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(value, "--tags"))
 447                         remote->fetch_tags = 2;
 448         } else if (!strcmp(subkey, ".proxy")) {
 449                 return git_config_string((const char **)&remote->http_proxy,
 450                                          key, value);
 451         } else if (!strcmp(subkey, ".vcs")) {
 452                 return git_config_string(&remote->foreign_vcs, key, value);
 453         }
 454         return 0;
 455 }
 456
 457 static void alias_all_urls(void)
 458 {
 459         int i, j;
 460         for (i = 0; i < remotes_nr; i++) {
 461                 int add_pushurl_aliases;
 462                 if (!remotes[i])
 463                         continue;
 464                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 465                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 466                 }
 467                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 468                 for (j = 0; j < remotes[i]->url_nr; j++) {
 469                         if (add_pushurl_aliases)
 470                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 471                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 472                 }
 473         }
 474 }
 475
 476 static void read_config(void)
 477 {
 478         unsigned char sha1[20];
 479         const char *head_ref;
 480         int flag;
 481         if (default_remote_name) /* did this already */
 482                 return;
 483         default_remote_name = xstrdup("origin");
 484         current_branch = NULL;
 485         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 486         if (head_ref && (flag & REF_ISSYMREF) &&
 487             !prefixcmp(head_ref, "refs/heads/")) {
 488                 current_branch =
 489                         make_branch(head_ref + strlen("refs/heads/"), 0);
 490         }
 491         git_config(handle_config, NULL);
 492         alias_all_urls();
 493 }
 494
 495 /*
 496  * This function frees a refspec array.
 497  * Warning: code paths should be checked to ensure that the src
 498  *          and dst pointers are always freeable pointers as well
 499  *          as the refspec pointer itself.
 500  */
 501 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 502 {
 503         int i;
 504
 505         if (!refspec)
 506                 return;
 507
 508         for (i = 0; i < nr_refspec; i++) {
 509                 free(refspec[i].src);
 510                 free(refspec[i].dst);
 511         }
 512         free(refspec);
 513 }
 514
 515 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 516 {
 517         int i;
 518         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 519
 520         for (i = 0; i < nr_refspec; i++) {
 521                 size_t llen;
 522                 int is_glob;
 523                 const char *lhs, *rhs;
 524                 int flags;
 525
 526                 is_glob = 0;
 527
 528                 lhs = refspec[i];
 529                 if (*lhs == '+') {
 530                         rs[i].force = 1;
 531                         lhs++;
 532                 }
 533
 534                 rhs = strrchr(lhs, ':');
 535
 536                 /*
 537                  * Before going on, special case ":" (or "+:") as a refspec
 538                  * for matching refs.
 539                  */
 540                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 541                         rs[i].matching = 1;
 542                         continue;
 543                 }
 544
 545                 if (rhs) {
 546                         size_t rlen = strlen(++rhs);
 547                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 548                         rs[i].dst = xstrndup(rhs, rlen);
 549                 }
 550
 551                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 552                 if (1 <= llen && memchr(lhs, '*', llen)) {
 553                         if ((rhs && !is_glob) || (!rhs && fetch))
 554                                 goto invalid;
 555                         is_glob = 1;
 556                 } else if (rhs && is_glob) {
 557                         goto invalid;
 558                 }
 559
 560                 rs[i].pattern = is_glob;
 561                 rs[i].src = xstrndup(lhs, llen);
 562                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 563
 564                 if (fetch) {
 565                         /*
 566                          * LHS
 567                          * - empty is allowed; it means HEAD.
 568                          * - otherwise it must be a valid looking ref.
 569                          */
 570                         if (!*rs[i].src)
 571                                 ; /* empty is ok */
 572                         else if (check_refname_format(rs[i].src, flags))
 573                                 goto invalid;
 574                         /*
 575                          * RHS
 576                          * - missing is ok, and is same as empty.
 577                          * - empty is ok; it means not to store.
 578                          * - otherwise it must be a valid looking ref.
 579                          */
 580                         if (!rs[i].dst)
 581                                 ; /* ok */
 582                         else if (!*rs[i].dst)
 583                                 ; /* ok */
 584                         else if (check_refname_format(rs[i].dst, flags))
 585                                 goto invalid;
 586                 } else {
 587                         /*
 588                          * LHS
 589                          * - empty is allowed; it means delete.
 590                          * - when wildcarded, it must be a valid looking ref.
 591                          * - otherwise, it must be an extended SHA-1, but
 592                          *   there is no existing way to validate this.
 593                          */
 594                         if (!*rs[i].src)
 595                                 ; /* empty is ok */
 596                         else if (is_glob) {
 597                                 if (check_refname_format(rs[i].src, flags))
 598                                         goto invalid;
 599                         }
 600                         else
 601                                 ; /* anything goes, for now */
 602                         /*
 603                          * RHS
 604                          * - missing is allowed, but LHS then must be a
 605                          *   valid looking ref.
