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 #include "string-list.h"
  10
  11 static struct refspec s_tag_refspec = {
  12         0,
  13         1,
  14         0,
  15         "refs/tags/*",
  16         "refs/tags/*"
  17 };
  18
  19 const struct refspec *tag_refspec = &s_tag_refspec;
  20
  21 struct counted_string {
  22         size_t len;
  23         const char *s;
  24 };
  25 struct rewrite {
  26         const char *base;
  27         size_t baselen;
  28         struct counted_string *instead_of;
  29         int instead_of_nr;
  30         int instead_of_alloc;
  31 };
  32 struct rewrites {
  33         struct rewrite **rewrite;
  34         int rewrite_alloc;
  35         int rewrite_nr;
  36 };
  37
  38 static struct remote **remotes;
  39 static int remotes_alloc;
  40 static int remotes_nr;
  41
  42 static struct branch **branches;
  43 static int branches_alloc;
  44 static int branches_nr;
  45
  46 static struct branch *current_branch;
  47 static const char *default_remote_name;
  48 static int explicit_default_remote_name;
  49
  50 static struct rewrites rewrites;
  51 static struct rewrites rewrites_push;
  52
  53 #define BUF_SIZE (2048)
  54 static char buffer[BUF_SIZE];
  55
  56 static const char *alias_url(const char *url, struct rewrites *r)
  57 {
  58         int i, j;
  59         char *ret;
  60         struct counted_string *longest;
  61         int longest_i;
  62
  63         longest = NULL;
  64         longest_i = -1;
  65         for (i = 0; i < r->rewrite_nr; i++) {
  66                 if (!r->rewrite[i])
  67                         continue;
  68                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  69                         if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  70                             (!longest ||
  71                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  72                                 longest = &(r->rewrite[i]->instead_of[j]);
  73                                 longest_i = i;
  74                         }
  75                 }
  76         }
  77         if (!longest)
  78                 return url;
  79
  80         ret = xmalloc(r->rewrite[longest_i]->baselen +
  81                      (strlen(url) - longest->len) + 1);
  82         strcpy(ret, r->rewrite[longest_i]->base);
  83         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  84         return ret;
  85 }
  86
  87 static void add_push_refspec(struct remote *remote, const char *ref)
  88 {
  89         ALLOC_GROW(remote->push_refspec,
  90                    remote->push_refspec_nr + 1,
  91                    remote->push_refspec_alloc);
  92         remote->push_refspec[remote->push_refspec_nr++] = ref;
  93 }
  94
  95 static void add_fetch_refspec(struct remote *remote, const char *ref)
  96 {
  97         ALLOC_GROW(remote->fetch_refspec,
  98                    remote->fetch_refspec_nr + 1,
  99                    remote->fetch_refspec_alloc);
 100         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 101 }
 102
 103 static void add_url(struct remote *remote, const char *url)
 104 {
 105         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 106         remote->url[remote->url_nr++] = url;
 107 }
 108
 109 static void add_pushurl(struct remote *remote, const char *pushurl)
 110 {
 111         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 112         remote->pushurl[remote->pushurl_nr++] = pushurl;
 113 }
 114
 115 static void add_pushurl_alias(struct remote *remote, const char *url)
 116 {
 117         const char *pushurl = alias_url(url, &rewrites_push);
 118         if (pushurl != url)
 119                 add_pushurl(remote, pushurl);
 120 }
 121
 122 static void add_url_alias(struct remote *remote, const char *url)
 123 {
 124         add_url(remote, alias_url(url, &rewrites));
 125         add_pushurl_alias(remote, url);
 126 }
 127
 128 static struct remote *make_remote(const char *name, int len)
 129 {
 130         struct remote *ret;
 131         int i;
 132
 133         for (i = 0; i < remotes_nr; i++) {
 134                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 135                            !remotes[i]->name[len]) :
 136                     !strcmp(name, remotes[i]->name))
 137                         return remotes[i];
 138         }
 139
 140         ret = xcalloc(1, sizeof(struct remote));
 141         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 142         remotes[remotes_nr++] = ret;
 143         if (len)
 144                 ret->name = xstrndup(name, len);
 145         else
 146                 ret->name = xstrdup(name);
 147         return ret;
 148 }
 149
 150 static void add_merge(struct branch *branch, const char *name)
 151 {
 152         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 153                    branch->merge_alloc);
 154         branch->merge_name[branch->merge_nr++] = name;
 155 }
 156
 157 static struct branch *make_branch(const char *name, int len)
 158 {
 159         struct branch *ret;
 160         int i;
 161         char *refname;
 162
 163         for (i = 0; i < branches_nr; i++) {
 164                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 165                            !branches[i]->name[len]) :
 166                     !strcmp(name, branches[i]->name))
 167                         return branches[i];
 168         }
 169
 170         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 171         ret = xcalloc(1, sizeof(struct branch));
 172         branches[branches_nr++] = ret;
 173         if (len)
 174                 ret->name = xstrndup(name, len);
 175         else
 176                 ret->name = xstrdup(name);
 177         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 178         strcpy(refname, "refs/heads/");
 179         strcpy(refname + strlen("refs/heads/"), ret->name);
 180         ret->refname = refname;
 181
 182         return ret;
 183 }
 184
 185 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 186 {
 187         struct rewrite *ret;
 188         int i;
 189
 190         for (i = 0; i < r->rewrite_nr; i++) {
 191                 if (len
 192                     ? (len == r->rewrite[i]->baselen &&
 193                        !strncmp(base, r->rewrite[i]->base, len))
 194                     : !strcmp(base, r->rewrite[i]->base))
 195                         return r->rewrite[i];
 196         }
 197
 198         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 199         ret = xcalloc(1, sizeof(struct rewrite));
 200         r->rewrite[r->rewrite_nr++] = ret;
 201         if (len) {
 202                 ret->base = xstrndup(base, len);
 203                 ret->baselen = len;
 204         }
 205         else {
 206                 ret->base = xstrdup(base);
 207                 ret->baselen = strlen(base);
 208         }
 209         return ret;
 210 }
 211
