git.oblomov.eu Git - git/blob - submodule.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "config.h"
   4 #include "submodule-config.h"
   5 #include "submodule.h"
   6 #include "dir.h"
   7 #include "diff.h"
   8 #include "commit.h"
   9 #include "revision.h"
  10 #include "run-command.h"
  11 #include "diffcore.h"
  12 #include "refs.h"
  13 #include "string-list.h"
  14 #include "sha1-array.h"
  15 #include "argv-array.h"
  16 #include "blob.h"
  17 #include "thread-utils.h"
  18 #include "quote.h"
  19 #include "remote.h"
  20 #include "worktree.h"
  21 #include "parse-options.h"
  22
  23 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
  24 static struct string_list changed_submodule_paths = STRING_LIST_INIT_DUP;
  25 static int initialized_fetch_ref_tips;
  26 static struct oid_array ref_tips_before_fetch;
  27 static struct oid_array ref_tips_after_fetch;
  28
  29 /*
  30  * Check if the .gitmodules file is unmerged. Parsing of the .gitmodules file
  31  * will be disabled because we can't guess what might be configured in
  32  * .gitmodules unless the user resolves the conflict.
  33  */
  34 int is_gitmodules_unmerged(const struct index_state *istate)
  35 {
  36         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  37         if (pos < 0) { /* .gitmodules not found or isn't merged */
  38                 pos = -1 - pos;
  39                 if (istate->cache_nr > pos) {  /* there is a .gitmodules */
  40                         const struct cache_entry *ce = istate->cache[pos];
  41                         if (ce_namelen(ce) == strlen(GITMODULES_FILE) &&
  42                             !strcmp(ce->name, GITMODULES_FILE))
  43                                 return 1;
  44                 }
  45         }
  46
  47         return 0;
  48 }
  49
  50 /*
  51  * Check if the .gitmodules file has unstaged modifications.  This must be
  52  * checked before allowing modifications to the .gitmodules file with the
  53  * intention to stage them later, because when continuing we would stage the
  54  * modifications the user didn't stage herself too. That might change in a
  55  * future version when we learn to stage the changes we do ourselves without
  56  * staging any previous modifications.
  57  */
  58 int is_staging_gitmodules_ok(const struct index_state *istate)
  59 {
  60         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  61
  62         if ((pos >= 0) && (pos < istate->cache_nr)) {
  63                 struct stat st;
  64                 if (lstat(GITMODULES_FILE, &st) == 0 &&
  65                     ce_match_stat(istate->cache[pos], &st, 0) & DATA_CHANGED)
  66                         return 0;
  67         }
  68
  69         return 1;
  70 }
  71
  72 /*
  73  * Try to update the "path" entry in the "submodule.<name>" section of the
  74  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
  75  * with the correct path=<oldpath> setting was found and we could update it.
  76  */
  77 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
  78 {
  79         struct strbuf entry = STRBUF_INIT;
  80         const struct submodule *submodule;
  81
  82         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
  83                 return -1;
  84
  85         if (is_gitmodules_unmerged(&the_index))
  86                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  87
  88         submodule = submodule_from_path(&null_oid, oldpath);
  89         if (!submodule || !submodule->name) {
  90                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
  91                 return -1;
  92         }
  93         strbuf_addstr(&entry, "submodule.");
  94         strbuf_addstr(&entry, submodule->name);
  95         strbuf_addstr(&entry, ".path");
  96         if (git_config_set_in_file_gently(GITMODULES_FILE, entry.buf, newpath) < 0) {
  97                 /* Maybe the user already did that, don't error out here */
  98                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
  99                 strbuf_release(&entry);
 100                 return -1;
 101         }
 102         strbuf_release(&entry);
 103         return 0;
 104 }
 105
 106 /*
 107  * Try to remove the "submodule.<name>" section from .gitmodules where the given
 108  * path is configured. Return 0 only if a .gitmodules file was found, a section
 109  * with the correct path=<path> setting was found and we could remove it.
 110  */
 111 int remove_path_from_gitmodules(const char *path)
 112 {
 113         struct strbuf sect = STRBUF_INIT;
 114         const struct submodule *submodule;
 115
 116         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
 117                 return -1;
 118
 119         if (is_gitmodules_unmerged(&the_index))
 120                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 121
 122         submodule = submodule_from_path(&null_oid, path);
 123         if (!submodule || !submodule->name) {
 124                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 125                 return -1;
 126         }
 127         strbuf_addstr(&sect, "submodule.");
 128         strbuf_addstr(&sect, submodule->name);
 129         if (git_config_rename_section_in_file(GITMODULES_FILE, sect.buf, NULL) < 0) {
 130                 /* Maybe the user already did that, don't error out here */
 131                 warning(_("Could not remove .gitmodules entry for %s"), path);
 132                 strbuf_release(&sect);
 133                 return -1;
 134         }
 135         strbuf_release(&sect);
 136         return 0;
 137 }
 138
 139 void stage_updated_gitmodules(void)
 140 {
 141         if (add_file_to_cache(GITMODULES_FILE, 0))
 142                 die(_("staging updated .gitmodules failed"));
 143 }
 144
 145 static int add_submodule_odb(const char *path)
 146 {
 147         struct strbuf objects_directory = STRBUF_INIT;
 148         int ret = 0;
 149
 150         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
 151         if (ret)
 152                 goto done;
 153         if (!is_directory(objects_directory.buf)) {
 154                 ret = -1;
 155                 goto done;
 156         }
 157         add_to_alternates_memory(objects_directory.buf);
 158 done:
 159         strbuf_release(&objects_directory);
 160         return ret;
 161 }
 162
 163 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 164                                              const char *path)
 165 {
 166         const struct submodule *submodule = submodule_from_path(&null_oid, path);
 167         if (submodule) {
 168                 if (submodule->ignore)
 169                         handle_ignore_submodules_arg(diffopt, submodule->ignore);
 170                 else if (is_gitmodules_unmerged(&the_index))
 171                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 172         }
 173 }
 174
 175 /* For loading from the .gitmodules file. */
 176 static int git_modules_config(const char *var, const char *value, void *cb)
 177 {
 178         if (starts_with(var, "submodule."))
 179                 return parse_submodule_config_option(var, value);
 180         return 0;
 181 }
 182
 183 /* Loads all submodule settings from the config. */
 184 int submodule_config(const char *var, const char *value, void *cb)
 185 {
 186         if (!strcmp(var, "submodule.recurse")) {
 187                 int v = git_config_bool(var, value) ?
 188                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 189                 config_update_recurse_submodules = v;
 190                 return 0;
 191         } else {
 192                 return git_modules_config(var, value, cb);
 193         }
 194 }
 195
 196 /* Cheap function that only determines if we're interested in submodules at all */
 197 int git_default_submodule_config(const char *var, const char *value, void *cb)
 198 {
 199         if (!strcmp(var, "submodule.recurse")) {
 200                 int v = git_config_bool(var, value) ?