 606                          * - empty is not allowed.
 607                          * - otherwise it must be a valid looking ref.
 608                          */
 609                         if (!rs[i].dst) {
 610                                 if (check_refname_format(rs[i].src, flags))
 611                                         goto invalid;
 612                         } else if (!*rs[i].dst) {
 613                                 goto invalid;
 614                         } else {
 615                                 if (check_refname_format(rs[i].dst, flags))
 616                                         goto invalid;
 617                         }
 618                 }
 619         }
 620         return rs;
 621
 622  invalid:
 623         if (verify) {
 624                 /*
 625                  * nr_refspec must be greater than zero and i must be valid
 626                  * since it is only possible to reach this point from within
 627                  * the for loop above.
 628                  */
 629                 free_refspecs(rs, i+1);
 630                 return NULL;
 631         }
 632         die("Invalid refspec '%s'", refspec[i]);
 633 }
 634
 635 int valid_fetch_refspec(const char *fetch_refspec_str)
 636 {
 637         struct refspec *refspec;
 638
 639         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 640         free_refspecs(refspec, 1);
 641         return !!refspec;
 642 }
 643
 644 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 645 {
 646         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 647 }
 648
 649 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 650 {
 651         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 652 }
 653
 654 void free_refspec(int nr_refspec, struct refspec *refspec)
 655 {
 656         int i;
 657         for (i = 0; i < nr_refspec; i++) {
 658                 free(refspec[i].src);
 659                 free(refspec[i].dst);
 660         }
 661         free(refspec);
 662 }
 663
 664 static int valid_remote_nick(const char *name)
 665 {
 666         if (!name[0] || is_dot_or_dotdot(name))
 667                 return 0;
 668         return !strchr(name, '/'); /* no slash */
 669 }
 670
 671 struct remote *remote_get(const char *name)
 672 {
 673         struct remote *ret;
 674         int name_given = 0;
 675
 676         read_config();
 677         if (name)
 678                 name_given = 1;
 679         else {
 680                 name = default_remote_name;
 681                 name_given = explicit_default_remote_name;
 682         }
 683
 684         ret = make_remote(name, 0);
 685         if (valid_remote_nick(name)) {
 686                 if (!valid_remote(ret))
 687                         read_remotes_file(ret);
 688                 if (!valid_remote(ret))
 689                         read_branches_file(ret);
 690         }
 691         if (name_given && !valid_remote(ret))
 692                 add_url_alias(ret, name);
 693         if (!valid_remote(ret))
 694                 return NULL;
 695         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 696         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 697         return ret;
 698 }
 699
 700 int remote_is_configured(const char *name)
 701 {
 702         int i;
 703         read_config();
 704
 705         for (i = 0; i < remotes_nr; i++)
 706                 if (!strcmp(name, remotes[i]->name))
 707                         return 1;
 708         return 0;
 709 }
 710
 711 int for_each_remote(each_remote_fn fn, void *priv)
 712 {
 713         int i, result = 0;
 714         read_config();
 715         for (i = 0; i < remotes_nr && !result; i++) {
 716                 struct remote *r = remotes[i];
 717                 if (!r)
 718                         continue;
 719                 if (!r->fetch)
 720                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 721                                                        r->fetch_refspec);
 722                 if (!r->push)
 723                         r->push = parse_push_refspec(r->push_refspec_nr,
 724                                                      r->push_refspec);
 725                 result = fn(r, priv);
 726         }
 727         return result;
 728 }
 729
 730 void ref_remove_duplicates(struct ref *ref_map)
 731 {
 732         struct string_list refs = STRING_LIST_INIT_NODUP;
 733         struct string_list_item *item = NULL;
 734         struct ref *prev = NULL, *next = NULL;
 735         for (; ref_map; prev = ref_map, ref_map = next) {
 736                 next = ref_map->next;
 737                 if (!ref_map->peer_ref)
 738                         continue;
 739
 740                 item = string_list_lookup(&refs, ref_map->peer_ref->name);
 741                 if (item) {
 742                         if (strcmp(((struct ref *)item->util)->name,
 743                                    ref_map->name))
 744                                 die("%s tracks both %s and %s",
 745                                     ref_map->peer_ref->name,
 746                                     ((struct ref *)item->util)->name,
 747                                     ref_map->name);
 748                         prev->next = ref_map->next;
 749                         free(ref_map->peer_ref);
 750                         free(ref_map);
 751                         ref_map = prev; /* skip this; we freed it */
 752                         continue;
 753                 }
 754
 755                 item = string_list_insert(&refs, ref_map->peer_ref->name);
 756                 item->util = ref_map;
 757         }
 758         string_list_clear(&refs, 0);
 759 }
 760
 761 int remote_has_url(struct remote *remote, const char *url)
 762 {
 763         int i;
 764         for (i = 0; i < remote->url_nr; i++) {
 765                 if (!strcmp(remote->url[i], url))
 766                         return 1;
 767         }
 768         return 0;
 769 }
 770
 771 static int match_name_with_pattern(const char *key, const char *name,
 772                                    const char *value, char **result)
 773 {
 774         const char *kstar = strchr(key, '*');
 775         size_t klen;
 776         size_t ksuffixlen;
 777         size_t namelen;
 778         int ret;
 779         if (!kstar)
