submodule.c

   1 #include "cache.h"
   2 #include "submodule.h"
   3 #include "dir.h"
   4 #include "diff.h"
   5 #include "commit.h"
   6 #include "revision.h"
   7 #include "run-command.h"
   8 #include "diffcore.h"
   9 #include "refs.h"
  10 #include "string-list.h"
  11 #include "sha1-array.h"
  12 #include "argv-array.h"
  13 #include "blob.h"
  14
  15 static struct string_list config_name_for_path;
  16 static struct string_list config_fetch_recurse_submodules_for_name;
  17 static struct string_list config_ignore_for_name;
  18 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
  19 static struct string_list changed_submodule_paths;
  20 static int initialized_fetch_ref_tips;
  21 static struct sha1_array ref_tips_before_fetch;
  22 static struct sha1_array ref_tips_after_fetch;
  23
  24 /*
  25  * The following flag is set if the .gitmodules file is unmerged. We then
  26  * disable recursion for all submodules where .git/config doesn't have a
  27  * matching config entry because we can't guess what might be configured in
  28  * .gitmodules unless the user resolves the conflict. When a command line
  29  * option is given (which always overrides configuration) this flag will be
  30  * ignored.
  31  */
  32 static int gitmodules_is_unmerged;
  33
  34 /*
  35  * This flag is set if the .gitmodules file had unstaged modifications on
  36  * startup. This must be checked before allowing modifications to the
  37  * .gitmodules file with the intention to stage them later, because when
  38  * continuing we would stage the modifications the user didn't stage herself
  39  * too. That might change in a future version when we learn to stage the
  40  * changes we do ourselves without staging any previous modifications.
  41  */
  42 static int gitmodules_is_modified;
  43
  44
  45 int is_staging_gitmodules_ok(void)
  46 {
  47         return !gitmodules_is_modified;
  48 }
  49
  50 /*
  51  * Try to update the "path" entry in the "submodule.<name>" section of the
  52  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
  53  * with the correct path=<oldpath> setting was found and we could update it.
  54  */
  55 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
  56 {
  57         struct strbuf entry = STRBUF_INIT;
  58         struct string_list_item *path_option;
  59
  60         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
  61                 return -1;
  62
  63         if (gitmodules_is_unmerged)
  64                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  65
  66         path_option = unsorted_string_list_lookup(&config_name_for_path, oldpath);
  67         if (!path_option) {
  68                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
  69                 return -1;
  70         }
  71         strbuf_addstr(&entry, "submodule.");
  72         strbuf_addstr(&entry, path_option->util);
  73         strbuf_addstr(&entry, ".path");
  74         if (git_config_set_in_file(".gitmodules", entry.buf, newpath) < 0) {
  75                 /* Maybe the user already did that, don't error out here */
  76                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
  77                 strbuf_release(&entry);
  78                 return -1;
  79         }
  80         strbuf_release(&entry);
  81         return 0;
  82 }
  83
  84 /*
  85  * Try to remove the "submodule.<name>" section from .gitmodules where the given
  86  * path is configured. Return 0 only if a .gitmodules file was found, a section
  87  * with the correct path=<path> setting was found and we could remove it.
  88  */
  89 int remove_path_from_gitmodules(const char *path)
  90 {
  91         struct strbuf sect = STRBUF_INIT;
  92         struct string_list_item *path_option;
  93
  94         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
  95                 return -1;
  96
  97         if (gitmodules_is_unmerged)
  98                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  99
 100         path_option = unsorted_string_list_lookup(&config_name_for_path, path);
 101         if (!path_option) {
 102                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 103                 return -1;
 104         }
 105         strbuf_addstr(&sect, "submodule.");
 106         strbuf_addstr(&sect, path_option->util);
 107         if (git_config_rename_section_in_file(".gitmodules", sect.buf, NULL) < 0) {
 108                 /* Maybe the user already did that, don't error out here */
 109                 warning(_("Could not remove .gitmodules entry for %s"), path);
 110                 strbuf_release(&sect);
 111                 return -1;
 112         }
 113         strbuf_release(&sect);
 114         return 0;
 115 }
 116
 117 void stage_updated_gitmodules(void)
 118 {
 119         if (add_file_to_cache(".gitmodules", 0))
 120                 die(_("staging updated .gitmodules failed"));
 121 }
 122
 123 static int add_submodule_odb(const char *path)
 124 {
 125         struct strbuf objects_directory = STRBUF_INIT;
 126         struct alternate_object_database *alt_odb;
 127         int ret = 0;
 128         const char *git_dir;
 129
 130         strbuf_addf(&objects_directory, "%s/.git", path);
 131         git_dir = read_gitfile(objects_directory.buf);
 132         if (git_dir) {
 133                 strbuf_reset(&objects_directory);
 134                 strbuf_addstr(&objects_directory, git_dir);
 135         }
 136         strbuf_addstr(&objects_directory, "/objects/");
 137         if (!is_directory(objects_directory.buf)) {
 138                 ret = -1;
 139                 goto done;
 140         }
 141         /* avoid adding it twice */
 142         for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
 143                 if (alt_odb->name - alt_odb->base == objects_directory.len &&
 144                                 !strncmp(alt_odb->base, objects_directory.buf,
 145                                         objects_directory.len))
 146                         goto done;
 147
 148         alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
 149         alt_odb->next = alt_odb_list;
 150         strcpy(alt_odb->base, objects_directory.buf);
 151         alt_odb->name = alt_odb->base + objects_directory.len;
 152         alt_odb->name[2] = '/';
 153         alt_odb->name[40] = '\0';
 154         alt_odb->name[41] = '\0';
 155         alt_odb_list = alt_odb;
 156
 157         /* add possible alternates from the submodule */
 158         read_info_alternates(objects_directory.buf, 0);
 159         prepare_alt_odb();
 160 done:
 161         strbuf_release(&objects_directory);
 162         return ret;
 163 }
 164
 165 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 166                                              const char *path)
 167 {
 168         struct string_list_item *path_option, *ignore_option;
 169         path_option = unsorted_string_list_lookup(&config_name_for_path, path);
 170         if (path_option) {
 171                 ignore_option = unsorted_string_list_lookup(&config_ignore_for_name, path_option->util);
 172                 if (ignore_option)
 173                         handle_ignore_submodules_arg(diffopt, ignore_option->util);
 174                 else if (gitmodules_is_unmerged)
 175                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 176         }
 177 }
 178
 179 int submodule_config(const char *var, const char *value, void *cb)
 180 {
 181         if (starts_with(var, "submodule."))
