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);
 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         struct each_ref_fn_sha1_adapter wrapped_has_remote =
 433                 {has_remote, NULL};
 434
 435         if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
 436                 return 0;
 437
 438         if (for_each_remote_ref_submodule(path, each_ref_fn_adapter, &wrapped_has_remote) > 0) {
 439                 struct child_process cp = CHILD_PROCESS_INIT;
 440                 const char *argv[] = {"rev-list", NULL, "--not", "--remotes", "-n", "1" , NULL};
 441                 struct strbuf buf = STRBUF_INIT;
 442                 int needs_pushing = 0;
 443
 444                 argv[1] = sha1_to_hex(sha1);
 445                 cp.argv = argv;
 446                 cp.env = local_repo_env;
 447                 cp.git_cmd = 1;
 448                 cp.no_stdin = 1;
 449                 cp.out = -1;
 450                 cp.dir = path;
 451                 if (start_command(&cp))
 452                         die("Could not run 'git rev-list %s --not --remotes -n 1' command in submodule %s",
 453                                 sha1_to_hex(sha1), path);
 454                 if (strbuf_read(&buf, cp.out, 41))
 455                         needs_pushing = 1;
 456                 finish_command(&cp);
 457                 close(cp.out);
 458                 strbuf_release(&buf);
 459                 return needs_pushing;
 460         }
 461
 462         return 0;
 463 }
 464
 465 static void collect_submodules_from_diff(struct diff_queue_struct *q,
 466                                          struct diff_options *options,
 467                                          void *data)
 468 {
 469         int i;
 470         struct string_list *needs_pushing = data;
 471
 472         for (i = 0; i < q->nr; i++) {
 473                 struct diff_filepair *p = q->queue[i];
 474                 if (!S_ISGITLINK(p->two->mode))
 475                         continue;
 476                 if (submodule_needs_pushing(p->two->path, p->two->sha1))
 477                         string_list_insert(needs_pushing, p->two->path);
 478         }
 479 }
 480
 481 static void find_unpushed_submodule_commits(struct commit *commit,
 482                 struct string_list *needs_pushing)
 483 {
 484         struct rev_info rev;
 485
 486         init_revisions(&rev, NULL);
 487         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 488         rev.diffopt.format_callback = collect_submodules_from_diff;
 489         rev.diffopt.format_callback_data = needs_pushing;
 490         diff_tree_combined_merge(commit, 1, &rev);
 491 }
 492
 493 int find_unpushed_submodules(unsigned char new_sha1[20],
 494                 const char *remotes_name, struct string_list *needs_pushing)
 495 {
 496         struct rev_info rev;
 497         struct commit *commit;
 498         const char *argv[] = {NULL, NULL, "--not", "NULL", NULL};
 499         int argc = ARRAY_SIZE(argv) - 1;
 500         char *sha1_copy;
 501
 502         struct strbuf remotes_arg = STRBUF_INIT;
 503
 504         strbuf_addf(&remotes_arg, "--remotes=%s", remotes_name);
 505         init_revisions(&rev, NULL);
 506         sha1_copy = xstrdup(sha1_to_hex(new_sha1));
 507         argv[1] = sha1_copy;
 508         argv[3] = remotes_arg.buf;
 509         setup_revisions(argc, argv, &rev, NULL);
 510         if (prepare_revision_walk(&rev))
 511                 die("revision walk setup failed");
 512
 513         while ((commit = get_revision(&rev)) != NULL)
 514                 find_unpushed_submodule_commits(commit, needs_pushing);
 515
 516         reset_revision_walk();
 517         free(sha1_copy);
 518         strbuf_release(&remotes_arg);
 519
 520         return needs_pushing->nr;
 521 }
 522
 523 static int push_submodule(const char *path)
 524 {
 525         struct each_ref_fn_sha1_adapter wrapped_has_remote =
 526                 {has_remote, NULL};
 527
 528         if (add_submodule_odb(path))
 529                 return 1;
 530
 531         if (for_each_remote_ref_submodule(path, each_ref_fn_adapter, &wrapped_has_remote) > 0) {
 532                 struct child_process cp = CHILD_PROCESS_INIT;
 533                 const char *argv[] = {"push", NULL};
 534
 535                 cp.argv = argv;
 536                 cp.env = local_repo_env;
 537                 cp.git_cmd = 1;
 538                 cp.no_stdin = 1;
 539                 cp.dir = path;
 540                 if (run_command(&cp))
 541                         return 0;
 542                 close(cp.out);
 543         }
 544
 545         return 1;
 546 }
 547
 548 int push_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_name)
 549 {
 550         int i, ret = 1;
 551         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
 552
 553         if (!find_unpushed_submodules(new_sha1, remotes_name, &needs_pushing))
 554                 return 1;
 555
 556         for (i = 0; i < needs_pushing.nr; i++) {
 557                 const char *path = needs_pushing.items[i].string;
