git.oblomov.eu Git - git/blob - 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          * Please update _git_status() in git-completion.bash when you
 437          * add new options
 438          */
 439 }
 440
 441 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 442                 struct commit *left, struct commit *right,
 443                 struct commit_list *merge_bases)
 444 {
 445         struct commit_list *list;
 446
 447         repo_init_revisions(the_repository, rev, NULL);
 448         setup_revisions(0, NULL, rev, NULL);
 449         rev->left_right = 1;
 450         rev->first_parent_only = 1;
 451         left->object.flags |= SYMMETRIC_LEFT;
 452         add_pending_object(rev, &left->object, path);
 453         add_pending_object(rev, &right->object, path);
 454         for (list = merge_bases; list; list = list->next) {
 455                 list->item->object.flags |= UNINTERESTING;
 456                 add_pending_object(rev, &list->item->object,
 457                         oid_to_hex(&list->item->object.oid));
 458         }
 459         return prepare_revision_walk(rev);
 460 }
 461
 462 static void print_submodule_summary(struct repository *r, struct rev_info *rev, struct diff_options *o)
 463 {
 464         static const char format[] = "  %m %s";
 465         struct strbuf sb = STRBUF_INIT;
 466         struct commit *commit;
 467
 468         while ((commit = get_revision(rev))) {
 469                 struct pretty_print_context ctx = {0};
 470                 ctx.date_mode = rev->date_mode;
 471                 ctx.output_encoding = get_log_output_encoding();
 472                 strbuf_setlen(&sb, 0);
 473                 repo_format_commit_message(r, commit, format, &sb,
 474                                       &ctx);
 475                 strbuf_addch(&sb, '\n');
 476                 if (commit->object.flags & SYMMETRIC_LEFT)
 477                         diff_emit_submodule_del(o, sb.buf);
 478                 else
 479                         diff_emit_submodule_add(o, sb.buf);
 480         }
 481         strbuf_release(&sb);
 482 }
 483
 484 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 485 {
 486         const char * const *var;
 487
 488         for (var = local_repo_env; *var; var++) {
 489                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 490                         argv_array_push(out, *var);
 491         }
 492 }
 493
 494 void prepare_submodule_repo_env(struct argv_array *out)
 495 {
 496         prepare_submodule_repo_env_no_git_dir(out);
 497         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 498                          DEFAULT_GIT_DIR_ENVIRONMENT);
 499 }
 500
 501 static void prepare_submodule_repo_env_in_gitdir(struct argv_array *out)
 502 {
 503         prepare_submodule_repo_env_no_git_dir(out);
 504         argv_array_pushf(out, "%s=.", GIT_DIR_ENVIRONMENT);
 505 }
 506
 507 /*
 508  * Initialize a repository struct for a submodule based on the provided 'path'.
 509  *
 510  * Unlike repo_submodule_init, this tolerates submodules not present
 511  * in .gitmodules. This function exists only to preserve historical behavior,
 512  *
 513  * Returns the repository struct on success,
 514  * NULL when the submodule is not present.
 515  */
 516 static struct repository *open_submodule(const char *path)
 517 {
 518         struct strbuf sb = STRBUF_INIT;
 519         struct repository *out = xmalloc(sizeof(*out));
 520
 521         if (submodule_to_gitdir(&sb, path) || repo_init(out, sb.buf, NULL)) {
 522                 strbuf_release(&sb);
 523                 free(out);
 524                 return NULL;
 525         }
 526
 527         /* Mark it as a submodule */
 528         out->submodule_prefix = xstrdup(path);
 529
 530         strbuf_release(&sb);
 531         return out;
 532 }
 533
 534 /*
 535  * Helper function to display the submodule header line prior to the full
 536  * summary output.
 537  *
 538  * If it can locate the submodule git directory it will create a repository
 539  * handle for the submodule and lookup both the left and right commits and
 540  * put them into the left and right pointers.
 541  */
 542 static void show_submodule_header(struct diff_options *o,
 543                 const char *path,
 544                 struct object_id *one, struct object_id *two,
 545                 unsigned dirty_submodule,
 546                 struct repository *sub,
 547                 struct commit **left, struct commit **right,
 548                 struct commit_list **merge_bases)
 549 {
 550         const char *message = NULL;
 551         struct strbuf sb = STRBUF_INIT;
 552         int fast_forward = 0, fast_backward = 0;
 553
 554         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 555                 diff_emit_submodule_untracked(o, path);
 556
 557         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 558                 diff_emit_submodule_modified(o, path);
 559
 560         if (is_null_oid(one))
 561                 message = "(new submodule)";
 562         else if (is_null_oid(two))
 563                 message = "(submodule deleted)";
 564
 565         if (!sub) {
 566                 if (!message)
 567                         message = "(commits not present)";
 568                 goto output_header;
 569         }
 570
 571         /*
 572          * Attempt to lookup the commit references, and determine if this is
 573          * a fast forward or fast backwards update.
 574          */
 575         *left = lookup_commit_reference(sub, one);
 576         *right = lookup_commit_reference(sub, two);
 577
 578         /*
 579          * Warn about missing commits in the submodule project, but only if
 580          * they aren't null.
 581          */
 582         if ((!is_null_oid(one) && !*left) ||
 583              (!is_null_oid(two) && !*right))
 584                 message = "(commits not present)";
 585
 586         *merge_bases = repo_get_merge_bases(sub, *left, *right);
 587         if (*merge_bases) {
 588                 if ((*merge_bases)->item == *left)
 589                         fast_forward = 1;
 590                 else if ((*merge_bases)->item == *right)
 591                         fast_backward = 1;
 592         }
 593
 594         if (oideq(one, two)) {
 595                 strbuf_release(&sb);
 596                 return;
 597         }
 598
 599 output_header:
 600         strbuf_addf(&sb, "Submodule %s ", path);
 601         strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
 602         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 603         strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
 604         if (message)
 605                 strbuf_addf(&sb, " %s\n", message);
 606         else
 607                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 608         diff_emit_submodule_header(o, sb.buf);
 609
 610         strbuf_release(&sb);
 611 }
 612
 613 void show_submodule_summary(struct diff_options *o, const char *path,
 614                 struct object_id *one, struct object_id *two,
 615                 unsigned dirty_submodule)
 616 {
 617         struct rev_info rev;
 618         struct commit *left = NULL, *right = NULL;
 619         struct commit_list *merge_bases = NULL;
 620         struct repository *sub;
 621
 622         sub = open_submodule(path);
 623         show_submodule_header(o, path, one, two, dirty_submodule,
 624                               sub, &left, &right, &merge_bases);
 625
 626         /*
 627          * If we don't have both a left and a right pointer, there is no
 628          * reason to try and display a summary. The header line should contain
 629          * all the information the user needs.
