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(&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(&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(&null_oid, path);
 178         if (submodule) {
 179                 const char *ignore;
 180                 char *key;
 181
 182                 key = xstrfmt("submodule.%s.ignore", submodule->name);
 183                 if (repo_config_get_string_const(the_repository, key, &ignore))
 184                         ignore = submodule->ignore;
 185                 free(key);
 186
 187                 if (ignore)
 188                         handle_ignore_submodules_arg(diffopt, ignore);
 189                 else if (is_gitmodules_unmerged(&the_index))
 190                         diffopt->flags.ignore_submodules = 1;
 191         }
 192 }
 193
 194 /* Cheap function that only determines if we're interested in submodules at all */
 195 int git_default_submodule_config(const char *var, const char *value, void *cb)
 196 {
 197         if (!strcmp(var, "submodule.recurse")) {
 198                 int v = git_config_bool(var, value) ?
 199                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 200                 config_update_recurse_submodules = v;
 201         }
 202         return 0;
 203 }
 204
 205 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 206                                                      const char *arg, int unset)
 207 {
 208         if (unset) {
 209                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 210                 return 0;
 211         }
 212         if (arg)
 213                 config_update_recurse_submodules =
 214                         parse_update_recurse_submodules_arg(opt->long_name,
 215                                                             arg);
 216         else
 217                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 218
 219         return 0;
 220 }
 221
 222 /*
 223  * Determine if a submodule has been initialized at a given 'path'
 224  */
 225 int is_submodule_active(struct repository *repo, const char *path)
 226 {
 227         int ret = 0;
 228         char *key = NULL;
 229         char *value = NULL;
 230         const struct string_list *sl;
 231         const struct submodule *module;
 232
 233         module = submodule_from_cache(repo, &null_oid, path);
 234
 235         /* early return if there isn't a path->module mapping */
 236         if (!module)
 237                 return 0;
 238
 239         /* submodule.<name>.active is set */
 240         key = xstrfmt("submodule.%s.active", module->name);
 241         if (!repo_config_get_bool(repo, key, &ret)) {
 242                 free(key);
 243                 return ret;
 244         }
 245         free(key);
 246
 247         /* submodule.active is set */
 248         sl = repo_config_get_value_multi(repo, "submodule.active");
 249         if (sl) {
 250                 struct pathspec ps;
 251                 struct argv_array args = ARGV_ARRAY_INIT;
 252                 const struct string_list_item *item;
 253
 254                 for_each_string_list_item(item, sl) {
 255                         argv_array_push(&args, item->string);
 256                 }
 257
 258                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 259                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
 260
 261                 argv_array_clear(&args);
 262                 clear_pathspec(&ps);
 263                 return ret;
 264         }
 265
 266         /* fallback to checking if the URL is set */
 267         key = xstrfmt("submodule.%s.url", module->name);
 268         ret = !repo_config_get_string(repo, key, &value);
 269
 270         free(value);
 271         free(key);
 272         return ret;
 273 }
 274
 275 int is_submodule_populated_gently(const char *path, int *return_error_code)
 276 {
 277         int ret = 0;
 278         char *gitdir = xstrfmt("%s/.git", path);
 279
 280         if (resolve_gitdir_gently(gitdir, return_error_code))
 281                 ret = 1;
 282
 283         free(gitdir);
 284         return ret;
 285 }
 286
 287 /*
 288  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 289  */
 290 void die_in_unpopulated_submodule(const struct index_state *istate,
 291                                   const char *prefix)
 292 {
 293         int i, prefixlen;
 294
 295         if (!prefix)
 296                 return;
 297
 298         prefixlen = strlen(prefix);
 299
 300         for (i = 0; i < istate->cache_nr; i++) {
 301                 struct cache_entry *ce = istate->cache[i];
 302                 int ce_len = ce_namelen(ce);
 303
 304                 if (!S_ISGITLINK(ce->ce_mode))
 305                         continue;
 306                 if (prefixlen <= ce_len)
 307                         continue;
 308                 if (strncmp(ce->name, prefix, ce_len))
 309                         continue;
 310                 if (prefix[ce_len] != '/')
 311                         continue;
 312
 313                 die(_("in unpopulated submodule '%s'"), ce->name);
 314         }
 315 }
 316
 317 /*
 318  * Dies if any paths in the provided pathspec descends into a submodule
 319  */
 320 void die_path_inside_submodule(const struct index_state *istate,
 321                                const struct pathspec *ps)
 322 {
 323         int i, j;
 324
 325         for (i = 0; i < istate->cache_nr; i++) {
 326                 struct cache_entry *ce = istate->cache[i];
 327                 int ce_len = ce_namelen(ce);
 328
 329                 if (!S_ISGITLINK(ce->ce_mode))
 330                         continue;
 331
 332                 for (j = 0; j < ps->nr ; j++) {
 333                         const struct pathspec_item *item = &ps->items[j];
 334
 335                         if (item->len <= ce_len)
 336                                 continue;
 337                         if (item->match[ce_len] != '/')
 338                                 continue;
 339                         if (strncmp(ce->name, item->match, ce_len))
 340                                 continue;
 341                         if (item->len == ce_len + 1)
 342                                 continue;
 343
 344                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 345                             item->original, ce_len, ce->name);
 346                 }
 347         }
 348 }
 349
 350 enum submodule_update_type parse_submodule_update_type(const char *value)
 351 {
 352         if (!strcmp(value, "none"))
 353                 return SM_UPDATE_NONE;
 354         else if (!strcmp(value, "checkout"))
 355                 return SM_UPDATE_CHECKOUT;
 356         else if (!strcmp(value, "rebase"))
 357                 return SM_UPDATE_REBASE;
 358         else if (!strcmp(value, "merge"))
 359                 return SM_UPDATE_MERGE;
 360         else if (*value == '!')
