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                 const char *ignore;
 169                 char *key;
 170
 171                 key = xstrfmt("submodule.%s.ignore", submodule->name);
 172                 if (repo_config_get_string_const(the_repository, key, &ignore))
 173                         ignore = submodule->ignore;
 174                 free(key);
 175
 176                 if (ignore)
 177                         handle_ignore_submodules_arg(diffopt, ignore);
 178                 else if (is_gitmodules_unmerged(&the_index))
 179                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 180         }
 181 }
 182
 183 /* Cheap function that only determines if we're interested in submodules at all */
 184 int git_default_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         }
 191         return 0;
 192 }
 193
 194 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 195                                                      const char *arg, int unset)
 196 {
 197         if (unset) {
 198                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 199                 return 0;
 200         }
 201         if (arg)
 202                 config_update_recurse_submodules =
 203                         parse_update_recurse_submodules_arg(opt->long_name,
 204                                                             arg);
 205         else
 206                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 207
 208         return 0;
 209 }
 210
 211 void load_submodule_cache(void)
 212 {
 213         if (config_update_recurse_submodules == RECURSE_SUBMODULES_OFF)
 214                 return;
 215
 216         gitmodules_config();
 217 }
 218
 219 static int gitmodules_cb(const char *var, const char *value, void *data)
 220 {
 221         struct repository *repo = data;
 222         return submodule_config_option(repo, var, value);
 223 }
 224
 225 void repo_read_gitmodules(struct repository *repo)
 226 {
 227         if (repo->worktree) {
 228                 char *gitmodules;
 229
 230                 if (repo_read_index(repo) < 0)
 231                         return;
 232
 233                 gitmodules = repo_worktree_path(repo, GITMODULES_FILE);
 234
 235                 if (!is_gitmodules_unmerged(repo->index))
 236                         git_config_from_file(gitmodules_cb, gitmodules, repo);
 237
 238                 free(gitmodules);
 239         }
 240 }
 241
 242 void gitmodules_config(void)
 243 {
 244         repo_read_gitmodules(the_repository);
 245 }
 246
 247 void gitmodules_config_oid(const struct object_id *commit_oid)
 248 {
 249         struct strbuf rev = STRBUF_INIT;
 250         struct object_id oid;
 251
 252         if (gitmodule_oid_from_commit(commit_oid, &oid, &rev)) {
 253                 git_config_from_blob_oid(gitmodules_cb, rev.buf,
 254                                          &oid, the_repository);
 255         }
 256         strbuf_release(&rev);
 257 }
 258
 259 /*
 260  * Determine if a submodule has been initialized at a given 'path'
 261  */
 262 int is_submodule_active(struct repository *repo, const char *path)
 263 {
 264         int ret = 0;
 265         char *key = NULL;
 266         char *value = NULL;
 267         const struct string_list *sl;
 268         const struct submodule *module;
 269
 270         module = submodule_from_cache(repo, &null_oid, path);
 271
 272         /* early return if there isn't a path->module mapping */
 273         if (!module)
 274                 return 0;
 275
 276         /* submodule.<name>.active is set */
 277         key = xstrfmt("submodule.%s.active", module->name);
 278         if (!repo_config_get_bool(repo, key, &ret)) {
 279                 free(key);
 280                 return ret;
 281         }
 282         free(key);
 283
 284         /* submodule.active is set */
 285         sl = repo_config_get_value_multi(repo, "submodule.active");
 286         if (sl) {
 287                 struct pathspec ps;
 288                 struct argv_array args = ARGV_ARRAY_INIT;
 289                 const struct string_list_item *item;
 290
 291                 for_each_string_list_item(item, sl) {
 292                         argv_array_push(&args, item->string);
 293                 }
 294
 295                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 296                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
 297
 298                 argv_array_clear(&args);
 299                 clear_pathspec(&ps);
 300                 return ret;
 301         }
 302
 303         /* fallback to checking if the URL is set */
 304         key = xstrfmt("submodule.%s.url", module->name);
 305         ret = !repo_config_get_string(repo, key, &value);
 306
 307         free(value);
 308         free(key);
 309         return ret;
 310 }
 311
 312 int is_submodule_populated_gently(const char *path, int *return_error_code)
 313 {
 314         int ret = 0;
 315         char *gitdir = xstrfmt("%s/.git", path);
 316
 317         if (resolve_gitdir_gently(gitdir, return_error_code))
 318                 ret = 1;
 319
 320         free(gitdir);
 321         return ret;
 322 }
 323
 324 /*
 325  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 326  */
 327 void die_in_unpopulated_submodule(const struct index_state *istate,
 328                                   const char *prefix)
 329 {
 330         int i, prefixlen;
 331
 332         if (!prefix)
 333                 return;
 334
 335         prefixlen = strlen(prefix);
 336
 337         for (i = 0; i < istate->cache_nr; i++) {
 338                 struct cache_entry *ce = istate->cache[i];
 339                 int ce_len = ce_namelen(ce);
 340
 341                 if (!S_ISGITLINK(ce->ce_mode))
 342                         continue;
 343                 if (prefixlen <= ce_len)
 344                         continue;
 345                 if (strncmp(ce->name, prefix, ce_len))
 346                         continue;
 347                 if (prefix[ce_len] != '/')
 348                         continue;
 349
 350                 die(_("in unpopulated submodule '%s'"), ce->name);
 351         }
 352 }
 353
 354 /*
 355  * Dies if any paths in the provided pathspec descends into a submodule
 356  */
 357 void die_path_inside_submodule(const struct index_state *istate,
 358                                const struct pathspec *ps)
 359 {
 360         int i, j;
 361
 362         for (i = 0; i < istate->cache_nr; i++) {