 630          */
 631         if (!left || !right || !sub)
 632                 goto out;
 633
 634         /* Treat revision walker failure the same as missing commits */
 635         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 636                 diff_emit_submodule_error(o, "(revision walker failed)\n");
 637                 goto out;
 638         }
 639
 640         print_submodule_summary(sub, &rev, o);
 641
 642 out:
 643         if (merge_bases)
 644                 free_commit_list(merge_bases);
 645         clear_commit_marks(left, ~0);
 646         clear_commit_marks(right, ~0);
 647         if (sub) {
 648                 repo_clear(sub);
 649                 free(sub);
 650         }
 651 }
 652
 653 void show_submodule_inline_diff(struct diff_options *o, const char *path,
 654                 struct object_id *one, struct object_id *two,
 655                 unsigned dirty_submodule)
 656 {
 657         const struct object_id *old_oid = the_hash_algo->empty_tree, *new_oid = the_hash_algo->empty_tree;
 658         struct commit *left = NULL, *right = NULL;
 659         struct commit_list *merge_bases = NULL;
 660         struct child_process cp = CHILD_PROCESS_INIT;
 661         struct strbuf sb = STRBUF_INIT;
 662         struct repository *sub;
 663
 664         sub = open_submodule(path);
 665         show_submodule_header(o, path, one, two, dirty_submodule,
 666                               sub, &left, &right, &merge_bases);
 667
 668         /* We need a valid left and right commit to display a difference */
 669         if (!(left || is_null_oid(one)) ||
 670             !(right || is_null_oid(two)))
 671                 goto done;
 672
 673         if (left)
 674                 old_oid = one;
 675         if (right)
 676                 new_oid = two;
 677
 678         cp.git_cmd = 1;
 679         cp.dir = path;
 680         cp.out = -1;
 681         cp.no_stdin = 1;
 682
 683         /* TODO: other options may need to be passed here. */
 684         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 685         argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 686                          "always" : "never");
 687
 688         if (o->flags.reverse_diff) {
 689                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 690                                  o->b_prefix, path);
 691                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 692                                  o->a_prefix, path);
 693         } else {
 694                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 695                                  o->a_prefix, path);
 696                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 697                                  o->b_prefix, path);
 698         }
 699         argv_array_push(&cp.args, oid_to_hex(old_oid));
 700         /*
 701          * If the submodule has modified content, we will diff against the
 702          * work tree, under the assumption that the user has asked for the
 703          * diff format and wishes to actually see all differences even if they
 704          * haven't yet been committed to the submodule yet.
 705          */
 706         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 707                 argv_array_push(&cp.args, oid_to_hex(new_oid));
 708
 709         prepare_submodule_repo_env(&cp.env_array);
 710         if (start_command(&cp))
 711                 diff_emit_submodule_error(o, "(diff failed)\n");
 712
 713         while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
 714                 diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
 715
 716         if (finish_command(&cp))
 717                 diff_emit_submodule_error(o, "(diff failed)\n");
 718
 719 done:
 720         strbuf_release(&sb);
 721         if (merge_bases)
 722                 free_commit_list(merge_bases);
 723         if (left)
 724                 clear_commit_marks(left, ~0);
 725         if (right)
 726                 clear_commit_marks(right, ~0);
 727         if (sub) {
 728                 repo_clear(sub);
 729                 free(sub);
 730         }
 731 }
 732
 733 int should_update_submodules(void)
 734 {
 735         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 736 }
 737
 738 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 739 {
 740         if (!S_ISGITLINK(ce->ce_mode))
 741                 return NULL;
 742
 743         if (!should_update_submodules())
 744                 return NULL;
 745
 746         return submodule_from_path(the_repository, &null_oid, ce->name);
 747 }
 748
 749 static struct oid_array *submodule_commits(struct string_list *submodules,
 750                                            const char *name)
 751 {
 752         struct string_list_item *item;
 753
 754         item = string_list_insert(submodules, name);
 755         if (item->util)
 756                 return (struct oid_array *) item->util;
 757
 758         /* NEEDSWORK: should we have oid_array_init()? */
 759         item->util = xcalloc(1, sizeof(struct oid_array));
 760         return (struct oid_array *) item->util;
 761 }
 762
 763 struct collect_changed_submodules_cb_data {
 764         struct repository *repo;
 765         struct string_list *changed;
 766         const struct object_id *commit_oid;
 767 };
 768
 769 /*
 770  * this would normally be two functions: default_name_from_path() and
 771  * path_from_default_name(). Since the default name is the same as
 772  * the submodule path we can get away with just one function which only
 773  * checks whether there is a submodule in the working directory at that
 774  * location.
 775  */
 776 static const char *default_name_or_path(const char *path_or_name)
 777 {
 778         int error_code;
 779
 780         if (!is_submodule_populated_gently(path_or_name, &error_code))
 781                 return NULL;
 782
 783         return path_or_name;
 784 }
 785
 786 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 787                                           struct diff_options *options,
 788                                           void *data)
 789 {
 790         struct collect_changed_submodules_cb_data *me = data;
 791         struct string_list *changed = me->changed;
 792         const struct object_id *commit_oid = me->commit_oid;
 793         int i;
 794
 795         for (i = 0; i < q->nr; i++) {
 796                 struct diff_filepair *p = q->queue[i];
 797                 struct oid_array *commits;
 798                 const struct submodule *submodule;
 799                 const char *name;
 800
 801                 if (!S_ISGITLINK(p->two->mode))
 802                         continue;
 803
 804                 submodule = submodule_from_path(me->repo,
 805                                                 commit_oid, p->two->path);
 806                 if (submodule)
 807                         name = submodule->name;
 808                 else {
 809                         name = default_name_or_path(p->two->path);
 810                         /* make sure name does not collide with existing one */
 811                         if (name)
 812                                 submodule = submodule_from_name(me->repo,
 813                                                                 commit_oid, name);
 814                         if (submodule) {
 815                                 warning("Submodule in commit %s at path: "
 816                                         "'%s' collides with a submodule named "
 817                                         "the same. Skipping it.",
 818                                         oid_to_hex(commit_oid), p->two->path);
 819                                 name = NULL;
 820                         }
 821                 }
 822
 823                 if (!name)
 824                         continue;
 825
 826                 commits = submodule_commits(changed, name);
 827                 oid_array_append(commits, &p->two->oid);
 828         }
 829 }
 830
 831 /*
 832  * Collect the paths of submodules in 'changed' which have changed based on
 833  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 834  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 835  * what the submodule pointers were updated to during the change.
 836  */
 837 static void collect_changed_submodules(struct repository *r,
 838                                        struct string_list *changed,
 839                                        struct argv_array *argv)
 840 {
 841         struct rev_info rev;
 842         const struct commit *commit;
 843
 844         repo_init_revisions(r, &rev, NULL);
 845         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 846         if (prepare_revision_walk(&rev))
 847                 die("revision walk setup failed");
 848
 849         while ((commit = get_revision(&rev))) {
 850                 struct rev_info diff_rev;
 851                 struct collect_changed_submodules_cb_data data;
 852                 data.repo = r;
 853                 data.changed = changed;
 854                 data.commit_oid = &commit->object.oid;
 855
 856                 repo_init_revisions(r, &diff_rev, NULL);
 857                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 858                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 859                 diff_rev.diffopt.format_callback_data = &data;
 860                 diff_tree_combined_merge(commit, 1, &diff_rev);
 861         }
 862
 863         reset_revision_walk();
 864 }
 865
 866 static void free_submodules_oids(struct string_list *submodules)
 867 {
 868         struct string_list_item *item;
 869         for_each_string_list_item(item, submodules)
 870                 oid_array_clear((struct oid_array *) item->util);
 871         string_list_clear(submodules, 1);
 872 }
 873
 874 static int has_remote(const char *refname, const struct object_id *oid,
 875                       int flags, void *cb_data)
 876 {
 877         return 1;
 878 }
 879
 880 static int append_oid_to_argv(const struct object_id *oid, void *data)
 881 {
 882         struct argv_array *argv = data;
 883         argv_array_push(argv, oid_to_hex(oid));
 884         return 0;
 885 }
 886
 887 struct has_commit_data {
 888         struct repository *repo;
 889         int result;
 890         const char *path;
 891 };
 892
 893 static int check_has_commit(const struct object_id *oid, void *data)
 894 {
 895         struct has_commit_data *cb = data;
 896
 897         enum object_type type = oid_object_info(cb->repo, oid, NULL);
 898
 899         switch (type) {
 900         case OBJ_COMMIT:
 901                 return 0;
 902         case OBJ_BAD:
 903                 /*
 904                  * Object is missing or invalid. If invalid, an error message
 905                  * has already been printed.
