_submodules = 0;
 413
 414         if (!strcmp(arg, "all"))
 415                 diffopt->flags.ignore_submodules = 1;
 416         else if (!strcmp(arg, "untracked"))
 417                 diffopt->flags.ignore_untracked_in_submodules = 1;
 418         else if (!strcmp(arg, "dirty"))
 419                 diffopt->flags.ignore_dirty_submodules = 1;
 420         else if (strcmp(arg, "none"))
 421                 die("bad --ignore-submodules argument: %s", arg);
 422 }
 423
 424 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 425                 struct commit *left, struct commit *right,
 426                 struct commit_list *merge_bases)
 427 {
 428         struct commit_list *list;
 429
 430         init_revisions(rev, NULL);
 431         setup_revisions(0, NULL, rev, NULL);
 432         rev->left_right = 1;
 433         rev->first_parent_only = 1;
 434         left->object.flags |= SYMMETRIC_LEFT;
 435         add_pending_object(rev, &left->object, path);
 436         add_pending_object(rev, &right->object, path);
 437         for (list = merge_bases; list; list = list->next) {
 438                 list->item->object.flags |= UNINTERESTING;
 439                 add_pending_object(rev, &list->item->object,
 440                         oid_to_hex(&list->item->object.oid));
 441         }
 442         return prepare_revision_walk(rev);
 443 }
 444
 445 static void print_submodule_summary(struct rev_info *rev, struct diff_options *o)
 446 {
 447         static const char format[] = "  %m %s";
 448         struct strbuf sb = STRBUF_INIT;
 449         struct commit *commit;
 450
 451         while ((commit = get_revision(rev))) {
 452                 struct pretty_print_context ctx = {0};
 453                 ctx.date_mode = rev->date_mode;
 454                 ctx.output_encoding = get_log_output_encoding();
 455                 strbuf_setlen(&sb, 0);
 456                 format_commit_message(commit, format, &sb, &ctx);
 457                 strbuf_addch(&sb, '\n');
 458                 if (commit->object.flags & SYMMETRIC_LEFT)
 459                         diff_emit_submodule_del(o, sb.buf);
 460                 else
 461                         diff_emit_submodule_add(o, sb.buf);
 462         }
 463         strbuf_release(&sb);
 464 }
 465
 466 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 467 {
 468         const char * const *var;
 469
 470         for (var = local_repo_env; *var; var++) {
 471                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 472                         argv_array_push(out, *var);
 473         }
 474 }
 475
 476 void prepare_submodule_repo_env(struct argv_array *out)
 477 {
 478         prepare_submodule_repo_env_no_git_dir(out);
 479         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 480                          DEFAULT_GIT_DIR_ENVIRONMENT);
 481 }
 482
 483 /* Helper function to display the submodule header line prior to the full
 484  * summary output. If it can locate the submodule objects directory it will
 485  * attempt to lookup both the left and right commits and put them into the
 486  * left and right pointers.
 487  */
 488 static void show_submodule_header(struct diff_options *o, const char *path,
 489                 struct object_id *one, struct object_id *two,
 490                 unsigned dirty_submodule,
 491                 struct commit **left, struct commit **right,
 492                 struct commit_list **merge_bases)
 493 {
 494         const char *message = NULL;
 495         struct strbuf sb = STRBUF_INIT;
 496         int fast_forward = 0, fast_backward = 0;
 497
 498         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 499                 diff_emit_submodule_untracked(o, path);
 500
 501         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 502                 diff_emit_submodule_modified(o, path);
 503
 504         if (is_null_oid(one))
 505                 message = "(new submodule)";
 506         else if (is_null_oid(two))
 507                 message = "(submodule deleted)";
 508
 509         if (add_submodule_odb(path)) {
 510                 if (!message)
 511                         message = "(commits not present)";
 512                 goto output_header;
 513         }
 514
 515         /*
 516          * Attempt to lookup the commit references, and determine if this is
 517          * a fast forward or fast backwards update.
 518          */
 519         *left = lookup_commit_reference(one);
 520         *right = lookup_commit_reference(two);
 521
 522         /*
 523          * Warn about missing commits in the submodule project, but only if
 524          * they aren't null.
 525          */
 526         if ((!is_null_oid(one) && !*left) ||
 527              (!is_null_oid(two) && !*right))
 528                 message = "(commits not present)";
 529
 530         *merge_bases = get_merge_bases(*left, *right);
 531         if (*merge_bases) {
 532                 if ((*merge_bases)->item == *left)
 533                         fast_forward = 1;
 534                 else if ((*merge_bases)->item == *right)
 535                         fast_backward = 1;
 536         }
 537
 538         if (!oidcmp(one, two)) {
 539                 strbuf_release(&sb);
 540                 return;
 541         }
 542
 543 output_header:
 544         strbuf_addf(&sb, "Submodule %s ", path);
 545         strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
 546         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 547         strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
 548         if (message)
 549                 strbuf_addf(&sb, " %s\n", message);
 550         else
 551                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 552         diff_emit_submodule_header(o, sb.buf);
 553
 554         strbuf_release(&sb);
 555 }
 556
 557 void show_submodule_summary(struct diff_options *o, const char *path,
 558                 struct object_id *one, struct object_id *two,
 559                 unsigned dirty_submodule)
 560 {
 561         struct rev_info rev;
 562         struct commit *left = NULL, *right = NULL;
 563         struct commit_list *merge_bases = NULL;
 564
 565         show_submodule_header(o, path, one, two, dirty_submodule,
 566                               &left, &right, &merge_bases);
 567
 568         /*
 569          * If we don't have both a left and a right pointer, there is no
 570          * reason to try and display a summary. The header line should contain
 571          * all the information the user needs.
 572          */
 573         if (!left || !right)
 574                 goto out;
 575
 576         /* Treat revision walker failure the same as missing commits */
 577         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 578                 diff_emit_submodule_error(o, "(revision walker failed)\n");
 579                 goto out;
 580         }
 581
 582         print_submodule_summary(&rev, o);
 583
 584 out:
 585         if (merge_bases)
 586                 free_commit_list(merge_bases);
 587         clear_commit_marks(left, ~0);
 588         clear_commit_marks(right, ~0);
 589 }
 590
 591 void show_submodule_inline_diff(struct diff_options *o, const char *path,
 592                 struct object_id *one, struct object_id *two,
 593                 unsigned dirty_submodule)
 594 {
 595         const struct object_id *old_oid = the_hash_algo->empty_tree, *new_oid = the_hash_algo->empty_tree;
 596         struct commit *left = NULL, *right = NULL;
 597         struct commit_list *merge_bases = NULL;
 598         struct child_process cp = CHILD_PROCESS_INIT;
 599         struct strbuf sb = STRBUF_INIT;
 600
 601         show_submodule_header(o, path, one, two, dirty_submodule,
 602                               &left, &right, &merge_bases);
 603
 604         /* We need a valid left and right commit to display a difference */
 605         if (!(left || is_null_oid(one)) ||
 606             !(right || is_null_oid(two)))
 607                 goto done;
 608
 609         if (left)
 610                 old_oid = one;
 611         if (right)
 612                 new_oid = two;
 613
 614         cp.git_cmd = 1;
 615         cp.dir = path;
 616         cp.out = -1;
 617         cp.no_stdin = 1;
 618
 619         /* TODO: other options may need to be passed here. */
 620         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 621         argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 622                          "always" : "never");
 623
 624         if (o->flags.reverse_diff) {
 625                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 626                                  o->b_prefix, path);
 627                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 628                                  o->a_prefix, path);
 629         } else {
 630                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 631                                  o->a_prefix, path);
 632                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 633                                  o->b_prefix, path);
 634         }
 635         argv_array_push(&cp.args, oid_to_hex(old_oid));
 636         /*
 637          * If the submodule has modified content, we will diff against the
 638          * work tree, under the assumption that the user has asked for the
 639          * diff format and wishes to actually see all differences even if they
 640          * haven't yet been committed to the submodule yet.
