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

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "submodule-config.h"
   4 #include "submodule.h"
   5 #include "dir.h"
   6 #include "diff.h"
   7 #include "commit.h"
   8 #include "revision.h"
   9 #include "run-command.h"
  10 #include "diffcore.h"
  11 #include "refs.h"
  12 #include "string-list.h"
  13 #include "sha1-array.h"
  14 #include "argv-array.h"
  15 #include "blob.h"
  16 #include "thread-utils.h"
  17 #include "quote.h"
  18 #include "remote.h"
  19 #include "worktree.h"
  20 #include "parse-options.h"
  21
  22 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
  23 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
  24 static int parallel_jobs = 1;
  25 static struct string_list changed_submodule_paths = STRING_LIST_INIT_DUP;
  26 static int initialized_fetch_ref_tips;
  27 static struct oid_array ref_tips_before_fetch;
  28 static struct oid_array ref_tips_after_fetch;
  29
  30 /*
  31  * The following flag is set if the .gitmodules file is unmerged. We then
  32  * disable recursion for all submodules where .git/config doesn't have a
  33  * matching config entry because we can't guess what might be configured in
  34  * .gitmodules unless the user resolves the conflict. When a command line
  35  * option is given (which always overrides configuration) this flag will be
  36  * ignored.
  37  */
  38 static int gitmodules_is_unmerged;
  39
  40 /*
  41  * This flag is set if the .gitmodules file had unstaged modifications on
  42  * startup. This must be checked before allowing modifications to the
  43  * .gitmodules file with the intention to stage them later, because when
  44  * continuing we would stage the modifications the user didn't stage herself
  45  * too. That might change in a future version when we learn to stage the
  46  * changes we do ourselves without staging any previous modifications.
  47  */
  48 static int gitmodules_is_modified;
  49
  50 int is_staging_gitmodules_ok(void)
  51 {
  52         return !gitmodules_is_modified;
  53 }
  54
  55 /*
  56  * Try to update the "path" entry in the "submodule.<name>" section of the
  57  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
  58  * with the correct path=<oldpath> setting was found and we could update it.
  59  */
  60 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
  61 {
  62         struct strbuf entry = STRBUF_INIT;
  63         const struct submodule *submodule;
  64
  65         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
  66                 return -1;
  67
  68         if (gitmodules_is_unmerged)
  69                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  70
  71         submodule = submodule_from_path(null_sha1, oldpath);
  72         if (!submodule || !submodule->name) {
  73                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
  74                 return -1;
  75         }
  76         strbuf_addstr(&entry, "submodule.");
  77         strbuf_addstr(&entry, submodule->name);
  78         strbuf_addstr(&entry, ".path");
  79         if (git_config_set_in_file_gently(".gitmodules", entry.buf, newpath) < 0) {
  80                 /* Maybe the user already did that, don't error out here */
  81                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
  82                 strbuf_release(&entry);
  83                 return -1;
  84         }
  85         strbuf_release(&entry);
  86         return 0;
  87 }
  88
  89 /*
  90  * Try to remove the "submodule.<name>" section from .gitmodules where the given
  91  * path is configured. Return 0 only if a .gitmodules file was found, a section
  92  * with the correct path=<path> setting was found and we could remove it.
  93  */
  94 int remove_path_from_gitmodules(const char *path)
  95 {
  96         struct strbuf sect = STRBUF_INIT;
  97         const struct submodule *submodule;
  98
  99         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
 100                 return -1;
 101
 102         if (gitmodules_is_unmerged)
 103                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 104
 105         submodule = submodule_from_path(null_sha1, path);
 106         if (!submodule || !submodule->name) {
 107                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 108                 return -1;
 109         }
 110         strbuf_addstr(&sect, "submodule.");
 111         strbuf_addstr(&sect, submodule->name);
 112         if (git_config_rename_section_in_file(".gitmodules", sect.buf, NULL) < 0) {
 113                 /* Maybe the user already did that, don't error out here */
 114                 warning(_("Could not remove .gitmodules entry for %s"), path);
 115                 strbuf_release(&sect);
 116                 return -1;
 117         }
 118         strbuf_release(&sect);
 119         return 0;
 120 }
 121
 122 void stage_updated_gitmodules(void)
 123 {
 124         if (add_file_to_cache(".gitmodules", 0))
 125                 die(_("staging updated .gitmodules failed"));
 126 }
 127
 128 static int add_submodule_odb(const char *path)
 129 {
 130         struct strbuf objects_directory = STRBUF_INIT;
 131         int ret = 0;
 132
 133         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
 134         if (ret)
 135                 goto done;
 136         if (!is_directory(objects_directory.buf)) {
 137                 ret = -1;
 138                 goto done;
 139         }
 140         add_to_alternates_memory(objects_directory.buf);
 141 done:
 142         strbuf_release(&objects_directory);
 143         return ret;
 144 }
 145
 146 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 147                                              const char *path)
 148 {
 149         const struct submodule *submodule = submodule_from_path(null_sha1, path);
 150         if (submodule) {
 151                 if (submodule->ignore)
 152                         handle_ignore_submodules_arg(diffopt, submodule->ignore);
 153                 else if (gitmodules_is_unmerged)
 154                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 155         }
 156 }
 157
 158 /* For loading from the .gitmodules file. */
 159 static int git_modules_config(const char *var, const char *value, void *cb)
 160 {
 161         if (!strcmp(var, "submodule.fetchjobs")) {
 162                 parallel_jobs = git_config_int(var, value);
 163                 if (parallel_jobs < 0)
 164                         die(_("negative values not allowed for submodule.fetchJobs"));
 165                 return 0;
 166         } else if (starts_with(var, "submodule."))
 167                 return parse_submodule_config_option(var, value);
 168         else if (!strcmp(var, "fetch.recursesubmodules")) {
 169                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
 170                 return 0;
 171         }
 172         return 0;
 173 }
 174
 175 /* Loads all submodule settings from the config. */
 176 int submodule_config(const char *var, const char *value, void *cb)
 177 {
 178         if (!strcmp(var, "submodule.recurse")) {
 179                 int v = git_config_bool(var, value) ?
 180                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 181                 config_update_recurse_submodules = v;
 182                 return 0;
 183         } else {
 184                 return git_modules_config(var, value, cb);
 185         }
 186 }
 187
 188 /* Cheap function that only determines if we're interested in submodules at all */
 189 int git_default_submodule_config(const char *var, const char *value, void *cb)
 190 {
 191         if (!strcmp(var, "submodule.recurse")) {
 192                 int v = git_config_bool(var, value) ?
 193                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 194                 config_update_recurse_submodules = v;
 195         }
 196         return 0;
 197 }
 198
 199 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 200                                                      const char *arg, int unset)
 201 {
 202         if (unset) {
 203                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 204                 return 0;
 205         }
 206         if (arg)
 207                 config_update_recurse_submodules =
 208                         parse_update_recurse_submodules_arg(opt->long_name,
 209                                                             arg);
 210         else
 211                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 212
 213         return 0;
 214 }
 215
 216 void load_submodule_cache(void)
 217 {
 218         if (config_update_recurse_submodules == RECURSE_SUBMODULES_OFF)
 219                 return;
 220
 221         gitmodules_config();
 222         git_config(submodule_config, NULL);
 223 }
 224
 225 void gitmodules_config(void)
 226 {
 227         const char *work_tree = get_git_work_tree();
 228         if (work_tree) {
 229                 struct strbuf gitmodules_path = STRBUF_INIT;
 230                 int pos;
 231                 strbuf_addstr(&gitmodules_path, work_tree);
 232                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
 233                 if (read_cache() < 0)
 234                         die("index file corrupt");
 235                 pos = cache_name_pos(".gitmodules", 11);
 236                 if (pos < 0) { /* .gitmodules not found or isn't merged */
 237                         pos = -1 - pos;
 238                         if (active_nr > pos) {  /* there is a .gitmodules */
 239                                 const struct cache_entry *ce = active_cache[pos];
 240                                 if (ce_namelen(ce) == 11 &&
 241                                     !memcmp(ce->name, ".gitmodules", 11))
 242                                         gitmodules_is_unmerged = 1;
 243                         }
 244                 } else if (pos < active_nr) {
 245                         struct stat st;
 246                         if (lstat(".gitmodules", &st) == 0 &&
 247                             ce_match_stat(active_cache[pos], &st, 0) & DATA_CHANGED)
 248                                 gitmodules_is_modified = 1;
 249                 }
 250
 251                 if (!gitmodules_is_unmerged)
 252                         git_config_from_file(git_modules_config,
 253                                 gitmodules_path.buf, NULL);
 254                 strbuf_release(&gitmodules_path);
 255         }
 256 }
 257
 258 void gitmodules_config_sha1(const unsigned char *commit_sha1)
 259 {
 260         struct strbuf rev = STRBUF_INIT;
 261         unsigned char sha1[20];
 262
 263         if (gitmodule_sha1_from_commit(commit_sha1, sha1, &rev)) {
 264                 git_config_from_blob_sha1(git_modules_config, rev.buf,
 265                                           sha1, NULL);
 266         }
 267         strbuf_release(&rev);
 268 }
 269
 270 /*
 271  * NEEDSWORK: With the addition of different configuration options to determine
 272  * if a submodule is of interests, the validity of this function's name comes
 273  * into question.  Once the dust has settled and more concrete terminology is
 274  * decided upon, come up with a more proper name for this function.  One
 275  * potential candidate could be 'is_submodule_active()'.
