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                 if (!subkey)
 224                         return 0;
 225                 if (!value)
 226                         return 0;
 227                 branch = make_branch(name, subkey - name);
 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         } else if (!strcmp(subkey, ".proxy")) {
 282                 remote->http_proxy = xstrdup(value);
 283         }
 284         return 0;
 285 }
 286
 287 static void read_config(void)
 288 {
 289         unsigned char sha1[20];
 290         const char *head_ref;
 291         int flag;
 292         if (default_remote_name) // did this already
 293                 return;
 294         default_remote_name = xstrdup("origin");
 295         current_branch = NULL;
 296         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 297         if (head_ref && (flag & REF_ISSYMREF) &&
 298             !prefixcmp(head_ref, "refs/heads/")) {
 299                 current_branch =
 300                         make_branch(head_ref + strlen("refs/heads/"), 0);
 301         }
 302         git_config(handle_config);
 303 }
 304
 305 struct refspec *parse_ref_spec(int nr_refspec, const char **refspec)
 306 {
 307         int i;
 308         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 309         for (i = 0; i < nr_refspec; i++) {
 310                 const char *sp, *ep, *gp;
 311                 sp = refspec[i];
 312                 if (*sp == '+') {
 313                         rs[i].force = 1;
 314                         sp++;
 315                 }
 316                 gp = strchr(sp, '*');
 317                 ep = strchr(sp, ':');
 318                 if (gp && ep && gp > ep)
 319                         gp = NULL;
 320                 if (ep) {
 321                         if (ep[1]) {
 322                                 const char *glob = strchr(ep + 1, '*');
 323                                 if (!glob)
 324                                         gp = NULL;
 325                                 if (gp)
 326                                         rs[i].dst = xstrndup(ep + 1,
 327                                                              glob - ep - 1);
 328                                 else
 329                                         rs[i].dst = xstrdup(ep + 1);
 330                         }
 331                 } else {
 332                         ep = sp + strlen(sp);
 333                 }
 334                 if (gp) {
 335                         rs[i].pattern = 1;
 336                         ep = gp;
 337                 }
 338                 rs[i].src = xstrndup(sp, ep - sp);
 339         }
 340         return rs;
 341 }
 342
 343 struct remote *remote_get(const char *name)
 344 {
 345         struct remote *ret;
 346
 347         read_config();
 348         if (!name)
 349                 name = default_remote_name;
 350         ret = make_remote(name, 0);
 351         if (name[0] != '/') {
 352                 if (!ret->url)
 353                         read_remotes_file(ret);
 354                 if (!ret->url)
 355                         read_branches_file(ret);
 356         }
 357         if (!ret->url)
 358                 add_url(ret, name);
 359         if (!ret->url)
 360                 return NULL;
 361         ret->fetch = parse_ref_spec(ret->fetch_refspec_nr, ret->fetch_refspec);
 362         ret->push = parse_ref_spec(ret->push_refspec_nr, ret->push_refspec);
 363         return ret;
 364 }
 365
 366 int for_each_remote(each_remote_fn fn, void *priv)
 367 {
 368         int i, result = 0;
 369         read_config();
 370         for (i = 0; i < allocated_remotes && !result; i++) {
 371                 struct remote *r = remotes[i];
 372                 if (!r)
 373                         continue;
 374                 if (!r->fetch)
 375                         r->fetch = parse_ref_spec(r->fetch_refspec_nr,
 376                                         r->fetch_refspec);
 377                 if (!r->push)
 378                         r->push = parse_ref_spec(r->push_refspec_nr,
 379                                         r->push_refspec);
 380                 result = fn(r, priv);
 381         }
 382         return result;
 383 }
 384
 385 void ref_remove_duplicates(struct ref *ref_map)
 386 {
 387         struct ref **posn;
 388         struct ref *next;
 389         for (; ref_map; ref_map = ref_map->next) {
 390                 if (!ref_map->peer_ref)
 391                         continue;
 392                 posn = &ref_map->next;
 393                 while (*posn) {
 394                         if ((*posn)->peer_ref &&
 395                             !strcmp((*posn)->peer_ref->name,
 396                                     ref_map->peer_ref->name)) {
 397                                 if (strcmp((*posn)->name, ref_map->name))
 398                                         die("%s tracks both %s and %s",