 201                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 202                 config_update_recurse_submodules = v;
 203         }
 204         return 0;
 205 }
 206
 207 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 208                                                      const char *arg, int unset)
 209 {
 210         if (unset) {
 211                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 212                 return 0;
 213         }
 214         if (arg)
 215                 config_update_recurse_submodules =
 216                         parse_update_recurse_submodules_arg(opt->long_name,
 217                                                             arg);
 218         else
 219                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 220
 221         return 0;
 222 }
 223
 224 void load_submodule_cache(void)
 225 {
 226         if (config_update_recurse_submodules == RECURSE_SUBMODULES_OFF)
 227                 return;
 228
 229         gitmodules_config();
 230         git_config(submodule_config, NULL);
 231 }
 232
 233 static int gitmodules_cb(const char *var, const char *value, void *data)
 234 {
 235         struct repository *repo = data;
 236         return submodule_config_option(repo, var, value);
 237 }
 238
 239 void repo_read_gitmodules(struct repository *repo)
 240 {
 241         if (repo->worktree) {
 242                 char *gitmodules;
 243
 244                 if (repo_read_index(repo) < 0)
 245                         return;
 246
 247                 gitmodules = repo_worktree_path(repo, GITMODULES_FILE);
 248
 249                 if (!is_gitmodules_unmerged(repo->index))
 250                         git_config_from_file(gitmodules_cb, gitmodules, repo);
 251
 252                 free(gitmodules);
 253         }
 254 }
 255
 256 void gitmodules_config(void)
 257 {
 258         repo_read_gitmodules(the_repository);
 259 }
 260
 261 void gitmodules_config_oid(const struct object_id *commit_oid)
 262 {
 263         struct strbuf rev = STRBUF_INIT;
 264         struct object_id oid;
 265
 266         if (gitmodule_oid_from_commit(commit_oid, &oid, &rev)) {
 267                 git_config_from_blob_oid(submodule_config, rev.buf,
 268                                          &oid, NULL);
 269         }
 270         strbuf_release(&rev);
 271 }
 272
 273 /*
 274  * Determine if a submodule has been initialized at a given 'path'
 275  */
 276 int is_submodule_active(struct repository *repo, const char *path)
 277 {
 278         int ret = 0;
 279         char *key = NULL;
 280         char *value = NULL;
 281         const struct string_list *sl;
 282         const struct submodule *module;
 283
 284         module = submodule_from_cache(repo, &null_oid, path);
 285
 286         /* early return if there isn't a path->module mapping */
 287         if (!module)
 288                 return 0;
 289
 290         /* submodule.<name>.active is set */
 291         key = xstrfmt("submodule.%s.active", module->name);
 292         if (!repo_config_get_bool(repo, key, &ret)) {
 293                 free(key);
 294                 return ret;
 295         }
 296         free(key);
 297
 298         /* submodule.active is set */
 299         sl = repo_config_get_value_multi(repo, "submodule.active");
 300         if (sl) {
 301                 struct pathspec ps;
 302                 struct argv_array args = ARGV_ARRAY_INIT;
 303                 const struct string_list_item *item;
 304
 305                 for_each_string_list_item(item, sl) {
 306                         argv_array_push(&args, item->string);
 307                 }
 308
 309                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 310                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
 311
 312                 argv_array_clear(&args);
 313                 clear_pathspec(&ps);
 314                 return ret;
 315         }
 316
 317         /* fallback to checking if the URL is set */
 318         key = xstrfmt("submodule.%s.url", module->name);
 319         ret = !repo_config_get_string(repo, key, &value);
 320
 321         free(value);
 322         free(key);
 323         return ret;
 324 }
 325
 326 int is_submodule_populated_gently(const char *path, int *return_error_code)
 327 {
 328         int ret = 0;
 329         char *gitdir = xstrfmt("%s/.git", path);
 330
 331         if (resolve_gitdir_gently(gitdir, return_error_code))
 332                 ret = 1;
 333
 334         free(gitdir);
 335         return ret;
 336 }
 337
 338 /*
 339  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 340  */
 341 void die_in_unpopulated_submodule(const struct index_state *istate,
 342                                   const char *prefix)
 343 {
 344         int i, prefixlen;
 345
 346         if (!prefix)
 347                 return;
 348
 349         prefixlen = strlen(prefix);
 350
 351         for (i = 0; i < istate->cache_nr; i++) {
 352                 struct cache_entry *ce = istate->cache[i];
 353                 int ce_len = ce_namelen(ce);
 354
 355                 if (!S_ISGITLINK(ce->ce_mode))
 356                         continue;
 357                 if (prefixlen <= ce_len)
 358                         continue;
 359                 if (strncmp(ce->name, prefix, ce_len))
 360                         continue;
 361                 if (prefix[ce_len] != '/')
 362                         continue;
 363
 364                 die(_("in unpopulated submodule '%s'"), ce->name);
 365         }
 366 }
 367
 368 /*
 369  * Dies if any paths in the provided pathspec descends into a submodule
 370  */
 371 void die_path_inside_submodule(const struct index_state *istate,
 372                                const struct pathspec *ps)
 373 {
 374         int i, j;
 375
 376         for (i = 0; i < istate->cache_nr; i++) {
 377                 struct cache_entry *ce = istate->cache[i];
 378                 int ce_len = ce_namelen(ce);
 379
 380                 if (!S_ISGITLINK(ce->ce_mode))
 381                         continue;
 382
 383                 for (j = 0; j < ps->nr ; j++) {
 384                         const struct pathspec_item *item = &ps->items[j];
 385
 386                         if (item->len <= ce_len)
 387                                 continue;
 388                         if (item->match[ce_len] != '/')
 389                                 continue;
 390                         if (strncmp(ce->name, item->match, ce_len))
 391                                 continue;
 392                         if (item->len == ce_len + 1)
 393                                 continue;
 394
 395                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 396                             item->original, ce_len, ce->name);
 397                 }
 398         }
 399 }
 400
 401 int parse_submodule_update_strategy(const char *value,
 402                 struct submodule_update_strategy *dst)
 403 {
 404         free((void*)dst->command);
 405         dst->command = NULL;
 406         if (!strcmp(value, "none"))
 407                 dst->type = SM_UPDATE_NONE;
 408         else if (!strcmp(value, "checkout"))
 409                 dst->type = SM_UPDATE_CHECKOUT;
 410         else if (!strcmp(value, "rebase"))
 411                 dst->type = SM_UPDATE_REBASE;
 412         else if (!strcmp(value, "merge"))
 413                 dst->type = SM_UPDATE_MERGE;
 414         else if (skip_prefix(value, "!", &value)) {
 415                 dst->type = SM_UPDATE_COMMAND;
 416                 dst->command = xstrdup(value);
 417         } else
 418                 return -1;
 419         return 0;
 420 }
 421
 422 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 423 {
 424         struct strbuf sb = STRBUF_INIT;
 425         switch (s->type) {
 426         case SM_UPDATE_CHECKOUT:
 427                 return "checkout";
 428         case SM_UPDATE_MERGE:
 429                 return "merge";
 430         case SM_UPDATE_REBASE:
 431                 return "rebase";
 432         case SM_UPDATE_NONE:
 433                 return "none";
 434         case SM_UPDATE_UNSPECIFIED:
 435                 return NULL;
 436         case SM_UPDATE_COMMAND:
 437                 strbuf_addf(&sb, "!%s", s->command);
 438                 return strbuf_detach(&sb, NULL);
 439         }
 440         return NULL;
 441 }
 442
 443 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 444                                   const char *arg)
 445 {
 446         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 447         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 448         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 449
 450         if (!strcmp(arg, "all"))
 451                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 452         else if (!strcmp(arg, "untracked"))
 453                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 454         else if (!strcmp(arg, "dirty"))
 455                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 456         else if (strcmp(arg, "none"))
 457                 die("bad --ignore-submodules argument: %s", arg);
 458 }
 459
 460 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 461                 struct commit *left, struct commit *right,
 462                 struct commit_list *merge_bases)
 463 {
 464         struct commit_list *list;
 465
 466         init_revisions(rev, NULL);
 467         setup_revisions(0, NULL, rev, NULL);
 468         rev->left_right = 1;
 469         rev->first_parent_only = 1;
 470         left->object.flags |= SYMMETRIC_LEFT;
 471         add_pending_object(rev, &left->object, path);
 472         add_pending_object(rev, &right->object, path);
 473         for (list = merge_bases; list; list = list->next) {
 474                 list->item->object.flags |= UNINTERESTING;
 475                 add_pending_object(rev, &list->item->object,
 476                         oid_to_hex(&list->item->object.oid));
 477         }
 478         return prepare_revision_walk(rev);
 479 }
 480
 481 static void print_submodule_summary(struct rev_info *rev, FILE *f,
 482                 const char *line_prefix,
 483                 const char *del, const char *add, const char *reset)
 484 {
 485         static const char format[] = "  %m %s";
 486         struct strbuf sb = STRBUF_INIT;
 487         struct commit *commit;
 488
 489         while ((commit = get_revision(rev))) {
 490                 struct pretty_print_context ctx = {0};
 491                 ctx.date_mode = rev->date_mode;
 492                 ctx.output_encoding = get_log_output_encoding();
 493                 strbuf_setlen(&sb, 0);
 494                 strbuf_addstr(&sb, line_prefix);
 495                 if (commit->object.flags & SYMMETRIC_LEFT) {
 496                         if (del)
 497                                 strbuf_addstr(&sb, del);
 498                 }
 499                 else if (add)
 500                         strbuf_addstr(&sb, add);
 501                 format_commit_message(commit, format, &sb, &ctx);
 502                 if (reset)
 503                         strbuf_addstr(&sb, reset);
 504                 strbuf_addch(&sb, '\n');
 505                 fprintf(f, "%s", sb.buf);
 506         }
 507         strbuf_release(&sb);
 508 }
 509
 510 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 511 {
 512         const char * const *var;
 513
 514         for (var = local_repo_env; *var; var++) {
 515                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 516                         argv_array_push(out, *var);
 517         }
 518 }
 519
 520 void prepare_submodule_repo_env(struct argv_array *out)
 521 {
 522         prepare_submodule_repo_env_no_git_dir(out);
 523         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 524                          DEFAULT_GIT_DIR_ENVIRONMENT);
 525 }
 526
 527 /* Helper function to display the submodule header line prior to the full
 528  * summary output. If it can locate the submodule objects directory it will
 529  * attempt to lookup both the left and right commits and put them into the
 530  * left and right pointers.
