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         struct strbuf 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
 262         /*
 263          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 264          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 265          * the partial URL obtained from the branches file plus
 266          * "/netdev-2.6" and does not store it in any tracking ref.
 267          * #branch specifier in the file is ignored.
 268          *
 269          * Otherwise, the branches file would have URL and optionally
 270          * #branch specified.  The "master" (or specified) branch is
 271          * fetched and stored in the local branch of the same name.
 272          */
 273         strbuf_init(&branch, 0);
 274         frag = strchr(p, '#');
 275         if (frag) {
 276                 *(frag++) = '\0';
 277                 strbuf_addf(&branch, "refs/heads/%s", frag);
 278         } else
 279                 strbuf_addstr(&branch, "refs/heads/master");
 280         if (!slash) {
 281                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 282         } else {
 283                 strbuf_reset(&branch);
 284                 strbuf_addstr(&branch, "HEAD:");
 285         }
 286         add_url_alias(remote, p);
 287         add_fetch_refspec(remote, strbuf_detach(&branch, 0));
 288         remote->fetch_tags = 1; /* always auto-follow */
 289 }
 290
 291 static int handle_config(const char *key, const char *value)
 292 {
 293         const char *name;
 294         const char *subkey;
 295         struct remote *remote;
 296         struct branch *branch;
 297         if (!prefixcmp(key, "branch.")) {
 298                 name = key + 7;
 299                 subkey = strrchr(name, '.');
 300                 if (!subkey)
 301                         return 0;
 302                 branch = make_branch(name, subkey - name);
 303                 if (!strcmp(subkey, ".remote")) {
 304                         if (!value)
 305                                 return config_error_nonbool(key);
 306                         branch->remote_name = xstrdup(value);
 307                         if (branch == current_branch)
 308                                 default_remote_name = branch->remote_name;
 309                 } else if (!strcmp(subkey, ".merge")) {
 310                         if (!value)
 311                                 return config_error_nonbool(key);
 312                         add_merge(branch, xstrdup(value));
 313                 }
 314                 return 0;
 315         }
 316         if (!prefixcmp(key, "url.")) {
 317                 struct rewrite *rewrite;
 318                 name = key + 5;
 319                 subkey = strrchr(name, '.');
 320                 if (!subkey)
 321                         return 0;
 322                 rewrite = make_rewrite(name, subkey - name);
 323                 if (!strcmp(subkey, ".insteadof")) {
 324                         if (!value)
 325                                 return config_error_nonbool(key);
 326                         add_instead_of(rewrite, xstrdup(value));
 327                 }
 328         }
 329         if (prefixcmp(key,  "remote."))
 330                 return 0;
 331         name = key + 7;
 332         subkey = strrchr(name, '.');
 333         if (!subkey)
 334                 return error("Config with no key for remote %s", name);
 335         if (*subkey == '/') {
 336                 warning("Config remote shorthand cannot begin with '/': %s", name);
 337                 return 0;
 338         }
 339         remote = make_remote(name, subkey - name);
 340         if (!value) {
 341                 /* if we ever have a boolean variable, e.g. "remote.*.disabled"
 342                  * [remote "frotz"]
 343                  *      disabled
 344                  * is a valid way to set it to true; we get NULL in value so
 345                  * we need to handle it here.
