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 const char *pushremote_name;
  53 static int explicit_default_remote_name;
  54
  55 static struct rewrites rewrites;
  56 static struct rewrites rewrites_push;
  57
  58 #define BUF_SIZE (2048)
  59 static char buffer[BUF_SIZE];
  60
  61 static int valid_remote(const struct remote *remote)
  62 {
  63         return (!!remote->url) || (!!remote->foreign_vcs);
  64 }
  65
  66 static const char *alias_url(const char *url, struct rewrites *r)
  67 {
  68         int i, j;
  69         char *ret;
  70         struct counted_string *longest;
  71         int longest_i;
  72
  73         longest = NULL;
  74         longest_i = -1;
  75         for (i = 0; i < r->rewrite_nr; i++) {
  76                 if (!r->rewrite[i])
  77                         continue;
  78                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  79                         if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  80                             (!longest ||
  81                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  82                                 longest = &(r->rewrite[i]->instead_of[j]);
  83                                 longest_i = i;
  84                         }
  85                 }
  86         }
  87         if (!longest)
  88                 return url;
  89
  90         ret = xmalloc(r->rewrite[longest_i]->baselen +
  91                      (strlen(url) - longest->len) + 1);
  92         strcpy(ret, r->rewrite[longest_i]->base);
  93         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  94         return ret;
  95 }
  96
  97 static void add_push_refspec(struct remote *remote, const char *ref)
  98 {
  99         ALLOC_GROW(remote->push_refspec,
 100                    remote->push_refspec_nr + 1,
 101                    remote->push_refspec_alloc);
 102         remote->push_refspec[remote->push_refspec_nr++] = ref;
 103 }
 104
 105 static void add_fetch_refspec(struct remote *remote, const char *ref)
 106 {
 107         ALLOC_GROW(remote->fetch_refspec,
 108                    remote->fetch_refspec_nr + 1,
 109                    remote->fetch_refspec_alloc);
 110         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 111 }
 112
 113 static void add_url(struct remote *remote, const char *url)
 114 {
 115         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 116         remote->url[remote->url_nr++] = url;
 117 }
 118
 119 static void add_pushurl(struct remote *remote, const char *pushurl)
 120 {
 121         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 122         remote->pushurl[remote->pushurl_nr++] = pushurl;
 123 }
 124
 125 static void add_pushurl_alias(struct remote *remote, const char *url)
 126 {
 127         const char *pushurl = alias_url(url, &rewrites_push);
 128         if (pushurl != url)
 129                 add_pushurl(remote, pushurl);
 130 }
 131
 132 static void add_url_alias(struct remote *remote, const char *url)
 133 {
 134         add_url(remote, alias_url(url, &rewrites));
 135         add_pushurl_alias(remote, url);
 136 }
 137
 138 static struct remote *make_remote(const char *name, int len)
 139 {
 140         struct remote *ret;
 141         int i;
 142
 143         for (i = 0; i < remotes_nr; i++) {
 144                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 145                            !remotes[i]->name[len]) :
 146                     !strcmp(name, remotes[i]->name))
 147                         return remotes[i];
 148         }
 149
 150         ret = xcalloc(1, sizeof(struct remote));
 151         ret->prune = -1;  /* unspecified */
 152         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 153         remotes[remotes_nr++] = ret;
 154         if (len)
 155                 ret->name = xstrndup(name, len);
 156         else
 157                 ret->name = xstrdup(name);
 158         return ret;
 159 }
 160
 161 static void add_merge(struct branch *branch, const char *name)
 162 {
 163         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 164                    branch->merge_alloc);
 165         branch->merge_name[branch->merge_nr++] = name;
 166 }
 167
 168 static struct branch *make_branch(const char *name, int len)
 169 {
 170         struct branch *ret;
 171         int i;
 172         char *refname;
 173
 174         for (i = 0; i < branches_nr; i++) {
 175                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 176                            !branches[i]->name[len]) :
 177                     !strcmp(name, branches[i]->name))
