remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4
   5 static struct refspec s_tag_refspec = {
   6         0,
   7         1,
   8         0,
   9         "refs/tags/",
  10         "refs/tags/"
  11 };
  12
  13 const struct refspec *tag_refspec = &s_tag_refspec;
  14
  15 struct counted_string {
  16         size_t len;
  17         const char *s;
  18 };
  19 struct rewrite {
  20         const char *base;
  21         size_t baselen;
  22         struct counted_string *instead_of;
  23         int instead_of_nr;
  24         int instead_of_alloc;
  25 };
  26
  27 static struct remote **remotes;
  28 static int remotes_alloc;
  29 static int remotes_nr;
  30
  31 static struct branch **branches;
  32 static int branches_alloc;
  33 static int branches_nr;
  34
  35 static struct branch *current_branch;
  36 static const char *default_remote_name;
  37
  38 static struct rewrite **rewrite;
  39 static int rewrite_alloc;
  40 static int rewrite_nr;
  41
  42 #define BUF_SIZE (2048)
  43 static char buffer[BUF_SIZE];
  44
  45 static const char *alias_url(const char *url)
  46 {
  47         int i, j;
  48         char *ret;
  49         struct counted_string *longest;
  50         int longest_i;
  51
  52         longest = NULL;
  53         longest_i = -1;
  54         for (i = 0; i < rewrite_nr; i++) {
  55                 if (!rewrite[i])
  56                         continue;
  57                 for (j = 0; j < rewrite[i]->instead_of_nr; j++) {
  58                         if (!prefixcmp(url, rewrite[i]->instead_of[j].s) &&
  59                             (!longest ||
  60                              longest->len < rewrite[i]->instead_of[j].len)) {
  61                                 longest = &(rewrite[i]->instead_of[j]);
  62                                 longest_i = i;
  63                         }
  64                 }
  65         }
  66         if (!longest)
  67                 return url;
  68
  69         ret = malloc(rewrite[longest_i]->baselen +
  70                      (strlen(url) - longest->len) + 1);
  71         strcpy(ret, rewrite[longest_i]->base);
  72         strcpy(ret + rewrite[longest_i]->baselen, url + longest->len);
  73         return ret;
  74 }
  75
  76 static void add_push_refspec(struct remote *remote, const char *ref)
  77 {
  78         ALLOC_GROW(remote->push_refspec,
  79                    remote->push_refspec_nr + 1,
  80                    remote->push_refspec_alloc);
  81         remote->push_refspec[remote->push_refspec_nr++] = ref;
  82 }
  83
  84 static void add_fetch_refspec(struct remote *remote, const char *ref)
  85 {
  86         ALLOC_GROW(remote->fetch_refspec,
  87                    remote->fetch_refspec_nr + 1,
  88                    remote->fetch_refspec_alloc);
  89         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
  90 }
  91
  92 static void add_url(struct remote *remote, const char *url)
  93 {
  94         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
  95         remote->url[remote->url_nr++] = url;
  96 }
  97
  98 static void add_url_alias(struct remote *remote, const char *url)
  99 {
 100         add_url(remote, alias_url(url));
 101 }
 102
 103 static struct remote *make_remote(const char *name, int len)
 104 {
 105         struct remote *ret;
 106         int i;
 107
 108         for (i = 0; i < remotes_nr; i++) {
 109                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 110                            !remotes[i]->name[len]) :
 111                     !strcmp(name, remotes[i]->name))
 112                         return remotes[i];
 113         }
 114
 115         ret = xcalloc(1, sizeof(struct remote));
 116         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 117         remotes[remotes_nr++] = ret;
 118         if (len)
 119                 ret->name = xstrndup(name, len);
 120         else
 121                 ret->name = xstrdup(name);
 122         return ret;
 123 }
 124
 125 static void add_merge(struct branch *branch, const char *name)
 126 {
 127         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 128                    branch->merge_alloc);
 129         branch->merge_name[branch->merge_nr++] = name;
 130 }
 131
 132 static struct branch *make_branch(const char *name, int len)
 133 {
 134         struct branch *ret;
 135         int i;
 136         char *refname;
 137
 138         for (i = 0; i < branches_nr; i++) {
 139                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 140                            !branches[i]->name[len]) :
 141                     !strcmp(name, branches[i]->name))
 142                         return branches[i];
 143         }
 144
 145         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 146         ret = xcalloc(1, sizeof(struct branch));
 147         branches[branches_nr++] = ret;
 148         if (len)
 149                 ret->name = xstrndup(name, len);
 150         else
 151                 ret->name = xstrdup(name);
 152         refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
 153         strcpy(refname, "refs/heads/");
 154         strcpy(refname + strlen("refs/heads/"), ret->name);
 155         ret->refname = refname;
 156
 157         return ret;
 158 }
 159
 160 static struct rewrite *make_rewrite(const char *base, int len)
 161 {
 162         struct rewrite *ret;
 163         int i;
 164
 165         for (i = 0; i < rewrite_nr; i++) {
 166                 if (len
 167                     ? (len == rewrite[i]->baselen &&
 168                        !strncmp(base, rewrite[i]->base, len))
 169                     : !strcmp(base, rewrite[i]->base))
 170                         return rewrite[i];
 171         }
 172
 173         ALLOC_GROW(rewrite, rewrite_nr + 1, rewrite_alloc);
 174         ret = xcalloc(1, sizeof(struct rewrite));
 175         rewrite[rewrite_nr++] = ret;
 176         if (len) {
 177                 ret->base = xstrndup(base, len);
 178                 ret->baselen = len;
 179         }
 180         else {
 181                 ret->base = xstrdup(base);