 641          */
 642         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 643                 argv_array_push(&cp.args, oid_to_hex(new_oid));
 644
 645         prepare_submodule_repo_env(&cp.env_array);
 646         if (start_command(&cp))
 647                 diff_emit_submodule_error(o, "(diff failed)\n");
 648
 649         while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
 650                 diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
 651
 652         if (finish_command(&cp))
 653                 diff_emit_submodule_error(o, "(diff failed)\n");
 654
 655 done:
 656         strbuf_release(&sb);
 657         if (merge_bases)
 658                 free_commit_list(merge_bases);
 659         if (left)
 660                 clear_commit_marks(left, ~0);
 661         if (right)
 662                 clear_commit_marks(right, ~0);
 663 }
 664
 665 int should_update_submodules(void)
 666 {
 667         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 668 }
 669
 670 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 671 {
 672         if (!S_ISGITLINK(ce->ce_mode))
 673                 return NULL;
 674
 675         if (!should_update_submodules())
 676                 return NULL;
 677
 678         return submodule_from_path(the_repository, &null_oid, ce->name);
 679 }
 680
 681 static struct oid_array *submodule_commits(struct string_list *submodules,
 682                                            const char *name)
 683 {
 684         struct string_list_item *item;
 685
 686         item = string_list_insert(submodules, name);
 687         if (item->util)
 688                 return (struct oid_array *) item->util;
 689
 690         /* NEEDSWORK: should we have oid_array_init()? */
 691         item->util = xcalloc(1, sizeof(struct oid_array));
 692         return (struct oid_array *) item->util;
 693 }
 694
 695 struct collect_changed_submodules_cb_data {
 696         struct string_list *changed;
 697         const struct object_id *commit_oid;
 698 };
 699
 700 /*
 701  * this would normally be two functions: default_name_from_path() and
 702  * path_from_default_name(). Since the default name is the same as
 703  * the submodule path we can get away with just one function which only
 704  * checks whether there is a submodule in the working directory at that
 705  * location.
 706  */
 707 static const char *default_name_or_path(const char *path_or_name)
 708 {
 709         int error_code;
 710
 711         if (!is_submodule_populated_gently(path_or_name, &error_code))
 712                 return NULL;
 713
 714         return path_or_name;
 715 }
 716
 717 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 718                                           struct diff_options *options,
 719                                           void *data)
 720 {
 721         struct collect_changed_submodules_cb_data *me = data;
 722         struct string_list *changed = me->changed;
 723         const struct object_id *commit_oid = me->commit_oid;
 724         int i;
 725
 726         for (i = 0; i < q->nr; i++) {
 727                 struct diff_filepair *p = q->queue[i];
 728                 struct oid_array *commits;
 729                 const struct submodule *submodule;
 730                 const char *name;
 731
 732                 if (!S_ISGITLINK(p->two->mode))
 733                         continue;
 734
 735                 submodule = submodule_from_path(the_repository,
 736                                                 commit_oid, p->two->path);
 737                 if (submodule)
 738                         name = submodule->name;
 739                 else {
 740                         name = default_name_or_path(p->two->path);
 741                         /* make sure name does not collide with existing one */
 742                         submodule = submodule_from_name(the_repository, commit_oid, name);
 743                         if (submodule) {
 744                                 warning("Submodule in commit %s at path: "
 745                                         "'%s' collides with a submodule named "
 746                                         "the same. Skipping it.",
 747                                         oid_to_hex(commit_oid), name);
 748                                 name = NULL;
 749                         }
 750                 }
 751
 752                 if (!name)
 753                         continue;
 754
 755                 commits = submodule_commits(changed, name);
 756                 oid_array_append(commits, &p->two->oid);
 757         }
 758 }
 759
 760 /*
 761  * Collect the paths of submodules in 'changed' which have changed based on
 762  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 763  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 764  * what the submodule pointers were updated to during the change.
 765  */
 766 static void collect_changed_submodules(struct string_list *changed,
 767                                        struct argv_array *argv)
 768 {
 769         struct rev_info rev;
 770         const struct commit *commit;
 771
 772         init_revisions(&rev, NULL);
 773         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 774         if (prepare_revision_walk(&rev))
 775                 die("revision walk setup failed");
 776
 777         while ((commit = get_revision(&rev))) {
 778                 struct rev_info diff_rev;
 779                 struct collect_changed_submodules_cb_data data;
 780                 data.changed = changed;
 781                 data.commit_oid = &commit->object.oid;
 782
 783                 init_revisions(&diff_rev, NULL);
 784                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 785                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 786                 diff_rev.diffopt.format_callback_data = &data;
 787                 diff_tree_combined_merge(commit, 1, &diff_rev);
 788         }
 789
 790         reset_revision_walk();
 791 }
 792
 793 static void free_submodules_oids(struct string_list *submodules)
 794 {
 795         struct string_list_item *item;
 796         for_each_string_list_item(item, submodules)
 797                 oid_array_clear((struct oid_array *) item->util);
 798         string_list_clear(submodules, 1);
 799 }
 800
 801 static int has_remote(const char *refname, const struct object_id *oid,
 802                       int flags, void *cb_data)
 803 {
 804         return 1;
 805 }
 806
 807 static int append_oid_to_argv(const struct object_id *oid, void *data)
 808 {
 809         struct argv_array *argv = data;
 810         argv_array_push(argv, oid_to_hex(oid));
 811         return 0;
 812 }
 813
 814 struct has_commit_data {
 815         int result;
 816         const char *path;
 817 };
 818
 819 static int check_has_commit(const struct object_id *oid, void *data)
 820 {
 821         struct has_commit_data *cb = data;
 822
 823         enum object_type type = oid_object_info(the_repository, oid, NULL);
 824
 825         switch (type) {
 826         case OBJ_COMMIT:
 827                 return 0;
 828         case OBJ_BAD:
 829                 /*
 830                  * Object is missing or invalid. If invalid, an error message
 831                  * has already been printed.
