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 #include "commit-reach.h"
  26
  27 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
  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 is safe to write.
  55  *
  56  * Writing to the .gitmodules file requires that the file exists in the
  57  * working tree or, if it doesn't, that a brand new .gitmodules file is going
  58  * to be created (i.e. it's neither in the index nor in the current branch).
  59  *
  60  * It is not safe to write to .gitmodules if it's not in the working tree but
  61  * it is in the index or in the current branch, because writing new values
  62  * (and staging them) would blindly overwrite ALL the old content.
  63  */
  64 int is_writing_gitmodules_ok(void)
  65 {
  66         struct object_id oid;
  67         return file_exists(GITMODULES_FILE) ||
  68                 (get_oid(GITMODULES_INDEX, &oid) < 0 && get_oid(GITMODULES_HEAD, &oid) < 0);
  69 }
  70
  71 /*
  72  * Check if the .gitmodules file has unstaged modifications.  This must be
  73  * checked before allowing modifications to the .gitmodules file with the
  74  * intention to stage them later, because when continuing we would stage the
  75  * modifications the user didn't stage herself too. That might change in a
  76  * future version when we learn to stage the changes we do ourselves without
  77  * staging any previous modifications.
  78  */
  79 int is_staging_gitmodules_ok(struct index_state *istate)
  80 {
  81         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  82
  83         if ((pos >= 0) && (pos < istate->cache_nr)) {
  84                 struct stat st;
  85                 if (lstat(GITMODULES_FILE, &st) == 0 &&
  86                     ie_match_stat(istate, istate->cache[pos], &st, 0) & DATA_CHANGED)
  87                         return 0;
  88         }
  89
  90         return 1;
  91 }
  92
  93 static int for_each_remote_ref_submodule(const char *submodule,
  94                                          each_ref_fn fn, void *cb_data)
  95 {
  96         return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
  97                                         fn, cb_data);
  98 }
  99
 100 /*
 101  * Try to update the "path" entry in the "submodule.<name>" section of the
 102  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
 103  * with the correct path=<oldpath> setting was found and we could update it.
 104  */
 105 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
 106 {
 107         struct strbuf entry = STRBUF_INIT;
 108         const struct submodule *submodule;
 109         int ret;
 110
 111         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
 112                 return -1;
 113
 114         if (is_gitmodules_unmerged(the_repository->index))
 115                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 116
 117         submodule = submodule_from_path(the_repository, &null_oid, oldpath);
 118         if (!submodule || !submodule->name) {
 119                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
 120                 return -1;
 121         }
 122         strbuf_addstr(&entry, "submodule.");
 123         strbuf_addstr(&entry, submodule->name);
 124         strbuf_addstr(&entry, ".path");
 125         ret = config_set_in_gitmodules_file_gently(entry.buf, newpath);
 126         strbuf_release(&entry);
 127         return ret;
 128 }
 129
 130 /*
 131  * Try to remove the "submodule.<name>" section from .gitmodules where the given
 132  * path is configured. Return 0 only if a .gitmodules file was found, a section
 133  * with the correct path=<path> setting was found and we could remove it.
 134  */
 135 int remove_path_from_gitmodules(const char *path)
 136 {
 137         struct strbuf sect = STRBUF_INIT;
 138         const struct submodule *submodule;
 139
 140         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
 141                 return -1;
 142
 143         if (is_gitmodules_unmerged(the_repository->index))
 144                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 145
 146         submodule = submodule_from_path(the_repository, &null_oid, path);
 147         if (!submodule || !submodule->name) {
 148                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 149                 return -1;
 150         }
 151         strbuf_addstr(&sect, "submodule.");
 152         strbuf_addstr(&sect, submodule->name);
 153         if (git_config_rename_section_in_file(GITMODULES_FILE, sect.buf, NULL) < 0) {
 154                 /* Maybe the user already did that, don't error out here */
 155                 warning(_("Could not remove .gitmodules entry for %s"), path);
 156                 strbuf_release(&sect);
 157                 return -1;
 158         }
 159         strbuf_release(&sect);
 160         return 0;
 161 }
 162
 163 void stage_updated_gitmodules(struct index_state *istate)
 164 {
 165         if (add_file_to_index(istate, GITMODULES_FILE, 0))
 166                 die(_("staging updated .gitmodules failed"));
 167 }
 168
 169 /* TODO: remove this function, use repo_submodule_init instead. */
 170 int add_submodule_odb(const char *path)
 171 {
 172         struct strbuf objects_directory = STRBUF_INIT;
 173         int ret = 0;
 174
 175         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
 176         if (ret)
 177                 goto done;
 178         if (!is_directory(objects_directory.buf)) {
 179                 ret = -1;
 180                 goto done;
 181         }
 182         add_to_alternates_memory(objects_directory.buf);
 183 done:
 184         strbuf_release(&objects_directory);
 185         return ret;
 186 }
 187
 188 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 189                                              const char *path)
 190 {
 191         const struct submodule *submodule = submodule_from_path(the_repository,
 192                                                                 &null_oid, path);
 193         if (submodule) {
 194                 const char *ignore;
 195                 char *key;
 196
 197                 key = xstrfmt("submodule.%s.ignore", submodule->name);
 198                 if (repo_config_get_string_const(the_repository, key, &ignore))
 199                         ignore = submodule->ignore;
 200                 free(key);
 201
 202                 if (ignore)
 203                         handle_ignore_submodules_arg(diffopt, ignore);
 204                 else if (is_gitmodules_unmerged(the_repository->index))
 205                         diffopt->flags.ignore_submodules = 1;
 206         }
 207 }
 208
 209 /* Cheap function that only determines if we're interested in submodules at all */
 210 int git_default_submodule_config(const char *var, const char *value, void *cb)
 211 {
 212         if (!strcmp(var, "submodule.recurse")) {
 213                 int v = git_config_bool(var, value) ?
 214                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 215                 config_update_recurse_submodules = v;
 216         }
 217         return 0;
 218 }
 219
 220 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 221                                                      const char *arg, int unset)
 222 {
 223         if (unset) {
 224                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 225                 return 0;
 226         }
 227         if (arg)
 228                 config_update_recurse_submodules =
 229                         parse_update_recurse_submodules_arg(opt->long_name,
 230                                                             arg);
 231         else
 232                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 233
 234         return 0;
 235 }
 236
 237 /*
 238  * Determine if a submodule has been initialized at a given 'path'
 239  */
 240 int is_submodule_active(struct repository *repo, const char *path)
 241 {
 242         int ret = 0;
 243         char *key = NULL;
 244         char *value = NULL;
 245         const struct string_list *sl;
 246         const struct submodule *module;
 247
 248         module = submodule_from_path(repo, &null_oid, path);
 249
 250         /* early return if there isn't a path->module mapping */
 251         if (!module)
 252                 return 0;
 253
 254         /* submodule.<name>.active is set */
 255         key = xstrfmt("submodule.%s.active", module->name);
 256         if (!repo_config_get_bool(repo, key, &ret)) {
 257                 free(key);
 258                 return ret;
 259         }
 260         free(key);
 261
 262         /* submodule.active is set */
 263         sl = repo_config_get_value_multi(repo, "submodule.active");
 264         if (sl) {
 265                 struct pathspec ps;
 266                 struct argv_array args = ARGV_ARRAY_INIT;
 267                 const struct string_list_item *item;
 268
 269                 for_each_string_list_item(item, sl) {
 270                         argv_array_push(&args, item->string);
 271                 }
 272
 273                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 274                 ret = match_pathspec(repo->index, &ps, path, strlen(path), 0, NULL, 1);
 275
 276                 argv_array_clear(&args);
 277                 clear_pathspec(&ps);
 278                 return ret;
 279         }
 280
 281         /* fallback to checking if the URL is set */
 282         key = xstrfmt("submodule.%s.url", module->name);
 283         ret = !repo_config_get_string(repo, key, &value);
 284
 285         free(value);
 286         free(key);
 287         return ret;
 288 }
 289
 290 int is_submodule_populated_gently(const char *path, int *return_error_code)
 291 {
 292         int ret = 0;
 293         char *gitdir = xstrfmt("%s/.git", path);
 294
 295         if (resolve_gitdir_gently(gitdir, return_error_code))
 296                 ret = 1;
 297
 298         free(gitdir);
 299         return ret;
 300 }
 301
 302 /*
 303  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 304  */
 305 void die_in_unpopulated_submodule(const struct index_state *istate,
 306                                   const char *prefix)
 307 {
 308         int i, prefixlen;
 309
 310         if (!prefix)
 311                 return;
 312
 313         prefixlen = strlen(prefix);
 314
 315         for (i = 0; i < istate->cache_nr; i++) {
 316                 struct cache_entry *ce = istate->cache[i];
 317                 int ce_len = ce_namelen(ce);
 318
 319                 if (!S_ISGITLINK(ce->ce_mode))
 320                         continue;
 321                 if (prefixlen <= ce_len)
 322                         continue;
 323                 if (strncmp(ce->name, prefix, ce_len))
 324                         continue;
 325                 if (prefix[ce_len] != '/')
 326                         continue;
 327
 328                 die(_("in unpopulated submodule '%s'"), ce->name);
 329         }
 330 }
 331
 332 /*
 333  * Dies if any paths in the provided pathspec descends into a submodule
 334  */
 335 void die_path_inside_submodule(const struct index_state *istate,
 336                                const struct pathspec *ps)
 337 {
 338         int i, j;
 339
 340         for (i = 0; i < istate->cache_nr; i++) {
 341                 struct cache_entry *ce = istate->cache[i];
 342                 int ce_len = ce_namelen(ce);
 343
 344                 if (!S_ISGITLINK(ce->ce_mode))
 345                         continue;
 346
 347                 for (j = 0; j < ps->nr ; j++) {
 348                         const struct pathspec_item *item = &ps->items[j];
 349
 350                         if (item->len <= ce_len)
 351                                 continue;
 352                         if (item->match[ce_len] != '/')
 353                                 continue;
 354                         if (strncmp(ce->name, item->match, ce_len))
 355                                 continue;
 356                         if (item->len == ce_len + 1)
 357                                 continue;
 358
 359                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 360                             item->original, ce_len, ce->name);
 361                 }
 362         }
 363 }
 364
 365 enum submodule_update_type parse_submodule_update_type(const char *value)
 366 {
 367         if (!strcmp(value, "none"))
 368                 return SM_UPDATE_NONE;
 369         else if (!strcmp(value, "checkout"))
 370                 return SM_UPDATE_CHECKOUT;
 371         else if (!strcmp(value, "rebase"))
 372                 return SM_UPDATE_REBASE;
 373         else if (!strcmp(value, "merge"))
 374                 return SM_UPDATE_MERGE;
 375         else if (*value == '!')
