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
  25 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
  26 static struct string_list changed_submodule_names = STRING_LIST_INIT_DUP;
  27 static int initialized_fetch_ref_tips;
  28 static struct oid_array ref_tips_before_fetch;
  29 static struct oid_array ref_tips_after_fetch;
  30
  31 /*
  32  * Check if the .gitmodules file is unmerged. Parsing of the .gitmodules file
  33  * will be disabled because we can't guess what might be configured in
  34  * .gitmodules unless the user resolves the conflict.
  35  */
  36 int is_gitmodules_unmerged(const struct index_state *istate)
  37 {
  38         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  39         if (pos < 0) { /* .gitmodules not found or isn't merged */
  40                 pos = -1 - pos;
  41                 if (istate->cache_nr > pos) {  /* there is a .gitmodules */
  42                         const struct cache_entry *ce = istate->cache[pos];
  43                         if (ce_namelen(ce) == strlen(GITMODULES_FILE) &&
  44                             !strcmp(ce->name, GITMODULES_FILE))
  45                                 return 1;
  46                 }
  47         }
  48
  49         return 0;
  50 }
  51
  52 /*
  53  * Check if the .gitmodules file has unstaged modifications.  This must be
  54  * checked before allowing modifications to the .gitmodules file with the
  55  * intention to stage them later, because when continuing we would stage the
  56  * modifications the user didn't stage herself too. That might change in a
  57  * future version when we learn to stage the changes we do ourselves without
  58  * staging any previous modifications.
  59  */
  60 int is_staging_gitmodules_ok(struct index_state *istate)
  61 {
  62         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  63
  64         if ((pos >= 0) && (pos < istate->cache_nr)) {
  65                 struct stat st;
  66                 if (lstat(GITMODULES_FILE, &st) == 0 &&
  67                     ie_match_stat(istate, istate->cache[pos], &st,
  68                                   CE_MATCH_IGNORE_FSMONITOR) & DATA_CHANGED)
  69                         return 0;
  70         }
  71
  72         return 1;
  73 }
  74
  75 static int for_each_remote_ref_submodule(const char *submodule,
  76                                          each_ref_fn fn, void *cb_data)
  77 {
  78         return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
  79                                         fn, cb_data);
  80 }
  81
  82 /*
  83  * Try to update the "path" entry in the "submodule.<name>" section of the
  84  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
  85  * with the correct path=<oldpath> setting was found and we could update it.
  86  */
  87 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
  88 {
  89         struct strbuf entry = STRBUF_INIT;
  90         const struct submodule *submodule;
  91
  92         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
  93                 return -1;
  94
  95         if (is_gitmodules_unmerged(&the_index))
  96                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  97
  98         submodule = submodule_from_path(&null_oid, oldpath);
  99         if (!submodule || !submodule->name) {
 100                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
 101                 return -1;
 102         }
 103         strbuf_addstr(&entry, "submodule.");
 104         strbuf_addstr(&entry, submodule->name);
 105         strbuf_addstr(&entry, ".path");
 106         if (git_config_set_in_file_gently(GITMODULES_FILE, entry.buf, newpath) < 0) {
 107                 /* Maybe the user already did that, don't error out here */
 108                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
 109                 strbuf_release(&entry);
 110                 return -1;
 111         }
 112         strbuf_release(&entry);
 113         return 0;
 114 }
 115
 116 /*
 117  * Try to remove the "submodule.<name>" section from .gitmodules where the given
 118  * path is configured. Return 0 only if a .gitmodules file was found, a section
 119  * with the correct path=<path> setting was found and we could remove it.