 182                 return parse_submodule_config_option(var, value);
 183         else if (!strcmp(var, "fetch.recursesubmodules")) {
 184                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
 185                 return 0;
 186         }
 187         return 0;
 188 }
 189
 190 void gitmodules_config(void)
 191 {
 192         const char *work_tree = get_git_work_tree();
 193         if (work_tree) {
 194                 struct strbuf gitmodules_path = STRBUF_INIT;
 195                 int pos;
 196                 strbuf_addstr(&gitmodules_path, work_tree);
 197                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
 198                 if (read_cache() < 0)
 199                         die("index file corrupt");
 200                 pos = cache_name_pos(".gitmodules", 11);
 201                 if (pos < 0) { /* .gitmodules not found or isn't merged */
 202                         pos = -1 - pos;
 203                         if (active_nr > pos) {  /* there is a .gitmodules */
 204                                 const struct cache_entry *ce = active_cache[pos];
 205                                 if (ce_namelen(ce) == 11 &&
 206                                     !memcmp(ce->name, ".gitmodules", 11))
 207                                         gitmodules_is_unmerged = 1;
 208                         }
 209                 } else if (pos < active_nr) {
 210                         struct stat st;
 211                         if (lstat(".gitmodules", &st) == 0 &&
 212                             ce_match_stat(active_cache[pos], &st, 0) & DATA_CHANGED)
 213                                 gitmodules_is_modified = 1;
 214                 }
 215
 216                 if (!gitmodules_is_unmerged)
 217                         git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
 218                 strbuf_release(&gitmodules_path);
 219         }
 220 }
 221
 222 int parse_submodule_config_option(const char *var, const char *value)
 223 {
 224         struct string_list_item *config;
 225         const char *name, *key;
 226         int namelen;
 227
 228         if (parse_config_key(var, "submodule", &name, &namelen, &key) < 0 || !name)
 229                 return 0;
 230
 231         if (!strcmp(key, "path")) {
 232                 if (!value)
 233                         return config_error_nonbool(var);
 234
 235                 config = unsorted_string_list_lookup(&config_name_for_path, value);
 236                 if (config)
 237                         free(config->util);
 238                 else
 239                         config = string_list_append(&config_name_for_path, xstrdup(value));
 240                 config->util = xmemdupz(name, namelen);
 241         } else if (!strcmp(key, "fetchrecursesubmodules")) {
 242                 char *name_cstr = xmemdupz(name, namelen);
 243                 config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name_cstr);
 244                 if (!config)
 245                         config = string_list_append(&config_fetch_recurse_submodules_for_name, name_cstr);
 246                 else
 247                         free(name_cstr);
 248                 config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
 249         } else if (!strcmp(key, "ignore")) {
 250                 char *name_cstr;
 251
 252                 if (!value)
 253                         return config_error_nonbool(var);
 254
 255                 if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
 256                     strcmp(value, "all") && strcmp(value, "none")) {
 257                         warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);
 258                         return 0;
 259                 }
 260
 261                 name_cstr = xmemdupz(name, namelen);
 262                 config = unsorted_string_list_lookup(&config_ignore_for_name, name_cstr);
 263                 if (config) {
 264                         free(config->util);
 265                         free(name_cstr);
 266                 } else
 267                         config = string_list_append(&config_ignore_for_name, name_cstr);
 268                 config->util = xstrdup(value);
 269                 return 0;
 270         }
 271         return 0;
 272 }
 273
 274 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 275                                   const char *arg)
 276 {
 277         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 278         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 279         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 280
 281         if (!strcmp(arg, "all"))
 282                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 283         else if (!strcmp(arg, "untracked"))
 284                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 285         else if (!strcmp(arg, "dirty"))
 286                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 287         else if (strcmp(arg, "none"))
 288                 die("bad --ignore-submodules argument: %s", arg);
 289 }
 290
 291 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 292                 struct commit *left, struct commit *right,
