remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4
   5 struct counted_string {
   6         size_t len;
   7         const char *s;
   8 };
   9 struct rewrite {
  10         const char *base;
  11         size_t baselen;
  12         struct counted_string *instead_of;
  13         int instead_of_nr;
  14         int instead_of_alloc;
  15 };
  16
  17 static struct remote **remotes;
  18 static int remotes_alloc;
  19 static int remotes_nr;
  20
  21 static struct branch **branches;
  22 static int branches_alloc;
  23 static int branches_nr;
  24
  25 static struct branch *current_branch;
  26 static const char *default_remote_name;
  27
  28 static struct rewrite **rewrite;
  29 static int rewrite_alloc;
  30 static int rewrite_nr;
  31
  32 #define BUF_SIZE (2048)
  33 static char buffer[BUF_SIZE];
  34
  35 static const char *alias_url(const char *url)
  36 {
  37         int i, j;
  38         char *ret;
  39         struct counted_string *longest;
  40         int longest_i;
  41
  42         longest = NULL;
  43         longest_i = -1;
  44         for (i = 0; i < rewrite_nr; i++) {
  45                 if (!rewrite[i])
  46                         continue;
  47                 for (j = 0; j < rewrite[i]->instead_of_nr; j++) {
  48                         if (!prefixcmp(url, rewrite[i]->instead_of[j].s) &&
  49                             (!longest ||
  50                              longest->len < rewrite[i]->instead_of[j].len)) {
  51                                 longest = &(rewrite[i]->instead_of[j]);
  52                                 longest_i = i;
  53                         }
  54                 }
  55         }
  56         if (!longest)
  57                 return url;
  58
  59         ret = malloc(rewrite[longest_i]->baselen +
  60                      (strlen(url) - longest->len) + 1);
  61         strcpy(ret, rewrite[longest_i]->base);
  62         strcpy(ret + rewrite[longest_i]->baselen, url + longest->len);
  63         return ret;
  64 }
  65
  66 static void add_push_refspec(struct remote *remote, const char *ref)
  67 {
  68         ALLOC_GROW(remote->push_refspec,
  69                    remote->push_refspec_nr + 1,
  70                    remote->push_refspec_alloc);
  71         remote->push_refspec[remote->push_refspec_nr++] = ref;
  72 }
  73
  74 static void add_fetch_refspec(struct remote *remote, const char *ref)
  75 {
  76         ALLOC_GROW(remote->fetch_refspec,
  77                    remote->fetch_refspec_nr + 1,
  78                    remote->fetch_refspec_alloc);
  79         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
  80 }
  81
  82 static void add_url(struct remote *remote, const char *url)
  83 {
  84         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
  85         remote->url[remote->url_nr++] = url;
  86 }
  87
  88 static void add_url_alias(struct remote *remote, const char *url)
  89 {
  90         add_url(remote, alias_url(url));
  91 }
  92
  93 static struct remote *make_remote(const char *name, int len)
  94 {
  95         struct remote *ret;
  96         int i;
  97
  98         for (i = 0; i < remotes_nr; i++) {
  99                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 100                            !remotes[i]->name[len]) :
 101                     !strcmp(name, remotes[i]->name))
 102                         return remotes[i];
 103         }
 104
 105         ret = xcalloc(1, sizeof(struct remote));
 106         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 107         remotes[remotes_nr++] = ret;
 108         if (len)
 109                 ret->name = xstrndup(name, len);
 110         else
 111                 ret->name = xstrdup(name);
 112         return ret;
 113 }
 114
 115 static void add_merge(struct branch *branch, const char *name)
 116 {
 117         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 118                    branch->merge_alloc);
 119         branch->merge_name[branch->merge_nr++] = name;
 120 }
 121
 122 static struct branch *make_branch(const char *name, int len)
 123 {
 124         struct branch *ret;
 125         int i;
 126         char *refname;
 127
 128         for (i = 0; i < branches_nr; i++) {
 129                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 130                            !branches[i]->name[len]) :
 131                     !strcmp(name, branches[i]->name))
 132                         return branches[i];
 133         }
 134
 135         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 136         ret = xcalloc(1, sizeof(struct branch));
 137         branches[branches_nr++] = ret;
 138         if (len)
 139                 ret->name = xstrndup(name, len);
 140         else
 141                 ret->name = xstrdup(name);
 142         refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
 143         strcpy(refname, "refs/heads/");
 144         strcpy(refname + strlen("refs/heads/"), ret->name);
 145         ret->refname = refname;
 146
 147         return ret;
 148 }
 149
 150 static struct rewrite *make_rewrite(const char *base, int len)
 151 {
 152         struct rewrite *ret;
 153         int i;
 154
 155         for (i = 0; i < rewrite_nr; i++) {
 156                 if (len
 157                     ? (len == rewrite[i]->baselen &&
 158                        !strncmp(base, rewrite[i]->base, len))
 159                     : !strcmp(base, rewrite[i]->base))
 160                         return rewrite[i];
 161         }
 162
 163         ALLOC_GROW(rewrite, rewrite_nr + 1, rewrite_alloc);
