git.oblomov.eu Git - git/blob - remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "dir.h"
   8 #include "tag.h"
   9
  10 static struct refspec s_tag_refspec = {
  11         0,
  12         1,
  13         0,
  14         "refs/tags/*",
  15         "refs/tags/*"
  16 };
  17
  18 const struct refspec *tag_refspec = &s_tag_refspec;
  19
  20 struct counted_string {
  21         size_t len;
  22         const char *s;
  23 };
  24 struct rewrite {
  25         const char *base;
  26         size_t baselen;
  27         struct counted_string *instead_of;
  28         int instead_of_nr;
  29         int instead_of_alloc;
  30 };
  31
  32 static struct remote **remotes;
  33 static int remotes_alloc;
  34 static int remotes_nr;
  35
  36 static struct branch **branches;
  37 static int branches_alloc;
  38 static int branches_nr;
  39
  40 static struct branch *current_branch;
  41 static const char *default_remote_name;
  42
  43 static struct rewrite **rewrite;
  44 static int rewrite_alloc;
  45 static int rewrite_nr;
  46
  47 #define BUF_SIZE (2048)
  48 static char buffer[BUF_SIZE];
  49
  50 static const char *alias_url(const char *url)
  51 {
  52         int i, j;
  53         char *ret;
  54         struct counted_string *longest;
  55         int longest_i;
  56
  57         longest = NULL;
  58         longest_i = -1;
  59         for (i = 0; i < rewrite_nr; i++) {
  60                 if (!rewrite[i])
  61                         continue;
  62                 for (j = 0; j < rewrite[i]->instead_of_nr; j++) {
  63                         if (!prefixcmp(url, rewrite[i]->instead_of[j].s) &&
  64                             (!longest ||
  65                              longest->len < rewrite[i]->instead_of[j].len)) {
  66                                 longest = &(rewrite[i]->instead_of[j]);
  67                                 longest_i = i;
  68                         }
  69                 }
  70         }
  71         if (!longest)
  72                 return url;
  73
  74         ret = xmalloc(rewrite[longest_i]->baselen +
  75                      (strlen(url) - longest->len) + 1);
  76         strcpy(ret, rewrite[longest_i]->base);
  77         strcpy(ret + rewrite[longest_i]->baselen, url + longest->len);
  78         return ret;
  79 }
  80
  81 static void add_push_refspec(struct remote *remote, const char *ref)
  82 {
  83         ALLOC_GROW(remote->push_refspec,
  84                    remote->push_refspec_nr + 1,
  85                    remote->push_refspec_alloc);
  86         remote->push_refspec[remote->push_refspec_nr++] = ref;
  87 }
  88
  89 static void add_fetch_refspec(struct remote *remote, const char *ref)
  90 {
  91         ALLOC_GROW(remote->fetch_refspec,
  92                    remote->fetch_refspec_nr + 1,
  93                    remote->fetch_refspec_alloc);
  94         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
  95 }
  96
  97 static void add_url(struct remote *remote, const char *url)
  98 {
  99         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 100         remote->url[remote->url_nr++] = url;
 101 }
 102
 103 static void add_url_alias(struct remote *remote, const char *url)
 104 {
 105         add_url(remote, alias_url(url));
 106 }
 107
 108 static struct remote *make_remote(const char *name, int len)
 109 {
 110         struct remote *ret;
 111         int i;
 112
 113         for (i = 0; i < remotes_nr; i++) {
 114                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 115                            !remotes[i]->name[len]) :
 116                     !strcmp(name, remotes[i]->name))
 117                         return remotes[i];
 118         }
 119
 120         ret = xcalloc(1, sizeof(struct remote));
 121         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 122         remotes[remotes_nr++] = ret;
 123         if (len)
 124                 ret->name = xstrndup(name, len);
 125         else
 126                 ret->name = xstrdup(name);
 127         return ret;
 128 }
 129
 130 static void add_merge(struct branch *branch, const char *name)
 131 {
 132         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 133                    branch->merge_alloc);
 134         branch->merge_name[branch->merge_nr++] = name;
 135 }
 136
 137 static struct branch *make_branch(const char *name, int len)
 138 {
 139         struct branch *ret;
 140         int i;
 141         char *refname;
 142
 143         for (i = 0; i < branches_nr; i++) {
 144                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 145                            !branches[i]->name[len]) :
 146                     !strcmp(name, branches[i]->name))
 147                         return branches[i];
 148         }
 149
 150         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 151         ret = xcalloc(1, sizeof(struct branch));
 152         branches[branches_nr++] = ret;
 153         if (len)
 154                 ret->name = xstrndup(name, len);
 155         else
 156                 ret->name = xstrdup(name);
 157         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 158         strcpy(refname, "refs/heads/");
 159         strcpy(refname + strlen("refs/heads/"), ret->name);
 160         ret->refname = refname;
 161
 162         return ret;
 163 }
 164
 165 static struct rewrite *make_rewrite(const char *base, int len)
 166 {
 167         struct rewrite *ret;
 168         int i;
 169
 170         for (i = 0; i < rewrite_nr; i++) {
 171                 if (len
 172                     ? (len == rewrite[i]->baselen &&
 173                        !strncmp(base, rewrite[i]->base, len))
 174                     : !strcmp(base, rewrite[i]->base))
 175                         return rewrite[i];
 176         }
 177
 178         ALLOC_GROW(rewrite, rewrite_nr + 1, rewrite_alloc);
 179         ret = xcalloc(1, sizeof(struct rewrite));
 180         rewrite[rewrite_nr++] = ret;
 181         if (len) {
 182                 ret->base = xstrndup(base, len);
 183                 ret->baselen = len;
 184         }
 185         else {
 186                 ret->base = xstrdup(base);
 187                 ret->baselen = strlen(base);
 188         }
 189         return ret;
 190 }
 191
 192 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 193 {
