git.oblomov.eu Git - git/blob - 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 #include "mergesort.h"
  11
  12 enum map_direction { FROM_SRC, FROM_DST };
  13
  14 static struct refspec s_tag_refspec = {
  15         0,
  16         1,
  17         0,
  18         "refs/tags/*",
  19         "refs/tags/*"
  20 };
  21
  22 const struct refspec *tag_refspec = &s_tag_refspec;
  23
  24 struct counted_string {
  25         size_t len;
  26         const char *s;
  27 };
  28 struct rewrite {
  29         const char *base;
  30         size_t baselen;
  31         struct counted_string *instead_of;
  32         int instead_of_nr;
  33         int instead_of_alloc;
  34 };
  35 struct rewrites {
  36         struct rewrite **rewrite;
  37         int rewrite_alloc;
  38         int rewrite_nr;
  39 };
  40
  41 static struct remote **remotes;
  42 static int remotes_alloc;
  43 static int remotes_nr;
  44
  45 static struct branch **branches;
  46 static int branches_alloc;
  47 static int branches_nr;
  48
  49 static struct branch *current_branch;
  50 static const char *default_remote_name;
  51 static int explicit_default_remote_name;
  52
  53 static struct rewrites rewrites;
  54 static struct rewrites rewrites_push;
  55
  56 #define BUF_SIZE (2048)
  57 static char buffer[BUF_SIZE];
  58
  59 static int valid_remote(const struct remote *remote)
  60 {
  61         return (!!remote->url) || (!!remote->foreign_vcs);
  62 }
  63
  64 static const char *alias_url(const char *url, struct rewrites *r)
  65 {
  66         int i, j;
  67         char *ret;
  68         struct counted_string *longest;
  69         int longest_i;
  70
  71         longest = NULL;
  72         longest_i = -1;
  73         for (i = 0; i < r->rewrite_nr; i++) {
  74                 if (!r->rewrite[i])
  75                         continue;
  76                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  77                         if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  78                             (!longest ||
  79                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  80                                 longest = &(r->rewrite[i]->instead_of[j]);
  81                                 longest_i = i;
  82                         }
  83                 }
  84         }
  85         if (!longest)
  86                 return url;
  87
  88         ret = xmalloc(r->rewrite[longest_i]->baselen +
  89                      (strlen(url) - longest->len) + 1);
  90         strcpy(ret, r->rewrite[longest_i]->base);
  91         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  92         return ret;
  93 }
  94
  95 static void add_push_refspec(struct remote *remote, const char *ref)
  96 {
  97         ALLOC_GROW(remote->push_refspec,
  98                    remote->push_refspec_nr + 1,
  99                    remote->push_refspec_alloc);
 100         remote->push_refspec[remote->push_refspec_nr++] = ref;
 101 }
 102
 103 static void add_fetch_refspec(struct remote *remote, const char *ref)
 104 {
 105         ALLOC_GROW(remote->fetch_refspec,
 106                    remote->fetch_refspec_nr + 1,
 107                    remote->fetch_refspec_alloc);
 108         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 109 }
 110
 111 static void add_url(struct remote *remote, const char *url)
 112 {
 113         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 114         remote->url[remote->url_nr++] = url;
 115 }
 116
 117 static void add_pushurl(struct remote *remote, const char *pushurl)
 118 {
 119         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 120         remote->pushurl[remote->pushurl_nr++] = pushurl;
 121 }
 122
 123 static void add_pushurl_alias(struct remote *remote, const char *url)
 124 {
 125         const char *pushurl = alias_url(url, &rewrites_push);
 126         if (pushurl != url)
 127                 add_pushurl(remote, pushurl);
 128 }
 129
 130 static void add_url_alias(struct remote *remote, const char *url)
 131 {
 132         add_url(remote, alias_url(url, &rewrites));
 133         add_pushurl_alias(remote, url);
 134 }
 135
 136 static struct remote *make_remote(const char *name, int len)
 137 {
 138         struct remote *ret;
 139         int i;
 140
 141         for (i = 0; i < remotes_nr; i++) {
 142                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 143                            !remotes[i]->name[len]) :
 144                     !strcmp(name, remotes[i]->name))
 145                         return remotes[i];
 146         }
 147
 148         ret = xcalloc(1, sizeof(struct remote));
 149         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 150         remotes[remotes_nr++] = ret;
 151         if (len)
 152                 ret->name = xstrndup(name, len);
 153         else
 154                 ret->name = xstrdup(name);
 155         return ret;
 156 }
 157
 158 static void add_merge(struct branch *branch, const char *name)
 159 {
 160         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 161                    branch->merge_alloc);
 162         branch->merge_name[branch->merge_nr++] = name;
 163 }
 164
 165 static struct branch *make_branch(const char *name, int len)
 166 {
 167         struct branch *ret;
 168         int i;
 169         char *refname;
 170
 171         for (i = 0; i < branches_nr; i++) {
 172                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 173                            !branches[i]->name[len]) :
 174                     !strcmp(name, branches[i]->name))
 175                         return branches[i];
 176         }
 177
 178         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 179         ret = xcalloc(1, sizeof(struct branch));
 180         branches[branches_nr++] = ret;
 181         if (len)
 182                 ret->name = xstrndup(name, len);
 183         else
 184                 ret->name = xstrdup(name);
 185         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 186         strcpy(refname, "refs/heads/");
 187         strcpy(refname + strlen("refs/heads/"), ret->name);
 188         ret->refname = refname;
 189
 190         return ret;
 191 }
 192
 193 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 194 {
 195         struct rewrite *ret;
 196         int i;
 197
 198         for (i = 0; i < r->rewrite_nr; i++) {
 199                 if (len
 200                     ? (len == r->rewrite[i]->baselen &&
 201                        !strncmp(base, r->rewrite[i]->base, len))
 202                     : !strcmp(base, r->rewrite[i]->base))
 203                         return r->rewrite[i];
 204         }
 205
 206         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 207         ret = xcalloc(1, sizeof(struct rewrite));
 208         r->rewrite[r->rewrite_nr++] = ret;
 209         if (len) {
 210                 ret->base = xstrndup(base, len);
 211                 ret->baselen = len;
 212         }
 213         else {
 214                 ret->base = xstrdup(base);
 215                 ret->baselen = strlen(base);
 216         }
 217         return ret;
 218 }
 219
 220 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 221 {
 222         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 223         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 224         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 225         rewrite->instead_of_nr++;
 226 }
 227
 228 static void read_remotes_file(struct remote *remote)
 229 {
 230         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 231
 232         if (!f)
 233                 return;
 234         remote->origin = REMOTE_REMOTES;
 235         while (fgets(buffer, BUF_SIZE, f)) {
 236                 int value_list;
 237                 char *s, *p;
 238
 239                 if (!prefixcmp(buffer, "URL:")) {
 240                         value_list = 0;
 241                         s = buffer + 4;
 242                 } else if (!prefixcmp(buffer, "Push:")) {
 243                         value_list = 1;
 244                         s = buffer + 5;
 245                 } else if (!prefixcmp(buffer, "Pull:")) {
 246                         value_list = 2;
 247                         s = buffer + 5;
 248                 } else
 249                         continue;
 250
 251                 while (isspace(*s))
 252                         s++;
 253                 if (!*s)
 254                         continue;
 255
 256                 p = s + strlen(s);
 257                 while (isspace(p[-1]))
 258                         *--p = 0;
 259
 260                 switch (value_list) {
 261                 case 0:
 262                         add_url_alias(remote, xstrdup(s));
 263                         break;
 264                 case 1:
 265                         add_push_refspec(remote, xstrdup(s));
 266                         break;
 267                 case 2:
 268                         add_fetch_refspec(remote, xstrdup(s));
 269                         break;
 270                 }
 271         }
 272         fclose(f);
 273 }
 274
 275 static void read_branches_file(struct remote *remote)
 276 {
 277         const char *slash = strchr(remote->name, '/');
 278         char *frag;
 279         struct strbuf branch = STRBUF_INIT;
 280         int n = slash ? slash - remote->name : 1000;
 281         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 282         char *s, *p;
 283         int len;
 284
 285         if (!f)
 286                 return;
 287         s = fgets(buffer, BUF_SIZE, f);
 288         fclose(f);
 289         if (!s)
 290                 return;
 291         while (isspace(*s))
 292                 s++;
 293         if (!*s)
 294                 return;
 295         remote->origin = REMOTE_BRANCHES;
 296         p = s + strlen(s);
 297         while (isspace(p[-1]))
 298                 *--p = 0;
 299         len = p - s;
 300         if (slash)
 301                 len += strlen(slash);
 302         p = xmalloc(len + 1);
 303         strcpy(p, s);
 304         if (slash)
 305                 strcat(p, slash);
 306
 307         /*
 308          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 309          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 310          * the partial URL obtained from the branches file plus
 311          * "/netdev-2.6" and does not store it in any tracking ref.