 276  *
 277  * Determine if a submodule has been initialized at a given 'path'
 278  */
 279 int is_submodule_initialized(const char *path)
 280 {
 281         int ret = 0;
 282         char *key = NULL;
 283         char *value = NULL;
 284         const struct string_list *sl;
 285         const struct submodule *module = submodule_from_path(null_sha1, path);
 286
 287         /* early return if there isn't a path->module mapping */
 288         if (!module)
 289                 return 0;
 290
 291         /* submodule.<name>.active is set */
 292         key = xstrfmt("submodule.%s.active", module->name);
 293         if (!git_config_get_bool(key, &ret)) {
 294                 free(key);
 295                 return ret;
 296         }
 297         free(key);
 298
 299         /* submodule.active is set */
 300         sl = git_config_get_value_multi("submodule.active");
 301         if (sl) {
 302                 struct pathspec ps;
 303                 struct argv_array args = ARGV_ARRAY_INIT;
 304                 const struct string_list_item *item;
 305
 306                 for_each_string_list_item(item, sl) {
 307                         argv_array_push(&args, item->string);
 308                 }
 309
 310                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
 311                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
 312
 313                 argv_array_clear(&args);
 314                 clear_pathspec(&ps);
 315                 return ret;
 316         }
 317
 318         /* fallback to checking if the URL is set */
 319         key = xstrfmt("submodule.%s.url", module->name);
 320         ret = !git_config_get_string(key, &value);
 321
 322         free(value);
 323         free(key);
 324         return ret;
 325 }
 326
 327 int is_submodule_populated_gently(const char *path, int *return_error_code)
 328 {
 329         int ret = 0;
 330         char *gitdir = xstrfmt("%s/.git", path);
 331
 332         if (resolve_gitdir_gently(gitdir, return_error_code))
 333                 ret = 1;
 334
 335         free(gitdir);
 336         return ret;
 337 }
 338
 339 /*
 340  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 341  */
 342 void die_in_unpopulated_submodule(const struct index_state *istate,
 343                                   const char *prefix)
 344 {
 345         int i, prefixlen;
 346
 347         if (!prefix)
 348                 return;
 349
 350         prefixlen = strlen(prefix);
 351
 352         for (i = 0; i < istate->cache_nr; i++) {
 353                 struct cache_entry *ce = istate->cache[i];
 354                 int ce_len = ce_namelen(ce);
 355
 356                 if (!S_ISGITLINK(ce->ce_mode))
 357                         continue;
 358                 if (prefixlen <= ce_len)
 359                         continue;
 360                 if (strncmp(ce->name, prefix, ce_len))
 361                         continue;
 362                 if (prefix[ce_len] != '/')
 363                         continue;
 364
 365                 die(_("in unpopulated submodule '%s'"), ce->name);
 366         }
 367 }
 368
 369 /*
 370  * Dies if any paths in the provided pathspec descends into a submodule
 371  */
 372 void die_path_inside_submodule(const struct index_state *istate,
 373                                const struct pathspec *ps)
 374 {
 375         int i, j;
 376
 377         for (i = 0; i < istate->cache_nr; i++) {
 378                 struct cache_entry *ce = istate->cache[i];
 379                 int ce_len = ce_namelen(ce);
 380
 381                 if (!S_ISGITLINK(ce->ce_mode))
 382                         continue;
 383
 384                 for (j = 0; j < ps->nr ; j++) {
 385                         const struct pathspec_item *item = &ps->items[j];
 386
 387                         if (item->len <= ce_len)
 388                                 continue;
 389                         if (item->match[ce_len] != '/')
 390                                 continue;
 391                         if (strncmp(ce->name, item->match, ce_len))
 392                                 continue;
 393                         if (item->len == ce_len + 1)
 394                                 continue;
 395
 396                         die(_("Pathspec '%s' is in submodule '%.*s'"),
 397                             item->original, ce_len, ce->name);
 398                 }
 399         }
 400 }
 401
 402 int parse_submodule_update_strategy(const char *value,
 403                 struct submodule_update_strategy *dst)
 404 {
 405         free((void*)dst->command);
 406         dst->command = NULL;
 407         if (!strcmp(value, "none"))
 408                 dst->type = SM_UPDATE_NONE;
 409         else if (!strcmp(value, "checkout"))
 410                 dst->type = SM_UPDATE_CHECKOUT;
 411         else if (!strcmp(value, "rebase"))
 412                 dst->type = SM_UPDATE_REBASE;
 413         else if (!strcmp(value, "merge"))
 414                 dst->type = SM_UPDATE_MERGE;
 415         else if (skip_prefix(value, "!", &value)) {
 416                 dst->type = SM_UPDATE_COMMAND;
 417                 dst->command = xstrdup(value);
 418         } else
 419                 return -1;
 420         return 0;
 421 }
 422
 423 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 424 {
 425         struct strbuf sb = STRBUF_INIT;
 426         switch (s->type) {
 427         case SM_UPDATE_CHECKOUT:
 428                 return "checkout";
 429         case SM_UPDATE_MERGE:
 430                 return "merge";
 431         case SM_UPDATE_REBASE:
 432                 return "rebase";
 433         case SM_UPDATE_NONE:
 434                 return "none";
 435         case SM_UPDATE_UNSPECIFIED:
 436                 return NULL;
 437         case SM_UPDATE_COMMAND:
 438                 strbuf_addf(&sb, "!%s", s->command);
 439                 return strbuf_detach(&sb, NULL);
 440         }
 441         return NULL;
 442 }
 443
 444 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 445                                   const char *arg)
 446 {
 447         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 448         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 449         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 450
 451         if (!strcmp(arg, "all"))
 452                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 453         else if (!strcmp(arg, "untracked"))
 454                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 455         else if (!strcmp(arg, "dirty"))
 456                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 457         else if (strcmp(arg, "none"))
 458                 die("bad --ignore-submodules argument: %s", arg);
 459 }
 460
 461 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 462                 struct commit *left, struct commit *right,
 463                 struct commit_list *merge_bases)
 464 {
 465         struct commit_list *list;
 466
 467         init_revisions(rev, NULL);
 468         setup_revisions(0, NULL, rev, NULL);
 469         rev->left_right = 1;
 470         rev->first_parent_only = 1;
 471         left->object.flags |= SYMMETRIC_LEFT;
 472         add_pending_object(rev, &left->object, path);
 473         add_pending_object(rev, &right->object, path);
 474         for (list = merge_bases; list; list = list->next) {
 475                 list->item->object.flags |= UNINTERESTING;
 476                 add_pending_object(rev, &list->item->object,
 477                         oid_to_hex(&list->item->object.oid));
 478         }
 479         return prepare_revision_walk(rev);
 480 }
 481
 482 static void print_submodule_summary(struct rev_info *rev, struct diff_options *o)
 483 {
 484         static const char format[] = "  %m %s";
 485         struct strbuf sb = STRBUF_INIT;
 486         struct commit *commit;
 487
 488         while ((commit = get_revision(rev))) {
 489                 struct pretty_print_context ctx = {0};
 490                 ctx.date_mode = rev->date_mode;
 491                 ctx.output_encoding = get_log_output_encoding();
 492                 strbuf_setlen(&sb, 0);
 493                 format_commit_message(commit, format, &sb, &ctx);
 494                 strbuf_addch(&sb, '\n');
 495                 if (commit->object.flags & SYMMETRIC_LEFT)
 496                         diff_emit_submodule_del(o, sb.buf);
 497                 else
 498                         diff_emit_submodule_add(o, sb.buf);
 499         }
 500         strbuf_release(&sb);
 501 }
 502
 503 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 504 {
 505         const char * const *var;
 506
 507         for (var = local_repo_env; *var; var++) {
 508                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 509                         argv_array_push(out, *var);
 510         }
 511 }
 512
 513 void prepare_submodule_repo_env(struct argv_array *out)
 514 {
 515         prepare_submodule_repo_env_no_git_dir(out);
 516         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 517                          DEFAULT_GIT_DIR_ENVIRONMENT);
 518 }
 519
 520 /* Helper function to display the submodule header line prior to the full
 521  * summary output. If it can locate the submodule objects directory it will
 522  * attempt to lookup both the left and right commits and put them into the
 523  * left and right pointers.