 906                  */
 907                 cb->result = 0;
 908                 return 0;
 909         default:
 910                 die(_("submodule entry '%s' (%s) is a %s, not a commit"),
 911                     cb->path, oid_to_hex(oid), type_name(type));
 912         }
 913 }
 914
 915 static int submodule_has_commits(struct repository *r,
 916                                  const char *path,
 917                                  struct oid_array *commits)
 918 {
 919         struct has_commit_data has_commit = { r, 1, path };
 920
 921         /*
 922          * Perform a cheap, but incorrect check for the existence of 'commits'.
 923          * This is done by adding the submodule's object store to the in-core
 924          * object store, and then querying for each commit's existence.  If we
 925          * do not have the commit object anywhere, there is no chance we have
 926          * it in the object store of the correct submodule and have it
 927          * reachable from a ref, so we can fail early without spawning rev-list
 928          * which is expensive.
 929          */
 930         if (add_submodule_odb(path))
 931                 return 0;
 932
 933         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 934
 935         if (has_commit.result) {
 936                 /*
 937                  * Even if the submodule is checked out and the commit is
 938                  * present, make sure it exists in the submodule's object store
 939                  * and that it is reachable from a ref.
 940                  */
 941                 struct child_process cp = CHILD_PROCESS_INIT;
 942                 struct strbuf out = STRBUF_INIT;
 943
 944                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 945                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 946                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 947
 948                 prepare_submodule_repo_env(&cp.env_array);
 949                 cp.git_cmd = 1;
 950                 cp.no_stdin = 1;
 951                 cp.dir = path;
 952
 953                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 954                         has_commit.result = 0;
 955
 956                 strbuf_release(&out);
 957         }
 958
 959         return has_commit.result;
 960 }
 961
 962 static int submodule_needs_pushing(struct repository *r,
 963                                    const char *path,
 964                                    struct oid_array *commits)
 965 {
 966         if (!submodule_has_commits(r, path, commits))
 967                 /*
 968                  * NOTE: We do consider it safe to return "no" here. The
 969                  * correct answer would be "We do not know" instead of
 970                  * "No push needed", but it is quite hard to change
 971                  * the submodule pointer without having the submodule
 972                  * around. If a user did however change the submodules
 973                  * without having the submodule around, this indicates
 974                  * an expert who knows what they are doing or a
 975                  * maintainer integrating work from other people. In
 976                  * both cases it should be safe to skip this check.
 977                  */
 978                 return 0;
 979
 980         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 981                 struct child_process cp = CHILD_PROCESS_INIT;
 982                 struct strbuf buf = STRBUF_INIT;
 983                 int needs_pushing = 0;
 984
 985                 argv_array_push(&cp.args, "rev-list");
 986                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 987                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 988
 989                 prepare_submodule_repo_env(&cp.env_array);
 990                 cp.git_cmd = 1;
 991                 cp.no_stdin = 1;
 992                 cp.out = -1;
 993                 cp.dir = path;
 994                 if (start_command(&cp))
 995                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 996                                         path);
 997                 if (strbuf_read(&buf, cp.out, the_hash_algo->hexsz + 1))
 998                         needs_pushing = 1;
 999                 finish_command(&cp);
1000                 close(cp.out);
1001                 strbuf_release(&buf);
1002                 return needs_pushing;
1003         }
1004
1005         return 0;
1006 }
1007
1008 int find_unpushed_submodules(struct repository *r,
1009                              struct oid_array *commits,
1010                              const char *remotes_name,
1011                              struct string_list *needs_pushing)
1012 {
1013         struct string_list submodules = STRING_LIST_INIT_DUP;
1014         struct string_list_item *name;
1015         struct argv_array argv = ARGV_ARRAY_INIT;
1016
1017         /* argv.argv[0] will be ignored by setup_revisions */
1018         argv_array_push(&argv, "find_unpushed_submodules");
1019         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
1020         argv_array_push(&argv, "--not");
1021         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
1022
1023         collect_changed_submodules(r, &submodules, &argv);
1024
1025         for_each_string_list_item(name, &submodules) {
1026                 struct oid_array *commits = name->util;
1027                 const struct submodule *submodule;
1028                 const char *path = NULL;
1029
1030                 submodule = submodule_from_name(r, &null_oid, name->string);
1031                 if (submodule)
1032                         path = submodule->path;
1033                 else
1034                         path = default_name_or_path(name->string);
1035
1036                 if (!path)
1037                         continue;
1038
1039                 if (submodule_needs_pushing(r, path, commits))
1040                         string_list_insert(needs_pushing, path);
1041         }
1042
1043         free_submodules_oids(&submodules);
1044         argv_array_clear(&argv);
1045
1046         return needs_pushing->nr;
1047 }
1048
1049 static int push_submodule(const char *path,
1050                           const struct remote *remote,
1051                           const struct refspec *rs,
1052                           const struct string_list *push_options,
1053                           int dry_run)
1054 {
1055         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
1056                 struct child_process cp = CHILD_PROCESS_INIT;
1057                 argv_array_push(&cp.args, "push");
1058                 if (dry_run)
1059                         argv_array_push(&cp.args, "--dry-run");
1060
1061                 if (push_options && push_options->nr) {
1062                         const struct string_list_item *item;
1063                         for_each_string_list_item(item, push_options)
1064                                 argv_array_pushf(&cp.args, "--push-option=%s",
1065                                                  item->string);
1066                 }
1067
1068                 if (remote->origin != REMOTE_UNCONFIGURED) {
1069                         int i;
1070                         argv_array_push(&cp.args, remote->name);
1071                         for (i = 0; i < rs->raw_nr; i++)
1072                                 argv_array_push(&cp.args, rs->raw[i]);
1073                 }
1074
1075                 prepare_submodule_repo_env(&cp.env_array);
1076                 cp.git_cmd = 1;
1077                 cp.no_stdin = 1;
1078                 cp.dir = path;
1079                 if (run_command(&cp))
1080                         return 0;
1081                 close(cp.out);
1082         }
1083
1084         return 1;
1085 }
1086
1087 /*
1088  * Perform a check in the submodule to see if the remote and refspec work.
1089  * Die if the submodule can't be pushed.
1090  */
1091 static void submodule_push_check(const char *path, const char *head,
1092                                  const struct remote *remote,
1093                                  const struct refspec *rs)
1094 {
1095         struct child_process cp = CHILD_PROCESS_INIT;
1096         int i;
1097
1098         argv_array_push(&cp.args, "submodule--helper");
1099         argv_array_push(&cp.args, "push-check");
1100         argv_array_push(&cp.args, head);
1101         argv_array_push(&cp.args, remote->name);
1102
1103         for (i = 0; i < rs->raw_nr; i++)
1104                 argv_array_push(&cp.args, rs->raw[i]);
1105
1106         prepare_submodule_repo_env(&cp.env_array);
1107         cp.git_cmd = 1;
1108         cp.no_stdin = 1;
1109         cp.no_stdout = 1;
1110         cp.dir = path;
1111
1112         /*
1113          * Simply indicate if 'submodule--helper push-check' failed.