 832                  */
 833                 cb->result = 0;
 834                 return 0;
 835         default:
 836                 die(_("submodule entry '%s' (%s) is a %s, not a commit"),
 837                     cb->path, oid_to_hex(oid), type_name(type));
 838         }
 839 }
 840
 841 static int submodule_has_commits(const char *path, struct oid_array *commits)
 842 {
 843         struct has_commit_data has_commit = { 1, path };
 844
 845         /*
 846          * Perform a cheap, but incorrect check for the existence of 'commits'.
 847          * This is done by adding the submodule's object store to the in-core
 848          * object store, and then querying for each commit's existence.  If we
 849          * do not have the commit object anywhere, there is no chance we have
 850          * it in the object store of the correct submodule and have it
 851          * reachable from a ref, so we can fail early without spawning rev-list
 852          * which is expensive.
 853          */
 854         if (add_submodule_odb(path))
 855                 return 0;
 856
 857         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 858
 859         if (has_commit.result) {
 860                 /*
 861                  * Even if the submodule is checked out and the commit is
 862                  * present, make sure it exists in the submodule's object store
 863                  * and that it is reachable from a ref.
 864                  */
 865                 struct child_process cp = CHILD_PROCESS_INIT;
 866                 struct strbuf out = STRBUF_INIT;
 867
 868                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 869                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 870                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 871
 872                 prepare_submodule_repo_env(&cp.env_array);
 873                 cp.git_cmd = 1;
 874                 cp.no_stdin = 1;
 875                 cp.dir = path;
 876
 877                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 878                         has_commit.result = 0;
 879
 880                 strbuf_release(&out);
 881         }
 882
 883         return has_commit.result;
 884 }
 885
 886 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
 887 {
 888         if (!submodule_has_commits(path, commits))
 889                 /*
 890                  * NOTE: We do consider it safe to return "no" here. The
 891                  * correct answer would be "We do not know" instead of
 892                  * "No push needed", but it is quite hard to change
 893                  * the submodule pointer without having the submodule
 894                  * around. If a user did however change the submodules
 895                  * without having the submodule around, this indicates
 896                  * an expert who knows what they are doing or a
 897                  * maintainer integrating work from other people. In
 898                  * both cases it should be safe to skip this check.
 899                  */
 900                 return 0;
 901
 902         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 903                 struct child_process cp = CHILD_PROCESS_INIT;
 904                 struct strbuf buf = STRBUF_INIT;
 905                 int needs_pushing = 0;
 906
 907                 argv_array_push(&cp.args, "rev-list");
 908                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 909                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 910
 911                 prepare_submodule_repo_env(&cp.env_array);
 912                 cp.git_cmd = 1;
 913                 cp.no_stdin = 1;
 914                 cp.out = -1;
 915                 cp.dir = path;
 916                 if (start_command(&cp))
 917                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 918                                         path);
 919                 if (strbuf_read(&buf, cp.out, 41))
 920                         needs_pushing = 1;
 921                 finish_command(&cp);
 922                 close(cp.out);
 923                 strbuf_release(&buf);
 924                 return needs_pushing;
 925         }
 926
 927         return 0;
 928 }
 929
 930 int find_unpushed_submodules(struct oid_array *commits,
 931                 const char *remotes_name, struct string_list *needs_pushing)
 932 {
 933         struct string_list submodules = STRING_LIST_INIT_DUP;
 934         struct string_list_item *name;
 935         struct argv_array argv = ARGV_ARRAY_INIT;
 936
 937         /* argv.argv[0] will be ignored by setup_revisions */
 938         argv_array_push(&argv, "find_unpushed_submodules");
 939         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
 940         argv_array_push(&argv, "--not");
 941         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
 942
 943         collect_changed_submodules(&submodules, &argv);
 944
 945         for_each_string_list_item(name, &submodules) {
 946                 struct oid_array *commits = name->util;
 947                 const struct submodule *submodule;
 948                 const char *path = NULL;
 949
 950                 submodule = submodule_from_name(the_repository, &null_oid, name->string);
 951                 if (submodule)
 952                         path = submodule->path;
 953                 else
 954                         path = default_name_or_path(name->string);
 955
 956                 if (!path)
 957                         continue;
 958
 959                 if (submodule_needs_pushing(path, commits))
 960                         string_list_insert(needs_pushing, path);
 961         }
 962
 963         free_submodules_oids(&submodules);
 964         argv_array_clear(&argv);
 965
 966         return needs_pushing->nr;
 967 }
 968
 969 static int push_submodule(const char *path,
 970                           const struct remote *remote,
 971                           const struct refspec *rs,
 972                           const struct string_list *push_options,
 973                           int dry_run)
 974 {
 975         if (add_submodule_odb(path))
 976                 return 1;
 977
 978         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 979                 struct child_process cp = CHILD_PROCESS_INIT;
 980                 argv_array_push(&cp.args, "push");
 981                 if (dry_run)
 982                         argv_array_push(&cp.args, "--dry-run");
 983
 984                 if (push_options && push_options->nr) {
 985                         const struct string_list_item *item;
 986                         for_each_string_list_item(item, push_options)
 987                                 argv_array_pushf(&cp.args, "--push-option=%s",
 988                                                  item->string);
 989                 }
 990
 991                 if (remote->origin != REMOTE_UNCONFIGURED) {
 992                         int i;
 993                         argv_array_push(&cp.args, remote->name);
 994                         for (i = 0; i < rs->raw_nr; i++)
 995                                 argv_array_push(&cp.args, rs->raw[i]);
 996                 }
 997
 998                 prepare_submodule_repo_env(&cp.env_array);
 999                 cp.git_cmd = 1;
1000                 cp.no_stdin = 1;
1001                 cp.dir = path;
1002                 if (run_command(&cp))
1003                         return 0;
1004                 close(cp.out);
1005         }
1006
1007         return 1;
1008 }
1009
1010 /*
1011  * Perform a check in the submodule to see if the remote and refspec work.
1012  * Die if the submodule can't be pushed.
1013  */
1014 static void submodule_push_check(const char *path, const char *head,
1015                                  const struct remote *remote,
1016                                  const struct refspec *rs)
1017 {
1018         struct child_process cp = CHILD_PROCESS_INIT;
1019         int i;
1020
1021         argv_array_push(&cp.args, "submodule--helper");
1022         argv_array_push(&cp.args, "push-check");
1023         argv_array_push(&cp.args, head);
1024         argv_array_push(&cp.args, remote->name);
1025
1026         for (i = 0; i < rs->raw_nr; i++)
1027                 argv_array_push(&cp.args, rs->raw[i]);
1028
1029         prepare_submodule_repo_env(&cp.env_array);
1030         cp.git_cmd = 1;
1031         cp.no_stdin = 1;
1032         cp.no_stdout = 1;
1033         cp.dir = path;
1034
1035         /*
1036          * Simply indicate if 'submodule--helper push-check' failed.
1037          * More detailed error information will be provided by the
1038          * child process.
