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