 194         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 195         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 196         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 197         rewrite->instead_of_nr++;
 198 }
 199
 200 static void read_remotes_file(struct remote *remote)
 201 {
 202         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 203
 204         if (!f)
 205                 return;
 206         remote->origin = REMOTE_REMOTES;
 207         while (fgets(buffer, BUF_SIZE, f)) {
 208                 int value_list;
 209                 char *s, *p;
 210
 211                 if (!prefixcmp(buffer, "URL:")) {
 212                         value_list = 0;
 213                         s = buffer + 4;
 214                 } else if (!prefixcmp(buffer, "Push:")) {
 215                         value_list = 1;
 216                         s = buffer + 5;
 217                 } else if (!prefixcmp(buffer, "Pull:")) {
 218                         value_list = 2;
 219                         s = buffer + 5;
 220                 } else
 221                         continue;
 222
 223                 while (isspace(*s))
 224                         s++;
 225                 if (!*s)
 226                         continue;
 227
 228                 p = s + strlen(s);
 229                 while (isspace(p[-1]))
 230                         *--p = 0;
 231
 232                 switch (value_list) {
 233                 case 0:
 234                         add_url_alias(remote, xstrdup(s));
 235                         break;
 236                 case 1:
 237                         add_push_refspec(remote, xstrdup(s));
 238                         break;
 239                 case 2:
 240                         add_fetch_refspec(remote, xstrdup(s));
 241                         break;
 242                 }
 243         }
 244         fclose(f);
 245 }
 246
 247 static void read_branches_file(struct remote *remote)
 248 {
 249         const char *slash = strchr(remote->name, '/');
 250         char *frag;
 251         struct strbuf branch = STRBUF_INIT;
 252         int n = slash ? slash - remote->name : 1000;
 253         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 254         char *s, *p;
 255         int len;
 256
 257         if (!f)
 258                 return;
 259         s = fgets(buffer, BUF_SIZE, f);
 260         fclose(f);
 261         if (!s)
 262                 return;
 263         while (isspace(*s))
 264                 s++;
 265         if (!*s)
 266                 return;
 267         remote->origin = REMOTE_BRANCHES;
 268         p = s + strlen(s);
 269         while (isspace(p[-1]))
 270                 *--p = 0;
 271         len = p - s;
 272         if (slash)
 273                 len += strlen(slash);
 274         p = xmalloc(len + 1);
 275         strcpy(p, s);
 276         if (slash)
 277                 strcat(p, slash);
 278
 279         /*
 280          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 281          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 282          * the partial URL obtained from the branches file plus
 283          * "/netdev-2.6" and does not store it in any tracking ref.
 284          * #branch specifier in the file is ignored.
 285          *
 286          * Otherwise, the branches file would have URL and optionally
 287          * #branch specified.  The "master" (or specified) branch is
 288          * fetched and stored in the local branch of the same name.
 289          */
 290         frag = strchr(p, '#');
 291         if (frag) {
 292                 *(frag++) = '\0';
 293                 strbuf_addf(&branch, "refs/heads/%s", frag);
 294         } else
 295                 strbuf_addstr(&branch, "refs/heads/master");
 296         if (!slash) {
 297                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 298         } else {
 299                 strbuf_reset(&branch);
 300                 strbuf_addstr(&branch, "HEAD:");
 301         }
 302         add_url_alias(remote, p);
 303         add_fetch_refspec(remote, strbuf_detach(&branch, 0));
 304         /*
 305          * Cogito compatible push: push current HEAD to remote #branch
 306          * (master if missing)
 307          */
 308         strbuf_init(&branch, 0);
 309         strbuf_addstr(&branch, "HEAD");
 310         if (frag)
 311                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 312         else
 313                 strbuf_addstr(&branch, ":refs/heads/master");
 314         add_push_refspec(remote, strbuf_detach(&branch, 0));
 315         remote->fetch_tags = 1; /* always auto-follow */
 316 }
 317
 318 static int handle_config(const char *key, const char *value, void *cb)
 319 {
 320         const char *name;
 321         const char *subkey;
 322         struct remote *remote;
 323         struct branch *branch;
 324         if (!prefixcmp(key, "branch.")) {
 325                 name = key + 7;
 326                 subkey = strrchr(name, '.');
 327                 if (!subkey)
 328                         return 0;
 329                 branch = make_branch(name, subkey - name);
 330                 if (!strcmp(subkey, ".remote")) {
 331                         if (!value)
 332                                 return config_error_nonbool(key);
 333                         branch->remote_name = xstrdup(value);
 334                         if (branch == current_branch)
 335                                 default_remote_name = branch->remote_name;
 336                 } else if (!strcmp(subkey, ".merge")) {
 337                         if (!value)
 338                                 return config_error_nonbool(key);
 339                         add_merge(branch, xstrdup(value));
 340                 }
 341                 return 0;
 342         }
 343         if (!prefixcmp(key, "url.")) {
 344                 struct rewrite *rewrite;
 345                 name = key + 4;
 346                 subkey = strrchr(name, '.');
 347                 if (!subkey)
 348                         return 0;
 349                 rewrite = make_rewrite(name, subkey - name);
 350                 if (!strcmp(subkey, ".insteadof")) {
 351                         if (!value)
 352                                 return config_error_nonbool(key);
 353                         add_instead_of(rewrite, xstrdup(value));
 354                 }
 355         }
 356         if (prefixcmp(key,  "remote."))