 376                 return SM_UPDATE_COMMAND;
 377         else
 378                 return SM_UPDATE_UNSPECIFIED;
 379 }
 380
 381 int parse_submodule_update_strategy(const char *value,
 382                 struct submodule_update_strategy *dst)
 383 {
 384         enum submodule_update_type type;
 385
 386         free((void*)dst->command);
 387         dst->command = NULL;
 388
 389         type = parse_submodule_update_type(value);
 390         if (type == SM_UPDATE_UNSPECIFIED)
 391                 return -1;
 392
 393         dst->type = type;
 394         if (type == SM_UPDATE_COMMAND)
 395                 dst->command = xstrdup(value + 1);
 396
 397         return 0;
 398 }
 399
 400 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 401 {
 402         struct strbuf sb = STRBUF_INIT;
 403         switch (s->type) {
 404         case SM_UPDATE_CHECKOUT:
 405                 return "checkout";
 406         case SM_UPDATE_MERGE:
 407                 return "merge";
 408         case SM_UPDATE_REBASE:
 409                 return "rebase";
 410         case SM_UPDATE_NONE:
 411                 return "none";
 412         case SM_UPDATE_UNSPECIFIED:
 413                 return NULL;
 414         case SM_UPDATE_COMMAND:
 415                 strbuf_addf(&sb, "!%s", s->command);
 416                 return strbuf_detach(&sb, NULL);
 417         }
 418         return NULL;
 419 }
 420
 421 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 422                                   const char *arg)
 423 {
 424         diffopt->flags.ignore_submodules = 0;
 425         diffopt->flags.ignore_untracked_in_submodules = 0;
 426         diffopt->flags.ignore_dirty_submodules = 0;
 427
 428         if (!strcmp(arg, "all"))
 429                 diffopt->flags.ignore_submodules = 1;
 430         else if (!strcmp(arg, "untracked"))
 431                 diffopt->flags.ignore_untracked_in_submodules = 1;
 432         else if (!strcmp(arg, "dirty"))
 433                 diffopt->flags.ignore_dirty_submodules = 1;
 434         else if (strcmp(arg, "none"))
 435                 die("bad --ignore-submodules argument: %s", arg);
 436 }
 437
 438 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 439                 struct commit *left, struct commit *right,
 440                 struct commit_list *merge_bases)
 441 {
 442         struct commit_list *list;
 443
 444         repo_init_revisions(the_repository, rev, NULL);
 445         setup_revisions(0, NULL, rev, NULL);
 446         rev->left_right = 1;
 447         rev->first_parent_only = 1;
 448         left->object.flags |= SYMMETRIC_LEFT;
 449         add_pending_object(rev, &left->object, path);
 450         add_pending_object(rev, &right->object, path);
 451         for (list = merge_bases; list; list = list->next) {
 452                 list->item->object.flags |= UNINTERESTING;
 453                 add_pending_object(rev, &list->item->object,
 454                         oid_to_hex(&list->item->object.oid));
 455         }
 456         return prepare_revision_walk(rev);
 457 }
 458
 459 static void print_submodule_summary(struct repository *r, struct rev_info *rev, struct diff_options *o)
 460 {
 461         static const char format[] = "  %m %s";
 462         struct strbuf sb = STRBUF_INIT;
 463         struct commit *commit;
 464
 465         while ((commit = get_revision(rev))) {
 466                 struct pretty_print_context ctx = {0};
 467                 ctx.date_mode = rev->date_mode;
 468                 ctx.output_encoding = get_log_output_encoding();
 469                 strbuf_setlen(&sb, 0);
 470                 repo_format_commit_message(r, commit, format, &sb,
 471                                       &ctx);
 472                 strbuf_addch(&sb, '\n');
 473                 if (commit->object.flags & SYMMETRIC_LEFT)
 474                         diff_emit_submodule_del(o, sb.buf);
 475                 else
 476                         diff_emit_submodule_add(o, sb.buf);
 477         }
 478         strbuf_release(&sb);
 479 }
 480
 481 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 482 {
 483         const char * const *var;
 484
 485         for (var = local_repo_env; *var; var++) {
 486                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 487                         argv_array_push(out, *var);
 488         }
 489 }
 490
 491 void prepare_submodule_repo_env(struct argv_array *out)
 492 {
 493         prepare_submodule_repo_env_no_git_dir(out);
 494         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 495                          DEFAULT_GIT_DIR_ENVIRONMENT);
 496 }
 497
 498 static void prepare_submodule_repo_env_in_gitdir(struct argv_array *out)
 499 {
 500         prepare_submodule_repo_env_no_git_dir(out);
 501         argv_array_pushf(out, "%s=.", GIT_DIR_ENVIRONMENT);
 502 }
 503
 504 /*
 505  * Initialize a repository struct for a submodule based on the provided 'path'.
 506  *
 507  * Unlike repo_submodule_init, this tolerates submodules not present
 508  * in .gitmodules. This function exists only to preserve historical behavior,
 509  *
 510  * Returns the repository struct on success,
 511  * NULL when the submodule is not present.
 512  */
 513 static struct repository *open_submodule(const char *path)
 514 {
 515         struct strbuf sb = STRBUF_INIT;
 516         struct repository *out = xmalloc(sizeof(*out));
 517
 518         if (submodule_to_gitdir(&sb, path) || repo_init(out, sb.buf, NULL)) {
 519                 strbuf_release(&sb);
 520                 free(out);
 521                 return NULL;
 522         }
 523
 524         /* Mark it as a submodule */
 525         out->submodule_prefix = xstrdup(path);
 526
 527         strbuf_release(&sb);
 528         return out;
 529 }
 530
 531 /*
 532  * Helper function to display the submodule header line prior to the full
 533  * summary output.
 534  *
 535  * If it can locate the submodule git directory it will create a repository
 536  * handle for the submodule and lookup both the left and right commits and
 537  * put them into the left and right pointers.
 538  */
 539 static void show_submodule_header(struct diff_options *o,
 540                 const char *path,
 541                 struct object_id *one, struct object_id *two,
 542                 unsigned dirty_submodule,
 543                 struct repository *sub,
 544                 struct commit **left, struct commit **right,
 545                 struct commit_list **merge_bases)
 546 {
 547         const char *message = NULL;
 548         struct strbuf sb = STRBUF_INIT;
 549         int fast_forward = 0, fast_backward = 0;
 550
 551         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 552                 diff_emit_submodule_untracked(o, path);
 553
 554         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 555                 diff_emit_submodule_modified(o, path);
 556
 557         if (is_null_oid(one))
 558                 message = "(new submodule)";
 559         else if (is_null_oid(two))
 560                 message = "(submodule deleted)";
 561
 562         if (!sub) {
 563                 if (!message)
 564                         message = "(commits not present)";
 565                 goto output_header;
 566         }
 567
 568         /*
 569          * Attempt to lookup the commit references, and determine if this is
 570          * a fast forward or fast backwards update.
 571          */
 572         *left = lookup_commit_reference(sub, one);
 573         *right = lookup_commit_reference(sub, two);
 574
 575         /*
 576          * Warn about missing commits in the submodule project, but only if
 577          * they aren't null.