 363                 struct cache_entry *ce = istate->cache[i];
 364                 int ce_len = ce_namelen(ce);
 365
 366                 if (!S_ISGITLINK(ce->ce_mode))
 367                         continue;
 368
 369                 for (j = 0; j < ps->nr ; j++) {
 370                         const struct pathspec_item *item = &ps->items[j];
 371
 372                         if (item->len <= ce_len)
 373                                 continue;
 374                         if (item->match[ce_len] != '/')
 375                                 continue;
 376                         if (strncmp(ce->name, item->match, ce_len))
 377                                 continue;
 378                         if (item->len == ce_len + 1)
 379                                 continue;
 380
 381                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 382                             item->original, ce_len, ce->name);
 383                 }
 384         }
 385 }
 386
 387 enum submodule_update_type parse_submodule_update_type(const char *value)
 388 {
 389         if (!strcmp(value, "none"))
 390                 return SM_UPDATE_NONE;
 391         else if (!strcmp(value, "checkout"))
 392                 return SM_UPDATE_CHECKOUT;
 393         else if (!strcmp(value, "rebase"))
 394                 return SM_UPDATE_REBASE;
 395         else if (!strcmp(value, "merge"))
 396                 return SM_UPDATE_MERGE;
 397         else if (*value == '!')
 398                 return SM_UPDATE_COMMAND;
 399         else
 400                 return SM_UPDATE_UNSPECIFIED;
 401 }
 402
 403 int parse_submodule_update_strategy(const char *value,
 404                 struct submodule_update_strategy *dst)
 405 {
 406         enum submodule_update_type type;
 407
 408         free((void*)dst->command);
 409         dst->command = NULL;
 410
 411         type = parse_submodule_update_type(value);
 412         if (type == SM_UPDATE_UNSPECIFIED)
 413                 return -1;
 414
 415         dst->type = type;
 416         if (type == SM_UPDATE_COMMAND)
 417                 dst->command = xstrdup(value + 1);
 418
 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 struct remote *remote,
1002                                  const char **refspec, int refspec_nr)
1003 {
1004         struct child_process cp = CHILD_PROCESS_INIT;
1005         int i;
1006
1007         argv_array_push(&cp.args, "submodule--helper");
1008         argv_array_push(&cp.args, "push-check");
1009         argv_array_push(&cp.args, remote->name);
1010
1011         for (i = 0; i < refspec_nr; i++)
1012                 argv_array_push(&cp.args, refspec[i]);
1013
1014         prepare_submodule_repo_env(&cp.env_array);
1015         cp.git_cmd = 1;
1016         cp.no_stdin = 1;
1017         cp.no_stdout = 1;
1018         cp.dir = path;
1019
1020         /*
1021          * Simply indicate if 'submodule--helper push-check' failed.
1022          * More detailed error information will be provided by the
1023          * child process.
1024          */
1025         if (run_command(&cp))
1026                 die("process for submodule '%s' failed", path);
1027 }
1028
1029 int push_unpushed_submodules(struct oid_array *commits,
1030                              const struct remote *remote,
1031                              const char **refspec, int refspec_nr,
1032                              const struct string_list *push_options,
1033                              int dry_run)
1034 {
1035         int i, ret = 1;
1036         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1037
1038         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1039                 return 1;
1040
1041         /*
1042          * Verify that the remote and refspec can be propagated to all
1043          * submodules.  This check can be skipped if the remote and refspec
1044          * won't be propagated due to the remote being unconfigured (e.g. a URL
1045          * instead of a remote name).
1046          */
1047         if (remote->origin != REMOTE_UNCONFIGURED)
1048                 for (i = 0; i < needs_pushing.nr; i++)
1049                         submodule_push_check(needs_pushing.items[i].string,
1050                                              remote, refspec, refspec_nr);
1051
1052         /* Actually push the submodules */
1053         for (i = 0; i < needs_pushing.nr; i++) {
1054                 const char *path = needs_pushing.items[i].string;
1055                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1056                 if (!push_submodule(path, remote, refspec, refspec_nr,
1057                                     push_options, dry_run)) {
1058                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1059                         ret = 0;
1060                 }
1061         }
1062
1063         string_list_clear(&needs_pushing, 0);
1064
1065         return ret;
1066 }
1067
1068 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1069                                int flags, void *data)
1070 {
1071         struct oid_array *array = data;
1072         oid_array_append(array, oid);
1073         return 0;
1074 }
1075
1076 void check_for_new_submodule_commits(struct object_id *oid)
1077 {
1078         if (!initialized_fetch_ref_tips) {
1079                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1080                 initialized_fetch_ref_tips = 1;
1081         }
1082
1083         oid_array_append(&ref_tips_after_fetch, oid);
1084 }
1085
1086 static void calculate_changed_submodule_paths(void)
1087 {
1088         struct argv_array argv = ARGV_ARRAY_INIT;
1089         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1090         const struct string_list_item *item;
1091
1092         /* No need to check if there are no submodules configured */
1093         if (!submodule_from_path(NULL, NULL))
1094                 return;
1095
1096         argv_array_push(&argv, "--"); /* argv[0] program name */
1097         oid_array_for_each_unique(&ref_tips_after_fetch,
1098                                    append_oid_to_argv, &argv);
1099         argv_array_push(&argv, "--not");
1100         oid_array_for_each_unique(&ref_tips_before_fetch,
1101                                    append_oid_to_argv, &argv);
1102
1103         /*
1104          * Collect all submodules (whether checked out or not) for which new
1105          * commits have been recorded upstream in "changed_submodule_paths".
