submodule.c

   1
   2 #include "cache.h"
   3 #include "repository.h"
   4 #include "config.h"
   5 #include "submodule-config.h"
   6 #include "submodule.h"
   7 #include "dir.h"
   8 #include "diff.h"
   9 #include "commit.h"
  10 #include "revision.h"
  11 #include "run-command.h"
  12 #include "diffcore.h"
  13 #include "refs.h"
  14 #include "string-list.h"
  15 #include "sha1-array.h"
  16 #include "argv-array.h"
  17 #include "blob.h"
  18 #include "thread-utils.h"
  19 #include "quote.h"
  20 #include "remote.h"
  21 #include "worktree.h"
  22 #include "parse-options.h"
  23 #include "object-store.h"
  24 #include "commit-reach.h"
  25
  26 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
  27 static int initialized_fetch_ref_tips;
  28 static struct oid_array ref_tips_before_fetch;
  29 static struct oid_array ref_tips_after_fetch;
  30
  31 /*
  32  * Check if the .gitmodules file is unmerged. Parsing of the .gitmodules file
  33  * will be disabled because we can't guess what might be configured in
  34  * .gitmodules unless the user resolves the conflict.
  35  */
  36 int is_gitmodules_unmerged(const struct index_state *istate)
  37 {
  38         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  39         if (pos < 0) { /* .gitmodules not found or isn't merged */
  40                 pos = -1 - pos;
  41                 if (istate->cache_nr > pos) {  /* there is a .gitmodules */
  42                         const struct cache_entry *ce = istate->cache[pos];
  43                         if (ce_namelen(ce) == strlen(GITMODULES_FILE) &&
  44                             !strcmp(ce->name, GITMODULES_FILE))
  45                                 return 1;
  46                 }
  47         }
  48
  49         return 0;
  50 }
  51
  52 /*
  53  * Check if the .gitmodules file is safe to write.
  54  *
  55  * Writing to the .gitmodules file requires that the file exists in the
  56  * working tree or, if it doesn't, that a brand new .gitmodules file is going
  57  * to be created (i.e. it's neither in the index nor in the current branch).
  58  *
  59  * It is not safe to write to .gitmodules if it's not in the working tree but
  60  * it is in the index or in the current branch, because writing new values
  61  * (and staging them) would blindly overwrite ALL the old content.
  62  */
  63 int is_writing_gitmodules_ok(void)
  64 {
  65         struct object_id oid;
  66         return file_exists(GITMODULES_FILE) ||
  67                 (get_oid(GITMODULES_INDEX, &oid) < 0 && get_oid(GITMODULES_HEAD, &oid) < 0);
  68 }
  69
  70 /*
  71  * Check if the .gitmodules file has unstaged modifications.  This must be
  72  * checked before allowing modifications to the .gitmodules file with the
  73  * intention to stage them later, because when continuing we would stage the
  74  * modifications the user didn't stage herself too. That might change in a
  75  * future version when we learn to stage the changes we do ourselves without
  76  * staging any previous modifications.
  77  */
  78 int is_staging_gitmodules_ok(struct index_state *istate)
  79 {
  80         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  81
  82         if ((pos >= 0) && (pos < istate->cache_nr)) {
  83                 struct stat st;
  84                 if (lstat(GITMODULES_FILE, &st) == 0 &&
  85                     ie_match_stat(istate, istate->cache[pos], &st, 0) & DATA_CHANGED)
  86                         return 0;
  87         }
  88
  89         return 1;
  90 }
  91
  92 static int for_each_remote_ref_submodule(const char *submodule,
  93                                          each_ref_fn fn, void *cb_data)
  94 {
  95         return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
  96                                         fn, cb_data);
  97 }
  98
  99 /*
 100  * Try to update the "path" entry in the "submodule.<name>" section of the
 101  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
 102  * with the correct path=<oldpath> setting was found and we could update it.
 103  */
 104 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
 105 {
 106         struct strbuf entry = STRBUF_INIT;
 107         const struct submodule *submodule;
 108         int ret;
 109
 110         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
 111                 return -1;
 112
 113         if (is_gitmodules_unmerged(the_repository->index))
 114                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 115
 116         submodule = submodule_from_path(the_repository, &null_oid, oldpath);
 117         if (!submodule || !submodule->name) {
 118                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
 119                 return -1;
 120         }
 121         strbuf_addstr(&entry, "submodule.");
 122         strbuf_addstr(&entry, submodule->name);
 123         strbuf_addstr(&entry, ".path");
 124         ret = config_set_in_gitmodules_file_gently(entry.buf, newpath);
 125         strbuf_release(&entry);
 126         return ret;
 127 }
 128
 129 /*
 130  * Try to remove the "submodule.<name>" section from .gitmodules where the given
 131  * path is configured. Return 0 only if a .gitmodules file was found, a section
 132  * with the correct path=<path> setting was found and we could remove it.
 133  */
 134 int remove_path_from_gitmodules(const char *path)
 135 {
 136         struct strbuf sect = STRBUF_INIT;
 137         const struct submodule *submodule;
 138
 139         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
 140                 return -1;
 141
 142         if (is_gitmodules_unmerged(the_repository->index))
 143                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 144
 145         submodule = submodule_from_path(the_repository, &null_oid, path);
 146         if (!submodule || !submodule->name) {
 147                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 148                 return -1;
 149         }
 150         strbuf_addstr(&sect, "submodule.");
 151         strbuf_addstr(&sect, submodule->name);
 152         if (git_config_rename_section_in_file(GITMODULES_FILE, sect.buf, NULL) < 0) {
 153                 /* Maybe the user already did that, don't error out here */
 154                 warning(_("Could not remove .gitmodules entry for %s"), path);
 155                 strbuf_release(&sect);
 156                 return -1;
 157         }
 158         strbuf_release(&sect);
 159         return 0;
 160 }
 161
 162 void stage_updated_gitmodules(struct index_state *istate)
 163 {
 164         if (add_file_to_index(istate, GITMODULES_FILE, 0))
 165                 die(_("staging updated .gitmodules failed"));
 166 }
 167
 168 /* TODO: remove this function, use repo_submodule_init instead. */
 169 int add_submodule_odb(const char *path)
 170 {
 171         struct strbuf objects_directory = STRBUF_INIT;
 172         int ret = 0;
 173
 174         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
 175         if (ret)
 176                 goto done;
 177         if (!is_directory(objects_directory.buf)) {
 178                 ret = -1;
 179                 goto done;
 180         }
 181         add_to_alternates_memory(objects_directory.buf);
 182 done:
 183         strbuf_release(&objects_directory);
 184         return ret;
 185 }
 186
 187 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 188                                              const char *path)
 189 {
 190         const struct submodule *submodule = submodule_from_path(the_repository,
 191                                                                 &null_oid, path);
 192         if (submodule) {
 193                 const char *ignore;
 194                 char *key;
 195
 196                 key = xstrfmt("submodule.%s.ignore", submodule->name);
 197                 if (repo_config_get_string_const(the_repository, key, &ignore))
 198                         ignore = submodule->ignore;
 199                 free(key);
 200
 201                 if (ignore)
 202                         handle_ignore_submodules_arg(diffopt, ignore);
 203                 else if (is_gitmodules_unmerged(the_repository->index))
 204                         diffopt->flags.ignore_submodules = 1;
 205         }
 206 }
 207
 208 /* Cheap function that only determines if we're interested in submodules at all */
 209 int git_default_submodule_config(const char *var, const char *value, void *cb)
 210 {
 211         if (!strcmp(var, "submodule.recurse")) {
 212                 int v = git_config_bool(var, value) ?
