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 "sha1-array.h"
  12 #include "argv-array.h"
  13
  14 static struct string_list config_name_for_path;
  15 static struct string_list config_fetch_recurse_submodules_for_name;
  16 static struct string_list config_ignore_for_name;
  17 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
  18 static struct string_list changed_submodule_paths;
  19 static int initialized_fetch_ref_tips;
  20 static struct sha1_array ref_tips_before_fetch;
  21 static struct sha1_array ref_tips_after_fetch;
  22
  23 /*
  24  * The following flag is set if the .gitmodules file is unmerged. We then
  25  * disable recursion for all submodules where .git/config doesn't have a
  26  * matching config entry because we can't guess what might be configured in
  27  * .gitmodules unless the user resolves the conflict. When a command line
  28  * option is given (which always overrides configuration) this flag will be
  29  * ignored.
  30  */
  31 static int gitmodules_is_unmerged;
  32
  33 static int add_submodule_odb(const char *path)
  34 {
  35         struct strbuf objects_directory = STRBUF_INIT;
  36         struct alternate_object_database *alt_odb;
  37         int ret = 0;
  38         const char *git_dir;
  39
  40         strbuf_addf(&objects_directory, "%s/.git", path);
  41         git_dir = read_gitfile(objects_directory.buf);
  42         if (git_dir) {
  43                 strbuf_reset(&objects_directory);
  44                 strbuf_addstr(&objects_directory, git_dir);
  45         }
  46         strbuf_addstr(&objects_directory, "/objects/");
  47         if (!is_directory(objects_directory.buf)) {
  48                 ret = -1;
  49                 goto done;
  50         }
  51         /* avoid adding it twice */
  52         for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
  53                 if (alt_odb->name - alt_odb->base == objects_directory.len &&
  54                                 !strncmp(alt_odb->base, objects_directory.buf,
  55                                         objects_directory.len))
  56                         goto done;
  57
  58         alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
  59         alt_odb->next = alt_odb_list;
  60         strcpy(alt_odb->base, objects_directory.buf);
  61         alt_odb->name = alt_odb->base + objects_directory.len;
  62         alt_odb->name[2] = '/';
  63         alt_odb->name[40] = '\0';
  64         alt_odb->name[41] = '\0';
  65         alt_odb_list = alt_odb;
  66         prepare_alt_odb();
  67 done:
  68         strbuf_release(&objects_directory);
  69         return ret;
  70 }
  71
  72 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
  73                                              const char *path)
  74 {
  75         struct string_list_item *path_option, *ignore_option;
  76         path_option = unsorted_string_list_lookup(&config_name_for_path, path);
  77         if (path_option) {
  78                 ignore_option = unsorted_string_list_lookup(&config_ignore_for_name, path_option->util);
  79                 if (ignore_option)
  80                         handle_ignore_submodules_arg(diffopt, ignore_option->util);
  81                 else if (gitmodules_is_unmerged)
  82                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
  83         }
  84 }
  85
  86 int submodule_config(const char *var, const char *value, void *cb)
  87 {
  88         if (!prefixcmp(var, "submodule."))
