remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "dir.h"
   8
   9 static struct refspec s_tag_refspec = {
  10         0,
  11         1,
  12         0,
  13         "refs/tags/",
  14         "refs/tags/"
  15 };
  16
  17 const struct refspec *tag_refspec = &s_tag_refspec;
  18
  19 struct counted_string {
  20         size_t len;
  21         const char *s;
  22 };
  23 struct rewrite {
  24         const char *base;
  25         size_t baselen;
  26         struct counted_string *instead_of;
  27         int instead_of_nr;
  28         int instead_of_alloc;
  29 };
  30
  31 static struct remote **remotes;
  32 static int remotes_alloc;
  33 static int remotes_nr;
  34
  35 static struct branch **branches;
  36 static int branches_alloc;
  37 static int branches_nr;
  38
  39 static struct branch *current_branch;
  40 static const char *default_remote_name;
  41 static int explicit_default_remote_name;
  42
  43 static struct rewrite **rewrite;
  44 static int rewrite_alloc;
  45 static int rewrite_nr;
  46
  47 #define BUF_SIZE (2048)
  48 static char buffer[BUF_SIZE];
  49
  50 static const char *alias_url(const char *url)
  51 {
  52         int i, j;
  53         char *ret;
  54         struct counted_string *longest;
  55         int longest_i;
  56
  57         longest = NULL;
  58         longest_i = -1;
  59         for (i = 0; i < rewrite_nr; i++) {
  60                 if (!rewrite[i])
  61                         continue;
  62                 for (j = 0; j < rewrite[i]->instead_of_nr; j++) {
  63                         if (!prefixcmp(url, rewrite[i]->instead_of[j].s) &&
  64                             (!longest ||
  65                              longest->len < rewrite[i]->instead_of[j].len)) {
  66                                 longest = &(rewrite[i]->instead_of[j]);
  67                                 longest_i = i;
  68                         }
  69                 }
  70         }
  71         if (!longest)
  72                 return url;
  73
  74         ret = xmalloc(rewrite[longest_i]->baselen +
  75                      (strlen(url) - longest->len) + 1);
  76         strcpy(ret, rewrite[longest_i]->base);
  77         strcpy(ret + rewrite[longest_i]->baselen, url + longest->len);
  78         return ret;
  79 }
  80
  81 static void add_push_refspec(struct remote *remote, const char *ref)
  82 {
  83         ALLOC_GROW(remote->push_refspec,
  84                    remote->push_refspec_nr + 1,
  85                    remote->push_refspec_alloc);
  86         remote->push_refspec[remote->push_refspec_nr++] = ref;
  87 }
  88
  89 static void add_fetch_refspec(struct remote *remote, const char *ref)
  90 {
  91         ALLOC_GROW(remote->fetch_refspec,
  92                    remote->fetch_refspec_nr + 1,
  93                    remote->fetch_refspec_alloc);
  94         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
  95 }
  96
  97 static void add_url(struct remote *remote, const char *url)
  98 {
  99         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 100         remote->url[remote->url_nr++] = url;
 101 }
 102
 103 static void add_url_alias(struct remote *remote, const char *url)
 104 {
 105         add_url(remote, alias_url(url));
 106 }
 107
 108 static struct remote *get_remote_by_name(const char *name)
 109 {
 110         int i;
 111         for (i = 0; i < remotes_nr; i++) {
 112                 if (!strcmp(name, remotes[i]->name))
 113                         return remotes[i];
 114         }
 115         return NULL;
 116 }
 117
 118 static struct remote *make_remote(const char *name, int len)
 119 {
 120         struct remote *ret;
 121         int i;
 122
 123         for (i = 0; i < remotes_nr; i++) {
 124                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 125                            !remotes[i]->name[len]) :
 126                     !strcmp(name, remotes[i]->name))
 127                         return remotes[i];
 128         }
 129
 130         ret = xcalloc(1, sizeof(struct remote));
 131         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 132         remotes[remotes_nr++] = ret;
 133         if (len)
 134                 ret->name = xstrndup(name, len);
 135         else
 136                 ret->name = xstrdup(name);
 137         return ret;
 138 }
 139
 140 static void add_merge(struct branch *branch, const char *name)
 141 {
 142         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 143                    branch->merge_alloc);
 144         branch->merge_name[branch->merge_nr++] = name;
 145 }
 146
 147 static struct branch *make_branch(const char *name, int len)
 148 {
 149         struct branch *ret;
 150         int i;
 151         char *refname;
 152
 153         for (i = 0; i < branches_nr; i++) {
 154                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 155                            !branches[i]->name[len]) :
 156                     !strcmp(name, branches[i]->name))
 157                         return branches[i];
 158         }
 159
 160         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 161         ret = xcalloc(1, sizeof(struct branch));
 162         branches[branches_nr++] = ret;
 163         if (len)
 164                 ret->name = xstrndup(name, len);
 165         else
 166                 ret->name = xstrdup(name);
 167         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 168         strcpy(refname, "refs/heads/");
 169         strcpy(refname + strlen("refs/heads/"), ret->name);
 170         ret->refname = refname;
 171
 172         return ret;
 173 }
 174
 175 static struct rewrite *make_rewrite(const char *base, int len)
 176 {
 177         struct rewrite *ret;
 178         int i;
 179
 180         for (i = 0; i < rewrite_nr; i++) {
 181                 if (len
 182                     ? (len == rewrite[i]->baselen &&
 183                        !strncmp(base, rewrite[i]->base, len))
 184                     : !strcmp(base, rewrite[i]->base))
 185                         return rewrite[i];
 186         }
 187
 188         ALLOC_GROW(rewrite, rewrite_nr + 1, rewrite_alloc);
 189         ret = xcalloc(1, sizeof(struct rewrite));
 190         rewrite[rewrite_nr++] = ret;
 191         if (len) {
 192                 ret->base = xstrndup(base, len);
 193                 ret->baselen = len;
 194         }
 195         else {
 196                 ret->base = xstrdup(base);
 197                 ret->baselen = strlen(base);
 198         }
 199         return ret;
 200 }
 201
 202 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 203 {