 780                 die("Key '%s' of pattern had no '*'", key);
 781         klen = kstar - key;
 782         ksuffixlen = strlen(kstar + 1);
 783         namelen = strlen(name);
 784         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 785                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 786         if (ret && value) {
 787                 const char *vstar = strchr(value, '*');
 788                 size_t vlen;
 789                 size_t vsuffixlen;
 790                 if (!vstar)
 791                         die("Value '%s' of pattern has no '*'", value);
 792                 vlen = vstar - value;
 793                 vsuffixlen = strlen(vstar + 1);
 794                 *result = xmalloc(vlen + vsuffixlen +
 795                                   strlen(name) -
 796                                   klen - ksuffixlen + 1);
 797                 strncpy(*result, value, vlen);
 798                 strncpy(*result + vlen,
 799                         name + klen, namelen - klen - ksuffixlen);
 800                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 801                        vstar + 1);
 802         }
 803         return ret;
 804 }
 805
 806 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 807                      const char *name)
 808 {
 809         int i;
 810         char *ret = NULL;
 811         for (i = 0; i < nr_refspec; i++) {
 812                 struct refspec *refspec = refspecs + i;
 813                 if (refspec->pattern) {
 814                         if (match_name_with_pattern(refspec->src, name,
 815                                                     refspec->dst, &ret))
 816                                 return ret;
 817                 } else if (!strcmp(refspec->src, name))
 818                         return xstrdup(refspec->dst);
 819         }
 820         return NULL;
 821 }
 822
 823 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 824 {
 825         int find_src = refspec->src == NULL;
 826         char *needle, **result;
 827         int i;
 828
 829         if (find_src) {
 830                 if (!refspec->dst)
 831                         return error("find_tracking: need either src or dst");
 832                 needle = refspec->dst;
 833                 result = &refspec->src;
 834         } else {
 835                 needle = refspec->src;
 836                 result = &refspec->dst;
 837         }
 838
 839         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 840                 struct refspec *fetch = &remote->fetch[i];
 841                 const char *key = find_src ? fetch->dst : fetch->src;
 842                 const char *value = find_src ? fetch->src : fetch->dst;
 843                 if (!fetch->dst)
 844                         continue;
 845                 if (fetch->pattern) {
 846                         if (match_name_with_pattern(key, needle, value, result)) {
 847                                 refspec->force = fetch->force;
 848                                 return 0;
 849                         }
 850                 } else if (!strcmp(needle, key)) {
 851                         *result = xstrdup(value);
 852                         refspec->force = fetch->force;
 853                         return 0;
 854                 }
 855         }
 856         return -1;
 857 }
 858
 859 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 860                 const char *name)
 861 {
 862         size_t len = strlen(name);
 863         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 864         memcpy(ref->name, prefix, prefixlen);
 865         memcpy(ref->name + prefixlen, name, len);
 866         return ref;
 867 }
 868
 869 struct ref *alloc_ref(const char *name)
 870 {
 871         return alloc_ref_with_prefix("", 0, name);
 872 }
 873
 874 struct ref *copy_ref(const struct ref *ref)
 875 {
 876         struct ref *cpy;
 877         size_t len;
 878         if (!ref)
 879                 return NULL;
 880         len = strlen(ref->name);
 881         cpy = xmalloc(sizeof(struct ref) + len + 1);
 882         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 883         cpy->next = NULL;
 884         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 885         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 886         cpy->peer_ref = copy_ref(ref->peer_ref);
 887         return cpy;
 888 }
 889
 890 struct ref *copy_ref_list(const struct ref *ref)
 891 {
 892         struct ref *ret = NULL;
 893         struct ref **tail = &ret;
 894         while (ref) {
 895                 *tail = copy_ref(ref);
 896                 ref = ref->next;
 897                 tail = &((*tail)->next);
 898         }
 899         return ret;
 900 }
 901
 902 static void free_ref(struct ref *ref)
 903 {
 904         if (!ref)
 905                 return;
 906         free_ref(ref->peer_ref);
 907         free(ref->remote_status);
 908         free(ref->symref);
 909         free(ref);
 910 }
 911
 912 void free_refs(struct ref *ref)
 913 {
 914         struct ref *next;
 915         while (ref) {
 916                 next = ref->next;
 917                 free_ref(ref);
 918                 ref = next;
 919         }
 920 }
 921
 922 static int count_refspec_match(const char *pattern,
 923                                struct ref *refs,
 924                                struct ref **matched_ref)
 925 {
 926         int patlen = strlen(pattern);
 927         struct ref *matched_weak = NULL;
 928         struct ref *matched = NULL;
 929         int weak_match = 0;
 930         int match = 0;
 931
 932         for (weak_match = match = 0; refs; refs = refs->next) {
 933                 char *name = refs->name;
 934                 int namelen = strlen(name);
 935
 936                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 937                         continue;
 938
 939                 /* A match is "weak" if it is with refs outside
 940                  * heads or tags, and did not specify the pattern
 941                  * in full (e.g. "refs/remotes/origin/master") or at
 942                  * least from the toplevel (e.g. "remotes/origin/master");
 943                  * otherwise "git push $URL master" would result in
 944                  * ambiguity between remotes/origin/master and heads/master
 945                  * at the remote site.