  89                 return parse_submodule_config_option(var, value);
  90         else if (!strcmp(var, "fetch.recursesubmodules")) {
  91                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
  92                 return 0;
  93         }
  94         return 0;
  95 }
  96
  97 void gitmodules_config(void)
  98 {
  99         const char *work_tree = get_git_work_tree();
 100         if (work_tree) {
 101                 struct strbuf gitmodules_path = STRBUF_INIT;
 102                 int pos;
 103                 strbuf_addstr(&gitmodules_path, work_tree);
 104                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
 105                 if (read_cache() < 0)
 106                         die("index file corrupt");
 107                 pos = cache_name_pos(".gitmodules", 11);
 108                 if (pos < 0) { /* .gitmodules not found or isn't merged */
 109                         pos = -1 - pos;
 110                         if (active_nr > pos) {  /* there is a .gitmodules */
 111                                 const struct cache_entry *ce = active_cache[pos];
 112                                 if (ce_namelen(ce) == 11 &&
 113                                     !memcmp(ce->name, ".gitmodules", 11))
 114                                         gitmodules_is_unmerged = 1;
 115                         }
 116                 }
 117
 118                 if (!gitmodules_is_unmerged)
 119                         git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
 120                 strbuf_release(&gitmodules_path);
 121         }
 122 }
 123
 124 int parse_submodule_config_option(const char *var, const char *value)
 125 {
 126         int len;
 127         struct string_list_item *config;
 128         struct strbuf submodname = STRBUF_INIT;
 129
 130         var += 10;              /* Skip "submodule." */
 131
 132         len = strlen(var);
 133         if ((len > 5) && !strcmp(var + len - 5, ".path")) {
 134                 strbuf_add(&submodname, var, len - 5);
 135                 config = unsorted_string_list_lookup(&config_name_for_path, value);
 136                 if (config)
 137                         free(config->util);
 138                 else
 139                         config = string_list_append(&config_name_for_path, xstrdup(value));
 140                 config->util = strbuf_detach(&submodname, NULL);
 141                 strbuf_release(&submodname);
 142         } else if ((len > 23) && !strcmp(var + len - 23, ".fetchrecursesubmodules")) {
 143                 strbuf_add(&submodname, var, len - 23);
 144                 config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, submodname.buf);
 145                 if (!config)
 146                         config = string_list_append(&config_fetch_recurse_submodules_for_name,
 147                                                     strbuf_detach(&submodname, NULL));
 148                 config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
 149                 strbuf_release(&submodname);
 150         } else if ((len > 7) && !strcmp(var + len - 7, ".ignore")) {
 151                 if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
 152                     strcmp(value, "all") && strcmp(value, "none")) {
 153                         warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);
 154                         return 0;
 155                 }
 156
 157                 strbuf_add(&submodname, var, len - 7);
 158                 config = unsorted_string_list_lookup(&config_ignore_for_name, submodname.buf);
 159                 if (config)
 160                         free(config->util);
 161                 else
 162                         config = string_list_append(&config_ignore_for_name,
 163                                                     strbuf_detach(&submodname, NULL));
 164                 strbuf_release(&submodname);
 165                 config->util = xstrdup(value);
 166                 return 0;
 167         }
 168         return 0;
 169 }
 170
 171 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 172                                   const char *arg)
 173 {
 174         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 175         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 176         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 177
 178         if (!strcmp(arg, "all"))
 179                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 180         else if (!strcmp(arg, "untracked"))
 181                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 182         else if (!strcmp(arg, "dirty"))
 183                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 184         else if (strcmp(arg, "none"))
 185                 die("bad --ignore-submodules argument: %s", arg);
 186 }
 187
 188 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 189                 struct commit *left, struct commit *right,
 190                 int *fast_forward, int *fast_backward)
 191 {
 192         struct commit_list *merge_bases, *list;
 193
 194         init_revisions(rev, NULL);
 195         setup_revisions(0, NULL, rev, NULL);
 196         rev->left_right = 1;
 197         rev->first_parent_only = 1;
 198         left->object.flags |= SYMMETRIC_LEFT;
 199         add_pending_object(rev, &left->object, path);
 200         add_pending_object(rev, &right->object, path);
 201         merge_bases = get_merge_bases(left, right, 1);
 202         if (merge_bases) {
 203                 if (merge_bases->item == left)
 204                         *fast_forward = 1;
 205                 else if (merge_bases->item == right)
 206                         *fast_backward = 1;
 207         }
 208         for (list = merge_bases; list; list = list->next) {
 209                 list->item->object.flags |= UNINTERESTING;