1114          * More detailed error information will be provided by the
1115          * child process.
1116          */
1117         if (run_command(&cp))
1118                 die("process for submodule '%s' failed", path);
1119 }
1120
1121 int push_unpushed_submodules(struct repository *r,
1122                              struct oid_array *commits,
1123                              const struct remote *remote,
1124                              const struct refspec *rs,
1125                              const struct string_list *push_options,
1126                              int dry_run)
1127 {
1128         int i, ret = 1;
1129         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1130
1131         if (!find_unpushed_submodules(r, commits,
1132                                       remote->name, &needs_pushing))
1133                 return 1;
1134
1135         /*
1136          * Verify that the remote and refspec can be propagated to all
1137          * submodules.  This check can be skipped if the remote and refspec
1138          * won't be propagated due to the remote being unconfigured (e.g. a URL
1139          * instead of a remote name).
1140          */
1141         if (remote->origin != REMOTE_UNCONFIGURED) {
1142                 char *head;
1143                 struct object_id head_oid;
1144
1145                 head = resolve_refdup("HEAD", 0, &head_oid, NULL);
1146                 if (!head)
1147                         die(_("Failed to resolve HEAD as a valid ref."));
1148
1149                 for (i = 0; i < needs_pushing.nr; i++)
1150                         submodule_push_check(needs_pushing.items[i].string,
1151                                              head, remote, rs);
1152                 free(head);
1153         }
1154
1155         /* Actually push the submodules */
1156         for (i = 0; i < needs_pushing.nr; i++) {
1157                 const char *path = needs_pushing.items[i].string;
1158                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1159                 if (!push_submodule(path, remote, rs,
1160                                     push_options, dry_run)) {
1161                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1162                         ret = 0;
1163                 }
1164         }
1165
1166         string_list_clear(&needs_pushing, 0);
1167
1168         return ret;
1169 }
1170
1171 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1172                                int flags, void *data)
1173 {
1174         struct oid_array *array = data;
1175         oid_array_append(array, oid);
1176         return 0;
1177 }
1178
1179 void check_for_new_submodule_commits(struct object_id *oid)
1180 {
1181         if (!initialized_fetch_ref_tips) {
1182                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1183                 initialized_fetch_ref_tips = 1;
1184         }
1185
1186         oid_array_append(&ref_tips_after_fetch, oid);
1187 }
1188
1189 static void calculate_changed_submodule_paths(struct repository *r,
1190                 struct string_list *changed_submodule_names)
1191 {
1192         struct argv_array argv = ARGV_ARRAY_INIT;
1193         struct string_list_item *name;
1194
1195         /* No need to check if there are no submodules configured */
1196         if (!submodule_from_path(r, NULL, NULL))
1197                 return;
1198
1199         argv_array_push(&argv, "--"); /* argv[0] program name */
1200         oid_array_for_each_unique(&ref_tips_after_fetch,
1201                                    append_oid_to_argv, &argv);
1202         argv_array_push(&argv, "--not");
1203         oid_array_for_each_unique(&ref_tips_before_fetch,
1204                                    append_oid_to_argv, &argv);
1205
1206         /*
1207          * Collect all submodules (whether checked out or not) for which new
1208          * commits have been recorded upstream in "changed_submodule_names".
1209          */
1210         collect_changed_submodules(r, changed_submodule_names, &argv);
1211
1212         for_each_string_list_item(name, changed_submodule_names) {
1213                 struct oid_array *commits = name->util;
1214                 const struct submodule *submodule;
1215                 const char *path = NULL;
1216
1217                 submodule = submodule_from_name(r, &null_oid, name->string);
1218                 if (submodule)
1219                         path = submodule->path;
1220                 else
1221                         path = default_name_or_path(name->string);
1222
1223                 if (!path)
1224                         continue;
1225
1226                 if (submodule_has_commits(r, path, commits)) {
1227                         oid_array_clear(commits);
1228                         *name->string = '\0';
1229                 }
1230         }
1231
1232         string_list_remove_empty_items(changed_submodule_names, 1);
1233
1234         argv_array_clear(&argv);
1235         oid_array_clear(&ref_tips_before_fetch);
1236         oid_array_clear(&ref_tips_after_fetch);
1237         initialized_fetch_ref_tips = 0;
1238 }
1239
1240 int submodule_touches_in_range(struct repository *r,
1241                                struct object_id *excl_oid,
1242                                struct object_id *incl_oid)
1243 {
1244         struct string_list subs = STRING_LIST_INIT_DUP;
1245         struct argv_array args = ARGV_ARRAY_INIT;
1246         int ret;
1247
1248         /* No need to check if there are no submodules configured */
1249         if (!submodule_from_path(r, NULL, NULL))
1250                 return 0;
1251
1252         argv_array_push(&args, "--"); /* args[0] program name */
1253         argv_array_push(&args, oid_to_hex(incl_oid));
1254         if (!is_null_oid(excl_oid)) {
1255                 argv_array_push(&args, "--not");
1256                 argv_array_push(&args, oid_to_hex(excl_oid));
1257         }
1258
1259         collect_changed_submodules(r, &subs, &args);
1260         ret = subs.nr;
1261
1262         argv_array_clear(&args);
1263
1264         free_submodules_oids(&subs);
1265         return ret;
1266 }
1267
1268 struct submodule_parallel_fetch {
1269         int count;
1270         struct argv_array args;
1271         struct repository *r;
1272         const char *prefix;
1273         int command_line_option;
1274         int default_option;
1275         int quiet;
1276         int result;
1277
1278         struct string_list changed_submodule_names;
1279
1280         /* Pending fetches by OIDs */
1281         struct fetch_task **oid_fetch_tasks;
1282         int oid_fetch_tasks_nr, oid_fetch_tasks_alloc;
1283 };
1284 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0, \
1285                   STRING_LIST_INIT_DUP, \
1286                   NULL, 0, 0}
1287
1288 static int get_fetch_recurse_config(const struct submodule *submodule,
1289                                     struct submodule_parallel_fetch *spf)
1290 {
1291         if (spf->command_line_option != RECURSE_SUBMODULES_DEFAULT)
1292                 return spf->command_line_option;
1293
1294         if (submodule) {
1295                 char *key;
1296                 const char *value;
1297
1298                 int fetch_recurse = submodule->fetch_recurse;
1299                 key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1300                 if (!repo_config_get_string_const(spf->r, key, &value)) {
1301                         fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1302                 }
1303                 free(key);
1304
1305                 if (fetch_recurse != RECURSE_SUBMODULES_NONE)
1306                         /* local config overrules everything except commandline */
1307                         return fetch_recurse;
1308         }
1309
1310         return spf->default_option;
1311 }
1312
1313 /*
1314  * Fetch in progress (if callback data) or
1315  * pending (if in oid_fetch_tasks in struct submodule_parallel_fetch)
1316  */
1317 struct fetch_task {
1318         struct repository *repo;
1319         const struct submodule *sub;
1320         unsigned free_sub : 1; /* Do we need to free the submodule? */
1321
1322         struct oid_array *commits; /* Ensure these commits are fetched */
1323 };
1324
1325 /**
1326  * When a submodule is not defined in .gitmodules, we cannot access it
1327  * via the regular submodule-config. Create a fake submodule, which we can
1328  * work on.
