git.oblomov.eu Git - git/blob - 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 "transport.h"
  12
  13 typedef int (*needs_push_func_t)(const char *path, const unsigned char sha1[20],
  14                 void *data);
  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 /*
  21  * The following flag is set if the .gitmodules file is unmerged. We then
  22  * disable recursion for all submodules where .git/config doesn't have a
  23  * matching config entry because we can't guess what might be configured in
  24  * .gitmodules unless the user resolves the conflict. When a command line
  25  * option is given (which always overrides configuration) this flag will be
  26  * ignored.
  27  */
  28 static int gitmodules_is_unmerged;
  29
  30 static int add_submodule_odb(const char *path)
  31 {
  32         struct strbuf objects_directory = STRBUF_INIT;
  33         struct alternate_object_database *alt_odb;
  34         int ret = 0;
  35         const char *git_dir;
  36
  37         strbuf_addf(&objects_directory, "%s/.git", path);
  38         git_dir = read_gitfile(objects_directory.buf);
  39         if (git_dir) {
  40                 strbuf_reset(&objects_directory);
  41                 strbuf_addstr(&objects_directory, git_dir);
  42         }
  43         strbuf_addstr(&objects_directory, "/objects/");
  44         if (!is_directory(objects_directory.buf)) {
  45                 ret = -1;
  46                 goto done;
  47         }
  48         /* avoid adding it twice */
  49         for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
  50                 if (alt_odb->name - alt_odb->base == objects_directory.len &&
  51                                 !strncmp(alt_odb->base, objects_directory.buf,
  52                                         objects_directory.len))
  53                         goto done;
  54
  55         alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
  56         alt_odb->next = alt_odb_list;
  57         strcpy(alt_odb->base, objects_directory.buf);
  58         alt_odb->name = alt_odb->base + objects_directory.len;
  59         alt_odb->name[2] = '/';
  60         alt_odb->name[40] = '\0';
  61         alt_odb->name[41] = '\0';
  62         alt_odb_list = alt_odb;
  63         prepare_alt_odb();
  64 done:
  65         strbuf_release(&objects_directory);
  66         return ret;
  67 }
  68
  69 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
  70                                              const char *path)
  71 {
  72         struct string_list_item *path_option, *ignore_option;
  73         path_option = unsorted_string_list_lookup(&config_name_for_path, path);
  74         if (path_option) {
  75                 ignore_option = unsorted_string_list_lookup(&config_ignore_for_name, path_option->util);
  76                 if (ignore_option)
  77                         handle_ignore_submodules_arg(diffopt, ignore_option->util);
  78                 else if (gitmodules_is_unmerged)
  79                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
  80         }
  81 }
  82
  83 int submodule_config(const char *var, const char *value, void *cb)
  84 {
  85         if (!prefixcmp(var, "submodule."))