 558                 fprintf(stderr, "Pushing submodule '%s'\n", path);
 559                 if (!push_submodule(path)) {
 560                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
 561                         ret = 0;
 562                 }
 563         }
 564
 565         string_list_clear(&needs_pushing, 0);
 566
 567         return ret;
 568 }
 569
 570 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
 571 {
 572         int is_present = 0;
 573         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
 574                 /* Even if the submodule is checked out and the commit is
 575                  * present, make sure it is reachable from a ref. */
 576                 struct child_process cp = CHILD_PROCESS_INIT;
 577                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
 578                 struct strbuf buf = STRBUF_INIT;
 579
 580                 argv[3] = sha1_to_hex(sha1);
 581                 cp.argv = argv;
 582                 cp.env = local_repo_env;
 583                 cp.git_cmd = 1;
 584                 cp.no_stdin = 1;
 585                 cp.dir = path;
 586                 if (!capture_command(&cp, &buf, 1024) && !buf.len)
 587                         is_present = 1;
 588
 589                 strbuf_release(&buf);
 590         }
 591         return is_present;
 592 }
 593
 594 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
 595                                          struct diff_options *options,
 596                                          void *data)
 597 {
 598         int i;
 599         for (i = 0; i < q->nr; i++) {
 600                 struct diff_filepair *p = q->queue[i];
 601                 if (!S_ISGITLINK(p->two->mode))
 602                         continue;
 603
 604                 if (S_ISGITLINK(p->one->mode)) {
 605                         /* NEEDSWORK: We should honor the name configured in
 606                          * the .gitmodules file of the commit we are examining
 607                          * here to be able to correctly follow submodules
 608                          * being moved around. */
 609                         struct string_list_item *path;
 610                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
 611                         if (!path && !is_submodule_commit_present(p->two->path, p->two->sha1))
 612                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
 613                 } else {
 614                         /* Submodule is new or was moved here */
 615                         /* NEEDSWORK: When the .git directories of submodules
 616                          * live inside the superprojects .git directory some
 617                          * day we should fetch new submodules directly into
 618                          * that location too when config or options request
 619                          * that so they can be checked out from there. */
 620                         continue;
 621                 }
 622         }
 623 }
 624
 625 static int add_sha1_to_array(const char *ref, const unsigned char *sha1,
 626                              int flags, void *data)
 627 {
 628         sha1_array_append(data, sha1);
 629         return 0;
 630 }
 631
 632 void check_for_new_submodule_commits(unsigned char new_sha1[20])
 633 {
 634         if (!initialized_fetch_ref_tips) {
 635                 struct each_ref_fn_sha1_adapter wrapped_add_sha1_to_array =
 636                         {add_sha1_to_array, &ref_tips_before_fetch};
 637
 638                 for_each_ref(each_ref_fn_adapter, &wrapped_add_sha1_to_array);
 639                 initialized_fetch_ref_tips = 1;
 640         }
 641
 642         sha1_array_append(&ref_tips_after_fetch, new_sha1);
 643 }
 644
 645 static void add_sha1_to_argv(const unsigned char sha1[20], void *data)
 646 {
 647         argv_array_push(data, sha1_to_hex(sha1));
 648 }
 649
 650 static void calculate_changed_submodule_paths(void)
 651 {
 652         struct rev_info rev;
 653         struct commit *commit;
 654         struct argv_array argv = ARGV_ARRAY_INIT;
 655
 656         /* No need to check if there are no submodules configured */
 657         if (!config_name_for_path.nr)
 658                 return;
 659
 660         init_revisions(&rev, NULL);
 661         argv_array_push(&argv, "--"); /* argv[0] program name */
 662         sha1_array_for_each_unique(&ref_tips_after_fetch,
 663                                    add_sha1_to_argv, &argv);
 664         argv_array_push(&argv, "--not");
 665         sha1_array_for_each_unique(&ref_tips_before_fetch,
 666                                    add_sha1_to_argv, &argv);
 667         setup_revisions(argv.argc, argv.argv, &rev, NULL);
 668         if (prepare_revision_walk(&rev))
 669                 die("revision walk setup failed");
 670
 671         /*
 672          * Collect all submodules (whether checked out or not) for which new
 673          * commits have been recorded upstream in "changed_submodule_paths".