1329  */
1330 static const struct submodule *get_non_gitmodules_submodule(const char *path)
1331 {
1332         struct submodule *ret = NULL;
1333         const char *name = default_name_or_path(path);
1334
1335         if (!name)
1336                 return NULL;
1337
1338         ret = xmalloc(sizeof(*ret));
1339         memset(ret, 0, sizeof(*ret));
1340         ret->path = name;
1341         ret->name = name;
1342
1343         return (const struct submodule *) ret;
1344 }
1345
1346 static struct fetch_task *fetch_task_create(struct repository *r,
1347                                             const char *path)
1348 {
1349         struct fetch_task *task = xmalloc(sizeof(*task));
1350         memset(task, 0, sizeof(*task));
1351
1352         task->sub = submodule_from_path(r, &null_oid, path);
1353         if (!task->sub) {
1354                 /*
1355                  * No entry in .gitmodules? Technically not a submodule,
1356                  * but historically we supported repositories that happen to be
1357                  * in-place where a gitlink is. Keep supporting them.
1358                  */
1359                 task->sub = get_non_gitmodules_submodule(path);
1360                 if (!task->sub) {
1361                         free(task);
1362                         return NULL;
1363                 }
1364
1365                 task->free_sub = 1;
1366         }
1367
1368         return task;
1369 }
1370
1371 static void fetch_task_release(struct fetch_task *p)
1372 {
1373         if (p->free_sub)
1374                 free((void*)p->sub);
1375         p->free_sub = 0;
1376         p->sub = NULL;
1377
1378         if (p->repo)
1379                 repo_clear(p->repo);
1380         FREE_AND_NULL(p->repo);
1381 }
1382
1383 static struct repository *get_submodule_repo_for(struct repository *r,
1384                                                  const struct submodule *sub)
1385 {
1386         struct repository *ret = xmalloc(sizeof(*ret));
1387
1388         if (repo_submodule_init(ret, r, sub)) {
1389                 /*
1390                  * No entry in .gitmodules? Technically not a submodule,
1391                  * but historically we supported repositories that happen to be
1392                  * in-place where a gitlink is. Keep supporting them.
1393                  */
1394                 struct strbuf gitdir = STRBUF_INIT;
1395                 strbuf_repo_worktree_path(&gitdir, r, "%s/.git", sub->path);
1396                 if (repo_init(ret, gitdir.buf, NULL)) {
1397                         strbuf_release(&gitdir);
1398                         free(ret);
1399                         return NULL;
1400                 }
1401                 strbuf_release(&gitdir);
1402         }
1403
1404         return ret;
1405 }
1406
1407 static int get_next_submodule(struct child_process *cp,
1408                               struct strbuf *err, void *data, void **task_cb)
1409 {
1410         struct submodule_parallel_fetch *spf = data;
1411
1412         for (; spf->count < spf->r->index->cache_nr; spf->count++) {
1413                 const struct cache_entry *ce = spf->r->index->cache[spf->count];
1414                 const char *default_argv;
1415                 struct fetch_task *task;
1416
1417                 if (!S_ISGITLINK(ce->ce_mode))
1418                         continue;
1419
1420                 task = fetch_task_create(spf->r, ce->name);
1421                 if (!task)
1422                         continue;
1423
1424                 switch (get_fetch_recurse_config(task->sub, spf))
1425                 {
1426                 default:
1427                 case RECURSE_SUBMODULES_DEFAULT:
1428                 case RECURSE_SUBMODULES_ON_DEMAND:
1429                         if (!task->sub ||
1430                             !string_list_lookup(
1431                                         &spf->changed_submodule_names,
1432                                         task->sub->name))
1433                                 continue;
1434                         default_argv = "on-demand";
1435                         break;
1436                 case RECURSE_SUBMODULES_ON:
1437                         default_argv = "yes";
1438                         break;
1439                 case RECURSE_SUBMODULES_OFF:
1440                         continue;
1441                 }
1442
1443                 task->repo = get_submodule_repo_for(spf->r, task->sub);
1444                 if (task->repo) {
1445                         struct strbuf submodule_prefix = STRBUF_INIT;
1446                         child_process_init(cp);
1447                         cp->dir = task->repo->gitdir;
1448                         prepare_submodule_repo_env_in_gitdir(&cp->env_array);
1449                         cp->git_cmd = 1;
1450                         if (!spf->quiet)
1451                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1452                                             spf->prefix, ce->name);
1453                         argv_array_init(&cp->args);
1454                         argv_array_pushv(&cp->args, spf->args.argv);
1455                         argv_array_push(&cp->args, default_argv);
1456                         argv_array_push(&cp->args, "--submodule-prefix");
1457
1458                         strbuf_addf(&submodule_prefix, "%s%s/",
1459                                                        spf->prefix,
1460                                                        task->sub->path);
1461                         argv_array_push(&cp->args, submodule_prefix.buf);
1462
1463                         spf->count++;
1464                         *task_cb = task;
1465
1466                         strbuf_release(&submodule_prefix);
1467                         return 1;
1468                 } else {
1469
1470                         fetch_task_release(task);
1471                         free(task);
1472
1473                         /*
1474                          * An empty directory is normal,
1475                          * the submodule is not initialized
1476                          */
1477                         if (S_ISGITLINK(ce->ce_mode) &&
1478                             !is_empty_dir(ce->name)) {
1479                                 spf->result = 1;
1480                                 strbuf_addf(err,
1481                                             _("Could not access submodule '%s'"),
1482                                             ce->name);
1483                         }
1484                 }
1485         }
1486
1487         if (spf->oid_fetch_tasks_nr) {
1488                 struct fetch_task *task =
1489                         spf->oid_fetch_tasks[spf->oid_fetch_tasks_nr - 1];
1490                 struct strbuf submodule_prefix = STRBUF_INIT;
1491                 spf->oid_fetch_tasks_nr--;
1492
1493                 strbuf_addf(&submodule_prefix, "%s%s/",
1494                             spf->prefix, task->sub->path);
1495
1496                 child_process_init(cp);
1497                 prepare_submodule_repo_env_in_gitdir(&cp->env_array);
1498                 cp->git_cmd = 1;
1499                 cp->dir = task->repo->gitdir;
1500
1501                 argv_array_init(&cp->args);
1502                 argv_array_pushv(&cp->args, spf->args.argv);
1503                 argv_array_push(&cp->args, "on-demand");
1504                 argv_array_push(&cp->args, "--submodule-prefix");
1505                 argv_array_push(&cp->args, submodule_prefix.buf);
1506
1507                 /* NEEDSWORK: have get_default_remote from submodule--helper */
1508                 argv_array_push(&cp->args, "origin");
1509                 oid_array_for_each_unique(task->commits,
1510                                           append_oid_to_argv, &cp->args);
1511
1512                 *task_cb = task;
1513                 strbuf_release(&submodule_prefix);
1514                 return 1;
1515         }
1516
1517         return 0;
1518 }
1519
1520 static int fetch_start_failure(struct strbuf *err,
1521                                void *cb, void *task_cb)
1522 {
1523         struct submodule_parallel_fetch *spf = cb;
1524         struct fetch_task *task = task_cb;
1525
1526         spf->result = 1;
1527
1528         fetch_task_release(task);
1529         return 0;
1530 }
1531
1532 static int commit_missing_in_sub(const struct object_id *oid, void *data)
1533 {
1534         struct repository *subrepo = data;
1535
1536         enum object_type type = oid_object_info(subrepo, oid, NULL);
1537
1538         return type != OBJ_COMMIT;
1539 }
1540
1541 static int fetch_finish(int retvalue, struct strbuf *err,
1542                         void *cb, void *task_cb)
1543 {
1544         struct submodule_parallel_fetch *spf = cb;
1545         struct fetch_task *task = task_cb;
1546
1547         struct string_list_item *it;
1548         struct oid_array *commits;
1549
1550         if (retvalue)
1551                 /*
1552                  * NEEDSWORK: This indicates that the overall fetch
1553                  * failed, even though there may be a subsequent fetch
1554                  * by commit hash that might work. It may be a good
1555                  * idea to not indicate failure in this case, and only
1556                  * indicate failure if the subsequent fetch fails.