 578          */
 579         if ((!is_null_oid(one) && !*left) ||
 580              (!is_null_oid(two) && !*right))
 581                 message = "(commits not present)";
 582
 583         *merge_bases = repo_get_merge_bases(sub, *left, *right);
 584         if (*merge_bases) {
 585                 if ((*merge_bases)->item == *left)
 586                         fast_forward = 1;
 587                 else if ((*merge_bases)->item == *right)
 588                         fast_backward = 1;
 589         }
 590
 591         if (oideq(one, two)) {
 592                 strbuf_release(&sb);
 593                 return;
 594         }
 595
 596 output_header:
 597         strbuf_addf(&sb, "Submodule %s ", path);
 598         strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
 599         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 600         strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
 601         if (message)
 602                 strbuf_addf(&sb, " %s\n", message);
 603         else
 604                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 605         diff_emit_submodule_header(o, sb.buf);
 606
 607         strbuf_release(&sb);
 608 }
 609
 610 void show_submodule_summary(struct diff_options *o, const char *path,
 611                 struct object_id *one, struct object_id *two,
 612                 unsigned dirty_submodule)
 613 {
 614         struct rev_info rev;
 615         struct commit *left = NULL, *right = NULL;
 616         struct commit_list *merge_bases = NULL;
 617         struct repository *sub;
 618
 619         sub = open_submodule(path);
 620         show_submodule_header(o, path, one, two, dirty_submodule,
 621                               sub, &left, &right, &merge_bases);
 622
 623         /*
 624          * If we don't have both a left and a right pointer, there is no
 625          * reason to try and display a summary. The header line should contain
 626          * all the information the user needs.
 627          */
 628         if (!left || !right || !sub)
 629                 goto out;
 630
 631         /* Treat revision walker failure the same as missing commits */
 632         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 633                 diff_emit_submodule_error(o, "(revision walker failed)\n");
 634                 goto out;
 635         }
 636
 637         print_submodule_summary(sub, &rev, o);
 638
 639 out:
 640         if (merge_bases)
 641                 free_commit_list(merge_bases);
 642         clear_commit_marks(left, ~0);
 643         clear_commit_marks(right, ~0);
 644         if (sub) {
 645                 repo_clear(sub);
 646                 free(sub);
 647         }
 648 }
 649
 650 void show_submodule_inline_diff(struct diff_options *o, const char *path,
 651                 struct object_id *one, struct object_id *two,
 652                 unsigned dirty_submodule)
 653 {
 654         const struct object_id *old_oid = the_hash_algo->empty_tree, *new_oid = the_hash_algo->empty_tree;
 655         struct commit *left = NULL, *right = NULL;
 656         struct commit_list *merge_bases = NULL;
 657         struct child_process cp = CHILD_PROCESS_INIT;
 658         struct strbuf sb = STRBUF_INIT;
 659         struct repository *sub;
 660
 661         sub = open_submodule(path);
 662         show_submodule_header(o, path, one, two, dirty_submodule,
 663                               sub, &left, &right, &merge_bases);
 664
 665         /* We need a valid left and right commit to display a difference */
 666         if (!(left || is_null_oid(one)) ||
 667             !(right || is_null_oid(two)))
 668                 goto done;
 669
 670         if (left)
 671                 old_oid = one;
 672         if (right)
 673                 new_oid = two;
 674
 675         cp.git_cmd = 1;
 676         cp.dir = path;
 677         cp.out = -1;
 678         cp.no_stdin = 1;
 679
 680         /* TODO: other options may need to be passed here. */
 681         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 682         argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 683                          "always" : "never");
 684
 685         if (o->flags.reverse_diff) {
 686                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 687                                  o->b_prefix, path);
 688                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 689                                  o->a_prefix, path);
 690         } else {
 691                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 692                                  o->a_prefix, path);
 693                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 694                                  o->b_prefix, path);
 695         }
 696         argv_array_push(&cp.args, oid_to_hex(old_oid));
 697         /*
 698          * If the submodule has modified content, we will diff against the
 699          * work tree, under the assumption that the user has asked for the
 700          * diff format and wishes to actually see all differences even if they
 701          * haven't yet been committed to the submodule yet.
 702          */
 703         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 704                 argv_array_push(&cp.args, oid_to_hex(new_oid));
 705
 706         prepare_submodule_repo_env(&cp.env_array);
 707         if (start_command(&cp))
 708                 diff_emit_submodule_error(o, "(diff failed)\n");
 709
 710         while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
 711                 diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
 712
 713         if (finish_command(&cp))
 714                 diff_emit_submodule_error(o, "(diff failed)\n");
 715
 716 done:
 717         strbuf_release(&sb);
 718         if (merge_bases)
 719                 free_commit_list(merge_bases);
 720         if (left)
 721                 clear_commit_marks(left, ~0);
 722         if (right)
 723                 clear_commit_marks(right, ~0);
 724         if (sub) {
 725                 repo_clear(sub);
 726                 free(sub);
 727         }
 728 }
 729
 730 int should_update_submodules(void)
 731 {
 732         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 733 }
 734
 735 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 736 {
 737         if (!S_ISGITLINK(ce->ce_mode))
 738                 return NULL;
 739
 740         if (!should_update_submodules())
 741                 return NULL;
 742
 743         return submodule_from_path(the_repository, &null_oid, ce->name);
 744 }
 745
 746 static struct oid_array *submodule_commits(struct string_list *submodules,
 747                                            const char *name)
 748 {
 749         struct string_list_item *item;
 750
 751         item = string_list_insert(submodules, name);
 752         if (item->util)
 753                 return (struct oid_array *) item->util;
 754
 755         /* NEEDSWORK: should we have oid_array_init()? */
 756         item->util = xcalloc(1, sizeof(struct oid_array));
 757         return (struct oid_array *) item->util;
 758 }
 759
 760 struct collect_changed_submodules_cb_data {
 761         struct repository *repo;
 762         struct string_list *changed;
 763         const struct object_id *commit_oid;
 764 };
 765
 766 /*
 767  * this would normally be two functions: default_name_from_path() and
 768  * path_from_default_name(). Since the default name is the same as
 769  * the submodule path we can get away with just one function which only
 770  * checks whether there is a submodule in the working directory at that
 771  * location.
 772  */
 773 static const char *default_name_or_path(const char *path_or_name)
 774 {
 775         int error_code;
 776
 777         if (!is_submodule_populated_gently(path_or_name, &error_code))
 778                 return NULL;
 779
 780         return path_or_name;
 781 }
 782
 783 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 784                                           struct diff_options *options,
 785                                           void *data)
 786 {
 787         struct collect_changed_submodules_cb_data *me = data;
 788         struct string_list *changed = me->changed;
 789         const struct object_id *commit_oid = me->commit_oid;
 790         int i;
 791
 792         for (i = 0; i < q->nr; i++) {
 793                 struct diff_filepair *p = q->queue[i];
 794                 struct oid_array *commits;
 795                 const struct submodule *submodule;
 796                 const char *name;
 797
 798                 if (!S_ISGITLINK(p->two->mode))
 799                         continue;
 800
 801                 submodule = submodule_from_path(me->repo,
 802                                                 commit_oid, p->two->path);
 803                 if (submodule)
 804                         name = submodule->name;
 805                 else {
 806                         name = default_name_or_path(p->two->path);
 807                         /* make sure name does not collide with existing one */
 808                         if (name)
 809                                 submodule = submodule_from_name(me->repo,
 810                                                                 commit_oid, name);
 811                         if (submodule) {
 812                                 warning("Submodule in commit %s at path: "
 813                                         "'%s' collides with a submodule named "
 814                                         "the same. Skipping it.",
 815                                         oid_to_hex(commit_oid), p->two->path);
 816                                 name = NULL;
 817                         }
 818                 }
 819
 820                 if (!name)
 821                         continue;
 822
 823                 commits = submodule_commits(changed, name);
 824                 oid_array_append(commits, &p->two->oid);
 825         }
 826 }
 827
 828 /*
 829  * Collect the paths of submodules in 'changed' which have changed based on
 830  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 831  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 832  * what the submodule pointers were updated to during the change.
 833  */
 834 static void collect_changed_submodules(struct repository *r,
 835                                        struct string_list *changed,
 836                                        struct argv_array *argv)
 837 {
 838         struct rev_info rev;
 839         const struct commit *commit;
 840
 841         repo_init_revisions(r, &rev, NULL);
 842         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 843         if (prepare_revision_walk(&rev))
 844                 die("revision walk setup failed");
 845
 846         while ((commit = get_revision(&rev))) {
 847                 struct rev_info diff_rev;
 848                 struct collect_changed_submodules_cb_data data;
 849                 data.repo = r;
 850                 data.changed = changed;
 851                 data.commit_oid = &commit->object.oid;
 852
 853                 repo_init_revisions(r, &diff_rev, NULL);
 854                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 855                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 856                 diff_rev.diffopt.format_callback_data = &data;
 857                 diff_tree_combined_merge(commit, 1, &diff_rev);
 858         }
 859
 860         reset_revision_walk();
 861 }
 862
 863 static void free_submodules_oids(struct string_list *submodules)
 864 {
 865         struct string_list_item *item;
 866         for_each_string_list_item(item, submodules)
 867                 oid_array_clear((struct oid_array *) item->util);
 868         string_list_clear(submodules, 1);
 869 }
 870
 871 static int has_remote(const char *refname, const struct object_id *oid,
 872                       int flags, void *cb_data)
 873 {
 874         return 1;
 875 }
 876
 877 static int append_oid_to_argv(const struct object_id *oid, void *data)
 878 {
 879         struct argv_array *argv = data;
 880         argv_array_push(argv, oid_to_hex(oid));
 881         return 0;
 882 }
 883
 884 struct has_commit_data {
 885         struct repository *repo;
 886         int result;
 887         const char *path;
 888 };
 889
 890 static int check_has_commit(const struct object_id *oid, void *data)
 891 {
 892         struct has_commit_data *cb = data;
 893
 894         enum object_type type = oid_object_info(cb->repo, oid, NULL);
 895
 896         switch (type) {
 897         case OBJ_COMMIT:
 898                 return 0;
 899         case OBJ_BAD:
 900                 /*
 901                  * Object is missing or invalid. If invalid, an error message
 902                  * has already been printed.
