remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "dir.h"
   8 #include "tag.h"
   9
  10 static struct refspec s_tag_refspec = {
  11         0,
  12         1,
  13         0,
  14         "refs/tags/*",
  15         "refs/tags/*"
  16 };
  17
  18 const struct refspec *tag_refspec = &s_tag_refspec;
  19
  20 struct counted_string {
  21         size_t len;
  22         const char *s;
  23 };
  24 struct rewrite {
  25         const char *base;
  26         size_t baselen;
  27         struct counted_string *instead_of;
  28         int instead_of_nr;
  29         int instead_of_alloc;
  30 };
  31 struct rewrites {
  32         struct rewrite **rewrite;
  33         int rewrite_alloc;
  34         int rewrite_nr;
  35 };
  36
  37 static struct remote **remotes;
  38 static int remotes_alloc;
  39 static int remotes_nr;
  40
  41 static struct branch **branches;
  42 static int branches_alloc;
  43 static int branches_nr;
  44
  45 static struct branch *current_branch;
  46 static const char *default_remote_name;
  47 static int explicit_default_remote_name;
  48
  49 static struct rewrites rewrites;
  50 static struct rewrites rewrites_push;
  51
  52 #define BUF_SIZE (2048)
  53 static char buffer[BUF_SIZE];
  54
  55 static int valid_remote(const struct remote *remote)
  56 {
  57         return (!!remote->url) || (!!remote->foreign_vcs);
  58 }
  59
  60 static const char *alias_url(const char *url, struct rewrites *r)
  61 {
  62         int i, j;
  63         char *ret;
  64         struct counted_string *longest;
  65         int longest_i;
  66
  67         longest = NULL;
  68         longest_i = -1;
  69         for (i = 0; i < r->rewrite_nr; i++) {
  70                 if (!r->rewrite[i])
  71                         continue;
  72                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  73                         if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  74                             (!longest ||
  75                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  76                                 longest = &(r->rewrite[i]->instead_of[j]);
  77                                 longest_i = i;
  78                         }
  79                 }
  80         }
  81         if (!longest)
  82                 return url;
  83
  84         ret = xmalloc(r->rewrite[longest_i]->baselen +
  85                      (strlen(url) - longest->len) + 1);
  86         strcpy(ret, r->rewrite[longest_i]->base);
  87         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  88         return ret;
  89 }
  90
  91 static void add_push_refspec(struct remote *remote, const char *ref)
  92 {
  93         ALLOC_GROW(remote->push_refspec,
  94                    remote->push_refspec_nr + 1,
  95                    remote->push_refspec_alloc);
  96         remote->push_refspec[remote->push_refspec_nr++] = ref;
  97 }
  98
  99 static void add_fetch_refspec(struct remote *remote, const char *ref)
 100 {
 101         ALLOC_GROW(remote->fetch_refspec,
 102                    remote->fetch_refspec_nr + 1,
 103                    remote->fetch_refspec_alloc);
 104         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 105 }
 106
 107 static void add_url(struct remote *remote, const char *url)
 108 {
 109         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 110         remote->url[remote->url_nr++] = url;
 111 }
 112
 113 static void add_pushurl(struct remote *remote, const char *pushurl)
 114 {
 115         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 116         remote->pushurl[remote->pushurl_nr++] = pushurl;
 117 }
 118
 119 static void add_pushurl_alias(struct remote *remote, const char *url)
 120 {
 121         const char *pushurl = alias_url(url, &rewrites_push);
 122         if (pushurl != url)
 123                 add_pushurl(remote, pushurl);
 124 }
 125
 126 static void add_url_alias(struct remote *remote, const char *url)
 127 {
 128         add_url(remote, alias_url(url, &rewrites));
 129         add_pushurl_alias(remote, url);
 130 }
 131
 132 static struct remote *make_remote(const char *name, int len)
 133 {
 134         struct remote *ret;
 135         int i;
 136
 137         for (i = 0; i < remotes_nr; i++) {
 138                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 139                            !remotes[i]->name[len]) :
 140                     !strcmp(name, remotes[i]->name))
 141                         return remotes[i];
 142         }
 143
 144         ret = xcalloc(1, sizeof(struct remote));
 145         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 146         remotes[remotes_nr++] = ret;
 147         if (len)
 148                 ret->name = xstrndup(name, len);
 149         else
 150                 ret->name = xstrdup(name);
 151         return ret;
 152 }
 153
 154 static void add_merge(struct branch *branch, const char *name)
 155 {
 156         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 157                    branch->merge_alloc);
 158         branch->merge_name[branch->merge_nr++] = name;
 159 }
 160
 161 static struct branch *make_branch(const char *name, int len)
 162 {
 163         struct branch *ret;
 164         int i;
 165         char *refname;
 166
 167         for (i = 0; i < branches_nr; i++) {
 168                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 169                            !branches[i]->name[len]) :
 170                     !strcmp(name, branches[i]->name))
 171                         return branches[i];
 172         }
 173
 174         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 175         ret = xcalloc(1, sizeof(struct branch));
 176         branches[branches_nr++] = ret;
 177         if (len)
 178                 ret->name = xstrndup(name, len);
 179         else
 180                 ret->name = xstrdup(name);
 181         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 182         strcpy(refname, "refs/heads/");
 183         strcpy(refname + strlen("refs/heads/"), ret->name);
 184         ret->refname = refname;
 185
 186         return ret;
 187 }
 188
 189 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 190 {
 191         struct rewrite *ret;
 192         int i;
 193
 194         for (i = 0; i < r->rewrite_nr; i++) {
 195                 if (len
 196                     ? (len == r->rewrite[i]->baselen &&
 197                        !strncmp(base, r->rewrite[i]->base, len))
 198                     : !strcmp(base, r->rewrite[i]->base))
 199                         return r->rewrite[i];
 200         }
 201
 202         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 203         ret = xcalloc(1, sizeof(struct rewrite));
 204         r->rewrite[r->rewrite_nr++] = ret;
 205         if (len) {
 206                 ret->base = xstrndup(base, len);
 207                 ret->baselen = len;
 208         }
 209         else {
 210                 ret->base = xstrdup(base);
 211                 ret->baselen = strlen(base);