 212 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 213 {
 214         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 215         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 216         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 217         rewrite->instead_of_nr++;
 218 }
 219
 220 static void read_remotes_file(struct remote *remote)
 221 {
 222         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 223
 224         if (!f)
 225                 return;
 226         remote->origin = REMOTE_REMOTES;
 227         while (fgets(buffer, BUF_SIZE, f)) {
 228                 int value_list;
 229                 char *s, *p;
 230
 231                 if (!prefixcmp(buffer, "URL:")) {
 232                         value_list = 0;
 233                         s = buffer + 4;
 234                 } else if (!prefixcmp(buffer, "Push:")) {
 235                         value_list = 1;
 236                         s = buffer + 5;
 237                 } else if (!prefixcmp(buffer, "Pull:")) {
 238                         value_list = 2;
 239                         s = buffer + 5;
 240                 } else
 241                         continue;
 242
 243                 while (isspace(*s))
 244                         s++;
 245                 if (!*s)
 246                         continue;
 247
 248                 p = s + strlen(s);
 249                 while (isspace(p[-1]))
 250                         *--p = 0;
 251
 252                 switch (value_list) {
 253                 case 0:
 254                         add_url_alias(remote, xstrdup(s));
 255                         break;
 256                 case 1:
 257                         add_push_refspec(remote, xstrdup(s));
 258                         break;
 259                 case 2:
 260                         add_fetch_refspec(remote, xstrdup(s));
 261                         break;
 262                 }
 263         }
 264         fclose(f);
 265 }
 266
 267 static void read_branches_file(struct remote *remote)
 268 {
 269         const char *slash = strchr(remote->name, '/');
 270         char *frag;
 271         struct strbuf branch = STRBUF_INIT;
 272         int n = slash ? slash - remote->name : 1000;
 273         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 274         char *s, *p;
 275         int len;
 276
 277         if (!f)
 278                 return;
 279         s = fgets(buffer, BUF_SIZE, f);
 280         fclose(f);
 281         if (!s)
 282                 return;
 283         while (isspace(*s))
 284                 s++;
 285         if (!*s)
 286                 return;
 287         remote->origin = REMOTE_BRANCHES;
 288         p = s + strlen(s);
 289         while (isspace(p[-1]))
 290                 *--p = 0;
 291         len = p - s;
 292         if (slash)
 293                 len += strlen(slash);
 294         p = xmalloc(len + 1);
 295         strcpy(p, s);
 296         if (slash)
 297                 strcat(p, slash);
 298
 299         /*
 300          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 301          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 302          * the partial URL obtained from the branches file plus
 303          * "/netdev-2.6" and does not store it in any tracking ref.
 304          * #branch specifier in the file is ignored.
 305          *
 306          * Otherwise, the branches file would have URL and optionally
 307          * #branch specified.  The "master" (or specified) branch is
 308          * fetched and stored in the local branch of the same name.
 309          */
 310         frag = strchr(p, '#');
 311         if (frag) {
 312                 *(frag++) = '\0';
 313                 strbuf_addf(&branch, "refs/heads/%s", frag);
 314         } else
 315                 strbuf_addstr(&branch, "refs/heads/master");
 316         if (!slash) {
 317                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 318         } else {
 319                 strbuf_reset(&branch);
 320                 strbuf_addstr(&branch, "HEAD:");
 321         }
 322         add_url_alias(remote, p);
 323         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 324         /*
 325          * Cogito compatible push: push current HEAD to remote #branch
 326          * (master if missing)
 327          */
 328         strbuf_init(&branch, 0);
 329         strbuf_addstr(&branch, "HEAD");
 330         if (frag)
 331                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 332         else
 333                 strbuf_addstr(&branch, ":refs/heads/master");
 334         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 335         remote->fetch_tags = 1; /* always auto-follow */
 336 }
 337
 338 static int handle_config(const char *key, const char *value, void *cb)
 339 {
 340         const char *name;
 341         const char *subkey;
 342         struct remote *remote;
 343         struct branch *branch;
 344         if (!prefixcmp(key, "branch.")) {
 345                 name = key + 7;
 346                 subkey = strrchr(name, '.');
 347                 if (!subkey)
 348                         return 0;
 349                 branch = make_branch(name, subkey - name);
 350                 if (!strcmp(subkey, ".remote")) {
 351                         if (!value)
 352                                 return config_error_nonbool(key);
 353                         branch->remote_name = xstrdup(value);
 354                         if (branch == current_branch) {
 355                                 default_remote_name = branch->remote_name;
 356                                 explicit_default_remote_name = 1;
 357                         }
 358                 } else if (!strcmp(subkey, ".merge")) {
 359                         if (!value)
 360                                 return config_error_nonbool(key);
 361                         add_merge(branch, xstrdup(value));
 362                 }
 363                 return 0;
 364         }
 365         if (!prefixcmp(key, "url.")) {
 366                 struct rewrite *rewrite;
 367                 name = key + 4;
 368                 subkey = strrchr(name, '.');
 369                 if (!subkey)
 370                         return 0;
 371                 if (!strcmp(subkey, ".insteadof")) {
 372                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 373                         if (!value)
 374                                 return config_error_nonbool(key);
 375                         add_instead_of(rewrite, xstrdup(value));
 376                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 377                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 378                         if (!value)
 379                                 return config_error_nonbool(key);
 380                         add_instead_of(rewrite, xstrdup(value));
 381                 }
 382         }
 383         if (prefixcmp(key,  "remote."))