 293                 int *fast_forward, int *fast_backward)
 294 {
 295         struct commit_list *merge_bases, *list;
 296
 297         init_revisions(rev, NULL);
 298         setup_revisions(0, NULL, rev, NULL);
 299         rev->left_right = 1;
 300         rev->first_parent_only = 1;
 301         left->object.flags |= SYMMETRIC_LEFT;
 302         add_pending_object(rev, &left->object, path);
 303         add_pending_object(rev, &right->object, path);
 304         merge_bases = get_merge_bases(left, right, 1);
 305         if (merge_bases) {
 306                 if (merge_bases->item == left)
 307                         *fast_forward = 1;
 308                 else if (merge_bases->item == right)
 309                         *fast_backward = 1;
 310         }
 311         for (list = merge_bases; list; list = list->next) {
 312                 list->item->object.flags |= UNINTERESTING;
 313                 add_pending_object(rev, &list->item->object,
 314                         sha1_to_hex(list->item->object.sha1));
 315         }
 316         return prepare_revision_walk(rev);
 317 }
 318
 319 static void print_submodule_summary(struct rev_info *rev, FILE *f,
 320                 const char *line_prefix,
 321                 const char *del, const char *add, const char *reset)
 322 {
 323         static const char format[] = "  %m %s";
 324         struct strbuf sb = STRBUF_INIT;
 325         struct commit *commit;
 326
 327         while ((commit = get_revision(rev))) {
 328                 struct pretty_print_context ctx = {0};
 329                 ctx.date_mode = rev->date_mode;
 330                 ctx.output_encoding = get_log_output_encoding();
 331                 strbuf_setlen(&sb, 0);
 332                 strbuf_addstr(&sb, line_prefix);
 333                 if (commit->object.flags & SYMMETRIC_LEFT) {
 334                         if (del)
 335                                 strbuf_addstr(&sb, del);
 336                 }
 337                 else if (add)
 338                         strbuf_addstr(&sb, add);
 339                 format_commit_message(commit, format, &sb, &ctx);
 340                 if (reset)
 341                         strbuf_addstr(&sb, reset);
 342                 strbuf_addch(&sb, '\n');
 343                 fprintf(f, "%s", sb.buf);
 344         }
 345         strbuf_release(&sb);
 346 }
 347
 348 int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
 349 {
 350         switch (git_config_maybe_bool(opt, arg)) {
 351         case 1:
 352                 return RECURSE_SUBMODULES_ON;
 353         case 0:
 354                 return RECURSE_SUBMODULES_OFF;
 355         default:
 356                 if (!strcmp(arg, "on-demand"))
 357                         return RECURSE_SUBMODULES_ON_DEMAND;
 358                 die("bad %s argument: %s", opt, arg);
 359         }
 360 }
 361
 362 void show_submodule_summary(FILE *f, const char *path,
 363                 const char *line_prefix,
 364                 unsigned char one[20], unsigned char two[20],
 365                 unsigned dirty_submodule, const char *meta,
 366                 const char *del, const char *add, const char *reset)
 367 {
 368         struct rev_info rev;
 369         struct commit *left = NULL, *right = NULL;
 370         const char *message = NULL;
 371         struct strbuf sb = STRBUF_INIT;
 372         int fast_forward = 0, fast_backward = 0;
 373
 374         if (is_null_sha1(two))
 375                 message = "(submodule deleted)";
 376         else if (add_submodule_odb(path))
 377                 message = "(not checked out)";
 378         else if (is_null_sha1(one))
 379                 message = "(new submodule)";
 380         else if (!(left = lookup_commit_reference(one)) ||
 381                  !(right = lookup_commit_reference(two)))
 382                 message = "(commits not present)";
 383         else if (prepare_submodule_summary(&rev, path, left, right,
 384                                            &fast_forward, &fast_backward))
 385                 message = "(revision walker failed)";
 386
 387         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 388                 fprintf(f, "%sSubmodule %s contains untracked content\n",
 389                         line_prefix, path);
 390         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 391                 fprintf(f, "%sSubmodule %s contains modified content\n",
 392                         line_prefix, path);
 393
 394         if (!hashcmp(one, two)) {
 395                 strbuf_release(&sb);
 396                 return;
 397         }
 398
 399         strbuf_addf(&sb, "%s%sSubmodule %s %s..", line_prefix, meta, path,
 400                         find_unique_abbrev(one, DEFAULT_ABBREV));
 401         if (!fast_backward && !fast_forward)
 402                 strbuf_addch(&sb, '.');
 403         strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
 404         if (message)
 405                 strbuf_addf(&sb, " %s%s\n", message, reset);
 406         else
 407                 strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
 408         fwrite(sb.buf, sb.len, 1, f);