 346                  *
 347                  * if (!strcmp(subkey, ".disabled")) {
 348                  *      val = git_config_bool(key, value);
 349                  *      return 0;
 350                  * } else
 351                  *
 352                  */
 353                 return 0; /* ignore unknown booleans */
 354         }
 355         if (!strcmp(subkey, ".url")) {
 356                 add_url(remote, xstrdup(value));
 357         } else if (!strcmp(subkey, ".push")) {
 358                 add_push_refspec(remote, xstrdup(value));
 359         } else if (!strcmp(subkey, ".fetch")) {
 360                 add_fetch_refspec(remote, xstrdup(value));
 361         } else if (!strcmp(subkey, ".receivepack")) {
 362                 if (!remote->receivepack)
 363                         remote->receivepack = xstrdup(value);
 364                 else
 365                         error("more than one receivepack given, using the first");
 366         } else if (!strcmp(subkey, ".uploadpack")) {
 367                 if (!remote->uploadpack)
 368                         remote->uploadpack = xstrdup(value);
 369                 else
 370                         error("more than one uploadpack given, using the first");
 371         } else if (!strcmp(subkey, ".tagopt")) {
 372                 if (!strcmp(value, "--no-tags"))
 373                         remote->fetch_tags = -1;
 374         } else if (!strcmp(subkey, ".proxy")) {
 375                 remote->http_proxy = xstrdup(value);
 376         } else if (!strcmp(subkey, ".skipdefaultupdate"))
 377                 remote->skip_default_update = 1;
 378         return 0;
 379 }
 380
 381 static void alias_all_urls(void)
 382 {
 383         int i, j;
 384         for (i = 0; i < remotes_nr; i++) {
 385                 if (!remotes[i])
 386                         continue;
 387                 for (j = 0; j < remotes[i]->url_nr; j++) {
 388                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 389                 }
 390         }
 391 }
 392
 393 static void read_config(void)
 394 {
 395         unsigned char sha1[20];
 396         const char *head_ref;
 397         int flag;
 398         if (default_remote_name) // did this already
 399                 return;
 400         default_remote_name = xstrdup("origin");
 401         current_branch = NULL;
 402         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 403         if (head_ref && (flag & REF_ISSYMREF) &&
 404             !prefixcmp(head_ref, "refs/heads/")) {
 405                 current_branch =
 406                         make_branch(head_ref + strlen("refs/heads/"), 0);
 407         }
 408         git_config(handle_config);
 409         alias_all_urls();
 410 }
 411
 412 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch)
 413 {
 414         int i;
 415         int st;
 416         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 417
 418         for (i = 0; i < nr_refspec; i++) {
 419                 size_t llen, rlen;
 420                 int is_glob;
 421                 const char *lhs, *rhs;
 422
 423                 llen = rlen = is_glob = 0;
 424
 425                 lhs = refspec[i];
 426                 if (*lhs == '+') {
 427                         rs[i].force = 1;
 428                         lhs++;
 429                 }
 430
 431                 rhs = strrchr(lhs, ':');
 432                 if (rhs) {
 433                         rhs++;
 434                         rlen = strlen(rhs);
 435                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
 436                         if (is_glob)
 437                                 rlen -= 2;
 438                         rs[i].dst = xstrndup(rhs, rlen);
 439                 }
 440
 441                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 442                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
 443                         if ((rhs && !is_glob) || (!rhs && fetch))
 444                                 goto invalid;
 445                         is_glob = 1;
 446                         llen -= 2;
 447                 } else if (rhs && is_glob) {
 448                         goto invalid;
 449                 }
 450
 451                 rs[i].pattern = is_glob;
 452                 rs[i].src = xstrndup(lhs, llen);
 453
 454                 if (fetch) {
 455                         /*
 456                          * LHS
 457                          * - empty is allowed; it means HEAD.
 458                          * - otherwise it must be a valid looking ref.
 459                          */
 460                         if (!*rs[i].src)
 461                                 ; /* empty is ok */
 462                         else {
 463                                 st = check_ref_format(rs[i].src);
 464                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 465                                         goto invalid;
 466                         }
 467                         /*
 468                          * RHS
 469                          * - missing is ok, and is same as empty.
 470                          * - empty is ok; it means not to store.
 471                          * - otherwise it must be a valid looking ref.
 472                          */
 473                         if (!rs[i].dst) {
 474                                 ; /* ok */
 475                         } else if (!*rs[i].dst) {
 476                                 ; /* ok */
 477                         } else {
 478                                 st = check_ref_format(rs[i].dst);
 479                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 480                                         goto invalid;
 481                         }
 482                 } else {
 483                         /*
 484                          * LHS
 485                          * - empty is allowed; it means delete.
 486                          * - when wildcarded, it must be a valid looking ref.
 487                          * - otherwise, it must be an extended SHA-1, but
 488                          *   there is no existing way to validate this.