 213                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 214                 config_update_recurse_submodules = v;
 215         }
 216         return 0;
 217 }
 218
 219 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 220                                                      const char *arg, int unset)
 221 {
 222         if (unset) {
 223                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 224                 return 0;
 225         }
 226         if (arg)
 227                 config_update_recurse_submodules =
 228                         parse_update_recurse_submodules_arg(opt->long_name,
 229                                                             arg);
 230         else
 231                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 232
 233         return 0;
 234 }
 235
 236 /*
 237  * Determine if a submodule has been initialized at a given 'path'
 238  */
 239 int is_submodule_active(struct repository *repo, const char *path)
 240 {
 241         int ret = 0;
 242         char *key = NULL;
 243         char *value = NULL;
 244         const struct string_list *sl;
 245         const struct submodule *module;
 246
 247         module = submodule_from_path(repo, &null_oid, path);
 248
 249         /* early return if there isn't a path->module mapping */
 250         if (!module)
 251                 return 0;
 252
 253         /* submodule.<name>.active is set */
 254         key = xstrfmt("submodule.%s.active", module->name);
 255         if (!repo_config_get_bool(repo, key, &ret)) {
 256                 free(key);
 257                 return ret;
 258         }
 259         free(key);
 260
 261         /* submodule.active is set */
 262         sl = repo_config_get_value_multi(repo, "submodule.active");
 263         if (sl) {
 264                 struct pathspec ps;
 265                 struct argv_array args = ARGV_ARRAY_INIT;
 266                 const struct string_list_item *item;
 267
 268                 for_each_string_list_item(item, sl) {
 269                         argv_array_push(&args, item->string);
 270                 }
 271
 272                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 273                 ret = match_pathspec(repo->index, &ps, path, strlen(path), 0, NULL, 1);
 274
 275                 argv_array_clear(&args);
 276                 clear_pathspec(&ps);
 277                 return ret;
 278         }
 279
 280         /* fallback to checking if the URL is set */
 281         key = xstrfmt("submodule.%s.url", module->name);
 282         ret = !repo_config_get_string(repo, key, &value);
 283
 284         free(value);
 285         free(key);
 286         return ret;
 287 }
 288
 289 int is_submodule_populated_gently(const char *path, int *return_error_code)
 290 {
 291         int ret = 0;
 292         char *gitdir = xstrfmt("%s/.git", path);
 293
 294         if (resolve_gitdir_gently(gitdir, return_error_code))
 295                 ret = 1;
 296
 297         free(gitdir);
 298         return ret;
 299 }
 300
 301 /*
 302  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 303  */
 304 void die_in_unpopulated_submodule(const struct index_state *istate,
 305                                   const char *prefix)
 306 {
 307         int i, prefixlen;
 308
 309         if (!prefix)
 310                 return;
 311
 312         prefixlen = strlen(prefix);
 313
 314         for (i = 0; i < istate->cache_nr; i++) {
 315                 struct cache_entry *ce = istate->cache[i];
 316                 int ce_len = ce_namelen(ce);
 317
 318                 if (!S_ISGITLINK(ce->ce_mode))
 319                         continue;
 320                 if (prefixlen <= ce_len)
 321                         continue;
 322                 if (strncmp(ce->name, prefix, ce_len))
 323                         continue;
 324                 if (prefix[ce_len] != '/')
 325                         continue;
 326
 327                 die(_("in unpopulated submodule '%s'"), ce->name);
 328         }
 329 }
 330
 331 /*
 332  * Dies if any paths in the provided pathspec descends into a submodule
 333  */
 334 void die_path_inside_submodule(const struct index_state *istate,
 335                                const struct pathspec *ps)
 336 {
 337         int i, j;
 338
 339         for (i = 0; i < istate->cache_nr; i++) {
 340                 struct cache_entry *ce = istate->cache[i];
 341                 int ce_len = ce_namelen(ce);
 342
 343                 if (!S_ISGITLINK(ce->ce_mode))
 344                         continue;
 345
 346                 for (j = 0; j < ps->nr ; j++) {
 347                         const struct pathspec_item *item = &ps->items[j];
 348
 349                         if (item->len <= ce_len)
 350                                 continue;
 351                         if (item->match[ce_len] != '/')
 352                                 continue;
 353                         if (strncmp(ce->name, item->match, ce_len))
 354                                 continue;
 355                         if (item->len == ce_len + 1)
 356                                 continue;
 357
 358                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 359                             item->original, ce_len, ce->name);
 360                 }
 361         }
 362 }
 363
 364 enum submodule_update_type parse_submodule_update_type(const char *value)
 365 {
 366         if (!strcmp(value, "none"))
 367                 return SM_UPDATE_NONE;
 368         else if (!strcmp(value, "checkout"))
 369                 return SM_UPDATE_CHECKOUT;
 370         else if (!strcmp(value, "rebase"))
 371                 return SM_UPDATE_REBASE;
 372         else if (!strcmp(value, "merge"))
 373                 return SM_UPDATE_MERGE;
 374         else if (*value == '!')
 375                 return SM_UPDATE_COMMAND;
 376         else
 377                 return SM_UPDATE_UNSPECIFIED;
 378 }
 379
 380 int parse_submodule_update_strategy(const char *value,
 381                 struct submodule_update_strategy *dst)
 382 {
 383         enum submodule_update_type type;
 384
 385         free((void*)dst->command);
 386         dst->command = NULL;
 387
 388         type = parse_submodule_update_type(value);
 389         if (type == SM_UPDATE_UNSPECIFIED)
 390                 return -1;
 391
 392         dst->type = type;
 393         if (type == SM_UPDATE_COMMAND)
 394                 dst->command = xstrdup(value + 1);
 395
 396         return 0;
 397 }
 398
 399 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 400 {
 401         struct strbuf sb = STRBUF_INIT;
 402         switch (s->type) {
 403         case SM_UPDATE_CHECKOUT:
 404                 return "checkout";
 405         case SM_UPDATE_MERGE:
 406                 return "merge";
 407         case SM_UPDATE_REBASE:
 408                 return "rebase";
 409         case SM_UPDATE_NONE:
 410                 return "none";
 411         case SM_UPDATE_UNSPECIFIED:
 412                 return NULL;
 413         case SM_UPDATE_COMMAND:
 414                 strbuf_addf(&sb, "!%s", s->command);
 415                 return strbuf_detach(&sb, NULL);
 416         }
 417         return NULL;
 418 }
 419
 420 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 421                                   const char *arg)
 422 {
 423         diffopt->flags.ignore_submodules = 0;
 424         diffopt->flags.ignore_untracked_in_submodules = 0;
 425         diffopt->flags.ignore_dirty_submodules = 0;
 426
 427         if (!strcmp(arg, "all"))
 428                 diffopt->flags.ignore_submodules = 1;
 429         else if (!strcmp(arg, "untracked"))
 430                 diffopt->flags.ignore_untracked_in_submodules = 1;
 431         else if (!strcmp(arg, "dirty"))
 432                 diffopt->flags.ignore_dirty_submodules = 1;
 433         else if (strcmp(arg, "none"))
 434                 die("bad --ignore-submodules argument: %s", arg);
 435 }
 436
 437 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 438                 struct commit *left, struct commit *right,
 439                 struct commit_list *merge_bases)
 440 {
 441         struct commit_list *list;
 442
 443         repo_init_revisions(the_repository, rev, NULL);
 444         setup_revisions(0, NULL, rev, NULL);
 445         rev->left_right = 1;
 446         rev->first_parent_only = 1;
 447         left->object.flags |= SYMMETRIC_LEFT;
 448         add_pending_object(rev, &left->object, path);
 449         add_pending_object(rev, &right->object, path);
 450         for (list = merge_bases; list; list = list->next) {
 451                 list->item->object.flags |= UNINTERESTING;
 452                 add_pending_object(rev, &list->item->object,
 453                         oid_to_hex(&list->item->object.oid));
 454         }
 455         return prepare_revision_walk(rev);
 456 }
 457
 458 static void print_submodule_summary(struct repository *r, struct rev_info *rev, struct diff_options *o)
 459 {
 460         static const char format[] = "  %m %s";
 461         struct strbuf sb = STRBUF_INIT;
 462         struct commit *commit;
 463
 464         while ((commit = get_revision(rev))) {
 465                 struct pretty_print_context ctx = {0};
 466                 ctx.date_mode = rev->date_mode;
 467                 ctx.output_encoding = get_log_output_encoding();
 468                 strbuf_setlen(&sb, 0);
 469                 repo_format_commit_message(r, commit, format, &sb,
 470                                       &ctx);
 471                 strbuf_addch(&sb, '\n');
 472                 if (commit->object.flags & SYMMETRIC_LEFT)
 473                         diff_emit_submodule_del(o, sb.buf);
 474                 else
 475                         diff_emit_submodule_add(o, sb.buf);
 476         }
 477         strbuf_release(&sb);
 478 }
 479
 480 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 481 {
 482         const char * const *var;
 483
 484         for (var = local_repo_env; *var; var++) {
 485                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 486                         argv_array_push(out, *var);
 487         }
 488 }
 489
 490 void prepare_submodule_repo_env(struct argv_array *out)
 491 {
 492         prepare_submodule_repo_env_no_git_dir(out);
 493         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 494                          DEFAULT_GIT_DIR_ENVIRONMENT);
 495 }
 496
 497 static void prepare_submodule_repo_env_in_gitdir(struct argv_array *out)
 498 {
 499         prepare_submodule_repo_env_no_git_dir(out);
 500         argv_array_pushf(out, "%s=.", GIT_DIR_ENVIRONMENT);
 501 }
 502
 503 /*
 504  * Initialize a repository struct for a submodule based on the provided 'path'.
 505  *
 506  * Unlike repo_submodule_init, this tolerates submodules not present
 507  * in .gitmodules. This function exists only to preserve historical behavior,
 508  *
 509  * Returns the repository struct on success,
 510  * NULL when the submodule is not present.
 511  */
 512 static struct repository *open_submodule(const char *path)
 513 {
 514         struct strbuf sb = STRBUF_INIT;
 515         struct repository *out = xmalloc(sizeof(*out));
 516
 517         if (submodule_to_gitdir(&sb, path) || repo_init(out, sb.buf, NULL)) {
 518                 strbuf_release(&sb);
 519                 free(out);
 520                 return NULL;
 521         }
 522
 523         /* Mark it as a submodule */
 524         out->submodule_prefix = xstrdup(path);
 525
 526         strbuf_release(&sb);
 527         return out;
 528 }
 529
 530 /*
 531  * Helper function to display the submodule header line prior to the full
 532  * summary output.
 533  *
 534  * If it can locate the submodule git directory it will create a repository
 535  * handle for the submodule and lookup both the left and right commits and
 536  * put them into the left and right pointers.
 537  */
 538 static void show_submodule_header(struct diff_options *o,
 539                 const char *path,
 540                 struct object_id *one, struct object_id *two,
 541                 unsigned dirty_submodule,
 542                 struct repository *sub,
 543                 struct commit **left, struct commit **right,
 544                 struct commit_list **merge_bases)
 545 {
 546         const char *message = NULL;
 547         struct strbuf sb = STRBUF_INIT;
 548         int fast_forward = 0, fast_backward = 0;
 549
 550         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 551                 diff_emit_submodule_untracked(o, path);
 552
 553         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 554                 diff_emit_submodule_modified(o, path);
 555
 556         if (is_null_oid(one))
 557                 message = "(new submodule)";
 558         else if (is_null_oid(two))
 559                 message = "(submodule deleted)";
 560
 561         if (!sub) {
 562                 if (!message)
 563                         message = "(commits not present)";
 564                 goto output_header;
 565         }
 566
 567         /*
 568          * Attempt to lookup the commit references, and determine if this is
 569          * a fast forward or fast backwards update.