 178                         return branches[i];
 179         }
 180
 181         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 182         ret = xcalloc(1, sizeof(struct branch));
 183         branches[branches_nr++] = ret;
 184         if (len)
 185                 ret->name = xstrndup(name, len);
 186         else
 187                 ret->name = xstrdup(name);
 188         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 189         strcpy(refname, "refs/heads/");
 190         strcpy(refname + strlen("refs/heads/"), ret->name);
 191         ret->refname = refname;
 192
 193         return ret;
 194 }
 195
 196 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 197 {
 198         struct rewrite *ret;
 199         int i;
 200
 201         for (i = 0; i < r->rewrite_nr; i++) {
 202                 if (len
 203                     ? (len == r->rewrite[i]->baselen &&
 204                        !strncmp(base, r->rewrite[i]->base, len))
 205                     : !strcmp(base, r->rewrite[i]->base))
 206                         return r->rewrite[i];
 207         }
 208
 209         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 210         ret = xcalloc(1, sizeof(struct rewrite));
 211         r->rewrite[r->rewrite_nr++] = ret;
 212         if (len) {
 213                 ret->base = xstrndup(base, len);
 214                 ret->baselen = len;
 215         }
 216         else {
 217                 ret->base = xstrdup(base);
 218                 ret->baselen = strlen(base);
 219         }
 220         return ret;
 221 }
 222
 223 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 224 {
 225         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 226         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 227         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 228         rewrite->instead_of_nr++;
 229 }
 230
 231 static void read_remotes_file(struct remote *remote)
 232 {
 233         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 234
 235         if (!f)
 236                 return;
 237         remote->origin = REMOTE_REMOTES;
 238         while (fgets(buffer, BUF_SIZE, f)) {
 239                 int value_list;
 240                 char *s, *p;
 241
 242                 if (!prefixcmp(buffer, "URL:")) {
 243                         value_list = 0;
 244                         s = buffer + 4;
 245                 } else if (!prefixcmp(buffer, "Push:")) {
 246                         value_list = 1;
 247                         s = buffer + 5;
 248                 } else if (!prefixcmp(buffer, "Pull:")) {
 249                         value_list = 2;
 250                         s = buffer + 5;
 251                 } else
 252                         continue;
 253
 254                 while (isspace(*s))
 255                         s++;
 256                 if (!*s)
 257                         continue;
 258
 259                 p = s + strlen(s);
 260                 while (isspace(p[-1]))
 261                         *--p = 0;
 262
 263                 switch (value_list) {
 264                 case 0:
 265                         add_url_alias(remote, xstrdup(s));
 266                         break;
 267                 case 1:
 268                         add_push_refspec(remote, xstrdup(s));
 269                         break;
 270                 case 2:
 271                         add_fetch_refspec(remote, xstrdup(s));
 272                         break;
 273                 }
 274         }
 275         fclose(f);
 276 }
 277
 278 static void read_branches_file(struct remote *remote)
 279 {
 280         char *frag;
 281         struct strbuf branch = STRBUF_INIT;
 282         int n = 1000;
 283         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 284         char *s, *p;
 285         int len;
 286
 287         if (!f)
 288                 return;
 289         s = fgets(buffer, BUF_SIZE, f);
 290         fclose(f);
 291         if (!s)
 292                 return;
 293         while (isspace(*s))
 294                 s++;
 295         if (!*s)
 296                 return;
 297         remote->origin = REMOTE_BRANCHES;
 298         p = s + strlen(s);
 299         while (isspace(p[-1]))
 300                 *--p = 0;
 301         len = p - s;
 302         p = xmalloc(len + 1);
 303         strcpy(p, s);
 304
 305         /*
 306          * The branches file would have URL and optionally
 307          * #branch specified.  The "master" (or specified) branch is
 308          * fetched and stored in the local branch of the same name.
