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 /*
 421  * Returns true if, under the matching rules for fetching, name is the
 422  * same as the given full name.
 423  */
 424 static int ref_matches_abbrev(const char *name, const char *full)
 425 {
 426         if (!prefixcmp(name, "refs/") || !strcmp(name, "HEAD"))
 427                 return !strcmp(name, full);
 428         if (prefixcmp(full, "refs/"))
 429                 return 0;
 430         if (!prefixcmp(name, "heads/") ||
 431             !prefixcmp(name, "tags/") ||
 432             !prefixcmp(name, "remotes/"))
 433                 return !strcmp(name, full + 5);
 434         if (prefixcmp(full + 5, "heads/"))
 435                 return 0;
 436         return !strcmp(full + 11, name);
 437 }
 438
 439 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 440 {
 441         int find_src = refspec->src == NULL;
 442         char *needle, **result;
 443         int i;
 444
 445         if (find_src) {
 446                 if (!refspec->dst)
 447                         return error("find_tracking: need either src or dst");
 448                 needle = refspec->dst;
 449                 result = &refspec->src;
 450         } else {
 451                 needle = refspec->src;
 452                 result = &refspec->dst;
 453         }
 454
 455         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 456                 struct refspec *fetch = &remote->fetch[i];
 457                 const char *key = find_src ? fetch->dst : fetch->src;
 458                 const char *value = find_src ? fetch->src : fetch->dst;
 459                 if (!fetch->dst)
 460                         continue;
 461                 if (fetch->pattern) {
 462                         if (!prefixcmp(needle, key)) {
 463                                 *result = xmalloc(strlen(value) +
 464                                                   strlen(needle) -
 465                                                   strlen(key) + 1);
 466                                 strcpy(*result, value);
 467                                 strcpy(*result + strlen(value),
 468                                        needle + strlen(key));
 469                                 refspec->force = fetch->force;
 470                                 return 0;
 471                         }
 472                 } else if (!strcmp(needle, key)) {
 473                         *result = xstrdup(value);
 474                         refspec->force = fetch->force;
 475                         return 0;
 476                 }
 477         }
 478         return -1;
 479 }
 480
 481 struct ref *alloc_ref(unsigned namelen)
 482 {
 483         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 484         memset(ret, 0, sizeof(struct ref) + namelen);
 485         return ret;
 486 }
 487
 488 static struct ref *copy_ref(const struct ref *ref)
 489 {
 490         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 491         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 492         ret->next = NULL;
 493         return ret;
 494 }
 495
 496 struct ref *copy_ref_list(const struct ref *ref)
 497 {
 498         struct ref *ret = NULL;
 499         struct ref **tail = &ret;
 500         while (ref) {
 501                 *tail = copy_ref(ref);
 502                 ref = ref->next;
 503                 tail = &((*tail)->next);
 504         }
 505         return ret;
 506 }
 507
 508 void free_refs(struct ref *ref)
 509 {
 510         struct ref *next;
 511         while (ref) {
 512                 next = ref->next;
 513                 if (ref->peer_ref)
 514                         free(ref->peer_ref);
 515                 free(ref);
 516                 ref = next;
 517         }
 518 }
 519
 520 static int count_refspec_match(const char *pattern,
 521                                struct ref *refs,
 522                                struct ref **matched_ref)
 523 {
 524         int patlen = strlen(pattern);
 525         struct ref *matched_weak = NULL;
 526         struct ref *matched = NULL;
 527         int weak_match = 0;
 528         int match = 0;
 529
 530         for (weak_match = match = 0; refs; refs = refs->next) {
 531                 char *name = refs->name;
 532                 int namelen = strlen(name);
 533
 534                 if (namelen < patlen ||
 535                     memcmp(name + namelen - patlen, pattern, patlen))
 536                         continue;
 537                 if (namelen != patlen && name[namelen - patlen - 1] != '/')
 538                         continue;
 539
 540                 /* A match is "weak" if it is with refs outside
 541                  * heads or tags, and did not specify the pattern
 542                  * in full (e.g. "refs/remotes/origin/master") or at
 543                  * least from the toplevel (e.g. "remotes/origin/master");
 544                  * otherwise "git push $URL master" would result in
 545                  * ambiguity between remotes/origin/master and heads/master
 546                  * at the remote site.