1039          */
1040         if (run_command(&cp))
1041                 die("process for submodule '%s' failed", path);
1042 }
1043
1044 int push_unpushed_submodules(struct oid_array *commits,
1045                              const struct remote *remote,
1046                              const struct refspec *rs,
1047                              const struct string_list *push_options,
1048                              int dry_run)
1049 {
1050         int i, ret = 1;
1051         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1052
1053         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1054                 return 1;
1055
1056         /*
1057          * Verify that the remote and refspec can be propagated to all
1058          * submodules.  This check can be skipped if the remote and refspec
1059          * won't be propagated due to the remote being unconfigured (e.g. a URL
1060          * instead of a remote name).
1061          */
1062         if (remote->origin != REMOTE_UNCONFIGURED) {
1063                 char *head;
1064                 struct object_id head_oid;
1065
1066                 head = resolve_refdup("HEAD", 0, &head_oid, NULL);
1067                 if (!head)
1068                         die(_("Failed to resolve HEAD as a valid ref."));
1069
1070                 for (i = 0; i < needs_pushing.nr; i++)
1071                         submodule_push_check(needs_pushing.items[i].string,
1072                                              head, remote, rs);
1073                 free(head);
1074         }
1075
1076         /* Actually push the submodules */
1077         for (i = 0; i < needs_pushing.nr; i++) {
1078                 const char *path = needs_pushing.items[i].string;
1079                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1080                 if (!push_submodule(path, remote, rs,
1081                                     push_options, dry_run)) {
1082                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1083                         ret = 0;
1084                 }
1085         }
1086
1087         string_list_clear(&needs_pushing, 0);
1088
1089         return ret;
1090 }
1091
1092 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1093                                int flags, void *data)
1094 {
1095         struct oid_array *array = data;
1096         oid_array_append(array, oid);
1097         return 0;
1098 }
1099
1100 void check_for_new_submodule_commits(struct object_id *oid)
1101 {
1102         if (!initialized_fetch_ref_tips) {
1103                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1104                 initialized_fetch_ref_tips = 1;
1105         }
1106
1107         oid_array_append(&ref_tips_after_fetch, oid);
1108 }
1109
1110 static void calculate_changed_submodule_paths(void)
1111 {
1112         struct argv_array argv = ARGV_ARRAY_INIT;
1113         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1114         const struct string_list_item *name;
1115
1116         /* No need to check if there are no submodules configured */
1117         if (!submodule_from_path(the_repository, NULL, NULL))
1118                 return;
1119
1120         argv_array_push(&argv, "--"); /* argv[0] program name */
1121         oid_array_for_each_unique(&ref_tips_after_fetch,
1122                                    append_oid_to_argv, &argv);
1123         argv_array_push(&argv, "--not");
1124         oid_array_for_each_unique(&ref_tips_before_fetch,
1125                                    append_oid_to_argv, &argv);
1126
1127         /*
1128          * Collect all submodules (whether checked out or not) for which new
1129          * commits have been recorded upstream in "changed_submodule_names".
1130          */
1131         collect_changed_submodules(&changed_submodules, &argv);
1132
1133         for_each_string_list_item(name, &changed_submodules) {
1134                 struct oid_array *commits = name->util;
1135                 const struct submodule *submodule;
1136                 const char *path = NULL;
1137
1138                 submodule = submodule_from_name(the_repository, &null_oid, name->string);
1139                 if (submodule)
1140                         path = submodule->path;
1141                 else
1142                         path = default_name_or_path(name->string);
1143
1144                 if (!path)
1145                         continue;
1146
1147                 if (!submodule_has_commits(path, commits))
1148                         string_list_append(&changed_submodule_names, name->string);
1149         }
1150
1151         free_submodules_oids(&changed_submodules);
1152         argv_array_clear(&argv);
1153         oid_array_clear(&ref_tips_before_fetch);
1154         oid_array_clear(&ref_tips_after_fetch);
1155         initialized_fetch_ref_tips = 0;
1156 }
1157
1158 int submodule_touches_in_range(struct object_id *excl_oid,
1159                                struct object_id *incl_oid)
1160 {
1161         struct string_list subs = STRING_LIST_INIT_DUP;
1162         struct argv_array args = ARGV_ARRAY_INIT;
1163         int ret;
1164
1165         /* No need to check if there are no submodules configured */
1166         if (!submodule_from_path(the_repository, NULL, NULL))
1167                 return 0;
1168
1169         argv_array_push(&args, "--"); /* args[0] program name */
1170         argv_array_push(&args, oid_to_hex(incl_oid));
1171         argv_array_push(&args, "--not");
1172         argv_array_push(&args, oid_to_hex(excl_oid));
1173
1174         collect_changed_submodules(&subs, &args);
1175         ret = subs.nr;
1176
1177         argv_array_clear(&args);
1178
1179         free_submodules_oids(&subs);
1180         return ret;
1181 }
1182
1183 struct submodule_parallel_fetch {
1184         int count;
1185         struct argv_array args;
1186         struct repository *r;
1187         const char *prefix;
1188         int command_line_option;
1189         int default_option;
1190         int quiet;
1191         int result;
1192 };
1193 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0}
1194
1195 static int get_fetch_recurse_config(const struct submodule *submodule,
1196                                     struct submodule_parallel_fetch *spf)
1197 {
1198         if (spf->command_line_option != RECURSE_SUBMODULES_DEFAULT)
1199                 return spf->command_line_option;
1200
1201         if (submodule) {
1202                 char *key;
1203                 const char *value;
1204
1205                 int fetch_recurse = submodule->fetch_recurse;
1206                 key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1207                 if (!repo_config_get_string_const(spf->r, key, &value)) {
1208                         fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1209                 }
1210                 free(key);
1211
1212                 if (fetch_recurse != RECURSE_SUBMODULES_NONE)
1213                         /* local config overrules everything except commandline */
1214                         return fetch_recurse;
1215         }
1216
1217         return spf->default_option;
1218 }
1219
1220 static int get_next_submodule(struct child_process *cp,
1221                               struct strbuf *err, void *data, void **task_cb)
1222 {
1223         int ret = 0;
1224         struct submodule_parallel_fetch *spf = data;
1225
1226         for (; spf->count < spf->r->index->cache_nr; spf->count++) {
1227                 struct strbuf submodule_path = STRBUF_INIT;
1228                 struct strbuf submodule_git_dir = STRBUF_INIT;
1229                 struct strbuf submodule_prefix = STRBUF_INIT;
1230                 const struct cache_entry *ce = spf->r->index->cache[spf->count];
1231                 const char *git_dir, *default_argv;
1232                 const struct submodule *submodule;
1233                 struct submodule default_submodule = SUBMODULE_INIT;
1234
1235                 if (!S_ISGITLINK(ce->ce_mode))
1236                         continue;
1237
1238                 submodule = submodule_from_path(spf->r, &null_oid, ce->name);
1239                 if (!submodule) {
1240                         const char *name = default_name_or_path(ce->name);
1241                         if (name) {
1242                                 default_submodule.path = default_submodule.name = name;
1243                                 submodule = &default_submodule;
1244                         }
1245                 }
1246
1247                 switch (get_fetch_recurse_config(submodule, spf))
1248                 {
1249                 default:
1250                 case RECURSE_SUBMODULES_DEFAULT:
1251                 case RECURSE_SUBMODULES_ON_DEMAND:
1252                         if (!submodule || !unsorted_string_list_lookup(&changed_submodule_names,
