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         /*
 303          * Cogito compatible push: push current HEAD to remote #branch
 304          * (master if missing)
 305          */
 306         strbuf_init(&branch, 0);
 307         strbuf_addstr(&branch, "HEAD");
 308         if (frag)
 309                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 310         else
 311                 strbuf_addstr(&branch, ":refs/heads/master");
 312         add_push_refspec(remote, strbuf_detach(&branch, 0));
 313         remote->fetch_tags = 1; /* always auto-follow */
 314 }
 315
 316 static int handle_config(const char *key, const char *value, void *cb)
 317 {
 318         const char *name;
 319         const char *subkey;
 320         struct remote *remote;
 321         struct branch *branch;
 322         if (!prefixcmp(key, "branch.")) {
 323                 name = key + 7;
 324                 subkey = strrchr(name, '.');
 325                 if (!subkey)
 326                         return 0;
 327                 branch = make_branch(name, subkey - name);
 328                 if (!strcmp(subkey, ".remote")) {
 329                         if (!value)
 330                                 return config_error_nonbool(key);
 331                         branch->remote_name = xstrdup(value);
 332                         if (branch == current_branch)
 333                                 default_remote_name = branch->remote_name;
 334                 } else if (!strcmp(subkey, ".merge")) {
 335                         if (!value)
 336                                 return config_error_nonbool(key);
 337                         add_merge(branch, xstrdup(value));
 338                 }
 339                 return 0;
 340         }
 341         if (!prefixcmp(key, "url.")) {
 342                 struct rewrite *rewrite;
 343                 name = key + 4;
 344                 subkey = strrchr(name, '.');
 345                 if (!subkey)
 346                         return 0;
 347                 rewrite = make_rewrite(name, subkey - name);
 348                 if (!strcmp(subkey, ".insteadof")) {
 349                         if (!value)
 350                                 return config_error_nonbool(key);
 351                         add_instead_of(rewrite, xstrdup(value));
 352                 }
 353         }
 354         if (prefixcmp(key,  "remote."))
 355                 return 0;
 356         name = key + 7;
 357         if (*name == '/') {
 358                 warning("Config remote shorthand cannot begin with '/': %s",
 359                         name);
 360                 return 0;
 361         }
 362         subkey = strrchr(name, '.');
 363         if (!subkey)
 364                 return error("Config with no key for remote %s", name);
 365         remote = make_remote(name, subkey - name);
 366         remote->origin = REMOTE_CONFIG;
 367         if (!strcmp(subkey, ".mirror"))
 368                 remote->mirror = git_config_bool(key, value);
 369         else if (!strcmp(subkey, ".skipdefaultupdate"))
 370                 remote->skip_default_update = git_config_bool(key, value);
 371
 372         else if (!strcmp(subkey, ".url")) {
 373                 const char *v;
 374                 if (git_config_string(&v, key, value))
 375                         return -1;
 376                 add_url(remote, v);
 377         } else if (!strcmp(subkey, ".push")) {
 378                 const char *v;
 379                 if (git_config_string(&v, key, value))
 380                         return -1;
 381                 add_push_refspec(remote, v);
 382         } else if (!strcmp(subkey, ".fetch")) {
 383                 const char *v;
 384                 if (git_config_string(&v, key, value))
 385                         return -1;
 386                 add_fetch_refspec(remote, v);
 387         } else if (!strcmp(subkey, ".receivepack")) {
 388                 const char *v;
 389                 if (git_config_string(&v, key, value))
 390                         return -1;
 391                 if (!remote->receivepack)
 392                         remote->receivepack = v;
 393                 else
 394                         error("more than one receivepack given, using the first");
 395         } else if (!strcmp(subkey, ".uploadpack")) {
 396                 const char *v;
 397                 if (git_config_string(&v, key, value))
 398                         return -1;
 399                 if (!remote->uploadpack)
 400                         remote->uploadpack = v;
 401                 else
 402                         error("more than one uploadpack given, using the first");
 403         } else if (!strcmp(subkey, ".tagopt")) {
 404                 if (!strcmp(value, "--no-tags"))
 405                         remote->fetch_tags = -1;
 406         } else if (!strcmp(subkey, ".proxy")) {
 407                 return git_config_string((const char **)&remote->http_proxy,
 408                                          key, value);
 409         }
 410         return 0;
 411 }
 412
 413 static void alias_all_urls(void)
 414 {
 415         int i, j;
 416         for (i = 0; i < remotes_nr; i++) {
 417                 if (!remotes[i])
 418                         continue;
 419                 for (j = 0; j < remotes[i]->url_nr; j++) {
 420                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 421                 }
 422         }
 423 }
 424
 425 static void read_config(void)
 426 {
 427         unsigned char sha1[20];
 428         const char *head_ref;
 429         int flag;
 430         if (default_remote_name) // did this already
 431                 return;
 432         default_remote_name = xstrdup("origin");
 433         current_branch = NULL;
 434         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 435         if (head_ref && (flag & REF_ISSYMREF) &&
 436             !prefixcmp(head_ref, "refs/heads/")) {
 437                 current_branch =
 438                         make_branch(head_ref + strlen("refs/heads/"), 0);
 439         }
 440         git_config(handle_config, NULL);
 441         alias_all_urls();
 442 }
 443
 444 /*
 445  * We need to make sure the tracking branches are well formed, but a
 446  * wildcard refspec in "struct refspec" must have a trailing slash. We
 447  * temporarily drop the trailing '/' while calling check_ref_format(),
 448  * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 449  * error return is Ok for a wildcard refspec.
