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 void free_refspec(int nr_refspec, struct refspec *refspec)
 677 {
 678         int i;
 679         for (i = 0; i < nr_refspec; i++) {
 680                 free(refspec[i].src);
 681                 free(refspec[i].dst);
 682         }
 683         free(refspec);
 684 }
 685
 686 static int valid_remote_nick(const char *name)
 687 {
 688         if (!name[0] || is_dot_or_dotdot(name))
 689                 return 0;
 690         return !strchr(name, '/'); /* no slash */
 691 }
 692
 693 struct remote *remote_get(const char *name)
 694 {
 695         struct remote *ret;
 696         int name_given = 0;
 697
 698         read_config();
 699         if (name)
 700                 name_given = 1;
 701         else {
 702                 name = default_remote_name;
 703                 name_given = explicit_default_remote_name;
 704         }
 705
 706         ret = make_remote(name, 0);
 707         if (valid_remote_nick(name)) {
 708                 if (!valid_remote(ret))
 709                         read_remotes_file(ret);
 710                 if (!valid_remote(ret))
 711                         read_branches_file(ret);
 712         }
 713         if (name_given && !valid_remote(ret))
 714                 add_url_alias(ret, name);
 715         if (!valid_remote(ret))
 716                 return NULL;
 717         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 718         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 719         return ret;
 720 }
 721
 722 int remote_is_configured(const char *name)
 723 {
 724         int i;
 725         read_config();
 726
 727         for (i = 0; i < remotes_nr; i++)
 728                 if (!strcmp(name, remotes[i]->name))
 729                         return 1;
 730         return 0;
 731 }
 732
 733 int for_each_remote(each_remote_fn fn, void *priv)
 734 {
 735         int i, result = 0;
 736         read_config();
 737         for (i = 0; i < remotes_nr && !result; i++) {
 738                 struct remote *r = remotes[i];
 739                 if (!r)
 740                         continue;
 741                 if (!r->fetch)
 742                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 743                                                        r->fetch_refspec);
 744                 if (!r->push)
 745                         r->push = parse_push_refspec(r->push_refspec_nr,
 746                                                      r->push_refspec);
 747                 result = fn(r, priv);
 748         }
 749         return result;
 750 }
 751
 752 void ref_remove_duplicates(struct ref *ref_map)
 753 {
 754         struct ref **posn;
 755         struct ref *next;
 756         for (; ref_map; ref_map = ref_map->next) {
 757                 if (!ref_map->peer_ref)
 758                         continue;
 759                 posn = &ref_map->next;
 760                 while (*posn) {
 761                         if ((*posn)->peer_ref &&
 762                             !strcmp((*posn)->peer_ref->name,
 763                                     ref_map->peer_ref->name)) {
 764                                 if (strcmp((*posn)->name, ref_map->name))
 765                                         die("%s tracks both %s and %s",
 766                                             ref_map->peer_ref->name,
 767                                             (*posn)->name, ref_map->name);
 768                                 next = (*posn)->next;
 769                                 free((*posn)->peer_ref);
 770                                 free(*posn);
 771                                 *posn = next;
 772                         } else {
 773                                 posn = &(*posn)->next;
 774                         }
 775                 }
 776         }
 777 }
 778
 779 int remote_has_url(struct remote *remote, const char *url)
 780 {
 781         int i;
 782         for (i = 0; i < remote->url_nr; i++) {
 783                 if (!strcmp(remote->url[i], url))
 784                         return 1;
 785         }
 786         return 0;
 787 }
 788
 789 static int match_name_with_pattern(const char *key, const char *name,
 790                                    const char *value, char **result)
 791 {
 792         const char *kstar = strchr(key, '*');
 793         size_t klen;
 794         size_t ksuffixlen;
 795         size_t namelen;
 796         int ret;
 797         if (!kstar)
 798                 die("Key '%s' of pattern had no '*'", key);
 799         klen = kstar - key;
 800         ksuffixlen = strlen(kstar + 1);
 801         namelen = strlen(name);
 802         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 803                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 804         if (ret && value) {
 805                 const char *vstar = strchr(value, '*');
 806                 size_t vlen;
 807                 size_t vsuffixlen;
 808                 if (!vstar)
 809                         die("Value '%s' of pattern has no '*'", value);
 810                 vlen = vstar - value;
 811                 vsuffixlen = strlen(vstar + 1);
 812                 *result = xmalloc(vlen + vsuffixlen +
 813                                   strlen(name) -
 814                                   klen - ksuffixlen + 1);
 815                 strncpy(*result, value, vlen);
 816                 strncpy(*result + vlen,
