remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "dir.h"
   8 #include "tag.h"
   9 #include "string-list.h"
  10
  11 enum map_direction { FROM_SRC, FROM_DST };
  12
  13 static struct refspec s_tag_refspec = {
  14         0,
  15         1,
  16         0,
  17         "refs/tags/*",
  18         "refs/tags/*"
  19 };
  20
  21 const struct refspec *tag_refspec = &s_tag_refspec;
  22
  23 struct counted_string {
  24         size_t len;
  25         const char *s;
  26 };
  27 struct rewrite {
  28         const char *base;
  29         size_t baselen;
  30         struct counted_string *instead_of;
  31         int instead_of_nr;
  32         int instead_of_alloc;
  33 };
  34 struct rewrites {
  35         struct rewrite **rewrite;
  36         int rewrite_alloc;
  37         int rewrite_nr;
  38 };
  39
  40 static struct remote **remotes;
  41 static int remotes_alloc;
  42 static int remotes_nr;
  43
  44 static struct branch **branches;
  45 static int branches_alloc;
  46 static int branches_nr;
  47
  48 static struct branch *current_branch;
  49 static const char *default_remote_name;
  50 static int explicit_default_remote_name;
  51
  52 static struct rewrites rewrites;
  53 static struct rewrites rewrites_push;
  54
  55 #define BUF_SIZE (2048)
  56 static char buffer[BUF_SIZE];
  57
  58 static int valid_remote(const struct remote *remote)
  59 {
  60         return (!!remote->url) || (!!remote->foreign_vcs);
  61 }
  62
  63 static const char *alias_url(const char *url, struct rewrites *r)
  64 {
  65         int i, j;
  66         char *ret;
  67         struct counted_string *longest;
  68         int longest_i;
  69
  70         longest = NULL;
  71         longest_i = -1;
  72         for (i = 0; i < r->rewrite_nr; i++) {
  73                 if (!r->rewrite[i])
  74                         continue;
  75                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  76                         if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  77                             (!longest ||
  78                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  79                                 longest = &(r->rewrite[i]->instead_of[j]);
  80                                 longest_i = i;
  81                         }
  82                 }
  83         }
  84         if (!longest)
  85                 return url;
  86
  87         ret = xmalloc(r->rewrite[longest_i]->baselen +
  88                      (strlen(url) - longest->len) + 1);
  89         strcpy(ret, r->rewrite[longest_i]->base);
  90         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  91         return ret;
  92 }
  93
  94 static void add_push_refspec(struct remote *remote, const char *ref)
  95 {
  96         ALLOC_GROW(remote->push_refspec,
  97                    remote->push_refspec_nr + 1,
  98                    remote->push_refspec_alloc);
  99         remote->push_refspec[remote->push_refspec_nr++] = ref;
 100 }
 101
 102 static void add_fetch_refspec(struct remote *remote, const char *ref)
 103 {
 104         ALLOC_GROW(remote->fetch_refspec,
 105                    remote->fetch_refspec_nr + 1,
 106                    remote->fetch_refspec_alloc);
 107         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 108 }
 109
 110 static void add_url(struct remote *remote, const char *url)
 111 {
 112         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 113         remote->url[remote->url_nr++] = url;
 114 }
 115
 116 static void add_pushurl(struct remote *remote, const char *pushurl)
 117 {
 118         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 119         remote->pushurl[remote->pushurl_nr++] = pushurl;
 120 }
 121
 122 static void add_pushurl_alias(struct remote *remote, const char *url)
 123 {
 124         const char *pushurl = alias_url(url, &rewrites_push);
 125         if (pushurl != url)
 126                 add_pushurl(remote, pushurl);
 127 }
 128
 129 static void add_url_alias(struct remote *remote, const char *url)
 130 {
 131         add_url(remote, alias_url(url, &rewrites));
 132         add_pushurl_alias(remote, url);
 133 }
 134
 135 static struct remote *make_remote(const char *name, int len)
 136 {
 137         struct remote *ret;
 138         int i;
 139
 140         for (i = 0; i < remotes_nr; i++) {
 141                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 142                            !remotes[i]->name[len]) :
 143                     !strcmp(name, remotes[i]->name))
 144                         return remotes[i];
 145         }
 146
 147         ret = xcalloc(1, sizeof(struct remote));
 148         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 149         remotes[remotes_nr++] = ret;
 150         if (len)
 151                 ret->name = xstrndup(name, len);
 152         else
 153                 ret->name = xstrdup(name);
 154         return ret;
 155 }
 156
 157 static void add_merge(struct branch *branch, const char *name)
 158 {
 159         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 160                    branch->merge_alloc);
 161         branch->merge_name[branch->merge_nr++] = name;
 162 }
 163
 164 static struct branch *make_branch(const char *name, int len)
 165 {
 166         struct branch *ret;
 167         int i;
 168         char *refname;
 169
 170         for (i = 0; i < branches_nr; i++) {
 171                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 172                            !branches[i]->name[len]) :
 173                     !strcmp(name, branches[i]->name))
 174                         return branches[i];
 175         }
 176
 177         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 178         ret = xcalloc(1, sizeof(struct branch));
 179         branches[branches_nr++] = ret;
 180         if (len)
 181                 ret->name = xstrndup(name, len);
 182         else
 183                 ret->name = xstrdup(name);
 184         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 185         strcpy(refname, "refs/heads/");
 186         strcpy(refname + strlen("refs/heads/"), ret->name);
 187         ret->refname = refname;
 188
 189         return ret;
 190 }
 191
 192 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 193 {
 194         struct rewrite *ret;
 195         int i;
 196
 197         for (i = 0; i < r->rewrite_nr; i++) {
 198                 if (len
 199                     ? (len == r->rewrite[i]->baselen &&
 200                        !strncmp(base, r->rewrite[i]->base, len))
 201                     : !strcmp(base, r->rewrite[i]->base))
 202                         return r->rewrite[i];
 203         }
 204
 205         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 206         ret = xcalloc(1, sizeof(struct rewrite));
 207         r->rewrite[r->rewrite_nr++] = ret;
 208         if (len) {
 209                 ret->base = xstrndup(base, len);
 210                 ret->baselen = len;
 211         }
 212         else {
 213                 ret->base = xstrdup(base);
