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         0,
  19         "refs/tags/*",
  20         "refs/tags/*"
  21 };
  22
  23 const struct refspec *tag_refspec = &s_tag_refspec;
  24
  25 struct counted_string {
  26         size_t len;
  27         const char *s;
  28 };
  29 struct rewrite {
  30         const char *base;
  31         size_t baselen;
  32         struct counted_string *instead_of;
  33         int instead_of_nr;
  34         int instead_of_alloc;
  35 };
  36 struct rewrites {
  37         struct rewrite **rewrite;
  38         int rewrite_alloc;
  39         int rewrite_nr;
  40 };
  41
  42 static struct remote **remotes;
  43 static int remotes_alloc;
  44 static int remotes_nr;
  45
  46 static struct branch **branches;
  47 static int branches_alloc;
  48 static int branches_nr;
  49
  50 static struct branch *current_branch;
  51 static const char *default_remote_name;
  52 static int explicit_default_remote_name;
  53
  54 static struct rewrites rewrites;
  55 static struct rewrites rewrites_push;
  56
  57 #define BUF_SIZE (2048)
  58 static char buffer[BUF_SIZE];
  59
  60 static int valid_remote(const struct remote *remote)
  61 {
  62         return (!!remote->url) || (!!remote->foreign_vcs);
  63 }
  64
  65 static const char *alias_url(const char *url, struct rewrites *r)
  66 {
  67         int i, j;
  68         char *ret;
  69         struct counted_string *longest;
  70         int longest_i;
  71
  72         longest = NULL;
  73         longest_i = -1;
  74         for (i = 0; i < r->rewrite_nr; i++) {
  75                 if (!r->rewrite[i])
  76                         continue;
  77                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  78                         if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  79                             (!longest ||
  80                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  81                                 longest = &(r->rewrite[i]->instead_of[j]);
  82                                 longest_i = i;
  83                         }
  84                 }
  85         }
  86         if (!longest)
  87                 return url;
  88
  89         ret = xmalloc(r->rewrite[longest_i]->baselen +
  90                      (strlen(url) - longest->len) + 1);
  91         strcpy(ret, r->rewrite[longest_i]->base);
  92         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  93         return ret;
  94 }
  95
  96 static void add_push_refspec(struct remote *remote, const char *ref)
  97 {
  98         ALLOC_GROW(remote->push_refspec,
  99                    remote->push_refspec_nr + 1,
 100                    remote->push_refspec_alloc);
 101         remote->push_refspec[remote->push_refspec_nr++] = ref;
 102 }
 103
 104 static void add_fetch_refspec(struct remote *remote, const char *ref)
 105 {
 106         ALLOC_GROW(remote->fetch_refspec,
 107                    remote->fetch_refspec_nr + 1,
 108                    remote->fetch_refspec_alloc);
 109         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 110 }
 111
 112 static void add_url(struct remote *remote, const char *url)
 113 {
 114         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 115         remote->url[remote->url_nr++] = url;
 116 }
 117
 118 static void add_pushurl(struct remote *remote, const char *pushurl)
 119 {
 120         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 121         remote->pushurl[remote->pushurl_nr++] = pushurl;
 122 }
 123
 124 static void add_pushurl_alias(struct remote *remote, const char *url)
 125 {
 126         const char *pushurl = alias_url(url, &rewrites_push);
 127         if (pushurl != url)
 128                 add_pushurl(remote, pushurl);
 129 }
 130
 131 static void add_url_alias(struct remote *remote, const char *url)
 132 {
 133         add_url(remote, alias_url(url, &rewrites));
 134         add_pushurl_alias(remote, url);
 135 }
 136
 137 static struct remote *make_remote(const char *name, int len)
 138 {
 139         struct remote *ret;
 140         int i;
 141
 142         for (i = 0; i < remotes_nr; i++) {
 143                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 144                            !remotes[i]->name[len]) :
 145                     !strcmp(name, remotes[i]->name))
 146                         return remotes[i];
 147         }
 148
 149         ret = xcalloc(1, sizeof(struct remote));
 150         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 151         remotes[remotes_nr++] = ret;
 152         if (len)
 153                 ret->name = xstrndup(name, len);
 154         else
 155                 ret->name = xstrdup(name);
 156         return ret;
 157 }
 158
 159 static void add_merge(struct branch *branch, const char *name)
 160 {
 161         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 162                    branch->merge_alloc);
 163         branch->merge_name[branch->merge_nr++] = name;
 164 }
 165
 166 static struct branch *make_branch(const char *name, int len)
 167 {
 168         struct branch *ret;
 169         int i;
 170         char *refname;
 171
 172         for (i = 0; i < branches_nr; i++) {
 173                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 174                            !branches[i]->name[len]) :
 175                     !strcmp(name, branches[i]->name))
 176                         return branches[i];
 177         }
 178
 179         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 180         ret = xcalloc(1, sizeof(struct branch));
 181         branches[branches_nr++] = ret;
 182         if (len)
 183                 ret->name = xstrndup(name, len);
 184         else
 185                 ret->name = xstrdup(name);
 186         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 187         strcpy(refname, "refs/heads/");
 188         strcpy(refname + strlen("refs/heads/"), ret->name);
 189         ret->refname = refname;
 190
 191         return ret;
 192 }
 193
 194 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 195 {
 196         struct rewrite *ret;
 197         int i;
 198
 199         for (i = 0; i < r->rewrite_nr; i++) {
 200                 if (len
 201                     ? (len == r->rewrite[i]->baselen &&
 202                        !strncmp(base, r->rewrite[i]->base, len))
 203                     : !strcmp(base, r->rewrite[i]->base))
 204                         return r->rewrite[i];
 205         }
 206
 207         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 208         ret = xcalloc(1, sizeof(struct rewrite));
 209         r->rewrite[r->rewrite_nr++] = ret;
 210         if (len) {
 211                 ret->base = xstrndup(base, len);
 212                 ret->baselen = len;
 213         }
 214         else {
 215                 ret->base = xstrdup(base);
 216                 ret->baselen = strlen(base);
 217         }
 218         return ret;
 219 }
 220
 221 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 222 {
 223         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 224         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 225         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 226         rewrite->instead_of_nr++;
 227 }
 228
 229 static void read_remotes_file(struct remote *remote)
 230 {
 231         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 232
 233         if (!f)
 234                 return;
 235         remote->origin = REMOTE_REMOTES;
 236         while (fgets(buffer, BUF_SIZE, f)) {
 237                 int value_list;
 238                 char *s, *p;
 239
 240                 if (!prefixcmp(buffer, "URL:")) {
 241                         value_list = 0;
 242                         s = buffer + 4;
 243                 } else if (!prefixcmp(buffer, "Push:")) {
 244                         value_list = 1;
 245                         s = buffer + 5;
 246                 } else if (!prefixcmp(buffer, "Pull:")) {
 247                         value_list = 2;
 248                         s = buffer + 5;
 249                 } else
 250                         continue;
 251
 252                 while (isspace(*s))
 253                         s++;
 254                 if (!*s)
 255                         continue;
 256
 257                 p = s + strlen(s);
 258                 while (isspace(p[-1]))
 259                         *--p = 0;
 260
 261                 switch (value_list) {
 262                 case 0:
 263                         add_url_alias(remote, xstrdup(s));
 264                         break;
 265                 case 1:
 266                         add_push_refspec(remote, xstrdup(s));
 267                         break;
 268                 case 2:
 269                         add_fetch_refspec(remote, xstrdup(s));
 270                         break;
 271                 }
 272         }
 273         fclose(f);
 274 }
 275
 276 static void read_branches_file(struct remote *remote)
 277 {
 278         const char *slash = strchr(remote->name, '/');
 279         char *frag;
 280         struct strbuf branch = STRBUF_INIT;
 281         int n = slash ? slash - remote->name : 1000;
 282         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 283         char *s, *p;
 284         int len;
 285
 286         if (!f)
 287                 return;
 288         s = fgets(buffer, BUF_SIZE, f);
 289         fclose(f);
 290         if (!s)
 291                 return;
 292         while (isspace(*s))
 293                 s++;
 294         if (!*s)
 295                 return;
 296         remote->origin = REMOTE_BRANCHES;
 297         p = s + strlen(s);
 298         while (isspace(p[-1]))
 299                 *--p = 0;
 300         len = p - s;
 301         if (slash)
 302                 len += strlen(slash);
 303         p = xmalloc(len + 1);
 304         strcpy(p, s);
 305         if (slash)
 306                 strcat(p, slash);
 307
 308         /*
 309          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 310          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 311          * the partial URL obtained from the branches file plus
 312          * "/netdev-2.6" and does not store it in any tracking ref.