 361                 return SM_UPDATE_COMMAND;
 362         else
 363                 return SM_UPDATE_UNSPECIFIED;
 364 }
 365
 366 int parse_submodule_update_strategy(const char *value,
 367                 struct submodule_update_strategy *dst)
 368 {
 369         enum submodule_update_type type;
 370
 371         free((void*)dst->command);
 372         dst->command = NULL;
 373
 374         type = parse_submodule_update_type(value);
 375         if (type == SM_UPDATE_UNSPECIFIED)
 376                 return -1;
 377
 378         dst->type = type;
 379         if (type == SM_UPDATE_COMMAND)
 380                 dst->command = xstrdup(value + 1);
 381
 382         return 0;
 383 }
 384
 385 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 386 {
 387         struct strbuf sb = STRBUF_INIT;
 388         switch (s->type) {
 389         case SM_UPDATE_CHECKOUT:
 390                 return "checkout";
 391         case SM_UPDATE_MERGE:
 392                 return "merge";
 393         case SM_UPDATE_REBASE:
 394                 return "rebase";
 395         case SM_UPDATE_NONE:
 396                 return "none";
 397         case SM_UPDATE_UNSPECIFIED:
 398                 return NULL;
 399         case SM_UPDATE_COMMAND:
 400                 strbuf_addf(&sb, "!%s", s->command);
 401                 return strbuf_detach(&sb, NULL);
 402         }
 403         return NULL;
 404 }
 405
 406 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 407                                   const char *arg)
 408 {
 409         diffopt->flags.ignore_submodules = 0;
 410         diffopt->flags.ignore_untracked_in_submodules = 0;
 411         diffopt->flags.ignore_dirty_submodules = 0;
 412
 413         if (!strcmp(arg, "all"))
 414                 diffopt->flags.ignore_submodules = 1;
 415         else if (!strcmp(arg, "untracked"))
 416                 diffopt->flags.ignore_untracked_in_submodules = 1;
 417         else if (!strcmp(arg, "dirty"))
 418                 diffopt->flags.ignore_dirty_submodules = 1;
 419         else if (strcmp(arg, "none"))
 420                 die("bad --ignore-submodules argument: %s", arg);
 421 }
 422
 423 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 424                 struct commit *left, struct commit *right,
 425                 struct commit_list *merge_bases)
 426 {
 427         struct commit_list *list;
 428
 429         init_revisions(rev, NULL);
 430         setup_revisions(0, NULL, rev, NULL);
 431         rev->left_right = 1;
 432         rev->first_parent_only = 1;
 433         left->object.flags |= SYMMETRIC_LEFT;
 434         add_pending_object(rev, &left->object, path);
 435         add_pending_object(rev, &right->object, path);
 436         for (list = merge_bases; list; list = list->next) {
 437                 list->item->object.flags |= UNINTERESTING;
 438                 add_pending_object(rev, &list->item->object,
 439                         oid_to_hex(&list->item->object.oid));
 440         }
 441         return prepare_revision_walk(rev);
 442 }
 443
 444 static void print_submodule_summary(struct rev_info *rev, struct diff_options *o)
 445 {
 446         static const char format[] = "  %m %s";
 447         struct strbuf sb = STRBUF_INIT;
 448         struct commit *commit;
 449
 450         while ((commit = get_revision(rev))) {
 451                 struct pretty_print_context ctx = {0};
 452                 ctx.date_mode = rev->date_mode;
 453                 ctx.output_encoding = get_log_output_encoding();
 454                 strbuf_setlen(&sb, 0);
 455                 format_commit_message(commit, format, &sb, &ctx);
 456                 strbuf_addch(&sb, '\n');
 457                 if (commit->object.flags & SYMMETRIC_LEFT)
 458                         diff_emit_submodule_del(o, sb.buf);
 459                 else
 460                         diff_emit_submodule_add(o, sb.buf);
 461         }
 462         strbuf_release(&sb);
 463 }
 464
 465 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 466 {
 467         const char * const *var;
 468
 469         for (var = local_repo_env; *var; var++) {
 470                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 471                         argv_array_push(out, *var);
 472         }
 473 }
 474
 475 void prepare_submodule_repo_env(struct argv_array *out)
 476 {
 477         prepare_submodule_repo_env_no_git_dir(out);
 478         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 479                          DEFAULT_GIT_DIR_ENVIRONMENT);
 480 }
 481
 482 /* Helper function to display the submodule header line prior to the full
 483  * summary output. If it can locate the submodule objects directory it will
 484  * attempt to lookup both the left and right commits and put them into the
 485  * left and right pointers.
 486  */
 487 static void show_submodule_header(struct diff_options *o, const char *path,
 488                 struct object_id *one, struct object_id *two,
 489                 unsigned dirty_submodule,
 490                 struct commit **left, struct commit **right,
 491                 struct commit_list **merge_bases)
 492 {
 493         const char *message = NULL;
 494         struct strbuf sb = STRBUF_INIT;
 495         int fast_forward = 0, fast_backward = 0;
 496
 497         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 498                 diff_emit_submodule_untracked(o, path);
 499
 500         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 501                 diff_emit_submodule_modified(o, path);
 502
 503         if (is_null_oid(one))
 504                 message = "(new submodule)";
 505         else if (is_null_oid(two))
 506                 message = "(submodule deleted)";
 507
 508         if (add_submodule_odb(path)) {
 509                 if (!message)
 510                         message = "(commits not present)";
 511                 goto output_header;
 512         }
 513
 514         /*
 515          * Attempt to lookup the commit references, and determine if this is
 516          * a fast forward or fast backwards update.
 517          */
 518         *left = lookup_commit_reference(one);
 519         *right = lookup_commit_reference(two);
 520
 521         /*
 522          * Warn about missing commits in the submodule project, but only if
 523          * they aren't null.
 524          */
 525         if ((!is_null_oid(one) && !*left) ||
 526              (!is_null_oid(two) && !*right))
 527                 message = "(commits not present)";
 528
 529         *merge_bases = get_merge_bases(*left, *right);
 530         if (*merge_bases) {
 531                 if ((*merge_bases)->item == *left)
 532                         fast_forward = 1;
 533                 else if ((*merge_bases)->item == *right)
 534                         fast_backward = 1;
 535         }
 536
 537         if (!oidcmp(one, two)) {
 538                 strbuf_release(&sb);
 539                 return;
 540         }
 541
 542 output_header:
 543         strbuf_addf(&sb, "Submodule %s ", path);
 544         strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
 545         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 546         strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
 547         if (message)
 548                 strbuf_addf(&sb, " %s\n", message);
 549         else
 550                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 551         diff_emit_submodule_header(o, sb.buf);
 552
 553         strbuf_release(&sb);
 554 }
 555
 556 void show_submodule_summary(struct diff_options *o, const char *path,
 557                 struct object_id *one, struct object_id *two,
 558                 unsigned dirty_submodule)
 559 {
 560         struct rev_info rev;
 561         struct commit *left = NULL, *right = NULL;
 562         struct commit_list *merge_bases = NULL;
 563
 564         show_submodule_header(o, path, one, two, dirty_submodule,
 565                               &left, &right, &merge_bases);
 566
 567         /*
 568          * If we don't have both a left and a right pointer, there is no
 569          * reason to try and display a summary. The header line should contain
 570          * all the information the user needs.
 571          */
 572         if (!left || !right)
 573                 goto out;
 574
 575         /* Treat revision walker failure the same as missing commits */
 576         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 577                 diff_emit_submodule_error(o, "(revision walker failed)\n");
 578                 goto out;
 579         }
 580
 581         print_submodule_summary(&rev, o);
 582
 583 out:
 584         if (merge_bases)
 585                 free_commit_list(merge_bases);
 586         clear_commit_marks(left, ~0);
 587         clear_commit_marks(right, ~0);
 588 }
 589
 590 void show_submodule_inline_diff(struct diff_options *o, const char *path,
 591                 struct object_id *one, struct object_id *two,
 592                 unsigned dirty_submodule)
 593 {
 594         const struct object_id *old_oid = the_hash_algo->empty_tree, *new_oid = the_hash_algo->empty_tree;
 595         struct commit *left = NULL, *right = NULL;
 596         struct commit_list *merge_bases = NULL;
 597         struct child_process cp = CHILD_PROCESS_INIT;
 598         struct strbuf sb = STRBUF_INIT;
 599
 600         show_submodule_header(o, path, one, two, dirty_submodule,
 601                               &left, &right, &merge_bases);
 602
 603         /* We need a valid left and right commit to display a difference */
 604         if (!(left || is_null_oid(one)) ||
 605             !(right || is_null_oid(two)))
 606                 goto done;
 607
 608         if (left)
 609                 old_oid = one;
 610         if (right)
 611                 new_oid = two;
 612
 613         cp.git_cmd = 1;
 614         cp.dir = path;
 615         cp.out = -1;
 616         cp.no_stdin = 1;
 617
 618         /* TODO: other options may need to be passed here. */
 619         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 620         argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 621                          "always" : "never");
 622
 623         if (o->flags.reverse_diff) {
 624                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 625                                  o->b_prefix, path);
 626                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 627                                  o->a_prefix, path);
 628         } else {
 629                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 630                                  o->a_prefix, path);
 631                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 632                                  o->b_prefix, path);
 633         }
 634         argv_array_push(&cp.args, oid_to_hex(old_oid));
 635         /*
 636          * If the submodule has modified content, we will diff against the
 637          * work tree, under the assumption that the user has asked for the
 638          * diff format and wishes to actually see all differences even if they
 639          * haven't yet been committed to the submodule yet.
