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