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 int valid_remote(const struct remote *remote)
  57 {
  58         return (!!remote->url) || (!!remote->foreign_vcs);
  59 }
  60
  61 static const char *alias_url(const char *url, struct rewrites *r)
  62 {
  63         int i, j;
  64         char *ret;
  65         struct counted_string *longest;
  66         int longest_i;
  67
  68         longest = NULL;
  69         longest_i = -1;
  70         for (i = 0; i < r->rewrite_nr; i++) {
  71                 if (!r->rewrite[i])
  72                         continue;
  73                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  74                         if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  75                             (!longest ||
  76                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  77                                 longest = &(r->rewrite[i]->instead_of[j]);
  78                                 longest_i = i;
  79                         }
  80                 }
  81         }
  82         if (!longest)
  83                 return url;
  84
  85         ret = xmalloc(r->rewrite[longest_i]->baselen +
  86                      (strlen(url) - longest->len) + 1);
  87         strcpy(ret, r->rewrite[longest_i]->base);
  88         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  89         return ret;
  90 }
  91
  92 static void add_push_refspec(struct remote *remote, const char *ref)
  93 {
  94         ALLOC_GROW(remote->push_refspec,
  95                    remote->push_refspec_nr + 1,
  96                    remote->push_refspec_alloc);
  97         remote->push_refspec[remote->push_refspec_nr++] = ref;
  98 }
  99
 100 static void add_fetch_refspec(struct remote *remote, const char *ref)
 101 {
 102         ALLOC_GROW(remote->fetch_refspec,
 103                    remote->fetch_refspec_nr + 1,
 104                    remote->fetch_refspec_alloc);
 105         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 106 }
 107
 108 static void add_url(struct remote *remote, const char *url)
 109 {
 110         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 111         remote->url[remote->url_nr++] = url;
 112 }
 113
 114 static void add_pushurl(struct remote *remote, const char *pushurl)
 115 {
 116         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 117         remote->pushurl[remote->pushurl_nr++] = pushurl;
 118 }
 119
 120 static void add_pushurl_alias(struct remote *remote, const char *url)
 121 {
 122         const char *pushurl = alias_url(url, &rewrites_push);
 123         if (pushurl != url)
 124                 add_pushurl(remote, pushurl);
 125 }
 126
 127 static void add_url_alias(struct remote *remote, const char *url)
 128 {
 129         add_url(remote, alias_url(url, &rewrites));
 130         add_pushurl_alias(remote, url);
 131 }
 132
 133 static struct remote *make_remote(const char *name, int len)
 134 {
 135         struct remote *ret;
 136         int i;
 137
 138         for (i = 0; i < remotes_nr; i++) {
 139                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 140                            !remotes[i]->name[len]) :
 141                     !strcmp(name, remotes[i]->name))
 142                         return remotes[i];
 143         }
 144
 145         ret = xcalloc(1, sizeof(struct remote));
 146         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 147         remotes[remotes_nr++] = ret;
 148         if (len)
 149                 ret->name = xstrndup(name, len);
 150         else
 151                 ret->name = xstrdup(name);
 152         return ret;
 153 }
 154
 155 static void add_merge(struct branch *branch, const char *name)
 156 {
 157         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 158                    branch->merge_alloc);
 159         branch->merge_name[branch->merge_nr++] = name;
 160 }
 161
 162 static struct branch *make_branch(const char *name, int len)
 163 {
 164         struct branch *ret;
 165         int i;
 166         char *refname;
 167
 168         for (i = 0; i < branches_nr; i++) {
 169                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 170                            !branches[i]->name[len]) :
 171                     !strcmp(name, branches[i]->name))
 172                         return branches[i];
 173         }
 174
 175         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 176         ret = xcalloc(1, sizeof(struct branch));
 177         branches[branches_nr++] = ret;
 178         if (len)
 179                 ret->name = xstrndup(name, len);
 180         else
 181                 ret->name = xstrdup(name);
 182         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 183         strcpy(refname, "refs/heads/");
 184         strcpy(refname + strlen("refs/heads/"), ret->name);
 185         ret->refname = refname;
 186
 187         return ret;
 188 }
 189
 190 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 191 {
 192         struct rewrite *ret;
 193         int i;
 194
 195         for (i = 0; i < r->rewrite_nr; i++) {
 196                 if (len
 197                     ? (len == r->rewrite[i]->baselen &&
 198                        !strncmp(base, r->rewrite[i]->base, len))
 199                     : !strcmp(base, r->rewrite[i]->base))
 200                         return r->rewrite[i];
 201         }
 202
 203         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 204         ret = xcalloc(1, sizeof(struct rewrite));
 205         r->rewrite[r->rewrite_nr++] = ret;
 206         if (len) {
 207                 ret->base = xstrndup(base, len);
 208                 ret->baselen = len;
 209         }
 210         else {
 211                 ret->base = xstrdup(base);
 212                 ret->baselen = strlen(base);
 213         }
 214         return ret;
 215 }
 216
 217 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 218 {
 219         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 220         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 221         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 222         rewrite->instead_of_nr++;
 223 }
 224
 225 static void read_remotes_file(struct remote *remote)
 226 {
 227         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 228
 229         if (!f)
 230                 return;
 231         remote->origin = REMOTE_REMOTES;
 232         while (fgets(buffer, BUF_SIZE, f)) {
 233                 int value_list;
 234                 char *s, *p;
 235
 236                 if (!prefixcmp(buffer, "URL:")) {
 237                         value_list = 0;
 238                         s = buffer + 4;
 239                 } else if (!prefixcmp(buffer, "Push:")) {
 240                         value_list = 1;
 241                         s = buffer + 5;
 242                 } else if (!prefixcmp(buffer, "Pull:")) {
 243                         value_list = 2;
 244                         s = buffer + 5;
 245                 } else
 246                         continue;
 247
 248                 while (isspace(*s))
 249                         s++;
 250                 if (!*s)
 251                         continue;
 252
 253                 p = s + strlen(s);
 254                 while (isspace(p[-1]))
 255                         *--p = 0;
 256
 257                 switch (value_list) {
 258                 case 0:
 259                         add_url_alias(remote, xstrdup(s));
 260                         break;
 261                 case 1:
 262                         add_push_refspec(remote, xstrdup(s));
 263                         break;
 264                 case 2:
 265                         add_fetch_refspec(remote, xstrdup(s));
 266                         break;
 267                 }
 268         }
 269         fclose(f);
 270 }
 271
 272 static void read_branches_file(struct remote *remote)
 273 {
 274         const char *slash = strchr(remote->name, '/');
 275         char *frag;
 276         struct strbuf branch = STRBUF_INIT;
 277         int n = slash ? slash - remote->name : 1000;
 278         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 279         char *s, *p;
 280         int len;
 281
 282         if (!f)
 283                 return;
 284         s = fgets(buffer, BUF_SIZE, f);
 285         fclose(f);
 286         if (!s)
 287                 return;
 288         while (isspace(*s))
 289                 s++;
 290         if (!*s)
 291                 return;
 292         remote->origin = REMOTE_BRANCHES;
 293         p = s + strlen(s);
 294         while (isspace(p[-1]))
 295                 *--p = 0;
 296         len = p - s;
 297         if (slash)
 298                 len += strlen(slash);
 299         p = xmalloc(len + 1);
 300         strcpy(p, s);
 301         if (slash)
 302                 strcat(p, slash);
 303
 304         /*
 305          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 306          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 307          * the partial URL obtained from the branches file plus
 308          * "/netdev-2.6" and does not store it in any tracking ref.