 120  */
 121 int remove_path_from_gitmodules(const char *path)
 122 {
 123         struct strbuf sect = STRBUF_INIT;
 124         const struct submodule *submodule;
 125
 126         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
 127                 return -1;
 128
 129         if (is_gitmodules_unmerged(&the_index))
 130                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 131
 132         submodule = submodule_from_path(&null_oid, path);
 133         if (!submodule || !submodule->name) {
 134                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 135                 return -1;
 136         }
 137         strbuf_addstr(&sect, "submodule.");
 138         strbuf_addstr(&sect, submodule->name);
 139         if (git_config_rename_section_in_file(GITMODULES_FILE, sect.buf, NULL) < 0) {
 140                 /* Maybe the user already did that, don't error out here */
 141                 warning(_("Could not remove .gitmodules entry for %s"), path);
 142                 strbuf_release(&sect);
 143                 return -1;
 144         }
 145         strbuf_release(&sect);
 146         return 0;
 147 }
 148
 149 void stage_updated_gitmodules(struct index_state *istate)
 150 {
 151         if (add_file_to_index(istate, GITMODULES_FILE, 0))
 152                 die(_("staging updated .gitmodules failed"));
 153 }
 154
 155 static int add_submodule_odb(const char *path)
 156 {
 157         struct strbuf objects_directory = STRBUF_INIT;
 158         int ret = 0;
 159
 160         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
 161         if (ret)
 162                 goto done;
 163         if (!is_directory(objects_directory.buf)) {
 164                 ret = -1;
 165                 goto done;
 166         }
 167         add_to_alternates_memory(objects_directory.buf);
 168 done:
 169         strbuf_release(&objects_directory);
 170         return ret;
 171 }
 172
 173 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 174                                              const char *path)
 175 {
 176         const struct submodule *submodule = submodule_from_path(&null_oid, path);
 177         if (submodule) {
 178                 const char *ignore;
 179                 char *key;
 180
 181                 key = xstrfmt("submodule.%s.ignore", submodule->name);
 182                 if (repo_config_get_string_const(the_repository, key, &ignore))
 183                         ignore = submodule->ignore;
 184                 free(key);
 185
 186                 if (ignore)
 187                         handle_ignore_submodules_arg(diffopt, ignore);
 188                 else if (is_gitmodules_unmerged(&the_index))
 189                         diffopt->flags.ignore_submodules = 1;
 190         }
 191 }
 192
 193 /* Cheap function that only determines if we're interested in submodules at all */
 194 int git_default_submodule_config(const char *var, const char *value, void *cb)
 195 {
 196         if (!strcmp(var, "submodule.recurse")) {
 197                 int v = git_config_bool(var, value) ?
 198                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 199                 config_update_recurse_submodules = v;
 200         }
 201         return 0;
 202 }
 203
 204 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 205                                                      const char *arg, int unset)
 206 {
 207         if (unset) {
 208                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 209                 return 0;
 210         }
 211         if (arg)
 212                 config_update_recurse_submodules =
 213                         parse_update_recurse_submodules_arg(opt->long_name,
 214                                                             arg);
 215         else
 216                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 217
 218         return 0;
 219 }
 220
 221 /*
 222  * Determine if a submodule has been initialized at a given 'path'
 223  */
 224 int is_submodule_active(struct repository *repo, const char *path)
 225 {
 226         int ret = 0;
 227         char *key = NULL;
 228         char *value = NULL;
 229         const struct string_list *sl;
 230         const struct submodule *module;
 231
 232         module = submodule_from_cache(repo, &null_oid, path);
 233
 234         /* early return if there isn't a path->module mapping */
 235         if (!module)
 236                 return 0;
 237
 238         /* submodule.<name>.active is set */
 239         key = xstrfmt("submodule.%s.active", module->name);
 240         if (!repo_config_get_bool(repo, key, &ret)) {
 241                 free(key);
 242                 return ret;
 243         }
 244         free(key);
 245
 246         /* submodule.active is set */
 247         sl = repo_config_get_value_multi(repo, "submodule.active");
 248         if (sl) {
 249                 struct pathspec ps;
 250                 struct argv_array args = ARGV_ARRAY_INIT;
 251                 const struct string_list_item *item;
 252
 253                 for_each_string_list_item(item, sl) {
 254                         argv_array_push(&args, item->string);
 255                 }
 256
 257                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 258                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
 259
 260                 argv_array_clear(&args);
 261                 clear_pathspec(&ps);
 262                 return ret;
 263         }
 264
 265         /* fallback to checking if the URL is set */
 266         key = xstrfmt("submodule.%s.url", module->name);
 267         ret = !repo_config_get_string(repo, key, &value);
 268
 269         free(value);
 270         free(key);
 271         return ret;
 272 }
 273
 274 int is_submodule_populated_gently(const char *path, int *return_error_code)
 275 {
 276         int ret = 0;
 277         char *gitdir = xstrfmt("%s/.git", path);
 278
 279         if (resolve_gitdir_gently(gitdir, return_error_code))
 280                 ret = 1;
 281
 282         free(gitdir);
 283         return ret;
 284 }
 285
 286 /*
 287  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 288  */
 289 void die_in_unpopulated_submodule(const struct index_state *istate,
 290                                   const char *prefix)
 291 {
 292         int i, prefixlen;
 293
 294         if (!prefix)
 295                 return;
 296
 297         prefixlen = strlen(prefix);
 298
 299         for (i = 0; i < istate->cache_nr; i++) {
 300                 struct cache_entry *ce = istate->cache[i];
 301                 int ce_len = ce_namelen(ce);
 302
 303                 if (!S_ISGITLINK(ce->ce_mode))
 304                         continue;
 305                 if (prefixlen <= ce_len)
 306                         continue;
 307                 if (strncmp(ce->name, prefix, ce_len))
 308                         continue;
 309                 if (prefix[ce_len] != '/')
 310                         continue;
 311
 312                 die(_("in unpopulated submodule '%s'"), ce->name);
 313         }
 314 }
 315
 316 /*
 317  * Dies if any paths in the provided pathspec descends into a submodule
 318  */
 319 void die_path_inside_submodule(const struct index_state *istate,
 320                                const struct pathspec *ps)
 321 {
 322         int i, j;
 323
 324         for (i = 0; i < istate->cache_nr; i++) {
 325                 struct cache_entry *ce = istate->cache[i];
 326                 int ce_len = ce_namelen(ce);
 327
 328                 if (!S_ISGITLINK(ce->ce_mode))
 329                         continue;
 330
 331                 for (j = 0; j < ps->nr ; j++) {
 332                         const struct pathspec_item *item = &ps->items[j];
 333
 334                         if (item->len <= ce_len)
 335                                 continue;
 336                         if (item->match[ce_len] != '/')
 337                                 continue;
 338                         if (strncmp(ce->name, item->match, ce_len))
 339                                 continue;
 340                         if (item->len == ce_len + 1)
 341                                 continue;
 342
 343                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 344                             item->original, ce_len, ce->name);
 345                 }
 346         }
 347 }
 348
 349 enum submodule_update_type parse_submodule_update_type(const char *value)
 350 {
 351         if (!strcmp(value, "none"))
 352                 return SM_UPDATE_NONE;
 353         else if (!strcmp(value, "checkout"))
 354                 return SM_UPDATE_CHECKOUT;
 355         else if (!strcmp(value, "rebase"))
 356                 return SM_UPDATE_REBASE;
 357         else if (!strcmp(value, "merge"))
 358                 return SM_UPDATE_MERGE;
 359         else if (*value == '!')