 946                  */
 947                 if (namelen != patlen &&
 948                     patlen != namelen - 5 &&
 949                     prefixcmp(name, "refs/heads/") &&
 950                     prefixcmp(name, "refs/tags/")) {
 951                         /* We want to catch the case where only weak
 952                          * matches are found and there are multiple
 953                          * matches, and where more than one strong
 954                          * matches are found, as ambiguous.  One
 955                          * strong match with zero or more weak matches
 956                          * are acceptable as a unique match.
 957                          */
 958                         matched_weak = refs;
 959                         weak_match++;
 960                 }
 961                 else {
 962                         matched = refs;
 963                         match++;
 964                 }
 965         }
 966         if (!matched) {
 967                 *matched_ref = matched_weak;
 968                 return weak_match;
 969         }
 970         else {
 971                 *matched_ref = matched;
 972                 return match;
 973         }
 974 }
 975
 976 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 977 {
 978         **tail = ref;
 979         while (ref->next)
 980                 ref = ref->next;
 981         *tail = &ref->next;
 982 }
 983
 984 static struct ref *try_explicit_object_name(const char *name)
 985 {
 986         unsigned char sha1[20];
 987         struct ref *ref;
 988
 989         if (!*name) {
 990                 ref = alloc_ref("(delete)");
 991                 hashclr(ref->new_sha1);
 992                 return ref;
 993         }
 994         if (get_sha1(name, sha1))
 995                 return NULL;
 996         ref = alloc_ref(name);
 997         hashcpy(ref->new_sha1, sha1);
 998         return ref;
 999 }
1000
1001 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1002 {
1003         struct ref *ret = alloc_ref(name);
1004         tail_link_ref(ret, tail);
1005         return ret;
1006 }
1007
1008 static char *guess_ref(const char *name, struct ref *peer)
1009 {
1010         struct strbuf buf = STRBUF_INIT;
1011         unsigned char sha1[20];
1012
1013         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
1014         if (!r)
1015                 return NULL;
1016
1017         if (!prefixcmp(r, "refs/heads/"))
1018                 strbuf_addstr(&buf, "refs/heads/");
1019         else if (!prefixcmp(r, "refs/tags/"))
1020                 strbuf_addstr(&buf, "refs/tags/");
1021         else
1022                 return NULL;
1023
1024         strbuf_addstr(&buf, name);
1025         return strbuf_detach(&buf, NULL);
1026 }
1027
1028 static int match_explicit(struct ref *src, struct ref *dst,
1029                           struct ref ***dst_tail,
1030                           struct refspec *rs)
1031 {
1032         struct ref *matched_src, *matched_dst;
1033         int copy_src;
1034
1035         const char *dst_value = rs->dst;
1036         char *dst_guess;
1037
1038         if (rs->pattern || rs->matching)
1039                 return 0;
1040
1041         matched_src = matched_dst = NULL;
1042         switch (count_refspec_match(rs->src, src, &matched_src)) {
1043         case 1:
1044                 copy_src = 1;
1045                 break;
1046         case 0:
1047                 /* The source could be in the get_sha1() format
1048                  * not a reference name.  :refs/other is a
1049                  * way to delete 'other' ref at the remote end.