 524  */
 525 static void show_submodule_header(struct diff_options *o, const char *path,
 526                 struct object_id *one, struct object_id *two,
 527                 unsigned dirty_submodule,
 528                 struct commit **left, struct commit **right,
 529                 struct commit_list **merge_bases)
 530 {
 531         const char *message = NULL;
 532         struct strbuf sb = STRBUF_INIT;
 533         int fast_forward = 0, fast_backward = 0;
 534
 535         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 536                 diff_emit_submodule_untracked(o, path);
 537
 538         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 539                 diff_emit_submodule_modified(o, path);
 540
 541         if (is_null_oid(one))
 542                 message = "(new submodule)";
 543         else if (is_null_oid(two))
 544                 message = "(submodule deleted)";
 545
 546         if (add_submodule_odb(path)) {
 547                 if (!message)
 548                         message = "(not initialized)";
 549                 goto output_header;
 550         }
 551
 552         /*
 553          * Attempt to lookup the commit references, and determine if this is
 554          * a fast forward or fast backwards update.
 555          */
 556         *left = lookup_commit_reference(one);
 557         *right = lookup_commit_reference(two);
 558
 559         /*
 560          * Warn about missing commits in the submodule project, but only if
 561          * they aren't null.
 562          */
 563         if ((!is_null_oid(one) && !*left) ||
 564              (!is_null_oid(two) && !*right))
 565                 message = "(commits not present)";
 566
 567         *merge_bases = get_merge_bases(*left, *right);
 568         if (*merge_bases) {
 569                 if ((*merge_bases)->item == *left)
 570                         fast_forward = 1;
 571                 else if ((*merge_bases)->item == *right)
 572                         fast_backward = 1;
 573         }
 574
 575         if (!oidcmp(one, two)) {
 576                 strbuf_release(&sb);
 577                 return;
 578         }
 579
 580 output_header:
 581         strbuf_addf(&sb, "Submodule %s ", path);
 582         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
 583         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 584         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
 585         if (message)
 586                 strbuf_addf(&sb, " %s\n", message);
 587         else
 588                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 589         diff_emit_submodule_header(o, sb.buf);
 590
 591         strbuf_release(&sb);
 592 }
 593
 594 void show_submodule_summary(struct diff_options *o, const char *path,
 595                 struct object_id *one, struct object_id *two,
 596                 unsigned dirty_submodule)
 597 {
 598         struct rev_info rev;
 599         struct commit *left = NULL, *right = NULL;
 600         struct commit_list *merge_bases = NULL;
 601
 602         show_submodule_header(o, path, one, two, dirty_submodule,
 603                               &left, &right, &merge_bases);
 604
 605         /*
 606          * If we don't have both a left and a right pointer, there is no
 607          * reason to try and display a summary. The header line should contain
 608          * all the information the user needs.
 609          */
 610         if (!left || !right)
 611                 goto out;
 612
 613         /* Treat revision walker failure the same as missing commits */
 614         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 615                 diff_emit_submodule_error(o, "(revision walker failed)\n");
 616                 goto out;
 617         }
 618
 619         print_submodule_summary(&rev, o);
 620
 621 out:
 622         if (merge_bases)
 623                 free_commit_list(merge_bases);
 624         clear_commit_marks(left, ~0);
 625         clear_commit_marks(right, ~0);
 626 }
 627
 628 void show_submodule_inline_diff(struct diff_options *o, const char *path,
 629                 struct object_id *one, struct object_id *two,
 630                 unsigned dirty_submodule)
 631 {
 632         const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
 633         struct commit *left = NULL, *right = NULL;
 634         struct commit_list *merge_bases = NULL;
 635         struct child_process cp = CHILD_PROCESS_INIT;
 636         struct strbuf sb = STRBUF_INIT;
 637
 638         show_submodule_header(o, path, one, two, dirty_submodule,
 639                               &left, &right, &merge_bases);
 640
 641         /* We need a valid left and right commit to display a difference */
 642         if (!(left || is_null_oid(one)) ||
 643             !(right || is_null_oid(two)))
 644                 goto done;
 645
 646         if (left)
 647                 old = one;
 648         if (right)
 649                 new = two;
 650
 651         cp.git_cmd = 1;
 652         cp.dir = path;
 653         cp.out = -1;
 654         cp.no_stdin = 1;
 655
 656         /* TODO: other options may need to be passed here. */
 657         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 658         argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 659                          "always" : "never");
 660
 661         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
 662                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 663                                  o->b_prefix, path);
 664                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 665                                  o->a_prefix, path);
 666         } else {
 667                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 668                                  o->a_prefix, path);
 669                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 670                                  o->b_prefix, path);
 671         }
 672         argv_array_push(&cp.args, oid_to_hex(old));
 673         /*
 674          * If the submodule has modified content, we will diff against the
 675          * work tree, under the assumption that the user has asked for the
 676          * diff format and wishes to actually see all differences even if they
 677          * haven't yet been committed to the submodule yet.
 678          */
 679         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 680                 argv_array_push(&cp.args, oid_to_hex(new));
 681
 682         prepare_submodule_repo_env(&cp.env_array);
 683         if (start_command(&cp))
 684                 diff_emit_submodule_error(o, "(diff failed)\n");
 685
 686         while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
 687                 diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
 688
 689         if (finish_command(&cp))
 690                 diff_emit_submodule_error(o, "(diff failed)\n");
 691
 692 done:
 693         strbuf_release(&sb);
 694         if (merge_bases)
 695                 free_commit_list(merge_bases);
 696         if (left)
 697                 clear_commit_marks(left, ~0);
 698         if (right)
 699                 clear_commit_marks(right, ~0);
 700 }
 701
 702 void set_config_fetch_recurse_submodules(int value)
 703 {
 704         config_fetch_recurse_submodules = value;
 705 }
 706
 707 int should_update_submodules(void)
 708 {
 709         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 710 }
 711
 712 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 713 {
 714         if (!S_ISGITLINK(ce->ce_mode))
 715                 return NULL;
 716
 717         if (!should_update_submodules())
 718                 return NULL;
 719
 720         return submodule_from_path(null_sha1, ce->name);
 721 }
 722
 723 static struct oid_array *submodule_commits(struct string_list *submodules,
 724                                            const char *path)
 725 {
 726         struct string_list_item *item;
 727
 728         item = string_list_insert(submodules, path);
 729         if (item->util)
 730                 return (struct oid_array *) item->util;
 731
 732         /* NEEDSWORK: should we have oid_array_init()? */
 733         item->util = xcalloc(1, sizeof(struct oid_array));
 734         return (struct oid_array *) item->util;
 735 }
 736
 737 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 738                                           struct diff_options *options,
 739                                           void *data)
 740 {
 741         int i;
 742         struct string_list *changed = data;
 743
 744         for (i = 0; i < q->nr; i++) {
 745                 struct diff_filepair *p = q->queue[i];
 746                 struct oid_array *commits;
 747                 if (!S_ISGITLINK(p->two->mode))
 748                         continue;
 749
 750                 if (S_ISGITLINK(p->one->mode)) {
 751                         /*
 752                          * NEEDSWORK: We should honor the name configured in
 753                          * the .gitmodules file of the commit we are examining
 754                          * here to be able to correctly follow submodules
 755                          * being moved around.