 360                 return SM_UPDATE_COMMAND;
 361         else
 362                 return SM_UPDATE_UNSPECIFIED;
 363 }
 364
 365 int parse_submodule_update_strategy(const char *value,
 366                 struct submodule_update_strategy *dst)
 367 {
 368         enum submodule_update_type type;
 369
 370         free((void*)dst->command);
 371         dst->command = NULL;
 372
 373         type = parse_submodule_update_type(value);
 374         if (type == SM_UPDATE_UNSPECIFIED)
 375                 return -1;
 376
 377         dst->type = type;
 378         if (type == SM_UPDATE_COMMAND)
 379                 dst->command = xstrdup(value + 1);
 380
 381         return 0;
 382 }
 383
 384 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 385 {
 386         struct strbuf sb = STRBUF_INIT;
 387         switch (s->type) {
 388         case SM_UPDATE_CHECKOUT:
 389                 return "checkout";
 390         case SM_UPDATE_MERGE:
 391                 return "merge";
 392         case SM_UPDATE_REBASE:
 393                 return "rebase";
 394         case SM_UPDATE_NONE:
 395                 return "none";
 396         case SM_UPDATE_UNSPECIFIED:
 397                 return NULL;
 398         case SM_UPDATE_COMMAND:
 399                 strbuf_addf(&sb, "!%s", s->command);
 400                 return strbuf_detach(&sb, NULL);
 401         }
 402         return NULL;
 403 }
 404
 405 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 406                                   const char *arg)
 407 {
 408         diffopt->flags.ignore_submodules = 0;
 409         diffopt->flags.ignore_untracked_in_submodules = 0;
 410         diffopt->flags.ignore_dirty_submodules = 0;
 411
 412         if (!strcmp(arg, "all"))
 413                 diffopt->flags.ignore_submodules = 1;
 414         else if (!strcmp(arg, "untracked"))
 415                 diffopt->flags.ignore_untracked_in_submodules = 1;
 416         else if (!strcmp(arg, "dirty"))
 417                 diffopt->flags.ignore_dirty_submodules = 1;
 418         else if (strcmp(arg, "none"))
 419                 die("bad --ignore-submodules argument: %s", arg);
 420 }
 421
 422 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 423                 struct commit *left, struct commit *right,
 424                 struct commit_list *merge_bases)
 425 {
 426         struct commit_list *list;
 427
 428         init_revisions(rev, NULL);
 429         setup_revisions(0, NULL, rev, NULL);
 430         rev->left_right = 1;
 431         rev->first_parent_only = 1;
 432         left->object.flags |= SYMMETRIC_LEFT;
 433         add_pending_object(rev, &left->object, path);
 434         add_pending_object(rev, &right->object, path);
 435         for (list = merge_bases; list; list = list->next) {
 436                 list->item->object.flags |= UNINTERESTING;
 437                 add_pending_object(rev, &list->item->object,
 438                         oid_to_hex(&list->item->object.oid));
 439         }
 440         return prepare_revision_walk(rev);
 441 }
 442
 443 static void print_submodule_summary(struct rev_info *rev, struct diff_options *o)
 444 {
 445         static const char format[] = "  %m %s";
 446         struct strbuf sb = STRBUF_INIT;
 447         struct commit *commit;
 448
 449         while ((commit = get_revision(rev))) {
 450                 struct pretty_print_context ctx = {0};
 451                 ctx.date_mode = rev->date_mode;
 452                 ctx.output_encoding = get_log_output_encoding();
 453                 strbuf_setlen(&sb, 0);
 454                 format_commit_message(commit, format, &sb, &ctx);
 455                 strbuf_addch(&sb, '\n');
 456                 if (commit->object.flags & SYMMETRIC_LEFT)
 457                         diff_emit_submodule_del(o, sb.buf);
 458                 else
 459                         diff_emit_submodule_add(o, sb.buf);
 460         }
 461         strbuf_release(&sb);
 462 }
 463
 464 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 465 {
 466         const char * const *var;
 467
 468         for (var = local_repo_env; *var; var++) {
 469                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 470                         argv_array_push(out, *var);
 471         }
 472 }
 473
 474 void prepare_submodule_repo_env(struct argv_array *out)
 475 {
 476         prepare_submodule_repo_env_no_git_dir(out);
 477         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 478                          DEFAULT_GIT_DIR_ENVIRONMENT);
 479 }
 480
 481 /* Helper function to display the submodule header line prior to the full
 482  * summary output. If it can locate the submodule objects directory it will
 483  * attempt to lookup both the left and right commits and put them into the
 484  * left and right pointers.