 450  */
 451 static int verify_refname(char *name, int is_glob)
 452 {
 453         int result, len = -1;
 454
 455         if (is_glob) {
 456                 len = strlen(name);
 457                 assert(name[len - 1] == '/');
 458                 name[len - 1] = '\0';
 459         }
 460         result = check_ref_format(name);
 461         if (is_glob)
 462                 name[len - 1] = '/';
 463         return result;
 464 }
 465
 466 /*
 467  * This function frees a refspec array.
 468  * Warning: code paths should be checked to ensure that the src
 469  *          and dst pointers are always freeable pointers as well
 470  *          as the refspec pointer itself.
 471  */
 472 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 473 {
 474         int i;
 475
 476         if (!refspec)
 477                 return;
 478
 479         for (i = 0; i < nr_refspec; i++) {
 480                 free(refspec[i].src);
 481                 free(refspec[i].dst);
 482         }
 483         free(refspec);
 484 }
 485
 486 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 487 {
 488         int i;
 489         int st;
 490         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 491
 492         for (i = 0; i < nr_refspec; i++) {
 493                 size_t llen;
 494                 int is_glob;
 495                 const char *lhs, *rhs;
 496
 497                 llen = is_glob = 0;
 498
 499                 lhs = refspec[i];
 500                 if (*lhs == '+') {
 501                         rs[i].force = 1;
 502                         lhs++;
 503                 }
 504
 505                 rhs = strrchr(lhs, ':');
 506
 507                 /*
 508                  * Before going on, special case ":" (or "+:") as a refspec
 509                  * for matching refs.
 510                  */
 511                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 512                         rs[i].matching = 1;
 513                         continue;
 514                 }
 515
 516                 if (rhs) {
 517                         size_t rlen = strlen(++rhs);
 518                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
 519                         rs[i].dst = xstrndup(rhs, rlen - is_glob);
 520                 }
 521
 522                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 523                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
 524                         if ((rhs && !is_glob) || (!rhs && fetch))
 525                                 goto invalid;
 526                         is_glob = 1;
 527                         llen--;
 528                 } else if (rhs && is_glob) {
 529                         goto invalid;
 530                 }
 531
 532                 rs[i].pattern = is_glob;
 533                 rs[i].src = xstrndup(lhs, llen);
 534
 535                 if (fetch) {
 536                         /*
 537                          * LHS
 538                          * - empty is allowed; it means HEAD.
 539                          * - otherwise it must be a valid looking ref.
 540                          */
 541                         if (!*rs[i].src)
 542                                 ; /* empty is ok */
 543                         else {
 544                                 st = verify_refname(rs[i].src, is_glob);
 545                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 546                                         goto invalid;
 547                         }
 548                         /*
 549                          * RHS
 550                          * - missing is ok, and is same as empty.
 551                          * - empty is ok; it means not to store.
 552                          * - otherwise it must be a valid looking ref.