 756                          */
 757                         commits = submodule_commits(changed, p->two->path);
 758                         oid_array_append(commits, &p->two->oid);
 759                 } else {
 760                         /* Submodule is new or was moved here */
 761                         /*
 762                          * NEEDSWORK: When the .git directories of submodules
 763                          * live inside the superprojects .git directory some
 764                          * day we should fetch new submodules directly into
 765                          * that location too when config or options request
 766                          * that so they can be checked out from there.
 767                          */
 768                         continue;
 769                 }
 770         }
 771 }
 772
 773 /*
 774  * Collect the paths of submodules in 'changed' which have changed based on
 775  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 776  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 777  * what the submodule pointers were updated to during the change.
 778  */
 779 static void collect_changed_submodules(struct string_list *changed,
 780                                        struct argv_array *argv)
 781 {
 782         struct rev_info rev;
 783         const struct commit *commit;
 784
 785         init_revisions(&rev, NULL);
 786         setup_revisions(argv->argc, argv->argv, &rev, NULL);
 787         if (prepare_revision_walk(&rev))
 788                 die("revision walk setup failed");
 789
 790         while ((commit = get_revision(&rev))) {
 791                 struct rev_info diff_rev;
 792
 793                 init_revisions(&diff_rev, NULL);
 794                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 795                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 796                 diff_rev.diffopt.format_callback_data = changed;
 797                 diff_tree_combined_merge(commit, 1, &diff_rev);
 798         }
 799
 800         reset_revision_walk();
 801 }
 802
 803 static void free_submodules_oids(struct string_list *submodules)
 804 {
 805         struct string_list_item *item;
 806         for_each_string_list_item(item, submodules)
 807                 oid_array_clear((struct oid_array *) item->util);
 808         string_list_clear(submodules, 1);
 809 }
 810
 811 static int has_remote(const char *refname, const struct object_id *oid,
 812                       int flags, void *cb_data)
 813 {
 814         return 1;
 815 }
 816
 817 static int append_oid_to_argv(const struct object_id *oid, void *data)
 818 {
 819         struct argv_array *argv = data;
 820         argv_array_push(argv, oid_to_hex(oid));
 821         return 0;
 822 }
 823
 824 static int check_has_commit(const struct object_id *oid, void *data)
 825 {
 826         int *has_commit = data;
 827
 828         if (!lookup_commit_reference(oid))
 829                 *has_commit = 0;
 830
 831         return 0;
 832 }
 833
 834 static int submodule_has_commits(const char *path, struct oid_array *commits)
 835 {
 836         int has_commit = 1;
 837
 838         /*
 839          * Perform a cheap, but incorrect check for the existance of 'commits'.
 840          * This is done by adding the submodule's object store to the in-core
 841          * object store, and then querying for each commit's existance.  If we
 842          * do not have the commit object anywhere, there is no chance we have
 843          * it in the object store of the correct submodule and have it
 844          * reachable from a ref, so we can fail early without spawning rev-list
 845          * which is expensive.
 846          */
 847         if (add_submodule_odb(path))
 848                 return 0;
 849
 850         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 851
 852         if (has_commit) {
 853                 /*
 854                  * Even if the submodule is checked out and the commit is
 855                  * present, make sure it exists in the submodule's object store
 856                  * and that it is reachable from a ref.
 857                  */
 858                 struct child_process cp = CHILD_PROCESS_INIT;
 859                 struct strbuf out = STRBUF_INIT;
 860
 861                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 862                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 863                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
 864
 865                 prepare_submodule_repo_env(&cp.env_array);
 866                 cp.git_cmd = 1;
 867                 cp.no_stdin = 1;
 868                 cp.dir = path;
 869
 870                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 871                         has_commit = 0;
 872
 873                 strbuf_release(&out);
 874         }
 875
 876         return has_commit;
 877 }
 878
 879 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
 880 {
 881         if (!submodule_has_commits(path, commits))
 882                 /*
 883                  * NOTE: We do consider it safe to return "no" here. The
 884                  * correct answer would be "We do not know" instead of
 885                  * "No push needed", but it is quite hard to change
 886                  * the submodule pointer without having the submodule
 887                  * around. If a user did however change the submodules
 888                  * without having the submodule around, this indicates
 889                  * an expert who knows what they are doing or a
 890                  * maintainer integrating work from other people. In
 891                  * both cases it should be safe to skip this check.
 892                  */
 893                 return 0;
 894
 895         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 896                 struct child_process cp = CHILD_PROCESS_INIT;
 897                 struct strbuf buf = STRBUF_INIT;
 898                 int needs_pushing = 0;
 899
 900                 argv_array_push(&cp.args, "rev-list");
 901                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 902                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 903
 904                 prepare_submodule_repo_env(&cp.env_array);
 905                 cp.git_cmd = 1;
 906                 cp.no_stdin = 1;
 907                 cp.out = -1;
 908                 cp.dir = path;
 909                 if (start_command(&cp))
 910                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 911                                         path);
 912                 if (strbuf_read(&buf, cp.out, 41))
 913                         needs_pushing = 1;
 914                 finish_command(&cp);
 915                 close(cp.out);
 916                 strbuf_release(&buf);
 917                 return needs_pushing;
 918         }
 919
 920         return 0;
 921 }
 922
 923 int find_unpushed_submodules(struct oid_array *commits,
 924                 const char *remotes_name, struct string_list *needs_pushing)
 925 {
 926         struct string_list submodules = STRING_LIST_INIT_DUP;
 927         struct string_list_item *submodule;
 928         struct argv_array argv = ARGV_ARRAY_INIT;
 929
 930         /* argv.argv[0] will be ignored by setup_revisions */
 931         argv_array_push(&argv, "find_unpushed_submodules");
 932         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
 933         argv_array_push(&argv, "--not");
 934         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
 935
 936         collect_changed_submodules(&submodules, &argv);
 937
 938         for_each_string_list_item(submodule, &submodules) {
 939                 struct oid_array *commits = submodule->util;
 940                 const char *path = submodule->string;
 941
 942                 if (submodule_needs_pushing(path, commits))
 943                         string_list_insert(needs_pushing, path);
 944         }
 945
 946         free_submodules_oids(&submodules);
 947         argv_array_clear(&argv);
 948
 949         return needs_pushing->nr;
 950 }
 951
 952 static int push_submodule(const char *path,
 953                           const struct remote *remote,
 954                           const char **refspec, int refspec_nr,
 955                           const struct string_list *push_options,
 956                           int dry_run)
 957 {
 958         if (add_submodule_odb(path))
 959                 return 1;
 960
 961         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 962                 struct child_process cp = CHILD_PROCESS_INIT;
 963                 argv_array_push(&cp.args, "push");
 964                 if (dry_run)
 965                         argv_array_push(&cp.args, "--dry-run");
 966
 967                 if (push_options && push_options->nr) {
 968                         const struct string_list_item *item;
 969                         for_each_string_list_item(item, push_options)
 970                                 argv_array_pushf(&cp.args, "--push-option=%s",
 971                                                  item->string);
 972                 }
 973
 974                 if (remote->origin != REMOTE_UNCONFIGURED) {
 975                         int i;
 976                         argv_array_push(&cp.args, remote->name);
 977                         for (i = 0; i < refspec_nr; i++)
 978                                 argv_array_push(&cp.args, refspec[i]);
 979                 }
 980
 981                 prepare_submodule_repo_env(&cp.env_array);
 982                 cp.git_cmd = 1;
 983                 cp.no_stdin = 1;
 984                 cp.dir = path;
 985                 if (run_command(&cp))
 986                         return 0;
 987                 close(cp.out);
 988         }
 989
 990         return 1;
 991 }
 992
 993 /*
 994  * Perform a check in the submodule to see if the remote and refspec work.
 995  * Die if the submodule can't be pushed.