 313          * #branch specifier in the file is ignored.
 314          *
 315          * Otherwise, the branches file would have URL and optionally
 316          * #branch specified.  The "master" (or specified) branch is
 317          * fetched and stored in the local branch of the same name.
 318          */
 319         frag = strchr(p, '#');
 320         if (frag) {
 321                 *(frag++) = '\0';
 322                 strbuf_addf(&branch, "refs/heads/%s", frag);
 323         } else
 324                 strbuf_addstr(&branch, "refs/heads/master");
 325         if (!slash) {
 326                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 327         } else {
 328                 strbuf_reset(&branch);
 329                 strbuf_addstr(&branch, "HEAD:");
 330         }
 331         add_url_alias(remote, p);
 332         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 333         /*
 334          * Cogito compatible push: push current HEAD to remote #branch
 335          * (master if missing)
 336          */
 337         strbuf_init(&branch, 0);
 338         strbuf_addstr(&branch, "HEAD");
 339         if (frag)
 340                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 341         else
 342                 strbuf_addstr(&branch, ":refs/heads/master");
 343         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 344         remote->fetch_tags = 1; /* always auto-follow */
 345 }
 346
 347 static int handle_config(const char *key, const char *value, void *cb)
 348 {
 349         const char *name;
 350         const char *subkey;
 351         struct remote *remote;
 352         struct branch *branch;
 353         if (!prefixcmp(key, "branch.")) {
 354                 name = key + 7;
 355                 subkey = strrchr(name, '.');
 356                 if (!subkey)
 357                         return 0;
 358                 branch = make_branch(name, subkey - name);
 359                 if (!strcmp(subkey, ".remote")) {
 360                         if (!value)
 361                                 return config_error_nonbool(key);
 362                         branch->remote_name = xstrdup(value);
 363                         if (branch == current_branch) {
 364                                 default_remote_name = branch->remote_name;
 365                                 explicit_default_remote_name = 1;
 366                         }
 367                 } else if (!strcmp(subkey, ".merge")) {
 368                         if (!value)
 369                                 return config_error_nonbool(key);
 370                         add_merge(branch, xstrdup(value));
 371                 }
 372                 return 0;
 373         }
 374         if (!prefixcmp(key, "url.")) {
 375                 struct rewrite *rewrite;
 376                 name = key + 4;
 377                 subkey = strrchr(name, '.');
 378                 if (!subkey)
 379                         return 0;
 380                 if (!strcmp(subkey, ".insteadof")) {
 381                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 382                         if (!value)
 383                                 return config_error_nonbool(key);
 384                         add_instead_of(rewrite, xstrdup(value));
 385                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 386                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 387                         if (!value)
 388                                 return config_error_nonbool(key);
 389                         add_instead_of(rewrite, xstrdup(value));
 390                 }
 391         }
 392         if (prefixcmp(key,  "remote."))
 393                 return 0;
 394         name = key + 7;
 395         if (*name == '/') {
 396                 warning("Config remote shorthand cannot begin with '/': %s",
 397                         name);
 398                 return 0;
 399         }
 400         subkey = strrchr(name, '.');
 401         if (!subkey)
 402                 return 0;
 403         remote = make_remote(name, subkey - name);
 404         remote->origin = REMOTE_CONFIG;
 405         if (!strcmp(subkey, ".mirror"))
 406                 remote->mirror = git_config_bool(key, value);
 407         else if (!strcmp(subkey, ".skipdefaultupdate"))
 408                 remote->skip_default_update = git_config_bool(key, value);
 409         else if (!strcmp(subkey, ".skipfetchall"))
 410                 remote->skip_default_update = git_config_bool(key, value);
 411         else if (!strcmp(subkey, ".url")) {
 412                 const char *v;
 413                 if (git_config_string(&v, key, value))
 414                         return -1;
 415                 add_url(remote, v);
 416         } else if (!strcmp(subkey, ".pushurl")) {
 417                 const char *v;
 418                 if (git_config_string(&v, key, value))
 419                         return -1;
 420                 add_pushurl(remote, v);
 421         } else if (!strcmp(subkey, ".push")) {
 422                 const char *v;
 423                 if (git_config_string(&v, key, value))
 424                         return -1;
 425                 add_push_refspec(remote, v);
 426         } else if (!strcmp(subkey, ".fetch")) {
 427                 const char *v;
 428                 if (git_config_string(&v, key, value))
 429                         return -1;
 430                 add_fetch_refspec(remote, v);
 431         } else if (!strcmp(subkey, ".receivepack")) {
 432                 const char *v;
 433                 if (git_config_string(&v, key, value))
 434                         return -1;
 435                 if (!remote->receivepack)
 436                         remote->receivepack = v;
 437                 else
 438                         error("more than one receivepack given, using the first");
 439         } else if (!strcmp(subkey, ".uploadpack")) {
 440                 const char *v;
 441                 if (git_config_string(&v, key, value))
 442                         return -1;
 443                 if (!remote->uploadpack)
 444                         remote->uploadpack = v;
 445                 else
 446                         error("more than one uploadpack given, using the first");
 447         } else if (!strcmp(subkey, ".tagopt")) {
 448                 if (!strcmp(value, "--no-tags"))
 449                         remote->fetch_tags = -1;
 450                 else if (!strcmp(value, "--tags"))
 451                         remote->fetch_tags = 2;
 452         } else if (!strcmp(subkey, ".proxy")) {
 453                 return git_config_string((const char **)&remote->http_proxy,
 454                                          key, value);
 455         } else if (!strcmp(subkey, ".vcs")) {
 456                 return git_config_string(&remote->foreign_vcs, key, value);
 457         }
 458         return 0;
 459 }
 460
 461 static void alias_all_urls(void)
 462 {
 463         int i, j;
 464         for (i = 0; i < remotes_nr; i++) {
 465                 int add_pushurl_aliases;
 466                 if (!remotes[i])
 467                         continue;
 468                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 469                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 470                 }
 471                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 472                 for (j = 0; j < remotes[i]->url_nr; j++) {
 473                         if (add_pushurl_aliases)
 474                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 475                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 476                 }
 477         }
 478 }
 479
 480 static void read_config(void)
 481 {
 482         unsigned char sha1[20];
 483         const char *head_ref;
 484         int flag;
 485         if (default_remote_name) /* did this already */
 486                 return;
 487         default_remote_name = xstrdup("origin");
 488         current_branch = NULL;
 489         head_ref = resolve_ref_unsafe("HEAD", sha1, 0, &flag);
 490         if (head_ref && (flag & REF_ISSYMREF) &&
 491             !prefixcmp(head_ref, "refs/heads/")) {
 492                 current_branch =
 493                         make_branch(head_ref + strlen("refs/heads/"), 0);
 494         }
 495         git_config(handle_config, NULL);
 496         alias_all_urls();
 497 }
 498
 499 /*
 500  * This function frees a refspec array.