 553                          */
 554                         if (!rs[i].dst) {
 555                                 ; /* ok */
 556                         } else if (!*rs[i].dst) {
 557                                 ; /* ok */
 558                         } else {
 559                                 st = verify_refname(rs[i].dst, is_glob);
 560                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 561                                         goto invalid;
 562                         }
 563                 } else {
 564                         /*
 565                          * LHS
 566                          * - empty is allowed; it means delete.
 567                          * - when wildcarded, it must be a valid looking ref.
 568                          * - otherwise, it must be an extended SHA-1, but
 569                          *   there is no existing way to validate this.
 570                          */
 571                         if (!*rs[i].src)
 572                                 ; /* empty is ok */
 573                         else if (is_glob) {
 574                                 st = verify_refname(rs[i].src, is_glob);
 575                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 576                                         goto invalid;
 577                         }
 578                         else
 579                                 ; /* anything goes, for now */
 580                         /*
 581                          * RHS
 582                          * - missing is allowed, but LHS then must be a
 583                          *   valid looking ref.
 584                          * - empty is not allowed.
 585                          * - otherwise it must be a valid looking ref.
 586                          */
 587                         if (!rs[i].dst) {
 588                                 st = verify_refname(rs[i].src, is_glob);
 589                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 590                                         goto invalid;
 591                         } else if (!*rs[i].dst) {
 592                                 goto invalid;
 593                         } else {
 594                                 st = verify_refname(rs[i].dst, is_glob);
 595                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 596                                         goto invalid;
 597                         }
 598                 }
 599         }
 600         return rs;
 601
 602  invalid:
 603         if (verify) {
 604                 /*
 605                  * nr_refspec must be greater than zero and i must be valid
 606                  * since it is only possible to reach this point from within
 607                  * the for loop above.
 608                  */
 609                 free_refspecs(rs, i+1);
 610                 return NULL;
 611         }
 612         die("Invalid refspec '%s'", refspec[i]);
 613 }
 614
 615 int valid_fetch_refspec(const char *fetch_refspec_str)
 616 {
 617         const char *fetch_refspec[] = { fetch_refspec_str };
 618         struct refspec *refspec;
 619
 620         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 621         free_refspecs(refspec, 1);
 622         return !!refspec;
 623 }
 624
 625 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 626 {
 627         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 628 }
 629
 630 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 631 {
 632         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 633 }
 634
 635 static int valid_remote_nick(const char *name)
 636 {
 637         if (!name[0] || /* not empty */
 638             (name[0] == '.' && /* not "." */
 639              (!name[1] || /* not ".." */
 640               (name[1] == '.' && !name[2]))))
 641                 return 0;
 642         return !strchr(name, '/'); /* no slash */
 643 }
 644
 645 struct remote *remote_get(const char *name)
 646 {
 647         struct remote *ret;
 648
 649         read_config();
 650         if (!name)
 651                 name = default_remote_name;
 652         ret = make_remote(name, 0);
 653         if (valid_remote_nick(name)) {
 654                 if (!ret->url)
 655                         read_remotes_file(ret);
 656                 if (!ret->url)
 657                         read_branches_file(ret);
 658         }
 659         if (!ret->url)
 660                 add_url_alias(ret, name);
 661         if (!ret->url)
 662                 return NULL;
 663         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 664         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 665         return ret;
 666 }
 667
 668 int for_each_remote(each_remote_fn fn, void *priv)
 669 {
 670         int i, result = 0;
 671         read_config();
 672         for (i = 0; i < remotes_nr && !result; i++) {
 673                 struct remote *r = remotes[i];
 674                 if (!r)
 675                         continue;
 676                 if (!r->fetch)
 677                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 678                                                        r->fetch_refspec);
 679                 if (!r->push)
 680                         r->push = parse_push_refspec(r->push_refspec_nr,
 681                                                      r->push_refspec);
 682                 result = fn(r, priv);
 683         }
 684         return result;
 685 }
 686
 687 void ref_remove_duplicates(struct ref *ref_map)
 688 {
 689         struct ref **posn;
 690         struct ref *next;
 691         for (; ref_map; ref_map = ref_map->next) {
 692                 if (!ref_map->peer_ref)
 693                         continue;
 694                 posn = &ref_map->next;