 817                         name + klen, namelen - klen - ksuffixlen);
 818                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 819                        vstar + 1);
 820         }
 821         return ret;
 822 }
 823
 824 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 825                      const char *name)
 826 {
 827         int i;
 828         char *ret = NULL;
 829         for (i = 0; i < nr_refspec; i++) {
 830                 struct refspec *refspec = refspecs + i;
 831                 if (refspec->pattern) {
 832                         if (match_name_with_pattern(refspec->src, name,
 833                                                     refspec->dst, &ret))
 834                                 return ret;
 835                 } else if (!strcmp(refspec->src, name))
 836                         return strdup(refspec->dst);
 837         }
 838         return NULL;
 839 }
 840
 841 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 842 {
 843         int find_src = refspec->src == NULL;
 844         char *needle, **result;
 845         int i;
 846
 847         if (find_src) {
 848                 if (!refspec->dst)
 849                         return error("find_tracking: need either src or dst");
 850                 needle = refspec->dst;
 851                 result = &refspec->src;
 852         } else {
 853                 needle = refspec->src;
 854                 result = &refspec->dst;
 855         }
 856
 857         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 858                 struct refspec *fetch = &remote->fetch[i];
 859                 const char *key = find_src ? fetch->dst : fetch->src;
 860                 const char *value = find_src ? fetch->src : fetch->dst;
 861                 if (!fetch->dst)
 862                         continue;
 863                 if (fetch->pattern) {
 864                         if (match_name_with_pattern(key, needle, value, result)) {
 865                                 refspec->force = fetch->force;
 866                                 return 0;
 867                         }
 868                 } else if (!strcmp(needle, key)) {
 869                         *result = xstrdup(value);
 870                         refspec->force = fetch->force;
 871                         return 0;
 872                 }
 873         }
 874         return -1;
 875 }
 876
 877 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 878                 const char *name)
 879 {
 880         size_t len = strlen(name);
 881         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 882         memcpy(ref->name, prefix, prefixlen);
 883         memcpy(ref->name + prefixlen, name, len);
 884         return ref;
 885 }
 886
 887 struct ref *alloc_ref(const char *name)
 888 {
 889         return alloc_ref_with_prefix("", 0, name);
 890 }
 891
 892 static struct ref *copy_ref(const struct ref *ref)
 893 {
 894         struct ref *cpy;
 895         size_t len;
 896         if (!ref)
 897                 return NULL;
 898         len = strlen(ref->name);
 899         cpy = xmalloc(sizeof(struct ref) + len + 1);
 900         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 901         cpy->next = NULL;
 902         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 903         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 904         cpy->peer_ref = copy_ref(ref->peer_ref);
 905         return cpy;
 906 }
 907
 908 struct ref *copy_ref_list(const struct ref *ref)
 909 {
 910         struct ref *ret = NULL;
 911         struct ref **tail = &ret;
 912         while (ref) {
 913                 *tail = copy_ref(ref);
 914                 ref = ref->next;
 915                 tail = &((*tail)->next);
 916         }
 917         return ret;
 918 }
 919
 920 static void free_ref(struct ref *ref)
 921 {
 922         if (!ref)
 923                 return;
 924         free_ref(ref->peer_ref);
 925         free(ref->remote_status);
 926         free(ref->symref);
 927         free(ref);
 928 }
 929
 930 void free_refs(struct ref *ref)
 931 {
 932         struct ref *next;
 933         while (ref) {
 934                 next = ref->next;
 935                 free_ref(ref);
 936                 ref = next;
 937         }
 938 }
 939
 940 static int count_refspec_match(const char *pattern,
 941                                struct ref *refs,
 942                                struct ref **matched_ref)
 943 {
 944         int patlen = strlen(pattern);
 945         struct ref *matched_weak = NULL;
 946         struct ref *matched = NULL;
 947         int weak_match = 0;
 948         int match = 0;
 949
 950         for (weak_match = match = 0; refs; refs = refs->next) {
 951                 char *name = refs->name;
 952                 int namelen = strlen(name);
 953
 954                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 955                         continue;
 956
 957                 /* A match is "weak" if it is with refs outside
 958                  * heads or tags, and did not specify the pattern
 959                  * in full (e.g. "refs/remotes/origin/master") or at
 960                  * least from the toplevel (e.g. "remotes/origin/master");
 961                  * otherwise "git push $URL master" would result in
 962                  * ambiguity between remotes/origin/master and heads/master
 963                  * at the remote site.
