builtin/fetch.c

   1 /*
   2  * "git fetch"
   3  */
   4 #include "cache.h"
   5 #include "refs.h"
   6 #include "commit.h"
   7 #include "builtin.h"
   8 #include "string-list.h"
   9 #include "remote.h"
  10 #include "transport.h"
  11 #include "run-command.h"
  12 #include "parse-options.h"
  13 #include "sigchain.h"
  14 #include "transport.h"
  15 #include "submodule.h"
  16
  17 static const char * const builtin_fetch_usage[] = {
  18         "git fetch [<options>] [<repository> [<refspec>...]]",
  19         "git fetch [<options>] <group>",
  20         "git fetch --multiple [<options>] [<repository> | <group>]...",
  21         "git fetch --all [<options>]",
  22         NULL
  23 };
  24
  25 enum {
  26         TAGS_UNSET = 0,
  27         TAGS_DEFAULT = 1,
  28         TAGS_SET = 2
  29 };
  30
  31 static int all, append, dry_run, force, keep, multiple, prune, update_head_ok, verbosity;
  32 static int progress, recurse_submodules;
  33 static int tags = TAGS_DEFAULT;
  34 static const char *depth;
  35 static const char *upload_pack;
  36 static struct strbuf default_rla = STRBUF_INIT;
  37 static struct transport *transport;
  38 static const char *submodule_prefix = "";
  39
  40 static struct option builtin_fetch_options[] = {
  41         OPT__VERBOSITY(&verbosity),
  42         OPT_BOOLEAN(0, "all", &all,
  43                     "fetch from all remotes"),
  44         OPT_BOOLEAN('a', "append", &append,
  45                     "append to .git/FETCH_HEAD instead of overwriting"),
  46         OPT_STRING(0, "upload-pack", &upload_pack, "PATH",
  47                    "path to upload pack on remote end"),
  48         OPT_BOOLEAN('f', "force", &force,
  49                     "force overwrite of local branch"),
  50         OPT_BOOLEAN('m', "multiple", &multiple,
  51                     "fetch from multiple remotes"),
  52         OPT_SET_INT('t', "tags", &tags,
  53                     "fetch all tags and associated objects", TAGS_SET),
  54         OPT_SET_INT('n', NULL, &tags,
  55                     "do not fetch all tags (--no-tags)", TAGS_UNSET),
  56         OPT_BOOLEAN('p', "prune", &prune,
  57                     "prune tracking branches no longer on remote"),
  58         OPT_BOOLEAN(0, "recurse-submodules", &recurse_submodules,
  59                     "control recursive fetching of submodules"),
  60         OPT_BOOLEAN(0, "dry-run", &dry_run,
  61                     "dry run"),
  62         OPT_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
  63         OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
  64                     "allow updating of HEAD ref"),
  65         OPT_BOOLEAN(0, "progress", &progress, "force progress reporting"),
  66         OPT_STRING(0, "depth", &depth, "DEPTH",
  67                    "deepen history of shallow clone"),
  68         { OPTION_STRING, 0, "submodule-prefix", &submodule_prefix, "DIR",
  69                    "prepend this to submodule path output", PARSE_OPT_HIDDEN },
  70         OPT_END()
  71 };
  72
  73 static void unlock_pack(void)
  74 {
  75         if (transport)
  76                 transport_unlock_pack(transport);
  77 }
  78
  79 static void unlock_pack_on_signal(int signo)
  80 {
  81         unlock_pack();
  82         sigchain_pop(signo);
  83         raise(signo);
  84 }
  85
  86 static void add_merge_config(struct ref **head,
  87                            const struct ref *remote_refs,
  88                            struct branch *branch,
  89                            struct ref ***tail)
  90 {
  91         int i;
  92
  93         for (i = 0; i < branch->merge_nr; i++) {
  94                 struct ref *rm, **old_tail = *tail;
  95                 struct refspec refspec;
  96
  97                 for (rm = *head; rm; rm = rm->next) {
  98                         if (branch_merge_matches(branch, i, rm->name)) {
  99                                 rm->merge = 1;
 100                                 break;
 101                         }
 102                 }
 103                 if (rm)
 104                         continue;
 105
 106                 /*
 107                  * Not fetched to a tracking branch?  We need to fetch
 108                  * it anyway to allow this branch's "branch.$name.merge"
 109                  * to be honored by 'git pull', but we do not have to
 110                  * fail if branch.$name.merge is misconfigured to point
 111                  * at a nonexisting branch.  If we were indeed called by
 112                  * 'git pull', it will notice the misconfiguration because
 113                  * there is no entry in the resulting FETCH_HEAD marked
 114                  * for merging.