 214                 ret->baselen = strlen(base);
 215         }
 216         return ret;
 217 }
 218
 219 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 220 {
 221         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 222         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 223         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 224         rewrite->instead_of_nr++;
 225 }
 226
 227 static void read_remotes_file(struct remote *remote)
 228 {
 229         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 230
 231         if (!f)
 232                 return;
 233         remote->origin = REMOTE_REMOTES;
 234         while (fgets(buffer, BUF_SIZE, f)) {
 235                 int value_list;
 236                 char *s, *p;
 237
 238                 if (!prefixcmp(buffer, "URL:")) {
 239                         value_list = 0;
 240                         s = buffer + 4;
 241                 } else if (!prefixcmp(buffer, "Push:")) {
 242                         value_list = 1;
 243                         s = buffer + 5;
 244                 } else if (!prefixcmp(buffer, "Pull:")) {
 245                         value_list = 2;
 246                         s = buffer + 5;
 247                 } else
 248                         continue;
 249
 250                 while (isspace(*s))
 251                         s++;
 252                 if (!*s)
 253                         continue;
 254
 255                 p = s + strlen(s);
 256                 while (isspace(p[-1]))
 257                         *--p = 0;
 258
 259                 switch (value_list) {
 260                 case 0:
 261                         add_url_alias(remote, xstrdup(s));
 262                         break;
 263                 case 1:
 264                         add_push_refspec(remote, xstrdup(s));
 265                         break;
 266                 case 2:
 267                         add_fetch_refspec(remote, xstrdup(s));
 268                         break;
 269                 }
 270         }
 271         fclose(f);
 272 }
 273
 274 static void read_branches_file(struct remote *remote)
 275 {
 276         const char *slash = strchr(remote->name, '/');
 277         char *frag;
 278         struct strbuf branch = STRBUF_INIT;
 279         int n = slash ? slash - remote->name : 1000;
 280         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 281         char *s, *p;
 282         int len;
 283
 284         if (!f)
 285                 return;
 286         s = fgets(buffer, BUF_SIZE, f);
 287         fclose(f);
 288         if (!s)
 289                 return;
 290         while (isspace(*s))
 291                 s++;
 292         if (!*s)
 293                 return;
 294         remote->origin = REMOTE_BRANCHES;
 295         p = s + strlen(s);
 296         while (isspace(p[-1]))
 297                 *--p = 0;
 298         len = p - s;
 299         if (slash)
 300                 len += strlen(slash);
 301         p = xmalloc(len + 1);
 302         strcpy(p, s);
 303         if (slash)
 304                 strcat(p, slash);
 305
 306         /*
 307          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 308          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 309          * the partial URL obtained from the branches file plus
 310          * "/netdev-2.6" and does not store it in any tracking ref.
 311          * #branch specifier in the file is ignored.
 312          *
 313          * Otherwise, the branches file would have URL and optionally
 314          * #branch specified.  The "master" (or specified) branch is
 315          * fetched and stored in the local branch of the same name.
 316          */
 317         frag = strchr(p, '#');
 318         if (frag) {
 319                 *(frag++) = '\0';
 320                 strbuf_addf(&branch, "refs/heads/%s", frag);
 321         } else
 322                 strbuf_addstr(&branch, "refs/heads/master");
 323         if (!slash) {
 324                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 325         } else {
 326                 strbuf_reset(&branch);
 327                 strbuf_addstr(&branch, "HEAD:");
 328         }
 329         add_url_alias(remote, p);
 330         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 331         /*
 332          * Cogito compatible push: push current HEAD to remote #branch
 333          * (master if missing)
 334          */
 335         strbuf_init(&branch, 0);
 336         strbuf_addstr(&branch, "HEAD");
 337         if (frag)
 338                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 339         else
 340                 strbuf_addstr(&branch, ":refs/heads/master");
 341         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 342         remote->fetch_tags = 1; /* always auto-follow */
 343 }
 344
 345 static int handle_config(const char *key, const char *value, void *cb)
 346 {
 347         const char *name;
 348         const char *subkey;
 349         struct remote *remote;
 350         struct branch *branch;
 351         if (!prefixcmp(key, "branch.")) {
 352                 name = key + 7;
 353                 subkey = strrchr(name, '.');
 354                 if (!subkey)
 355                         return 0;
 356                 branch = make_branch(name, subkey - name);
 357                 if (!strcmp(subkey, ".remote")) {
 358                         if (!value)
 359                                 return config_error_nonbool(key);
 360                         branch->remote_name = xstrdup(value);
 361                         if (branch == current_branch) {
 362                                 default_remote_name = branch->remote_name;
 363                                 explicit_default_remote_name = 1;
 364                         }
 365                 } else if (!strcmp(subkey, ".merge")) {
 366                         if (!value)
 367                                 return config_error_nonbool(key);
 368                         add_merge(branch, xstrdup(value));
 369                 }
 370                 return 0;
 371         }
 372         if (!prefixcmp(key, "url.")) {
 373                 struct rewrite *rewrite;
 374                 name = key + 4;
 375                 subkey = strrchr(name, '.');
 376                 if (!subkey)
 377                         return 0;
 378                 if (!strcmp(subkey, ".insteadof")) {
 379                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 380                         if (!value)
 381                                 return config_error_nonbool(key);
 382                         add_instead_of(rewrite, xstrdup(value));
 383                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 384                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 385                         if (!value)
 386                                 return config_error_nonbool(key);
 387                         add_instead_of(rewrite, xstrdup(value));
 388                 }
 389         }
 390         if (prefixcmp(key,  "remote."))