 531  */
 532 static void show_submodule_header(FILE *f, const char *path,
 533                 const char *line_prefix,
 534                 struct object_id *one, struct object_id *two,
 535                 unsigned dirty_submodule, const char *meta,
 536                 const char *reset,
 537                 struct commit **left, struct commit **right,
 538                 struct commit_list **merge_bases)
 539 {
 540         const char *message = NULL;
 541         struct strbuf sb = STRBUF_INIT;
 542         int fast_forward = 0, fast_backward = 0;
 543
 544         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 545                 fprintf(f, "%sSubmodule %s contains untracked content\n",
 546                         line_prefix, path);
 547         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 548                 fprintf(f, "%sSubmodule %s contains modified content\n",
 549                         line_prefix, path);
 550
 551         if (is_null_oid(one))
 552                 message = "(new submodule)";
 553         else if (is_null_oid(two))
 554                 message = "(submodule deleted)";
 555
 556         if (add_submodule_odb(path)) {
 557                 if (!message)
 558                         message = "(not initialized)";
 559                 goto output_header;
 560         }
 561
 562         /*
 563          * Attempt to lookup the commit references, and determine if this is
 564          * a fast forward or fast backwards update.
 565          */
 566         *left = lookup_commit_reference(one);
 567         *right = lookup_commit_reference(two);
 568
 569         /*
 570          * Warn about missing commits in the submodule project, but only if
 571          * they aren't null.
 572          */
 573         if ((!is_null_oid(one) && !*left) ||
 574              (!is_null_oid(two) && !*right))
 575                 message = "(commits not present)";
 576
 577         *merge_bases = get_merge_bases(*left, *right);
 578         if (*merge_bases) {
 579                 if ((*merge_bases)->item == *left)
 580                         fast_forward = 1;
 581                 else if ((*merge_bases)->item == *right)
 582                         fast_backward = 1;
 583         }
 584
 585         if (!oidcmp(one, two)) {
 586                 strbuf_release(&sb);
 587                 return;
 588         }
 589
 590 output_header:
 591         strbuf_addf(&sb, "%s%sSubmodule %s ", line_prefix, meta, path);
 592         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
 593         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 594         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
 595         if (message)
 596                 strbuf_addf(&sb, " %s%s\n", message, reset);
 597         else
 598                 strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
 599         fwrite(sb.buf, sb.len, 1, f);
 600
 601         strbuf_release(&sb);
 602 }
 603
 604 void show_submodule_summary(FILE *f, const char *path,
 605                 const char *line_prefix,
 606                 struct object_id *one, struct object_id *two,
 607                 unsigned dirty_submodule, const char *meta,
 608                 const char *del, const char *add, const char *reset)
 609 {
 610         struct rev_info rev;
 611         struct commit *left = NULL, *right = NULL;
 612         struct commit_list *merge_bases = NULL;
 613
 614         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
 615                               meta, reset, &left, &right, &merge_bases);
 616
 617         /*
 618          * If we don't have both a left and a right pointer, there is no
 619          * reason to try and display a summary. The header line should contain
 620          * all the information the user needs.
 621          */
 622         if (!left || !right)
 623                 goto out;
 624
 625         /* Treat revision walker failure the same as missing commits */
 626         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 627                 fprintf(f, "%s(revision walker failed)\n", line_prefix);
 628                 goto out;
 629         }
 630
 631         print_submodule_summary(&rev, f, line_prefix, del, add, reset);
 632
 633 out:
 634         if (merge_bases)
 635                 free_commit_list(merge_bases);
 636         clear_commit_marks(left, ~0);
 637         clear_commit_marks(right, ~0);
 638 }
 639
 640 void show_submodule_inline_diff(FILE *f, const char *path,
 641                 const char *line_prefix,
 642                 struct object_id *one, struct object_id *two,
 643                 unsigned dirty_submodule, const char *meta,
 644                 const char *del, const char *add, const char *reset,
 645                 const struct diff_options *o)
 646 {
 647         const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
 648         struct commit *left = NULL, *right = NULL;
 649         struct commit_list *merge_bases = NULL;
 650         struct strbuf submodule_dir = STRBUF_INIT;
 651         struct child_process cp = CHILD_PROCESS_INIT;
 652
 653         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
 654                               meta, reset, &left, &right, &merge_bases);
 655
 656         /* We need a valid left and right commit to display a difference */
 657         if (!(left || is_null_oid(one)) ||
 658             !(right || is_null_oid(two)))
 659                 goto done;
 660
 661         if (left)
 662                 old = one;
 663         if (right)
 664                 new = two;
 665
 666         fflush(f);
 667         cp.git_cmd = 1;
 668         cp.dir = path;
 669         cp.out = dup(fileno(f));
 670         cp.no_stdin = 1;
 671
 672         /* TODO: other options may need to be passed here. */
 673         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 674
 675         argv_array_pushf(&cp.args, "--line-prefix=%s", line_prefix);
 676         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
 677                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 678                                  o->b_prefix, path);
 679                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 680                                  o->a_prefix, path);
 681         } else {
 682                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 683                                  o->a_prefix, path);
 684                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 685                                  o->b_prefix, path);
 686         }
 687         argv_array_push(&cp.args, oid_to_hex(old));
 688         /*
 689          * If the submodule has modified content, we will diff against the
 690          * work tree, under the assumption that the user has asked for the
 691          * diff format and wishes to actually see all differences even if they
 692          * haven't yet been committed to the submodule yet.
 693          */
 694         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 695                 argv_array_push(&cp.args, oid_to_hex(new));
 696
 697         prepare_submodule_repo_env(&cp.env_array);
 698         if (run_command(&cp))
 699                 fprintf(f, "(diff failed)\n");
 700
 701 done:
 702         strbuf_release(&submodule_dir);
 703         if (merge_bases)
 704                 free_commit_list(merge_bases);
 705         if (left)
 706                 clear_commit_marks(left, ~0);
 707         if (right)
 708                 clear_commit_marks(right, ~0);
 709 }
 710
 711 int should_update_submodules(void)
 712 {
 713         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 714 }
 715
 716 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 717 {
 718         if (!S_ISGITLINK(ce->ce_mode))
 719                 return NULL;
 720
 721         if (!should_update_submodules())
 722                 return NULL;
 723
 724         return submodule_from_path(&null_oid, ce->name);
 725 }
 726
 727 static struct oid_array *submodule_commits(struct string_list *submodules,
 728                                            const char *path)
 729 {
 730         struct string_list_item *item;
 731
 732         item = string_list_insert(submodules, path);
 733         if (item->util)
 734                 return (struct oid_array *) item->util;
 735
 736         /* NEEDSWORK: should we have oid_array_init()? */
 737         item->util = xcalloc(1, sizeof(struct oid_array));
 738         return (struct oid_array *) item->util;
 739 }
 740
 741 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 742                                           struct diff_options *options,
 743                                           void *data)
 744 {
 745         int i;
 746         struct string_list *changed = data;
 747
 748         for (i = 0; i < q->nr; i++) {
 749                 struct diff_filepair *p = q->queue[i];
 750                 struct oid_array *commits;
 751                 if (!S_ISGITLINK(p->two->mode))
 752                         continue;
 753
 754                 if (S_ISGITLINK(p->one->mode)) {
 755                         /*
 756                          * NEEDSWORK: We should honor the name configured in
 757                          * the .gitmodules file of the commit we are examining
 758                          * here to be able to correctly follow submodules
 759                          * being moved around.
 760                          */
 761                         commits = submodule_commits(changed, p->two->path);
 762                         oid_array_append(commits, &p->two->oid);
 763                 } else {
 764                         /* Submodule is new or was moved here */
 765                         /*
 766                          * NEEDSWORK: When the .git directories of submodules
 767                          * live inside the superprojects .git directory some
 768                          * day we should fetch new submodules directly into
 769                          * that location too when config or options request
 770                          * that so they can be checked out from there.