  86                 return parse_submodule_config_option(var, value);
  87         else if (!strcmp(var, "fetch.recursesubmodules")) {
  88                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
  89                 return 0;
  90         }
  91         return 0;
  92 }
  93
  94 void gitmodules_config(void)
  95 {
  96         const char *work_tree = get_git_work_tree();
  97         if (work_tree) {
  98                 struct strbuf gitmodules_path = STRBUF_INIT;
  99                 int pos;
 100                 strbuf_addstr(&gitmodules_path, work_tree);
 101                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
 102                 if (read_cache() < 0)
 103                         die("index file corrupt");
 104                 pos = cache_name_pos(".gitmodules", 11);
 105                 if (pos < 0) { /* .gitmodules not found or isn't merged */
 106                         pos = -1 - pos;
 107                         if (active_nr > pos) {  /* there is a .gitmodules */
 108                                 const struct cache_entry *ce = active_cache[pos];
 109                                 if (ce_namelen(ce) == 11 &&
 110                                     !memcmp(ce->name, ".gitmodules", 11))
 111                                         gitmodules_is_unmerged = 1;
 112                         }
 113                 }
 114
 115                 if (!gitmodules_is_unmerged)
 116                         git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
 117                 strbuf_release(&gitmodules_path);
 118         }
 119 }
 120
 121 int parse_submodule_config_option(const char *var, const char *value)
 122 {
 123         int len;
 124         struct string_list_item *config;
 125         struct strbuf submodname = STRBUF_INIT;
 126
 127         var += 10;              /* Skip "submodule." */
 128
 129         len = strlen(var);
 130         if ((len > 5) && !strcmp(var + len - 5, ".path")) {
 131                 strbuf_add(&submodname, var, len - 5);
 132                 config = unsorted_string_list_lookup(&config_name_for_path, value);
 133                 if (config)
 134                         free(config->util);
 135                 else
 136                         config = string_list_append(&config_name_for_path, xstrdup(value));
 137                 config->util = strbuf_detach(&submodname, NULL);
 138                 strbuf_release(&submodname);
 139         } else if ((len > 23) && !strcmp(var + len - 23, ".fetchrecursesubmodules")) {
 140                 strbuf_add(&submodname, var, len - 23);
 141                 config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, submodname.buf);
 142                 if (!config)
 143                         config = string_list_append(&config_fetch_recurse_submodules_for_name,
 144                                                     strbuf_detach(&submodname, NULL));
 145                 config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
 146                 strbuf_release(&submodname);
 147         } else if ((len > 7) && !strcmp(var + len - 7, ".ignore")) {
 148                 if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
 149                     strcmp(value, "all") && strcmp(value, "none")) {
 150                         warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);
 151                         return 0;
 152                 }
 153
 154                 strbuf_add(&submodname, var, len - 7);
 155                 config = unsorted_string_list_lookup(&config_ignore_for_name, submodname.buf);
 156                 if (config)
 157                         free(config->util);
 158                 else
 159                         config = string_list_append(&config_ignore_for_name,
 160                                                     strbuf_detach(&submodname, NULL));
 161                 strbuf_release(&submodname);
 162                 config->util = xstrdup(value);
 163                 return 0;
 164         }
 165         return 0;
 166 }
 167
 168 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 169                                   const char *arg)
 170 {
 171         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 172         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 173         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 174
 175         if (!strcmp(arg, "all"))
 176                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 177         else if (!strcmp(arg, "untracked"))
 178                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 179         else if (!strcmp(arg, "dirty"))
 180                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 181         else if (strcmp(arg, "none"))
 182                 die("bad --ignore-submodules argument: %s", arg);
 183 }
 184