 312          * #branch specifier in the file is ignored.
 313          *
 314          * Otherwise, the branches file would have URL and optionally
 315          * #branch specified.  The "master" (or specified) branch is
 316          * fetched and stored in the local branch of the same name.
 317          */
 318         frag = strchr(p, '#');
 319         if (frag) {
 320                 *(frag++) = '\0';
 321                 strbuf_addf(&branch, "refs/heads/%s", frag);
 322         } else
 323                 strbuf_addstr(&branch, "refs/heads/master");
 324         if (!slash) {
 325                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 326         } else {
 327                 strbuf_reset(&branch);
 328                 strbuf_addstr(&branch, "HEAD:");
 329         }
 330         add_url_alias(remote, p);
 331         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 332         /*
 333          * Cogito compatible push: push current HEAD to remote #branch
 334          * (master if missing)
 335          */
 336         strbuf_init(&branch, 0);
 337         strbuf_addstr(&branch, "HEAD");
 338         if (frag)
 339                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 340         else
 341                 strbuf_addstr(&branch, ":refs/heads/master");
 342         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 343         remote->fetch_tags = 1; /* always auto-follow */
 344 }
 345
 346 static int handle_config(const char *key, const char *value, void *cb)
 347 {
 348         const char *name;
 349         const char *subkey;
 350         struct remote *remote;
 351         struct branch *branch;
 352         if (!prefixcmp(key, "branch.")) {
 353                 name = key + 7;
 354                 subkey = strrchr(name, '.');
 355                 if (!subkey)
 356                         return 0;
 357                 branch = make_branch(name, subkey - name);
 358                 if (!strcmp(subkey, ".remote")) {
 359                         if (!value)
 360                                 return config_error_nonbool(key);
 361                         branch->remote_name = xstrdup(value);
 362                         if (branch == current_branch) {
 363                                 default_remote_name = branch->remote_name;
 364                                 explicit_default_remote_name = 1;
 365                         }
 366                 } else if (!strcmp(subkey, ".merge")) {
 367                         if (!value)
 368                                 return config_error_nonbool(key);
 369                         add_merge(branch, xstrdup(value));
 370                 }
 371                 return 0;
 372         }
 373         if (!prefixcmp(key, "url.")) {
 374                 struct rewrite *rewrite;
 375                 name = key + 4;
 376                 subkey = strrchr(name, '.');
 377                 if (!subkey)
 378                         return 0;
 379                 if (!strcmp(subkey, ".insteadof")) {
 380                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 381                         if (!value)
 382                                 return config_error_nonbool(key);
 383                         add_instead_of(rewrite, xstrdup(value));
 384                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 385                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 386                         if (!value)
 387                                 return config_error_nonbool(key);
 388                         add_instead_of(rewrite, xstrdup(value));
 389                 }
 390         }
 391         if (prefixcmp(key,  "remote."))
 392                 return 0;
 393         name = key + 7;
 394         if (*name == '/') {
 395                 warning("Config remote shorthand cannot begin with '/': %s",
 396                         name);
 397                 return 0;
 398         }
 399         subkey = strrchr(name, '.');
 400         if (!subkey)
 401                 return 0;
 402         remote = make_remote(name, subkey - name);
 403         remote->origin = REMOTE_CONFIG;
 404         if (!strcmp(subkey, ".mirror"))
 405                 remote->mirror = git_config_bool(key, value);
 406         else if (!strcmp(subkey, ".skipdefaultupdate"))
 407                 remote->skip_default_update = git_config_bool(key, value);
 408         else if (!strcmp(subkey, ".skipfetchall"))
 409                 remote->skip_default_update = git_config_bool(key, value);
 410         else if (!strcmp(subkey, ".url")) {
 411                 const char *v;
 412                 if (git_config_string(&v, key, value))
 413                         return -1;
 414                 add_url(remote, v);
 415         } else if (!strcmp(subkey, ".pushurl")) {
 416                 const char *v;
 417                 if (git_config_string(&v, key, value))
 418                         return -1;
 419                 add_pushurl(remote, v);
 420         } else if (!strcmp(subkey, ".push")) {
 421                 const char *v;
 422                 if (git_config_string(&v, key, value))
 423                         return -1;
 424                 add_push_refspec(remote, v);
 425         } else if (!strcmp(subkey, ".fetch")) {
 426                 const char *v;
 427                 if (git_config_string(&v, key, value))
 428                         return -1;
 429                 add_fetch_refspec(remote, v);
 430         } else if (!strcmp(subkey, ".receivepack")) {
 431                 const char *v;
 432                 if (git_config_string(&v, key, value))
 433                         return -1;
 434                 if (!remote->receivepack)
 435                         remote->receivepack = v;
 436                 else
 437                         error("more than one receivepack given, using the first");
 438         } else if (!strcmp(subkey, ".uploadpack")) {
 439                 const char *v;
 440                 if (git_config_string(&v, key, value))
 441                         return -1;
 442                 if (!remote->uploadpack)
 443                         remote->uploadpack = v;
 444                 else
 445                         error("more than one uploadpack given, using the first");
 446         } else if (!strcmp(subkey, ".tagopt")) {
 447                 if (!strcmp(value, "--no-tags"))
 448                         remote->fetch_tags = -1;
 449                 else if (!strcmp(value, "--tags"))
 450                         remote->fetch_tags = 2;
 451         } else if (!strcmp(subkey, ".proxy")) {
 452                 return git_config_string((const char **)&remote->http_proxy,
 453                                          key, value);
 454         } else if (!strcmp(subkey, ".vcs")) {
 455                 return git_config_string(&remote->foreign_vcs, key, value);
 456         }
 457         return 0;
 458 }
 459
 460 static void alias_all_urls(void)
 461 {
 462         int i, j;
 463         for (i = 0; i < remotes_nr; i++) {
 464                 int add_pushurl_aliases;
 465                 if (!remotes[i])
 466                         continue;
 467                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 468                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 469                 }
 470                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 471                 for (j = 0; j < remotes[i]->url_nr; j++) {
 472                         if (add_pushurl_aliases)
 473                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 474                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 475                 }
 476         }
 477 }
 478
 479 static void read_config(void)
 480 {
 481         unsigned char sha1[20];
 482         const char *head_ref;
 483         int flag;
 484         if (default_remote_name) /* did this already */
 485                 return;
 486         default_remote_name = xstrdup("origin");
 487         current_branch = NULL;
 488         head_ref = resolve_ref_unsafe("HEAD", sha1, 0, &flag);
 489         if (head_ref && (flag & REF_ISSYMREF) &&
 490             !prefixcmp(head_ref, "refs/heads/")) {
 491                 current_branch =
 492                         make_branch(head_ref + strlen("refs/heads/"), 0);
 493         }
 494         git_config(handle_config, NULL);
 495         alias_all_urls();
 496 }
 497
 498 /*
 499  * This function frees a refspec array.