 903                  */
 904                 cb->result = 0;
 905                 return 0;
 906         default:
 907                 die(_("submodule entry '%s' (%s) is a %s, not a commit"),
 908                     cb->path, oid_to_hex(oid), type_name(type));
 909         }
 910 }
 911
 912 static int submodule_has_commits(struct repository *r,
 913                                  const char *path,
 914                                  struct oid_array *commits)
 915 {
 916         struct has_commit_data has_commit = { r, 1, path };
 917
 918         /*
 919          * Perform a cheap, but incorrect check for the existence of 'commits'.
 920          * This is done by adding the submodule's object store to the in-core
 921          * object store, and then querying for each commit's existence.  If we
 922          * do not have the commit object anywhere, there is no chance we have
 923          * it in the object store of the correct submodule and have it
 924          * reachable from a ref, so we can fail early without spawning rev-list
 925          * which is expensive.
 926          */
 927         if (add_submodule_odb(path))
 928                 return 0;
 929
 930         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 931
 932         if (has_commit.result) {
 933                 /*
 934                  * Even if the submodule is checked out and the commit is
 935                  * present, make sure it exists in the submodule's object store
 936                  * and that it is reachable from a ref.
 937                  */
 938                 struct child_process cp = CHILD_PROCESS_INIT;
 939                 struct strbuf out = STRBUF_INIT;
 940
 941                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 942                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 943                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 944
 945                 prepare_submodule_repo_env(&cp.env_array);
 946                 cp.git_cmd = 1;
 947                 cp.no_stdin = 1;
 948                 cp.dir = path;
 949
 950                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 951                         has_commit.result = 0;
 952
 953                 strbuf_release(&out);
 954         }
 955
 956         return has_commit.result;
 957 }
 958
 959 static int submodule_needs_pushing(struct repository *r,
 960                                    const char *path,
 961                                    struct oid_array *commits)
 962 {
 963         if (!submodule_has_commits(r, path, commits))
 964                 /*
 965                  * NOTE: We do consider it safe to return "no" here. The
 966                  * correct answer would be "We do not know" instead of
 967                  * "No push needed", but it is quite hard to change
 968                  * the submodule pointer without having the submodule
 969                  * around. If a user did however change the submodules
 970                  * without having the submodule around, this indicates
 971                  * an expert who knows what they are doing or a
 972                  * maintainer integrating work from other people. In
 973                  * both cases it should be safe to skip this check.
 974                  */
 975                 return 0;
 976
 977         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 978                 struct child_process cp = CHILD_PROCESS_INIT;
 979                 struct strbuf buf = STRBUF_INIT;
 980                 int needs_pushing = 0;
 981
 982                 argv_array_push(&cp.args, "rev-list");
 983                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 984                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 985
 986                 prepare_submodule_repo_env(&cp.env_array);
 987                 cp.git_cmd = 1;
 988                 cp.no_stdin = 1;
 989                 cp.out = -1;
 990                 cp.dir = path;
 991                 if (start_command(&cp))
 992                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 993                                         path);
 994                 if (strbuf_read(&buf, cp.out, 41))
 995                         needs_pushing = 1;
 996                 finish_command(&cp);
 997                 close(cp.out);
 998                 strbuf_release(&buf);
 999                 return needs_pushing;
1000         }
1001
1002         return 0;
1003 }
1004
1005 int find_unpushed_submodules(struct repository *r,
1006                              struct oid_array *commits,
1007                              const char *remotes_name,
1008                              struct string_list *needs_pushing)
1009 {
1010         struct string_list submodules = STRING_LIST_INIT_DUP;
1011         struct string_list_item *name;
1012         struct argv_array argv = ARGV_ARRAY_INIT;
1013
1014         /* argv.argv[0] will be ignored by setup_revisions */
1015         argv_array_push(&argv, "find_unpushed_submodules");
1016         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
1017         argv_array_push(&argv, "--not");
1018         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
1019
1020         collect_changed_submodules(r, &submodules, &argv);
1021
1022         for_each_string_list_item(name, &submodules) {
1023                 struct oid_array *commits = name->util;
1024                 const struct submodule *submodule;
1025                 const char *path = NULL;
1026
1027                 submodule = submodule_from_name(r, &null_oid, name->string);
1028                 if (submodule)
1029                         path = submodule->path;
1030                 else
1031                         path = default_name_or_path(name->string);
1032
1033                 if (!path)
1034                         continue;
1035
1036                 if (submodule_needs_pushing(r, path, commits))
1037                         string_list_insert(needs_pushing, path);
1038         }
1039
1040         free_submodules_oids(&submodules);
1041         argv_array_clear(&argv);
1042
1043         return needs_pushing->nr;
1044 }
1045
1046 static int push_submodule(const char *path,
1047                           const struct remote *remote,
1048                           const struct refspec *rs,
1049                           const struct string_list *push_options,
1050                           int dry_run)
1051 {
1052         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
1053                 struct child_process cp = CHILD_PROCESS_INIT;
1054                 argv_array_push(&cp.args, "push");
1055                 if (dry_run)
1056                         argv_array_push(&cp.args, "--dry-run");
1057
1058                 if (push_options && push_options->nr) {
1059                         const struct string_list_item *item;
1060                         for_each_string_list_item(item, push_options)
1061                                 argv_array_pushf(&cp.args, "--push-option=%s",
1062                                                  item->string);
1063                 }
1064
1065                 if (remote->origin != REMOTE_UNCONFIGURED) {
1066                         int i;
1067                         argv_array_push(&cp.args, remote->name);
1068                         for (i = 0; i < rs->raw_nr; i++)
1069                                 argv_array_push(&cp.args, rs->raw[i]);
1070                 }
1071
1072                 prepare_submodule_repo_env(&cp.env_array);
1073                 cp.git_cmd = 1;
1074                 cp.no_stdin = 1;
1075                 cp.dir = path;
1076                 if (run_command(&cp))
1077                         return 0;
1078                 close(cp.out);
1079         }
1080
1081         return 1;
1082 }
1083
1084 /*
1085  * Perform a check in the submodule to see if the remote and refspec work.
1086  * Die if the submodule can't be pushed.
1087  */
1088 static void submodule_push_check(const char *path, const char *head,
1089                                  const struct remote *remote,
1090                                  const struct refspec *rs)
1091 {
1092         struct child_process cp = CHILD_PROCESS_INIT;
1093         int i;
1094
1095         argv_array_push(&cp.args, "submodule--helper");
1096         argv_array_push(&cp.args, "push-check");
1097         argv_array_push(&cp.args, head);
1098         argv_array_push(&cp.args, remote->name);
1099
1100         for (i = 0; i < rs->raw_nr; i++)
1101                 argv_array_push(&cp.args, rs->raw[i]);
1102
1103         prepare_submodule_repo_env(&cp.env_array);
1104         cp.git_cmd = 1;
1105         cp.no_stdin = 1;
1106         cp.no_stdout = 1;
1107         cp.dir = path;
1108
1109         /*
1110          * Simply indicate if 'submodule--helper push-check' failed.
1111          * More detailed error information will be provided by the
1112          * child process.
1113          */
1114         if (run_command(&cp))
1115                 die("process for submodule '%s' failed", path);
1116 }
1117
1118 int push_unpushed_submodules(struct repository *r,
1119                              struct oid_array *commits,
1120                              const struct remote *remote,
1121                              const struct refspec *rs,
1122                              const struct string_list *push_options,
1123                              int dry_run)
1124 {
1125         int i, ret = 1;
1126         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1127
1128         if (!find_unpushed_submodules(r, commits,
1129                                       remote->name, &needs_pushing))
1130                 return 1;
1131
1132         /*
1133          * Verify that the remote and refspec can be propagated to all
1134          * submodules.  This check can be skipped if the remote and refspec
1135          * won't be propagated due to the remote being unconfigured (e.g. a URL
1136          * instead of a remote name).