 964                  */
 965                 if (namelen != patlen &&
 966                     patlen != namelen - 5 &&
 967                     prefixcmp(name, "refs/heads/") &&
 968                     prefixcmp(name, "refs/tags/")) {
 969                         /* We want to catch the case where only weak
 970                          * matches are found and there are multiple
 971                          * matches, and where more than one strong
 972                          * matches are found, as ambiguous.  One
 973                          * strong match with zero or more weak matches
 974                          * are acceptable as a unique match.
 975                          */
 976                         matched_weak = refs;
 977                         weak_match++;
 978                 }
 979                 else {
 980                         matched = refs;
 981                         match++;
 982                 }
 983         }
 984         if (!matched) {
 985                 *matched_ref = matched_weak;
 986                 return weak_match;
 987         }
 988         else {
 989                 *matched_ref = matched;
 990                 return match;
 991         }
 992 }
 993
 994 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 995 {
 996         **tail = ref;
 997         while (ref->next)
 998                 ref = ref->next;
 999         *tail = &ref->next;
1000 }
1001
1002 static struct ref *try_explicit_object_name(const char *name)
1003 {
1004         unsigned char sha1[20];
1005         struct ref *ref;
1006
1007         if (!*name) {
1008                 ref = alloc_ref("(delete)");
1009                 hashclr(ref->new_sha1);
1010                 return ref;
1011         }
1012         if (get_sha1(name, sha1))
1013                 return NULL;
1014         ref = alloc_ref(name);
1015         hashcpy(ref->new_sha1, sha1);
1016         return ref;
1017 }
1018
1019 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1020 {
1021         struct ref *ret = alloc_ref(name);
1022         tail_link_ref(ret, tail);
1023         return ret;
1024 }
1025
1026 static char *guess_ref(const char *name, struct ref *peer)
1027 {
1028         struct strbuf buf = STRBUF_INIT;
1029         unsigned char sha1[20];
1030
1031         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
1032         if (!r)
1033                 return NULL;
1034
1035         if (!prefixcmp(r, "refs/heads/"))
1036                 strbuf_addstr(&buf, "refs/heads/");
1037         else if (!prefixcmp(r, "refs/tags/"))
1038                 strbuf_addstr(&buf, "refs/tags/");
1039         else
1040                 return NULL;
1041
1042         strbuf_addstr(&buf, name);
1043         return strbuf_detach(&buf, NULL);
1044 }
1045
1046 static int match_explicit(struct ref *src, struct ref *dst,
1047                           struct ref ***dst_tail,
1048                           struct refspec *rs)
1049 {
1050         struct ref *matched_src, *matched_dst;
1051         int copy_src;
1052
1053         const char *dst_value = rs->dst;
1054         char *dst_guess;
1055
1056         if (rs->pattern || rs->matching)
1057                 return 0;
1058
1059         matched_src = matched_dst = NULL;
1060         switch (count_refspec_match(rs->src, src, &matched_src)) {
1061         case 1:
1062                 copy_src = 1;
1063                 break;
1064         case 0:
1065                 /* The source could be in the get_sha1() format
1066                  * not a reference name.  :refs/other is a
1067                  * way to delete 'other' ref at the remote end.