 501  * Warning: code paths should be checked to ensure that the src
 502  *          and dst pointers are always freeable pointers as well
 503  *          as the refspec pointer itself.
 504  */
 505 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 506 {
 507         int i;
 508
 509         if (!refspec)
 510                 return;
 511
 512         for (i = 0; i < nr_refspec; i++) {
 513                 free(refspec[i].src);
 514                 free(refspec[i].dst);
 515         }
 516         free(refspec);
 517 }
 518
 519 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 520 {
 521         int i;
 522         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 523
 524         for (i = 0; i < nr_refspec; i++) {
 525                 size_t llen;
 526                 int is_glob;
 527                 const char *lhs, *rhs;
 528                 int flags;
 529
 530                 is_glob = 0;
 531
 532                 lhs = refspec[i];
 533                 if (*lhs == '+') {
 534                         rs[i].force = 1;
 535                         lhs++;
 536                 }
 537
 538                 rhs = strrchr(lhs, ':');
 539
 540                 /*
 541                  * Before going on, special case ":" (or "+:") as a refspec
 542                  * for pushing matching refs.
 543                  */
 544                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 545                         rs[i].matching = 1;
 546                         continue;
 547                 }
 548
 549                 if (rhs) {
 550                         size_t rlen = strlen(++rhs);
 551                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 552                         rs[i].dst = xstrndup(rhs, rlen);
 553                 }
 554
 555                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 556                 if (1 <= llen && memchr(lhs, '*', llen)) {
 557                         if ((rhs && !is_glob) || (!rhs && fetch))
 558                                 goto invalid;
 559                         is_glob = 1;
 560                 } else if (rhs && is_glob) {
 561                         goto invalid;
 562                 }
 563
 564                 rs[i].pattern = is_glob;
 565                 rs[i].src = xstrndup(lhs, llen);
 566                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 567
 568                 if (fetch) {
 569                         unsigned char unused[40];
 570
 571                         /* LHS */
 572                         if (!*rs[i].src)
 573                                 ; /* empty is ok; it means "HEAD" */
 574                         else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 575                                 rs[i].exact_sha1 = 1; /* ok */
 576                         else if (!check_refname_format(rs[i].src, flags))
 577                                 ; /* valid looking ref is ok */
 578                         else
 579                                 goto invalid;
 580                         /* RHS */
 581                         if (!rs[i].dst)
 582                                 ; /* missing is ok; it is the same as empty */
 583                         else if (!*rs[i].dst)
 584                                 ; /* empty is ok; it means "do not store" */
 585                         else if (!check_refname_format(rs[i].dst, flags))
 586                                 ; /* valid looking ref is ok */
 587                         else
 588                                 goto invalid;
 589                 } else {
 590                         /*
 591                          * LHS
 592                          * - empty is allowed; it means delete.
 593                          * - when wildcarded, it must be a valid looking ref.
 594                          * - otherwise, it must be an extended SHA-1, but
 595                          *   there is no existing way to validate this.
 596                          */
 597                         if (!*rs[i].src)
 598                                 ; /* empty is ok */
 599                         else if (is_glob) {
 600                                 if (check_refname_format(rs[i].src, flags))
 601                                         goto invalid;
 602                         }
 603                         else
 604                                 ; /* anything goes, for now */
 605                         /*
 606                          * RHS
 607                          * - missing is allowed, but LHS then must be a
 608                          *   valid looking ref.
 609                          * - empty is not allowed.
 610                          * - otherwise it must be a valid looking ref.
 611                          */
 612                         if (!rs[i].dst) {
 613                                 if (check_refname_format(rs[i].src, flags))
 614                                         goto invalid;
 615                         } else if (!*rs[i].dst) {
 616                                 goto invalid;
 617                         } else {
 618                                 if (check_refname_format(rs[i].dst, flags))
 619                                         goto invalid;
 620                         }
 621                 }
 622         }
 623         return rs;
 624
 625  invalid:
 626         if (verify) {
 627                 /*
 628                  * nr_refspec must be greater than zero and i must be valid
 629                  * since it is only possible to reach this point from within
 630                  * the for loop above.
 631                  */
 632                 free_refspecs(rs, i+1);
 633                 return NULL;
 634         }
 635         die("Invalid refspec '%s'", refspec[i]);
 636 }
 637
 638 int valid_fetch_refspec(const char *fetch_refspec_str)
 639 {
 640         struct refspec *refspec;
 641
 642         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 643         free_refspecs(refspec, 1);
 644         return !!refspec;
 645 }
 646
 647 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 648 {
 649         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 650 }
 651
 652 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 653 {
 654         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 655 }
 656
 657 void free_refspec(int nr_refspec, struct refspec *refspec)
 658 {
 659         int i;
 660         for (i = 0; i < nr_refspec; i++) {
 661                 free(refspec[i].src);
 662                 free(refspec[i].dst);
 663         }
 664         free(refspec);
 665 }
 666
 667 static int valid_remote_nick(const char *name)
 668 {
 669         if (!name[0] || is_dot_or_dotdot(name))
 670                 return 0;
 671         return !strchr(name, '/'); /* no slash */
 672 }
 673
 674 struct remote *remote_get(const char *name)
 675 {
 676         struct remote *ret;
 677         int name_given = 0;
 678
 679         read_config();
 680         if (name)
 681                 name_given = 1;
 682         else {
 683                 name = default_remote_name;
 684                 name_given = explicit_default_remote_name;
 685         }
 686
 687         ret = make_remote(name, 0);
 688         if (valid_remote_nick(name)) {
 689                 if (!valid_remote(ret))
 690                         read_remotes_file(ret);
 691                 if (!valid_remote(ret))
 692                         read_branches_file(ret);
 693         }
 694         if (name_given && !valid_remote(ret))
 695                 add_url_alias(ret, name);
 696         if (!valid_remote(ret))
 697                 return NULL;
 698         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 699         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 700         return ret;
 701 }
 702
 703 int remote_is_configured(const char *name)
 704 {
 705         int i;
 706         read_config();
 707
 708         for (i = 0; i < remotes_nr; i++)
 709                 if (!strcmp(name, remotes[i]->name))
 710                         return 1;
 711         return 0;
 712 }
 713
 714 int for_each_remote(each_remote_fn fn, void *priv)
 715 {
 716         int i, result = 0;
 717         read_config();
 718         for (i = 0; i < remotes_nr && !result; i++) {
 719                 struct remote *r = remotes[i];
 720                 if (!r)
 721                         continue;
 722                 if (!r->fetch)
 723                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 724                                                        r->fetch_refspec);
 725                 if (!r->push)
 726                         r->push = parse_push_refspec(r->push_refspec_nr,
 727                                                      r->push_refspec);
