remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4
   5 static struct remote **remotes;
   6 static int allocated_remotes;
   7
   8 static struct branch **branches;
   9 static int allocated_branches;
  10
  11 static struct branch *current_branch;
  12 static const char *default_remote_name;
  13
  14 #define BUF_SIZE (2048)
  15 static char buffer[BUF_SIZE];
  16
  17 static void add_push_refspec(struct remote *remote, const char *ref)
  18 {
  19         int nr = remote->push_refspec_nr + 1;
  20         remote->push_refspec =
  21                 xrealloc(remote->push_refspec, nr * sizeof(char *));
  22         remote->push_refspec[nr-1] = ref;
  23         remote->push_refspec_nr = nr;
  24 }
  25
  26 static void add_fetch_refspec(struct remote *remote, const char *ref)
  27 {
  28         int nr = remote->fetch_refspec_nr + 1;
  29         remote->fetch_refspec =
  30                 xrealloc(remote->fetch_refspec, nr * sizeof(char *));
  31         remote->fetch_refspec[nr-1] = ref;
  32         remote->fetch_refspec_nr = nr;
  33 }
  34
  35 static void add_url(struct remote *remote, const char *url)
  36 {
  37         int nr = remote->url_nr + 1;
  38         remote->url =
  39                 xrealloc(remote->url, nr * sizeof(char *));
  40         remote->url[nr-1] = url;
  41         remote->url_nr = nr;
  42 }
  43
  44 static struct remote *make_remote(const char *name, int len)
  45 {
  46         int i, empty = -1;
  47
  48         for (i = 0; i < allocated_remotes; i++) {
  49                 if (!remotes[i]) {
  50                         if (empty < 0)
  51                                 empty = i;
  52                 } else {
  53                         if (len ? (!strncmp(name, remotes[i]->name, len) &&
  54                                    !remotes[i]->name[len]) :
  55                             !strcmp(name, remotes[i]->name))
  56                                 return remotes[i];
  57                 }
  58         }
  59
  60         if (empty < 0) {
  61                 empty = allocated_remotes;
  62                 allocated_remotes += allocated_remotes ? allocated_remotes : 1;
  63                 remotes = xrealloc(remotes,
  64                                    sizeof(*remotes) * allocated_remotes);
  65                 memset(remotes + empty, 0,
  66                        (allocated_remotes - empty) * sizeof(*remotes));
  67         }
  68         remotes[empty] = xcalloc(1, sizeof(struct remote));
  69         if (len)
  70                 remotes[empty]->name = xstrndup(name, len);
  71         else
  72                 remotes[empty]->name = xstrdup(name);
  73         return remotes[empty];
  74 }
  75
  76 static void add_merge(struct branch *branch, const char *name)
  77 {
  78         int nr = branch->merge_nr + 1;
  79         branch->merge_name =
  80                 xrealloc(branch->merge_name, nr * sizeof(char *));
  81         branch->merge_name[nr-1] = name;
  82         branch->merge_nr = nr;
  83 }
  84
  85 static struct branch *make_branch(const char *name, int len)
  86 {
  87         int i, empty = -1;
  88         char *refname;
  89
  90         for (i = 0; i < allocated_branches; i++) {
  91                 if (!branches[i]) {
  92                         if (empty < 0)
  93                                 empty = i;
  94                 } else {
  95                         if (len ? (!strncmp(name, branches[i]->name, len) &&
  96                                    !branches[i]->name[len]) :
  97                             !strcmp(name, branches[i]->name))
  98                                 return branches[i];
  99                 }
 100         }
 101
 102         if (empty < 0) {
 103                 empty = allocated_branches;
 104                 allocated_branches += allocated_branches ? allocated_branches : 1;
 105                 branches = xrealloc(branches,
 106                                    sizeof(*branches) * allocated_branches);
 107                 memset(branches + empty, 0,
 108                        (allocated_branches - empty) * sizeof(*branches));
 109         }
 110         branches[empty] = xcalloc(1, sizeof(struct branch));
 111         if (len)
 112                 branches[empty]->name = xstrndup(name, len);
 113         else
 114                 branches[empty]->name = xstrdup(name);
 115         refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
 116         strcpy(refname, "refs/heads/");
 117         strcpy(refname + strlen("refs/heads/"),
 118                branches[empty]->name);
 119         branches[empty]->refname = refname;
 120
 121         return branches[empty];
 122 }
 123
 124 static void read_remotes_file(struct remote *remote)
 125 {
