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

   1 #include "cache.h"
   2 #include "submodule-config.h"
   3 #include "submodule.h"
   4 #include "dir.h"
   5 #include "diff.h"
   6 #include "commit.h"
   7 #include "revision.h"
   8 #include "run-command.h"
   9 #include "diffcore.h"
  10 #include "refs.h"
  11 #include "string-list.h"
  12 #include "sha1-array.h"
  13 #include "argv-array.h"
  14 #include "blob.h"
  15 #include "thread-utils.h"
  16 #include "quote.h"
  17 #include "worktree.h"
  18
  19 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
  20 static int parallel_jobs = 1;
  21 static struct string_list changed_submodule_paths = STRING_LIST_INIT_NODUP;
  22 static int initialized_fetch_ref_tips;
  23 static struct sha1_array ref_tips_before_fetch;
  24 static struct sha1_array ref_tips_after_fetch;
  25
  26 /*
  27  * The following flag is set if the .gitmodules file is unmerged. We then
  28  * disable recursion for all submodules where .git/config doesn't have a
  29  * matching config entry because we can't guess what might be configured in
  30  * .gitmodules unless the user resolves the conflict. When a command line
  31  * option is given (which always overrides configuration) this flag will be
  32  * ignored.
  33  */
  34 static int gitmodules_is_unmerged;
  35
  36 /*
  37  * This flag is set if the .gitmodules file had unstaged modifications on
  38  * startup. This must be checked before allowing modifications to the
  39  * .gitmodules file with the intention to stage them later, because when
  40  * continuing we would stage the modifications the user didn't stage herself
  41  * too. That might change in a future version when we learn to stage the
  42  * changes we do ourselves without staging any previous modifications.
  43  */
  44 static int gitmodules_is_modified;
  45
  46 int is_staging_gitmodules_ok(void)
  47 {
  48         return !gitmodules_is_modified;
  49 }
  50
  51 /*
  52  * Try to update the "path" entry in the "submodule.<name>" section of the
  53  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
  54  * with the correct path=<oldpath> setting was found and we could update it.
  55  */
  56 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
  57 {
  58         struct strbuf entry = STRBUF_INIT;
  59         const struct submodule *submodule;
  60
  61         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
  62                 return -1;
  63
  64         if (gitmodules_is_unmerged)
  65                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  66
  67         submodule = submodule_from_path(null_sha1, oldpath);
  68         if (!submodule || !submodule->name) {
  69                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
  70                 return -1;
  71         }
  72         strbuf_addstr(&entry, "submodule.");
  73         strbuf_addstr(&entry, submodule->name);
  74         strbuf_addstr(&entry, ".path");
  75         if (git_config_set_in_file_gently(".gitmodules", entry.buf, newpath) < 0) {
  76                 /* Maybe the user already did that, don't error out here */
  77                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
  78                 strbuf_release(&entry);
  79                 return -1;
  80         }
  81         strbuf_release(&entry);
  82         return 0;
  83 }
  84
  85 /*
  86  * Try to remove the "submodule.<name>" section from .gitmodules where the given
  87  * path is configured. Return 0 only if a .gitmodules file was found, a section
  88  * with the correct path=<path> setting was found and we could remove it.
  89  */
  90 int remove_path_from_gitmodules(const char *path)
  91 {
  92         struct strbuf sect = STRBUF_INIT;
  93         const struct submodule *submodule;
  94
  95         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
  96                 return -1;
  97
  98         if (gitmodules_is_unmerged)
  99                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 100
 101         submodule = submodule_from_path(null_sha1, path);
 102         if (!submodule || !submodule->name) {
 103                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 104                 return -1;
 105         }
 106         strbuf_addstr(&sect, "submodule.");
 107         strbuf_addstr(&sect, submodule->name);
 108         if (git_config_rename_section_in_file(".gitmodules", sect.buf, NULL) < 0) {
 109                 /* Maybe the user already did that, don't error out here */
 110                 warning(_("Could not remove .gitmodules entry for %s"), path);
 111                 strbuf_release(&sect);
 112                 return -1;
 113         }
 114         strbuf_release(&sect);
 115         return 0;
 116 }
 117
 118 void stage_updated_gitmodules(void)
 119 {
 120         if (add_file_to_cache(".gitmodules", 0))
 121                 die(_("staging updated .gitmodules failed"));
 122 }
 123
 124 static int add_submodule_odb(const char *path)
 125 {
 126         struct strbuf objects_directory = STRBUF_INIT;
 127         int ret = 0;
 128
 129         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
 130         if (ret)
 131                 goto done;
 132         if (!is_directory(objects_directory.buf)) {
 133                 ret = -1;
 134                 goto done;
 135         }
 136         add_to_alternates_memory(objects_directory.buf);
 137 done:
 138         strbuf_release(&objects_directory);
 139         return ret;
 140 }
 141
 142 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 143                                              const char *path)
 144 {
 145         const struct submodule *submodule = submodule_from_path(null_sha1, path);
 146         if (submodule) {
 147                 if (submodule->ignore)
 148                         handle_ignore_submodules_arg(diffopt, submodule->ignore);
 149                 else if (gitmodules_is_unmerged)
 150                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 151         }
 152 }
 153
 154 int submodule_config(const char *var, const char *value, void *cb)
 155 {
 156         if (!strcmp(var, "submodule.fetchjobs")) {
 157                 parallel_jobs = git_config_int(var, value);
 158                 if (parallel_jobs < 0)
 159                         die(_("negative values not allowed for submodule.fetchJobs"));
 160                 return 0;
 161         } else if (starts_with(var, "submodule."))