 640          */
 641         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 642                 argv_array_push(&cp.args, oid_to_hex(new_oid));
 643
 644         prepare_submodule_repo_env(&cp.env_array);
 645         if (start_command(&cp))
 646                 diff_emit_submodule_error(o, "(diff failed)\n");
 647
 648         while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
 649                 diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
 650
 651         if (finish_command(&cp))
 652                 diff_emit_submodule_error(o, "(diff failed)\n");
 653
 654 done:
 655         strbuf_release(&sb);
 656         if (merge_bases)
 657                 free_commit_list(merge_bases);
 658         if (left)
 659                 clear_commit_marks(left, ~0);
 660         if (right)
 661                 clear_commit_marks(right, ~0);
 662 }
 663
 664 int should_update_submodules(void)
 665 {
 666         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 667 }
 668
 669 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 670 {
 671         if (!S_ISGITLINK(ce->ce_mode))
 672                 return NULL;
 673
 674         if (!should_update_submodules())
 675                 return NULL;
 676
 677         return submodule_from_path(&null_oid, ce->name);
 678 }
 679
 680 static struct oid_array *submodule_commits(struct string_list *submodules,
 681                                            const char *name)
 682 {
 683         struct string_list_item *item;
 684
 685         item = string_list_insert(submodules, name);
 686         if (item->util)
 687                 return (struct oid_array *) item->util;
 688
 689         /* NEEDSWORK: should we have oid_array_init()? */
 690         item->util = xcalloc(1, sizeof(struct oid_array));
 691         return (struct oid_array *) item->util;
 692 }
 693
 694 struct collect_changed_submodules_cb_data {
 695         struct string_list *changed;
 696         const struct object_id *commit_oid;
 697 };
 698
 699 /*
 700  * this would normally be two functions: default_name_from_path() and
 701  * path_from_default_name(). Since the default name is the same as
 702  * the submodule path we can get away with just one function which only
 703  * checks whether there is a submodule in the working directory at that
 704  * location.
 705  */
 706 static const char *default_name_or_path(const char *path_or_name)
 707 {
 708         int error_code;
 709
 710         if (!is_submodule_populated_gently(path_or_name, &error_code))
 711                 return NULL;
 712
 713         return path_or_name;
 714 }
 715
 716 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 717                                           struct diff_options *options,
 718                                           void *data)
 719 {
 720         struct collect_changed_submodules_cb_data *me = data;
 721         struct string_list *changed = me->changed;
 722         const struct object_id *commit_oid = me->commit_oid;
 723         int i;
 724
 725         for (i = 0; i < q->nr; i++) {
 726                 struct diff_filepair *p = q->queue[i];
 727                 struct oid_array *commits;
 728                 const struct submodule *submodule;
 729                 const char *name;
 730
 731                 if (!S_ISGITLINK(p->two->mode))
 732                         continue;
 733
 734                 submodule = submodule_from_path(commit_oid, p->two->path);
 735                 if (submodule)
 736                         name = submodule->name;
 737                 else {
 738                         name = default_name_or_path(p->two->path);
 739                         /* make sure name does not collide with existing one */
 740                         submodule = submodule_from_name(commit_oid, name);
 741                         if (submodule) {
 742                                 warning("Submodule in commit %s at path: "
 743                                         "'%s' collides with a submodule named "
 744                                         "the same. Skipping it.",
 745                                         oid_to_hex(commit_oid), name);
 746                                 name = NULL;
 747                         }
 748                 }
 749
 750                 if (!name)
 751                         continue;
 752
 753                 commits = submodule_commits(changed, name);
 754                 oid_array_append(commits, &p->two->oid);
 755         }
 756 }
 757
 758 /*
 759  * Collect the paths of submodules in 'changed' which have changed based on
 760  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 761  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 762  * what the submodule pointers were updated to during the change.
 763  */
 764 static void collect_changed_submodules(struct string_list *changed,
 765                                        struct argv_array *argv)
 766 {
 767         struct rev_info rev;
 768         const struct commit *commit;
 769
 770         init_revisions(&rev, NULL);
 771         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 772         if (prepare_revision_walk(&rev))
 773                 die("revision walk setup failed");
 774
 775         while ((commit = get_revision(&rev))) {
 776                 struct rev_info diff_rev;
 777                 struct collect_changed_submodules_cb_data data;
 778                 data.changed = changed;
 779                 data.commit_oid = &commit->object.oid;
 780
 781                 init_revisions(&diff_rev, NULL);
 782                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 783                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 784                 diff_rev.diffopt.format_callback_data = &data;
 785                 diff_tree_combined_merge(commit, 1, &diff_rev);
 786         }
 787
 788         reset_revision_walk();
 789 }
 790
 791 static void free_submodules_oids(struct string_list *submodules)
 792 {
 793         struct string_list_item *item;
 794         for_each_string_list_item(item, submodules)
 795                 oid_array_clear((struct oid_array *) item->util);
 796         string_list_clear(submodules, 1);
 797 }
 798
 799 static int has_remote(const char *refname, const struct object_id *oid,
 800                       int flags, void *cb_data)
 801 {
 802         return 1;
 803 }
 804
 805 static int append_oid_to_argv(const struct object_id *oid, void *data)
 806 {
 807         struct argv_array *argv = data;
 808         argv_array_push(argv, oid_to_hex(oid));
 809         return 0;
 810 }
 811
 812 struct has_commit_data {
 813         int result;
 814         const char *path;
 815 };
 816
 817 static int check_has_commit(const struct object_id *oid, void *data)
 818 {
 819         struct has_commit_data *cb = data;
 820
 821         enum object_type type = oid_object_info(oid, NULL);
 822
 823         switch (type) {
 824         case OBJ_COMMIT:
 825                 return 0;
 826         case OBJ_BAD:
 827                 /*
 828                  * Object is missing or invalid. If invalid, an error message
 829                  * has already been printed.
 830                  */
 831                 cb->result = 0;
 832                 return 0;
 833         default:
 834                 die(_("submodule entry '%s' (%s) is a %s, not a commit"),
 835                     cb->path, oid_to_hex(oid), type_name(type));
 836         }
 837 }
 838
 839 static int submodule_has_commits(const char *path, struct oid_array *commits)
 840 {
 841         struct has_commit_data has_commit = { 1, path };
 842
 843         /*
 844          * Perform a cheap, but incorrect check for the existence of 'commits'.
 845          * This is done by adding the submodule's object store to the in-core
 846          * object store, and then querying for each commit's existence.  If we
 847          * do not have the commit object anywhere, there is no chance we have
 848          * it in the object store of the correct submodule and have it
 849          * reachable from a ref, so we can fail early without spawning rev-list
 850          * which is expensive.
 851          */
 852         if (add_submodule_odb(path))
 853                 return 0;
 854
 855         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 856
 857         if (has_commit.result) {
 858                 /*
 859                  * Even if the submodule is checked out and the commit is
 860                  * present, make sure it exists in the submodule's object store
 861                  * and that it is reachable from a ref.
 862                  */
 863                 struct child_process cp = CHILD_PROCESS_INIT;
 864                 struct strbuf out = STRBUF_INIT;
 865
 866                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 867                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 868                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 869
 870                 prepare_submodule_repo_env(&cp.env_array);
 871                 cp.git_cmd = 1;
 872                 cp.no_stdin = 1;
 873                 cp.dir = path;
 874
 875                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 876                         has_commit.result = 0;
 877
 878                 strbuf_release(&out);
 879         }
 880
 881         return has_commit.result;
 882 }
 883
 884 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
 885 {
 886         if (!submodule_has_commits(path, commits))
 887                 /*
 888                  * NOTE: We do consider it safe to return "no" here. The
 889                  * correct answer would be "We do not know" instead of
 890                  * "No push needed", but it is quite hard to change
 891                  * the submodule pointer without having the submodule
 892                  * around. If a user did however change the submodules
 893                  * without having the submodule around, this indicates
 894                  * an expert who knows what they are doing or a
 895                  * maintainer integrating work from other people. In
 896                  * both cases it should be safe to skip this check.