 164         ret = xcalloc(1, sizeof(struct rewrite));
 165         rewrite[rewrite_nr++] = ret;
 166         if (len) {
 167                 ret->base = xstrndup(base, len);
 168                 ret->baselen = len;
 169         }
 170         else {
 171                 ret->base = xstrdup(base);
 172                 ret->baselen = strlen(base);
 173         }
 174         return ret;
 175 }
 176
 177 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 178 {
 179         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 180         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 181         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 182         rewrite->instead_of_nr++;
 183 }
 184
 185 static void read_remotes_file(struct remote *remote)
 186 {
 187         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 188
 189         if (!f)
 190                 return;
 191         while (fgets(buffer, BUF_SIZE, f)) {
 192                 int value_list;
 193                 char *s, *p;
 194
 195                 if (!prefixcmp(buffer, "URL:")) {
 196                         value_list = 0;
 197                         s = buffer + 4;
 198                 } else if (!prefixcmp(buffer, "Push:")) {
 199                         value_list = 1;
 200                         s = buffer + 5;
 201                 } else if (!prefixcmp(buffer, "Pull:")) {
 202                         value_list = 2;
 203                         s = buffer + 5;
 204                 } else
 205                         continue;
 206
 207                 while (isspace(*s))
 208                         s++;
 209                 if (!*s)
 210                         continue;
 211
 212                 p = s + strlen(s);
 213                 while (isspace(p[-1]))
 214                         *--p = 0;
 215
 216                 switch (value_list) {
 217                 case 0:
 218                         add_url_alias(remote, xstrdup(s));
 219                         break;
 220                 case 1:
 221                         add_push_refspec(remote, xstrdup(s));
 222                         break;
 223                 case 2:
 224                         add_fetch_refspec(remote, xstrdup(s));
 225                         break;
 226                 }
 227         }
 228         fclose(f);
 229 }
 230
 231 static void read_branches_file(struct remote *remote)
 232 {
 233         const char *slash = strchr(remote->name, '/');
 234         char *frag;
 235         char *branch;
 236         int n = slash ? slash - remote->name : 1000;
 237         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 238         char *s, *p;
 239         int len;
 240
 241         if (!f)
 242                 return;
 243         s = fgets(buffer, BUF_SIZE, f);
 244         fclose(f);
 245         if (!s)
 246                 return;
 247         while (isspace(*s))
 248                 s++;
 249         if (!*s)
 250                 return;
 251         p = s + strlen(s);
 252         while (isspace(p[-1]))
 253                 *--p = 0;
 254         len = p - s;
 255         if (slash)
 256                 len += strlen(slash);
 257         p = xmalloc(len + 1);
 258         strcpy(p, s);
 259         if (slash)
 260                 strcat(p, slash);
 261         frag = strchr(p, '#');
 262         if (frag) {
 263                 *(frag++) = '\0';
 264                 branch = xmalloc(strlen(frag) + 12);
 265                 strcpy(branch, "refs/heads/");
 266                 strcat(branch, frag);
 267         } else {
 268                 branch = "refs/heads/master";
 269         }
 270         add_url_alias(remote, p);
 271         add_fetch_refspec(remote, branch);
 272         remote->fetch_tags = 1; /* always auto-follow */
 273 }
 274
 275 static int handle_config(const char *key, const char *value)
 276 {
 277         const char *name;
 278         const char *subkey;
 279         struct remote *remote;
 280         struct branch *branch;
 281         if (!prefixcmp(key, "branch.")) {
 282                 name = key + 7;
 283                 subkey = strrchr(name, '.');
 284                 if (!subkey)
 285                         return 0;
 286                 branch = make_branch(name, subkey - name);
 287                 if (!strcmp(subkey, ".remote")) {
 288                         if (!value)
 289                                 return config_error_nonbool(key);
 290                         branch->remote_name = xstrdup(value);
 291                         if (branch == current_branch)
 292                                 default_remote_name = branch->remote_name;
 293                 } else if (!strcmp(subkey, ".merge")) {
 294                         if (!value)
 295                                 return config_error_nonbool(key);
 296                         add_merge(branch, xstrdup(value));
 297                 }
 298                 return 0;
 299         }
 300         if (!prefixcmp(key, "url.")) {
 301                 struct rewrite *rewrite;
 302                 name = key + 5;
 303                 subkey = strrchr(name, '.');
 304                 if (!subkey)
 305                         return 0;
 306                 rewrite = make_rewrite(name, subkey - name);
 307                 if (!strcmp(subkey, ".insteadof")) {
 308                         if (!value)
 309                                 return config_error_nonbool(key);
 310                         add_instead_of(rewrite, xstrdup(value));
 311                 }
 312         }
 313         if (prefixcmp(key,  "remote."))