1106          */
1107         collect_changed_submodules(&changed_submodules, &argv);
1108
1109         for_each_string_list_item(item, &changed_submodules) {
1110                 struct oid_array *commits = item->util;
1111                 const char *path = item->string;
1112
1113                 if (!submodule_has_commits(path, commits))
1114                         string_list_append(&changed_submodule_paths, path);
1115         }
1116
1117         free_submodules_oids(&changed_submodules);
1118         argv_array_clear(&argv);
1119         oid_array_clear(&ref_tips_before_fetch);
1120         oid_array_clear(&ref_tips_after_fetch);
1121         initialized_fetch_ref_tips = 0;
1122 }
1123
1124 int submodule_touches_in_range(struct object_id *excl_oid,
1125                                struct object_id *incl_oid)
1126 {
1127         struct string_list subs = STRING_LIST_INIT_DUP;
1128         struct argv_array args = ARGV_ARRAY_INIT;
1129         int ret;
1130
1131         gitmodules_config();
1132         /* No need to check if there are no submodules configured */
1133         if (!submodule_from_path(NULL, NULL))
1134                 return 0;
1135
1136         argv_array_push(&args, "--"); /* args[0] program name */
1137         argv_array_push(&args, oid_to_hex(incl_oid));
1138         argv_array_push(&args, "--not");
1139         argv_array_push(&args, oid_to_hex(excl_oid));
1140
1141         collect_changed_submodules(&subs, &args);
1142         ret = subs.nr;
1143
1144         argv_array_clear(&args);
1145
1146         free_submodules_oids(&subs);
1147         return ret;
1148 }
1149
1150 struct submodule_parallel_fetch {
1151         int count;
1152         struct argv_array args;
1153         const char *work_tree;
1154         const char *prefix;
1155         int command_line_option;
1156         int default_option;
1157         int quiet;
1158         int result;
1159 };
1160 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0}
1161
1162 static int get_next_submodule(struct child_process *cp,
1163                               struct strbuf *err, void *data, void **task_cb)
1164 {
1165         int ret = 0;
1166         struct submodule_parallel_fetch *spf = data;
1167
1168         for (; spf->count < active_nr; spf->count++) {
1169                 struct strbuf submodule_path = STRBUF_INIT;
1170                 struct strbuf submodule_git_dir = STRBUF_INIT;
1171                 struct strbuf submodule_prefix = STRBUF_INIT;
1172                 const struct cache_entry *ce = active_cache[spf->count];
1173                 const char *git_dir, *default_argv;
1174                 const struct submodule *submodule;
1175
1176                 if (!S_ISGITLINK(ce->ce_mode))
1177                         continue;
1178
1179                 submodule = submodule_from_path(&null_oid, ce->name);
1180
1181                 default_argv = "yes";
1182                 if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
1183                         int fetch_recurse = RECURSE_SUBMODULES_NONE;
1184
1185                         if (submodule) {
1186                                 char *key;
1187                                 const char *value;
1188
1189                                 fetch_recurse = submodule->fetch_recurse;
1190                                 key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1191                                 if (!repo_config_get_string_const(the_repository, key, &value)) {
1192                                         fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1193                                 }
1194                                 free(key);
1195                         }
1196
1197                         if (fetch_recurse != RECURSE_SUBMODULES_NONE) {
1198                                 if (fetch_recurse == RECURSE_SUBMODULES_OFF)
1199                                         continue;
1200                                 if (fetch_recurse == RECURSE_SUBMODULES_ON_DEMAND) {
1201                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1202                                                 continue;
1203                                         default_argv = "on-demand";
1204                                 }
1205                         } else {
1206                                 if (spf->default_option == RECURSE_SUBMODULES_OFF)
1207                                         continue;
1208                                 if (spf->default_option == RECURSE_SUBMODULES_ON_DEMAND) {
1209                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1210                                                 continue;
1211                                         default_argv = "on-demand";
1212                                 }
1213                         }
1214                 } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
1215                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1216                                 continue;
1217                         default_argv = "on-demand";
1218                 }
1219
1220                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1221                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1222                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1223                 git_dir = read_gitfile(submodule_git_dir.buf);
1224                 if (!git_dir)
1225                         git_dir = submodule_git_dir.buf;
1226                 if (is_directory(git_dir)) {
1227                         child_process_init(cp);
1228                         cp->dir = strbuf_detach(&submodule_path, NULL);
1229                         prepare_submodule_repo_env(&cp->env_array);
1230                         cp->git_cmd = 1;
1231                         if (!spf->quiet)
1232                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1233                                             spf->prefix, ce->name);