 185 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 186                 struct commit *left, struct commit *right,
 187                 int *fast_forward, int *fast_backward)
 188 {
 189         struct commit_list *merge_bases, *list;
 190
 191         init_revisions(rev, NULL);
 192         setup_revisions(0, NULL, rev, NULL);
 193         rev->left_right = 1;
 194         rev->first_parent_only = 1;
 195         left->object.flags |= SYMMETRIC_LEFT;
 196         add_pending_object(rev, &left->object, path);
 197         add_pending_object(rev, &right->object, path);
 198         merge_bases = get_merge_bases(left, right, 1);
 199         if (merge_bases) {
 200                 if (merge_bases->item == left)
 201                         *fast_forward = 1;
 202                 else if (merge_bases->item == right)
 203                         *fast_backward = 1;
 204         }
 205         for (list = merge_bases; list; list = list->next) {
 206                 list->item->object.flags |= UNINTERESTING;
 207                 add_pending_object(rev, &list->item->object,
 208                         sha1_to_hex(list->item->object.sha1));
 209         }
 210         return prepare_revision_walk(rev);
 211 }
 212
 213 static void print_submodule_summary(struct rev_info *rev, FILE *f,
 214                 const char *del, const char *add, const char *reset)
 215 {
 216         static const char format[] = "  %m %s";
 217         struct strbuf sb = STRBUF_INIT;
 218         struct commit *commit;
 219
 220         while ((commit = get_revision(rev))) {
 221                 struct pretty_print_context ctx = {0};
 222                 ctx.date_mode = rev->date_mode;
 223                 strbuf_setlen(&sb, 0);
 224                 if (commit->object.flags & SYMMETRIC_LEFT) {
 225                         if (del)
 226                                 strbuf_addstr(&sb, del);
 227                 }
 228                 else if (add)
 229                         strbuf_addstr(&sb, add);
 230                 format_commit_message(commit, format, &sb, &ctx);
 231                 if (reset)
 232                         strbuf_addstr(&sb, reset);
 233                 strbuf_addch(&sb, '\n');
 234                 fprintf(f, "%s", sb.buf);
 235         }
 236         strbuf_release(&sb);
 237 }
 238
 239 int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
 240 {
 241         switch (git_config_maybe_bool(opt, arg)) {
 242         case 1:
 243                 return RECURSE_SUBMODULES_ON;
 244         case 0:
 245                 return RECURSE_SUBMODULES_OFF;
 246         default:
 247                 if (!strcmp(arg, "on-demand"))
 248                         return RECURSE_SUBMODULES_ON_DEMAND;
 249                 die("bad %s argument: %s", opt, arg);
 250         }
 251 }
 252
 253 void show_submodule_summary(FILE *f, const char *path,
 254                 unsigned char one[20], unsigned char two[20],
 255                 unsigned dirty_submodule,
 256                 const char *del, const char *add, const char *reset)
 257 {
 258         struct rev_info rev;
 259         struct commit *left = left, *right = right;
 260         const char *message = NULL;
 261         struct strbuf sb = STRBUF_INIT;
 262         int fast_forward = 0, fast_backward = 0;
 263
 264         if (is_null_sha1(two))
 265                 message = "(submodule deleted)";
 266         else if (add_submodule_odb(path))
 267                 message = "(not checked out)";
 268         else if (is_null_sha1(one))
 269                 message = "(new submodule)";
 270         else if (!(left = lookup_commit_reference(one)) ||
 271                  !(right = lookup_commit_reference(two)))
 272                 message = "(commits not present)";
 273
 274         if (!message &&
 275             prepare_submodule_summary(&rev, path, left, right,
 276                                         &fast_forward, &fast_backward))
 277                 message = "(revision walker failed)";
 278
 279         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 280                 fprintf(f, "Submodule %s contains untracked content\n", path);
 281         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 282                 fprintf(f, "Submodule %s contains modified content\n", path);
 283
 284         if (!hashcmp(one, two)) {
 285                 strbuf_release(&sb);
 286                 return;
 287         }
 288
 289         strbuf_addf(&sb, "Submodule %s %s..", path,
 290                         find_unique_abbrev(one, DEFAULT_ABBREV));
 291         if (!fast_backward && !fast_forward)
 292                 strbuf_addch(&sb, '.');
 293         strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
 294         if (message)
 295                 strbuf_addf(&sb, " %s\n", message);
 296         else
 297                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 298         fwrite(sb.buf, sb.len, 1, f);
 299
