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