 409
 410         if (!message) /* only NULL if we succeeded in setting up the walk */
 411                 print_submodule_summary(&rev, f, line_prefix, del, add, reset);
 412         if (left)
 413                 clear_commit_marks(left, ~0);
 414         if (right)
 415                 clear_commit_marks(right, ~0);
 416
 417         strbuf_release(&sb);
 418 }
 419
 420 void set_config_fetch_recurse_submodules(int value)
 421 {
 422         config_fetch_recurse_submodules = value;
 423 }
 424
 425 static int has_remote(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
 426 {
 427         return 1;
 428 }
 429
 430 static int submodule_needs_pushing(const char *path, const unsigned char sha1[20])
 431 {
 432         if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
 433                 return 0;
 434
 435         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 436                 struct child_process cp = CHILD_PROCESS_INIT;
 437                 const char *argv[] = {"rev-list", NULL, "--not", "--remotes", "-n", "1" , NULL};
 438                 struct strbuf buf = STRBUF_INIT;
 439                 int needs_pushing = 0;
 440
 441                 argv[1] = sha1_to_hex(sha1);
 442                 cp.argv = argv;
 443                 cp.env = local_repo_env;
 444                 cp.git_cmd = 1;
 445                 cp.no_stdin = 1;
 446                 cp.out = -1;
 447                 cp.dir = path;
 448                 if (start_command(&cp))
 449                         die("Could not run 'git rev-list %s --not --remotes -n 1' command in submodule %s",
 450                                 sha1_to_hex(sha1), path);
 451                 if (strbuf_read(&buf, cp.out, 41))
 452                         needs_pushing = 1;
 453                 finish_command(&cp);
 454                 close(cp.out);
 455                 strbuf_release(&buf);
 456                 return needs_pushing;
 457         }
 458
 459         return 0;
 460 }
 461
 462 static void collect_submodules_from_diff(struct diff_queue_struct *q,
 463                                          struct diff_options *options,
 464                                          void *data)
 465 {
 466         int i;
 467         struct string_list *needs_pushing = data;
 468
 469         for (i = 0; i < q->nr; i++) {
 470                 struct diff_filepair *p = q->queue[i];
 471                 if (!S_ISGITLINK(p->two->mode))
 472                         continue;
 473                 if (submodule_needs_pushing(p->two->path, p->two->sha1))
 474                         string_list_insert(needs_pushing, p->two->path);
 475         }
 476 }
 477
 478 static void find_unpushed_submodule_commits(struct commit *commit,
 479                 struct string_list *needs_pushing)
 480 {
 481         struct rev_info rev;
 482
 483         init_revisions(&rev, NULL);
 484         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 485         rev.diffopt.format_callback = collect_submodules_from_diff;
 486         rev.diffopt.format_callback_data = needs_pushing;
 487         diff_tree_combined_merge(commit, 1, &rev);
 488 }
 489
 490 int find_unpushed_submodules(unsigned char new_sha1[20],
 491                 const char *remotes_name, struct string_list *needs_pushing)
 492 {
 493         struct rev_info rev;
 494         struct commit *commit;
 495         const char *argv[] = {NULL, NULL, "--not", "NULL", NULL};
 496         int argc = ARRAY_SIZE(argv) - 1;
 497         char *sha1_copy;
 498
 499         struct strbuf remotes_arg = STRBUF_INIT;
 500
 501         strbuf_addf(&remotes_arg, "--remotes=%s", remotes_name);
 502         init_revisions(&rev, NULL);
 503         sha1_copy = xstrdup(sha1_to_hex(new_sha1));
 504         argv[1] = sha1_copy;
 505         argv[3] = remotes_arg.buf;
 506         setup_revisions(argc, argv, &rev, NULL);
 507         if (prepare_revision_walk(&rev))
 508                 die("revision walk setup failed");
 509
 510         while ((commit = get_revision(&rev)) != NULL)
 511                 find_unpushed_submodule_commits(commit, needs_pushing);
 512
 513         reset_revision_walk();
 514         free(sha1_copy);
 515         strbuf_release(&remotes_arg);
 516
 517         return needs_pushing->nr;
 518 }
 519
 520 static int push_submodule(const char *path)
 521 {
 522         if (add_submodule_odb(path))
 523                 return 1;
 524
 525         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 526                 struct child_process cp = CHILD_PROCESS_INIT;
 527                 const char *argv[] = {"push", NULL};
 528
 529                 cp.argv = argv;
 530                 cp.env = local_repo_env;
 531                 cp.git_cmd = 1;
 532                 cp.no_stdin = 1;
 533                 cp.dir = path;
 534                 if (run_command(&cp))
 535                         return 0;
 536                 close(cp.out);
 537         }
 538
 539         return 1;
 540 }
 541
 542 int push_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_name)
 543 {
 544         int i, ret = 1;
 545         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
 546