 115                  */
 116                 memset(&refspec, 0, sizeof(refspec));
 117                 refspec.src = branch->merge[i]->src;
 118                 get_fetch_map(remote_refs, &refspec, tail, 1);
 119                 for (rm = *old_tail; rm; rm = rm->next)
 120                         rm->merge = 1;
 121         }
 122 }
 123
 124 static void find_non_local_tags(struct transport *transport,
 125                         struct ref **head,
 126                         struct ref ***tail);
 127
 128 static struct ref *get_ref_map(struct transport *transport,
 129                                struct refspec *refs, int ref_count, int tags,
 130                                int *autotags)
 131 {
 132         int i;
 133         struct ref *rm;
 134         struct ref *ref_map = NULL;
 135         struct ref **tail = &ref_map;
 136
 137         const struct ref *remote_refs = transport_get_remote_refs(transport);
 138
 139         if (ref_count || tags == TAGS_SET) {
 140                 for (i = 0; i < ref_count; i++) {
 141                         get_fetch_map(remote_refs, &refs[i], &tail, 0);
 142                         if (refs[i].dst && refs[i].dst[0])
 143                                 *autotags = 1;
 144                 }
 145                 /* Merge everything on the command line, but not --tags */
 146                 for (rm = ref_map; rm; rm = rm->next)
 147                         rm->merge = 1;
 148                 if (tags == TAGS_SET)
 149                         get_fetch_map(remote_refs, tag_refspec, &tail, 0);
 150         } else {
 151                 /* Use the defaults */
 152                 struct remote *remote = transport->remote;
 153                 struct branch *branch = branch_get(NULL);
 154                 int has_merge = branch_has_merge_config(branch);
 155                 if (remote && (remote->fetch_refspec_nr || has_merge)) {
 156                         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 157                                 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
 158                                 if (remote->fetch[i].dst &&
 159                                     remote->fetch[i].dst[0])
 160                                         *autotags = 1;
 161                                 if (!i && !has_merge && ref_map &&
 162                                     !remote->fetch[0].pattern)
 163                                         ref_map->merge = 1;
 164                         }
 165                         /*
 166                          * if the remote we're fetching from is the same
 167                          * as given in branch.<name>.remote, we add the
 168                          * ref given in branch.<name>.merge, too.
 169                          */
 170                         if (has_merge &&
 171                             !strcmp(branch->remote_name, remote->name))
 172                                 add_merge_config(&ref_map, remote_refs, branch, &tail);
 173                 } else {
 174                         ref_map = get_remote_ref(remote_refs, "HEAD");
 175                         if (!ref_map)
 176                                 die("Couldn't find remote ref HEAD");
 177                         ref_map->merge = 1;
 178                         tail = &ref_map->next;
 179                 }
 180         }
 181         if (tags == TAGS_DEFAULT && *autotags)
 182                 find_non_local_tags(transport, &ref_map, &tail);
 183         ref_remove_duplicates(ref_map);
 184
 185         return ref_map;
 186 }
 187
 188 #define STORE_REF_ERROR_OTHER 1
 189 #define STORE_REF_ERROR_DF_CONFLICT 2
 190
 191 static int s_update_ref(const char *action,
 192                         struct ref *ref,
 193                         int check_old)
 194 {
 195         char msg[1024];
 196         char *rla = getenv("GIT_REFLOG_ACTION");
 197         static struct ref_lock *lock;
 198
 199         if (dry_run)
 200                 return 0;
 201         if (!rla)
 202                 rla = default_rla.buf;
 203         snprintf(msg, sizeof(msg), "%s: %s", rla, action);
 204         lock = lock_any_ref_for_update(ref->name,
 205                                        check_old ? ref->old_sha1 : NULL, 0);
 206         if (!lock)
 207                 return errno == ENOTDIR ? STORE_REF_ERROR_DF_CONFLICT :
 208                                           STORE_REF_ERROR_OTHER;
 209         if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
 210                 return errno == ENOTDIR ? STORE_REF_ERROR_DF_CONFLICT :
 211                                           STORE_REF_ERROR_OTHER;
 212         return 0;
 213 }
 214
 215 #define REFCOL_WIDTH  10
 216
 217 static int update_local_ref(struct ref *ref,
 218                             const char *remote,
 219                             char *display)
 220 {
 221         struct commit *current = NULL, *updated;
 222         enum object_type type;
 223         struct branch *current_branch = branch_get(NULL);
 224         const char *pretty_ref = prettify_refname(ref->name);
 225
 226         *display = 0;
 227         type = sha1_object_info(ref->new_sha1, NULL);
 228         if (type < 0)
 229                 die("object %s not found", sha1_to_hex(ref->new_sha1));
 230
 231         if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
 232                 if (verbosity > 0)
 233                         sprintf(display, "= %-*s %-*s -> %s", TRANSPORT_SUMMARY_WIDTH,
 234                                 "[up to date]", REFCOL_WIDTH, remote,
 235                                 pretty_ref);
 236                 return 0;
 237         }
 238
 239         if (current_branch &&
 240             !strcmp(ref->name, current_branch->name) &&
 241             !(update_head_ok || is_bare_repository()) &&
 242             !is_null_sha1(ref->old_sha1)) {
 243                 /*
 244                  * If this is the head, and it's not okay to update
 245                  * the head, and the old value of the head isn't empty...