 309          * #branch specifier in the file is ignored.
 310          *
 311          * Otherwise, the branches file would have URL and optionally
 312          * #branch specified.  The "master" (or specified) branch is
 313          * fetched and stored in the local branch of the same name.
 314          */
 315         frag = strchr(p, '#');
 316         if (frag) {
 317                 *(frag++) = '\0';
 318                 strbuf_addf(&branch, "refs/heads/%s", frag);
 319         } else
 320                 strbuf_addstr(&branch, "refs/heads/master");
 321         if (!slash) {
 322                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 323         } else {
 324                 strbuf_reset(&branch);
 325                 strbuf_addstr(&branch, "HEAD:");
 326         }
 327         add_url_alias(remote, p);
 328         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 329         /*
 330          * Cogito compatible push: push current HEAD to remote #branch
 331          * (master if missing)
 332          */
 333         strbuf_init(&branch, 0);
 334         strbuf_addstr(&branch, "HEAD");
 335         if (frag)
 336                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 337         else
 338                 strbuf_addstr(&branch, ":refs/heads/master");
 339         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 340         remote->fetch_tags = 1; /* always auto-follow */
 341 }
 342
 343 static int handle_config(const char *key, const char *value, void *cb)
 344 {
 345         const char *name;
 346         const char *subkey;
 347         struct remote *remote;
 348         struct branch *branch;
 349         if (!prefixcmp(key, "branch.")) {
 350                 name = key + 7;
 351                 subkey = strrchr(name, '.');
 352                 if (!subkey)
 353                         return 0;
 354                 branch = make_branch(name, subkey - name);
 355                 if (!strcmp(subkey, ".remote")) {
 356                         if (!value)
 357                                 return config_error_nonbool(key);
 358                         branch->remote_name = xstrdup(value);
 359                         if (branch == current_branch) {
 360                                 default_remote_name = branch->remote_name;
 361                                 explicit_default_remote_name = 1;
 362                         }
 363                 } else if (!strcmp(subkey, ".merge")) {
 364                         if (!value)
 365                                 return config_error_nonbool(key);
 366                         add_merge(branch, xstrdup(value));
 367                 }
 368                 return 0;
 369         }
 370         if (!prefixcmp(key, "url.")) {
 371                 struct rewrite *rewrite;
 372                 name = key + 4;
 373                 subkey = strrchr(name, '.');
 374                 if (!subkey)
 375                         return 0;
 376                 if (!strcmp(subkey, ".insteadof")) {
 377                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 378                         if (!value)
 379                                 return config_error_nonbool(key);
 380                         add_instead_of(rewrite, xstrdup(value));
 381                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 382                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 383                         if (!value)
 384                                 return config_error_nonbool(key);
 385                         add_instead_of(rewrite, xstrdup(value));
 386                 }
 387         }
 388         if (prefixcmp(key,  "remote."))
 389                 return 0;
 390         name = key + 7;
 391         if (*name == '/') {
 392                 warning("Config remote shorthand cannot begin with '/': %s",
 393                         name);
 394                 return 0;
 395         }
 396         subkey = strrchr(name, '.');
 397         if (!subkey)
 398                 return 0;
 399         remote = make_remote(name, subkey - name);
 400         remote->origin = REMOTE_CONFIG;
 401         if (!strcmp(subkey, ".mirror"))
 402                 remote->mirror = git_config_bool(key, value);
 403         else if (!strcmp(subkey, ".skipdefaultupdate"))
 404                 remote->skip_default_update = git_config_bool(key, value);
 405         else if (!strcmp(subkey, ".skipfetchall"))
 406                 remote->skip_default_update = git_config_bool(key, value);
 407         else if (!strcmp(subkey, ".url")) {
 408                 const char *v;
 409                 if (git_config_string(&v, key, value))
 410                         return -1;
 411                 add_url(remote, v);
 412         } else if (!strcmp(subkey, ".pushurl")) {
 413                 const char *v;
 414                 if (git_config_string(&v, key, value))
 415                         return -1;
 416                 add_pushurl(remote, v);
 417         } else if (!strcmp(subkey, ".push")) {
 418                 const char *v;
 419                 if (git_config_string(&v, key, value))
 420                         return -1;
 421                 add_push_refspec(remote, v);
 422         } else if (!strcmp(subkey, ".fetch")) {
 423                 const char *v;
 424                 if (git_config_string(&v, key, value))
 425                         return -1;
 426                 add_fetch_refspec(remote, v);
 427         } else if (!strcmp(subkey, ".receivepack")) {
 428                 const char *v;
 429                 if (git_config_string(&v, key, value))
 430                         return -1;
 431                 if (!remote->receivepack)
 432                         remote->receivepack = v;
 433                 else
 434                         error("more than one receivepack given, using the first");
 435         } else if (!strcmp(subkey, ".uploadpack")) {
 436                 const char *v;
 437                 if (git_config_string(&v, key, value))
 438                         return -1;
 439                 if (!remote->uploadpack)
 440                         remote->uploadpack = v;
 441                 else
 442                         error("more than one uploadpack given, using the first");
 443         } else if (!strcmp(subkey, ".tagopt")) {
 444                 if (!strcmp(value, "--no-tags"))
 445                         remote->fetch_tags = -1;
 446         } else if (!strcmp(subkey, ".proxy")) {
 447                 return git_config_string((const char **)&remote->http_proxy,
 448                                          key, value);
 449         } else if (!strcmp(subkey, ".vcs")) {
 450                 return git_config_string(&remote->foreign_vcs, key, value);
 451         }
 452         return 0;
 453 }
 454
 455 static void alias_all_urls(void)
 456 {
 457         int i, j;
 458         for (i = 0; i < remotes_nr; i++) {
 459                 int add_pushurl_aliases;
 460                 if (!remotes[i])
 461                         continue;
 462                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 463                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 464                 }
 465                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 466                 for (j = 0; j < remotes[i]->url_nr; j++) {
 467                         if (add_pushurl_aliases)
 468                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 469                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 470                 }
 471         }
 472 }
 473
 474 static void read_config(void)
 475 {
 476         unsigned char sha1[20];
 477         const char *head_ref;
 478         int flag;
 479         if (default_remote_name) // did this already
 480                 return;
 481         default_remote_name = xstrdup("origin");
 482         current_branch = NULL;
 483         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 484         if (head_ref && (flag & REF_ISSYMREF) &&
 485             !prefixcmp(head_ref, "refs/heads/")) {
 486                 current_branch =
 487                         make_branch(head_ref + strlen("refs/heads/"), 0);
 488         }
 489         git_config(handle_config, NULL);
 490         alias_all_urls();
 491 }
 492
 493 /*
 494  * We need to make sure the tracking branches are well formed, but a
 495  * wildcard refspec in "struct refspec" must have a trailing slash. We
 496  * temporarily drop the trailing '/' while calling check_ref_format(),
 497  * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 498  * error return is Ok for a wildcard refspec.