 771                          */
 772                         continue;
 773                 }
 774         }
 775 }
 776
 777 /*
 778  * Collect the paths of submodules in 'changed' which have changed based on
 779  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 780  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 781  * what the submodule pointers were updated to during the change.
 782  */
 783 static void collect_changed_submodules(struct string_list *changed,
 784                                        struct argv_array *argv)
 785 {
 786         struct rev_info rev;
 787         const struct commit *commit;
 788
 789         init_revisions(&rev, NULL);
 790         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 791         if (prepare_revision_walk(&rev))
 792                 die("revision walk setup failed");
 793
 794         while ((commit = get_revision(&rev))) {
 795                 struct rev_info diff_rev;
 796
 797                 init_revisions(&diff_rev, NULL);
 798                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 799                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 800                 diff_rev.diffopt.format_callback_data = changed;
 801                 diff_tree_combined_merge(commit, 1, &diff_rev);
 802         }
 803
 804         reset_revision_walk();
 805 }
 806
 807 static void free_submodules_oids(struct string_list *submodules)
 808 {
 809         struct string_list_item *item;
 810         for_each_string_list_item(item, submodules)
 811                 oid_array_clear((struct oid_array *) item->util);
 812         string_list_clear(submodules, 1);
 813 }
 814
 815 static int has_remote(const char *refname, const struct object_id *oid,
 816                       int flags, void *cb_data)
 817 {
 818         return 1;
 819 }
 820
 821 static int append_oid_to_argv(const struct object_id *oid, void *data)
 822 {
 823         struct argv_array *argv = data;
 824         argv_array_push(argv, oid_to_hex(oid));
 825         return 0;
 826 }
 827
 828 static int check_has_commit(const struct object_id *oid, void *data)
 829 {
 830         int *has_commit = data;
 831
 832         if (!lookup_commit_reference(oid))
 833                 *has_commit = 0;
 834
 835         return 0;
 836 }
 837
 838 static int submodule_has_commits(const char *path, struct oid_array *commits)
 839 {
 840         int has_commit = 1;
 841
 842         /*
 843          * Perform a cheap, but incorrect check for the existence of 'commits'.
 844          * This is done by adding the submodule's object store to the in-core
 845          * object store, and then querying for each commit's existence.  If we
 846          * do not have the commit object anywhere, there is no chance we have
 847          * it in the object store of the correct submodule and have it
 848          * reachable from a ref, so we can fail early without spawning rev-list
 849          * which is expensive.
 850          */
 851         if (add_submodule_odb(path))
 852                 return 0;
 853
 854         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 855
 856         if (has_commit) {
 857                 /*
 858                  * Even if the submodule is checked out and the commit is
 859                  * present, make sure it exists in the submodule's object store
 860                  * and that it is reachable from a ref.
 861                  */
 862                 struct child_process cp = CHILD_PROCESS_INIT;
 863                 struct strbuf out = STRBUF_INIT;
 864
 865                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 866                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 867                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 868
 869                 prepare_submodule_repo_env(&cp.env_array);
 870                 cp.git_cmd = 1;
 871                 cp.no_stdin = 1;
 872                 cp.dir = path;
 873
 874                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 875                         has_commit = 0;
 876
 877                 strbuf_release(&out);
 878         }
 879
 880         return has_commit;
 881 }
 882
 883 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
 884 {
 885         if (!submodule_has_commits(path, commits))
 886                 /*
 887                  * NOTE: We do consider it safe to return "no" here. The
 888                  * correct answer would be "We do not know" instead of
 889                  * "No push needed", but it is quite hard to change
 890                  * the submodule pointer without having the submodule
 891                  * around. If a user did however change the submodules
 892                  * without having the submodule around, this indicates
 893                  * an expert who knows what they are doing or a
 894                  * maintainer integrating work from other people. In
 895                  * both cases it should be safe to skip this check.
 896                  */
 897                 return 0;
 898
 899         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 900                 struct child_process cp = CHILD_PROCESS_INIT;
 901                 struct strbuf buf = STRBUF_INIT;
 902                 int needs_pushing = 0;
 903
 904                 argv_array_push(&cp.args, "rev-list");
 905                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 906                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 907
 908                 prepare_submodule_repo_env(&cp.env_array);
 909                 cp.git_cmd = 1;
 910                 cp.no_stdin = 1;
 911                 cp.out = -1;
 912                 cp.dir = path;
 913                 if (start_command(&cp))
 914                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 915                                         path);
 916                 if (strbuf_read(&buf, cp.out, 41))
 917                         needs_pushing = 1;
 918                 finish_command(&cp);
 919                 close(cp.out);
 920                 strbuf_release(&buf);
 921                 return needs_pushing;
 922         }
 923
 924         return 0;
 925 }
 926
 927 int find_unpushed_submodules(struct oid_array *commits,
 928                 const char *remotes_name, struct string_list *needs_pushing)
 929 {
 930         struct string_list submodules = STRING_LIST_INIT_DUP;
 931         struct string_list_item *submodule;
 932         struct argv_array argv = ARGV_ARRAY_INIT;
 933
 934         /* argv.argv[0] will be ignored by setup_revisions */
 935         argv_array_push(&argv, "find_unpushed_submodules");
 936         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
 937         argv_array_push(&argv, "--not");
 938         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
 939
 940         collect_changed_submodules(&submodules, &argv);
 941
 942         for_each_string_list_item(submodule, &submodules) {
 943                 struct oid_array *commits = submodule->util;
 944                 const char *path = submodule->string;
 945
 946                 if (submodule_needs_pushing(path, commits))
 947                         string_list_insert(needs_pushing, path);
 948         }
 949
 950         free_submodules_oids(&submodules);
 951         argv_array_clear(&argv);
 952
 953         return needs_pushing->nr;
 954 }
 955
 956 static int push_submodule(const char *path,
 957                           const struct remote *remote,
 958                           const char **refspec, int refspec_nr,
 959                           const struct string_list *push_options,
 960                           int dry_run)
 961 {
 962         if (add_submodule_odb(path))
 963                 return 1;
 964
 965         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 966                 struct child_process cp = CHILD_PROCESS_INIT;
 967                 argv_array_push(&cp.args, "push");
 968                 if (dry_run)
 969                         argv_array_push(&cp.args, "--dry-run");
 970
 971                 if (push_options && push_options->nr) {
 972                         const struct string_list_item *item;
 973                         for_each_string_list_item(item, push_options)
 974                                 argv_array_pushf(&cp.args, "--push-option=%s",
 975                                                  item->string);
 976                 }
 977
 978                 if (remote->origin != REMOTE_UNCONFIGURED) {
 979                         int i;
 980                         argv_array_push(&cp.args, remote->name);
 981                         for (i = 0; i < refspec_nr; i++)
 982                                 argv_array_push(&cp.args, refspec[i]);
 983                 }
 984
 985                 prepare_submodule_repo_env(&cp.env_array);
 986                 cp.git_cmd = 1;
 987                 cp.no_stdin = 1;
 988                 cp.dir = path;
 989                 if (run_command(&cp))
 990                         return 0;
 991                 close(cp.out);
 992         }
 993
 994         return 1;
 995 }
 996
 997 /*
 998  * Perform a check in the submodule to see if the remote and refspec work.
 999  * Die if the submodule can't be pushed.
1000  */
1001 static void submodule_push_check(const char *path, const char *head,
1002                                  const struct remote *remote,
1003                                  const char **refspec, int refspec_nr)
1004 {
1005         struct child_process cp = CHILD_PROCESS_INIT;
1006         int i;
1007
1008         argv_array_push(&cp.args, "submodule--helper");
1009         argv_array_push(&cp.args, "push-check");
1010         argv_array_push(&cp.args, head);
1011         argv_array_push(&cp.args, remote->name);
1012
1013         for (i = 0; i < refspec_nr; i++)
1014                 argv_array_push(&cp.args, refspec[i]);
1015
1016         prepare_submodule_repo_env(&cp.env_array);
1017         cp.git_cmd = 1;
1018         cp.no_stdin = 1;
1019         cp.no_stdout = 1;
1020         cp.dir = path;
1021
1022         /*
1023          * Simply indicate if 'submodule--helper push-check' failed.