 728                 result = fn(r, priv);
 729         }
 730         return result;
 731 }
 732
 733 void ref_remove_duplicates(struct ref *ref_map)
 734 {
 735         struct string_list refs = STRING_LIST_INIT_NODUP;
 736         struct string_list_item *item = NULL;
 737         struct ref *prev = NULL, *next = NULL;
 738         for (; ref_map; prev = ref_map, ref_map = next) {
 739                 next = ref_map->next;
 740                 if (!ref_map->peer_ref)
 741                         continue;
 742
 743                 item = string_list_lookup(&refs, ref_map->peer_ref->name);
 744                 if (item) {
 745                         if (strcmp(((struct ref *)item->util)->name,
 746                                    ref_map->name))
 747                                 die("%s tracks both %s and %s",
 748                                     ref_map->peer_ref->name,
 749                                     ((struct ref *)item->util)->name,
 750                                     ref_map->name);
 751                         prev->next = ref_map->next;
 752                         free(ref_map->peer_ref);
 753                         free(ref_map);
 754                         ref_map = prev; /* skip this; we freed it */
 755                         continue;
 756                 }
 757
 758                 item = string_list_insert(&refs, ref_map->peer_ref->name);
 759                 item->util = ref_map;
 760         }
 761         string_list_clear(&refs, 0);
 762 }
 763
 764 int remote_has_url(struct remote *remote, const char *url)
 765 {
 766         int i;
 767         for (i = 0; i < remote->url_nr; i++) {
 768                 if (!strcmp(remote->url[i], url))
 769                         return 1;
 770         }
 771         return 0;
 772 }
 773
 774 static int match_name_with_pattern(const char *key, const char *name,
 775                                    const char *value, char **result)
 776 {
 777         const char *kstar = strchr(key, '*');
 778         size_t klen;
 779         size_t ksuffixlen;
 780         size_t namelen;
 781         int ret;
 782         if (!kstar)
 783                 die("Key '%s' of pattern had no '*'", key);
 784         klen = kstar - key;
 785         ksuffixlen = strlen(kstar + 1);
 786         namelen = strlen(name);
 787         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 788                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 789         if (ret && value) {
 790                 const char *vstar = strchr(value, '*');
 791                 size_t vlen;
 792                 size_t vsuffixlen;
 793                 if (!vstar)
 794                         die("Value '%s' of pattern has no '*'", value);
 795                 vlen = vstar - value;
 796                 vsuffixlen = strlen(vstar + 1);
 797                 *result = xmalloc(vlen + vsuffixlen +
 798                                   strlen(name) -
 799                                   klen - ksuffixlen + 1);
 800                 strncpy(*result, value, vlen);
 801                 strncpy(*result + vlen,
 802                         name + klen, namelen - klen - ksuffixlen);
 803                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 804                        vstar + 1);
 805         }
 806         return ret;
 807 }
 808
 809 static int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 810 {
 811         int i;
 812         int find_src = !query->src;
 813
 814         if (find_src && !query->dst)
 815                 return error("query_refspecs: need either src or dst");
 816
 817         for (i = 0; i < ref_count; i++) {
 818                 struct refspec *refspec = &refs[i];
 819                 const char *key = find_src ? refspec->dst : refspec->src;
 820                 const char *value = find_src ? refspec->src : refspec->dst;
 821                 const char *needle = find_src ? query->dst : query->src;
 822                 char **result = find_src ? &query->src : &query->dst;
 823
 824                 if (!refspec->dst)
 825                         continue;
 826                 if (refspec->pattern) {
 827                         if (match_name_with_pattern(key, needle, value, result)) {
 828                                 query->force = refspec->force;
 829                                 return 0;
 830                         }
 831                 } else if (!strcmp(needle, key)) {
 832                         *result = xstrdup(value);
 833                         query->force = refspec->force;
 834                         return 0;
 835                 }
 836         }
 837         return -1;
 838 }
 839
 840 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 841                      const char *name)
 842 {
 843         struct refspec query;
 844
 845         memset(&query, 0, sizeof(struct refspec));
 846         query.src = (char *)name;
 847
 848         if (query_refspecs(refspecs, nr_refspec, &query))
 849                 return NULL;
 850
 851         return query.dst;
 852 }
 853
 854 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 855 {
 856         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 857 }
 858
 859 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 860                 const char *name)
 861 {
 862         size_t len = strlen(name);
 863         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 864         memcpy(ref->name, prefix, prefixlen);
 865         memcpy(ref->name + prefixlen, name, len);
 866         return ref;
 867 }
 868
 869 struct ref *alloc_ref(const char *name)
 870 {
 871         return alloc_ref_with_prefix("", 0, name);
 872 }
 873
 874 struct ref *copy_ref(const struct ref *ref)
 875 {
 876         struct ref *cpy;
 877         size_t len;
 878         if (!ref)
 879                 return NULL;
 880         len = strlen(ref->name);
 881         cpy = xmalloc(sizeof(struct ref) + len + 1);
 882         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 883         cpy->next = NULL;
 884         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 885         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 886         cpy->peer_ref = copy_ref(ref->peer_ref);
 887         return cpy;
 888 }
 889
 890 struct ref *copy_ref_list(const struct ref *ref)
 891 {
 892         struct ref *ret = NULL;
 893         struct ref **tail = &ret;
 894         while (ref) {
 895                 *tail = copy_ref(ref);
 896                 ref = ref->next;
 897                 tail = &((*tail)->next);
 898         }
 899         return ret;
 900 }
 901
 902 static void free_ref(struct ref *ref)
 903 {
 904         if (!ref)
 905                 return;
 906         free_ref(ref->peer_ref);
 907         free(ref->remote_status);
 908         free(ref->symref);
 909         free(ref);
 910 }
 911
 912 void free_refs(struct ref *ref)
 913 {
 914         struct ref *next;
 915         while (ref) {
 916                 next = ref->next;
 917                 free_ref(ref);
 918                 ref = next;
 919         }
 920 }
 921
 922 int ref_compare_name(const void *va, const void *vb)
 923 {
 924         const struct ref *a = va, *b = vb;
 925         return strcmp(a->name, b->name);
 926 }
 927
 928 static void *ref_list_get_next(const void *a)
 929 {
 930         return ((const struct ref *)a)->next;
 931 }
 932
 933 static void ref_list_set_next(void *a, void *next)
 934 {
 935         ((struct ref *)a)->next = next;
 936 }
 937
 938 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 939 {
 940         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 941 }
 942
 943 static int count_refspec_match(const char *pattern,
 944                                struct ref *refs,
 945                                struct ref **matched_ref)
 946 {
 947         int patlen = strlen(pattern);
 948         struct ref *matched_weak = NULL;
 949         struct ref *matched = NULL;
 950         int weak_match = 0;
 951         int match = 0;
 952
 953         for (weak_match = match = 0; refs; refs = refs->next) {
 954                 char *name = refs->name;
 955                 int namelen = strlen(name);
 956
 957                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 958                         continue;
 959
 960                 /* A match is "weak" if it is with refs outside
 961                  * heads or tags, and did not specify the pattern
 962                  * in full (e.g. "refs/remotes/origin/master") or at
 963                  * least from the toplevel (e.g. "remotes/origin/master");
 964                  * otherwise "git push $URL master" would result in
 965                  * ambiguity between remotes/origin/master and heads/master
 966                  * at the remote site.