 162                 return parse_submodule_config_option(var, value);
 163         else if (!strcmp(var, "fetch.recursesubmodules")) {
 164                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
 165                 return 0;
 166         }
 167         return 0;
 168 }
 169
 170 void gitmodules_config(void)
 171 {
 172         const char *work_tree = get_git_work_tree();
 173         if (work_tree) {
 174                 struct strbuf gitmodules_path = STRBUF_INIT;
 175                 int pos;
 176                 strbuf_addstr(&gitmodules_path, work_tree);
 177                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
 178                 if (read_cache() < 0)
 179                         die("index file corrupt");
 180                 pos = cache_name_pos(".gitmodules", 11);
 181                 if (pos < 0) { /* .gitmodules not found or isn't merged */
 182                         pos = -1 - pos;
 183                         if (active_nr > pos) {  /* there is a .gitmodules */
 184                                 const struct cache_entry *ce = active_cache[pos];
 185                                 if (ce_namelen(ce) == 11 &&
 186                                     !memcmp(ce->name, ".gitmodules", 11))
 187                                         gitmodules_is_unmerged = 1;
 188                         }
 189                 } else if (pos < active_nr) {
 190                         struct stat st;
 191                         if (lstat(".gitmodules", &st) == 0 &&
 192                             ce_match_stat(active_cache[pos], &st, 0) & DATA_CHANGED)
 193                                 gitmodules_is_modified = 1;
 194                 }
 195
 196                 if (!gitmodules_is_unmerged)
 197                         git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
 198                 strbuf_release(&gitmodules_path);
 199         }
 200 }
 201
 202 void gitmodules_config_sha1(const unsigned char *commit_sha1)
 203 {
 204         struct strbuf rev = STRBUF_INIT;
 205         unsigned char sha1[20];
 206
 207         if (gitmodule_sha1_from_commit(commit_sha1, sha1, &rev)) {
 208                 git_config_from_blob_sha1(submodule_config, rev.buf,
 209                                           sha1, NULL);
 210         }
 211         strbuf_release(&rev);
 212 }
 213
 214 /*
 215  * Determine if a submodule has been initialized at a given 'path'
 216  */
 217 int is_submodule_initialized(const char *path)
 218 {
 219         int ret = 0;
 220         const struct submodule *module = NULL;
 221
 222         module = submodule_from_path(null_sha1, path);
 223
 224         if (module) {
 225                 char *key = xstrfmt("submodule.%s.url", module->name);
 226                 char *value = NULL;
 227
 228                 ret = !git_config_get_string(key, &value);
 229
 230                 free(value);
 231                 free(key);
 232         }
 233
 234         return ret;
 235 }
 236
 237 /*
 238  * Determine if a submodule has been populated at a given 'path'
 239  */
 240 int is_submodule_populated(const char *path)
 241 {
 242         int ret = 0;
 243         char *gitdir = xstrfmt("%s/.git", path);
 244
 245         if (resolve_gitdir(gitdir))
 246                 ret = 1;
 247
 248         free(gitdir);
 249         return ret;
 250 }
 251
 252 int parse_submodule_update_strategy(const char *value,
 253                 struct submodule_update_strategy *dst)
 254 {
 255         free((void*)dst->command);
 256         dst->command = NULL;
 257         if (!strcmp(value, "none"))
 258                 dst->type = SM_UPDATE_NONE;
 259         else if (!strcmp(value, "checkout"))
 260                 dst->type = SM_UPDATE_CHECKOUT;
 261         else if (!strcmp(value, "rebase"))
 262                 dst->type = SM_UPDATE_REBASE;
 263         else if (!strcmp(value, "merge"))
 264                 dst->type = SM_UPDATE_MERGE;
 265         else if (skip_prefix(value, "!", &value)) {
 266                 dst->type = SM_UPDATE_COMMAND;
 267                 dst->command = xstrdup(value);
 268         } else
 269                 return -1;
 270         return 0;
 271 }
 272
 273 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 274 {
 275         struct strbuf sb = STRBUF_INIT;
 276         switch (s->type) {
 277         case SM_UPDATE_CHECKOUT:
 278                 return "checkout";
 279         case SM_UPDATE_MERGE:
 280                 return "merge";
 281         case SM_UPDATE_REBASE:
 282                 return "rebase";
 283         case SM_UPDATE_NONE:
 284                 return "none";
 285         case SM_UPDATE_UNSPECIFIED:
 286                 return NULL;
 287         case SM_UPDATE_COMMAND:
 288                 strbuf_addf(&sb, "!%s", s->command);
 289                 return strbuf_detach(&sb, NULL);
 290         }
 291         return NULL;
 292 }
 293
 294 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 295                                   const char *arg)
 296 {
 297         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 298         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 299         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 300
 301         if (!strcmp(arg, "all"))
 302                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 303         else if (!strcmp(arg, "untracked"))
 304                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 305         else if (!strcmp(arg, "dirty"))
 306                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 307         else if (strcmp(arg, "none"))
 308                 die("bad --ignore-submodules argument: %s", arg);
 309 }
 310
 311 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 312                 struct commit *left, struct commit *right,
 313                 struct commit_list *merge_bases)
 314 {
 315         struct commit_list *list;
 316
 317         init_revisions(rev, NULL);
 318         setup_revisions(0, NULL, rev, NULL);
 319         rev->left_right = 1;
 320         rev->first_parent_only = 1;
 321         left->object.flags |= SYMMETRIC_LEFT;
 322         add_pending_object(rev, &left->object, path);
 323         add_pending_object(rev, &right->object, path);
 324         for (list = merge_bases; list; list = list->next) {
 325                 list->item->object.flags |= UNINTERESTING;
 326                 add_pending_object(rev, &list->item->object,
 327                         oid_to_hex(&list->item->object.oid));
 328         }
 329         return prepare_revision_walk(rev);
 330 }
 331
 332 static void print_submodule_summary(struct rev_info *rev, FILE *f,
 333                 const char *line_prefix,
 334                 const char *del, const char *add, const char *reset)
 335 {
 336         static const char format[] = "  %m %s";
 337         struct strbuf sb = STRBUF_INIT;
 338         struct commit *commit;
 339
 340         while ((commit = get_revision(rev))) {
 341                 struct pretty_print_context ctx = {0};
 342                 ctx.date_mode = rev->date_mode;
 343                 ctx.output_encoding = get_log_output_encoding();
 344                 strbuf_setlen(&sb, 0);
 345                 strbuf_addstr(&sb, line_prefix);
 346                 if (commit->object.flags & SYMMETRIC_LEFT) {
 347                         if (del)
 348                                 strbuf_addstr(&sb, del);
 349                 }
 350                 else if (add)
 351                         strbuf_addstr(&sb, add);
 352                 format_commit_message(commit, format, &sb, &ctx);
 353                 if (reset)
 354                         strbuf_addstr(&sb, reset);
 355                 strbuf_addch(&sb, '\n');
 356                 fprintf(f, "%s", sb.buf);
 357         }
 358         strbuf_release(&sb);
 359 }
 360
 361 /* Helper function to display the submodule header line prior to the full
 362  * summary output. If it can locate the submodule objects directory it will
 363  * attempt to lookup both the left and right commits and put them into the
 364  * left and right pointers.