1024          * More detailed error information will be provided by the
1025          * child process.
1026          */
1027         if (run_command(&cp))
1028                 die("process for submodule '%s' failed", path);
1029 }
1030
1031 int push_unpushed_submodules(struct oid_array *commits,
1032                              const struct remote *remote,
1033                              const char **refspec, int refspec_nr,
1034                              const struct string_list *push_options,
1035                              int dry_run)
1036 {
1037         int i, ret = 1;
1038         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1039
1040         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1041                 return 1;
1042
1043         /*
1044          * Verify that the remote and refspec can be propagated to all
1045          * submodules.  This check can be skipped if the remote and refspec
1046          * won't be propagated due to the remote being unconfigured (e.g. a URL
1047          * instead of a remote name).
1048          */
1049         if (remote->origin != REMOTE_UNCONFIGURED) {
1050                 char *head;
1051                 struct object_id head_oid;
1052
1053                 head = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
1054                 if (!head)
1055                         die(_("Failed to resolve HEAD as a valid ref."));
1056
1057                 for (i = 0; i < needs_pushing.nr; i++)
1058                         submodule_push_check(needs_pushing.items[i].string,
1059                                              head, remote,
1060                                              refspec, refspec_nr);
1061                 free(head);
1062         }
1063
1064         /* Actually push the submodules */
1065         for (i = 0; i < needs_pushing.nr; i++) {
1066                 const char *path = needs_pushing.items[i].string;
1067                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1068                 if (!push_submodule(path, remote, refspec, refspec_nr,
1069                                     push_options, dry_run)) {
1070                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1071                         ret = 0;
1072                 }
1073         }
1074
1075         string_list_clear(&needs_pushing, 0);
1076
1077         return ret;
1078 }
1079
1080 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1081                                int flags, void *data)
1082 {
1083         struct oid_array *array = data;
1084         oid_array_append(array, oid);
1085         return 0;
1086 }
1087
1088 void check_for_new_submodule_commits(struct object_id *oid)
1089 {
1090         if (!initialized_fetch_ref_tips) {
1091                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1092                 initialized_fetch_ref_tips = 1;
1093         }
1094
1095         oid_array_append(&ref_tips_after_fetch, oid);
1096 }
1097
1098 static void calculate_changed_submodule_paths(void)
1099 {
1100         struct argv_array argv = ARGV_ARRAY_INIT;
1101         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1102         const struct string_list_item *item;
1103
1104         /* No need to check if there are no submodules configured */
1105         if (!submodule_from_path(NULL, NULL))
1106                 return;
1107
1108         argv_array_push(&argv, "--"); /* argv[0] program name */
1109         oid_array_for_each_unique(&ref_tips_after_fetch,
1110                                    append_oid_to_argv, &argv);
1111         argv_array_push(&argv, "--not");
1112         oid_array_for_each_unique(&ref_tips_before_fetch,
1113                                    append_oid_to_argv, &argv);
1114
1115         /*
1116          * Collect all submodules (whether checked out or not) for which new
1117          * commits have been recorded upstream in "changed_submodule_paths".
1118          */
1119         collect_changed_submodules(&changed_submodules, &argv);
1120
1121         for_each_string_list_item(item, &changed_submodules) {
1122                 struct oid_array *commits = item->util;
1123                 const char *path = item->string;
1124
1125                 if (!submodule_has_commits(path, commits))
1126                         string_list_append(&changed_submodule_paths, path);
1127         }
1128
1129         free_submodules_oids(&changed_submodules);
1130         argv_array_clear(&argv);
1131         oid_array_clear(&ref_tips_before_fetch);
1132         oid_array_clear(&ref_tips_after_fetch);
1133         initialized_fetch_ref_tips = 0;
1134 }
1135
1136 int submodule_touches_in_range(struct object_id *excl_oid,
1137                                struct object_id *incl_oid)
1138 {
1139         struct string_list subs = STRING_LIST_INIT_DUP;
1140         struct argv_array args = ARGV_ARRAY_INIT;
1141         int ret;
1142
1143         gitmodules_config();
1144         /* No need to check if there are no submodules configured */
1145         if (!submodule_from_path(NULL, NULL))
1146                 return 0;
1147
1148         argv_array_push(&args, "--"); /* args[0] program name */
1149         argv_array_push(&args, oid_to_hex(incl_oid));
1150         argv_array_push(&args, "--not");
1151         argv_array_push(&args, oid_to_hex(excl_oid));
1152
1153         collect_changed_submodules(&subs, &args);
1154         ret = subs.nr;
1155
1156         argv_array_clear(&args);
1157
1158         free_submodules_oids(&subs);
1159         return ret;
1160 }
1161
1162 struct submodule_parallel_fetch {
1163         int count;
1164         struct argv_array args;
1165         const char *work_tree;
1166         const char *prefix;
1167         int command_line_option;
1168         int default_option;
1169         int quiet;
1170         int result;
1171 };
1172 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0}
1173
1174 static int get_next_submodule(struct child_process *cp,
1175                               struct strbuf *err, void *data, void **task_cb)
1176 {
1177         int ret = 0;
1178         struct submodule_parallel_fetch *spf = data;
1179
1180         for (; spf->count < active_nr; spf->count++) {
1181                 struct strbuf submodule_path = STRBUF_INIT;
1182                 struct strbuf submodule_git_dir = STRBUF_INIT;
1183                 struct strbuf submodule_prefix = STRBUF_INIT;
1184                 const struct cache_entry *ce = active_cache[spf->count];
1185                 const char *git_dir, *default_argv;
1186                 const struct submodule *submodule;
1187
1188                 if (!S_ISGITLINK(ce->ce_mode))
1189                         continue;
1190
1191                 submodule = submodule_from_path(&null_oid, ce->name);
1192                 if (!submodule)
1193                         submodule = submodule_from_name(&null_oid, ce->name);
1194
1195                 default_argv = "yes";
1196                 if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
1197                         if (submodule &&
1198                             submodule->fetch_recurse !=
1199                                                 RECURSE_SUBMODULES_NONE) {
1200                                 if (submodule->fetch_recurse ==
1201                                                 RECURSE_SUBMODULES_OFF)
1202                                         continue;
1203                                 if (submodule->fetch_recurse ==
1204                                                 RECURSE_SUBMODULES_ON_DEMAND) {
1205                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1206                                                 continue;
1207                                         default_argv = "on-demand";
1208                                 }
1209                         } else {
1210                                 if (spf->default_option == RECURSE_SUBMODULES_OFF)
1211                                         continue;
1212                                 if (spf->default_option == RECURSE_SUBMODULES_ON_DEMAND) {
1213                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1214                                                 continue;
1215                                         default_argv = "on-demand";
1216                                 }
1217                         }
1218                 } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
1219                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1220                                 continue;
1221                         default_argv = "on-demand";
1222                 }
1223
1224                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1225                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1226                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1227                 git_dir = read_gitfile(submodule_git_dir.buf);
1228                 if (!git_dir)
1229                         git_dir = submodule_git_dir.buf;
1230                 if (is_directory(git_dir)) {
1231                         child_process_init(cp);
1232                         cp->dir = strbuf_detach(&submodule_path, NULL);
1233                         prepare_submodule_repo_env(&cp->env_array);
1234                         cp->git_cmd = 1;
1235                         if (!spf->quiet)
1236                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1237                                             spf->prefix, ce->name);
1238                         argv_array_init(&cp->args);
1239                         argv_array_pushv(&cp->args, spf->args.argv);
1240                         argv_array_push(&cp->args, default_argv);
1241                         argv_array_push(&cp->args, "--submodule-prefix");
1242                         argv_array_push(&cp->args, submodule_prefix.buf);
1243                         ret = 1;
1244                 }
1245                 strbuf_release(&submodule_path);
1246                 strbuf_release(&submodule_git_dir);
1247                 strbuf_release(&submodule_prefix);
1248                 if (ret) {
1249                         spf->count++;
1250                         return 1;
1251                 }
1252         }
1253         return 0;
1254 }
1255