1050                  */
1051                 matched_src = try_explicit_object_name(rs->src);
1052                 if (!matched_src)
1053                         return error("src refspec %s does not match any.", rs->src);
1054                 copy_src = 0;
1055                 break;
1056         default:
1057                 return error("src refspec %s matches more than one.", rs->src);
1058         }
1059
1060         if (!dst_value) {
1061                 unsigned char sha1[20];
1062                 int flag;
1063
1064                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
1065                 if (!dst_value ||
1066                     ((flag & REF_ISSYMREF) &&
1067                      prefixcmp(dst_value, "refs/heads/")))
1068                         die("%s cannot be resolved to branch.",
1069                             matched_src->name);
1070         }
1071
1072         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1073         case 1:
1074                 break;
1075         case 0:
1076                 if (!memcmp(dst_value, "refs/", 5))
1077                         matched_dst = make_linked_ref(dst_value, dst_tail);
1078                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1079                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1080                 else
1081                         error("unable to push to unqualified destination: %s\n"
1082                               "The destination refspec neither matches an "
1083                               "existing ref on the remote nor\n"
1084                               "begins with refs/, and we are unable to "
1085                               "guess a prefix based on the source ref.",
1086                               dst_value);
1087                 break;
1088         default:
1089                 matched_dst = NULL;
1090                 error("dst refspec %s matches more than one.",
1091                       dst_value);
1092                 break;
1093         }
1094         if (!matched_dst)
1095                 return -1;
1096         if (matched_dst->peer_ref)
1097                 return error("dst ref %s receives from more than one src.",
1098                       matched_dst->name);
1099         else {
1100                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1101                 matched_dst->force = rs->force;
1102         }
1103         return 0;
1104 }
1105
1106 static int match_explicit_refs(struct ref *src, struct ref *dst,
1107                                struct ref ***dst_tail, struct refspec *rs,
1108                                int rs_nr)
1109 {
1110         int i, errs;
1111         for (i = errs = 0; i < rs_nr; i++)
1112                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1113         return errs;
1114 }
1115
1116 static const struct refspec *check_pattern_match(const struct refspec *rs,
1117                                                  int rs_nr,
1118                                                  const struct ref *src)
1119 {
1120         int i;
1121         int matching_refs = -1;
1122         for (i = 0; i < rs_nr; i++) {
1123                 if (rs[i].matching &&
1124                     (matching_refs == -1 || rs[i].force)) {
1125                         matching_refs = i;
1126                         continue;
1127                 }
1128
1129                 if (rs[i].pattern && match_name_with_pattern(rs[i].src, src->name,
1130                                                              NULL, NULL))
1131                         return rs + i;
1132         }
1133         if (matching_refs != -1)
1134                 return rs + matching_refs;
1135         else
1136                 return NULL;
1137 }
1138
1139 static struct ref **tail_ref(struct ref **head)
1140 {
1141         struct ref **tail = head;
1142         while (*tail)
1143                 tail = &((*tail)->next);
1144         return tail;
1145 }
1146
1147 /*
1148  * Given the set of refs the local repository has, the set of refs the
1149  * remote repository has, and the refspec used for push, determine
1150  * what remote refs we will update and with what value by setting
1151  * peer_ref (which object is being pushed) and force (if the push is
1152  * forced) in elements of "dst". The function may add new elements to
1153  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1154  */
1155 int match_push_refs(struct ref *src, struct ref **dst,
1156                     int nr_refspec, const char **refspec, int flags)
1157 {
1158         struct refspec *rs;
1159         int send_all = flags & MATCH_REFS_ALL;
1160         int send_mirror = flags & MATCH_REFS_MIRROR;
1161         int errs;
1162         static const char *default_refspec[] = { ":", NULL };
1163         struct ref **dst_tail = tail_ref(dst);
1164
1165         if (!nr_refspec) {
1166                 nr_refspec = 1;
1167                 refspec = default_refspec;
1168         }
1169         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1170         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1171
1172         /* pick the remainder */
1173         for ( ; src; src = src->next) {
1174                 struct ref *dst_peer;
1175                 const struct refspec *pat = NULL;
1176                 char *dst_name;
1177                 if (src->peer_ref)
1178                         continue;
1179
1180                 pat = check_pattern_match(rs, nr_refspec, src);
1181                 if (!pat)
1182                         continue;
1183
1184                 if (pat->matching) {
1185                         /*
1186                          * "matching refs"; traditionally we pushed everything
1187                          * including refs outside refs/heads/ hierarchy, but
1188                          * that does not make much sense these days.
1189                          */
1190                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1191                                 continue;
1192                         dst_name = xstrdup(src->name);
1193
1194                 } else {
1195                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1196                         if (!match_name_with_pattern(pat->src, src->name,
1197                                                      dst_side, &dst_name))
1198                                 die("Didn't think it matches any more");
1199                 }
1200                 dst_peer = find_ref_by_name(*dst, dst_name);
1201                 if (dst_peer) {
1202                         if (dst_peer->peer_ref)
1203                                 /* We're already sending something to this ref. */
1204                                 goto free_name;
1205
1206                 } else {
1207                         if (pat->matching && !(send_all || send_mirror))
1208                                 /*
1209                                  * Remote doesn't have it, and we have no
1210                                  * explicit pattern, and we don't have
1211                                  * --all nor --mirror.
1212                                  */
1213                                 goto free_name;
1214
1215                         /* Create a new one and link it */
1216                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1217                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1218                 }
1219                 dst_peer->peer_ref = copy_ref(src);
1220                 dst_peer->force = pat->force;
1221         free_name:
1222                 free(dst_name);
1223         }
1224         if (errs)
1225                 return -1;
1226         return 0;
1227 }
1228
1229 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1230         int force_update)
1231 {
1232         struct ref *ref;
1233
1234         for (ref = remote_refs; ref; ref = ref->next) {
1235                 if (ref->peer_ref)
1236                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1237                 else if (!send_mirror)
1238                         continue;
1239
1240                 ref->deletion = is_null_sha1(ref->new_sha1);
1241                 if (!ref->deletion &&
1242                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1243                         ref->status = REF_STATUS_UPTODATE;
1244                         continue;
1245                 }
1246
1247                 /* This part determines what can overwrite what.