 357                 return 0;
 358         name = key + 7;
 359         if (*name == '/') {
 360                 warning("Config remote shorthand cannot begin with '/': %s",
 361                         name);
 362                 return 0;
 363         }
 364         subkey = strrchr(name, '.');
 365         if (!subkey)
 366                 return error("Config with no key for remote %s", name);
 367         remote = make_remote(name, subkey - name);
 368         remote->origin = REMOTE_CONFIG;
 369         if (!strcmp(subkey, ".mirror"))
 370                 remote->mirror = git_config_bool(key, value);
 371         else if (!strcmp(subkey, ".skipdefaultupdate"))
 372                 remote->skip_default_update = git_config_bool(key, value);
 373
 374         else if (!strcmp(subkey, ".url")) {
 375                 const char *v;
 376                 if (git_config_string(&v, key, value))
 377                         return -1;
 378                 add_url(remote, v);
 379         } else if (!strcmp(subkey, ".push")) {
 380                 const char *v;
 381                 if (git_config_string(&v, key, value))
 382                         return -1;
 383                 add_push_refspec(remote, v);
 384         } else if (!strcmp(subkey, ".fetch")) {
 385                 const char *v;
 386                 if (git_config_string(&v, key, value))
 387                         return -1;
 388                 add_fetch_refspec(remote, v);
 389         } else if (!strcmp(subkey, ".receivepack")) {
 390                 const char *v;
 391                 if (git_config_string(&v, key, value))
 392                         return -1;
 393                 if (!remote->receivepack)
 394                         remote->receivepack = v;
 395                 else
 396                         error("more than one receivepack given, using the first");
 397         } else if (!strcmp(subkey, ".uploadpack")) {
 398                 const char *v;
 399                 if (git_config_string(&v, key, value))
 400                         return -1;
 401                 if (!remote->uploadpack)
 402                         remote->uploadpack = v;
 403                 else
 404                         error("more than one uploadpack given, using the first");
 405         } else if (!strcmp(subkey, ".tagopt")) {
 406                 if (!strcmp(value, "--no-tags"))
 407                         remote->fetch_tags = -1;
 408         } else if (!strcmp(subkey, ".proxy")) {
 409                 return git_config_string((const char **)&remote->http_proxy,
 410                                          key, value);
 411         }
 412         return 0;
 413 }
 414
 415 static void alias_all_urls(void)
 416 {
 417         int i, j;
 418         for (i = 0; i < remotes_nr; i++) {
 419                 if (!remotes[i])
 420                         continue;
 421                 for (j = 0; j < remotes[i]->url_nr; j++) {
 422                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 423                 }
 424         }
 425 }
 426
 427 static void read_config(void)
 428 {
 429         unsigned char sha1[20];
 430         const char *head_ref;
 431         int flag;
 432         if (default_remote_name) // did this already
 433                 return;
 434         default_remote_name = xstrdup("origin");
 435         current_branch = NULL;
 436         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 437         if (head_ref && (flag & REF_ISSYMREF) &&
 438             !prefixcmp(head_ref, "refs/heads/")) {
 439                 current_branch =
 440                         make_branch(head_ref + strlen("refs/heads/"), 0);
 441         }
 442         git_config(handle_config, NULL);
 443         alias_all_urls();
 444 }
 445
 446 /*
 447  * We need to make sure the tracking branches are well formed, but a
 448  * wildcard refspec in "struct refspec" must have a trailing slash. We
 449  * temporarily drop the trailing '/' while calling check_ref_format(),
 450  * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 451  * error return is Ok for a wildcard refspec.
 452  */
 453 static int verify_refname(char *name, int is_glob)
 454 {
 455         int result;
 456
 457         result = check_ref_format(name);
 458         if (is_glob && result == CHECK_REF_FORMAT_WILDCARD)
 459                 result = CHECK_REF_FORMAT_OK;
 460         return result;
 461 }
 462
 463 /*
 464  * This function frees a refspec array.
 465  * Warning: code paths should be checked to ensure that the src
 466  *          and dst pointers are always freeable pointers as well
 467  *          as the refspec pointer itself.
 468  */
 469 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 470 {
 471         int i;
 472
 473         if (!refspec)
 474                 return;
 475
 476         for (i = 0; i < nr_refspec; i++) {
 477                 free(refspec[i].src);
 478                 free(refspec[i].dst);
 479         }
 480         free(refspec);
 481 }
 482
 483 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 484 {
 485         int i;
 486         int st;
 487         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 488
 489         for (i = 0; i < nr_refspec; i++) {
 490                 size_t llen;
 491                 int is_glob;
 492                 const char *lhs, *rhs;
 493
 494                 llen = is_glob = 0;
 495
 496                 lhs = refspec[i];
 497                 if (*lhs == '+') {
 498                         rs[i].force = 1;
 499                         lhs++;
 500                 }
 501
 502                 rhs = strrchr(lhs, ':');
 503
 504                 /*
 505                  * Before going on, special case ":" (or "+:") as a refspec
 506                  * for matching refs.
 507                  */
 508                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 509                         rs[i].matching = 1;
 510                         continue;
 511                 }
 512
 513                 if (rhs) {
 514                         size_t rlen = strlen(++rhs);
 515                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 516                         rs[i].dst = xstrndup(rhs, rlen);
 517                 }
 518
 519                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 520                 if (1 <= llen && memchr(lhs, '*', llen)) {
 521                         if ((rhs && !is_glob) || (!rhs && fetch))
 522                                 goto invalid;
 523                         is_glob = 1;
 524                 } else if (rhs && is_glob) {
 525                         goto invalid;
 526                 }
 527
 528                 rs[i].pattern = is_glob;
 529                 rs[i].src = xstrndup(lhs, llen);
 530
 531                 if (fetch) {
 532                         /*
 533                          * LHS
 534                          * - empty is allowed; it means HEAD.
 535                          * - otherwise it must be a valid looking ref.
 536                          */
 537                         if (!*rs[i].src)
 538                                 ; /* empty is ok */
 539                         else {
 540                                 st = verify_refname(rs[i].src, is_glob);
 541                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 542                                         goto invalid;
 543                         }
 544                         /*
 545                          * RHS
 546                          * - missing is ok, and is same as empty.
 547                          * - empty is ok; it means not to store.
 548                          * - otherwise it must be a valid looking ref.
 549                          */
 550                         if (!rs[i].dst) {
 551                                 ; /* ok */
 552                         } else if (!*rs[i].dst) {
 553                                 ; /* ok */
 554                         } else {
 555                                 st = verify_refname(rs[i].dst, is_glob);
 556                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 557                                         goto invalid;
 558                         }
 559                 } else {
 560                         /*
 561                          * LHS
 562                          * - empty is allowed; it means delete.