 365  */
 366 static void show_submodule_header(FILE *f, const char *path,
 367                 const char *line_prefix,
 368                 struct object_id *one, struct object_id *two,
 369                 unsigned dirty_submodule, const char *meta,
 370                 const char *reset,
 371                 struct commit **left, struct commit **right,
 372                 struct commit_list **merge_bases)
 373 {
 374         const char *message = NULL;
 375         struct strbuf sb = STRBUF_INIT;
 376         int fast_forward = 0, fast_backward = 0;
 377
 378         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 379                 fprintf(f, "%sSubmodule %s contains untracked content\n",
 380                         line_prefix, path);
 381         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 382                 fprintf(f, "%sSubmodule %s contains modified content\n",
 383                         line_prefix, path);
 384
 385         if (is_null_oid(one))
 386                 message = "(new submodule)";
 387         else if (is_null_oid(two))
 388                 message = "(submodule deleted)";
 389
 390         if (add_submodule_odb(path)) {
 391                 if (!message)
 392                         message = "(not initialized)";
 393                 goto output_header;
 394         }
 395
 396         /*
 397          * Attempt to lookup the commit references, and determine if this is
 398          * a fast forward or fast backwards update.
 399          */
 400         *left = lookup_commit_reference(one->hash);
 401         *right = lookup_commit_reference(two->hash);
 402
 403         /*
 404          * Warn about missing commits in the submodule project, but only if
 405          * they aren't null.
 406          */
 407         if ((!is_null_oid(one) && !*left) ||
 408              (!is_null_oid(two) && !*right))
 409                 message = "(commits not present)";
 410
 411         *merge_bases = get_merge_bases(*left, *right);
 412         if (*merge_bases) {
 413                 if ((*merge_bases)->item == *left)
 414                         fast_forward = 1;
 415                 else if ((*merge_bases)->item == *right)
 416                         fast_backward = 1;
 417         }
 418
 419         if (!oidcmp(one, two)) {
 420                 strbuf_release(&sb);
 421                 return;
 422         }
 423
 424 output_header:
 425         strbuf_addf(&sb, "%s%sSubmodule %s ", line_prefix, meta, path);
 426         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
 427         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 428         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
 429         if (message)
 430                 strbuf_addf(&sb, " %s%s\n", message, reset);
 431         else
 432                 strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
 433         fwrite(sb.buf, sb.len, 1, f);
 434
 435         strbuf_release(&sb);
 436 }
 437
 438 void show_submodule_summary(FILE *f, const char *path,
 439                 const char *line_prefix,
 440                 struct object_id *one, struct object_id *two,
 441                 unsigned dirty_submodule, const char *meta,
 442                 const char *del, const char *add, const char *reset)
 443 {
 444         struct rev_info rev;
 445         struct commit *left = NULL, *right = NULL;
 446         struct commit_list *merge_bases = NULL;
 447
 448         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
 449                               meta, reset, &left, &right, &merge_bases);
 450
 451         /*
 452          * If we don't have both a left and a right pointer, there is no
 453          * reason to try and display a summary. The header line should contain
 454          * all the information the user needs.
 455          */
 456         if (!left || !right)
 457                 goto out;
 458
 459         /* Treat revision walker failure the same as missing commits */
 460         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 461                 fprintf(f, "%s(revision walker failed)\n", line_prefix);
 462                 goto out;
 463         }
 464
 465         print_submodule_summary(&rev, f, line_prefix, del, add, reset);
 466
 467 out:
 468         if (merge_bases)
 469                 free_commit_list(merge_bases);
 470         clear_commit_marks(left, ~0);
 471         clear_commit_marks(right, ~0);
 472 }
 473
 474 void show_submodule_inline_diff(FILE *f, const char *path,
 475                 const char *line_prefix,
 476                 struct object_id *one, struct object_id *two,
 477                 unsigned dirty_submodule, const char *meta,
 478                 const char *del, const char *add, const char *reset,
 479                 const struct diff_options *o)
 480 {
 481         const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
 482         struct commit *left = NULL, *right = NULL;
 483         struct commit_list *merge_bases = NULL;
 484         struct strbuf submodule_dir = STRBUF_INIT;
 485         struct child_process cp = CHILD_PROCESS_INIT;
 486
 487         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
 488                               meta, reset, &left, &right, &merge_bases);
 489
 490         /* We need a valid left and right commit to display a difference */
 491         if (!(left || is_null_oid(one)) ||
 492             !(right || is_null_oid(two)))
 493                 goto done;
 494
 495         if (left)
 496                 old = one;
 497         if (right)
 498                 new = two;
 499
 500         fflush(f);
 501         cp.git_cmd = 1;
 502         cp.dir = path;
 503         cp.out = dup(fileno(f));
 504         cp.no_stdin = 1;
 505
 506         /* TODO: other options may need to be passed here. */
 507         argv_array_push(&cp.args, "diff");
 508         argv_array_pushf(&cp.args, "--line-prefix=%s", line_prefix);
 509         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
 510                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 511                                  o->b_prefix, path);
 512                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 513                                  o->a_prefix, path);
 514         } else {
 515                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 516                                  o->a_prefix, path);
 517                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 518                                  o->b_prefix, path);
 519         }
 520         argv_array_push(&cp.args, oid_to_hex(old));
 521         /*
 522          * If the submodule has modified content, we will diff against the
 523          * work tree, under the assumption that the user has asked for the
 524          * diff format and wishes to actually see all differences even if they
 525          * haven't yet been committed to the submodule yet.
 526          */
 527         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 528                 argv_array_push(&cp.args, oid_to_hex(new));
 529
 530         if (run_command(&cp))
 531                 fprintf(f, "(diff failed)\n");
 532
 533 done:
 534         strbuf_release(&submodule_dir);
 535         if (merge_bases)
 536                 free_commit_list(merge_bases);
 537         if (left)
 538                 clear_commit_marks(left, ~0);
 539         if (right)
 540                 clear_commit_marks(right, ~0);
 541 }
 542
 543 void set_config_fetch_recurse_submodules(int value)
 544 {
 545         config_fetch_recurse_submodules = value;
 546 }
 547
 548 static int has_remote(const char *refname, const struct object_id *oid,
 549                       int flags, void *cb_data)
 550 {
 551         return 1;
 552 }
 553
 554 static int append_sha1_to_argv(const unsigned char sha1[20], void *data)
 555 {
 556         struct argv_array *argv = data;
 557         argv_array_push(argv, sha1_to_hex(sha1));
 558         return 0;
 559 }
 560
 561 static int check_has_commit(const unsigned char sha1[20], void *data)
 562 {
 563         int *has_commit = data;
 564
 565         if (!lookup_commit_reference(sha1))
 566                 *has_commit = 0;
 567
 568         return 0;
 569 }
 570
 571 static int submodule_has_commits(const char *path, struct sha1_array *commits)
 572 {
 573         int has_commit = 1;
 574
 575         if (add_submodule_odb(path))
 576                 return 0;
 577
 578         sha1_array_for_each_unique(commits, check_has_commit, &has_commit);
 579         return has_commit;
 580 }
 581
 582 static int submodule_needs_pushing(const char *path, struct sha1_array *commits)
 583 {
 584         if (!submodule_has_commits(path, commits))
 585                 /*
 586                  * NOTE: We do consider it safe to return "no" here. The
 587                  * correct answer would be "We do not know" instead of
 588                  * "No push needed", but it is quite hard to change
 589                  * the submodule pointer without having the submodule
 590                  * around. If a user did however change the submodules
 591                  * without having the submodule around, this indicates
 592                  * an expert who knows what they are doing or a
 593                  * maintainer integrating work from other people. In
 594                  * both cases it should be safe to skip this check.