 695                 while (*posn) {
 696                         if ((*posn)->peer_ref &&
 697                             !strcmp((*posn)->peer_ref->name,
 698                                     ref_map->peer_ref->name)) {
 699                                 if (strcmp((*posn)->name, ref_map->name))
 700                                         die("%s tracks both %s and %s",
 701                                             ref_map->peer_ref->name,
 702                                             (*posn)->name, ref_map->name);
 703                                 next = (*posn)->next;
 704                                 free((*posn)->peer_ref);
 705                                 free(*posn);
 706                                 *posn = next;
 707                         } else {
 708                                 posn = &(*posn)->next;
 709                         }
 710                 }
 711         }
 712 }
 713
 714 int remote_has_url(struct remote *remote, const char *url)
 715 {
 716         int i;
 717         for (i = 0; i < remote->url_nr; i++) {
 718                 if (!strcmp(remote->url[i], url))
 719                         return 1;
 720         }
 721         return 0;
 722 }
 723
 724 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 725 {
 726         int find_src = refspec->src == NULL;
 727         char *needle, **result;
 728         int i;
 729
 730         if (find_src) {
 731                 if (!refspec->dst)
 732                         return error("find_tracking: need either src or dst");
 733                 needle = refspec->dst;
 734                 result = &refspec->src;
 735         } else {
 736                 needle = refspec->src;
 737                 result = &refspec->dst;
 738         }
 739
 740         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 741                 struct refspec *fetch = &remote->fetch[i];
 742                 const char *key = find_src ? fetch->dst : fetch->src;
 743                 const char *value = find_src ? fetch->src : fetch->dst;
 744                 if (!fetch->dst)
 745                         continue;
 746                 if (fetch->pattern) {
 747                         if (!prefixcmp(needle, key)) {
 748                                 *result = xmalloc(strlen(value) +
 749                                                   strlen(needle) -
 750                                                   strlen(key) + 1);
 751                                 strcpy(*result, value);
 752                                 strcpy(*result + strlen(value),
 753                                        needle + strlen(key));
 754                                 refspec->force = fetch->force;
 755                                 return 0;
 756                         }
 757                 } else if (!strcmp(needle, key)) {
 758                         *result = xstrdup(value);
 759                         refspec->force = fetch->force;
 760                         return 0;
 761                 }
 762         }
 763         return -1;
 764 }
 765
 766 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 767                 const char *name)
 768 {
 769         size_t len = strlen(name);
 770         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 771         memcpy(ref->name, prefix, prefixlen);
 772         memcpy(ref->name + prefixlen, name, len);
 773         return ref;
 774 }
 775
 776 struct ref *alloc_ref(const char *name)
 777 {
 778         return alloc_ref_with_prefix("", 0, name);
 779 }
 780
 781 static struct ref *copy_ref(const struct ref *ref)
 782 {
 783         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 784         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 785         ret->next = NULL;
 786         return ret;
 787 }
 788
 789 struct ref *copy_ref_list(const struct ref *ref)
 790 {
 791         struct ref *ret = NULL;
 792         struct ref **tail = &ret;
 793         while (ref) {
 794                 *tail = copy_ref(ref);
 795                 ref = ref->next;
 796                 tail = &((*tail)->next);
 797         }
 798         return ret;
 799 }
 800
 801 static void free_ref(struct ref *ref)
 802 {
 803         if (!ref)
 804                 return;
 805         free(ref->remote_status);
 806         free(ref->symref);
 807         free(ref);
 808 }
 809
 810 void free_refs(struct ref *ref)
 811 {
 812         struct ref *next;
 813         while (ref) {
 814                 next = ref->next;
 815                 free(ref->peer_ref);
 816                 free_ref(ref);
 817                 ref = next;
 818         }
 819 }
 820
 821 static int count_refspec_match(const char *pattern,
 822                                struct ref *refs,
 823                                struct ref **matched_ref)
 824 {
 825         int patlen = strlen(pattern);
 826         struct ref *matched_weak = NULL;
 827         struct ref *matched = NULL;
 828         int weak_match = 0;
 829         int match = 0;
 830
 831         for (weak_match = match = 0; refs; refs = refs->next) {
 832                 char *name = refs->name;
 833                 int namelen = strlen(name);
 834
 835                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 836                         continue;
 837
 838                 /* A match is "weak" if it is with refs outside
 839                  * heads or tags, and did not specify the pattern
 840                  * in full (e.g. "refs/remotes/origin/master") or at
 841                  * least from the toplevel (e.g. "remotes/origin/master");
 842                  * otherwise "git push $URL master" would result in
 843                  * ambiguity between remotes/origin/master and heads/master
 844                  * at the remote site.
