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 = malloc(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 = malloc(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         while (fgets(buffer, BUF_SIZE, f)) {
 205                 int value_list;
 206                 char *s, *p;
 207
 208                 if (!prefixcmp(buffer, "URL:")) {
 209                         value_list = 0;
 210                         s = buffer + 4;
 211                 } else if (!prefixcmp(buffer, "Push:")) {
 212                         value_list = 1;
 213                         s = buffer + 5;
 214                 } else if (!prefixcmp(buffer, "Pull:")) {
 215                         value_list = 2;
 216                         s = buffer + 5;
 217                 } else
 218                         continue;
 219
 220                 while (isspace(*s))
 221                         s++;
 222                 if (!*s)
 223                         continue;
 224
 225                 p = s + strlen(s);
 226                 while (isspace(p[-1]))
 227                         *--p = 0;
 228
 229                 switch (value_list) {
 230                 case 0:
 231                         add_url_alias(remote, xstrdup(s));
 232                         break;
 233                 case 1:
 234                         add_push_refspec(remote, xstrdup(s));
 235                         break;
 236                 case 2:
 237                         add_fetch_refspec(remote, xstrdup(s));
 238                         break;
 239                 }
 240         }
 241         fclose(f);
 242 }
 243
 244 static void read_branches_file(struct remote *remote)
 245 {
 246         const char *slash = strchr(remote->name, '/');
 247         char *frag;
 248         struct strbuf branch;
 249         int n = slash ? slash - remote->name : 1000;
 250         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 251         char *s, *p;
 252         int len;
 253
 254         if (!f)
 255                 return;
 256         s = fgets(buffer, BUF_SIZE, f);
 257         fclose(f);
 258         if (!s)
 259                 return;
 260         while (isspace(*s))
 261                 s++;
 262         if (!*s)
 263                 return;
 264         p = s + strlen(s);
 265         while (isspace(p[-1]))
 266                 *--p = 0;
 267         len = p - s;
 268         if (slash)
 269                 len += strlen(slash);
 270         p = xmalloc(len + 1);
 271         strcpy(p, s);
 272         if (slash)
 273                 strcat(p, slash);
 274
 275         /*
 276          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 277          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 278          * the partial URL obtained from the branches file plus
 279          * "/netdev-2.6" and does not store it in any tracking ref.
 280          * #branch specifier in the file is ignored.
 281          *
 282          * Otherwise, the branches file would have URL and optionally
 283          * #branch specified.  The "master" (or specified) branch is
 284          * fetched and stored in the local branch of the same name.
 285          */
 286         strbuf_init(&branch, 0);
 287         frag = strchr(p, '#');
 288         if (frag) {
 289                 *(frag++) = '\0';
 290                 strbuf_addf(&branch, "refs/heads/%s", frag);
 291         } else
 292                 strbuf_addstr(&branch, "refs/heads/master");
 293         if (!slash) {
 294                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 295         } else {
 296                 strbuf_reset(&branch);
 297                 strbuf_addstr(&branch, "HEAD:");
 298         }
 299         add_url_alias(remote, p);
 300         add_fetch_refspec(remote, strbuf_detach(&branch, 0));
 301         /*
 302          * Cogito compatible push: push current HEAD to remote #branch
 303          * (master if missing)
 304          */
 305         strbuf_init(&branch, 0);
 306         strbuf_addstr(&branch, "HEAD");
 307         if (frag)
 308                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 309         else
 310                 strbuf_addstr(&branch, ":refs/heads/master");
 311         add_push_refspec(remote, strbuf_detach(&branch, 0));
 312         remote->fetch_tags = 1; /* always auto-follow */
 313 }
 314
 315 static int handle_config(const char *key, const char *value, void *cb)
 316 {
 317         const char *name;
 318         const char *subkey;
 319         struct remote *remote;
 320         struct branch *branch;
 321         if (!prefixcmp(key, "branch.")) {
 322                 name = key + 7;
 323                 subkey = strrchr(name, '.');
 324                 if (!subkey)
 325                         return 0;
 326                 branch = make_branch(name, subkey - name);
 327                 if (!strcmp(subkey, ".remote")) {
 328                         if (!value)
 329                                 return config_error_nonbool(key);
 330                         branch->remote_name = xstrdup(value);
 331                         if (branch == current_branch)
 332                                 default_remote_name = branch->remote_name;
 333                 } else if (!strcmp(subkey, ".merge")) {
 334                         if (!value)
 335                                 return config_error_nonbool(key);
 336                         add_merge(branch, xstrdup(value));
 337                 }
 338                 return 0;
 339         }
 340         if (!prefixcmp(key, "url.")) {
 341                 struct rewrite *rewrite;
 342                 name = key + 4;
 343                 subkey = strrchr(name, '.');
 344                 if (!subkey)
 345                         return 0;
 346                 rewrite = make_rewrite(name, subkey - name);
 347                 if (!strcmp(subkey, ".insteadof")) {
 348                         if (!value)
 349                                 return config_error_nonbool(key);
 350                         add_instead_of(rewrite, xstrdup(value));
 351                 }
 352         }
 353         if (prefixcmp(key,  "remote."))