 126         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 127
 128         if (!f)
 129                 return;
 130         while (fgets(buffer, BUF_SIZE, f)) {
 131                 int value_list;
 132                 char *s, *p;
 133
 134                 if (!prefixcmp(buffer, "URL:")) {
 135                         value_list = 0;
 136                         s = buffer + 4;
 137                 } else if (!prefixcmp(buffer, "Push:")) {
 138                         value_list = 1;
 139                         s = buffer + 5;
 140                 } else if (!prefixcmp(buffer, "Pull:")) {
 141                         value_list = 2;
 142                         s = buffer + 5;
 143                 } else
 144                         continue;
 145
 146                 while (isspace(*s))
 147                         s++;
 148                 if (!*s)
 149                         continue;
 150
 151                 p = s + strlen(s);
 152                 while (isspace(p[-1]))
 153                         *--p = 0;
 154
 155                 switch (value_list) {
 156                 case 0:
 157                         add_url(remote, xstrdup(s));
 158                         break;
 159                 case 1:
 160                         add_push_refspec(remote, xstrdup(s));
 161                         break;
 162                 case 2:
 163                         add_fetch_refspec(remote, xstrdup(s));
 164                         break;
 165                 }
 166         }
 167         fclose(f);
 168 }
 169
 170 static void read_branches_file(struct remote *remote)
 171 {
 172         const char *slash = strchr(remote->name, '/');
 173         char *frag;
 174         char *branch;
 175         int n = slash ? slash - remote->name : 1000;
 176         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 177         char *s, *p;
 178         int len;
 179
 180         if (!f)
 181                 return;
 182         s = fgets(buffer, BUF_SIZE, f);
 183         fclose(f);
 184         if (!s)
 185                 return;
 186         while (isspace(*s))
 187                 s++;
 188         if (!*s)
 189                 return;
 190         p = s + strlen(s);
 191         while (isspace(p[-1]))
 192                 *--p = 0;
 193         len = p - s;
 194         if (slash)
 195                 len += strlen(slash);
 196         p = xmalloc(len + 1);
 197         strcpy(p, s);
 198         if (slash)
 199                 strcat(p, slash);
 200         frag = strchr(p, '#');
 201         if (frag) {
 202                 *(frag++) = '\0';
 203                 branch = xmalloc(strlen(frag) + 12);
 204                 strcpy(branch, "refs/heads/");
 205                 strcat(branch, frag);
 206         } else {
 207                 branch = "refs/heads/master";
 208         }
 209         add_url(remote, p);
 210         add_fetch_refspec(remote, branch);
 211         remote->fetch_tags = 1; /* always auto-follow */
 212 }
 213
 214 static int handle_config(const char *key, const char *value)
 215 {
 216         const char *name;
 217         const char *subkey;
 218         struct remote *remote;
 219         struct branch *branch;
 220         if (!prefixcmp(key, "branch.")) {
 221                 name = key + 7;
 222                 subkey = strrchr(name, '.');
 223                 branch = make_branch(name, subkey - name);
 224                 if (!subkey)
 225                         return 0;
 226                 if (!value)
 227                         return 0;
 228                 if (!strcmp(subkey, ".remote")) {
 229                         branch->remote_name = xstrdup(value);
 230                         if (branch == current_branch)
 231                                 default_remote_name = branch->remote_name;
 232                 } else if (!strcmp(subkey, ".merge"))
 233                         add_merge(branch, xstrdup(value));
 234                 return 0;
 235         }
 236         if (prefixcmp(key,  "remote."))
 237                 return 0;
 238         name = key + 7;
 239         subkey = strrchr(name, '.');
 240         if (!subkey)
 241                 return error("Config with no key for remote %s", name);
 242         if (*subkey == '/') {
 243                 warning("Config remote shorthand cannot begin with '/': %s", name);
 244                 return 0;
 245         }
 246         remote = make_remote(name, subkey - name);
 247         if (!value) {
 248                 /* if we ever have a boolean variable, e.g. "remote.*.disabled"
 249                  * [remote "frotz"]
 250                  *      disabled
 251                  * is a valid way to set it to true; we get NULL in value so
 252                  * we need to handle it here.