1234                         argv_array_init(&cp->args);
1235                         argv_array_pushv(&cp->args, spf->args.argv);
1236                         argv_array_push(&cp->args, default_argv);
1237                         argv_array_push(&cp->args, "--submodule-prefix");
1238                         argv_array_push(&cp->args, submodule_prefix.buf);
1239                         ret = 1;
1240                 }
1241                 strbuf_release(&submodule_path);
1242                 strbuf_release(&submodule_git_dir);
1243                 strbuf_release(&submodule_prefix);
1244                 if (ret) {
1245                         spf->count++;
1246                         return 1;
1247                 }
1248         }
1249         return 0;
1250 }
1251
1252 static int fetch_start_failure(struct strbuf *err,
1253                                void *cb, void *task_cb)
1254 {
1255         struct submodule_parallel_fetch *spf = cb;
1256
1257         spf->result = 1;
1258
1259         return 0;
1260 }
1261
1262 static int fetch_finish(int retvalue, struct strbuf *err,
1263                         void *cb, void *task_cb)
1264 {
1265         struct submodule_parallel_fetch *spf = cb;
1266
1267         if (retvalue)
1268                 spf->result = 1;
1269
1270         return 0;
1271 }
1272
1273 int fetch_populated_submodules(const struct argv_array *options,
1274                                const char *prefix, int command_line_option,
1275                                int default_option,
1276                                int quiet, int max_parallel_jobs)
1277 {
1278         int i;
1279         struct submodule_parallel_fetch spf = SPF_INIT;
1280
1281         spf.work_tree = get_git_work_tree();
1282         spf.command_line_option = command_line_option;
1283         spf.default_option = default_option;
1284         spf.quiet = quiet;
1285         spf.prefix = prefix;
1286
1287         if (!spf.work_tree)
1288                 goto out;
1289
1290         if (read_cache() < 0)
1291                 die("index file corrupt");
1292
1293         argv_array_push(&spf.args, "fetch");
1294         for (i = 0; i < options->argc; i++)
1295                 argv_array_push(&spf.args, options->argv[i]);
1296         argv_array_push(&spf.args, "--recurse-submodules-default");
1297         /* default value, "--submodule-prefix" and its value are added later */
1298
1299         calculate_changed_submodule_paths();
1300         run_processes_parallel(max_parallel_jobs,
1301                                get_next_submodule,
1302                                fetch_start_failure,
1303                                fetch_finish,
1304                                &spf);
1305
1306         argv_array_clear(&spf.args);
1307 out:
1308         string_list_clear(&changed_submodule_paths, 1);
1309         return spf.result;
1310 }
1311
1312 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1313 {
1314         struct child_process cp = CHILD_PROCESS_INIT;
1315         struct strbuf buf = STRBUF_INIT;
1316         FILE *fp;
1317         unsigned dirty_submodule = 0;
1318         const char *git_dir;
1319         int ignore_cp_exit_code = 0;
1320
1321         strbuf_addf(&buf, "%s/.git", path);
1322         git_dir = read_gitfile(buf.buf);
1323         if (!git_dir)
1324                 git_dir = buf.buf;
1325         if (!is_git_directory(git_dir)) {
1326                 if (is_directory(git_dir))
1327                         die(_("'%s' not recognized as a git repository"), git_dir);
1328                 strbuf_release(&buf);
1329                 /* The submodule is not checked out, so it is not modified */
1330                 return 0;
1331         }
1332         strbuf_reset(&buf);
1333
1334         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1335         if (ignore_untracked)
1336                 argv_array_push(&cp.args, "-uno");
1337
1338         prepare_submodule_repo_env(&cp.env_array);
1339         cp.git_cmd = 1;
1340         cp.no_stdin = 1;
1341         cp.out = -1;
1342         cp.dir = path;
1343         if (start_command(&cp))
1344                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1345
1346         fp = xfdopen(cp.out, "r");
1347         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1348                 /* regular untracked files */
1349                 if (buf.buf[0] == '?')
1350                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1351
1352                 if (buf.buf[0] == 'u' ||
1353                     buf.buf[0] == '1' ||
1354                     buf.buf[0] == '2') {
1355                         /* T = line type, XY = status, SSSS = submodule state */
1356                         if (buf.len < strlen("T XY SSSS"))
1357                                 die("BUG: invalid status --porcelain=2 line %s",
1358                                     buf.buf);
1359
1360                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1361                                 /* nested untracked file */
1362                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1363
1364                         if (buf.buf[0] == 'u' ||
1365                             buf.buf[0] == '2' ||
1366                             memcmp(buf.buf + 5, "S..U", 4))
1367                                 /* other change */
1368                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1369                 }
1370
1371                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1372                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1373                      ignore_untracked)) {
1374                         /*
1375                          * We're not interested in any further information from
1376                          * the child any more, neither output nor its exit code.