1248                  * The rules are:
1249                  *
1250                  * (0) you can always use --force or +A:B notation to
1251                  *     selectively force individual ref pairs.
1252                  *
1253                  * (1) if the old thing does not exist, it is OK.
1254                  *
1255                  * (2) if you do not have the old thing, you are not allowed
1256                  *     to overwrite it; you would not know what you are losing
1257                  *     otherwise.
1258                  *
1259                  * (3) if both new and old are commit-ish, and new is a
1260                  *     descendant of old, it is OK.
1261                  *
1262                  * (4) regardless of all of the above, removing :B is
1263                  *     always allowed.
1264                  */
1265
1266                 ref->nonfastforward =
1267                         !ref->deletion &&
1268                         !is_null_sha1(ref->old_sha1) &&
1269                         (!has_sha1_file(ref->old_sha1)
1270                           || !ref_newer(ref->new_sha1, ref->old_sha1));
1271
1272                 if (ref->nonfastforward && !ref->force && !force_update) {
1273                         ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
1274                         continue;
1275                 }
1276         }
1277 }
1278
1279 struct branch *branch_get(const char *name)
1280 {
1281         struct branch *ret;
1282
1283         read_config();
1284         if (!name || !*name || !strcmp(name, "HEAD"))
1285                 ret = current_branch;
1286         else
1287                 ret = make_branch(name, 0);
1288         if (ret && ret->remote_name) {
1289                 ret->remote = remote_get(ret->remote_name);
1290                 if (ret->merge_nr) {
1291                         int i;
1292                         ret->merge = xcalloc(sizeof(*ret->merge),
1293                                              ret->merge_nr);
1294                         for (i = 0; i < ret->merge_nr; i++) {
1295                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1296                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1297                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1298                                     && !strcmp(ret->remote_name, "."))
1299                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1300                         }
1301                 }
1302         }
1303         return ret;
1304 }
1305
1306 int branch_has_merge_config(struct branch *branch)
1307 {
1308         return branch && !!branch->merge;
1309 }
1310
1311 int branch_merge_matches(struct branch *branch,
1312                                  int i,
1313                                  const char *refname)
1314 {
1315         if (!branch || i < 0 || i >= branch->merge_nr)
1316                 return 0;
1317         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1318 }
1319
1320 static struct ref *get_expanded_map(const struct ref *remote_refs,
1321                                     const struct refspec *refspec)
1322 {
1323         const struct ref *ref;
1324         struct ref *ret = NULL;
1325         struct ref **tail = &ret;
1326
1327         char *expn_name;
1328
1329         for (ref = remote_refs; ref; ref = ref->next) {
1330                 if (strchr(ref->name, '^'))
1331                         continue; /* a dereference item */
1332                 if (match_name_with_pattern(refspec->src, ref->name,
1333                                             refspec->dst, &expn_name)) {
1334                         struct ref *cpy = copy_ref(ref);
1335
1336                         cpy->peer_ref = alloc_ref(expn_name);
1337                         free(expn_name);
1338                         if (refspec->force)
1339                                 cpy->peer_ref->force = 1;
1340                         *tail = cpy;
1341                         tail = &cpy->next;
1342                 }
1343         }
1344
1345         return ret;
1346 }
1347
1348 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1349 {
1350         const struct ref *ref;
1351         for (ref = refs; ref; ref = ref->next) {
1352                 if (refname_match(name, ref->name, ref_fetch_rules))
1353                         return ref;
1354         }
1355         return NULL;
1356 }
1357
1358 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1359 {
1360         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1361
1362         if (!ref)
1363                 return NULL;
1364
1365         return copy_ref(ref);
1366 }
1367
1368 static struct ref *get_local_ref(const char *name)
1369 {
1370         if (!name || name[0] == '\0')
1371                 return NULL;
1372
1373         if (!prefixcmp(name, "refs/"))
1374                 return alloc_ref(name);
1375
1376         if (!prefixcmp(name, "heads/") ||
1377             !prefixcmp(name, "tags/") ||
1378             !prefixcmp(name, "remotes/"))
1379                 return alloc_ref_with_prefix("refs/", 5, name);
1380
1381         return alloc_ref_with_prefix("refs/heads/", 11, name);
1382 }
1383
1384 int get_fetch_map(const struct ref *remote_refs,
1385                   const struct refspec *refspec,
1386                   struct ref ***tail,
1387                   int missing_ok)
1388 {
1389         struct ref *ref_map, **rmp;
1390
1391         if (refspec->pattern) {
1392                 ref_map = get_expanded_map(remote_refs, refspec);
1393         } else {
1394                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1395
1396                 ref_map = get_remote_ref(remote_refs, name);
1397                 if (!missing_ok && !ref_map)
1398                         die("Couldn't find remote ref %s", name);
1399                 if (ref_map) {