 309          */
 310         frag = strchr(p, '#');
 311         if (frag) {
 312                 *(frag++) = '\0';
 313                 strbuf_addf(&branch, "refs/heads/%s", frag);
 314         } else
 315                 strbuf_addstr(&branch, "refs/heads/master");
 316
 317         strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 318         add_url_alias(remote, p);
 319         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 320         /*
 321          * Cogito compatible push: push current HEAD to remote #branch
 322          * (master if missing)
 323          */
 324         strbuf_init(&branch, 0);
 325         strbuf_addstr(&branch, "HEAD");
 326         if (frag)
 327                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 328         else
 329                 strbuf_addstr(&branch, ":refs/heads/master");
 330         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 331         remote->fetch_tags = 1; /* always auto-follow */
 332 }
 333
 334 static int handle_config(const char *key, const char *value, void *cb)
 335 {
 336         const char *name;
 337         const char *subkey;
 338         struct remote *remote;
 339         struct branch *branch;
 340         if (!prefixcmp(key, "branch.")) {
 341                 name = key + 7;
 342                 subkey = strrchr(name, '.');
 343                 if (!subkey)
 344                         return 0;
 345                 branch = make_branch(name, subkey - name);
 346                 if (!strcmp(subkey, ".remote")) {
 347                         if (git_config_string(&branch->remote_name, key, value))
 348                                 return -1;
 349                         if (branch == current_branch) {
 350                                 default_remote_name = branch->remote_name;
 351                                 explicit_default_remote_name = 1;
 352                         }
 353                 } else if (!strcmp(subkey, ".pushremote")) {
 354                         if (branch == current_branch)
 355                                 if (git_config_string(&pushremote_name, key, value))
 356                                         return -1;
 357                 } else if (!strcmp(subkey, ".merge")) {
 358                         if (!value)
 359                                 return config_error_nonbool(key);
 360                         add_merge(branch, xstrdup(value));
 361                 }
 362                 return 0;
 363         }
 364         if (!prefixcmp(key, "url.")) {
 365                 struct rewrite *rewrite;
 366                 name = key + 4;
 367                 subkey = strrchr(name, '.');
 368                 if (!subkey)
 369                         return 0;
 370                 if (!strcmp(subkey, ".insteadof")) {
 371                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 372                         if (!value)
 373                                 return config_error_nonbool(key);
 374                         add_instead_of(rewrite, xstrdup(value));
 375                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 376                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 377                         if (!value)
 378                                 return config_error_nonbool(key);
 379                         add_instead_of(rewrite, xstrdup(value));
 380                 }
 381         }
 382
 383         if (prefixcmp(key,  "remote."))
 384                 return 0;
 385         name = key + 7;
 386
 387         /* Handle remote.* variables */
 388         if (!strcmp(name, "pushdefault"))
 389                 return git_config_string(&pushremote_name, key, value);
 390
 391         /* Handle remote.<name>.* variables */
 392         if (*name == '/') {
 393                 warning("Config remote shorthand cannot begin with '/': %s",
 394                         name);
 395                 return 0;
 396         }
 397         subkey = strrchr(name, '.');
 398         if (!subkey)
 399                 return 0;
 400         remote = make_remote(name, subkey - name);
 401         remote->origin = REMOTE_CONFIG;
 402         if (!strcmp(subkey, ".mirror"))
 403                 remote->mirror = git_config_bool(key, value);
 404         else if (!strcmp(subkey, ".skipdefaultupdate"))
 405                 remote->skip_default_update = git_config_bool(key, value);
 406         else if (!strcmp(subkey, ".skipfetchall"))
 407                 remote->skip_default_update = git_config_bool(key, value);
 408         else if (!strcmp(subkey, ".prune"))
 409                 remote->prune = 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                         unsigned char unused[40];
 569
 570                         /* LHS */
 571                         if (!*rs[i].src)
 572                                 ; /* empty is ok; it means "HEAD" */
 573                         else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 574                                 rs[i].exact_sha1 = 1; /* ok */
 575                         else if (!check_refname_format(rs[i].src, flags))
 576                                 ; /* valid looking ref is ok */
 577                         else
 578                                 goto invalid;
 579                         /* RHS */
 580                         if (!rs[i].dst)
 581                                 ; /* missing is ok; it is the same as empty */
 582                         else if (!*rs[i].dst)
 583                                 ; /* empty is ok; it means "do not store" */
 584                         else if (!check_refname_format(rs[i].dst, flags))
 585                                 ; /* valid looking ref is ok */
 586                         else
 587                                 goto invalid;
 588                 } else {
 589                         /*
 590                          * LHS
 591                          * - empty is allowed; it means delete.