 354                 return 0;
 355         name = key + 7;
 356         if (*name == '/') {
 357                 warning("Config remote shorthand cannot begin with '/': %s",
 358                         name);
 359                 return 0;
 360         }
 361         subkey = strrchr(name, '.');
 362         if (!subkey)
 363                 return error("Config with no key for remote %s", name);
 364         remote = make_remote(name, subkey - name);
 365         if (!strcmp(subkey, ".mirror"))
 366                 remote->mirror = git_config_bool(key, value);
 367         else if (!strcmp(subkey, ".skipdefaultupdate"))
 368                 remote->skip_default_update = git_config_bool(key, value);
 369
 370         else if (!strcmp(subkey, ".url")) {
 371                 const char *v;
 372                 if (git_config_string(&v, key, value))
 373                         return -1;
 374                 add_url(remote, v);
 375         } else if (!strcmp(subkey, ".push")) {
 376                 const char *v;
 377                 if (git_config_string(&v, key, value))
 378                         return -1;
 379                 add_push_refspec(remote, v);
 380         } else if (!strcmp(subkey, ".fetch")) {
 381                 const char *v;
 382                 if (git_config_string(&v, key, value))
 383                         return -1;
 384                 add_fetch_refspec(remote, v);
 385         } else if (!strcmp(subkey, ".receivepack")) {
 386                 const char *v;
 387                 if (git_config_string(&v, key, value))
 388                         return -1;
 389                 if (!remote->receivepack)
 390                         remote->receivepack = v;
 391                 else
 392                         error("more than one receivepack given, using the first");
 393         } else if (!strcmp(subkey, ".uploadpack")) {
 394                 const char *v;
 395                 if (git_config_string(&v, key, value))
 396                         return -1;
 397                 if (!remote->uploadpack)
 398                         remote->uploadpack = v;
 399                 else
 400                         error("more than one uploadpack given, using the first");
 401         } else if (!strcmp(subkey, ".tagopt")) {
 402                 if (!strcmp(value, "--no-tags"))
 403                         remote->fetch_tags = -1;
 404         } else if (!strcmp(subkey, ".proxy")) {
 405                 return git_config_string((const char **)&remote->http_proxy,
 406                                          key, value);
 407         }
 408         return 0;
 409 }
 410
 411 static void alias_all_urls(void)
 412 {
 413         int i, j;
 414         for (i = 0; i < remotes_nr; i++) {
 415                 if (!remotes[i])
 416                         continue;
 417                 for (j = 0; j < remotes[i]->url_nr; j++) {
 418                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 419                 }
 420         }
 421 }
 422
 423 static void read_config(void)
 424 {
 425         unsigned char sha1[20];
 426         const char *head_ref;
 427         int flag;
 428         if (default_remote_name) // did this already
 429                 return;
 430         default_remote_name = xstrdup("origin");
 431         current_branch = NULL;
 432         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 433         if (head_ref && (flag & REF_ISSYMREF) &&
 434             !prefixcmp(head_ref, "refs/heads/")) {
 435                 current_branch =
 436                         make_branch(head_ref + strlen("refs/heads/"), 0);
 437         }
 438         git_config(handle_config, NULL);
 439         alias_all_urls();
 440 }
 441
 442 /*
 443  * We need to make sure the tracking branches are well formed, but a
 444  * wildcard refspec in "struct refspec" must have a trailing slash. We
 445  * temporarily drop the trailing '/' while calling check_ref_format(),
 446  * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 447  * error return is Ok for a wildcard refspec.
 448  */
 449 static int verify_refname(char *name, int is_glob)
 450 {
 451         int result, len = -1;
 452
 453         if (is_glob) {
 454                 len = strlen(name);
 455                 assert(name[len - 1] == '/');
 456                 name[len - 1] = '\0';
 457         }
 458         result = check_ref_format(name);
 459         if (is_glob)
 460                 name[len - 1] = '/';
 461         return result;
 462 }
 463
 464 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 465 {
 466         int i;
 467         int st;
 468         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 469
 470         for (i = 0; i < nr_refspec; i++) {
 471                 size_t llen;
 472                 int is_glob;
 473                 const char *lhs, *rhs;
 474
 475                 llen = is_glob = 0;
 476
 477                 lhs = refspec[i];
 478                 if (*lhs == '+') {
 479                         rs[i].force = 1;
 480                         lhs++;
 481                 }
 482
 483                 rhs = strrchr(lhs, ':');
 484
 485                 /*
 486                  * Before going on, special case ":" (or "+:") as a refspec
 487                  * for matching refs.