 253                  *
 254                  * if (!strcmp(subkey, ".disabled")) {
 255                  *      val = git_config_bool(key, value);
 256                  *      return 0;
 257                  * } else
 258                  *
 259                  */
 260                 return 0; /* ignore unknown booleans */
 261         }
 262         if (!strcmp(subkey, ".url")) {
 263                 add_url(remote, xstrdup(value));
 264         } else if (!strcmp(subkey, ".push")) {
 265                 add_push_refspec(remote, xstrdup(value));
 266         } else if (!strcmp(subkey, ".fetch")) {
 267                 add_fetch_refspec(remote, xstrdup(value));
 268         } else if (!strcmp(subkey, ".receivepack")) {
 269                 if (!remote->receivepack)
 270                         remote->receivepack = xstrdup(value);
 271                 else
 272                         error("more than one receivepack given, using the first");
 273         } else if (!strcmp(subkey, ".uploadpack")) {
 274                 if (!remote->uploadpack)
 275                         remote->uploadpack = xstrdup(value);
 276                 else
 277                         error("more than one uploadpack given, using the first");
 278         } else if (!strcmp(subkey, ".tagopt")) {
 279                 if (!strcmp(value, "--no-tags"))
 280                         remote->fetch_tags = -1;
 281         }
 282         return 0;
 283 }
 284
 285 static void read_config(void)
 286 {
 287         unsigned char sha1[20];
 288         const char *head_ref;
 289         int flag;
 290         if (default_remote_name) // did this already
 291                 return;
 292         default_remote_name = xstrdup("origin");
 293         current_branch = NULL;
 294         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 295         if (head_ref && (flag & REF_ISSYMREF) &&
 296             !prefixcmp(head_ref, "refs/heads/")) {
 297                 current_branch =
 298                         make_branch(head_ref + strlen("refs/heads/"), 0);
 299         }
 300         git_config(handle_config);
 301 }
 302
 303 struct refspec *parse_ref_spec(int nr_refspec, const char **refspec)
 304 {
 305         int i;
 306         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 307         for (i = 0; i < nr_refspec; i++) {
 308                 const char *sp, *ep, *gp;
 309                 sp = refspec[i];
 310                 if (*sp == '+') {
 311                         rs[i].force = 1;
 312                         sp++;
 313                 }
 314                 gp = strchr(sp, '*');
 315                 ep = strchr(sp, ':');
 316                 if (gp && ep && gp > ep)
 317                         gp = NULL;
 318                 if (ep) {
 319                         if (ep[1]) {
 320                                 const char *glob = strchr(ep + 1, '*');
 321                                 if (!glob)
 322                                         gp = NULL;
 323                                 if (gp)
 324                                         rs[i].dst = xstrndup(ep + 1,
 325                                                              glob - ep - 1);
 326                                 else
 327                                         rs[i].dst = xstrdup(ep + 1);
 328                         }
 329                 } else {
 330                         ep = sp + strlen(sp);
 331                 }
 332                 if (gp) {
 333                         rs[i].pattern = 1;
 334                         ep = gp;
 335                 }
 336                 rs[i].src = xstrndup(sp, ep - sp);
 337         }
 338         return rs;
 339 }
 340
 341 struct remote *remote_get(const char *name)
 342 {
 343         struct remote *ret;
 344
 345         read_config();
 346         if (!name)
 347                 name = default_remote_name;
 348         ret = make_remote(name, 0);
 349         if (name[0] != '/') {
 350                 if (!ret->url)
 351                         read_remotes_file(ret);
 352                 if (!ret->url)
 353                         read_branches_file(ret);
 354         }
 355         if (!ret->url)
 356                 add_url(ret, name);
 357         if (!ret->url)
 358                 return NULL;
 359         ret->fetch = parse_ref_spec(ret->fetch_refspec_nr, ret->fetch_refspec);
 360         ret->push = parse_ref_spec(ret->push_refspec_nr, ret->push_refspec);
 361         return ret;
 362 }
 363
 364 int for_each_remote(each_remote_fn fn, void *priv)
 365 {
 366         int i, result = 0;
 367         read_config();
 368         for (i = 0; i < allocated_remotes && !result; i++) {
 369                 struct remote *r = remotes[i];
 370                 if (!r)
 371                         continue;
 372                 if (!r->fetch)
 373                         r->fetch = parse_ref_spec(r->fetch_refspec_nr,
 374                                         r->fetch_refspec);
 375                 if (!r->push)
 376                         r->push = parse_ref_spec(r->push_refspec_nr,
 377                                         r->push_refspec);
 378                 result = fn(r, priv);
 379         }
 380         return result;
 381 }
 382
 383 void ref_remove_duplicates(struct ref *ref_map)