 845                  */
 846                 if (namelen != patlen &&
 847                     patlen != namelen - 5 &&
 848                     prefixcmp(name, "refs/heads/") &&
 849                     prefixcmp(name, "refs/tags/")) {
 850                         /* We want to catch the case where only weak
 851                          * matches are found and there are multiple
 852                          * matches, and where more than one strong
 853                          * matches are found, as ambiguous.  One
 854                          * strong match with zero or more weak matches
 855                          * are acceptable as a unique match.
 856                          */
 857                         matched_weak = refs;
 858                         weak_match++;
 859                 }
 860                 else {
 861                         matched = refs;
 862                         match++;
 863                 }
 864         }
 865         if (!matched) {
 866                 *matched_ref = matched_weak;
 867                 return weak_match;
 868         }
 869         else {
 870                 *matched_ref = matched;
 871                 return match;
 872         }
 873 }
 874
 875 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 876 {
 877         **tail = ref;
 878         while (ref->next)
 879                 ref = ref->next;
 880         *tail = &ref->next;
 881 }
 882
 883 static struct ref *try_explicit_object_name(const char *name)
 884 {
 885         unsigned char sha1[20];
 886         struct ref *ref;
 887
 888         if (!*name) {
 889                 ref = alloc_ref("(delete)");
 890                 hashclr(ref->new_sha1);
 891                 return ref;
 892         }
 893         if (get_sha1(name, sha1))
 894                 return NULL;
 895         ref = alloc_ref(name);
 896         hashcpy(ref->new_sha1, sha1);
 897         return ref;
 898 }
 899
 900 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 901 {
 902         struct ref *ret = alloc_ref(name);
 903         tail_link_ref(ret, tail);
 904         return ret;
 905 }
 906
 907 static char *guess_ref(const char *name, struct ref *peer)
 908 {
 909         struct strbuf buf = STRBUF_INIT;
 910         unsigned char sha1[20];
 911
 912         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
 913         if (!r)
 914                 return NULL;
 915
 916         if (!prefixcmp(r, "refs/heads/"))
 917                 strbuf_addstr(&buf, "refs/heads/");
 918         else if (!prefixcmp(r, "refs/tags/"))
 919                 strbuf_addstr(&buf, "refs/tags/");
 920         else
 921                 return NULL;
 922
 923         strbuf_addstr(&buf, name);
 924         return strbuf_detach(&buf, NULL);
 925 }
 926
 927 static int match_explicit(struct ref *src, struct ref *dst,
 928                           struct ref ***dst_tail,
 929                           struct refspec *rs)
 930 {
 931         struct ref *matched_src, *matched_dst;
 932
 933         const char *dst_value = rs->dst;
 934         char *dst_guess;
 935
 936         if (rs->pattern || rs->matching)
 937                 return 0;
 938
 939         matched_src = matched_dst = NULL;
 940         switch (count_refspec_match(rs->src, src, &matched_src)) {
 941         case 1:
 942                 break;
 943         case 0:
 944                 /* The source could be in the get_sha1() format
 945                  * not a reference name.  :refs/other is a
 946                  * way to delete 'other' ref at the remote end.