1253                                                          submodule->name))
1254                                 continue;
1255                         default_argv = "on-demand";
1256                         break;
1257                 case RECURSE_SUBMODULES_ON:
1258                         default_argv = "yes";
1259                         break;
1260                 case RECURSE_SUBMODULES_OFF:
1261                         continue;
1262                 }
1263
1264                 strbuf_repo_worktree_path(&submodule_path, spf->r, "%s", ce->name);
1265                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1266                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1267                 git_dir = read_gitfile(submodule_git_dir.buf);
1268                 if (!git_dir)
1269                         git_dir = submodule_git_dir.buf;
1270                 if (is_directory(git_dir)) {
1271                         child_process_init(cp);
1272                         cp->dir = strbuf_detach(&submodule_path, NULL);
1273                         prepare_submodule_repo_env(&cp->env_array);
1274                         cp->git_cmd = 1;
1275                         if (!spf->quiet)
1276                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1277                                             spf->prefix, ce->name);
1278                         argv_array_init(&cp->args);
1279                         argv_array_pushv(&cp->args, spf->args.argv);
1280                         argv_array_push(&cp->args, default_argv);
1281                         argv_array_push(&cp->args, "--submodule-prefix");
1282                         argv_array_push(&cp->args, submodule_prefix.buf);
1283                         ret = 1;
1284                 }
1285                 strbuf_release(&submodule_path);
1286                 strbuf_release(&submodule_git_dir);
1287                 strbuf_release(&submodule_prefix);
1288                 if (ret) {
1289                         spf->count++;
1290                         return 1;
1291                 }
1292         }
1293         return 0;
1294 }
1295
1296 static int fetch_start_failure(struct strbuf *err,
1297                                void *cb, void *task_cb)
1298 {
1299         struct submodule_parallel_fetch *spf = cb;
1300
1301         spf->result = 1;
1302
1303         return 0;
1304 }
1305
1306 static int fetch_finish(int retvalue, struct strbuf *err,
1307                         void *cb, void *task_cb)
1308 {
1309         struct submodule_parallel_fetch *spf = cb;
1310
1311         if (retvalue)
1312                 spf->result = 1;
1313
1314         return 0;
1315 }
1316
1317 int fetch_populated_submodules(struct repository *r,
1318                                const struct argv_array *options,
1319                                const char *prefix, int command_line_option,
1320                                int default_option,
1321                                int quiet, int max_parallel_jobs)
1322 {
1323         int i;
1324         struct submodule_parallel_fetch spf = SPF_INIT;
1325
1326         spf.r = r;
1327         spf.command_line_option = command_line_option;
1328         spf.default_option = default_option;
1329         spf.quiet = quiet;
1330         spf.prefix = prefix;
1331
1332         if (!r->worktree)
1333                 goto out;
1334
1335         if (repo_read_index(r) < 0)
1336                 die("index file corrupt");
1337
1338         argv_array_push(&spf.args, "fetch");
1339         for (i = 0; i < options->argc; i++)
1340                 argv_array_push(&spf.args, options->argv[i]);
1341         argv_array_push(&spf.args, "--recurse-submodules-default");
1342         /* default value, "--submodule-prefix" and its value are added later */
1343
1344         calculate_changed_submodule_paths();
1345         run_processes_parallel(max_parallel_jobs,
1346                                get_next_submodule,
1347                                fetch_start_failure,
1348                                fetch_finish,
1349                                &spf);
1350
1351         argv_array_clear(&spf.args);
1352 out:
1353         string_list_clear(&changed_submodule_names, 1);
1354         return spf.result;
1355 }
1356
1357 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1358 {
1359         struct child_process cp = CHILD_PROCESS_INIT;
1360         struct strbuf buf = STRBUF_INIT;
1361         FILE *fp;
1362         unsigned dirty_submodule = 0;
1363         const char *git_dir;
1364         int ignore_cp_exit_code = 0;
1365
1366         strbuf_addf(&buf, "%s/.git", path);
1367         git_dir = read_gitfile(buf.buf);
1368         if (!git_dir)
1369                 git_dir = buf.buf;
1370         if (!is_git_directory(git_dir)) {
1371                 if (is_directory(git_dir))
1372                         die(_("'%s' not recognized as a git repository"), git_dir);
1373                 strbuf_release(&buf);
1374                 /* The submodule is not checked out, so it is not modified */
1375                 return 0;
1376         }
1377         strbuf_reset(&buf);
1378
1379         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1380         if (ignore_untracked)
1381                 argv_array_push(&cp.args, "-uno");
1382
1383         prepare_submodule_repo_env(&cp.env_array);
1384         cp.git_cmd = 1;
1385         cp.no_stdin = 1;
1386         cp.out = -1;
1387         cp.dir = path;
1388         if (start_command(&cp))
1389                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1390
1391         fp = xfdopen(cp.out, "r");
1392         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1393                 /* regular untracked files */
1394                 if (buf.buf[0] == '?')
1395                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1396
1397                 if (buf.buf[0] == 'u' ||
1398                     buf.buf[0] == '1' ||
1399                     buf.buf[0] == '2') {
1400                         /* T = line type, XY = status, SSSS = submodule state */
1401                         if (buf.len < strlen("T XY SSSS"))
1402                                 BUG("invalid status --porcelain=2 line %s",
1403                                     buf.buf);
1404
1405                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1406                                 /* nested untracked file */
1407                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1408
1409                         if (buf.buf[0] == 'u' ||
1410                             buf.buf[0] == '2' ||
1411                             memcmp(buf.buf + 5, "S..U", 4))
1412                                 /* other change */
1413                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1414                 }
1415
1416                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1417                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1418                      ignore_untracked)) {
1419                         /*
1420                          * We're not interested in any further information from
1421                          * the child any more, neither output nor its exit code.
1422                          */
1423                         ignore_cp_exit_code = 1;
1424                         break;
1425                 }
1426         }
1427         fclose(fp);
1428
1429         if (finish_command(&cp) && !ignore_cp_exit_code)
1430                 die("'git status --porcelain=2' failed in submodule %s", path);
1431
1432         strbuf_release(&buf);
1433         return dirty_submodule;
1434 }
1435
1436 int submodule_uses_gitfile(const char *path)
1437 {
1438         struct child_process cp = CHILD_PROCESS_INIT;
1439         const char *argv[] = {
1440                 "submodule",
1441                 "foreach",
1442                 "--quiet",
1443                 "--recursive",
1444                 "test -f .git",
1445                 NULL,
1446         };
1447         struct strbuf buf = STRBUF_INIT;
1448         const char *git_dir;
1449
1450         strbuf_addf(&buf, "%s/.git", path);
1451         git_dir = read_gitfile(buf.buf);
1452         if (!git_dir) {
1453                 strbuf_release(&buf);
1454                 return 0;
1455         }
1456         strbuf_release(&buf);
1457
1458         /* Now test that all nested submodules use a gitfile too */
1459         cp.argv = argv;
1460         prepare_submodule_repo_env(&cp.env_array);
1461         cp.git_cmd = 1;
1462         cp.no_stdin = 1;
1463         cp.no_stderr = 1;
1464         cp.no_stdout = 1;
1465         cp.dir = path;
1466         if (run_command(&cp))
1467                 return 0;
1468
1469         return 1;
1470 }
1471
1472 /*
1473  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1474  * when doing so.