1557                  */
1558                 spf->result = 1;
1559
1560         if (!task || !task->sub)
1561                 BUG("callback cookie bogus");
1562
1563         /* Is this the second time we process this submodule? */
1564         if (task->commits)
1565                 goto out;
1566
1567         it = string_list_lookup(&spf->changed_submodule_names, task->sub->name);
1568         if (!it)
1569                 /* Could be an unchanged submodule, not contained in the list */
1570                 goto out;
1571
1572         commits = it->util;
1573         oid_array_filter(commits,
1574                          commit_missing_in_sub,
1575                          task->repo);
1576
1577         /* Are there commits we want, but do not exist? */
1578         if (commits->nr) {
1579                 task->commits = commits;
1580                 ALLOC_GROW(spf->oid_fetch_tasks,
1581                            spf->oid_fetch_tasks_nr + 1,
1582                            spf->oid_fetch_tasks_alloc);
1583                 spf->oid_fetch_tasks[spf->oid_fetch_tasks_nr] = task;
1584                 spf->oid_fetch_tasks_nr++;
1585                 return 0;
1586         }
1587
1588 out:
1589         fetch_task_release(task);
1590
1591         return 0;
1592 }
1593
1594 int fetch_populated_submodules(struct repository *r,
1595                                const struct argv_array *options,
1596                                const char *prefix, int command_line_option,
1597                                int default_option,
1598                                int quiet, int max_parallel_jobs)
1599 {
1600         int i;
1601         struct submodule_parallel_fetch spf = SPF_INIT;
1602
1603         spf.r = r;
1604         spf.command_line_option = command_line_option;
1605         spf.default_option = default_option;
1606         spf.quiet = quiet;
1607         spf.prefix = prefix;
1608
1609         if (!r->worktree)
1610                 goto out;
1611
1612         if (repo_read_index(r) < 0)
1613                 die("index file corrupt");
1614
1615         argv_array_push(&spf.args, "fetch");
1616         for (i = 0; i < options->argc; i++)
1617                 argv_array_push(&spf.args, options->argv[i]);
1618         argv_array_push(&spf.args, "--recurse-submodules-default");
1619         /* default value, "--submodule-prefix" and its value are added later */
1620
1621         calculate_changed_submodule_paths(r, &spf.changed_submodule_names);
1622         string_list_sort(&spf.changed_submodule_names);
1623         run_processes_parallel_tr2(max_parallel_jobs,
1624                                    get_next_submodule,
1625                                    fetch_start_failure,
1626                                    fetch_finish,
1627                                    &spf,
1628                                    "submodule", "parallel/fetch");
1629
1630         argv_array_clear(&spf.args);
1631 out:
1632         free_submodules_oids(&spf.changed_submodule_names);
1633         return spf.result;
1634 }
1635
1636 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1637 {
1638         struct child_process cp = CHILD_PROCESS_INIT;
1639         struct strbuf buf = STRBUF_INIT;
1640         FILE *fp;
1641         unsigned dirty_submodule = 0;
1642         const char *git_dir;
1643         int ignore_cp_exit_code = 0;
1644
1645         strbuf_addf(&buf, "%s/.git", path);
1646         git_dir = read_gitfile(buf.buf);
1647         if (!git_dir)
1648                 git_dir = buf.buf;
1649         if (!is_git_directory(git_dir)) {
1650                 if (is_directory(git_dir))
1651                         die(_("'%s' not recognized as a git repository"), git_dir);
1652                 strbuf_release(&buf);
1653                 /* The submodule is not checked out, so it is not modified */
1654                 return 0;
1655         }
1656         strbuf_reset(&buf);
1657
1658         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1659         if (ignore_untracked)
1660                 argv_array_push(&cp.args, "-uno");
1661
1662         prepare_submodule_repo_env(&cp.env_array);
1663         cp.git_cmd = 1;
1664         cp.no_stdin = 1;
1665         cp.out = -1;
1666         cp.dir = path;
1667         if (start_command(&cp))
1668                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1669
1670         fp = xfdopen(cp.out, "r");
1671         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1672                 /* regular untracked files */
1673                 if (buf.buf[0] == '?')
1674                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1675
1676                 if (buf.buf[0] == 'u' ||
1677                     buf.buf[0] == '1' ||
1678                     buf.buf[0] == '2') {
1679                         /* T = line type, XY = status, SSSS = submodule state */
1680                         if (buf.len < strlen("T XY SSSS"))
1681                                 BUG("invalid status --porcelain=2 line %s",
1682                                     buf.buf);
1683
1684                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1685                                 /* nested untracked file */
1686                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1687
1688                         if (buf.buf[0] == 'u' ||
1689                             buf.buf[0] == '2' ||
1690                             memcmp(buf.buf + 5, "S..U", 4))
1691                                 /* other change */
1692                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1693                 }
1694
1695                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1696                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1697                      ignore_untracked)) {
1698                         /*
1699                          * We're not interested in any further information from
1700                          * the child any more, neither output nor its exit code.
1701                          */
1702                         ignore_cp_exit_code = 1;
1703                         break;
1704                 }
1705         }
1706         fclose(fp);
1707
1708         if (finish_command(&cp) && !ignore_cp_exit_code)
1709                 die("'git status --porcelain=2' failed in submodule %s", path);
1710
1711         strbuf_release(&buf);
1712         return dirty_submodule;
1713 }
1714
1715 int submodule_uses_gitfile(const char *path)
1716 {
1717         struct child_process cp = CHILD_PROCESS_INIT;
1718         const char *argv[] = {
1719                 "submodule",
1720                 "foreach",
1721                 "--quiet",
1722                 "--recursive",
1723                 "test -f .git",
1724                 NULL,
1725         };
1726         struct strbuf buf = STRBUF_INIT;
1727         const char *git_dir;
1728
1729         strbuf_addf(&buf, "%s/.git", path);
1730         git_dir = read_gitfile(buf.buf);
1731         if (!git_dir) {
1732                 strbuf_release(&buf);
1733                 return 0;
1734         }
1735         strbuf_release(&buf);
1736
1737         /* Now test that all nested submodules use a gitfile too */
1738         cp.argv = argv;
1739         prepare_submodule_repo_env(&cp.env_array);
1740         cp.git_cmd = 1;
1741         cp.no_stdin = 1;
1742         cp.no_stderr = 1;
1743         cp.no_stdout = 1;
1744         cp.dir = path;
1745         if (run_command(&cp))
1746                 return 0;
1747
1748         return 1;
1749 }
1750
1751 /*
1752  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1753  * when doing so.
1754  *
1755  * Return 1 if we'd lose data, return 0 if the removal is fine,
1756  * and negative values for errors.