 996  */
 997 static void submodule_push_check(const char *path, const struct remote *remote,
 998                                  const char **refspec, int refspec_nr)
 999 {
1000         struct child_process cp = CHILD_PROCESS_INIT;
1001         int i;
1002
1003         argv_array_push(&cp.args, "submodule--helper");
1004         argv_array_push(&cp.args, "push-check");
1005         argv_array_push(&cp.args, remote->name);
1006
1007         for (i = 0; i < refspec_nr; i++)
1008                 argv_array_push(&cp.args, refspec[i]);
1009
1010         prepare_submodule_repo_env(&cp.env_array);
1011         cp.git_cmd = 1;
1012         cp.no_stdin = 1;
1013         cp.no_stdout = 1;
1014         cp.dir = path;
1015
1016         /*
1017          * Simply indicate if 'submodule--helper push-check' failed.
1018          * More detailed error information will be provided by the
1019          * child process.
1020          */
1021         if (run_command(&cp))
1022                 die("process for submodule '%s' failed", path);
1023 }
1024
1025 int push_unpushed_submodules(struct oid_array *commits,
1026                              const struct remote *remote,
1027                              const char **refspec, int refspec_nr,
1028                              const struct string_list *push_options,
1029                              int dry_run)
1030 {
1031         int i, ret = 1;
1032         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1033
1034         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1035                 return 1;
1036
1037         /*
1038          * Verify that the remote and refspec can be propagated to all
1039          * submodules.  This check can be skipped if the remote and refspec
1040          * won't be propagated due to the remote being unconfigured (e.g. a URL
1041          * instead of a remote name).
1042          */
1043         if (remote->origin != REMOTE_UNCONFIGURED)
1044                 for (i = 0; i < needs_pushing.nr; i++)
1045                         submodule_push_check(needs_pushing.items[i].string,
1046                                              remote, refspec, refspec_nr);
1047
1048         /* Actually push the submodules */
1049         for (i = 0; i < needs_pushing.nr; i++) {
1050                 const char *path = needs_pushing.items[i].string;
1051                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1052                 if (!push_submodule(path, remote, refspec, refspec_nr,
1053                                     push_options, dry_run)) {
1054                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1055                         ret = 0;
1056                 }
1057         }
1058
1059         string_list_clear(&needs_pushing, 0);
1060
1061         return ret;
1062 }
1063
1064 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1065                                int flags, void *data)
1066 {
1067         struct oid_array *array = data;
1068         oid_array_append(array, oid);
1069         return 0;
1070 }
1071
1072 void check_for_new_submodule_commits(struct object_id *oid)
1073 {
1074         if (!initialized_fetch_ref_tips) {
1075                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1076                 initialized_fetch_ref_tips = 1;
1077         }
1078
1079         oid_array_append(&ref_tips_after_fetch, oid);
1080 }
1081
1082 static void calculate_changed_submodule_paths(void)
1083 {
1084         struct argv_array argv = ARGV_ARRAY_INIT;
1085         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1086         const struct string_list_item *item;
1087
1088         /* No need to check if there are no submodules configured */
1089         if (!submodule_from_path(NULL, NULL))
1090                 return;
1091
1092         argv_array_push(&argv, "--"); /* argv[0] program name */
1093         oid_array_for_each_unique(&ref_tips_after_fetch,
1094                                    append_oid_to_argv, &argv);
1095         argv_array_push(&argv, "--not");
1096         oid_array_for_each_unique(&ref_tips_before_fetch,
1097                                    append_oid_to_argv, &argv);
1098
1099         /*
1100          * Collect all submodules (whether checked out or not) for which new
1101          * commits have been recorded upstream in "changed_submodule_paths".
1102          */
1103         collect_changed_submodules(&changed_submodules, &argv);
1104
1105         for_each_string_list_item(item, &changed_submodules) {
1106                 struct oid_array *commits = item->util;
1107                 const char *path = item->string;
1108
1109                 if (!submodule_has_commits(path, commits))
1110                         string_list_append(&changed_submodule_paths, path);
1111         }
1112
1113         free_submodules_oids(&changed_submodules);
1114         argv_array_clear(&argv);
1115         oid_array_clear(&ref_tips_before_fetch);
1116         oid_array_clear(&ref_tips_after_fetch);
1117         initialized_fetch_ref_tips = 0;
1118 }
1119
1120 struct submodule_parallel_fetch {
1121         int count;
1122         struct argv_array args;
1123         const char *work_tree;
1124         const char *prefix;
1125         int command_line_option;
1126         int quiet;
1127         int result;
1128 };
1129 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0}
1130
1131 static int get_next_submodule(struct child_process *cp,
1132                               struct strbuf *err, void *data, void **task_cb)
1133 {
1134         int ret = 0;
1135         struct submodule_parallel_fetch *spf = data;
1136
1137         for (; spf->count < active_nr; spf->count++) {
1138                 struct strbuf submodule_path = STRBUF_INIT;
1139                 struct strbuf submodule_git_dir = STRBUF_INIT;
1140                 struct strbuf submodule_prefix = STRBUF_INIT;
1141                 const struct cache_entry *ce = active_cache[spf->count];
1142                 const char *git_dir, *default_argv;
1143                 const struct submodule *submodule;
1144
1145                 if (!S_ISGITLINK(ce->ce_mode))
1146                         continue;
1147
1148                 submodule = submodule_from_path(null_sha1, ce->name);
1149                 if (!submodule)
1150                         submodule = submodule_from_name(null_sha1, ce->name);
1151
1152                 default_argv = "yes";
1153                 if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
1154                         if (submodule &&
1155                             submodule->fetch_recurse !=
1156                                                 RECURSE_SUBMODULES_NONE) {
1157                                 if (submodule->fetch_recurse ==
1158                                                 RECURSE_SUBMODULES_OFF)
1159                                         continue;
1160                                 if (submodule->fetch_recurse ==
1161                                                 RECURSE_SUBMODULES_ON_DEMAND) {
1162                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1163                                                 continue;
1164                                         default_argv = "on-demand";
1165                                 }
1166                         } else {
1167                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
1168                                     gitmodules_is_unmerged)
1169                                         continue;
1170                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
1171                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1172                                                 continue;
1173                                         default_argv = "on-demand";
1174                                 }
1175                         }
1176                 } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
1177                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1178                                 continue;
1179                         default_argv = "on-demand";
1180                 }
1181
1182                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1183                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1184                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1185                 git_dir = read_gitfile(submodule_git_dir.buf);
1186                 if (!git_dir)
1187                         git_dir = submodule_git_dir.buf;
1188                 if (is_directory(git_dir)) {
1189                         child_process_init(cp);
1190                         cp->dir = strbuf_detach(&submodule_path, NULL);
1191                         prepare_submodule_repo_env(&cp->env_array);
1192                         cp->git_cmd = 1;
1193                         if (!spf->quiet)
1194                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1195                                             spf->prefix, ce->name);
1196                         argv_array_init(&cp->args);
1197                         argv_array_pushv(&cp->args, spf->args.argv);
1198                         argv_array_push(&cp->args, default_argv);
1199                         argv_array_push(&cp->args, "--submodule-prefix");
1200                         argv_array_push(&cp->args, submodule_prefix.buf);
1201                         ret = 1;
1202                 }
1203                 strbuf_release(&submodule_path);
1204                 strbuf_release(&submodule_git_dir);
1205                 strbuf_release(&submodule_prefix);
1206                 if (ret) {
1207                         spf->count++;
1208                         return 1;
1209                 }
1210         }
1211         return 0;
1212 }
1213
1214 static int fetch_start_failure(struct strbuf *err,
1215                                void *cb, void *task_cb)
1216 {
1217         struct submodule_parallel_fetch *spf = cb;
1218
1219         spf->result = 1;
1220
1221         return 0;
1222 }
1223
1224 static int fetch_finish(int retvalue, struct strbuf *err,
1225                         void *cb, void *task_cb)
1226 {
1227         struct submodule_parallel_fetch *spf = cb;
1228
1229         if (retvalue)
1230                 spf->result = 1;
1231
1232         return 0;
1233 }
1234
1235 int fetch_populated_submodules(const struct argv_array *options,
1236                                const char *prefix, int command_line_option,
1237                                int quiet, int max_parallel_jobs)
1238 {
1239         int i;
1240         struct submodule_parallel_fetch spf = SPF_INIT;
1241
1242         spf.work_tree = get_git_work_tree();
1243         spf.command_line_option = command_line_option;
1244         spf.quiet = quiet;
1245         spf.prefix = prefix;
1246
1247         if (!spf.work_tree)
1248                 goto out;
1249
1250         if (read_cache() < 0)
1251                 die("index file corrupt");
1252
1253         argv_array_push(&spf.args, "fetch");
1254         for (i = 0; i < options->argc; i++)
1255                 argv_array_push(&spf.args, options->argv[i]);
1256         argv_array_push(&spf.args, "--recurse-submodules-default");
1257         /* default value, "--submodule-prefix" and its value are added later */
1258
1259         if (max_parallel_jobs < 0)
1260                 max_parallel_jobs = parallel_jobs;
1261
1262         calculate_changed_submodule_paths();
1263         run_processes_parallel(max_parallel_jobs,
1264                                get_next_submodule,
1265                                fetch_start_failure,
1266                                fetch_finish,
1267                                &spf);
1268
1269         argv_array_clear(&spf.args);
1270 out:
1271         string_list_clear(&changed_submodule_paths, 1);
1272         return spf.result;
1273 }
1274
1275 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1276 {
1277         struct child_process cp = CHILD_PROCESS_INIT;
1278         struct strbuf buf = STRBUF_INIT;
1279         FILE *fp;
1280         unsigned dirty_submodule = 0;
1281         const char *git_dir;
1282         int ignore_cp_exit_code = 0;
1283
1284         strbuf_addf(&buf, "%s/.git", path);
1285         git_dir = read_gitfile(buf.buf);
1286         if (!git_dir)
1287                 git_dir = buf.buf;
1288         if (!is_git_directory(git_dir)) {
1289                 if (is_directory(git_dir))
1290                         die(_("'%s' not recognized as a git repository"), git_dir);
1291                 strbuf_release(&buf);
1292                 /* The submodule is not checked out, so it is not modified */
1293                 return 0;
1294         }
1295         strbuf_reset(&buf);
1296
1297         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1298         if (ignore_untracked)
1299                 argv_array_push(&cp.args, "-uno");
1300
1301         prepare_submodule_repo_env(&cp.env_array);
1302         cp.git_cmd = 1;
1303         cp.no_stdin = 1;
1304         cp.out = -1;
1305         cp.dir = path;
1306         if (start_command(&cp))
1307                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1308
1309         fp = xfdopen(cp.out, "r");
1310         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1311                 /* regular untracked files */
1312                 if (buf.buf[0] == '?')