1377                          */
1378                         ignore_cp_exit_code = 1;
1379                         break;
1380                 }
1381         }
1382         fclose(fp);
1383
1384         if (finish_command(&cp) && !ignore_cp_exit_code)
1385                 die("'git status --porcelain=2' failed in submodule %s", path);
1386
1387         strbuf_release(&buf);
1388         return dirty_submodule;
1389 }
1390
1391 int submodule_uses_gitfile(const char *path)
1392 {
1393         struct child_process cp = CHILD_PROCESS_INIT;
1394         const char *argv[] = {
1395                 "submodule",
1396                 "foreach",
1397                 "--quiet",
1398                 "--recursive",
1399                 "test -f .git",
1400                 NULL,
1401         };
1402         struct strbuf buf = STRBUF_INIT;
1403         const char *git_dir;
1404
1405         strbuf_addf(&buf, "%s/.git", path);
1406         git_dir = read_gitfile(buf.buf);
1407         if (!git_dir) {
1408                 strbuf_release(&buf);
1409                 return 0;
1410         }
1411         strbuf_release(&buf);
1412
1413         /* Now test that all nested submodules use a gitfile too */
1414         cp.argv = argv;
1415         prepare_submodule_repo_env(&cp.env_array);
1416         cp.git_cmd = 1;
1417         cp.no_stdin = 1;
1418         cp.no_stderr = 1;
1419         cp.no_stdout = 1;
1420         cp.dir = path;
1421         if (run_command(&cp))
1422                 return 0;
1423
1424         return 1;
1425 }
1426
1427 /*
1428  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1429  * when doing so.
1430  *
1431  * Return 1 if we'd lose data, return 0 if the removal is fine,
1432  * and negative values for errors.
1433  */
1434 int bad_to_remove_submodule(const char *path, unsigned flags)
1435 {
1436         ssize_t len;
1437         struct child_process cp = CHILD_PROCESS_INIT;
1438         struct strbuf buf = STRBUF_INIT;
1439         int ret = 0;
1440
1441         if (!file_exists(path) || is_empty_dir(path))
1442                 return 0;
1443
1444         if (!submodule_uses_gitfile(path))
1445                 return 1;
1446
1447         argv_array_pushl(&cp.args, "status", "--porcelain",
1448                                    "--ignore-submodules=none", NULL);
1449
1450         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1451                 argv_array_push(&cp.args, "-uno");
1452         else
1453                 argv_array_push(&cp.args, "-uall");
1454
1455         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1456                 argv_array_push(&cp.args, "--ignored");
1457
1458         prepare_submodule_repo_env(&cp.env_array);
1459         cp.git_cmd = 1;
1460         cp.no_stdin = 1;
1461         cp.out = -1;
1462         cp.dir = path;
1463         if (start_command(&cp)) {
1464                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1465                         die(_("could not start 'git status' in submodule '%s'"),
1466                                 path);
1467                 ret = -1;
1468                 goto out;
1469         }
1470
1471         len = strbuf_read(&buf, cp.out, 1024);
1472         if (len > 2)
1473                 ret = 1;
1474         close(cp.out);
1475
1476         if (finish_command(&cp)) {
1477                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1478                         die(_("could not run 'git status' in submodule '%s'"),
1479                                 path);
1480                 ret = -1;
1481         }
1482 out:
1483         strbuf_release(&buf);
1484         return ret;
1485 }
1486
1487 static const char *get_super_prefix_or_empty(void)
1488 {
1489         const char *s = get_super_prefix();
1490         if (!s)
1491                 s = "";
1492         return s;
1493 }
1494
1495 static int submodule_has_dirty_index(const struct submodule *sub)
1496 {
1497         struct child_process cp = CHILD_PROCESS_INIT;
1498
1499         prepare_submodule_repo_env(&cp.env_array);
1500
1501         cp.git_cmd = 1;
1502         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1503                                    "--cached", "HEAD", NULL);
1504         cp.no_stdin = 1;
1505         cp.no_stdout = 1;
1506         cp.dir = sub->path;
1507         if (start_command(&cp))
1508                 die("could not recurse into submodule '%s'", sub->path);
1509
1510         return finish_command(&cp);
1511 }
1512
1513 static void submodule_reset_index(const char *path)
1514 {
1515         struct child_process cp = CHILD_PROCESS_INIT;
1516         prepare_submodule_repo_env(&cp.env_array);
1517
1518         cp.git_cmd = 1;
1519         cp.no_stdin = 1;
1520         cp.dir = path;
1521
1522         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1523                                    get_super_prefix_or_empty(), path);
1524         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1525
1526         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1527
1528         if (run_command(&cp))
1529                 die("could not reset submodule index");
1530 }
1531
1532 /**
1533  * Moves a submodule at a given path from a given head to another new head.
1534  * For edge cases (a submodule coming into existence or removing a submodule)
1535  * pass NULL for old or new respectively.
1536  */
1537 int submodule_move_head(const char *path,
1538                          const char *old,
1539                          const char *new,
1540                          unsigned flags)
1541 {
1542         int ret = 0;
1543         struct child_process cp = CHILD_PROCESS_INIT;
1544         const struct submodule *sub;
1545         int *error_code_ptr, error_code;
1546
1547         if (!is_submodule_active(the_repository, path))
1548                 return 0;
1549
1550         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1551                 /*
1552                  * Pass non NULL pointer to is_submodule_populated_gently
1553                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1554                  * to fixup the submodule in the force case later.