 570          */
 571         *left = lookup_commit_reference(sub, one);
 572         *right = lookup_commit_reference(sub, two);
 573
 574         /*
 575          * Warn about missing commits in the submodule project, but only if
 576          * they aren't null.
 577          */
 578         if ((!is_null_oid(one) && !*left) ||
 579              (!is_null_oid(two) && !*right))
 580                 message = "(commits not present)";
 581
 582         *merge_bases = repo_get_merge_bases(sub, *left, *right);
 583         if (*merge_bases) {
 584                 if ((*merge_bases)->item == *left)
 585                         fast_forward = 1;
 586                 else if ((*merge_bases)->item == *right)
 587                         fast_backward = 1;
 588         }
 589
 590         if (oideq(one, two)) {
 591                 strbuf_release(&sb);
 592                 return;
 593         }
 594
 595 output_header:
 596         strbuf_addf(&sb, "Submodule %s ", path);
 597         strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
 598         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 599         strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
 600         if (message)
 601                 strbuf_addf(&sb, " %s\n", message);
 602         else
 603                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 604         diff_emit_submodule_header(o, sb.buf);
 605
 606         strbuf_release(&sb);
 607 }
 608
 609 void show_submodule_summary(struct diff_options *o, const char *path,
 610                 struct object_id *one, struct object_id *two,
 611                 unsigned dirty_submodule)
 612 {
 613         struct rev_info rev;
 614         struct commit *left = NULL, *right = NULL;
 615         struct commit_list *merge_bases = NULL;
 616         struct repository *sub;
 617
 618         sub = open_submodule(path);
 619         show_submodule_header(o, path, one, two, dirty_submodule,
 620                               sub, &left, &right, &merge_bases);
 621
 622         /*
 623          * If we don't have both a left and a right pointer, there is no
 624          * reason to try and display a summary. The header line should contain
 625          * all the information the user needs.
 626          */
 627         if (!left || !right || !sub)
 628                 goto out;
 629
 630         /* Treat revision walker failure the same as missing commits */
 631         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 632                 diff_emit_submodule_error(o, "(revision walker failed)\n");
 633                 goto out;
 634         }
 635
 636         print_submodule_summary(sub, &rev, o);
 637
 638 out:
 639         if (merge_bases)
 640                 free_commit_list(merge_bases);
 641         clear_commit_marks(left, ~0);
 642         clear_commit_marks(right, ~0);
 643         if (sub) {
 644                 repo_clear(sub);
 645                 free(sub);
 646         }
 647 }
 648
 649 void show_submodule_inline_diff(struct diff_options *o, const char *path,
 650                 struct object_id *one, struct object_id *two,
 651                 unsigned dirty_submodule)
 652 {
 653         const struct object_id *old_oid = the_hash_algo->empty_tree, *new_oid = the_hash_algo->empty_tree;
 654         struct commit *left = NULL, *right = NULL;
 655         struct commit_list *merge_bases = NULL;
 656         struct child_process cp = CHILD_PROCESS_INIT;
 657         struct strbuf sb = STRBUF_INIT;
 658         struct repository *sub;
 659
 660         sub = open_submodule(path);
 661         show_submodule_header(o, path, one, two, dirty_submodule,
 662                               sub, &left, &right, &merge_bases);
 663
 664         /* We need a valid left and right commit to display a difference */
 665         if (!(left || is_null_oid(one)) ||
 666             !(right || is_null_oid(two)))
 667                 goto done;
 668
 669         if (left)
 670                 old_oid = one;
 671         if (right)
 672                 new_oid = two;
 673
 674         cp.git_cmd = 1;
 675         cp.dir = path;
 676         cp.out = -1;
 677         cp.no_stdin = 1;
 678
 679         /* TODO: other options may need to be passed here. */
 680         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 681         argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 682                          "always" : "never");
 683
 684         if (o->flags.reverse_diff) {
 685                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 686                                  o->b_prefix, path);
 687                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 688                                  o->a_prefix, path);
 689         } else {
 690                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 691                                  o->a_prefix, path);
 692                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 693                                  o->b_prefix, path);
 694         }
 695         argv_array_push(&cp.args, oid_to_hex(old_oid));
 696         /*
 697          * If the submodule has modified content, we will diff against the
 698          * work tree, under the assumption that the user has asked for the
 699          * diff format and wishes to actually see all differences even if they
 700          * haven't yet been committed to the submodule yet.
 701          */
 702         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 703                 argv_array_push(&cp.args, oid_to_hex(new_oid));
 704
 705         prepare_submodule_repo_env(&cp.env_array);
 706         if (start_command(&cp))
 707                 diff_emit_submodule_error(o, "(diff failed)\n");
 708
 709         while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
 710                 diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
 711
 712         if (finish_command(&cp))
 713                 diff_emit_submodule_error(o, "(diff failed)\n");
 714
 715 done:
 716         strbuf_release(&sb);
 717         if (merge_bases)
 718                 free_commit_list(merge_bases);
 719         if (left)
 720                 clear_commit_marks(left, ~0);
 721         if (right)
 722                 clear_commit_marks(right, ~0);
 723         if (sub) {
 724                 repo_clear(sub);
 725                 free(sub);
 726         }
 727 }
 728
 729 int should_update_submodules(void)
 730 {
 731         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 732 }
 733
 734 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 735 {
 736         if (!S_ISGITLINK(ce->ce_mode))
 737                 return NULL;
 738
 739         if (!should_update_submodules())
 740                 return NULL;
 741
 742         return submodule_from_path(the_repository, &null_oid, ce->name);
 743 }
 744
 745 static struct oid_array *submodule_commits(struct string_list *submodules,
 746                                            const char *name)
 747 {
 748         struct string_list_item *item;
 749
 750         item = string_list_insert(submodules, name);
 751         if (item->util)
 752                 return (struct oid_array *) item->util;
 753
 754         /* NEEDSWORK: should we have oid_array_init()? */
 755         item->util = xcalloc(1, sizeof(struct oid_array));
 756         return (struct oid_array *) item->util;
 757 }
 758
 759 struct collect_changed_submodules_cb_data {
 760         struct repository *repo;
 761         struct string_list *changed;
 762         const struct object_id *commit_oid;
 763 };
 764
 765 /*
 766  * this would normally be two functions: default_name_from_path() and
 767  * path_from_default_name(). Since the default name is the same as
 768  * the submodule path we can get away with just one function which only
 769  * checks whether there is a submodule in the working directory at that
 770  * location.
 771  */
 772 static const char *default_name_or_path(const char *path_or_name)
 773 {
 774         int error_code;
 775
 776         if (!is_submodule_populated_gently(path_or_name, &error_code))
 777                 return NULL;
 778
 779         return path_or_name;
 780 }
 781
 782 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 783                                           struct diff_options *options,
 784                                           void *data)
 785 {
 786         struct collect_changed_submodules_cb_data *me = data;
 787         struct string_list *changed = me->changed;
 788         const struct object_id *commit_oid = me->commit_oid;
 789         int i;
 790
 791         for (i = 0; i < q->nr; i++) {
 792                 struct diff_filepair *p = q->queue[i];
 793                 struct oid_array *commits;
 794                 const struct submodule *submodule;
 795                 const char *name;
 796
 797                 if (!S_ISGITLINK(p->two->mode))
 798                         continue;
 799
 800                 submodule = submodule_from_path(me->repo,
 801                                                 commit_oid, p->two->path);
 802                 if (submodule)
 803                         name = submodule->name;
 804                 else {
 805                         name = default_name_or_path(p->two->path);
 806                         /* make sure name does not collide with existing one */
 807                         if (name)
 808                                 submodule = submodule_from_name(me->repo,
 809                                                                 commit_oid, name);
 810                         if (submodule) {
 811                                 warning("Submodule in commit %s at path: "
 812                                         "'%s' collides with a submodule named "
 813                                         "the same. Skipping it.",
 814                                         oid_to_hex(commit_oid), p->two->path);
 815                                 name = NULL;
 816                         }
 817                 }
 818
 819                 if (!name)
 820                         continue;
 821
 822                 commits = submodule_commits(changed, name);
 823                 oid_array_append(commits, &p->two->oid);
 824         }
 825 }
 826
 827 /*
 828  * Collect the paths of submodules in 'changed' which have changed based on
 829  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 830  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 831  * what the submodule pointers were updated to during the change.