 897                  */
 898                 return 0;
 899
 900         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 901                 struct child_process cp = CHILD_PROCESS_INIT;
 902                 struct strbuf buf = STRBUF_INIT;
 903                 int needs_pushing = 0;
 904
 905                 argv_array_push(&cp.args, "rev-list");
 906                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 907                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 908
 909                 prepare_submodule_repo_env(&cp.env_array);
 910                 cp.git_cmd = 1;
 911                 cp.no_stdin = 1;
 912                 cp.out = -1;
 913                 cp.dir = path;
 914                 if (start_command(&cp))
 915                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 916                                         path);
 917                 if (strbuf_read(&buf, cp.out, 41))
 918                         needs_pushing = 1;
 919                 finish_command(&cp);
 920                 close(cp.out);
 921                 strbuf_release(&buf);
 922                 return needs_pushing;
 923         }
 924
 925         return 0;
 926 }
 927
 928 int find_unpushed_submodules(struct oid_array *commits,
 929                 const char *remotes_name, struct string_list *needs_pushing)
 930 {
 931         struct string_list submodules = STRING_LIST_INIT_DUP;
 932         struct string_list_item *name;
 933         struct argv_array argv = ARGV_ARRAY_INIT;
 934
 935         /* argv.argv[0] will be ignored by setup_revisions */
 936         argv_array_push(&argv, "find_unpushed_submodules");
 937         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
 938         argv_array_push(&argv, "--not");
 939         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
 940
 941         collect_changed_submodules(&submodules, &argv);
 942
 943         for_each_string_list_item(name, &submodules) {
 944                 struct oid_array *commits = name->util;
 945                 const struct submodule *submodule;
 946                 const char *path = NULL;
 947
 948                 submodule = submodule_from_name(&null_oid, name->string);
 949                 if (submodule)
 950                         path = submodule->path;
 951                 else
 952                         path = default_name_or_path(name->string);
 953
 954                 if (!path)
 955                         continue;
 956
 957                 if (submodule_needs_pushing(path, commits))
 958                         string_list_insert(needs_pushing, path);
 959         }
 960
 961         free_submodules_oids(&submodules);
 962         argv_array_clear(&argv);
 963
 964         return needs_pushing->nr;
 965 }
 966
 967 static int push_submodule(const char *path,
 968                           const struct remote *remote,
 969                           const char **refspec, int refspec_nr,
 970                           const struct string_list *push_options,
 971                           int dry_run)
 972 {
 973         if (add_submodule_odb(path))
 974                 return 1;
 975
 976         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 977                 struct child_process cp = CHILD_PROCESS_INIT;
 978                 argv_array_push(&cp.args, "push");
 979                 if (dry_run)
 980                         argv_array_push(&cp.args, "--dry-run");
 981
 982                 if (push_options && push_options->nr) {
 983                         const struct string_list_item *item;
 984                         for_each_string_list_item(item, push_options)
 985                                 argv_array_pushf(&cp.args, "--push-option=%s",
 986                                                  item->string);
 987                 }
 988
 989                 if (remote->origin != REMOTE_UNCONFIGURED) {
 990                         int i;
 991                         argv_array_push(&cp.args, remote->name);
 992                         for (i = 0; i < refspec_nr; i++)
 993                                 argv_array_push(&cp.args, refspec[i]);
 994                 }
 995
 996                 prepare_submodule_repo_env(&cp.env_array);
 997                 cp.git_cmd = 1;
 998                 cp.no_stdin = 1;
 999                 cp.dir = path;
1000                 if (run_command(&cp))
1001                         return 0;
1002                 close(cp.out);
1003         }
1004
1005         return 1;
1006 }
1007
1008 /*
1009  * Perform a check in the submodule to see if the remote and refspec work.
1010  * Die if the submodule can't be pushed.
1011  */
1012 static void submodule_push_check(const char *path, const char *head,
1013                                  const struct remote *remote,
1014                                  const char **refspec, int refspec_nr)
1015 {
1016         struct child_process cp = CHILD_PROCESS_INIT;
1017         int i;
1018
1019         argv_array_push(&cp.args, "submodule--helper");
1020         argv_array_push(&cp.args, "push-check");
1021         argv_array_push(&cp.args, head);
1022         argv_array_push(&cp.args, remote->name);
1023
1024         for (i = 0; i < refspec_nr; i++)
1025                 argv_array_push(&cp.args, refspec[i]);
1026
1027         prepare_submodule_repo_env(&cp.env_array);
1028         cp.git_cmd = 1;
1029         cp.no_stdin = 1;
1030         cp.no_stdout = 1;
1031         cp.dir = path;
1032
1033         /*
1034          * Simply indicate if 'submodule--helper push-check' failed.
1035          * More detailed error information will be provided by the
1036          * child process.
1037          */
1038         if (run_command(&cp))
1039                 die("process for submodule '%s' failed", path);
1040 }
1041
1042 int push_unpushed_submodules(struct oid_array *commits,
1043                              const struct remote *remote,
1044                              const char **refspec, int refspec_nr,
1045                              const struct string_list *push_options,
1046                              int dry_run)
1047 {
1048         int i, ret = 1;
1049         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1050
1051         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1052                 return 1;
1053
1054         /*
1055          * Verify that the remote and refspec can be propagated to all
1056          * submodules.  This check can be skipped if the remote and refspec
1057          * won't be propagated due to the remote being unconfigured (e.g. a URL
1058          * instead of a remote name).
1059          */
1060         if (remote->origin != REMOTE_UNCONFIGURED) {
1061                 char *head;
1062                 struct object_id head_oid;
1063
1064                 head = resolve_refdup("HEAD", 0, &head_oid, NULL);
1065                 if (!head)
1066                         die(_("Failed to resolve HEAD as a valid ref."));
1067
1068                 for (i = 0; i < needs_pushing.nr; i++)
1069                         submodule_push_check(needs_pushing.items[i].string,
1070                                              head, remote,
1071                                              refspec, refspec_nr);
1072                 free(head);
1073         }
1074
1075         /* Actually push the submodules */
1076         for (i = 0; i < needs_pushing.nr; i++) {
1077                 const char *path = needs_pushing.items[i].string;
1078                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1079                 if (!push_submodule(path, remote, refspec, refspec_nr,
1080                                     push_options, dry_run)) {
1081                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1082                         ret = 0;
1083                 }
1084         }
1085
1086         string_list_clear(&needs_pushing, 0);
1087
1088         return ret;
1089 }
1090
1091 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1092                                int flags, void *data)
1093 {
1094         struct oid_array *array = data;
1095         oid_array_append(array, oid);
1096         return 0;
1097 }
1098
1099 void check_for_new_submodule_commits(struct object_id *oid)
1100 {
1101         if (!initialized_fetch_ref_tips) {
1102                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1103                 initialized_fetch_ref_tips = 1;
1104         }
1105
1106         oid_array_append(&ref_tips_after_fetch, oid);
1107 }
1108
1109 static void calculate_changed_submodule_paths(void)
1110 {
1111         struct argv_array argv = ARGV_ARRAY_INIT;
1112         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1113         const struct string_list_item *name;
1114
1115         /* No need to check if there are no submodules configured */
1116         if (!submodule_from_path(NULL, NULL))
1117                 return;
1118
1119         argv_array_push(&argv, "--"); /* argv[0] program name */
1120         oid_array_for_each_unique(&ref_tips_after_fetch,
1121                                    append_oid_to_argv, &argv);
1122         argv_array_push(&argv, "--not");
1123         oid_array_for_each_unique(&ref_tips_before_fetch,
1124                                    append_oid_to_argv, &argv);
1125
1126         /*
1127          * Collect all submodules (whether checked out or not) for which new
1128          * commits have been recorded upstream in "changed_submodule_names".