 399                                             ref_map->peer_ref->name,
 400                                             (*posn)->name, ref_map->name);
 401                                 next = (*posn)->next;
 402                                 free((*posn)->peer_ref);
 403                                 free(*posn);
 404                                 *posn = next;
 405                         } else {
 406                                 posn = &(*posn)->next;
 407                         }
 408                 }
 409         }
 410 }
 411
 412 int remote_has_url(struct remote *remote, const char *url)
 413 {
 414         int i;
 415         for (i = 0; i < remote->url_nr; i++) {
 416                 if (!strcmp(remote->url[i], url))
 417                         return 1;
 418         }
 419         return 0;
 420 }
 421
 422 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 423 {
 424         int find_src = refspec->src == NULL;
 425         char *needle, **result;
 426         int i;
 427
 428         if (find_src) {
 429                 if (!refspec->dst)
 430                         return error("find_tracking: need either src or dst");
 431                 needle = refspec->dst;
 432                 result = &refspec->src;
 433         } else {
 434                 needle = refspec->src;
 435                 result = &refspec->dst;
 436         }
 437
 438         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 439                 struct refspec *fetch = &remote->fetch[i];
 440                 const char *key = find_src ? fetch->dst : fetch->src;
 441                 const char *value = find_src ? fetch->src : fetch->dst;
 442                 if (!fetch->dst)
 443                         continue;
 444                 if (fetch->pattern) {
 445                         if (!prefixcmp(needle, key)) {
 446                                 *result = xmalloc(strlen(value) +
 447                                                   strlen(needle) -
 448                                                   strlen(key) + 1);
 449                                 strcpy(*result, value);
 450                                 strcpy(*result + strlen(value),
 451                                        needle + strlen(key));
 452                                 refspec->force = fetch->force;
 453                                 return 0;
 454                         }
 455                 } else if (!strcmp(needle, key)) {
 456                         *result = xstrdup(value);
 457                         refspec->force = fetch->force;
 458                         return 0;
 459                 }
 460         }
 461         return -1;
 462 }
 463
 464 struct ref *alloc_ref(unsigned namelen)
 465 {
 466         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 467         memset(ret, 0, sizeof(struct ref) + namelen);
 468         return ret;
 469 }
 470
 471 static struct ref *copy_ref(const struct ref *ref)
 472 {
 473         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 474         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 475         ret->next = NULL;
 476         return ret;
 477 }
 478
 479 struct ref *copy_ref_list(const struct ref *ref)
 480 {
 481         struct ref *ret = NULL;
 482         struct ref **tail = &ret;
 483         while (ref) {
 484                 *tail = copy_ref(ref);
 485                 ref = ref->next;
 486                 tail = &((*tail)->next);
 487         }
 488         return ret;
 489 }
 490
 491 void free_refs(struct ref *ref)
 492 {
 493         struct ref *next;
 494         while (ref) {
 495                 next = ref->next;
 496                 if (ref->peer_ref)
 497                         free(ref->peer_ref);
 498                 free(ref);
 499                 ref = next;
 500         }
 501 }
 502
 503 static int count_refspec_match(const char *pattern,
 504                                struct ref *refs,
 505                                struct ref **matched_ref)
 506 {
 507         int patlen = strlen(pattern);
 508         struct ref *matched_weak = NULL;
 509         struct ref *matched = NULL;
 510         int weak_match = 0;
 511         int match = 0;
 512
 513         for (weak_match = match = 0; refs; refs = refs->next) {
 514                 char *name = refs->name;
 515                 int namelen = strlen(name);
 516
 517                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 518                         continue;
 519
 520                 /* A match is "weak" if it is with refs outside
 521                  * heads or tags, and did not specify the pattern
 522                  * in full (e.g. "refs/remotes/origin/master") or at
 523                  * least from the toplevel (e.g. "remotes/origin/master");
 524                  * otherwise "git push $URL master" would result in
 525                  * ambiguity between remotes/origin/master and heads/master
 526                  * at the remote site.