 674          */
 675         while ((commit = get_revision(&rev))) {
 676                 struct commit_list *parent = commit->parents;
 677                 while (parent) {
 678                         struct diff_options diff_opts;
 679                         diff_setup(&diff_opts);
 680                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
 681                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
 682                         diff_opts.format_callback = submodule_collect_changed_cb;
 683                         diff_setup_done(&diff_opts);
 684                         diff_tree_sha1(parent->item->object.sha1, commit->object.sha1, "", &diff_opts);
 685                         diffcore_std(&diff_opts);
 686                         diff_flush(&diff_opts);
 687                         parent = parent->next;
 688                 }
 689         }
 690
 691         argv_array_clear(&argv);
 692         sha1_array_clear(&ref_tips_before_fetch);
 693         sha1_array_clear(&ref_tips_after_fetch);
 694         initialized_fetch_ref_tips = 0;
 695 }
 696
 697 int fetch_populated_submodules(const struct argv_array *options,
 698                                const char *prefix, int command_line_option,
 699                                int quiet)
 700 {
 701         int i, result = 0;
 702         struct child_process cp = CHILD_PROCESS_INIT;
 703         struct argv_array argv = ARGV_ARRAY_INIT;
 704         struct string_list_item *name_for_path;
 705         const char *work_tree = get_git_work_tree();
 706         if (!work_tree)
 707                 goto out;
 708
 709         if (read_cache() < 0)
 710                 die("index file corrupt");
 711
 712         argv_array_push(&argv, "fetch");
 713         for (i = 0; i < options->argc; i++)
 714                 argv_array_push(&argv, options->argv[i]);
 715         argv_array_push(&argv, "--recurse-submodules-default");
 716         /* default value, "--submodule-prefix" and its value are added later */
 717
 718         cp.env = local_repo_env;
 719         cp.git_cmd = 1;
 720         cp.no_stdin = 1;
 721
 722         calculate_changed_submodule_paths();
 723
 724         for (i = 0; i < active_nr; i++) {
 725                 struct strbuf submodule_path = STRBUF_INIT;
 726                 struct strbuf submodule_git_dir = STRBUF_INIT;
 727                 struct strbuf submodule_prefix = STRBUF_INIT;
 728                 const struct cache_entry *ce = active_cache[i];
 729                 const char *git_dir, *name, *default_argv;
 730
 731                 if (!S_ISGITLINK(ce->ce_mode))
 732                         continue;
 733
 734                 name = ce->name;
 735                 name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
 736                 if (name_for_path)
 737                         name = name_for_path->util;
 738
 739                 default_argv = "yes";
 740                 if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
 741                         struct string_list_item *fetch_recurse_submodules_option;
 742                         fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
 743                         if (fetch_recurse_submodules_option) {
 744                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
 745                                         continue;
 746                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
 747                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 748                                                 continue;
 749                                         default_argv = "on-demand";
 750                                 }
 751                         } else {
 752                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
 753                                     gitmodules_is_unmerged)
 754                                         continue;
 755                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
 756                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 757                                                 continue;
 758                                         default_argv = "on-demand";
 759                                 }