1137          */
1138         if (remote->origin != REMOTE_UNCONFIGURED) {
1139                 char *head;
1140                 struct object_id head_oid;
1141
1142                 head = resolve_refdup("HEAD", 0, &head_oid, NULL);
1143                 if (!head)
1144                         die(_("Failed to resolve HEAD as a valid ref."));
1145
1146                 for (i = 0; i < needs_pushing.nr; i++)
1147                         submodule_push_check(needs_pushing.items[i].string,
1148                                              head, remote, rs);
1149                 free(head);
1150         }
1151
1152         /* Actually push the submodules */
1153         for (i = 0; i < needs_pushing.nr; i++) {
1154                 const char *path = needs_pushing.items[i].string;
1155                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1156                 if (!push_submodule(path, remote, rs,
1157                                     push_options, dry_run)) {
1158                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1159                         ret = 0;
1160                 }
1161         }
1162
1163         string_list_clear(&needs_pushing, 0);
1164
1165         return ret;
1166 }
1167
1168 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1169                                int flags, void *data)
1170 {
1171         struct oid_array *array = data;
1172         oid_array_append(array, oid);
1173         return 0;
1174 }
1175
1176 void check_for_new_submodule_commits(struct object_id *oid)
1177 {
1178         if (!initialized_fetch_ref_tips) {
1179                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1180                 initialized_fetch_ref_tips = 1;
1181         }
1182
1183         oid_array_append(&ref_tips_after_fetch, oid);
1184 }
1185
1186 static void calculate_changed_submodule_paths(struct repository *r,
1187                 struct string_list *changed_submodule_names)
1188 {
1189         struct argv_array argv = ARGV_ARRAY_INIT;
1190         struct string_list_item *name;
1191
1192         /* No need to check if there are no submodules configured */
1193         if (!submodule_from_path(r, NULL, NULL))
1194                 return;
1195
1196         argv_array_push(&argv, "--"); /* argv[0] program name */
1197         oid_array_for_each_unique(&ref_tips_after_fetch,
1198                                    append_oid_to_argv, &argv);
1199         argv_array_push(&argv, "--not");
1200         oid_array_for_each_unique(&ref_tips_before_fetch,
1201                                    append_oid_to_argv, &argv);
1202
1203         /*
1204          * Collect all submodules (whether checked out or not) for which new
1205          * commits have been recorded upstream in "changed_submodule_names".
1206          */
1207         collect_changed_submodules(r, changed_submodule_names, &argv);
1208
1209         for_each_string_list_item(name, changed_submodule_names) {
1210                 struct oid_array *commits = name->util;
1211                 const struct submodule *submodule;
1212                 const char *path = NULL;
1213
1214                 submodule = submodule_from_name(r, &null_oid, name->string);
1215                 if (submodule)
1216                         path = submodule->path;
1217                 else
1218                         path = default_name_or_path(name->string);
1219
1220                 if (!path)
1221                         continue;
1222
1223                 if (submodule_has_commits(r, path, commits)) {
1224                         oid_array_clear(commits);
1225                         *name->string = '\0';
1226                 }
1227         }
1228
1229         string_list_remove_empty_items(changed_submodule_names, 1);
1230
1231         argv_array_clear(&argv);
1232         oid_array_clear(&ref_tips_before_fetch);
1233         oid_array_clear(&ref_tips_after_fetch);
1234         initialized_fetch_ref_tips = 0;
1235 }
1236
1237 int submodule_touches_in_range(struct repository *r,
1238                                struct object_id *excl_oid,
1239                                struct object_id *incl_oid)
1240 {
1241         struct string_list subs = STRING_LIST_INIT_DUP;
1242         struct argv_array args = ARGV_ARRAY_INIT;
1243         int ret;
1244
1245         /* No need to check if there are no submodules configured */
1246         if (!submodule_from_path(r, NULL, NULL))
1247                 return 0;
1248
1249         argv_array_push(&args, "--"); /* args[0] program name */
1250         argv_array_push(&args, oid_to_hex(incl_oid));
1251         if (!is_null_oid(excl_oid)) {
1252                 argv_array_push(&args, "--not");
1253                 argv_array_push(&args, oid_to_hex(excl_oid));
1254         }
1255
1256         collect_changed_submodules(r, &subs, &args);
1257         ret = subs.nr;
1258
1259         argv_array_clear(&args);
1260
1261         free_submodules_oids(&subs);
1262         return ret;
1263 }
1264
1265 struct submodule_parallel_fetch {
1266         int count;
1267         struct argv_array args;
1268         struct repository *r;
1269         const char *prefix;
1270         int command_line_option;
1271         int default_option;
1272         int quiet;
1273         int result;
1274
1275         struct string_list changed_submodule_names;
1276
1277         /* Pending fetches by OIDs */
1278         struct fetch_task **oid_fetch_tasks;
1279         int oid_fetch_tasks_nr, oid_fetch_tasks_alloc;
1280 };
1281 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0, \
1282                   STRING_LIST_INIT_DUP, \
1283                   NULL, 0, 0}
1284
1285 static int get_fetch_recurse_config(const struct submodule *submodule,
1286                                     struct submodule_parallel_fetch *spf)
1287 {
1288         if (spf->command_line_option != RECURSE_SUBMODULES_DEFAULT)
1289                 return spf->command_line_option;
1290
1291         if (submodule) {
1292                 char *key;
1293                 const char *value;
1294
1295                 int fetch_recurse = submodule->fetch_recurse;
1296                 key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1297                 if (!repo_config_get_string_const(spf->r, key, &value)) {
1298                         fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1299                 }
1300                 free(key);
1301
1302                 if (fetch_recurse != RECURSE_SUBMODULES_NONE)
1303                         /* local config overrules everything except commandline */
1304                         return fetch_recurse;
1305         }
1306
1307         return spf->default_option;
1308 }
1309
1310 /*
1311  * Fetch in progress (if callback data) or
1312  * pending (if in oid_fetch_tasks in struct submodule_parallel_fetch)
1313  */
1314 struct fetch_task {
1315         struct repository *repo;
1316         const struct submodule *sub;
1317         unsigned free_sub : 1; /* Do we need to free the submodule? */
1318
1319         struct oid_array *commits; /* Ensure these commits are fetched */
1320 };
1321
1322 /**
1323  * When a submodule is not defined in .gitmodules, we cannot access it
1324  * via the regular submodule-config. Create a fake submodule, which we can
1325  * work on.
1326  */
1327 static const struct submodule *get_non_gitmodules_submodule(const char *path)
1328 {
1329         struct submodule *ret = NULL;
1330         const char *name = default_name_or_path(path);
1331
1332         if (!name)
1333                 return NULL;
1334
1335         ret = xmalloc(sizeof(*ret));
1336         memset(ret, 0, sizeof(*ret));
1337         ret->path = name;
1338         ret->name = name;
1339
1340         return (const struct submodule *) ret;
1341 }
1342
1343 static struct fetch_task *fetch_task_create(struct repository *r,
1344                                             const char *path)
1345 {
1346         struct fetch_task *task = xmalloc(sizeof(*task));
1347         memset(task, 0, sizeof(*task));
1348
1349         task->sub = submodule_from_path(r, &null_oid, path);
1350         if (!task->sub) {
1351                 /*
1352                  * No entry in .gitmodules? Technically not a submodule,
1353                  * but historically we supported repositories that happen to be
1354                  * in-place where a gitlink is. Keep supporting them.
1355                  */
1356                 task->sub = get_non_gitmodules_submodule(path);
1357                 if (!task->sub) {
1358                         free(task);
1359                         return NULL;
1360                 }
1361
1362                 task->free_sub = 1;
1363         }
1364
1365         return task;
1366 }
1367
1368 static void fetch_task_release(struct fetch_task *p)
1369 {
1370         if (p->free_sub)
1371                 free((void*)p->sub);
1372         p->free_sub = 0;
1373         p->sub = NULL;
1374
1375         if (p->repo)
1376                 repo_clear(p->repo);
1377         FREE_AND_NULL(p->repo);
1378 }
1379
1380 static struct repository *get_submodule_repo_for(struct repository *r,
1381                                                  const struct submodule *sub)
1382 {
1383         struct repository *ret = xmalloc(sizeof(*ret));
1384
1385         if (repo_submodule_init(ret, r, sub)) {
1386                 /*
1387                  * No entry in .gitmodules? Technically not a submodule,
1388                  * but historically we supported repositories that happen to be
1389                  * in-place where a gitlink is. Keep supporting them.