 592                          * - when wildcarded, it must be a valid looking ref.
 593                          * - otherwise, it must be an extended SHA-1, but
 594                          *   there is no existing way to validate this.
 595                          */
 596                         if (!*rs[i].src)
 597                                 ; /* empty is ok */
 598                         else if (is_glob) {
 599                                 if (check_refname_format(rs[i].src, flags))
 600                                         goto invalid;
 601                         }
 602                         else
 603                                 ; /* anything goes, for now */
 604                         /*
 605                          * RHS
 606                          * - missing is allowed, but LHS then must be a
 607                          *   valid looking ref.
 608                          * - empty is not allowed.
 609                          * - otherwise it must be a valid looking ref.
 610                          */
 611                         if (!rs[i].dst) {
 612                                 if (check_refname_format(rs[i].src, flags))
 613                                         goto invalid;
 614                         } else if (!*rs[i].dst) {
 615                                 goto invalid;
 616                         } else {
 617                                 if (check_refname_format(rs[i].dst, flags))
 618                                         goto invalid;
 619                         }
 620                 }
 621         }
 622         return rs;
 623
 624  invalid:
 625         if (verify) {
 626                 /*
 627                  * nr_refspec must be greater than zero and i must be valid
 628                  * since it is only possible to reach this point from within
 629                  * the for loop above.
 630                  */
 631                 free_refspecs(rs, i+1);
 632                 return NULL;
 633         }
 634         die("Invalid refspec '%s'", refspec[i]);
 635 }
 636
 637 int valid_fetch_refspec(const char *fetch_refspec_str)
 638 {
 639         struct refspec *refspec;
 640
 641         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 642         free_refspecs(refspec, 1);
 643         return !!refspec;
 644 }
 645
 646 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 647 {
 648         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 649 }
 650
 651 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 652 {
 653         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 654 }
 655
 656 void free_refspec(int nr_refspec, struct refspec *refspec)
 657 {
 658         int i;
 659         for (i = 0; i < nr_refspec; i++) {
 660                 free(refspec[i].src);
 661                 free(refspec[i].dst);
 662         }
 663         free(refspec);
 664 }
 665
 666 static int valid_remote_nick(const char *name)
 667 {
 668         if (!name[0] || is_dot_or_dotdot(name))
 669                 return 0;
 670         return !strchr(name, '/'); /* no slash */
 671 }
 672
 673 static struct remote *remote_get_1(const char *name, const char *pushremote_name)
 674 {
 675         struct remote *ret;
 676         int name_given = 0;
 677
 678         if (name)
 679                 name_given = 1;
 680         else {
 681                 if (pushremote_name) {
 682                         name = pushremote_name;
 683                         name_given = 1;
 684                 } else {
 685                         name = default_remote_name;
 686                         name_given = explicit_default_remote_name;
 687                 }
 688         }
 689
 690         ret = make_remote(name, 0);
 691         if (valid_remote_nick(name)) {
 692                 if (!valid_remote(ret))
 693                         read_remotes_file(ret);
 694                 if (!valid_remote(ret))
 695                         read_branches_file(ret);
 696         }
 697         if (name_given && !valid_remote(ret))
 698                 add_url_alias(ret, name);
 699         if (!valid_remote(ret))
 700                 return NULL;
 701         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 702         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 703         return ret;
 704 }
 705
 706 struct remote *remote_get(const char *name)
 707 {
 708         read_config();
 709         return remote_get_1(name, NULL);
 710 }
 711
 712 struct remote *pushremote_get(const char *name)
 713 {
 714         read_config();
 715         return remote_get_1(name, pushremote_name);
 716 }
 717
 718 int remote_is_configured(const char *name)
 719 {
 720         int i;
 721         read_config();
 722
 723         for (i = 0; i < remotes_nr; i++)
 724                 if (!strcmp(name, remotes[i]->name))
 725                         return 1;
 726         return 0;
 727 }
 728
 729 int for_each_remote(each_remote_fn fn, void *priv)
 730 {
 731         int i, result = 0;
 732         read_config();