 485  */
 486 static void show_submodule_header(struct diff_options *o, const char *path,
 487                 struct object_id *one, struct object_id *two,
 488                 unsigned dirty_submodule,
 489                 struct commit **left, struct commit **right,
 490                 struct commit_list **merge_bases)
 491 {
 492         const char *message = NULL;
 493         struct strbuf sb = STRBUF_INIT;
 494         int fast_forward = 0, fast_backward = 0;
 495
 496         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 497                 diff_emit_submodule_untracked(o, path);
 498
 499         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 500                 diff_emit_submodule_modified(o, path);
 501
 502         if (is_null_oid(one))
 503                 message = "(new submodule)";
 504         else if (is_null_oid(two))
 505                 message = "(submodule deleted)";
 506
 507         if (add_submodule_odb(path)) {
 508                 if (!message)
 509                         message = "(commits not present)";
 510                 goto output_header;
 511         }
 512
 513         /*
 514          * Attempt to lookup the commit references, and determine if this is
 515          * a fast forward or fast backwards update.
 516          */
 517         *left = lookup_commit_reference(one);
 518         *right = lookup_commit_reference(two);
 519
 520         /*
 521          * Warn about missing commits in the submodule project, but only if
 522          * they aren't null.
 523          */
 524         if ((!is_null_oid(one) && !*left) ||
 525              (!is_null_oid(two) && !*right))
 526                 message = "(commits not present)";
 527
 528         *merge_bases = get_merge_bases(*left, *right);
 529         if (*merge_bases) {
 530                 if ((*merge_bases)->item == *left)
 531                         fast_forward = 1;
 532                 else if ((*merge_bases)->item == *right)
 533                         fast_backward = 1;
 534         }
 535
 536         if (!oidcmp(one, two)) {
 537                 strbuf_release(&sb);
 538                 return;
 539         }
 540
 541 output_header:
 542         strbuf_addf(&sb, "Submodule %s ", path);
 543         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
 544         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 545         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
 546         if (message)
 547                 strbuf_addf(&sb, " %s\n", message);
 548         else
 549                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 550         diff_emit_submodule_header(o, sb.buf);
 551
 552         strbuf_release(&sb);
 553 }
 554
 555 void show_submodule_summary(struct diff_options *o, const char *path,
 556                 struct object_id *one, struct object_id *two,
 557                 unsigned dirty_submodule)
 558 {
 559         struct rev_info rev;
 560         struct commit *left = NULL, *right = NULL;
 561         struct commit_list *merge_bases = NULL;
 562
 563         show_submodule_header(o, path, one, two, dirty_submodule,
 564                               &left, &right, &merge_bases);
 565
 566         /*
 567          * If we don't have both a left and a right pointer, there is no
 568          * reason to try and display a summary. The header line should contain
 569          * all the information the user needs.