 547                  */
 548                 if (namelen != patlen &&
 549                     patlen != namelen - 5 &&
 550                     prefixcmp(name, "refs/heads/") &&
 551                     prefixcmp(name, "refs/tags/")) {
 552                         /* We want to catch the case where only weak
 553                          * matches are found and there are multiple
 554                          * matches, and where more than one strong
 555                          * matches are found, as ambiguous.  One
 556                          * strong match with zero or more weak matches
 557                          * are acceptable as a unique match.
 558                          */
 559                         matched_weak = refs;
 560                         weak_match++;
 561                 }
 562                 else {
 563                         matched = refs;
 564                         match++;
 565                 }
 566         }
 567         if (!matched) {
 568                 *matched_ref = matched_weak;
 569                 return weak_match;
 570         }
 571         else {
 572                 *matched_ref = matched;
 573                 return match;
 574         }
 575 }
 576
 577 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 578 {
 579         **tail = ref;
 580         while (ref->next)
 581                 ref = ref->next;
 582         *tail = &ref->next;
 583 }
 584
 585 static struct ref *try_explicit_object_name(const char *name)
 586 {
 587         unsigned char sha1[20];
 588         struct ref *ref;
 589         int len;
 590
 591         if (!*name) {
 592                 ref = alloc_ref(20);
 593                 strcpy(ref->name, "(delete)");
 594                 hashclr(ref->new_sha1);
 595                 return ref;
 596         }
 597         if (get_sha1(name, sha1))
 598                 return NULL;
 599         len = strlen(name) + 1;
 600         ref = alloc_ref(len);
 601         memcpy(ref->name, name, len);
 602         hashcpy(ref->new_sha1, sha1);
 603         return ref;
 604 }
 605
 606 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 607 {
 608         struct ref *ret;
 609         size_t len;
 610
 611         len = strlen(name) + 1;
 612         ret = alloc_ref(len);
 613         memcpy(ret->name, name, len);
 614         tail_link_ref(ret, tail);
 615         return ret;
 616 }
 617
 618 static int match_explicit(struct ref *src, struct ref *dst,
 619                           struct ref ***dst_tail,
 620                           struct refspec *rs,
 621                           int errs)
 622 {
 623         struct ref *matched_src, *matched_dst;
 624
 625         const char *dst_value = rs->dst;
 626
 627         if (rs->pattern)
 628                 return errs;
 629
 630         matched_src = matched_dst = NULL;
 631         switch (count_refspec_match(rs->src, src, &matched_src)) {
 632         case 1:
 633                 break;
 634         case 0:
 635                 /* The source could be in the get_sha1() format
 636                  * not a reference name.  :refs/other is a
 637                  * way to delete 'other' ref at the remote end.
 638                  */
 639                 matched_src = try_explicit_object_name(rs->src);
 640                 if (!matched_src)
 641                         error("src refspec %s does not match any.", rs->src);
 642                 break;
 643         default:
 644                 matched_src = NULL;
 645                 error("src refspec %s matches more than one.", rs->src);
 646                 break;
 647         }
 648
 649         if (!matched_src)
 650                 errs = 1;
 651
 652         if (!dst_value) {
 653                 if (!matched_src)
 654                         return errs;
 655                 dst_value = matched_src->name;
 656         }
 657
 658         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 659         case 1:
 660                 break;
 661         case 0:
 662                 if (!memcmp(dst_value, "refs/", 5))
 663                         matched_dst = make_linked_ref(dst_value, dst_tail);
 664                 else
 665                         error("dst refspec %s does not match any "
 666                               "existing ref on the remote and does "
 667                               "not start with refs/.", dst_value);
 668                 break;
 669         default:
 670                 matched_dst = NULL;
 671                 error("dst refspec %s matches more than one.",
 672                       dst_value);
 673                 break;
 674         }
 675         if (errs || !matched_dst)
 676                 return 1;
 677         if (matched_dst->peer_ref) {
 678                 errs = 1;
 679                 error("dst ref %s receives from more than one src.",
 680                       matched_dst->name);
 681         }
 682         else {
 683                 matched_dst->peer_ref = matched_src;
 684                 matched_dst->force = rs->force;
 685         }
 686         return errs;
 687 }
 688
 689 static int match_explicit_refs(struct ref *src, struct ref *dst,
 690                                struct ref ***dst_tail, struct refspec *rs,
 691                                int rs_nr)
 692 {
 693         int i, errs;
 694         for (i = errs = 0; i < rs_nr; i++)
 695                 errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
 696         return -errs;
 697 }
 698
 699 static const struct refspec *check_pattern_match(const struct refspec *rs,
 700                                                  int rs_nr,
 701                                                  const struct ref *src)
 702 {
 703         int i;
 704         for (i = 0; i < rs_nr; i++) {
 705                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
 706                         return rs + i;
 707         }
 708         return NULL;
 709 }
 710
 711 /*
 712  * Note. This is used only by "push"; refspec matching rules for
 713  * push and fetch are subtly different, so do not try to reuse it
 714  * without thinking.