 314                 return 0;
 315         name = key + 7;
 316         subkey = strrchr(name, '.');
 317         if (!subkey)
 318                 return error("Config with no key for remote %s", name);
 319         if (*subkey == '/') {
 320                 warning("Config remote shorthand cannot begin with '/': %s", name);
 321                 return 0;
 322         }
 323         remote = make_remote(name, subkey - name);
 324         if (!value) {
 325                 /* if we ever have a boolean variable, e.g. "remote.*.disabled"
 326                  * [remote "frotz"]
 327                  *      disabled
 328                  * is a valid way to set it to true; we get NULL in value so
 329                  * we need to handle it here.
 330                  *
 331                  * if (!strcmp(subkey, ".disabled")) {
 332                  *      val = git_config_bool(key, value);
 333                  *      return 0;
 334                  * } else
 335                  *
 336                  */
 337                 return 0; /* ignore unknown booleans */
 338         }
 339         if (!strcmp(subkey, ".url")) {
 340                 add_url(remote, xstrdup(value));
 341         } else if (!strcmp(subkey, ".push")) {
 342                 add_push_refspec(remote, xstrdup(value));
 343         } else if (!strcmp(subkey, ".fetch")) {
 344                 add_fetch_refspec(remote, xstrdup(value));
 345         } else if (!strcmp(subkey, ".receivepack")) {
 346                 if (!remote->receivepack)
 347                         remote->receivepack = xstrdup(value);
 348                 else
 349                         error("more than one receivepack given, using the first");
 350         } else if (!strcmp(subkey, ".uploadpack")) {
 351                 if (!remote->uploadpack)
 352                         remote->uploadpack = xstrdup(value);
 353                 else
 354                         error("more than one uploadpack given, using the first");
 355         } else if (!strcmp(subkey, ".tagopt")) {
 356                 if (!strcmp(value, "--no-tags"))
 357                         remote->fetch_tags = -1;
 358         } else if (!strcmp(subkey, ".proxy")) {
 359                 remote->http_proxy = xstrdup(value);
 360         } else if (!strcmp(subkey, ".skipdefaultupdate"))
 361                 remote->skip_default_update = 1;
 362         return 0;
 363 }
 364
 365 static void alias_all_urls(void)
 366 {
 367         int i, j;
 368         for (i = 0; i < remotes_nr; i++) {
 369                 if (!remotes[i])
 370                         continue;
 371                 for (j = 0; j < remotes[i]->url_nr; j++) {
 372                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 373                 }
 374         }
 375 }
 376
 377 static void read_config(void)
 378 {
 379         unsigned char sha1[20];
 380         const char *head_ref;
 381         int flag;
 382         if (default_remote_name) // did this already
 383                 return;
 384         default_remote_name = xstrdup("origin");
 385         current_branch = NULL;
 386         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 387         if (head_ref && (flag & REF_ISSYMREF) &&
 388             !prefixcmp(head_ref, "refs/heads/")) {
 389                 current_branch =
 390                         make_branch(head_ref + strlen("refs/heads/"), 0);
 391         }
 392         git_config(handle_config);
 393         alias_all_urls();
 394 }
 395
 396 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch)
 397 {
 398         int i;
 399         int st;
 400         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 401
 402         for (i = 0; i < nr_refspec; i++) {
 403                 size_t llen, rlen;
 404                 int is_glob;
 405                 const char *lhs, *rhs;
 406
 407                 llen = rlen = is_glob = 0;
 408
 409                 lhs = refspec[i];
 410                 if (*lhs == '+') {
 411                         rs[i].force = 1;
 412                         lhs++;
 413                 }
 414
 415                 rhs = strrchr(lhs, ':');
 416                 if (rhs) {
 417                         rhs++;
 418                         rlen = strlen(rhs);
 419                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
 420                         rs[i].dst = xstrndup(rhs, rlen - is_glob * 2);
 421                 }
 422
 423                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 424                 if (is_glob != (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)))
 425                         goto invalid;
 426
 427                 if (is_glob) {
 428                         llen -= 2;
 429                         rlen -= 2;
 430                 }
 431                 rs[i].pattern = is_glob;
 432                 rs[i].src = xstrndup(lhs, llen);
 433
 434                 if (fetch) {
 435                         /*
 436                          * LHS
 437                          * - empty is allowed; it means HEAD.