1475  *
1476  * Return 1 if we'd lose data, return 0 if the removal is fine,
1477  * and negative values for errors.
1478  */
1479 int bad_to_remove_submodule(const char *path, unsigned flags)
1480 {
1481         ssize_t len;
1482         struct child_process cp = CHILD_PROCESS_INIT;
1483         struct strbuf buf = STRBUF_INIT;
1484         int ret = 0;
1485
1486         if (!file_exists(path) || is_empty_dir(path))
1487                 return 0;
1488
1489         if (!submodule_uses_gitfile(path))
1490                 return 1;
1491
1492         argv_array_pushl(&cp.args, "status", "--porcelain",
1493                                    "--ignore-submodules=none", NULL);
1494
1495         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1496                 argv_array_push(&cp.args, "-uno");
1497         else
1498                 argv_array_push(&cp.args, "-uall");
1499
1500         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1501                 argv_array_push(&cp.args, "--ignored");
1502
1503         prepare_submodule_repo_env(&cp.env_array);
1504         cp.git_cmd = 1;
1505         cp.no_stdin = 1;
1506         cp.out = -1;
1507         cp.dir = path;
1508         if (start_command(&cp)) {
1509                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1510                         die(_("could not start 'git status' in submodule '%s'"),
1511                                 path);
1512                 ret = -1;
1513                 goto out;
1514         }
1515
1516         len = strbuf_read(&buf, cp.out, 1024);
1517         if (len > 2)
1518                 ret = 1;
1519         close(cp.out);
1520
1521         if (finish_command(&cp)) {
1522                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1523                         die(_("could not run 'git status' in submodule '%s'"),
1524                                 path);
1525                 ret = -1;
1526         }
1527 out:
1528         strbuf_release(&buf);
1529         return ret;
1530 }
1531
1532 static const char *get_super_prefix_or_empty(void)
1533 {
1534         const char *s = get_super_prefix();
1535         if (!s)
1536                 s = "";
1537         return s;
1538 }
1539
1540 static int submodule_has_dirty_index(const struct submodule *sub)
1541 {
1542         struct child_process cp = CHILD_PROCESS_INIT;
1543
1544         prepare_submodule_repo_env(&cp.env_array);
1545
1546         cp.git_cmd = 1;
1547         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1548                                    "--cached", "HEAD", NULL);
1549         cp.no_stdin = 1;
1550         cp.no_stdout = 1;
1551         cp.dir = sub->path;
1552         if (start_command(&cp))
1553                 die("could not recurse into submodule '%s'", sub->path);
1554
1555         return finish_command(&cp);
1556 }
1557
1558 static void submodule_reset_index(const char *path)
1559 {
1560         struct child_process cp = CHILD_PROCESS_INIT;
1561         prepare_submodule_repo_env(&cp.env_array);
1562
1563         cp.git_cmd = 1;
1564         cp.no_stdin = 1;
1565         cp.dir = path;
1566
1567         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1568                                    get_super_prefix_or_empty(), path);
1569         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1570
1571         argv_array_push(&cp.args, empty_tree_oid_hex());
1572
1573         if (run_command(&cp))
1574                 die("could not reset submodule index");
1575 }
1576
1577 /**
1578  * Moves a submodule at a given path from a given head to another new head.
1579  * For edge cases (a submodule coming into existence or removing a submodule)
1580  * pass NULL for old or new respectively.
1581  */
1582 int submodule_move_head(const char *path,
1583                          const char *old_head,
1584                          const char *new_head,
1585                          unsigned flags)
1586 {
1587         int ret = 0;
1588         struct child_process cp = CHILD_PROCESS_INIT;
1589         const struct submodule *sub;
1590         int *error_code_ptr, error_code;
1591
1592         if (!is_submodule_active(the_repository, path))
1593                 return 0;
1594
1595         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1596                 /*
1597                  * Pass non NULL pointer to is_submodule_populated_gently
1598                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1599                  * to fixup the submodule in the force case later.
1600                  */
1601                 error_code_ptr = &error_code;
1602         else
1603                 error_code_ptr = NULL;
1604
1605         if (old_head && !is_submodule_populated_gently(path, error_code_ptr))
1606                 return 0;
1607
1608         sub = submodule_from_path(the_repository, &null_oid, path);
1609
1610         if (!sub)
1611                 BUG("could not get submodule information for '%s'", path);
1612
1613         if (old_head && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1614                 /* Check if the submodule has a dirty index. */
1615                 if (submodule_has_dirty_index(sub))
1616                         return error(_("submodule '%s' has dirty index"), path);
1617         }
1618
1619         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1620                 if (old_head) {
1621                         if (!submodule_uses_gitfile(path))
1622                                 absorb_git_dir_into_superproject("", path,
1623                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1624                 } else {
1625                         char *gitdir = xstrfmt("%s/modules/%s",
1626                                     get_git_common_dir(), sub->name);
1627                         connect_work_tree_and_git_dir(path, gitdir, 0);
1628                         free(gitdir);
1629
1630                         /* make sure the index is clean as well */
1631                         submodule_reset_index(path);
1632                 }
1633
1634                 if (old_head && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1635                         char *gitdir = xstrfmt("%s/modules/%s",
1636                                     get_git_common_dir(), sub->name);
1637                         connect_work_tree_and_git_dir(path, gitdir, 1);
1638                         free(gitdir);
1639                 }
1640         }
1641
1642         prepare_submodule_repo_env(&cp.env_array);
1643
1644         cp.git_cmd = 1;
1645         cp.no_stdin = 1;
1646         cp.dir = path;
1647
1648         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1649                         get_super_prefix_or_empty(), path);
1650         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1651
1652         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1653                 argv_array_push(&cp.args, "-n");
1654         else
1655                 argv_array_push(&cp.args, "-u");
1656
1657         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1658                 argv_array_push(&cp.args, "--reset");
1659         else
1660                 argv_array_push(&cp.args, "-m");
1661
1662         if (!(flags & SUBMODULE_MOVE_HEAD_FORCE))
1663                 argv_array_push(&cp.args, old_head ? old_head : empty_tree_oid_hex());
1664
1665         argv_array_push(&cp.args, new_head ? new_head : empty_tree_oid_hex());
1666
1667         if (run_command(&cp)) {
1668                 ret = -1;
1669                 goto out;
1670         }
1671
1672         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1673                 if (new_head) {
1674                         child_process_init(&cp);
1675                         /* also set the HEAD accordingly */