1390                  */
1391                 struct strbuf gitdir = STRBUF_INIT;
1392                 strbuf_repo_worktree_path(&gitdir, r, "%s/.git", sub->path);
1393                 if (repo_init(ret, gitdir.buf, NULL)) {
1394                         strbuf_release(&gitdir);
1395                         free(ret);
1396                         return NULL;
1397                 }
1398                 strbuf_release(&gitdir);
1399         }
1400
1401         return ret;
1402 }
1403
1404 static int get_next_submodule(struct child_process *cp,
1405                               struct strbuf *err, void *data, void **task_cb)
1406 {
1407         struct submodule_parallel_fetch *spf = data;
1408
1409         for (; spf->count < spf->r->index->cache_nr; spf->count++) {
1410                 const struct cache_entry *ce = spf->r->index->cache[spf->count];
1411                 const char *default_argv;
1412                 struct fetch_task *task;
1413
1414                 if (!S_ISGITLINK(ce->ce_mode))
1415                         continue;
1416
1417                 task = fetch_task_create(spf->r, ce->name);
1418                 if (!task)
1419                         continue;
1420
1421                 switch (get_fetch_recurse_config(task->sub, spf))
1422                 {
1423                 default:
1424                 case RECURSE_SUBMODULES_DEFAULT:
1425                 case RECURSE_SUBMODULES_ON_DEMAND:
1426                         if (!task->sub ||
1427                             !string_list_lookup(
1428                                         &spf->changed_submodule_names,
1429                                         task->sub->name))
1430                                 continue;
1431                         default_argv = "on-demand";
1432                         break;
1433                 case RECURSE_SUBMODULES_ON:
1434                         default_argv = "yes";
1435                         break;
1436                 case RECURSE_SUBMODULES_OFF:
1437                         continue;
1438                 }
1439
1440                 task->repo = get_submodule_repo_for(spf->r, task->sub);
1441                 if (task->repo) {
1442                         struct strbuf submodule_prefix = STRBUF_INIT;
1443                         child_process_init(cp);
1444                         cp->dir = task->repo->gitdir;
1445                         prepare_submodule_repo_env_in_gitdir(&cp->env_array);
1446                         cp->git_cmd = 1;
1447                         if (!spf->quiet)
1448                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1449                                             spf->prefix, ce->name);
1450                         argv_array_init(&cp->args);
1451                         argv_array_pushv(&cp->args, spf->args.argv);
1452                         argv_array_push(&cp->args, default_argv);
1453                         argv_array_push(&cp->args, "--submodule-prefix");
1454
1455                         strbuf_addf(&submodule_prefix, "%s%s/",
1456                                                        spf->prefix,
1457                                                        task->sub->path);
1458                         argv_array_push(&cp->args, submodule_prefix.buf);
1459
1460                         spf->count++;
1461                         *task_cb = task;
1462
1463                         strbuf_release(&submodule_prefix);
1464                         return 1;
1465                 } else {
1466
1467                         fetch_task_release(task);
1468                         free(task);
1469
1470                         /*
1471                          * An empty directory is normal,
1472                          * the submodule is not initialized
1473                          */
1474                         if (S_ISGITLINK(ce->ce_mode) &&
1475                             !is_empty_dir(ce->name)) {
1476                                 spf->result = 1;
1477                                 strbuf_addf(err,
1478                                             _("Could not access submodule '%s'"),
1479                                             ce->name);
1480                         }
1481                 }
1482         }
1483
1484         if (spf->oid_fetch_tasks_nr) {
1485                 struct fetch_task *task =
1486                         spf->oid_fetch_tasks[spf->oid_fetch_tasks_nr - 1];
1487                 struct strbuf submodule_prefix = STRBUF_INIT;
1488                 spf->oid_fetch_tasks_nr--;
1489
1490                 strbuf_addf(&submodule_prefix, "%s%s/",
1491                             spf->prefix, task->sub->path);
1492
1493                 child_process_init(cp);
1494                 prepare_submodule_repo_env_in_gitdir(&cp->env_array);
1495                 cp->git_cmd = 1;
1496                 cp->dir = task->repo->gitdir;
1497
1498                 argv_array_init(&cp->args);
1499                 argv_array_pushv(&cp->args, spf->args.argv);
1500                 argv_array_push(&cp->args, "on-demand");
1501                 argv_array_push(&cp->args, "--submodule-prefix");
1502                 argv_array_push(&cp->args, submodule_prefix.buf);
1503
1504                 /* NEEDSWORK: have get_default_remote from submodule--helper */
1505                 argv_array_push(&cp->args, "origin");
1506                 oid_array_for_each_unique(task->commits,
1507                                           append_oid_to_argv, &cp->args);
1508
1509                 *task_cb = task;
1510                 strbuf_release(&submodule_prefix);
1511                 return 1;
1512         }
1513
1514         return 0;
1515 }
1516
1517 static int fetch_start_failure(struct strbuf *err,
1518                                void *cb, void *task_cb)
1519 {
1520         struct submodule_parallel_fetch *spf = cb;
1521         struct fetch_task *task = task_cb;
1522
1523         spf->result = 1;
1524
1525         fetch_task_release(task);
1526         return 0;
1527 }
1528
1529 static int commit_missing_in_sub(const struct object_id *oid, void *data)
1530 {
1531         struct repository *subrepo = data;
1532
1533         enum object_type type = oid_object_info(subrepo, oid, NULL);
1534
1535         return type != OBJ_COMMIT;
1536 }
1537
1538 static int fetch_finish(int retvalue, struct strbuf *err,
1539                         void *cb, void *task_cb)
1540 {
1541         struct submodule_parallel_fetch *spf = cb;
1542         struct fetch_task *task = task_cb;
1543
1544         struct string_list_item *it;
1545         struct oid_array *commits;
1546
1547         if (retvalue)
1548                 spf->result = 1;
1549
1550         if (!task || !task->sub)
1551                 BUG("callback cookie bogus");
1552
1553         /* Is this the second time we process this submodule? */
1554         if (task->commits)
1555                 goto out;
1556
1557         it = string_list_lookup(&spf->changed_submodule_names, task->sub->name);
1558         if (!it)
1559                 /* Could be an unchanged submodule, not contained in the list */
1560                 goto out;
1561
1562         commits = it->util;
1563         oid_array_filter(commits,
1564                          commit_missing_in_sub,
1565                          task->repo);
1566
1567         /* Are there commits we want, but do not exist? */
1568         if (commits->nr) {
1569                 task->commits = commits;
1570                 ALLOC_GROW(spf->oid_fetch_tasks,
1571                            spf->oid_fetch_tasks_nr + 1,
1572                            spf->oid_fetch_tasks_alloc);
1573                 spf->oid_fetch_tasks[spf->oid_fetch_tasks_nr] = task;
1574                 spf->oid_fetch_tasks_nr++;
1575                 return 0;
1576         }
1577
1578 out:
1579         fetch_task_release(task);
1580
1581         return 0;
1582 }
1583
1584 int fetch_populated_submodules(struct repository *r,
1585                                const struct argv_array *options,
1586                                const char *prefix, int command_line_option,
1587                                int default_option,
1588                                int quiet, int max_parallel_jobs)
1589 {
1590         int i;
1591         struct submodule_parallel_fetch spf = SPF_INIT;
1592
1593         spf.r = r;
1594         spf.command_line_option = command_line_option;
1595         spf.default_option = default_option;
1596         spf.quiet = quiet;
1597         spf.prefix = prefix;
1598
1599         if (!r->worktree)
1600                 goto out;
1601
1602         if (repo_read_index(r) < 0)
1603                 die("index file corrupt");
1604
1605         argv_array_push(&spf.args, "fetch");
1606         for (i = 0; i < options->argc; i++)
1607                 argv_array_push(&spf.args, options->argv[i]);
1608         argv_array_push(&spf.args, "--recurse-submodules-default");
1609         /* default value, "--submodule-prefix" and its value are added later */
1610
1611         calculate_changed_submodule_paths(r, &spf.changed_submodule_names);
1612         string_list_sort(&spf.changed_submodule_names);
1613         run_processes_parallel(max_parallel_jobs,
1614                                get_next_submodule,
1615                                fetch_start_failure,
1616                                fetch_finish,
1617                                &spf);
1618
1619         argv_array_clear(&spf.args);
1620 out:
1621         free_submodules_oids(&spf.changed_submodule_names);
1622         return spf.result;
1623 }
1624
1625 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1626 {
1627         struct child_process cp = CHILD_PROCESS_INIT;
1628         struct strbuf buf = STRBUF_INIT;
1629         FILE *fp;
1630         unsigned dirty_submodule = 0;
1631         const char *git_dir;
1632         int ignore_cp_exit_code = 0;
1633
1634         strbuf_addf(&buf, "%s/.git", path);
1635         git_dir = read_gitfile(buf.buf);
1636         if (!git_dir)
1637                 git_dir = buf.buf;
1638         if (!is_git_directory(git_dir)) {
1639                 if (is_directory(git_dir))
1640                         die(_("'%s' not recognized as a git repository"), git_dir);
1641                 strbuf_release(&buf);
1642                 /* The submodule is not checked out, so it is not modified */
1643                 return 0;
1644         }
1645         strbuf_reset(&buf);
1646
1647         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1648         if (ignore_untracked)
1649                 argv_array_push(&cp.args, "-uno");
1650
1651         prepare_submodule_repo_env(&cp.env_array);
1652         cp.git_cmd = 1;
1653         cp.no_stdin = 1;
1654         cp.out = -1;
1655         cp.dir = path;
1656         if (start_command(&cp))
1657                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1658
1659         fp = xfdopen(cp.out, "r");
1660         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1661                 /* regular untracked files */
1662                 if (buf.buf[0] == '?')