 563                          * - when wildcarded, it must be a valid looking ref.
 564                          * - otherwise, it must be an extended SHA-1, but
 565                          *   there is no existing way to validate this.
 566                          */
 567                         if (!*rs[i].src)
 568                                 ; /* empty is ok */
 569                         else if (is_glob) {
 570                                 st = verify_refname(rs[i].src, is_glob);
 571                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 572                                         goto invalid;
 573                         }
 574                         else
 575                                 ; /* anything goes, for now */
 576                         /*
 577                          * RHS
 578                          * - missing is allowed, but LHS then must be a
 579                          *   valid looking ref.
 580                          * - empty is not allowed.
 581                          * - otherwise it must be a valid looking ref.
 582                          */
 583                         if (!rs[i].dst) {
 584                                 st = verify_refname(rs[i].src, is_glob);
 585                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 586                                         goto invalid;
 587                         } else if (!*rs[i].dst) {
 588                                 goto invalid;
 589                         } else {
 590                                 st = verify_refname(rs[i].dst, is_glob);
 591                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 592                                         goto invalid;
 593                         }
 594                 }
 595         }
 596         return rs;
 597
 598  invalid:
 599         if (verify) {
 600                 /*
 601                  * nr_refspec must be greater than zero and i must be valid
 602                  * since it is only possible to reach this point from within
 603                  * the for loop above.
 604                  */
 605                 free_refspecs(rs, i+1);
 606                 return NULL;
 607         }
 608         die("Invalid refspec '%s'", refspec[i]);
 609 }
 610
 611 int valid_fetch_refspec(const char *fetch_refspec_str)
 612 {
 613         const char *fetch_refspec[] = { fetch_refspec_str };
 614         struct refspec *refspec;
 615
 616         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 617         free_refspecs(refspec, 1);
 618         return !!refspec;
 619 }
 620
 621 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 622 {
 623         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 624 }
 625
 626 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 627 {
 628         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 629 }
 630
 631 static int valid_remote_nick(const char *name)
 632 {
 633         if (!name[0] || is_dot_or_dotdot(name))
 634                 return 0;
 635         return !strchr(name, '/'); /* no slash */
 636 }
 637
 638 struct remote *remote_get(const char *name)
 639 {
 640         struct remote *ret;
 641
 642         read_config();
 643         if (!name)
 644                 name = default_remote_name;
 645         ret = make_remote(name, 0);
 646         if (valid_remote_nick(name)) {
 647                 if (!ret->url)
 648                         read_remotes_file(ret);
 649                 if (!ret->url)
 650                         read_branches_file(ret);
 651         }
 652         if (!ret->url)
 653                 add_url_alias(ret, name);
 654         if (!ret->url)
 655                 return NULL;
 656         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 657         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 658         return ret;
 659 }
 660
 661 int for_each_remote(each_remote_fn fn, void *priv)
 662 {
 663         int i, result = 0;
 664         read_config();
 665         for (i = 0; i < remotes_nr && !result; i++) {
 666                 struct remote *r = remotes[i];
 667                 if (!r)
 668                         continue;
 669                 if (!r->fetch)
 670                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 671                                                        r->fetch_refspec);
 672                 if (!r->push)
 673                         r->push = parse_push_refspec(r->push_refspec_nr,
 674                                                      r->push_refspec);
 675                 result = fn(r, priv);
 676         }
 677         return result;
 678 }
 679
 680 void ref_remove_duplicates(struct ref *ref_map)
 681 {
 682         struct ref **posn;
 683         struct ref *next;
 684         for (; ref_map; ref_map = ref_map->next) {
 685                 if (!ref_map->peer_ref)
 686                         continue;
 687                 posn = &ref_map->next;
 688                 while (*posn) {
 689                         if ((*posn)->peer_ref &&
 690                             !strcmp((*posn)->peer_ref->name,
 691                                     ref_map->peer_ref->name)) {
 692                                 if (strcmp((*posn)->name, ref_map->name))
 693                                         die("%s tracks both %s and %s",
 694                                             ref_map->peer_ref->name,
 695                                             (*posn)->name, ref_map->name);
 696                                 next = (*posn)->next;
 697                                 free((*posn)->peer_ref);
 698                                 free(*posn);
 699                                 *posn = next;
 700                         } else {
 701                                 posn = &(*posn)->next;
 702                         }
 703                 }
 704         }
 705 }
 706
 707 int remote_has_url(struct remote *remote, const char *url)
 708 {
 709         int i;
 710         for (i = 0; i < remote->url_nr; i++) {
 711                 if (!strcmp(remote->url[i], url))
 712                         return 1;
 713         }
 714         return 0;
 715 }
 716
 717 static int match_name_with_pattern(const char *key, const char *name,
 718                                    const char *value, char **result)
 719 {
 720         const char *kstar = strchr(key, '*');
 721         size_t klen;
 722         size_t ksuffixlen;
 723         size_t namelen;
 724         int ret;
 725         if (!kstar)
 726                 die("Key '%s' of pattern had no '*'", key);
 727         klen = kstar - key;
 728         ksuffixlen = strlen(kstar + 1);
 729         namelen = strlen(name);
 730         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 731                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 732         if (ret && value) {
 733                 const char *vstar = strchr(value, '*');
 734                 size_t vlen;
 735                 size_t vsuffixlen;
 736                 if (!vstar)
 737                         die("Value '%s' of pattern has no '*'", value);
 738                 vlen = vstar - value;
 739                 vsuffixlen = strlen(vstar + 1);
 740                 *result = xmalloc(vlen + vsuffixlen +
 741                                   strlen(name) -
 742                                   klen - ksuffixlen + 1);
 743                 strncpy(*result, value, vlen);
 744                 strncpy(*result + vlen,
 745                         name + klen, namelen - klen - ksuffixlen);
 746                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 747                        vstar + 1);
 748         }
 749         return ret;
 750 }
 751
 752 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 753 {
 754         int find_src = refspec->src == NULL;
 755         char *needle, **result;
 756         int i;
 757
 758         if (find_src) {