 488                  */
 489                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 490                         rs[i].matching = 1;
 491                         continue;
 492                 }
 493
 494                 if (rhs) {
 495                         size_t rlen = strlen(++rhs);
 496                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
 497                         rs[i].dst = xstrndup(rhs, rlen - is_glob);
 498                 }
 499
 500                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 501                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
 502                         if ((rhs && !is_glob) || (!rhs && fetch))
 503                                 goto invalid;
 504                         is_glob = 1;
 505                         llen--;
 506                 } else if (rhs && is_glob) {
 507                         goto invalid;
 508                 }
 509
 510                 rs[i].pattern = is_glob;
 511                 rs[i].src = xstrndup(lhs, llen);
 512
 513                 if (fetch) {
 514                         /*
 515                          * LHS
 516                          * - empty is allowed; it means HEAD.
 517                          * - otherwise it must be a valid looking ref.
 518                          */
 519                         if (!*rs[i].src)
 520                                 ; /* empty is ok */
 521                         else {
 522                                 st = verify_refname(rs[i].src, is_glob);
 523                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 524                                         goto invalid;
 525                         }
 526                         /*
 527                          * RHS
 528                          * - missing is ok, and is same as empty.
 529                          * - empty is ok; it means not to store.
 530                          * - otherwise it must be a valid looking ref.
 531                          */
 532                         if (!rs[i].dst) {
 533                                 ; /* ok */
 534                         } else if (!*rs[i].dst) {
 535                                 ; /* ok */
 536                         } else {
 537                                 st = verify_refname(rs[i].dst, is_glob);
 538                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 539                                         goto invalid;
 540                         }
 541                 } else {
 542                         /*
 543                          * LHS
 544                          * - empty is allowed; it means delete.
 545                          * - when wildcarded, it must be a valid looking ref.
 546                          * - otherwise, it must be an extended SHA-1, but
 547                          *   there is no existing way to validate this.
 548                          */
 549                         if (!*rs[i].src)
 550                                 ; /* empty is ok */
 551                         else if (is_glob) {
 552                                 st = verify_refname(rs[i].src, is_glob);
 553                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 554                                         goto invalid;
 555                         }
 556                         else
 557                                 ; /* anything goes, for now */
 558                         /*
 559                          * RHS
 560                          * - missing is allowed, but LHS then must be a
 561                          *   valid looking ref.
 562                          * - empty is not allowed.
 563                          * - otherwise it must be a valid looking ref.
 564                          */
 565                         if (!rs[i].dst) {
 566                                 st = verify_refname(rs[i].src, is_glob);
 567                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 568                                         goto invalid;
 569                         } else if (!*rs[i].dst) {
 570                                 goto invalid;
 571                         } else {
 572                                 st = verify_refname(rs[i].dst, is_glob);
 573                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 574                                         goto invalid;
 575                         }
 576                 }
 577         }
 578         return rs;
 579
 580  invalid:
 581         if (verify) {
 582                 free(rs);
 583                 return NULL;
 584         }
 585         die("Invalid refspec '%s'", refspec[i]);
 586 }
 587
 588 int valid_fetch_refspec(const char *fetch_refspec_str)
 589 {
 590         const char *fetch_refspec[] = { fetch_refspec_str };
 591         struct refspec *refspec;
 592
 593         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 594         free(refspec);
 595         return !!refspec;
 596 }
 597
 598 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 599 {
 600         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 601 }
 602
 603 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 604 {
 605         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 606 }
 607
 608 static int valid_remote_nick(const char *name)
 609 {
 610         if (!name[0] || /* not empty */
 611             (name[0] == '.' && /* not "." */
 612              (!name[1] || /* not ".." */
 613               (name[1] == '.' && !name[2]))))
 614                 return 0;
 615         return !strchr(name, '/'); /* no slash */
 616 }
 617
 618 struct remote *remote_get(const char *name)
 619 {
 620         struct remote *ret;
 621
 622         read_config();
 623         if (!name)
 624                 name = default_remote_name;
 625         ret = make_remote(name, 0);
 626         if (valid_remote_nick(name)) {
 627                 if (!ret->url)
 628                         read_remotes_file(ret);
 629                 if (!ret->url)
 630                         read_branches_file(ret);
 631         }
 632         if (!ret->url)
 633                 add_url_alias(ret, name);
 634         if (!ret->url)
 635                 return NULL;
 636         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 637         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 638         return ret;
 639 }
 640
 641 int for_each_remote(each_remote_fn fn, void *priv)
 642 {
 643         int i, result = 0;
 644         read_config();
 645         for (i = 0; i < remotes_nr && !result; i++) {