 246                  */
 247                 sprintf(display, "! %-*s %-*s -> %s  (can't fetch in current branch)",
 248                         TRANSPORT_SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
 249                         pretty_ref);
 250                 return 1;
 251         }
 252
 253         if (!is_null_sha1(ref->old_sha1) &&
 254             !prefixcmp(ref->name, "refs/tags/")) {
 255                 int r;
 256                 r = s_update_ref("updating tag", ref, 0);
 257                 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '-',
 258                         TRANSPORT_SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
 259                         pretty_ref, r ? "  (unable to update local ref)" : "");
 260                 return r;
 261         }
 262
 263         current = lookup_commit_reference_gently(ref->old_sha1, 1);
 264         updated = lookup_commit_reference_gently(ref->new_sha1, 1);
 265         if (!current || !updated) {
 266                 const char *msg;
 267                 const char *what;
 268                 int r;
 269                 if (!strncmp(ref->name, "refs/tags/", 10)) {
 270                         msg = "storing tag";
 271                         what = "[new tag]";
 272                 }
 273                 else {
 274                         msg = "storing head";
 275                         what = "[new branch]";
 276                 }
 277
 278                 r = s_update_ref(msg, ref, 0);
 279                 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '*',
 280                         TRANSPORT_SUMMARY_WIDTH, what, REFCOL_WIDTH, remote, pretty_ref,
 281                         r ? "  (unable to update local ref)" : "");
 282                 return r;
 283         }
 284
 285         if (in_merge_bases(current, &updated, 1)) {
 286                 char quickref[83];
 287                 int r;
 288                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
 289                 strcat(quickref, "..");
 290                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
 291                 r = s_update_ref("fast-forward", ref, 1);
 292                 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : ' ',
 293                         TRANSPORT_SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
 294                         pretty_ref, r ? "  (unable to update local ref)" : "");
 295                 return r;
 296         } else if (force || ref->force) {
 297                 char quickref[84];
 298                 int r;
 299                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
 300                 strcat(quickref, "...");
 301                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
 302                 r = s_update_ref("forced-update", ref, 1);
 303                 sprintf(display, "%c %-*s %-*s -> %s  (%s)", r ? '!' : '+',
 304                         TRANSPORT_SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
 305                         pretty_ref,
 306                         r ? "unable to update local ref" : "forced update");
 307                 return r;
 308         } else {
 309                 sprintf(display, "! %-*s %-*s -> %s  (non-fast-forward)",
 310                         TRANSPORT_SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
 311                         pretty_ref);
 312                 return 1;
 313         }
 314 }
 315
 316 static int store_updated_refs(const char *raw_url, const char *remote_name,
 317                 struct ref *ref_map)
 318 {
 319         FILE *fp;
 320         struct commit *commit;
 321         int url_len, i, note_len, shown_url = 0, rc = 0;
 322         char note[1024];
 323         const char *what, *kind;
 324         struct ref *rm;
 325         char *url, *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
 326
 327         fp = fopen(filename, "a");
 328         if (!fp)
 329                 return error("cannot open %s: %s\n", filename, strerror(errno));
 330
 331         if (raw_url)
 332                 url = transport_anonymize_url(raw_url);
 333         else
 334                 url = xstrdup("foreign");
 335         for (rm = ref_map; rm; rm = rm->next) {
 336                 struct ref *ref = NULL;
 337
 338                 if (rm->peer_ref) {
 339                         ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
 340                         strcpy(ref->name, rm->peer_ref->name);
 341                         hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
 342                         hashcpy(ref->new_sha1, rm->old_sha1);
 343                         ref->force = rm->peer_ref->force;
 344                 }
 345