 300         if (!message) {
 301                 print_submodule_summary(&rev, f, del, add, reset);
 302                 clear_commit_marks(left, ~0);
 303                 clear_commit_marks(right, ~0);
 304         }
 305
 306         strbuf_release(&sb);
 307 }
 308
 309 void set_config_fetch_recurse_submodules(int value)
 310 {
 311         config_fetch_recurse_submodules = value;
 312 }
 313
 314 typedef int (*module_func_t)(const char *path, const unsigned char sha1[20], void *data);
 315
 316 static int has_remote(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
 317 {
 318         return 1;
 319 }
 320
 321 int submodule_needs_pushing(const char *path, const unsigned char sha1[20], void *data)
 322 {
 323         int *needs_pushing = data;
 324
 325         if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
 326                 return 1;
 327
 328         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 329                 struct child_process cp;
 330                 const char *argv[] = {"rev-list", NULL, "--not", "--remotes", "-n", "1" , NULL};
 331                 struct strbuf buf = STRBUF_INIT;
 332
 333                 argv[1] = sha1_to_hex(sha1);
 334                 memset(&cp, 0, sizeof(cp));
 335                 cp.argv = argv;
 336                 cp.env = local_repo_env;
 337                 cp.git_cmd = 1;
 338                 cp.no_stdin = 1;
 339                 cp.out = -1;
 340                 cp.dir = path;
 341                 if (start_command(&cp))
 342                         die("Could not run 'git rev-list %s --not --remotes -n 1' command in submodule %s",
 343                                 sha1_to_hex(sha1), path);
 344                 if (strbuf_read(&buf, cp.out, 41))
 345                         *needs_pushing = 1;
 346                 finish_command(&cp);
 347                 close(cp.out);
 348                 strbuf_release(&buf);
 349                 return !*needs_pushing;
 350         }
 351
 352         return 1;
 353 }
 354
 355 int push_submodule(const char *path, const unsigned char sha1[20], void *data)
 356 {
 357         if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
 358                 return 1;
 359
 360         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 361                 struct child_process cp;
 362                 const char *argv[] = {"push", NULL};
 363
 364                 memset(&cp, 0, sizeof(cp));
 365                 cp.argv = argv;
 366                 cp.env = local_repo_env;
 367                 cp.git_cmd = 1;
 368                 cp.no_stdin = 1;
 369                 cp.out = -1;
 370                 cp.dir = path;
 371                 if (run_command(&cp))
 372                         die("Could not run 'git push' command in submodule %s", path);
 373                 close(cp.out);
 374         }
 375
 376         return 1;
 377 }
 378
 379 struct collect_submodules_data {
 380         module_func_t func;
 381         void *data;
 382         int ret;
 383 };
 384
 385 static void collect_submodules_from_diff(struct diff_queue_struct *q,
 386                                          struct diff_options *options,
 387                                          void *data)
 388 {
 389         int i;
 390         struct collect_submodules_data *me = data;
 391
 392         for (i = 0; i < q->nr; i++) {
 393                 struct diff_filepair *p = q->queue[i];
 394                 if (!S_ISGITLINK(p->two->mode))
 395                         continue;
 396                 if (!(me->ret = me->func(p->two->path, p->two->sha1, me->data)))
 397                         break;
 398         }
 399 }
 400
 401 static int commit_need_pushing(struct commit *commit, struct commit_list *parent,
 402         module_func_t func, void *data)
 403 {
 404         const unsigned char (*parents)[20];
 405         unsigned int i, n;
 406         struct rev_info rev;
 407
 408         struct collect_submodules_data cb;
 409         cb.func = func;
 410         cb.data = data;
 411         cb.ret = 1;
 412
 413         n = commit_list_count(parent);
 414         parents = xmalloc(n * sizeof(*parents));
 415
 416         for (i = 0; i < n; i++) {
 417                 hashcpy((unsigned char *)(parents + i), parent->item->object.sha1);
 418                 parent = parent->next;
 419         }
 420
 421         init_revisions(&rev, NULL);
 422         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 423         rev.diffopt.format_callback = collect_submodules_from_diff;
 424         rev.diffopt.format_callback_data = &cb;
 425         diff_tree_combined(commit->object.sha1, parents, n, 1, &rev);
 426
 427         free(parents);
 428         return cb.ret;
 429 }
 430
 431 static int inspect_superproject_commits(unsigned char new_sha1[20], const char *remotes_name,
 432         module_func_t func, void *data)
 433 {
 434         struct rev_info rev;