 210                 add_pending_object(rev, &list->item->object,
 211                         sha1_to_hex(list->item->object.sha1));
 212         }
 213         return prepare_revision_walk(rev);
 214 }
 215
 216 static void print_submodule_summary(struct rev_info *rev, FILE *f,
 217                 const char *del, const char *add, const char *reset)
 218 {
 219         static const char format[] = "  %m %s";
 220         struct strbuf sb = STRBUF_INIT;
 221         struct commit *commit;
 222
 223         while ((commit = get_revision(rev))) {
 224                 struct pretty_print_context ctx = {0};
 225                 ctx.date_mode = rev->date_mode;
 226                 strbuf_setlen(&sb, 0);
 227                 if (commit->object.flags & SYMMETRIC_LEFT) {
 228                         if (del)
 229                                 strbuf_addstr(&sb, del);
 230                 }
 231                 else if (add)
 232                         strbuf_addstr(&sb, add);
 233                 format_commit_message(commit, format, &sb, &ctx);
 234                 if (reset)
 235                         strbuf_addstr(&sb, reset);
 236                 strbuf_addch(&sb, '\n');
 237                 fprintf(f, "%s", sb.buf);
 238         }
 239         strbuf_release(&sb);
 240 }
 241
 242 int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
 243 {
 244         switch (git_config_maybe_bool(opt, arg)) {
 245         case 1:
 246                 return RECURSE_SUBMODULES_ON;
 247         case 0:
 248                 return RECURSE_SUBMODULES_OFF;
 249         default:
 250                 if (!strcmp(arg, "on-demand"))
 251                         return RECURSE_SUBMODULES_ON_DEMAND;
 252                 die("bad %s argument: %s", opt, arg);
 253         }
 254 }
 255
 256 void show_submodule_summary(FILE *f, const char *path,
 257                 unsigned char one[20], unsigned char two[20],
 258                 unsigned dirty_submodule,
 259                 const char *del, const char *add, const char *reset)
 260 {
 261         struct rev_info rev;
 262         struct commit *left = left, *right = right;
 263         const char *message = NULL;
 264         struct strbuf sb = STRBUF_INIT;
 265         int fast_forward = 0, fast_backward = 0;
 266
 267         if (is_null_sha1(two))
 268                 message = "(submodule deleted)";
 269         else if (add_submodule_odb(path))
 270                 message = "(not checked out)";
 271         else if (is_null_sha1(one))
 272                 message = "(new submodule)";
 273         else if (!(left = lookup_commit_reference(one)) ||
 274                  !(right = lookup_commit_reference(two)))
 275                 message = "(commits not present)";
 276
 277         if (!message &&
 278             prepare_submodule_summary(&rev, path, left, right,
 279                                         &fast_forward, &fast_backward))
 280                 message = "(revision walker failed)";
 281
 282         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 283                 fprintf(f, "Submodule %s contains untracked content\n", path);
 284         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 285                 fprintf(f, "Submodule %s contains modified content\n", path);
 286
 287         if (!hashcmp(one, two)) {
 288                 strbuf_release(&sb);
 289                 return;
 290         }
 291
 292         strbuf_addf(&sb, "Submodule %s %s..", path,
 293                         find_unique_abbrev(one, DEFAULT_ABBREV));
 294         if (!fast_backward && !fast_forward)
 295                 strbuf_addch(&sb, '.');
 296         strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
 297         if (message)
 298                 strbuf_addf(&sb, " %s\n", message);
 299         else
 300                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 301         fwrite(sb.buf, sb.len, 1, f);
 302
 303         if (!message) {
 304                 print_submodule_summary(&rev, f, del, add, reset);
 305                 clear_commit_marks(left, ~0);
 306                 clear_commit_marks(right, ~0);
 307         }
 308
 309         strbuf_release(&sb);
 310 }
 311
 312 void set_config_fetch_recurse_submodules(int value)
 313 {
 314         config_fetch_recurse_submodules = value;
 315 }
 316
 317 static int has_remote(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
 318 {
 319         return 1;
 320 }
 321
 322 static int submodule_needs_pushing(const char *path, const unsigned char sha1[20])
 323 {
 324         if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
 325                 return 0;
 326
 327         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 328                 struct child_process cp;
 329                 const char *argv[] = {"rev-list", NULL, "--not", "--remotes", "-n", "1" , NULL};
 330                 struct strbuf buf = STRBUF_INIT;
 331                 int needs_pushing = 0;
 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 0;
 353 }
 354
 355 static void collect_submodules_from_diff(struct diff_queue_struct *q,
 356                                          struct diff_options *options,
 357                                          void *data)
 358 {
 359         int i;
 360         int *needs_pushing = data;
 361
 362         for (i = 0; i < q->nr; i++) {
 363                 struct diff_filepair *p = q->queue[i];
 364                 if (!S_ISGITLINK(p->two->mode))
 365                         continue;
 366                 if (submodule_needs_pushing(p->two->path, p->two->sha1)) {
 367                         *needs_pushing = 1;
 368                         break;
 369                 }
 370         }
 371 }
 372
 373
 374 static void commit_need_pushing(struct commit *commit, int *needs_pushing)
 375 {
 376         struct rev_info rev;
 377
 378         init_revisions(&rev, NULL);