1555                  */
1556                 error_code_ptr = &error_code;
1557         else
1558                 error_code_ptr = NULL;
1559
1560         if (old && !is_submodule_populated_gently(path, error_code_ptr))
1561                 return 0;
1562
1563         sub = submodule_from_path(&null_oid, path);
1564
1565         if (!sub)
1566                 die("BUG: could not get submodule information for '%s'", path);
1567
1568         if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1569                 /* Check if the submodule has a dirty index. */
1570                 if (submodule_has_dirty_index(sub))
1571                         return error(_("submodule '%s' has dirty index"), path);
1572         }
1573
1574         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1575                 if (old) {
1576                         if (!submodule_uses_gitfile(path))
1577                                 absorb_git_dir_into_superproject("", path,
1578                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1579                 } else {
1580                         char *gitdir = xstrfmt("%s/modules/%s",
1581                                     get_git_common_dir(), sub->name);
1582                         connect_work_tree_and_git_dir(path, gitdir);
1583                         free(gitdir);
1584
1585                         /* make sure the index is clean as well */
1586                         submodule_reset_index(path);
1587                 }
1588
1589                 if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1590                         char *gitdir = xstrfmt("%s/modules/%s",
1591                                     get_git_common_dir(), sub->name);
1592                         connect_work_tree_and_git_dir(path, gitdir);
1593                         free(gitdir);
1594                 }
1595         }
1596
1597         prepare_submodule_repo_env(&cp.env_array);
1598
1599         cp.git_cmd = 1;
1600         cp.no_stdin = 1;
1601         cp.dir = path;
1602
1603         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1604                         get_super_prefix_or_empty(), path);
1605         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1606
1607         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1608                 argv_array_push(&cp.args, "-n");
1609         else
1610                 argv_array_push(&cp.args, "-u");
1611
1612         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1613                 argv_array_push(&cp.args, "--reset");
1614         else
1615                 argv_array_push(&cp.args, "-m");
1616
1617         argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1618         argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1619
1620         if (run_command(&cp)) {
1621                 ret = -1;
1622                 goto out;
1623         }
1624
1625         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1626                 if (new) {
1627                         child_process_init(&cp);
1628                         /* also set the HEAD accordingly */
1629                         cp.git_cmd = 1;
1630                         cp.no_stdin = 1;
1631                         cp.dir = path;
1632
1633                         prepare_submodule_repo_env(&cp.env_array);
1634                         argv_array_pushl(&cp.args, "update-ref", "HEAD", new, NULL);
1635
1636                         if (run_command(&cp)) {
1637                                 ret = -1;
1638                                 goto out;
1639                         }
1640                 } else {
1641                         struct strbuf sb = STRBUF_INIT;
1642
1643                         strbuf_addf(&sb, "%s/.git", path);
1644                         unlink_or_warn(sb.buf);
1645                         strbuf_release(&sb);
1646
1647                         if (is_empty_dir(path))
1648                                 rmdir_or_warn(path);
1649                 }
1650         }
1651 out:
1652         return ret;
1653 }
1654
1655 static int find_first_merges(struct object_array *result, const char *path,
1656                 struct commit *a, struct commit *b)
1657 {
1658         int i, j;
1659         struct object_array merges = OBJECT_ARRAY_INIT;
1660         struct commit *commit;
1661         int contains_another;
1662
1663         char merged_revision[42];
1664         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1665                                    "--all", merged_revision, NULL };
1666         struct rev_info revs;
1667         struct setup_revision_opt rev_opts;
1668
1669         memset(result, 0, sizeof(struct object_array));
1670         memset(&rev_opts, 0, sizeof(rev_opts));
1671
1672         /* get all revisions that merge commit a */
1673         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1674                         oid_to_hex(&a->object.oid));
1675         init_revisions(&revs, NULL);
1676         rev_opts.submodule = path;
1677         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1678
1679         /* save all revisions from the above list that contain b */
1680         if (prepare_revision_walk(&revs))
1681                 die("revision walk setup failed");
1682         while ((commit = get_revision(&revs)) != NULL) {
1683                 struct object *o = &(commit->object);
1684                 if (in_merge_bases(b, commit))
1685                         add_object_array(o, NULL, &merges);
1686         }
1687         reset_revision_walk();
1688
1689         /* Now we've got all merges that contain a and b. Prune all
1690          * merges that contain another found merge and save them in
1691          * result.