 489                          */
 490                         if (!*rs[i].src)
 491                                 ; /* empty is ok */
 492                         else if (is_glob) {
 493                                 st = check_ref_format(rs[i].src);
 494                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 495                                         goto invalid;
 496                         }
 497                         else
 498                                 ; /* anything goes, for now */
 499                         /*
 500                          * RHS
 501                          * - missing is allowed, but LHS then must be a
 502                          *   valid looking ref.
 503                          * - empty is not allowed.
 504                          * - otherwise it must be a valid looking ref.
 505                          */
 506                         if (!rs[i].dst) {
 507                                 st = check_ref_format(rs[i].src);
 508                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 509                                         goto invalid;
 510                         } else if (!*rs[i].dst) {
 511                                 goto invalid;
 512                         } else {
 513                                 st = check_ref_format(rs[i].dst);
 514                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 515                                         goto invalid;
 516                         }
 517                 }
 518         }
 519         return rs;
 520
 521  invalid:
 522         die("Invalid refspec '%s'", refspec[i]);
 523 }
 524
 525 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 526 {
 527         return parse_refspec_internal(nr_refspec, refspec, 1);
 528 }
 529
 530 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 531 {
 532         return parse_refspec_internal(nr_refspec, refspec, 0);
 533 }
 534
 535 static int valid_remote_nick(const char *name)
 536 {
 537         if (!name[0] || /* not empty */
 538             (name[0] == '.' && /* not "." */
 539              (!name[1] || /* not ".." */
 540               (name[1] == '.' && !name[2]))))
 541                 return 0;
 542         return !strchr(name, '/'); /* no slash */
 543 }
 544
 545 struct remote *remote_get(const char *name)
 546 {
 547         struct remote *ret;
 548
 549         read_config();
 550         if (!name)
 551                 name = default_remote_name;
 552         ret = make_remote(name, 0);
 553         if (valid_remote_nick(name)) {
 554                 if (!ret->url)
 555                         read_remotes_file(ret);
 556                 if (!ret->url)
 557                         read_branches_file(ret);
 558         }
 559         if (!ret->url)
 560                 add_url_alias(ret, name);
 561         if (!ret->url)
 562                 return NULL;
 563         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 564         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 565         return ret;
 566 }
 567
 568 int for_each_remote(each_remote_fn fn, void *priv)
 569 {
 570         int i, result = 0;
 571         read_config();
 572         for (i = 0; i < remotes_nr && !result; i++) {
 573                 struct remote *r = remotes[i];
 574                 if (!r)
 575                         continue;
 576                 if (!r->fetch)
 577                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 578                                                        r->fetch_refspec);
 579                 if (!r->push)
 580                         r->push = parse_push_refspec(r->push_refspec_nr,
 581                                                      r->push_refspec);
 582                 result = fn(r, priv);
 583         }
 584         return result;
 585 }
 586
 587 void ref_remove_duplicates(struct ref *ref_map)
 588 {
 589         struct ref **posn;
 590         struct ref *next;
 591         for (; ref_map; ref_map = ref_map->next) {
 592                 if (!ref_map->peer_ref)
 593                         continue;
 594                 posn = &ref_map->next;
 595                 while (*posn) {
 596                         if ((*posn)->peer_ref &&
 597                             !strcmp((*posn)->peer_ref->name,
 598                                     ref_map->peer_ref->name)) {
 599                                 if (strcmp((*posn)->name, ref_map->name))
 600                                         die("%s tracks both %s and %s",
 601                                             ref_map->peer_ref->name,
 602                                             (*posn)->name, ref_map->name);
 603                                 next = (*posn)->next;
 604                                 free((*posn)->peer_ref);
 605                                 free(*posn);
 606                                 *posn = next;
 607                         } else {
 608                                 posn = &(*posn)->next;
 609                         }
 610                 }
 611         }
 612 }
 613