1663                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1664
1665                 if (buf.buf[0] == 'u' ||
1666                     buf.buf[0] == '1' ||
1667                     buf.buf[0] == '2') {
1668                         /* T = line type, XY = status, SSSS = submodule state */
1669                         if (buf.len < strlen("T XY SSSS"))
1670                                 BUG("invalid status --porcelain=2 line %s",
1671                                     buf.buf);
1672
1673                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1674                                 /* nested untracked file */
1675                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1676
1677                         if (buf.buf[0] == 'u' ||
1678                             buf.buf[0] == '2' ||
1679                             memcmp(buf.buf + 5, "S..U", 4))
1680                                 /* other change */
1681                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1682                 }
1683
1684                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1685                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1686                      ignore_untracked)) {
1687                         /*
1688                          * We're not interested in any further information from
1689                          * the child any more, neither output nor its exit code.
1690                          */
1691                         ignore_cp_exit_code = 1;
1692                         break;
1693                 }
1694         }
1695         fclose(fp);
1696
1697         if (finish_command(&cp) && !ignore_cp_exit_code)
1698                 die("'git status --porcelain=2' failed in submodule %s", path);
1699
1700         strbuf_release(&buf);
1701         return dirty_submodule;
1702 }
1703
1704 int submodule_uses_gitfile(const char *path)
1705 {
1706         struct child_process cp = CHILD_PROCESS_INIT;
1707         const char *argv[] = {
1708                 "submodule",
1709                 "foreach",
1710                 "--quiet",
1711                 "--recursive",
1712                 "test -f .git",
1713                 NULL,
1714         };
1715         struct strbuf buf = STRBUF_INIT;
1716         const char *git_dir;
1717
1718         strbuf_addf(&buf, "%s/.git", path);
1719         git_dir = read_gitfile(buf.buf);
1720         if (!git_dir) {
1721                 strbuf_release(&buf);
1722                 return 0;
1723         }
1724         strbuf_release(&buf);
1725
1726         /* Now test that all nested submodules use a gitfile too */
1727         cp.argv = argv;
1728         prepare_submodule_repo_env(&cp.env_array);
1729         cp.git_cmd = 1;
1730         cp.no_stdin = 1;
1731         cp.no_stderr = 1;
1732         cp.no_stdout = 1;
1733         cp.dir = path;
1734         if (run_command(&cp))
1735                 return 0;
1736
1737         return 1;
1738 }
1739
1740 /*
1741  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1742  * when doing so.
1743  *
1744  * Return 1 if we'd lose data, return 0 if the removal is fine,
1745  * and negative values for errors.
1746  */
1747 int bad_to_remove_submodule(const char *path, unsigned flags)
1748 {
1749         ssize_t len;
1750         struct child_process cp = CHILD_PROCESS_INIT;
1751         struct strbuf buf = STRBUF_INIT;
1752         int ret = 0;
1753
1754         if (!file_exists(path) || is_empty_dir(path))
1755                 return 0;
1756
1757         if (!submodule_uses_gitfile(path))
1758                 return 1;
1759
1760         argv_array_pushl(&cp.args, "status", "--porcelain",
1761                                    "--ignore-submodules=none", NULL);
1762
1763         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1764                 argv_array_push(&cp.args, "-uno");
1765         else
1766                 argv_array_push(&cp.args, "-uall");
1767
1768         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1769                 argv_array_push(&cp.args, "--ignored");
1770
1771         prepare_submodule_repo_env(&cp.env_array);
1772         cp.git_cmd = 1;
1773         cp.no_stdin = 1;
1774         cp.out = -1;
1775         cp.dir = path;
1776         if (start_command(&cp)) {
1777                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1778                         die(_("could not start 'git status' in submodule '%s'"),
1779                                 path);
1780                 ret = -1;
1781                 goto out;
1782         }
1783
1784         len = strbuf_read(&buf, cp.out, 1024);
1785         if (len > 2)
1786                 ret = 1;
1787         close(cp.out);
1788
1789         if (finish_command(&cp)) {
1790                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1791                         die(_("could not run 'git status' in submodule '%s'"),
1792                                 path);
1793                 ret = -1;
1794         }
1795 out:
1796         strbuf_release(&buf);
1797         return ret;
1798 }
1799
1800 void submodule_unset_core_worktree(const struct submodule *sub)
1801 {
1802         char *config_path = xstrfmt("%s/modules/%s/config",
1803                                     get_git_common_dir(), sub->name);
1804
1805         if (git_config_set_in_file_gently(config_path, "core.worktree", NULL))
1806                 warning(_("Could not unset core.worktree setting in submodule '%s'"),
1807                           sub->path);
1808
1809         free(config_path);
1810 }
1811
1812 static const char *get_super_prefix_or_empty(void)
1813 {
1814         const char *s = get_super_prefix();
1815         if (!s)
1816                 s = "";
1817         return s;
1818 }
1819
1820 static int submodule_has_dirty_index(const struct submodule *sub)
1821 {
1822         struct child_process cp = CHILD_PROCESS_INIT;
1823
1824         prepare_submodule_repo_env(&cp.env_array);
1825
1826         cp.git_cmd = 1;
1827         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1828                                    "--cached", "HEAD", NULL);
1829         cp.no_stdin = 1;
1830         cp.no_stdout = 1;
1831         cp.dir = sub->path;
1832         if (start_command(&cp))
1833                 die("could not recurse into submodule '%s'", sub->path);
1834
1835         return finish_command(&cp);
1836 }
1837
1838 static void submodule_reset_index(const char *path)
1839 {
1840         struct child_process cp = CHILD_PROCESS_INIT;
1841         prepare_submodule_repo_env(&cp.env_array);
1842
1843         cp.git_cmd = 1;
1844         cp.no_stdin = 1;
1845         cp.dir = path;
1846
1847         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1848                                    get_super_prefix_or_empty(), path);
1849         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1850
1851         argv_array_push(&cp.args, empty_tree_oid_hex());
1852
1853         if (run_command(&cp))
1854                 die("could not reset submodule index");
1855 }
1856
1857 /**
1858  * Moves a submodule at a given path from a given head to another new head.
1859  * For edge cases (a submodule coming into existence or removing a submodule)
1860  * pass NULL for old or new respectively.
1861  */
1862 int submodule_move_head(const char *path,
1863                          const char *old_head,
1864                          const char *new_head,
1865                          unsigned flags)
1866 {
1867         int ret = 0;
1868         struct child_process cp = CHILD_PROCESS_INIT;
1869         const struct submodule *sub;
1870         int *error_code_ptr, error_code;
1871
1872         if (!is_submodule_active(the_repository, path))
1873                 return 0;
1874
1875         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1876                 /*
1877                  * Pass non NULL pointer to is_submodule_populated_gently
1878                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1879                  * to fixup the submodule in the force case later.
1880                  */
1881                 error_code_ptr = &error_code;
1882         else
1883                 error_code_ptr = NULL;
1884
1885         if (old_head && !is_submodule_populated_gently(path, error_code_ptr))
1886                 return 0;
1887
1888         sub = submodule_from_path(the_repository, &null_oid, path);
1889
1890         if (!sub)
1891                 BUG("could not get submodule information for '%s'", path);
1892
1893         if (old_head && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1894                 /* Check if the submodule has a dirty index. */
1895                 if (submodule_has_dirty_index(sub))
1896                         return error(_("submodule '%s' has dirty index"), path);
1897         }
1898
1899         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1900                 if (old_head) {
1901                         if (!submodule_uses_gitfile(path))
1902                                 absorb_git_dir_into_superproject("", path,
1903                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1904                 } else {
1905                         char *gitdir = xstrfmt("%s/modules/%s",
1906                                     get_git_common_dir(), sub->name);
1907                         connect_work_tree_and_git_dir(path, gitdir, 0);
1908                         free(gitdir);
1909
1910                         /* make sure the index is clean as well */
1911                         submodule_reset_index(path);
1912                 }
1913
1914                 if (old_head && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1915                         char *gitdir = xstrfmt("%s/modules/%s",
1916                                     get_git_common_dir(), sub->name);
1917                         connect_work_tree_and_git_dir(path, gitdir, 1);
1918                         free(gitdir);
1919                 }
1920         }
1921
1922         prepare_submodule_repo_env(&cp.env_array);
1923
1924         cp.git_cmd = 1;
1925         cp.no_stdin = 1;
1926         cp.dir = path;
1927
1928         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1929                         get_super_prefix_or_empty(), path);
1930         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1931
1932         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1933                 argv_array_push(&cp.args, "-n");
1934         else
1935                 argv_array_push(&cp.args, "-u");
1936
1937         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1938                 argv_array_push(&cp.args, "--reset");
1939         else
1940                 argv_array_push(&cp.args, "-m");
1941
1942         if (!(flags & SUBMODULE_MOVE_HEAD_FORCE))
1943                 argv_array_push(&cp.args, old_head ? old_head : empty_tree_oid_hex());
1944
1945         argv_array_push(&cp.args, new_head ? new_head : empty_tree_oid_hex());
1946
1947         if (run_command(&cp)) {
1948                 ret = error(_("Submodule '%s' could not be updated."), path);
1949                 goto out;
1950         }
1951
1952         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1953                 if (new_head) {
1954                         child_process_init(&cp);
1955                         /* also set the HEAD accordingly */
1956                         cp.git_cmd = 1;
1957                         cp.no_stdin = 1;
1958                         cp.dir = path;
1959
1960                         prepare_submodule_repo_env(&cp.env_array);
1961                         argv_array_pushl(&cp.args, "update-ref", "HEAD",
1962                                          "--no-deref", new_head, NULL);
1963
1964                         if (run_command(&cp)) {
1965                                 ret = -1;
1966                                 goto out;
1967                         }
1968                 } else {
1969                         struct strbuf sb = STRBUF_INIT;
1970
1971                         strbuf_addf(&sb, "%s/.git", path);
1972                         unlink_or_warn(sb.buf);
1973                         strbuf_release(&sb);
1974
1975                         if (is_empty_dir(path))
1976                                 rmdir_or_warn(path);
1977
1978                         submodule_unset_core_worktree(sub);
1979                 }
1980         }
1981 out:
1982         return ret;
1983 }
1984
1985 /*
1986  * Embeds a single submodules git directory into the superprojects git dir,
1987  * non recursively.
