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