 204         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 205         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 206         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 207         rewrite->instead_of_nr++;
 208 }
 209
 210 static void read_remotes_file(struct remote *remote)
 211 {
 212         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 213
 214         if (!f)
 215                 return;
 216         remote->origin = REMOTE_REMOTES;
 217         while (fgets(buffer, BUF_SIZE, f)) {
 218                 int value_list;
 219                 char *s, *p;
 220
 221                 if (!prefixcmp(buffer, "URL:")) {
 222                         value_list = 0;
 223                         s = buffer + 4;
 224                 } else if (!prefixcmp(buffer, "Push:")) {
 225                         value_list = 1;
 226                         s = buffer + 5;
 227                 } else if (!prefixcmp(buffer, "Pull:")) {
 228                         value_list = 2;
 229                         s = buffer + 5;
 230                 } else
 231                         continue;
 232
 233                 while (isspace(*s))
 234                         s++;
 235                 if (!*s)
 236                         continue;
 237
 238                 p = s + strlen(s);
 239                 while (isspace(p[-1]))
 240                         *--p = 0;
 241
 242                 switch (value_list) {
 243                 case 0:
 244                         add_url_alias(remote, xstrdup(s));
 245                         break;
 246                 case 1:
 247                         add_push_refspec(remote, xstrdup(s));
 248                         break;
 249                 case 2:
 250                         add_fetch_refspec(remote, xstrdup(s));
 251                         break;
 252                 }
 253         }
 254         fclose(f);
 255 }
 256
 257 static void read_branches_file(struct remote *remote)
 258 {
 259         const char *slash = strchr(remote->name, '/');
 260         char *frag;
 261         struct strbuf branch = STRBUF_INIT;
 262         int n = slash ? slash - remote->name : 1000;
 263         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 264         char *s, *p;
 265         int len;
 266
 267         if (!f)
 268                 return;
 269         s = fgets(buffer, BUF_SIZE, f);
 270         fclose(f);
 271         if (!s)
 272                 return;
 273         while (isspace(*s))
 274                 s++;
 275         if (!*s)
 276                 return;
 277         remote->origin = REMOTE_BRANCHES;
 278         p = s + strlen(s);
 279         while (isspace(p[-1]))
 280                 *--p = 0;
 281         len = p - s;
 282         if (slash)
 283                 len += strlen(slash);
 284         p = xmalloc(len + 1);
 285         strcpy(p, s);
 286         if (slash)
 287                 strcat(p, slash);
 288
 289         /*
 290          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 291          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 292          * the partial URL obtained from the branches file plus
 293          * "/netdev-2.6" and does not store it in any tracking ref.
 294          * #branch specifier in the file is ignored.
 295          *
 296          * Otherwise, the branches file would have URL and optionally
 297          * #branch specified.  The "master" (or specified) branch is
 298          * fetched and stored in the local branch of the same name.
 299          */
 300         frag = strchr(p, '#');
 301         if (frag) {
 302                 *(frag++) = '\0';
 303                 strbuf_addf(&branch, "refs/heads/%s", frag);
 304         } else
 305                 strbuf_addstr(&branch, "refs/heads/master");
 306         if (!slash) {
 307                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 308         } else {
 309                 strbuf_reset(&branch);
 310                 strbuf_addstr(&branch, "HEAD:");
 311         }
 312         add_url_alias(remote, p);
 313         add_fetch_refspec(remote, strbuf_detach(&branch, 0));
 314         /*
 315          * Cogito compatible push: push current HEAD to remote #branch
 316          * (master if missing)
 317          */
 318         strbuf_init(&branch, 0);
 319         strbuf_addstr(&branch, "HEAD");
 320         if (frag)
 321                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 322         else
 323                 strbuf_addstr(&branch, ":refs/heads/master");
 324         add_push_refspec(remote, strbuf_detach(&branch, 0));
 325         remote->fetch_tags = 1; /* always auto-follow */
 326 }
 327
 328 static int handle_config(const char *key, const char *value, void *cb)
 329 {
 330         const char *name;
 331         const char *subkey;
 332         struct remote *remote;
 333         struct branch *branch;
 334         if (!prefixcmp(key, "branch.")) {
 335                 name = key + 7;
 336                 subkey = strrchr(name, '.');
 337                 if (!subkey)
 338                         return 0;
 339                 branch = make_branch(name, subkey - name);
 340                 if (!strcmp(subkey, ".remote")) {
 341                         if (!value)
 342                                 return config_error_nonbool(key);
 343                         branch->remote_name = xstrdup(value);
 344                         if (branch == current_branch) {
 345                                 default_remote_name = branch->remote_name;
 346                                 explicit_default_remote_name = 1;
 347                         }
 348                 } else if (!strcmp(subkey, ".merge")) {
 349                         if (!value)
 350                                 return config_error_nonbool(key);
 351                         add_merge(branch, xstrdup(value));
 352                 }
 353                 return 0;
 354         }
 355         if (!prefixcmp(key, "url.")) {
 356                 struct rewrite *rewrite;
 357                 name = key + 4;
 358                 subkey = strrchr(name, '.');
 359                 if (!subkey)
 360                         return 0;
 361                 rewrite = make_rewrite(name, subkey - name);
 362                 if (!strcmp(subkey, ".insteadof")) {
 363                         if (!value)
 364                                 return config_error_nonbool(key);
 365                         add_instead_of(rewrite, xstrdup(value));
 366                 }
 367         }
 368         if (prefixcmp(key,  "remote."))