 646                 struct remote *r = remotes[i];
 647                 if (!r)
 648                         continue;
 649                 if (!r->fetch)
 650                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 651                                                        r->fetch_refspec);
 652                 if (!r->push)
 653                         r->push = parse_push_refspec(r->push_refspec_nr,
 654                                                      r->push_refspec);
 655                 result = fn(r, priv);
 656         }
 657         return result;
 658 }
 659
 660 void ref_remove_duplicates(struct ref *ref_map)
 661 {
 662         struct ref **posn;
 663         struct ref *next;
 664         for (; ref_map; ref_map = ref_map->next) {
 665                 if (!ref_map->peer_ref)
 666                         continue;
 667                 posn = &ref_map->next;
 668                 while (*posn) {
 669                         if ((*posn)->peer_ref &&
 670                             !strcmp((*posn)->peer_ref->name,
 671                                     ref_map->peer_ref->name)) {
 672                                 if (strcmp((*posn)->name, ref_map->name))
 673                                         die("%s tracks both %s and %s",
 674                                             ref_map->peer_ref->name,
 675                                             (*posn)->name, ref_map->name);
 676                                 next = (*posn)->next;
 677                                 free((*posn)->peer_ref);
 678                                 free(*posn);
 679                                 *posn = next;
 680                         } else {
 681                                 posn = &(*posn)->next;
 682                         }
 683                 }
 684         }
 685 }
 686
 687 int remote_has_url(struct remote *remote, const char *url)
 688 {
 689         int i;
 690         for (i = 0; i < remote->url_nr; i++) {
 691                 if (!strcmp(remote->url[i], url))
 692                         return 1;
 693         }
 694         return 0;
 695 }
 696
 697 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 698 {
 699         int find_src = refspec->src == NULL;
 700         char *needle, **result;
 701         int i;
 702
 703         if (find_src) {
 704                 if (!refspec->dst)
 705                         return error("find_tracking: need either src or dst");
 706                 needle = refspec->dst;
 707                 result = &refspec->src;
 708         } else {
 709                 needle = refspec->src;
 710                 result = &refspec->dst;
 711         }
 712
 713         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 714                 struct refspec *fetch = &remote->fetch[i];
 715                 const char *key = find_src ? fetch->dst : fetch->src;
 716                 const char *value = find_src ? fetch->src : fetch->dst;
 717                 if (!fetch->dst)
 718                         continue;
 719                 if (fetch->pattern) {
 720                         if (!prefixcmp(needle, key)) {
 721                                 *result = xmalloc(strlen(value) +
 722                                                   strlen(needle) -
 723                                                   strlen(key) + 1);
 724                                 strcpy(*result, value);
 725                                 strcpy(*result + strlen(value),
 726                                        needle + strlen(key));
 727                                 refspec->force = fetch->force;
 728                                 return 0;
 729                         }
 730                 } else if (!strcmp(needle, key)) {
 731                         *result = xstrdup(value);
 732                         refspec->force = fetch->force;
 733                         return 0;
 734                 }
 735         }
 736         return -1;
 737 }
 738
 739 struct ref *alloc_ref(unsigned namelen)
 740 {
 741         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 742         memset(ret, 0, sizeof(struct ref) + namelen);
 743         return ret;
 744 }
 745
 746 struct ref *alloc_ref_from_str(const char* str)
 747 {
 748         struct ref *ret = alloc_ref(strlen(str) + 1);
 749         strcpy(ret->name, str);
 750         return ret;
 751 }
 752
 753 static struct ref *copy_ref(const struct ref *ref)
 754 {
 755         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 756         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 757         ret->next = NULL;
 758         return ret;
 759 }
 760
 761 struct ref *copy_ref_list(const struct ref *ref)
 762 {
 763         struct ref *ret = NULL;
 764         struct ref **tail = &ret;
 765         while (ref) {
 766                 *tail = copy_ref(ref);
 767                 ref = ref->next;
 768                 tail = &((*tail)->next);
 769         }
 770         return ret;
 771 }
 772
 773 void free_ref(struct ref *ref)
 774 {
 775         if (!ref)
 776                 return;
 777         free(ref->remote_status);
 778         free(ref->symref);
 779         free(ref);
 780 }
 781
 782 void free_refs(struct ref *ref)
 783 {
 784         struct ref *next;
 785         while (ref) {
 786                 next = ref->next;
 787                 free(ref->peer_ref);
 788                 free_ref(ref);
 789                 ref = next;
 790         }
 791 }
 792
 793 static int count_refspec_match(const char *pattern,
 794                                struct ref *refs,
 795                                struct ref **matched_ref)
 796 {
 797         int patlen = strlen(pattern);
 798         struct ref *matched_weak = NULL;
 799         struct ref *matched = NULL;
 800         int weak_match = 0;
 801         int match = 0;
 802
 803         for (weak_match = match = 0; refs; refs = refs->next) {
 804                 char *name = refs->name;
 805                 int namelen = strlen(name);
 806
 807                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 808                         continue;
 809
 810                 /* A match is "weak" if it is with refs outside
 811                  * heads or tags, and did not specify the pattern
 812                  * in full (e.g. "refs/remotes/origin/master") or at
 813                  * least from the toplevel (e.g. "remotes/origin/master");
 814                  * otherwise "git push $URL master" would result in
 815                  * ambiguity between remotes/origin/master and heads/master
 816                  * at the remote site.