1313                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1314
1315                 if (buf.buf[0] == 'u' ||
1316                     buf.buf[0] == '1' ||
1317                     buf.buf[0] == '2') {
1318                         /* T = line type, XY = status, SSSS = submodule state */
1319                         if (buf.len < strlen("T XY SSSS"))
1320                                 die("BUG: invalid status --porcelain=2 line %s",
1321                                     buf.buf);
1322
1323                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1324                                 /* nested untracked file */
1325                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1326
1327                         if (buf.buf[0] == 'u' ||
1328                             buf.buf[0] == '2' ||
1329                             memcmp(buf.buf + 5, "S..U", 4))
1330                                 /* other change */
1331                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1332                 }
1333
1334                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1335                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1336                      ignore_untracked)) {
1337                         /*
1338                          * We're not interested in any further information from
1339                          * the child any more, neither output nor its exit code.
1340                          */
1341                         ignore_cp_exit_code = 1;
1342                         break;
1343                 }
1344         }
1345         fclose(fp);
1346
1347         if (finish_command(&cp) && !ignore_cp_exit_code)
1348                 die("'git status --porcelain=2' failed in submodule %s", path);
1349
1350         strbuf_release(&buf);
1351         return dirty_submodule;
1352 }
1353
1354 int submodule_uses_gitfile(const char *path)
1355 {
1356         struct child_process cp = CHILD_PROCESS_INIT;
1357         const char *argv[] = {
1358                 "submodule",
1359                 "foreach",
1360                 "--quiet",
1361                 "--recursive",
1362                 "test -f .git",
1363                 NULL,
1364         };
1365         struct strbuf buf = STRBUF_INIT;
1366         const char *git_dir;
1367
1368         strbuf_addf(&buf, "%s/.git", path);
1369         git_dir = read_gitfile(buf.buf);
1370         if (!git_dir) {
1371                 strbuf_release(&buf);
1372                 return 0;
1373         }
1374         strbuf_release(&buf);
1375
1376         /* Now test that all nested submodules use a gitfile too */
1377         cp.argv = argv;
1378         prepare_submodule_repo_env(&cp.env_array);
1379         cp.git_cmd = 1;
1380         cp.no_stdin = 1;
1381         cp.no_stderr = 1;
1382         cp.no_stdout = 1;
1383         cp.dir = path;
1384         if (run_command(&cp))
1385                 return 0;
1386
1387         return 1;
1388 }
1389
1390 /*
1391  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1392  * when doing so.
1393  *
1394  * Return 1 if we'd lose data, return 0 if the removal is fine,
1395  * and negative values for errors.
1396  */
1397 int bad_to_remove_submodule(const char *path, unsigned flags)
1398 {
1399         ssize_t len;
1400         struct child_process cp = CHILD_PROCESS_INIT;
1401         struct strbuf buf = STRBUF_INIT;
1402         int ret = 0;
1403
1404         if (!file_exists(path) || is_empty_dir(path))
1405                 return 0;
1406
1407         if (!submodule_uses_gitfile(path))
1408                 return 1;
1409
1410         argv_array_pushl(&cp.args, "status", "--porcelain",
1411                                    "--ignore-submodules=none", NULL);
1412
1413         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1414                 argv_array_push(&cp.args, "-uno");
1415         else
1416                 argv_array_push(&cp.args, "-uall");
1417
1418         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1419                 argv_array_push(&cp.args, "--ignored");
1420
1421         prepare_submodule_repo_env(&cp.env_array);
1422         cp.git_cmd = 1;
1423         cp.no_stdin = 1;
1424         cp.out = -1;
1425         cp.dir = path;
1426         if (start_command(&cp)) {
1427                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1428                         die(_("could not start 'git status' in submodule '%s'"),
1429                                 path);
1430                 ret = -1;
1431                 goto out;
1432         }
1433
1434         len = strbuf_read(&buf, cp.out, 1024);
1435         if (len > 2)
1436                 ret = 1;
1437         close(cp.out);
1438
1439         if (finish_command(&cp)) {
1440                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1441                         die(_("could not run 'git status' in submodule '%s'"),
1442                                 path);
1443                 ret = -1;
1444         }
1445 out:
1446         strbuf_release(&buf);
1447         return ret;
1448 }
1449
1450 static const char *get_super_prefix_or_empty(void)
1451 {
1452         const char *s = get_super_prefix();
1453         if (!s)
1454                 s = "";
1455         return s;
1456 }
1457
1458 static int submodule_has_dirty_index(const struct submodule *sub)
1459 {
1460         struct child_process cp = CHILD_PROCESS_INIT;
1461
1462         prepare_submodule_repo_env(&cp.env_array);
1463
1464         cp.git_cmd = 1;
1465         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1466                                    "--cached", "HEAD", NULL);
1467         cp.no_stdin = 1;
1468         cp.no_stdout = 1;
1469         cp.dir = sub->path;
1470         if (start_command(&cp))
1471                 die("could not recurse into submodule '%s'", sub->path);
1472
1473         return finish_command(&cp);
1474 }
1475
1476 static void submodule_reset_index(const char *path)
1477 {
1478         struct child_process cp = CHILD_PROCESS_INIT;
1479         prepare_submodule_repo_env(&cp.env_array);
1480
1481         cp.git_cmd = 1;
1482         cp.no_stdin = 1;
1483         cp.dir = path;
1484
1485         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1486                                    get_super_prefix_or_empty(), path);
1487         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1488
1489         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1490
1491         if (run_command(&cp))
1492                 die("could not reset submodule index");
1493 }
1494
1495 /**
1496  * Moves a submodule at a given path from a given head to another new head.
1497  * For edge cases (a submodule coming into existence or removing a submodule)
1498  * pass NULL for old or new respectively.