 438                          * - otherwise it must be a valid looking ref.
 439                          */
 440                         if (!*rs[i].src)
 441                                 ; /* empty is ok */
 442                         else {
 443                                 st = check_ref_format(rs[i].src);
 444                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 445                                         goto invalid;
 446                         }
 447                         /*
 448                          * RHS
 449                          * - missing is allowed.
 450                          * - empty is ok; it means not to store.
 451                          * - otherwise it must be a valid looking ref.
 452                          */
 453                         if (!rs[i].dst) {
 454                                 ; /* ok */
 455                         } else if (!*rs[i].dst) {
 456                                 ; /* ok */
 457                         } else {
 458                                 st = check_ref_format(rs[i].dst);
 459                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 460                                         goto invalid;
 461                         }
 462                 } else {
 463                         /*
 464                          * LHS
 465                          * - empty is allowed; it means delete.
 466                          * - when wildcarded, it must be a valid looking ref.
 467                          * - otherwise, it must be an extended SHA-1, but
 468                          *   there is no existing way to validate this.
 469                          */
 470                         if (!*rs[i].src)
 471                                 ; /* empty is ok */
 472                         else if (is_glob) {
 473                                 st = check_ref_format(rs[i].src);
 474                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 475                                         goto invalid;
 476                         }
 477                         else
 478                                 ; /* anything goes, for now */
 479                         /*
 480                          * RHS
 481                          * - missing is allowed, but LHS then must be a
 482                          *   valid looking ref.
 483                          * - empty is not allowed.
 484                          * - otherwise it must be a valid looking ref.
 485                          */
 486                         if (!rs[i].dst) {
 487                                 st = check_ref_format(rs[i].src);
 488                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 489                                         goto invalid;
 490                         } else if (!*rs[i].dst) {
 491                                 goto invalid;
 492                         } else {
 493                                 st = check_ref_format(rs[i].dst);
 494                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 495                                         goto invalid;
 496                         }
 497                 }
 498         }
 499         return rs;
 500
 501  invalid:
 502         die("Invalid refspec '%s'", refspec[i]);
 503 }
 504
 505 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 506 {
 507         return parse_refspec_internal(nr_refspec, refspec, 1);
 508 }
 509
 510 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 511 {
 512         return parse_refspec_internal(nr_refspec, refspec, 0);
 513 }
 514
 515 static int valid_remote_nick(const char *name)
 516 {
 517         if (!name[0] || /* not empty */
 518             (name[0] == '.' && /* not "." */
 519              (!name[1] || /* not ".." */
 520               (name[1] == '.' && !name[2]))))
 521                 return 0;
 522         return !strchr(name, '/'); /* no slash */
 523 }
 524
 525 struct remote *remote_get(const char *name)
 526 {
 527         struct remote *ret;
 528
 529         read_config();
 530         if (!name)
 531                 name = default_remote_name;
 532         ret = make_remote(name, 0);
 533         if (valid_remote_nick(name)) {
 534                 if (!ret->url)
 535                         read_remotes_file(ret);
 536                 if (!ret->url)
 537                         read_branches_file(ret);
 538         }
 539         if (!ret->url)
 540                 add_url_alias(ret, name);
 541         if (!ret->url)
 542                 return NULL;
 543         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 544         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 545         return ret;
 546 }
 547
 548 int for_each_remote(each_remote_fn fn, void *priv)
 549 {
 550         int i, result = 0;
 551         read_config();
 552         for (i = 0; i < remotes_nr && !result; i++) {
 553                 struct remote *r = remotes[i];
 554                 if (!r)
 555                         continue;
 556                 if (!r->fetch)
 557                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 558                                                        r->fetch_refspec);
 559                 if (!r->push)
 560                         r->push = parse_push_refspec(r->push_refspec_nr,
 561                                                      r->push_refspec);
 562                 result = fn(r, priv);
 563         }
 564         return result;
 565 }
 566
 567 void ref_remove_duplicates(struct ref *ref_map)
 568 {
 569         struct ref **posn;