 384 {
 385         struct ref **posn;
 386         struct ref *next;
 387         for (; ref_map; ref_map = ref_map->next) {
 388                 if (!ref_map->peer_ref)
 389                         continue;
 390                 posn = &ref_map->next;
 391                 while (*posn) {
 392                         if ((*posn)->peer_ref &&
 393                             !strcmp((*posn)->peer_ref->name,
 394                                     ref_map->peer_ref->name)) {
 395                                 if (strcmp((*posn)->name, ref_map->name))
 396                                         die("%s tracks both %s and %s",
 397                                             ref_map->peer_ref->name,
 398                                             (*posn)->name, ref_map->name);
 399                                 next = (*posn)->next;
 400                                 free((*posn)->peer_ref);
 401                                 free(*posn);
 402                                 *posn = next;
 403                         } else {
 404                                 posn = &(*posn)->next;
 405                         }
 406                 }
 407         }
 408 }
 409
 410 int remote_has_url(struct remote *remote, const char *url)
 411 {
 412         int i;
 413         for (i = 0; i < remote->url_nr; i++) {
 414                 if (!strcmp(remote->url[i], url))
 415                         return 1;
 416         }
 417         return 0;
 418 }
 419
 420 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 421 {
 422         int find_src = refspec->src == NULL;
 423         char *needle, **result;
 424         int i;
 425
 426         if (find_src) {
 427                 if (!refspec->dst)
 428                         return error("find_tracking: need either src or dst");
 429                 needle = refspec->dst;
 430                 result = &refspec->src;
 431         } else {
 432                 needle = refspec->src;
 433                 result = &refspec->dst;
 434         }
 435
 436         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 437                 struct refspec *fetch = &remote->fetch[i];
 438                 const char *key = find_src ? fetch->dst : fetch->src;
 439                 const char *value = find_src ? fetch->src : fetch->dst;
 440                 if (!fetch->dst)
 441                         continue;
 442                 if (fetch->pattern) {
 443                         if (!prefixcmp(needle, key)) {
 444                                 *result = xmalloc(strlen(value) +
 445                                                   strlen(needle) -
 446                                                   strlen(key) + 1);
 447                                 strcpy(*result, value);
 448                                 strcpy(*result + strlen(value),
 449                                        needle + strlen(key));
 450                                 refspec->force = fetch->force;
 451                                 return 0;
 452                         }
 453                 } else if (!strcmp(needle, key)) {
 454                         *result = xstrdup(value);
 455                         refspec->force = fetch->force;
 456                         return 0;
 457                 }
 458         }
 459         return -1;
 460 }
 461
 462 struct ref *alloc_ref(unsigned namelen)
 463 {
 464         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 465         memset(ret, 0, sizeof(struct ref) + namelen);
 466         return ret;
 467 }
 468
 469 static struct ref *copy_ref(struct ref *ref)
 470 {
 471         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 472         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 473         ret->next = NULL;
 474         return ret;
 475 }
 476
 477 void free_refs(struct ref *ref)
 478 {
 479         struct ref *next;
 480         while (ref) {
 481                 next = ref->next;
 482                 if (ref->peer_ref)
 483                         free(ref->peer_ref);
 484                 free(ref);
 485                 ref = next;
 486         }
 487 }
 488
 489 static int count_refspec_match(const char *pattern,
 490                                struct ref *refs,
 491                                struct ref **matched_ref)
 492 {
 493         int patlen = strlen(pattern);
 494         struct ref *matched_weak = NULL;
 495         struct ref *matched = NULL;
 496         int weak_match = 0;
 497         int match = 0;
 498
 499         for (weak_match = match = 0; refs; refs = refs->next) {
 500                 char *name = refs->name;
 501                 int namelen = strlen(name);
 502
 503                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 504                         continue;
 505
 506                 /* A match is "weak" if it is with refs outside
 507                  * heads or tags, and did not specify the pattern
 508                  * in full (e.g. "refs/remotes/origin/master") or at
 509                  * least from the toplevel (e.g. "remotes/origin/master");
 510                  * otherwise "git push $URL master" would result in
 511                  * ambiguity between remotes/origin/master and heads/master
 512                  * at the remote site.