 595                  */
 596                 return 0;
 597
 598         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 599                 struct child_process cp = CHILD_PROCESS_INIT;
 600                 struct strbuf buf = STRBUF_INIT;
 601                 int needs_pushing = 0;
 602
 603                 argv_array_push(&cp.args, "rev-list");
 604                 sha1_array_for_each_unique(commits, append_sha1_to_argv, &cp.args);
 605                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 606
 607                 prepare_submodule_repo_env(&cp.env_array);
 608                 cp.git_cmd = 1;
 609                 cp.no_stdin = 1;
 610                 cp.out = -1;
 611                 cp.dir = path;
 612                 if (start_command(&cp))
 613                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 614                                         path);
 615                 if (strbuf_read(&buf, cp.out, 41))
 616                         needs_pushing = 1;
 617                 finish_command(&cp);
 618                 close(cp.out);
 619                 strbuf_release(&buf);
 620                 return needs_pushing;
 621         }
 622
 623         return 0;
 624 }
 625
 626 static struct sha1_array *submodule_commits(struct string_list *submodules,
 627                                             const char *path)
 628 {
 629         struct string_list_item *item;
 630
 631         item = string_list_insert(submodules, path);
 632         if (item->util)
 633                 return (struct sha1_array *) item->util;
 634
 635         /* NEEDSWORK: should we have sha1_array_init()? */
 636         item->util = xcalloc(1, sizeof(struct sha1_array));
 637         return (struct sha1_array *) item->util;
 638 }
 639
 640 static void collect_submodules_from_diff(struct diff_queue_struct *q,
 641                                          struct diff_options *options,
 642                                          void *data)
 643 {
 644         int i;
 645         struct string_list *submodules = data;
 646
 647         for (i = 0; i < q->nr; i++) {
 648                 struct diff_filepair *p = q->queue[i];
 649                 struct sha1_array *commits;
 650                 if (!S_ISGITLINK(p->two->mode))
 651                         continue;
 652                 commits = submodule_commits(submodules, p->two->path);
 653                 sha1_array_append(commits, p->two->oid.hash);
 654         }
 655 }
 656
 657 static void find_unpushed_submodule_commits(struct commit *commit,
 658                 struct string_list *needs_pushing)
 659 {
 660         struct rev_info rev;
 661
 662         init_revisions(&rev, NULL);
 663         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 664         rev.diffopt.format_callback = collect_submodules_from_diff;
 665         rev.diffopt.format_callback_data = needs_pushing;
 666         diff_tree_combined_merge(commit, 1, &rev);
 667 }
 668
 669 static void free_submodules_sha1s(struct string_list *submodules)
 670 {
 671         struct string_list_item *item;
 672         for_each_string_list_item(item, submodules)
 673                 sha1_array_clear((struct sha1_array *) item->util);
 674         string_list_clear(submodules, 1);
 675 }
 676
 677 int find_unpushed_submodules(struct sha1_array *commits,
 678                 const char *remotes_name, struct string_list *needs_pushing)
 679 {
 680         struct rev_info rev;
 681         struct commit *commit;
 682         struct string_list submodules = STRING_LIST_INIT_DUP;
 683         struct string_list_item *submodule;
 684         struct argv_array argv = ARGV_ARRAY_INIT;
 685
 686         init_revisions(&rev, NULL);
 687
 688         /* argv.argv[0] will be ignored by setup_revisions */
 689         argv_array_push(&argv, "find_unpushed_submodules");
 690         sha1_array_for_each_unique(commits, append_sha1_to_argv, &argv);
 691         argv_array_push(&argv, "--not");
 692         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
 693
 694         setup_revisions(argv.argc, argv.argv, &rev, NULL);
 695         if (prepare_revision_walk(&rev))
 696                 die("revision walk setup failed");
 697
 698         while ((commit = get_revision(&rev)) != NULL)
 699                 find_unpushed_submodule_commits(commit, &submodules);
 700
 701         reset_revision_walk();
 702         argv_array_clear(&argv);
 703
 704         for_each_string_list_item(submodule, &submodules) {
 705                 struct sha1_array *commits = (struct sha1_array *) submodule->util;
 706
 707                 if (submodule_needs_pushing(submodule->string, commits))
 708                         string_list_insert(needs_pushing, submodule->string);
 709         }
 710         free_submodules_sha1s(&submodules);
 711
 712         return needs_pushing->nr;
 713 }
 714
 715 static int push_submodule(const char *path, int dry_run)
 716 {
 717         if (add_submodule_odb(path))
 718                 return 1;
 719
 720         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 721                 struct child_process cp = CHILD_PROCESS_INIT;
 722                 argv_array_push(&cp.args, "push");
 723                 if (dry_run)
 724                         argv_array_push(&cp.args, "--dry-run");
 725
 726                 prepare_submodule_repo_env(&cp.env_array);
 727                 cp.git_cmd = 1;
 728                 cp.no_stdin = 1;
 729                 cp.dir = path;
 730                 if (run_command(&cp))
 731                         return 0;
 732                 close(cp.out);
 733         }
 734
 735         return 1;
 736 }
 737
 738 int push_unpushed_submodules(struct sha1_array *commits,
 739                              const char *remotes_name,
 740                              int dry_run)
 741 {
 742         int i, ret = 1;
 743         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
 744
 745         if (!find_unpushed_submodules(commits, remotes_name, &needs_pushing))
 746                 return 1;
 747
 748         for (i = 0; i < needs_pushing.nr; i++) {
 749                 const char *path = needs_pushing.items[i].string;
 750                 fprintf(stderr, "Pushing submodule '%s'\n", path);
 751                 if (!push_submodule(path, dry_run)) {
 752                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
 753                         ret = 0;
 754                 }
 755         }
 756
 757         string_list_clear(&needs_pushing, 0);
 758
 759         return ret;
 760 }
 761
 762 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
 763 {
 764         int is_present = 0;
 765         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
 766                 /* Even if the submodule is checked out and the commit is
 767                  * present, make sure it is reachable from a ref. */
 768                 struct child_process cp = CHILD_PROCESS_INIT;
 769                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
 770                 struct strbuf buf = STRBUF_INIT;
 771
 772                 argv[3] = sha1_to_hex(sha1);
 773                 cp.argv = argv;
 774                 prepare_submodule_repo_env(&cp.env_array);
 775                 cp.git_cmd = 1;
 776                 cp.no_stdin = 1;
 777                 cp.dir = path;
 778                 if (!capture_command(&cp, &buf, 1024) && !buf.len)
 779                         is_present = 1;
 780
 781                 strbuf_release(&buf);
 782         }
 783         return is_present;
 784 }
 785
 786 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