 369                 return 0;
 370         name = key + 7;
 371         if (*name == '/') {
 372                 warning("Config remote shorthand cannot begin with '/': %s",
 373                         name);
 374                 return 0;
 375         }
 376         subkey = strrchr(name, '.');
 377         if (!subkey)
 378                 return error("Config with no key for remote %s", name);
 379         remote = make_remote(name, subkey - name);
 380         remote->origin = REMOTE_CONFIG;
 381         if (!strcmp(subkey, ".mirror"))
 382                 remote->mirror = git_config_bool(key, value);
 383         else if (!strcmp(subkey, ".skipdefaultupdate"))
 384                 remote->skip_default_update = git_config_bool(key, value);
 385
 386         else if (!strcmp(subkey, ".url")) {
 387                 const char *v;
 388                 if (git_config_string(&v, key, value))
 389                         return -1;
 390                 add_url(remote, v);
 391         } else if (!strcmp(subkey, ".push")) {
 392                 const char *v;
 393                 if (git_config_string(&v, key, value))
 394                         return -1;
 395                 add_push_refspec(remote, v);
 396         } else if (!strcmp(subkey, ".fetch")) {
 397                 const char *v;
 398                 if (git_config_string(&v, key, value))
 399                         return -1;
 400                 add_fetch_refspec(remote, v);
 401         } else if (!strcmp(subkey, ".receivepack")) {
 402                 const char *v;
 403                 if (git_config_string(&v, key, value))
 404                         return -1;
 405                 if (!remote->receivepack)
 406                         remote->receivepack = v;
 407                 else
 408                         error("more than one receivepack given, using the first");
 409         } else if (!strcmp(subkey, ".uploadpack")) {
 410                 const char *v;
 411                 if (git_config_string(&v, key, value))
 412                         return -1;
 413                 if (!remote->uploadpack)
 414                         remote->uploadpack = v;
 415                 else
 416                         error("more than one uploadpack given, using the first");
 417         } else if (!strcmp(subkey, ".tagopt")) {
 418                 if (!strcmp(value, "--no-tags"))
 419                         remote->fetch_tags = -1;
 420         } else if (!strcmp(subkey, ".proxy")) {
 421                 return git_config_string((const char **)&remote->http_proxy,
 422                                          key, value);
 423         }
 424         return 0;
 425 }
 426
 427 static void alias_all_urls(void)
 428 {
 429         int i, j;
 430         for (i = 0; i < remotes_nr; i++) {
 431                 if (!remotes[i])
 432                         continue;
 433                 for (j = 0; j < remotes[i]->url_nr; j++) {
 434                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 435                 }
 436         }
 437 }
 438
 439 static void read_config(void)
 440 {
 441         unsigned char sha1[20];
 442         const char *head_ref;
 443         int flag;
 444         if (default_remote_name) // did this already
 445                 return;
 446         default_remote_name = xstrdup("origin");
 447         current_branch = NULL;
 448         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 449         if (head_ref && (flag & REF_ISSYMREF) &&
 450             !prefixcmp(head_ref, "refs/heads/")) {
 451                 current_branch =
 452                         make_branch(head_ref + strlen("refs/heads/"), 0);
 453         }
 454         git_config(handle_config, NULL);
 455         alias_all_urls();
 456 }
 457
 458 /*
 459  * We need to make sure the tracking branches are well formed, but a
 460  * wildcard refspec in "struct refspec" must have a trailing slash. We
 461  * temporarily drop the trailing '/' while calling check_ref_format(),
 462  * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 463  * error return is Ok for a wildcard refspec.
 464  */
 465 static int verify_refname(char *name, int is_glob)
 466 {
 467         int result, len = -1;
 468
 469         if (is_glob) {
 470                 len = strlen(name);
 471                 assert(name[len - 1] == '/');
 472                 name[len - 1] = '\0';
 473         }
 474         result = check_ref_format(name);
 475         if (is_glob)
 476                 name[len - 1] = '/';
 477         return result;
 478 }
 479
 480 /*
 481  * This function frees a refspec array.
 482  * Warning: code paths should be checked to ensure that the src
 483  *          and dst pointers are always freeable pointers as well
 484  *          as the refspec pointer itself.
 485  */
 486 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 487 {
 488         int i;
 489
 490         if (!refspec)
 491                 return;
 492
 493         for (i = 0; i < nr_refspec; i++) {
 494                 free(refspec[i].src);
 495                 free(refspec[i].dst);
 496         }
 497         free(refspec);
 498 }
 499
 500 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 501 {
 502         int i;
 503         int st;
 504         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 505
 506         for (i = 0; i < nr_refspec; i++) {
 507                 size_t llen;
 508                 int is_glob;
 509                 const char *lhs, *rhs;
 510
 511                 llen = is_glob = 0;
 512
 513                 lhs = refspec[i];
 514                 if (*lhs == '+') {
 515                         rs[i].force = 1;
 516                         lhs++;
 517                 }
 518
 519                 rhs = strrchr(lhs, ':');
 520
 521                 /*
 522                  * Before going on, special case ":" (or "+:") as a refspec
 523                  * for matching refs.