 947                  */
 948                 matched_src = try_explicit_object_name(rs->src);
 949                 if (!matched_src)
 950                         return error("src refspec %s does not match any.", rs->src);
 951                 break;
 952         default:
 953                 return error("src refspec %s matches more than one.", rs->src);
 954         }
 955
 956         if (!dst_value) {
 957                 unsigned char sha1[20];
 958                 int flag;
 959
 960                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 961                 if (!dst_value ||
 962                     ((flag & REF_ISSYMREF) &&
 963                      prefixcmp(dst_value, "refs/heads/")))
 964                         die("%s cannot be resolved to branch.",
 965                             matched_src->name);
 966         }
 967
 968         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 969         case 1:
 970                 break;
 971         case 0:
 972                 if (!memcmp(dst_value, "refs/", 5))
 973                         matched_dst = make_linked_ref(dst_value, dst_tail);
 974                 else if((dst_guess = guess_ref(dst_value, matched_src)))
 975                         matched_dst = make_linked_ref(dst_guess, dst_tail);
 976                 else
 977                         error("unable to push to unqualified destination: %s\n"
 978                               "The destination refspec neither matches an "
 979                               "existing ref on the remote nor\n"
 980                               "begins with refs/, and we are unable to "
 981                               "guess a prefix based on the source ref.",
 982                               dst_value);
 983                 break;
 984         default:
 985                 matched_dst = NULL;
 986                 error("dst refspec %s matches more than one.",
 987                       dst_value);
 988                 break;
 989         }
 990         if (!matched_dst)
 991                 return -1;
 992         if (matched_dst->peer_ref)
 993                 return error("dst ref %s receives from more than one src.",
 994                       matched_dst->name);
 995         else {
 996                 matched_dst->peer_ref = matched_src;
 997                 matched_dst->force = rs->force;
 998         }
 999         return 0;
1000 }
1001
1002 static int match_explicit_refs(struct ref *src, struct ref *dst,
1003                                struct ref ***dst_tail, struct refspec *rs,
1004                                int rs_nr)
1005 {
1006         int i, errs;
1007         for (i = errs = 0; i < rs_nr; i++)
1008                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1009         return errs;
1010 }
1011
1012 static const struct refspec *check_pattern_match(const struct refspec *rs,
1013                                                  int rs_nr,
1014                                                  const struct ref *src)
1015 {
1016         int i;
1017         int matching_refs = -1;
1018         for (i = 0; i < rs_nr; i++) {
1019                 if (rs[i].matching &&
1020                     (matching_refs == -1 || rs[i].force)) {
1021                         matching_refs = i;
1022                         continue;
1023                 }
1024
1025                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
1026                         return rs + i;
1027         }
1028         if (matching_refs != -1)
1029                 return rs + matching_refs;
1030         else
1031                 return NULL;
1032 }
1033
1034 /*
1035  * Note. This is used only by "push"; refspec matching rules for
1036  * push and fetch are subtly different, so do not try to reuse it
1037  * without thinking.
1038  */
1039 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
1040                int nr_refspec, const char **refspec, int flags)
1041 {
1042         struct refspec *rs;
1043         int send_all = flags & MATCH_REFS_ALL;
1044         int send_mirror = flags & MATCH_REFS_MIRROR;
1045         static const char *default_refspec[] = { ":", 0 };
1046
1047         if (!nr_refspec) {
1048                 nr_refspec = 1;
1049                 refspec = default_refspec;
1050         }
1051         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1052         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
1053                 return -1;
1054
1055         /* pick the remainder */
1056         for ( ; src; src = src->next) {
1057                 struct ref *dst_peer;
1058                 const struct refspec *pat = NULL;
1059                 char *dst_name;
1060                 if (src->peer_ref)
1061                         continue;
1062
1063                 pat = check_pattern_match(rs, nr_refspec, src);
1064                 if (!pat)
1065                         continue;
1066
1067                 if (pat->matching) {
1068                         /*
1069                          * "matching refs"; traditionally we pushed everything
1070                          * including refs outside refs/heads/ hierarchy, but
1071                          * that does not make much sense these days.
1072                          */
1073                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1074                                 continue;
1075                         dst_name = xstrdup(src->name);
1076
1077                 } else {
1078                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1079                         dst_name = xmalloc(strlen(dst_side) +
1080                                            strlen(src->name) -
1081                                            strlen(pat->src) + 2);
1082                         strcpy(dst_name, dst_side);
1083                         strcat(dst_name, src->name + strlen(pat->src));
1084                 }
1085                 dst_peer = find_ref_by_name(dst, dst_name);
1086                 if (dst_peer) {
1087                         if (dst_peer->peer_ref)
1088                                 /* We're already sending something to this ref. */
1089                                 goto free_name;
1090
1091                 } else {
1092                         if (pat->matching && !(send_all || send_mirror))
1093                                 /*
1094                                  * Remote doesn't have it, and we have no
1095                                  * explicit pattern, and we don't have
1096                                  * --all nor --mirror.