 527                  */
 528                 if (namelen != patlen &&
 529                     patlen != namelen - 5 &&
 530                     prefixcmp(name, "refs/heads/") &&
 531                     prefixcmp(name, "refs/tags/")) {
 532                         /* We want to catch the case where only weak
 533                          * matches are found and there are multiple
 534                          * matches, and where more than one strong
 535                          * matches are found, as ambiguous.  One
 536                          * strong match with zero or more weak matches
 537                          * are acceptable as a unique match.
 538                          */
 539                         matched_weak = refs;
 540                         weak_match++;
 541                 }
 542                 else {
 543                         matched = refs;
 544                         match++;
 545                 }
 546         }
 547         if (!matched) {
 548                 *matched_ref = matched_weak;
 549                 return weak_match;
 550         }
 551         else {
 552                 *matched_ref = matched;
 553                 return match;
 554         }
 555 }
 556
 557 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 558 {
 559         **tail = ref;
 560         while (ref->next)
 561                 ref = ref->next;
 562         *tail = &ref->next;
 563 }
 564
 565 static struct ref *try_explicit_object_name(const char *name)
 566 {
 567         unsigned char sha1[20];
 568         struct ref *ref;
 569         int len;
 570
 571         if (!*name) {
 572                 ref = alloc_ref(20);
 573                 strcpy(ref->name, "(delete)");
 574                 hashclr(ref->new_sha1);
 575                 return ref;
 576         }
 577         if (get_sha1(name, sha1))
 578                 return NULL;
 579         len = strlen(name) + 1;
 580         ref = alloc_ref(len);
 581         memcpy(ref->name, name, len);
 582         hashcpy(ref->new_sha1, sha1);
 583         return ref;
 584 }
 585
 586 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 587 {
 588         struct ref *ret;
 589         size_t len;
 590
 591         len = strlen(name) + 1;
 592         ret = alloc_ref(len);
 593         memcpy(ret->name, name, len);
 594         tail_link_ref(ret, tail);
 595         return ret;
 596 }
 597
 598 static int match_explicit(struct ref *src, struct ref *dst,
 599                           struct ref ***dst_tail,
 600                           struct refspec *rs,
 601                           int errs)
 602 {
 603         struct ref *matched_src, *matched_dst;
 604
 605         const char *dst_value = rs->dst;
 606
 607         if (rs->pattern)
 608                 return errs;
 609
 610         matched_src = matched_dst = NULL;
 611         switch (count_refspec_match(rs->src, src, &matched_src)) {
 612         case 1:
 613                 break;
 614         case 0:
 615                 /* The source could be in the get_sha1() format
 616                  * not a reference name.  :refs/other is a
 617                  * way to delete 'other' ref at the remote end.
 618                  */
 619                 matched_src = try_explicit_object_name(rs->src);
 620                 if (!matched_src)
 621                         error("src refspec %s does not match any.", rs->src);
 622                 break;
 623         default:
 624                 matched_src = NULL;
 625                 error("src refspec %s matches more than one.", rs->src);
 626                 break;
 627         }
 628
 629         if (!matched_src)
 630                 errs = 1;
 631
 632         if (!dst_value) {
 633                 if (!matched_src)
 634                         return errs;
 635                 dst_value = matched_src->name;
 636         }
 637
 638         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 639         case 1:
 640                 break;
 641         case 0:
 642                 if (!memcmp(dst_value, "refs/", 5))
 643                         matched_dst = make_linked_ref(dst_value, dst_tail);
 644                 else
 645                         error("dst refspec %s does not match any "
 646                               "existing ref on the remote and does "
 647                               "not start with refs/.", dst_value);
 648                 break;
 649         default:
 650                 matched_dst = NULL;
 651                 error("dst refspec %s matches more than one.",
 652                       dst_value);
 653                 break;
 654         }
 655         if (errs || !matched_dst)
 656                 return 1;
 657         if (matched_dst->peer_ref) {
 658                 errs = 1;
 659                 error("dst ref %s receives from more than one src.",
 660                       matched_dst->name);
 661         }
 662         else {
 663                 matched_dst->peer_ref = matched_src;
 664                 matched_dst->force = rs->force;
 665         }
 666         return errs;
 667 }
 668
 669 static int match_explicit_refs(struct ref *src, struct ref *dst,
 670                                struct ref ***dst_tail, struct refspec *rs,
 671                                int rs_nr)
 672 {
 673         int i, errs;
 674         for (i = errs = 0; i < rs_nr; i++)
 675                 errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
 676         return -errs;
 677 }
 678
 679 static const struct refspec *check_pattern_match(const struct refspec *rs,
 680                                                  int rs_nr,
 681                                                  const struct ref *src)
 682 {
 683         int i;
 684         for (i = 0; i < rs_nr; i++) {
 685                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
 686                         return rs + i;
 687         }
 688         return NULL;
 689 }
 690
 691 /*
 692  * Note. This is used only by "push"; refspec matching rules for
 693  * push and fetch are subtly different, so do not try to reuse it
 694  * without thinking.