 384                 return 0;
 385         name = key + 7;
 386         if (*name == '/') {
 387                 warning("Config remote shorthand cannot begin with '/': %s",
 388                         name);
 389                 return 0;
 390         }
 391         subkey = strrchr(name, '.');
 392         if (!subkey)
 393                 return 0;
 394         remote = make_remote(name, subkey - name);
 395         remote->origin = REMOTE_CONFIG;
 396         if (!strcmp(subkey, ".mirror"))
 397                 remote->mirror = git_config_bool(key, value);
 398         else if (!strcmp(subkey, ".skipdefaultupdate"))
 399                 remote->skip_default_update = git_config_bool(key, value);
 400         else if (!strcmp(subkey, ".skipfetchall"))
 401                 remote->skip_default_update = git_config_bool(key, value);
 402         else if (!strcmp(subkey, ".url")) {
 403                 const char *v;
 404                 if (git_config_string(&v, key, value))
 405                         return -1;
 406                 add_url(remote, v);
 407         } else if (!strcmp(subkey, ".pushurl")) {
 408                 const char *v;
 409                 if (git_config_string(&v, key, value))
 410                         return -1;
 411                 add_pushurl(remote, v);
 412         } else if (!strcmp(subkey, ".push")) {
 413                 const char *v;
 414                 if (git_config_string(&v, key, value))
 415                         return -1;
 416                 add_push_refspec(remote, v);
 417         } else if (!strcmp(subkey, ".fetch")) {
 418                 const char *v;
 419                 if (git_config_string(&v, key, value))
 420                         return -1;
 421                 add_fetch_refspec(remote, v);
 422         } else if (!strcmp(subkey, ".receivepack")) {
 423                 const char *v;
 424                 if (git_config_string(&v, key, value))
 425                         return -1;
 426                 if (!remote->receivepack)
 427                         remote->receivepack = v;
 428                 else
 429                         error("more than one receivepack given, using the first");
 430         } else if (!strcmp(subkey, ".uploadpack")) {
 431                 const char *v;
 432                 if (git_config_string(&v, key, value))
 433                         return -1;
 434                 if (!remote->uploadpack)
 435                         remote->uploadpack = v;
 436                 else
 437                         error("more than one uploadpack given, using the first");
 438         } else if (!strcmp(subkey, ".tagopt")) {
 439                 if (!strcmp(value, "--no-tags"))
 440                         remote->fetch_tags = -1;
 441         } else if (!strcmp(subkey, ".proxy")) {
 442                 return git_config_string((const char **)&remote->http_proxy,
 443                                          key, value);
 444         }
 445         return 0;
 446 }
 447
 448 static void alias_all_urls(void)
 449 {
 450         int i, j;
 451         for (i = 0; i < remotes_nr; i++) {
 452                 int add_pushurl_aliases;
 453                 if (!remotes[i])
 454                         continue;
 455                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 456                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 457                 }
 458                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 459                 for (j = 0; j < remotes[i]->url_nr; j++) {
 460                         if (add_pushurl_aliases)
 461                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 462                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 463                 }
 464         }
 465 }
 466
 467 static void read_config(void)
 468 {
 469         unsigned char sha1[20];
 470         const char *head_ref;
 471         int flag;
 472         if (default_remote_name) // did this already
 473                 return;
 474         default_remote_name = xstrdup("origin");
 475         current_branch = NULL;
 476         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 477         if (head_ref && (flag & REF_ISSYMREF) &&
 478             !prefixcmp(head_ref, "refs/heads/")) {
 479                 current_branch =
 480                         make_branch(head_ref + strlen("refs/heads/"), 0);
 481         }
 482         git_config(handle_config, NULL);
 483         alias_all_urls();
 484 }
 485
 486 /*
 487  * We need to make sure the tracking branches are well formed, but a
 488  * wildcard refspec in "struct refspec" must have a trailing slash. We
 489  * temporarily drop the trailing '/' while calling check_ref_format(),
 490  * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 491  * error return is Ok for a wildcard refspec.
 492  */
 493 static int verify_refname(char *name, int is_glob)
 494 {
 495         int result;
 496
 497         result = check_ref_format(name);
 498         if (is_glob && result == CHECK_REF_FORMAT_WILDCARD)
 499                 result = CHECK_REF_FORMAT_OK;
 500         return result;
 501 }
 502
 503 /*
 504  * This function frees a refspec array.
 505  * Warning: code paths should be checked to ensure that the src
 506  *          and dst pointers are always freeable pointers as well
 507  *          as the refspec pointer itself.
 508  */
 509 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 510 {
 511         int i;
 512
 513         if (!refspec)
 514                 return;
 515
 516         for (i = 0; i < nr_refspec; i++) {
 517                 free(refspec[i].src);
 518                 free(refspec[i].dst);
 519         }
 520         free(refspec);
 521 }
 522
 523 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 524 {
 525         int i;
 526         int st;
 527         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 528
 529         for (i = 0; i < nr_refspec; i++) {
 530                 size_t llen;
 531                 int is_glob;
 532                 const char *lhs, *rhs;
 533
 534                 is_glob = 0;
 535
 536                 lhs = refspec[i];
 537                 if (*lhs == '+') {
 538                         rs[i].force = 1;
 539                         lhs++;
 540                 }
 541
 542                 rhs = strrchr(lhs, ':');
 543
 544                 /*
 545                  * Before going on, special case ":" (or "+:") as a refspec
 546                  * for matching refs.
 547                  */
 548                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 549                         rs[i].matching = 1;
 550                         continue;
 551                 }
 552
 553                 if (rhs) {
 554                         size_t rlen = strlen(++rhs);
 555                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 556                         rs[i].dst = xstrndup(rhs, rlen);
 557                 }
 558
 559                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 560                 if (1 <= llen && memchr(lhs, '*', llen)) {
 561                         if ((rhs && !is_glob) || (!rhs && fetch))
 562                                 goto invalid;
 563                         is_glob = 1;
 564                 } else if (rhs && is_glob) {
 565                         goto invalid;
 566                 }
 567
 568                 rs[i].pattern = is_glob;
 569                 rs[i].src = xstrndup(lhs, llen);
 570
 571                 if (fetch) {
 572                         /*
 573                          * LHS
 574                          * - empty is allowed; it means HEAD.
 575                          * - otherwise it must be a valid looking ref.
 576                          */
 577                         if (!*rs[i].src)
 578                                 ; /* empty is ok */
 579                         else {
 580                                 st = verify_refname(rs[i].src, is_glob);
 581                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 582                                         goto invalid;
 583                         }
 584                         /*
 585                          * RHS
 586                          * - missing is ok, and is same as empty.
 587                          * - empty is ok; it means not to store.
 588                          * - otherwise it must be a valid looking ref.
 589                          */
 590                         if (!rs[i].dst) {
 591                                 ; /* ok */
 592                         } else if (!*rs[i].dst) {
 593                                 ; /* ok */
 594                         } else {
 595                                 st = verify_refname(rs[i].dst, is_glob);
 596                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 597                                         goto invalid;
 598                         }
 599                 } else {
 600                         /*
 601                          * LHS
 602                          * - empty is allowed; it means delete.
 603                          * - when wildcarded, it must be a valid looking ref.
 604                          * - otherwise, it must be an extended SHA-1, but
 605                          *   there is no existing way to validate this.