 182                 ret->baselen = strlen(base);
 183         }
 184         return ret;
 185 }
 186
 187 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 188 {
 189         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 190         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 191         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 192         rewrite->instead_of_nr++;
 193 }
 194
 195 static void read_remotes_file(struct remote *remote)
 196 {
 197         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 198
 199         if (!f)
 200                 return;
 201         while (fgets(buffer, BUF_SIZE, f)) {
 202                 int value_list;
 203                 char *s, *p;
 204
 205                 if (!prefixcmp(buffer, "URL:")) {
 206                         value_list = 0;
 207                         s = buffer + 4;
 208                 } else if (!prefixcmp(buffer, "Push:")) {
 209                         value_list = 1;
 210                         s = buffer + 5;
 211                 } else if (!prefixcmp(buffer, "Pull:")) {
 212                         value_list = 2;
 213                         s = buffer + 5;
 214                 } else
 215                         continue;
 216
 217                 while (isspace(*s))
 218                         s++;
 219                 if (!*s)
 220                         continue;
 221
 222                 p = s + strlen(s);
 223                 while (isspace(p[-1]))
 224                         *--p = 0;
 225
 226                 switch (value_list) {
 227                 case 0:
 228                         add_url_alias(remote, xstrdup(s));
 229                         break;
 230                 case 1:
 231                         add_push_refspec(remote, xstrdup(s));
 232                         break;
 233                 case 2:
 234                         add_fetch_refspec(remote, xstrdup(s));
 235                         break;
 236                 }
 237         }
 238         fclose(f);
 239 }
 240
 241 static void read_branches_file(struct remote *remote)
 242 {
 243         const char *slash = strchr(remote->name, '/');
 244         char *frag;
 245         struct strbuf branch;
 246         int n = slash ? slash - remote->name : 1000;
 247         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 248         char *s, *p;
 249         int len;
 250
 251         if (!f)
 252                 return;
 253         s = fgets(buffer, BUF_SIZE, f);
 254         fclose(f);
 255         if (!s)
 256                 return;
 257         while (isspace(*s))
 258                 s++;
 259         if (!*s)
 260                 return;
 261         p = s + strlen(s);
 262         while (isspace(p[-1]))
 263                 *--p = 0;
 264         len = p - s;
 265         if (slash)
 266                 len += strlen(slash);
 267         p = xmalloc(len + 1);
 268         strcpy(p, s);
 269         if (slash)
 270                 strcat(p, slash);
 271
 272         /*
 273          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 274          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 275          * the partial URL obtained from the branches file plus
 276          * "/netdev-2.6" and does not store it in any tracking ref.
 277          * #branch specifier in the file is ignored.
 278          *
 279          * Otherwise, the branches file would have URL and optionally
 280          * #branch specified.  The "master" (or specified) branch is
 281          * fetched and stored in the local branch of the same name.
 282          */
 283         strbuf_init(&branch, 0);
 284         frag = strchr(p, '#');
 285         if (frag) {
 286                 *(frag++) = '\0';
 287                 strbuf_addf(&branch, "refs/heads/%s", frag);
 288         } else
 289                 strbuf_addstr(&branch, "refs/heads/master");
 290         if (!slash) {
 291                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 292         } else {
 293                 strbuf_reset(&branch);
 294                 strbuf_addstr(&branch, "HEAD:");
 295         }
 296         add_url_alias(remote, p);
 297         add_fetch_refspec(remote, strbuf_detach(&branch, 0));
 298         remote->fetch_tags = 1; /* always auto-follow */
 299 }
 300
 301 static int handle_config(const char *key, const char *value)
 302 {
 303         const char *name;
 304         const char *subkey;
 305         struct remote *remote;
 306         struct branch *branch;
 307         if (!prefixcmp(key, "branch.")) {
 308                 name = key + 7;
 309                 subkey = strrchr(name, '.');
 310                 if (!subkey)
 311                         return 0;
 312                 branch = make_branch(name, subkey - name);
 313                 if (!strcmp(subkey, ".remote")) {
 314                         if (!value)
 315                                 return config_error_nonbool(key);
 316                         branch->remote_name = xstrdup(value);
 317                         if (branch == current_branch)
 318                                 default_remote_name = branch->remote_name;
 319                 } else if (!strcmp(subkey, ".merge")) {
 320                         if (!value)
 321                                 return config_error_nonbool(key);
 322                         add_merge(branch, xstrdup(value));
 323                 }
 324                 return 0;
 325         }
 326         if (!prefixcmp(key, "url.")) {
 327                 struct rewrite *rewrite;
 328                 name = key + 4;
 329                 subkey = strrchr(name, '.');
 330                 if (!subkey)
 331                         return 0;
 332                 rewrite = make_rewrite(name, subkey - name);
 333                 if (!strcmp(subkey, ".insteadof")) {
 334                         if (!value)
 335                                 return config_error_nonbool(key);
 336                         add_instead_of(rewrite, xstrdup(value));
 337                 }
 338         }
 339         if (prefixcmp(key,  "remote."))