 212         }
 213         return ret;
 214 }
 215
 216 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 217 {
 218         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 219         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 220         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 221         rewrite->instead_of_nr++;
 222 }
 223
 224 static void read_remotes_file(struct remote *remote)
 225 {
 226         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 227
 228         if (!f)
 229                 return;
 230         remote->origin = REMOTE_REMOTES;
 231         while (fgets(buffer, BUF_SIZE, f)) {
 232                 int value_list;
 233                 char *s, *p;
 234
 235                 if (!prefixcmp(buffer, "URL:")) {
 236                         value_list = 0;
 237                         s = buffer + 4;
 238                 } else if (!prefixcmp(buffer, "Push:")) {
 239                         value_list = 1;
 240                         s = buffer + 5;
 241                 } else if (!prefixcmp(buffer, "Pull:")) {
 242                         value_list = 2;
 243                         s = buffer + 5;
 244                 } else
 245                         continue;
 246
 247                 while (isspace(*s))
 248                         s++;
 249                 if (!*s)
 250                         continue;
 251
 252                 p = s + strlen(s);
 253                 while (isspace(p[-1]))
 254                         *--p = 0;
 255
 256                 switch (value_list) {
 257                 case 0:
 258                         add_url_alias(remote, xstrdup(s));
 259                         break;
 260                 case 1:
 261                         add_push_refspec(remote, xstrdup(s));
 262                         break;
 263                 case 2:
 264                         add_fetch_refspec(remote, xstrdup(s));
 265                         break;
 266                 }
 267         }
 268         fclose(f);
 269 }
 270
 271 static void read_branches_file(struct remote *remote)
 272 {
 273         const char *slash = strchr(remote->name, '/');
 274         char *frag;
 275         struct strbuf branch = STRBUF_INIT;
 276         int n = slash ? slash - remote->name : 1000;
 277         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 278         char *s, *p;
 279         int len;
 280
 281         if (!f)
 282                 return;
 283         s = fgets(buffer, BUF_SIZE, f);
 284         fclose(f);
 285         if (!s)
 286                 return;
 287         while (isspace(*s))
 288                 s++;
 289         if (!*s)
 290                 return;
 291         remote->origin = REMOTE_BRANCHES;
 292         p = s + strlen(s);
 293         while (isspace(p[-1]))
 294                 *--p = 0;
 295         len = p - s;
 296         if (slash)
 297                 len += strlen(slash);
 298         p = xmalloc(len + 1);
 299         strcpy(p, s);
 300         if (slash)
 301                 strcat(p, slash);
 302
 303         /*
 304          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 305          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 306          * the partial URL obtained from the branches file plus
 307          * "/netdev-2.6" and does not store it in any tracking ref.
 308          * #branch specifier in the file is ignored.
 309          *
 310          * Otherwise, the branches file would have URL and optionally
 311          * #branch specified.  The "master" (or specified) branch is
 312          * fetched and stored in the local branch of the same name.
 313          */
 314         frag = strchr(p, '#');
 315         if (frag) {
 316                 *(frag++) = '\0';
 317                 strbuf_addf(&branch, "refs/heads/%s", frag);
 318         } else
 319                 strbuf_addstr(&branch, "refs/heads/master");
 320         if (!slash) {
 321                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 322         } else {
 323                 strbuf_reset(&branch);
 324                 strbuf_addstr(&branch, "HEAD:");
 325         }
 326         add_url_alias(remote, p);
 327         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 328         /*
 329          * Cogito compatible push: push current HEAD to remote #branch
 330          * (master if missing)
 331          */
 332         strbuf_init(&branch, 0);
 333         strbuf_addstr(&branch, "HEAD");
 334         if (frag)
 335                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 336         else
 337                 strbuf_addstr(&branch, ":refs/heads/master");
 338         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 339         remote->fetch_tags = 1; /* always auto-follow */
 340 }
 341
 342 static int handle_config(const char *key, const char *value, void *cb)
 343 {
 344         const char *name;
 345         const char *subkey;
 346         struct remote *remote;
 347         struct branch *branch;
 348         if (!prefixcmp(key, "branch.")) {
 349                 name = key + 7;
 350                 subkey = strrchr(name, '.');
 351                 if (!subkey)
 352                         return 0;
 353                 branch = make_branch(name, subkey - name);
 354                 if (!strcmp(subkey, ".remote")) {
 355                         if (!value)
 356                                 return config_error_nonbool(key);
 357                         branch->remote_name = xstrdup(value);
 358                         if (branch == current_branch) {
 359                                 default_remote_name = branch->remote_name;
 360                                 explicit_default_remote_name = 1;
 361                         }
 362                 } else if (!strcmp(subkey, ".merge")) {
 363                         if (!value)
 364                                 return config_error_nonbool(key);
 365                         add_merge(branch, xstrdup(value));
 366                 }
 367                 return 0;
 368         }
 369         if (!prefixcmp(key, "url.")) {
 370                 struct rewrite *rewrite;
 371                 name = key + 4;
 372                 subkey = strrchr(name, '.');
 373                 if (!subkey)
 374                         return 0;
 375                 if (!strcmp(subkey, ".insteadof")) {
 376                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 377                         if (!value)
 378                                 return config_error_nonbool(key);
 379                         add_instead_of(rewrite, xstrdup(value));
 380                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 381                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 382                         if (!value)
 383                                 return config_error_nonbool(key);
 384                         add_instead_of(rewrite, xstrdup(value));
 385                 }
 386         }
 387         if (prefixcmp(key,  "remote."))