 570         struct ref *next;
 571         for (; ref_map; ref_map = ref_map->next) {
 572                 if (!ref_map->peer_ref)
 573                         continue;
 574                 posn = &ref_map->next;
 575                 while (*posn) {
 576                         if ((*posn)->peer_ref &&
 577                             !strcmp((*posn)->peer_ref->name,
 578                                     ref_map->peer_ref->name)) {
 579                                 if (strcmp((*posn)->name, ref_map->name))
 580                                         die("%s tracks both %s and %s",
 581                                             ref_map->peer_ref->name,
 582                                             (*posn)->name, ref_map->name);
 583                                 next = (*posn)->next;
 584                                 free((*posn)->peer_ref);
 585                                 free(*posn);
 586                                 *posn = next;
 587                         } else {
 588                                 posn = &(*posn)->next;
 589                         }
 590                 }
 591         }
 592 }
 593
 594 int remote_has_url(struct remote *remote, const char *url)
 595 {
 596         int i;
 597         for (i = 0; i < remote->url_nr; i++) {
 598                 if (!strcmp(remote->url[i], url))
 599                         return 1;
 600         }
 601         return 0;
 602 }
 603
 604 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 605 {
 606         int find_src = refspec->src == NULL;
 607         char *needle, **result;
 608         int i;
 609
 610         if (find_src) {
 611                 if (!refspec->dst)
 612                         return error("find_tracking: need either src or dst");
 613                 needle = refspec->dst;
 614                 result = &refspec->src;
 615         } else {
 616                 needle = refspec->src;
 617                 result = &refspec->dst;
 618         }
 619
 620         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 621                 struct refspec *fetch = &remote->fetch[i];
 622                 const char *key = find_src ? fetch->dst : fetch->src;
 623                 const char *value = find_src ? fetch->src : fetch->dst;
 624                 if (!fetch->dst)
 625                         continue;
 626                 if (fetch->pattern) {
 627                         if (!prefixcmp(needle, key) &&
 628                             needle[strlen(key)] == '/') {
 629                                 *result = xmalloc(strlen(value) +
 630                                                   strlen(needle) -
 631                                                   strlen(key) + 1);
 632                                 strcpy(*result, value);
 633                                 strcpy(*result + strlen(value),
 634                                        needle + strlen(key));
 635                                 refspec->force = fetch->force;
 636                                 return 0;
 637                         }
 638                 } else if (!strcmp(needle, key)) {
 639                         *result = xstrdup(value);
 640                         refspec->force = fetch->force;
 641                         return 0;
 642                 }
 643         }
 644         return -1;
 645 }
 646
 647 struct ref *alloc_ref(unsigned namelen)
 648 {
 649         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 650         memset(ret, 0, sizeof(struct ref) + namelen);
 651         return ret;
 652 }
 653
 654 static struct ref *copy_ref(const struct ref *ref)
 655 {
 656         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 657         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 658         ret->next = NULL;
 659         return ret;
 660 }
 661
 662 struct ref *copy_ref_list(const struct ref *ref)
 663 {
 664         struct ref *ret = NULL;
 665         struct ref **tail = &ret;
 666         while (ref) {
 667                 *tail = copy_ref(ref);
 668                 ref = ref->next;
 669                 tail = &((*tail)->next);
 670         }
 671         return ret;
 672 }
 673
 674 void free_refs(struct ref *ref)
 675 {
 676         struct ref *next;
 677         while (ref) {
 678                 next = ref->next;
 679                 free(ref->peer_ref);
 680                 free(ref);
 681                 ref = next;
 682         }
 683 }
 684
 685 static int count_refspec_match(const char *pattern,
 686                                struct ref *refs,
 687                                struct ref **matched_ref)
 688 {
 689         int patlen = strlen(pattern);
 690         struct ref *matched_weak = NULL;
 691         struct ref *matched = NULL;
 692         int weak_match = 0;
 693         int match = 0;
 694
 695         for (weak_match = match = 0; refs; refs = refs->next) {
 696                 char *name = refs->name;
 697                 int namelen = strlen(name);
 698
 699                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 700                         continue;
 701
 702                 /* A match is "weak" if it is with refs outside
 703                  * heads or tags, and did not specify the pattern
 704                  * in full (e.g. "refs/remotes/origin/master") or at
 705                  * least from the toplevel (e.g. "remotes/origin/master");
 706                  * otherwise "git push $URL master" would result in
 707                  * ambiguity between remotes/origin/master and heads/master
 708                  * at the remote site.