1757  */
1758 int bad_to_remove_submodule(const char *path, unsigned flags)
1759 {
1760         ssize_t len;
1761         struct child_process cp = CHILD_PROCESS_INIT;
1762         struct strbuf buf = STRBUF_INIT;
1763         int ret = 0;
1764
1765         if (!file_exists(path) || is_empty_dir(path))
1766                 return 0;
1767
1768         if (!submodule_uses_gitfile(path))
1769                 return 1;
1770
1771         argv_array_pushl(&cp.args, "status", "--porcelain",
1772                                    "--ignore-submodules=none", NULL);
1773
1774         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1775                 argv_array_push(&cp.args, "-uno");
1776         else
1777                 argv_array_push(&cp.args, "-uall");
1778
1779         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1780                 argv_array_push(&cp.args, "--ignored");
1781
1782         prepare_submodule_repo_env(&cp.env_array);
1783         cp.git_cmd = 1;
1784         cp.no_stdin = 1;
1785         cp.out = -1;
1786         cp.dir = path;
1787         if (start_command(&cp)) {
1788                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1789                         die(_("could not start 'git status' in submodule '%s'"),
1790                                 path);
1791                 ret = -1;
1792                 goto out;
1793         }
1794
1795         len = strbuf_read(&buf, cp.out, 1024);
1796         if (len > 2)
1797                 ret = 1;
1798         close(cp.out);
1799
1800         if (finish_command(&cp)) {
1801                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1802                         die(_("could not run 'git status' in submodule '%s'"),
1803                                 path);
1804                 ret = -1;
1805         }
1806 out:
1807         strbuf_release(&buf);
1808         return ret;
1809 }
1810
1811 void submodule_unset_core_worktree(const struct submodule *sub)
1812 {
1813         char *config_path = xstrfmt("%s/modules/%s/config",
1814                                     get_git_common_dir(), sub->name);
1815
1816         if (git_config_set_in_file_gently(config_path, "core.worktree", NULL))
1817                 warning(_("Could not unset core.worktree setting in submodule '%s'"),
1818                           sub->path);
1819
1820         free(config_path);
1821 }
1822
1823 static const char *get_super_prefix_or_empty(void)
1824 {
1825         const char *s = get_super_prefix();
1826         if (!s)
1827                 s = "";
1828         return s;
1829 }
1830
1831 static int submodule_has_dirty_index(const struct submodule *sub)
1832 {
1833         struct child_process cp = CHILD_PROCESS_INIT;
1834
1835         prepare_submodule_repo_env(&cp.env_array);
1836
1837         cp.git_cmd = 1;
1838         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1839                                    "--cached", "HEAD", NULL);
1840         cp.no_stdin = 1;
1841         cp.no_stdout = 1;
1842         cp.dir = sub->path;
1843         if (start_command(&cp))
1844                 die("could not recurse into submodule '%s'", sub->path);
1845
1846         return finish_command(&cp);
1847 }
1848
1849 static void submodule_reset_index(const char *path)
1850 {
1851         struct child_process cp = CHILD_PROCESS_INIT;
1852         prepare_submodule_repo_env(&cp.env_array);
1853
1854         cp.git_cmd = 1;
1855         cp.no_stdin = 1;
1856         cp.dir = path;
1857
1858         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1859                                    get_super_prefix_or_empty(), path);
1860         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1861
1862         argv_array_push(&cp.args, empty_tree_oid_hex());
1863
1864         if (run_command(&cp))
1865                 die("could not reset submodule index");
1866 }
1867
1868 /**
1869  * Moves a submodule at a given path from a given head to another new head.
1870  * For edge cases (a submodule coming into existence or removing a submodule)
1871  * pass NULL for old or new respectively.
1872  */
1873 int submodule_move_head(const char *path,
1874                          const char *old_head,
1875                          const char *new_head,
1876                          unsigned flags)
1877 {
1878         int ret = 0;
1879         struct child_process cp = CHILD_PROCESS_INIT;
1880         const struct submodule *sub;
1881         int *error_code_ptr, error_code;
1882
1883         if (!is_submodule_active(the_repository, path))
1884                 return 0;
1885
1886         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1887                 /*
1888                  * Pass non NULL pointer to is_submodule_populated_gently
1889                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1890                  * to fixup the submodule in the force case later.
1891                  */
1892                 error_code_ptr = &error_code;
1893         else
1894                 error_code_ptr = NULL;
1895
1896         if (old_head && !is_submodule_populated_gently(path, error_code_ptr))
1897                 return 0;
1898
1899         sub = submodule_from_path(the_repository, &null_oid, path);
1900
1901         if (!sub)
1902                 BUG("could not get submodule information for '%s'", path);
1903
1904         if (old_head && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1905                 /* Check if the submodule has a dirty index. */
1906                 if (submodule_has_dirty_index(sub))
1907                         return error(_("submodule '%s' has dirty index"), path);
1908         }
1909
1910         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1911                 if (old_head) {
1912                         if (!submodule_uses_gitfile(path))
1913                                 absorb_git_dir_into_superproject(path,
1914                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1915                 } else {
1916                         char *gitdir = xstrfmt("%s/modules/%s",
1917                                     get_git_common_dir(), sub->name);
1918                         connect_work_tree_and_git_dir(path, gitdir, 0);
1919                         free(gitdir);
1920
1921                         /* make sure the index is clean as well */
1922                         submodule_reset_index(path);
1923                 }
1924
1925                 if (old_head && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1926                         char *gitdir = xstrfmt("%s/modules/%s",
1927                                     get_git_common_dir(), sub->name);
1928                         connect_work_tree_and_git_dir(path, gitdir, 1);
1929                         free(gitdir);
1930                 }
1931         }
1932
1933         prepare_submodule_repo_env(&cp.env_array);
1934
1935         cp.git_cmd = 1;
1936         cp.no_stdin = 1;
1937         cp.dir = path;
1938
1939         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1940                         get_super_prefix_or_empty(), path);
1941         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1942
1943         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1944                 argv_array_push(&cp.args, "-n");
1945         else
1946                 argv_array_push(&cp.args, "-u");
1947
1948         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1949                 argv_array_push(&cp.args, "--reset");
1950         else
1951                 argv_array_push(&cp.args, "-m");
1952
1953         if (!(flags & SUBMODULE_MOVE_HEAD_FORCE))
1954                 argv_array_push(&cp.args, old_head ? old_head : empty_tree_oid_hex());
1955
1956         argv_array_push(&cp.args, new_head ? new_head : empty_tree_oid_hex());
1957
1958         if (run_command(&cp)) {
1959                 ret = error(_("Submodule '%s' could not be updated."), path);
1960                 goto out;
1961         }
1962
1963         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1964                 if (new_head) {
1965                         child_process_init(&cp);
1966                         /* also set the HEAD accordingly */
1967                         cp.git_cmd = 1;
1968                         cp.no_stdin = 1;
1969                         cp.dir = path;
1970
1971                         prepare_submodule_repo_env(&cp.env_array);
1972                         argv_array_pushl(&cp.args, "update-ref", "HEAD",
1973                                          "--no-deref", new_head, NULL);
1974
1975                         if (run_command(&cp)) {
1976                                 ret = -1;
1977                                 goto out;
1978                         }
1979                 } else {
1980                         struct strbuf sb = STRBUF_INIT;
1981
1982                         strbuf_addf(&sb, "%s/.git", path);
1983                         unlink_or_warn(sb.buf);
1984                         strbuf_release(&sb);
1985
1986                         if (is_empty_dir(path))
1987                                 rmdir_or_warn(path);
1988
1989                         submodule_unset_core_worktree(sub);
1990                 }
1991         }
1992 out:
1993         return ret;
1994 }
1995
1996 /*
1997  * Embeds a single submodules git directory into the superprojects git dir,
1998  * non recursively.