 967                  */
 968                 if (namelen != patlen &&
 969                     patlen != namelen - 5 &&
 970                     prefixcmp(name, "refs/heads/") &&
 971                     prefixcmp(name, "refs/tags/")) {
 972                         /* We want to catch the case where only weak
 973                          * matches are found and there are multiple
 974                          * matches, and where more than one strong
 975                          * matches are found, as ambiguous.  One
 976                          * strong match with zero or more weak matches
 977                          * are acceptable as a unique match.
 978                          */
 979                         matched_weak = refs;
 980                         weak_match++;
 981                 }
 982                 else {
 983                         matched = refs;
 984                         match++;
 985                 }
 986         }
 987         if (!matched) {
 988                 *matched_ref = matched_weak;
 989                 return weak_match;
 990         }
 991         else {
 992                 *matched_ref = matched;
 993                 return match;
 994         }
 995 }
 996
 997 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 998 {
 999         **tail = ref;
1000         while (ref->next)
1001                 ref = ref->next;
1002         *tail = &ref->next;
1003 }
1004
1005 static struct ref *alloc_delete_ref(void)
1006 {
1007         struct ref *ref = alloc_ref("(delete)");
1008         hashclr(ref->new_sha1);
1009         return ref;
1010 }
1011
1012 static struct ref *try_explicit_object_name(const char *name)
1013 {
1014         unsigned char sha1[20];
1015         struct ref *ref;
1016
1017         if (!*name)
1018                 return alloc_delete_ref();
1019         if (get_sha1(name, sha1))
1020                 return NULL;
1021         ref = alloc_ref(name);
1022         hashcpy(ref->new_sha1, sha1);
1023         return ref;
1024 }
1025
1026 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1027 {
1028         struct ref *ret = alloc_ref(name);
1029         tail_link_ref(ret, tail);
1030         return ret;
1031 }
1032
1033 static char *guess_ref(const char *name, struct ref *peer)
1034 {
1035         struct strbuf buf = STRBUF_INIT;
1036         unsigned char sha1[20];
1037
1038         const char *r = resolve_ref_unsafe(peer->name, sha1, 1, NULL);
1039         if (!r)
1040                 return NULL;
1041
1042         if (!prefixcmp(r, "refs/heads/"))
1043                 strbuf_addstr(&buf, "refs/heads/");
1044         else if (!prefixcmp(r, "refs/tags/"))
1045                 strbuf_addstr(&buf, "refs/tags/");
1046         else
1047                 return NULL;
1048
1049         strbuf_addstr(&buf, name);
1050         return strbuf_detach(&buf, NULL);
1051 }
1052
1053 static int match_explicit(struct ref *src, struct ref *dst,
1054                           struct ref ***dst_tail,
1055                           struct refspec *rs)
1056 {
1057         struct ref *matched_src, *matched_dst;
1058         int copy_src;
1059
1060         const char *dst_value = rs->dst;
1061         char *dst_guess;
1062
1063         if (rs->pattern || rs->matching)
1064                 return 0;
1065
1066         matched_src = matched_dst = NULL;
1067         switch (count_refspec_match(rs->src, src, &matched_src)) {
1068         case 1:
1069                 copy_src = 1;
1070                 break;
1071         case 0:
1072                 /* The source could be in the get_sha1() format
1073                  * not a reference name.  :refs/other is a
1074                  * way to delete 'other' ref at the remote end.
1075                  */
1076                 matched_src = try_explicit_object_name(rs->src);
1077                 if (!matched_src)
1078                         return error("src refspec %s does not match any.", rs->src);
1079                 copy_src = 0;
1080                 break;
1081         default:
1082                 return error("src refspec %s matches more than one.", rs->src);
1083         }
1084
1085         if (!dst_value) {
1086                 unsigned char sha1[20];
1087                 int flag;
1088
1089                 dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag);
1090                 if (!dst_value ||
1091                     ((flag & REF_ISSYMREF) &&
1092                      prefixcmp(dst_value, "refs/heads/")))
1093                         die("%s cannot be resolved to branch.",
1094                             matched_src->name);
1095         }
1096
1097         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1098         case 1:
1099                 break;
1100         case 0:
1101                 if (!memcmp(dst_value, "refs/", 5))
1102                         matched_dst = make_linked_ref(dst_value, dst_tail);
1103                 else if (is_null_sha1(matched_src->new_sha1))
1104                         error("unable to delete '%s': remote ref does not exist",
1105                               dst_value);
1106                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1107                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1108                 else
1109                         error("unable to push to unqualified destination: %s\n"
1110                               "The destination refspec neither matches an "
1111                               "existing ref on the remote nor\n"
1112                               "begins with refs/, and we are unable to "
1113                               "guess a prefix based on the source ref.",
1114                               dst_value);
1115                 break;
1116         default:
1117                 matched_dst = NULL;
1118                 error("dst refspec %s matches more than one.",
1119                       dst_value);
1120                 break;
1121         }
1122         if (!matched_dst)
1123                 return -1;
1124         if (matched_dst->peer_ref)
1125                 return error("dst ref %s receives from more than one src.",
1126                       matched_dst->name);
1127         else {
1128                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1129                 matched_dst->force = rs->force;
1130         }
1131         return 0;
1132 }
1133
1134 static int match_explicit_refs(struct ref *src, struct ref *dst,
1135                                struct ref ***dst_tail, struct refspec *rs,
1136                                int rs_nr)
1137 {
1138         int i, errs;
1139         for (i = errs = 0; i < rs_nr; i++)
1140                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1141         return errs;
1142 }
1143
1144 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1145                 int send_mirror, int direction, const struct refspec **ret_pat)
1146 {
1147         const struct refspec *pat;
1148         char *name;
1149         int i;
1150         int matching_refs = -1;
1151         for (i = 0; i < rs_nr; i++) {
1152                 if (rs[i].matching &&
1153                     (matching_refs == -1 || rs[i].force)) {
1154                         matching_refs = i;
1155                         continue;
1156                 }
1157
1158                 if (rs[i].pattern) {
1159                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1160                         int match;
1161                         if (direction == FROM_SRC)
1162                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1163                         else
1164                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1165                         if (match) {
1166                                 matching_refs = i;
1167                                 break;
1168                         }
1169                 }
1170         }
1171         if (matching_refs == -1)
1172                 return NULL;
1173
1174         pat = rs + matching_refs;
1175         if (pat->matching) {
1176                 /*
1177                  * "matching refs"; traditionally we pushed everything
1178                  * including refs outside refs/heads/ hierarchy, but
1179                  * that does not make much sense these days.
1180                  */
1181                 if (!send_mirror && prefixcmp(ref->name, "refs/heads/"))
1182                         return NULL;
1183                 name = xstrdup(ref->name);
1184         }
1185         if (ret_pat)
1186                 *ret_pat = pat;
1187         return name;
1188 }
1189
1190 static struct ref **tail_ref(struct ref **head)
1191 {
1192         struct ref **tail = head;
1193         while (*tail)
1194                 tail = &((*tail)->next);
1195         return tail;
1196 }
1197
1198 struct tips {
1199         struct commit **tip;
1200         int nr, alloc;
1201 };
1202
1203 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1204 {
1205         struct commit *commit;
1206
1207         if (is_null_sha1(sha1))
1208                 return;
1209         commit = lookup_commit_reference_gently(sha1, 1);
1210         if (!commit || (commit->object.flags & TMP_MARK))
1211                 return;
1212         commit->object.flags |= TMP_MARK;
1213         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1214         tips->tip[tips->nr++] = commit;
1215 }
1216
1217 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1218 {
1219         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1220         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1221         struct string_list_item *item;
1222         struct ref *ref;
1223         struct tips sent_tips;
1224
1225         /*
1226          * Collect everything we know they would have at the end of
1227          * this push, and collect all tags they have.