 614 int remote_has_url(struct remote *remote, const char *url)
 615 {
 616         int i;
 617         for (i = 0; i < remote->url_nr; i++) {
 618                 if (!strcmp(remote->url[i], url))
 619                         return 1;
 620         }
 621         return 0;
 622 }
 623
 624 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 625 {
 626         int find_src = refspec->src == NULL;
 627         char *needle, **result;
 628         int i;
 629
 630         if (find_src) {
 631                 if (!refspec->dst)
 632                         return error("find_tracking: need either src or dst");
 633                 needle = refspec->dst;
 634                 result = &refspec->src;
 635         } else {
 636                 needle = refspec->src;
 637                 result = &refspec->dst;
 638         }
 639
 640         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 641                 struct refspec *fetch = &remote->fetch[i];
 642                 const char *key = find_src ? fetch->dst : fetch->src;
 643                 const char *value = find_src ? fetch->src : fetch->dst;
 644                 if (!fetch->dst)
 645                         continue;
 646                 if (fetch->pattern) {
 647                         if (!prefixcmp(needle, key) &&
 648                             needle[strlen(key)] == '/') {
 649                                 *result = xmalloc(strlen(value) +
 650                                                   strlen(needle) -
 651                                                   strlen(key) + 1);
 652                                 strcpy(*result, value);
 653                                 strcpy(*result + strlen(value),
 654                                        needle + strlen(key));
 655                                 refspec->force = fetch->force;
 656                                 return 0;
 657                         }
 658                 } else if (!strcmp(needle, key)) {
 659                         *result = xstrdup(value);
 660                         refspec->force = fetch->force;
 661                         return 0;
 662                 }
 663         }
 664         return -1;
 665 }
 666
 667 struct ref *alloc_ref(unsigned namelen)
 668 {
 669         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 670         memset(ret, 0, sizeof(struct ref) + namelen);
 671         return ret;
 672 }
 673
 674 static struct ref *copy_ref(const struct ref *ref)
 675 {
 676         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 677         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 678         ret->next = NULL;
 679         return ret;
 680 }
 681
 682 struct ref *copy_ref_list(const struct ref *ref)
 683 {
 684         struct ref *ret = NULL;
 685         struct ref **tail = &ret;
 686         while (ref) {
 687                 *tail = copy_ref(ref);
 688                 ref = ref->next;
 689                 tail = &((*tail)->next);
 690         }
 691         return ret;
 692 }
 693
 694 void free_refs(struct ref *ref)
 695 {
 696         struct ref *next;
 697         while (ref) {
 698                 next = ref->next;
 699                 free(ref->peer_ref);
 700                 free(ref);
 701                 ref = next;
 702         }
 703 }
 704
 705 static int count_refspec_match(const char *pattern,
 706                                struct ref *refs,
 707                                struct ref **matched_ref)
 708 {
 709         int patlen = strlen(pattern);
 710         struct ref *matched_weak = NULL;
 711         struct ref *matched = NULL;
 712         int weak_match = 0;
 713         int match = 0;
 714
 715         for (weak_match = match = 0; refs; refs = refs->next) {
 716                 char *name = refs->name;
 717                 int namelen = strlen(name);
 718
 719                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 720                         continue;
 721
 722                 /* A match is "weak" if it is with refs outside
 723                  * heads or tags, and did not specify the pattern
 724                  * in full (e.g. "refs/remotes/origin/master") or at
 725                  * least from the toplevel (e.g. "remotes/origin/master");
 726                  * otherwise "git push $URL master" would result in
 727                  * ambiguity between remotes/origin/master and heads/master
 728                  * at the remote site.
 729                  */
 730                 if (namelen != patlen &&
 731                     patlen != namelen - 5 &&
 732                     prefixcmp(name, "refs/heads/") &&
 733                     prefixcmp(name, "refs/tags/")) {
 734                         /* We want to catch the case where only weak
 735                          * matches are found and there are multiple
 736                          * matches, and where more than one strong
 737                          * matches are found, as ambiguous.  One
 738                          * strong match with zero or more weak matches
 739                          * are acceptable as a unique match.