 500  * Warning: code paths should be checked to ensure that the src
 501  *          and dst pointers are always freeable pointers as well
 502  *          as the refspec pointer itself.
 503  */
 504 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 505 {
 506         int i;
 507
 508         if (!refspec)
 509                 return;
 510
 511         for (i = 0; i < nr_refspec; i++) {
 512                 free(refspec[i].src);
 513                 free(refspec[i].dst);
 514         }
 515         free(refspec);
 516 }
 517
 518 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 519 {
 520         int i;
 521         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 522
 523         for (i = 0; i < nr_refspec; i++) {
 524                 size_t llen;
 525                 int is_glob;
 526                 const char *lhs, *rhs;
 527                 int flags;
 528
 529                 is_glob = 0;
 530
 531                 lhs = refspec[i];
 532                 if (*lhs == '+') {
 533                         rs[i].force = 1;
 534                         lhs++;
 535                 }
 536
 537                 rhs = strrchr(lhs, ':');
 538
 539                 /*
 540                  * Before going on, special case ":" (or "+:") as a refspec
 541                  * for pushing matching refs.
 542                  */
 543                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 544                         rs[i].matching = 1;
 545                         continue;
 546                 }
 547
 548                 if (rhs) {
 549                         size_t rlen = strlen(++rhs);
 550                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 551                         rs[i].dst = xstrndup(rhs, rlen);
 552                 }
 553
 554                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 555                 if (1 <= llen && memchr(lhs, '*', llen)) {
 556                         if ((rhs && !is_glob) || (!rhs && fetch))
 557                                 goto invalid;
 558                         is_glob = 1;
 559                 } else if (rhs && is_glob) {
 560                         goto invalid;
 561                 }
 562
 563                 rs[i].pattern = is_glob;
 564                 rs[i].src = xstrndup(lhs, llen);
 565                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 566
 567                 if (fetch) {
 568                         /* LHS */
 569                         if (!*rs[i].src)
 570                                 ; /* empty is ok; it means "HEAD" */
 571                         else if (!check_refname_format(rs[i].src, flags))
 572                                 ; /* valid looking ref is ok */
 573                         else
 574                                 goto invalid;
 575                         /* RHS */
 576                         if (!rs[i].dst)
 577                                 ; /* missing is ok; it is the same as empty */
 578                         else if (!*rs[i].dst)
 579                                 ; /* empty is ok; it means "do not store" */
 580                         else if (!check_refname_format(rs[i].dst, flags))
 581                                 ; /* valid looking ref is ok */
 582                         else
 583                                 goto invalid;
 584                 } else {
 585                         /*
 586                          * LHS
 587                          * - empty is allowed; it means delete.
 588                          * - when wildcarded, it must be a valid looking ref.
 589                          * - otherwise, it must be an extended SHA-1, but
 590                          *   there is no existing way to validate this.
 591                          */
 592                         if (!*rs[i].src)
 593                                 ; /* empty is ok */
 594                         else if (is_glob) {
 595                                 if (check_refname_format(rs[i].src, flags))
 596                                         goto invalid;
 597                         }
 598                         else
 599                                 ; /* anything goes, for now */
 600                         /*
 601                          * RHS
 602                          * - missing is allowed, but LHS then must be a
 603                          *   valid looking ref.
 604                          * - empty is not allowed.
 605                          * - otherwise it must be a valid looking ref.
 606                          */
 607                         if (!rs[i].dst) {
 608                                 if (check_refname_format(rs[i].src, flags))
 609                                         goto invalid;
 610                         } else if (!*rs[i].dst) {
 611                                 goto invalid;
 612                         } else {
 613                                 if (check_refname_format(rs[i].dst, flags))
 614                                         goto invalid;
 615                         }
 616                 }
 617         }
 618         return rs;
 619
 620  invalid:
 621         if (verify) {
 622                 /*
 623                  * nr_refspec must be greater than zero and i must be valid
 624                  * since it is only possible to reach this point from within
 625                  * the for loop above.