 524                  */
 525                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 526                         rs[i].matching = 1;
 527                         continue;
 528                 }
 529
 530                 if (rhs) {
 531                         size_t rlen = strlen(++rhs);
 532                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
 533                         rs[i].dst = xstrndup(rhs, rlen - is_glob);
 534                 }
 535
 536                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 537                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
 538                         if ((rhs && !is_glob) || (!rhs && fetch))
 539                                 goto invalid;
 540                         is_glob = 1;
 541                         llen--;
 542                 } else if (rhs && is_glob) {
 543                         goto invalid;
 544                 }
 545
 546                 rs[i].pattern = is_glob;
 547                 rs[i].src = xstrndup(lhs, llen);
 548
 549                 if (fetch) {
 550                         /*
 551                          * LHS
 552                          * - empty is allowed; it means HEAD.
 553                          * - otherwise it must be a valid looking ref.
 554                          */
 555                         if (!*rs[i].src)
 556                                 ; /* empty is ok */
 557                         else {
 558                                 st = verify_refname(rs[i].src, is_glob);
 559                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 560                                         goto invalid;
 561                         }
 562                         /*
 563                          * RHS
 564                          * - missing is ok, and is same as empty.
 565                          * - empty is ok; it means not to store.
 566                          * - otherwise it must be a valid looking ref.
 567                          */
 568                         if (!rs[i].dst) {
 569                                 ; /* ok */
 570                         } else if (!*rs[i].dst) {
 571                                 ; /* ok */
 572                         } else {
 573                                 st = verify_refname(rs[i].dst, is_glob);
 574                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 575                                         goto invalid;
 576                         }
 577                 } else {
 578                         /*
 579                          * LHS
 580                          * - empty is allowed; it means delete.
 581                          * - when wildcarded, it must be a valid looking ref.
 582                          * - otherwise, it must be an extended SHA-1, but
 583                          *   there is no existing way to validate this.
 584                          */
 585                         if (!*rs[i].src)
 586                                 ; /* empty is ok */
 587                         else if (is_glob) {
 588                                 st = verify_refname(rs[i].src, is_glob);
 589                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 590                                         goto invalid;
 591                         }
 592                         else
 593                                 ; /* anything goes, for now */
 594                         /*
 595                          * RHS
 596                          * - missing is allowed, but LHS then must be a
 597                          *   valid looking ref.
 598                          * - empty is not allowed.
 599                          * - otherwise it must be a valid looking ref.
 600                          */
 601                         if (!rs[i].dst) {
 602                                 st = verify_refname(rs[i].src, is_glob);
 603                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 604                                         goto invalid;
 605                         } else if (!*rs[i].dst) {
 606                                 goto invalid;
 607                         } else {
 608                                 st = verify_refname(rs[i].dst, is_glob);
 609                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 610                                         goto invalid;
 611                         }
 612                 }
 613         }
 614         return rs;
 615
 616  invalid:
 617         if (verify) {
 618                 /*
 619                  * nr_refspec must be greater than zero and i must be valid
 620                  * since it is only possible to reach this point from within
 621                  * the for loop above.
 622                  */
 623                 free_refspecs(rs, i+1);
 624                 return NULL;
 625         }
 626         die("Invalid refspec '%s'", refspec[i]);
 627 }
 628
 629 int valid_fetch_refspec(const char *fetch_refspec_str)
 630 {
 631         const char *fetch_refspec[] = { fetch_refspec_str };
 632         struct refspec *refspec;
 633
 634         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 635         free_refspecs(refspec, 1);
 636         return !!refspec;
 637 }
 638
 639 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 640 {
 641         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 642 }
 643
 644 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 645 {
 646         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 647 }
 648
 649 static int valid_remote_nick(const char *name)
 650 {
 651         if (!name[0] || is_dot_or_dotdot(name))
 652                 return 0;
 653         return !strchr(name, '/'); /* no slash */
 654 }
 655
 656 struct remote *remote_get(const char *name)
 657 {
 658         struct remote *ret;
 659         int name_given = 0;
 660
 661         read_config();
 662         if (name)
 663                 name_given = 1;
 664         else {
 665                 name = default_remote_name;
 666                 name_given = explicit_default_remote_name;
 667         }
 668         if (name_given)
 669                 ret = make_remote(name, 0);
 670         else {
 671                 ret = get_remote_by_name(name);
 672                 if (!ret)
 673                         return NULL;
 674         }
 675         if (valid_remote_nick(name)) {
 676                 if (!ret->url)
 677                         read_remotes_file(ret);
 678                 if (!ret->url)
 679                         read_branches_file(ret);
 680         }
 681         if (!ret->url)
 682                 add_url_alias(ret, name);
 683         if (!ret->url)
 684                 return NULL;
 685         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 686         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 687         return ret;
 688 }
 689
 690 int for_each_remote(each_remote_fn fn, void *priv)
 691 {
 692         int i, result = 0;
 693         read_config();
 694         for (i = 0; i < remotes_nr && !result; i++) {
 695                 struct remote *r = remotes[i];
 696                 if (!r)
 697                         continue;