1988  */
1989 static void relocate_single_git_dir_into_superproject(const char *prefix,
1990                                                       const char *path)
1991 {
1992         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1993         const char *new_git_dir;
1994         const struct submodule *sub;
1995
1996         if (submodule_uses_worktrees(path))
1997                 die(_("relocate_gitdir for submodule '%s' with "
1998                       "more than one worktree not supported"), path);
1999
2000         old_git_dir = xstrfmt("%s/.git", path);
2001         if (read_gitfile(old_git_dir))
2002                 /* If it is an actual gitfile, it doesn't need migration. */
2003                 return;
2004
2005         real_old_git_dir = real_pathdup(old_git_dir, 1);
2006
2007         sub = submodule_from_path(the_repository, &null_oid, path);
2008         if (!sub)
2009                 die(_("could not lookup name for submodule '%s'"), path);
2010
2011         new_git_dir = git_path("modules/%s", sub->name);
2012         if (safe_create_leading_directories_const(new_git_dir) < 0)
2013                 die(_("could not create directory '%s'"), new_git_dir);
2014         real_new_git_dir = real_pathdup(new_git_dir, 1);
2015
2016         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
2017                 get_super_prefix_or_empty(), path,
2018                 real_old_git_dir, real_new_git_dir);
2019
2020         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
2021
2022         free(old_git_dir);
2023         free(real_old_git_dir);
2024         free(real_new_git_dir);
2025 }
2026
2027 /*
2028  * Migrate the git directory of the submodule given by path from
2029  * having its git directory within the working tree to the git dir nested
2030  * in its superprojects git dir under modules/.
2031  */
2032 void absorb_git_dir_into_superproject(const char *prefix,
2033                                       const char *path,
2034                                       unsigned flags)
2035 {
2036         int err_code;
2037         const char *sub_git_dir;
2038         struct strbuf gitdir = STRBUF_INIT;
2039         strbuf_addf(&gitdir, "%s/.git", path);
2040         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
2041
2042         /* Not populated? */
2043         if (!sub_git_dir) {
2044                 const struct submodule *sub;
2045
2046                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
2047                         /* unpopulated as expected */
2048                         strbuf_release(&gitdir);
2049                         return;
2050                 }
2051
2052                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
2053                         /* We don't know what broke here. */
2054                         read_gitfile_error_die(err_code, path, NULL);
2055
2056                 /*
2057                 * Maybe populated, but no git directory was found?
2058                 * This can happen if the superproject is a submodule
2059                 * itself and was just absorbed. The absorption of the
2060                 * superproject did not rewrite the git file links yet,
2061                 * fix it now.
2062                 */
2063                 sub = submodule_from_path(the_repository, &null_oid, path);
2064                 if (!sub)
2065                         die(_("could not lookup name for submodule '%s'"), path);
2066                 connect_work_tree_and_git_dir(path,
2067                         git_path("modules/%s", sub->name), 0);
2068         } else {
2069                 /* Is it already absorbed into the superprojects git dir? */
2070                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
2071                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
2072
2073                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
2074                         relocate_single_git_dir_into_superproject(prefix, path);
2075
2076                 free(real_sub_git_dir);
2077                 free(real_common_git_dir);
2078         }
2079         strbuf_release(&gitdir);
2080
2081         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
2082                 struct child_process cp = CHILD_PROCESS_INIT;
2083                 struct strbuf sb = STRBUF_INIT;
2084
2085                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
2086                         BUG("we don't know how to pass the flags down?");
2087
2088                 strbuf_addstr(&sb, get_super_prefix_or_empty());
2089                 strbuf_addstr(&sb, path);
2090                 strbuf_addch(&sb, '/');
2091
2092                 cp.dir = path;
2093                 cp.git_cmd = 1;
2094                 cp.no_stdin = 1;
2095                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
2096                                            "submodule--helper",
2097                                            "absorb-git-dirs", NULL);
2098                 prepare_submodule_repo_env(&cp.env_array);
2099                 if (run_command(&cp))
2100                         die(_("could not recurse into submodule '%s'"), path);
2101
2102                 strbuf_release(&sb);
2103         }
2104 }
2105
2106 const char *get_superproject_working_tree(void)
2107 {
2108         struct child_process cp = CHILD_PROCESS_INIT;
2109         struct strbuf sb = STRBUF_INIT;
2110         const char *one_up = real_path_if_valid("../");
2111         const char *cwd = xgetcwd();
2112         const char *ret = NULL;
2113         const char *subpath;
2114         int code;
2115         ssize_t len;
2116
2117         if (!is_inside_work_tree())
2118                 /*
2119                  * FIXME:
2120                  * We might have a superproject, but it is harder
2121                  * to determine.
2122                  */
2123                 return NULL;
2124
2125         if (!one_up)
2126                 return NULL;
2127
2128         subpath = relative_path(cwd, one_up, &sb);
2129
2130         prepare_submodule_repo_env(&cp.env_array);
2131         argv_array_pop(&cp.env_array);
2132
2133         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
2134                         "ls-files", "-z", "--stage", "--full-name", "--",
2135                         subpath, NULL);
2136         strbuf_reset(&sb);
2137
2138         cp.no_stdin = 1;
2139         cp.no_stderr = 1;
2140         cp.out = -1;
2141         cp.git_cmd = 1;
2142
2143         if (start_command(&cp))
2144                 die(_("could not start ls-files in .."));
2145
2146         len = strbuf_read(&sb, cp.out, PATH_MAX);
2147         close(cp.out);
2148
2149         if (starts_with(sb.buf, "160000")) {
2150                 int super_sub_len;
2151                 int cwd_len = strlen(cwd);
2152                 char *super_sub, *super_wt;
2153
2154                 /*
2155                  * There is a superproject having this repo as a submodule.
2156                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
2157                  * We're only interested in the name after the tab.
2158                  */
2159                 super_sub = strchr(sb.buf, '\t') + 1;
2160                 super_sub_len = strlen(super_sub);
2161
2162                 if (super_sub_len > cwd_len ||
2163                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
2164                         BUG("returned path string doesn't match cwd?");
2165
2166                 super_wt = xstrdup(cwd);
2167                 super_wt[cwd_len - super_sub_len] = '\0';
2168
2169                 ret = real_path(super_wt);
2170                 free(super_wt);
2171         }
2172         strbuf_release(&sb);
2173
2174         code = finish_command(&cp);
2175
2176         if (code == 128)
2177                 /* '../' is not a git repository */
2178                 return NULL;
2179         if (code == 0 && len == 0)
2180                 /* There is an unrelated git repository at '../' */
2181                 return NULL;
2182         if (code)
2183                 die(_("ls-tree returned unexpected return code %d"), code);
2184
2185         return ret;
2186 }
2187
2188 /*
2189  * Put the gitdir for a submodule (given relative to the main
2190  * repository worktree) into `buf`, or return -1 on error.
2191  */
2192 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2193 {
2194         const struct submodule *sub;
2195         const char *git_dir;
2196         int ret = 0;
2197
2198         strbuf_reset(buf);
2199         strbuf_addstr(buf, submodule);
2200         strbuf_complete(buf, '/');
2201         strbuf_addstr(buf, ".git");
2202
2203         git_dir = read_gitfile(buf->buf);
2204         if (git_dir) {
2205                 strbuf_reset(buf);
2206                 strbuf_addstr(buf, git_dir);
2207         }
2208         if (!is_git_directory(buf->buf)) {
2209                 sub = submodule_from_path(the_repository, &null_oid, submodule);
2210                 if (!sub) {
2211                         ret = -1;
2212                         goto cleanup;
2213                 }
2214                 strbuf_reset(buf);
2215                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2216         }
2217
2218 cleanup:
2219         return ret;
2220 }