 832  */
 833 static void collect_changed_submodules(struct repository *r,
 834                                        struct string_list *changed,
 835                                        struct argv_array *argv)
 836 {
 837         struct rev_info rev;
 838         const struct commit *commit;
 839
 840         repo_init_revisions(r, &rev, NULL);
 841         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 842         if (prepare_revision_walk(&rev))
 843                 die("revision walk setup failed");
 844
 845         while ((commit = get_revision(&rev))) {
 846                 struct rev_info diff_rev;
 847                 struct collect_changed_submodules_cb_data data;
 848                 data.repo = r;
 849                 data.changed = changed;
 850                 data.commit_oid = &commit->object.oid;
 851
 852                 repo_init_revisions(r, &diff_rev, NULL);
 853                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 854                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 855                 diff_rev.diffopt.format_callback_data = &data;
 856                 diff_tree_combined_merge(commit, 1, &diff_rev);
 857         }
 858
 859         reset_revision_walk();
 860 }
 861
 862 static void free_submodules_oids(struct string_list *submodules)
 863 {
 864         struct string_list_item *item;
 865         for_each_string_list_item(item, submodules)
 866                 oid_array_clear((struct oid_array *) item->util);
 867         string_list_clear(submodules, 1);
 868 }
 869
 870 static int has_remote(const char *refname, const struct object_id *oid,
 871                       int flags, void *cb_data)
 872 {
 873         return 1;
 874 }
 875
 876 static int append_oid_to_argv(const struct object_id *oid, void *data)
 877 {
 878         struct argv_array *argv = data;
 879         argv_array_push(argv, oid_to_hex(oid));
 880         return 0;
 881 }
 882
 883 struct has_commit_data {
 884         struct repository *repo;
 885         int result;
 886         const char *path;
 887 };
 888
 889 static int check_has_commit(const struct object_id *oid, void *data)
 890 {
 891         struct has_commit_data *cb = data;
 892
 893         enum object_type type = oid_object_info(cb->repo, oid, NULL);
 894
 895         switch (type) {
 896         case OBJ_COMMIT:
 897                 return 0;
 898         case OBJ_BAD:
 899                 /*
 900                  * Object is missing or invalid. If invalid, an error message
 901                  * has already been printed.
 902                  */
 903                 cb->result = 0;
 904                 return 0;
 905         default:
 906                 die(_("submodule entry '%s' (%s) is a %s, not a commit"),
 907                     cb->path, oid_to_hex(oid), type_name(type));
 908         }
 909 }
 910
 911 static int submodule_has_commits(struct repository *r,
 912                                  const char *path,
 913                                  struct oid_array *commits)
 914 {
 915         struct has_commit_data has_commit = { r, 1, path };
 916
 917         /*
 918          * Perform a cheap, but incorrect check for the existence of 'commits'.
 919          * This is done by adding the submodule's object store to the in-core
 920          * object store, and then querying for each commit's existence.  If we
 921          * do not have the commit object anywhere, there is no chance we have
 922          * it in the object store of the correct submodule and have it
 923          * reachable from a ref, so we can fail early without spawning rev-list
 924          * which is expensive.
 925          */
 926         if (add_submodule_odb(path))
 927                 return 0;
 928
 929         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 930
 931         if (has_commit.result) {
 932                 /*
 933                  * Even if the submodule is checked out and the commit is
 934                  * present, make sure it exists in the submodule's object store
 935                  * and that it is reachable from a ref.
 936                  */
 937                 struct child_process cp = CHILD_PROCESS_INIT;
 938                 struct strbuf out = STRBUF_INIT;
 939
 940                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 941                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 942                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 943
 944                 prepare_submodule_repo_env(&cp.env_array);
 945                 cp.git_cmd = 1;
 946                 cp.no_stdin = 1;
 947                 cp.dir = path;
 948
 949                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 950                         has_commit.result = 0;
 951
 952                 strbuf_release(&out);
 953         }
 954
 955         return has_commit.result;
 956 }
 957
 958 static int submodule_needs_pushing(struct repository *r,
 959                                    const char *path,
 960                                    struct oid_array *commits)
 961 {
 962         if (!submodule_has_commits(r, path, commits))
 963                 /*
 964                  * NOTE: We do consider it safe to return "no" here. The
 965                  * correct answer would be "We do not know" instead of
 966                  * "No push needed", but it is quite hard to change
 967                  * the submodule pointer without having the submodule
 968                  * around. If a user did however change the submodules
 969                  * without having the submodule around, this indicates
 970                  * an expert who knows what they are doing or a
 971                  * maintainer integrating work from other people. In
 972                  * both cases it should be safe to skip this check.
 973                  */
 974                 return 0;
 975
 976         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 977                 struct child_process cp = CHILD_PROCESS_INIT;
 978                 struct strbuf buf = STRBUF_INIT;
 979                 int needs_pushing = 0;
 980
 981                 argv_array_push(&cp.args, "rev-list");
 982                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 983                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 984
 985                 prepare_submodule_repo_env(&cp.env_array);
 986                 cp.git_cmd = 1;
 987                 cp.no_stdin = 1;
 988                 cp.out = -1;
 989                 cp.dir = path;
 990                 if (start_command(&cp))
 991                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 992                                         path);
 993                 if (strbuf_read(&buf, cp.out, 41))
 994                         needs_pushing = 1;
 995                 finish_command(&cp);
 996                 close(cp.out);
 997                 strbuf_release(&buf);
 998                 return needs_pushing;
 999         }
1000
1001         return 0;
1002 }
1003
1004 int find_unpushed_submodules(struct repository *r,
1005                              struct oid_array *commits,
1006                              const char *remotes_name,
1007                              struct string_list *needs_pushing)
1008 {
1009         struct string_list submodules = STRING_LIST_INIT_DUP;
1010         struct string_list_item *name;
1011         struct argv_array argv = ARGV_ARRAY_INIT;
1012
1013         /* argv.argv[0] will be ignored by setup_revisions */
1014         argv_array_push(&argv, "find_unpushed_submodules");
1015         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
1016         argv_array_push(&argv, "--not");
1017         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
1018
1019         collect_changed_submodules(r, &submodules, &argv);
1020
1021         for_each_string_list_item(name, &submodules) {
1022                 struct oid_array *commits = name->util;
1023                 const struct submodule *submodule;
1024                 const char *path = NULL;
1025
1026                 submodule = submodule_from_name(r, &null_oid, name->string);
1027                 if (submodule)
1028                         path = submodule->path;
1029                 else
1030                         path = default_name_or_path(name->string);
1031
1032                 if (!path)
1033                         continue;
1034
1035                 if (submodule_needs_pushing(r, path, commits))
1036                         string_list_insert(needs_pushing, path);
1037         }
1038
1039         free_submodules_oids(&submodules);
1040         argv_array_clear(&argv);
1041
1042         return needs_pushing->nr;
1043 }
1044
1045 static int push_submodule(const char *path,
1046                           const struct remote *remote,
1047                           const struct refspec *rs,
1048                           const struct string_list *push_options,
1049                           int dry_run)
1050 {
1051         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
1052                 struct child_process cp = CHILD_PROCESS_INIT;
1053                 argv_array_push(&cp.args, "push");
1054                 if (dry_run)
1055                         argv_array_push(&cp.args, "--dry-run");
1056
1057                 if (push_options && push_options->nr) {
1058                         const struct string_list_item *item;
1059                         for_each_string_list_item(item, push_options)
1060                                 argv_array_pushf(&cp.args, "--push-option=%s",
1061                                                  item->string);
1062                 }
1063
1064                 if (remote->origin != REMOTE_UNCONFIGURED) {
1065                         int i;
1066                         argv_array_push(&cp.args, remote->name);
1067                         for (i = 0; i < rs->raw_nr; i++)
1068                                 argv_array_push(&cp.args, rs->raw[i]);
1069                 }
1070
1071                 prepare_submodule_repo_env(&cp.env_array);
1072                 cp.git_cmd = 1;
1073                 cp.no_stdin = 1;
1074                 cp.dir = path;
1075                 if (run_command(&cp))
1076                         return 0;
1077                 close(cp.out);
1078         }
1079
1080         return 1;
1081 }
1082
1083 /*
1084  * Perform a check in the submodule to see if the remote and refspec work.
1085  * Die if the submodule can't be pushed.
1086  */
1087 static void submodule_push_check(const char *path, const char *head,
1088                                  const struct remote *remote,
1089                                  const struct refspec *rs)
1090 {
1091         struct child_process cp = CHILD_PROCESS_INIT;
1092         int i;
1093
1094         argv_array_push(&cp.args, "submodule--helper");
1095         argv_array_push(&cp.args, "push-check");
1096         argv_array_push(&cp.args, head);
1097         argv_array_push(&cp.args, remote->name);
1098
1099         for (i = 0; i < rs->raw_nr; i++)
1100                 argv_array_push(&cp.args, rs->raw[i]);
1101
1102         prepare_submodule_repo_env(&cp.env_array);
1103         cp.git_cmd = 1;
1104         cp.no_stdin = 1;
1105         cp.no_stdout = 1;
1106         cp.dir = path;
1107
1108         /*
1109          * Simply indicate if 'submodule--helper push-check' failed.
1110          * More detailed error information will be provided by the
1111          * child process.
1112          */
1113         if (run_command(&cp))
1114                 die("process for submodule '%s' failed", path);
1115 }
1116
1117 int push_unpushed_submodules(struct repository *r,
1118                              struct oid_array *commits,
1119                              const struct remote *remote,
1120                              const struct refspec *rs,
1121                              const struct string_list *push_options,
1122                              int dry_run)
1123 {
1124         int i, ret = 1;
1125         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1126
1127         if (!find_unpushed_submodules(r, commits,
1128                                       remote->name, &needs_pushing))
1129                 return 1;
1130
1131         /*
1132          * Verify that the remote and refspec can be propagated to all
1133          * submodules.  This check can be skipped if the remote and refspec
1134          * won't be propagated due to the remote being unconfigured (e.g. a URL
1135          * instead of a remote name).