 715  */
 716 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 717                int nr_refspec, const char **refspec, int flags)
 718 {
 719         struct refspec *rs =
 720                 parse_ref_spec(nr_refspec, (const char **) refspec);
 721         int send_all = flags & MATCH_REFS_ALL;
 722         int send_mirror = flags & MATCH_REFS_MIRROR;
 723
 724         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
 725                 return -1;
 726
 727         /* pick the remainder */
 728         for ( ; src; src = src->next) {
 729                 struct ref *dst_peer;
 730                 const struct refspec *pat = NULL;
 731                 char *dst_name;
 732                 if (src->peer_ref)
 733                         continue;
 734                 if (nr_refspec) {
 735                         pat = check_pattern_match(rs, nr_refspec, src);
 736                         if (!pat)
 737                                 continue;
 738                 }
 739                 else if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
 740                         /*
 741                          * "matching refs"; traditionally we pushed everything
 742                          * including refs outside refs/heads/ hierarchy, but
 743                          * that does not make much sense these days.
 744                          */
 745                         continue;
 746
 747                 if (pat) {
 748                         const char *dst_side = pat->dst ? pat->dst : pat->src;
 749                         dst_name = xmalloc(strlen(dst_side) +
 750                                            strlen(src->name) -
 751                                            strlen(pat->src) + 2);
 752                         strcpy(dst_name, dst_side);
 753                         strcat(dst_name, src->name + strlen(pat->src));
 754                 } else
 755                         dst_name = xstrdup(src->name);
 756                 dst_peer = find_ref_by_name(dst, dst_name);
 757                 if (dst_peer && dst_peer->peer_ref)
 758                         /* We're already sending something to this ref. */
 759                         goto free_name;
 760
 761                 if (!dst_peer && !nr_refspec && !(send_all || send_mirror))
 762                         /*
 763                          * Remote doesn't have it, and we have no
 764                          * explicit pattern, and we don't have
 765                          * --all nor --mirror.
 766                          */
 767                         goto free_name;
 768                 if (!dst_peer) {
 769                         /* Create a new one and link it */
 770                         dst_peer = make_linked_ref(dst_name, dst_tail);
 771                         hashcpy(dst_peer->new_sha1, src->new_sha1);
 772                 }
 773                 dst_peer->peer_ref = src;
 774                 if (pat)
 775                         dst_peer->force = pat->force;
 776         free_name:
 777                 free(dst_name);
 778         }
 779         return 0;
 780 }
 781
 782 struct branch *branch_get(const char *name)
 783 {
 784         struct branch *ret;
 785
 786         read_config();
 787         if (!name || !*name || !strcmp(name, "HEAD"))
 788                 ret = current_branch;
 789         else
 790                 ret = make_branch(name, 0);
 791         if (ret && ret->remote_name) {
 792                 ret->remote = remote_get(ret->remote_name);
 793                 if (ret->merge_nr) {
 794                         int i;
 795                         ret->merge = xcalloc(sizeof(*ret->merge),
 796                                              ret->merge_nr);
 797                         for (i = 0; i < ret->merge_nr; i++) {
 798                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
 799                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
 800                                 remote_find_tracking(ret->remote,
 801                                                      ret->merge[i]);
 802                         }
 803                 }
 804         }
 805         return ret;
 806 }
 807
 808 int branch_has_merge_config(struct branch *branch)
 809 {
 810         return branch && !!branch->merge;
 811 }
 812
 813 int branch_merge_matches(struct branch *branch,