 695  */
 696 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 697                int nr_refspec, const char **refspec, int flags)
 698 {
 699         struct refspec *rs =
 700                 parse_ref_spec(nr_refspec, (const char **) refspec);
 701         int send_all = flags & MATCH_REFS_ALL;
 702         int send_mirror = flags & MATCH_REFS_MIRROR;
 703
 704         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
 705                 return -1;
 706
 707         /* pick the remainder */
 708         for ( ; src; src = src->next) {
 709                 struct ref *dst_peer;
 710                 const struct refspec *pat = NULL;
 711                 char *dst_name;
 712                 if (src->peer_ref)
 713                         continue;
 714                 if (nr_refspec) {
 715                         pat = check_pattern_match(rs, nr_refspec, src);
 716                         if (!pat)
 717                                 continue;
 718                 }
 719                 else if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
 720                         /*
 721                          * "matching refs"; traditionally we pushed everything
 722                          * including refs outside refs/heads/ hierarchy, but
 723                          * that does not make much sense these days.
 724                          */
 725                         continue;
 726
 727                 if (pat) {
 728                         const char *dst_side = pat->dst ? pat->dst : pat->src;
 729                         dst_name = xmalloc(strlen(dst_side) +
 730                                            strlen(src->name) -
 731                                            strlen(pat->src) + 2);
 732                         strcpy(dst_name, dst_side);
 733                         strcat(dst_name, src->name + strlen(pat->src));
 734                 } else
 735                         dst_name = xstrdup(src->name);
 736                 dst_peer = find_ref_by_name(dst, dst_name);
 737                 if (dst_peer && dst_peer->peer_ref)
 738                         /* We're already sending something to this ref. */
 739                         goto free_name;
 740
 741                 if (!dst_peer && !nr_refspec && !(send_all || send_mirror))
 742                         /*
 743                          * Remote doesn't have it, and we have no
 744                          * explicit pattern, and we don't have
 745                          * --all nor --mirror.
 746                          */
 747                         goto free_name;
 748                 if (!dst_peer) {
 749                         /* Create a new one and link it */
 750                         dst_peer = make_linked_ref(dst_name, dst_tail);
 751                         hashcpy(dst_peer->new_sha1, src->new_sha1);
 752                 }
 753                 dst_peer->peer_ref = src;
 754                 if (pat)
 755                         dst_peer->force = pat->force;
 756         free_name:
 757                 free(dst_name);
 758         }
 759         return 0;
 760 }
 761
 762 struct branch *branch_get(const char *name)
 763 {
 764         struct branch *ret;
 765
 766         read_config();
 767         if (!name || !*name || !strcmp(name, "HEAD"))
 768                 ret = current_branch;
 769         else
 770                 ret = make_branch(name, 0);
 771         if (ret && ret->remote_name) {
 772                 ret->remote = remote_get(ret->remote_name);
 773                 if (ret->merge_nr) {
 774                         int i;
 775                         ret->merge = xcalloc(sizeof(*ret->merge),
 776                                              ret->merge_nr);
 777                         for (i = 0; i < ret->merge_nr; i++) {
 778                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
 779                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
 780                                 remote_find_tracking(ret->remote,
 781                                                      ret->merge[i]);
 782                         }
 783                 }
 784         }
 785         return ret;
 786 }
 787
 788 int branch_has_merge_config(struct branch *branch)
 789 {
 790         return branch && !!branch->merge;
 791 }
 792
 793 int branch_merge_matches(struct branch *branch,