 709                  */
 710                 if (namelen != patlen &&
 711                     patlen != namelen - 5 &&
 712                     prefixcmp(name, "refs/heads/") &&
 713                     prefixcmp(name, "refs/tags/")) {
 714                         /* We want to catch the case where only weak
 715                          * matches are found and there are multiple
 716                          * matches, and where more than one strong
 717                          * matches are found, as ambiguous.  One
 718                          * strong match with zero or more weak matches
 719                          * are acceptable as a unique match.
 720                          */
 721                         matched_weak = refs;
 722                         weak_match++;
 723                 }
 724                 else {
 725                         matched = refs;
 726                         match++;
 727                 }
 728         }
 729         if (!matched) {
 730                 *matched_ref = matched_weak;
 731                 return weak_match;
 732         }
 733         else {
 734                 *matched_ref = matched;
 735                 return match;
 736         }
 737 }
 738
 739 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 740 {
 741         **tail = ref;
 742         while (ref->next)
 743                 ref = ref->next;
 744         *tail = &ref->next;
 745 }
 746
 747 static struct ref *try_explicit_object_name(const char *name)
 748 {
 749         unsigned char sha1[20];
 750         struct ref *ref;
 751         int len;
 752
 753         if (!*name) {
 754                 ref = alloc_ref(20);
 755                 strcpy(ref->name, "(delete)");
 756                 hashclr(ref->new_sha1);
 757                 return ref;
 758         }
 759         if (get_sha1(name, sha1))
 760                 return NULL;
 761         len = strlen(name) + 1;
 762         ref = alloc_ref(len);
 763         memcpy(ref->name, name, len);
 764         hashcpy(ref->new_sha1, sha1);
 765         return ref;
 766 }
 767
 768 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 769 {
 770         struct ref *ret;
 771         size_t len;
 772
 773         len = strlen(name) + 1;
 774         ret = alloc_ref(len);
 775         memcpy(ret->name, name, len);
 776         tail_link_ref(ret, tail);
 777         return ret;
 778 }
 779
 780 static int match_explicit(struct ref *src, struct ref *dst,
 781                           struct ref ***dst_tail,
 782                           struct refspec *rs,
 783                           int errs)
 784 {
 785         struct ref *matched_src, *matched_dst;
 786
 787         const char *dst_value = rs->dst;
 788
 789         if (rs->pattern)
 790                 return errs;
 791
 792         matched_src = matched_dst = NULL;
 793         switch (count_refspec_match(rs->src, src, &matched_src)) {
 794         case 1:
 795                 break;
 796         case 0:
 797                 /* The source could be in the get_sha1() format
 798                  * not a reference name.  :refs/other is a
 799                  * way to delete 'other' ref at the remote end.
 800                  */
 801                 matched_src = try_explicit_object_name(rs->src);
 802                 if (!matched_src)
 803                         error("src refspec %s does not match any.", rs->src);
 804                 break;
 805         default:
 806                 matched_src = NULL;
 807                 error("src refspec %s matches more than one.", rs->src);
 808                 break;
 809         }
 810
 811         if (!matched_src)
 812                 errs = 1;
 813
 814         if (!dst_value) {
 815                 unsigned char sha1[20];
 816                 int flag;
 817
 818                 if (!matched_src)
 819                         return errs;
 820                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 821                 if (!dst_value ||
 822                     ((flag & REF_ISSYMREF) &&
 823                      prefixcmp(dst_value, "refs/heads/")))
 824                         die("%s cannot be resolved to branch.",
 825                             matched_src->name);
 826         }
 827
 828         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 829         case 1:
 830                 break;
 831         case 0:
 832                 if (!memcmp(dst_value, "refs/", 5))
 833                         matched_dst = make_linked_ref(dst_value, dst_tail);
 834                 else
 835                         error("dst refspec %s does not match any "
 836                               "existing ref on the remote and does "
 837                               "not start with refs/.", dst_value);
 838                 break;
 839         default:
 840                 matched_dst = NULL;
 841                 error("dst refspec %s matches more than one.",
 842                       dst_value);
 843                 break;
 844         }
 845         if (errs || !matched_dst)
 846                 return 1;
 847         if (matched_dst->peer_ref) {
 848                 errs = 1;
 849                 error("dst ref %s receives from more than one src.",
 850                       matched_dst->name);
 851         }
 852         else {
 853                 matched_dst->peer_ref = matched_src;
 854                 matched_dst->force = rs->force;
 855         }
 856         return errs;
 857 }
 858
 859 static int match_explicit_refs(struct ref *src, struct ref *dst,
 860                                struct ref ***dst_tail, struct refspec *rs,
 861                                int rs_nr)
 862 {
 863         int i, errs;
 864         for (i = errs = 0; i < rs_nr; i++)
 865                 errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
 866         return -errs;
 867 }
 868
 869 static const struct refspec *check_pattern_match(const struct refspec *rs,
 870                                                  int rs_nr,
 871                                                  const struct ref *src)
 872 {
 873         int i;
 874         for (i = 0; i < rs_nr; i++) {
 875                 if (rs[i].pattern &&
 876                     !prefixcmp(src->name, rs[i].src) &&
 877                     src->name[strlen(rs[i].src)] == '/')
 878                         return rs + i;
 879         }
 880         return NULL;
 881 }
 882
 883 /*
 884  * Note. This is used only by "push"; refspec matching rules for
 885  * push and fetch are subtly different, so do not try to reuse it
 886  * without thinking.