 787                                          struct diff_options *options,
 788                                          void *data)
 789 {
 790         int i;
 791         for (i = 0; i < q->nr; i++) {
 792                 struct diff_filepair *p = q->queue[i];
 793                 if (!S_ISGITLINK(p->two->mode))
 794                         continue;
 795
 796                 if (S_ISGITLINK(p->one->mode)) {
 797                         /* NEEDSWORK: We should honor the name configured in
 798                          * the .gitmodules file of the commit we are examining
 799                          * here to be able to correctly follow submodules
 800                          * being moved around. */
 801                         struct string_list_item *path;
 802                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
 803                         if (!path && !is_submodule_commit_present(p->two->path, p->two->oid.hash))
 804                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
 805                 } else {
 806                         /* Submodule is new or was moved here */
 807                         /* NEEDSWORK: When the .git directories of submodules
 808                          * live inside the superprojects .git directory some
 809                          * day we should fetch new submodules directly into
 810                          * that location too when config or options request
 811                          * that so they can be checked out from there. */
 812                         continue;
 813                 }
 814         }
 815 }
 816
 817 static int add_sha1_to_array(const char *ref, const struct object_id *oid,
 818                              int flags, void *data)
 819 {
 820         sha1_array_append(data, oid->hash);
 821         return 0;
 822 }
 823
 824 void check_for_new_submodule_commits(unsigned char new_sha1[20])
 825 {
 826         if (!initialized_fetch_ref_tips) {
 827                 for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
 828                 initialized_fetch_ref_tips = 1;
 829         }
 830
 831         sha1_array_append(&ref_tips_after_fetch, new_sha1);
 832 }
 833
 834 static int add_sha1_to_argv(const unsigned char sha1[20], void *data)
 835 {
 836         argv_array_push(data, sha1_to_hex(sha1));
 837         return 0;
 838 }
 839
 840 static void calculate_changed_submodule_paths(void)
 841 {
 842         struct rev_info rev;
 843         struct commit *commit;
 844         struct argv_array argv = ARGV_ARRAY_INIT;
 845
 846         /* No need to check if there are no submodules configured */
 847         if (!submodule_from_path(NULL, NULL))
 848                 return;
 849
 850         init_revisions(&rev, NULL);
 851         argv_array_push(&argv, "--"); /* argv[0] program name */
 852         sha1_array_for_each_unique(&ref_tips_after_fetch,
 853                                    add_sha1_to_argv, &argv);
 854         argv_array_push(&argv, "--not");
 855         sha1_array_for_each_unique(&ref_tips_before_fetch,
 856                                    add_sha1_to_argv, &argv);
 857         setup_revisions(argv.argc, argv.argv, &rev, NULL);
 858         if (prepare_revision_walk(&rev))
 859                 die("revision walk setup failed");
 860
 861         /*
 862          * Collect all submodules (whether checked out or not) for which new
 863          * commits have been recorded upstream in "changed_submodule_paths".
 864          */
 865         while ((commit = get_revision(&rev))) {
 866                 struct commit_list *parent = commit->parents;
 867                 while (parent) {
 868                         struct diff_options diff_opts;
 869                         diff_setup(&diff_opts);
 870                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
 871                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
 872                         diff_opts.format_callback = submodule_collect_changed_cb;
 873                         diff_setup_done(&diff_opts);
 874                         diff_tree_sha1(parent->item->object.oid.hash, commit->object.oid.hash, "", &diff_opts);
 875                         diffcore_std(&diff_opts);
 876                         diff_flush(&diff_opts);
 877                         parent = parent->next;
 878                 }
 879         }
 880
 881         argv_array_clear(&argv);
 882         sha1_array_clear(&ref_tips_before_fetch);
 883         sha1_array_clear(&ref_tips_after_fetch);
 884         initialized_fetch_ref_tips = 0;
 885 }
 886
 887 struct submodule_parallel_fetch {
 888         int count;
 889         struct argv_array args;
 890         const char *work_tree;
 891         const char *prefix;
 892         int command_line_option;
 893         int quiet;
 894         int result;
 895 };
 896 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0}
 897
 898 static int get_next_submodule(struct child_process *cp,
 899                               struct strbuf *err, void *data, void **task_cb)
 900 {
 901         int ret = 0;
 902         struct submodule_parallel_fetch *spf = data;
 903
 904         for (; spf->count < active_nr; spf->count++) {
 905                 struct strbuf submodule_path = STRBUF_INIT;
 906                 struct strbuf submodule_git_dir = STRBUF_INIT;
 907                 struct strbuf submodule_prefix = STRBUF_INIT;
 908                 const struct cache_entry *ce = active_cache[spf->count];
 909                 const char *git_dir, *default_argv;
 910                 const struct submodule *submodule;
 911
 912                 if (!S_ISGITLINK(ce->ce_mode))
 913                         continue;
 914
 915                 submodule = submodule_from_path(null_sha1, ce->name);
 916                 if (!submodule)
 917                         submodule = submodule_from_name(null_sha1, ce->name);
 918
 919                 default_argv = "yes";
 920                 if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
 921                         if (submodule &&
 922                             submodule->fetch_recurse !=
 923                                                 RECURSE_SUBMODULES_NONE) {
 924                                 if (submodule->fetch_recurse ==
 925                                                 RECURSE_SUBMODULES_OFF)
 926                                         continue;
 927                                 if (submodule->fetch_recurse ==
 928                                                 RECURSE_SUBMODULES_ON_DEMAND) {
 929                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 930                                                 continue;
 931                                         default_argv = "on-demand";
 932                                 }
 933                         } else {
 934                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
 935                                     gitmodules_is_unmerged)
 936                                         continue;
 937                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
 938                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 939                                                 continue;
 940                                         default_argv = "on-demand";
 941                                 }
 942                         }
 943                 } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
 944                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 945                                 continue;