 388                 return 0;
 389         name = key + 7;
 390         if (*name == '/') {
 391                 warning("Config remote shorthand cannot begin with '/': %s",
 392                         name);
 393                 return 0;
 394         }
 395         subkey = strrchr(name, '.');
 396         if (!subkey)
 397                 return 0;
 398         remote = make_remote(name, subkey - name);
 399         remote->origin = REMOTE_CONFIG;
 400         if (!strcmp(subkey, ".mirror"))
 401                 remote->mirror = git_config_bool(key, value);
 402         else if (!strcmp(subkey, ".skipdefaultupdate"))
 403                 remote->skip_default_update = git_config_bool(key, value);
 404
 405         else if (!strcmp(subkey, ".url")) {
 406                 const char *v;
 407                 if (git_config_string(&v, key, value))
 408                         return -1;
 409                 add_url(remote, v);
 410         } else if (!strcmp(subkey, ".pushurl")) {
 411                 const char *v;
 412                 if (git_config_string(&v, key, value))
 413                         return -1;
 414                 add_pushurl(remote, v);
 415         } else if (!strcmp(subkey, ".push")) {
 416                 const char *v;
 417                 if (git_config_string(&v, key, value))
 418                         return -1;
 419                 add_push_refspec(remote, v);
 420         } else if (!strcmp(subkey, ".fetch")) {
 421                 const char *v;
 422                 if (git_config_string(&v, key, value))
 423                         return -1;
 424                 add_fetch_refspec(remote, v);
 425         } else if (!strcmp(subkey, ".receivepack")) {
 426                 const char *v;
 427                 if (git_config_string(&v, key, value))
 428                         return -1;
 429                 if (!remote->receivepack)
 430                         remote->receivepack = v;
 431                 else
 432                         error("more than one receivepack given, using the first");
 433         } else if (!strcmp(subkey, ".uploadpack")) {
 434                 const char *v;
 435                 if (git_config_string(&v, key, value))
 436                         return -1;
 437                 if (!remote->uploadpack)
 438                         remote->uploadpack = v;
 439                 else
 440                         error("more than one uploadpack given, using the first");
 441         } else if (!strcmp(subkey, ".tagopt")) {
 442                 if (!strcmp(value, "--no-tags"))
 443                         remote->fetch_tags = -1;
 444         } else if (!strcmp(subkey, ".proxy")) {
 445                 return git_config_string((const char **)&remote->http_proxy,
 446                                          key, value);
 447         } else if (!strcmp(subkey, ".vcs")) {
 448                 return git_config_string(&remote->foreign_vcs, key, value);
 449         }
 450         return 0;
 451 }
 452
 453 static void alias_all_urls(void)
 454 {
 455         int i, j;
 456         for (i = 0; i < remotes_nr; i++) {
 457                 int add_pushurl_aliases;
 458                 if (!remotes[i])
 459                         continue;
 460                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 461                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 462                 }
 463                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 464                 for (j = 0; j < remotes[i]->url_nr; j++) {
 465                         if (add_pushurl_aliases)
 466                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 467                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 468                 }
 469         }
 470 }
 471
 472 static void read_config(void)
 473 {
 474         unsigned char sha1[20];
 475         const char *head_ref;
 476         int flag;
 477         if (default_remote_name) // did this already
 478                 return;
 479         default_remote_name = xstrdup("origin");
 480         current_branch = NULL;
 481         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 482         if (head_ref && (flag & REF_ISSYMREF) &&
 483             !prefixcmp(head_ref, "refs/heads/")) {
 484                 current_branch =
 485                         make_branch(head_ref + strlen("refs/heads/"), 0);
 486         }
 487         git_config(handle_config, NULL);
 488         alias_all_urls();
 489 }
 490
 491 /*
 492  * We need to make sure the tracking branches are well formed, but a
 493  * wildcard refspec in "struct refspec" must have a trailing slash. We
 494  * temporarily drop the trailing '/' while calling check_ref_format(),
 495  * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 496  * error return is Ok for a wildcard refspec.
 497  */
 498 static int verify_refname(char *name, int is_glob)
 499 {
 500         int result;
 501
 502         result = check_ref_format(name);
 503         if (is_glob && result == CHECK_REF_FORMAT_WILDCARD)
 504                 result = CHECK_REF_FORMAT_OK;
 505         return result;
 506 }
 507
 508 /*
 509  * This function frees a refspec array.
 510  * Warning: code paths should be checked to ensure that the src
 511  *          and dst pointers are always freeable pointers as well
 512  *          as the refspec pointer itself.
 513  */
 514 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 515 {
 516         int i;
 517
 518         if (!refspec)
 519                 return;
 520
 521         for (i = 0; i < nr_refspec; i++) {
 522                 free(refspec[i].src);
 523                 free(refspec[i].dst);
 524         }
 525         free(refspec);
 526 }
 527
 528 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 529 {
 530         int i;
 531         int st;
 532         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 533
 534         for (i = 0; i < nr_refspec; i++) {
 535                 size_t llen;
 536                 int is_glob;
 537                 const char *lhs, *rhs;
 538
 539                 is_glob = 0;
 540
 541                 lhs = refspec[i];
 542                 if (*lhs == '+') {
 543                         rs[i].force = 1;
 544                         lhs++;
 545                 }
 546
 547                 rhs = strrchr(lhs, ':');
 548
 549                 /*
 550                  * Before going on, special case ":" (or "+:") as a refspec
 551                  * for matching refs.
 552                  */
 553                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 554                         rs[i].matching = 1;
 555                         continue;
 556                 }
 557
 558                 if (rhs) {
 559                         size_t rlen = strlen(++rhs);
 560                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 561                         rs[i].dst = xstrndup(rhs, rlen);
 562                 }
 563
 564                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 565                 if (1 <= llen && memchr(lhs, '*', llen)) {
 566                         if ((rhs && !is_glob) || (!rhs && fetch))
 567                                 goto invalid;
 568                         is_glob = 1;
 569                 } else if (rhs && is_glob) {
 570                         goto invalid;
 571                 }
 572
 573                 rs[i].pattern = is_glob;
 574                 rs[i].src = xstrndup(lhs, llen);
 575
 576                 if (fetch) {
 577                         /*
 578                          * LHS
 579                          * - empty is allowed; it means HEAD.
 580                          * - otherwise it must be a valid looking ref.
 581                          */
 582                         if (!*rs[i].src)
 583                                 ; /* empty is ok */
 584                         else {
 585                                 st = verify_refname(rs[i].src, is_glob);
 586                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 587                                         goto invalid;
 588                         }
 589                         /*
 590                          * RHS
 591                          * - missing is ok, and is same as empty.
 592                          * - empty is ok; it means not to store.
 593                          * - otherwise it must be a valid looking ref.