1499  */
1500 int submodule_move_head(const char *path,
1501                          const char *old,
1502                          const char *new,
1503                          unsigned flags)
1504 {
1505         int ret = 0;
1506         struct child_process cp = CHILD_PROCESS_INIT;
1507         const struct submodule *sub;
1508         int *error_code_ptr, error_code;
1509
1510         if (!is_submodule_initialized(path))
1511                 return 0;
1512
1513         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1514                 /*
1515                  * Pass non NULL pointer to is_submodule_populated_gently
1516                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1517                  * to fixup the submodule in the force case later.
1518                  */
1519                 error_code_ptr = &error_code;
1520         else
1521                 error_code_ptr = NULL;
1522
1523         if (old && !is_submodule_populated_gently(path, error_code_ptr))
1524                 return 0;
1525
1526         sub = submodule_from_path(null_sha1, path);
1527
1528         if (!sub)
1529                 die("BUG: could not get submodule information for '%s'", path);
1530
1531         if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1532                 /* Check if the submodule has a dirty index. */
1533                 if (submodule_has_dirty_index(sub))
1534                         return error(_("submodule '%s' has dirty index"), path);
1535         }
1536
1537         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1538                 if (old) {
1539                         if (!submodule_uses_gitfile(path))
1540                                 absorb_git_dir_into_superproject("", path,
1541                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1542                 } else {
1543                         char *gitdir = xstrfmt("%s/modules/%s",
1544                                     get_git_common_dir(), sub->name);
1545                         connect_work_tree_and_git_dir(path, gitdir);
1546                         free(gitdir);
1547
1548                         /* make sure the index is clean as well */
1549                         submodule_reset_index(path);
1550                 }
1551
1552                 if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1553                         char *gitdir = xstrfmt("%s/modules/%s",
1554                                     get_git_common_dir(), sub->name);
1555                         connect_work_tree_and_git_dir(path, gitdir);
1556                         free(gitdir);
1557                 }
1558         }
1559
1560         prepare_submodule_repo_env(&cp.env_array);
1561
1562         cp.git_cmd = 1;
1563         cp.no_stdin = 1;
1564         cp.dir = path;
1565
1566         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1567                         get_super_prefix_or_empty(), path);
1568         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1569
1570         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1571                 argv_array_push(&cp.args, "-n");
1572         else
1573                 argv_array_push(&cp.args, "-u");
1574
1575         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1576                 argv_array_push(&cp.args, "--reset");
1577         else
1578                 argv_array_push(&cp.args, "-m");
1579
1580         argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1581         argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1582
1583         if (run_command(&cp)) {
1584                 ret = -1;
1585                 goto out;
1586         }
1587
1588         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1589                 if (new) {
1590                         child_process_init(&cp);
1591                         /* also set the HEAD accordingly */
1592                         cp.git_cmd = 1;
1593                         cp.no_stdin = 1;
1594                         cp.dir = path;
1595
1596                         prepare_submodule_repo_env(&cp.env_array);
1597                         argv_array_pushl(&cp.args, "update-ref", "HEAD", new, NULL);
1598
1599                         if (run_command(&cp)) {
1600                                 ret = -1;
1601                                 goto out;
1602                         }
1603                 } else {
1604                         struct strbuf sb = STRBUF_INIT;
1605
1606                         strbuf_addf(&sb, "%s/.git", path);
1607                         unlink_or_warn(sb.buf);
1608                         strbuf_release(&sb);
1609
1610                         if (is_empty_dir(path))
1611                                 rmdir_or_warn(path);
1612                 }
1613         }
1614 out:
1615         return ret;
1616 }
1617
1618 static int find_first_merges(struct object_array *result, const char *path,
1619                 struct commit *a, struct commit *b)
1620 {
1621         int i, j;
1622         struct object_array merges = OBJECT_ARRAY_INIT;
1623         struct commit *commit;
1624         int contains_another;
1625
1626         char merged_revision[42];
1627         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1628                                    "--all", merged_revision, NULL };
1629         struct rev_info revs;
1630         struct setup_revision_opt rev_opts;
1631
1632         memset(result, 0, sizeof(struct object_array));
1633         memset(&rev_opts, 0, sizeof(rev_opts));
1634
1635         /* get all revisions that merge commit a */
1636         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1637                         oid_to_hex(&a->object.oid));
1638         init_revisions(&revs, NULL);
1639         rev_opts.submodule = path;
1640         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1641
1642         /* save all revisions from the above list that contain b */
1643         if (prepare_revision_walk(&revs))
1644                 die("revision walk setup failed");
1645         while ((commit = get_revision(&revs)) != NULL) {
1646                 struct object *o = &(commit->object);
1647                 if (in_merge_bases(b, commit))
1648                         add_object_array(o, NULL, &merges);
1649         }
1650         reset_revision_walk();
1651
1652         /* Now we've got all merges that contain a and b. Prune all
1653          * merges that contain another found merge and save them in
1654          * result.
1655          */
1656         for (i = 0; i < merges.nr; i++) {
1657                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1658
1659                 contains_another = 0;
1660                 for (j = 0; j < merges.nr; j++) {
1661                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1662                         if (i != j && in_merge_bases(m2, m1)) {
1663                                 contains_another = 1;
1664                                 break;
1665                         }
1666                 }
1667
1668                 if (!contains_another)
1669                         add_object_array(merges.objects[i].item, NULL, result);
1670         }
1671
1672         free(merges.objects);
1673         return result->nr;
1674 }
1675
1676 static void print_commit(struct commit *commit)
1677 {
1678         struct strbuf sb = STRBUF_INIT;
1679         struct pretty_print_context ctx = {0};
1680         ctx.date_mode.type = DATE_NORMAL;
1681         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1682         fprintf(stderr, "%s\n", sb.buf);
1683         strbuf_release(&sb);
1684 }
1685
1686 #define MERGE_WARNING(path, msg) \
1687         warning("Failed to merge submodule %s (%s)", path, msg);
1688
1689 int merge_submodule(struct object_id *result, const char *path,
1690                     const struct object_id *base, const struct object_id *a,
1691                     const struct object_id *b, int search)
1692 {
1693         struct commit *commit_base, *commit_a, *commit_b;
1694         int parent_count;
1695         struct object_array merges;
1696
1697         int i;
1698
1699         /* store a in result in case we fail */
1700         oidcpy(result, a);
1701
1702         /* we can not handle deletion conflicts */
1703         if (is_null_oid(base))
1704                 return 0;
1705         if (is_null_oid(a))
1706                 return 0;
1707         if (is_null_oid(b))
1708                 return 0;
1709
1710         if (add_submodule_odb(path)) {
1711                 MERGE_WARNING(path, "not checked out");
1712                 return 0;
1713         }
1714
1715         if (!(commit_base = lookup_commit_reference(base)) ||
1716             !(commit_a = lookup_commit_reference(a)) ||
1717             !(commit_b = lookup_commit_reference(b))) {
1718                 MERGE_WARNING(path, "commits not present");
1719                 return 0;
1720         }
1721
1722         /* check whether both changes are forward */
1723         if (!in_merge_bases(commit_base, commit_a) ||
1724             !in_merge_bases(commit_base, commit_b)) {
1725                 MERGE_WARNING(path, "commits don't follow merge-base");
1726                 return 0;
1727         }
1728
1729         /* Case #1: a is contained in b or vice versa */
1730         if (in_merge_bases(commit_a, commit_b)) {
1731                 oidcpy(result, b);
1732                 return 1;
1733         }
1734         if (in_merge_bases(commit_b, commit_a)) {
1735                 oidcpy(result, a);
1736                 return 1;
1737         }
1738
1739         /*
1740          * Case #2: There are one or more merges that contain a and b in
1741          * the submodule. If there is only one, then present it as a
1742          * suggestion to the user, but leave it marked unmerged so the
1743          * user needs to confirm the resolution.