 435         struct commit *commit;
 436         const char *argv[] = {NULL, NULL, "--not", "NULL", NULL};
 437         int argc = ARRAY_SIZE(argv) - 1;
 438         char *sha1_copy;
 439         struct strbuf remotes_arg = STRBUF_INIT;
 440         int do_continue = 1;
 441
 442         strbuf_addf(&remotes_arg, "--remotes=%s", remotes_name);
 443         init_revisions(&rev, NULL);
 444         sha1_copy = xstrdup(sha1_to_hex(new_sha1));
 445         argv[1] = sha1_copy;
 446         argv[3] = remotes_arg.buf;
 447         setup_revisions(argc, argv, &rev, NULL);
 448         if (prepare_revision_walk(&rev))
 449                 die("revision walk setup failed");
 450
 451         while ((commit = get_revision(&rev)) && do_continue)
 452                 do_continue = commit_need_pushing(commit, commit->parents, func, data);
 453
 454         free(sha1_copy);
 455         strbuf_release(&remotes_arg);
 456
 457         return do_continue;
 458 }
 459
 460 int check_submodule_needs_pushing(unsigned char new_sha1[20], const char *remotes_name)
 461 {
 462         int needs_push = 0;
 463         inspect_superproject_commits(new_sha1, remotes_name, submodule_needs_pushing, &needs_push);
 464         return needs_push;
 465 }
 466
 467 void push_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_name)
 468 {
 469         inspect_superproject_commits(new_sha1, remotes_name, push_submodule, NULL);
 470 }
 471
 472 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
 473 {
 474         int is_present = 0;
 475         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
 476                 /* Even if the submodule is checked out and the commit is
 477                  * present, make sure it is reachable from a ref. */
 478                 struct child_process cp;
 479                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
 480                 struct strbuf buf = STRBUF_INIT;
 481
 482                 argv[3] = sha1_to_hex(sha1);
 483                 memset(&cp, 0, sizeof(cp));
 484                 cp.argv = argv;
 485                 cp.env = local_repo_env;
 486                 cp.git_cmd = 1;
 487                 cp.no_stdin = 1;
 488                 cp.out = -1;
 489                 cp.dir = path;
 490                 if (!run_command(&cp) && !strbuf_read(&buf, cp.out, 1024))
 491                         is_present = 1;
 492
 493                 close(cp.out);
 494                 strbuf_release(&buf);
 495         }
 496         return is_present;
 497 }
 498
 499 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
 500                                          struct diff_options *options,
 501                                          void *data)
 502 {
 503         int i;
 504         for (i = 0; i < q->nr; i++) {
 505                 struct diff_filepair *p = q->queue[i];
 506                 if (!S_ISGITLINK(p->two->mode))
 507                         continue;
 508
 509                 if (S_ISGITLINK(p->one->mode)) {
 510                         /* NEEDSWORK: We should honor the name configured in
 511                          * the .gitmodules file of the commit we are examining
 512                          * here to be able to correctly follow submodules
 513                          * being moved around. */
 514                         struct string_list_item *path;
 515                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
 516                         if (!path && !is_submodule_commit_present(p->two->path, p->two->sha1))
 517                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
 518                 } else {
 519                         /* Submodule is new or was moved here */
 520                         /* NEEDSWORK: When the .git directories of submodules
 521                          * live inside the superprojects .git directory some
 522                          * day we should fetch new submodules directly into
 523                          * that location too when config or options request
 524                          * that so they can be checked out from there. */
 525                         continue;
 526                 }
 527         }
 528 }
 529
 530 void check_for_new_submodule_commits(unsigned char new_sha1[20])
 531 {
 532         struct rev_info rev;
 533         struct commit *commit;
 534         const char *argv[] = {NULL, NULL, "--not", "--all", NULL};
 535         int argc = ARRAY_SIZE(argv) - 1;
 536
 537         init_revisions(&rev, NULL);
 538         argv[1] = xstrdup(sha1_to_hex(new_sha1));
 539         setup_revisions(argc, argv, &rev, NULL);
 540         if (prepare_revision_walk(&rev))
 541                 die("revision walk setup failed");
 542
 543         /*
 544          * Collect all submodules (whether checked out or not) for which new
 545          * commits have been recorded upstream in "changed_submodule_paths".