1129          */
1130         collect_changed_submodules(&changed_submodules, &argv);
1131
1132         for_each_string_list_item(name, &changed_submodules) {
1133                 struct oid_array *commits = name->util;
1134                 const struct submodule *submodule;
1135                 const char *path = NULL;
1136
1137                 submodule = submodule_from_name(&null_oid, name->string);
1138                 if (submodule)
1139                         path = submodule->path;
1140                 else
1141                         path = default_name_or_path(name->string);
1142
1143                 if (!path)
1144                         continue;
1145
1146                 if (!submodule_has_commits(path, commits))
1147                         string_list_append(&changed_submodule_names, name->string);
1148         }
1149
1150         free_submodules_oids(&changed_submodules);
1151         argv_array_clear(&argv);
1152         oid_array_clear(&ref_tips_before_fetch);
1153         oid_array_clear(&ref_tips_after_fetch);
1154         initialized_fetch_ref_tips = 0;
1155 }
1156
1157 int submodule_touches_in_range(struct object_id *excl_oid,
1158                                struct object_id *incl_oid)
1159 {
1160         struct string_list subs = STRING_LIST_INIT_DUP;
1161         struct argv_array args = ARGV_ARRAY_INIT;
1162         int ret;
1163
1164         /* No need to check if there are no submodules configured */
1165         if (!submodule_from_path(NULL, NULL))
1166                 return 0;
1167
1168         argv_array_push(&args, "--"); /* args[0] program name */
1169         argv_array_push(&args, oid_to_hex(incl_oid));
1170         argv_array_push(&args, "--not");
1171         argv_array_push(&args, oid_to_hex(excl_oid));
1172
1173         collect_changed_submodules(&subs, &args);
1174         ret = subs.nr;
1175
1176         argv_array_clear(&args);
1177
1178         free_submodules_oids(&subs);
1179         return ret;
1180 }
1181
1182 struct submodule_parallel_fetch {
1183         int count;
1184         struct argv_array args;
1185         struct repository *r;
1186         const char *prefix;
1187         int command_line_option;
1188         int default_option;
1189         int quiet;
1190         int result;
1191 };
1192 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0}
1193
1194 static int get_fetch_recurse_config(const struct submodule *submodule,
1195                                     struct submodule_parallel_fetch *spf)
1196 {
1197         if (spf->command_line_option != RECURSE_SUBMODULES_DEFAULT)
1198                 return spf->command_line_option;
1199
1200         if (submodule) {
1201                 char *key;
1202                 const char *value;
1203
1204                 int fetch_recurse = submodule->fetch_recurse;
1205                 key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1206                 if (!repo_config_get_string_const(spf->r, key, &value)) {
1207                         fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1208                 }
1209                 free(key);
1210
1211                 if (fetch_recurse != RECURSE_SUBMODULES_NONE)
1212                         /* local config overrules everything except commandline */
1213                         return fetch_recurse;
1214         }
1215
1216         return spf->default_option;
1217 }
1218
1219 static int get_next_submodule(struct child_process *cp,
1220                               struct strbuf *err, void *data, void **task_cb)
1221 {
1222         int ret = 0;
1223         struct submodule_parallel_fetch *spf = data;
1224
1225         for (; spf->count < spf->r->index->cache_nr; spf->count++) {
1226                 struct strbuf submodule_path = STRBUF_INIT;
1227                 struct strbuf submodule_git_dir = STRBUF_INIT;
1228                 struct strbuf submodule_prefix = STRBUF_INIT;
1229                 const struct cache_entry *ce = spf->r->index->cache[spf->count];
1230                 const char *git_dir, *default_argv;
1231                 const struct submodule *submodule;
1232                 struct submodule default_submodule = SUBMODULE_INIT;
1233
1234                 if (!S_ISGITLINK(ce->ce_mode))
1235                         continue;
1236
1237                 submodule = submodule_from_cache(spf->r, &null_oid, ce->name);
1238                 if (!submodule) {
1239                         const char *name = default_name_or_path(ce->name);
1240                         if (name) {
1241                                 default_submodule.path = default_submodule.name = name;
1242                                 submodule = &default_submodule;
1243                         }
1244                 }
1245
1246                 switch (get_fetch_recurse_config(submodule, spf))
1247                 {
1248                 default:
1249                 case RECURSE_SUBMODULES_DEFAULT:
1250                 case RECURSE_SUBMODULES_ON_DEMAND:
1251                         if (!submodule || !unsorted_string_list_lookup(&changed_submodule_names,
1252                                                          submodule->name))
1253                                 continue;
1254                         default_argv = "on-demand";
1255                         break;
1256                 case RECURSE_SUBMODULES_ON:
1257                         default_argv = "yes";
1258                         break;
1259                 case RECURSE_SUBMODULES_OFF:
1260                         continue;
1261                 }
1262
1263                 strbuf_repo_worktree_path(&submodule_path, spf->r, "%s", ce->name);
1264                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1265                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1266                 git_dir = read_gitfile(submodule_git_dir.buf);
1267                 if (!git_dir)
1268                         git_dir = submodule_git_dir.buf;
1269                 if (is_directory(git_dir)) {
1270                         child_process_init(cp);
1271                         cp->dir = strbuf_detach(&submodule_path, NULL);
1272                         prepare_submodule_repo_env(&cp->env_array);
1273                         cp->git_cmd = 1;
1274                         if (!spf->quiet)
1275                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1276                                             spf->prefix, ce->name);
1277                         argv_array_init(&cp->args);
1278                         argv_array_pushv(&cp->args, spf->args.argv);
1279                         argv_array_push(&cp->args, default_argv);
1280                         argv_array_push(&cp->args, "--submodule-prefix");
1281                         argv_array_push(&cp->args, submodule_prefix.buf);
1282                         ret = 1;
1283                 }
1284                 strbuf_release(&submodule_path);
1285                 strbuf_release(&submodule_git_dir);
1286                 strbuf_release(&submodule_prefix);
1287                 if (ret) {
1288                         spf->count++;
1289                         return 1;
1290                 }
1291         }
1292         return 0;
1293 }
1294
1295 static int fetch_start_failure(struct strbuf *err,
1296                                void *cb, void *task_cb)
1297 {
1298         struct submodule_parallel_fetch *spf = cb;
1299
1300         spf->result = 1;
1301
1302         return 0;
1303 }
1304
1305 static int fetch_finish(int retvalue, struct strbuf *err,
1306                         void *cb, void *task_cb)
1307 {
1308         struct submodule_parallel_fetch *spf = cb;
1309
1310         if (retvalue)
1311                 spf->result = 1;
1312
1313         return 0;
1314 }
1315
1316 int fetch_populated_submodules(struct repository *r,
1317                                const struct argv_array *options,
1318                                const char *prefix, int command_line_option,
1319                                int default_option,
1320                                int quiet, int max_parallel_jobs)
1321 {
1322         int i;
1323         struct submodule_parallel_fetch spf = SPF_INIT;
1324
1325         spf.r = r;
1326         spf.command_line_option = command_line_option;
1327         spf.default_option = default_option;
1328         spf.quiet = quiet;
1329         spf.prefix = prefix;
1330
1331         if (!r->worktree)
1332                 goto out;
1333
1334         if (repo_read_index(r) < 0)
1335                 die("index file corrupt");
1336
1337         argv_array_push(&spf.args, "fetch");
1338         for (i = 0; i < options->argc; i++)
1339                 argv_array_push(&spf.args, options->argv[i]);
1340         argv_array_push(&spf.args, "--recurse-submodules-default");
1341         /* default value, "--submodule-prefix" and its value are added later */
1342
1343         calculate_changed_submodule_paths();
1344         run_processes_parallel(max_parallel_jobs,
1345                                get_next_submodule,
1346                                fetch_start_failure,
1347                                fetch_finish,
1348                                &spf);
1349
1350         argv_array_clear(&spf.args);
1351 out:
1352         string_list_clear(&changed_submodule_names, 1);
1353         return spf.result;
1354 }
1355
1356 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1357 {
1358         struct child_process cp = CHILD_PROCESS_INIT;
1359         struct strbuf buf = STRBUF_INIT;
1360         FILE *fp;
1361         unsigned dirty_submodule = 0;
1362         const char *git_dir;
1363         int ignore_cp_exit_code = 0;
1364
1365         strbuf_addf(&buf, "%s/.git", path);
1366         git_dir = read_gitfile(buf.buf);
1367         if (!git_dir)
1368                 git_dir = buf.buf;
1369         if (!is_git_directory(git_dir)) {
1370                 if (is_directory(git_dir))
1371                         die(_("'%s' not recognized as a git repository"), git_dir);
1372                 strbuf_release(&buf);
1373                 /* The submodule is not checked out, so it is not modified */
1374                 return 0;
1375         }
1376         strbuf_reset(&buf);
1377
1378         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1379         if (ignore_untracked)
1380                 argv_array_push(&cp.args, "-uno");
1381
1382         prepare_submodule_repo_env(&cp.env_array);
1383         cp.git_cmd = 1;
1384         cp.no_stdin = 1;
1385         cp.out = -1;
1386         cp.dir = path;
1387         if (start_command(&cp))
1388                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1389
1390         fp = xfdopen(cp.out, "r");
1391         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1392                 /* regular untracked files */
1393                 if (buf.buf[0] == '?')