 626                  */
 627                 free_refspecs(rs, i+1);
 628                 return NULL;
 629         }
 630         die("Invalid refspec '%s'", refspec[i]);
 631 }
 632
 633 int valid_fetch_refspec(const char *fetch_refspec_str)
 634 {
 635         struct refspec *refspec;
 636
 637         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 638         free_refspecs(refspec, 1);
 639         return !!refspec;
 640 }
 641
 642 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 643 {
 644         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 645 }
 646
 647 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 648 {
 649         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 650 }
 651
 652 void free_refspec(int nr_refspec, struct refspec *refspec)
 653 {
 654         int i;
 655         for (i = 0; i < nr_refspec; i++) {
 656                 free(refspec[i].src);
 657                 free(refspec[i].dst);
 658         }
 659         free(refspec);
 660 }
 661
 662 static int valid_remote_nick(const char *name)
 663 {
 664         if (!name[0] || is_dot_or_dotdot(name))
 665                 return 0;
 666         return !strchr(name, '/'); /* no slash */
 667 }
 668
 669 struct remote *remote_get(const char *name)
 670 {
 671         struct remote *ret;
 672         int name_given = 0;
 673
 674         read_config();
 675         if (name)
 676                 name_given = 1;
 677         else {
 678                 name = default_remote_name;
 679                 name_given = explicit_default_remote_name;
 680         }
 681
 682         ret = make_remote(name, 0);
 683         if (valid_remote_nick(name)) {
 684                 if (!valid_remote(ret))
 685                         read_remotes_file(ret);
 686                 if (!valid_remote(ret))
 687                         read_branches_file(ret);
 688         }
 689         if (name_given && !valid_remote(ret))
 690                 add_url_alias(ret, name);
 691         if (!valid_remote(ret))
 692                 return NULL;
 693         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 694         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 695         return ret;
 696 }
 697
 698 int remote_is_configured(const char *name)
 699 {
 700         int i;
 701         read_config();
 702
 703         for (i = 0; i < remotes_nr; i++)
 704                 if (!strcmp(name, remotes[i]->name))
 705                         return 1;
 706         return 0;
 707 }
 708
 709 int for_each_remote(each_remote_fn fn, void *priv)
 710 {
 711         int i, result = 0;
 712         read_config();
 713         for (i = 0; i < remotes_nr && !result; i++) {
 714                 struct remote *r = remotes[i];
 715                 if (!r)
 716                         continue;
 717                 if (!r->fetch)
 718                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 719                                                        r->fetch_refspec);
 720                 if (!r->push)
 721                         r->push = parse_push_refspec(r->push_refspec_nr,
 722                                                      r->push_refspec);
 723                 result = fn(r, priv);
 724         }
 725         return result;
 726 }
 727
 728 void ref_remove_duplicates(struct ref *ref_map)
 729 {
 730         struct string_list refs = STRING_LIST_INIT_NODUP;
 731         struct string_list_item *item = NULL;
 732         struct ref *prev = NULL, *next = NULL;
 733         for (; ref_map; prev = ref_map, ref_map = next) {
 734                 next = ref_map->next;
 735                 if (!ref_map->peer_ref)
 736                         continue;
 737
 738                 item = string_list_lookup(&refs, ref_map->peer_ref->name);
 739                 if (item) {
 740                         if (strcmp(((struct ref *)item->util)->name,
 741                                    ref_map->name))
 742                                 die("%s tracks both %s and %s",
 743                                     ref_map->peer_ref->name,
 744                                     ((struct ref *)item->util)->name,
 745                                     ref_map->name);
 746                         prev->next = ref_map->next;
 747                         free(ref_map->peer_ref);
 748                         free(ref_map);
 749                         ref_map = prev; /* skip this; we freed it */
 750                         continue;
 751                 }
 752
 753                 item = string_list_insert(&refs, ref_map->peer_ref->name);
 754                 item->util = ref_map;
 755         }
 756         string_list_clear(&refs, 0);
 757 }
 758
 759 int remote_has_url(struct remote *remote, const char *url)
 760 {
 761         int i;
 762         for (i = 0; i < remote->url_nr; i++) {
 763                 if (!strcmp(remote->url[i], url))
 764                         return 1;
 765         }
 766         return 0;
 767 }
 768
 769 static int match_name_with_pattern(const char *key, const char *name,
 770                                    const char *value, char **result)
 771 {
 772         const char *kstar = strchr(key, '*');
 773         size_t klen;
 774         size_t ksuffixlen;
 775         size_t namelen;
 776         int ret;
 777         if (!kstar)
 778                 die("Key '%s' of pattern had no '*'", key);
 779         klen = kstar - key;
 780         ksuffixlen = strlen(kstar + 1);
 781         namelen = strlen(name);
 782         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 783                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 784         if (ret && value) {
 785                 const char *vstar = strchr(value, '*');
 786                 size_t vlen;
 787                 size_t vsuffixlen;
 788                 if (!vstar)
 789                         die("Value '%s' of pattern has no '*'", value);
 790                 vlen = vstar - value;
 791                 vsuffixlen = strlen(vstar + 1);
 792                 *result = xmalloc(vlen + vsuffixlen +
 793                                   strlen(name) -
 794                                   klen - ksuffixlen + 1);
 795                 strncpy(*result, value, vlen);
 796                 strncpy(*result + vlen,
 797                         name + klen, namelen - klen - ksuffixlen);
 798                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 799                        vstar + 1);
 800         }
 801         return ret;
 802 }
 803
 804 static int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 805 {
 806         int i;
 807         int find_src = !query->src;
 808
 809         if (find_src && !query->dst)
 810                 return error("query_refspecs: need either src or dst");
 811
 812         for (i = 0; i < ref_count; i++) {
 813                 struct refspec *refspec = &refs[i];
 814                 const char *key = find_src ? refspec->dst : refspec->src;
 815                 const char *value = find_src ? refspec->src : refspec->dst;
 816                 const char *needle = find_src ? query->dst : query->src;
 817                 char **result = find_src ? &query->src : &query->dst;
 818
 819                 if (!refspec->dst)
 820                         continue;
 821                 if (refspec->pattern) {
 822                         if (match_name_with_pattern(key, needle, value, result)) {
 823                                 query->force = refspec->force;
 824                                 return 0;
 825                         }
 826                 } else if (!strcmp(needle, key)) {
 827                         *result = xstrdup(value);
 828                         query->force = refspec->force;
 829                         return 0;
 830                 }
 831         }
 832         return -1;
 833 }
 834
 835 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 836                      const char *name)
 837 {
 838         struct refspec query;
 839
 840         memset(&query, 0, sizeof(struct refspec));
 841         query.src = (char *)name;
 842
 843         if (query_refspecs(refspecs, nr_refspec, &query))
 844                 return NULL;
 845
 846         return query.dst;
 847 }
 848
 849 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 850 {
 851         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 852 }
 853
 854 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 855                 const char *name)
 856 {
 857         size_t len = strlen(name);
 858         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 859         memcpy(ref->name, prefix, prefixlen);
 860         memcpy(ref->name + prefixlen, name, len);
 861         return ref;
 862 }
 863
 864 struct ref *alloc_ref(const char *name)
 865 {
 866         return alloc_ref_with_prefix("", 0, name);
 867 }
 868
 869 struct ref *copy_ref(const struct ref *ref)
 870 {
 871         struct ref *cpy;
 872         size_t len;
 873         if (!ref)
 874                 return NULL;
 875         len = strlen(ref->name);
 876         cpy = xmalloc(sizeof(struct ref) + len + 1);
 877         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 878         cpy->next = NULL;
 879         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 880         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 881         cpy->peer_ref = copy_ref(ref->peer_ref);
 882         return cpy;
 883 }
 884
 885 struct ref *copy_ref_list(const struct ref *ref)
 886 {
 887         struct ref *ret = NULL;
 888         struct ref **tail = &ret;
 889         while (ref) {
 890                 *tail = copy_ref(ref);
 891                 ref = ref->next;
 892                 tail = &((*tail)->next);
 893         }
 894         return ret;
 895 }
 896
 897 static void free_ref(struct ref *ref)
 898 {
 899         if (!ref)
 900                 return;
 901         free_ref(ref->peer_ref);
 902         free(ref->remote_status);
 903         free(ref->symref);
 904         free(ref);
 905 }
 906
 907 void free_refs(struct ref *ref)
 908 {
 909         struct ref *next;
 910         while (ref) {
 911                 next = ref->next;
 912                 free_ref(ref);
 913                 ref = next;
 914         }
 915 }
 916
 917 int ref_compare_name(const void *va, const void *vb)
 918 {
 919         const struct ref *a = va, *b = vb;
 920         return strcmp(a->name, b->name);
 921 }
 922
 923 static void *ref_list_get_next(const void *a)
 924 {
 925         return ((const struct ref *)a)->next;
 926 }
 927
 928 static void ref_list_set_next(void *a, void *next)
 929 {
 930         ((struct ref *)a)->next = next;
 931 }
 932
 933 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 934 {
 935         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 936 }
 937
 938 static int count_refspec_match(const char *pattern,
 939                                struct ref *refs,
 940                                struct ref **matched_ref)
 941 {
 942         int patlen = strlen(pattern);
 943         struct ref *matched_weak = NULL;
 944         struct ref *matched = NULL;
 945         int weak_match = 0;
 946         int match = 0;
 947
 948         for (weak_match = match = 0; refs; refs = refs->next) {
 949                 char *name = refs->name;
 950                 int namelen = strlen(name);
 951
 952                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 953                         continue;
 954
 955                 /* A match is "weak" if it is with refs outside
 956                  * heads or tags, and did not specify the pattern
 957                  * in full (e.g. "refs/remotes/origin/master") or at
 958                  * least from the toplevel (e.g. "remotes/origin/master");
 959                  * otherwise "git push $URL master" would result in
 960                  * ambiguity between remotes/origin/master and heads/master
 961                  * at the remote site.
