remote.c

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