 946                         default_argv = "on-demand";
 947                 }
 948
 949                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
 950                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
 951                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
 952                 git_dir = read_gitfile(submodule_git_dir.buf);
 953                 if (!git_dir)
 954                         git_dir = submodule_git_dir.buf;
 955                 if (is_directory(git_dir)) {
 956                         child_process_init(cp);
 957                         cp->dir = strbuf_detach(&submodule_path, NULL);
 958                         prepare_submodule_repo_env(&cp->env_array);
 959                         cp->git_cmd = 1;
 960                         if (!spf->quiet)
 961                                 strbuf_addf(err, "Fetching submodule %s%s\n",
 962                                             spf->prefix, ce->name);
 963                         argv_array_init(&cp->args);
 964                         argv_array_pushv(&cp->args, spf->args.argv);
 965                         argv_array_push(&cp->args, default_argv);
 966                         argv_array_push(&cp->args, "--submodule-prefix");
 967                         argv_array_push(&cp->args, submodule_prefix.buf);
 968                         ret = 1;
 969                 }
 970                 strbuf_release(&submodule_path);
 971                 strbuf_release(&submodule_git_dir);
 972                 strbuf_release(&submodule_prefix);
 973                 if (ret) {
 974                         spf->count++;
 975                         return 1;
 976                 }
 977         }
 978         return 0;
 979 }
 980
 981 static int fetch_start_failure(struct strbuf *err,
 982                                void *cb, void *task_cb)
 983 {
 984         struct submodule_parallel_fetch *spf = cb;
 985
 986         spf->result = 1;
 987
 988         return 0;
 989 }
 990
 991 static int fetch_finish(int retvalue, struct strbuf *err,
 992                         void *cb, void *task_cb)
 993 {
 994         struct submodule_parallel_fetch *spf = cb;
 995
 996         if (retvalue)
 997                 spf->result = 1;
 998
 999         return 0;
1000 }
1001
1002 int fetch_populated_submodules(const struct argv_array *options,
1003                                const char *prefix, int command_line_option,
1004                                int quiet, int max_parallel_jobs)
1005 {
1006         int i;
1007         struct submodule_parallel_fetch spf = SPF_INIT;
1008
1009         spf.work_tree = get_git_work_tree();
1010         spf.command_line_option = command_line_option;
1011         spf.quiet = quiet;
1012         spf.prefix = prefix;
1013
1014         if (!spf.work_tree)
1015                 goto out;
1016
1017         if (read_cache() < 0)
1018                 die("index file corrupt");
1019
1020         argv_array_push(&spf.args, "fetch");
1021         for (i = 0; i < options->argc; i++)
1022                 argv_array_push(&spf.args, options->argv[i]);
1023         argv_array_push(&spf.args, "--recurse-submodules-default");
1024         /* default value, "--submodule-prefix" and its value are added later */
1025
1026         if (max_parallel_jobs < 0)
1027                 max_parallel_jobs = parallel_jobs;
1028
1029         calculate_changed_submodule_paths();
1030         run_processes_parallel(max_parallel_jobs,
1031                                get_next_submodule,
1032                                fetch_start_failure,
1033                                fetch_finish,
1034                                &spf);
1035
1036         argv_array_clear(&spf.args);
1037 out:
1038         string_list_clear(&changed_submodule_paths, 1);
1039         return spf.result;
1040 }
1041
1042 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1043 {
1044         ssize_t len;
1045         struct child_process cp = CHILD_PROCESS_INIT;
1046         const char *argv[] = {
1047                 "status",
1048                 "--porcelain",
1049                 NULL,
1050                 NULL,
1051         };
1052         struct strbuf buf = STRBUF_INIT;
1053         unsigned dirty_submodule = 0;
1054         const char *line, *next_line;
1055         const char *git_dir;
1056
1057         strbuf_addf(&buf, "%s/.git", path);
1058         git_dir = read_gitfile(buf.buf);
1059         if (!git_dir)
1060                 git_dir = buf.buf;
1061         if (!is_directory(git_dir)) {
1062                 strbuf_release(&buf);
1063                 /* The submodule is not checked out, so it is not modified */
1064                 return 0;
1065
1066         }
1067         strbuf_reset(&buf);
1068
1069         if (ignore_untracked)
1070                 argv[2] = "-uno";
1071
1072         cp.argv = argv;
1073         prepare_submodule_repo_env(&cp.env_array);
1074         cp.git_cmd = 1;
1075         cp.no_stdin = 1;
1076         cp.out = -1;
1077         cp.dir = path;
1078         if (start_command(&cp))
1079                 die("Could not run 'git status --porcelain' in submodule %s", path);
1080
1081         len = strbuf_read(&buf, cp.out, 1024);
1082         line = buf.buf;
1083         while (len > 2) {
1084                 if ((line[0] == '?') && (line[1] == '?')) {
1085                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1086                         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
1087                                 break;
1088                 } else {
1089                         dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1090                         if (ignore_untracked ||
1091                             (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
1092                                 break;
1093                 }
1094                 next_line = strchr(line, '\n');
1095                 if (!next_line)
1096                         break;
1097                 next_line++;
1098                 len -= (next_line - line);
1099                 line = next_line;
1100         }
1101         close(cp.out);
1102
1103         if (finish_command(&cp))
1104                 die("'git status --porcelain' failed in submodule %s", path);
1105
1106         strbuf_release(&buf);
1107         return dirty_submodule;
1108 }
1109
1110 int submodule_uses_gitfile(const char *path)
1111 {
1112         struct child_process cp = CHILD_PROCESS_INIT;
1113         const char *argv[] = {
1114                 "submodule",
1115                 "foreach",
1116                 "--quiet",
1117                 "--recursive",
1118                 "test -f .git",
1119                 NULL,
1120         };
1121         struct strbuf buf = STRBUF_INIT;
1122         const char *git_dir;
1123
1124         strbuf_addf(&buf, "%s/.git", path);
1125         git_dir = read_gitfile(buf.buf);
1126         if (!git_dir) {
1127                 strbuf_release(&buf);
1128                 return 0;
1129         }
1130         strbuf_release(&buf);
1131
1132         /* Now test that all nested submodules use a gitfile too */
1133         cp.argv = argv;
1134         prepare_submodule_repo_env(&cp.env_array);
1135         cp.git_cmd = 1;
1136         cp.no_stdin = 1;
1137         cp.no_stderr = 1;
1138         cp.no_stdout = 1;
1139         cp.dir = path;
1140         if (run_command(&cp))
1141                 return 0;
1142
1143         return 1;
1144 }
1145
1146 /*
1147  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1148  * when doing so.