 740                          */
 741                         matched_weak = refs;
 742                         weak_match++;
 743                 }
 744                 else {
 745                         matched = refs;
 746                         match++;
 747                 }
 748         }
 749         if (!matched) {
 750                 *matched_ref = matched_weak;
 751                 return weak_match;
 752         }
 753         else {
 754                 *matched_ref = matched;
 755                 return match;
 756         }
 757 }
 758
 759 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 760 {
 761         **tail = ref;
 762         while (ref->next)
 763                 ref = ref->next;
 764         *tail = &ref->next;
 765 }
 766
 767 static struct ref *try_explicit_object_name(const char *name)
 768 {
 769         unsigned char sha1[20];
 770         struct ref *ref;
 771         int len;
 772
 773         if (!*name) {
 774                 ref = alloc_ref(20);
 775                 strcpy(ref->name, "(delete)");
 776                 hashclr(ref->new_sha1);
 777                 return ref;
 778         }
 779         if (get_sha1(name, sha1))
 780                 return NULL;
 781         len = strlen(name) + 1;
 782         ref = alloc_ref(len);
 783         memcpy(ref->name, name, len);
 784         hashcpy(ref->new_sha1, sha1);
 785         return ref;
 786 }
 787
 788 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 789 {
 790         struct ref *ret;
 791         size_t len;
 792
 793         len = strlen(name) + 1;
 794         ret = alloc_ref(len);
 795         memcpy(ret->name, name, len);
 796         tail_link_ref(ret, tail);
 797         return ret;
 798 }
 799
 800 static int match_explicit(struct ref *src, struct ref *dst,
 801                           struct ref ***dst_tail,
 802                           struct refspec *rs,
 803                           int errs)
 804 {
 805         struct ref *matched_src, *matched_dst;
 806
 807         const char *dst_value = rs->dst;
 808
 809         if (rs->pattern)
 810                 return errs;
 811
 812         matched_src = matched_dst = NULL;
 813         switch (count_refspec_match(rs->src, src, &matched_src)) {
 814         case 1:
 815                 break;
 816         case 0:
 817                 /* The source could be in the get_sha1() format
 818                  * not a reference name.  :refs/other is a
 819                  * way to delete 'other' ref at the remote end.
 820                  */
 821                 matched_src = try_explicit_object_name(rs->src);
 822                 if (!matched_src)
 823                         error("src refspec %s does not match any.", rs->src);
 824                 break;
 825         default:
 826                 matched_src = NULL;
 827                 error("src refspec %s matches more than one.", rs->src);
 828                 break;
 829         }
 830
 831         if (!matched_src)
 832                 errs = 1;
 833
 834         if (!dst_value) {
 835                 unsigned char sha1[20];
 836                 int flag;
 837
 838                 if (!matched_src)
 839                         return errs;
 840                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 841                 if (!dst_value ||
 842                     ((flag & REF_ISSYMREF) &&
 843                      prefixcmp(dst_value, "refs/heads/")))
 844                         die("%s cannot be resolved to branch.",
 845                             matched_src->name);
 846         }
 847
 848         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 849         case 1:
 850                 break;
 851         case 0:
 852                 if (!memcmp(dst_value, "refs/", 5))
 853                         matched_dst = make_linked_ref(dst_value, dst_tail);
 854                 else
 855                         error("dst refspec %s does not match any "
 856                               "existing ref on the remote and does "
 857                               "not start with refs/.", dst_value);
 858                 break;
 859         default:
 860                 matched_dst = NULL;
 861                 error("dst refspec %s matches more than one.",
 862                       dst_value);
 863                 break;
 864         }
 865         if (errs || !matched_dst)
 866                 return 1;
 867         if (matched_dst->peer_ref) {
 868                 errs = 1;
 869                 error("dst ref %s receives from more than one src.",
 870                       matched_dst->name);
 871         }
 872         else {
 873                 matched_dst->peer_ref = matched_src;
 874                 matched_dst->force = rs->force;
 875         }
 876         return errs;
 877 }
 878
 879 static int match_explicit_refs(struct ref *src, struct ref *dst,
 880                                struct ref ***dst_tail, struct refspec *rs,
 881                                int rs_nr)
 882 {
 883         int i, errs;
 884         for (i = errs = 0; i < rs_nr; i++)
 885                 errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
 886         return -errs;
 887 }
 888
 889 static const struct refspec *check_pattern_match(const struct refspec *rs,
 890                                                  int rs_nr,
 891                                                  const struct ref *src)
 892 {
 893         int i;
 894         for (i = 0; i < rs_nr; i++) {
 895                 if (rs[i].pattern &&
 896                     !prefixcmp(src->name, rs[i].src) &&
 897                     src->name[strlen(rs[i].src)] == '/')
 898                         return rs + i;
 899         }
 900         return NULL;
 901 }
 902
 903 /*
 904  * Note. This is used only by "push"; refspec matching rules for
 905  * push and fetch are subtly different, so do not try to reuse it
 906  * without thinking.