 391                 return 0;
 392         name = key + 7;
 393         if (*name == '/') {
 394                 warning("Config remote shorthand cannot begin with '/': %s",
 395                         name);
 396                 return 0;
 397         }
 398         subkey = strrchr(name, '.');
 399         if (!subkey)
 400                 return 0;
 401         remote = make_remote(name, subkey - name);
 402         remote->origin = REMOTE_CONFIG;
 403         if (!strcmp(subkey, ".mirror"))
 404                 remote->mirror = git_config_bool(key, value);
 405         else if (!strcmp(subkey, ".skipdefaultupdate"))
 406                 remote->skip_default_update = git_config_bool(key, value);
 407         else if (!strcmp(subkey, ".skipfetchall"))
 408                 remote->skip_default_update = git_config_bool(key, value);
 409         else if (!strcmp(subkey, ".url")) {
 410                 const char *v;
 411                 if (git_config_string(&v, key, value))
 412                         return -1;
 413                 add_url(remote, v);
 414         } else if (!strcmp(subkey, ".pushurl")) {
 415                 const char *v;
 416                 if (git_config_string(&v, key, value))
 417                         return -1;
 418                 add_pushurl(remote, v);
 419         } else if (!strcmp(subkey, ".push")) {
 420                 const char *v;
 421                 if (git_config_string(&v, key, value))
 422                         return -1;
 423                 add_push_refspec(remote, v);
 424         } else if (!strcmp(subkey, ".fetch")) {
 425                 const char *v;
 426                 if (git_config_string(&v, key, value))
 427                         return -1;
 428                 add_fetch_refspec(remote, v);
 429         } else if (!strcmp(subkey, ".receivepack")) {
 430                 const char *v;
 431                 if (git_config_string(&v, key, value))
 432                         return -1;
 433                 if (!remote->receivepack)
 434                         remote->receivepack = v;
 435                 else
 436                         error("more than one receivepack given, using the first");
 437         } else if (!strcmp(subkey, ".uploadpack")) {
 438                 const char *v;
 439                 if (git_config_string(&v, key, value))
 440                         return -1;
 441                 if (!remote->uploadpack)
 442                         remote->uploadpack = v;
 443                 else
 444                         error("more than one uploadpack given, using the first");
 445         } else if (!strcmp(subkey, ".tagopt")) {
 446                 if (!strcmp(value, "--no-tags"))
 447                         remote->fetch_tags = -1;
 448                 else if (!strcmp(value, "--tags"))
 449                         remote->fetch_tags = 2;
 450         } else if (!strcmp(subkey, ".proxy")) {
 451                 return git_config_string((const char **)&remote->http_proxy,
 452                                          key, value);
 453         } else if (!strcmp(subkey, ".vcs")) {
 454                 return git_config_string(&remote->foreign_vcs, key, value);
 455         }
 456         return 0;
 457 }
 458
 459 static void alias_all_urls(void)
 460 {
 461         int i, j;
 462         for (i = 0; i < remotes_nr; i++) {
 463                 int add_pushurl_aliases;
 464                 if (!remotes[i])
 465                         continue;
 466                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 467                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 468                 }
 469                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 470                 for (j = 0; j < remotes[i]->url_nr; j++) {
 471                         if (add_pushurl_aliases)
 472                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 473                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 474                 }
 475         }
 476 }
 477
 478 static void read_config(void)
 479 {
 480         unsigned char sha1[20];
 481         const char *head_ref;
 482         int flag;
 483         if (default_remote_name) /* did this already */
 484                 return;
 485         default_remote_name = xstrdup("origin");
 486         current_branch = NULL;
 487         head_ref = resolve_ref_unsafe("HEAD", sha1, 0, &flag);
 488         if (head_ref && (flag & REF_ISSYMREF) &&
 489             !prefixcmp(head_ref, "refs/heads/")) {
 490                 current_branch =
 491                         make_branch(head_ref + strlen("refs/heads/"), 0);
 492         }
 493         git_config(handle_config, NULL);
 494         alias_all_urls();
 495 }
 496
 497 /*
 498  * This function frees a refspec array.
 499  * Warning: code paths should be checked to ensure that the src
 500  *          and dst pointers are always freeable pointers as well
 501  *          as the refspec pointer itself.
 502  */
 503 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 504 {
 505         int i;
 506
 507         if (!refspec)
 508                 return;
 509
 510         for (i = 0; i < nr_refspec; i++) {
 511                 free(refspec[i].src);
 512                 free(refspec[i].dst);
 513         }
 514         free(refspec);
 515 }
 516
 517 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 518 {
 519         int i;
 520         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 521
 522         for (i = 0; i < nr_refspec; i++) {
 523                 size_t llen;
 524                 int is_glob;
 525                 const char *lhs, *rhs;
 526                 int flags;
 527
 528                 is_glob = 0;
 529
 530                 lhs = refspec[i];
 531                 if (*lhs == '+') {
 532                         rs[i].force = 1;
 533                         lhs++;
 534                 }
 535
 536                 rhs = strrchr(lhs, ':');
 537
 538                 /*
 539                  * Before going on, special case ":" (or "+:") as a refspec
 540                  * for matching refs.
 541                  */
 542                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 543                         rs[i].matching = 1;
 544                         continue;
 545                 }
 546
 547                 if (rhs) {
 548                         size_t rlen = strlen(++rhs);
 549                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 550                         rs[i].dst = xstrndup(rhs, rlen);
 551                 }
 552
 553                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 554                 if (1 <= llen && memchr(lhs, '*', llen)) {
 555                         if ((rhs && !is_glob) || (!rhs && fetch))
 556                                 goto invalid;
 557                         is_glob = 1;
 558                 } else if (rhs && is_glob) {
 559                         goto invalid;
 560                 }
 561
 562                 rs[i].pattern = is_glob;
 563                 rs[i].src = xstrndup(lhs, llen);
 564                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 565
 566                 if (fetch) {
 567                         /*
 568                          * LHS
 569                          * - empty is allowed; it means HEAD.
 570                          * - otherwise it must be a valid looking ref.
 571                          */
 572                         if (!*rs[i].src)
 573                                 ; /* empty is ok */
 574                         else if (check_refname_format(rs[i].src, flags))
 575                                 goto invalid;
 576                         /*
 577                          * RHS
 578                          * - missing is ok, and is same as empty.
 579                          * - empty is ok; it means not to store.
 580                          * - otherwise it must be a valid looking ref.
 581                          */
 582                         if (!rs[i].dst)
 583                                 ; /* ok */
 584                         else if (!*rs[i].dst)
 585                                 ; /* ok */
 586                         else if (check_refname_format(rs[i].dst, flags))
 587                                 goto invalid;
 588                 } else {
 589                         /*
 590                          * LHS
 591                          * - empty is allowed; it means delete.
 592                          * - when wildcarded, it must be a valid looking ref.
 593                          * - otherwise, it must be an extended SHA-1, but
 594                          *   there is no existing way to validate this.
 595                          */
 596                         if (!*rs[i].src)
 597                                 ; /* empty is ok */
 598                         else if (is_glob) {
 599                                 if (check_refname_format(rs[i].src, flags))
 600                                         goto invalid;
 601                         }
 602                         else
 603                                 ; /* anything goes, for now */
 604                         /*
 605                          * RHS
 606                          * - missing is allowed, but LHS then must be a
 607                          *   valid looking ref.
 608                          * - empty is not allowed.
 609                          * - otherwise it must be a valid looking ref.
 610                          */
 611                         if (!rs[i].dst) {
 612                                 if (check_refname_format(rs[i].src, flags))
 613                                         goto invalid;
 614                         } else if (!*rs[i].dst) {
 615                                 goto invalid;
 616                         } else {
 617                                 if (check_refname_format(rs[i].dst, flags))
 618                                         goto invalid;
 619                         }
 620                 }
 621         }
 622         return rs;
 623
 624  invalid:
 625         if (verify) {
 626                 /*
 627                  * nr_refspec must be greater than zero and i must be valid
 628                  * since it is only possible to reach this point from within
 629                  * the for loop above.