 594                          */
 595                         if (!rs[i].dst) {
 596                                 ; /* ok */
 597                         } else if (!*rs[i].dst) {
 598                                 ; /* ok */
 599                         } else {
 600                                 st = verify_refname(rs[i].dst, is_glob);
 601                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 602                                         goto invalid;
 603                         }
 604                 } else {
 605                         /*
 606                          * LHS
 607                          * - empty is allowed; it means delete.
 608                          * - when wildcarded, it must be a valid looking ref.
 609                          * - otherwise, it must be an extended SHA-1, but
 610                          *   there is no existing way to validate this.
 611                          */
 612                         if (!*rs[i].src)
 613                                 ; /* empty is ok */
 614                         else if (is_glob) {
 615                                 st = verify_refname(rs[i].src, is_glob);
 616                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 617                                         goto invalid;
 618                         }
 619                         else
 620                                 ; /* anything goes, for now */
 621                         /*
 622                          * RHS
 623                          * - missing is allowed, but LHS then must be a
 624                          *   valid looking ref.
 625                          * - empty is not allowed.
 626                          * - otherwise it must be a valid looking ref.
 627                          */
 628                         if (!rs[i].dst) {
 629                                 st = verify_refname(rs[i].src, is_glob);
 630                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 631                                         goto invalid;
 632                         } else if (!*rs[i].dst) {
 633                                 goto invalid;
 634                         } else {
 635                                 st = verify_refname(rs[i].dst, is_glob);
 636                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 637                                         goto invalid;
 638                         }
 639                 }
 640         }
 641         return rs;
 642
 643  invalid:
 644         if (verify) {
 645                 /*
 646                  * nr_refspec must be greater than zero and i must be valid
 647                  * since it is only possible to reach this point from within
 648                  * the for loop above.
 649                  */
 650                 free_refspecs(rs, i+1);
 651                 return NULL;
 652         }
 653         die("Invalid refspec '%s'", refspec[i]);
 654 }
 655
 656 int valid_fetch_refspec(const char *fetch_refspec_str)
 657 {
 658         const char *fetch_refspec[] = { fetch_refspec_str };
 659         struct refspec *refspec;
 660
 661         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 662         free_refspecs(refspec, 1);
 663         return !!refspec;
 664 }
 665
 666 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 667 {
 668         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 669 }
 670
 671 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 672 {
 673         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 674 }
 675
 676 static int valid_remote_nick(const char *name)
 677 {
 678         if (!name[0] || is_dot_or_dotdot(name))
 679                 return 0;
 680         return !strchr(name, '/'); /* no slash */
 681 }
 682
 683 struct remote *remote_get(const char *name)
 684 {
 685         struct remote *ret;
 686         int name_given = 0;
 687
 688         read_config();
 689         if (name)
 690                 name_given = 1;
 691         else {
 692                 name = default_remote_name;
 693                 name_given = explicit_default_remote_name;
 694         }
 695
 696         ret = make_remote(name, 0);
 697         if (valid_remote_nick(name)) {
 698                 if (!valid_remote(ret))
 699                         read_remotes_file(ret);
 700                 if (!valid_remote(ret))
 701                         read_branches_file(ret);
 702         }
 703         if (name_given && !valid_remote(ret))
 704                 add_url_alias(ret, name);
 705         if (!valid_remote(ret))
 706                 return NULL;
 707         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 708         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 709         return ret;
 710 }
 711
 712 int remote_is_configured(const char *name)
 713 {
 714         int i;
 715         read_config();
 716
 717         for (i = 0; i < remotes_nr; i++)
 718                 if (!strcmp(name, remotes[i]->name))
 719                         return 1;
 720         return 0;
 721 }
 722
 723 int for_each_remote(each_remote_fn fn, void *priv)
 724 {
 725         int i, result = 0;
 726         read_config();
 727         for (i = 0; i < remotes_nr && !result; i++) {
 728                 struct remote *r = remotes[i];
 729                 if (!r)
 730                         continue;
 731                 if (!r->fetch)
 732                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 733                                                        r->fetch_refspec);
 734                 if (!r->push)
 735                         r->push = parse_push_refspec(r->push_refspec_nr,
 736                                                      r->push_refspec);
 737                 result = fn(r, priv);
 738         }
 739         return result;
 740 }
 741
 742 void ref_remove_duplicates(struct ref *ref_map)
 743 {
 744         struct ref **posn;
 745         struct ref *next;
 746         for (; ref_map; ref_map = ref_map->next) {
 747                 if (!ref_map->peer_ref)
 748                         continue;
 749                 posn = &ref_map->next;
 750                 while (*posn) {
 751                         if ((*posn)->peer_ref &&
 752                             !strcmp((*posn)->peer_ref->name,
 753                                     ref_map->peer_ref->name)) {
 754                                 if (strcmp((*posn)->name, ref_map->name))
 755                                         die("%s tracks both %s and %s",
 756                                             ref_map->peer_ref->name,
 757                                             (*posn)->name, ref_map->name);
 758                                 next = (*posn)->next;
 759                                 free((*posn)->peer_ref);
 760                                 free(*posn);
 761                                 *posn = next;
 762                         } else {
 763                                 posn = &(*posn)->next;
 764                         }
