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