 570          */
 571         if (!left || !right)
 572                 goto out;
 573
 574         /* Treat revision walker failure the same as missing commits */
 575         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 576                 diff_emit_submodule_error(o, "(revision walker failed)\n");
 577                 goto out;
 578         }
 579
 580         print_submodule_summary(&rev, o);
 581
 582 out:
 583         if (merge_bases)
 584                 free_commit_list(merge_bases);
 585         clear_commit_marks(left, ~0);
 586         clear_commit_marks(right, ~0);
 587 }
 588
 589 void show_submodule_inline_diff(struct diff_options *o, const char *path,
 590                 struct object_id *one, struct object_id *two,
 591                 unsigned dirty_submodule)
 592 {
 593         const struct object_id *old_oid = the_hash_algo->empty_tree, *new_oid = the_hash_algo->empty_tree;
 594         struct commit *left = NULL, *right = NULL;
 595         struct commit_list *merge_bases = NULL;
 596         struct child_process cp = CHILD_PROCESS_INIT;
 597         struct strbuf sb = STRBUF_INIT;
 598
 599         show_submodule_header(o, path, one, two, dirty_submodule,
 600                               &left, &right, &merge_bases);
 601
 602         /* We need a valid left and right commit to display a difference */
 603         if (!(left || is_null_oid(one)) ||
 604             !(right || is_null_oid(two)))
 605                 goto done;
 606
 607         if (left)
 608                 old_oid = one;
 609         if (right)
 610                 new_oid = two;
 611
 612         cp.git_cmd = 1;
 613         cp.dir = path;
 614         cp.out = -1;
 615         cp.no_stdin = 1;
 616
 617         /* TODO: other options may need to be passed here. */
 618         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 619         argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 620                          "always" : "never");
 621
 622         if (o->flags.reverse_diff) {
 623                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 624                                  o->b_prefix, path);
 625                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 626                                  o->a_prefix, path);
 627         } else {
 628                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 629                                  o->a_prefix, path);
 630                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 631                                  o->b_prefix, path);
 632         }
 633         argv_array_push(&cp.args, oid_to_hex(old_oid));
 634         /*
 635          * If the submodule has modified content, we will diff against the
 636          * work tree, under the assumption that the user has asked for the
 637          * diff format and wishes to actually see all differences even if they
 638          * haven't yet been committed to the submodule yet.
 639          */
 640         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 641                 argv_array_push(&cp.args, oid_to_hex(new_oid));
 642
 643         prepare_submodule_repo_env(&cp.env_array);
 644         if (start_command(&cp))
 645                 diff_emit_submodule_error(o, "(diff failed)\n");
 646
 647         while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
 648                 diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
 649
 650         if (finish_command(&cp))
 651                 diff_emit_submodule_error(o, "(diff failed)\n");
 652
 653 done:
 654         strbuf_release(&sb);
 655         if (merge_bases)
 656                 free_commit_list(merge_bases);
 657         if (left)
 658                 clear_commit_marks(left, ~0);
 659         if (right)
 660                 clear_commit_marks(right, ~0);
 661 }
 662
 663 int should_update_submodules(void)
 664 {
 665         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 666 }
 667
 668 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 669 {
 670         if (!S_ISGITLINK(ce->ce_mode))
 671                 return NULL;
 672
 673         if (!should_update_submodules())
 674                 return NULL;
 675
 676         return submodule_from_path(&null_oid, ce->name);
 677 }
 678
 679 static struct oid_array *submodule_commits(struct string_list *submodules,
 680                                            const char *name)
 681 {
 682         struct string_list_item *item;
 683
 684         item = string_list_insert(submodules, name);
 685         if (item->util)
 686                 return (struct oid_array *) item->util;
 687
 688         /* NEEDSWORK: should we have oid_array_init()? */
 689         item->util = xcalloc(1, sizeof(struct oid_array));
 690         return (struct oid_array *) item->util;
 691 }
 692
 693 struct collect_changed_submodules_cb_data {
 694         struct string_list *changed;
 695         const struct object_id *commit_oid;
 696 };
 697
 698 /*
 699  * this would normally be two functions: default_name_from_path() and
 700  * path_from_default_name(). Since the default name is the same as
 701  * the submodule path we can get away with just one function which only
 702  * checks whether there is a submodule in the working directory at that
 703  * location.
 704  */
 705 static const char *default_name_or_path(const char *path_or_name)
 706 {
 707         int error_code;
 708
 709         if (!is_submodule_populated_gently(path_or_name, &error_code))
 710                 return NULL;
 711
 712         return path_or_name;
 713 }
 714
 715 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 716                                           struct diff_options *options,
 717                                           void *data)
 718 {
 719         struct collect_changed_submodules_cb_data *me = data;
 720         struct string_list *changed = me->changed;
 721         const struct object_id *commit_oid = me->commit_oid;
 722         int i;
 723
 724         for (i = 0; i < q->nr; i++) {
 725                 struct diff_filepair *p = q->queue[i];
 726                 struct oid_array *commits;
 727                 const struct submodule *submodule;
 728                 const char *name;
 729
 730                 if (!S_ISGITLINK(p->two->mode))
 731                         continue;
 732
 733                 submodule = submodule_from_path(commit_oid, p->two->path);
 734                 if (submodule)
 735                         name = submodule->name;
 736                 else {
 737                         name = default_name_or_path(p->two->path);
 738                         /* make sure name does not collide with existing one */
 739                         submodule = submodule_from_name(commit_oid, name);
 740                         if (submodule) {
 741                                 warning("Submodule in commit %s at path: "
 742                                         "'%s' collides with a submodule named "
 743                                         "the same. Skipping it.",
 744                                         oid_to_hex(commit_oid), name);
 745                                 name = NULL;
 746                         }
 747                 }
 748
 749                 if (!name)
 750                         continue;
 751
 752                 commits = submodule_commits(changed, name);
 753                 oid_array_append(commits, &p->two->oid);
 754         }
 755 }
 756
 757 /*
 758  * Collect the paths of submodules in 'changed' which have changed based on
 759  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 760  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 761  * what the submodule pointers were updated to during the change.