 962                  */
 963                 if (namelen != patlen &&
 964                     patlen != namelen - 5 &&
 965                     prefixcmp(name, "refs/heads/") &&
 966                     prefixcmp(name, "refs/tags/")) {
 967                         /* We want to catch the case where only weak
 968                          * matches are found and there are multiple
 969                          * matches, and where more than one strong
 970                          * matches are found, as ambiguous.  One
 971                          * strong match with zero or more weak matches
 972                          * are acceptable as a unique match.
 973                          */
 974                         matched_weak = refs;
 975                         weak_match++;
 976                 }
 977                 else {
 978                         matched = refs;
 979                         match++;
 980                 }
 981         }
 982         if (!matched) {
 983                 *matched_ref = matched_weak;
 984                 return weak_match;
 985         }
 986         else {
 987                 *matched_ref = matched;
 988                 return match;
 989         }
 990 }
 991
 992 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 993 {
 994         **tail = ref;
 995         while (ref->next)
 996                 ref = ref->next;
 997         *tail = &ref->next;
 998 }
 999
1000 static struct ref *alloc_delete_ref(void)
1001 {
1002         struct ref *ref = alloc_ref("(delete)");
1003         hashclr(ref->new_sha1);
1004         return ref;
1005 }
1006
1007 static struct ref *try_explicit_object_name(const char *name)
1008 {
1009         unsigned char sha1[20];
1010         struct ref *ref;
1011
1012         if (!*name)
1013                 return alloc_delete_ref();
1014         if (get_sha1(name, sha1))
1015                 return NULL;
1016         ref = alloc_ref(name);
1017         hashcpy(ref->new_sha1, sha1);
1018         return ref;
1019 }
1020
1021 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1022 {
1023         struct ref *ret = alloc_ref(name);
1024         tail_link_ref(ret, tail);
1025         return ret;
1026 }
1027
1028 static char *guess_ref(const char *name, struct ref *peer)
1029 {
1030         struct strbuf buf = STRBUF_INIT;
1031         unsigned char sha1[20];
1032
1033         const char *r = resolve_ref_unsafe(peer->name, sha1, 1, NULL);
1034         if (!r)
1035                 return NULL;
1036
1037         if (!prefixcmp(r, "refs/heads/"))
1038                 strbuf_addstr(&buf, "refs/heads/");
1039         else if (!prefixcmp(r, "refs/tags/"))
1040                 strbuf_addstr(&buf, "refs/tags/");
1041         else
1042                 return NULL;
1043
1044         strbuf_addstr(&buf, name);
1045         return strbuf_detach(&buf, NULL);
1046 }
1047
1048 static int match_explicit(struct ref *src, struct ref *dst,
1049                           struct ref ***dst_tail,
1050                           struct refspec *rs)
1051 {
1052         struct ref *matched_src, *matched_dst;
1053         int copy_src;
1054
1055         const char *dst_value = rs->dst;
1056         char *dst_guess;
1057
1058         if (rs->pattern || rs->matching)
1059                 return 0;
1060
1061         matched_src = matched_dst = NULL;
1062         switch (count_refspec_match(rs->src, src, &matched_src)) {
1063         case 1:
1064                 copy_src = 1;
1065                 break;
1066         case 0:
1067                 /* The source could be in the get_sha1() format
1068                  * not a reference name.  :refs/other is a
1069                  * way to delete 'other' ref at the remote end.
1070                  */
1071                 matched_src = try_explicit_object_name(rs->src);
1072                 if (!matched_src)
1073                         return error("src refspec %s does not match any.", rs->src);
1074                 copy_src = 0;
1075                 break;
1076         default:
1077                 return error("src refspec %s matches more than one.", rs->src);
1078         }
1079
1080         if (!dst_value) {
1081                 unsigned char sha1[20];
1082                 int flag;
1083
1084                 dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag);
1085                 if (!dst_value ||
1086                     ((flag & REF_ISSYMREF) &&
1087                      prefixcmp(dst_value, "refs/heads/")))
1088                         die("%s cannot be resolved to branch.",
1089                             matched_src->name);
1090         }
1091
1092         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1093         case 1:
1094                 break;
1095         case 0:
1096                 if (!memcmp(dst_value, "refs/", 5))
1097                         matched_dst = make_linked_ref(dst_value, dst_tail);
1098                 else if (is_null_sha1(matched_src->new_sha1))
1099                         error("unable to delete '%s': remote ref does not exist",
1100                               dst_value);
1101                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1102                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1103                 else
1104                         error("unable to push to unqualified destination: %s\n"
1105                               "The destination refspec neither matches an "
1106                               "existing ref on the remote nor\n"
1107                               "begins with refs/, and we are unable to "
1108                               "guess a prefix based on the source ref.",
1109                               dst_value);
1110                 break;
1111         default:
1112                 matched_dst = NULL;
1113                 error("dst refspec %s matches more than one.",
1114                       dst_value);
1115                 break;
1116         }
1117         if (!matched_dst)
1118                 return -1;
1119         if (matched_dst->peer_ref)
1120                 return error("dst ref %s receives from more than one src.",
1121                       matched_dst->name);
1122         else {
1123                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1124                 matched_dst->force = rs->force;
1125         }
1126         return 0;
1127 }
1128
1129 static int match_explicit_refs(struct ref *src, struct ref *dst,
1130                                struct ref ***dst_tail, struct refspec *rs,
1131                                int rs_nr)
1132 {
1133         int i, errs;
1134         for (i = errs = 0; i < rs_nr; i++)
1135                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1136         return errs;
1137 }
1138
1139 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1140                 int send_mirror, int direction, const struct refspec **ret_pat)
1141 {
1142         const struct refspec *pat;
1143         char *name;
1144         int i;
1145         int matching_refs = -1;
1146         for (i = 0; i < rs_nr; i++) {
1147                 if (rs[i].matching &&
1148                     (matching_refs == -1 || rs[i].force)) {
1149                         matching_refs = i;
1150                         continue;
1151                 }
1152
1153                 if (rs[i].pattern) {
1154                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1155                         int match;
1156                         if (direction == FROM_SRC)
1157                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1158                         else
1159                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1160                         if (match) {
1161                                 matching_refs = i;
1162                                 break;
1163                         }
1164                 }
1165         }
1166         if (matching_refs == -1)
1167                 return NULL;
1168
1169         pat = rs + matching_refs;
1170         if (pat->matching) {
1171                 /*
1172                  * "matching refs"; traditionally we pushed everything
1173                  * including refs outside refs/heads/ hierarchy, but
1174                  * that does not make much sense these days.