 630                  */
 631                 free_refspecs(rs, i+1);
 632                 return NULL;
 633         }
 634         die("Invalid refspec '%s'", refspec[i]);
 635 }
 636
 637 int valid_fetch_refspec(const char *fetch_refspec_str)
 638 {
 639         struct refspec *refspec;
 640
 641         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 642         free_refspecs(refspec, 1);
 643         return !!refspec;
 644 }
 645
 646 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 647 {
 648         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 649 }
 650
 651 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 652 {
 653         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 654 }
 655
 656 void free_refspec(int nr_refspec, struct refspec *refspec)
 657 {
 658         int i;
 659         for (i = 0; i < nr_refspec; i++) {
 660                 free(refspec[i].src);
 661                 free(refspec[i].dst);
 662         }
 663         free(refspec);
 664 }
 665
 666 static int valid_remote_nick(const char *name)
 667 {
 668         if (!name[0] || is_dot_or_dotdot(name))
 669                 return 0;
 670         return !strchr(name, '/'); /* no slash */
 671 }
 672
 673 struct remote *remote_get(const char *name)
 674 {
 675         struct remote *ret;
 676         int name_given = 0;
 677
 678         read_config();
 679         if (name)
 680                 name_given = 1;
 681         else {
 682                 name = default_remote_name;
 683                 name_given = explicit_default_remote_name;
 684         }
 685
 686         ret = make_remote(name, 0);
 687         if (valid_remote_nick(name)) {
 688                 if (!valid_remote(ret))
 689                         read_remotes_file(ret);
 690                 if (!valid_remote(ret))
 691                         read_branches_file(ret);
 692         }
 693         if (name_given && !valid_remote(ret))
 694                 add_url_alias(ret, name);
 695         if (!valid_remote(ret))
 696                 return NULL;
 697         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 698         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 699         return ret;
 700 }
 701
 702 int remote_is_configured(const char *name)
 703 {
 704         int i;
 705         read_config();
 706
 707         for (i = 0; i < remotes_nr; i++)
 708                 if (!strcmp(name, remotes[i]->name))
 709                         return 1;
 710         return 0;
 711 }
 712
 713 int for_each_remote(each_remote_fn fn, void *priv)
 714 {
 715         int i, result = 0;
 716         read_config();
 717         for (i = 0; i < remotes_nr && !result; i++) {
 718                 struct remote *r = remotes[i];
 719                 if (!r)
 720                         continue;
 721                 if (!r->fetch)
 722                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 723                                                        r->fetch_refspec);
 724                 if (!r->push)
 725                         r->push = parse_push_refspec(r->push_refspec_nr,
 726                                                      r->push_refspec);
 727                 result = fn(r, priv);
 728         }
 729         return result;
 730 }
 731
 732 void ref_remove_duplicates(struct ref *ref_map)
 733 {
 734         struct string_list refs = STRING_LIST_INIT_NODUP;
 735         struct string_list_item *item = NULL;
 736         struct ref *prev = NULL, *next = NULL;
 737         for (; ref_map; prev = ref_map, ref_map = next) {
 738                 next = ref_map->next;
 739                 if (!ref_map->peer_ref)
 740                         continue;
 741
 742                 item = string_list_lookup(&refs, ref_map->peer_ref->name);
 743                 if (item) {
 744                         if (strcmp(((struct ref *)item->util)->name,
 745                                    ref_map->name))
 746                                 die("%s tracks both %s and %s",
 747                                     ref_map->peer_ref->name,
 748                                     ((struct ref *)item->util)->name,
 749                                     ref_map->name);
 750                         prev->next = ref_map->next;
 751                         free(ref_map->peer_ref);
 752                         free(ref_map);
 753                         ref_map = prev; /* skip this; we freed it */
 754                         continue;
 755                 }
 756
 757                 item = string_list_insert(&refs, ref_map->peer_ref->name);
 758                 item->util = ref_map;
 759         }
 760         string_list_clear(&refs, 0);
 761 }
 762
 763 int remote_has_url(struct remote *remote, const char *url)
 764 {
 765         int i;
 766         for (i = 0; i < remote->url_nr; i++) {
 767                 if (!strcmp(remote->url[i], url))
 768                         return 1;
 769         }
 770         return 0;
 771 }
 772
 773 static int match_name_with_pattern(const char *key, const char *name,
 774                                    const char *value, char **result)
 775 {
 776         const char *kstar = strchr(key, '*');
 777         size_t klen;
 778         size_t ksuffixlen;
 779         size_t namelen;
 780         int ret;
 781         if (!kstar)
 782                 die("Key '%s' of pattern had no '*'", key);
 783         klen = kstar - key;
 784         ksuffixlen = strlen(kstar + 1);
 785         namelen = strlen(name);
 786         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 787                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 788         if (ret && value) {
 789                 const char *vstar = strchr(value, '*');
 790                 size_t vlen;
 791                 size_t vsuffixlen;
 792                 if (!vstar)
 793                         die("Value '%s' of pattern has no '*'", value);
 794                 vlen = vstar - value;
 795                 vsuffixlen = strlen(vstar + 1);
 796                 *result = xmalloc(vlen + vsuffixlen +
 797                                   strlen(name) -
 798                                   klen - ksuffixlen + 1);
 799                 strncpy(*result, value, vlen);
 800                 strncpy(*result + vlen,
 801                         name + klen, namelen - klen - ksuffixlen);
 802                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 803                        vstar + 1);
 804         }
 805         return ret;
 806 }
 807
 808 static int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 809 {
 810         int i;
 811         int find_src = !query->src;
 812
 813         if (find_src && !query->dst)
 814                 return error("query_refspecs: need either src or dst");
 815
 816         for (i = 0; i < ref_count; i++) {
 817                 struct refspec *refspec = &refs[i];
 818                 const char *key = find_src ? refspec->dst : refspec->src;
 819                 const char *value = find_src ? refspec->src : refspec->dst;
 820                 const char *needle = find_src ? query->dst : query->src;
 821                 char **result = find_src ? &query->src : &query->dst;
 822
 823                 if (!refspec->dst)
 824                         continue;
 825                 if (refspec->pattern) {
 826                         if (match_name_with_pattern(key, needle, value, result)) {
 827                                 query->force = refspec->force;
 828                                 return 0;
 829                         }
 830                 } else if (!strcmp(needle, key)) {
 831                         *result = xstrdup(value);
 832                         query->force = refspec->force;
 833                         return 0;
 834                 }
 835         }
 836         return -1;
 837 }
 838
 839 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 840                      const char *name)
 841 {
 842         struct refspec query;
 843
 844         memset(&query, 0, sizeof(struct refspec));
 845         query.src = (char *)name;
 846
 847         if (query_refspecs(refspecs, nr_refspec, &query))
 848                 return NULL;
 849
 850         return query.dst;
 851 }
 852
 853 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 854 {
 855         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 856 }
 857
 858 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 859                 const char *name)
 860 {
 861         size_t len = strlen(name);
 862         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 863         memcpy(ref->name, prefix, prefixlen);
 864         memcpy(ref->name + prefixlen, name, len);
 865         return ref;
 866 }
 867
 868 struct ref *alloc_ref(const char *name)
 869 {
 870         return alloc_ref_with_prefix("", 0, name);
 871 }
 872
 873 struct ref *copy_ref(const struct ref *ref)
 874 {
 875         struct ref *cpy;
 876         size_t len;
 877         if (!ref)
 878                 return NULL;
 879         len = strlen(ref->name);
 880         cpy = xmalloc(sizeof(struct ref) + len + 1);
 881         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 882         cpy->next = NULL;
 883         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 884         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 885         cpy->peer_ref = copy_ref(ref->peer_ref);
 886         return cpy;
 887 }
 888
 889 struct ref *copy_ref_list(const struct ref *ref)
 890 {
 891         struct ref *ret = NULL;
 892         struct ref **tail = &ret;
 893         while (ref) {
 894                 *tail = copy_ref(ref);
 895                 ref = ref->next;
 896                 tail = &((*tail)->next);
 897         }
 898         return ret;
 899 }
 900
 901 static void free_ref(struct ref *ref)
 902 {
 903         if (!ref)
 904                 return;
 905         free_ref(ref->peer_ref);
 906         free(ref->remote_status);
 907         free(ref->symref);
 908         free(ref);
 909 }
 910
 911 void free_refs(struct ref *ref)
 912 {
 913         struct ref *next;
 914         while (ref) {
 915                 next = ref->next;
 916                 free_ref(ref);
 917                 ref = next;
 918         }
 919 }
 920
 921 static int count_refspec_match(const char *pattern,
 922                                struct ref *refs,
 923                                struct ref **matched_ref)
 924 {
 925         int patlen = strlen(pattern);
 926         struct ref *matched_weak = NULL;
 927         struct ref *matched = NULL;
 928         int weak_match = 0;
 929         int match = 0;
 930
 931         for (weak_match = match = 0; refs; refs = refs->next) {
 932                 char *name = refs->name;
 933                 int namelen = strlen(name);
 934
 935                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 936                         continue;
 937
 938                 /* A match is "weak" if it is with refs outside
 939                  * heads or tags, and did not specify the pattern
 940                  * in full (e.g. "refs/remotes/origin/master") or at
 941                  * least from the toplevel (e.g. "remotes/origin/master");
 942                  * otherwise "git push $URL master" would result in
 943                  * ambiguity between remotes/origin/master and heads/master
 944                  * at the remote site.