 606                          */
 607                         if (!*rs[i].src)
 608                                 ; /* empty is ok */
 609                         else if (is_glob) {
 610                                 st = verify_refname(rs[i].src, is_glob);
 611                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 612                                         goto invalid;
 613                         }
 614                         else
 615                                 ; /* anything goes, for now */
 616                         /*
 617                          * RHS
 618                          * - missing is allowed, but LHS then must be a
 619                          *   valid looking ref.
 620                          * - empty is not allowed.
 621                          * - otherwise it must be a valid looking ref.
 622                          */
 623                         if (!rs[i].dst) {
 624                                 st = verify_refname(rs[i].src, is_glob);
 625                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 626                                         goto invalid;
 627                         } else if (!*rs[i].dst) {
 628                                 goto invalid;
 629                         } else {
 630                                 st = verify_refname(rs[i].dst, is_glob);
 631                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 632                                         goto invalid;
 633                         }
 634                 }
 635         }
 636         return rs;
 637
 638  invalid:
 639         if (verify) {
 640                 /*
 641                  * nr_refspec must be greater than zero and i must be valid
 642                  * since it is only possible to reach this point from within
 643                  * the for loop above.
 644                  */
 645                 free_refspecs(rs, i+1);
 646                 return NULL;
 647         }
 648         die("Invalid refspec '%s'", refspec[i]);
 649 }
 650
 651 int valid_fetch_refspec(const char *fetch_refspec_str)
 652 {
 653         const char *fetch_refspec[] = { fetch_refspec_str };
 654         struct refspec *refspec;
 655
 656         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 657         free_refspecs(refspec, 1);
 658         return !!refspec;
 659 }
 660
 661 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 662 {
 663         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 664 }
 665
 666 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 667 {
 668         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 669 }
 670
 671 static int valid_remote_nick(const char *name)
 672 {
 673         if (!name[0] || is_dot_or_dotdot(name))
 674                 return 0;
 675         return !strchr(name, '/'); /* no slash */
 676 }
 677
 678 struct remote *remote_get(const char *name)
 679 {
 680         struct remote *ret;
 681         int name_given = 0;
 682
 683         read_config();
 684         if (name)
 685                 name_given = 1;
 686         else {
 687                 name = default_remote_name;
 688                 name_given = explicit_default_remote_name;
 689         }
 690
 691         ret = make_remote(name, 0);
 692         if (valid_remote_nick(name)) {
 693                 if (!ret->url)
 694                         read_remotes_file(ret);
 695                 if (!ret->url)
 696                         read_branches_file(ret);
 697         }
 698         if (name_given && !ret->url)
 699                 add_url_alias(ret, name);
 700         if (!ret->url)
 701                 return NULL;
 702         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 703         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 704         return ret;
 705 }
 706
 707 int remote_is_configured(const char *name)
 708 {
 709         int i;
 710         read_config();
 711
 712         for (i = 0; i < remotes_nr; i++)
 713                 if (!strcmp(name, remotes[i]->name))
 714                         return 1;
 715         return 0;
 716 }
 717
 718 int for_each_remote(each_remote_fn fn, void *priv)
 719 {
 720         int i, result = 0;
 721         read_config();
 722         for (i = 0; i < remotes_nr && !result; i++) {
 723                 struct remote *r = remotes[i];
 724                 if (!r)
 725                         continue;
 726                 if (!r->fetch)
 727                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 728                                                        r->fetch_refspec);
 729                 if (!r->push)
 730                         r->push = parse_push_refspec(r->push_refspec_nr,
 731                                                      r->push_refspec);
 732                 result = fn(r, priv);
 733         }
 734         return result;
 735 }
 736
 737 void ref_remove_duplicates(struct ref *ref_map)
 738 {
 739         struct string_list refs = { NULL, 0, 0, 0 };
 740         struct string_list_item *item = NULL;
 741         struct ref *prev = NULL, *next = NULL;
 742         for (; ref_map; prev = ref_map, ref_map = next) {
 743                 next = ref_map->next;
 744                 if (!ref_map->peer_ref)
 745                         continue;
 746
 747                 item = string_list_lookup(ref_map->peer_ref->name, &refs);
 748                 if (item) {
 749                         if (strcmp(((struct ref *)item->util)->name,
 750                                    ref_map->name))
 751                                 die("%s tracks both %s and %s",
 752                                     ref_map->peer_ref->name,
 753                                     ((struct ref *)item->util)->name,
 754                                     ref_map->name);
 755                         prev->next = ref_map->next;
 756                         free(ref_map->peer_ref);
 757                         free(ref_map);
 758                         ref_map = prev; /* skip this; we freed it */
 759                         continue;
 760                 }
 761
 762                 item = string_list_insert(ref_map->peer_ref->name, &refs);
 763                 item->util = ref_map;
 764         }
 765         string_list_clear(&refs, 0);
 766 }
 767
 768 int remote_has_url(struct remote *remote, const char *url)
 769 {
 770         int i;
 771         for (i = 0; i < remote->url_nr; i++) {
 772                 if (!strcmp(remote->url[i], url))
 773                         return 1;
 774         }
 775         return 0;
 776 }
 777
 778 static int match_name_with_pattern(const char *key, const char *name,
 779                                    const char *value, char **result)
 780 {
 781         const char *kstar = strchr(key, '*');
 782         size_t klen;
 783         size_t ksuffixlen;
 784         size_t namelen;
 785         int ret;
 786         if (!kstar)
 787                 die("Key '%s' of pattern had no '*'", key);
 788         klen = kstar - key;
 789         ksuffixlen = strlen(kstar + 1);
 790         namelen = strlen(name);
 791         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 792                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 793         if (ret && value) {
 794                 const char *vstar = strchr(value, '*');
 795                 size_t vlen;
 796                 size_t vsuffixlen;
 797                 if (!vstar)
 798                         die("Value '%s' of pattern has no '*'", value);
 799                 vlen = vstar - value;
 800                 vsuffixlen = strlen(vstar + 1);
 801                 *result = xmalloc(vlen + vsuffixlen +
 802                                   strlen(name) -
 803                                   klen - ksuffixlen + 1);
 804                 strncpy(*result, value, vlen);
 805                 strncpy(*result + vlen,
 806                         name + klen, namelen - klen - ksuffixlen);
 807                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 808                        vstar + 1);
 809         }
 810         return ret;
 811 }