 817                  */
 818                 if (namelen != patlen &&
 819                     patlen != namelen - 5 &&
 820                     prefixcmp(name, "refs/heads/") &&
 821                     prefixcmp(name, "refs/tags/")) {
 822                         /* We want to catch the case where only weak
 823                          * matches are found and there are multiple
 824                          * matches, and where more than one strong
 825                          * matches are found, as ambiguous.  One
 826                          * strong match with zero or more weak matches
 827                          * are acceptable as a unique match.
 828                          */
 829                         matched_weak = refs;
 830                         weak_match++;
 831                 }
 832                 else {
 833                         matched = refs;
 834                         match++;
 835                 }
 836         }
 837         if (!matched) {
 838                 *matched_ref = matched_weak;
 839                 return weak_match;
 840         }
 841         else {
 842                 *matched_ref = matched;
 843                 return match;
 844         }
 845 }
 846
 847 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 848 {
 849         **tail = ref;
 850         while (ref->next)
 851                 ref = ref->next;
 852         *tail = &ref->next;
 853 }
 854
 855 static struct ref *try_explicit_object_name(const char *name)
 856 {
 857         unsigned char sha1[20];
 858         struct ref *ref;
 859
 860         if (!*name) {
 861                 ref = alloc_ref(20);
 862                 strcpy(ref->name, "(delete)");
 863                 hashclr(ref->new_sha1);
 864                 return ref;
 865         }
 866         if (get_sha1(name, sha1))
 867                 return NULL;
 868         ref = alloc_ref_from_str(name);
 869         hashcpy(ref->new_sha1, sha1);
 870         return ref;
 871 }
 872
 873 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 874 {
 875         struct ref *ret = alloc_ref_from_str(name);
 876         tail_link_ref(ret, tail);
 877         return ret;
 878 }
 879
 880 static char *guess_ref(const char *name, struct ref *peer)
 881 {
 882         struct strbuf buf = STRBUF_INIT;
 883         unsigned char sha1[20];
 884
 885         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
 886         if (!r)
 887                 return NULL;
 888
 889         if (!prefixcmp(r, "refs/heads/"))
 890                 strbuf_addstr(&buf, "refs/heads/");
 891         else if (!prefixcmp(r, "refs/tags/"))
 892                 strbuf_addstr(&buf, "refs/tags/");
 893         else
 894                 return NULL;
 895
 896         strbuf_addstr(&buf, name);
 897         return strbuf_detach(&buf, NULL);
 898 }
 899
 900 static int match_explicit(struct ref *src, struct ref *dst,
 901                           struct ref ***dst_tail,
 902                           struct refspec *rs)
 903 {
 904         struct ref *matched_src, *matched_dst;
 905
 906         const char *dst_value = rs->dst;
 907         char *dst_guess;
 908
 909         if (rs->pattern || rs->matching)
 910                 return 0;
 911
 912         matched_src = matched_dst = NULL;
 913         switch (count_refspec_match(rs->src, src, &matched_src)) {
 914         case 1:
 915                 break;
 916         case 0:
 917                 /* The source could be in the get_sha1() format
 918                  * not a reference name.  :refs/other is a
 919                  * way to delete 'other' ref at the remote end.