 340                 return 0;
 341         name = key + 7;
 342         subkey = strrchr(name, '.');
 343         if (!subkey)
 344                 return error("Config with no key for remote %s", name);
 345         if (*subkey == '/') {
 346                 warning("Config remote shorthand cannot begin with '/': %s", name);
 347                 return 0;
 348         }
 349         remote = make_remote(name, subkey - name);
 350         if (!strcmp(subkey, ".mirror"))
 351                 remote->mirror = git_config_bool(key, value);
 352         else if (!strcmp(subkey, ".skipdefaultupdate"))
 353                 remote->skip_default_update = git_config_bool(key, value);
 354
 355         else if (!strcmp(subkey, ".url")) {
 356                 const char *v;
 357                 if (git_config_string(&v, key, value))
 358                         return -1;
 359                 add_url(remote, v);
 360         } else if (!strcmp(subkey, ".push")) {
 361                 const char *v;
 362                 if (git_config_string(&v, key, value))
 363                         return -1;
 364                 add_push_refspec(remote, v);
 365         } else if (!strcmp(subkey, ".fetch")) {
 366                 const char *v;
 367                 if (git_config_string(&v, key, value))
 368                         return -1;
 369                 add_fetch_refspec(remote, v);
 370         } else if (!strcmp(subkey, ".receivepack")) {
 371                 const char *v;
 372                 if (git_config_string(&v, key, value))
 373                         return -1;
 374                 if (!remote->receivepack)
 375                         remote->receivepack = v;
 376                 else
 377                         error("more than one receivepack given, using the first");
 378         } else if (!strcmp(subkey, ".uploadpack")) {
 379                 const char *v;
 380                 if (git_config_string(&v, key, value))
 381                         return -1;
 382                 if (!remote->uploadpack)
 383                         remote->uploadpack = v;
 384                 else
 385                         error("more than one uploadpack given, using the first");
 386         } else if (!strcmp(subkey, ".tagopt")) {
 387                 if (!strcmp(value, "--no-tags"))
 388                         remote->fetch_tags = -1;
 389         } else if (!strcmp(subkey, ".proxy")) {
 390                 return git_config_string((const char **)&remote->http_proxy,
 391                                          key, value);
 392         }
 393         return 0;
 394 }
 395
 396 static void alias_all_urls(void)
 397 {
 398         int i, j;
 399         for (i = 0; i < remotes_nr; i++) {
 400                 if (!remotes[i])
 401                         continue;
 402                 for (j = 0; j < remotes[i]->url_nr; j++) {
 403                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 404                 }
 405         }
 406 }
 407
 408 static void read_config(void)
 409 {
 410         unsigned char sha1[20];
 411         const char *head_ref;
 412         int flag;
 413         if (default_remote_name) // did this already
 414                 return;
 415         default_remote_name = xstrdup("origin");
 416         current_branch = NULL;
 417         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 418         if (head_ref && (flag & REF_ISSYMREF) &&
 419             !prefixcmp(head_ref, "refs/heads/")) {
 420                 current_branch =
 421                         make_branch(head_ref + strlen("refs/heads/"), 0);
 422         }
 423         git_config(handle_config);
 424         alias_all_urls();
 425 }
 426
 427 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 428 {
 429         int i;
 430         int st;
 431         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 432
 433         for (i = 0; i < nr_refspec; i++) {
 434                 size_t llen, rlen;
 435                 int is_glob;
 436                 const char *lhs, *rhs;
 437
 438                 llen = rlen = is_glob = 0;
 439
 440                 lhs = refspec[i];
 441                 if (*lhs == '+') {
 442                         rs[i].force = 1;
 443                         lhs++;
 444                 }
 445
 446                 rhs = strrchr(lhs, ':');
 447
 448                 /*
 449                  * Before going on, special case ":" (or "+:") as a refspec
 450                  * for matching refs.