 812
 813 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 814 {
 815         int find_src = refspec->src == NULL;
 816         char *needle, **result;
 817         int i;
 818
 819         if (find_src) {
 820                 if (!refspec->dst)
 821                         return error("find_tracking: need either src or dst");
 822                 needle = refspec->dst;
 823                 result = &refspec->src;
 824         } else {
 825                 needle = refspec->src;
 826                 result = &refspec->dst;
 827         }
 828
 829         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 830                 struct refspec *fetch = &remote->fetch[i];
 831                 const char *key = find_src ? fetch->dst : fetch->src;
 832                 const char *value = find_src ? fetch->src : fetch->dst;
 833                 if (!fetch->dst)
 834                         continue;
 835                 if (fetch->pattern) {
 836                         if (match_name_with_pattern(key, needle, value, result)) {
 837                                 refspec->force = fetch->force;
 838                                 return 0;
 839                         }
 840                 } else if (!strcmp(needle, key)) {
 841                         *result = xstrdup(value);
 842                         refspec->force = fetch->force;
 843                         return 0;
 844                 }
 845         }
 846         return -1;
 847 }
 848
 849 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 850                 const char *name)
 851 {
 852         size_t len = strlen(name);
 853         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 854         memcpy(ref->name, prefix, prefixlen);
 855         memcpy(ref->name + prefixlen, name, len);
 856         return ref;
 857 }
 858
 859 struct ref *alloc_ref(const char *name)
 860 {
 861         return alloc_ref_with_prefix("", 0, name);
 862 }
 863
 864 static struct ref *copy_ref(const struct ref *ref)
 865 {
 866         struct ref *cpy;
 867         size_t len;
 868         if (!ref)
 869                 return NULL;
 870         len = strlen(ref->name);
 871         cpy = xmalloc(sizeof(struct ref) + len + 1);
 872         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 873         cpy->next = NULL;
 874         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 875         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 876         cpy->peer_ref = copy_ref(ref->peer_ref);
 877         return cpy;
 878 }
 879
 880 struct ref *copy_ref_list(const struct ref *ref)
 881 {
 882         struct ref *ret = NULL;
 883         struct ref **tail = &ret;
 884         while (ref) {
 885                 *tail = copy_ref(ref);
 886                 ref = ref->next;
 887                 tail = &((*tail)->next);
 888         }
 889         return ret;
 890 }
 891
 892 static void free_ref(struct ref *ref)
 893 {
 894         if (!ref)
 895                 return;
 896         free_ref(ref->peer_ref);
 897         free(ref->remote_status);
 898         free(ref->symref);
 899         free(ref);
 900 }
 901
 902 void free_refs(struct ref *ref)
 903 {
 904         struct ref *next;
 905         while (ref) {
 906                 next = ref->next;
 907                 free_ref(ref);
 908                 ref = next;
 909         }
 910 }
 911
 912 static int count_refspec_match(const char *pattern,
 913                                struct ref *refs,
 914                                struct ref **matched_ref)
 915 {
 916         int patlen = strlen(pattern);
 917         struct ref *matched_weak = NULL;
 918         struct ref *matched = NULL;
 919         int weak_match = 0;
 920         int match = 0;
 921
 922         for (weak_match = match = 0; refs; refs = refs->next) {
 923                 char *name = refs->name;
 924                 int namelen = strlen(name);
 925
 926                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 927                         continue;
 928
 929                 /* A match is "weak" if it is with refs outside
 930                  * heads or tags, and did not specify the pattern
 931                  * in full (e.g. "refs/remotes/origin/master") or at
 932                  * least from the toplevel (e.g. "remotes/origin/master");
 933                  * otherwise "git push $URL master" would result in
 934                  * ambiguity between remotes/origin/master and heads/master
 935                  * at the remote site.
 936                  */
 937                 if (namelen != patlen &&
 938                     patlen != namelen - 5 &&
 939                     prefixcmp(name, "refs/heads/") &&
 940                     prefixcmp(name, "refs/tags/")) {
 941                         /* We want to catch the case where only weak
 942                          * matches are found and there are multiple
 943                          * matches, and where more than one strong
 944                          * matches are found, as ambiguous.  One
 945                          * strong match with zero or more weak matches
 946                          * are acceptable as a unique match.
 947                          */
 948                         matched_weak = refs;
 949                         weak_match++;
 950                 }
 951                 else {
 952                         matched = refs;
 953                         match++;
 954                 }
 955         }
 956         if (!matched) {
 957                 *matched_ref = matched_weak;
 958                 return weak_match;
 959         }
 960         else {
 961                 *matched_ref = matched;
 962                 return match;
 963         }
 964 }
 965
 966 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 967 {
 968         **tail = ref;
 969         while (ref->next)
 970                 ref = ref->next;
 971         *tail = &ref->next;
 972 }
 973
 974 static struct ref *try_explicit_object_name(const char *name)
 975 {
 976         unsigned char sha1[20];
 977         struct ref *ref;
 978
 979         if (!*name) {
 980                 ref = alloc_ref("(delete)");
 981                 hashclr(ref->new_sha1);
 982                 return ref;
 983         }
 984         if (get_sha1(name, sha1))
 985                 return NULL;
 986         ref = alloc_ref(name);
 987         hashcpy(ref->new_sha1, sha1);
 988         return ref;
 989 }
 990
 991 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 992 {
 993         struct ref *ret = alloc_ref(name);
 994         tail_link_ref(ret, tail);
 995         return ret;
 996 }
 997
 998 static char *guess_ref(const char *name, struct ref *peer)
 999 {
1000         struct strbuf buf = STRBUF_INIT;
1001         unsigned char sha1[20];
1002
1003         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
1004         if (!r)
1005                 return NULL;
1006
1007         if (!prefixcmp(r, "refs/heads/"))
1008                 strbuf_addstr(&buf, "refs/heads/");
1009         else if (!prefixcmp(r, "refs/tags/"))
1010                 strbuf_addstr(&buf, "refs/tags/");
1011         else
1012                 return NULL;
1013
1014         strbuf_addstr(&buf, name);
1015         return strbuf_detach(&buf, NULL);
1016 }
1017
1018 static int match_explicit(struct ref *src, struct ref *dst,
1019                           struct ref ***dst_tail,
1020                           struct refspec *rs)
1021 {
1022         struct ref *matched_src, *matched_dst;
1023         int copy_src;
1024
1025         const char *dst_value = rs->dst;
1026         char *dst_guess;
1027
1028         if (rs->pattern || rs->matching)
1029                 return 0;
1030
1031         matched_src = matched_dst = NULL;
1032         switch (count_refspec_match(rs->src, src, &matched_src)) {
1033         case 1:
1034                 copy_src = 1;
1035                 break;
1036         case 0:
1037                 /* The source could be in the get_sha1() format
1038                  * not a reference name.  :refs/other is a
1039                  * way to delete 'other' ref at the remote end.