 759                 if (!refspec->dst)
 760                         return error("find_tracking: need either src or dst");
 761                 needle = refspec->dst;
 762                 result = &refspec->src;
 763         } else {
 764                 needle = refspec->src;
 765                 result = &refspec->dst;
 766         }
 767
 768         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 769                 struct refspec *fetch = &remote->fetch[i];
 770                 const char *key = find_src ? fetch->dst : fetch->src;
 771                 const char *value = find_src ? fetch->src : fetch->dst;
 772                 if (!fetch->dst)
 773                         continue;
 774                 if (fetch->pattern) {
 775                         if (match_name_with_pattern(key, needle, value, result)) {
 776                                 refspec->force = fetch->force;
 777                                 return 0;
 778                         }
 779                 } else if (!strcmp(needle, key)) {
 780                         *result = xstrdup(value);
 781                         refspec->force = fetch->force;
 782                         return 0;
 783                 }
 784         }
 785         return -1;
 786 }
 787
 788 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 789                 const char *name)
 790 {
 791         size_t len = strlen(name);
 792         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 793         memcpy(ref->name, prefix, prefixlen);
 794         memcpy(ref->name + prefixlen, name, len);
 795         return ref;
 796 }
 797
 798 struct ref *alloc_ref(const char *name)
 799 {
 800         return alloc_ref_with_prefix("", 0, name);
 801 }
 802
 803 static struct ref *copy_ref(const struct ref *ref)
 804 {
 805         struct ref *cpy;
 806         size_t len;
 807         if (!ref)
 808                 return NULL;
 809         len = strlen(ref->name);
 810         cpy = xmalloc(sizeof(struct ref) + len + 1);
 811         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 812         cpy->next = NULL;
 813         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 814         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 815         cpy->peer_ref = copy_ref(ref->peer_ref);
 816         return cpy;
 817 }
 818
 819 struct ref *copy_ref_list(const struct ref *ref)
 820 {
 821         struct ref *ret = NULL;
 822         struct ref **tail = &ret;
 823         while (ref) {
 824                 *tail = copy_ref(ref);
 825                 ref = ref->next;
 826                 tail = &((*tail)->next);
 827         }
 828         return ret;
 829 }
 830
 831 static void free_ref(struct ref *ref)
 832 {
 833         if (!ref)
 834                 return;
 835         free_ref(ref->peer_ref);
 836         free(ref->remote_status);
 837         free(ref->symref);
 838         free(ref);
 839 }
 840
 841 void free_refs(struct ref *ref)
 842 {
 843         struct ref *next;
 844         while (ref) {
 845                 next = ref->next;
 846                 free_ref(ref);
 847                 ref = next;
 848         }
 849 }
 850
 851 static int count_refspec_match(const char *pattern,
 852                                struct ref *refs,
 853                                struct ref **matched_ref)
 854 {
 855         int patlen = strlen(pattern);
 856         struct ref *matched_weak = NULL;
 857         struct ref *matched = NULL;
 858         int weak_match = 0;
 859         int match = 0;
 860
 861         for (weak_match = match = 0; refs; refs = refs->next) {
 862                 char *name = refs->name;
 863                 int namelen = strlen(name);
 864
 865                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 866                         continue;
 867
 868                 /* A match is "weak" if it is with refs outside
 869                  * heads or tags, and did not specify the pattern
 870                  * in full (e.g. "refs/remotes/origin/master") or at
 871                  * least from the toplevel (e.g. "remotes/origin/master");
 872                  * otherwise "git push $URL master" would result in
 873                  * ambiguity between remotes/origin/master and heads/master
 874                  * at the remote site.
 875                  */
 876                 if (namelen != patlen &&
 877                     patlen != namelen - 5 &&
 878                     prefixcmp(name, "refs/heads/") &&
 879                     prefixcmp(name, "refs/tags/")) {
 880                         /* We want to catch the case where only weak
 881                          * matches are found and there are multiple
 882                          * matches, and where more than one strong
 883                          * matches are found, as ambiguous.  One
 884                          * strong match with zero or more weak matches
 885                          * are acceptable as a unique match.
 886                          */
 887                         matched_weak = refs;
 888                         weak_match++;
 889                 }
 890                 else {
 891                         matched = refs;
 892                         match++;
 893                 }
 894         }
 895         if (!matched) {
 896                 *matched_ref = matched_weak;
 897                 return weak_match;
 898         }
 899         else {
 900                 *matched_ref = matched;
 901                 return match;
 902         }
 903 }
 904
 905 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 906 {
 907         **tail = ref;
 908         while (ref->next)
 909                 ref = ref->next;
 910         *tail = &ref->next;
 911 }
 912
 913 static struct ref *try_explicit_object_name(const char *name)
 914 {
 915         unsigned char sha1[20];
 916         struct ref *ref;
 917
 918         if (!*name) {
 919                 ref = alloc_ref("(delete)");
 920                 hashclr(ref->new_sha1);
 921                 return ref;
 922         }
 923         if (get_sha1(name, sha1))
 924                 return NULL;
 925         ref = alloc_ref(name);
 926         hashcpy(ref->new_sha1, sha1);
 927         return ref;
 928 }
 929
 930 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 931 {
 932         struct ref *ret = alloc_ref(name);
 933         tail_link_ref(ret, tail);
 934         return ret;
 935 }
 936
 937 static char *guess_ref(const char *name, struct ref *peer)
 938 {
 939         struct strbuf buf = STRBUF_INIT;
 940         unsigned char sha1[20];
 941
 942         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
 943         if (!r)
 944                 return NULL;
 945
 946         if (!prefixcmp(r, "refs/heads/"))
 947                 strbuf_addstr(&buf, "refs/heads/");
 948         else if (!prefixcmp(r, "refs/tags/"))
 949                 strbuf_addstr(&buf, "refs/tags/");
 950         else
 951                 return NULL;
 952
 953         strbuf_addstr(&buf, name);
 954         return strbuf_detach(&buf, NULL);
 955 }
 956
 957 static int match_explicit(struct ref *src, struct ref *dst,
 958                           struct ref ***dst_tail,
 959                           struct refspec *rs)
 960 {
 961         struct ref *matched_src, *matched_dst;
 962         int copy_src;
 963
 964         const char *dst_value = rs->dst;
 965         char *dst_guess;
 966
 967         if (rs->pattern || rs->matching)
 968                 return 0;
 969
 970         matched_src = matched_dst = NULL;
 971         switch (count_refspec_match(rs->src, src, &matched_src)) {
 972         case 1:
 973                 copy_src = 1;
 974                 break;
 975         case 0:
 976                 /* The source could be in the get_sha1() format
 977                  * not a reference name.  :refs/other is a
 978                  * way to delete 'other' ref at the remote end.