1744          */
1745
1746         /* Skip the search if makes no sense to the calling context.  */
1747         if (!search)
1748                 return 0;
1749
1750         /* find commit which merges them */
1751         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1752         switch (parent_count) {
1753         case 0:
1754                 MERGE_WARNING(path, "merge following commits not found");
1755                 break;
1756
1757         case 1:
1758                 MERGE_WARNING(path, "not fast-forward");
1759                 fprintf(stderr, "Found a possible merge resolution "
1760                                 "for the submodule:\n");
1761                 print_commit((struct commit *) merges.objects[0].item);
1762                 fprintf(stderr,
1763                         "If this is correct simply add it to the index "
1764                         "for example\n"
1765                         "by using:\n\n"
1766                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1767                         "which will accept this suggestion.\n",
1768                         oid_to_hex(&merges.objects[0].item->oid), path);
1769                 break;
1770
1771         default:
1772                 MERGE_WARNING(path, "multiple merges found");
1773                 for (i = 0; i < merges.nr; i++)
1774                         print_commit((struct commit *) merges.objects[i].item);
1775         }
1776
1777         free(merges.objects);
1778         return 0;
1779 }
1780
1781 int parallel_submodules(void)
1782 {
1783         return parallel_jobs;
1784 }
1785
1786 /*
1787  * Embeds a single submodules git directory into the superprojects git dir,
1788  * non recursively.
1789  */
1790 static void relocate_single_git_dir_into_superproject(const char *prefix,
1791                                                       const char *path)
1792 {
1793         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1794         const char *new_git_dir;
1795         const struct submodule *sub;
1796
1797         if (submodule_uses_worktrees(path))
1798                 die(_("relocate_gitdir for submodule '%s' with "
1799                       "more than one worktree not supported"), path);
1800
1801         old_git_dir = xstrfmt("%s/.git", path);
1802         if (read_gitfile(old_git_dir))
1803                 /* If it is an actual gitfile, it doesn't need migration. */
1804                 return;
1805
1806         real_old_git_dir = real_pathdup(old_git_dir, 1);
1807
1808         sub = submodule_from_path(null_sha1, path);
1809         if (!sub)
1810                 die(_("could not lookup name for submodule '%s'"), path);
1811
1812         new_git_dir = git_path("modules/%s", sub->name);
1813         if (safe_create_leading_directories_const(new_git_dir) < 0)
1814                 die(_("could not create directory '%s'"), new_git_dir);
1815         real_new_git_dir = real_pathdup(new_git_dir, 1);
1816
1817         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1818                 get_super_prefix_or_empty(), path,
1819                 real_old_git_dir, real_new_git_dir);
1820
1821         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1822
1823         free(old_git_dir);
1824         free(real_old_git_dir);
1825         free(real_new_git_dir);
1826 }
1827
1828 /*
1829  * Migrate the git directory of the submodule given by path from
1830  * having its git directory within the working tree to the git dir nested
1831  * in its superprojects git dir under modules/.
1832  */
1833 void absorb_git_dir_into_superproject(const char *prefix,
1834                                       const char *path,
1835                                       unsigned flags)
1836 {
1837         int err_code;
1838         const char *sub_git_dir;
1839         struct strbuf gitdir = STRBUF_INIT;
1840         strbuf_addf(&gitdir, "%s/.git", path);
1841         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1842
1843         /* Not populated? */
1844         if (!sub_git_dir) {
1845                 const struct submodule *sub;
1846
1847                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1848                         /* unpopulated as expected */
1849                         strbuf_release(&gitdir);
1850                         return;
1851                 }
1852
1853                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1854                         /* We don't know what broke here. */
1855                         read_gitfile_error_die(err_code, path, NULL);
1856
1857                 /*
1858                 * Maybe populated, but no git directory was found?
1859                 * This can happen if the superproject is a submodule
1860                 * itself and was just absorbed. The absorption of the
1861                 * superproject did not rewrite the git file links yet,
1862                 * fix it now.
1863                 */
1864                 sub = submodule_from_path(null_sha1, path);
1865                 if (!sub)
1866                         die(_("could not lookup name for submodule '%s'"), path);
1867                 connect_work_tree_and_git_dir(path,
1868                         git_path("modules/%s", sub->name));
1869         } else {
1870                 /* Is it already absorbed into the superprojects git dir? */
1871                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1872                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1873
1874                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1875                         relocate_single_git_dir_into_superproject(prefix, path);
1876
1877                 free(real_sub_git_dir);
1878                 free(real_common_git_dir);
1879         }
1880         strbuf_release(&gitdir);
1881
1882         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1883                 struct child_process cp = CHILD_PROCESS_INIT;
1884                 struct strbuf sb = STRBUF_INIT;
1885
1886                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1887                         die("BUG: we don't know how to pass the flags down?");
1888
1889                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1890                 strbuf_addstr(&sb, path);
1891                 strbuf_addch(&sb, '/');
1892
1893                 cp.dir = path;
1894                 cp.git_cmd = 1;
1895                 cp.no_stdin = 1;
1896                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1897                                            "submodule--helper",
1898                                            "absorb-git-dirs", NULL);
1899                 prepare_submodule_repo_env(&cp.env_array);
1900                 if (run_command(&cp))
1901                         die(_("could not recurse into submodule '%s'"), path);
1902
1903                 strbuf_release(&sb);
1904         }
1905 }
1906
1907 const char *get_superproject_working_tree(void)
1908 {
1909         struct child_process cp = CHILD_PROCESS_INIT;
1910         struct strbuf sb = STRBUF_INIT;
1911         const char *one_up = real_path_if_valid("../");
1912         const char *cwd = xgetcwd();
1913         const char *ret = NULL;
1914         const char *subpath;
1915         int code;
1916         ssize_t len;
1917
1918         if (!is_inside_work_tree())
1919                 /*
1920                  * FIXME:
1921                  * We might have a superproject, but it is harder
1922                  * to determine.
1923                  */
1924                 return NULL;
1925
1926         if (!one_up)
1927                 return NULL;
1928
1929         subpath = relative_path(cwd, one_up, &sb);
1930
1931         prepare_submodule_repo_env(&cp.env_array);
1932         argv_array_pop(&cp.env_array);
1933
1934         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
1935                         "ls-files", "-z", "--stage", "--full-name", "--",
1936                         subpath, NULL);
1937         strbuf_reset(&sb);
1938
1939         cp.no_stdin = 1;
1940         cp.no_stderr = 1;
1941         cp.out = -1;
1942         cp.git_cmd = 1;
1943
1944         if (start_command(&cp))
1945                 die(_("could not start ls-files in .."));
1946
1947         len = strbuf_read(&sb, cp.out, PATH_MAX);
1948         close(cp.out);
1949
1950         if (starts_with(sb.buf, "160000")) {
1951                 int super_sub_len;
1952                 int cwd_len = strlen(cwd);
1953                 char *super_sub, *super_wt;
1954
1955                 /*
1956                  * There is a superproject having this repo as a submodule.
1957                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
1958                  * We're only interested in the name after the tab.
1959                  */
1960                 super_sub = strchr(sb.buf, '\t') + 1;
1961                 super_sub_len = sb.buf + sb.len - super_sub - 1;
1962
1963                 if (super_sub_len > cwd_len ||
1964                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
1965                         die (_("BUG: returned path string doesn't match cwd?"));
1966
1967                 super_wt = xstrdup(cwd);
1968                 super_wt[cwd_len - super_sub_len] = '\0';
1969
1970                 ret = real_path(super_wt);
1971                 free(super_wt);
1972         }
1973         strbuf_release(&sb);
1974
1975         code = finish_command(&cp);
1976
1977         if (code == 128)
1978                 /* '../' is not a git repository */
1979                 return NULL;
1980         if (code == 0 && len == 0)
1981                 /* There is an unrelated git repository at '../' */
1982                 return NULL;
1983         if (code)
1984                 die(_("ls-tree returned unexpected return code %d"), code);
1985
1986         return ret;
1987 }
1988
1989 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
1990 {
1991         const struct submodule *sub;
1992         const char *git_dir;
1993         int ret = 0;
1994
1995         strbuf_reset(buf);
1996         strbuf_addstr(buf, submodule);
1997         strbuf_complete(buf, '/');
1998         strbuf_addstr(buf, ".git");
1999
2000         git_dir = read_gitfile(buf->buf);
2001         if (git_dir) {
2002                 strbuf_reset(buf);
2003                 strbuf_addstr(buf, git_dir);
2004         }
2005         if (!is_git_directory(buf->buf)) {
2006                 gitmodules_config();
2007                 sub = submodule_from_path(null_sha1, submodule);
2008                 if (!sub) {
2009                         ret = -1;
2010                         goto cleanup;
2011                 }
2012                 strbuf_reset(buf);
2013                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2014         }
2015
2016 cleanup:
2017         return ret;
2018 }