 733         for (i = 0; i < remotes_nr && !result; i++) {
 734                 struct remote *r = remotes[i];
 735                 if (!r)
 736                         continue;
 737                 if (!r->fetch)
 738                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 739                                                        r->fetch_refspec);
 740                 if (!r->push)
 741                         r->push = parse_push_refspec(r->push_refspec_nr,
 742                                                      r->push_refspec);
 743                 result = fn(r, priv);
 744         }
 745         return result;
 746 }
 747
 748 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 749 {
 750         if (strcmp(ref1->name, ref2->name))
 751                 die("%s tracks both %s and %s",
 752                     ref2->peer_ref->name, ref1->name, ref2->name);
 753         free(ref2->peer_ref);
 754         free(ref2);
 755 }
 756
 757 struct ref *ref_remove_duplicates(struct ref *ref_map)
 758 {
 759         struct string_list refs = STRING_LIST_INIT_NODUP;
 760         struct ref *retval = NULL;
 761         struct ref **p = &retval;
 762
 763         while (ref_map) {
 764                 struct ref *ref = ref_map;
 765
 766                 ref_map = ref_map->next;
 767                 ref->next = NULL;
 768
 769                 if (!ref->peer_ref) {
 770                         *p = ref;
 771                         p = &ref->next;
 772                 } else {
 773                         struct string_list_item *item =
 774                                 string_list_insert(&refs, ref->peer_ref->name);
 775
 776                         if (item->util) {
 777                                 /* Entry already existed */
 778                                 handle_duplicate((struct ref *)item->util, ref);
 779                         } else {
 780                                 *p = ref;
 781                                 p = &ref->next;
 782                                 item->util = ref;
 783                         }
 784                 }
 785         }
 786
 787         string_list_clear(&refs, 0);
 788         return retval;
 789 }
 790
 791 int remote_has_url(struct remote *remote, const char *url)
 792 {
 793         int i;
 794         for (i = 0; i < remote->url_nr; i++) {
 795                 if (!strcmp(remote->url[i], url))
 796                         return 1;
 797         }
 798         return 0;
 799 }
 800
 801 static int match_name_with_pattern(const char *key, const char *name,
 802                                    const char *value, char **result)
 803 {
 804         const char *kstar = strchr(key, '*');
 805         size_t klen;
 806         size_t ksuffixlen;
 807         size_t namelen;
 808         int ret;
 809         if (!kstar)
 810                 die("Key '%s' of pattern had no '*'", key);
 811         klen = kstar - key;
 812         ksuffixlen = strlen(kstar + 1);
 813         namelen = strlen(name);
 814         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 815                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 816         if (ret && value) {
 817                 const char *vstar = strchr(value, '*');
 818                 size_t vlen;
 819                 size_t vsuffixlen;
 820                 if (!vstar)
 821                         die("Value '%s' of pattern has no '*'", value);
 822                 vlen = vstar - value;
 823                 vsuffixlen = strlen(vstar + 1);
 824                 *result = xmalloc(vlen + vsuffixlen +
 825                                   strlen(name) -
 826                                   klen - ksuffixlen + 1);
 827                 strncpy(*result, value, vlen);
 828                 strncpy(*result + vlen,
 829                         name + klen, namelen - klen - ksuffixlen);
 830                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 831                        vstar + 1);
 832         }
 833         return ret;
 834 }
 835
 836 static int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 837 {
 838         int i;
 839         int find_src = !query->src;
 840         const char *needle = find_src ? query->dst : query->src;
 841         char **result = find_src ? &query->src : &query->dst;
 842
 843         if (find_src && !query->dst)
 844                 return error("query_refspecs: need either src or dst");
 845
 846         for (i = 0; i < ref_count; i++) {
 847                 struct refspec *refspec = &refs[i];
 848                 const char *key = find_src ? refspec->dst : refspec->src;
 849                 const char *value = find_src ? refspec->src : refspec->dst;
 850
 851                 if (!refspec->dst)
 852                         continue;
 853                 if (refspec->pattern) {
 854                         if (match_name_with_pattern(key, needle, value, result)) {
 855                                 query->force = refspec->force;
 856                                 return 0;
 857                         }
 858                 } else if (!strcmp(needle, key)) {