1040                  */
1041                 matched_src = try_explicit_object_name(rs->src);
1042                 if (!matched_src)
1043                         return error("src refspec %s does not match any.", rs->src);
1044                 copy_src = 0;
1045                 break;
1046         default:
1047                 return error("src refspec %s matches more than one.", rs->src);
1048         }
1049
1050         if (!dst_value) {
1051                 unsigned char sha1[20];
1052                 int flag;
1053
1054                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
1055                 if (!dst_value ||
1056                     ((flag & REF_ISSYMREF) &&
1057                      prefixcmp(dst_value, "refs/heads/")))
1058                         die("%s cannot be resolved to branch.",
1059                             matched_src->name);
1060         }
1061
1062         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1063         case 1:
1064                 break;
1065         case 0:
1066                 if (!memcmp(dst_value, "refs/", 5))
1067                         matched_dst = make_linked_ref(dst_value, dst_tail);
1068                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1069                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1070                 else
1071                         error("unable to push to unqualified destination: %s\n"
1072                               "The destination refspec neither matches an "
1073                               "existing ref on the remote nor\n"
1074                               "begins with refs/, and we are unable to "
1075                               "guess a prefix based on the source ref.",
1076                               dst_value);
1077                 break;
1078         default:
1079                 matched_dst = NULL;
1080                 error("dst refspec %s matches more than one.",
1081                       dst_value);
1082                 break;
1083         }
1084         if (!matched_dst)
1085                 return -1;
1086         if (matched_dst->peer_ref)
1087                 return error("dst ref %s receives from more than one src.",
1088                       matched_dst->name);
1089         else {
1090                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1091                 matched_dst->force = rs->force;
1092         }
1093         return 0;
1094 }
1095
1096 static int match_explicit_refs(struct ref *src, struct ref *dst,
1097                                struct ref ***dst_tail, struct refspec *rs,
1098                                int rs_nr)
1099 {
1100         int i, errs;
1101         for (i = errs = 0; i < rs_nr; i++)
1102                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1103         return errs;
1104 }
1105
1106 static const struct refspec *check_pattern_match(const struct refspec *rs,
1107                                                  int rs_nr,
1108                                                  const struct ref *src)
1109 {
1110         int i;
1111         int matching_refs = -1;
1112         for (i = 0; i < rs_nr; i++) {
1113                 if (rs[i].matching &&
1114                     (matching_refs == -1 || rs[i].force)) {
1115                         matching_refs = i;
1116                         continue;
1117                 }
1118
1119                 if (rs[i].pattern && match_name_with_pattern(rs[i].src, src->name,
1120                                                              NULL, NULL))
1121                         return rs + i;
1122         }
1123         if (matching_refs != -1)
1124                 return rs + matching_refs;
1125         else
1126                 return NULL;
1127 }
1128
1129 static struct ref **tail_ref(struct ref **head)
1130 {
1131         struct ref **tail = head;
1132         while (*tail)
1133                 tail = &((*tail)->next);
1134         return tail;
1135 }
1136
1137 /*
1138  * Note. This is used only by "push"; refspec matching rules for
1139  * push and fetch are subtly different, so do not try to reuse it
1140  * without thinking.
1141  */
1142 int match_refs(struct ref *src, struct ref **dst,
1143                int nr_refspec, const char **refspec, int flags)
1144 {
1145         struct refspec *rs;
1146         int send_all = flags & MATCH_REFS_ALL;
1147         int send_mirror = flags & MATCH_REFS_MIRROR;
1148         int errs;
1149         static const char *default_refspec[] = { ":", NULL };
1150         struct ref **dst_tail = tail_ref(dst);
1151
1152         if (!nr_refspec) {
1153                 nr_refspec = 1;
1154                 refspec = default_refspec;
1155         }
1156         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1157         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1158
1159         /* pick the remainder */
1160         for ( ; src; src = src->next) {
1161                 struct ref *dst_peer;
1162                 const struct refspec *pat = NULL;
1163                 char *dst_name;
1164                 if (src->peer_ref)
1165                         continue;
1166
1167                 pat = check_pattern_match(rs, nr_refspec, src);
1168                 if (!pat)
1169                         continue;
1170
1171                 if (pat->matching) {
1172                         /*
1173                          * "matching refs"; traditionally we pushed everything
1174                          * including refs outside refs/heads/ hierarchy, but
1175                          * that does not make much sense these days.
1176                          */
1177                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1178                                 continue;
1179                         dst_name = xstrdup(src->name);
1180
1181                 } else {
1182                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1183                         if (!match_name_with_pattern(pat->src, src->name,
1184                                                      dst_side, &dst_name))
1185                                 die("Didn't think it matches any more");
1186                 }
1187                 dst_peer = find_ref_by_name(*dst, dst_name);
1188                 if (dst_peer) {
1189                         if (dst_peer->peer_ref)
1190                                 /* We're already sending something to this ref. */
1191                                 goto free_name;
1192
1193                 } else {
1194                         if (pat->matching && !(send_all || send_mirror))
1195                                 /*
1196                                  * Remote doesn't have it, and we have no
1197                                  * explicit pattern, and we don't have
1198                                  * --all nor --mirror.
1199                                  */
1200                                 goto free_name;
1201
1202                         /* Create a new one and link it */
1203                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1204                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1205                 }
1206                 dst_peer->peer_ref = copy_ref(src);
1207                 dst_peer->force = pat->force;
1208         free_name:
1209                 free(dst_name);
1210         }
1211         if (errs)
1212                 return -1;
1213         return 0;
1214 }
1215
1216 struct branch *branch_get(const char *name)
1217 {
1218         struct branch *ret;
1219
1220         read_config();
1221         if (!name || !*name || !strcmp(name, "HEAD"))
1222                 ret = current_branch;
1223         else
1224                 ret = make_branch(name, 0);
1225         if (ret && ret->remote_name) {
1226                 ret->remote = remote_get(ret->remote_name);
1227                 if (ret->merge_nr) {
1228                         int i;
1229                         ret->merge = xcalloc(sizeof(*ret->merge),
1230                                              ret->merge_nr);
1231                         for (i = 0; i < ret->merge_nr; i++) {
1232                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1233                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1234                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1235                                     && !strcmp(ret->remote_name, "."))