 907  */
 908 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 909                int nr_refspec, const char **refspec, int flags)
 910 {
 911         struct refspec *rs =
 912                 parse_push_refspec(nr_refspec, (const char **) refspec);
 913         int send_all = flags & MATCH_REFS_ALL;
 914         int send_mirror = flags & MATCH_REFS_MIRROR;
 915
 916         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
 917                 return -1;
 918
 919         /* pick the remainder */
 920         for ( ; src; src = src->next) {
 921                 struct ref *dst_peer;
 922                 const struct refspec *pat = NULL;
 923                 char *dst_name;
 924                 if (src->peer_ref)
 925                         continue;
 926                 if (nr_refspec) {
 927                         pat = check_pattern_match(rs, nr_refspec, src);
 928                         if (!pat)
 929                                 continue;
 930                 }
 931                 else if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
 932                         /*
 933                          * "matching refs"; traditionally we pushed everything
 934                          * including refs outside refs/heads/ hierarchy, but
 935                          * that does not make much sense these days.
 936                          */
 937                         continue;
 938
 939                 if (pat) {
 940                         const char *dst_side = pat->dst ? pat->dst : pat->src;
 941                         dst_name = xmalloc(strlen(dst_side) +
 942                                            strlen(src->name) -
 943                                            strlen(pat->src) + 2);
 944                         strcpy(dst_name, dst_side);
 945                         strcat(dst_name, src->name + strlen(pat->src));
 946                 } else
 947                         dst_name = xstrdup(src->name);
 948                 dst_peer = find_ref_by_name(dst, dst_name);
 949                 if (dst_peer && dst_peer->peer_ref)
 950                         /* We're already sending something to this ref. */
 951                         goto free_name;
 952
 953                 if (!dst_peer && !nr_refspec && !(send_all || send_mirror))
 954                         /*
 955                          * Remote doesn't have it, and we have no
 956                          * explicit pattern, and we don't have
 957                          * --all nor --mirror.
 958                          */
 959                         goto free_name;
 960                 if (!dst_peer) {
 961                         /* Create a new one and link it */
 962                         dst_peer = make_linked_ref(dst_name, dst_tail);
 963                         hashcpy(dst_peer->new_sha1, src->new_sha1);
 964                 }
 965                 dst_peer->peer_ref = src;
 966                 if (pat)
 967                         dst_peer->force = pat->force;
 968         free_name:
 969                 free(dst_name);
 970         }
 971         return 0;
 972 }
 973
 974 struct branch *branch_get(const char *name)
 975 {
 976         struct branch *ret;
 977
 978         read_config();
 979         if (!name || !*name || !strcmp(name, "HEAD"))
 980                 ret = current_branch;
 981         else
 982                 ret = make_branch(name, 0);
 983         if (ret && ret->remote_name) {
 984                 ret->remote = remote_get(ret->remote_name);
 985                 if (ret->merge_nr) {
 986                         int i;
 987                         ret->merge = xcalloc(sizeof(*ret->merge),
 988                                              ret->merge_nr);
 989                         for (i = 0; i < ret->merge_nr; i++) {
 990                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
 991                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
 992                                 remote_find_tracking(ret->remote,
 993                                                      ret->merge[i]);
 994                         }
 995                 }
 996         }
 997         return ret;
 998 }
 999
1000 int branch_has_merge_config(struct branch *branch)
1001 {
1002         return branch && !!branch->merge;
1003 }
1004
1005 int branch_merge_matches(struct branch *branch,
1006                                  int i,
1007                                  const char *refname)
1008 {
1009         if (!branch || i < 0 || i >= branch->merge_nr)
1010                 return 0;