 513                  */
 514                 if (namelen != patlen &&
 515                     patlen != namelen - 5 &&
 516                     prefixcmp(name, "refs/heads/") &&
 517                     prefixcmp(name, "refs/tags/")) {
 518                         /* We want to catch the case where only weak
 519                          * matches are found and there are multiple
 520                          * matches, and where more than one strong
 521                          * matches are found, as ambiguous.  One
 522                          * strong match with zero or more weak matches
 523                          * are acceptable as a unique match.
 524                          */
 525                         matched_weak = refs;
 526                         weak_match++;
 527                 }
 528                 else {
 529                         matched = refs;
 530                         match++;
 531                 }
 532         }
 533         if (!matched) {
 534                 *matched_ref = matched_weak;
 535                 return weak_match;
 536         }
 537         else {
 538                 *matched_ref = matched;
 539                 return match;
 540         }
 541 }
 542
 543 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 544 {
 545         **tail = ref;
 546         while (ref->next)
 547                 ref = ref->next;
 548         *tail = &ref->next;
 549 }
 550
 551 static struct ref *try_explicit_object_name(const char *name)
 552 {
 553         unsigned char sha1[20];
 554         struct ref *ref;
 555         int len;
 556
 557         if (!*name) {
 558                 ref = alloc_ref(20);
 559                 strcpy(ref->name, "(delete)");
 560                 hashclr(ref->new_sha1);
 561                 return ref;
 562         }
 563         if (get_sha1(name, sha1))
 564                 return NULL;
 565         len = strlen(name) + 1;
 566         ref = alloc_ref(len);
 567         memcpy(ref->name, name, len);
 568         hashcpy(ref->new_sha1, sha1);
 569         return ref;
 570 }
 571
 572 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 573 {
 574         struct ref *ret;
 575         size_t len;
 576
 577         len = strlen(name) + 1;
 578         ret = alloc_ref(len);
 579         memcpy(ret->name, name, len);
 580         tail_link_ref(ret, tail);
 581         return ret;
 582 }
 583
 584 static int match_explicit(struct ref *src, struct ref *dst,
 585                           struct ref ***dst_tail,
 586                           struct refspec *rs,
 587                           int errs)
 588 {
 589         struct ref *matched_src, *matched_dst;
 590
 591         const char *dst_value = rs->dst;
 592
 593         if (rs->pattern)
 594                 return errs;
 595
 596         matched_src = matched_dst = NULL;
 597         switch (count_refspec_match(rs->src, src, &matched_src)) {
 598         case 1:
 599                 break;
 600         case 0:
 601                 /* The source could be in the get_sha1() format
 602                  * not a reference name.  :refs/other is a
 603                  * way to delete 'other' ref at the remote end.
 604                  */
 605                 matched_src = try_explicit_object_name(rs->src);
 606                 if (!matched_src)
 607                         error("src refspec %s does not match any.", rs->src);
 608                 break;
 609         default:
 610                 matched_src = NULL;
 611                 error("src refspec %s matches more than one.", rs->src);
 612                 break;
 613         }
 614
 615         if (!matched_src)
 616                 errs = 1;
 617
 618         if (!dst_value) {
 619                 if (!matched_src)
 620                         return errs;
 621                 dst_value = matched_src->name;
 622         }
 623
 624         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 625         case 1:
 626                 break;
 627         case 0:
 628                 if (!memcmp(dst_value, "refs/", 5))
 629                         matched_dst = make_linked_ref(dst_value, dst_tail);
 630                 else
 631                         error("dst refspec %s does not match any "
 632                               "existing ref on the remote and does "
 633                               "not start with refs/.", dst_value);
 634                 break;
 635         default:
 636                 matched_dst = NULL;
 637                 error("dst refspec %s matches more than one.",
 638                       dst_value);
 639                 break;
 640         }
 641         if (errs || !matched_dst)
 642                 return 1;
 643         if (matched_dst->peer_ref) {
 644                 errs = 1;
 645                 error("dst ref %s receives from more than one src.",
 646                       matched_dst->name);
 647         }
 648         else {
 649                 matched_dst->peer_ref = matched_src;
 650                 matched_dst->force = rs->force;
 651         }
 652         return errs;
 653 }
 654
 655 static int match_explicit_refs(struct ref *src, struct ref *dst,
 656                                struct ref ***dst_tail, struct refspec *rs,
 657                                int rs_nr)
 658 {
 659         int i, errs;
 660         for (i = errs = 0; i < rs_nr; i++)
 661                 errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
 662         return -errs;
 663 }
 664
 665 static struct ref *find_ref_by_name(struct ref *list, const char *name)
 666 {
 667         for ( ; list; list = list->next)
 668                 if (!strcmp(list->name, name))
 669                         return list;
 670         return NULL;
 671 }
 672
 673 static const struct refspec *check_pattern_match(const struct refspec *rs,
 674                                                  int rs_nr,
 675                                                  const struct ref *src)
 676 {
 677         int i;
 678         for (i = 0; i < rs_nr; i++) {
 679                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
 680                         return rs + i;
 681         }
 682         return NULL;
 683 }
 684
 685 /*
 686  * Note. This is used only by "push"; refspec matching rules for
 687  * push and fetch are subtly different, so do not try to reuse it
 688  * without thinking.