1692          */
1693         for (i = 0; i < merges.nr; i++) {
1694                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1695
1696                 contains_another = 0;
1697                 for (j = 0; j < merges.nr; j++) {
1698                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1699                         if (i != j && in_merge_bases(m2, m1)) {
1700                                 contains_another = 1;
1701                                 break;
1702                         }
1703                 }
1704
1705                 if (!contains_another)
1706                         add_object_array(merges.objects[i].item, NULL, result);
1707         }
1708
1709         free(merges.objects);
1710         return result->nr;
1711 }
1712
1713 static void print_commit(struct commit *commit)
1714 {
1715         struct strbuf sb = STRBUF_INIT;
1716         struct pretty_print_context ctx = {0};
1717         ctx.date_mode.type = DATE_NORMAL;
1718         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1719         fprintf(stderr, "%s\n", sb.buf);
1720         strbuf_release(&sb);
1721 }
1722
1723 #define MERGE_WARNING(path, msg) \
1724         warning("Failed to merge submodule %s (%s)", path, msg);
1725
1726 int merge_submodule(struct object_id *result, const char *path,
1727                     const struct object_id *base, const struct object_id *a,
1728                     const struct object_id *b, int search)
1729 {
1730         struct commit *commit_base, *commit_a, *commit_b;
1731         int parent_count;
1732         struct object_array merges;
1733
1734         int i;
1735
1736         /* store a in result in case we fail */
1737         oidcpy(result, a);
1738
1739         /* we can not handle deletion conflicts */
1740         if (is_null_oid(base))
1741                 return 0;
1742         if (is_null_oid(a))
1743                 return 0;
1744         if (is_null_oid(b))
1745                 return 0;
1746
1747         if (add_submodule_odb(path)) {
1748                 MERGE_WARNING(path, "not checked out");
1749                 return 0;
1750         }
1751
1752         if (!(commit_base = lookup_commit_reference(base)) ||
1753             !(commit_a = lookup_commit_reference(a)) ||
1754             !(commit_b = lookup_commit_reference(b))) {
1755                 MERGE_WARNING(path, "commits not present");
1756                 return 0;
1757         }
1758
1759         /* check whether both changes are forward */
1760         if (!in_merge_bases(commit_base, commit_a) ||
1761             !in_merge_bases(commit_base, commit_b)) {
1762                 MERGE_WARNING(path, "commits don't follow merge-base");
1763                 return 0;
1764         }
1765
1766         /* Case #1: a is contained in b or vice versa */
1767         if (in_merge_bases(commit_a, commit_b)) {
1768                 oidcpy(result, b);
1769                 return 1;
1770         }
1771         if (in_merge_bases(commit_b, commit_a)) {
1772                 oidcpy(result, a);
1773                 return 1;
1774         }
1775
1776         /*
1777          * Case #2: There are one or more merges that contain a and b in
1778          * the submodule. If there is only one, then present it as a
1779          * suggestion to the user, but leave it marked unmerged so the
1780          * user needs to confirm the resolution.
1781          */
1782
1783         /* Skip the search if makes no sense to the calling context.  */
1784         if (!search)
1785                 return 0;
1786
1787         /* find commit which merges them */
1788         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1789         switch (parent_count) {
1790         case 0:
1791                 MERGE_WARNING(path, "merge following commits not found");
1792                 break;
1793
1794         case 1:
1795                 MERGE_WARNING(path, "not fast-forward");
1796                 fprintf(stderr, "Found a possible merge resolution "
1797                                 "for the submodule:\n");
1798                 print_commit((struct commit *) merges.objects[0].item);
1799                 fprintf(stderr,
1800                         "If this is correct simply add it to the index "
1801                         "for example\n"
1802                         "by using:\n\n"
1803                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1804                         "which will accept this suggestion.\n",
1805                         oid_to_hex(&merges.objects[0].item->oid), path);
1806                 break;
1807
1808         default:
1809                 MERGE_WARNING(path, "multiple merges found");
1810                 for (i = 0; i < merges.nr; i++)
1811                         print_commit((struct commit *) merges.objects[i].item);
1812         }
1813
1814         free(merges.objects);
1815         return 0;
1816 }
1817
1818 /*
1819  * Embeds a single submodules git directory into the superprojects git dir,
1820  * non recursively.
1821  */
1822 static void relocate_single_git_dir_into_superproject(const char *prefix,
1823                                                       const char *path)
1824 {
1825         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1826         const char *new_git_dir;
1827         const struct submodule *sub;
1828
1829         if (submodule_uses_worktrees(path))
1830                 die(_("relocate_gitdir for submodule '%s' with "
1831                       "more than one worktree not supported"), path);
1832
1833         old_git_dir = xstrfmt("%s/.git", path);
1834         if (read_gitfile(old_git_dir))
1835                 /* If it is an actual gitfile, it doesn't need migration. */
1836                 return;
1837
1838         real_old_git_dir = real_pathdup(old_git_dir, 1);
1839
1840         sub = submodule_from_path(&null_oid, path);
1841         if (!sub)
1842                 die(_("could not lookup name for submodule '%s'"), path);
1843
1844         new_git_dir = git_path("modules/%s", sub->name);
1845         if (safe_create_leading_directories_const(new_git_dir) < 0)
1846                 die(_("could not create directory '%s'"), new_git_dir);
1847         real_new_git_dir = real_pathdup(new_git_dir, 1);
1848
1849         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1850                 get_super_prefix_or_empty(), path,
1851                 real_old_git_dir, real_new_git_dir);
1852
1853         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1854
1855         free(old_git_dir);
1856         free(real_old_git_dir);
1857         free(real_new_git_dir);
1858 }
1859
1860 /*
1861  * Migrate the git directory of the submodule given by path from
1862  * having its git directory within the working tree to the git dir nested
1863  * in its superprojects git dir under modules/.
1864  */
1865 void absorb_git_dir_into_superproject(const char *prefix,
1866                                       const char *path,
1867                                       unsigned flags)
1868 {
1869         int err_code;
1870         const char *sub_git_dir;
1871         struct strbuf gitdir = STRBUF_INIT;
1872         strbuf_addf(&gitdir, "%s/.git", path);
1873         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1874
1875         /* Not populated? */
1876         if (!sub_git_dir) {
1877                 const struct submodule *sub;
1878
1879                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1880                         /* unpopulated as expected */
1881                         strbuf_release(&gitdir);
1882                         return;
1883                 }
1884
1885                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1886                         /* We don't know what broke here. */
1887                         read_gitfile_error_die(err_code, path, NULL);
1888
1889                 /*
1890                 * Maybe populated, but no git directory was found?