1236                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1237                         }
1238                 }
1239         }
1240         return ret;
1241 }
1242
1243 int branch_has_merge_config(struct branch *branch)
1244 {
1245         return branch && !!branch->merge;
1246 }
1247
1248 int branch_merge_matches(struct branch *branch,
1249                                  int i,
1250                                  const char *refname)
1251 {
1252         if (!branch || i < 0 || i >= branch->merge_nr)
1253                 return 0;
1254         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1255 }
1256
1257 static struct ref *get_expanded_map(const struct ref *remote_refs,
1258                                     const struct refspec *refspec)
1259 {
1260         const struct ref *ref;
1261         struct ref *ret = NULL;
1262         struct ref **tail = &ret;
1263
1264         char *expn_name;
1265
1266         for (ref = remote_refs; ref; ref = ref->next) {
1267                 if (strchr(ref->name, '^'))
1268                         continue; /* a dereference item */
1269                 if (match_name_with_pattern(refspec->src, ref->name,
1270                                             refspec->dst, &expn_name)) {
1271                         struct ref *cpy = copy_ref(ref);
1272
1273                         cpy->peer_ref = alloc_ref(expn_name);
1274                         free(expn_name);
1275                         if (refspec->force)
1276                                 cpy->peer_ref->force = 1;
1277                         *tail = cpy;
1278                         tail = &cpy->next;
1279                 }
1280         }
1281
1282         return ret;
1283 }
1284
1285 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1286 {
1287         const struct ref *ref;
1288         for (ref = refs; ref; ref = ref->next) {
1289                 if (refname_match(name, ref->name, ref_fetch_rules))
1290                         return ref;
1291         }
1292         return NULL;
1293 }
1294
1295 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1296 {
1297         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1298
1299         if (!ref)
1300                 return NULL;
1301
1302         return copy_ref(ref);
1303 }
1304
1305 static struct ref *get_local_ref(const char *name)
1306 {
1307         if (!name || name[0] == '\0')
1308                 return NULL;
1309
1310         if (!prefixcmp(name, "refs/"))
1311                 return alloc_ref(name);
1312
1313         if (!prefixcmp(name, "heads/") ||
1314             !prefixcmp(name, "tags/") ||
1315             !prefixcmp(name, "remotes/"))
1316                 return alloc_ref_with_prefix("refs/", 5, name);
1317
1318         return alloc_ref_with_prefix("refs/heads/", 11, name);
1319 }
1320
1321 int get_fetch_map(const struct ref *remote_refs,
1322                   const struct refspec *refspec,
1323                   struct ref ***tail,
1324                   int missing_ok)
1325 {
1326         struct ref *ref_map, **rmp;
1327
1328         if (refspec->pattern) {
1329                 ref_map = get_expanded_map(remote_refs, refspec);
1330         } else {
1331                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1332
1333                 ref_map = get_remote_ref(remote_refs, name);
1334                 if (!missing_ok && !ref_map)
1335                         die("Couldn't find remote ref %s", name);
1336                 if (ref_map) {
1337                         ref_map->peer_ref = get_local_ref(refspec->dst);
1338                         if (ref_map->peer_ref && refspec->force)
1339                                 ref_map->peer_ref->force = 1;
1340                 }
1341         }
1342
1343         for (rmp = &ref_map; *rmp; ) {
1344                 if ((*rmp)->peer_ref) {
1345                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1346                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1347                                 struct ref *ignore = *rmp;
1348                                 error("* Ignoring funny ref '%s' locally",
1349                                       (*rmp)->peer_ref->name);
1350                                 *rmp = (*rmp)->next;
1351                                 free(ignore->peer_ref);
1352                                 free(ignore);
1353                                 continue;
1354                         }
1355                 }
1356                 rmp = &((*rmp)->next);
1357         }
1358
1359         if (ref_map)
1360                 tail_link_ref(ref_map, tail);
1361
1362         return 0;
1363 }
1364
1365 int resolve_remote_symref(struct ref *ref, struct ref *list)
1366 {
1367         if (!ref->symref)
1368                 return 0;
1369         for (; list; list = list->next)
1370                 if (!strcmp(ref->symref, list->name)) {
1371                         hashcpy(ref->old_sha1, list->old_sha1);
1372                         return 0;
1373                 }
1374         return 1;
1375 }
1376
1377 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1378 {
1379         while (list) {
1380                 struct commit_list *temp = list;
1381                 temp->item->object.flags &= ~mark;
1382                 list = temp->next;
1383                 free(temp);
1384         }
1385 }
1386
1387 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1388 {
1389         struct object *o;
1390         struct commit *old, *new;
1391         struct commit_list *list, *used;
1392         int found = 0;
1393
1394         /* Both new and old must be commit-ish and new is descendant of
1395          * old.  Otherwise we require --force.
1396          */
1397         o = deref_tag(parse_object(old_sha1), NULL, 0);
1398         if (!o || o->type != OBJ_COMMIT)
1399                 return 0;
1400         old = (struct commit *) o;
1401
1402         o = deref_tag(parse_object(new_sha1), NULL, 0);
1403         if (!o || o->type != OBJ_COMMIT)
1404                 return 0;
1405         new = (struct commit *) o;
1406
1407         if (parse_commit(new) < 0)
1408                 return 0;
1409
1410         used = list = NULL;
1411         commit_list_insert(new, &list);
1412         while (list) {
1413                 new = pop_most_recent_commit(&list, TMP_MARK);
1414                 commit_list_insert(new, &used);
1415                 if (new == old) {
1416                         found = 1;
1417                         break;
1418                 }
1419         }
1420         unmark_and_free(list, TMP_MARK);
1421         unmark_and_free(used, TMP_MARK);
1422         return found;
1423 }
1424
1425 /*
1426  * Return true if there is anything to report, otherwise false.
1427  */
1428 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1429 {
1430         unsigned char sha1[20];
1431         struct commit *ours, *theirs;
1432         char symmetric[84];
1433         struct rev_info revs;
1434         const char *rev_argv[10], *base;
1435         int rev_argc;
1436
1437         /*
1438          * Nothing to report unless we are marked to build on top of
1439          * somebody else.