 546          */
 547         while ((commit = get_revision(&rev))) {
 548                 struct commit_list *parent = commit->parents;
 549                 while (parent) {
 550                         struct diff_options diff_opts;
 551                         diff_setup(&diff_opts);
 552                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
 553                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
 554                         diff_opts.format_callback = submodule_collect_changed_cb;
 555                         if (diff_setup_done(&diff_opts) < 0)
 556                                 die("diff_setup_done failed");
 557                         diff_tree_sha1(parent->item->object.sha1, commit->object.sha1, "", &diff_opts);
 558                         diffcore_std(&diff_opts);
 559                         diff_flush(&diff_opts);
 560                         parent = parent->next;
 561                 }
 562         }
 563         free((char *)argv[1]);
 564 }
 565
 566 int fetch_populated_submodules(int num_options, const char **options,
 567                                const char *prefix, int command_line_option,
 568                                int quiet)
 569 {
 570         int i, result = 0, argc = 0, default_argc;
 571         struct child_process cp;
 572         const char **argv;
 573         struct string_list_item *name_for_path;
 574         const char *work_tree = get_git_work_tree();
 575         if (!work_tree)
 576                 goto out;
 577
 578         if (!the_index.initialized)
 579                 if (read_cache() < 0)
 580                         die("index file corrupt");
 581
 582         /* 6: "fetch" (options) --recurse-submodules-default default "--submodule-prefix" prefix NULL */
 583         argv = xcalloc(num_options + 6, sizeof(const char *));
 584         argv[argc++] = "fetch";
 585         for (i = 0; i < num_options; i++)
 586                 argv[argc++] = options[i];
 587         argv[argc++] = "--recurse-submodules-default";
 588         default_argc = argc++;
 589         argv[argc++] = "--submodule-prefix";
 590
 591         memset(&cp, 0, sizeof(cp));
 592         cp.argv = argv;
 593         cp.env = local_repo_env;
 594         cp.git_cmd = 1;
 595         cp.no_stdin = 1;
 596
 597         for (i = 0; i < active_nr; i++) {
 598                 struct strbuf submodule_path = STRBUF_INIT;
 599                 struct strbuf submodule_git_dir = STRBUF_INIT;
 600                 struct strbuf submodule_prefix = STRBUF_INIT;
 601                 struct cache_entry *ce = active_cache[i];
 602                 const char *git_dir, *name, *default_argv;
 603
 604                 if (!S_ISGITLINK(ce->ce_mode))
 605                         continue;
 606
 607                 name = ce->name;
 608                 name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
 609                 if (name_for_path)
 610                         name = name_for_path->util;
 611
 612                 default_argv = "yes";
 613                 if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
 614                         struct string_list_item *fetch_recurse_submodules_option;
 615                         fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
 616                         if (fetch_recurse_submodules_option) {
 617                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
 618                                         continue;
 619                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
 620                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 621                                                 continue;
 622                                         default_argv = "on-demand";
 623                                 }
 624                         } else {
 625                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
 626                                     gitmodules_is_unmerged)
 627                                         continue;
 628                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
 629                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 630                                                 continue;
 631                                         default_argv = "on-demand";
 632                                 }
 633                         }
 634                 } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
 635                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 636                                 continue;
 637                         default_argv = "on-demand";
 638                 }
 639
 640                 strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
 641                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
 642                 strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
 643                 git_dir = read_gitfile(submodule_git_dir.buf);
 644                 if (!git_dir)