1175                  */
1176                 if (!send_mirror && prefixcmp(ref->name, "refs/heads/"))
1177                         return NULL;
1178                 name = xstrdup(ref->name);
1179         }
1180         if (ret_pat)
1181                 *ret_pat = pat;
1182         return name;
1183 }
1184
1185 static struct ref **tail_ref(struct ref **head)
1186 {
1187         struct ref **tail = head;
1188         while (*tail)
1189                 tail = &((*tail)->next);
1190         return tail;
1191 }
1192
1193 /*
1194  * Given the set of refs the local repository has, the set of refs the
1195  * remote repository has, and the refspec used for push, determine
1196  * what remote refs we will update and with what value by setting
1197  * peer_ref (which object is being pushed) and force (if the push is
1198  * forced) in elements of "dst". The function may add new elements to
1199  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1200  */
1201 int match_push_refs(struct ref *src, struct ref **dst,
1202                     int nr_refspec, const char **refspec, int flags)
1203 {
1204         struct refspec *rs;
1205         int send_all = flags & MATCH_REFS_ALL;
1206         int send_mirror = flags & MATCH_REFS_MIRROR;
1207         int send_prune = flags & MATCH_REFS_PRUNE;
1208         int errs;
1209         static const char *default_refspec[] = { ":", NULL };
1210         struct ref *ref, **dst_tail = tail_ref(dst);
1211
1212         if (!nr_refspec) {
1213                 nr_refspec = 1;
1214                 refspec = default_refspec;
1215         }
1216         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1217         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1218
1219         /* pick the remainder */
1220         for (ref = src; ref; ref = ref->next) {
1221                 struct ref *dst_peer;
1222                 const struct refspec *pat = NULL;
1223                 char *dst_name;
1224
1225                 if (ref->peer_ref)
1226                         continue;
1227
1228                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1229                 if (!dst_name)
1230                         continue;
1231
1232                 dst_peer = find_ref_by_name(*dst, dst_name);
1233                 if (dst_peer) {
1234                         if (dst_peer->peer_ref)
1235                                 /* We're already sending something to this ref. */
1236                                 goto free_name;
1237                 } else {
1238                         if (pat->matching && !(send_all || send_mirror))
1239                                 /*
1240                                  * Remote doesn't have it, and we have no
1241                                  * explicit pattern, and we don't have
1242                                  * --all nor --mirror.
1243                                  */
1244                                 goto free_name;
1245
1246                         /* Create a new one and link it */
1247                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1248                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1249                 }
1250                 dst_peer->peer_ref = copy_ref(ref);
1251                 dst_peer->force = pat->force;
1252         free_name:
1253                 free(dst_name);
1254         }
1255         if (send_prune) {
1256                 /* check for missing refs on the remote */
1257                 for (ref = *dst; ref; ref = ref->next) {
1258                         char *src_name;
1259
1260                         if (ref->peer_ref)
1261                                 /* We're already sending something to this ref. */
1262                                 continue;
1263
1264                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1265                         if (src_name) {
1266                                 if (!find_ref_by_name(src, src_name))
1267                                         ref->peer_ref = alloc_delete_ref();
1268                                 free(src_name);
1269                         }
1270                 }
1271         }
1272         if (errs)
1273                 return -1;
1274         return 0;
1275 }
1276
1277 static inline int is_forwardable(struct ref* ref)
1278 {
1279         struct object *o;
1280
1281         if (!prefixcmp(ref->name, "refs/tags/"))
1282                 return 0;
1283
1284         /* old object must be a commit */
1285         o = parse_object(ref->old_sha1);
1286         if (!o || o->type != OBJ_COMMIT)
1287                 return 0;
1288
1289         /* new object must be commit-ish */
1290         o = deref_tag(parse_object(ref->new_sha1), NULL, 0);
1291         if (!o || o->type != OBJ_COMMIT)
1292                 return 0;
1293
1294         return 1;
1295 }
1296
1297 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1298         int force_update)
1299 {
1300         struct ref *ref;
1301
1302         for (ref = remote_refs; ref; ref = ref->next) {
1303                 int force_ref_update = ref->force || force_update;
1304
1305                 if (ref->peer_ref)
1306                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1307                 else if (!send_mirror)
1308                         continue;
1309
1310                 ref->deletion = is_null_sha1(ref->new_sha1);
1311                 if (!ref->deletion &&
1312                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1313                         ref->status = REF_STATUS_UPTODATE;
1314                         continue;
1315                 }
1316
1317                 /*
1318                  * The below logic determines whether an individual
1319                  * refspec A:B can be pushed.  The push will succeed
1320                  * if any of the following are true:
1321                  *
1322                  * (1) the remote reference B does not exist
1323                  *
1324                  * (2) the remote reference B is being removed (i.e.,
1325                  *     pushing :B where no source is specified)
1326                  *
1327                  * (3) the update meets all fast-forwarding criteria:
1328                  *
1329                  *     (a) the destination is not under refs/tags/
1330                  *     (b) the old is a commit
1331                  *     (c) the new is a descendant of the old
1332                  *
1333                  *     NOTE: We must actually have the old object in
1334                  *     order to overwrite it in the remote reference,
1335                  *     and the new object must be commit-ish.  These are
1336                  *     implied by (b) and (c) respectively.
1337                  *
1338                  * (4) it is forced using the +A:B notation, or by
1339                  *     passing the --force argument
1340                  */
1341
1342                 ref->not_forwardable = !is_forwardable(ref);
1343
1344                 ref->update =
1345                         !ref->deletion &&
1346                         !is_null_sha1(ref->old_sha1);
1347
1348                 if (ref->update) {
1349                         ref->nonfastforward =
1350                                 !has_sha1_file(ref->old_sha1)
1351                                   || !ref_newer(ref->new_sha1, ref->old_sha1);
1352
1353                         if (ref->not_forwardable) {
1354                                 ref->requires_force = 1;
1355                                 if (!force_ref_update) {
1356                                         ref->status = REF_STATUS_REJECT_ALREADY_EXISTS;
1357                                         continue;
1358                                 }
1359                         } else if (ref->nonfastforward) {
1360                                 ref->requires_force = 1;
1361                                 if (!force_ref_update) {
1362                                         ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
1363                                         continue;
1364                                 }
1365                         }
1366                 }
1367         }
1368 }
1369
1370 struct branch *branch_get(const char *name)
1371 {
1372         struct branch *ret;
1373
1374         read_config();
1375         if (!name || !*name || !strcmp(name, "HEAD"))
1376                 ret = current_branch;
1377         else
1378                 ret = make_branch(name, 0);
1379         if (ret && ret->remote_name) {
1380                 ret->remote = remote_get(ret->remote_name);
1381                 if (ret->merge_nr) {
1382                         int i;
1383                         ret->merge = xcalloc(sizeof(*ret->merge),
1384                                              ret->merge_nr);
1385                         for (i = 0; i < ret->merge_nr; i++) {
1386                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1387                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1388                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1389                                     && !strcmp(ret->remote_name, "."))