1440          */
1441         if (!branch ||
1442             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1443                 return 0;
1444
1445         /*
1446          * If what we used to build on no longer exists, there is
1447          * nothing to report.
1448          */
1449         base = branch->merge[0]->dst;
1450         if (!resolve_ref(base, sha1, 1, NULL))
1451                 return 0;
1452         theirs = lookup_commit_reference(sha1);
1453         if (!theirs)
1454                 return 0;
1455
1456         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1457                 return 0;
1458         ours = lookup_commit_reference(sha1);
1459         if (!ours)
1460                 return 0;
1461
1462         /* are we the same? */
1463         if (theirs == ours)
1464                 return 0;
1465
1466         /* Run "rev-list --left-right ours...theirs" internally... */
1467         rev_argc = 0;
1468         rev_argv[rev_argc++] = NULL;
1469         rev_argv[rev_argc++] = "--left-right";
1470         rev_argv[rev_argc++] = symmetric;
1471         rev_argv[rev_argc++] = "--";
1472         rev_argv[rev_argc] = NULL;
1473
1474         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1475         strcpy(symmetric + 40, "...");
1476         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1477
1478         init_revisions(&revs, NULL);
1479         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1480         prepare_revision_walk(&revs);
1481
1482         /* ... and count the commits on each side. */
1483         *num_ours = 0;
1484         *num_theirs = 0;
1485         while (1) {
1486                 struct commit *c = get_revision(&revs);
1487                 if (!c)
1488                         break;
1489                 if (c->object.flags & SYMMETRIC_LEFT)
1490                         (*num_ours)++;
1491                 else
1492                         (*num_theirs)++;
1493         }
1494
1495         /* clear object flags smudged by the above traversal */
1496         clear_commit_marks(ours, ALL_REV_FLAGS);
1497         clear_commit_marks(theirs, ALL_REV_FLAGS);
1498         return 1;
1499 }
1500
1501 /*
1502  * Return true when there is anything to report, otherwise false.
1503  */
1504 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1505 {
1506         int num_ours, num_theirs;
1507         const char *base;
1508
1509         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1510                 return 0;
1511
1512         base = branch->merge[0]->dst;
1513         base = shorten_unambiguous_ref(base, 0);
1514         if (!num_theirs)
1515                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1516                             "by %d commit%s.\n",
1517                             base, num_ours, (num_ours == 1) ? "" : "s");
1518         else if (!num_ours)
1519                 strbuf_addf(sb, "Your branch is behind '%s' "
1520                             "by %d commit%s, "
1521                             "and can be fast-forwarded.\n",
1522                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1523         else
1524                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1525                             "and have %d and %d different commit(s) each, "
1526                             "respectively.\n",
1527                             base, num_ours, num_theirs);
1528         return 1;
1529 }
1530
1531 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1532 {
1533         struct ref ***local_tail = cb_data;
1534         struct ref *ref;
1535         int len;
1536
1537         /* we already know it starts with refs/ to get here */
1538         if (check_ref_format(refname + 5))
1539                 return 0;
1540
1541         len = strlen(refname) + 1;
1542         ref = xcalloc(1, sizeof(*ref) + len);
1543         hashcpy(ref->new_sha1, sha1);
1544         memcpy(ref->name, refname, len);
1545         **local_tail = ref;
1546         *local_tail = &ref->next;
1547         return 0;
1548 }
1549
1550 struct ref *get_local_heads(void)
1551 {
1552         struct ref *local_refs = NULL, **local_tail = &local_refs;
1553         for_each_ref(one_local_ref, &local_tail);
1554         return local_refs;
1555 }
1556
1557 struct ref *guess_remote_head(const struct ref *head,
1558                               const struct ref *refs,
1559                               int all)
1560 {
1561         const struct ref *r;
1562         struct ref *list = NULL;
1563         struct ref **tail = &list;
1564
1565         if (!head)
1566                 return NULL;
1567
1568         /*
1569          * Some transports support directly peeking at
1570          * where HEAD points; if that is the case, then
1571          * we don't have to guess.
1572          */
1573         if (head->symref)
1574                 return copy_ref(find_ref_by_name(refs, head->symref));
1575
1576         /* If refs/heads/master could be right, it is. */
1577         if (!all) {
1578                 r = find_ref_by_name(refs, "refs/heads/master");
1579                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1580                         return copy_ref(r);
1581         }
1582
1583         /* Look for another ref that points there */
1584         for (r = refs; r; r = r->next) {
1585                 if (r != head && !hashcmp(r->old_sha1, head->old_sha1)) {
1586                         *tail = copy_ref(r);
1587                         tail = &((*tail)->next);
1588                         if (!all)
1589                                 break;
1590                 }
1591         }
1592
1593         return list;
1594 }
1595
1596 struct stale_heads_info {
1597         struct remote *remote;
1598         struct string_list *ref_names;
1599         struct ref **stale_refs_tail;
1600 };
1601
1602 static int get_stale_heads_cb(const char *refname,
1603         const unsigned char *sha1, int flags, void *cb_data)
1604 {
1605         struct stale_heads_info *info = cb_data;
1606         struct refspec refspec;
1607         memset(&refspec, 0, sizeof(refspec));
1608         refspec.dst = (char *)refname;
1609         if (!remote_find_tracking(info->remote, &refspec)) {
1610                 if (!((flags & REF_ISSYMREF) ||
1611                     string_list_has_string(info->ref_names, refspec.src))) {
1612                         struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1613                         hashcpy(ref->new_sha1, sha1);
1614                 }
1615         }
1616         return 0;
1617 }
1618
1619 struct ref *get_stale_heads(struct remote *remote, struct ref *fetch_map)
1620 {
1621         struct ref *ref, *stale_refs = NULL;
1622         struct string_list ref_names = { NULL, 0, 0, 0 };
1623         struct stale_heads_info info;
1624         info.remote = remote;
1625         info.ref_names = &ref_names;
1626         info.stale_refs_tail = &stale_refs;
1627         for (ref = fetch_map; ref; ref = ref->next)
1628                 string_list_append(ref->name, &ref_names);
1629         sort_string_list(&ref_names);
1630         for_each_ref(get_stale_heads_cb, &info);
1631         string_list_clear(&ref_names, 0);
1632         return stale_refs;
1633 }