 979                  */
 980                 matched_src = try_explicit_object_name(rs->src);
 981                 if (!matched_src)
 982                         return error("src refspec %s does not match any.", rs->src);
 983                 copy_src = 0;
 984                 break;
 985         default:
 986                 return error("src refspec %s matches more than one.", rs->src);
 987         }
 988
 989         if (!dst_value) {
 990                 unsigned char sha1[20];
 991                 int flag;
 992
 993                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 994                 if (!dst_value ||
 995                     ((flag & REF_ISSYMREF) &&
 996                      prefixcmp(dst_value, "refs/heads/")))
 997                         die("%s cannot be resolved to branch.",
 998                             matched_src->name);
 999         }
1000
1001         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1002         case 1:
1003                 break;
1004         case 0:
1005                 if (!memcmp(dst_value, "refs/", 5))
1006                         matched_dst = make_linked_ref(dst_value, dst_tail);
1007                 else if((dst_guess = guess_ref(dst_value, matched_src)))
1008                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1009                 else
1010                         error("unable to push to unqualified destination: %s\n"
1011                               "The destination refspec neither matches an "
1012                               "existing ref on the remote nor\n"
1013                               "begins with refs/, and we are unable to "
1014                               "guess a prefix based on the source ref.",
1015                               dst_value);
1016                 break;
1017         default:
1018                 matched_dst = NULL;
1019                 error("dst refspec %s matches more than one.",
1020                       dst_value);
1021                 break;
1022         }
1023         if (!matched_dst)
1024                 return -1;
1025         if (matched_dst->peer_ref)
1026                 return error("dst ref %s receives from more than one src.",
1027                       matched_dst->name);
1028         else {
1029                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1030                 matched_dst->force = rs->force;
1031         }
1032         return 0;
1033 }
1034
1035 static int match_explicit_refs(struct ref *src, struct ref *dst,
1036                                struct ref ***dst_tail, struct refspec *rs,
1037                                int rs_nr)
1038 {
1039         int i, errs;
1040         for (i = errs = 0; i < rs_nr; i++)
1041                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1042         return errs;
1043 }
1044
1045 static const struct refspec *check_pattern_match(const struct refspec *rs,
1046                                                  int rs_nr,
1047                                                  const struct ref *src)
1048 {
1049         int i;
1050         int matching_refs = -1;
1051         for (i = 0; i < rs_nr; i++) {
1052                 if (rs[i].matching &&
1053                     (matching_refs == -1 || rs[i].force)) {
1054                         matching_refs = i;
1055                         continue;
1056                 }
1057
1058                 if (rs[i].pattern && match_name_with_pattern(rs[i].src, src->name,
1059                                                              NULL, NULL))
1060                         return rs + i;
1061         }
1062         if (matching_refs != -1)
1063                 return rs + matching_refs;
1064         else
1065                 return NULL;
1066 }
1067
1068 /*
1069  * Note. This is used only by "push"; refspec matching rules for
1070  * push and fetch are subtly different, so do not try to reuse it
1071  * without thinking.
1072  */
1073 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
1074                int nr_refspec, const char **refspec, int flags)
1075 {
1076         struct refspec *rs;
1077         int send_all = flags & MATCH_REFS_ALL;
1078         int send_mirror = flags & MATCH_REFS_MIRROR;
1079         int errs;
1080         static const char *default_refspec[] = { ":", 0 };
1081
1082         if (!nr_refspec) {
1083                 nr_refspec = 1;
1084                 refspec = default_refspec;
1085         }
1086         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1087         errs = match_explicit_refs(src, dst, dst_tail, rs, nr_refspec);
1088
1089         /* pick the remainder */
1090         for ( ; src; src = src->next) {
1091                 struct ref *dst_peer;
1092                 const struct refspec *pat = NULL;
1093                 char *dst_name;
1094                 if (src->peer_ref)
1095                         continue;
1096
1097                 pat = check_pattern_match(rs, nr_refspec, src);
1098                 if (!pat)
1099                         continue;
1100
1101                 if (pat->matching) {
1102                         /*
1103                          * "matching refs"; traditionally we pushed everything
1104                          * including refs outside refs/heads/ hierarchy, but
1105                          * that does not make much sense these days.
1106                          */
1107                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1108                                 continue;
1109                         dst_name = xstrdup(src->name);
1110
1111                 } else {
1112                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1113                         if (!match_name_with_pattern(pat->src, src->name,
1114                                                      dst_side, &dst_name))
1115                                 die("Didn't think it matches any more");
1116                 }
1117                 dst_peer = find_ref_by_name(dst, dst_name);
1118                 if (dst_peer) {
1119                         if (dst_peer->peer_ref)
1120                                 /* We're already sending something to this ref. */
1121                                 goto free_name;
1122
1123                 } else {
1124                         if (pat->matching && !(send_all || send_mirror))
1125                                 /*
1126                                  * Remote doesn't have it, and we have no
1127                                  * explicit pattern, and we don't have
1128                                  * --all nor --mirror.