1149  *
1150  * Return 1 if we'd lose data, return 0 if the removal is fine,
1151  * and negative values for errors.
1152  */
1153 int bad_to_remove_submodule(const char *path, unsigned flags)
1154 {
1155         ssize_t len;
1156         struct child_process cp = CHILD_PROCESS_INIT;
1157         struct strbuf buf = STRBUF_INIT;
1158         int ret = 0;
1159
1160         if (!file_exists(path) || is_empty_dir(path))
1161                 return 0;
1162
1163         if (!submodule_uses_gitfile(path))
1164                 return 1;
1165
1166         argv_array_pushl(&cp.args, "status", "--porcelain",
1167                                    "--ignore-submodules=none", NULL);
1168
1169         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1170                 argv_array_push(&cp.args, "-uno");
1171         else
1172                 argv_array_push(&cp.args, "-uall");
1173
1174         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1175                 argv_array_push(&cp.args, "--ignored");
1176
1177         prepare_submodule_repo_env(&cp.env_array);
1178         cp.git_cmd = 1;
1179         cp.no_stdin = 1;
1180         cp.out = -1;
1181         cp.dir = path;
1182         if (start_command(&cp)) {
1183                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1184                         die(_("could not start 'git status in submodule '%s'"),
1185                                 path);
1186                 ret = -1;
1187                 goto out;
1188         }
1189
1190         len = strbuf_read(&buf, cp.out, 1024);
1191         if (len > 2)
1192                 ret = 1;
1193         close(cp.out);
1194
1195         if (finish_command(&cp)) {
1196                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1197                         die(_("could not run 'git status in submodule '%s'"),
1198                                 path);
1199                 ret = -1;
1200         }
1201 out:
1202         strbuf_release(&buf);
1203         return ret;
1204 }
1205
1206 static int find_first_merges(struct object_array *result, const char *path,
1207                 struct commit *a, struct commit *b)
1208 {
1209         int i, j;
1210         struct object_array merges = OBJECT_ARRAY_INIT;
1211         struct commit *commit;
1212         int contains_another;
1213
1214         char merged_revision[42];
1215         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1216                                    "--all", merged_revision, NULL };
1217         struct rev_info revs;
1218         struct setup_revision_opt rev_opts;
1219
1220         memset(result, 0, sizeof(struct object_array));
1221         memset(&rev_opts, 0, sizeof(rev_opts));
1222
1223         /* get all revisions that merge commit a */
1224         snprintf(merged_revision, sizeof(merged_revision), "^%s",
1225                         oid_to_hex(&a->object.oid));
1226         init_revisions(&revs, NULL);
1227         rev_opts.submodule = path;
1228         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1229
1230         /* save all revisions from the above list that contain b */
1231         if (prepare_revision_walk(&revs))
1232                 die("revision walk setup failed");
1233         while ((commit = get_revision(&revs)) != NULL) {
1234                 struct object *o = &(commit->object);
1235                 if (in_merge_bases(b, commit))
1236                         add_object_array(o, NULL, &merges);
1237         }
1238         reset_revision_walk();
1239
1240         /* Now we've got all merges that contain a and b. Prune all
1241          * merges that contain another found merge and save them in
1242          * result.
1243          */
1244         for (i = 0; i < merges.nr; i++) {
1245                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1246
1247                 contains_another = 0;
1248                 for (j = 0; j < merges.nr; j++) {
1249                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1250                         if (i != j && in_merge_bases(m2, m1)) {
1251                                 contains_another = 1;
1252                                 break;
1253                         }
1254                 }
1255
1256                 if (!contains_another)
1257                         add_object_array(merges.objects[i].item, NULL, result);
1258         }
1259
1260         free(merges.objects);
1261         return result->nr;
1262 }
1263
1264 static void print_commit(struct commit *commit)
1265 {
1266         struct strbuf sb = STRBUF_INIT;
1267         struct pretty_print_context ctx = {0};
1268         ctx.date_mode.type = DATE_NORMAL;
1269         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1270         fprintf(stderr, "%s\n", sb.buf);
1271         strbuf_release(&sb);
1272 }
1273
1274 #define MERGE_WARNING(path, msg) \
1275         warning("Failed to merge submodule %s (%s)", path, msg);
1276
1277 int merge_submodule(unsigned char result[20], const char *path,
1278                     const unsigned char base[20], const unsigned char a[20],
1279                     const unsigned char b[20], int search)
1280 {
1281         struct commit *commit_base, *commit_a, *commit_b;
1282         int parent_count;
1283         struct object_array merges;
1284
1285         int i;
1286
1287         /* store a in result in case we fail */
1288         hashcpy(result, a);
1289
1290         /* we can not handle deletion conflicts */
1291         if (is_null_sha1(base))
1292                 return 0;
1293         if (is_null_sha1(a))
1294                 return 0;
1295         if (is_null_sha1(b))
1296                 return 0;
1297
1298         if (add_submodule_odb(path)) {
1299                 MERGE_WARNING(path, "not checked out");
1300                 return 0;
1301         }
1302
1303         if (!(commit_base = lookup_commit_reference(base)) ||
1304             !(commit_a = lookup_commit_reference(a)) ||
1305             !(commit_b = lookup_commit_reference(b))) {
1306                 MERGE_WARNING(path, "commits not present");
1307                 return 0;
1308         }
1309
1310         /* check whether both changes are forward */
1311         if (!in_merge_bases(commit_base, commit_a) ||
1312             !in_merge_bases(commit_base, commit_b)) {
1313                 MERGE_WARNING(path, "commits don't follow merge-base");
1314                 return 0;
1315         }
1316
1317         /* Case #1: a is contained in b or vice versa */
1318         if (in_merge_bases(commit_a, commit_b)) {
1319                 hashcpy(result, b);
1320                 return 1;
1321         }
1322         if (in_merge_bases(commit_b, commit_a)) {
1323                 hashcpy(result, a);
1324                 return 1;
1325         }
1326
1327         /*
1328          * Case #2: There are one or more merges that contain a and b in
1329          * the submodule. If there is only one, then present it as a
1330          * suggestion to the user, but leave it marked unmerged so the
1331          * user needs to confirm the resolution.
