remote.c

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