 698                 if (!r->fetch)
 699                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 700                                                        r->fetch_refspec);
 701                 if (!r->push)
 702                         r->push = parse_push_refspec(r->push_refspec_nr,
 703                                                      r->push_refspec);
 704                 result = fn(r, priv);
 705         }
 706         return result;
 707 }
 708
 709 void ref_remove_duplicates(struct ref *ref_map)
 710 {
 711         struct ref **posn;
 712         struct ref *next;
 713         for (; ref_map; ref_map = ref_map->next) {
 714                 if (!ref_map->peer_ref)
 715                         continue;
 716                 posn = &ref_map->next;
 717                 while (*posn) {
 718                         if ((*posn)->peer_ref &&
 719                             !strcmp((*posn)->peer_ref->name,
 720                                     ref_map->peer_ref->name)) {
 721                                 if (strcmp((*posn)->name, ref_map->name))
 722                                         die("%s tracks both %s and %s",
 723                                             ref_map->peer_ref->name,
 724                                             (*posn)->name, ref_map->name);
 725                                 next = (*posn)->next;
 726                                 free((*posn)->peer_ref);
 727                                 free(*posn);
 728                                 *posn = next;
 729                         } else {
 730                                 posn = &(*posn)->next;
 731                         }
 732                 }
 733         }
 734 }
 735
 736 int remote_has_url(struct remote *remote, const char *url)
 737 {
 738         int i;
 739         for (i = 0; i < remote->url_nr; i++) {
 740                 if (!strcmp(remote->url[i], url))
 741                         return 1;
 742         }
 743         return 0;
 744 }
 745
 746 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 747 {
 748         int find_src = refspec->src == NULL;
 749         char *needle, **result;
 750         int i;
 751
 752         if (find_src) {
 753                 if (!refspec->dst)
 754                         return error("find_tracking: need either src or dst");
 755                 needle = refspec->dst;
 756                 result = &refspec->src;
 757         } else {
 758                 needle = refspec->src;
 759                 result = &refspec->dst;
 760         }
 761
 762         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 763                 struct refspec *fetch = &remote->fetch[i];
 764                 const char *key = find_src ? fetch->dst : fetch->src;
 765                 const char *value = find_src ? fetch->src : fetch->dst;
 766                 if (!fetch->dst)
 767                         continue;
 768                 if (fetch->pattern) {
 769                         if (!prefixcmp(needle, key)) {
 770                                 *result = xmalloc(strlen(value) +
 771                                                   strlen(needle) -
 772                                                   strlen(key) + 1);
 773                                 strcpy(*result, value);
 774                                 strcpy(*result + strlen(value),
 775                                        needle + strlen(key));
 776                                 refspec->force = fetch->force;
 777                                 return 0;
 778                         }
 779                 } else if (!strcmp(needle, key)) {
 780                         *result = xstrdup(value);
 781                         refspec->force = fetch->force;
 782                         return 0;
 783                 }
 784         }
 785         return -1;
 786 }
 787
 788 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 789                 const char *name)
 790 {
 791         size_t len = strlen(name);
 792         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 793         memcpy(ref->name, prefix, prefixlen);
 794         memcpy(ref->name + prefixlen, name, len);
 795         return ref;
 796 }
 797
 798 struct ref *alloc_ref(const char *name)
 799 {
 800         return alloc_ref_with_prefix("", 0, name);
 801 }
 802
 803 static struct ref *copy_ref(const struct ref *ref)
 804 {
 805         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 806         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 807         ret->next = NULL;
 808         return ret;
 809 }
 810
 811 struct ref *copy_ref_list(const struct ref *ref)
 812 {
 813         struct ref *ret = NULL;
 814         struct ref **tail = &ret;
 815         while (ref) {
 816                 *tail = copy_ref(ref);
 817                 ref = ref->next;
 818                 tail = &((*tail)->next);
 819         }
 820         return ret;
 821 }
 822
 823 static void free_ref(struct ref *ref)
 824 {
 825         if (!ref)
 826                 return;
 827         free(ref->remote_status);
 828         free(ref->symref);
 829         free(ref);
 830 }
 831
 832 void free_refs(struct ref *ref)
 833 {
 834         struct ref *next;
 835         while (ref) {
 836                 next = ref->next;
 837                 free(ref->peer_ref);
 838                 free_ref(ref);
 839                 ref = next;
 840         }
 841 }
 842
 843 static int count_refspec_match(const char *pattern,
 844                                struct ref *refs,
 845                                struct ref **matched_ref)
 846 {
 847         int patlen = strlen(pattern);
 848         struct ref *matched_weak = NULL;
 849         struct ref *matched = NULL;
 850         int weak_match = 0;
 851         int match = 0;
 852
 853         for (weak_match = match = 0; refs; refs = refs->next) {
 854                 char *name = refs->name;
 855                 int namelen = strlen(name);
 856
 857                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 858                         continue;
 859
 860                 /* A match is "weak" if it is with refs outside
 861                  * heads or tags, and did not specify the pattern
 862                  * in full (e.g. "refs/remotes/origin/master") or at
 863                  * least from the toplevel (e.g. "remotes/origin/master");
 864                  * otherwise "git push $URL master" would result in
 865                  * ambiguity between remotes/origin/master and heads/master
 866                  * at the remote site.
 867                  */
 868                 if (namelen != patlen &&
 869                     patlen != namelen - 5 &&
 870                     prefixcmp(name, "refs/heads/") &&
 871                     prefixcmp(name, "refs/tags/")) {
 872                         /* We want to catch the case where only weak
 873                          * matches are found and there are multiple
 874                          * matches, and where more than one strong
 875                          * matches are found, as ambiguous.  One
 876                          * strong match with zero or more weak matches
 877                          * are acceptable as a unique match.