 379         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 380         rev.diffopt.format_callback = collect_submodules_from_diff;
 381         rev.diffopt.format_callback_data = needs_pushing;
 382         diff_tree_combined_merge(commit, 1, &rev);
 383 }
 384
 385 int check_submodule_needs_pushing(unsigned char new_sha1[20], const char *remotes_name)
 386 {
 387         struct rev_info rev;
 388         struct commit *commit;
 389         const char *argv[] = {NULL, NULL, "--not", "NULL", NULL};
 390         int argc = ARRAY_SIZE(argv) - 1;
 391         char *sha1_copy;
 392         int needs_pushing = 0;
 393         struct strbuf remotes_arg = STRBUF_INIT;
 394
 395         strbuf_addf(&remotes_arg, "--remotes=%s", remotes_name);
 396         init_revisions(&rev, NULL);
 397         sha1_copy = xstrdup(sha1_to_hex(new_sha1));
 398         argv[1] = sha1_copy;
 399         argv[3] = remotes_arg.buf;
 400         setup_revisions(argc, argv, &rev, NULL);
 401         if (prepare_revision_walk(&rev))
 402                 die("revision walk setup failed");
 403
 404         while ((commit = get_revision(&rev)) && !needs_pushing)
 405                 commit_need_pushing(commit, &needs_pushing);
 406
 407         free(sha1_copy);
 408         strbuf_release(&remotes_arg);
 409
 410         return needs_pushing;
 411 }
 412
 413 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
 414 {
 415         int is_present = 0;
 416         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
 417                 /* Even if the submodule is checked out and the commit is
 418                  * present, make sure it is reachable from a ref. */
 419                 struct child_process cp;
 420                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
 421                 struct strbuf buf = STRBUF_INIT;
 422
 423                 argv[3] = sha1_to_hex(sha1);
 424                 memset(&cp, 0, sizeof(cp));
 425                 cp.argv = argv;
 426                 cp.env = local_repo_env;
 427                 cp.git_cmd = 1;
 428                 cp.no_stdin = 1;
 429                 cp.out = -1;
 430                 cp.dir = path;
 431                 if (!run_command(&cp) && !strbuf_read(&buf, cp.out, 1024))
 432                         is_present = 1;
 433
 434                 close(cp.out);
 435                 strbuf_release(&buf);
 436         }
 437         return is_present;
 438 }
 439
 440 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
 441                                          struct diff_options *options,
 442                                          void *data)
 443 {
 444         int i;
 445         for (i = 0; i < q->nr; i++) {
 446                 struct diff_filepair *p = q->queue[i];
 447                 if (!S_ISGITLINK(p->two->mode))
 448                         continue;
 449
 450                 if (S_ISGITLINK(p->one->mode)) {
 451                         /* NEEDSWORK: We should honor the name configured in
 452                          * the .gitmodules file of the commit we are examining
 453                          * here to be able to correctly follow submodules
 454                          * being moved around. */
 455                         struct string_list_item *path;
 456                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
 457                         if (!path && !is_submodule_commit_present(p->two->path, p->two->sha1))
 458                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
 459                 } else {
 460                         /* Submodule is new or was moved here */
 461                         /* NEEDSWORK: When the .git directories of submodules
 462                          * live inside the superprojects .git directory some
 463                          * day we should fetch new submodules directly into
 464                          * that location too when config or options request
 465                          * that so they can be checked out from there. */
 466                         continue;
 467                 }
 468         }
 469 }
 470
 471 static int add_sha1_to_array(const char *ref, const unsigned char *sha1,
 472                              int flags, void *data)
 473 {
 474         sha1_array_append(data, sha1);
 475         return 0;
 476 }
 477
 478 void check_for_new_submodule_commits(unsigned char new_sha1[20])
 479 {
 480         if (!initialized_fetch_ref_tips) {
 481                 for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
 482                 initialized_fetch_ref_tips = 1;
 483         }
 484
 485         sha1_array_append(&ref_tips_after_fetch, new_sha1);
 486 }
 487
 488 static void add_sha1_to_argv(const unsigned char sha1[20], void *data)
 489 {
 490         argv_array_push(data, sha1_to_hex(sha1));
 491 }
 492
 493 static void calculate_changed_submodule_paths(void)
 494 {
 495         struct rev_info rev;
 496         struct commit *commit;
 497         struct argv_array argv = ARGV_ARRAY_INIT;
 498
 499         /* No need to check if there are no submodules configured */
 500         if (!config_name_for_path.nr)
 501                 return;
 502
 503         init_revisions(&rev, NULL);
 504         argv_array_push(&argv, "--"); /* argv[0] program name */
 505         sha1_array_for_each_unique(&ref_tips_after_fetch,
 506                                    add_sha1_to_argv, &argv);
 507         argv_array_push(&argv, "--not");
 508         sha1_array_for_each_unique(&ref_tips_before_fetch,
 509                                    add_sha1_to_argv, &argv);
 510         setup_revisions(argv.argc, argv.argv, &rev, NULL);
 511         if (prepare_revision_walk(&rev))
 512                 die("revision walk setup failed");
 513
 514         /*
 515          * Collect all submodules (whether checked out or not) for which new
 516          * commits have been recorded upstream in "changed_submodule_paths".