 945                  */
 946                 if (namelen != patlen &&
 947                     patlen != namelen - 5 &&
 948                     prefixcmp(name, "refs/heads/") &&
 949                     prefixcmp(name, "refs/tags/")) {
 950                         /* We want to catch the case where only weak
 951                          * matches are found and there are multiple
 952                          * matches, and where more than one strong
 953                          * matches are found, as ambiguous.  One
 954                          * strong match with zero or more weak matches
 955                          * are acceptable as a unique match.
 956                          */
 957                         matched_weak = refs;
 958                         weak_match++;
 959                 }
 960                 else {
 961                         matched = refs;
 962                         match++;
 963                 }
 964         }
 965         if (!matched) {
 966                 *matched_ref = matched_weak;
 967                 return weak_match;
 968         }
 969         else {
 970                 *matched_ref = matched;
 971                 return match;
 972         }
 973 }
 974
 975 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 976 {
 977         **tail = ref;
 978         while (ref->next)
 979                 ref = ref->next;
 980         *tail = &ref->next;
 981 }
 982
 983 static struct ref *alloc_delete_ref(void)
 984 {
 985         struct ref *ref = alloc_ref("(delete)");
 986         hashclr(ref->new_sha1);
 987         return ref;
 988 }
 989
 990 static struct ref *try_explicit_object_name(const char *name)
 991 {
 992         unsigned char sha1[20];
 993         struct ref *ref;
 994
 995         if (!*name)
 996                 return alloc_delete_ref();
 997         if (get_sha1(name, sha1))
 998                 return NULL;
 999         ref = alloc_ref(name);
1000         hashcpy(ref->new_sha1, sha1);
1001         return ref;
1002 }
1003
1004 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1005 {
1006         struct ref *ret = alloc_ref(name);
1007         tail_link_ref(ret, tail);
1008         return ret;
1009 }
1010
1011 static char *guess_ref(const char *name, struct ref *peer)
1012 {
1013         struct strbuf buf = STRBUF_INIT;
1014         unsigned char sha1[20];
1015
1016         const char *r = resolve_ref_unsafe(peer->name, sha1, 1, NULL);
1017         if (!r)
1018                 return NULL;
1019
1020         if (!prefixcmp(r, "refs/heads/"))
1021                 strbuf_addstr(&buf, "refs/heads/");
1022         else if (!prefixcmp(r, "refs/tags/"))
1023                 strbuf_addstr(&buf, "refs/tags/");
1024         else
1025                 return NULL;
1026
1027         strbuf_addstr(&buf, name);
1028         return strbuf_detach(&buf, NULL);
1029 }
1030
1031 static int match_explicit(struct ref *src, struct ref *dst,
1032                           struct ref ***dst_tail,
1033                           struct refspec *rs)
1034 {
1035         struct ref *matched_src, *matched_dst;
1036         int copy_src;
1037
1038         const char *dst_value = rs->dst;
1039         char *dst_guess;
1040
1041         if (rs->pattern || rs->matching)
1042                 return 0;
1043
1044         matched_src = matched_dst = NULL;
1045         switch (count_refspec_match(rs->src, src, &matched_src)) {
1046         case 1:
1047                 copy_src = 1;
1048                 break;
1049         case 0:
1050                 /* The source could be in the get_sha1() format
1051                  * not a reference name.  :refs/other is a
1052                  * way to delete 'other' ref at the remote end.