 760                         }
 761                 } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
 762                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 763                                 continue;
 764                         default_argv = "on-demand";
 765                 }
 766
 767                 strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
 768                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
 769                 strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
 770                 git_dir = read_gitfile(submodule_git_dir.buf);
 771                 if (!git_dir)
 772                         git_dir = submodule_git_dir.buf;
 773                 if (is_directory(git_dir)) {
 774                         if (!quiet)
 775                                 printf("Fetching submodule %s%s\n", prefix, ce->name);
 776                         cp.dir = submodule_path.buf;
 777                         argv_array_push(&argv, default_argv);
 778                         argv_array_push(&argv, "--submodule-prefix");
 779                         argv_array_push(&argv, submodule_prefix.buf);
 780                         cp.argv = argv.argv;
 781                         if (run_command(&cp))
 782                                 result = 1;
 783                         argv_array_pop(&argv);
 784                         argv_array_pop(&argv);
 785                         argv_array_pop(&argv);
 786                 }
 787                 strbuf_release(&submodule_path);
 788                 strbuf_release(&submodule_git_dir);
 789                 strbuf_release(&submodule_prefix);
 790         }
 791         argv_array_clear(&argv);
 792 out:
 793         string_list_clear(&changed_submodule_paths, 1);
 794         return result;
 795 }
 796
 797 unsigned is_submodule_modified(const char *path, int ignore_untracked)
 798 {
 799         ssize_t len;
 800         struct child_process cp = CHILD_PROCESS_INIT;
 801         const char *argv[] = {
 802                 "status",
 803                 "--porcelain",
 804                 NULL,
 805                 NULL,
 806         };
 807         struct strbuf buf = STRBUF_INIT;
 808         unsigned dirty_submodule = 0;
 809         const char *line, *next_line;
 810         const char *git_dir;
 811
 812         strbuf_addf(&buf, "%s/.git", path);
 813         git_dir = read_gitfile(buf.buf);
 814         if (!git_dir)
 815                 git_dir = buf.buf;
 816         if (!is_directory(git_dir)) {
 817                 strbuf_release(&buf);
 818                 /* The submodule is not checked out, so it is not modified */
 819                 return 0;
 820
 821         }
 822         strbuf_reset(&buf);
 823
 824         if (ignore_untracked)
 825                 argv[2] = "-uno";
 826
 827         cp.argv = argv;
 828         cp.env = local_repo_env;
 829         cp.git_cmd = 1;
 830         cp.no_stdin = 1;
 831         cp.out = -1;
 832         cp.dir = path;
 833         if (start_command(&cp))
 834                 die("Could not run 'git status --porcelain' in submodule %s", path);
 835
 836         len = strbuf_read(&buf, cp.out, 1024);
 837         line = buf.buf;
 838         while (len > 2) {
 839                 if ((line[0] == '?') && (line[1] == '?')) {
 840                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
 841                         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 842                                 break;
 843                 } else {
 844                         dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
 845                         if (ignore_untracked ||
 846                             (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
 847                                 break;
 848                 }
 849                 next_line = strchr(line, '\n');
 850                 if (!next_line)
 851                         break;
 852                 next_line++;
 853                 len -= (next_line - line);
 854                 line = next_line;
 855         }
 856         close(cp.out);
 857
 858         if (finish_command(&cp))
 859                 die("'git status --porcelain' failed in submodule %s", path);