 499  */
 500 static int verify_refname(char *name, int is_glob)
 501 {
 502         int result;
 503
 504         result = check_ref_format(name);
 505         if (is_glob && result == CHECK_REF_FORMAT_WILDCARD)
 506                 result = CHECK_REF_FORMAT_OK;
 507         return result;
 508 }
 509
 510 /*
 511  * This function frees a refspec array.
 512  * Warning: code paths should be checked to ensure that the src
 513  *          and dst pointers are always freeable pointers as well
 514  *          as the refspec pointer itself.
 515  */
 516 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 517 {
 518         int i;
 519
 520         if (!refspec)
 521                 return;
 522
 523         for (i = 0; i < nr_refspec; i++) {
 524                 free(refspec[i].src);
 525                 free(refspec[i].dst);
 526         }
 527         free(refspec);
 528 }
 529
 530 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 531 {
 532         int i;
 533         int st;
 534         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 535
 536         for (i = 0; i < nr_refspec; i++) {
 537                 size_t llen;
 538                 int is_glob;
 539                 const char *lhs, *rhs;
 540
 541                 is_glob = 0;
 542
 543                 lhs = refspec[i];
 544                 if (*lhs == '+') {
 545                         rs[i].force = 1;
 546                         lhs++;
 547                 }
 548
 549                 rhs = strrchr(lhs, ':');
 550
 551                 /*
 552                  * Before going on, special case ":" (or "+:") as a refspec
 553                  * for matching refs.
 554                  */
 555                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 556                         rs[i].matching = 1;
 557                         continue;
 558                 }
 559
 560                 if (rhs) {
 561                         size_t rlen = strlen(++rhs);
 562                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 563                         rs[i].dst = xstrndup(rhs, rlen);
 564                 }
 565
 566                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 567                 if (1 <= llen && memchr(lhs, '*', llen)) {
 568                         if ((rhs && !is_glob) || (!rhs && fetch))
 569                                 goto invalid;
 570                         is_glob = 1;
 571                 } else if (rhs && is_glob) {
 572                         goto invalid;
 573                 }
 574
 575                 rs[i].pattern = is_glob;
 576                 rs[i].src = xstrndup(lhs, llen);
 577
 578                 if (fetch) {
 579                         /*
 580                          * LHS
 581                          * - empty is allowed; it means HEAD.
 582                          * - otherwise it must be a valid looking ref.
 583                          */
 584                         if (!*rs[i].src)
 585                                 ; /* empty is ok */
 586                         else {
 587                                 st = verify_refname(rs[i].src, is_glob);
 588                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 589                                         goto invalid;
 590                         }
 591                         /*
 592                          * RHS
 593                          * - missing is ok, and is same as empty.
 594                          * - empty is ok; it means not to store.
 595                          * - otherwise it must be a valid looking ref.
 596                          */
 597                         if (!rs[i].dst) {
 598                                 ; /* ok */
 599                         } else if (!*rs[i].dst) {
 600                                 ; /* ok */
 601                         } else {
 602                                 st = verify_refname(rs[i].dst, is_glob);
 603                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 604                                         goto invalid;
 605                         }
 606                 } else {
 607                         /*
 608                          * LHS
 609                          * - empty is allowed; it means delete.
 610                          * - when wildcarded, it must be a valid looking ref.
 611                          * - otherwise, it must be an extended SHA-1, but
 612                          *   there is no existing way to validate this.
 613                          */
 614                         if (!*rs[i].src)
 615                                 ; /* empty is ok */
 616                         else if (is_glob) {
 617                                 st = verify_refname(rs[i].src, is_glob);
 618                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 619                                         goto invalid;
 620                         }
 621                         else
 622                                 ; /* anything goes, for now */
 623                         /*
 624                          * RHS
 625                          * - missing is allowed, but LHS then must be a
 626                          *   valid looking ref.
 627                          * - empty is not allowed.
 628                          * - otherwise it must be a valid looking ref.
 629                          */
 630                         if (!rs[i].dst) {
 631                                 st = verify_refname(rs[i].src, is_glob);
 632                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 633                                         goto invalid;
 634                         } else if (!*rs[i].dst) {
 635                                 goto invalid;
 636                         } else {
 637                                 st = verify_refname(rs[i].dst, is_glob);
 638                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 639                                         goto invalid;
 640                         }
 641                 }
 642         }
 643         return rs;
 644
 645  invalid:
 646         if (verify) {
 647                 /*
 648                  * nr_refspec must be greater than zero and i must be valid
 649                  * since it is only possible to reach this point from within
 650                  * the for loop above.