 878                          */
 879                         matched_weak = refs;
 880                         weak_match++;
 881                 }
 882                 else {
 883                         matched = refs;
 884                         match++;
 885                 }
 886         }
 887         if (!matched) {
 888                 *matched_ref = matched_weak;
 889                 return weak_match;
 890         }
 891         else {
 892                 *matched_ref = matched;
 893                 return match;
 894         }
 895 }
 896
 897 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 898 {
 899         **tail = ref;
 900         while (ref->next)
 901                 ref = ref->next;
 902         *tail = &ref->next;
 903 }
 904
 905 static struct ref *try_explicit_object_name(const char *name)
 906 {
 907         unsigned char sha1[20];
 908         struct ref *ref;
 909
 910         if (!*name) {
 911                 ref = alloc_ref("(delete)");
 912                 hashclr(ref->new_sha1);
 913                 return ref;
 914         }
 915         if (get_sha1(name, sha1))
 916                 return NULL;
 917         ref = alloc_ref(name);
 918         hashcpy(ref->new_sha1, sha1);
 919         return ref;
 920 }
 921
 922 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 923 {
 924         struct ref *ret = alloc_ref(name);
 925         tail_link_ref(ret, tail);
 926         return ret;
 927 }
 928
 929 static char *guess_ref(const char *name, struct ref *peer)
 930 {
 931         struct strbuf buf = STRBUF_INIT;
 932         unsigned char sha1[20];
 933
 934         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
 935         if (!r)
 936                 return NULL;
 937
 938         if (!prefixcmp(r, "refs/heads/"))
 939                 strbuf_addstr(&buf, "refs/heads/");
 940         else if (!prefixcmp(r, "refs/tags/"))
 941                 strbuf_addstr(&buf, "refs/tags/");
 942         else
 943                 return NULL;
 944
 945         strbuf_addstr(&buf, name);
 946         return strbuf_detach(&buf, NULL);
 947 }
 948
 949 static int match_explicit(struct ref *src, struct ref *dst,
 950                           struct ref ***dst_tail,
 951                           struct refspec *rs)
 952 {
 953         struct ref *matched_src, *matched_dst;
 954
 955         const char *dst_value = rs->dst;
 956         char *dst_guess;
 957
 958         if (rs->pattern || rs->matching)
 959                 return 0;
 960
 961         matched_src = matched_dst = NULL;
 962         switch (count_refspec_match(rs->src, src, &matched_src)) {
 963         case 1:
 964                 break;
 965         case 0:
 966                 /* The source could be in the get_sha1() format
 967                  * not a reference name.  :refs/other is a
 968                  * way to delete 'other' ref at the remote end.
 969                  */
 970                 matched_src = try_explicit_object_name(rs->src);
 971                 if (!matched_src)
 972                         return error("src refspec %s does not match any.", rs->src);
 973                 break;
 974         default:
 975                 return error("src refspec %s matches more than one.", rs->src);
 976         }
 977
 978         if (!dst_value) {
 979                 unsigned char sha1[20];
 980                 int flag;
 981
 982                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 983                 if (!dst_value ||
 984                     ((flag & REF_ISSYMREF) &&
 985                      prefixcmp(dst_value, "refs/heads/")))
 986                         die("%s cannot be resolved to branch.",
 987                             matched_src->name);
 988         }
 989
 990         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 991         case 1:
 992                 break;
 993         case 0:
 994                 if (!memcmp(dst_value, "refs/", 5))
 995                         matched_dst = make_linked_ref(dst_value, dst_tail);
 996                 else if((dst_guess = guess_ref(dst_value, matched_src)))
 997                         matched_dst = make_linked_ref(dst_guess, dst_tail);
 998                 else
 999                         error("unable to push to unqualified destination: %s\n"
1000                               "The destination refspec neither matches an "
1001                               "existing ref on the remote nor\n"
1002                               "begins with refs/, and we are unable to "
1003                               "guess a prefix based on the source ref.",
1004                               dst_value);
1005                 break;
1006         default:
1007                 matched_dst = NULL;
1008                 error("dst refspec %s matches more than one.",
1009                       dst_value);
1010                 break;
1011         }
1012         if (!matched_dst)
1013                 return -1;
1014         if (matched_dst->peer_ref)
1015                 return error("dst ref %s receives from more than one src.",
1016                       matched_dst->name);
1017         else {
1018                 matched_dst->peer_ref = matched_src;
1019                 matched_dst->force = rs->force;
1020         }
1021         return 0;
1022 }
1023
1024 static int match_explicit_refs(struct ref *src, struct ref *dst,
1025                                struct ref ***dst_tail, struct refspec *rs,
1026                                int rs_nr)
1027 {
1028         int i, errs;
1029         for (i = errs = 0; i < rs_nr; i++)
1030                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1031         return errs;
1032 }
1033
1034 static const struct refspec *check_pattern_match(const struct refspec *rs,
1035                                                  int rs_nr,
1036                                                  const struct ref *src)
1037 {
1038         int i;
1039         int matching_refs = -1;
1040         for (i = 0; i < rs_nr; i++) {
1041                 if (rs[i].matching &&
1042                     (matching_refs == -1 || rs[i].force)) {
1043                         matching_refs = i;
1044                         continue;
1045                 }
1046
1047                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
1048                         return rs + i;
1049         }
1050         if (matching_refs != -1)
1051                 return rs + matching_refs;
1052         else
1053                 return NULL;
1054 }
1055
1056 /*
1057  * Note. This is used only by "push"; refspec matching rules for
1058  * push and fetch are subtly different, so do not try to reuse it
1059  * without thinking.