1129                                  */
1130                                 goto free_name;
1131
1132                         /* Create a new one and link it */
1133                         dst_peer = make_linked_ref(dst_name, dst_tail);
1134                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1135                 }
1136                 dst_peer->peer_ref = copy_ref(src);
1137                 dst_peer->force = pat->force;
1138         free_name:
1139                 free(dst_name);
1140         }
1141         if (errs)
1142                 return -1;
1143         return 0;
1144 }
1145
1146 struct branch *branch_get(const char *name)
1147 {
1148         struct branch *ret;
1149
1150         read_config();
1151         if (!name || !*name || !strcmp(name, "HEAD"))
1152                 ret = current_branch;
1153         else
1154                 ret = make_branch(name, 0);
1155         if (ret && ret->remote_name) {
1156                 ret->remote = remote_get(ret->remote_name);
1157                 if (ret->merge_nr) {
1158                         int i;
1159                         ret->merge = xcalloc(sizeof(*ret->merge),
1160                                              ret->merge_nr);
1161                         for (i = 0; i < ret->merge_nr; i++) {
1162                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1163                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1164                                 remote_find_tracking(ret->remote,
1165                                                      ret->merge[i]);
1166                         }
1167                 }
1168         }
1169         return ret;
1170 }
1171
1172 int branch_has_merge_config(struct branch *branch)
1173 {
1174         return branch && !!branch->merge;
1175 }
1176
1177 int branch_merge_matches(struct branch *branch,
1178                                  int i,
1179                                  const char *refname)
1180 {
1181         if (!branch || i < 0 || i >= branch->merge_nr)
1182                 return 0;
1183         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1184 }
1185
1186 static struct ref *get_expanded_map(const struct ref *remote_refs,
1187                                     const struct refspec *refspec)
1188 {
1189         const struct ref *ref;
1190         struct ref *ret = NULL;
1191         struct ref **tail = &ret;
1192
1193         char *expn_name;
1194
1195         for (ref = remote_refs; ref; ref = ref->next) {
1196                 if (strchr(ref->name, '^'))
1197                         continue; /* a dereference item */
1198                 if (match_name_with_pattern(refspec->src, ref->name,
1199                                             refspec->dst, &expn_name)) {
1200                         struct ref *cpy = copy_ref(ref);
1201
1202                         cpy->peer_ref = alloc_ref(expn_name);
1203                         free(expn_name);
1204                         if (refspec->force)
1205                                 cpy->peer_ref->force = 1;
1206                         *tail = cpy;
1207                         tail = &cpy->next;
1208                 }
1209         }
1210
1211         return ret;
1212 }
1213
1214 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1215 {
1216         const struct ref *ref;
1217         for (ref = refs; ref; ref = ref->next) {
1218                 if (refname_match(name, ref->name, ref_fetch_rules))
1219                         return ref;
1220         }
1221         return NULL;
1222 }
1223
1224 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1225 {
1226         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1227
1228         if (!ref)
1229                 return NULL;
1230
1231         return copy_ref(ref);
1232 }
1233
1234 static struct ref *get_local_ref(const char *name)
1235 {
1236         if (!name)
1237                 return NULL;
1238
1239         if (!prefixcmp(name, "refs/"))
1240                 return alloc_ref(name);
1241
1242         if (!prefixcmp(name, "heads/") ||
1243             !prefixcmp(name, "tags/") ||
1244             !prefixcmp(name, "remotes/"))
1245                 return alloc_ref_with_prefix("refs/", 5, name);
1246
1247         return alloc_ref_with_prefix("refs/heads/", 11, name);
1248 }
1249
1250 int get_fetch_map(const struct ref *remote_refs,
1251                   const struct refspec *refspec,
1252                   struct ref ***tail,
1253                   int missing_ok)
1254 {
1255         struct ref *ref_map, **rmp;
1256
1257         if (refspec->pattern) {
1258                 ref_map = get_expanded_map(remote_refs, refspec);
1259         } else {
1260                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1261
1262                 ref_map = get_remote_ref(remote_refs, name);
1263                 if (!missing_ok && !ref_map)
1264                         die("Couldn't find remote ref %s", name);
1265                 if (ref_map) {
1266                         ref_map->peer_ref = get_local_ref(refspec->dst);
1267                         if (ref_map->peer_ref && refspec->force)
1268                                 ref_map->peer_ref->force = 1;
1269                 }
1270         }
1271
1272         for (rmp = &ref_map; *rmp; ) {
1273                 if ((*rmp)->peer_ref) {
1274                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1275                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1276                                 struct ref *ignore = *rmp;
1277                                 error("* Ignoring funny ref '%s' locally",
1278                                       (*rmp)->peer_ref->name);
1279                                 *rmp = (*rmp)->next;
1280                                 free(ignore->peer_ref);
1281                                 free(ignore);
1282                                 continue;
1283                         }
1284                 }
1285                 rmp = &((*rmp)->next);
1286         }
1287
1288         if (ref_map)
1289                 tail_link_ref(ref_map, tail);
1290
1291         return 0;
1292 }
1293
1294 int resolve_remote_symref(struct ref *ref, struct ref *list)
1295 {
1296         if (!ref->symref)
1297                 return 0;
1298         for (; list; list = list->next)
1299                 if (!strcmp(ref->symref, list->name)) {
1300                         hashcpy(ref->old_sha1, list->old_sha1);
1301                         return 0;
1302                 }
1303         return 1;
1304 }
1305
1306 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1307 {
1308         while (list) {
1309                 struct commit_list *temp = list;
1310                 temp->item->object.flags &= ~mark;
1311                 list = temp->next;
1312                 free(temp);
1313         }
1314 }
1315
1316 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1317 {
1318         struct object *o;
1319         struct commit *old, *new;
1320         struct commit_list *list, *used;
1321         int found = 0;
1322
1323         /* Both new and old must be commit-ish and new is descendant of
1324          * old.  Otherwise we require --force.