1394                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1395
1396                 if (buf.buf[0] == 'u' ||
1397                     buf.buf[0] == '1' ||
1398                     buf.buf[0] == '2') {
1399                         /* T = line type, XY = status, SSSS = submodule state */
1400                         if (buf.len < strlen("T XY SSSS"))
1401                                 die("BUG: invalid status --porcelain=2 line %s",
1402                                     buf.buf);
1403
1404                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1405                                 /* nested untracked file */
1406                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1407
1408                         if (buf.buf[0] == 'u' ||
1409                             buf.buf[0] == '2' ||
1410                             memcmp(buf.buf + 5, "S..U", 4))
1411                                 /* other change */
1412                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1413                 }
1414
1415                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1416                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1417                      ignore_untracked)) {
1418                         /*
1419                          * We're not interested in any further information from
1420                          * the child any more, neither output nor its exit code.
1421                          */
1422                         ignore_cp_exit_code = 1;
1423                         break;
1424                 }
1425         }
1426         fclose(fp);
1427
1428         if (finish_command(&cp) && !ignore_cp_exit_code)
1429                 die("'git status --porcelain=2' failed in submodule %s", path);
1430
1431         strbuf_release(&buf);
1432         return dirty_submodule;
1433 }
1434
1435 int submodule_uses_gitfile(const char *path)
1436 {
1437         struct child_process cp = CHILD_PROCESS_INIT;
1438         const char *argv[] = {
1439                 "submodule",
1440                 "foreach",
1441                 "--quiet",
1442                 "--recursive",
1443                 "test -f .git",
1444                 NULL,
1445         };
1446         struct strbuf buf = STRBUF_INIT;
1447         const char *git_dir;
1448
1449         strbuf_addf(&buf, "%s/.git", path);
1450         git_dir = read_gitfile(buf.buf);
1451         if (!git_dir) {
1452                 strbuf_release(&buf);
1453                 return 0;
1454         }
1455         strbuf_release(&buf);
1456
1457         /* Now test that all nested submodules use a gitfile too */
1458         cp.argv = argv;
1459         prepare_submodule_repo_env(&cp.env_array);
1460         cp.git_cmd = 1;
1461         cp.no_stdin = 1;
1462         cp.no_stderr = 1;
1463         cp.no_stdout = 1;
1464         cp.dir = path;
1465         if (run_command(&cp))
1466                 return 0;
1467
1468         return 1;
1469 }
1470
1471 /*
1472  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1473  * when doing so.
1474  *
1475  * Return 1 if we'd lose data, return 0 if the removal is fine,
1476  * and negative values for errors.
1477  */
1478 int bad_to_remove_submodule(const char *path, unsigned flags)
1479 {
1480         ssize_t len;
1481         struct child_process cp = CHILD_PROCESS_INIT;
1482         struct strbuf buf = STRBUF_INIT;
1483         int ret = 0;
1484
1485         if (!file_exists(path) || is_empty_dir(path))
1486                 return 0;
1487
1488         if (!submodule_uses_gitfile(path))
1489                 return 1;
1490
1491         argv_array_pushl(&cp.args, "status", "--porcelain",
1492                                    "--ignore-submodules=none", NULL);
1493
1494         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1495                 argv_array_push(&cp.args, "-uno");
1496         else
1497                 argv_array_push(&cp.args, "-uall");
1498
1499         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1500                 argv_array_push(&cp.args, "--ignored");
1501
1502         prepare_submodule_repo_env(&cp.env_array);
1503         cp.git_cmd = 1;
1504         cp.no_stdin = 1;
1505         cp.out = -1;
1506         cp.dir = path;
1507         if (start_command(&cp)) {
1508                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1509                         die(_("could not start 'git status' in submodule '%s'"),
1510                                 path);
1511                 ret = -1;
1512                 goto out;
1513         }
1514
1515         len = strbuf_read(&buf, cp.out, 1024);
1516         if (len > 2)
1517                 ret = 1;
1518         close(cp.out);
1519
1520         if (finish_command(&cp)) {
1521                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1522                         die(_("could not run 'git status' in submodule '%s'"),
1523                                 path);
1524                 ret = -1;
1525         }
1526 out:
1527         strbuf_release(&buf);
1528         return ret;
1529 }
1530
1531 static const char *get_super_prefix_or_empty(void)
1532 {
1533         const char *s = get_super_prefix();
1534         if (!s)
1535                 s = "";
1536         return s;
1537 }
1538
1539 static int submodule_has_dirty_index(const struct submodule *sub)
1540 {
1541         struct child_process cp = CHILD_PROCESS_INIT;
1542
1543         prepare_submodule_repo_env(&cp.env_array);
1544
1545         cp.git_cmd = 1;
1546         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1547                                    "--cached", "HEAD", NULL);
1548         cp.no_stdin = 1;
1549         cp.no_stdout = 1;
1550         cp.dir = sub->path;
1551         if (start_command(&cp))
1552                 die("could not recurse into submodule '%s'", sub->path);
1553
1554         return finish_command(&cp);
1555 }
1556
1557 static void submodule_reset_index(const char *path)
1558 {
1559         struct child_process cp = CHILD_PROCESS_INIT;
1560         prepare_submodule_repo_env(&cp.env_array);
1561
1562         cp.git_cmd = 1;
1563         cp.no_stdin = 1;
1564         cp.dir = path;
1565
1566         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1567                                    get_super_prefix_or_empty(), path);
1568         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1569
1570         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1571
1572         if (run_command(&cp))
1573                 die("could not reset submodule index");
1574 }
1575
1576 /**
1577  * Moves a submodule at a given path from a given head to another new head.
1578  * For edge cases (a submodule coming into existence or removing a submodule)
1579  * pass NULL for old or new respectively.
1580  */
1581 int submodule_move_head(const char *path,
1582                          const char *old_head,
1583                          const char *new_head,
1584                          unsigned flags)
1585 {
1586         int ret = 0;
1587         struct child_process cp = CHILD_PROCESS_INIT;
1588         const struct submodule *sub;
1589         int *error_code_ptr, error_code;
1590
1591         if (!is_submodule_active(the_repository, path))
1592                 return 0;
1593
1594         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1595                 /*
1596                  * Pass non NULL pointer to is_submodule_populated_gently
1597                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1598                  * to fixup the submodule in the force case later.