 645                         git_dir = submodule_git_dir.buf;
 646                 if (is_directory(git_dir)) {
 647                         if (!quiet)
 648                                 printf("Fetching submodule %s%s\n", prefix, ce->name);
 649                         cp.dir = submodule_path.buf;
 650                         argv[default_argc] = default_argv;
 651                         argv[argc] = submodule_prefix.buf;
 652                         if (run_command(&cp))
 653                                 result = 1;
 654                 }
 655                 strbuf_release(&submodule_path);
 656                 strbuf_release(&submodule_git_dir);
 657                 strbuf_release(&submodule_prefix);
 658         }
 659         free(argv);
 660 out:
 661         string_list_clear(&changed_submodule_paths, 1);
 662         return result;
 663 }
 664
 665 unsigned is_submodule_modified(const char *path, int ignore_untracked)
 666 {
 667         ssize_t len;
 668         struct child_process cp;
 669         const char *argv[] = {
 670                 "status",
 671                 "--porcelain",
 672                 NULL,
 673                 NULL,
 674         };
 675         struct strbuf buf = STRBUF_INIT;
 676         unsigned dirty_submodule = 0;
 677         const char *line, *next_line;
 678         const char *git_dir;
 679
 680         strbuf_addf(&buf, "%s/.git", path);
 681         git_dir = read_gitfile(buf.buf);
 682         if (!git_dir)
 683                 git_dir = buf.buf;
 684         if (!is_directory(git_dir)) {
 685                 strbuf_release(&buf);
 686                 /* The submodule is not checked out, so it is not modified */
 687                 return 0;
 688
 689         }
 690         strbuf_reset(&buf);
 691
 692         if (ignore_untracked)
 693                 argv[2] = "-uno";
 694
 695         memset(&cp, 0, sizeof(cp));
 696         cp.argv = argv;
 697         cp.env = local_repo_env;
 698         cp.git_cmd = 1;
 699         cp.no_stdin = 1;
 700         cp.out = -1;
 701         cp.dir = path;
 702         if (start_command(&cp))
 703                 die("Could not run git status --porcelain");
 704
 705         len = strbuf_read(&buf, cp.out, 1024);
 706         line = buf.buf;
 707         while (len > 2) {
 708                 if ((line[0] == '?') && (line[1] == '?')) {
 709                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
 710                         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 711                                 break;
 712                 } else {
 713                         dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
 714                         if (ignore_untracked ||
 715                             (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
 716                                 break;
 717                 }
 718                 next_line = strchr(line, '\n');
 719                 if (!next_line)
 720                         break;
 721                 next_line++;
 722                 len -= (next_line - line);
 723                 line = next_line;
 724         }
 725         close(cp.out);
 726
 727         if (finish_command(&cp))
 728                 die("git status --porcelain failed");
 729
 730         strbuf_release(&buf);
 731         return dirty_submodule;
 732 }
 733
 734 static int find_first_merges(struct object_array *result, const char *path,
 735                 struct commit *a, struct commit *b)
 736 {
 737         int i, j;
 738         struct object_array merges;
 739         struct commit *commit;
 740         int contains_another;
 741
 742         char merged_revision[42];
 743         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
 744                                    "--all", merged_revision, NULL };
 745         struct rev_info revs;
 746         struct setup_revision_opt rev_opts;
 747
 748         memset(&merges, 0, sizeof(merges));
 749         memset(result, 0, sizeof(struct object_array));
 750         memset(&rev_opts, 0, sizeof(rev_opts));
 751
 752         /* get all revisions that merge commit a */
 753         snprintf(merged_revision, sizeof(merged_revision), "^%s",
 754                         sha1_to_hex(a->object.sha1));
 755         init_revisions(&revs, NULL);
 756         rev_opts.submodule = path;
 757         setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts);
 758
 759         /* save all revisions from the above list that contain b */
 760         if (prepare_revision_walk(&revs))
 761                 die("revision walk setup failed");
 762         while ((commit = get_revision(&revs)) != NULL) {
 763                 struct object *o = &(commit->object);
 764                 if (in_merge_bases(b, &commit, 1))
 765                         add_object_array(o, NULL, &merges);
 766         }
 767
 768         /* Now we've got all merges that contain a and b. Prune all
 769          * merges that contain another found merge and save them in
 770          * result.