1228          */
1229         memset(&sent_tips, 0, sizeof(sent_tips));
1230         for (ref = *dst; ref; ref = ref->next) {
1231                 if (ref->peer_ref &&
1232                     !is_null_sha1(ref->peer_ref->new_sha1))
1233                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1234                 else
1235                         add_to_tips(&sent_tips, ref->old_sha1);
1236                 if (!prefixcmp(ref->name, "refs/tags/"))
1237                         string_list_append(&dst_tag, ref->name);
1238         }
1239         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1240
1241         sort_string_list(&dst_tag);
1242
1243         /* Collect tags they do not have. */
1244         for (ref = src; ref; ref = ref->next) {
1245                 if (prefixcmp(ref->name, "refs/tags/"))
1246                         continue; /* not a tag */
1247                 if (string_list_has_string(&dst_tag, ref->name))
1248                         continue; /* they already have it */
1249                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1250                         continue; /* be conservative */
1251                 item = string_list_append(&src_tag, ref->name);
1252                 item->util = ref;
1253         }
1254         string_list_clear(&dst_tag, 0);
1255
1256         /*
1257          * At this point, src_tag lists tags that are missing from
1258          * dst, and sent_tips lists the tips we are pushing or those
1259          * that we know they already have. An element in the src_tag
1260          * that is an ancestor of any of the sent_tips needs to be
1261          * sent to the other side.
1262          */
1263         if (sent_tips.nr) {
1264                 for_each_string_list_item(item, &src_tag) {
1265                         struct ref *ref = item->util;
1266                         struct ref *dst_ref;
1267                         struct commit *commit;
1268
1269                         if (is_null_sha1(ref->new_sha1))
1270                                 continue;
1271                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1272                         if (!commit)
1273                                 /* not pushing a commit, which is not an error */
1274                                 continue;
1275
1276                         /*
1277                          * Is this tag, which they do not have, reachable from
1278                          * any of the commits we are sending?
1279                          */
1280                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1281                                 continue;
1282
1283                         /* Add it in */
1284                         dst_ref = make_linked_ref(ref->name, dst_tail);
1285                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1286                         dst_ref->peer_ref = copy_ref(ref);
1287                 }
1288         }
1289         string_list_clear(&src_tag, 0);
1290         free(sent_tips.tip);
1291 }
1292
1293 /*
1294  * Given the set of refs the local repository has, the set of refs the
1295  * remote repository has, and the refspec used for push, determine
1296  * what remote refs we will update and with what value by setting
1297  * peer_ref (which object is being pushed) and force (if the push is
1298  * forced) in elements of "dst". The function may add new elements to
1299  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1300  */
1301 int match_push_refs(struct ref *src, struct ref **dst,
1302                     int nr_refspec, const char **refspec, int flags)
1303 {
1304         struct refspec *rs;
1305         int send_all = flags & MATCH_REFS_ALL;
1306         int send_mirror = flags & MATCH_REFS_MIRROR;
1307         int send_prune = flags & MATCH_REFS_PRUNE;
1308         int errs;
1309         static const char *default_refspec[] = { ":", NULL };
1310         struct ref *ref, **dst_tail = tail_ref(dst);
1311
1312         if (!nr_refspec) {
1313                 nr_refspec = 1;
1314                 refspec = default_refspec;
1315         }
1316         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1317         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1318
1319         /* pick the remainder */
1320         for (ref = src; ref; ref = ref->next) {
1321                 struct ref *dst_peer;
1322                 const struct refspec *pat = NULL;
1323                 char *dst_name;
1324
1325                 if (ref->peer_ref)
1326                         continue;
1327
1328                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1329                 if (!dst_name)
1330                         continue;
1331
1332                 dst_peer = find_ref_by_name(*dst, dst_name);
1333                 if (dst_peer) {
1334                         if (dst_peer->peer_ref)
1335                                 /* We're already sending something to this ref. */
1336                                 goto free_name;
1337                 } else {
1338                         if (pat->matching && !(send_all || send_mirror))
1339                                 /*
1340                                  * Remote doesn't have it, and we have no
1341                                  * explicit pattern, and we don't have
1342                                  * --all nor --mirror.
1343                                  */
1344                                 goto free_name;
1345
1346                         /* Create a new one and link it */
1347                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1348                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1349                 }
1350                 dst_peer->peer_ref = copy_ref(ref);
1351                 dst_peer->force = pat->force;
1352         free_name:
1353                 free(dst_name);
1354         }
1355
1356         if (flags & MATCH_REFS_FOLLOW_TAGS)
1357                 add_missing_tags(src, dst, &dst_tail);
1358
1359         if (send_prune) {
1360                 /* check for missing refs on the remote */
1361                 for (ref = *dst; ref; ref = ref->next) {
1362                         char *src_name;
1363
1364                         if (ref->peer_ref)
1365                                 /* We're already sending something to this ref. */
1366                                 continue;
1367
1368                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1369                         if (src_name) {
1370                                 if (!find_ref_by_name(src, src_name))
1371                                         ref->peer_ref = alloc_delete_ref();
1372                                 free(src_name);
1373                         }
1374                 }
1375         }
1376         if (errs)
1377                 return -1;
1378         return 0;
1379 }
1380
1381 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1382         int force_update)
1383 {
1384         struct ref *ref;
1385
1386         for (ref = remote_refs; ref; ref = ref->next) {
1387                 int force_ref_update = ref->force || force_update;
1388
1389                 if (ref->peer_ref)
1390                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1391                 else if (!send_mirror)
1392                         continue;
1393
1394                 ref->deletion = is_null_sha1(ref->new_sha1);
1395                 if (!ref->deletion &&
1396                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1397                         ref->status = REF_STATUS_UPTODATE;
1398                         continue;
1399                 }
1400
1401                 /*
1402                  * Decide whether an individual refspec A:B can be
1403                  * pushed.  The push will succeed if any of the
1404                  * following are true:
1405                  *
1406                  * (1) the remote reference B does not exist
1407                  *
1408                  * (2) the remote reference B is being removed (i.e.,
1409                  *     pushing :B where no source is specified)
1410                  *
1411                  * (3) the destination is not under refs/tags/, and
1412                  *     if the old and new value is a commit, the new
1413                  *     is a descendant of the old.
1414                  *
1415                  * (4) it is forced using the +A:B notation, or by
1416                  *     passing the --force argument
1417                  */
1418
1419                 if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1420                         int why = 0; /* why would this push require --force? */
1421
1422                         if (!prefixcmp(ref->name, "refs/tags/"))
1423                                 why = REF_STATUS_REJECT_ALREADY_EXISTS;
1424                         else if (!has_sha1_file(ref->old_sha1))
1425                                 why = REF_STATUS_REJECT_FETCH_FIRST;
1426                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1427                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1428                                 why = REF_STATUS_REJECT_NEEDS_FORCE;
1429                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1430                                 why = REF_STATUS_REJECT_NONFASTFORWARD;
1431
1432                         if (!force_ref_update)
1433                                 ref->status = why;
1434                         else if (why)
1435                                 ref->forced_update = 1;
1436                 }
1437         }
1438 }
1439
1440 struct branch *branch_get(const char *name)
1441 {
1442         struct branch *ret;
1443
1444         read_config();
1445         if (!name || !*name || !strcmp(name, "HEAD"))
1446                 ret = current_branch;
1447         else
1448                 ret = make_branch(name, 0);
1449         if (ret && ret->remote_name) {
1450                 ret->remote = remote_get(ret->remote_name);
1451                 if (ret->merge_nr) {
1452                         int i;
1453                         ret->merge = xcalloc(sizeof(*ret->merge),
1454                                              ret->merge_nr);
1455                         for (i = 0; i < ret->merge_nr; i++) {
1456                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1457                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1458                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1459                                     && !strcmp(ret->remote_name, "."))