 517          */
 518         while ((commit = get_revision(&rev))) {
 519                 struct commit_list *parent = commit->parents;
 520                 while (parent) {
 521                         struct diff_options diff_opts;
 522                         diff_setup(&diff_opts);
 523                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
 524                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
 525                         diff_opts.format_callback = submodule_collect_changed_cb;
 526                         if (diff_setup_done(&diff_opts) < 0)
 527                                 die("diff_setup_done failed");
 528                         diff_tree_sha1(parent->item->object.sha1, commit->object.sha1, "", &diff_opts);
 529                         diffcore_std(&diff_opts);
 530                         diff_flush(&diff_opts);
 531                         parent = parent->next;
 532                 }
 533         }
 534
 535         argv_array_clear(&argv);
 536         sha1_array_clear(&ref_tips_before_fetch);
 537         sha1_array_clear(&ref_tips_after_fetch);
 538         initialized_fetch_ref_tips = 0;
 539 }
 540
 541 int fetch_populated_submodules(int num_options, const char **options,
 542                                const char *prefix, int command_line_option,
 543                                int quiet)
 544 {
 545         int i, result = 0, argc = 0, default_argc;
 546         struct child_process cp;
 547         const char **argv;
 548         struct string_list_item *name_for_path;
 549         const char *work_tree = get_git_work_tree();
 550         if (!work_tree)
 551                 goto out;
 552
 553         if (!the_index.initialized)
 554                 if (read_cache() < 0)
 555                         die("index file corrupt");
 556
 557         /* 6: "fetch" (options) --recurse-submodules-default default "--submodule-prefix" prefix NULL */
 558         argv = xcalloc(num_options + 6, sizeof(const char *));
 559         argv[argc++] = "fetch";
 560         for (i = 0; i < num_options; i++)
 561                 argv[argc++] = options[i];
 562         argv[argc++] = "--recurse-submodules-default";
 563         default_argc = argc++;
 564         argv[argc++] = "--submodule-prefix";
 565
 566         memset(&cp, 0, sizeof(cp));
 567         cp.argv = argv;
 568         cp.env = local_repo_env;
 569         cp.git_cmd = 1;
 570         cp.no_stdin = 1;
 571
 572         calculate_changed_submodule_paths();
 573
 574         for (i = 0; i < active_nr; i++) {
 575                 struct strbuf submodule_path = STRBUF_INIT;
 576                 struct strbuf submodule_git_dir = STRBUF_INIT;
 577                 struct strbuf submodule_prefix = STRBUF_INIT;
 578                 struct cache_entry *ce = active_cache[i];
 579                 const char *git_dir, *name, *default_argv;
 580
 581                 if (!S_ISGITLINK(ce->ce_mode))
 582                         continue;
 583
 584                 name = ce->name;
 585                 name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
 586                 if (name_for_path)
 587                         name = name_for_path->util;
 588
 589                 default_argv = "yes";
 590                 if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
 591                         struct string_list_item *fetch_recurse_submodules_option;
 592                         fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
 593                         if (fetch_recurse_submodules_option) {
 594                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
 595                                         continue;
 596                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
 597                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 598                                                 continue;
 599                                         default_argv = "on-demand";
 600                                 }
 601                         } else {
 602                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
 603                                     gitmodules_is_unmerged)
 604                                         continue;
 605                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
 606                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 607                                                 continue;
 608                                         default_argv = "on-demand";
 609                                 }
 610                         }
 611                 } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
 612                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 613                                 continue;
 614                         default_argv = "on-demand";
 615                 }
 616
 617                 strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
 618                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
 619                 strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
 620                 git_dir = read_gitfile(submodule_git_dir.buf);