 794                                  int i,
 795                                  const char *refname)
 796 {
 797         if (!branch || i < 0 || i >= branch->merge_nr)
 798                 return 0;
 799         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
 800 }
 801
 802 static struct ref *get_expanded_map(const struct ref *remote_refs,
 803                                     const struct refspec *refspec)
 804 {
 805         const struct ref *ref;
 806         struct ref *ret = NULL;
 807         struct ref **tail = &ret;
 808
 809         int remote_prefix_len = strlen(refspec->src);
 810         int local_prefix_len = strlen(refspec->dst);
 811
 812         for (ref = remote_refs; ref; ref = ref->next) {
 813                 if (strchr(ref->name, '^'))
 814                         continue; /* a dereference item */
 815                 if (!prefixcmp(ref->name, refspec->src)) {
 816                         const char *match;
 817                         struct ref *cpy = copy_ref(ref);
 818                         match = ref->name + remote_prefix_len;
 819
 820                         cpy->peer_ref = alloc_ref(local_prefix_len +
 821                                                   strlen(match) + 1);
 822                         sprintf(cpy->peer_ref->name, "%s%s",
 823                                 refspec->dst, match);
 824                         if (refspec->force)
 825                                 cpy->peer_ref->force = 1;
 826                         *tail = cpy;
 827                         tail = &cpy->next;
 828                 }
 829         }
 830
 831         return ret;
 832 }
 833
 834 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
 835 {
 836         const struct ref *ref;
 837         for (ref = refs; ref; ref = ref->next) {
 838                 if (refname_match(name, ref->name, ref_fetch_rules))
 839                         return ref;
 840         }
 841         return NULL;
 842 }
 843
 844 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
 845 {
 846         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
 847
 848         if (!ref)
 849                 return NULL;
 850
 851         return copy_ref(ref);
 852 }
 853
 854 static struct ref *get_local_ref(const char *name)
 855 {
 856         struct ref *ret;
 857         if (!name)
 858                 return NULL;
 859
 860         if (!prefixcmp(name, "refs/")) {
 861                 ret = alloc_ref(strlen(name) + 1);
 862                 strcpy(ret->name, name);
 863                 return ret;
 864         }
 865
 866         if (!prefixcmp(name, "heads/") ||
 867             !prefixcmp(name, "tags/") ||
 868             !prefixcmp(name, "remotes/")) {
 869                 ret = alloc_ref(strlen(name) + 6);
 870                 sprintf(ret->name, "refs/%s", name);
 871                 return ret;
 872         }
 873
 874         ret = alloc_ref(strlen(name) + 12);
 875         sprintf(ret->name, "refs/heads/%s", name);
 876         return ret;
 877 }
 878
 879 int get_fetch_map(const struct ref *remote_refs,
 880                   const struct refspec *refspec,
 881                   struct ref ***tail,
 882                   int missing_ok)
 883 {
 884         struct ref *ref_map, *rm;
 885
 886         if (refspec->pattern) {
 887                 ref_map = get_expanded_map(remote_refs, refspec);
 888         } else {
 889                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
 890
 891                 ref_map = get_remote_ref(remote_refs, name);
 892                 if (!missing_ok && !ref_map)
 893                         die("Couldn't find remote ref %s", name);
 894                 if (ref_map) {
 895                         ref_map->peer_ref = get_local_ref(refspec->dst);
 896                         if (ref_map->peer_ref && refspec->force)
 897                                 ref_map->peer_ref->force = 1;
 898                 }
 899         }
 900
 901         for (rm = ref_map; rm; rm = rm->next) {
 902                 if (rm->peer_ref && check_ref_format(rm->peer_ref->name + 5))
 903                         die("* refusing to create funny ref '%s' locally",
 904                             rm->peer_ref->name);
 905         }
 906
 907         if (ref_map)
 908                 tail_link_ref(ref_map, tail);
 909
 910         return 0;
 911 }