 762  */
 763 static void collect_changed_submodules(struct string_list *changed,
 764                                        struct argv_array *argv)
 765 {
 766         struct rev_info rev;
 767         const struct commit *commit;
 768
 769         init_revisions(&rev, NULL);
 770         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 771         if (prepare_revision_walk(&rev))
 772                 die("revision walk setup failed");
 773
 774         while ((commit = get_revision(&rev))) {
 775                 struct rev_info diff_rev;
 776                 struct collect_changed_submodules_cb_data data;
 777                 data.changed = changed;
 778                 data.commit_oid = &commit->object.oid;
 779
 780                 init_revisions(&diff_rev, NULL);
 781                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 782                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 783                 diff_rev.diffopt.format_callback_data = &data;
 784                 diff_tree_combined_merge(commit, 1, &diff_rev);
 785         }
 786
 787         reset_revision_walk();
 788 }
 789
 790 static void free_submodules_oids(struct string_list *submodules)
 791 {
 792         struct string_list_item *item;
 793         for_each_string_list_item(item, submodules)
 794                 oid_array_clear((struct oid_array *) item->util);
 795         string_list_clear(submodules, 1);
 796 }
 797
 798 static int has_remote(const char *refname, const struct object_id *oid,
 799                       int flags, void *cb_data)
 800 {
 801         return 1;
 802 }
 803
 804 static int append_oid_to_argv(const struct object_id *oid, void *data)
 805 {
 806         struct argv_array *argv = data;
 807         argv_array_push(argv, oid_to_hex(oid));
 808         return 0;
 809 }
 810
 811 struct has_commit_data {
 812         int result;
 813         const char *path;
 814 };
 815
 816 static int check_has_commit(const struct object_id *oid, void *data)
 817 {
 818         struct has_commit_data *cb = data;
 819
 820         enum object_type type = sha1_object_info(oid->hash, NULL);
 821
 822         switch (type) {
 823         case OBJ_COMMIT:
 824                 return 0;
 825         case OBJ_BAD:
 826                 /*
 827                  * Object is missing or invalid. If invalid, an error message
 828                  * has already been printed.
 829                  */
 830                 cb->result = 0;
 831                 return 0;
 832         default:
 833                 die(_("submodule entry '%s' (%s) is a %s, not a commit"),
 834                     cb->path, oid_to_hex(oid), type_name(type));
 835         }
 836 }
 837
 838 static int submodule_has_commits(const char *path, struct oid_array *commits)
 839 {
 840         struct has_commit_data has_commit = { 1, path };
 841
 842         /*
 843          * Perform a cheap, but incorrect check for the existence of 'commits'.
 844          * This is done by adding the submodule's object store to the in-core
 845          * object store, and then querying for each commit's existence.  If we
 846          * do not have the commit object anywhere, there is no chance we have
 847          * it in the object store of the correct submodule and have it
 848          * reachable from a ref, so we can fail early without spawning rev-list
 849          * which is expensive.
 850          */
 851         if (add_submodule_odb(path))
 852                 return 0;
 853
 854         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 855
 856         if (has_commit.result) {
 857                 /*
 858                  * Even if the submodule is checked out and the commit is
 859                  * present, make sure it exists in the submodule's object store
 860                  * and that it is reachable from a ref.
 861                  */
 862                 struct child_process cp = CHILD_PROCESS_INIT;
 863                 struct strbuf out = STRBUF_INIT;
 864
 865                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 866                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 867                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 868
 869                 prepare_submodule_repo_env(&cp.env_array);
 870                 cp.git_cmd = 1;
 871                 cp.no_stdin = 1;
 872                 cp.dir = path;
 873
 874                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 875                         has_commit.result = 0;
 876
 877                 strbuf_release(&out);
 878         }
 879
 880         return has_commit.result;
 881 }
 882
 883 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
 884 {
 885         if (!submodule_has_commits(path, commits))
 886                 /*
 887                  * NOTE: We do consider it safe to return "no" here. The
 888                  * correct answer would be "We do not know" instead of
 889                  * "No push needed", but it is quite hard to change
 890                  * the submodule pointer without having the submodule
 891                  * around. If a user did however change the submodules
 892                  * without having the submodule around, this indicates
 893                  * an expert who knows what they are doing or a
 894                  * maintainer integrating work from other people. In
 895                  * both cases it should be safe to skip this check.