 920                  */
 921                 matched_src = try_explicit_object_name(rs->src);
 922                 if (!matched_src)
 923                         return error("src refspec %s does not match any.", rs->src);
 924                 break;
 925         default:
 926                 return error("src refspec %s matches more than one.", rs->src);
 927         }
 928
 929         if (!dst_value) {
 930                 unsigned char sha1[20];
 931                 int flag;
 932
 933                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 934                 if (!dst_value ||
 935                     ((flag & REF_ISSYMREF) &&
 936                      prefixcmp(dst_value, "refs/heads/")))
 937                         die("%s cannot be resolved to branch.",
 938                             matched_src->name);
 939         }
 940
 941         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 942         case 1:
 943                 break;
 944         case 0:
 945                 if (!memcmp(dst_value, "refs/", 5))
 946                         matched_dst = make_linked_ref(dst_value, dst_tail);
 947                 else if((dst_guess = guess_ref(dst_value, matched_src)))
 948                         matched_dst = make_linked_ref(dst_guess, dst_tail);
 949                 else
 950                         error("unable to push to unqualified destination: %s\n"
 951                               "The destination refspec neither matches an "
 952                               "existing ref on the remote nor\n"
 953                               "begins with refs/, and we are unable to "
 954                               "guess a prefix based on the source ref.",
 955                               dst_value);
 956                 break;
 957         default:
 958                 matched_dst = NULL;
 959                 error("dst refspec %s matches more than one.",
 960                       dst_value);
 961                 break;
 962         }
 963         if (!matched_dst)
 964                 return -1;
 965         if (matched_dst->peer_ref)
 966                 return error("dst ref %s receives from more than one src.",
 967                       matched_dst->name);
 968         else {
 969                 matched_dst->peer_ref = matched_src;
 970                 matched_dst->force = rs->force;
 971         }
 972         return 0;
 973 }
 974
 975 static int match_explicit_refs(struct ref *src, struct ref *dst,
 976                                struct ref ***dst_tail, struct refspec *rs,
 977                                int rs_nr)
 978 {
 979         int i, errs;
 980         for (i = errs = 0; i < rs_nr; i++)
 981                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
 982         return errs;
 983 }
 984
 985 static const struct refspec *check_pattern_match(const struct refspec *rs,
 986                                                  int rs_nr,
 987                                                  const struct ref *src)
 988 {
 989         int i;
 990         int matching_refs = -1;
 991         for (i = 0; i < rs_nr; i++) {
 992                 if (rs[i].matching &&
 993                     (matching_refs == -1 || rs[i].force)) {
 994                         matching_refs = i;
 995                         continue;
 996                 }
 997
 998                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
 999                         return rs + i;
1000         }
1001         if (matching_refs != -1)
1002                 return rs + matching_refs;
1003         else
1004                 return NULL;
1005 }
1006
1007 /*
1008  * Note. This is used only by "push"; refspec matching rules for
1009  * push and fetch are subtly different, so do not try to reuse it
1010  * without thinking.
1011  */
1012 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
1013                int nr_refspec, const char **refspec, int flags)
1014 {
1015         struct refspec *rs;
1016         int send_all = flags & MATCH_REFS_ALL;
1017         int send_mirror = flags & MATCH_REFS_MIRROR;
1018         static const char *default_refspec[] = { ":", 0 };
1019
1020         if (!nr_refspec) {
1021                 nr_refspec = 1;
1022                 refspec = default_refspec;
1023         }
1024         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1025         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
1026                 return -1;
1027
1028         /* pick the remainder */
1029         for ( ; src; src = src->next) {
1030                 struct ref *dst_peer;
1031                 const struct refspec *pat = NULL;
1032                 char *dst_name;
1033                 if (src->peer_ref)
1034                         continue;
1035
1036                 pat = check_pattern_match(rs, nr_refspec, src);
1037                 if (!pat)
1038                         continue;
1039
1040                 if (pat->matching) {
1041                         /*
1042                          * "matching refs"; traditionally we pushed everything
1043                          * including refs outside refs/heads/ hierarchy, but
1044                          * that does not make much sense these days.
1045                          */
1046                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1047                                 continue;
1048                         dst_name = xstrdup(src->name);
1049
1050                 } else {
1051                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1052                         dst_name = xmalloc(strlen(dst_side) +
1053                                            strlen(src->name) -
1054                                            strlen(pat->src) + 2);
1055                         strcpy(dst_name, dst_side);
1056                         strcat(dst_name, src->name + strlen(pat->src));
1057                 }
1058                 dst_peer = find_ref_by_name(dst, dst_name);
1059                 if (dst_peer) {
1060                         if (dst_peer->peer_ref)
1061                                 /* We're already sending something to this ref. */
1062                                 goto free_name;
1063
1064                 } else {
1065                         if (pat->matching && !(send_all || send_mirror))
1066                                 /*
1067                                  * Remote doesn't have it, and we have no
1068                                  * explicit pattern, and we don't have
1069                                  * --all nor --mirror.