1256 static int fetch_start_failure(struct strbuf *err,
1257                                void *cb, void *task_cb)
1258 {
1259         struct submodule_parallel_fetch *spf = cb;
1260
1261         spf->result = 1;
1262
1263         return 0;
1264 }
1265
1266 static int fetch_finish(int retvalue, struct strbuf *err,
1267                         void *cb, void *task_cb)
1268 {
1269         struct submodule_parallel_fetch *spf = cb;
1270
1271         if (retvalue)
1272                 spf->result = 1;
1273
1274         return 0;
1275 }
1276
1277 int fetch_populated_submodules(const struct argv_array *options,
1278                                const char *prefix, int command_line_option,
1279                                int default_option,
1280                                int quiet, int max_parallel_jobs)
1281 {
1282         int i;
1283         struct submodule_parallel_fetch spf = SPF_INIT;
1284
1285         spf.work_tree = get_git_work_tree();
1286         spf.command_line_option = command_line_option;
1287         spf.default_option = default_option;
1288         spf.quiet = quiet;
1289         spf.prefix = prefix;
1290
1291         if (!spf.work_tree)
1292                 goto out;
1293
1294         if (read_cache() < 0)
1295                 die("index file corrupt");
1296
1297         argv_array_push(&spf.args, "fetch");
1298         for (i = 0; i < options->argc; i++)
1299                 argv_array_push(&spf.args, options->argv[i]);
1300         argv_array_push(&spf.args, "--recurse-submodules-default");
1301         /* default value, "--submodule-prefix" and its value are added later */
1302
1303         calculate_changed_submodule_paths();
1304         run_processes_parallel(max_parallel_jobs,
1305                                get_next_submodule,
1306                                fetch_start_failure,
1307                                fetch_finish,
1308                                &spf);
1309
1310         argv_array_clear(&spf.args);
1311 out:
1312         string_list_clear(&changed_submodule_paths, 1);
1313         return spf.result;
1314 }
1315
1316 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1317 {
1318         struct child_process cp = CHILD_PROCESS_INIT;
1319         struct strbuf buf = STRBUF_INIT;
1320         FILE *fp;
1321         unsigned dirty_submodule = 0;
1322         const char *git_dir;
1323         int ignore_cp_exit_code = 0;
1324
1325         strbuf_addf(&buf, "%s/.git", path);
1326         git_dir = read_gitfile(buf.buf);
1327         if (!git_dir)
1328                 git_dir = buf.buf;
1329         if (!is_git_directory(git_dir)) {
1330                 if (is_directory(git_dir))
1331                         die(_("'%s' not recognized as a git repository"), git_dir);
1332                 strbuf_release(&buf);
1333                 /* The submodule is not checked out, so it is not modified */
1334                 return 0;
1335         }
1336         strbuf_reset(&buf);
1337
1338         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1339         if (ignore_untracked)
1340                 argv_array_push(&cp.args, "-uno");
1341
1342         prepare_submodule_repo_env(&cp.env_array);
1343         cp.git_cmd = 1;
1344         cp.no_stdin = 1;
1345         cp.out = -1;
1346         cp.dir = path;
1347         if (start_command(&cp))
1348                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1349
1350         fp = xfdopen(cp.out, "r");
1351         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1352                 /* regular untracked files */
1353                 if (buf.buf[0] == '?')
1354                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1355
1356                 if (buf.buf[0] == 'u' ||
1357                     buf.buf[0] == '1' ||
1358                     buf.buf[0] == '2') {
1359                         /* T = line type, XY = status, SSSS = submodule state */
1360                         if (buf.len < strlen("T XY SSSS"))
1361                                 die("BUG: invalid status --porcelain=2 line %s",
1362                                     buf.buf);
1363
1364                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1365                                 /* nested untracked file */
1366                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1367
1368                         if (buf.buf[0] == 'u' ||
1369                             buf.buf[0] == '2' ||
1370                             memcmp(buf.buf + 5, "S..U", 4))
1371                                 /* other change */
1372                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1373                 }
1374
1375                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1376                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1377                      ignore_untracked)) {
1378                         /*
1379                          * We're not interested in any further information from
1380                          * the child any more, neither output nor its exit code.
1381                          */
1382                         ignore_cp_exit_code = 1;
1383                         break;
1384                 }
1385         }
1386         fclose(fp);
1387
1388         if (finish_command(&cp) && !ignore_cp_exit_code)
1389                 die("'git status --porcelain=2' failed in submodule %s", path);
1390
1391         strbuf_release(&buf);
1392         return dirty_submodule;
1393 }
1394
1395 int submodule_uses_gitfile(const char *path)
1396 {
1397         struct child_process cp = CHILD_PROCESS_INIT;
1398         const char *argv[] = {
1399                 "submodule",
1400                 "foreach",
1401                 "--quiet",
1402                 "--recursive",
1403                 "test -f .git",
1404                 NULL,
1405         };
1406         struct strbuf buf = STRBUF_INIT;
1407         const char *git_dir;
1408
1409         strbuf_addf(&buf, "%s/.git", path);
1410         git_dir = read_gitfile(buf.buf);
1411         if (!git_dir) {
1412                 strbuf_release(&buf);
1413                 return 0;
1414         }
1415         strbuf_release(&buf);
1416
1417         /* Now test that all nested submodules use a gitfile too */
1418         cp.argv = argv;
1419         prepare_submodule_repo_env(&cp.env_array);
1420         cp.git_cmd = 1;
1421         cp.no_stdin = 1;
1422         cp.no_stderr = 1;
1423         cp.no_stdout = 1;
1424         cp.dir = path;
1425         if (run_command(&cp))
1426                 return 0;
1427
1428         return 1;
1429 }
1430
1431 /*
1432  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1433  * when doing so.
1434  *
1435  * Return 1 if we'd lose data, return 0 if the removal is fine,
1436  * and negative values for errors.
1437  */
1438 int bad_to_remove_submodule(const char *path, unsigned flags)
1439 {
1440         ssize_t len;
1441         struct child_process cp = CHILD_PROCESS_INIT;
1442         struct strbuf buf = STRBUF_INIT;
1443         int ret = 0;
1444
1445         if (!file_exists(path) || is_empty_dir(path))
1446                 return 0;
1447
1448         if (!submodule_uses_gitfile(path))
1449                 return 1;
1450
1451         argv_array_pushl(&cp.args, "status", "--porcelain",
1452                                    "--ignore-submodules=none", NULL);
1453
1454         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1455                 argv_array_push(&cp.args, "-uno");
1456         else
1457                 argv_array_push(&cp.args, "-uall");
1458
1459         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1460                 argv_array_push(&cp.args, "--ignored");
1461
1462         prepare_submodule_repo_env(&cp.env_array);
1463         cp.git_cmd = 1;
1464         cp.no_stdin = 1;
1465         cp.out = -1;
1466         cp.dir = path;
1467         if (start_command(&cp)) {
1468                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1469                         die(_("could not start 'git status' in submodule '%s'"),
1470                                 path);
1471                 ret = -1;
1472                 goto out;
1473         }
1474
1475         len = strbuf_read(&buf, cp.out, 1024);
1476         if (len > 2)
1477                 ret = 1;
1478         close(cp.out);
1479
1480         if (finish_command(&cp)) {
1481                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1482                         die(_("could not run 'git status' in submodule '%s'"),
1483                                 path);
1484                 ret = -1;
1485         }
1486 out:
1487         strbuf_release(&buf);
1488         return ret;
1489 }
1490
1491 static const char *get_super_prefix_or_empty(void)
1492 {
1493         const char *s = get_super_prefix();
1494         if (!s)
1495                 s = "";
1496         return s;
1497 }
1498
1499 static int submodule_has_dirty_index(const struct submodule *sub)
1500 {
1501         struct child_process cp = CHILD_PROCESS_INIT;
1502
1503         prepare_submodule_repo_env(&cp.env_array);
1504
1505         cp.git_cmd = 1;
1506         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1507                                    "--cached", "HEAD", NULL);
1508         cp.no_stdin = 1;
1509         cp.no_stdout = 1;
1510         cp.dir = sub->path;
1511         if (start_command(&cp))
1512                 die("could not recurse into submodule '%s'", sub->path);
1513
1514         return finish_command(&cp);
1515 }
1516
1517 static void submodule_reset_index(const char *path)
1518 {
1519         struct child_process cp = CHILD_PROCESS_INIT;
1520         prepare_submodule_repo_env(&cp.env_array);
1521
1522         cp.git_cmd = 1;
1523         cp.no_stdin = 1;
1524         cp.dir = path;
1525
1526         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1527                                    get_super_prefix_or_empty(), path);
1528         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1529
1530         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1531
1532         if (run_command(&cp))
1533                 die("could not reset submodule index");
1534 }
1535
1536 /**
1537  * Moves a submodule at a given path from a given head to another new head.