1097                                  */
1098                                 goto free_name;
1099
1100                         /* Create a new one and link it */
1101                         dst_peer = make_linked_ref(dst_name, dst_tail);
1102                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1103                 }
1104                 dst_peer->peer_ref = src;
1105                 dst_peer->force = pat->force;
1106         free_name:
1107                 free(dst_name);
1108         }
1109         return 0;
1110 }
1111
1112 struct branch *branch_get(const char *name)
1113 {
1114         struct branch *ret;
1115
1116         read_config();
1117         if (!name || !*name || !strcmp(name, "HEAD"))
1118                 ret = current_branch;
1119         else
1120                 ret = make_branch(name, 0);
1121         if (ret && ret->remote_name) {
1122                 ret->remote = remote_get(ret->remote_name);
1123                 if (ret->merge_nr) {
1124                         int i;
1125                         ret->merge = xcalloc(sizeof(*ret->merge),
1126                                              ret->merge_nr);
1127                         for (i = 0; i < ret->merge_nr; i++) {
1128                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1129                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1130                                 remote_find_tracking(ret->remote,
1131                                                      ret->merge[i]);
1132                         }
1133                 }
1134         }
1135         return ret;
1136 }
1137
1138 int branch_has_merge_config(struct branch *branch)
1139 {
1140         return branch && !!branch->merge;
1141 }
1142
1143 int branch_merge_matches(struct branch *branch,
1144                                  int i,
1145                                  const char *refname)
1146 {
1147         if (!branch || i < 0 || i >= branch->merge_nr)
1148                 return 0;
1149         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1150 }
1151
1152 static struct ref *get_expanded_map(const struct ref *remote_refs,
1153                                     const struct refspec *refspec)
1154 {
1155         const struct ref *ref;
1156         struct ref *ret = NULL;
1157         struct ref **tail = &ret;
1158
1159         int remote_prefix_len = strlen(refspec->src);
1160         int local_prefix_len = strlen(refspec->dst);
1161
1162         for (ref = remote_refs; ref; ref = ref->next) {
1163                 if (strchr(ref->name, '^'))
1164                         continue; /* a dereference item */
1165                 if (!prefixcmp(ref->name, refspec->src)) {
1166                         const char *match;
1167                         struct ref *cpy = copy_ref(ref);
1168                         match = ref->name + remote_prefix_len;
1169
1170                         cpy->peer_ref = alloc_ref_with_prefix(refspec->dst,
1171                                         local_prefix_len, match);
1172                         if (refspec->force)
1173                                 cpy->peer_ref->force = 1;
1174                         *tail = cpy;
1175                         tail = &cpy->next;
1176                 }
1177         }
1178
1179         return ret;
1180 }
1181
1182 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1183 {
1184         const struct ref *ref;
1185         for (ref = refs; ref; ref = ref->next) {
1186                 if (refname_match(name, ref->name, ref_fetch_rules))
1187                         return ref;
1188         }
1189         return NULL;
1190 }
1191
1192 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1193 {
1194         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1195
1196         if (!ref)
1197                 return NULL;
1198
1199         return copy_ref(ref);
1200 }
1201
1202 static struct ref *get_local_ref(const char *name)
1203 {
1204         if (!name)
1205                 return NULL;
1206
1207         if (!prefixcmp(name, "refs/"))
1208                 return alloc_ref(name);
1209
1210         if (!prefixcmp(name, "heads/") ||
1211             !prefixcmp(name, "tags/") ||
1212             !prefixcmp(name, "remotes/"))
1213                 return alloc_ref_with_prefix("refs/", 5, name);
1214
1215         return alloc_ref_with_prefix("refs/heads/", 11, name);
1216 }
1217
1218 int get_fetch_map(const struct ref *remote_refs,
1219                   const struct refspec *refspec,
1220                   struct ref ***tail,
1221                   int missing_ok)
1222 {
1223         struct ref *ref_map, **rmp;
1224
1225         if (refspec->pattern) {
1226                 ref_map = get_expanded_map(remote_refs, refspec);
1227         } else {
1228                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1229
1230                 ref_map = get_remote_ref(remote_refs, name);
1231                 if (!missing_ok && !ref_map)
1232                         die("Couldn't find remote ref %s", name);
1233                 if (ref_map) {
1234                         ref_map->peer_ref = get_local_ref(refspec->dst);
1235                         if (ref_map->peer_ref && refspec->force)
1236                                 ref_map->peer_ref->force = 1;
1237                 }
1238         }
1239
1240         for (rmp = &ref_map; *rmp; ) {
1241                 if ((*rmp)->peer_ref) {
1242                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1243                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1244                                 struct ref *ignore = *rmp;
1245                                 error("* Ignoring funny ref '%s' locally",
1246                                       (*rmp)->peer_ref->name);
1247                                 *rmp = (*rmp)->next;
1248                                 free(ignore->peer_ref);
1249                                 free(ignore);
1250                                 continue;
1251                         }
1252                 }
1253                 rmp = &((*rmp)->next);
1254         }
1255
1256         if (ref_map)
1257                 tail_link_ref(ref_map, tail);
1258
1259         return 0;
1260 }
1261
1262 int resolve_remote_symref(struct ref *ref, struct ref *list)
1263 {
1264         if (!ref->symref)
1265                 return 0;
1266         for (; list; list = list->next)
1267                 if (!strcmp(ref->symref, list->name)) {
1268                         hashcpy(ref->old_sha1, list->old_sha1);
1269                         return 0;
1270                 }
1271         return 1;
1272 }
1273
1274 /*
1275  * Return true if there is anything to report, otherwise false.