1136          */
1137         if (remote->origin != REMOTE_UNCONFIGURED) {
1138                 char *head;
1139                 struct object_id head_oid;
1140
1141                 head = resolve_refdup("HEAD", 0, &head_oid, NULL);
1142                 if (!head)
1143                         die(_("Failed to resolve HEAD as a valid ref."));
1144
1145                 for (i = 0; i < needs_pushing.nr; i++)
1146                         submodule_push_check(needs_pushing.items[i].string,
1147                                              head, remote, rs);
1148                 free(head);
1149         }
1150
1151         /* Actually push the submodules */
1152         for (i = 0; i < needs_pushing.nr; i++) {
1153                 const char *path = needs_pushing.items[i].string;
1154                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1155                 if (!push_submodule(path, remote, rs,
1156                                     push_options, dry_run)) {
1157                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1158                         ret = 0;
1159                 }
1160         }
1161
1162         string_list_clear(&needs_pushing, 0);
1163
1164         return ret;
1165 }
1166
1167 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1168                                int flags, void *data)
1169 {
1170         struct oid_array *array = data;
1171         oid_array_append(array, oid);
1172         return 0;
1173 }
1174
1175 void check_for_new_submodule_commits(struct object_id *oid)
1176 {
1177         if (!initialized_fetch_ref_tips) {
1178                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1179                 initialized_fetch_ref_tips = 1;
1180         }
1181
1182         oid_array_append(&ref_tips_after_fetch, oid);
1183 }
1184
1185 static void calculate_changed_submodule_paths(struct repository *r,
1186                 struct string_list *changed_submodule_names)
1187 {
1188         struct argv_array argv = ARGV_ARRAY_INIT;
1189         struct string_list_item *name;
1190
1191         /* No need to check if there are no submodules configured */
1192         if (!submodule_from_path(r, NULL, NULL))
1193                 return;
1194
1195         argv_array_push(&argv, "--"); /* argv[0] program name */
1196         oid_array_for_each_unique(&ref_tips_after_fetch,
1197                                    append_oid_to_argv, &argv);
1198         argv_array_push(&argv, "--not");
1199         oid_array_for_each_unique(&ref_tips_before_fetch,
1200                                    append_oid_to_argv, &argv);
1201
1202         /*
1203          * Collect all submodules (whether checked out or not) for which new
1204          * commits have been recorded upstream in "changed_submodule_names".
1205          */
1206         collect_changed_submodules(r, changed_submodule_names, &argv);
1207
1208         for_each_string_list_item(name, changed_submodule_names) {
1209                 struct oid_array *commits = name->util;
1210                 const struct submodule *submodule;
1211                 const char *path = NULL;
1212
1213                 submodule = submodule_from_name(r, &null_oid, name->string);
1214                 if (submodule)
1215                         path = submodule->path;
1216                 else
1217                         path = default_name_or_path(name->string);
1218
1219                 if (!path)
1220                         continue;
1221
1222                 if (submodule_has_commits(r, path, commits)) {
1223                         oid_array_clear(commits);
1224                         *name->string = '\0';
1225                 }
1226         }
1227
1228         string_list_remove_empty_items(changed_submodule_names, 1);
1229
1230         argv_array_clear(&argv);
1231         oid_array_clear(&ref_tips_before_fetch);
1232         oid_array_clear(&ref_tips_after_fetch);
1233         initialized_fetch_ref_tips = 0;
1234 }
1235
1236 int submodule_touches_in_range(struct repository *r,
1237                                struct object_id *excl_oid,
1238                                struct object_id *incl_oid)
1239 {
1240         struct string_list subs = STRING_LIST_INIT_DUP;
1241         struct argv_array args = ARGV_ARRAY_INIT;
1242         int ret;
1243
1244         /* No need to check if there are no submodules configured */
1245         if (!submodule_from_path(r, NULL, NULL))
1246                 return 0;
1247
1248         argv_array_push(&args, "--"); /* args[0] program name */
1249         argv_array_push(&args, oid_to_hex(incl_oid));
1250         if (!is_null_oid(excl_oid)) {
1251                 argv_array_push(&args, "--not");
1252                 argv_array_push(&args, oid_to_hex(excl_oid));
1253         }
1254
1255         collect_changed_submodules(r, &subs, &args);
1256         ret = subs.nr;
1257
1258         argv_array_clear(&args);
1259
1260         free_submodules_oids(&subs);
1261         return ret;
1262 }
1263
1264 struct submodule_parallel_fetch {
1265         int count;
1266         struct argv_array args;
1267         struct repository *r;
1268         const char *prefix;
1269         int command_line_option;
1270         int default_option;
1271         int quiet;
1272         int result;
1273
1274         struct string_list changed_submodule_names;
1275
1276         /* Pending fetches by OIDs */
1277         struct fetch_task **oid_fetch_tasks;
1278         int oid_fetch_tasks_nr, oid_fetch_tasks_alloc;
1279 };
1280 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0, \
1281                   STRING_LIST_INIT_DUP, \
1282                   NULL, 0, 0}
1283
1284 static int get_fetch_recurse_config(const struct submodule *submodule,
1285                                     struct submodule_parallel_fetch *spf)
1286 {
1287         if (spf->command_line_option != RECURSE_SUBMODULES_DEFAULT)
1288                 return spf->command_line_option;
1289
1290         if (submodule) {
1291                 char *key;
1292                 const char *value;
1293
1294                 int fetch_recurse = submodule->fetch_recurse;
1295                 key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1296                 if (!repo_config_get_string_const(spf->r, key, &value)) {
1297                         fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1298                 }
1299                 free(key);
1300
1301                 if (fetch_recurse != RECURSE_SUBMODULES_NONE)
1302                         /* local config overrules everything except commandline */
1303                         return fetch_recurse;
1304         }
1305
1306         return spf->default_option;
1307 }
1308
1309 /*
1310  * Fetch in progress (if callback data) or
1311  * pending (if in oid_fetch_tasks in struct submodule_parallel_fetch)
1312  */
1313 struct fetch_task {
1314         struct repository *repo;
1315         const struct submodule *sub;
1316         unsigned free_sub : 1; /* Do we need to free the submodule? */
1317
1318         struct oid_array *commits; /* Ensure these commits are fetched */
1319 };
1320
1321 /**
1322  * When a submodule is not defined in .gitmodules, we cannot access it
1323  * via the regular submodule-config. Create a fake submodule, which we can
1324  * work on.
1325  */
1326 static const struct submodule *get_non_gitmodules_submodule(const char *path)
1327 {
1328         struct submodule *ret = NULL;
1329         const char *name = default_name_or_path(path);
1330
1331         if (!name)
1332                 return NULL;
1333
1334         ret = xmalloc(sizeof(*ret));
1335         memset(ret, 0, sizeof(*ret));
1336         ret->path = name;
1337         ret->name = name;
1338
1339         return (const struct submodule *) ret;
1340 }
1341
1342 static struct fetch_task *fetch_task_create(struct repository *r,
1343                                             const char *path)
1344 {
1345         struct fetch_task *task = xmalloc(sizeof(*task));
1346         memset(task, 0, sizeof(*task));
1347
1348         task->sub = submodule_from_path(r, &null_oid, path);
1349         if (!task->sub) {
1350                 /*
1351                  * No entry in .gitmodules? Technically not a submodule,
1352                  * but historically we supported repositories that happen to be
1353                  * in-place where a gitlink is. Keep supporting them.
1354                  */
1355                 task->sub = get_non_gitmodules_submodule(path);
1356                 if (!task->sub) {
1357                         free(task);
1358                         return NULL;
1359                 }
1360
1361                 task->free_sub = 1;
1362         }
1363
1364         return task;
1365 }
1366
1367 static void fetch_task_release(struct fetch_task *p)
1368 {
1369         if (p->free_sub)
1370                 free((void*)p->sub);
1371         p->free_sub = 0;
1372         p->sub = NULL;
1373
1374         if (p->repo)
1375                 repo_clear(p->repo);
1376         FREE_AND_NULL(p->repo);
1377 }
1378
1379 static struct repository *get_submodule_repo_for(struct repository *r,
1380                                                  const struct submodule *sub)
1381 {
1382         struct repository *ret = xmalloc(sizeof(*ret));
1383
1384         if (repo_submodule_init(ret, r, sub)) {
1385                 /*
1386                  * No entry in .gitmodules? Technically not a submodule,
1387                  * but historically we supported repositories that happen to be
1388                  * in-place where a gitlink is. Keep supporting them.