 547         if (!find_unpushed_submodules(new_sha1, remotes_name, &needs_pushing))
 548                 return 1;
 549
 550         for (i = 0; i < needs_pushing.nr; i++) {
 551                 const char *path = needs_pushing.items[i].string;
 552                 fprintf(stderr, "Pushing submodule '%s'\n", path);
 553                 if (!push_submodule(path)) {
 554                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
 555                         ret = 0;
 556                 }
 557         }
 558
 559         string_list_clear(&needs_pushing, 0);
 560
 561         return ret;
 562 }
 563
 564 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
 565 {
 566         int is_present = 0;
 567         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
 568                 /* Even if the submodule is checked out and the commit is
 569                  * present, make sure it is reachable from a ref. */
 570                 struct child_process cp = CHILD_PROCESS_INIT;
 571                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
 572                 struct strbuf buf = STRBUF_INIT;
 573
 574                 argv[3] = sha1_to_hex(sha1);
 575                 cp.argv = argv;
 576                 cp.env = local_repo_env;
 577                 cp.git_cmd = 1;
 578                 cp.no_stdin = 1;
 579                 cp.out = -1;
 580                 cp.dir = path;
 581                 if (!run_command(&cp) && !strbuf_read(&buf, cp.out, 1024))
 582                         is_present = 1;
 583
 584                 close(cp.out);
 585                 strbuf_release(&buf);
 586         }
 587         return is_present;
 588 }
 589
 590 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
 591                                          struct diff_options *options,
 592                                          void *data)
 593 {
 594         int i;
 595         for (i = 0; i < q->nr; i++) {
 596                 struct diff_filepair *p = q->queue[i];
 597                 if (!S_ISGITLINK(p->two->mode))
 598                         continue;
 599
 600                 if (S_ISGITLINK(p->one->mode)) {
 601                         /* NEEDSWORK: We should honor the name configured in
 602                          * the .gitmodules file of the commit we are examining
 603                          * here to be able to correctly follow submodules
 604                          * being moved around. */
 605                         struct string_list_item *path;
 606                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
 607                         if (!path && !is_submodule_commit_present(p->two->path, p->two->sha1))
 608                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
 609                 } else {
 610                         /* Submodule is new or was moved here */
 611                         /* NEEDSWORK: When the .git directories of submodules
 612                          * live inside the superprojects .git directory some
 613                          * day we should fetch new submodules directly into
 614                          * that location too when config or options request
 615                          * that so they can be checked out from there. */
 616                         continue;
 617                 }
 618         }
 619 }
 620
 621 static int add_sha1_to_array(const char *ref, const unsigned char *sha1,
 622                              int flags, void *data)
 623 {
 624         sha1_array_append(data, sha1);
 625         return 0;
 626 }
 627
 628 void check_for_new_submodule_commits(unsigned char new_sha1[20])
 629 {
 630         if (!initialized_fetch_ref_tips) {
 631                 for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
 632                 initialized_fetch_ref_tips = 1;
 633         }
 634
 635         sha1_array_append(&ref_tips_after_fetch, new_sha1);
 636 }
 637
 638 static void add_sha1_to_argv(const unsigned char sha1[20], void *data)
 639 {
 640         argv_array_push(data, sha1_to_hex(sha1));
 641 }
 642
 643 static void calculate_changed_submodule_paths(void)
 644 {
 645         struct rev_info rev;
 646         struct commit *commit;
 647         struct argv_array argv = ARGV_ARRAY_INIT;
 648
 649         /* No need to check if there are no submodules configured */
 650         if (!config_name_for_path.nr)
 651                 return;
 652
 653         init_revisions(&rev, NULL);
 654         argv_array_push(&argv, "--"); /* argv[0] program name */
 655         sha1_array_for_each_unique(&ref_tips_after_fetch,
 656                                    add_sha1_to_argv, &argv);
 657         argv_array_push(&argv, "--not");
 658         sha1_array_for_each_unique(&ref_tips_before_fetch,
 659                                    add_sha1_to_argv, &argv);
 660         setup_revisions(argv.argc, argv.argv, &rev, NULL);
 661         if (prepare_revision_walk(&rev))
 662                 die("revision walk setup failed");
 663
 664         /*
 665          * Collect all submodules (whether checked out or not) for which new
 666          * commits have been recorded upstream in "changed_submodule_paths".