1276  */
1277 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1278 {
1279         unsigned char sha1[20];
1280         struct commit *ours, *theirs;
1281         char symmetric[84];
1282         struct rev_info revs;
1283         const char *rev_argv[10], *base;
1284         int rev_argc;
1285
1286         /*
1287          * Nothing to report unless we are marked to build on top of
1288          * somebody else.
1289          */
1290         if (!branch ||
1291             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1292                 return 0;
1293
1294         /*
1295          * If what we used to build on no longer exists, there is
1296          * nothing to report.
1297          */
1298         base = branch->merge[0]->dst;
1299         if (!resolve_ref(base, sha1, 1, NULL))
1300                 return 0;
1301         theirs = lookup_commit(sha1);
1302         if (!theirs)
1303                 return 0;
1304
1305         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1306                 return 0;
1307         ours = lookup_commit(sha1);
1308         if (!ours)
1309                 return 0;
1310
1311         /* are we the same? */
1312         if (theirs == ours)
1313                 return 0;
1314
1315         /* Run "rev-list --left-right ours...theirs" internally... */
1316         rev_argc = 0;
1317         rev_argv[rev_argc++] = NULL;
1318         rev_argv[rev_argc++] = "--left-right";
1319         rev_argv[rev_argc++] = symmetric;
1320         rev_argv[rev_argc++] = "--";
1321         rev_argv[rev_argc] = NULL;
1322
1323         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1324         strcpy(symmetric + 40, "...");
1325         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1326
1327         init_revisions(&revs, NULL);
1328         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1329         prepare_revision_walk(&revs);
1330
1331         /* ... and count the commits on each side. */
1332         *num_ours = 0;
1333         *num_theirs = 0;
1334         while (1) {
1335                 struct commit *c = get_revision(&revs);
1336                 if (!c)
1337                         break;
1338                 if (c->object.flags & SYMMETRIC_LEFT)
1339                         (*num_ours)++;
1340                 else
1341                         (*num_theirs)++;
1342         }
1343
1344         /* clear object flags smudged by the above traversal */
1345         clear_commit_marks(ours, ALL_REV_FLAGS);
1346         clear_commit_marks(theirs, ALL_REV_FLAGS);
1347         return 1;
1348 }
1349
1350 /*
1351  * Return true when there is anything to report, otherwise false.
1352  */
1353 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1354 {
1355         int num_ours, num_theirs;
1356         const char *base;
1357
1358         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1359                 return 0;
1360
1361         base = branch->merge[0]->dst;
1362         if (!prefixcmp(base, "refs/remotes/")) {
1363                 base += strlen("refs/remotes/");
1364         }
1365         if (!num_theirs)
1366                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1367                             "by %d commit%s.\n",
1368                             base, num_ours, (num_ours == 1) ? "" : "s");
1369         else if (!num_ours)
1370                 strbuf_addf(sb, "Your branch is behind '%s' "
1371                             "by %d commit%s, "
1372                             "and can be fast-forwarded.\n",
1373                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1374         else
1375                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1376                             "and have %d and %d different commit(s) each, "
1377                             "respectively.\n",
1378                             base, num_ours, num_theirs);
1379         return 1;
1380 }