 765                 }
 766         }
 767 }
 768
 769 int remote_has_url(struct remote *remote, const char *url)
 770 {
 771         int i;
 772         for (i = 0; i < remote->url_nr; i++) {
 773                 if (!strcmp(remote->url[i], url))
 774                         return 1;
 775         }
 776         return 0;
 777 }
 778
 779 static int match_name_with_pattern(const char *key, const char *name,
 780                                    const char *value, char **result)
 781 {
 782         const char *kstar = strchr(key, '*');
 783         size_t klen;
 784         size_t ksuffixlen;
 785         size_t namelen;
 786         int ret;
 787         if (!kstar)
 788                 die("Key '%s' of pattern had no '*'", key);
 789         klen = kstar - key;
 790         ksuffixlen = strlen(kstar + 1);
 791         namelen = strlen(name);
 792         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 793                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 794         if (ret && value) {
 795                 const char *vstar = strchr(value, '*');
 796                 size_t vlen;
 797                 size_t vsuffixlen;
 798                 if (!vstar)
 799                         die("Value '%s' of pattern has no '*'", value);
 800                 vlen = vstar - value;
 801                 vsuffixlen = strlen(vstar + 1);
 802                 *result = xmalloc(vlen + vsuffixlen +
 803                                   strlen(name) -
 804                                   klen - ksuffixlen + 1);
 805                 strncpy(*result, value, vlen);
 806                 strncpy(*result + vlen,
 807                         name + klen, namelen - klen - ksuffixlen);
 808                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 809                        vstar + 1);
 810         }
 811         return ret;
 812 }
 813
 814 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 815 {
 816         int find_src = refspec->src == NULL;
 817         char *needle, **result;
 818         int i;
 819
 820         if (find_src) {
 821                 if (!refspec->dst)
 822                         return error("find_tracking: need either src or dst");
 823                 needle = refspec->dst;
 824                 result = &refspec->src;
 825         } else {
 826                 needle = refspec->src;
 827                 result = &refspec->dst;
 828         }
 829
 830         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 831                 struct refspec *fetch = &remote->fetch[i];
 832                 const char *key = find_src ? fetch->dst : fetch->src;
 833                 const char *value = find_src ? fetch->src : fetch->dst;
 834                 if (!fetch->dst)
 835                         continue;
 836                 if (fetch->pattern) {
 837                         if (match_name_with_pattern(key, needle, value, result)) {
 838                                 refspec->force = fetch->force;
 839                                 return 0;
 840                         }
 841                 } else if (!strcmp(needle, key)) {
 842                         *result = xstrdup(value);
 843                         refspec->force = fetch->force;
 844                         return 0;
 845                 }
 846         }
 847         return -1;
 848 }
 849
 850 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 851                 const char *name)
 852 {
 853         size_t len = strlen(name);
 854         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 855         memcpy(ref->name, prefix, prefixlen);
 856         memcpy(ref->name + prefixlen, name, len);
 857         return ref;
 858 }
 859
 860 struct ref *alloc_ref(const char *name)
 861 {
 862         return alloc_ref_with_prefix("", 0, name);
 863 }
 864
 865 static struct ref *copy_ref(const struct ref *ref)
 866 {
 867         struct ref *cpy;
 868         size_t len;
 869         if (!ref)
 870                 return NULL;
 871         len = strlen(ref->name);
 872         cpy = xmalloc(sizeof(struct ref) + len + 1);
 873         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 874         cpy->next = NULL;
 875         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 876         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 877         cpy->peer_ref = copy_ref(ref->peer_ref);
 878         return cpy;
 879 }
 880
 881 struct ref *copy_ref_list(const struct ref *ref)
 882 {
 883         struct ref *ret = NULL;
 884         struct ref **tail = &ret;
 885         while (ref) {
 886                 *tail = copy_ref(ref);
 887                 ref = ref->next;
 888                 tail = &((*tail)->next);
 889         }
 890         return ret;
 891 }
 892
 893 static void free_ref(struct ref *ref)
 894 {
 895         if (!ref)
 896                 return;
 897         free_ref(ref->peer_ref);
 898         free(ref->remote_status);
 899         free(ref->symref);
 900         free(ref);
 901 }
 902
 903 void free_refs(struct ref *ref)
 904 {
 905         struct ref *next;
 906         while (ref) {
 907                 next = ref->next;
 908                 free_ref(ref);
 909                 ref = next;
 910         }
 911 }
 912
 913 static int count_refspec_match(const char *pattern,
 914                                struct ref *refs,
 915                                struct ref **matched_ref)
 916 {
 917         int patlen = strlen(pattern);
 918         struct ref *matched_weak = NULL;
 919         struct ref *matched = NULL;
 920         int weak_match = 0;
 921         int match = 0;
 922
 923         for (weak_match = match = 0; refs; refs = refs->next) {
 924                 char *name = refs->name;
 925                 int namelen = strlen(name);
 926
 927                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 928                         continue;
 929
 930                 /* A match is "weak" if it is with refs outside
 931                  * heads or tags, and did not specify the pattern
 932                  * in full (e.g. "refs/remotes/origin/master") or at
 933                  * least from the toplevel (e.g. "remotes/origin/master");
 934                  * otherwise "git push $URL master" would result in
 935                  * ambiguity between remotes/origin/master and heads/master
 936                  * at the remote site.
 937                  */
 938                 if (namelen != patlen &&
 939                     patlen != namelen - 5 &&
 940                     prefixcmp(name, "refs/heads/") &&
 941                     prefixcmp(name, "refs/tags/")) {
 942                         /* We want to catch the case where only weak
 943                          * matches are found and there are multiple
 944                          * matches, and where more than one strong
 945                          * matches are found, as ambiguous.  One
 946                          * strong match with zero or more weak matches
 947                          * are acceptable as a unique match.