1460                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1461                         }
1462                 }
1463         }
1464         return ret;
1465 }
1466
1467 int branch_has_merge_config(struct branch *branch)
1468 {
1469         return branch && !!branch->merge;
1470 }
1471
1472 int branch_merge_matches(struct branch *branch,
1473                                  int i,
1474                                  const char *refname)
1475 {
1476         if (!branch || i < 0 || i >= branch->merge_nr)
1477                 return 0;
1478         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1479 }
1480
1481 static int ignore_symref_update(const char *refname)
1482 {
1483         unsigned char sha1[20];
1484         int flag;
1485
1486         if (!resolve_ref_unsafe(refname, sha1, 0, &flag))
1487                 return 0; /* non-existing refs are OK */
1488         return (flag & REF_ISSYMREF);
1489 }
1490
1491 static struct ref *get_expanded_map(const struct ref *remote_refs,
1492                                     const struct refspec *refspec)
1493 {
1494         const struct ref *ref;
1495         struct ref *ret = NULL;
1496         struct ref **tail = &ret;
1497
1498         char *expn_name;
1499
1500         for (ref = remote_refs; ref; ref = ref->next) {
1501                 if (strchr(ref->name, '^'))
1502                         continue; /* a dereference item */
1503                 if (match_name_with_pattern(refspec->src, ref->name,
1504                                             refspec->dst, &expn_name) &&
1505                     !ignore_symref_update(expn_name)) {
1506                         struct ref *cpy = copy_ref(ref);
1507
1508                         cpy->peer_ref = alloc_ref(expn_name);
1509                         free(expn_name);
1510                         if (refspec->force)
1511                                 cpy->peer_ref->force = 1;
1512                         *tail = cpy;
1513                         tail = &cpy->next;
1514                 }
1515         }
1516
1517         return ret;
1518 }
1519
1520 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1521 {
1522         const struct ref *ref;
1523         for (ref = refs; ref; ref = ref->next) {
1524                 if (refname_match(name, ref->name, ref_fetch_rules))
1525                         return ref;
1526         }
1527         return NULL;
1528 }
1529
1530 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1531 {
1532         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1533
1534         if (!ref)
1535                 return NULL;
1536
1537         return copy_ref(ref);
1538 }
1539
1540 static struct ref *get_local_ref(const char *name)
1541 {
1542         if (!name || name[0] == '\0')
1543                 return NULL;
1544
1545         if (!prefixcmp(name, "refs/"))
1546                 return alloc_ref(name);
1547
1548         if (!prefixcmp(name, "heads/") ||
1549             !prefixcmp(name, "tags/") ||
1550             !prefixcmp(name, "remotes/"))
1551                 return alloc_ref_with_prefix("refs/", 5, name);
1552
1553         return alloc_ref_with_prefix("refs/heads/", 11, name);
1554 }
1555
1556 int get_fetch_map(const struct ref *remote_refs,
1557                   const struct refspec *refspec,
1558                   struct ref ***tail,
1559                   int missing_ok)
1560 {
1561         struct ref *ref_map, **rmp;
1562
1563         if (refspec->pattern) {
1564                 ref_map = get_expanded_map(remote_refs, refspec);
1565         } else {
1566                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1567
1568                 if (refspec->exact_sha1) {
1569                         ref_map = alloc_ref(name);
1570                         get_sha1_hex(name, ref_map->old_sha1);
1571                 } else {
1572                         ref_map = get_remote_ref(remote_refs, name);
1573                 }
1574                 if (!missing_ok && !ref_map)
1575                         die("Couldn't find remote ref %s", name);
1576                 if (ref_map) {
1577                         ref_map->peer_ref = get_local_ref(refspec->dst);
1578                         if (ref_map->peer_ref && refspec->force)
1579                                 ref_map->peer_ref->force = 1;
1580                 }
1581         }
1582
1583         for (rmp = &ref_map; *rmp; ) {
1584                 if ((*rmp)->peer_ref) {
1585                         if (prefixcmp((*rmp)->peer_ref->name, "refs/") ||
1586                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1587                                 struct ref *ignore = *rmp;
1588                                 error("* Ignoring funny ref '%s' locally",
1589                                       (*rmp)->peer_ref->name);
1590                                 *rmp = (*rmp)->next;
1591                                 free(ignore->peer_ref);
1592                                 free(ignore);
1593                                 continue;
1594                         }
1595                 }
1596                 rmp = &((*rmp)->next);
1597         }
1598
1599         if (ref_map)
1600                 tail_link_ref(ref_map, tail);
1601
1602         return 0;
1603 }
1604
1605 int resolve_remote_symref(struct ref *ref, struct ref *list)
1606 {
1607         if (!ref->symref)
1608                 return 0;
1609         for (; list; list = list->next)
1610                 if (!strcmp(ref->symref, list->name)) {
1611                         hashcpy(ref->old_sha1, list->old_sha1);
1612                         return 0;
1613                 }
1614         return 1;
1615 }
1616
1617 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1618 {
1619         while (list) {
1620                 struct commit_list *temp = list;
1621                 temp->item->object.flags &= ~mark;
1622                 list = temp->next;
1623                 free(temp);
1624         }
1625 }
1626
1627 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1628 {
1629         struct object *o;
1630         struct commit *old, *new;
1631         struct commit_list *list, *used;
1632         int found = 0;
1633
1634         /*
1635          * Both new and old must be commit-ish and new is descendant of
1636          * old.  Otherwise we require --force.
1637          */
1638         o = deref_tag(parse_object(old_sha1), NULL, 0);
1639         if (!o || o->type != OBJ_COMMIT)
1640                 return 0;
1641         old = (struct commit *) o;
1642
1643         o = deref_tag(parse_object(new_sha1), NULL, 0);
1644         if (!o || o->type != OBJ_COMMIT)
1645                 return 0;
1646         new = (struct commit *) o;
1647
1648         if (parse_commit(new) < 0)
1649                 return 0;
1650
1651         used = list = NULL;
1652         commit_list_insert(new, &list);
1653         while (list) {
1654                 new = pop_most_recent_commit(&list, TMP_MARK);
1655                 commit_list_insert(new, &used);
1656                 if (new == old) {
1657                         found = 1;
1658                         break;
1659                 }
1660         }
1661         unmark_and_free(list, TMP_MARK);
1662         unmark_and_free(used, TMP_MARK);
1663         return found;
1664 }
1665
1666 /*
1667  * Return true if there is anything to report, otherwise false.
1668  */
1669 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1670 {
1671         unsigned char sha1[20];
1672         struct commit *ours, *theirs;
1673         char symmetric[84];
1674         struct rev_info revs;
1675         const char *rev_argv[10], *base;
1676         int rev_argc;
1677
1678         /*
1679          * Nothing to report unless we are marked to build on top of
1680          * somebody else.