 451                  */
 452                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 453                         rs[i].matching = 1;
 454                         continue;
 455                 }
 456
 457                 if (rhs) {
 458                         rhs++;
 459                         rlen = strlen(rhs);
 460                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
 461                         if (is_glob)
 462                                 rlen -= 2;
 463                         rs[i].dst = xstrndup(rhs, rlen);
 464                 }
 465
 466                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 467                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
 468                         if ((rhs && !is_glob) || (!rhs && fetch))
 469                                 goto invalid;
 470                         is_glob = 1;
 471                         llen -= 2;
 472                 } else if (rhs && is_glob) {
 473                         goto invalid;
 474                 }
 475
 476                 rs[i].pattern = is_glob;
 477                 rs[i].src = xstrndup(lhs, llen);
 478
 479                 if (fetch) {
 480                         /*
 481                          * LHS
 482                          * - empty is allowed; it means HEAD.
 483                          * - otherwise it must be a valid looking ref.
 484                          */
 485                         if (!*rs[i].src)
 486                                 ; /* empty is ok */
 487                         else {
 488                                 st = check_ref_format(rs[i].src);
 489                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 490                                         goto invalid;
 491                         }
 492                         /*
 493                          * RHS
 494                          * - missing is ok, and is same as empty.
 495                          * - empty is ok; it means not to store.
 496                          * - otherwise it must be a valid looking ref.
 497                          */
 498                         if (!rs[i].dst) {
 499                                 ; /* ok */
 500                         } else if (!*rs[i].dst) {
 501                                 ; /* ok */
 502                         } else {
 503                                 st = check_ref_format(rs[i].dst);
 504                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 505                                         goto invalid;
 506                         }
 507                 } else {
 508                         /*
 509                          * LHS
 510                          * - empty is allowed; it means delete.
 511                          * - when wildcarded, it must be a valid looking ref.
 512                          * - otherwise, it must be an extended SHA-1, but
 513                          *   there is no existing way to validate this.
 514                          */
 515                         if (!*rs[i].src)
 516                                 ; /* empty is ok */
 517                         else if (is_glob) {
 518                                 st = check_ref_format(rs[i].src);
 519                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 520                                         goto invalid;
 521                         }
 522                         else
 523                                 ; /* anything goes, for now */
 524                         /*
 525                          * RHS
 526                          * - missing is allowed, but LHS then must be a
 527                          *   valid looking ref.
 528                          * - empty is not allowed.
 529                          * - otherwise it must be a valid looking ref.
 530                          */
 531                         if (!rs[i].dst) {
 532                                 st = check_ref_format(rs[i].src);
 533                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 534                                         goto invalid;
 535                         } else if (!*rs[i].dst) {
 536                                 goto invalid;
 537                         } else {
 538                                 st = check_ref_format(rs[i].dst);
 539                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 540                                         goto invalid;
 541                         }
 542                 }
 543         }
 544         return rs;
 545
 546  invalid:
 547         if (verify) {
 548                 free(rs);
 549                 return NULL;
 550         }
 551         die("Invalid refspec '%s'", refspec[i]);
 552 }
 553
 554 int valid_fetch_refspec(const char *fetch_refspec_str)
 555 {
 556         const char *fetch_refspec[] = { fetch_refspec_str };
 557         struct refspec *refspec;
 558
 559         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 560         if (refspec)
 561                 free(refspec);
 562         return !!refspec;
 563 }
 564
 565 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 566 {
 567         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 568 }
 569
 570 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 571 {
 572         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 573 }
 574
 575 static int valid_remote_nick(const char *name)
 576 {
 577         if (!name[0] || /* not empty */
 578             (name[0] == '.' && /* not "." */
 579              (!name[1] || /* not ".." */
 580               (name[1] == '.' && !name[2]))))
 581                 return 0;
 582         return !strchr(name, '/'); /* no slash */
 583 }
 584
 585 struct remote *remote_get(const char *name)
 586 {
 587         struct remote *ret;
 588
 589         read_config();
 590         if (!name)
 591                 name = default_remote_name;
 592         ret = make_remote(name, 0);
 593         if (valid_remote_nick(name)) {
 594                 if (!ret->url)
 595                         read_remotes_file(ret);
 596                 if (!ret->url)
 597                         read_branches_file(ret);
 598         }
 599         if (!ret->url)
 600                 add_url_alias(ret, name);
 601         if (!ret->url)
 602                 return NULL;
 603         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 604         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 605         return ret;
 606 }
 607
 608 int for_each_remote(each_remote_fn fn, void *priv)
 609 {
 610         int i, result = 0;
 611         read_config();
 612         for (i = 0; i < remotes_nr && !result; i++) {