 689  */
 690 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 691                int nr_refspec, char **refspec, int all)
 692 {
 693         struct refspec *rs =
 694                 parse_ref_spec(nr_refspec, (const char **) refspec);
 695
 696         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
 697                 return -1;
 698
 699         /* pick the remainder */
 700         for ( ; src; src = src->next) {
 701                 struct ref *dst_peer;
 702                 const struct refspec *pat = NULL;
 703                 char *dst_name;
 704                 if (src->peer_ref)
 705                         continue;
 706                 if (nr_refspec) {
 707                         pat = check_pattern_match(rs, nr_refspec, src);
 708                         if (!pat)
 709                                 continue;
 710                 }
 711                 else if (prefixcmp(src->name, "refs/heads/"))
 712                         /*
 713                          * "matching refs"; traditionally we pushed everything
 714                          * including refs outside refs/heads/ hierarchy, but
 715                          * that does not make much sense these days.
 716                          */
 717                         continue;
 718
 719                 if (pat) {
 720                         const char *dst_side = pat->dst ? pat->dst : pat->src;
 721                         dst_name = xmalloc(strlen(dst_side) +
 722                                            strlen(src->name) -
 723                                            strlen(pat->src) + 2);
 724                         strcpy(dst_name, dst_side);
 725                         strcat(dst_name, src->name + strlen(pat->src));
 726                 } else
 727                         dst_name = xstrdup(src->name);
 728                 dst_peer = find_ref_by_name(dst, dst_name);
 729                 if (dst_peer && dst_peer->peer_ref)
 730                         /* We're already sending something to this ref. */
 731                         goto free_name;
 732                 if (!dst_peer && !nr_refspec && !all)
 733                         /* Remote doesn't have it, and we have no
 734                          * explicit pattern, and we don't have
 735                          * --all. */
 736                         goto free_name;
 737                 if (!dst_peer) {
 738                         /* Create a new one and link it */
 739                         dst_peer = make_linked_ref(dst_name, dst_tail);
 740                         hashcpy(dst_peer->new_sha1, src->new_sha1);
 741                 }
 742                 dst_peer->peer_ref = src;
 743                 if (pat)
 744                         dst_peer->force = pat->force;
 745         free_name:
 746                 free(dst_name);
 747         }
 748         return 0;
 749 }
 750
 751 struct branch *branch_get(const char *name)
 752 {
 753         struct branch *ret;
 754
 755         read_config();
 756         if (!name || !*name || !strcmp(name, "HEAD"))
 757                 ret = current_branch;
 758         else
 759                 ret = make_branch(name, 0);
 760         if (ret && ret->remote_name) {
 761                 ret->remote = remote_get(ret->remote_name);
 762                 if (ret->merge_nr) {
 763                         int i;
 764                         ret->merge = xcalloc(sizeof(*ret->merge),
 765                                              ret->merge_nr);
 766                         for (i = 0; i < ret->merge_nr; i++) {
 767                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
 768                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
 769                                 remote_find_tracking(ret->remote,
 770                                                      ret->merge[i]);
 771                         }
 772                 }
 773         }
 774         return ret;
 775 }
 776
 777 int branch_has_merge_config(struct branch *branch)
 778 {
 779         return branch && !!branch->merge;
 780 }
 781
 782 int branch_merge_matches(struct branch *branch,
 783                                  int i,
 784                                  const char *refname)
 785 {