1891                 * This can happen if the superproject is a submodule
1892                 * itself and was just absorbed. The absorption of the
1893                 * superproject did not rewrite the git file links yet,
1894                 * fix it now.
1895                 */
1896                 sub = submodule_from_path(&null_oid, path);
1897                 if (!sub)
1898                         die(_("could not lookup name for submodule '%s'"), path);
1899                 connect_work_tree_and_git_dir(path,
1900                         git_path("modules/%s", sub->name));
1901         } else {
1902                 /* Is it already absorbed into the superprojects git dir? */
1903                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1904                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1905
1906                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1907                         relocate_single_git_dir_into_superproject(prefix, path);
1908
1909                 free(real_sub_git_dir);
1910                 free(real_common_git_dir);
1911         }
1912         strbuf_release(&gitdir);
1913
1914         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1915                 struct child_process cp = CHILD_PROCESS_INIT;
1916                 struct strbuf sb = STRBUF_INIT;
1917
1918                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1919                         die("BUG: we don't know how to pass the flags down?");
1920
1921                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1922                 strbuf_addstr(&sb, path);
1923                 strbuf_addch(&sb, '/');
1924
1925                 cp.dir = path;
1926                 cp.git_cmd = 1;
1927                 cp.no_stdin = 1;
1928                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1929                                            "submodule--helper",
1930                                            "absorb-git-dirs", NULL);
1931                 prepare_submodule_repo_env(&cp.env_array);
1932                 if (run_command(&cp))
1933                         die(_("could not recurse into submodule '%s'"), path);
1934
1935                 strbuf_release(&sb);
1936         }
1937 }
1938
1939 const char *get_superproject_working_tree(void)
1940 {
1941         struct child_process cp = CHILD_PROCESS_INIT;
1942         struct strbuf sb = STRBUF_INIT;
1943         const char *one_up = real_path_if_valid("../");
1944         const char *cwd = xgetcwd();
1945         const char *ret = NULL;
1946         const char *subpath;
1947         int code;
1948         ssize_t len;
1949
1950         if (!is_inside_work_tree())
1951                 /*
1952                  * FIXME:
1953                  * We might have a superproject, but it is harder
1954                  * to determine.
1955                  */
1956                 return NULL;
1957
1958         if (!one_up)
1959                 return NULL;
1960
1961         subpath = relative_path(cwd, one_up, &sb);
1962
1963         prepare_submodule_repo_env(&cp.env_array);
1964         argv_array_pop(&cp.env_array);
1965
1966         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
1967                         "ls-files", "-z", "--stage", "--full-name", "--",
1968                         subpath, NULL);
1969         strbuf_reset(&sb);
1970
1971         cp.no_stdin = 1;
1972         cp.no_stderr = 1;
1973         cp.out = -1;
1974         cp.git_cmd = 1;
1975
1976         if (start_command(&cp))
1977                 die(_("could not start ls-files in .."));
1978
1979         len = strbuf_read(&sb, cp.out, PATH_MAX);
1980         close(cp.out);
1981
1982         if (starts_with(sb.buf, "160000")) {
1983                 int super_sub_len;
1984                 int cwd_len = strlen(cwd);
1985                 char *super_sub, *super_wt;
1986
1987                 /*
1988                  * There is a superproject having this repo as a submodule.
1989                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
1990                  * We're only interested in the name after the tab.
1991                  */
1992                 super_sub = strchr(sb.buf, '\t') + 1;
1993                 super_sub_len = sb.buf + sb.len - super_sub - 1;
1994
1995                 if (super_sub_len > cwd_len ||
1996                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
1997                         die (_("BUG: returned path string doesn't match cwd?"));
1998
1999                 super_wt = xstrdup(cwd);
2000                 super_wt[cwd_len - super_sub_len] = '\0';
2001
2002                 ret = real_path(super_wt);
2003                 free(super_wt);
2004         }
2005         strbuf_release(&sb);
2006
2007         code = finish_command(&cp);
2008
2009         if (code == 128)
2010                 /* '../' is not a git repository */
2011                 return NULL;
2012         if (code == 0 && len == 0)
2013                 /* There is an unrelated git repository at '../' */
2014                 return NULL;
2015         if (code)
2016                 die(_("ls-tree returned unexpected return code %d"), code);
2017
2018         return ret;
2019 }
2020
2021 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2022 {
2023         const struct submodule *sub;
2024         const char *git_dir;
2025         int ret = 0;
2026
2027         strbuf_reset(buf);
2028         strbuf_addstr(buf, submodule);
2029         strbuf_complete(buf, '/');
2030         strbuf_addstr(buf, ".git");
2031
2032         git_dir = read_gitfile(buf->buf);
2033         if (git_dir) {
2034                 strbuf_reset(buf);
2035                 strbuf_addstr(buf, git_dir);
2036         }
2037         if (!is_git_directory(buf->buf)) {
2038                 gitmodules_config();
2039                 sub = submodule_from_path(&null_oid, submodule);
2040                 if (!sub) {
2041                         ret = -1;
2042                         goto cleanup;
2043                 }
2044                 strbuf_reset(buf);
2045                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2046         }
2047
2048 cleanup:
2049         return ret;
2050 }