 621                 if (!git_dir)
 622                         git_dir = submodule_git_dir.buf;
 623                 if (is_directory(git_dir)) {
 624                         if (!quiet)
 625                                 printf("Fetching submodule %s%s\n", prefix, ce->name);
 626                         cp.dir = submodule_path.buf;
 627                         argv[default_argc] = default_argv;
 628                         argv[argc] = submodule_prefix.buf;
 629                         if (run_command(&cp))
 630                                 result = 1;
 631                 }
 632                 strbuf_release(&submodule_path);
 633                 strbuf_release(&submodule_git_dir);
 634                 strbuf_release(&submodule_prefix);
 635         }
 636         free(argv);
 637 out:
 638         string_list_clear(&changed_submodule_paths, 1);
 639         return result;
 640 }
 641
 642 unsigned is_submodule_modified(const char *path, int ignore_untracked)
 643 {
 644         ssize_t len;
 645         struct child_process cp;
 646         const char *argv[] = {
 647                 "status",
 648                 "--porcelain",
 649                 NULL,
 650                 NULL,
 651         };
 652         struct strbuf buf = STRBUF_INIT;
 653         unsigned dirty_submodule = 0;
 654         const char *line, *next_line;
 655         const char *git_dir;
 656
 657         strbuf_addf(&buf, "%s/.git", path);
 658         git_dir = read_gitfile(buf.buf);
 659         if (!git_dir)
 660                 git_dir = buf.buf;
 661         if (!is_directory(git_dir)) {
 662                 strbuf_release(&buf);
 663                 /* The submodule is not checked out, so it is not modified */
 664                 return 0;
 665
 666         }
 667         strbuf_reset(&buf);
 668
 669         if (ignore_untracked)
 670                 argv[2] = "-uno";
 671
 672         memset(&cp, 0, sizeof(cp));
 673         cp.argv = argv;
 674         cp.env = local_repo_env;
 675         cp.git_cmd = 1;
 676         cp.no_stdin = 1;
 677         cp.out = -1;
 678         cp.dir = path;
 679         if (start_command(&cp))
 680                 die("Could not run 'git status --porcelain' in submodule %s", path);
 681
 682         len = strbuf_read(&buf, cp.out, 1024);
 683         line = buf.buf;
 684         while (len > 2) {
 685                 if ((line[0] == '?') && (line[1] == '?')) {
 686                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
 687                         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 688                                 break;
 689                 } else {
 690                         dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
 691                         if (ignore_untracked ||
 692                             (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
 693                                 break;
 694                 }
 695                 next_line = strchr(line, '\n');
 696                 if (!next_line)
 697                         break;
 698                 next_line++;
 699                 len -= (next_line - line);
 700                 line = next_line;
 701         }
 702         close(cp.out);
 703
 704         if (finish_command(&cp))
 705                 die("'git status --porcelain' failed in submodule %s", path);
 706
 707         strbuf_release(&buf);
 708         return dirty_submodule;
 709 }
 710
 711 static int find_first_merges(struct object_array *result, const char *path,
 712                 struct commit *a, struct commit *b)
 713 {
 714         int i, j;
 715         struct object_array merges;
 716         struct commit *commit;
 717         int contains_another;
 718
 719         char merged_revision[42];
 720         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
 721                                    "--all", merged_revision, NULL };
 722         struct rev_info revs;
 723         struct setup_revision_opt rev_opts;
 724
 725         memset(&merges, 0, sizeof(merges));
 726         memset(result, 0, sizeof(struct object_array));
 727         memset(&rev_opts, 0, sizeof(rev_opts));
 728
 729         /* get all revisions that merge commit a */
 730         snprintf(merged_revision, sizeof(merged_revision), "^%s",
 731                         sha1_to_hex(a->object.sha1));
 732         init_revisions(&revs, NULL);
 733         rev_opts.submodule = path;
 734         setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts);
 735
 736         /* save all revisions from the above list that contain b */
 737         if (prepare_revision_walk(&revs))
 738                 die("revision walk setup failed");
 739         while ((commit = get_revision(&revs)) != NULL) {
 740                 struct object *o = &(commit->object);
 741                 if (in_merge_bases(b, &commit, 1))
 742                         add_object_array(o, NULL, &merges);
 743         }
 744
 745         /* Now we've got all merges that contain a and b. Prune all
 746          * merges that contain another found merge and save them in
 747          * result.