1060  */
1061 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
1062                int nr_refspec, const char **refspec, int flags)
1063 {
1064         struct refspec *rs;
1065         int send_all = flags & MATCH_REFS_ALL;
1066         int send_mirror = flags & MATCH_REFS_MIRROR;
1067         static const char *default_refspec[] = { ":", 0 };
1068
1069         if (!nr_refspec) {
1070                 nr_refspec = 1;
1071                 refspec = default_refspec;
1072         }
1073         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1074         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
1075                 return -1;
1076
1077         /* pick the remainder */
1078         for ( ; src; src = src->next) {
1079                 struct ref *dst_peer;
1080                 const struct refspec *pat = NULL;
1081                 char *dst_name;
1082                 if (src->peer_ref)
1083                         continue;
1084
1085                 pat = check_pattern_match(rs, nr_refspec, src);
1086                 if (!pat)
1087                         continue;
1088
1089                 if (pat->matching) {
1090                         /*
1091                          * "matching refs"; traditionally we pushed everything
1092                          * including refs outside refs/heads/ hierarchy, but
1093                          * that does not make much sense these days.
1094                          */
1095                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1096                                 continue;
1097                         dst_name = xstrdup(src->name);
1098
1099                 } else {
1100                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1101                         dst_name = xmalloc(strlen(dst_side) +
1102                                            strlen(src->name) -
1103                                            strlen(pat->src) + 2);
1104                         strcpy(dst_name, dst_side);
1105                         strcat(dst_name, src->name + strlen(pat->src));
1106                 }
1107                 dst_peer = find_ref_by_name(dst, dst_name);
1108                 if (dst_peer) {
1109                         if (dst_peer->peer_ref)
1110                                 /* We're already sending something to this ref. */
1111                                 goto free_name;
1112
1113                 } else {
1114                         if (pat->matching && !(send_all || send_mirror))
1115                                 /*
1116                                  * Remote doesn't have it, and we have no
1117                                  * explicit pattern, and we don't have
1118                                  * --all nor --mirror.
1119                                  */
1120                                 goto free_name;
1121
1122                         /* Create a new one and link it */
1123                         dst_peer = make_linked_ref(dst_name, dst_tail);
1124                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1125                 }
1126                 dst_peer->peer_ref = src;
1127                 dst_peer->force = pat->force;
1128         free_name:
1129                 free(dst_name);
1130         }
1131         return 0;
1132 }
1133
1134 struct branch *branch_get(const char *name)
1135 {
1136         struct branch *ret;
1137
1138         read_config();
1139         if (!name || !*name || !strcmp(name, "HEAD"))
1140                 ret = current_branch;
1141         else
1142                 ret = make_branch(name, 0);
1143         if (ret && ret->remote_name) {
1144                 ret->remote = remote_get(ret->remote_name);
1145                 if (ret->merge_nr) {
1146                         int i;
1147                         ret->merge = xcalloc(sizeof(*ret->merge),
1148                                              ret->merge_nr);
1149                         for (i = 0; i < ret->merge_nr; i++) {
1150                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1151                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1152                                 remote_find_tracking(ret->remote,
1153                                                      ret->merge[i]);
1154                         }
1155                 }
1156         }
1157         return ret;
1158 }
1159
1160 int branch_has_merge_config(struct branch *branch)
1161 {
1162         return branch && !!branch->merge;
1163 }
1164
1165 int branch_merge_matches(struct branch *branch,
1166                                  int i,
1167                                  const char *refname)
1168 {
1169         if (!branch || i < 0 || i >= branch->merge_nr)
1170                 return 0;
1171         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1172 }
1173
1174 static struct ref *get_expanded_map(const struct ref *remote_refs,
1175                                     const struct refspec *refspec)
1176 {
1177         const struct ref *ref;
1178         struct ref *ret = NULL;
1179         struct ref **tail = &ret;
1180
1181         int remote_prefix_len = strlen(refspec->src);
1182         int local_prefix_len = strlen(refspec->dst);
1183
1184         for (ref = remote_refs; ref; ref = ref->next) {
1185                 if (strchr(ref->name, '^'))
1186                         continue; /* a dereference item */
1187                 if (!prefixcmp(ref->name, refspec->src)) {
1188                         const char *match;
1189                         struct ref *cpy = copy_ref(ref);
1190                         match = ref->name + remote_prefix_len;
1191
1192                         cpy->peer_ref = alloc_ref_with_prefix(refspec->dst,
1193                                         local_prefix_len, match);
1194                         if (refspec->force)
1195                                 cpy->peer_ref->force = 1;
1196                         *tail = cpy;
1197                         tail = &cpy->next;
1198                 }
1199         }
1200
1201         return ret;
1202 }
1203
1204 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1205 {
1206         const struct ref *ref;
1207         for (ref = refs; ref; ref = ref->next) {
1208                 if (refname_match(name, ref->name, ref_fetch_rules))
1209                         return ref;
1210         }
1211         return NULL;
1212 }
1213
1214 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1215 {
1216         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1217
1218         if (!ref)
1219                 return NULL;
1220
1221         return copy_ref(ref);
1222 }
1223
1224 static struct ref *get_local_ref(const char *name)