 786         if (!branch || i < 0 || i >= branch->merge_nr)
 787                 return 0;
 788         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
 789 }
 790
 791 static struct ref *get_expanded_map(struct ref *remote_refs,
 792                                     const struct refspec *refspec)
 793 {
 794         struct ref *ref;
 795         struct ref *ret = NULL;
 796         struct ref **tail = &ret;
 797
 798         int remote_prefix_len = strlen(refspec->src);
 799         int local_prefix_len = strlen(refspec->dst);
 800
 801         for (ref = remote_refs; ref; ref = ref->next) {
 802                 if (strchr(ref->name, '^'))
 803                         continue; /* a dereference item */
 804                 if (!prefixcmp(ref->name, refspec->src)) {
 805                         char *match;
 806                         struct ref *cpy = copy_ref(ref);
 807                         match = ref->name + remote_prefix_len;
 808
 809                         cpy->peer_ref = alloc_ref(local_prefix_len +
 810                                                   strlen(match) + 1);
 811                         sprintf(cpy->peer_ref->name, "%s%s",
 812                                 refspec->dst, match);
 813                         if (refspec->force)
 814                                 cpy->peer_ref->force = 1;
 815                         *tail = cpy;
 816                         tail = &cpy->next;
 817                 }
 818         }
 819
 820         return ret;
 821 }
 822
 823 static struct ref *find_ref_by_name_abbrev(struct ref *refs, const char *name)
 824 {
 825         struct ref *ref;
 826         for (ref = refs; ref; ref = ref->next) {
 827                 if (refname_match(name, ref->name, ref_fetch_rules))
 828                         return ref;
 829         }
 830         return NULL;
 831 }
 832
 833 struct ref *get_remote_ref(struct ref *remote_refs, const char *name)
 834 {
 835         struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
 836
 837         if (!ref)
 838                 return NULL;
 839
 840         return copy_ref(ref);
 841 }
 842
 843 static struct ref *get_local_ref(const char *name)
 844 {
 845         struct ref *ret;
 846         if (!name)
 847                 return NULL;
 848
 849         if (!prefixcmp(name, "refs/")) {
 850                 ret = alloc_ref(strlen(name) + 1);
 851                 strcpy(ret->name, name);
 852                 return ret;
 853         }
 854
 855         if (!prefixcmp(name, "heads/") ||
 856             !prefixcmp(name, "tags/") ||
 857             !prefixcmp(name, "remotes/")) {
 858                 ret = alloc_ref(strlen(name) + 6);
 859                 sprintf(ret->name, "refs/%s", name);
 860                 return ret;
 861         }
 862
 863         ret = alloc_ref(strlen(name) + 12);
 864         sprintf(ret->name, "refs/heads/%s", name);
 865         return ret;
 866 }
 867
 868 int get_fetch_map(struct ref *remote_refs,
 869                   const struct refspec *refspec,
 870                   struct ref ***tail,
 871                   int missing_ok)
 872 {
 873         struct ref *ref_map, *rm;
 874
 875         if (refspec->pattern) {
 876                 ref_map = get_expanded_map(remote_refs, refspec);
 877         } else {
 878                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
 879
 880                 ref_map = get_remote_ref(remote_refs, name);
 881                 if (!missing_ok && !ref_map)
 882                         die("Couldn't find remote ref %s", name);
 883                 if (ref_map) {
 884                         ref_map->peer_ref = get_local_ref(refspec->dst);
 885                         if (ref_map->peer_ref && refspec->force)
 886                                 ref_map->peer_ref->force = 1;
 887                 }
 888         }
 889
 890         for (rm = ref_map; rm; rm = rm->next) {
 891                 if (rm->peer_ref && check_ref_format(rm->peer_ref->name + 5))
 892                         die("* refusing to create funny ref '%s' locally",
 893                             rm->peer_ref->name);
 894         }
 895
 896         if (ref_map)
 897                 tail_link_ref(ref_map, tail);
 898
 899         return 0;
 900 }