1053                  */
1054                 matched_src = try_explicit_object_name(rs->src);
1055                 if (!matched_src)
1056                         return error("src refspec %s does not match any.", rs->src);
1057                 copy_src = 0;
1058                 break;
1059         default:
1060                 return error("src refspec %s matches more than one.", rs->src);
1061         }
1062
1063         if (!dst_value) {
1064                 unsigned char sha1[20];
1065                 int flag;
1066
1067                 dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag);
1068                 if (!dst_value ||
1069                     ((flag & REF_ISSYMREF) &&
1070                      prefixcmp(dst_value, "refs/heads/")))
1071                         die("%s cannot be resolved to branch.",
1072                             matched_src->name);
1073         }
1074
1075         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1076         case 1:
1077                 break;
1078         case 0:
1079                 if (!memcmp(dst_value, "refs/", 5))
1080                         matched_dst = make_linked_ref(dst_value, dst_tail);
1081                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1082                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1083                 else
1084                         error("unable to push to unqualified destination: %s\n"
1085                               "The destination refspec neither matches an "
1086                               "existing ref on the remote nor\n"
1087                               "begins with refs/, and we are unable to "
1088                               "guess a prefix based on the source ref.",
1089                               dst_value);
1090                 break;
1091         default:
1092                 matched_dst = NULL;
1093                 error("dst refspec %s matches more than one.",
1094                       dst_value);
1095                 break;
1096         }
1097         if (!matched_dst)
1098                 return -1;
1099         if (matched_dst->peer_ref)
1100                 return error("dst ref %s receives from more than one src.",
1101                       matched_dst->name);
1102         else {
1103                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1104                 matched_dst->force = rs->force;
1105         }
1106         return 0;
1107 }
1108
1109 static int match_explicit_refs(struct ref *src, struct ref *dst,
1110                                struct ref ***dst_tail, struct refspec *rs,
1111                                int rs_nr)
1112 {
1113         int i, errs;
1114         for (i = errs = 0; i < rs_nr; i++)
1115                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1116         return errs;
1117 }
1118
1119 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1120                 int send_mirror, int direction, const struct refspec **ret_pat)
1121 {
1122         const struct refspec *pat;
1123         char *name;
1124         int i;
1125         int matching_refs = -1;
1126         for (i = 0; i < rs_nr; i++) {
1127                 if (rs[i].matching &&
1128                     (matching_refs == -1 || rs[i].force)) {
1129                         matching_refs = i;
1130                         continue;
1131                 }
1132
1133                 if (rs[i].pattern) {
1134                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1135                         int match;
1136                         if (direction == FROM_SRC)
1137                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1138                         else
1139                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1140                         if (match) {
1141                                 matching_refs = i;
1142                                 break;
1143                         }
1144                 }
1145         }
1146         if (matching_refs == -1)
1147                 return NULL;
1148
1149         pat = rs + matching_refs;
1150         if (pat->matching) {
1151                 /*
1152                  * "matching refs"; traditionally we pushed everything
1153                  * including refs outside refs/heads/ hierarchy, but
1154                  * that does not make much sense these days.
1155                  */
1156                 if (!send_mirror && prefixcmp(ref->name, "refs/heads/"))
1157                         return NULL;
1158                 name = xstrdup(ref->name);
1159         }
1160         if (ret_pat)
1161                 *ret_pat = pat;
1162         return name;
1163 }
1164
1165 static struct ref **tail_ref(struct ref **head)
1166 {
1167         struct ref **tail = head;
1168         while (*tail)
1169                 tail = &((*tail)->next);
1170         return tail;
1171 }
1172
1173 /*
1174  * Given the set of refs the local repository has, the set of refs the
1175  * remote repository has, and the refspec used for push, determine
1176  * what remote refs we will update and with what value by setting
1177  * peer_ref (which object is being pushed) and force (if the push is
1178  * forced) in elements of "dst". The function may add new elements to
1179  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1180  */
1181 int match_push_refs(struct ref *src, struct ref **dst,
1182                     int nr_refspec, const char **refspec, int flags)
1183 {
1184         struct refspec *rs;
1185         int send_all = flags & MATCH_REFS_ALL;
1186         int send_mirror = flags & MATCH_REFS_MIRROR;
1187         int send_prune = flags & MATCH_REFS_PRUNE;
1188         int errs;
1189         static const char *default_refspec[] = { ":", NULL };
1190         struct ref *ref, **dst_tail = tail_ref(dst);
1191
1192         if (!nr_refspec) {
1193                 nr_refspec = 1;
1194                 refspec = default_refspec;
1195         }
1196         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1197         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1198
1199         /* pick the remainder */
1200         for (ref = src; ref; ref = ref->next) {
1201                 struct ref *dst_peer;
1202                 const struct refspec *pat = NULL;
1203                 char *dst_name;
1204
1205                 if (ref->peer_ref)
1206                         continue;
1207
1208                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1209                 if (!dst_name)
1210                         continue;
1211
1212                 dst_peer = find_ref_by_name(*dst, dst_name);
1213                 if (dst_peer) {
1214                         if (dst_peer->peer_ref)
1215                                 /* We're already sending something to this ref. */
1216                                 goto free_name;
1217                 } else {
1218                         if (pat->matching && !(send_all || send_mirror))
1219                                 /*
1220                                  * Remote doesn't have it, and we have no
1221                                  * explicit pattern, and we don't have
1222                                  * --all nor --mirror.
1223                                  */
1224                                 goto free_name;
1225
1226                         /* Create a new one and link it */
1227                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1228                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1229                 }
1230                 dst_peer->peer_ref = copy_ref(ref);
1231                 dst_peer->force = pat->force;
1232         free_name:
1233                 free(dst_name);
1234         }
1235         if (send_prune) {
1236                 /* check for missing refs on the remote */
1237                 for (ref = *dst; ref; ref = ref->next) {
1238                         char *src_name;
1239
1240                         if (ref->peer_ref)
1241                                 /* We're already sending something to this ref. */
1242                                 continue;
1243
1244                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1245                         if (src_name) {
1246                                 if (!find_ref_by_name(src, src_name))
1247                                         ref->peer_ref = alloc_delete_ref();
1248                                 free(src_name);
1249                         }
1250                 }
1251         }
1252         if (errs)
1253                 return -1;
1254         return 0;
1255 }
1256
1257 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1258         int force_update)
1259 {
1260         struct ref *ref;
1261
1262         for (ref = remote_refs; ref; ref = ref->next) {
1263                 if (ref->peer_ref)
1264                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1265                 else if (!send_mirror)
1266                         continue;
1267
1268                 ref->deletion = is_null_sha1(ref->new_sha1);
1269                 if (!ref->deletion &&
1270                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1271                         ref->status = REF_STATUS_UPTODATE;
1272                         continue;
1273                 }
1274
1275                 /* This part determines what can overwrite what.
1276                  * The rules are:
1277                  *
1278                  * (0) you can always use --force or +A:B notation to
1279                  *     selectively force individual ref pairs.
1280                  *
1281                  * (1) if the old thing does not exist, it is OK.
1282                  *
1283                  * (2) if you do not have the old thing, you are not allowed
1284                  *     to overwrite it; you would not know what you are losing
1285                  *     otherwise.
1286                  *
1287                  * (3) if both new and old are commit-ish, and new is a
1288                  *     descendant of old, it is OK.
1289                  *
1290                  * (4) regardless of all of the above, removing :B is
1291                  *     always allowed.
1292                  */
1293
1294                 ref->nonfastforward =
1295                         !ref->deletion &&
1296                         !is_null_sha1(ref->old_sha1) &&
1297                         (!has_sha1_file(ref->old_sha1)
1298                           || !ref_newer(ref->new_sha1, ref->old_sha1));
1299
1300                 if (ref->nonfastforward && !ref->force && !force_update) {
1301                         ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
1302                         continue;
1303                 }
1304         }
1305 }
1306
1307 struct branch *branch_get(const char *name)
1308 {
1309         struct branch *ret;
1310
1311         read_config();
1312         if (!name || !*name || !strcmp(name, "HEAD"))
1313                 ret = current_branch;
1314         else
1315                 ret = make_branch(name, 0);
1316         if (ret && ret->remote_name) {
1317                 ret->remote = remote_get(ret->remote_name);
1318                 if (ret->merge_nr) {
1319                         int i;
1320                         ret->merge = xcalloc(sizeof(*ret->merge),
1321                                              ret->merge_nr);
1322                         for (i = 0; i < ret->merge_nr; i++) {
1323                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1324                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1325                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1326                                     && !strcmp(ret->remote_name, "."))