 748          */
 749         for (i = 0; i < merges.nr; i++) {
 750                 struct commit *m1 = (struct commit *) merges.objects[i].item;
 751
 752                 contains_another = 0;
 753                 for (j = 0; j < merges.nr; j++) {
 754                         struct commit *m2 = (struct commit *) merges.objects[j].item;
 755                         if (i != j && in_merge_bases(m2, &m1, 1)) {
 756                                 contains_another = 1;
 757                                 break;
 758                         }
 759                 }
 760
 761                 if (!contains_another)
 762                         add_object_array(merges.objects[i].item,
 763                                          merges.objects[i].name, result);
 764         }
 765
 766         free(merges.objects);
 767         return result->nr;
 768 }
 769
 770 static void print_commit(struct commit *commit)
 771 {
 772         struct strbuf sb = STRBUF_INIT;
 773         struct pretty_print_context ctx = {0};
 774         ctx.date_mode = DATE_NORMAL;
 775         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
 776         fprintf(stderr, "%s\n", sb.buf);
 777         strbuf_release(&sb);
 778 }
 779
 780 #define MERGE_WARNING(path, msg) \
 781         warning("Failed to merge submodule %s (%s)", path, msg);
 782
 783 int merge_submodule(unsigned char result[20], const char *path,
 784                     const unsigned char base[20], const unsigned char a[20],
 785                     const unsigned char b[20], int search)
 786 {
 787         struct commit *commit_base, *commit_a, *commit_b;
 788         int parent_count;
 789         struct object_array merges;
 790
 791         int i;
 792
 793         /* store a in result in case we fail */
 794         hashcpy(result, a);
 795
 796         /* we can not handle deletion conflicts */
 797         if (is_null_sha1(base))
 798                 return 0;
 799         if (is_null_sha1(a))
 800                 return 0;
 801         if (is_null_sha1(b))
 802                 return 0;
 803
 804         if (add_submodule_odb(path)) {
 805                 MERGE_WARNING(path, "not checked out");
 806                 return 0;
 807         }
 808
 809         if (!(commit_base = lookup_commit_reference(base)) ||
 810             !(commit_a = lookup_commit_reference(a)) ||
 811             !(commit_b = lookup_commit_reference(b))) {
 812                 MERGE_WARNING(path, "commits not present");
 813                 return 0;
 814         }
 815
 816         /* check whether both changes are forward */
 817         if (!in_merge_bases(commit_base, &commit_a, 1) ||
 818             !in_merge_bases(commit_base, &commit_b, 1)) {
 819                 MERGE_WARNING(path, "commits don't follow merge-base");
 820                 return 0;
 821         }
 822
 823         /* Case #1: a is contained in b or vice versa */
 824         if (in_merge_bases(commit_a, &commit_b, 1)) {
 825                 hashcpy(result, b);
 826                 return 1;
 827         }
 828         if (in_merge_bases(commit_b, &commit_a, 1)) {
 829                 hashcpy(result, a);
 830                 return 1;
 831         }
 832
 833         /*
 834          * Case #2: There are one or more merges that contain a and b in
 835          * the submodule. If there is only one, then present it as a
 836          * suggestion to the user, but leave it marked unmerged so the
 837          * user needs to confirm the resolution.
 838          */
 839
 840         /* Skip the search if makes no sense to the calling context.  */
 841         if (!search)
 842                 return 0;
 843
 844         /* find commit which merges them */
 845         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
 846         switch (parent_count) {
 847         case 0:
 848                 MERGE_WARNING(path, "merge following commits not found");
 849                 break;
 850
 851         case 1:
 852                 MERGE_WARNING(path, "not fast-forward");
 853                 fprintf(stderr, "Found a possible merge resolution "
 854                                 "for the submodule:\n");
 855                 print_commit((struct commit *) merges.objects[0].item);
 856                 fprintf(stderr,
 857                         "If this is correct simply add it to the index "
 858                         "for example\n"
 859                         "by using:\n\n"
 860                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
 861                         "which will accept this suggestion.\n",
 862                         sha1_to_hex(merges.objects[0].item->sha1), path);
 863                 break;
 864
 865         default:
 866                 MERGE_WARNING(path, "multiple merges found");
 867                 for (i = 0; i < merges.nr; i++)
 868                         print_commit((struct commit *) merges.objects[i].item);
 869         }
 870
 871         free(merges.objects);
 872         return 0;
 873 }