 651                  */
 652                 free_refspecs(rs, i+1);
 653                 return NULL;
 654         }
 655         die("Invalid refspec '%s'", refspec[i]);
 656 }
 657
 658 int valid_fetch_refspec(const char *fetch_refspec_str)
 659 {
 660         const char *fetch_refspec[] = { fetch_refspec_str };
 661         struct refspec *refspec;
 662
 663         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 664         free_refspecs(refspec, 1);
 665         return !!refspec;
 666 }
 667
 668 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 669 {
 670         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 671 }
 672
 673 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 674 {
 675         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 676 }
 677
 678 void free_refspec(int nr_refspec, struct refspec *refspec)
 679 {
 680         int i;
 681         for (i = 0; i < nr_refspec; i++) {
 682                 free(refspec[i].src);
 683                 free(refspec[i].dst);
 684         }
 685         free(refspec);
 686 }
 687
 688 static int valid_remote_nick(const char *name)
 689 {
 690         if (!name[0] || is_dot_or_dotdot(name))
 691                 return 0;
 692         return !strchr(name, '/'); /* no slash */
 693 }
 694
 695 struct remote *remote_get(const char *name)
 696 {
 697         struct remote *ret;
 698         int name_given = 0;
 699
 700         read_config();
 701         if (name)
 702                 name_given = 1;
 703         else {
 704                 name = default_remote_name;
 705                 name_given = explicit_default_remote_name;
 706         }
 707
 708         ret = make_remote(name, 0);
 709         if (valid_remote_nick(name)) {
 710                 if (!valid_remote(ret))
 711                         read_remotes_file(ret);
 712                 if (!valid_remote(ret))
 713                         read_branches_file(ret);
 714         }
 715         if (name_given && !valid_remote(ret))
 716                 add_url_alias(ret, name);
 717         if (!valid_remote(ret))
 718                 return NULL;
 719         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 720         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 721         return ret;
 722 }
 723
 724 int remote_is_configured(const char *name)
 725 {
 726         int i;
 727         read_config();
 728
 729         for (i = 0; i < remotes_nr; i++)
 730                 if (!strcmp(name, remotes[i]->name))
 731                         return 1;
 732         return 0;
 733 }
 734
 735 int for_each_remote(each_remote_fn fn, void *priv)
 736 {
 737         int i, result = 0;
 738         read_config();
 739         for (i = 0; i < remotes_nr && !result; i++) {
 740                 struct remote *r = remotes[i];
 741                 if (!r)
 742                         continue;
 743                 if (!r->fetch)
 744                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 745                                                        r->fetch_refspec);
 746                 if (!r->push)
 747                         r->push = parse_push_refspec(r->push_refspec_nr,
 748                                                      r->push_refspec);
 749                 result = fn(r, priv);
 750         }
 751         return result;
 752 }
 753
 754 void ref_remove_duplicates(struct ref *ref_map)
 755 {
 756         struct string_list refs = { NULL, 0, 0, 0 };
 757         struct string_list_item *item = NULL;
 758         struct ref *prev = NULL, *next = NULL;
 759         for (; ref_map; prev = ref_map, ref_map = next) {
 760                 next = ref_map->next;
 761                 if (!ref_map->peer_ref)
 762                         continue;
 763
 764                 item = string_list_lookup(ref_map->peer_ref->name, &refs);
 765                 if (item) {
 766                         if (strcmp(((struct ref *)item->util)->name,
 767                                    ref_map->name))
 768                                 die("%s tracks both %s and %s",
 769                                     ref_map->peer_ref->name,
 770                                     ((struct ref *)item->util)->name,
 771                                     ref_map->name);
 772                         prev->next = ref_map->next;
 773                         free(ref_map->peer_ref);
 774                         free(ref_map);
 775                         ref_map = prev; /* skip this; we freed it */
 776                         continue;
 777                 }
 778
 779                 item = string_list_insert(ref_map->peer_ref->name, &refs);
 780                 item->util = ref_map;
 781         }
 782         string_list_clear(&refs, 0);
 783 }
 784
 785 int remote_has_url(struct remote *remote, const char *url)
 786 {
 787         int i;
 788         for (i = 0; i < remote->url_nr; i++) {
 789                 if (!strcmp(remote->url[i], url))
 790                         return 1;
 791         }
 792         return 0;
 793 }
 794
 795 static int match_name_with_pattern(const char *key, const char *name,
 796                                    const char *value, char **result)
 797 {
 798         const char *kstar = strchr(key, '*');
 799         size_t klen;
 800         size_t ksuffixlen;
 801         size_t namelen;
 802         int ret;
 803         if (!kstar)
 804                 die("Key '%s' of pattern had no '*'", key);
 805         klen = kstar - key;
 806         ksuffixlen = strlen(kstar + 1);
 807         namelen = strlen(name);
 808         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 809                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 810         if (ret && value) {
 811                 const char *vstar = strchr(value, '*');
 812                 size_t vlen;
 813                 size_t vsuffixlen;
 814                 if (!vstar)
 815                         die("Value '%s' of pattern has no '*'", value);
 816                 vlen = vstar - value;
 817                 vsuffixlen = strlen(vstar + 1);
 818                 *result = xmalloc(vlen + vsuffixlen +
 819                                   strlen(name) -
 820                                   klen - ksuffixlen + 1);
 821                 strncpy(*result, value, vlen);
 822                 strncpy(*result + vlen,
 823                         name + klen, namelen - klen - ksuffixlen);
 824                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 825                        vstar + 1);
 826         }
 827         return ret;
 828 }
 829
 830 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 831                      const char *name)
 832 {
 833         int i;
 834         char *ret = NULL;
 835         for (i = 0; i < nr_refspec; i++) {
 836                 struct refspec *refspec = refspecs + i;
 837                 if (refspec->pattern) {
 838                         if (match_name_with_pattern(refspec->src, name,
 839                                                     refspec->dst, &ret))
 840                                 return ret;
 841                 } else if (!strcmp(refspec->src, name))
 842                         return strdup(refspec->dst);
 843         }
 844         return NULL;
 845 }
 846
 847 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 848 {
 849         int find_src = refspec->src == NULL;
 850         char *needle, **result;
 851         int i;
 852
 853         if (find_src) {
 854                 if (!refspec->dst)
 855                         return error("find_tracking: need either src or dst");
 856                 needle = refspec->dst;
 857                 result = &refspec->src;
 858         } else {