1011         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1012 }
1013
1014 static struct ref *get_expanded_map(const struct ref *remote_refs,
1015                                     const struct refspec *refspec)
1016 {
1017         const struct ref *ref;
1018         struct ref *ret = NULL;
1019         struct ref **tail = &ret;
1020
1021         int remote_prefix_len = strlen(refspec->src);
1022         int local_prefix_len = strlen(refspec->dst);
1023
1024         for (ref = remote_refs; ref; ref = ref->next) {
1025                 if (strchr(ref->name, '^'))
1026                         continue; /* a dereference item */
1027                 if (!prefixcmp(ref->name, refspec->src)) {
1028                         const char *match;
1029                         struct ref *cpy = copy_ref(ref);
1030                         match = ref->name + remote_prefix_len;
1031
1032                         cpy->peer_ref = alloc_ref(local_prefix_len +
1033                                                   strlen(match) + 1);
1034                         sprintf(cpy->peer_ref->name, "%s%s",
1035                                 refspec->dst, match);
1036                         if (refspec->force)
1037                                 cpy->peer_ref->force = 1;
1038                         *tail = cpy;
1039                         tail = &cpy->next;
1040                 }
1041         }
1042
1043         return ret;
1044 }
1045
1046 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1047 {
1048         const struct ref *ref;
1049         for (ref = refs; ref; ref = ref->next) {
1050                 if (refname_match(name, ref->name, ref_fetch_rules))
1051                         return ref;
1052         }
1053         return NULL;
1054 }
1055
1056 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1057 {
1058         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1059
1060         if (!ref)
1061                 return NULL;
1062
1063         return copy_ref(ref);
1064 }
1065
1066 static struct ref *get_local_ref(const char *name)
1067 {
1068         struct ref *ret;
1069         if (!name)
1070                 return NULL;
1071
1072         if (!prefixcmp(name, "refs/")) {
1073                 ret = alloc_ref(strlen(name) + 1);
1074                 strcpy(ret->name, name);
1075                 return ret;
1076         }
1077
1078         if (!prefixcmp(name, "heads/") ||
1079             !prefixcmp(name, "tags/") ||
1080             !prefixcmp(name, "remotes/")) {
1081                 ret = alloc_ref(strlen(name) + 6);
1082                 sprintf(ret->name, "refs/%s", name);
1083                 return ret;
1084         }
1085
1086         ret = alloc_ref(strlen(name) + 12);
1087         sprintf(ret->name, "refs/heads/%s", name);
1088         return ret;
1089 }
1090
1091 int get_fetch_map(const struct ref *remote_refs,
1092                   const struct refspec *refspec,
1093                   struct ref ***tail,
1094                   int missing_ok)
1095 {
1096         struct ref *ref_map, **rmp;
1097
1098         if (refspec->pattern) {
1099                 ref_map = get_expanded_map(remote_refs, refspec);
1100         } else {
1101                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1102
1103                 ref_map = get_remote_ref(remote_refs, name);
1104                 if (!missing_ok && !ref_map)
1105                         die("Couldn't find remote ref %s", name);
1106                 if (ref_map) {
1107                         ref_map->peer_ref = get_local_ref(refspec->dst);
1108                         if (ref_map->peer_ref && refspec->force)
1109                                 ref_map->peer_ref->force = 1;
1110                 }
1111         }
1112
1113         for (rmp = &ref_map; *rmp; ) {
1114                 if ((*rmp)->peer_ref) {
1115                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1116                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1117                                 struct ref *ignore = *rmp;
1118                                 error("* Ignoring funny ref '%s' locally",
1119                                       (*rmp)->peer_ref->name);
1120                                 *rmp = (*rmp)->next;
1121                                 free(ignore->peer_ref);
1122                                 free(ignore);
1123                                 continue;
1124                         }
1125                 }
1126                 rmp = &((*rmp)->next);
1127         }
1128
1129         if (ref_map)
1130                 tail_link_ref(ref_map, tail);
1131
1132         return 0;
1133 }