 346                 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
 347                 if (!commit)
 348                         rm->merge = 0;
 349
 350                 if (!strcmp(rm->name, "HEAD")) {
 351                         kind = "";
 352                         what = "";
 353                 }
 354                 else if (!prefixcmp(rm->name, "refs/heads/")) {
 355                         kind = "branch";
 356                         what = rm->name + 11;
 357                 }
 358                 else if (!prefixcmp(rm->name, "refs/tags/")) {
 359                         kind = "tag";
 360                         what = rm->name + 10;
 361                 }
 362                 else if (!prefixcmp(rm->name, "refs/remotes/")) {
 363                         kind = "remote branch";
 364                         what = rm->name + 13;
 365                 }
 366                 else {
 367                         kind = "";
 368                         what = rm->name;
 369                 }
 370
 371                 url_len = strlen(url);
 372                 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
 373                         ;
 374                 url_len = i + 1;
 375                 if (4 < i && !strncmp(".git", url + i - 3, 4))
 376                         url_len = i - 3;
 377
 378                 note_len = 0;
 379                 if (*what) {
 380                         if (*kind)
 381                                 note_len += sprintf(note + note_len, "%s ",
 382                                                     kind);
 383                         note_len += sprintf(note + note_len, "'%s' of ", what);
 384                 }
 385                 note[note_len] = '\0';
 386                 fprintf(fp, "%s\t%s\t%s",
 387                         sha1_to_hex(commit ? commit->object.sha1 :
 388                                     rm->old_sha1),
 389                         rm->merge ? "" : "not-for-merge",
 390                         note);
 391                 for (i = 0; i < url_len; ++i)
 392                         if ('\n' == url[i])
 393                                 fputs("\\n", fp);
 394                         else
 395                                 fputc(url[i], fp);
 396                 fputc('\n', fp);
 397
 398                 if (ref) {
 399                         rc |= update_local_ref(ref, what, note);
 400                         free(ref);
 401                 } else
 402                         sprintf(note, "* %-*s %-*s -> FETCH_HEAD",
 403                                 TRANSPORT_SUMMARY_WIDTH, *kind ? kind : "branch",
 404                                  REFCOL_WIDTH, *what ? what : "HEAD");
 405                 if (*note) {
 406                         if (verbosity >= 0 && !shown_url) {
 407                                 fprintf(stderr, "From %.*s\n",
 408                                                 url_len, url);
 409                                 shown_url = 1;
 410                         }
 411                         if (verbosity >= 0)
 412                                 fprintf(stderr, " %s\n", note);
 413                 }
 414         }
 415         free(url);
 416         fclose(fp);
 417         if (rc & STORE_REF_ERROR_DF_CONFLICT)
 418                 error("some local refs could not be updated; try running\n"
 419                       " 'git remote prune %s' to remove any old, conflicting "
 420                       "branches", remote_name);
 421         return rc;
 422 }
 423
 424 /*
 425  * We would want to bypass the object transfer altogether if
 426  * everything we are going to fetch already exists and is connected
 427  * locally.
 428  *
 429  * The refs we are going to fetch are in ref_map.  If running
 430  *
 431  *  $ git rev-list --objects --stdin --not --all
 432  *
 433  * (feeding all the refs in ref_map on its standard input)
 434  * does not error out, that means everything reachable from the
 435  * refs we are going to fetch exists and is connected to some of
 436  * our existing refs.
 437  */
 438 static int quickfetch(struct ref *ref_map)
 439 {
 440         struct child_process revlist;
 441         struct ref *ref;
 442         int err;
 443         const char *argv[] = {"rev-list",
 444                 "--quiet", "--objects", "--stdin", "--not", "--all", NULL};
 445
 446         /*
 447          * If we are deepening a shallow clone we already have these
 448          * objects reachable.  Running rev-list here will return with
 449          * a good (0) exit status and we'll bypass the fetch that we
 450          * really need to perform.  Claiming failure now will ensure
 451          * we perform the network exchange to deepen our history.