 613                 struct remote *r = remotes[i];
 614                 if (!r)
 615                         continue;
 616                 if (!r->fetch)
 617                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 618                                                        r->fetch_refspec);
 619                 if (!r->push)
 620                         r->push = parse_push_refspec(r->push_refspec_nr,
 621                                                      r->push_refspec);
 622                 result = fn(r, priv);
 623         }
 624         return result;
 625 }
 626
 627 void ref_remove_duplicates(struct ref *ref_map)
 628 {
 629         struct ref **posn;
 630         struct ref *next;
 631         for (; ref_map; ref_map = ref_map->next) {
 632                 if (!ref_map->peer_ref)
 633                         continue;
 634                 posn = &ref_map->next;
 635                 while (*posn) {
 636                         if ((*posn)->peer_ref &&
 637                             !strcmp((*posn)->peer_ref->name,
 638                                     ref_map->peer_ref->name)) {
 639                                 if (strcmp((*posn)->name, ref_map->name))
 640                                         die("%s tracks both %s and %s",
 641                                             ref_map->peer_ref->name,
 642                                             (*posn)->name, ref_map->name);
 643                                 next = (*posn)->next;
 644                                 free((*posn)->peer_ref);
 645                                 free(*posn);
 646                                 *posn = next;
 647                         } else {
 648                                 posn = &(*posn)->next;
 649                         }
 650                 }
 651         }
 652 }
 653
 654 int remote_has_url(struct remote *remote, const char *url)
 655 {
 656         int i;
 657         for (i = 0; i < remote->url_nr; i++) {
 658                 if (!strcmp(remote->url[i], url))
 659                         return 1;
 660         }
 661         return 0;
 662 }
 663
 664 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 665 {
 666         int find_src = refspec->src == NULL;
 667         char *needle, **result;
 668         int i;
 669
 670         if (find_src) {
 671                 if (!refspec->dst)
 672                         return error("find_tracking: need either src or dst");
 673                 needle = refspec->dst;
 674                 result = &refspec->src;
 675         } else {
 676                 needle = refspec->src;
 677                 result = &refspec->dst;
 678         }
 679
 680         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 681                 struct refspec *fetch = &remote->fetch[i];
 682                 const char *key = find_src ? fetch->dst : fetch->src;
 683                 const char *value = find_src ? fetch->src : fetch->dst;
 684                 if (!fetch->dst)
 685                         continue;
 686                 if (fetch->pattern) {
 687                         if (!prefixcmp(needle, key) &&
 688                             needle[strlen(key)] == '/') {
 689                                 *result = xmalloc(strlen(value) +
 690                                                   strlen(needle) -
 691                                                   strlen(key) + 1);
 692                                 strcpy(*result, value);
 693                                 strcpy(*result + strlen(value),
 694                                        needle + strlen(key));
 695                                 refspec->force = fetch->force;
 696                                 return 0;
 697                         }
 698                 } else if (!strcmp(needle, key)) {
 699                         *result = xstrdup(value);
 700                         refspec->force = fetch->force;
 701                         return 0;
 702                 }
 703         }
 704         return -1;
 705 }
 706
 707 struct ref *alloc_ref(unsigned namelen)
 708 {
 709         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 710         memset(ret, 0, sizeof(struct ref) + namelen);
 711         return ret;
 712 }
 713
 714 struct ref *alloc_ref_from_str(const char* str)
 715 {
 716         struct ref *ret = alloc_ref(strlen(str) + 1);
 717         strcpy(ret->name, str);
 718         return ret;
 719 }
 720
 721 static struct ref *copy_ref(const struct ref *ref)
 722 {
 723         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 724         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 725         ret->next = NULL;
 726         return ret;
 727 }
 728
 729 struct ref *copy_ref_list(const struct ref *ref)
 730 {
 731         struct ref *ret = NULL;
 732         struct ref **tail = &ret;
 733         while (ref) {
 734                 *tail = copy_ref(ref);
 735                 ref = ref->next;
 736                 tail = &((*tail)->next);
 737         }
 738         return ret;
 739 }
 740
 741 void free_ref(struct ref *ref)
 742 {
 743         if (!ref)
 744                 return;
 745         free(ref->remote_status);
 746         free(ref->symref);
 747         free(ref);
 748 }
 749
 750 void free_refs(struct ref *ref)
 751 {
 752         struct ref *next;
 753         while (ref) {
 754                 next = ref->next;
 755                 free(ref->peer_ref);
 756                 free_ref(ref);
 757                 ref = next;
 758         }
 759 }
 760
 761 static int count_refspec_match(const char *pattern,
 762                                struct ref *refs,
 763                                struct ref **matched_ref)
 764 {
 765         int patlen = strlen(pattern);
 766         struct ref *matched_weak = NULL;
 767         struct ref *matched = NULL;
 768         int weak_match = 0;
 769         int match = 0;
 770
 771         for (weak_match = match = 0; refs; refs = refs->next) {
 772                 char *name = refs->name;
 773                 int namelen = strlen(name);
 774
 775                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 776                         continue;
 777
 778                 /* A match is "weak" if it is with refs outside
 779                  * heads or tags, and did not specify the pattern
 780                  * in full (e.g. "refs/remotes/origin/master") or at
 781                  * least from the toplevel (e.g. "remotes/origin/master");
 782                  * otherwise "git push $URL master" would result in
 783                  * ambiguity between remotes/origin/master and heads/master
 784                  * at the remote site.