1599                  */
1600                 error_code_ptr = &error_code;
1601         else
1602                 error_code_ptr = NULL;
1603
1604         if (old_head && !is_submodule_populated_gently(path, error_code_ptr))
1605                 return 0;
1606
1607         sub = submodule_from_path(&null_oid, path);
1608
1609         if (!sub)
1610                 die("BUG: could not get submodule information for '%s'", path);
1611
1612         if (old_head && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1613                 /* Check if the submodule has a dirty index. */
1614                 if (submodule_has_dirty_index(sub))
1615                         return error(_("submodule '%s' has dirty index"), path);
1616         }
1617
1618         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1619                 if (old_head) {
1620                         if (!submodule_uses_gitfile(path))
1621                                 absorb_git_dir_into_superproject("", path,
1622                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1623                 } else {
1624                         char *gitdir = xstrfmt("%s/modules/%s",
1625                                     get_git_common_dir(), sub->name);
1626                         connect_work_tree_and_git_dir(path, gitdir);
1627                         free(gitdir);
1628
1629                         /* make sure the index is clean as well */
1630                         submodule_reset_index(path);
1631                 }
1632
1633                 if (old_head && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1634                         char *gitdir = xstrfmt("%s/modules/%s",
1635                                     get_git_common_dir(), sub->name);
1636                         connect_work_tree_and_git_dir(path, gitdir);
1637                         free(gitdir);
1638                 }
1639         }
1640
1641         prepare_submodule_repo_env(&cp.env_array);
1642
1643         cp.git_cmd = 1;
1644         cp.no_stdin = 1;
1645         cp.dir = path;
1646
1647         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1648                         get_super_prefix_or_empty(), path);
1649         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1650
1651         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1652                 argv_array_push(&cp.args, "-n");
1653         else
1654                 argv_array_push(&cp.args, "-u");
1655
1656         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1657                 argv_array_push(&cp.args, "--reset");
1658         else
1659                 argv_array_push(&cp.args, "-m");
1660
1661         if (!(flags & SUBMODULE_MOVE_HEAD_FORCE))
1662                 argv_array_push(&cp.args, old_head ? old_head : EMPTY_TREE_SHA1_HEX);
1663
1664         argv_array_push(&cp.args, new_head ? new_head : EMPTY_TREE_SHA1_HEX);
1665
1666         if (run_command(&cp)) {
1667                 ret = -1;
1668                 goto out;
1669         }
1670
1671         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1672                 if (new_head) {
1673                         child_process_init(&cp);
1674                         /* also set the HEAD accordingly */
1675                         cp.git_cmd = 1;
1676                         cp.no_stdin = 1;
1677                         cp.dir = path;
1678
1679                         prepare_submodule_repo_env(&cp.env_array);
1680                         argv_array_pushl(&cp.args, "update-ref", "HEAD",
1681                                          "--no-deref", new_head, NULL);
1682
1683                         if (run_command(&cp)) {
1684                                 ret = -1;
1685                                 goto out;
1686                         }
1687                 } else {
1688                         struct strbuf sb = STRBUF_INIT;
1689
1690                         strbuf_addf(&sb, "%s/.git", path);
1691                         unlink_or_warn(sb.buf);
1692                         strbuf_release(&sb);
1693
1694                         if (is_empty_dir(path))
1695                                 rmdir_or_warn(path);
1696                 }
1697         }
1698 out:
1699         return ret;
1700 }
1701
1702 static int find_first_merges(struct object_array *result, const char *path,
1703                 struct commit *a, struct commit *b)
1704 {
1705         int i, j;
1706         struct object_array merges = OBJECT_ARRAY_INIT;
1707         struct commit *commit;
1708         int contains_another;
1709
1710         char merged_revision[42];
1711         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1712                                    "--all", merged_revision, NULL };
1713         struct rev_info revs;
1714         struct setup_revision_opt rev_opts;
1715
1716         memset(result, 0, sizeof(struct object_array));
1717         memset(&rev_opts, 0, sizeof(rev_opts));
1718
1719         /* get all revisions that merge commit a */
1720         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1721                         oid_to_hex(&a->object.oid));
1722         init_revisions(&revs, NULL);
1723         rev_opts.submodule = path;
1724         /* FIXME: can't handle linked worktrees in submodules yet */
1725         revs.single_worktree = path != NULL;
1726         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1727
1728         /* save all revisions from the above list that contain b */
1729         if (prepare_revision_walk(&revs))
1730                 die("revision walk setup failed");
1731         while ((commit = get_revision(&revs)) != NULL) {
1732                 struct object *o = &(commit->object);
1733                 if (in_merge_bases(b, commit))
1734                         add_object_array(o, NULL, &merges);
1735         }
1736         reset_revision_walk();
1737
1738         /* Now we've got all merges that contain a and b. Prune all
1739          * merges that contain another found merge and save them in
1740          * result.
1741          */
1742         for (i = 0; i < merges.nr; i++) {
1743                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1744
1745                 contains_another = 0;
1746                 for (j = 0; j < merges.nr; j++) {
1747                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1748                         if (i != j && in_merge_bases(m2, m1)) {
1749                                 contains_another = 1;
1750                                 break;
1751                         }
1752                 }
1753
1754                 if (!contains_another)
1755                         add_object_array(merges.objects[i].item, NULL, result);
1756         }
1757
1758         object_array_clear(&merges);
1759         return result->nr;
1760 }
1761
1762 static void print_commit(struct commit *commit)
1763 {
1764         struct strbuf sb = STRBUF_INIT;
1765         struct pretty_print_context ctx = {0};
1766         ctx.date_mode.type = DATE_NORMAL;
1767         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1768         fprintf(stderr, "%s\n", sb.buf);
1769         strbuf_release(&sb);
1770 }
1771
1772 #define MERGE_WARNING(path, msg) \
1773         warning("Failed to merge submodule %s (%s)", path, msg);
1774
1775 int merge_submodule(struct object_id *result, const char *path,
1776                     const struct object_id *base, const struct object_id *a,
1777                     const struct object_id *b, int search)
1778 {
1779         struct commit *commit_base, *commit_a, *commit_b;
1780         int parent_count;
1781         struct object_array merges;
1782
1783         int i;
1784
1785         /* store a in result in case we fail */
1786         oidcpy(result, a);
1787
1788         /* we can not handle deletion conflicts */
1789         if (is_null_oid(base))
1790                 return 0;
1791         if (is_null_oid(a))
1792                 return 0;
1793         if (is_null_oid(b))
1794                 return 0;
1795
1796         if (add_submodule_odb(path)) {
1797                 MERGE_WARNING(path, "not checked out");
1798                 return 0;
1799         }
1800
1801         if (!(commit_base = lookup_commit_reference(base)) ||
1802             !(commit_a = lookup_commit_reference(a)) ||
1803             !(commit_b = lookup_commit_reference(b))) {
1804                 MERGE_WARNING(path, "commits not present");
1805                 return 0;
1806         }
1807
1808         /* check whether both changes are forward */
1809         if (!in_merge_bases(commit_base, commit_a) ||
1810             !in_merge_bases(commit_base, commit_b)) {
1811                 MERGE_WARNING(path, "commits don't follow merge-base");
1812                 return 0;
1813         }
1814
1815         /* Case #1: a is contained in b or vice versa */
1816         if (in_merge_bases(commit_a, commit_b)) {
1817                 oidcpy(result, b);
1818                 return 1;
1819         }
1820         if (in_merge_bases(commit_b, commit_a)) {
1821                 oidcpy(result, a);
1822                 return 1;
1823         }
1824
1825         /*
1826          * Case #2: There are one or more merges that contain a and b in
1827          * the submodule. If there is only one, then present it as a
1828          * suggestion to the user, but leave it marked unmerged so the
1829          * user needs to confirm the resolution.
1830          */
1831
1832         /* Skip the search if makes no sense to the calling context.  */
1833         if (!search)
1834                 return 0;
1835
1836         /* find commit which merges them */
1837         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1838         switch (parent_count) {
1839         case 0:
1840                 MERGE_WARNING(path, "merge following commits not found");
1841                 break;
1842
1843         case 1:
1844                 MERGE_WARNING(path, "not fast-forward");
1845                 fprintf(stderr, "Found a possible merge resolution "
1846                                 "for the submodule:\n");
1847                 print_commit((struct commit *) merges.objects[0].item);
1848                 fprintf(stderr,
1849                         "If this is correct simply add it to the index "
1850                         "for example\n"
1851                         "by using:\n\n"
1852                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1853                         "which will accept this suggestion.\n",
1854                         oid_to_hex(&merges.objects[0].item->oid), path);
1855                 break;
1856
1857         default:
1858                 MERGE_WARNING(path, "multiple merges found");
1859                 for (i = 0; i < merges.nr; i++)
1860                         print_commit((struct commit *) merges.objects[i].item);
1861         }
1862
1863         object_array_clear(&merges);
1864         return 0;
1865 }
1866
1867 /*
1868  * Embeds a single submodules git directory into the superprojects git dir,
1869  * non recursively.