 667          */
 668         while ((commit = get_revision(&rev))) {
 669                 struct commit_list *parent = commit->parents;
 670                 while (parent) {
 671                         struct diff_options diff_opts;
 672                         diff_setup(&diff_opts);
 673                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
 674                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
 675                         diff_opts.format_callback = submodule_collect_changed_cb;
 676                         diff_setup_done(&diff_opts);
 677                         diff_tree_sha1(parent->item->object.sha1, commit->object.sha1, "", &diff_opts);
 678                         diffcore_std(&diff_opts);
 679                         diff_flush(&diff_opts);
 680                         parent = parent->next;
 681                 }
 682         }
 683
 684         argv_array_clear(&argv);
 685         sha1_array_clear(&ref_tips_before_fetch);
 686         sha1_array_clear(&ref_tips_after_fetch);
 687         initialized_fetch_ref_tips = 0;
 688 }
 689
 690 int fetch_populated_submodules(const struct argv_array *options,
 691                                const char *prefix, int command_line_option,
 692                                int quiet)
 693 {
 694         int i, result = 0;
 695         struct child_process cp = CHILD_PROCESS_INIT;
 696         struct argv_array argv = ARGV_ARRAY_INIT;
 697         struct string_list_item *name_for_path;
 698         const char *work_tree = get_git_work_tree();
 699         if (!work_tree)
 700                 goto out;
 701
 702         if (read_cache() < 0)
 703                 die("index file corrupt");
 704
 705         argv_array_push(&argv, "fetch");
 706         for (i = 0; i < options->argc; i++)
 707                 argv_array_push(&argv, options->argv[i]);
 708         argv_array_push(&argv, "--recurse-submodules-default");
 709         /* default value, "--submodule-prefix" and its value are added later */
 710
 711         cp.env = local_repo_env;
 712         cp.git_cmd = 1;
 713         cp.no_stdin = 1;
 714
 715         calculate_changed_submodule_paths();
 716
 717         for (i = 0; i < active_nr; i++) {
 718                 struct strbuf submodule_path = STRBUF_INIT;
 719                 struct strbuf submodule_git_dir = STRBUF_INIT;
 720                 struct strbuf submodule_prefix = STRBUF_INIT;
 721                 const struct cache_entry *ce = active_cache[i];
 722                 const char *git_dir, *name, *default_argv;
 723
 724                 if (!S_ISGITLINK(ce->ce_mode))
 725                         continue;
 726
 727                 name = ce->name;
 728                 name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
 729                 if (name_for_path)
 730                         name = name_for_path->util;
 731
 732                 default_argv = "yes";
 733                 if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
 734                         struct string_list_item *fetch_recurse_submodules_option;
 735                         fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
 736                         if (fetch_recurse_submodules_option) {
 737                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
 738                                         continue;
 739                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
 740                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 741                                                 continue;
 742                                         default_argv = "on-demand";
 743                                 }
 744                         } else {
 745                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
 746                                     gitmodules_is_unmerged)
 747                                         continue;
 748                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
 749                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 750                                                 continue;
 751                                         default_argv = "on-demand";
 752                                 }
 753                         }
 754                 } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
 755                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 756                                 continue;
 757                         default_argv = "on-demand";
 758                 }
 759
 760                 strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
 761                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
 762                 strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
 763                 git_dir = read_gitfile(submodule_git_dir.buf);
 764                 if (!git_dir)
 765                         git_dir = submodule_git_dir.buf;
 766                 if (is_directory(git_dir)) {
 767                         if (!quiet)
 768                                 printf("Fetching submodule %s%s\n", prefix, ce->name);
 769                         cp.dir = submodule_path.buf;
 770                         argv_array_push(&argv, default_argv);
 771                         argv_array_push(&argv, "--submodule-prefix");
 772                         argv_array_push(&argv, submodule_prefix.buf);
 773                         cp.argv = argv.argv;
 774                         if (run_command(&cp))
 775                                 result = 1;
 776                         argv_array_pop(&argv);
 777                         argv_array_pop(&argv);
 778                         argv_array_pop(&argv);
 779                 }
 780                 strbuf_release(&submodule_path);
 781                 strbuf_release(&submodule_git_dir);
 782                 strbuf_release(&submodule_prefix);
 783         }
 784         argv_array_clear(&argv);
 785 out:
 786         string_list_clear(&changed_submodule_paths, 1);
 787         return result;
 788 }
 789
 790 unsigned is_submodule_modified(const char *path, int ignore_untracked)
 791 {
 792         ssize_t len;
 793         struct child_process cp = CHILD_PROCESS_INIT;
 794         const char *argv[] = {
 795                 "status",
 796                 "--porcelain",
 797                 NULL,