 887  */
 888 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 889                int nr_refspec, const char **refspec, int flags)
 890 {
 891         struct refspec *rs =
 892                 parse_push_refspec(nr_refspec, (const char **) refspec);
 893         int send_all = flags & MATCH_REFS_ALL;
 894         int send_mirror = flags & MATCH_REFS_MIRROR;
 895
 896         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
 897                 return -1;
 898
 899         /* pick the remainder */
 900         for ( ; src; src = src->next) {
 901                 struct ref *dst_peer;
 902                 const struct refspec *pat = NULL;
 903                 char *dst_name;
 904                 if (src->peer_ref)
 905                         continue;
 906                 if (nr_refspec) {
 907                         pat = check_pattern_match(rs, nr_refspec, src);
 908                         if (!pat)
 909                                 continue;
 910                 }
 911                 else if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
 912                         /*
 913                          * "matching refs"; traditionally we pushed everything
 914                          * including refs outside refs/heads/ hierarchy, but
 915                          * that does not make much sense these days.
 916                          */
 917                         continue;
 918
 919                 if (pat) {
 920                         const char *dst_side = pat->dst ? pat->dst : pat->src;
 921                         dst_name = xmalloc(strlen(dst_side) +
 922                                            strlen(src->name) -
 923                                            strlen(pat->src) + 2);
 924                         strcpy(dst_name, dst_side);
 925                         strcat(dst_name, src->name + strlen(pat->src));
 926                 } else
 927                         dst_name = xstrdup(src->name);
 928                 dst_peer = find_ref_by_name(dst, dst_name);
 929                 if (dst_peer && dst_peer->peer_ref)
 930                         /* We're already sending something to this ref. */
 931                         goto free_name;
 932
 933                 if (!dst_peer && !nr_refspec && !(send_all || send_mirror))
 934                         /*
 935                          * Remote doesn't have it, and we have no
 936                          * explicit pattern, and we don't have
 937                          * --all nor --mirror.