 948                          */
 949                         matched_weak = refs;
 950                         weak_match++;
 951                 }
 952                 else {
 953                         matched = refs;
 954                         match++;
 955                 }
 956         }
 957         if (!matched) {
 958                 *matched_ref = matched_weak;
 959                 return weak_match;
 960         }
 961         else {
 962                 *matched_ref = matched;
 963                 return match;
 964         }
 965 }
 966
 967 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 968 {
 969         **tail = ref;
 970         while (ref->next)
 971                 ref = ref->next;
 972         *tail = &ref->next;
 973 }
 974
 975 static struct ref *try_explicit_object_name(const char *name)
 976 {
 977         unsigned char sha1[20];
 978         struct ref *ref;
 979
 980         if (!*name) {
 981                 ref = alloc_ref("(delete)");
 982                 hashclr(ref->new_sha1);
 983                 return ref;
 984         }
 985         if (get_sha1(name, sha1))
 986                 return NULL;
 987         ref = alloc_ref(name);
 988         hashcpy(ref->new_sha1, sha1);
 989         return ref;
 990 }
 991
 992 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 993 {
 994         struct ref *ret = alloc_ref(name);
 995         tail_link_ref(ret, tail);
 996         return ret;
 997 }
 998
 999 static char *guess_ref(const char *name, struct ref *peer)
1000 {
1001         struct strbuf buf = STRBUF_INIT;
1002         unsigned char sha1[20];
1003
1004         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
1005         if (!r)
1006                 return NULL;
1007
1008         if (!prefixcmp(r, "refs/heads/"))
1009                 strbuf_addstr(&buf, "refs/heads/");
1010         else if (!prefixcmp(r, "refs/tags/"))
1011                 strbuf_addstr(&buf, "refs/tags/");
1012         else
1013                 return NULL;
1014
1015         strbuf_addstr(&buf, name);
1016         return strbuf_detach(&buf, NULL);
1017 }
1018
1019 static int match_explicit(struct ref *src, struct ref *dst,
1020                           struct ref ***dst_tail,
1021                           struct refspec *rs)
1022 {
1023         struct ref *matched_src, *matched_dst;
1024         int copy_src;
1025
1026         const char *dst_value = rs->dst;
1027         char *dst_guess;
1028
1029         if (rs->pattern || rs->matching)
1030                 return 0;
1031
1032         matched_src = matched_dst = NULL;
1033         switch (count_refspec_match(rs->src, src, &matched_src)) {
1034         case 1:
1035                 copy_src = 1;
1036                 break;
1037         case 0:
1038                 /* The source could be in the get_sha1() format
1039                  * not a reference name.  :refs/other is a
1040                  * way to delete 'other' ref at the remote end.
1041                  */
1042                 matched_src = try_explicit_object_name(rs->src);
1043                 if (!matched_src)
1044                         return error("src refspec %s does not match any.", rs->src);
1045                 copy_src = 0;
1046                 break;
1047         default:
1048                 return error("src refspec %s matches more than one.", rs->src);
1049         }
1050
1051         if (!dst_value) {
1052                 unsigned char sha1[20];
1053                 int flag;
1054
1055                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
1056                 if (!dst_value ||
1057                     ((flag & REF_ISSYMREF) &&
1058                      prefixcmp(dst_value, "refs/heads/")))
1059                         die("%s cannot be resolved to branch.",
1060                             matched_src->name);
1061         }
1062
1063         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1064         case 1:
1065                 break;
1066         case 0:
1067                 if (!memcmp(dst_value, "refs/", 5))
1068                         matched_dst = make_linked_ref(dst_value, dst_tail);
1069                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1070                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1071                 else
1072                         error("unable to push to unqualified destination: %s\n"
1073                               "The destination refspec neither matches an "
1074                               "existing ref on the remote nor\n"
1075                               "begins with refs/, and we are unable to "
1076                               "guess a prefix based on the source ref.",
1077                               dst_value);
1078                 break;
1079         default:
1080                 matched_dst = NULL;
1081                 error("dst refspec %s matches more than one.",
1082                       dst_value);
1083                 break;
1084         }
1085         if (!matched_dst)
1086                 return -1;
1087         if (matched_dst->peer_ref)
1088                 return error("dst ref %s receives from more than one src.",
1089                       matched_dst->name);
1090         else {
1091                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1092                 matched_dst->force = rs->force;
1093         }
1094         return 0;
1095 }
1096
1097 static int match_explicit_refs(struct ref *src, struct ref *dst,
1098                                struct ref ***dst_tail, struct refspec *rs,
1099                                int rs_nr)
1100 {
1101         int i, errs;
1102         for (i = errs = 0; i < rs_nr; i++)
1103                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1104         return errs;
1105 }
1106
1107 static const struct refspec *check_pattern_match(const struct refspec *rs,
1108                                                  int rs_nr,
1109                                                  const struct ref *src)
1110 {
1111         int i;
1112         int matching_refs = -1;
1113         for (i = 0; i < rs_nr; i++) {
1114                 if (rs[i].matching &&
1115                     (matching_refs == -1 || rs[i].force)) {
1116                         matching_refs = i;
1117                         continue;
1118                 }
1119
1120                 if (rs[i].pattern && match_name_with_pattern(rs[i].src, src->name,
1121                                                              NULL, NULL))
1122                         return rs + i;
1123         }
1124         if (matching_refs != -1)
1125                 return rs + matching_refs;
1126         else
1127                 return NULL;
1128 }
1129
1130 static struct ref **tail_ref(struct ref **head)
1131 {
1132         struct ref **tail = head;
1133         while (*tail)
1134                 tail = &((*tail)->next);
1135         return tail;
1136 }
1137
1138 /*
1139  * Note. This is used only by "push"; refspec matching rules for
1140  * push and fetch are subtly different, so do not try to reuse it
1141  * without thinking.
1142  */
1143 int match_refs(struct ref *src, struct ref **dst,
1144                int nr_refspec, const char **refspec, int flags)
1145 {
1146         struct refspec *rs;
1147         int send_all = flags & MATCH_REFS_ALL;
1148         int send_mirror = flags & MATCH_REFS_MIRROR;
1149         int errs;
1150         static const char *default_refspec[] = { ":", NULL };
1151         struct ref **dst_tail = tail_ref(dst);
1152
1153         if (!nr_refspec) {
1154                 nr_refspec = 1;
1155                 refspec = default_refspec;
1156         }
1157         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1158         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1159
1160         /* pick the remainder */
1161         for ( ; src; src = src->next) {
1162                 struct ref *dst_peer;
1163                 const struct refspec *pat = NULL;
1164                 char *dst_name;
1165                 if (src->peer_ref)
1166                         continue;
1167
1168                 pat = check_pattern_match(rs, nr_refspec, src);
1169                 if (!pat)
1170                         continue;
1171
1172                 if (pat->matching) {
1173                         /*
1174                          * "matching refs"; traditionally we pushed everything
1175                          * including refs outside refs/heads/ hierarchy, but
1176                          * that does not make much sense these days.
1177                          */
1178                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1179                                 continue;
1180                         dst_name = xstrdup(src->name);
1181
1182                 } else {
1183                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1184                         if (!match_name_with_pattern(pat->src, src->name,
1185                                                      dst_side, &dst_name))
1186                                 die("Didn't think it matches any more");
1187                 }
1188                 dst_peer = find_ref_by_name(*dst, dst_name);
1189                 if (dst_peer) {
1190                         if (dst_peer->peer_ref)
1191                                 /* We're already sending something to this ref. */
1192                                 goto free_name;
1193
1194                 } else {
1195                         if (pat->matching && !(send_all || send_mirror))
1196                                 /*
1197                                  * Remote doesn't have it, and we have no
1198                                  * explicit pattern, and we don't have
1199                                  * --all nor --mirror.