1390                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1391                         }
1392                 }
1393         }
1394         return ret;
1395 }
1396
1397 int branch_has_merge_config(struct branch *branch)
1398 {
1399         return branch && !!branch->merge;
1400 }
1401
1402 int branch_merge_matches(struct branch *branch,
1403                                  int i,
1404                                  const char *refname)
1405 {
1406         if (!branch || i < 0 || i >= branch->merge_nr)
1407                 return 0;
1408         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1409 }
1410
1411 static int ignore_symref_update(const char *refname)
1412 {
1413         unsigned char sha1[20];
1414         int flag;
1415
1416         if (!resolve_ref_unsafe(refname, sha1, 0, &flag))
1417                 return 0; /* non-existing refs are OK */
1418         return (flag & REF_ISSYMREF);
1419 }
1420
1421 static struct ref *get_expanded_map(const struct ref *remote_refs,
1422                                     const struct refspec *refspec)
1423 {
1424         const struct ref *ref;
1425         struct ref *ret = NULL;
1426         struct ref **tail = &ret;
1427
1428         char *expn_name;
1429
1430         for (ref = remote_refs; ref; ref = ref->next) {
1431                 if (strchr(ref->name, '^'))
1432                         continue; /* a dereference item */
1433                 if (match_name_with_pattern(refspec->src, ref->name,
1434                                             refspec->dst, &expn_name) &&
1435                     !ignore_symref_update(expn_name)) {
1436                         struct ref *cpy = copy_ref(ref);
1437
1438                         cpy->peer_ref = alloc_ref(expn_name);
1439                         free(expn_name);
1440                         if (refspec->force)
1441                                 cpy->peer_ref->force = 1;
1442                         *tail = cpy;
1443                         tail = &cpy->next;
1444                 }
1445         }
1446
1447         return ret;
1448 }
1449
1450 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1451 {
1452         const struct ref *ref;
1453         for (ref = refs; ref; ref = ref->next) {
1454                 if (refname_match(name, ref->name, ref_fetch_rules))
1455                         return ref;
1456         }
1457         return NULL;
1458 }
1459
1460 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1461 {
1462         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1463
1464         if (!ref)
1465                 return NULL;
1466
1467         return copy_ref(ref);
1468 }
1469
1470 static struct ref *get_local_ref(const char *name)
1471 {
1472         if (!name || name[0] == '\0')
1473                 return NULL;
1474
1475         if (!prefixcmp(name, "refs/"))
1476                 return alloc_ref(name);
1477
1478         if (!prefixcmp(name, "heads/") ||
1479             !prefixcmp(name, "tags/") ||
1480             !prefixcmp(name, "remotes/"))
1481                 return alloc_ref_with_prefix("refs/", 5, name);
1482
1483         return alloc_ref_with_prefix("refs/heads/", 11, name);
1484 }
1485
1486 int get_fetch_map(const struct ref *remote_refs,
1487                   const struct refspec *refspec,
1488                   struct ref ***tail,
1489                   int missing_ok)
1490 {
1491         struct ref *ref_map, **rmp;
1492
1493         if (refspec->pattern) {
1494                 ref_map = get_expanded_map(remote_refs, refspec);
1495         } else {
1496                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1497
1498                 ref_map = get_remote_ref(remote_refs, name);
1499                 if (!missing_ok && !ref_map)
1500                         die("Couldn't find remote ref %s", name);
1501                 if (ref_map) {
1502                         ref_map->peer_ref = get_local_ref(refspec->dst);
1503                         if (ref_map->peer_ref && refspec->force)
1504                                 ref_map->peer_ref->force = 1;
1505                 }
1506         }
1507
1508         for (rmp = &ref_map; *rmp; ) {
1509                 if ((*rmp)->peer_ref) {
1510                         if (prefixcmp((*rmp)->peer_ref->name, "refs/") ||
1511                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1512                                 struct ref *ignore = *rmp;
1513                                 error("* Ignoring funny ref '%s' locally",
1514                                       (*rmp)->peer_ref->name);
1515                                 *rmp = (*rmp)->next;
1516                                 free(ignore->peer_ref);
1517                                 free(ignore);
1518                                 continue;
1519                         }
1520                 }
1521                 rmp = &((*rmp)->next);
1522         }
1523
1524         if (ref_map)
1525                 tail_link_ref(ref_map, tail);
1526
1527         return 0;
1528 }
1529
1530 int resolve_remote_symref(struct ref *ref, struct ref *list)
1531 {
1532         if (!ref->symref)
1533                 return 0;
1534         for (; list; list = list->next)
1535                 if (!strcmp(ref->symref, list->name)) {
1536                         hashcpy(ref->old_sha1, list->old_sha1);
1537                         return 0;
1538                 }
1539         return 1;
1540 }
1541
1542 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1543 {
1544         while (list) {
1545                 struct commit_list *temp = list;
1546                 temp->item->object.flags &= ~mark;
1547                 list = temp->next;
1548                 free(temp);
1549         }
1550 }
1551
1552 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1553 {
1554         struct object *o;
1555         struct commit *old, *new;
1556         struct commit_list *list, *used;
1557         int found = 0;
1558
1559         /* Both new and old must be commit-ish and new is descendant of
1560          * old.  Otherwise we require --force.
1561          */
1562         o = deref_tag(parse_object(old_sha1), NULL, 0);
1563         if (!o || o->type != OBJ_COMMIT)
1564                 return 0;
1565         old = (struct commit *) o;
1566
1567         o = deref_tag(parse_object(new_sha1), NULL, 0);
1568         if (!o || o->type != OBJ_COMMIT)
1569                 return 0;
1570         new = (struct commit *) o;
1571
1572         if (parse_commit(new) < 0)
1573                 return 0;
1574
1575         used = list = NULL;
1576         commit_list_insert(new, &list);
1577         while (list) {
1578                 new = pop_most_recent_commit(&list, TMP_MARK);
1579                 commit_list_insert(new, &used);
1580                 if (new == old) {
1581                         found = 1;
1582                         break;
1583                 }
1584         }
1585         unmark_and_free(list, TMP_MARK);
1586         unmark_and_free(used, TMP_MARK);
1587         return found;
1588 }
1589
1590 /*
1591  * Return true if there is anything to report, otherwise false.
1592  */
1593 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1594 {
1595         unsigned char sha1[20];
1596         struct commit *ours, *theirs;
1597         char symmetric[84];
1598         struct rev_info revs;
1599         const char *rev_argv[10], *base;
1600         int rev_argc;
1601
1602         /*
1603          * Nothing to report unless we are marked to build on top of
1604          * somebody else.
1605          */
1606         if (!branch ||
1607             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1608                 return 0;
1609
1610         /*
1611          * If what we used to build on no longer exists, there is
1612          * nothing to report.