 860
 861         strbuf_release(&buf);
 862         return dirty_submodule;
 863 }
 864
 865 int submodule_uses_gitfile(const char *path)
 866 {
 867         struct child_process cp = CHILD_PROCESS_INIT;
 868         const char *argv[] = {
 869                 "submodule",
 870                 "foreach",
 871                 "--quiet",
 872                 "--recursive",
 873                 "test -f .git",
 874                 NULL,
 875         };
 876         struct strbuf buf = STRBUF_INIT;
 877         const char *git_dir;
 878
 879         strbuf_addf(&buf, "%s/.git", path);
 880         git_dir = read_gitfile(buf.buf);
 881         if (!git_dir) {
 882                 strbuf_release(&buf);
 883                 return 0;
 884         }
 885         strbuf_release(&buf);
 886
 887         /* Now test that all nested submodules use a gitfile too */
 888         cp.argv = argv;
 889         cp.env = local_repo_env;
 890         cp.git_cmd = 1;
 891         cp.no_stdin = 1;
 892         cp.no_stderr = 1;
 893         cp.no_stdout = 1;
 894         cp.dir = path;
 895         if (run_command(&cp))
 896                 return 0;
 897
 898         return 1;
 899 }
 900
 901 int ok_to_remove_submodule(const char *path)
 902 {
 903         struct stat st;
 904         ssize_t len;
 905         struct child_process cp = CHILD_PROCESS_INIT;
 906         const char *argv[] = {
 907                 "status",
 908                 "--porcelain",
 909                 "-u",
 910                 "--ignore-submodules=none",
 911                 NULL,
 912         };
 913         struct strbuf buf = STRBUF_INIT;
 914         int ok_to_remove = 1;
 915
 916         if ((lstat(path, &st) < 0) || is_empty_dir(path))
 917                 return 1;
 918
 919         if (!submodule_uses_gitfile(path))
 920                 return 0;
 921
 922         cp.argv = argv;
 923         cp.env = local_repo_env;
 924         cp.git_cmd = 1;
 925         cp.no_stdin = 1;
 926         cp.out = -1;
 927         cp.dir = path;
 928         if (start_command(&cp))
 929                 die("Could not run 'git status --porcelain -uall --ignore-submodules=none' in submodule %s", path);
 930
 931         len = strbuf_read(&buf, cp.out, 1024);
 932         if (len > 2)
 933                 ok_to_remove = 0;
 934         close(cp.out);
 935
 936         if (finish_command(&cp))
 937                 die("'git status --porcelain -uall --ignore-submodules=none' failed in submodule %s", path);
 938
 939         strbuf_release(&buf);
 940         return ok_to_remove;
 941 }
 942
 943 static int find_first_merges(struct object_array *result, const char *path,
 944                 struct commit *a, struct commit *b)
 945 {
 946         int i, j;
 947         struct object_array merges = OBJECT_ARRAY_INIT;
 948         struct commit *commit;
 949         int contains_another;
 950
 951         char merged_revision[42];
 952         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
 953                                    "--all", merged_revision, NULL };
 954         struct rev_info revs;
 955         struct setup_revision_opt rev_opts;
 956
 957         memset(result, 0, sizeof(struct object_array));
 958         memset(&rev_opts, 0, sizeof(rev_opts));
 959
 960         /* get all revisions that merge commit a */
 961         snprintf(merged_revision, sizeof(merged_revision), "^%s",
 962                         sha1_to_hex(a->object.sha1));
 963         init_revisions(&revs, NULL);
 964         rev_opts.submodule = path;
 965         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
 966
 967         /* save all revisions from the above list that contain b */
 968         if (prepare_revision_walk(&revs))
 969                 die("revision walk setup failed");
 970         while ((commit = get_revision(&revs)) != NULL) {
 971                 struct object *o = &(commit->object);
 972                 if (in_merge_bases(b, commit))
 973                         add_object_array(o, NULL, &merges);
 974         }
 975         reset_revision_walk();
 976
 977         /* Now we've got all merges that contain a and b. Prune all
 978          * merges that contain another found merge and save them in
 979          * result.