1400                         ref_map->peer_ref = get_local_ref(refspec->dst);
1401                         if (ref_map->peer_ref && refspec->force)
1402                                 ref_map->peer_ref->force = 1;
1403                 }
1404         }
1405
1406         for (rmp = &ref_map; *rmp; ) {
1407                 if ((*rmp)->peer_ref) {
1408                         if (check_refname_format((*rmp)->peer_ref->name + 5,
1409                                 REFNAME_ALLOW_ONELEVEL)) {
1410                                 struct ref *ignore = *rmp;
1411                                 error("* Ignoring funny ref '%s' locally",
1412                                       (*rmp)->peer_ref->name);
1413                                 *rmp = (*rmp)->next;
1414                                 free(ignore->peer_ref);
1415                                 free(ignore);
1416                                 continue;
1417                         }
1418                 }
1419                 rmp = &((*rmp)->next);
1420         }
1421
1422         if (ref_map)
1423                 tail_link_ref(ref_map, tail);
1424
1425         return 0;
1426 }
1427
1428 int resolve_remote_symref(struct ref *ref, struct ref *list)
1429 {
1430         if (!ref->symref)
1431                 return 0;
1432         for (; list; list = list->next)
1433                 if (!strcmp(ref->symref, list->name)) {
1434                         hashcpy(ref->old_sha1, list->old_sha1);
1435                         return 0;
1436                 }
1437         return 1;
1438 }
1439
1440 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1441 {
1442         while (list) {
1443                 struct commit_list *temp = list;
1444                 temp->item->object.flags &= ~mark;
1445                 list = temp->next;
1446                 free(temp);
1447         }
1448 }
1449
1450 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1451 {
1452         struct object *o;
1453         struct commit *old, *new;
1454         struct commit_list *list, *used;
1455         int found = 0;
1456
1457         /* Both new and old must be commit-ish and new is descendant of
1458          * old.  Otherwise we require --force.
1459          */
1460         o = deref_tag(parse_object(old_sha1), NULL, 0);
1461         if (!o || o->type != OBJ_COMMIT)
1462                 return 0;
1463         old = (struct commit *) o;
1464
1465         o = deref_tag(parse_object(new_sha1), NULL, 0);
1466         if (!o || o->type != OBJ_COMMIT)
1467                 return 0;
1468         new = (struct commit *) o;
1469
1470         if (parse_commit(new) < 0)
1471                 return 0;
1472
1473         used = list = NULL;
1474         commit_list_insert(new, &list);
1475         while (list) {
1476                 new = pop_most_recent_commit(&list, TMP_MARK);
1477                 commit_list_insert(new, &used);
1478                 if (new == old) {
1479                         found = 1;
1480                         break;
1481                 }
1482         }
1483         unmark_and_free(list, TMP_MARK);
1484         unmark_and_free(used, TMP_MARK);
1485         return found;
1486 }
1487
1488 /*
1489  * Return true if there is anything to report, otherwise false.
1490  */
1491 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1492 {
1493         unsigned char sha1[20];
1494         struct commit *ours, *theirs;
1495         char symmetric[84];
1496         struct rev_info revs;
1497         const char *rev_argv[10], *base;
1498         int rev_argc;
1499
1500         /*
1501          * Nothing to report unless we are marked to build on top of
1502          * somebody else.
1503          */
1504         if (!branch ||
1505             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1506                 return 0;
1507
1508         /*
1509          * If what we used to build on no longer exists, there is
1510          * nothing to report.
1511          */
1512         base = branch->merge[0]->dst;
1513         if (!resolve_ref(base, sha1, 1, NULL))
1514                 return 0;
1515         theirs = lookup_commit_reference(sha1);
1516         if (!theirs)
1517                 return 0;
1518
1519         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1520                 return 0;
1521         ours = lookup_commit_reference(sha1);
1522         if (!ours)
1523                 return 0;
1524
1525         /* are we the same? */
1526         if (theirs == ours)
1527                 return 0;
1528
1529         /* Run "rev-list --left-right ours...theirs" internally... */
1530         rev_argc = 0;
1531         rev_argv[rev_argc++] = NULL;
1532         rev_argv[rev_argc++] = "--left-right";
1533         rev_argv[rev_argc++] = symmetric;
1534         rev_argv[rev_argc++] = "--";
1535         rev_argv[rev_argc] = NULL;
1536
1537         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1538         strcpy(symmetric + 40, "...");
1539         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1540
1541         init_revisions(&revs, NULL);
1542         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1543         prepare_revision_walk(&revs);
1544
1545         /* ... and count the commits on each side. */
1546         *num_ours = 0;
1547         *num_theirs = 0;
1548         while (1) {
1549                 struct commit *c = get_revision(&revs);
1550                 if (!c)
1551                         break;
1552                 if (c->object.flags & SYMMETRIC_LEFT)
1553                         (*num_ours)++;
1554                 else
1555                         (*num_theirs)++;
1556         }
1557
1558         /* clear object flags smudged by the above traversal */
1559         clear_commit_marks(ours, ALL_REV_FLAGS);
1560         clear_commit_marks(theirs, ALL_REV_FLAGS);
1561         return 1;
1562 }
1563
1564 /*
1565  * Return true when there is anything to report, otherwise false.