 452          */
 453         if (depth)
 454                 return -1;
 455
 456         if (!ref_map)
 457                 return 0;
 458
 459         memset(&revlist, 0, sizeof(revlist));
 460         revlist.argv = argv;
 461         revlist.git_cmd = 1;
 462         revlist.no_stdout = 1;
 463         revlist.no_stderr = 1;
 464         revlist.in = -1;
 465
 466         err = start_command(&revlist);
 467         if (err) {
 468                 error("could not run rev-list");
 469                 return err;
 470         }
 471
 472         /*
 473          * If rev-list --stdin encounters an unknown commit, it terminates,
 474          * which will cause SIGPIPE in the write loop below.
 475          */
 476         sigchain_push(SIGPIPE, SIG_IGN);
 477
 478         for (ref = ref_map; ref; ref = ref->next) {
 479                 if (write_in_full(revlist.in, sha1_to_hex(ref->old_sha1), 40) < 0 ||
 480                     write_str_in_full(revlist.in, "\n") < 0) {
 481                         if (errno != EPIPE && errno != EINVAL)
 482                                 error("failed write to rev-list: %s", strerror(errno));
 483                         err = -1;
 484                         break;
 485                 }
 486         }
 487
 488         if (close(revlist.in)) {
 489                 error("failed to close rev-list's stdin: %s", strerror(errno));
 490                 err = -1;
 491         }
 492
 493         sigchain_pop(SIGPIPE);
 494
 495         return finish_command(&revlist) || err;
 496 }
 497
 498 static int fetch_refs(struct transport *transport, struct ref *ref_map)
 499 {
 500         int ret = quickfetch(ref_map);
 501         if (ret)
 502                 ret = transport_fetch_refs(transport, ref_map);
 503         if (!ret)
 504                 ret |= store_updated_refs(transport->url,
 505                                 transport->remote->name,
 506                                 ref_map);
 507         transport_unlock_pack(transport);
 508         return ret;
 509 }
 510
 511 static int prune_refs(struct transport *transport, struct ref *ref_map)
 512 {
 513         int result = 0;
 514         struct ref *ref, *stale_refs = get_stale_heads(transport->remote, ref_map);
 515         const char *dangling_msg = dry_run
 516                 ? "   (%s will become dangling)\n"
 517                 : "   (%s has become dangling)\n";
 518
 519         for (ref = stale_refs; ref; ref = ref->next) {
 520                 if (!dry_run)
 521                         result |= delete_ref(ref->name, NULL, 0);
 522                 if (verbosity >= 0) {
 523                         fprintf(stderr, " x %-*s %-*s -> %s\n",
 524                                 TRANSPORT_SUMMARY_WIDTH, "[deleted]",
 525                                 REFCOL_WIDTH, "(none)", prettify_refname(ref->name));
 526                         warn_dangling_symref(stderr, dangling_msg, ref->name);
 527                 }
 528         }
 529         free_refs(stale_refs);
 530         return result;
 531 }
 532
 533 static int add_existing(const char *refname, const unsigned char *sha1,
 534                         int flag, void *cbdata)
 535 {
 536         struct string_list *list = (struct string_list *)cbdata;
 537         struct string_list_item *item = string_list_insert(list, refname);
 538         item->util = (void *)sha1;
 539         return 0;
 540 }
 541
 542 static int will_fetch(struct ref **head, const unsigned char *sha1)
 543 {
 544         struct ref *rm = *head;
 545         while (rm) {
 546                 if (!hashcmp(rm->old_sha1, sha1))
 547                         return 1;
 548                 rm = rm->next;
 549         }
 550         return 0;
 551 }
 552
 553 static void find_non_local_tags(struct transport *transport,
 554                         struct ref **head,
 555                         struct ref ***tail)
 556 {
 557         struct string_list existing_refs = STRING_LIST_INIT_NODUP;
 558         struct string_list remote_refs = STRING_LIST_INIT_NODUP;
 559         const struct ref *ref;
 560         struct string_list_item *item = NULL;
 561
 562         for_each_ref(add_existing, &existing_refs);
 563         for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
 564                 if (prefixcmp(ref->name, "refs/tags"))
 565                         continue;
 566
 567                 /*
 568                  * The peeled ref always follows the matching base
 569                  * ref, so if we see a peeled ref that we don't want
 570                  * to fetch then we can mark the ref entry in the list
 571                  * as one to ignore by setting util to NULL.