1325          */
1326         o = deref_tag(parse_object(old_sha1), NULL, 0);
1327         if (!o || o->type != OBJ_COMMIT)
1328                 return 0;
1329         old = (struct commit *) o;
1330
1331         o = deref_tag(parse_object(new_sha1), NULL, 0);
1332         if (!o || o->type != OBJ_COMMIT)
1333                 return 0;
1334         new = (struct commit *) o;
1335
1336         if (parse_commit(new) < 0)
1337                 return 0;
1338
1339         used = list = NULL;
1340         commit_list_insert(new, &list);
1341         while (list) {
1342                 new = pop_most_recent_commit(&list, TMP_MARK);
1343                 commit_list_insert(new, &used);
1344                 if (new == old) {
1345                         found = 1;
1346                         break;
1347                 }
1348         }
1349         unmark_and_free(list, TMP_MARK);
1350         unmark_and_free(used, TMP_MARK);
1351         return found;
1352 }
1353
1354 /*
1355  * Return true if there is anything to report, otherwise false.
1356  */
1357 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1358 {
1359         unsigned char sha1[20];
1360         struct commit *ours, *theirs;
1361         char symmetric[84];
1362         struct rev_info revs;
1363         const char *rev_argv[10], *base;
1364         int rev_argc;
1365
1366         /*
1367          * Nothing to report unless we are marked to build on top of
1368          * somebody else.
1369          */
1370         if (!branch ||
1371             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1372                 return 0;
1373
1374         /*
1375          * If what we used to build on no longer exists, there is
1376          * nothing to report.
1377          */
1378         base = branch->merge[0]->dst;
1379         if (!resolve_ref(base, sha1, 1, NULL))
1380                 return 0;
1381         theirs = lookup_commit(sha1);
1382         if (!theirs)
1383                 return 0;
1384
1385         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1386                 return 0;
1387         ours = lookup_commit(sha1);
1388         if (!ours)
1389                 return 0;
1390
1391         /* are we the same? */
1392         if (theirs == ours)
1393                 return 0;
1394
1395         /* Run "rev-list --left-right ours...theirs" internally... */
1396         rev_argc = 0;
1397         rev_argv[rev_argc++] = NULL;
1398         rev_argv[rev_argc++] = "--left-right";
1399         rev_argv[rev_argc++] = symmetric;
1400         rev_argv[rev_argc++] = "--";
1401         rev_argv[rev_argc] = NULL;
1402
1403         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1404         strcpy(symmetric + 40, "...");
1405         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1406
1407         init_revisions(&revs, NULL);
1408         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1409         prepare_revision_walk(&revs);
1410
1411         /* ... and count the commits on each side. */
1412         *num_ours = 0;
1413         *num_theirs = 0;
1414         while (1) {
1415                 struct commit *c = get_revision(&revs);
1416                 if (!c)
1417                         break;
1418                 if (c->object.flags & SYMMETRIC_LEFT)
1419                         (*num_ours)++;
1420                 else
1421                         (*num_theirs)++;
1422         }
1423
1424         /* clear object flags smudged by the above traversal */
1425         clear_commit_marks(ours, ALL_REV_FLAGS);
1426         clear_commit_marks(theirs, ALL_REV_FLAGS);
1427         return 1;
1428 }
1429
1430 /*
1431  * Return true when there is anything to report, otherwise false.
1432  */
1433 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1434 {
1435         int num_ours, num_theirs;
1436         const char *base;
1437
1438         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1439                 return 0;
1440
1441         base = branch->merge[0]->dst;
1442         if (!prefixcmp(base, "refs/remotes/")) {
1443                 base += strlen("refs/remotes/");
1444         }
1445         if (!num_theirs)
1446                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1447                             "by %d commit%s.\n",
1448                             base, num_ours, (num_ours == 1) ? "" : "s");
1449         else if (!num_ours)
1450                 strbuf_addf(sb, "Your branch is behind '%s' "
1451                             "by %d commit%s, "
1452                             "and can be fast-forwarded.\n",
1453                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1454         else
1455                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1456                             "and have %d and %d different commit(s) each, "
1457                             "respectively.\n",
1458                             base, num_ours, num_theirs);
1459         return 1;
1460 }
1461
1462 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1463 {
1464         struct ref ***local_tail = cb_data;
1465         struct ref *ref;
1466         int len;
1467
1468         /* we already know it starts with refs/ to get here */
1469         if (check_ref_format(refname + 5))
1470                 return 0;
1471
1472         len = strlen(refname) + 1;
1473         ref = xcalloc(1, sizeof(*ref) + len);
1474         hashcpy(ref->new_sha1, sha1);
1475         memcpy(ref->name, refname, len);
1476         **local_tail = ref;
1477         *local_tail = &ref->next;
1478         return 0;
1479 }
1480
1481 struct ref *get_local_heads(void)
1482 {
1483         struct ref *local_refs, **local_tail = &local_refs;
1484         for_each_ref(one_local_ref, &local_tail);
1485         return local_refs;
1486 }
1487
1488 struct ref *guess_remote_head(const struct ref *head,
1489                               const struct ref *refs,
1490                               int all)
1491 {
1492         const struct ref *r;
1493         struct ref *list = NULL;
1494         struct ref **tail = &list;
1495
1496         if (!head)
1497                 return NULL;
1498
1499         /*
1500          * Some transports support directly peeking at
1501          * where HEAD points; if that is the case, then
1502          * we don't have to guess.
1503          */
1504         if (head->symref)
1505                 return copy_ref(find_ref_by_name(refs, head->symref));
1506
1507         /* If refs/heads/master could be right, it is. */
1508         if (!all) {
1509                 r = find_ref_by_name(refs, "refs/heads/master");
1510                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1511                         return copy_ref(r);
1512         }
1513
1514         /* Look for another ref that points there */
1515         for (r = refs; r; r = r->next) {
1516                 if (r != head && !hashcmp(r->old_sha1, head->old_sha1)) {
1517                         *tail = copy_ref(r);
1518                         tail = &((*tail)->next);
1519                         if (!all)
1520                                 break;
1521                 }
1522         }
1523
1524         return list;
1525 }