1870  */
1871 static void relocate_single_git_dir_into_superproject(const char *prefix,
1872                                                       const char *path)
1873 {
1874         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1875         const char *new_git_dir;
1876         const struct submodule *sub;
1877
1878         if (submodule_uses_worktrees(path))
1879                 die(_("relocate_gitdir for submodule '%s' with "
1880                       "more than one worktree not supported"), path);
1881
1882         old_git_dir = xstrfmt("%s/.git", path);
1883         if (read_gitfile(old_git_dir))
1884                 /* If it is an actual gitfile, it doesn't need migration. */
1885                 return;
1886
1887         real_old_git_dir = real_pathdup(old_git_dir, 1);
1888
1889         sub = submodule_from_path(&null_oid, path);
1890         if (!sub)
1891                 die(_("could not lookup name for submodule '%s'"), path);
1892
1893         new_git_dir = git_path("modules/%s", sub->name);
1894         if (safe_create_leading_directories_const(new_git_dir) < 0)
1895                 die(_("could not create directory '%s'"), new_git_dir);
1896         real_new_git_dir = real_pathdup(new_git_dir, 1);
1897
1898         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1899                 get_super_prefix_or_empty(), path,
1900                 real_old_git_dir, real_new_git_dir);
1901
1902         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1903
1904         free(old_git_dir);
1905         free(real_old_git_dir);
1906         free(real_new_git_dir);
1907 }
1908
1909 /*
1910  * Migrate the git directory of the submodule given by path from
1911  * having its git directory within the working tree to the git dir nested
1912  * in its superprojects git dir under modules/.
1913  */
1914 void absorb_git_dir_into_superproject(const char *prefix,
1915                                       const char *path,
1916                                       unsigned flags)
1917 {
1918         int err_code;
1919         const char *sub_git_dir;
1920         struct strbuf gitdir = STRBUF_INIT;
1921         strbuf_addf(&gitdir, "%s/.git", path);
1922         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1923
1924         /* Not populated? */
1925         if (!sub_git_dir) {
1926                 const struct submodule *sub;
1927
1928                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1929                         /* unpopulated as expected */
1930                         strbuf_release(&gitdir);
1931                         return;
1932                 }
1933
1934                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1935                         /* We don't know what broke here. */
1936                         read_gitfile_error_die(err_code, path, NULL);
1937
1938                 /*
1939                 * Maybe populated, but no git directory was found?
1940                 * This can happen if the superproject is a submodule
1941                 * itself and was just absorbed. The absorption of the
1942                 * superproject did not rewrite the git file links yet,
1943                 * fix it now.
1944                 */
1945                 sub = submodule_from_path(&null_oid, path);
1946                 if (!sub)
1947                         die(_("could not lookup name for submodule '%s'"), path);
1948                 connect_work_tree_and_git_dir(path,
1949                         git_path("modules/%s", sub->name));
1950         } else {
1951                 /* Is it already absorbed into the superprojects git dir? */
1952                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1953                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1954
1955                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1956                         relocate_single_git_dir_into_superproject(prefix, path);
1957
1958                 free(real_sub_git_dir);
1959                 free(real_common_git_dir);
1960         }
1961         strbuf_release(&gitdir);
1962
1963         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1964                 struct child_process cp = CHILD_PROCESS_INIT;
1965                 struct strbuf sb = STRBUF_INIT;
1966
1967                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1968                         die("BUG: we don't know how to pass the flags down?");
1969
1970                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1971                 strbuf_addstr(&sb, path);
1972                 strbuf_addch(&sb, '/');
1973
1974                 cp.dir = path;
1975                 cp.git_cmd = 1;
1976                 cp.no_stdin = 1;
1977                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1978                                            "submodule--helper",
1979                                            "absorb-git-dirs", NULL);
1980                 prepare_submodule_repo_env(&cp.env_array);
1981                 if (run_command(&cp))
1982                         die(_("could not recurse into submodule '%s'"), path);
1983
1984                 strbuf_release(&sb);
1985         }
1986 }
1987
1988 const char *get_superproject_working_tree(void)
1989 {
1990         struct child_process cp = CHILD_PROCESS_INIT;
1991         struct strbuf sb = STRBUF_INIT;
1992         const char *one_up = real_path_if_valid("../");
1993         const char *cwd = xgetcwd();
1994         const char *ret = NULL;
1995         const char *subpath;
1996         int code;
1997         ssize_t len;
1998
1999         if (!is_inside_work_tree())
2000                 /*
2001                  * FIXME:
2002                  * We might have a superproject, but it is harder
2003                  * to determine.
2004                  */
2005                 return NULL;
2006
2007         if (!one_up)
2008                 return NULL;
2009
2010         subpath = relative_path(cwd, one_up, &sb);
2011
2012         prepare_submodule_repo_env(&cp.env_array);
2013         argv_array_pop(&cp.env_array);
2014
2015         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
2016                         "ls-files", "-z", "--stage", "--full-name", "--",
2017                         subpath, NULL);
2018         strbuf_reset(&sb);
2019
2020         cp.no_stdin = 1;
2021         cp.no_stderr = 1;
2022         cp.out = -1;
2023         cp.git_cmd = 1;
2024
2025         if (start_command(&cp))
2026                 die(_("could not start ls-files in .."));
2027
2028         len = strbuf_read(&sb, cp.out, PATH_MAX);
2029         close(cp.out);
2030
2031         if (starts_with(sb.buf, "160000")) {
2032                 int super_sub_len;
2033                 int cwd_len = strlen(cwd);
2034                 char *super_sub, *super_wt;
2035
2036                 /*
2037                  * There is a superproject having this repo as a submodule.
2038                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
2039                  * We're only interested in the name after the tab.
2040                  */
2041                 super_sub = strchr(sb.buf, '\t') + 1;
2042                 super_sub_len = sb.buf + sb.len - super_sub - 1;
2043
2044                 if (super_sub_len > cwd_len ||
2045                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
2046                         die (_("BUG: returned path string doesn't match cwd?"));
2047
2048                 super_wt = xstrdup(cwd);
2049                 super_wt[cwd_len - super_sub_len] = '\0';
2050
2051                 ret = real_path(super_wt);
2052                 free(super_wt);
2053         }
2054         strbuf_release(&sb);
2055
2056         code = finish_command(&cp);
2057
2058         if (code == 128)
2059                 /* '../' is not a git repository */
2060                 return NULL;
2061         if (code == 0 && len == 0)
2062                 /* There is an unrelated git repository at '../' */
2063                 return NULL;
2064         if (code)
2065                 die(_("ls-tree returned unexpected return code %d"), code);
2066
2067         return ret;
2068 }
2069
2070 /*
2071  * Put the gitdir for a submodule (given relative to the main
2072  * repository worktree) into `buf`, or return -1 on error.
2073  */
2074 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2075 {
2076         const struct submodule *sub;
2077         const char *git_dir;
2078         int ret = 0;
2079
2080         strbuf_reset(buf);
2081         strbuf_addstr(buf, submodule);
2082         strbuf_complete(buf, '/');
2083         strbuf_addstr(buf, ".git");
2084
2085         git_dir = read_gitfile(buf->buf);
2086         if (git_dir) {
2087                 strbuf_reset(buf);
2088                 strbuf_addstr(buf, git_dir);
2089         }
2090         if (!is_git_directory(buf->buf)) {
2091                 sub = submodule_from_path(&null_oid, submodule);
2092                 if (!sub) {
2093                         ret = -1;
2094                         goto cleanup;
2095                 }
2096                 strbuf_reset(buf);
2097                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2098         }
2099
2100 cleanup:
2101         return ret;
2102 }