1200                                  */
1201                                 goto free_name;
1202
1203                         /* Create a new one and link it */
1204                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1205                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1206                 }
1207                 dst_peer->peer_ref = copy_ref(src);
1208                 dst_peer->force = pat->force;
1209         free_name:
1210                 free(dst_name);
1211         }
1212         if (errs)
1213                 return -1;
1214         return 0;
1215 }
1216
1217 struct branch *branch_get(const char *name)
1218 {
1219         struct branch *ret;
1220
1221         read_config();
1222         if (!name || !*name || !strcmp(name, "HEAD"))
1223                 ret = current_branch;
1224         else
1225                 ret = make_branch(name, 0);
1226         if (ret && ret->remote_name) {
1227                 ret->remote = remote_get(ret->remote_name);
1228                 if (ret->merge_nr) {
1229                         int i;
1230                         ret->merge = xcalloc(sizeof(*ret->merge),
1231                                              ret->merge_nr);
1232                         for (i = 0; i < ret->merge_nr; i++) {
1233                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1234                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1235                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1236                                     && !strcmp(ret->remote_name, "."))
1237                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1238                         }
1239                 }
1240         }
1241         return ret;
1242 }
1243
1244 int branch_has_merge_config(struct branch *branch)
1245 {
1246         return branch && !!branch->merge;
1247 }
1248
1249 int branch_merge_matches(struct branch *branch,
1250                                  int i,
1251                                  const char *refname)
1252 {
1253         if (!branch || i < 0 || i >= branch->merge_nr)
1254                 return 0;
1255         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1256 }
1257
1258 static struct ref *get_expanded_map(const struct ref *remote_refs,
1259                                     const struct refspec *refspec)
1260 {
1261         const struct ref *ref;
1262         struct ref *ret = NULL;
1263         struct ref **tail = &ret;
1264
1265         char *expn_name;
1266
1267         for (ref = remote_refs; ref; ref = ref->next) {
1268                 if (strchr(ref->name, '^'))
1269                         continue; /* a dereference item */
1270                 if (match_name_with_pattern(refspec->src, ref->name,
1271                                             refspec->dst, &expn_name)) {
1272                         struct ref *cpy = copy_ref(ref);
1273
1274                         cpy->peer_ref = alloc_ref(expn_name);
1275                         free(expn_name);
1276                         if (refspec->force)
1277                                 cpy->peer_ref->force = 1;
1278                         *tail = cpy;
1279                         tail = &cpy->next;
1280                 }
1281         }
1282
1283         return ret;
1284 }
1285
1286 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1287 {
1288         const struct ref *ref;
1289         for (ref = refs; ref; ref = ref->next) {
1290                 if (refname_match(name, ref->name, ref_fetch_rules))
1291                         return ref;
1292         }
1293         return NULL;
1294 }
1295
1296 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1297 {
1298         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1299
1300         if (!ref)
1301                 return NULL;
1302
1303         return copy_ref(ref);
1304 }
1305
1306 static struct ref *get_local_ref(const char *name)
1307 {
1308         if (!name || name[0] == '\0')
1309                 return NULL;
1310
1311         if (!prefixcmp(name, "refs/"))
1312                 return alloc_ref(name);
1313
1314         if (!prefixcmp(name, "heads/") ||
1315             !prefixcmp(name, "tags/") ||
1316             !prefixcmp(name, "remotes/"))
1317                 return alloc_ref_with_prefix("refs/", 5, name);
1318
1319         return alloc_ref_with_prefix("refs/heads/", 11, name);
1320 }
1321
1322 int get_fetch_map(const struct ref *remote_refs,
1323                   const struct refspec *refspec,
1324                   struct ref ***tail,
1325                   int missing_ok)
1326 {
1327         struct ref *ref_map, **rmp;
1328
1329         if (refspec->pattern) {
1330                 ref_map = get_expanded_map(remote_refs, refspec);
1331         } else {
1332                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1333
1334                 ref_map = get_remote_ref(remote_refs, name);
1335                 if (!missing_ok && !ref_map)
1336                         die("Couldn't find remote ref %s", name);
1337                 if (ref_map) {
1338                         ref_map->peer_ref = get_local_ref(refspec->dst);
1339                         if (ref_map->peer_ref && refspec->force)
1340                                 ref_map->peer_ref->force = 1;
1341                 }
1342         }
1343
1344         for (rmp = &ref_map; *rmp; ) {
1345                 if ((*rmp)->peer_ref) {
1346                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1347                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1348                                 struct ref *ignore = *rmp;
1349                                 error("* Ignoring funny ref '%s' locally",
1350                                       (*rmp)->peer_ref->name);
1351                                 *rmp = (*rmp)->next;
1352                                 free(ignore->peer_ref);
1353                                 free(ignore);
1354                                 continue;
1355                         }
1356                 }
1357                 rmp = &((*rmp)->next);
1358         }
1359
1360         if (ref_map)
1361                 tail_link_ref(ref_map, tail);
1362
1363         return 0;
1364 }
1365
1366 int resolve_remote_symref(struct ref *ref, struct ref *list)
1367 {
1368         if (!ref->symref)
1369                 return 0;
1370         for (; list; list = list->next)
1371                 if (!strcmp(ref->symref, list->name)) {
1372                         hashcpy(ref->old_sha1, list->old_sha1);
1373                         return 0;
1374                 }
1375         return 1;
1376 }
1377
1378 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1379 {
1380         while (list) {
1381                 struct commit_list *temp = list;
1382                 temp->item->object.flags &= ~mark;
1383                 list = temp->next;
1384                 free(temp);
1385         }
1386 }
1387
1388 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1389 {
1390         struct object *o;
1391         struct commit *old, *new;
1392         struct commit_list *list, *used;
1393         int found = 0;
1394
1395         /* Both new and old must be commit-ish and new is descendant of
1396          * old.  Otherwise we require --force.