1389                  */
1390                 struct strbuf gitdir = STRBUF_INIT;
1391                 strbuf_repo_worktree_path(&gitdir, r, "%s/.git", sub->path);
1392                 if (repo_init(ret, gitdir.buf, NULL)) {
1393                         strbuf_release(&gitdir);
1394                         free(ret);
1395                         return NULL;
1396                 }
1397                 strbuf_release(&gitdir);
1398         }
1399
1400         return ret;
1401 }
1402
1403 static int get_next_submodule(struct child_process *cp,
1404                               struct strbuf *err, void *data, void **task_cb)
1405 {
1406         struct submodule_parallel_fetch *spf = data;
1407
1408         for (; spf->count < spf->r->index->cache_nr; spf->count++) {
1409                 const struct cache_entry *ce = spf->r->index->cache[spf->count];
1410                 const char *default_argv;
1411                 struct fetch_task *task;
1412
1413                 if (!S_ISGITLINK(ce->ce_mode))
1414                         continue;
1415
1416                 task = fetch_task_create(spf->r, ce->name);
1417                 if (!task)
1418                         continue;
1419
1420                 switch (get_fetch_recurse_config(task->sub, spf))
1421                 {
1422                 default:
1423                 case RECURSE_SUBMODULES_DEFAULT:
1424                 case RECURSE_SUBMODULES_ON_DEMAND:
1425                         if (!task->sub ||
1426                             !string_list_lookup(
1427                                         &spf->changed_submodule_names,
1428                                         task->sub->name))
1429                                 continue;
1430                         default_argv = "on-demand";
1431                         break;
1432                 case RECURSE_SUBMODULES_ON:
1433                         default_argv = "yes";
1434                         break;
1435                 case RECURSE_SUBMODULES_OFF:
1436                         continue;
1437                 }
1438
1439                 task->repo = get_submodule_repo_for(spf->r, task->sub);
1440                 if (task->repo) {
1441                         struct strbuf submodule_prefix = STRBUF_INIT;
1442                         child_process_init(cp);
1443                         cp->dir = task->repo->gitdir;
1444                         prepare_submodule_repo_env_in_gitdir(&cp->env_array);
1445                         cp->git_cmd = 1;
1446                         if (!spf->quiet)
1447                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1448                                             spf->prefix, ce->name);
1449                         argv_array_init(&cp->args);
1450                         argv_array_pushv(&cp->args, spf->args.argv);
1451                         argv_array_push(&cp->args, default_argv);
1452                         argv_array_push(&cp->args, "--submodule-prefix");
1453
1454                         strbuf_addf(&submodule_prefix, "%s%s/",
1455                                                        spf->prefix,
1456                                                        task->sub->path);
1457                         argv_array_push(&cp->args, submodule_prefix.buf);
1458
1459                         spf->count++;
1460                         *task_cb = task;
1461
1462                         strbuf_release(&submodule_prefix);
1463                         return 1;
1464                 } else {
1465
1466                         fetch_task_release(task);
1467                         free(task);
1468
1469                         /*
1470                          * An empty directory is normal,
1471                          * the submodule is not initialized
1472                          */
1473                         if (S_ISGITLINK(ce->ce_mode) &&
1474                             !is_empty_dir(ce->name)) {
1475                                 spf->result = 1;
1476                                 strbuf_addf(err,
1477                                             _("Could not access submodule '%s'"),
1478                                             ce->name);
1479                         }
1480                 }
1481         }
1482
1483         if (spf->oid_fetch_tasks_nr) {
1484                 struct fetch_task *task =
1485                         spf->oid_fetch_tasks[spf->oid_fetch_tasks_nr - 1];
1486                 struct strbuf submodule_prefix = STRBUF_INIT;
1487                 spf->oid_fetch_tasks_nr--;
1488
1489                 strbuf_addf(&submodule_prefix, "%s%s/",
1490                             spf->prefix, task->sub->path);
1491
1492                 child_process_init(cp);
1493                 prepare_submodule_repo_env_in_gitdir(&cp->env_array);
1494                 cp->git_cmd = 1;
1495                 cp->dir = task->repo->gitdir;
1496
1497                 argv_array_init(&cp->args);
1498                 argv_array_pushv(&cp->args, spf->args.argv);
1499                 argv_array_push(&cp->args, "on-demand");
1500                 argv_array_push(&cp->args, "--submodule-prefix");
1501                 argv_array_push(&cp->args, submodule_prefix.buf);
1502
1503                 /* NEEDSWORK: have get_default_remote from submodule--helper */
1504                 argv_array_push(&cp->args, "origin");
1505                 oid_array_for_each_unique(task->commits,
1506                                           append_oid_to_argv, &cp->args);
1507
1508                 *task_cb = task;
1509                 strbuf_release(&submodule_prefix);
1510                 return 1;
1511         }
1512
1513         return 0;
1514 }
1515
1516 static int fetch_start_failure(struct strbuf *err,
1517                                void *cb, void *task_cb)
1518 {
1519         struct submodule_parallel_fetch *spf = cb;
1520         struct fetch_task *task = task_cb;
1521
1522         spf->result = 1;
1523
1524         fetch_task_release(task);
1525         return 0;
1526 }
1527
1528 static int commit_missing_in_sub(const struct object_id *oid, void *data)
1529 {
1530         struct repository *subrepo = data;
1531
1532         enum object_type type = oid_object_info(subrepo, oid, NULL);
1533
1534         return type != OBJ_COMMIT;
1535 }
1536
1537 static int fetch_finish(int retvalue, struct strbuf *err,
1538                         void *cb, void *task_cb)
1539 {
1540         struct submodule_parallel_fetch *spf = cb;
1541         struct fetch_task *task = task_cb;
1542
1543         struct string_list_item *it;
1544         struct oid_array *commits;
1545
1546         if (retvalue)
1547                 spf->result = 1;
1548
1549         if (!task || !task->sub)
1550                 BUG("callback cookie bogus");
1551
1552         /* Is this the second time we process this submodule? */
1553         if (task->commits)
1554                 goto out;
1555
1556         it = string_list_lookup(&spf->changed_submodule_names, task->sub->name);
1557         if (!it)
1558                 /* Could be an unchanged submodule, not contained in the list */
1559                 goto out;
1560
1561         commits = it->util;
1562         oid_array_filter(commits,
1563                          commit_missing_in_sub,
1564                          task->repo);
1565
1566         /* Are there commits we want, but do not exist? */
1567         if (commits->nr) {
1568                 task->commits = commits;
1569                 ALLOC_GROW(spf->oid_fetch_tasks,
1570                            spf->oid_fetch_tasks_nr + 1,
1571                            spf->oid_fetch_tasks_alloc);
1572                 spf->oid_fetch_tasks[spf->oid_fetch_tasks_nr] = task;
1573                 spf->oid_fetch_tasks_nr++;
1574                 return 0;
1575         }
1576
1577 out:
1578         fetch_task_release(task);
1579
1580         return 0;
1581 }
1582
1583 int fetch_populated_submodules(struct repository *r,
1584                                const struct argv_array *options,
1585                                const char *prefix, int command_line_option,
1586                                int default_option,
1587                                int quiet, int max_parallel_jobs)
1588 {
1589         int i;
1590         struct submodule_parallel_fetch spf = SPF_INIT;
1591
1592         spf.r = r;
1593         spf.command_line_option = command_line_option;
1594         spf.default_option = default_option;
1595         spf.quiet = quiet;
1596         spf.prefix = prefix;
1597
1598         if (!r->worktree)
1599                 goto out;
1600
1601         if (repo_read_index(r) < 0)
1602                 die("index file corrupt");
1603
1604         argv_array_push(&spf.args, "fetch");
1605         for (i = 0; i < options->argc; i++)
1606                 argv_array_push(&spf.args, options->argv[i]);
1607         argv_array_push(&spf.args, "--recurse-submodules-default");
1608         /* default value, "--submodule-prefix" and its value are added later */
1609
1610         calculate_changed_submodule_paths(r, &spf.changed_submodule_names);
1611         string_list_sort(&spf.changed_submodule_names);
1612         run_processes_parallel(max_parallel_jobs,
1613                                get_next_submodule,
1614                                fetch_start_failure,
1615                                fetch_finish,
1616                                &spf);
1617
1618         argv_array_clear(&spf.args);
1619 out:
1620         free_submodules_oids(&spf.changed_submodule_names);
1621         return spf.result;
1622 }
1623
1624 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1625 {
1626         struct child_process cp = CHILD_PROCESS_INIT;
1627         struct strbuf buf = STRBUF_INIT;
1628         FILE *fp;
1629         unsigned dirty_submodule = 0;
1630         const char *git_dir;
1631         int ignore_cp_exit_code = 0;
1632
1633         strbuf_addf(&buf, "%s/.git", path);
1634         git_dir = read_gitfile(buf.buf);
1635         if (!git_dir)
1636                 git_dir = buf.buf;
1637         if (!is_git_directory(git_dir)) {
1638                 if (is_directory(git_dir))
1639                         die(_("'%s' not recognized as a git repository"), git_dir);
1640                 strbuf_release(&buf);
1641                 /* The submodule is not checked out, so it is not modified */
1642                 return 0;
1643         }
1644         strbuf_reset(&buf);
1645
1646         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1647         if (ignore_untracked)
1648                 argv_array_push(&cp.args, "-uno");
1649
1650         prepare_submodule_repo_env(&cp.env_array);
1651         cp.git_cmd = 1;
1652         cp.no_stdin = 1;
1653         cp.out = -1;
1654         cp.dir = path;
1655         if (start_command(&cp))
1656                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1657
1658         fp = xfdopen(cp.out, "r");
1659         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1660                 /* regular untracked files */
1661                 if (buf.buf[0] == '?')
1662                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1663
1664                 if (buf.buf[0] == 'u' ||
1665                     buf.buf[0] == '1' ||
1666                     buf.buf[0] == '2') {
1667                         /* T = line type, XY = status, SSSS = submodule state */
1668                         if (buf.len < strlen("T XY SSSS"))
1669                                 BUG("invalid status --porcelain=2 line %s",
1670                                     buf.buf);
1671
1672                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1673                                 /* nested untracked file */
1674                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1675
1676                         if (buf.buf[0] == 'u' ||
1677                             buf.buf[0] == '2' ||
1678                             memcmp(buf.buf + 5, "S..U", 4))
1679                                 /* other change */
1680                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1681                 }
1682
1683                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1684                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1685                      ignore_untracked)) {
1686                         /*
1687                          * We're not interested in any further information from
1688                          * the child any more, neither output nor its exit code.