 572                  */
 573                 if (!suffixcmp(ref->name, "^{}")) {
 574                         if (item && !has_sha1_file(ref->old_sha1) &&
 575                             !will_fetch(head, ref->old_sha1) &&
 576                             !has_sha1_file(item->util) &&
 577                             !will_fetch(head, item->util))
 578                                 item->util = NULL;
 579                         item = NULL;
 580                         continue;
 581                 }
 582
 583                 /*
 584                  * If item is non-NULL here, then we previously saw a
 585                  * ref not followed by a peeled reference, so we need
 586                  * to check if it is a lightweight tag that we want to
 587                  * fetch.
 588                  */
 589                 if (item && !has_sha1_file(item->util) &&
 590                     !will_fetch(head, item->util))
 591                         item->util = NULL;
 592
 593                 item = NULL;
 594
 595                 /* skip duplicates and refs that we already have */
 596                 if (string_list_has_string(&remote_refs, ref->name) ||
 597                     string_list_has_string(&existing_refs, ref->name))
 598                         continue;
 599
 600                 item = string_list_insert(&remote_refs, ref->name);
 601                 item->util = (void *)ref->old_sha1;
 602         }
 603         string_list_clear(&existing_refs, 0);
 604
 605         /*
 606          * We may have a final lightweight tag that needs to be
 607          * checked to see if it needs fetching.
 608          */
 609         if (item && !has_sha1_file(item->util) &&
 610             !will_fetch(head, item->util))
 611                 item->util = NULL;
 612
 613         /*
 614          * For all the tags in the remote_refs string list,
 615          * add them to the list of refs to be fetched
 616          */
 617         for_each_string_list_item(item, &remote_refs) {
 618                 /* Unless we have already decided to ignore this item... */
 619                 if (item->util)
 620                 {
 621                         struct ref *rm = alloc_ref(item->string);
 622                         rm->peer_ref = alloc_ref(item->string);
 623                         hashcpy(rm->old_sha1, item->util);
 624                         **tail = rm;
 625                         *tail = &rm->next;
 626                 }
 627         }
 628
 629         string_list_clear(&remote_refs, 0);
 630 }
 631
 632 static void check_not_current_branch(struct ref *ref_map)
 633 {
 634         struct branch *current_branch = branch_get(NULL);
 635
 636         if (is_bare_repository() || !current_branch)
 637                 return;
 638
 639         for (; ref_map; ref_map = ref_map->next)
 640                 if (ref_map->peer_ref && !strcmp(current_branch->refname,
 641                                         ref_map->peer_ref->name))
 642                         die("Refusing to fetch into current branch %s "
 643                             "of non-bare repository", current_branch->refname);
 644 }
 645
 646 static int truncate_fetch_head(void)
 647 {
 648         char *filename = git_path("FETCH_HEAD");
 649         FILE *fp = fopen(filename, "w");
 650
 651         if (!fp)
 652                 return error("cannot open %s: %s\n", filename, strerror(errno));
 653         fclose(fp);
 654         return 0;
 655 }
 656
 657 static int do_fetch(struct transport *transport,
 658                     struct refspec *refs, int ref_count)
 659 {
 660         struct string_list existing_refs = STRING_LIST_INIT_NODUP;
 661         struct string_list_item *peer_item = NULL;
 662         struct ref *ref_map;
 663         struct ref *rm;
 664         int autotags = (transport->remote->fetch_tags == 1);
 665
 666         for_each_ref(add_existing, &existing_refs);
 667
 668         if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
 669                 tags = TAGS_SET;
 670         if (transport->remote->fetch_tags == -1)
 671                 tags = TAGS_UNSET;
 672
 673         if (!transport->get_refs_list || !transport->fetch)
 674                 die("Don't know how to fetch from %s", transport->url);
 675
 676         /* if not appending, truncate FETCH_HEAD */
 677         if (!append && !dry_run) {
 678                 int errcode = truncate_fetch_head();
 679                 if (errcode)
 680                         return errcode;
 681         }
 682
 683         ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
 684         if (!update_head_ok)
 685                 check_not_current_branch(ref_map);
 686
 687         for (rm = ref_map; rm; rm = rm->next) {
 688                 if (rm->peer_ref) {
 689                         peer_item = string_list_lookup(&existing_refs,
 690                                                        rm->peer_ref->name);
 691                         if (peer_item)
 692                                 hashcpy(rm->peer_ref->old_sha1,
 693                                         peer_item->util);
 694                 }
 695         }
 696