1613          */
1614         base = branch->merge[0]->dst;
1615         if (read_ref(base, sha1))
1616                 return 0;
1617         theirs = lookup_commit_reference(sha1);
1618         if (!theirs)
1619                 return 0;
1620
1621         if (read_ref(branch->refname, sha1))
1622                 return 0;
1623         ours = lookup_commit_reference(sha1);
1624         if (!ours)
1625                 return 0;
1626
1627         /* are we the same? */
1628         if (theirs == ours)
1629                 return 0;
1630
1631         /* Run "rev-list --left-right ours...theirs" internally... */
1632         rev_argc = 0;
1633         rev_argv[rev_argc++] = NULL;
1634         rev_argv[rev_argc++] = "--left-right";
1635         rev_argv[rev_argc++] = symmetric;
1636         rev_argv[rev_argc++] = "--";
1637         rev_argv[rev_argc] = NULL;
1638
1639         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1640         strcpy(symmetric + 40, "...");
1641         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1642
1643         init_revisions(&revs, NULL);
1644         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1645         prepare_revision_walk(&revs);
1646
1647         /* ... and count the commits on each side. */
1648         *num_ours = 0;
1649         *num_theirs = 0;
1650         while (1) {
1651                 struct commit *c = get_revision(&revs);
1652                 if (!c)
1653                         break;
1654                 if (c->object.flags & SYMMETRIC_LEFT)
1655                         (*num_ours)++;
1656                 else
1657                         (*num_theirs)++;
1658         }
1659
1660         /* clear object flags smudged by the above traversal */
1661         clear_commit_marks(ours, ALL_REV_FLAGS);
1662         clear_commit_marks(theirs, ALL_REV_FLAGS);
1663         return 1;
1664 }
1665
1666 /*
1667  * Return true when there is anything to report, otherwise false.
1668  */
1669 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1670 {
1671         int num_ours, num_theirs;
1672         const char *base;
1673
1674         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1675                 return 0;
1676
1677         base = branch->merge[0]->dst;
1678         base = shorten_unambiguous_ref(base, 0);
1679         if (!num_theirs) {
1680                 strbuf_addf(sb,
1681                         Q_("Your branch is ahead of '%s' by %d commit.\n",
1682                            "Your branch is ahead of '%s' by %d commits.\n",
1683                            num_ours),
1684                         base, num_ours);
1685                 if (advice_status_hints)
1686                         strbuf_addf(sb,
1687                                 _("  (use \"git push\" to publish your local commits)\n"));
1688         } else if (!num_ours) {
1689                 strbuf_addf(sb,
1690                         Q_("Your branch is behind '%s' by %d commit, "
1691                                "and can be fast-forwarded.\n",
1692                            "Your branch is behind '%s' by %d commits, "
1693                                "and can be fast-forwarded.\n",
1694                            num_theirs),
1695                         base, num_theirs);
1696                 if (advice_status_hints)
1697                         strbuf_addf(sb,
1698                                 _("  (use \"git pull\" to update your local branch)\n"));
1699         } else {
1700                 strbuf_addf(sb,
1701                         Q_("Your branch and '%s' have diverged,\n"
1702                                "and have %d and %d different commit each, "
1703                                "respectively.\n",
1704                            "Your branch and '%s' have diverged,\n"
1705                                "and have %d and %d different commits each, "
1706                                "respectively.\n",
1707                            num_theirs),
1708                         base, num_ours, num_theirs);
1709                 if (advice_status_hints)
1710                         strbuf_addf(sb,
1711                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1712         }
1713         return 1;
1714 }
1715
1716 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1717 {
1718         struct ref ***local_tail = cb_data;
1719         struct ref *ref;
1720         int len;
1721
1722         /* we already know it starts with refs/ to get here */
1723         if (check_refname_format(refname + 5, 0))
1724                 return 0;
1725
1726         len = strlen(refname) + 1;
1727         ref = xcalloc(1, sizeof(*ref) + len);
1728         hashcpy(ref->new_sha1, sha1);
1729         memcpy(ref->name, refname, len);
1730         **local_tail = ref;
1731         *local_tail = &ref->next;
1732         return 0;
1733 }
1734
1735 struct ref *get_local_heads(void)
1736 {
1737         struct ref *local_refs = NULL, **local_tail = &local_refs;
1738         for_each_ref(one_local_ref, &local_tail);
1739         return local_refs;
1740 }
1741
1742 struct ref *guess_remote_head(const struct ref *head,
1743                               const struct ref *refs,
1744                               int all)
1745 {
1746         const struct ref *r;
1747         struct ref *list = NULL;
1748         struct ref **tail = &list;
1749
1750         if (!head)
1751                 return NULL;
1752
1753         /*
1754          * Some transports support directly peeking at
1755          * where HEAD points; if that is the case, then
1756          * we don't have to guess.
1757          */
1758         if (head->symref)
1759                 return copy_ref(find_ref_by_name(refs, head->symref));
1760
1761         /* If refs/heads/master could be right, it is. */
1762         if (!all) {
1763                 r = find_ref_by_name(refs, "refs/heads/master");
1764                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1765                         return copy_ref(r);
1766         }
1767
1768         /* Look for another ref that points there */
1769         for (r = refs; r; r = r->next) {
1770                 if (r != head &&
1771                     !prefixcmp(r->name, "refs/heads/") &&
1772                     !hashcmp(r->old_sha1, head->old_sha1)) {
1773                         *tail = copy_ref(r);
1774                         tail = &((*tail)->next);
1775                         if (!all)
1776                                 break;
1777                 }
1778         }
1779
1780         return list;
1781 }
1782
1783 struct stale_heads_info {
1784         struct string_list *ref_names;
1785         struct ref **stale_refs_tail;
1786         struct refspec *refs;
1787         int ref_count;
1788 };
1789
1790 static int get_stale_heads_cb(const char *refname,
1791         const unsigned char *sha1, int flags, void *cb_data)
1792 {
1793         struct stale_heads_info *info = cb_data;
1794         struct refspec query;
1795         memset(&query, 0, sizeof(struct refspec));
1796         query.dst = (char *)refname;
1797
1798         if (query_refspecs(info->refs, info->ref_count, &query))
1799                 return 0; /* No matches */
1800
1801         /*
1802          * If we did find a suitable refspec and it's not a symref and
1803          * it's not in the list of refs that currently exist in that
1804          * remote we consider it to be stale.
1805          */
1806         if (!((flags & REF_ISSYMREF) ||
1807               string_list_has_string(info->ref_names, query.src))) {
1808                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1809                 hashcpy(ref->new_sha1, sha1);
1810         }
1811
1812         free(query.src);
1813         return 0;
1814 }
1815
1816 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
1817 {
1818         struct ref *ref, *stale_refs = NULL;
1819         struct string_list ref_names = STRING_LIST_INIT_NODUP;
1820         struct stale_heads_info info;
1821         info.ref_names = &ref_names;
1822         info.stale_refs_tail = &stale_refs;
1823         info.refs = refs;
1824         info.ref_count = ref_count;
1825         for (ref = fetch_map; ref; ref = ref->next)
1826                 string_list_append(&ref_names, ref->name);
1827         sort_string_list(&ref_names);
1828         for_each_ref(get_stale_heads_cb, &info);
1829         string_list_clear(&ref_names, 0);
1830         return stale_refs;
1831 }