1397          */
1398         o = deref_tag(parse_object(old_sha1), NULL, 0);
1399         if (!o || o->type != OBJ_COMMIT)
1400                 return 0;
1401         old = (struct commit *) o;
1402
1403         o = deref_tag(parse_object(new_sha1), NULL, 0);
1404         if (!o || o->type != OBJ_COMMIT)
1405                 return 0;
1406         new = (struct commit *) o;
1407
1408         if (parse_commit(new) < 0)
1409                 return 0;
1410
1411         used = list = NULL;
1412         commit_list_insert(new, &list);
1413         while (list) {
1414                 new = pop_most_recent_commit(&list, TMP_MARK);
1415                 commit_list_insert(new, &used);
1416                 if (new == old) {
1417                         found = 1;
1418                         break;
1419                 }
1420         }
1421         unmark_and_free(list, TMP_MARK);
1422         unmark_and_free(used, TMP_MARK);
1423         return found;
1424 }
1425
1426 /*
1427  * Return true if there is anything to report, otherwise false.
1428  */
1429 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1430 {
1431         unsigned char sha1[20];
1432         struct commit *ours, *theirs;
1433         char symmetric[84];
1434         struct rev_info revs;
1435         const char *rev_argv[10], *base;
1436         int rev_argc;
1437
1438         /*
1439          * Nothing to report unless we are marked to build on top of
1440          * somebody else.
1441          */
1442         if (!branch ||
1443             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1444                 return 0;
1445
1446         /*
1447          * If what we used to build on no longer exists, there is
1448          * nothing to report.
1449          */
1450         base = branch->merge[0]->dst;
1451         if (!resolve_ref(base, sha1, 1, NULL))
1452                 return 0;
1453         theirs = lookup_commit_reference(sha1);
1454         if (!theirs)
1455                 return 0;
1456
1457         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1458                 return 0;
1459         ours = lookup_commit_reference(sha1);
1460         if (!ours)
1461                 return 0;
1462
1463         /* are we the same? */
1464         if (theirs == ours)
1465                 return 0;
1466
1467         /* Run "rev-list --left-right ours...theirs" internally... */
1468         rev_argc = 0;
1469         rev_argv[rev_argc++] = NULL;
1470         rev_argv[rev_argc++] = "--left-right";
1471         rev_argv[rev_argc++] = symmetric;
1472         rev_argv[rev_argc++] = "--";
1473         rev_argv[rev_argc] = NULL;
1474
1475         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1476         strcpy(symmetric + 40, "...");
1477         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1478
1479         init_revisions(&revs, NULL);
1480         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1481         prepare_revision_walk(&revs);
1482
1483         /* ... and count the commits on each side. */
1484         *num_ours = 0;
1485         *num_theirs = 0;
1486         while (1) {
1487                 struct commit *c = get_revision(&revs);
1488                 if (!c)
1489                         break;
1490                 if (c->object.flags & SYMMETRIC_LEFT)
1491                         (*num_ours)++;
1492                 else
1493                         (*num_theirs)++;
1494         }
1495
1496         /* clear object flags smudged by the above traversal */
1497         clear_commit_marks(ours, ALL_REV_FLAGS);
1498         clear_commit_marks(theirs, ALL_REV_FLAGS);
1499         return 1;
1500 }
1501
1502 /*
1503  * Return true when there is anything to report, otherwise false.
1504  */
1505 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1506 {
1507         int num_ours, num_theirs;
1508         const char *base;
1509
1510         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1511                 return 0;
1512
1513         base = branch->merge[0]->dst;
1514         base = shorten_unambiguous_ref(base, 0);
1515         if (!num_theirs)
1516                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1517                             "by %d commit%s.\n",
1518                             base, num_ours, (num_ours == 1) ? "" : "s");
1519         else if (!num_ours)
1520                 strbuf_addf(sb, "Your branch is behind '%s' "
1521                             "by %d commit%s, "
1522                             "and can be fast-forwarded.\n",
1523                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1524         else
1525                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1526                             "and have %d and %d different commit(s) each, "
1527                             "respectively.\n",
1528                             base, num_ours, num_theirs);
1529         return 1;
1530 }
1531
1532 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1533 {
1534         struct ref ***local_tail = cb_data;
1535         struct ref *ref;
1536         int len;
1537
1538         /* we already know it starts with refs/ to get here */
1539         if (check_ref_format(refname + 5))
1540                 return 0;
1541
1542         len = strlen(refname) + 1;
1543         ref = xcalloc(1, sizeof(*ref) + len);
1544         hashcpy(ref->new_sha1, sha1);
1545         memcpy(ref->name, refname, len);
1546         **local_tail = ref;
1547         *local_tail = &ref->next;
1548         return 0;
1549 }
1550
1551 struct ref *get_local_heads(void)
1552 {
1553         struct ref *local_refs = NULL, **local_tail = &local_refs;
1554         for_each_ref(one_local_ref, &local_tail);
1555         return local_refs;
1556 }
1557
1558 struct ref *guess_remote_head(const struct ref *head,
1559                               const struct ref *refs,
1560                               int all)
1561 {
1562         const struct ref *r;
1563         struct ref *list = NULL;
1564         struct ref **tail = &list;
1565
1566         if (!head)
1567                 return NULL;
1568
1569         /*
1570          * Some transports support directly peeking at
1571          * where HEAD points; if that is the case, then
1572          * we don't have to guess.
1573          */
1574         if (head->symref)
1575                 return copy_ref(find_ref_by_name(refs, head->symref));
1576
1577         /* If refs/heads/master could be right, it is. */
1578         if (!all) {
1579                 r = find_ref_by_name(refs, "refs/heads/master");
1580                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1581                         return copy_ref(r);
1582         }
1583
1584         /* Look for another ref that points there */
1585         for (r = refs; r; r = r->next) {
1586                 if (r != head && !hashcmp(r->old_sha1, head->old_sha1)) {
1587                         *tail = copy_ref(r);
1588                         tail = &((*tail)->next);
1589                         if (!all)
1590                                 break;
1591                 }
1592         }
1593
1594         return list;
1595 }