1332          */
1333
1334         /* Skip the search if makes no sense to the calling context.  */
1335         if (!search)
1336                 return 0;
1337
1338         /* find commit which merges them */
1339         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1340         switch (parent_count) {
1341         case 0:
1342                 MERGE_WARNING(path, "merge following commits not found");
1343                 break;
1344
1345         case 1:
1346                 MERGE_WARNING(path, "not fast-forward");
1347                 fprintf(stderr, "Found a possible merge resolution "
1348                                 "for the submodule:\n");
1349                 print_commit((struct commit *) merges.objects[0].item);
1350                 fprintf(stderr,
1351                         "If this is correct simply add it to the index "
1352                         "for example\n"
1353                         "by using:\n\n"
1354                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1355                         "which will accept this suggestion.\n",
1356                         oid_to_hex(&merges.objects[0].item->oid), path);
1357                 break;
1358
1359         default:
1360                 MERGE_WARNING(path, "multiple merges found");
1361                 for (i = 0; i < merges.nr; i++)
1362                         print_commit((struct commit *) merges.objects[i].item);
1363         }
1364
1365         free(merges.objects);
1366         return 0;
1367 }
1368
1369 int parallel_submodules(void)
1370 {
1371         return parallel_jobs;
1372 }
1373
1374 void prepare_submodule_repo_env(struct argv_array *out)
1375 {
1376         const char * const *var;
1377
1378         for (var = local_repo_env; *var; var++) {
1379                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
1380                         argv_array_push(out, *var);
1381         }
1382         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
1383                          DEFAULT_GIT_DIR_ENVIRONMENT);
1384 }
1385
1386 /*
1387  * Embeds a single submodules git directory into the superprojects git dir,
1388  * non recursively.
1389  */
1390 static void relocate_single_git_dir_into_superproject(const char *prefix,
1391                                                       const char *path)
1392 {
1393         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1394         const char *new_git_dir;
1395         const struct submodule *sub;
1396
1397         if (submodule_uses_worktrees(path))
1398                 die(_("relocate_gitdir for submodule '%s' with "
1399                       "more than one worktree not supported"), path);
1400
1401         old_git_dir = xstrfmt("%s/.git", path);
1402         if (read_gitfile(old_git_dir))
1403                 /* If it is an actual gitfile, it doesn't need migration. */
1404                 return;
1405
1406         real_old_git_dir = real_pathdup(old_git_dir);
1407
1408         sub = submodule_from_path(null_sha1, path);
1409         if (!sub)
1410                 die(_("could not lookup name for submodule '%s'"), path);
1411
1412         new_git_dir = git_path("modules/%s", sub->name);
1413         if (safe_create_leading_directories_const(new_git_dir) < 0)
1414                 die(_("could not create directory '%s'"), new_git_dir);
1415         real_new_git_dir = real_pathdup(new_git_dir);
1416
1417         if (!prefix)
1418                 prefix = get_super_prefix();
1419
1420         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1421                 prefix ? prefix : "", path,
1422                 real_old_git_dir, real_new_git_dir);
1423
1424         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1425
1426         free(old_git_dir);
1427         free(real_old_git_dir);
1428         free(real_new_git_dir);
1429 }
1430
1431 /*
1432  * Migrate the git directory of the submodule given by path from
1433  * having its git directory within the working tree to the git dir nested
1434  * in its superprojects git dir under modules/.
1435  */
1436 void absorb_git_dir_into_superproject(const char *prefix,
1437                                       const char *path,
1438                                       unsigned flags)
1439 {
1440         int err_code;
1441         const char *sub_git_dir;
1442         struct strbuf gitdir = STRBUF_INIT;
1443         strbuf_addf(&gitdir, "%s/.git", path);
1444         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1445
1446         /* Not populated? */
1447         if (!sub_git_dir) {
1448                 char *real_new_git_dir;
1449                 const char *new_git_dir;
1450                 const struct submodule *sub;
1451
1452                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1453                         /* unpopulated as expected */
1454                         strbuf_release(&gitdir);
1455                         return;
1456                 }
1457
1458                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1459                         /* We don't know what broke here. */
1460                         read_gitfile_error_die(err_code, path, NULL);
1461
1462                 /*
1463                 * Maybe populated, but no git directory was found?
1464                 * This can happen if the superproject is a submodule
1465                 * itself and was just absorbed. The absorption of the
1466                 * superproject did not rewrite the git file links yet,
1467                 * fix it now.
1468                 */
1469                 sub = submodule_from_path(null_sha1, path);
1470                 if (!sub)
1471                         die(_("could not lookup name for submodule '%s'"), path);
1472                 new_git_dir = git_path("modules/%s", sub->name);
1473                 if (safe_create_leading_directories_const(new_git_dir) < 0)
1474                         die(_("could not create directory '%s'"), new_git_dir);
1475                 real_new_git_dir = real_pathdup(new_git_dir);
1476                 connect_work_tree_and_git_dir(path, real_new_git_dir);
1477
1478                 free(real_new_git_dir);
1479         } else {
1480                 /* Is it already absorbed into the superprojects git dir? */
1481                 char *real_sub_git_dir = real_pathdup(sub_git_dir);
1482                 char *real_common_git_dir = real_pathdup(get_git_common_dir());
1483
1484                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1485                         relocate_single_git_dir_into_superproject(prefix, path);
1486
1487                 free(real_sub_git_dir);
1488                 free(real_common_git_dir);
1489         }
1490         strbuf_release(&gitdir);
1491
1492         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1493                 struct child_process cp = CHILD_PROCESS_INIT;
1494                 struct strbuf sb = STRBUF_INIT;
1495
1496                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1497                         die("BUG: we don't know how to pass the flags down?");
1498
1499                 if (get_super_prefix())
1500                         strbuf_addstr(&sb, get_super_prefix());
1501                 strbuf_addstr(&sb, path);
1502                 strbuf_addch(&sb, '/');
1503
1504                 cp.dir = path;
1505                 cp.git_cmd = 1;
1506                 cp.no_stdin = 1;
1507                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1508                                            "submodule--helper",
1509                                            "absorb-git-dirs", NULL);
1510                 prepare_submodule_repo_env(&cp.env_array);
1511                 if (run_command(&cp))
1512                         die(_("could not recurse into submodule '%s'"), path);
1513
1514                 strbuf_release(&sb);
1515         }
1516 }