 980          */
 981         for (i = 0; i < merges.nr; i++) {
 982                 struct commit *m1 = (struct commit *) merges.objects[i].item;
 983
 984                 contains_another = 0;
 985                 for (j = 0; j < merges.nr; j++) {
 986                         struct commit *m2 = (struct commit *) merges.objects[j].item;
 987                         if (i != j && in_merge_bases(m2, m1)) {
 988                                 contains_another = 1;
 989                                 break;
 990                         }
 991                 }
 992
 993                 if (!contains_another)
 994                         add_object_array(merges.objects[i].item, NULL, result);
 995         }
 996
 997         free(merges.objects);
 998         return result->nr;
 999 }
1000
1001 static void print_commit(struct commit *commit)
1002 {
1003         struct strbuf sb = STRBUF_INIT;
1004         struct pretty_print_context ctx = {0};
1005         ctx.date_mode = DATE_NORMAL;
1006         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1007         fprintf(stderr, "%s\n", sb.buf);
1008         strbuf_release(&sb);
1009 }
1010
1011 #define MERGE_WARNING(path, msg) \
1012         warning("Failed to merge submodule %s (%s)", path, msg);
1013
1014 int merge_submodule(unsigned char result[20], const char *path,
1015                     const unsigned char base[20], const unsigned char a[20],
1016                     const unsigned char b[20], int search)
1017 {
1018         struct commit *commit_base, *commit_a, *commit_b;
1019         int parent_count;
1020         struct object_array merges;
1021
1022         int i;
1023
1024         /* store a in result in case we fail */
1025         hashcpy(result, a);
1026
1027         /* we can not handle deletion conflicts */
1028         if (is_null_sha1(base))
1029                 return 0;
1030         if (is_null_sha1(a))
1031                 return 0;
1032         if (is_null_sha1(b))
1033                 return 0;
1034
1035         if (add_submodule_odb(path)) {
1036                 MERGE_WARNING(path, "not checked out");
1037                 return 0;
1038         }
1039
1040         if (!(commit_base = lookup_commit_reference(base)) ||
1041             !(commit_a = lookup_commit_reference(a)) ||
1042             !(commit_b = lookup_commit_reference(b))) {
1043                 MERGE_WARNING(path, "commits not present");
1044                 return 0;
1045         }
1046
1047         /* check whether both changes are forward */
1048         if (!in_merge_bases(commit_base, commit_a) ||
1049             !in_merge_bases(commit_base, commit_b)) {
1050                 MERGE_WARNING(path, "commits don't follow merge-base");
1051                 return 0;
1052         }
1053
1054         /* Case #1: a is contained in b or vice versa */
1055         if (in_merge_bases(commit_a, commit_b)) {
1056                 hashcpy(result, b);
1057                 return 1;
1058         }
1059         if (in_merge_bases(commit_b, commit_a)) {
1060                 hashcpy(result, a);
1061                 return 1;
1062         }
1063
1064         /*
1065          * Case #2: There are one or more merges that contain a and b in
1066          * the submodule. If there is only one, then present it as a
1067          * suggestion to the user, but leave it marked unmerged so the
1068          * user needs to confirm the resolution.
1069          */
1070
1071         /* Skip the search if makes no sense to the calling context.  */
1072         if (!search)
1073                 return 0;
1074
1075         /* find commit which merges them */
1076         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1077         switch (parent_count) {
1078         case 0:
1079                 MERGE_WARNING(path, "merge following commits not found");
1080                 break;
1081
1082         case 1:
1083                 MERGE_WARNING(path, "not fast-forward");
1084                 fprintf(stderr, "Found a possible merge resolution "
1085                                 "for the submodule:\n");
1086                 print_commit((struct commit *) merges.objects[0].item);
1087                 fprintf(stderr,
1088                         "If this is correct simply add it to the index "
1089                         "for example\n"
1090                         "by using:\n\n"
1091                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1092                         "which will accept this suggestion.\n",
1093                         sha1_to_hex(merges.objects[0].item->sha1), path);
1094                 break;
1095
1096         default:
1097                 MERGE_WARNING(path, "multiple merges found");
1098                 for (i = 0; i < merges.nr; i++)
1099                         print_commit((struct commit *) merges.objects[i].item);
1100         }
1101
1102         free(merges.objects);
1103         return 0;
1104 }
1105
1106 /* Update gitfile and core.worktree setting to connect work tree and git dir */
1107 void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
1108 {
1109         struct strbuf file_name = STRBUF_INIT;
1110         struct strbuf rel_path = STRBUF_INIT;
1111         const char *real_work_tree = xstrdup(real_path(work_tree));
1112
1113         /* Update gitfile */
1114         strbuf_addf(&file_name, "%s/.git", work_tree);
1115         write_file(file_name.buf, 1, "gitdir: %s\n",
1116                    relative_path(git_dir, real_work_tree, &rel_path));
1117
1118         /* Update core.worktree setting */
1119         strbuf_reset(&file_name);
1120         strbuf_addf(&file_name, "%s/config", git_dir);
1121         if (git_config_set_in_file(file_name.buf, "core.worktree",
1122                                    relative_path(real_work_tree, git_dir,
1123                                                  &rel_path)))
1124                 die(_("Could not set core.worktree in %s"),
1125                     file_name.buf);
1126
1127         strbuf_release(&file_name);
1128         strbuf_release(&rel_path);
1129         free((void *)real_work_tree);
1130 }