1070                                  */
1071                                 goto free_name;
1072
1073                         /* Create a new one and link it */
1074                         dst_peer = make_linked_ref(dst_name, dst_tail);
1075                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1076                 }
1077                 dst_peer->peer_ref = src;
1078                 dst_peer->force = pat->force;
1079         free_name:
1080                 free(dst_name);
1081         }
1082         return 0;
1083 }
1084
1085 struct branch *branch_get(const char *name)
1086 {
1087         struct branch *ret;
1088
1089         read_config();
1090         if (!name || !*name || !strcmp(name, "HEAD"))
1091                 ret = current_branch;
1092         else
1093                 ret = make_branch(name, 0);
1094         if (ret && ret->remote_name) {
1095                 ret->remote = remote_get(ret->remote_name);
1096                 if (ret->merge_nr) {
1097                         int i;
1098                         ret->merge = xcalloc(sizeof(*ret->merge),
1099                                              ret->merge_nr);
1100                         for (i = 0; i < ret->merge_nr; i++) {
1101                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1102                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1103                                 remote_find_tracking(ret->remote,
1104                                                      ret->merge[i]);
1105                         }
1106                 }
1107         }
1108         return ret;
1109 }
1110
1111 int branch_has_merge_config(struct branch *branch)
1112 {
1113         return branch && !!branch->merge;
1114 }
1115
1116 int branch_merge_matches(struct branch *branch,
1117                                  int i,
1118                                  const char *refname)
1119 {
1120         if (!branch || i < 0 || i >= branch->merge_nr)
1121                 return 0;
1122         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1123 }
1124
1125 static struct ref *get_expanded_map(const struct ref *remote_refs,
1126                                     const struct refspec *refspec)
1127 {
1128         const struct ref *ref;
1129         struct ref *ret = NULL;
1130         struct ref **tail = &ret;
1131
1132         int remote_prefix_len = strlen(refspec->src);
1133         int local_prefix_len = strlen(refspec->dst);
1134
1135         for (ref = remote_refs; ref; ref = ref->next) {
1136                 if (strchr(ref->name, '^'))
1137                         continue; /* a dereference item */
1138                 if (!prefixcmp(ref->name, refspec->src)) {
1139                         const char *match;
1140                         struct ref *cpy = copy_ref(ref);
1141                         match = ref->name + remote_prefix_len;
1142
1143                         cpy->peer_ref = alloc_ref(local_prefix_len +
1144                                                   strlen(match) + 1);
1145                         sprintf(cpy->peer_ref->name, "%s%s",
1146                                 refspec->dst, match);
1147                         if (refspec->force)
1148                                 cpy->peer_ref->force = 1;
1149                         *tail = cpy;
1150                         tail = &cpy->next;
1151                 }
1152         }
1153
1154         return ret;
1155 }
1156
1157 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1158 {
1159         const struct ref *ref;
1160         for (ref = refs; ref; ref = ref->next) {
1161                 if (refname_match(name, ref->name, ref_fetch_rules))
1162                         return ref;
1163         }
1164         return NULL;
1165 }
1166
1167 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1168 {
1169         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1170
1171         if (!ref)
1172                 return NULL;
1173
1174         return copy_ref(ref);
1175 }
1176
1177 static struct ref *get_local_ref(const char *name)
1178 {
1179         struct ref *ret;
1180         if (!name)
1181                 return NULL;
1182
1183         if (!prefixcmp(name, "refs/")) {
1184                 return alloc_ref_from_str(name);
1185         }
1186
1187         if (!prefixcmp(name, "heads/") ||
1188             !prefixcmp(name, "tags/") ||
1189             !prefixcmp(name, "remotes/")) {
1190                 ret = alloc_ref(strlen(name) + 6);
1191                 sprintf(ret->name, "refs/%s", name);
1192                 return ret;
1193         }
1194
1195         ret = alloc_ref(strlen(name) + 12);
1196         sprintf(ret->name, "refs/heads/%s", name);
1197         return ret;
1198 }
1199
1200 int get_fetch_map(const struct ref *remote_refs,
1201                   const struct refspec *refspec,
1202                   struct ref ***tail,
1203                   int missing_ok)
1204 {
1205         struct ref *ref_map, **rmp;
1206
1207         if (refspec->pattern) {
1208                 ref_map = get_expanded_map(remote_refs, refspec);
1209         } else {
1210                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1211
1212                 ref_map = get_remote_ref(remote_refs, name);
1213                 if (!missing_ok && !ref_map)
1214                         die("Couldn't find remote ref %s", name);
1215                 if (ref_map) {
1216                         ref_map->peer_ref = get_local_ref(refspec->dst);