 896                  */
 897                 return 0;
 898
 899         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 900                 struct child_process cp = CHILD_PROCESS_INIT;
 901                 struct strbuf buf = STRBUF_INIT;
 902                 int needs_pushing = 0;
 903
 904                 argv_array_push(&cp.args, "rev-list");
 905                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 906                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 907
 908                 prepare_submodule_repo_env(&cp.env_array);
 909                 cp.git_cmd = 1;
 910                 cp.no_stdin = 1;
 911                 cp.out = -1;
 912                 cp.dir = path;
 913                 if (start_command(&cp))
 914                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 915                                         path);
 916                 if (strbuf_read(&buf, cp.out, 41))
 917                         needs_pushing = 1;
 918                 finish_command(&cp);
 919                 close(cp.out);
 920                 strbuf_release(&buf);
 921                 return needs_pushing;
 922         }
 923
 924         return 0;
 925 }
 926
 927 int find_unpushed_submodules(struct oid_array *commits,
 928                 const char *remotes_name, struct string_list *needs_pushing)
 929 {
 930         struct string_list submodules = STRING_LIST_INIT_DUP;
 931         struct string_list_item *name;
 932         struct argv_array argv = ARGV_ARRAY_INIT;
 933
 934         /* argv.argv[0] will be ignored by setup_revisions */
 935         argv_array_push(&argv, "find_unpushed_submodules");
 936         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
 937         argv_array_push(&argv, "--not");
 938         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
 939
 940         collect_changed_submodules(&submodules, &argv);
 941
 942         for_each_string_list_item(name, &submodules) {
 943                 struct oid_array *commits = name->util;
 944                 const struct submodule *submodule;
 945                 const char *path = NULL;
 946
 947                 submodule = submodule_from_name(&null_oid, name->string);
 948                 if (submodule)
 949                         path = submodule->path;
 950                 else
 951                         path = default_name_or_path(name->string);
 952
 953                 if (!path)
 954                         continue;
 955
 956                 if (submodule_needs_pushing(path, commits))
 957                         string_list_insert(needs_pushing, path);
 958         }
 959
 960         free_submodules_oids(&submodules);
 961         argv_array_clear(&argv);
 962
 963         return needs_pushing->nr;
 964 }
 965
 966 static int push_submodule(const char *path,
 967                           const struct remote *remote,
 968                           const char **refspec, int refspec_nr,
 969                           const struct string_list *push_options,
 970                           int dry_run)
 971 {
 972         if (add_submodule_odb(path))
 973                 return 1;
 974
 975         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 976                 struct child_process cp = CHILD_PROCESS_INIT;
 977                 argv_array_push(&cp.args, "push");
 978                 if (dry_run)
 979                         argv_array_push(&cp.args, "--dry-run");
 980
 981                 if (push_options && push_options->nr) {
 982                         const struct string_list_item *item;
 983                         for_each_string_list_item(item, push_options)
 984                                 argv_array_pushf(&cp.args, "--push-option=%s",
 985                                                  item->string);
 986                 }
 987
 988                 if (remote->origin != REMOTE_UNCONFIGURED) {
 989                         int i;
 990                         argv_array_push(&cp.args, remote->name);
 991                         for (i = 0; i < refspec_nr; i++)
 992                                 argv_array_push(&cp.args, refspec[i]);
 993                 }
 994
 995                 prepare_submodule_repo_env(&cp.env_array);
 996                 cp.git_cmd = 1;
 997                 cp.no_stdin = 1;
 998                 cp.dir = path;
 999                 if (run_command(&cp))
1000                         return 0;
1001                 close(cp.out);
1002         }
1003
1004         return 1;
1005 }
1006
1007 /*
1008  * Perform a check in the submodule to see if the remote and refspec work.
1009  * Die if the submodule can't be pushed.
1010  */
1011 static void submodule_push_check(const char *path, const char *head,
1012                                  const struct remote *remote,
1013                                  const char **refspec, int refspec_nr)
1014 {
1015         struct child_process cp = CHILD_PROCESS_INIT;
1016         int i;
1017
1018         argv_array_push(&cp.args, "submodule--helper");
1019         argv_array_push(&cp.args, "push-check");
1020         argv_array_push(&cp.args, head);
1021         argv_array_push(&cp.args, remote->name);
1022
1023         for (i = 0; i < refspec_nr; i++)
1024                 argv_array_push(&cp.args, refspec[i]);
1025
1026         prepare_submodule_repo_env(&cp.env_array);
1027         cp.git_cmd = 1;
1028         cp.no_stdin = 1;
1029         cp.no_stdout = 1;
1030         cp.dir = path;
1031
1032         /*
1033          * Simply indicate if 'submodule--helper push-check' failed.
1034          * More detailed error information will be provided by the
1035          * child process.