 859                 needle = refspec->src;
 860                 result = &refspec->dst;
 861         }
 862
 863         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 864                 struct refspec *fetch = &remote->fetch[i];
 865                 const char *key = find_src ? fetch->dst : fetch->src;
 866                 const char *value = find_src ? fetch->src : fetch->dst;
 867                 if (!fetch->dst)
 868                         continue;
 869                 if (fetch->pattern) {
 870                         if (match_name_with_pattern(key, needle, value, result)) {
 871                                 refspec->force = fetch->force;
 872                                 return 0;
 873                         }
 874                 } else if (!strcmp(needle, key)) {
 875                         *result = xstrdup(value);
 876                         refspec->force = fetch->force;
 877                         return 0;
 878                 }
 879         }
 880         return -1;
 881 }
 882
 883 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 884                 const char *name)
 885 {
 886         size_t len = strlen(name);
 887         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 888         memcpy(ref->name, prefix, prefixlen);
 889         memcpy(ref->name + prefixlen, name, len);
 890         return ref;
 891 }
 892
 893 struct ref *alloc_ref(const char *name)
 894 {
 895         return alloc_ref_with_prefix("", 0, name);
 896 }
 897
 898 static struct ref *copy_ref(const struct ref *ref)
 899 {
 900         struct ref *cpy;
 901         size_t len;
 902         if (!ref)
 903                 return NULL;
 904         len = strlen(ref->name);
 905         cpy = xmalloc(sizeof(struct ref) + len + 1);
 906         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 907         cpy->next = NULL;
 908         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 909         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 910         cpy->peer_ref = copy_ref(ref->peer_ref);
 911         return cpy;
 912 }
 913
 914 struct ref *copy_ref_list(const struct ref *ref)
 915 {
 916         struct ref *ret = NULL;
 917         struct ref **tail = &ret;
 918         while (ref) {
 919                 *tail = copy_ref(ref);
 920                 ref = ref->next;
 921                 tail = &((*tail)->next);
 922         }
 923         return ret;
 924 }
 925
 926 static void free_ref(struct ref *ref)
 927 {
 928         if (!ref)
 929                 return;
 930         free_ref(ref->peer_ref);
 931         free(ref->remote_status);
 932         free(ref->symref);
 933         free(ref);
 934 }
 935
 936 void free_refs(struct ref *ref)
 937 {
 938         struct ref *next;
 939         while (ref) {
 940                 next = ref->next;
 941                 free_ref(ref);
 942                 ref = next;
 943         }
 944 }
 945
 946 static int count_refspec_match(const char *pattern,
 947                                struct ref *refs,
 948                                struct ref **matched_ref)
 949 {
 950         int patlen = strlen(pattern);
 951         struct ref *matched_weak = NULL;
 952         struct ref *matched = NULL;
 953         int weak_match = 0;
 954         int match = 0;
 955
 956         for (weak_match = match = 0; refs; refs = refs->next) {
 957                 char *name = refs->name;
 958                 int namelen = strlen(name);
 959
 960                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 961                         continue;
 962
 963                 /* A match is "weak" if it is with refs outside
 964                  * heads or tags, and did not specify the pattern
 965                  * in full (e.g. "refs/remotes/origin/master") or at
 966                  * least from the toplevel (e.g. "remotes/origin/master");
 967                  * otherwise "git push $URL master" would result in
 968                  * ambiguity between remotes/origin/master and heads/master
 969                  * at the remote site.
 970                  */
 971                 if (namelen != patlen &&
 972                     patlen != namelen - 5 &&
 973                     prefixcmp(name, "refs/heads/") &&
 974                     prefixcmp(name, "refs/tags/")) {
 975                         /* We want to catch the case where only weak
 976                          * matches are found and there are multiple
 977                          * matches, and where more than one strong
 978                          * matches are found, as ambiguous.  One
 979                          * strong match with zero or more weak matches
 980                          * are acceptable as a unique match.
 981                          */
 982                         matched_weak = refs;
 983                         weak_match++;
 984                 }
 985                 else {
 986                         matched = refs;
 987                         match++;
 988                 }
 989         }
 990         if (!matched) {
 991                 *matched_ref = matched_weak;
 992                 return weak_match;
 993         }
 994         else {
 995                 *matched_ref = matched;
 996                 return match;
 997         }
 998 }
 999
1000 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1001 {
1002         **tail = ref;
1003         while (ref->next)
1004                 ref = ref->next;
1005         *tail = &ref->next;
1006 }
1007
1008 static struct ref *try_explicit_object_name(const char *name)
1009 {
1010         unsigned char sha1[20];
1011         struct ref *ref;
1012
1013         if (!*name) {
1014                 ref = alloc_ref("(delete)");
1015                 hashclr(ref->new_sha1);
1016                 return ref;
1017         }
1018         if (get_sha1(name, sha1))
1019                 return NULL;
1020         ref = alloc_ref(name);
1021         hashcpy(ref->new_sha1, sha1);
1022         return ref;
1023 }
1024
1025 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1026 {
1027         struct ref *ret = alloc_ref(name);
1028         tail_link_ref(ret, tail);
1029         return ret;
1030 }
1031
1032 static char *guess_ref(const char *name, struct ref *peer)
1033 {
1034         struct strbuf buf = STRBUF_INIT;
1035         unsigned char sha1[20];
1036
1037         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
1038         if (!r)
1039                 return NULL;
1040
1041         if (!prefixcmp(r, "refs/heads/"))
1042                 strbuf_addstr(&buf, "refs/heads/");
1043         else if (!prefixcmp(r, "refs/tags/"))
1044                 strbuf_addstr(&buf, "refs/tags/");
1045         else
1046                 return NULL;
1047
1048         strbuf_addstr(&buf, name);
1049         return strbuf_detach(&buf, NULL);
1050 }
1051
1052 static int match_explicit(struct ref *src, struct ref *dst,
1053                           struct ref ***dst_tail,
1054                           struct refspec *rs)
1055 {
1056         struct ref *matched_src, *matched_dst;
1057         int copy_src;
1058
1059         const char *dst_value = rs->dst;
1060         char *dst_guess;
1061
1062         if (rs->pattern || rs->matching)
1063                 return 0;
1064
1065         matched_src = matched_dst = NULL;
1066         switch (count_refspec_match(rs->src, src, &matched_src)) {
1067         case 1:
1068                 copy_src = 1;
1069                 break;
1070         case 0:
1071                 /* The source could be in the get_sha1() format
1072                  * not a reference name.  :refs/other is a
1073                  * way to delete 'other' ref at the remote end.