1538  * For edge cases (a submodule coming into existence or removing a submodule)
1539  * pass NULL for old or new respectively.
1540  */
1541 int submodule_move_head(const char *path,
1542                          const char *old,
1543                          const char *new,
1544                          unsigned flags)
1545 {
1546         int ret = 0;
1547         struct child_process cp = CHILD_PROCESS_INIT;
1548         const struct submodule *sub;
1549         int *error_code_ptr, error_code;
1550
1551         if (!is_submodule_active(the_repository, path))
1552                 return 0;
1553
1554         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1555                 /*
1556                  * Pass non NULL pointer to is_submodule_populated_gently
1557                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1558                  * to fixup the submodule in the force case later.
1559                  */
1560                 error_code_ptr = &error_code;
1561         else
1562                 error_code_ptr = NULL;
1563
1564         if (old && !is_submodule_populated_gently(path, error_code_ptr))
1565                 return 0;
1566
1567         sub = submodule_from_path(&null_oid, path);
1568
1569         if (!sub)
1570                 die("BUG: could not get submodule information for '%s'", path);
1571
1572         if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1573                 /* Check if the submodule has a dirty index. */
1574                 if (submodule_has_dirty_index(sub))
1575                         return error(_("submodule '%s' has dirty index"), path);
1576         }
1577
1578         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1579                 if (old) {
1580                         if (!submodule_uses_gitfile(path))
1581                                 absorb_git_dir_into_superproject("", path,
1582                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1583                 } else {
1584                         char *gitdir = xstrfmt("%s/modules/%s",
1585                                     get_git_common_dir(), sub->name);
1586                         connect_work_tree_and_git_dir(path, gitdir);
1587                         free(gitdir);
1588
1589                         /* make sure the index is clean as well */
1590                         submodule_reset_index(path);
1591                 }
1592
1593                 if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1594                         char *gitdir = xstrfmt("%s/modules/%s",
1595                                     get_git_common_dir(), sub->name);
1596                         connect_work_tree_and_git_dir(path, gitdir);
1597                         free(gitdir);
1598                 }
1599         }
1600
1601         prepare_submodule_repo_env(&cp.env_array);
1602
1603         cp.git_cmd = 1;
1604         cp.no_stdin = 1;
1605         cp.dir = path;
1606
1607         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1608                         get_super_prefix_or_empty(), path);
1609         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1610
1611         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1612                 argv_array_push(&cp.args, "-n");
1613         else
1614                 argv_array_push(&cp.args, "-u");
1615
1616         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1617                 argv_array_push(&cp.args, "--reset");
1618         else
1619                 argv_array_push(&cp.args, "-m");
1620
1621         argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1622         argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1623
1624         if (run_command(&cp)) {
1625                 ret = -1;
1626                 goto out;
1627         }
1628
1629         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1630                 if (new) {
1631                         child_process_init(&cp);
1632                         /* also set the HEAD accordingly */
1633                         cp.git_cmd = 1;
1634                         cp.no_stdin = 1;
1635                         cp.dir = path;
1636
1637                         prepare_submodule_repo_env(&cp.env_array);
1638                         argv_array_pushl(&cp.args, "update-ref", "HEAD", new, NULL);
1639
1640                         if (run_command(&cp)) {
1641                                 ret = -1;
1642                                 goto out;
1643                         }
1644                 } else {
1645                         struct strbuf sb = STRBUF_INIT;
1646
1647                         strbuf_addf(&sb, "%s/.git", path);
1648                         unlink_or_warn(sb.buf);
1649                         strbuf_release(&sb);
1650
1651                         if (is_empty_dir(path))
1652                                 rmdir_or_warn(path);
1653                 }
1654         }
1655 out:
1656         return ret;
1657 }
1658
1659 static int find_first_merges(struct object_array *result, const char *path,
1660                 struct commit *a, struct commit *b)
1661 {
1662         int i, j;
1663         struct object_array merges = OBJECT_ARRAY_INIT;
1664         struct commit *commit;
1665         int contains_another;
1666
1667         char merged_revision[42];
1668         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1669                                    "--all", merged_revision, NULL };
1670         struct rev_info revs;
1671         struct setup_revision_opt rev_opts;
1672
1673         memset(result, 0, sizeof(struct object_array));
1674         memset(&rev_opts, 0, sizeof(rev_opts));
1675
1676         /* get all revisions that merge commit a */
1677         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1678                         oid_to_hex(&a->object.oid));
1679         init_revisions(&revs, NULL);
1680         rev_opts.submodule = path;
1681         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1682
1683         /* save all revisions from the above list that contain b */
1684         if (prepare_revision_walk(&revs))
1685                 die("revision walk setup failed");
1686         while ((commit = get_revision(&revs)) != NULL) {
1687                 struct object *o = &(commit->object);
1688                 if (in_merge_bases(b, commit))
1689                         add_object_array(o, NULL, &merges);
1690         }
1691         reset_revision_walk();
1692
1693         /* Now we've got all merges that contain a and b. Prune all
1694          * merges that contain another found merge and save them in
1695          * result.
1696          */
1697         for (i = 0; i < merges.nr; i++) {
1698                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1699
1700                 contains_another = 0;
1701                 for (j = 0; j < merges.nr; j++) {
1702                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1703                         if (i != j && in_merge_bases(m2, m1)) {
1704                                 contains_another = 1;
1705                                 break;
1706                         }
1707                 }
1708
1709                 if (!contains_another)
1710                         add_object_array(merges.objects[i].item, NULL, result);
1711         }
1712
1713         free(merges.objects);
1714         return result->nr;
1715 }
1716
1717 static void print_commit(struct commit *commit)
1718 {
1719         struct strbuf sb = STRBUF_INIT;
1720         struct pretty_print_context ctx = {0};
1721         ctx.date_mode.type = DATE_NORMAL;
1722         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1723         fprintf(stderr, "%s\n", sb.buf);
1724         strbuf_release(&sb);
1725 }
1726
1727 #define MERGE_WARNING(path, msg) \
1728         warning("Failed to merge submodule %s (%s)", path, msg);
1729
1730 int merge_submodule(struct object_id *result, const char *path,
1731                     const struct object_id *base, const struct object_id *a,
1732                     const struct object_id *b, int search)
1733 {
1734         struct commit *commit_base, *commit_a, *commit_b;
1735         int parent_count;
1736         struct object_array merges;
1737
1738         int i;
1739
1740         /* store a in result in case we fail */
1741         oidcpy(result, a);
1742
1743         /* we can not handle deletion conflicts */
1744         if (is_null_oid(base))
1745                 return 0;
1746         if (is_null_oid(a))
1747                 return 0;
1748         if (is_null_oid(b))
1749                 return 0;
1750
1751         if (add_submodule_odb(path)) {
1752                 MERGE_WARNING(path, "not checked out");
1753                 return 0;
1754         }
1755
1756         if (!(commit_base = lookup_commit_reference(base)) ||
1757             !(commit_a = lookup_commit_reference(a)) ||
1758             !(commit_b = lookup_commit_reference(b))) {
1759                 MERGE_WARNING(path, "commits not present");
1760                 return 0;
1761         }
1762
1763         /* check whether both changes are forward */
1764         if (!in_merge_bases(commit_base, commit_a) ||
1765             !in_merge_bases(commit_base, commit_b)) {
1766                 MERGE_WARNING(path, "commits don't follow merge-base");
1767                 return 0;
1768         }
1769
1770         /* Case #1: a is contained in b or vice versa */
1771         if (in_merge_bases(commit_a, commit_b)) {
1772                 oidcpy(result, b);
1773                 return 1;
1774         }
1775         if (in_merge_bases(commit_b, commit_a)) {
1776                 oidcpy(result, a);
1777                 return 1;
1778         }
1779
1780         /*
1781          * Case #2: There are one or more merges that contain a and b in
1782          * the submodule. If there is only one, then present it as a
1783          * suggestion to the user, but leave it marked unmerged so the
1784          * user needs to confirm the resolution.