1068                  */
1069                 matched_src = try_explicit_object_name(rs->src);
1070                 if (!matched_src)
1071                         return error("src refspec %s does not match any.", rs->src);
1072                 copy_src = 0;
1073                 break;
1074         default:
1075                 return error("src refspec %s matches more than one.", rs->src);
1076         }
1077
1078         if (!dst_value) {
1079                 unsigned char sha1[20];
1080                 int flag;
1081
1082                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
1083                 if (!dst_value ||
1084                     ((flag & REF_ISSYMREF) &&
1085                      prefixcmp(dst_value, "refs/heads/")))
1086                         die("%s cannot be resolved to branch.",
1087                             matched_src->name);
1088         }
1089
1090         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1091         case 1:
1092                 break;
1093         case 0:
1094                 if (!memcmp(dst_value, "refs/", 5))
1095                         matched_dst = make_linked_ref(dst_value, dst_tail);
1096                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1097                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1098                 else
1099                         error("unable to push to unqualified destination: %s\n"
1100                               "The destination refspec neither matches an "
1101                               "existing ref on the remote nor\n"
1102                               "begins with refs/, and we are unable to "
1103                               "guess a prefix based on the source ref.",
1104                               dst_value);
1105                 break;
1106         default:
1107                 matched_dst = NULL;
1108                 error("dst refspec %s matches more than one.",
1109                       dst_value);
1110                 break;
1111         }
1112         if (!matched_dst)
1113                 return -1;
1114         if (matched_dst->peer_ref)
1115                 return error("dst ref %s receives from more than one src.",
1116                       matched_dst->name);
1117         else {
1118                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1119                 matched_dst->force = rs->force;
1120         }
1121         return 0;
1122 }
1123
1124 static int match_explicit_refs(struct ref *src, struct ref *dst,
1125                                struct ref ***dst_tail, struct refspec *rs,
1126                                int rs_nr)
1127 {
1128         int i, errs;
1129         for (i = errs = 0; i < rs_nr; i++)
1130                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1131         return errs;
1132 }
1133
1134 static const struct refspec *check_pattern_match(const struct refspec *rs,
1135                                                  int rs_nr,
1136                                                  const struct ref *src)
1137 {
1138         int i;
1139         int matching_refs = -1;
1140         for (i = 0; i < rs_nr; i++) {
1141                 if (rs[i].matching &&
1142                     (matching_refs == -1 || rs[i].force)) {
1143                         matching_refs = i;
1144                         continue;
1145                 }
1146
1147                 if (rs[i].pattern && match_name_with_pattern(rs[i].src, src->name,
1148                                                              NULL, NULL))
1149                         return rs + i;
1150         }
1151         if (matching_refs != -1)
1152                 return rs + matching_refs;
1153         else
1154                 return NULL;
1155 }
1156
1157 static struct ref **tail_ref(struct ref **head)
1158 {
1159         struct ref **tail = head;
1160         while (*tail)
1161                 tail = &((*tail)->next);
1162         return tail;
1163 }
1164
1165 /*
1166  * Note. This is used only by "push"; refspec matching rules for
1167  * push and fetch are subtly different, so do not try to reuse it
1168  * without thinking.
1169  */
1170 int match_refs(struct ref *src, struct ref **dst,
1171                int nr_refspec, const char **refspec, int flags)
1172 {
1173         struct refspec *rs;
1174         int send_all = flags & MATCH_REFS_ALL;
1175         int send_mirror = flags & MATCH_REFS_MIRROR;
1176         int errs;
1177         static const char *default_refspec[] = { ":", NULL };
1178         struct ref **dst_tail = tail_ref(dst);
1179
1180         if (!nr_refspec) {
1181                 nr_refspec = 1;
1182                 refspec = default_refspec;
1183         }
1184         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1185         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1186
1187         /* pick the remainder */
1188         for ( ; src; src = src->next) {
1189                 struct ref *dst_peer;
1190                 const struct refspec *pat = NULL;
1191                 char *dst_name;
1192                 if (src->peer_ref)
1193                         continue;
1194
1195                 pat = check_pattern_match(rs, nr_refspec, src);
1196                 if (!pat)
1197                         continue;
1198
1199                 if (pat->matching) {
1200                         /*
1201                          * "matching refs"; traditionally we pushed everything
1202                          * including refs outside refs/heads/ hierarchy, but
1203                          * that does not make much sense these days.