1074                  */
1075                 matched_src = try_explicit_object_name(rs->src);
1076                 if (!matched_src)
1077                         return error("src refspec %s does not match any.", rs->src);
1078                 copy_src = 0;
1079                 break;
1080         default:
1081                 return error("src refspec %s matches more than one.", rs->src);
1082         }
1083
1084         if (!dst_value) {
1085                 unsigned char sha1[20];
1086                 int flag;
1087
1088                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
1089                 if (!dst_value ||
1090                     ((flag & REF_ISSYMREF) &&
1091                      prefixcmp(dst_value, "refs/heads/")))
1092                         die("%s cannot be resolved to branch.",
1093                             matched_src->name);
1094         }
1095
1096         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1097         case 1:
1098                 break;
1099         case 0:
1100                 if (!memcmp(dst_value, "refs/", 5))
1101                         matched_dst = make_linked_ref(dst_value, dst_tail);
1102                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1103                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1104                 else
1105                         error("unable to push to unqualified destination: %s\n"
1106                               "The destination refspec neither matches an "
1107                               "existing ref on the remote nor\n"
1108                               "begins with refs/, and we are unable to "
1109                               "guess a prefix based on the source ref.",
1110                               dst_value);
1111                 break;
1112         default:
1113                 matched_dst = NULL;
1114                 error("dst refspec %s matches more than one.",
1115                       dst_value);
1116                 break;
1117         }
1118         if (!matched_dst)
1119                 return -1;
1120         if (matched_dst->peer_ref)
1121                 return error("dst ref %s receives from more than one src.",
1122                       matched_dst->name);
1123         else {
1124                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1125                 matched_dst->force = rs->force;
1126         }
1127         return 0;
1128 }
1129
1130 static int match_explicit_refs(struct ref *src, struct ref *dst,
1131                                struct ref ***dst_tail, struct refspec *rs,
1132                                int rs_nr)
1133 {
1134         int i, errs;
1135         for (i = errs = 0; i < rs_nr; i++)
1136                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1137         return errs;
1138 }
1139
1140 static const struct refspec *check_pattern_match(const struct refspec *rs,
1141                                                  int rs_nr,
1142                                                  const struct ref *src)
1143 {
1144         int i;
1145         int matching_refs = -1;
1146         for (i = 0; i < rs_nr; i++) {
1147                 if (rs[i].matching &&
1148                     (matching_refs == -1 || rs[i].force)) {
1149                         matching_refs = i;
1150                         continue;
1151                 }
1152
1153                 if (rs[i].pattern && match_name_with_pattern(rs[i].src, src->name,
1154                                                              NULL, NULL))
1155                         return rs + i;
1156         }
1157         if (matching_refs != -1)
1158                 return rs + matching_refs;
1159         else
1160                 return NULL;
1161 }
1162
1163 static struct ref **tail_ref(struct ref **head)
1164 {
1165         struct ref **tail = head;
1166         while (*tail)
1167                 tail = &((*tail)->next);
1168         return tail;
1169 }
1170
1171 /*
1172  * Note. This is used only by "push"; refspec matching rules for
1173  * push and fetch are subtly different, so do not try to reuse it
1174  * without thinking.
1175  */
1176 int match_refs(struct ref *src, struct ref **dst,
1177                int nr_refspec, const char **refspec, int flags)
1178 {
1179         struct refspec *rs;
1180         int send_all = flags & MATCH_REFS_ALL;
1181         int send_mirror = flags & MATCH_REFS_MIRROR;
1182         int errs;
1183         static const char *default_refspec[] = { ":", NULL };
1184         struct ref **dst_tail = tail_ref(dst);
1185
1186         if (!nr_refspec) {
1187                 nr_refspec = 1;
1188                 refspec = default_refspec;
1189         }
1190         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1191         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1192
1193         /* pick the remainder */
1194         for ( ; src; src = src->next) {
1195                 struct ref *dst_peer;
1196                 const struct refspec *pat = NULL;
1197                 char *dst_name;
1198                 if (src->peer_ref)
1199                         continue;
1200
1201                 pat = check_pattern_match(rs, nr_refspec, src);
1202                 if (!pat)
1203                         continue;
1204
1205                 if (pat->matching) {
1206                         /*
1207                          * "matching refs"; traditionally we pushed everything
1208                          * including refs outside refs/heads/ hierarchy, but
1209                          * that does not make much sense these days.
1210                          */
1211                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1212                                 continue;
1213                         dst_name = xstrdup(src->name);
1214
1215                 } else {
1216                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1217                         if (!match_name_with_pattern(pat->src, src->name,
1218                                                      dst_side, &dst_name))
1219                                 die("Didn't think it matches any more");
1220                 }
1221                 dst_peer = find_ref_by_name(*dst, dst_name);
1222                 if (dst_peer) {
1223                         if (dst_peer->peer_ref)
1224                                 /* We're already sending something to this ref. */
1225                                 goto free_name;
1226
1227                 } else {
1228                         if (pat->matching && !(send_all || send_mirror))
1229                                 /*
1230                                  * Remote doesn't have it, and we have no
1231                                  * explicit pattern, and we don't have
1232                                  * --all nor --mirror.
1233                                  */
1234                                 goto free_name;
1235
1236                         /* Create a new one and link it */
1237                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1238                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1239                 }
1240                 dst_peer->peer_ref = copy_ref(src);
1241                 dst_peer->force = pat->force;
1242         free_name:
1243                 free(dst_name);
1244         }
1245         if (errs)
1246                 return -1;
1247         return 0;
1248 }
1249
1250 struct branch *branch_get(const char *name)
1251 {
1252         struct branch *ret;
1253
1254         read_config();
1255         if (!name || !*name || !strcmp(name, "HEAD"))
1256                 ret = current_branch;
1257         else
1258                 ret = make_branch(name, 0);
1259         if (ret && ret->remote_name) {
1260                 ret->remote = remote_get(ret->remote_name);
1261                 if (ret->merge_nr) {
1262                         int i;
1263                         ret->merge = xcalloc(sizeof(*ret->merge),
1264                                              ret->merge_nr);
1265                         for (i = 0; i < ret->merge_nr; i++) {
1266                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1267                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1268                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1269                                     && !strcmp(ret->remote_name, "."))