1676                         cp.git_cmd = 1;
1677                         cp.no_stdin = 1;
1678                         cp.dir = path;
1679
1680                         prepare_submodule_repo_env(&cp.env_array);
1681                         argv_array_pushl(&cp.args, "update-ref", "HEAD",
1682                                          "--no-deref", new_head, NULL);
1683
1684                         if (run_command(&cp)) {
1685                                 ret = -1;
1686                                 goto out;
1687                         }
1688                 } else {
1689                         struct strbuf sb = STRBUF_INIT;
1690
1691                         strbuf_addf(&sb, "%s/.git", path);
1692                         unlink_or_warn(sb.buf);
1693                         strbuf_release(&sb);
1694
1695                         if (is_empty_dir(path))
1696                                 rmdir_or_warn(path);
1697                 }
1698         }
1699 out:
1700         return ret;
1701 }
1702
1703 static int find_first_merges(struct object_array *result, const char *path,
1704                 struct commit *a, struct commit *b)
1705 {
1706         int i, j;
1707         struct object_array merges = OBJECT_ARRAY_INIT;
1708         struct commit *commit;
1709         int contains_another;
1710
1711         char merged_revision[42];
1712         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1713                                    "--all", merged_revision, NULL };
1714         struct rev_info revs;
1715         struct setup_revision_opt rev_opts;
1716
1717         memset(result, 0, sizeof(struct object_array));
1718         memset(&rev_opts, 0, sizeof(rev_opts));
1719
1720         /* get all revisions that merge commit a */
1721         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1722                         oid_to_hex(&a->object.oid));
1723         init_revisions(&revs, NULL);
1724         rev_opts.submodule = path;
1725         /* FIXME: can't handle linked worktrees in submodules yet */
1726         revs.single_worktree = path != NULL;
1727         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1728
1729         /* save all revisions from the above list that contain b */
1730         if (prepare_revision_walk(&revs))
1731                 die("revision walk setup failed");
1732         while ((commit = get_revision(&revs)) != NULL) {
1733                 struct object *o = &(commit->object);
1734                 if (in_merge_bases(b, commit))
1735                         add_object_array(o, NULL, &merges);
1736         }
1737         reset_revision_walk();
1738
1739         /* Now we've got all merges that contain a and b. Prune all
1740          * merges that contain another found merge and save them in
1741          * result.
1742          */
1743         for (i = 0; i < merges.nr; i++) {
1744                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1745
1746                 contains_another = 0;
1747                 for (j = 0; j < merges.nr; j++) {
1748                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1749                         if (i != j && in_merge_bases(m2, m1)) {
1750                                 contains_another = 1;
1751                                 break;
1752                         }
1753                 }
1754
1755                 if (!contains_another)
1756                         add_object_array(merges.objects[i].item, NULL, result);
1757         }
1758
1759         object_array_clear(&merges);
1760         return result->nr;
1761 }
1762
1763 static void print_commit(struct commit *commit)
1764 {
1765         struct strbuf sb = STRBUF_INIT;
1766         struct pretty_print_context ctx = {0};
1767         ctx.date_mode.type = DATE_NORMAL;
1768         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1769         fprintf(stderr, "%s\n", sb.buf);
1770         strbuf_release(&sb);
1771 }
1772
1773 #define MERGE_WARNING(path, msg) \
1774         warning("Failed to merge submodule %s (%s)", path, msg);
1775
1776 int merge_submodule(struct object_id *result, const char *path,
1777                     const struct object_id *base, const struct object_id *a,
1778                     const struct object_id *b, int search)
1779 {
1780         struct commit *commit_base, *commit_a, *commit_b;
1781         int parent_count;
1782         struct object_array merges;
1783
1784         int i;
1785
1786         /* store a in result in case we fail */
1787         oidcpy(result, a);
1788
1789         /* we can not handle deletion conflicts */
1790         if (is_null_oid(base))
1791                 return 0;
1792         if (is_null_oid(a))
1793                 return 0;
1794         if (is_null_oid(b))
1795                 return 0;
1796
1797         if (add_submodule_odb(path)) {
1798                 MERGE_WARNING(path, "not checked out");
1799                 return 0;
1800         }
1801
1802         if (!(commit_base = lookup_commit_reference(base)) ||
1803             !(commit_a = lookup_commit_reference(a)) ||
1804             !(commit_b = lookup_commit_reference(b))) {
1805                 MERGE_WARNING(path, "commits not present");
1806                 return 0;
1807         }
1808
1809         /* check whether both changes are forward */
1810         if (!in_merge_bases(commit_base, commit_a) ||
1811             !in_merge_bases(commit_base, commit_b)) {
1812                 MERGE_WARNING(path, "commits don't follow merge-base");
1813                 return 0;
1814         }
1815
1816         /* Case #1: a is contained in b or vice versa */
1817         if (in_merge_bases(commit_a, commit_b)) {
1818                 oidcpy(result, b);
1819                 return 1;
1820         }
1821         if (in_merge_bases(commit_b, commit_a)) {
1822                 oidcpy(result, a);
1823                 return 1;
1824         }
1825
1826         /*
1827          * Case #2: There are one or more merges that contain a and b in
1828          * the submodule. If there is only one, then present it as a
1829          * suggestion to the user, but leave it marked unmerged so the
1830          * user needs to confirm the resolution.
1831          */
1832
1833         /* Skip the search if makes no sense to the calling context.  */
1834         if (!search)
1835                 return 0;
1836
1837         /* find commit which merges them */
1838         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1839         switch (parent_count) {
1840         case 0:
1841                 MERGE_WARNING(path, "merge following commits not found");
1842                 break;
1843
1844         case 1:
1845                 MERGE_WARNING(path, "not fast-forward");
1846                 fprintf(stderr, "Found a possible merge resolution "
1847                                 "for the submodule:\n");
1848                 print_commit((struct commit *) merges.objects[0].item);
1849                 fprintf(stderr,
1850                         "If this is correct simply add it to the index "
1851                         "for example\n"
1852                         "by using:\n\n"
1853                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1854                         "which will accept this suggestion.\n",
1855                         oid_to_hex(&merges.objects[0].item->oid), path);
1856                 break;
1857
1858         default:
1859                 MERGE_WARNING(path, "multiple merges found");
1860                 for (i = 0; i < merges.nr; i++)
1861                         print_commit((struct commit *) merges.objects[i].item);
1862         }
1863
1864         object_array_clear(&merges);
1865         return 0;
1866 }
1867
1868 /*
1869  * Embeds a single submodules git directory into the superprojects git dir,
1870  * non recursively.