1204                          */
1205                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1206                                 continue;
1207                         dst_name = xstrdup(src->name);
1208
1209                 } else {
1210                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1211                         if (!match_name_with_pattern(pat->src, src->name,
1212                                                      dst_side, &dst_name))
1213                                 die("Didn't think it matches any more");
1214                 }
1215                 dst_peer = find_ref_by_name(*dst, dst_name);
1216                 if (dst_peer) {
1217                         if (dst_peer->peer_ref)
1218                                 /* We're already sending something to this ref. */
1219                                 goto free_name;
1220
1221                 } else {
1222                         if (pat->matching && !(send_all || send_mirror))
1223                                 /*
1224                                  * Remote doesn't have it, and we have no
1225                                  * explicit pattern, and we don't have
1226                                  * --all nor --mirror.
1227                                  */
1228                                 goto free_name;
1229
1230                         /* Create a new one and link it */
1231                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1232                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1233                 }
1234                 dst_peer->peer_ref = copy_ref(src);
1235                 dst_peer->force = pat->force;
1236         free_name:
1237                 free(dst_name);
1238         }
1239         if (errs)
1240                 return -1;
1241         return 0;
1242 }
1243
1244 struct branch *branch_get(const char *name)
1245 {
1246         struct branch *ret;
1247
1248         read_config();
1249         if (!name || !*name || !strcmp(name, "HEAD"))
1250                 ret = current_branch;
1251         else
1252                 ret = make_branch(name, 0);
1253         if (ret && ret->remote_name) {
1254                 ret->remote = remote_get(ret->remote_name);
1255                 if (ret->merge_nr) {
1256                         int i;
1257                         ret->merge = xcalloc(sizeof(*ret->merge),
1258                                              ret->merge_nr);
1259                         for (i = 0; i < ret->merge_nr; i++) {
1260                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1261                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1262                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1263                                     && !strcmp(ret->remote_name, "."))
1264                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1265                         }
1266                 }
1267         }
1268         return ret;
1269 }
1270
1271 int branch_has_merge_config(struct branch *branch)
1272 {
1273         return branch && !!branch->merge;
1274 }
1275
1276 int branch_merge_matches(struct branch *branch,
1277                                  int i,
1278                                  const char *refname)
1279 {
1280         if (!branch || i < 0 || i >= branch->merge_nr)
1281                 return 0;
1282         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1283 }
1284
1285 static struct ref *get_expanded_map(const struct ref *remote_refs,
1286                                     const struct refspec *refspec)
1287 {
1288         const struct ref *ref;
1289         struct ref *ret = NULL;
1290         struct ref **tail = &ret;
1291
1292         char *expn_name;
1293
1294         for (ref = remote_refs; ref; ref = ref->next) {
1295                 if (strchr(ref->name, '^'))
1296                         continue; /* a dereference item */
1297                 if (match_name_with_pattern(refspec->src, ref->name,
1298                                             refspec->dst, &expn_name)) {
1299                         struct ref *cpy = copy_ref(ref);
1300
1301                         cpy->peer_ref = alloc_ref(expn_name);
1302                         free(expn_name);
1303                         if (refspec->force)
1304                                 cpy->peer_ref->force = 1;
1305                         *tail = cpy;
1306                         tail = &cpy->next;
1307                 }
1308         }
1309
1310         return ret;
1311 }
1312
1313 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1314 {
1315         const struct ref *ref;
1316         for (ref = refs; ref; ref = ref->next) {
1317                 if (refname_match(name, ref->name, ref_fetch_rules))
1318                         return ref;
1319         }
1320         return NULL;
1321 }
1322
1323 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1324 {
1325         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1326
1327         if (!ref)
1328                 return NULL;
1329
1330         return copy_ref(ref);
1331 }
1332
