remote.c

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