 938                          */
 939                         goto free_name;
 940                 if (!dst_peer) {
 941                         /* Create a new one and link it */
 942                         dst_peer = make_linked_ref(dst_name, dst_tail);
 943                         hashcpy(dst_peer->new_sha1, src->new_sha1);
 944                 }
 945                 dst_peer->peer_ref = src;
 946                 if (pat)
 947                         dst_peer->force = pat->force;
 948         free_name:
 949                 free(dst_name);
 950         }
 951         return 0;
 952 }
 953
 954 struct branch *branch_get(const char *name)
 955 {
 956         struct branch *ret;
 957
 958         read_config();
 959         if (!name || !*name || !strcmp(name, "HEAD"))
 960                 ret = current_branch;
 961         else
 962                 ret = make_branch(name, 0);
 963         if (ret && ret->remote_name) {
 964                 ret->remote = remote_get(ret->remote_name);
 965                 if (ret->merge_nr) {
 966                         int i;
 967                         ret->merge = xcalloc(sizeof(*ret->merge),
 968                                              ret->merge_nr);
 969                         for (i = 0; i < ret->merge_nr; i++) {
 970                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
 971                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
 972                                 remote_find_tracking(ret->remote,
 973                                                      ret->merge[i]);
 974                         }
 975                 }
 976         }
 977         return ret;
 978 }
 979
 980 int branch_has_merge_config(struct branch *branch)
 981 {
 982         return branch && !!branch->merge;
 983 }
 984
 985 int branch_merge_matches(struct branch *branch,
 986                                  int i,
 987                                  const char *refname)
 988 {
 989         if (!branch || i < 0 || i >= branch->merge_nr)
 990                 return 0;
 991         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
 992 }
 993
 994 static struct ref *get_expanded_map(const struct ref *remote_refs,
 995                                     const struct refspec *refspec)
 996 {
 997         const struct ref *ref;
 998         struct ref *ret = NULL;
 999         struct ref **tail = &ret;
1000
1001         int remote_prefix_len = strlen(refspec->src);
1002         int local_prefix_len = strlen(refspec->dst);
1003
1004         for (ref = remote_refs; ref; ref = ref->next) {
1005                 if (strchr(ref->name, '^'))
1006                         continue; /* a dereference item */
1007                 if (!prefixcmp(ref->name, refspec->src)) {
1008                         const char *match;
1009                         struct ref *cpy = copy_ref(ref);
1010                         match = ref->name + remote_prefix_len;
1011
1012                         cpy->peer_ref = alloc_ref(local_prefix_len +
1013                                                   strlen(match) + 1);
1014                         sprintf(cpy->peer_ref->name, "%s%s",
1015                                 refspec->dst, match);
1016                         if (refspec->force)
1017                                 cpy->peer_ref->force = 1;
1018                         *tail = cpy;
1019                         tail = &cpy->next;
1020                 }
1021         }
1022
1023         return ret;
1024 }
1025
1026 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1027 {
1028         const struct ref *ref;
1029         for (ref = refs; ref; ref = ref->next) {
1030                 if (refname_match(name, ref->name, ref_fetch_rules))
1031                         return ref;
1032         }
1033         return NULL;
1034 }
1035
1036 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1037 {
1038         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1039
1040         if (!ref)
1041                 return NULL;
1042
1043         return copy_ref(ref);
1044 }
1045
1046 static struct ref *get_local_ref(const char *name)
1047 {
1048         struct ref *ret;
1049         if (!name)
1050                 return NULL;
1051
1052         if (!prefixcmp(name, "refs/")) {
1053                 ret = alloc_ref(strlen(name) + 1);
1054                 strcpy(ret->name, name);
1055                 return ret;
1056         }
1057
1058         if (!prefixcmp(name, "heads/") ||
1059             !prefixcmp(name, "tags/") ||
1060             !prefixcmp(name, "remotes/")) {
1061                 ret = alloc_ref(strlen(name) + 6);
1062                 sprintf(ret->name, "refs/%s", name);
1063                 return ret;
1064         }
1065
1066         ret = alloc_ref(strlen(name) + 12);
1067         sprintf(ret->name, "refs/heads/%s", name);
1068         return ret;
1069 }
1070
1071 int get_fetch_map(const struct ref *remote_refs,
1072                   const struct refspec *refspec,
1073                   struct ref ***tail,
1074                   int missing_ok)
1075 {
1076         struct ref *ref_map, **rmp;
1077
1078         if (refspec->pattern) {
1079                 ref_map = get_expanded_map(remote_refs, refspec);
1080         } else {
1081                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1082
1083                 ref_map = get_remote_ref(remote_refs, name);
1084                 if (!missing_ok && !ref_map)
1085                         die("Couldn't find remote ref %s", name);
1086                 if (ref_map) {
1087                         ref_map->peer_ref = get_local_ref(refspec->dst);
1088                         if (ref_map->peer_ref && refspec->force)
1089                                 ref_map->peer_ref->force = 1;
1090                 }
1091         }
1092
1093         for (rmp = &ref_map; *rmp; ) {
1094                 if ((*rmp)->peer_ref) {
1095                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1096                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1097                                 struct ref *ignore = *rmp;
1098                                 error("* Ignoring funny ref '%s' locally",
1099                                       (*rmp)->peer_ref->name);
1100                                 *rmp = (*rmp)->next;
1101                                 free(ignore->peer_ref);
1102                                 free(ignore);
1103                                 continue;
1104                         }
1105                 }
1106                 rmp = &((*rmp)->next);
1107         }
1108
1109         if (ref_map)
1110                 tail_link_ref(ref_map, tail);
1111
1112         return 0;
1113 }