1681          */
1682         if (!branch ||
1683             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1684                 return 0;
1685
1686         /*
1687          * If what we used to build on no longer exists, there is
1688          * nothing to report.
1689          */
1690         base = branch->merge[0]->dst;
1691         if (read_ref(base, sha1))
1692                 return 0;
1693         theirs = lookup_commit_reference(sha1);
1694         if (!theirs)
1695                 return 0;
1696
1697         if (read_ref(branch->refname, sha1))
1698                 return 0;
1699         ours = lookup_commit_reference(sha1);
1700         if (!ours)
1701                 return 0;
1702
1703         /* are we the same? */
1704         if (theirs == ours)
1705                 return 0;
1706
1707         /* Run "rev-list --left-right ours...theirs" internally... */
1708         rev_argc = 0;
1709         rev_argv[rev_argc++] = NULL;
1710         rev_argv[rev_argc++] = "--left-right";
1711         rev_argv[rev_argc++] = symmetric;
1712         rev_argv[rev_argc++] = "--";
1713         rev_argv[rev_argc] = NULL;
1714
1715         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1716         strcpy(symmetric + 40, "...");
1717         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1718
1719         init_revisions(&revs, NULL);
1720         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1721         prepare_revision_walk(&revs);
1722
1723         /* ... and count the commits on each side. */
1724         *num_ours = 0;
1725         *num_theirs = 0;
1726         while (1) {
1727                 struct commit *c = get_revision(&revs);
1728                 if (!c)
1729                         break;
1730                 if (c->object.flags & SYMMETRIC_LEFT)
1731                         (*num_ours)++;
1732                 else
1733                         (*num_theirs)++;
1734         }
1735
1736         /* clear object flags smudged by the above traversal */
1737         clear_commit_marks(ours, ALL_REV_FLAGS);
1738         clear_commit_marks(theirs, ALL_REV_FLAGS);
1739         return 1;
1740 }
1741
1742 /*
1743  * Return true when there is anything to report, otherwise false.
1744  */
1745 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1746 {
1747         int num_ours, num_theirs;
1748         const char *base;
1749
1750         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1751                 return 0;
1752
1753         base = branch->merge[0]->dst;
1754         base = shorten_unambiguous_ref(base, 0);
1755         if (!num_theirs) {
1756                 strbuf_addf(sb,
1757                         Q_("Your branch is ahead of '%s' by %d commit.\n",
1758                            "Your branch is ahead of '%s' by %d commits.\n",
1759                            num_ours),
1760                         base, num_ours);
1761                 if (advice_status_hints)
1762                         strbuf_addf(sb,
1763                                 _("  (use \"git push\" to publish your local commits)\n"));
1764         } else if (!num_ours) {
1765                 strbuf_addf(sb,
1766                         Q_("Your branch is behind '%s' by %d commit, "
1767                                "and can be fast-forwarded.\n",
1768                            "Your branch is behind '%s' by %d commits, "
1769                                "and can be fast-forwarded.\n",
1770                            num_theirs),
1771                         base, num_theirs);
1772                 if (advice_status_hints)
1773                         strbuf_addf(sb,
1774                                 _("  (use \"git pull\" to update your local branch)\n"));
1775         } else {
1776                 strbuf_addf(sb,
1777                         Q_("Your branch and '%s' have diverged,\n"
1778                                "and have %d and %d different commit each, "
1779                                "respectively.\n",
1780                            "Your branch and '%s' have diverged,\n"
1781                                "and have %d and %d different commits each, "
1782                                "respectively.\n",
1783                            num_theirs),
1784                         base, num_ours, num_theirs);
1785                 if (advice_status_hints)
1786                         strbuf_addf(sb,
1787                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1788         }
1789         return 1;
1790 }
1791
1792 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1793 {
1794         struct ref ***local_tail = cb_data;
1795         struct ref *ref;
1796         int len;
1797
1798         /* we already know it starts with refs/ to get here */
1799         if (check_refname_format(refname + 5, 0))
1800                 return 0;
1801
1802         len = strlen(refname) + 1;
1803         ref = xcalloc(1, sizeof(*ref) + len);
1804         hashcpy(ref->new_sha1, sha1);
1805         memcpy(ref->name, refname, len);
1806         **local_tail = ref;
1807         *local_tail = &ref->next;
1808         return 0;
1809 }
1810
1811 struct ref *get_local_heads(void)
1812 {
1813         struct ref *local_refs = NULL, **local_tail = &local_refs;
1814         for_each_ref(one_local_ref, &local_tail);
1815         return local_refs;
1816 }
1817
1818 struct ref *guess_remote_head(const struct ref *head,
1819                               const struct ref *refs,
1820                               int all)
1821 {
1822         const struct ref *r;
1823         struct ref *list = NULL;
1824         struct ref **tail = &list;
1825
1826         if (!head)
1827                 return NULL;
1828
1829         /*
1830          * Some transports support directly peeking at
1831          * where HEAD points; if that is the case, then
1832          * we don't have to guess.
1833          */
1834         if (head->symref)
1835                 return copy_ref(find_ref_by_name(refs, head->symref));
1836
1837         /* If refs/heads/master could be right, it is. */
1838         if (!all) {
1839                 r = find_ref_by_name(refs, "refs/heads/master");
1840                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1841                         return copy_ref(r);
1842         }
1843
1844         /* Look for another ref that points there */
1845         for (r = refs; r; r = r->next) {
1846                 if (r != head &&
1847                     !prefixcmp(r->name, "refs/heads/") &&
1848                     !hashcmp(r->old_sha1, head->old_sha1)) {
1849                         *tail = copy_ref(r);
1850                         tail = &((*tail)->next);
1851                         if (!all)
1852                                 break;
1853                 }
1854         }
1855
1856         return list;
1857 }
1858
1859 struct stale_heads_info {
1860         struct string_list *ref_names;
1861         struct ref **stale_refs_tail;
1862         struct refspec *refs;
1863         int ref_count;
1864 };
1865
1866 static int get_stale_heads_cb(const char *refname,
1867         const unsigned char *sha1, int flags, void *cb_data)
1868 {
1869         struct stale_heads_info *info = cb_data;
1870         struct refspec query;
1871         memset(&query, 0, sizeof(struct refspec));
1872         query.dst = (char *)refname;
1873
1874         if (query_refspecs(info->refs, info->ref_count, &query))
1875                 return 0; /* No matches */
1876
1877         /*
1878          * If we did find a suitable refspec and it's not a symref and
1879          * it's not in the list of refs that currently exist in that
1880          * remote we consider it to be stale.
1881          */
1882         if (!((flags & REF_ISSYMREF) ||
1883               string_list_has_string(info->ref_names, query.src))) {
1884                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1885                 hashcpy(ref->new_sha1, sha1);
1886         }
1887
1888         free(query.src);
1889         return 0;
1890 }
1891
1892 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
1893 {
1894         struct ref *ref, *stale_refs = NULL;
1895         struct string_list ref_names = STRING_LIST_INIT_NODUP;
1896         struct stale_heads_info info;
1897         info.ref_names = &ref_names;
1898         info.stale_refs_tail = &stale_refs;
1899         info.refs = refs;
1900         info.ref_count = ref_count;
1901         for (ref = fetch_map; ref; ref = ref->next)
1902                 string_list_append(&ref_names, ref->name);
1903         sort_string_list(&ref_names);
1904         for_each_ref(get_stale_heads_cb, &info);
1905         string_list_clear(&ref_names, 0);
1906         return stale_refs;
1907 }