 798                 NULL,
 799         };
 800         struct strbuf buf = STRBUF_INIT;
 801         unsigned dirty_submodule = 0;
 802         const char *line, *next_line;
 803         const char *git_dir;
 804
 805         strbuf_addf(&buf, "%s/.git", path);
 806         git_dir = read_gitfile(buf.buf);
 807         if (!git_dir)
 808                 git_dir = buf.buf;
 809         if (!is_directory(git_dir)) {
 810                 strbuf_release(&buf);
 811                 /* The submodule is not checked out, so it is not modified */
 812                 return 0;
 813
 814         }
 815         strbuf_reset(&buf);
 816
 817         if (ignore_untracked)
 818                 argv[2] = "-uno";
 819
 820         cp.argv = argv;
 821         cp.env = local_repo_env;
 822         cp.git_cmd = 1;
 823         cp.no_stdin = 1;
 824         cp.out = -1;
 825         cp.dir = path;
 826         if (start_command(&cp))
 827                 die("Could not run 'git status --porcelain' in submodule %s", path);
 828
 829         len = strbuf_read(&buf, cp.out, 1024);
 830         line = buf.buf;
 831         while (len > 2) {
 832                 if ((line[0] == '?') && (line[1] == '?')) {
 833                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
 834                         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 835                                 break;
 836                 } else {
 837                         dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
 838                         if (ignore_untracked ||
 839                             (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
 840                                 break;
 841                 }
 842                 next_line = strchr(line, '\n');
 843                 if (!next_line)
 844                         break;
 845                 next_line++;
 846                 len -= (next_line - line);
 847                 line = next_line;
 848         }
 849         close(cp.out);
 850
 851         if (finish_command(&cp))
 852                 die("'git status --porcelain' failed in submodule %s", path);
 853
 854         strbuf_release(&buf);
 855         return dirty_submodule;
 856 }
 857
 858 int submodule_uses_gitfile(const char *path)
 859 {
 860         struct child_process cp = CHILD_PROCESS_INIT;
 861         const char *argv[] = {
 862                 "submodule",
 863                 "foreach",
 864                 "--quiet",
 865                 "--recursive",
 866                 "test -f .git",
 867                 NULL,
 868         };
 869         struct strbuf buf = STRBUF_INIT;
 870         const char *git_dir;
 871
 872         strbuf_addf(&buf, "%s/.git", path);
 873         git_dir = read_gitfile(buf.buf);
 874         if (!git_dir) {
 875                 strbuf_release(&buf);
 876                 return 0;
 877         }
 878         strbuf_release(&buf);
 879
 880         /* Now test that all nested submodules use a gitfile too */
 881         cp.argv = argv;
 882         cp.env = local_repo_env;
 883         cp.git_cmd = 1;
 884         cp.no_stdin = 1;
 885         cp.no_stderr = 1;
 886         cp.no_stdout = 1;
 887         cp.dir = path;
 888         if (run_command(&cp))
 889                 return 0;
 890
 891         return 1;
 892 }
 893
 894 int ok_to_remove_submodule(const char *path)
 895 {
 896         struct stat st;
 897         ssize_t len;
 898         struct child_process cp = CHILD_PROCESS_INIT;
 899         const char *argv[] = {
 900                 "status",
 901                 "--porcelain",
 902                 "-u",
 903                 "--ignore-submodules=none",
 904                 NULL,
 905         };
 906         struct strbuf buf = STRBUF_INIT;
 907         int ok_to_remove = 1;
 908
 909         if ((lstat(path, &st) < 0) || is_empty_dir(path))
 910                 return 1;
 911
 912         if (!submodule_uses_gitfile(path))
 913                 return 0;
 914
 915         cp.argv = argv;
 916         cp.env = local_repo_env;
 917         cp.git_cmd = 1;
 918         cp.no_stdin = 1;
 919         cp.out = -1;
 920         cp.dir = path;
 921         if (start_command(&cp))
 922                 die("Could not run 'git status --porcelain -uall --ignore-submodules=none' in submodule %s", path);
 923
 924         len = strbuf_read(&buf, cp.out, 1024);
 925         if (len > 2)
 926                 ok_to_remove = 0;
 927         close(cp.out);
 928
 929         if (finish_command(&cp))
 930                 die("'git status --porcelain -uall --ignore-submodules=none' failed in submodule %s", path);
 931
 932         strbuf_release(&buf);
 933         return ok_to_remove;
 934 }
 935
 936 static int find_first_merges(struct object_array *result, const char *path,
 937                 struct commit *a, struct commit *b)
 938 {
 939         int i, j;
 940         struct object_array merges = OBJECT_ARRAY_INIT;
 941         struct commit *commit;
 942         int contains_another;
 943
 944         char merged_revision[42];
 945         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
 946                                    "--all", merged_revision, NULL };
 947         struct rev_info revs;
 948         struct setup_revision_opt rev_opts;
 949
 950         memset(result, 0, sizeof(struct object_array));
 951         memset(&rev_opts, 0, sizeof(rev_opts));
 952
 953         /* get all revisions that merge commit a */
 954         snprintf(merged_revision, sizeof(merged_revision), "^%s",
 955                         sha1_to_hex(a->object.sha1));
 956         init_revisions(&revs, NULL);
 957         rev_opts.submodule = path;
 958         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
 959
 960         /* save all revisions from the above list that contain b */
 961         if (prepare_revision_walk(&revs))
 962                 die("revision walk setup failed");
 963         while ((commit = get_revision(&revs)) != NULL) {
 964                 struct object *o = &(commit->object);
 965                 if (in_merge_bases(b, commit))
 966                         add_object_array(o, NULL, &merges);
 967         }
 968         reset_revision_walk();
 969
 970         /* Now we've got all merges that contain a and b. Prune all
 971          * merges that contain another found merge and save them in
 972          * result.