1689                          */
1690                         ignore_cp_exit_code = 1;
1691                         break;
1692                 }
1693         }
1694         fclose(fp);
1695
1696         if (finish_command(&cp) && !ignore_cp_exit_code)
1697                 die("'git status --porcelain=2' failed in submodule %s", path);
1698
1699         strbuf_release(&buf);
1700         return dirty_submodule;
1701 }
1702
1703 int submodule_uses_gitfile(const char *path)
1704 {
1705         struct child_process cp = CHILD_PROCESS_INIT;
1706         const char *argv[] = {
1707                 "submodule",
1708                 "foreach",
1709                 "--quiet",
1710                 "--recursive",
1711                 "test -f .git",
1712                 NULL,
1713         };
1714         struct strbuf buf = STRBUF_INIT;
1715         const char *git_dir;
1716
1717         strbuf_addf(&buf, "%s/.git", path);
1718         git_dir = read_gitfile(buf.buf);
1719         if (!git_dir) {
1720                 strbuf_release(&buf);
1721                 return 0;
1722         }
1723         strbuf_release(&buf);
1724
1725         /* Now test that all nested submodules use a gitfile too */
1726         cp.argv = argv;
1727         prepare_submodule_repo_env(&cp.env_array);
1728         cp.git_cmd = 1;
1729         cp.no_stdin = 1;
1730         cp.no_stderr = 1;
1731         cp.no_stdout = 1;
1732         cp.dir = path;
1733         if (run_command(&cp))
1734                 return 0;
1735
1736         return 1;
1737 }
1738
1739 /*
1740  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1741  * when doing so.
1742  *
1743  * Return 1 if we'd lose data, return 0 if the removal is fine,
1744  * and negative values for errors.
1745  */
1746 int bad_to_remove_submodule(const char *path, unsigned flags)
1747 {
1748         ssize_t len;
1749         struct child_process cp = CHILD_PROCESS_INIT;
1750         struct strbuf buf = STRBUF_INIT;
1751         int ret = 0;
1752
1753         if (!file_exists(path) || is_empty_dir(path))
1754                 return 0;
1755
1756         if (!submodule_uses_gitfile(path))
1757                 return 1;
1758
1759         argv_array_pushl(&cp.args, "status", "--porcelain",
1760                                    "--ignore-submodules=none", NULL);
1761
1762         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1763                 argv_array_push(&cp.args, "-uno");
1764         else
1765                 argv_array_push(&cp.args, "-uall");
1766
1767         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1768                 argv_array_push(&cp.args, "--ignored");
1769
1770         prepare_submodule_repo_env(&cp.env_array);
1771         cp.git_cmd = 1;
1772         cp.no_stdin = 1;
1773         cp.out = -1;
1774         cp.dir = path;
1775         if (start_command(&cp)) {
1776                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1777                         die(_("could not start 'git status' in submodule '%s'"),
1778                                 path);
1779                 ret = -1;
1780                 goto out;
1781         }
1782
1783         len = strbuf_read(&buf, cp.out, 1024);
1784         if (len > 2)
1785                 ret = 1;
1786         close(cp.out);
1787
1788         if (finish_command(&cp)) {
1789                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1790                         die(_("could not run 'git status' in submodule '%s'"),
1791                                 path);
1792                 ret = -1;
1793         }
1794 out:
1795         strbuf_release(&buf);
1796         return ret;
1797 }
1798
1799 void submodule_unset_core_worktree(const struct submodule *sub)
1800 {
1801         char *config_path = xstrfmt("%s/modules/%s/config",
1802                                     get_git_common_dir(), sub->name);
1803
1804         if (git_config_set_in_file_gently(config_path, "core.worktree", NULL))
1805                 warning(_("Could not unset core.worktree setting in submodule '%s'"),
1806                           sub->path);
1807
1808         free(config_path);
1809 }
1810
1811 static const char *get_super_prefix_or_empty(void)
1812 {
1813         const char *s = get_super_prefix();
1814         if (!s)
1815                 s = "";
1816         return s;
1817 }
1818
1819 static int submodule_has_dirty_index(const struct submodule *sub)
1820 {
1821         struct child_process cp = CHILD_PROCESS_INIT;
1822
1823         prepare_submodule_repo_env(&cp.env_array);
1824
1825         cp.git_cmd = 1;
1826         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1827                                    "--cached", "HEAD", NULL);
1828         cp.no_stdin = 1;
1829         cp.no_stdout = 1;
1830         cp.dir = sub->path;
1831         if (start_command(&cp))
1832                 die("could not recurse into submodule '%s'", sub->path);
1833
1834         return finish_command(&cp);
1835 }
1836
1837 static void submodule_reset_index(const char *path)
1838 {
1839         struct child_process cp = CHILD_PROCESS_INIT;
1840         prepare_submodule_repo_env(&cp.env_array);
1841
1842         cp.git_cmd = 1;
1843         cp.no_stdin = 1;
1844         cp.dir = path;
1845
1846         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1847                                    get_super_prefix_or_empty(), path);
1848         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1849
1850         argv_array_push(&cp.args, empty_tree_oid_hex());
1851
1852         if (run_command(&cp))
1853                 die("could not reset submodule index");
1854 }
1855
1856 /**
1857  * Moves a submodule at a given path from a given head to another new head.
1858  * For edge cases (a submodule coming into existence or removing a submodule)
1859  * pass NULL for old or new respectively.
1860  */
1861 int submodule_move_head(const char *path,
1862                          const char *old_head,
1863                          const char *new_head,
1864                          unsigned flags)
1865 {
1866         int ret = 0;
1867         struct child_process cp = CHILD_PROCESS_INIT;
1868         const struct submodule *sub;
1869         int *error_code_ptr, error_code;
1870
1871         if (!is_submodule_active(the_repository, path))
1872                 return 0;
1873
1874         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1875                 /*
1876                  * Pass non NULL pointer to is_submodule_populated_gently
1877                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1878                  * to fixup the submodule in the force case later.
1879                  */
1880                 error_code_ptr = &error_code;
1881         else
1882                 error_code_ptr = NULL;
1883
1884         if (old_head && !is_submodule_populated_gently(path, error_code_ptr))
1885                 return 0;
1886
1887         sub = submodule_from_path(the_repository, &null_oid, path);
1888
1889         if (!sub)
1890                 BUG("could not get submodule information for '%s'", path);
1891
1892         if (old_head && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1893                 /* Check if the submodule has a dirty index. */
1894                 if (submodule_has_dirty_index(sub))
1895                         return error(_("submodule '%s' has dirty index"), path);
1896         }
1897
1898         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1899                 if (old_head) {
1900                         if (!submodule_uses_gitfile(path))
1901                                 absorb_git_dir_into_superproject("", path,
1902                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1903                 } else {
1904                         char *gitdir = xstrfmt("%s/modules/%s",
1905                                     get_git_common_dir(), sub->name);
1906                         connect_work_tree_and_git_dir(path, gitdir, 0);
1907                         free(gitdir);
1908
1909                         /* make sure the index is clean as well */
1910                         submodule_reset_index(path);
1911                 }
1912
1913                 if (old_head && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1914                         char *gitdir = xstrfmt("%s/modules/%s",
1915                                     get_git_common_dir(), sub->name);
1916                         connect_work_tree_and_git_dir(path, gitdir, 1);
1917                         free(gitdir);
1918                 }
1919         }
1920
1921         prepare_submodule_repo_env(&cp.env_array);
1922
1923         cp.git_cmd = 1;
1924         cp.no_stdin = 1;
1925         cp.dir = path;
1926
1927         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1928                         get_super_prefix_or_empty(), path);
1929         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1930
1931         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1932                 argv_array_push(&cp.args, "-n");
1933         else
1934                 argv_array_push(&cp.args, "-u");
1935
1936         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1937                 argv_array_push(&cp.args, "--reset");
1938         else
1939                 argv_array_push(&cp.args, "-m");
1940
1941         if (!(flags & SUBMODULE_MOVE_HEAD_FORCE))
1942                 argv_array_push(&cp.args, old_head ? old_head : empty_tree_oid_hex());
1943
1944         argv_array_push(&cp.args, new_head ? new_head : empty_tree_oid_hex());
1945
1946         if (run_command(&cp)) {
1947                 ret = error(_("Submodule '%s' could not be updated."), path);
1948                 goto out;
1949         }
1950
1951         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1952                 if (new_head) {
1953                         child_process_init(&cp);
1954                         /* also set the HEAD accordingly */
1955                         cp.git_cmd = 1;
1956                         cp.no_stdin = 1;
1957                         cp.dir = path;
1958
1959                         prepare_submodule_repo_env(&cp.env_array);
1960                         argv_array_pushl(&cp.args, "update-ref", "HEAD",
1961                                          "--no-deref", new_head, NULL);
1962
1963                         if (run_command(&cp)) {
1964                                 ret = -1;
1965                                 goto out;
1966                         }
1967                 } else {
1968                         struct strbuf sb = STRBUF_INIT;
1969
1970                         strbuf_addf(&sb, "%s/.git", path);
1971                         unlink_or_warn(sb.buf);
1972                         strbuf_release(&sb);
1973
1974                         if (is_empty_dir(path))
1975                                 rmdir_or_warn(path);
1976
1977                         submodule_unset_core_worktree(sub);
1978                 }
1979         }
1980 out:
1981         return ret;
1982 }
1983
1984 int validate_submodule_git_dir(char *git_dir, const char *submodule_name)
1985 {
1986         size_t len = strlen(git_dir), suffix_len = strlen(submodule_name);
1987         char *p;
1988         int ret = 0;
1989
1990         if (len <= suffix_len || (p = git_dir + len - suffix_len)[-1] != '/' ||
1991             strcmp(p, submodule_name))
1992                 BUG("submodule name '%s' not a suffix of git dir '%s'",
1993                     submodule_name, git_dir);
1994
1995         /*
1996          * We prevent the contents of sibling submodules' git directories to
1997          * clash.