 697         if (tags == TAGS_DEFAULT && autotags)
 698                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
 699         if (fetch_refs(transport, ref_map)) {
 700                 free_refs(ref_map);
 701                 return 1;
 702         }
 703         if (prune)
 704                 prune_refs(transport, ref_map);
 705         free_refs(ref_map);
 706
 707         /* if neither --no-tags nor --tags was specified, do automated tag
 708          * following ... */
 709         if (tags == TAGS_DEFAULT && autotags) {
 710                 struct ref **tail = &ref_map;
 711                 ref_map = NULL;
 712                 find_non_local_tags(transport, &ref_map, &tail);
 713                 if (ref_map) {
 714                         transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
 715                         transport_set_option(transport, TRANS_OPT_DEPTH, "0");
 716                         fetch_refs(transport, ref_map);
 717                 }
 718                 free_refs(ref_map);
 719         }
 720
 721         return 0;
 722 }
 723
 724 static void set_option(const char *name, const char *value)
 725 {
 726         int r = transport_set_option(transport, name, value);
 727         if (r < 0)
 728                 die("Option \"%s\" value \"%s\" is not valid for %s",
 729                         name, value, transport->url);
 730         if (r > 0)
 731                 warning("Option \"%s\" is ignored for %s\n",
 732                         name, transport->url);
 733 }
 734
 735 static int get_one_remote_for_fetch(struct remote *remote, void *priv)
 736 {
 737         struct string_list *list = priv;
 738         if (!remote->skip_default_update)
 739                 string_list_append(list, remote->name);
 740         return 0;
 741 }
 742
 743 struct remote_group_data {
 744         const char *name;
 745         struct string_list *list;
 746 };
 747
 748 static int get_remote_group(const char *key, const char *value, void *priv)
 749 {
 750         struct remote_group_data *g = priv;
 751
 752         if (!prefixcmp(key, "remotes.") &&
 753                         !strcmp(key + 8, g->name)) {
 754                 /* split list by white space */
 755                 int space = strcspn(value, " \t\n");
 756                 while (*value) {
 757                         if (space > 1) {
 758                                 string_list_append(g->list,
 759                                                    xstrndup(value, space));
 760                         }
 761                         value += space + (value[space] != '\0');
 762                         space = strcspn(value, " \t\n");
 763                 }
 764         }
 765
 766         return 0;
 767 }
 768
 769 static int add_remote_or_group(const char *name, struct string_list *list)
 770 {
 771         int prev_nr = list->nr;
 772         struct remote_group_data g;
 773         g.name = name; g.list = list;
 774
 775         git_config(get_remote_group, &g);
 776         if (list->nr == prev_nr) {
 777                 struct remote *remote;
 778                 if (!remote_is_configured(name))
 779                         return 0;
 780                 remote = remote_get(name);
 781                 string_list_append(list, remote->name);
 782         }
 783         return 1;
 784 }
 785
 786 static void add_options_to_argv(int *argc, const char **argv)
 787 {
 788         if (dry_run)
 789                 argv[(*argc)++] = "--dry-run";
 790         if (prune)
 791                 argv[(*argc)++] = "--prune";
 792         if (update_head_ok)
 793                 argv[(*argc)++] = "--update-head-ok";
 794         if (force)
 795                 argv[(*argc)++] = "--force";
 796         if (keep)
 797                 argv[(*argc)++] = "--keep";
 798         if (recurse_submodules)
 799                 argv[(*argc)++] = "--recurse-submodules";
 800         if (verbosity >= 2)
 801                 argv[(*argc)++] = "-v";
 802         if (verbosity >= 1)
 803                 argv[(*argc)++] = "-v";
 804         else if (verbosity < 0)
 805                 argv[(*argc)++] = "-q";
 806
 807 }
 808
 809 static int fetch_multiple(struct string_list *list)
 810 {
 811         int i, result = 0;
 812         const char *argv[12] = { "fetch", "--append" };
 813         int argc = 2;
 814
 815         add_options_to_argv(&argc, argv);
 816
 817         if (!append && !dry_run) {
 818                 int errcode = truncate_fetch_head();
 819                 if (errcode)
 820                         return errcode;
 821         }
 822
 823         for (i = 0; i < list->nr; i++) {
 824                 const char *name = list->items[i].string;
 825                 argv[argc] = name;
 826                 argv[argc + 1] = NULL;
 827                 if (verbosity >= 0)
 828                         printf("Fetching %s\n", name);
 829                 if (run_command_v_opt(argv, RUN_GIT_CMD)) {
 830                         error("Could not fetch %s", name);
 831                         result = 1;
 832                 }
 833         }
 834
 835         return result;
 836 }
 837