1036          */
1037         if (run_command(&cp))
1038                 die("process for submodule '%s' failed", path);
1039 }
1040
1041 int push_unpushed_submodules(struct oid_array *commits,
1042                              const struct remote *remote,
1043                              const char **refspec, int refspec_nr,
1044                              const struct string_list *push_options,
1045                              int dry_run)
1046 {
1047         int i, ret = 1;
1048         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1049
1050         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1051                 return 1;
1052
1053         /*
1054          * Verify that the remote and refspec can be propagated to all
1055          * submodules.  This check can be skipped if the remote and refspec
1056          * won't be propagated due to the remote being unconfigured (e.g. a URL
1057          * instead of a remote name).
1058          */
1059         if (remote->origin != REMOTE_UNCONFIGURED) {
1060                 char *head;
1061                 struct object_id head_oid;
1062
1063                 head = resolve_refdup("HEAD", 0, &head_oid, NULL);
1064                 if (!head)
1065                         die(_("Failed to resolve HEAD as a valid ref."));
1066
1067                 for (i = 0; i < needs_pushing.nr; i++)
1068                         submodule_push_check(needs_pushing.items[i].string,
1069                                              head, remote,
1070                                              refspec, refspec_nr);
1071                 free(head);
1072         }
1073
1074         /* Actually push the submodules */
1075         for (i = 0; i < needs_pushing.nr; i++) {
1076                 const char *path = needs_pushing.items[i].string;
1077                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1078                 if (!push_submodule(path, remote, refspec, refspec_nr,
1079                                     push_options, dry_run)) {
1080                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1081                         ret = 0;
1082                 }
1083         }
1084
1085         string_list_clear(&needs_pushing, 0);
1086
1087         return ret;
1088 }
1089
1090 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1091                                int flags, void *data)
1092 {
1093         struct oid_array *array = data;
1094         oid_array_append(array, oid);
1095         return 0;
1096 }
1097
1098 void check_for_new_submodule_commits(struct object_id *oid)
1099 {
1100         if (!initialized_fetch_ref_tips) {
1101                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1102                 initialized_fetch_ref_tips = 1;
1103         }
1104
1105         oid_array_append(&ref_tips_after_fetch, oid);
1106 }
1107
1108 static void calculate_changed_submodule_paths(void)
1109 {
1110         struct argv_array argv = ARGV_ARRAY_INIT;
1111         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1112         const struct string_list_item *name;
1113
1114         /* No need to check if there are no submodules configured */
1115         if (!submodule_from_path(NULL, NULL))
1116                 return;
1117
1118         argv_array_push(&argv, "--"); /* argv[0] program name */
1119         oid_array_for_each_unique(&ref_tips_after_fetch,
1120                                    append_oid_to_argv, &argv);
1121         argv_array_push(&argv, "--not");
1122         oid_array_for_each_unique(&ref_tips_before_fetch,
1123                                    append_oid_to_argv, &argv);
1124
1125         /*
1126          * Collect all submodules (whether checked out or not) for which new
1127          * commits have been recorded upstream in "changed_submodule_names".
1128          */
1129         collect_changed_submodules(&changed_submodules, &argv);
1130
1131         for_each_string_list_item(name, &changed_submodules) {
1132                 struct oid_array *commits = name->util;
1133                 const struct submodule *submodule;
1134                 const char *path = NULL;
1135
1136                 submodule = submodule_from_name(&null_oid, name->string);
1137                 if (submodule)
1138                         path = submodule->path;
1139                 else
1140                         path = default_name_or_path(name->string);
1141
1142                 if (!path)
1143                         continue;
1144
1145                 if (!submodule_has_commits(path, commits))
1146                         string_list_append(&changed_submodule_names, name->string);
1147         }
1148
1149         free_submodules_oids(&changed_submodules);
1150         argv_array_clear(&argv);
1151         oid_array_clear(&ref_tips_before_fetch);
1152         oid_array_clear(&ref_tips_after_fetch);
1153         initialized_fetch_ref_tips = 0;
1154 }
1155
1156 int submodule_touches_in_range(struct object_id *excl_oid,
1157                                struct object_id *incl_oid)
1158 {
1159         struct string_list subs = STRING_LIST_INIT_DUP;
1160         struct argv_array args = ARGV_ARRAY_INIT;
1161         int ret;
1162
1163         /* No need to check if there are no submodules configured */
1164         if (!submodule_from_path(NULL, NULL))
1165                 return 0;
1166
1167         argv_array_push(&args, "--"); /* args[0] program name */
1168         argv_array_push(&args, oid_to_hex(incl_oid));
1169         if (!is_null_oid(excl_oid)) {
1170                 argv_array_push(&args, "--not");
1171                 argv_array_push(&args, oid_to_hex(excl_oid));
1172         }
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_cache(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                                 die("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_SHA1_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(&null_oid, path);
1609
1610         if (!sub)
1611                 die("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);
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);
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_SHA1_HEX);
1664
1665         argv_array_push(&cp.args, new_head ? new_head : EMPTY_TREE_SHA1_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(&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(&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));
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                         die("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                         die (_("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(&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 }