 785                  */
 786                 if (namelen != patlen &&
 787                     patlen != namelen - 5 &&
 788                     prefixcmp(name, "refs/heads/") &&
 789                     prefixcmp(name, "refs/tags/")) {
 790                         /* We want to catch the case where only weak
 791                          * matches are found and there are multiple
 792                          * matches, and where more than one strong
 793                          * matches are found, as ambiguous.  One
 794                          * strong match with zero or more weak matches
 795                          * are acceptable as a unique match.
 796                          */
 797                         matched_weak = refs;
 798                         weak_match++;
 799                 }
 800                 else {
 801                         matched = refs;
 802                         match++;
 803                 }
 804         }
 805         if (!matched) {
 806                 *matched_ref = matched_weak;
 807                 return weak_match;
 808         }
 809         else {
 810                 *matched_ref = matched;
 811                 return match;
 812         }
 813 }
 814
 815 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 816 {
 817         **tail = ref;
 818         while (ref->next)
 819                 ref = ref->next;
 820         *tail = &ref->next;
 821 }
 822
 823 static struct ref *try_explicit_object_name(const char *name)
 824 {
 825         unsigned char sha1[20];
 826         struct ref *ref;
 827
 828         if (!*name) {
 829                 ref = alloc_ref(20);
 830                 strcpy(ref->name, "(delete)");
 831                 hashclr(ref->new_sha1);
 832                 return ref;
 833         }
 834         if (get_sha1(name, sha1))
 835                 return NULL;
 836         ref = alloc_ref_from_str(name);
 837         hashcpy(ref->new_sha1, sha1);
 838         return ref;
 839 }
 840
 841 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 842 {
 843         struct ref *ret = alloc_ref_from_str(name);
 844         tail_link_ref(ret, tail);
 845         return ret;
 846 }
 847
 848 static char *guess_ref(const char *name, struct ref *peer)
 849 {
 850         struct strbuf buf = STRBUF_INIT;
 851         unsigned char sha1[20];
 852
 853         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
 854         if (!r)
 855                 return NULL;
 856
 857         if (!prefixcmp(r, "refs/heads/"))
 858                 strbuf_addstr(&buf, "refs/heads/");
 859         else if (!prefixcmp(r, "refs/tags/"))
 860                 strbuf_addstr(&buf, "refs/tags/");
 861         else
 862                 return NULL;
 863
 864         strbuf_addstr(&buf, name);
 865         return strbuf_detach(&buf, NULL);
 866 }
 867
 868 static int match_explicit(struct ref *src, struct ref *dst,
 869                           struct ref ***dst_tail,
 870                           struct refspec *rs,
 871                           int errs)
 872 {
 873         struct ref *matched_src, *matched_dst;
 874
 875         const char *dst_value = rs->dst;
 876         char *dst_guess;
 877
 878         if (rs->pattern || rs->matching)
 879                 return errs;
 880
 881         matched_src = matched_dst = NULL;
 882         switch (count_refspec_match(rs->src, src, &matched_src)) {
 883         case 1:
 884                 break;
 885         case 0:
 886                 /* The source could be in the get_sha1() format
 887                  * not a reference name.  :refs/other is a
 888                  * way to delete 'other' ref at the remote end.