1225 {
1226         if (!name)
1227                 return NULL;
1228
1229         if (!prefixcmp(name, "refs/"))
1230                 return alloc_ref(name);
1231
1232         if (!prefixcmp(name, "heads/") ||
1233             !prefixcmp(name, "tags/") ||
1234             !prefixcmp(name, "remotes/"))
1235                 return alloc_ref_with_prefix("refs/", 5, name);
1236
1237         return alloc_ref_with_prefix("refs/heads/", 11, name);
1238 }
1239
1240 int get_fetch_map(const struct ref *remote_refs,
1241                   const struct refspec *refspec,
1242                   struct ref ***tail,
1243                   int missing_ok)
1244 {
1245         struct ref *ref_map, **rmp;
1246
1247         if (refspec->pattern) {
1248                 ref_map = get_expanded_map(remote_refs, refspec);
1249         } else {
1250                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1251
1252                 ref_map = get_remote_ref(remote_refs, name);
1253                 if (!missing_ok && !ref_map)
1254                         die("Couldn't find remote ref %s", name);
1255                 if (ref_map) {
1256                         ref_map->peer_ref = get_local_ref(refspec->dst);
1257                         if (ref_map->peer_ref && refspec->force)
1258                                 ref_map->peer_ref->force = 1;
1259                 }
1260         }
1261
1262         for (rmp = &ref_map; *rmp; ) {
1263                 if ((*rmp)->peer_ref) {
1264                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1265                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1266                                 struct ref *ignore = *rmp;
1267                                 error("* Ignoring funny ref '%s' locally",
1268                                       (*rmp)->peer_ref->name);
1269                                 *rmp = (*rmp)->next;
1270                                 free(ignore->peer_ref);
1271                                 free(ignore);
1272                                 continue;
1273                         }
1274                 }
1275                 rmp = &((*rmp)->next);
1276         }
1277
1278         if (ref_map)
1279                 tail_link_ref(ref_map, tail);
1280
1281         return 0;
1282 }
1283
1284 int resolve_remote_symref(struct ref *ref, struct ref *list)
1285 {
1286         if (!ref->symref)
1287                 return 0;
1288         for (; list; list = list->next)
1289                 if (!strcmp(ref->symref, list->name)) {
1290                         hashcpy(ref->old_sha1, list->old_sha1);
1291                         return 0;
1292                 }
1293         return 1;
1294 }
1295
1296 /*
1297  * Return true if there is anything to report, otherwise false.
1298  */
1299 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1300 {
1301         unsigned char sha1[20];
1302         struct commit *ours, *theirs;
1303         char symmetric[84];
1304         struct rev_info revs;
1305         const char *rev_argv[10], *base;
1306         int rev_argc;
1307
1308         /*
1309          * Nothing to report unless we are marked to build on top of
1310          * somebody else.
1311          */
1312         if (!branch ||
1313             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1314                 return 0;
1315
1316         /*
1317          * If what we used to build on no longer exists, there is
1318          * nothing to report.
1319          */
1320         base = branch->merge[0]->dst;
1321         if (!resolve_ref(base, sha1, 1, NULL))
1322                 return 0;
1323         theirs = lookup_commit(sha1);
1324         if (!theirs)
1325                 return 0;
1326
1327         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1328                 return 0;
1329         ours = lookup_commit(sha1);
1330         if (!ours)
1331                 return 0;
1332
1333         /* are we the same? */
1334         if (theirs == ours)
1335                 return 0;
1336
1337         /* Run "rev-list --left-right ours...theirs" internally... */
1338         rev_argc = 0;
1339         rev_argv[rev_argc++] = NULL;
1340         rev_argv[rev_argc++] = "--left-right";
1341         rev_argv[rev_argc++] = symmetric;
1342         rev_argv[rev_argc++] = "--";
1343         rev_argv[rev_argc] = NULL;
1344
1345         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1346         strcpy(symmetric + 40, "...");
1347         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1348
1349         init_revisions(&revs, NULL);
1350         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1351         prepare_revision_walk(&revs);
1352
1353         /* ... and count the commits on each side. */
1354         *num_ours = 0;
1355         *num_theirs = 0;
1356         while (1) {
1357                 struct commit *c = get_revision(&revs);
1358                 if (!c)
1359                         break;
1360                 if (c->object.flags & SYMMETRIC_LEFT)
1361                         (*num_ours)++;
1362                 else
1363                         (*num_theirs)++;
1364         }
1365
1366         /* clear object flags smudged by the above traversal */
1367         clear_commit_marks(ours, ALL_REV_FLAGS);
1368         clear_commit_marks(theirs, ALL_REV_FLAGS);
1369         return 1;
1370 }
1371
1372 /*
1373  * Return true when there is anything to report, otherwise false.
1374  */
1375 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1376 {
1377         int num_ours, num_theirs;
1378         const char *base;
1379
1380         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1381                 return 0;
1382
1383         base = branch->merge[0]->dst;
1384         if (!prefixcmp(base, "refs/remotes/")) {
1385                 base += strlen("refs/remotes/");
1386         }
1387         if (!num_theirs)
1388                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1389                             "by %d commit%s.\n",
1390                             base, num_ours, (num_ours == 1) ? "" : "s");
1391         else if (!num_ours)
1392                 strbuf_addf(sb, "Your branch is behind '%s' "
1393                             "by %d commit%s, "
1394                             "and can be fast-forwarded.\n",
1395                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1396         else
1397                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1398                             "and have %d and %d different commit(s) each, "
1399                             "respectively.\n",
1400                             base, num_ours, num_theirs);
1401         return 1;
1402 }