1566  */
1567 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1568 {
1569         int num_ours, num_theirs;
1570         const char *base;
1571
1572         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1573                 return 0;
1574
1575         base = branch->merge[0]->dst;
1576         base = shorten_unambiguous_ref(base, 0);
1577         if (!num_theirs)
1578                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1579                             "by %d commit%s.\n",
1580                             base, num_ours, (num_ours == 1) ? "" : "s");
1581         else if (!num_ours)
1582                 strbuf_addf(sb, "Your branch is behind '%s' "
1583                             "by %d commit%s, "
1584                             "and can be fast-forwarded.\n",
1585                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1586         else
1587                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1588                             "and have %d and %d different commit(s) each, "
1589                             "respectively.\n",
1590                             base, num_ours, num_theirs);
1591         return 1;
1592 }
1593
1594 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1595 {
1596         struct ref ***local_tail = cb_data;
1597         struct ref *ref;
1598         int len;
1599
1600         /* we already know it starts with refs/ to get here */
1601         if (check_refname_format(refname + 5, 0))
1602                 return 0;
1603
1604         len = strlen(refname) + 1;
1605         ref = xcalloc(1, sizeof(*ref) + len);
1606         hashcpy(ref->new_sha1, sha1);
1607         memcpy(ref->name, refname, len);
1608         **local_tail = ref;
1609         *local_tail = &ref->next;
1610         return 0;
1611 }
1612
1613 struct ref *get_local_heads(void)
1614 {
1615         struct ref *local_refs = NULL, **local_tail = &local_refs;
1616         for_each_ref(one_local_ref, &local_tail);
1617         return local_refs;
1618 }
1619
1620 struct ref *guess_remote_head(const struct ref *head,
1621                               const struct ref *refs,
1622                               int all)
1623 {
1624         const struct ref *r;
1625         struct ref *list = NULL;
1626         struct ref **tail = &list;
1627
1628         if (!head)
1629                 return NULL;
1630
1631         /*
1632          * Some transports support directly peeking at
1633          * where HEAD points; if that is the case, then
1634          * we don't have to guess.
1635          */
1636         if (head->symref)
1637                 return copy_ref(find_ref_by_name(refs, head->symref));
1638
1639         /* If refs/heads/master could be right, it is. */
1640         if (!all) {
1641                 r = find_ref_by_name(refs, "refs/heads/master");
1642                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1643                         return copy_ref(r);
1644         }
1645
1646         /* Look for another ref that points there */
1647         for (r = refs; r; r = r->next) {
1648                 if (r != head &&
1649                     !prefixcmp(r->name, "refs/heads/") &&
1650                     !hashcmp(r->old_sha1, head->old_sha1)) {
1651                         *tail = copy_ref(r);
1652                         tail = &((*tail)->next);
1653                         if (!all)
1654                                 break;
1655                 }
1656         }
1657
1658         return list;
1659 }
1660
1661 struct stale_heads_info {
1662         struct remote *remote;
1663         struct string_list *ref_names;
1664         struct ref **stale_refs_tail;
1665 };
1666
1667 static int get_stale_heads_cb(const char *refname,
1668         const unsigned char *sha1, int flags, void *cb_data)
1669 {
1670         struct stale_heads_info *info = cb_data;
1671         struct refspec refspec;
1672         memset(&refspec, 0, sizeof(refspec));
1673         refspec.dst = (char *)refname;
1674         if (!remote_find_tracking(info->remote, &refspec)) {
1675                 if (!((flags & REF_ISSYMREF) ||
1676                     string_list_has_string(info->ref_names, refspec.src))) {
1677                         struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1678                         hashcpy(ref->new_sha1, sha1);
1679                 }
1680         }
1681         return 0;
1682 }
1683
1684 struct ref *get_stale_heads(struct remote *remote, struct ref *fetch_map)
1685 {
1686         struct ref *ref, *stale_refs = NULL;
1687         struct string_list ref_names = STRING_LIST_INIT_NODUP;
1688         struct stale_heads_info info;
1689         info.remote = remote;
1690         info.ref_names = &ref_names;
1691         info.stale_refs_tail = &stale_refs;
1692         for (ref = fetch_map; ref; ref = ref->next)
1693                 string_list_append(&ref_names, ref->name);
1694         sort_string_list(&ref_names);
1695         for_each_ref(get_stale_heads_cb, &info);
1696         string_list_clear(&ref_names, 0);
1697         return stale_refs;
1698 }