1333 static struct ref *get_local_ref(const char *name)
1334 {
1335         if (!name || name[0] == '\0')
1336                 return NULL;
1337
1338         if (!prefixcmp(name, "refs/"))
1339                 return alloc_ref(name);
1340
1341         if (!prefixcmp(name, "heads/") ||
1342             !prefixcmp(name, "tags/") ||
1343             !prefixcmp(name, "remotes/"))
1344                 return alloc_ref_with_prefix("refs/", 5, name);
1345
1346         return alloc_ref_with_prefix("refs/heads/", 11, name);
1347 }
1348
1349 int get_fetch_map(const struct ref *remote_refs,
1350                   const struct refspec *refspec,
1351                   struct ref ***tail,
1352                   int missing_ok)
1353 {
1354         struct ref *ref_map, **rmp;
1355
1356         if (refspec->pattern) {
1357                 ref_map = get_expanded_map(remote_refs, refspec);
1358         } else {
1359                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1360
1361                 ref_map = get_remote_ref(remote_refs, name);
1362                 if (!missing_ok && !ref_map)
1363                         die("Couldn't find remote ref %s", name);
1364                 if (ref_map) {
1365                         ref_map->peer_ref = get_local_ref(refspec->dst);
1366                         if (ref_map->peer_ref && refspec->force)
1367                                 ref_map->peer_ref->force = 1;
1368                 }
1369         }
1370
1371         for (rmp = &ref_map; *rmp; ) {
1372                 if ((*rmp)->peer_ref) {
1373                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1374                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1375                                 struct ref *ignore = *rmp;
1376                                 error("* Ignoring funny ref '%s' locally",
1377                                       (*rmp)->peer_ref->name);
1378                                 *rmp = (*rmp)->next;
1379                                 free(ignore->peer_ref);
1380                                 free(ignore);
1381                                 continue;
1382                         }
1383                 }
1384                 rmp = &((*rmp)->next);
1385         }
1386
1387         if (ref_map)
1388                 tail_link_ref(ref_map, tail);
1389
1390         return 0;
1391 }
1392
1393 int resolve_remote_symref(struct ref *ref, struct ref *list)
1394 {
1395         if (!ref->symref)
1396                 return 0;
1397         for (; list; list = list->next)
1398                 if (!strcmp(ref->symref, list->name)) {
1399                         hashcpy(ref->old_sha1, list->old_sha1);
1400                         return 0;
1401                 }
1402         return 1;
1403 }
1404
1405 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1406 {
1407         while (list) {
1408                 struct commit_list *temp = list;
1409                 temp->item->object.flags &= ~mark;
1410                 list = temp->next;
1411                 free(temp);
1412         }
1413 }
1414
1415 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1416 {
1417         struct object *o;
1418         struct commit *old, *new;
1419         struct commit_list *list, *used;
1420         int found = 0;
1421
1422         /* Both new and old must be commit-ish and new is descendant of
1423          * old.  Otherwise we require --force.
1424          */
1425         o = deref_tag(parse_object(old_sha1), NULL, 0);
1426         if (!o || o->type != OBJ_COMMIT)
1427                 return 0;
1428         old = (struct commit *) o;
1429
1430         o = deref_tag(parse_object(new_sha1), NULL, 0);
1431         if (!o || o->type != OBJ_COMMIT)
1432                 return 0;
1433         new = (struct commit *) o;
1434
1435         if (parse_commit(new) < 0)
1436                 return 0;
1437
1438         used = list = NULL;
1439         commit_list_insert(new, &list);
1440         while (list) {
1441                 new = pop_most_recent_commit(&list, TMP_MARK);
1442                 commit_list_insert(new, &used);
1443                 if (new == old) {
1444                         found = 1;
1445                         break;
1446                 }
1447         }
1448         unmark_and_free(list, TMP_MARK);
1449         unmark_and_free(used, TMP_MARK);
1450         return found;
1451 }
1452
1453 /*
1454  * Return true if there is anything to report, otherwise false.
1455  */
1456 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1457 {
1458         unsigned char sha1[20];
1459         struct commit *ours, *theirs;
1460         char symmetric[84];
1461         struct rev_info revs;
1462         const char *rev_argv[10], *base;
1463         int rev_argc;
1464
1465         /*
1466          * Nothing to report unless we are marked to build on top of
1467          * somebody else.
1468          */
1469         if (!branch ||
1470             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1471                 return 0;
1472
1473         /*
1474          * If what we used to build on no longer exists, there is
1475          * nothing to report.