 838 static int fetch_one(struct remote *remote, int argc, const char **argv)
 839 {
 840         int i;
 841         static const char **refs = NULL;
 842         int ref_nr = 0;
 843         int exit_code;
 844
 845         if (!remote)
 846                 die("No remote repository specified.  Please, specify either a URL or a\n"
 847                     "remote name from which new revisions should be fetched.");
 848
 849         transport = transport_get(remote, NULL);
 850         transport_set_verbosity(transport, verbosity, progress);
 851         if (upload_pack)
 852                 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
 853         if (keep)
 854                 set_option(TRANS_OPT_KEEP, "yes");
 855         if (depth)
 856                 set_option(TRANS_OPT_DEPTH, depth);
 857
 858         if (argc > 0) {
 859                 int j = 0;
 860                 refs = xcalloc(argc + 1, sizeof(const char *));
 861                 for (i = 0; i < argc; i++) {
 862                         if (!strcmp(argv[i], "tag")) {
 863                                 char *ref;
 864                                 i++;
 865                                 if (i >= argc)
 866                                         die("You need to specify a tag name.");
 867                                 ref = xmalloc(strlen(argv[i]) * 2 + 22);
 868                                 strcpy(ref, "refs/tags/");
 869                                 strcat(ref, argv[i]);
 870                                 strcat(ref, ":refs/tags/");
 871                                 strcat(ref, argv[i]);
 872                                 refs[j++] = ref;
 873                         } else
 874                                 refs[j++] = argv[i];
 875                 }
 876                 refs[j] = NULL;
 877                 ref_nr = j;
 878         }
 879
 880         sigchain_push_common(unlock_pack_on_signal);
 881         atexit(unlock_pack);
 882         exit_code = do_fetch(transport,
 883                         parse_fetch_refspec(ref_nr, refs), ref_nr);
 884         transport_disconnect(transport);
 885         transport = NULL;
 886         return exit_code;
 887 }
 888
 889 int cmd_fetch(int argc, const char **argv, const char *prefix)
 890 {
 891         int i;
 892         struct string_list list = STRING_LIST_INIT_NODUP;
 893         struct remote *remote;
 894         int result = 0;
 895
 896         /* Record the command line for the reflog */
 897         strbuf_addstr(&default_rla, "fetch");
 898         for (i = 1; i < argc; i++)
 899                 strbuf_addf(&default_rla, " %s", argv[i]);
 900
 901         argc = parse_options(argc, argv, prefix,
 902                              builtin_fetch_options, builtin_fetch_usage, 0);
 903
 904         if (all) {
 905                 if (argc == 1)
 906                         die("fetch --all does not take a repository argument");
 907                 else if (argc > 1)
 908                         die("fetch --all does not make sense with refspecs");
 909                 (void) for_each_remote(get_one_remote_for_fetch, &list);
 910                 result = fetch_multiple(&list);
 911         } else if (argc == 0) {
 912                 /* No arguments -- use default remote */
 913                 remote = remote_get(NULL);
 914                 result = fetch_one(remote, argc, argv);
 915         } else if (multiple) {
 916                 /* All arguments are assumed to be remotes or groups */
 917                 for (i = 0; i < argc; i++)
 918                         if (!add_remote_or_group(argv[i], &list))
 919                                 die("No such remote or remote group: %s", argv[i]);
 920                 result = fetch_multiple(&list);
 921         } else {
 922                 /* Single remote or group */
 923                 (void) add_remote_or_group(argv[0], &list);
 924                 if (list.nr > 1) {
 925                         /* More than one remote */
 926                         if (argc > 1)
 927                                 die("Fetching a group and specifying refspecs does not make sense");
 928                         result = fetch_multiple(&list);
 929                 } else {
 930                         /* Zero or one remotes */
 931                         remote = remote_get(argv[0]);
 932                         result = fetch_one(remote, argc-1, argv+1);
 933                 }
 934         }
 935
 936         if (!result && recurse_submodules) {
 937                 const char *options[10];
 938                 int num_options = 0;
 939                 gitmodules_config();
 940                 git_config(submodule_config, NULL);
 941                 add_options_to_argv(&num_options, options);
 942                 result = fetch_populated_submodules(num_options, options,
 943                                                     submodule_prefix,
 944                                                     verbosity < 0);
 945         }
 946
 947         /* All names were strdup()ed or strndup()ed */
 948         list.strdup_strings = 1;
 949         string_list_clear(&list, 0);
 950
 951         return result;
 952 }