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