1999  */
2000 static void relocate_single_git_dir_into_superproject(const char *path)
2001 {
2002         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
2003         const char *new_git_dir;
2004         const struct submodule *sub;
2005
2006         if (submodule_uses_worktrees(path))
2007                 die(_("relocate_gitdir for submodule '%s' with "
2008                       "more than one worktree not supported"), path);
2009
2010         old_git_dir = xstrfmt("%s/.git", path);
2011         if (read_gitfile(old_git_dir))
2012                 /* If it is an actual gitfile, it doesn't need migration. */
2013                 return;
2014
2015         real_old_git_dir = real_pathdup(old_git_dir, 1);
2016
2017         sub = submodule_from_path(the_repository, &null_oid, path);
2018         if (!sub)
2019                 die(_("could not lookup name for submodule '%s'"), path);
2020
2021         new_git_dir = git_path("modules/%s", sub->name);
2022         if (safe_create_leading_directories_const(new_git_dir) < 0)
2023                 die(_("could not create directory '%s'"), new_git_dir);
2024         real_new_git_dir = real_pathdup(new_git_dir, 1);
2025
2026         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
2027                 get_super_prefix_or_empty(), path,
2028                 real_old_git_dir, real_new_git_dir);
2029
2030         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
2031
2032         free(old_git_dir);
2033         free(real_old_git_dir);
2034         free(real_new_git_dir);
2035 }
2036
2037 /*
2038  * Migrate the git directory of the submodule given by path from
2039  * having its git directory within the working tree to the git dir nested
2040  * in its superprojects git dir under modules/.
2041  */
2042 void absorb_git_dir_into_superproject(const char *path,
2043                                       unsigned flags)
2044 {
2045         int err_code;
2046         const char *sub_git_dir;
2047         struct strbuf gitdir = STRBUF_INIT;
2048         strbuf_addf(&gitdir, "%s/.git", path);
2049         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
2050
2051         /* Not populated? */
2052         if (!sub_git_dir) {
2053                 const struct submodule *sub;
2054
2055                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
2056                         /* unpopulated as expected */
2057                         strbuf_release(&gitdir);
2058                         return;
2059                 }
2060
2061                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
2062                         /* We don't know what broke here. */
2063                         read_gitfile_error_die(err_code, path, NULL);
2064
2065                 /*
2066                 * Maybe populated, but no git directory was found?
2067                 * This can happen if the superproject is a submodule
2068                 * itself and was just absorbed. The absorption of the
2069                 * superproject did not rewrite the git file links yet,
2070                 * fix it now.
2071                 */
2072                 sub = submodule_from_path(the_repository, &null_oid, path);
2073                 if (!sub)
2074                         die(_("could not lookup name for submodule '%s'"), path);
2075                 connect_work_tree_and_git_dir(path,
2076                         git_path("modules/%s", sub->name), 0);
2077         } else {
2078                 /* Is it already absorbed into the superprojects git dir? */
2079                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
2080                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
2081
2082                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
2083                         relocate_single_git_dir_into_superproject(path);
2084
2085                 free(real_sub_git_dir);
2086                 free(real_common_git_dir);
2087         }
2088         strbuf_release(&gitdir);
2089
2090         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
2091                 struct child_process cp = CHILD_PROCESS_INIT;
2092                 struct strbuf sb = STRBUF_INIT;
2093
2094                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
2095                         BUG("we don't know how to pass the flags down?");
2096
2097                 strbuf_addstr(&sb, get_super_prefix_or_empty());
2098                 strbuf_addstr(&sb, path);
2099                 strbuf_addch(&sb, '/');
2100
2101                 cp.dir = path;
2102                 cp.git_cmd = 1;
2103                 cp.no_stdin = 1;
2104                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
2105                                            "submodule--helper",
2106                                            "absorb-git-dirs", NULL);
2107                 prepare_submodule_repo_env(&cp.env_array);
2108                 if (run_command(&cp))
2109                         die(_("could not recurse into submodule '%s'"), path);
2110
2111                 strbuf_release(&sb);
2112         }
2113 }
2114
2115 const char *get_superproject_working_tree(void)
2116 {
2117         struct child_process cp = CHILD_PROCESS_INIT;
2118         struct strbuf sb = STRBUF_INIT;
2119         const char *one_up = real_path_if_valid("../");
2120         const char *cwd = xgetcwd();
2121         const char *ret = NULL;
2122         const char *subpath;
2123         int code;
2124         ssize_t len;
2125
2126         if (!is_inside_work_tree())
2127                 /*
2128                  * FIXME:
2129                  * We might have a superproject, but it is harder
2130                  * to determine.
2131                  */
2132                 return NULL;
2133
2134         if (!one_up)
2135                 return NULL;
2136
2137         subpath = relative_path(cwd, one_up, &sb);
2138
2139         prepare_submodule_repo_env(&cp.env_array);
2140         argv_array_pop(&cp.env_array);
2141
2142         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
2143                         "ls-files", "-z", "--stage", "--full-name", "--",
2144                         subpath, NULL);
2145         strbuf_reset(&sb);
2146
2147         cp.no_stdin = 1;
2148         cp.no_stderr = 1;
2149         cp.out = -1;
2150         cp.git_cmd = 1;
2151
2152         if (start_command(&cp))
2153                 die(_("could not start ls-files in .."));
2154
2155         len = strbuf_read(&sb, cp.out, PATH_MAX);
2156         close(cp.out);
2157
2158         if (starts_with(sb.buf, "160000")) {
2159                 int super_sub_len;
2160                 int cwd_len = strlen(cwd);
2161                 char *super_sub, *super_wt;
2162
2163                 /*
2164                  * There is a superproject having this repo as a submodule.
2165                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
2166                  * We're only interested in the name after the tab.
2167                  */
2168                 super_sub = strchr(sb.buf, '\t') + 1;
2169                 super_sub_len = strlen(super_sub);
2170
2171                 if (super_sub_len > cwd_len ||
2172                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
2173                         BUG("returned path string doesn't match cwd?");
2174
2175                 super_wt = xstrdup(cwd);
2176                 super_wt[cwd_len - super_sub_len] = '\0';
2177
2178                 ret = real_path(super_wt);
2179                 free(super_wt);
2180         }
2181         strbuf_release(&sb);
2182
2183         code = finish_command(&cp);
2184
2185         if (code == 128)
2186                 /* '../' is not a git repository */
2187                 return NULL;
2188         if (code == 0 && len == 0)
2189                 /* There is an unrelated git repository at '../' */
2190                 return NULL;
2191         if (code)
2192                 die(_("ls-tree returned unexpected return code %d"), code);
2193
2194         return ret;
2195 }
2196
2197 /*
2198  * Put the gitdir for a submodule (given relative to the main
2199  * repository worktree) into `buf`, or return -1 on error.
2200  */
2201 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2202 {
2203         const struct submodule *sub;
2204         const char *git_dir;
2205         int ret = 0;
2206
2207         strbuf_reset(buf);
2208         strbuf_addstr(buf, submodule);
2209         strbuf_complete(buf, '/');
2210         strbuf_addstr(buf, ".git");
2211
2212         git_dir = read_gitfile(buf->buf);
2213         if (git_dir) {
2214                 strbuf_reset(buf);
2215                 strbuf_addstr(buf, git_dir);
2216         }
2217         if (!is_git_directory(buf->buf)) {
2218                 sub = submodule_from_path(the_repository, &null_oid, submodule);
2219                 if (!sub) {
2220                         ret = -1;
2221                         goto cleanup;
2222                 }
2223                 strbuf_reset(buf);
2224                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2225         }
2226
2227 cleanup:
2228         return ret;
2229 }