1270                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1271                         }
1272                 }
1273         }
1274         return ret;
1275 }
1276
1277 int branch_has_merge_config(struct branch *branch)
1278 {
1279         return branch && !!branch->merge;
1280 }
1281
1282 int branch_merge_matches(struct branch *branch,
1283                                  int i,
1284                                  const char *refname)
1285 {
1286         if (!branch || i < 0 || i >= branch->merge_nr)
1287                 return 0;
1288         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1289 }
1290
1291 static struct ref *get_expanded_map(const struct ref *remote_refs,
1292                                     const struct refspec *refspec)
1293 {
1294         const struct ref *ref;
1295         struct ref *ret = NULL;
1296         struct ref **tail = &ret;
1297
1298         char *expn_name;
1299
1300         for (ref = remote_refs; ref; ref = ref->next) {
1301                 if (strchr(ref->name, '^'))
1302                         continue; /* a dereference item */
1303                 if (match_name_with_pattern(refspec->src, ref->name,
1304                                             refspec->dst, &expn_name)) {
1305                         struct ref *cpy = copy_ref(ref);
1306
1307                         cpy->peer_ref = alloc_ref(expn_name);
1308                         free(expn_name);
1309                         if (refspec->force)
1310                                 cpy->peer_ref->force = 1;
1311                         *tail = cpy;
1312                         tail = &cpy->next;
1313                 }
1314         }
1315
1316         return ret;
1317 }
1318
1319 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1320 {
1321         const struct ref *ref;
1322         for (ref = refs; ref; ref = ref->next) {
1323                 if (refname_match(name, ref->name, ref_fetch_rules))
1324                         return ref;
1325         }
1326         return NULL;
1327 }
1328
1329 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1330 {
1331         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1332
1333         if (!ref)
1334                 return NULL;
1335
1336         return copy_ref(ref);
1337 }
1338
1339 static struct ref *get_local_ref(const char *name)
1340 {
1341         if (!name || name[0] == '\0')
1342                 return NULL;
1343
1344         if (!prefixcmp(name, "refs/"))
1345                 return alloc_ref(name);
1346
1347         if (!prefixcmp(name, "heads/") ||
1348             !prefixcmp(name, "tags/") ||
1349             !prefixcmp(name, "remotes/"))
1350                 return alloc_ref_with_prefix("refs/", 5, name);
1351
1352         return alloc_ref_with_prefix("refs/heads/", 11, name);
1353 }
1354
1355 int get_fetch_map(const struct ref *remote_refs,
1356                   const struct refspec *refspec,
1357                   struct ref ***tail,
1358                   int missing_ok)
1359 {
1360         struct ref *ref_map, **rmp;
1361
1362         if (refspec->pattern) {
1363                 ref_map = get_expanded_map(remote_refs, refspec);
1364         } else {
1365                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1366
1367                 ref_map = get_remote_ref(remote_refs, name);
1368                 if (!missing_ok && !ref_map)
1369                         die("Couldn't find remote ref %s", name);
1370                 if (ref_map) {
1371                         ref_map->peer_ref = get_local_ref(refspec->dst);
1372                         if (ref_map->peer_ref && refspec->force)
1373                                 ref_map->peer_ref->force = 1;
1374                 }
1375         }
1376
1377         for (rmp = &ref_map; *rmp; ) {
1378                 if ((*rmp)->peer_ref) {
1379                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1380                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1381                                 struct ref *ignore = *rmp;
1382                                 error("* Ignoring funny ref '%s' locally",
1383                                       (*rmp)->peer_ref->name);
1384                                 *rmp = (*rmp)->next;
1385                                 free(ignore->peer_ref);
1386                                 free(ignore);
1387                                 continue;
1388                         }
1389                 }
1390                 rmp = &((*rmp)->next);
1391         }
1392
1393         if (ref_map)
1394                 tail_link_ref(ref_map, tail);
1395
1396         return 0;
1397 }
1398
1399 int resolve_remote_symref(struct ref *ref, struct ref *list)
1400 {
1401         if (!ref->symref)
1402                 return 0;
1403         for (; list; list = list->next)
1404                 if (!strcmp(ref->symref, list->name)) {
1405                         hashcpy(ref->old_sha1, list->old_sha1);
1406                         return 0;
1407                 }
1408         return 1;
1409 }
1410
1411 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1412 {
1413         while (list) {
1414                 struct commit_list *temp = list;
1415                 temp->item->object.flags &= ~mark;
1416                 list = temp->next;
1417                 free(temp);
1418         }
1419 }
1420
1421 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1422 {
1423         struct object *o;
1424         struct commit *old, *new;
1425         struct commit_list *list, *used;
1426         int found = 0;
1427
1428         /* Both new and old must be commit-ish and new is descendant of
1429          * old.  Otherwise we require --force.
1430          */
1431         o = deref_tag(parse_object(old_sha1), NULL, 0);
1432         if (!o || o->type != OBJ_COMMIT)
1433                 return 0;
1434         old = (struct commit *) o;
1435
1436         o = deref_tag(parse_object(new_sha1), NULL, 0);
1437         if (!o || o->type != OBJ_COMMIT)
1438                 return 0;
1439         new = (struct commit *) o;
1440
1441         if (parse_commit(new) < 0)
1442                 return 0;
1443
1444         used = list = NULL;
1445         commit_list_insert(new, &list);
1446         while (list) {
1447                 new = pop_most_recent_commit(&list, TMP_MARK);
1448                 commit_list_insert(new, &used);
1449                 if (new == old) {
1450                         found = 1;
1451                         break;
1452                 }
1453         }
1454         unmark_and_free(list, TMP_MARK);
1455         unmark_and_free(used, TMP_MARK);
1456         return found;
1457 }
1458
1459 /*
1460  * Return true if there is anything to report, otherwise false.
1461  */
1462 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1463 {
1464         unsigned char sha1[20];
1465         struct commit *ours, *theirs;
1466         char symmetric[84];
1467         struct rev_info revs;
1468         const char *rev_argv[10], *base;
1469         int rev_argc;
1470
1471         /*
1472          * Nothing to report unless we are marked to build on top of
1473          * somebody else.