1476          */
1477         base = branch->merge[0]->dst;
1478         if (!resolve_ref(base, sha1, 1, NULL))
1479                 return 0;
1480         theirs = lookup_commit_reference(sha1);
1481         if (!theirs)
1482                 return 0;
1483
1484         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1485                 return 0;
1486         ours = lookup_commit_reference(sha1);
1487         if (!ours)
1488                 return 0;
1489
1490         /* are we the same? */
1491         if (theirs == ours)
1492                 return 0;
1493
1494         /* Run "rev-list --left-right ours...theirs" internally... */
1495         rev_argc = 0;
1496         rev_argv[rev_argc++] = NULL;
1497         rev_argv[rev_argc++] = "--left-right";
1498         rev_argv[rev_argc++] = symmetric;
1499         rev_argv[rev_argc++] = "--";
1500         rev_argv[rev_argc] = NULL;
1501
1502         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1503         strcpy(symmetric + 40, "...");
1504         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1505
1506         init_revisions(&revs, NULL);
1507         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1508         prepare_revision_walk(&revs);
1509
1510         /* ... and count the commits on each side. */
1511         *num_ours = 0;
1512         *num_theirs = 0;
1513         while (1) {
1514                 struct commit *c = get_revision(&revs);
1515                 if (!c)
1516                         break;
1517                 if (c->object.flags & SYMMETRIC_LEFT)
1518                         (*num_ours)++;
1519                 else
1520                         (*num_theirs)++;
1521         }
1522
1523         /* clear object flags smudged by the above traversal */
1524         clear_commit_marks(ours, ALL_REV_FLAGS);
1525         clear_commit_marks(theirs, ALL_REV_FLAGS);
1526         return 1;
1527 }
1528
1529 /*
1530  * Return true when there is anything to report, otherwise false.
1531  */
1532 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1533 {
1534         int num_ours, num_theirs;
1535         const char *base;
1536
1537         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1538                 return 0;
1539
1540         base = branch->merge[0]->dst;
1541         base = shorten_unambiguous_ref(base, 0);
1542         if (!num_theirs)
1543                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1544                             "by %d commit%s.\n",
1545                             base, num_ours, (num_ours == 1) ? "" : "s");
1546         else if (!num_ours)
1547                 strbuf_addf(sb, "Your branch is behind '%s' "
1548                             "by %d commit%s, "
1549                             "and can be fast-forwarded.\n",
1550                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1551         else
1552                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1553                             "and have %d and %d different commit(s) each, "
1554                             "respectively.\n",
1555                             base, num_ours, num_theirs);
1556         return 1;
1557 }
1558
1559 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1560 {
1561         struct ref ***local_tail = cb_data;
1562         struct ref *ref;
1563         int len;
1564
1565         /* we already know it starts with refs/ to get here */
1566         if (check_ref_format(refname + 5))
1567                 return 0;
1568
1569         len = strlen(refname) + 1;
1570         ref = xcalloc(1, sizeof(*ref) + len);
1571         hashcpy(ref->new_sha1, sha1);
1572         memcpy(ref->name, refname, len);
1573         **local_tail = ref;
1574         *local_tail = &ref->next;
1575         return 0;
1576 }
1577
1578 struct ref *get_local_heads(void)
1579 {
1580         struct ref *local_refs = NULL, **local_tail = &local_refs;
1581         for_each_ref(one_local_ref, &local_tail);
1582         return local_refs;
1583 }
1584
1585 struct ref *guess_remote_head(const struct ref *head,
1586                               const struct ref *refs,
1587                               int all)
1588 {
1589         const struct ref *r;
1590         struct ref *list = NULL;
1591         struct ref **tail = &list;
1592
1593         if (!head)
1594                 return NULL;
1595
1596         /*
1597          * Some transports support directly peeking at
1598          * where HEAD points; if that is the case, then
1599          * we don't have to guess.
1600          */
1601         if (head->symref)
1602                 return copy_ref(find_ref_by_name(refs, head->symref));
1603
1604         /* If refs/heads/master could be right, it is. */
1605         if (!all) {
1606                 r = find_ref_by_name(refs, "refs/heads/master");
1607                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1608                         return copy_ref(r);
1609         }
1610
1611         /* Look for another ref that points there */
1612         for (r = refs; r; r = r->next) {
1613                 if (r != head && !hashcmp(r->old_sha1, head->old_sha1)) {
1614                         *tail = copy_ref(r);
1615                         tail = &((*tail)->next);
1616                         if (!all)
1617                                 break;
1618                 }
1619         }
1620
1621         return list;
1622 }