 973          */
 974         for (i = 0; i < merges.nr; i++) {
 975                 struct commit *m1 = (struct commit *) merges.objects[i].item;
 976
 977                 contains_another = 0;
 978                 for (j = 0; j < merges.nr; j++) {
 979                         struct commit *m2 = (struct commit *) merges.objects[j].item;
 980                         if (i != j && in_merge_bases(m2, m1)) {
 981                                 contains_another = 1;
 982                                 break;
 983                         }
 984                 }
 985
 986                 if (!contains_another)
 987                         add_object_array(merges.objects[i].item, NULL, result);
 988         }
 989
 990         free(merges.objects);
 991         return result->nr;
 992 }
 993
 994 static void print_commit(struct commit *commit)
 995 {
 996         struct strbuf sb = STRBUF_INIT;
 997         struct pretty_print_context ctx = {0};
 998         ctx.date_mode = DATE_NORMAL;
 999         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1000         fprintf(stderr, "%s\n", sb.buf);
1001         strbuf_release(&sb);
1002 }
1003
1004 #define MERGE_WARNING(path, msg) \
1005         warning("Failed to merge submodule %s (%s)", path, msg);
1006
1007 int merge_submodule(unsigned char result[20], const char *path,
1008                     const unsigned char base[20], const unsigned char a[20],
1009                     const unsigned char b[20], int search)
1010 {
1011         struct commit *commit_base, *commit_a, *commit_b;
1012         int parent_count;
1013         struct object_array merges;
1014
1015         int i;
1016
1017         /* store a in result in case we fail */
1018         hashcpy(result, a);
1019
1020         /* we can not handle deletion conflicts */
1021         if (is_null_sha1(base))
1022                 return 0;
1023         if (is_null_sha1(a))
1024                 return 0;
1025         if (is_null_sha1(b))
1026                 return 0;
1027
1028         if (add_submodule_odb(path)) {
1029                 MERGE_WARNING(path, "not checked out");
1030                 return 0;
1031         }
1032
1033         if (!(commit_base = lookup_commit_reference(base)) ||
1034             !(commit_a = lookup_commit_reference(a)) ||
1035             !(commit_b = lookup_commit_reference(b))) {
1036                 MERGE_WARNING(path, "commits not present");
1037                 return 0;
1038         }
1039
1040         /* check whether both changes are forward */
1041         if (!in_merge_bases(commit_base, commit_a) ||
1042             !in_merge_bases(commit_base, commit_b)) {
1043                 MERGE_WARNING(path, "commits don't follow merge-base");
1044                 return 0;
1045         }
1046
1047         /* Case #1: a is contained in b or vice versa */
1048         if (in_merge_bases(commit_a, commit_b)) {
1049                 hashcpy(result, b);
1050                 return 1;
1051         }
1052         if (in_merge_bases(commit_b, commit_a)) {
1053                 hashcpy(result, a);
1054                 return 1;
1055         }
1056
1057         /*
1058          * Case #2: There are one or more merges that contain a and b in
1059          * the submodule. If there is only one, then present it as a
1060          * suggestion to the user, but leave it marked unmerged so the
1061          * user needs to confirm the resolution.
1062          */
1063
1064         /* Skip the search if makes no sense to the calling context.  */
1065         if (!search)
1066                 return 0;
1067
1068         /* find commit which merges them */
1069         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1070         switch (parent_count) {
1071         case 0:
1072                 MERGE_WARNING(path, "merge following commits not found");
1073                 break;
1074
1075         case 1:
1076                 MERGE_WARNING(path, "not fast-forward");
1077                 fprintf(stderr, "Found a possible merge resolution "
1078                                 "for the submodule:\n");
1079                 print_commit((struct commit *) merges.objects[0].item);
1080                 fprintf(stderr,
1081                         "If this is correct simply add it to the index "
1082                         "for example\n"
1083                         "by using:\n\n"
1084                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1085                         "which will accept this suggestion.\n",
1086                         sha1_to_hex(merges.objects[0].item->sha1), path);
1087                 break;
1088
1089         default:
1090                 MERGE_WARNING(path, "multiple merges found");
1091                 for (i = 0; i < merges.nr; i++)
1092                         print_commit((struct commit *) merges.objects[i].item);
1093         }
1094
1095         free(merges.objects);
1096         return 0;
1097 }
1098
1099 /* Update gitfile and core.worktree setting to connect work tree and git dir */
1100 void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
1101 {
1102         struct strbuf file_name = STRBUF_INIT;
1103         struct strbuf rel_path = STRBUF_INIT;
1104         const char *real_work_tree = xstrdup(real_path(work_tree));
1105         FILE *fp;
1106
1107         /* Update gitfile */
1108         strbuf_addf(&file_name, "%s/.git", work_tree);
1109         fp = fopen(file_name.buf, "w");
1110         if (!fp)
1111                 die(_("Could not create git link %s"), file_name.buf);
1112         fprintf(fp, "gitdir: %s\n", relative_path(git_dir, real_work_tree,
1113                                                   &rel_path));
1114         fclose(fp);
1115
1116         /* Update core.worktree setting */
1117         strbuf_reset(&file_name);
1118         strbuf_addf(&file_name, "%s/config", git_dir);
1119         if (git_config_set_in_file(file_name.buf, "core.worktree",
1120                                    relative_path(real_work_tree, git_dir,
1121                                                  &rel_path)))
1122                 die(_("Could not set core.worktree in %s"),
1123                     file_name.buf);
1124
1125         strbuf_release(&file_name);
1126         strbuf_release(&rel_path);
1127         free((void *)real_work_tree);
1128 }