1785          */
1786
1787         /* Skip the search if makes no sense to the calling context.  */
1788         if (!search)
1789                 return 0;
1790
1791         /* find commit which merges them */
1792         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1793         switch (parent_count) {
1794         case 0:
1795                 MERGE_WARNING(path, "merge following commits not found");
1796                 break;
1797
1798         case 1:
1799                 MERGE_WARNING(path, "not fast-forward");
1800                 fprintf(stderr, "Found a possible merge resolution "
1801                                 "for the submodule:\n");
1802                 print_commit((struct commit *) merges.objects[0].item);
1803                 fprintf(stderr,
1804                         "If this is correct simply add it to the index "
1805                         "for example\n"
1806                         "by using:\n\n"
1807                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1808                         "which will accept this suggestion.\n",
1809                         oid_to_hex(&merges.objects[0].item->oid), path);
1810                 break;
1811
1812         default:
1813                 MERGE_WARNING(path, "multiple merges found");
1814                 for (i = 0; i < merges.nr; i++)
1815                         print_commit((struct commit *) merges.objects[i].item);
1816         }
1817
1818         free(merges.objects);
1819         return 0;
1820 }
1821
1822 /*
1823  * Embeds a single submodules git directory into the superprojects git dir,
1824  * non recursively.
1825  */
1826 static void relocate_single_git_dir_into_superproject(const char *prefix,
1827                                                       const char *path)
1828 {
1829         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1830         const char *new_git_dir;
1831         const struct submodule *sub;
1832
1833         if (submodule_uses_worktrees(path))
1834                 die(_("relocate_gitdir for submodule '%s' with "
1835                       "more than one worktree not supported"), path);
1836
1837         old_git_dir = xstrfmt("%s/.git", path);
1838         if (read_gitfile(old_git_dir))
1839                 /* If it is an actual gitfile, it doesn't need migration. */
1840                 return;
1841
1842         real_old_git_dir = real_pathdup(old_git_dir, 1);
1843
1844         sub = submodule_from_path(&null_oid, path);
1845         if (!sub)
1846                 die(_("could not lookup name for submodule '%s'"), path);
1847
1848         new_git_dir = git_path("modules/%s", sub->name);
1849         if (safe_create_leading_directories_const(new_git_dir) < 0)
1850                 die(_("could not create directory '%s'"), new_git_dir);
1851         real_new_git_dir = real_pathdup(new_git_dir, 1);
1852
1853         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1854                 get_super_prefix_or_empty(), path,
1855                 real_old_git_dir, real_new_git_dir);
1856
1857         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1858
1859         free(old_git_dir);
1860         free(real_old_git_dir);
1861         free(real_new_git_dir);
1862 }
1863
1864 /*
1865  * Migrate the git directory of the submodule given by path from
1866  * having its git directory within the working tree to the git dir nested
1867  * in its superprojects git dir under modules/.
1868  */
1869 void absorb_git_dir_into_superproject(const char *prefix,
1870                                       const char *path,
1871                                       unsigned flags)
1872 {
1873         int err_code;
1874         const char *sub_git_dir;
1875         struct strbuf gitdir = STRBUF_INIT;
1876         strbuf_addf(&gitdir, "%s/.git", path);
1877         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1878
1879         /* Not populated? */
1880         if (!sub_git_dir) {
1881                 const struct submodule *sub;
1882
1883                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1884                         /* unpopulated as expected */
1885                         strbuf_release(&gitdir);
1886                         return;
1887                 }
1888
1889                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1890                         /* We don't know what broke here. */
1891                         read_gitfile_error_die(err_code, path, NULL);
1892
1893                 /*
1894                 * Maybe populated, but no git directory was found?
1895                 * This can happen if the superproject is a submodule
1896                 * itself and was just absorbed. The absorption of the
1897                 * superproject did not rewrite the git file links yet,
1898                 * fix it now.
1899                 */
1900                 sub = submodule_from_path(&null_oid, path);
1901                 if (!sub)
1902                         die(_("could not lookup name for submodule '%s'"), path);
1903                 connect_work_tree_and_git_dir(path,
1904                         git_path("modules/%s", sub->name));
1905         } else {
1906                 /* Is it already absorbed into the superprojects git dir? */
1907                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1908                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1909
1910                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1911                         relocate_single_git_dir_into_superproject(prefix, path);
1912
1913                 free(real_sub_git_dir);
1914                 free(real_common_git_dir);
1915         }
1916         strbuf_release(&gitdir);
1917
1918         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1919                 struct child_process cp = CHILD_PROCESS_INIT;
1920                 struct strbuf sb = STRBUF_INIT;
1921
1922                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1923                         die("BUG: we don't know how to pass the flags down?");
1924
1925                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1926                 strbuf_addstr(&sb, path);
1927                 strbuf_addch(&sb, '/');
1928
1929                 cp.dir = path;
1930                 cp.git_cmd = 1;
1931                 cp.no_stdin = 1;
1932                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1933                                            "submodule--helper",
1934                                            "absorb-git-dirs", NULL);
1935                 prepare_submodule_repo_env(&cp.env_array);
1936                 if (run_command(&cp))
1937                         die(_("could not recurse into submodule '%s'"), path);
1938
1939                 strbuf_release(&sb);
1940         }
1941 }
1942
1943 const char *get_superproject_working_tree(void)
1944 {
1945         struct child_process cp = CHILD_PROCESS_INIT;
1946         struct strbuf sb = STRBUF_INIT;
1947         const char *one_up = real_path_if_valid("../");
1948         const char *cwd = xgetcwd();
1949         const char *ret = NULL;
1950         const char *subpath;
1951         int code;
1952         ssize_t len;
1953
1954         if (!is_inside_work_tree())
1955                 /*
1956                  * FIXME:
1957                  * We might have a superproject, but it is harder
1958                  * to determine.
1959                  */
1960                 return NULL;
1961
1962         if (!one_up)
1963                 return NULL;
1964
1965         subpath = relative_path(cwd, one_up, &sb);
1966
1967         prepare_submodule_repo_env(&cp.env_array);
1968         argv_array_pop(&cp.env_array);
1969
1970         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
1971                         "ls-files", "-z", "--stage", "--full-name", "--",
1972                         subpath, NULL);
1973         strbuf_reset(&sb);
1974
1975         cp.no_stdin = 1;
1976         cp.no_stderr = 1;
1977         cp.out = -1;
1978         cp.git_cmd = 1;
1979
1980         if (start_command(&cp))
1981                 die(_("could not start ls-files in .."));
1982
1983         len = strbuf_read(&sb, cp.out, PATH_MAX);
1984         close(cp.out);
1985
1986         if (starts_with(sb.buf, "160000")) {
1987                 int super_sub_len;
1988                 int cwd_len = strlen(cwd);
1989                 char *super_sub, *super_wt;
1990
1991                 /*
1992                  * There is a superproject having this repo as a submodule.
1993                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
1994                  * We're only interested in the name after the tab.
1995                  */
1996                 super_sub = strchr(sb.buf, '\t') + 1;
1997                 super_sub_len = sb.buf + sb.len - super_sub - 1;
1998
1999                 if (super_sub_len > cwd_len ||
2000                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
2001                         die (_("BUG: returned path string doesn't match cwd?"));
2002
2003                 super_wt = xstrdup(cwd);
2004                 super_wt[cwd_len - super_sub_len] = '\0';
2005
2006                 ret = real_path(super_wt);
2007                 free(super_wt);
2008         }
2009         strbuf_release(&sb);
2010
2011         code = finish_command(&cp);
2012
2013         if (code == 128)
2014                 /* '../' is not a git repository */
2015                 return NULL;
2016         if (code == 0 && len == 0)
2017                 /* There is an unrelated git repository at '../' */
2018                 return NULL;
2019         if (code)
2020                 die(_("ls-tree returned unexpected return code %d"), code);
2021
2022         return ret;
2023 }
2024
2025 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2026 {
2027         const struct submodule *sub;
2028         const char *git_dir;
2029         int ret = 0;
2030
2031         strbuf_reset(buf);
2032         strbuf_addstr(buf, submodule);
2033         strbuf_complete(buf, '/');
2034         strbuf_addstr(buf, ".git");
2035
2036         git_dir = read_gitfile(buf->buf);
2037         if (git_dir) {
2038                 strbuf_reset(buf);
2039                 strbuf_addstr(buf, git_dir);
2040         }
2041         if (!is_git_directory(buf->buf)) {
2042                 gitmodules_config();
2043                 sub = submodule_from_path(&null_oid, submodule);
2044                 if (!sub) {
2045                         ret = -1;
2046                         goto cleanup;
2047                 }
2048                 strbuf_reset(buf);
2049                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2050         }
2051
2052 cleanup:
2053         return ret;
2054 }