1998          *
1999          * Example: having a submodule named `hippo` and another one named
2000          * `hippo/hooks` would result in the git directories
2001          * `.git/modules/hippo/` and `.git/modules/hippo/hooks/`, respectively,
2002          * but the latter directory is already designated to contain the hooks
2003          * of the former.
2004          */
2005         for (; *p; p++) {
2006                 if (is_dir_sep(*p)) {
2007                         char c = *p;
2008
2009                         *p = '\0';
2010                         if (is_git_directory(git_dir))
2011                                 ret = -1;
2012                         *p = c;
2013
2014                         if (ret < 0)
2015                                 return error(_("submodule git dir '%s' is "
2016                                                "inside git dir '%.*s'"),
2017                                              git_dir,
2018                                              (int)(p - git_dir), git_dir);
2019                 }
2020         }
2021
2022         return 0;
2023 }
2024
2025 /*
2026  * Embeds a single submodules git directory into the superprojects git dir,
2027  * non recursively.
2028  */
2029 static void relocate_single_git_dir_into_superproject(const char *prefix,
2030                                                       const char *path)
2031 {
2032         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
2033         char *new_git_dir;
2034         const struct submodule *sub;
2035
2036         if (submodule_uses_worktrees(path))
2037                 die(_("relocate_gitdir for submodule '%s' with "
2038                       "more than one worktree not supported"), path);
2039
2040         old_git_dir = xstrfmt("%s/.git", path);
2041         if (read_gitfile(old_git_dir))
2042                 /* If it is an actual gitfile, it doesn't need migration. */
2043                 return;
2044
2045         real_old_git_dir = real_pathdup(old_git_dir, 1);
2046
2047         sub = submodule_from_path(the_repository, &null_oid, path);
2048         if (!sub)
2049                 die(_("could not lookup name for submodule '%s'"), path);
2050
2051         new_git_dir = git_pathdup("modules/%s", sub->name);
2052         if (validate_submodule_git_dir(new_git_dir, sub->name) < 0)
2053                 die(_("refusing to move '%s' into an existing git dir"),
2054                     real_old_git_dir);
2055         if (safe_create_leading_directories_const(new_git_dir) < 0)
2056                 die(_("could not create directory '%s'"), new_git_dir);
2057         real_new_git_dir = real_pathdup(new_git_dir, 1);
2058         free(new_git_dir);
2059
2060         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
2061                 get_super_prefix_or_empty(), path,
2062                 real_old_git_dir, real_new_git_dir);
2063
2064         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
2065
2066         free(old_git_dir);
2067         free(real_old_git_dir);
2068         free(real_new_git_dir);
2069 }
2070
2071 /*
2072  * Migrate the git directory of the submodule given by path from
2073  * having its git directory within the working tree to the git dir nested
2074  * in its superprojects git dir under modules/.
2075  */
2076 void absorb_git_dir_into_superproject(const char *prefix,
2077                                       const char *path,
2078                                       unsigned flags)
2079 {
2080         int err_code;
2081         const char *sub_git_dir;
2082         struct strbuf gitdir = STRBUF_INIT;
2083         strbuf_addf(&gitdir, "%s/.git", path);
2084         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
2085
2086         /* Not populated? */
2087         if (!sub_git_dir) {
2088                 const struct submodule *sub;
2089
2090                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
2091                         /* unpopulated as expected */
2092                         strbuf_release(&gitdir);
2093                         return;
2094                 }
2095
2096                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
2097                         /* We don't know what broke here. */
2098                         read_gitfile_error_die(err_code, path, NULL);
2099
2100                 /*
2101                 * Maybe populated, but no git directory was found?
2102                 * This can happen if the superproject is a submodule
2103                 * itself and was just absorbed. The absorption of the
2104                 * superproject did not rewrite the git file links yet,
2105                 * fix it now.
2106                 */
2107                 sub = submodule_from_path(the_repository, &null_oid, path);
2108                 if (!sub)
2109                         die(_("could not lookup name for submodule '%s'"), path);
2110                 connect_work_tree_and_git_dir(path,
2111                         git_path("modules/%s", sub->name), 0);
2112         } else {
2113                 /* Is it already absorbed into the superprojects git dir? */
2114                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
2115                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
2116
2117                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
2118                         relocate_single_git_dir_into_superproject(prefix, path);
2119
2120                 free(real_sub_git_dir);
2121                 free(real_common_git_dir);
2122         }
2123         strbuf_release(&gitdir);
2124
2125         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
2126                 struct child_process cp = CHILD_PROCESS_INIT;
2127                 struct strbuf sb = STRBUF_INIT;
2128
2129                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
2130                         BUG("we don't know how to pass the flags down?");
2131
2132                 strbuf_addstr(&sb, get_super_prefix_or_empty());
2133                 strbuf_addstr(&sb, path);
2134                 strbuf_addch(&sb, '/');
2135
2136                 cp.dir = path;
2137                 cp.git_cmd = 1;
2138                 cp.no_stdin = 1;
2139                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
2140                                            "submodule--helper",
2141                                            "absorb-git-dirs", NULL);
2142                 prepare_submodule_repo_env(&cp.env_array);
2143                 if (run_command(&cp))
2144                         die(_("could not recurse into submodule '%s'"), path);
2145
2146                 strbuf_release(&sb);
2147         }
2148 }
2149
2150 const char *get_superproject_working_tree(void)
2151 {
2152         struct child_process cp = CHILD_PROCESS_INIT;
2153         struct strbuf sb = STRBUF_INIT;
2154         const char *one_up = real_path_if_valid("../");
2155         const char *cwd = xgetcwd();
2156         const char *ret = NULL;
2157         const char *subpath;
2158         int code;
2159         ssize_t len;
2160
2161         if (!is_inside_work_tree())
2162                 /*
2163                  * FIXME:
2164                  * We might have a superproject, but it is harder
2165                  * to determine.
2166                  */
2167                 return NULL;
2168
2169         if (!one_up)
2170                 return NULL;
2171
2172         subpath = relative_path(cwd, one_up, &sb);
2173
2174         prepare_submodule_repo_env(&cp.env_array);
2175         argv_array_pop(&cp.env_array);
2176
2177         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
2178                         "ls-files", "-z", "--stage", "--full-name", "--",
2179                         subpath, NULL);
2180         strbuf_reset(&sb);
2181
2182         cp.no_stdin = 1;
2183         cp.no_stderr = 1;
2184         cp.out = -1;
2185         cp.git_cmd = 1;
2186
2187         if (start_command(&cp))
2188                 die(_("could not start ls-files in .."));
2189
2190         len = strbuf_read(&sb, cp.out, PATH_MAX);
2191         close(cp.out);
2192
2193         if (starts_with(sb.buf, "160000")) {
2194                 int super_sub_len;
2195                 int cwd_len = strlen(cwd);
2196                 char *super_sub, *super_wt;
2197
2198                 /*
2199                  * There is a superproject having this repo as a submodule.
2200                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
2201                  * We're only interested in the name after the tab.
2202                  */
2203                 super_sub = strchr(sb.buf, '\t') + 1;
2204                 super_sub_len = strlen(super_sub);
2205
2206                 if (super_sub_len > cwd_len ||
2207                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
2208                         BUG("returned path string doesn't match cwd?");
2209
2210                 super_wt = xstrdup(cwd);
2211                 super_wt[cwd_len - super_sub_len] = '\0';
2212
2213                 ret = real_path(super_wt);
2214                 free(super_wt);
2215         }
2216         strbuf_release(&sb);
2217
2218         code = finish_command(&cp);
2219
2220         if (code == 128)
2221                 /* '../' is not a git repository */
2222                 return NULL;
2223         if (code == 0 && len == 0)
2224                 /* There is an unrelated git repository at '../' */
2225                 return NULL;
2226         if (code)
2227                 die(_("ls-tree returned unexpected return code %d"), code);
2228
2229         return ret;
2230 }
2231
2232 /*
2233  * Put the gitdir for a submodule (given relative to the main
2234  * repository worktree) into `buf`, or return -1 on error.
2235  */
2236 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2237 {
2238         const struct submodule *sub;
2239         const char *git_dir;
2240         int ret = 0;
2241
2242         strbuf_reset(buf);
2243         strbuf_addstr(buf, submodule);
2244         strbuf_complete(buf, '/');
2245         strbuf_addstr(buf, ".git");
2246
2247         git_dir = read_gitfile(buf->buf);
2248         if (git_dir) {
2249                 strbuf_reset(buf);
2250                 strbuf_addstr(buf, git_dir);
2251         }
2252         if (!is_git_directory(buf->buf)) {
2253                 sub = submodule_from_path(the_repository, &null_oid, submodule);
2254                 if (!sub) {
2255                         ret = -1;
2256                         goto cleanup;
2257                 }
2258                 strbuf_reset(buf);
2259                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2260         }
2261
2262 cleanup:
2263         return ret;
2264 }