1327                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1328                         }
1329                 }
1330         }
1331         return ret;
1332 }
1333
1334 int branch_has_merge_config(struct branch *branch)
1335 {
1336         return branch && !!branch->merge;
1337 }
1338
1339 int branch_merge_matches(struct branch *branch,
1340                                  int i,
1341                                  const char *refname)
1342 {
1343         if (!branch || i < 0 || i >= branch->merge_nr)
1344                 return 0;
1345         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1346 }
1347
1348 static struct ref *get_expanded_map(const struct ref *remote_refs,
1349                                     const struct refspec *refspec)
1350 {
1351         const struct ref *ref;
1352         struct ref *ret = NULL;
1353         struct ref **tail = &ret;
1354
1355         char *expn_name;
1356
1357         for (ref = remote_refs; ref; ref = ref->next) {
1358                 if (strchr(ref->name, '^'))
1359                         continue; /* a dereference item */
1360                 if (match_name_with_pattern(refspec->src, ref->name,
1361                                             refspec->dst, &expn_name)) {
1362                         struct ref *cpy = copy_ref(ref);
1363
1364                         cpy->peer_ref = alloc_ref(expn_name);
1365                         free(expn_name);
1366                         if (refspec->force)
1367                                 cpy->peer_ref->force = 1;
1368                         *tail = cpy;
1369                         tail = &cpy->next;
1370                 }
1371         }
1372
1373         return ret;
1374 }
1375
1376 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1377 {
1378         const struct ref *ref;
1379         for (ref = refs; ref; ref = ref->next) {
1380                 if (refname_match(name, ref->name, ref_fetch_rules))
1381                         return ref;
1382         }
1383         return NULL;
1384 }
1385
1386 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1387 {
1388         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1389
1390         if (!ref)
1391                 return NULL;
1392
1393         return copy_ref(ref);
1394 }
1395
1396 static struct ref *get_local_ref(const char *name)
1397 {
1398         if (!name || name[0] == '\0')
1399                 return NULL;
1400
1401         if (!prefixcmp(name, "refs/"))
1402                 return alloc_ref(name);
1403
1404         if (!prefixcmp(name, "heads/") ||
1405             !prefixcmp(name, "tags/") ||
1406             !prefixcmp(name, "remotes/"))
1407                 return alloc_ref_with_prefix("refs/", 5, name);
1408
1409         return alloc_ref_with_prefix("refs/heads/", 11, name);
1410 }
1411
1412 int get_fetch_map(const struct ref *remote_refs,
1413                   const struct refspec *refspec,
1414                   struct ref ***tail,
1415                   int missing_ok)
1416 {
1417         struct ref *ref_map, **rmp;
1418
1419         if (refspec->pattern) {
1420                 ref_map = get_expanded_map(remote_refs, refspec);
1421         } else {
1422                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1423
1424                 ref_map = get_remote_ref(remote_refs, name);
1425                 if (!missing_ok && !ref_map)
1426                         die("Couldn't find remote ref %s", name);
1427                 if (ref_map) {
1428                         ref_map->peer_ref = get_local_ref(refspec->dst);
1429                         if (ref_map->peer_ref && refspec->force)
1430                                 ref_map->peer_ref->force = 1;
1431                 }
1432         }
1433
1434         for (rmp = &ref_map; *rmp; ) {
1435                 if ((*rmp)->peer_ref) {
1436                         if (check_refname_format((*rmp)->peer_ref->name + 5,
1437                                 REFNAME_ALLOW_ONELEVEL)) {
1438                                 struct ref *ignore = *rmp;
1439                                 error("* Ignoring funny ref '%s' locally",
1440                                       (*rmp)->peer_ref->name);
1441                                 *rmp = (*rmp)->next;
1442                                 free(ignore->peer_ref);
1443                                 free(ignore);
1444                                 continue;
1445                         }
1446                 }
1447                 rmp = &((*rmp)->next);
1448         }
1449
1450         if (ref_map)
1451                 tail_link_ref(ref_map, tail);
1452
1453         return 0;
1454 }
1455
1456 int resolve_remote_symref(struct ref *ref, struct ref *list)
1457 {
1458         if (!ref->symref)
1459                 return 0;
1460         for (; list; list = list->next)
1461                 if (!strcmp(ref->symref, list->name)) {
1462                         hashcpy(ref->old_sha1, list->old_sha1);
1463                         return 0;
1464                 }
1465         return 1;
1466 }
1467
1468 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1469 {
1470         while (list) {
1471                 struct commit_list *temp = list;
1472                 temp->item->object.flags &= ~mark;
1473                 list = temp->next;
1474                 free(temp);
1475         }
1476 }
1477
1478 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1479 {
1480         struct object *o;
1481         struct commit *old, *new;
1482         struct commit_list *list, *used;
1483         int found = 0;
1484
1485         /* Both new and old must be commit-ish and new is descendant of
1486          * old.  Otherwise we require --force.
1487          */
1488         o = deref_tag(parse_object(old_sha1), NULL, 0);
1489         if (!o || o->type != OBJ_COMMIT)
1490                 return 0;
1491         old = (struct commit *) o;
1492
1493         o = deref_tag(parse_object(new_sha1), NULL, 0);
1494         if (!o || o->type != OBJ_COMMIT)
1495                 return 0;
1496         new = (struct commit *) o;
1497
1498         if (parse_commit(new) < 0)
1499                 return 0;
1500
1501         used = list = NULL;
1502         commit_list_insert(new, &list);
1503         while (list) {
1504                 new = pop_most_recent_commit(&list, TMP_MARK);
1505                 commit_list_insert(new, &used);
1506                 if (new == old) {
1507                         found = 1;
1508                         break;
1509                 }
1510         }
1511         unmark_and_free(list, TMP_MARK);
1512         unmark_and_free(used, TMP_MARK);
1513         return found;
1514 }
1515
1516 /*
1517  * Return true if there is anything to report, otherwise false.
1518  */
1519 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1520 {
1521         unsigned char sha1[20];
1522         struct commit *ours, *theirs;
1523         char symmetric[84];
1524         struct rev_info revs;
1525         const char *rev_argv[10], *base;
1526         int rev_argc;
1527
1528         /*
1529          * Nothing to report unless we are marked to build on top of
1530          * somebody else.
1531          */
1532         if (!branch ||
1533             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1534                 return 0;
1535
1536         /*
1537          * If what we used to build on no longer exists, there is
1538          * nothing to report.