1871  */
1872 static void relocate_single_git_dir_into_superproject(const char *prefix,
1873                                                       const char *path)
1874 {
1875         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1876         const char *new_git_dir;
1877         const struct submodule *sub;
1878
1879         if (submodule_uses_worktrees(path))
1880                 die(_("relocate_gitdir for submodule '%s' with "
1881                       "more than one worktree not supported"), path);
1882
1883         old_git_dir = xstrfmt("%s/.git", path);
1884         if (read_gitfile(old_git_dir))
1885                 /* If it is an actual gitfile, it doesn't need migration. */
1886                 return;
1887
1888         real_old_git_dir = real_pathdup(old_git_dir, 1);
1889
1890         sub = submodule_from_path(the_repository, &null_oid, path);
1891         if (!sub)
1892                 die(_("could not lookup name for submodule '%s'"), path);
1893
1894         new_git_dir = git_path("modules/%s", sub->name);
1895         if (safe_create_leading_directories_const(new_git_dir) < 0)
1896                 die(_("could not create directory '%s'"), new_git_dir);
1897         real_new_git_dir = real_pathdup(new_git_dir, 1);
1898
1899         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1900                 get_super_prefix_or_empty(), path,
1901                 real_old_git_dir, real_new_git_dir);
1902
1903         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1904
1905         free(old_git_dir);
1906         free(real_old_git_dir);
1907         free(real_new_git_dir);
1908 }
1909
1910 /*
1911  * Migrate the git directory of the submodule given by path from
1912  * having its git directory within the working tree to the git dir nested
1913  * in its superprojects git dir under modules/.
1914  */
1915 void absorb_git_dir_into_superproject(const char *prefix,
1916                                       const char *path,
1917                                       unsigned flags)
1918 {
1919         int err_code;
1920         const char *sub_git_dir;
1921         struct strbuf gitdir = STRBUF_INIT;
1922         strbuf_addf(&gitdir, "%s/.git", path);
1923         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1924
1925         /* Not populated? */
1926         if (!sub_git_dir) {
1927                 const struct submodule *sub;
1928
1929                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1930                         /* unpopulated as expected */
1931                         strbuf_release(&gitdir);
1932                         return;
1933                 }
1934
1935                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1936                         /* We don't know what broke here. */
1937                         read_gitfile_error_die(err_code, path, NULL);
1938
1939                 /*
1940                 * Maybe populated, but no git directory was found?
1941                 * This can happen if the superproject is a submodule
1942                 * itself and was just absorbed. The absorption of the
1943                 * superproject did not rewrite the git file links yet,
1944                 * fix it now.
1945                 */
1946                 sub = submodule_from_path(the_repository, &null_oid, path);
1947                 if (!sub)
1948                         die(_("could not lookup name for submodule '%s'"), path);
1949                 connect_work_tree_and_git_dir(path,
1950                         git_path("modules/%s", sub->name), 0);
1951         } else {
1952                 /* Is it already absorbed into the superprojects git dir? */
1953                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1954                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1955
1956                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1957                         relocate_single_git_dir_into_superproject(prefix, path);
1958
1959                 free(real_sub_git_dir);
1960                 free(real_common_git_dir);
1961         }
1962         strbuf_release(&gitdir);
1963
1964         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1965                 struct child_process cp = CHILD_PROCESS_INIT;
1966                 struct strbuf sb = STRBUF_INIT;
1967
1968                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1969                         BUG("we don't know how to pass the flags down?");
1970
1971                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1972                 strbuf_addstr(&sb, path);
1973                 strbuf_addch(&sb, '/');
1974
1975                 cp.dir = path;
1976                 cp.git_cmd = 1;
1977                 cp.no_stdin = 1;
1978                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1979                                            "submodule--helper",
1980                                            "absorb-git-dirs", NULL);
1981                 prepare_submodule_repo_env(&cp.env_array);
1982                 if (run_command(&cp))
1983                         die(_("could not recurse into submodule '%s'"), path);
1984
1985                 strbuf_release(&sb);
1986         }
1987 }
1988
1989 const char *get_superproject_working_tree(void)
1990 {
1991         struct child_process cp = CHILD_PROCESS_INIT;
1992         struct strbuf sb = STRBUF_INIT;
1993         const char *one_up = real_path_if_valid("../");
1994         const char *cwd = xgetcwd();
1995         const char *ret = NULL;
1996         const char *subpath;
1997         int code;
1998         ssize_t len;
1999
2000         if (!is_inside_work_tree())
2001                 /*
2002                  * FIXME:
2003                  * We might have a superproject, but it is harder
2004                  * to determine.
2005                  */
2006                 return NULL;
2007
2008         if (!one_up)
2009                 return NULL;
2010
2011         subpath = relative_path(cwd, one_up, &sb);
2012
2013         prepare_submodule_repo_env(&cp.env_array);
2014         argv_array_pop(&cp.env_array);
2015
2016         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
2017                         "ls-files", "-z", "--stage", "--full-name", "--",
2018                         subpath, NULL);
2019         strbuf_reset(&sb);
2020
2021         cp.no_stdin = 1;
2022         cp.no_stderr = 1;
2023         cp.out = -1;
2024         cp.git_cmd = 1;
2025
2026         if (start_command(&cp))
2027                 die(_("could not start ls-files in .."));
2028
2029         len = strbuf_read(&sb, cp.out, PATH_MAX);
2030         close(cp.out);
2031
2032         if (starts_with(sb.buf, "160000")) {
2033                 int super_sub_len;
2034                 int cwd_len = strlen(cwd);
2035                 char *super_sub, *super_wt;
2036
2037                 /*
2038                  * There is a superproject having this repo as a submodule.
2039                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
2040                  * We're only interested in the name after the tab.
2041                  */
2042                 super_sub = strchr(sb.buf, '\t') + 1;
2043                 super_sub_len = sb.buf + sb.len - super_sub - 1;
2044
2045                 if (super_sub_len > cwd_len ||
2046                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
2047                         BUG("returned path string doesn't match cwd?");
2048
2049                 super_wt = xstrdup(cwd);
2050                 super_wt[cwd_len - super_sub_len] = '\0';
2051
2052                 ret = real_path(super_wt);
2053                 free(super_wt);
2054         }
2055         strbuf_release(&sb);
2056
2057         code = finish_command(&cp);
2058
2059         if (code == 128)
2060                 /* '../' is not a git repository */
2061                 return NULL;
2062         if (code == 0 && len == 0)
2063                 /* There is an unrelated git repository at '../' */
2064                 return NULL;
2065         if (code)
2066                 die(_("ls-tree returned unexpected return code %d"), code);
2067
2068         return ret;
2069 }
2070
2071 /*
2072  * Put the gitdir for a submodule (given relative to the main
2073  * repository worktree) into `buf`, or return -1 on error.
2074  */
2075 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2076 {
2077         const struct submodule *sub;
2078         const char *git_dir;
2079         int ret = 0;
2080
2081         strbuf_reset(buf);
2082         strbuf_addstr(buf, submodule);
2083         strbuf_complete(buf, '/');
2084         strbuf_addstr(buf, ".git");
2085
2086         git_dir = read_gitfile(buf->buf);
2087         if (git_dir) {
2088                 strbuf_reset(buf);
2089                 strbuf_addstr(buf, git_dir);
2090         }
2091         if (!is_git_directory(buf->buf)) {
2092                 sub = submodule_from_path(the_repository, &null_oid, submodule);
2093                 if (!sub) {
2094                         ret = -1;
2095                         goto cleanup;
2096                 }
2097                 strbuf_reset(buf);
2098                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2099         }
2100
2101 cleanup:
2102         return ret;
2103 }