 814                                  int i,
 815                                  const char *refname)
 816 {
 817         if (!branch || i < 0 || i >= branch->merge_nr)
 818                 return 0;
 819         return ref_matches_abbrev(branch->merge[i]->src, refname);
 820 }
 821
 822 static struct ref *get_expanded_map(const struct ref *remote_refs,
 823                                     const struct refspec *refspec)
 824 {
 825         const struct ref *ref;
 826         struct ref *ret = NULL;
 827         struct ref **tail = &ret;
 828
 829         int remote_prefix_len = strlen(refspec->src);
 830         int local_prefix_len = strlen(refspec->dst);
 831
 832         for (ref = remote_refs; ref; ref = ref->next) {
 833                 if (strchr(ref->name, '^'))
 834                         continue; /* a dereference item */
 835                 if (!prefixcmp(ref->name, refspec->src)) {
 836                         const char *match;
 837                         struct ref *cpy = copy_ref(ref);
 838                         match = ref->name + remote_prefix_len;
 839
 840                         cpy->peer_ref = alloc_ref(local_prefix_len +
 841                                                   strlen(match) + 1);
 842                         sprintf(cpy->peer_ref->name, "%s%s",
 843                                 refspec->dst, match);
 844                         if (refspec->force)
 845                                 cpy->peer_ref->force = 1;
 846                         *tail = cpy;
 847                         tail = &cpy->next;
 848                 }
 849         }
 850
 851         return ret;
 852 }
 853
 854 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
 855 {
 856         const struct ref *ref;
 857         for (ref = refs; ref; ref = ref->next) {
 858                 if (ref_matches_abbrev(name, ref->name))
 859                         return ref;
 860         }
 861         return NULL;
 862 }
 863
 864 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
 865 {
 866         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
 867
 868         if (!ref)
 869                 return NULL;
 870
 871         return copy_ref(ref);
 872 }
 873
 874 static struct ref *get_local_ref(const char *name)
 875 {
 876         struct ref *ret;
 877         if (!name)
 878                 return NULL;
 879
 880         if (!prefixcmp(name, "refs/")) {
 881                 ret = alloc_ref(strlen(name) + 1);
 882                 strcpy(ret->name, name);
 883                 return ret;
 884         }
 885
 886         if (!prefixcmp(name, "heads/") ||
 887             !prefixcmp(name, "tags/") ||
 888             !prefixcmp(name, "remotes/")) {
 889                 ret = alloc_ref(strlen(name) + 6);
 890                 sprintf(ret->name, "refs/%s", name);
 891                 return ret;
 892         }
 893
 894         ret = alloc_ref(strlen(name) + 12);
 895         sprintf(ret->name, "refs/heads/%s", name);
 896         return ret;
 897 }
 898
 899 int get_fetch_map(const struct ref *remote_refs,
 900                   const struct refspec *refspec,
 901                   struct ref ***tail,
 902                   int missing_ok)
 903 {
 904         struct ref *ref_map, *rm;
 905
 906         if (refspec->pattern) {
 907                 ref_map = get_expanded_map(remote_refs, refspec);
 908         } else {
 909                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
 910
 911                 ref_map = get_remote_ref(remote_refs, name);
 912                 if (!missing_ok && !ref_map)
 913                         die("Couldn't find remote ref %s", name);
 914                 if (ref_map) {
 915                         ref_map->peer_ref = get_local_ref(refspec->dst);
 916                         if (ref_map->peer_ref && refspec->force)
 917                                 ref_map->peer_ref->force = 1;
 918                 }
 919         }
 920
 921         for (rm = ref_map; rm; rm = rm->next) {
 922                 if (rm->peer_ref && check_ref_format(rm->peer_ref->name + 5))
 923                         die("* refusing to create funny ref '%s' locally",
 924                             rm->peer_ref->name);
 925         }
 926
 927         if (ref_map)
 928                 tail_link_ref(ref_map, tail);
 929
 930         return 0;
 931 }