 889                  */
 890                 matched_src = try_explicit_object_name(rs->src);
 891                 if (!matched_src)
 892                         error("src refspec %s does not match any.", rs->src);
 893                 break;
 894         default:
 895                 matched_src = NULL;
 896                 error("src refspec %s matches more than one.", rs->src);
 897                 break;
 898         }
 899
 900         if (!matched_src)
 901                 errs = 1;
 902
 903         if (!dst_value) {
 904                 unsigned char sha1[20];
 905                 int flag;
 906
 907                 if (!matched_src)
 908                         return errs;
 909                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 910                 if (!dst_value ||
 911                     ((flag & REF_ISSYMREF) &&
 912                      prefixcmp(dst_value, "refs/heads/")))
 913                         die("%s cannot be resolved to branch.",
 914                             matched_src->name);
 915         }
 916
 917         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 918         case 1:
 919                 break;
 920         case 0:
 921                 if (!memcmp(dst_value, "refs/", 5))
 922                         matched_dst = make_linked_ref(dst_value, dst_tail);
 923                 else if((dst_guess = guess_ref(dst_value, matched_src)))
 924                         matched_dst = make_linked_ref(dst_guess, dst_tail);
 925                 else
 926                         error("unable to push to unqualified destination: %s\n"
 927                               "The destination refspec neither matches an "
 928                               "existing ref on the remote nor\n"
 929                               "begins with refs/, and we are unable to "
 930                               "guess a prefix based on the source ref.",
 931                               dst_value);
 932                 break;
 933         default:
 934                 matched_dst = NULL;
 935                 error("dst refspec %s matches more than one.",
 936                       dst_value);
 937                 break;
 938         }
 939         if (errs || !matched_dst)
 940                 return 1;
 941         if (matched_dst->peer_ref) {
 942                 errs = 1;
 943                 error("dst ref %s receives from more than one src.",
 944                       matched_dst->name);
 945         }
 946         else {
 947                 matched_dst->peer_ref = matched_src;
 948                 matched_dst->force = rs->force;
 949         }
 950         return errs;
 951 }
 952
 953 static int match_explicit_refs(struct ref *src, struct ref *dst,
 954                                struct ref ***dst_tail, struct refspec *rs,
 955                                int rs_nr)
 956 {
 957         int i, errs;
 958         for (i = errs = 0; i < rs_nr; i++)
 959                 errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
 960         return -errs;
 961 }
 962
 963 static const struct refspec *check_pattern_match(const struct refspec *rs,
 964                                                  int rs_nr,
 965                                                  const struct ref *src)
 966 {
 967         int i;
 968         int matching_refs = -1;
 969         for (i = 0; i < rs_nr; i++) {
 970                 if (rs[i].matching &&
 971                     (matching_refs == -1 || rs[i].force)) {
 972                         matching_refs = i;
 973                         continue;
 974                 }
 975
 976                 if (rs[i].pattern &&
 977                     !prefixcmp(src->name, rs[i].src) &&
 978                     src->name[strlen(rs[i].src)] == '/')
 979                         return rs + i;
 980         }
 981         if (matching_refs != -1)
 982                 return rs + matching_refs;
 983         else
 984                 return NULL;
 985 }
 986
 987 /*
 988  * Note. This is used only by "push"; refspec matching rules for
 989  * push and fetch are subtly different, so do not try to reuse it
 990  * without thinking.
 991  */
 992 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 993                int nr_refspec, const char **refspec, int flags)
 994 {
 995         struct refspec *rs;
 996         int send_all = flags & MATCH_REFS_ALL;
 997         int send_mirror = flags & MATCH_REFS_MIRROR;
 998         static const char *default_refspec[] = { ":", 0 };
 999
1000         if (!nr_refspec) {
1001                 nr_refspec = 1;
1002                 refspec = default_refspec;
1003         }
1004         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1005         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
1006                 return -1;
1007
1008         /* pick the remainder */
1009         for ( ; src; src = src->next) {
1010                 struct ref *dst_peer;
1011                 const struct refspec *pat = NULL;
1012                 char *dst_name;
1013                 if (src->peer_ref)
1014                         continue;
1015
1016                 pat = check_pattern_match(rs, nr_refspec, src);
1017                 if (!pat)
1018                         continue;
1019
1020                 if (pat->matching) {
1021                         /*
1022                          * "matching refs"; traditionally we pushed everything
1023                          * including refs outside refs/heads/ hierarchy, but
1024                          * that does not make much sense these days.
1025                          */
1026                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1027                                 continue;
1028                         dst_name = xstrdup(src->name);
1029
1030                 } else {
1031                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1032                         dst_name = xmalloc(strlen(dst_side) +
1033                                            strlen(src->name) -
1034                                            strlen(pat->src) + 2);
1035                         strcpy(dst_name, dst_side);
1036                         strcat(dst_name, src->name + strlen(pat->src));
1037                 }
1038                 dst_peer = find_ref_by_name(dst, dst_name);
1039                 if (dst_peer) {
1040                         if (dst_peer->peer_ref)
1041                                 /* We're already sending something to this ref. */
1042                                 goto free_name;
1043
1044                 } else {
1045                         if (pat->matching && !(send_all || send_mirror))
1046                                 /*
1047                                  * Remote doesn't have it, and we have no
1048                                  * explicit pattern, and we don't have
1049                                  * --all nor --mirror.