 771          */
 772         for (i = 0; i < merges.nr; i++) {
 773                 struct commit *m1 = (struct commit *) merges.objects[i].item;
 774
 775                 contains_another = 0;
 776                 for (j = 0; j < merges.nr; j++) {
 777                         struct commit *m2 = (struct commit *) merges.objects[j].item;
 778                         if (i != j && in_merge_bases(m2, &m1, 1)) {
 779                                 contains_another = 1;
 780                                 break;
 781                         }
 782                 }
 783
 784                 if (!contains_another)
 785                         add_object_array(merges.objects[i].item,
 786                                          merges.objects[i].name, result);
 787         }
 788
 789         free(merges.objects);
 790         return result->nr;
 791 }
 792
 793 static void print_commit(struct commit *commit)
 794 {
 795         struct strbuf sb = STRBUF_INIT;
 796         struct pretty_print_context ctx = {0};
 797         ctx.date_mode = DATE_NORMAL;
 798         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
 799         fprintf(stderr, "%s\n", sb.buf);
 800         strbuf_release(&sb);
 801 }
 802
 803 #define MERGE_WARNING(path, msg) \
 804         warning("Failed to merge submodule %s (%s)", path, msg);
 805
 806 int merge_submodule(unsigned char result[20], const char *path,
 807                     const unsigned char base[20], const unsigned char a[20],
 808                     const unsigned char b[20])
 809 {
 810         struct commit *commit_base, *commit_a, *commit_b;
 811         int parent_count;
 812         struct object_array merges;
 813
 814         int i;
 815
 816         /* store a in result in case we fail */
 817         hashcpy(result, a);
 818
 819         /* we can not handle deletion conflicts */
 820         if (is_null_sha1(base))
 821                 return 0;
 822         if (is_null_sha1(a))
 823                 return 0;
 824         if (is_null_sha1(b))
 825                 return 0;
 826
 827         if (add_submodule_odb(path)) {
 828                 MERGE_WARNING(path, "not checked out");
 829                 return 0;
 830         }
 831
 832         if (!(commit_base = lookup_commit_reference(base)) ||
 833             !(commit_a = lookup_commit_reference(a)) ||
 834             !(commit_b = lookup_commit_reference(b))) {
 835                 MERGE_WARNING(path, "commits not present");
 836                 return 0;
 837         }
 838
 839         /* check whether both changes are forward */
 840         if (!in_merge_bases(commit_base, &commit_a, 1) ||
 841             !in_merge_bases(commit_base, &commit_b, 1)) {
 842                 MERGE_WARNING(path, "commits don't follow merge-base");
 843                 return 0;
 844         }
 845
 846         /* Case #1: a is contained in b or vice versa */
 847         if (in_merge_bases(commit_a, &commit_b, 1)) {
 848                 hashcpy(result, b);
 849                 return 1;
 850         }
 851         if (in_merge_bases(commit_b, &commit_a, 1)) {
 852                 hashcpy(result, a);
 853                 return 1;
 854         }
 855
 856         /*
 857          * Case #2: There are one or more merges that contain a and b in
 858          * the submodule. If there is only one, then present it as a
 859          * suggestion to the user, but leave it marked unmerged so the
 860          * user needs to confirm the resolution.
 861          */
 862
 863         /* find commit which merges them */
 864         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
 865         switch (parent_count) {
 866         case 0:
 867                 MERGE_WARNING(path, "merge following commits not found");
 868                 break;
 869
 870         case 1:
 871                 MERGE_WARNING(path, "not fast-forward");
 872                 fprintf(stderr, "Found a possible merge resolution "
 873                                 "for the submodule:\n");
 874                 print_commit((struct commit *) merges.objects[0].item);
 875                 fprintf(stderr,
 876                         "If this is correct simply add it to the index "
 877                         "for example\n"
 878                         "by using:\n\n"
 879                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
 880                         "which will accept this suggestion.\n",
 881                         sha1_to_hex(merges.objects[0].item->sha1), path);
 882                 break;
 883
 884         default:
 885                 MERGE_WARNING(path, "multiple merges found");
 886                 for (i = 0; i < merges.nr; i++)
 887                         print_commit((struct commit *) merges.objects[i].item);
 888         }
 889
 890         free(merges.objects);
 891         return 0;
 892 }