1474          */
1475         if (!branch ||
1476             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1477                 return 0;
1478
1479         /*
1480          * If what we used to build on no longer exists, there is
1481          * nothing to report.
1482          */
1483         base = branch->merge[0]->dst;
1484         if (!resolve_ref(base, sha1, 1, NULL))
1485                 return 0;
1486         theirs = lookup_commit_reference(sha1);
1487         if (!theirs)
1488                 return 0;
1489
1490         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1491                 return 0;
1492         ours = lookup_commit_reference(sha1);
1493         if (!ours)
1494                 return 0;
1495
1496         /* are we the same? */
1497         if (theirs == ours)
1498                 return 0;
1499
1500         /* Run "rev-list --left-right ours...theirs" internally... */
1501         rev_argc = 0;
1502         rev_argv[rev_argc++] = NULL;
1503         rev_argv[rev_argc++] = "--left-right";
1504         rev_argv[rev_argc++] = symmetric;
1505         rev_argv[rev_argc++] = "--";
1506         rev_argv[rev_argc] = NULL;
1507
1508         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1509         strcpy(symmetric + 40, "...");
1510         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1511
1512         init_revisions(&revs, NULL);
1513         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1514         prepare_revision_walk(&revs);
1515
1516         /* ... and count the commits on each side. */
1517         *num_ours = 0;
1518         *num_theirs = 0;
1519         while (1) {
1520                 struct commit *c = get_revision(&revs);
1521                 if (!c)
1522                         break;
1523                 if (c->object.flags & SYMMETRIC_LEFT)
1524                         (*num_ours)++;
1525                 else
1526                         (*num_theirs)++;
1527         }
1528
1529         /* clear object flags smudged by the above traversal */
1530         clear_commit_marks(ours, ALL_REV_FLAGS);
1531         clear_commit_marks(theirs, ALL_REV_FLAGS);
1532         return 1;
1533 }
1534
1535 /*
1536  * Return true when there is anything to report, otherwise false.
1537  */
1538 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1539 {
1540         int num_ours, num_theirs;
1541         const char *base;
1542
1543         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1544                 return 0;
1545
1546         base = branch->merge[0]->dst;
1547         base = shorten_unambiguous_ref(base, 0);
1548         if (!num_theirs)
1549                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1550                             "by %d commit%s.\n",
1551                             base, num_ours, (num_ours == 1) ? "" : "s");
1552         else if (!num_ours)
1553                 strbuf_addf(sb, "Your branch is behind '%s' "
1554                             "by %d commit%s, "
1555                             "and can be fast-forwarded.\n",
1556                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1557         else
1558                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1559                             "and have %d and %d different commit(s) each, "
1560                             "respectively.\n",
1561                             base, num_ours, num_theirs);
1562         return 1;
1563 }
1564
1565 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1566 {
1567         struct ref ***local_tail = cb_data;
1568         struct ref *ref;
1569         int len;
1570
1571         /* we already know it starts with refs/ to get here */
1572         if (check_ref_format(refname + 5))
1573                 return 0;
1574
1575         len = strlen(refname) + 1;
1576         ref = xcalloc(1, sizeof(*ref) + len);
1577         hashcpy(ref->new_sha1, sha1);
1578         memcpy(ref->name, refname, len);
1579         **local_tail = ref;
1580         *local_tail = &ref->next;
1581         return 0;
1582 }
1583
1584 struct ref *get_local_heads(void)
1585 {
1586         struct ref *local_refs = NULL, **local_tail = &local_refs;
1587         for_each_ref(one_local_ref, &local_tail);
1588         return local_refs;
1589 }
1590
1591 struct ref *guess_remote_head(const struct ref *head,
1592                               const struct ref *refs,
1593                               int all)
1594 {
1595         const struct ref *r;
1596         struct ref *list = NULL;
1597         struct ref **tail = &list;
1598
1599         if (!head)
1600                 return NULL;
1601
1602         /*
1603          * Some transports support directly peeking at
1604          * where HEAD points; if that is the case, then
1605          * we don't have to guess.
1606          */
1607         if (head->symref)
1608                 return copy_ref(find_ref_by_name(refs, head->symref));
1609
1610         /* If refs/heads/master could be right, it is. */
1611         if (!all) {
1612                 r = find_ref_by_name(refs, "refs/heads/master");
1613                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1614                         return copy_ref(r);
1615         }
1616
1617         /* Look for another ref that points there */
1618         for (r = refs; r; r = r->next) {
1619                 if (r != head && !hashcmp(r->old_sha1, head->old_sha1)) {
1620                         *tail = copy_ref(r);
1621                         tail = &((*tail)->next);
1622                         if (!all)
1623                                 break;
1624                 }
1625         }
1626
1627         return list;
1628 }
1629
1630 struct stale_heads_info {
1631         struct remote *remote;
1632         struct string_list *ref_names;
1633         struct ref **stale_refs_tail;
1634 };
1635
1636 static int get_stale_heads_cb(const char *refname,
1637         const unsigned char *sha1, int flags, void *cb_data)
1638 {
1639         struct stale_heads_info *info = cb_data;
1640         struct refspec refspec;
1641         memset(&refspec, 0, sizeof(refspec));
1642         refspec.dst = (char *)refname;
1643         if (!remote_find_tracking(info->remote, &refspec)) {
1644                 if (!((flags & REF_ISSYMREF) ||
1645                     string_list_has_string(info->ref_names, refspec.src))) {
1646                         struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1647                         hashcpy(ref->new_sha1, sha1);
1648                 }
1649         }
1650         return 0;
1651 }
1652
1653 struct ref *get_stale_heads(struct remote *remote, struct ref *fetch_map)
1654 {
1655         struct ref *ref, *stale_refs = NULL;
1656         struct string_list ref_names = { NULL, 0, 0, 0 };
1657         struct stale_heads_info info;
1658         info.remote = remote;
1659         info.ref_names = &ref_names;
1660         info.stale_refs_tail = &stale_refs;
1661         for (ref = fetch_map; ref; ref = ref->next)
1662                 string_list_append(ref->name, &ref_names);
1663         sort_string_list(&ref_names);
1664         for_each_ref(get_stale_heads_cb, &info);
1665         string_list_clear(&ref_names, 0);
1666         return stale_refs;
1667 }