1217                         if (ref_map->peer_ref && refspec->force)
1218                                 ref_map->peer_ref->force = 1;
1219                 }
1220         }
1221
1222         for (rmp = &ref_map; *rmp; ) {
1223                 if ((*rmp)->peer_ref) {
1224                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1225                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1226                                 struct ref *ignore = *rmp;
1227                                 error("* Ignoring funny ref '%s' locally",
1228                                       (*rmp)->peer_ref->name);
1229                                 *rmp = (*rmp)->next;
1230                                 free(ignore->peer_ref);
1231                                 free(ignore);
1232                                 continue;
1233                         }
1234                 }
1235                 rmp = &((*rmp)->next);
1236         }
1237
1238         if (ref_map)
1239                 tail_link_ref(ref_map, tail);
1240
1241         return 0;
1242 }
1243
1244 int resolve_remote_symref(struct ref *ref, struct ref *list)
1245 {
1246         if (!ref->symref)
1247                 return 0;
1248         for (; list; list = list->next)
1249                 if (!strcmp(ref->symref, list->name)) {
1250                         hashcpy(ref->old_sha1, list->old_sha1);
1251                         return 0;
1252                 }
1253         return 1;
1254 }
1255
1256 /*
1257  * Return true if there is anything to report, otherwise false.
1258  */
1259 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1260 {
1261         unsigned char sha1[20];
1262         struct commit *ours, *theirs;
1263         char symmetric[84];
1264         struct rev_info revs;
1265         const char *rev_argv[10], *base;
1266         int rev_argc;
1267
1268         /*
1269          * Nothing to report unless we are marked to build on top of
1270          * somebody else.
1271          */
1272         if (!branch ||
1273             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1274                 return 0;
1275
1276         /*
1277          * If what we used to build on no longer exists, there is
1278          * nothing to report.
1279          */
1280         base = branch->merge[0]->dst;
1281         if (!resolve_ref(base, sha1, 1, NULL))
1282                 return 0;
1283         theirs = lookup_commit(sha1);
1284         if (!theirs)
1285                 return 0;
1286
1287         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1288                 return 0;
1289         ours = lookup_commit(sha1);
1290         if (!ours)
1291                 return 0;
1292
1293         /* are we the same? */
1294         if (theirs == ours)
1295                 return 0;
1296
1297         /* Run "rev-list --left-right ours...theirs" internally... */
1298         rev_argc = 0;
1299         rev_argv[rev_argc++] = NULL;
1300         rev_argv[rev_argc++] = "--left-right";
1301         rev_argv[rev_argc++] = symmetric;
1302         rev_argv[rev_argc++] = "--";
1303         rev_argv[rev_argc] = NULL;
1304
1305         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1306         strcpy(symmetric + 40, "...");
1307         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1308
1309         init_revisions(&revs, NULL);
1310         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1311         prepare_revision_walk(&revs);
1312
1313         /* ... and count the commits on each side. */
1314         *num_ours = 0;
1315         *num_theirs = 0;
1316         while (1) {
1317                 struct commit *c = get_revision(&revs);
1318                 if (!c)
1319                         break;
1320                 if (c->object.flags & SYMMETRIC_LEFT)
1321                         (*num_ours)++;
1322                 else
1323                         (*num_theirs)++;
1324         }
1325
1326         /* clear object flags smudged by the above traversal */
1327         clear_commit_marks(ours, ALL_REV_FLAGS);
1328         clear_commit_marks(theirs, ALL_REV_FLAGS);
1329         return 1;
1330 }
1331
1332 /*
1333  * Return true when there is anything to report, otherwise false.
1334  */
1335 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1336 {
1337         int num_ours, num_theirs;
1338         const char *base;
1339
1340         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1341                 return 0;
1342
1343         base = branch->merge[0]->dst;
1344         if (!prefixcmp(base, "refs/remotes/")) {
1345                 base += strlen("refs/remotes/");
1346         }
1347         if (!num_theirs)
1348                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1349                             "by %d commit%s.\n",
1350                             base, num_ours, (num_ours == 1) ? "" : "s");
1351         else if (!num_ours)
1352                 strbuf_addf(sb, "Your branch is behind '%s' "
1353                             "by %d commit%s, "
1354                             "and can be fast-forwarded.\n",
1355                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1356         else
1357                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1358                             "and have %d and %d different commit(s) each, "
1359                             "respectively.\n",
1360                             base, num_ours, num_theirs);
1361         return 1;
1362 }