1050                                  */
1051                                 goto free_name;
1052
1053                         /* Create a new one and link it */
1054                         dst_peer = make_linked_ref(dst_name, dst_tail);
1055                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1056                 }
1057                 dst_peer->peer_ref = src;
1058                 dst_peer->force = pat->force;
1059         free_name:
1060                 free(dst_name);
1061         }
1062         return 0;
1063 }
1064
1065 struct branch *branch_get(const char *name)
1066 {
1067         struct branch *ret;
1068
1069         read_config();
1070         if (!name || !*name || !strcmp(name, "HEAD"))
1071                 ret = current_branch;
1072         else
1073                 ret = make_branch(name, 0);
1074         if (ret && ret->remote_name) {
1075                 ret->remote = remote_get(ret->remote_name);
1076                 if (ret->merge_nr) {
1077                         int i;
1078                         ret->merge = xcalloc(sizeof(*ret->merge),
1079                                              ret->merge_nr);
1080                         for (i = 0; i < ret->merge_nr; i++) {
1081                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1082                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1083                                 remote_find_tracking(ret->remote,
1084                                                      ret->merge[i]);
1085                         }
1086                 }
1087         }
1088         return ret;
1089 }
1090
1091 int branch_has_merge_config(struct branch *branch)
1092 {
1093         return branch && !!branch->merge;
1094 }
1095
1096 int branch_merge_matches(struct branch *branch,
1097                                  int i,
1098                                  const char *refname)
1099 {
1100         if (!branch || i < 0 || i >= branch->merge_nr)
1101                 return 0;
1102         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1103 }
1104
1105 static struct ref *get_expanded_map(const struct ref *remote_refs,
1106                                     const struct refspec *refspec)
1107 {
1108         const struct ref *ref;
1109         struct ref *ret = NULL;
1110         struct ref **tail = &ret;
1111
1112         int remote_prefix_len = strlen(refspec->src);
1113         int local_prefix_len = strlen(refspec->dst);
1114
1115         for (ref = remote_refs; ref; ref = ref->next) {
1116                 if (strchr(ref->name, '^'))
1117                         continue; /* a dereference item */
1118                 if (!prefixcmp(ref->name, refspec->src)) {
1119                         const char *match;
1120                         struct ref *cpy = copy_ref(ref);
1121                         match = ref->name + remote_prefix_len;
1122
1123                         cpy->peer_ref = alloc_ref(local_prefix_len +
1124                                                   strlen(match) + 1);
1125                         sprintf(cpy->peer_ref->name, "%s%s",
1126                                 refspec->dst, match);
1127                         if (refspec->force)
1128                                 cpy->peer_ref->force = 1;
1129                         *tail = cpy;
1130                         tail = &cpy->next;
1131                 }
1132         }
1133
1134         return ret;
1135 }
1136
1137 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1138 {
1139         const struct ref *ref;
1140         for (ref = refs; ref; ref = ref->next) {
1141                 if (refname_match(name, ref->name, ref_fetch_rules))
1142                         return ref;
1143         }
1144         return NULL;
1145 }
1146
1147 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1148 {
1149         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1150
1151         if (!ref)
1152                 return NULL;
1153
1154         return copy_ref(ref);
1155 }
1156
1157 static struct ref *get_local_ref(const char *name)
1158 {
1159         struct ref *ret;
1160         if (!name)
1161                 return NULL;
1162
1163         if (!prefixcmp(name, "refs/")) {
1164                 return alloc_ref_from_str(name);
1165         }
1166
1167         if (!prefixcmp(name, "heads/") ||
1168             !prefixcmp(name, "tags/") ||
1169             !prefixcmp(name, "remotes/")) {
1170                 ret = alloc_ref(strlen(name) + 6);
1171                 sprintf(ret->name, "refs/%s", name);
1172                 return ret;
1173         }
1174
1175         ret = alloc_ref(strlen(name) + 12);
1176         sprintf(ret->name, "refs/heads/%s", name);
1177         return ret;
1178 }
1179
1180 int get_fetch_map(const struct ref *remote_refs,
1181                   const struct refspec *refspec,
1182                   struct ref ***tail,
1183                   int missing_ok)
1184 {
1185         struct ref *ref_map, **rmp;
1186
1187         if (refspec->pattern) {
1188                 ref_map = get_expanded_map(remote_refs, refspec);
1189         } else {
1190                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1191
1192                 ref_map = get_remote_ref(remote_refs, name);
1193                 if (!missing_ok && !ref_map)
1194                         die("Couldn't find remote ref %s", name);
1195                 if (ref_map) {
1196                         ref_map->peer_ref = get_local_ref(refspec->dst);
1197                         if (ref_map->peer_ref && refspec->force)
1198                                 ref_map->peer_ref->force = 1;
1199                 }
1200         }
1201
1202         for (rmp = &ref_map; *rmp; ) {
1203                 if ((*rmp)->peer_ref) {
1204                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1205                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1206                                 struct ref *ignore = *rmp;
1207                                 error("* Ignoring funny ref '%s' locally",
1208                                       (*rmp)->peer_ref->name);
1209                                 *rmp = (*rmp)->next;
1210                                 free(ignore->peer_ref);
1211                                 free(ignore);
1212                                 continue;
1213                         }
1214                 }
1215                 rmp = &((*rmp)->next);
1216         }
1217
1218         if (ref_map)
1219                 tail_link_ref(ref_map, tail);
1220
1221         return 0;
1222 }
1223
1224 int resolve_remote_symref(struct ref *ref, struct ref *list)
1225 {
1226         if (!ref->symref)
1227                 return 0;
1228         for (; list; list = list->next)
1229                 if (!strcmp(ref->symref, list->name)) {
1230                         hashcpy(ref->old_sha1, list->old_sha1);
1231                         return 0;
1232                 }
1233         return 1;
1234 }