1539          */
1540         base = branch->merge[0]->dst;
1541         if (read_ref(base, sha1))
1542                 return 0;
1543         theirs = lookup_commit_reference(sha1);
1544         if (!theirs)
1545                 return 0;
1546
1547         if (read_ref(branch->refname, sha1))
1548                 return 0;
1549         ours = lookup_commit_reference(sha1);
1550         if (!ours)
1551                 return 0;
1552
1553         /* are we the same? */
1554         if (theirs == ours)
1555                 return 0;
1556
1557         /* Run "rev-list --left-right ours...theirs" internally... */
1558         rev_argc = 0;
1559         rev_argv[rev_argc++] = NULL;
1560         rev_argv[rev_argc++] = "--left-right";
1561         rev_argv[rev_argc++] = symmetric;
1562         rev_argv[rev_argc++] = "--";
1563         rev_argv[rev_argc] = NULL;
1564
1565         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1566         strcpy(symmetric + 40, "...");
1567         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1568
1569         init_revisions(&revs, NULL);
1570         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1571         prepare_revision_walk(&revs);
1572
1573         /* ... and count the commits on each side. */
1574         *num_ours = 0;
1575         *num_theirs = 0;
1576         while (1) {
1577                 struct commit *c = get_revision(&revs);
1578                 if (!c)
1579                         break;
1580                 if (c->object.flags & SYMMETRIC_LEFT)
1581                         (*num_ours)++;
1582                 else
1583                         (*num_theirs)++;
1584         }
1585
1586         /* clear object flags smudged by the above traversal */
1587         clear_commit_marks(ours, ALL_REV_FLAGS);
1588         clear_commit_marks(theirs, ALL_REV_FLAGS);
1589         return 1;
1590 }
1591
1592 /*
1593  * Return true when there is anything to report, otherwise false.
1594  */
1595 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1596 {
1597         int num_ours, num_theirs;
1598         const char *base;
1599
1600         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1601                 return 0;
1602
1603         base = branch->merge[0]->dst;
1604         base = shorten_unambiguous_ref(base, 0);
1605         if (!num_theirs)
1606                 strbuf_addf(sb,
1607                         Q_("Your branch is ahead of '%s' by %d commit.\n",
1608                            "Your branch is ahead of '%s' by %d commits.\n",
1609                            num_ours),
1610                         base, num_ours);
1611         else if (!num_ours)
1612                 strbuf_addf(sb,
1613                         Q_("Your branch is behind '%s' by %d commit, "
1614                                "and can be fast-forwarded.\n",
1615                            "Your branch is behind '%s' by %d commits, "
1616                                "and can be fast-forwarded.\n",
1617                            num_theirs),
1618                         base, num_theirs);
1619         else
1620                 strbuf_addf(sb,
1621                         Q_("Your branch and '%s' have diverged,\n"
1622                                "and have %d and %d different commit each, "
1623                                "respectively.\n",
1624                            "Your branch and '%s' have diverged,\n"
1625                                "and have %d and %d different commits each, "
1626                                "respectively.\n",
1627                            num_theirs),
1628                         base, num_ours, num_theirs);
1629         return 1;
1630 }
1631
1632 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1633 {
1634         struct ref ***local_tail = cb_data;
1635         struct ref *ref;
1636         int len;
1637
1638         /* we already know it starts with refs/ to get here */
1639         if (check_refname_format(refname + 5, 0))
1640                 return 0;
1641
1642         len = strlen(refname) + 1;
1643         ref = xcalloc(1, sizeof(*ref) + len);
1644         hashcpy(ref->new_sha1, sha1);
1645         memcpy(ref->name, refname, len);
1646         **local_tail = ref;
1647         *local_tail = &ref->next;
1648         return 0;
1649 }
1650
1651 struct ref *get_local_heads(void)
1652 {
1653         struct ref *local_refs = NULL, **local_tail = &local_refs;
1654         for_each_ref(one_local_ref, &local_tail);
1655         return local_refs;
1656 }
1657
1658 struct ref *guess_remote_head(const struct ref *head,
1659                               const struct ref *refs,
1660                               int all)
1661 {
1662         const struct ref *r;
1663         struct ref *list = NULL;
1664         struct ref **tail = &list;
1665
1666         if (!head)
1667                 return NULL;
1668
1669         /*
1670          * Some transports support directly peeking at
1671          * where HEAD points; if that is the case, then
1672          * we don't have to guess.
1673          */
1674         if (head->symref)
1675                 return copy_ref(find_ref_by_name(refs, head->symref));
1676
1677         /* If refs/heads/master could be right, it is. */
1678         if (!all) {
1679                 r = find_ref_by_name(refs, "refs/heads/master");
1680                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1681                         return copy_ref(r);
1682         }
1683
1684         /* Look for another ref that points there */
1685         for (r = refs; r; r = r->next) {
1686                 if (r != head &&
1687                     !prefixcmp(r->name, "refs/heads/") &&
1688                     !hashcmp(r->old_sha1, head->old_sha1)) {
1689                         *tail = copy_ref(r);
1690                         tail = &((*tail)->next);
1691                         if (!all)
1692                                 break;
1693                 }
1694         }
1695
1696         return list;
1697 }
1698
1699 struct stale_heads_info {
1700         struct string_list *ref_names;
1701         struct ref **stale_refs_tail;
1702         struct refspec *refs;
1703         int ref_count;
1704 };
1705
1706 static int get_stale_heads_cb(const char *refname,
1707         const unsigned char *sha1, int flags, void *cb_data)
1708 {
1709         struct stale_heads_info *info = cb_data;
1710         struct refspec query;
1711         memset(&query, 0, sizeof(struct refspec));
1712         query.dst = (char *)refname;
1713
1714         if (query_refspecs(info->refs, info->ref_count, &query))
1715                 return 0; /* No matches */
1716
1717         /*
1718          * If we did find a suitable refspec and it's not a symref and
1719          * it's not in the list of refs that currently exist in that
1720          * remote we consider it to be stale.
1721          */
1722         if (!((flags & REF_ISSYMREF) ||
1723               string_list_has_string(info->ref_names, query.src))) {
1724                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1725                 hashcpy(ref->new_sha1, sha1);
1726         }
1727
1728         free(query.src);
1729         return 0;
1730 }
1731
1732 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
1733 {
1734         struct ref *ref, *stale_refs = NULL;
1735         struct string_list ref_names = STRING_LIST_INIT_NODUP;
1736         struct stale_heads_info info;
1737         info.ref_names = &ref_names;
1738         info.stale_refs_tail = &stale_refs;
1739         info.refs = refs;
1740         info.ref_count = ref_count;
1741         for (ref = fetch_map; ref; ref = ref->next)
1742                 string_list_append(&ref_names, ref->name);
1743         sort_string_list(&ref_names);
1744         for_each_ref(get_stale_heads_cb, &info);
1745         string_list_clear(&ref_names, 0);
1746         return stale_refs;
1747 }