 859                         *result = xstrdup(value);
 860                         query->force = refspec->force;
 861                         return 0;
 862                 }
 863         }
 864         return -1;
 865 }
 866
 867 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 868                      const char *name)
 869 {
 870         struct refspec query;
 871
 872         memset(&query, 0, sizeof(struct refspec));
 873         query.src = (char *)name;
 874
 875         if (query_refspecs(refspecs, nr_refspec, &query))
 876                 return NULL;
 877
 878         return query.dst;
 879 }
 880
 881 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 882 {
 883         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 884 }
 885
 886 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 887                 const char *name)
 888 {
 889         size_t len = strlen(name);
 890         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 891         memcpy(ref->name, prefix, prefixlen);
 892         memcpy(ref->name + prefixlen, name, len);
 893         return ref;
 894 }
 895
 896 struct ref *alloc_ref(const char *name)
 897 {
 898         return alloc_ref_with_prefix("", 0, name);
 899 }
 900
 901 struct ref *copy_ref(const struct ref *ref)
 902 {
 903         struct ref *cpy;
 904         size_t len;
 905         if (!ref)
 906                 return NULL;
 907         len = strlen(ref->name);
 908         cpy = xmalloc(sizeof(struct ref) + len + 1);
 909         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 910         cpy->next = NULL;
 911         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 912         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 913         cpy->peer_ref = copy_ref(ref->peer_ref);
 914         return cpy;
 915 }
 916
 917 struct ref *copy_ref_list(const struct ref *ref)
 918 {
 919         struct ref *ret = NULL;
 920         struct ref **tail = &ret;
 921         while (ref) {
 922                 *tail = copy_ref(ref);
 923                 ref = ref->next;
 924                 tail = &((*tail)->next);
 925         }
 926         return ret;
 927 }
 928
 929 static void free_ref(struct ref *ref)
 930 {
 931         if (!ref)
 932                 return;
 933         free_ref(ref->peer_ref);
 934         free(ref->remote_status);
 935         free(ref->symref);
 936         free(ref);
 937 }
 938
 939 void free_refs(struct ref *ref)
 940 {
 941         struct ref *next;
 942         while (ref) {
 943                 next = ref->next;
 944                 free_ref(ref);
 945                 ref = next;
 946         }
 947 }
 948
 949 int ref_compare_name(const void *va, const void *vb)
 950 {
 951         const struct ref *a = va, *b = vb;
 952         return strcmp(a->name, b->name);
 953 }
 954
 955 static void *ref_list_get_next(const void *a)
 956 {
 957         return ((const struct ref *)a)->next;
 958 }
 959
 960 static void ref_list_set_next(void *a, void *next)
 961 {
 962         ((struct ref *)a)->next = next;
 963 }
 964
 965 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 966 {
 967         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 968 }
 969
 970 static int count_refspec_match(const char *pattern,
 971                                struct ref *refs,
 972                                struct ref **matched_ref)
 973 {
 974         int patlen = strlen(pattern);
 975         struct ref *matched_weak = NULL;
 976         struct ref *matched = NULL;
 977         int weak_match = 0;
 978         int match = 0;
 979
 980         for (weak_match = match = 0; refs; refs = refs->next) {
 981                 char *name = refs->name;
 982                 int namelen = strlen(name);
 983
 984                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 985                         continue;
 986
 987                 /* A match is "weak" if it is with refs outside
 988                  * heads or tags, and did not specify the pattern
 989                  * in full (e.g. "refs/remotes/origin/master") or at
 990                  * least from the toplevel (e.g. "remotes/origin/master");
 991                  * otherwise "git push $URL master" would result in
 992                  * ambiguity between remotes/origin/master and heads/master
 993                  * at the remote site.
 994                  */
 995                 if (namelen != patlen &&
 996                     patlen != namelen - 5 &&
 997                     prefixcmp(name, "refs/heads/") &&
 998                     prefixcmp(name, "refs/tags/")) {
 999                         /* We want to catch the case where only weak
1000                          * matches are found and there are multiple
1001                          * matches, and where more than one strong
1002                          * matches are found, as ambiguous.  One
1003                          * strong match with zero or more weak matches
1004                          * are acceptable as a unique match.
1005                          */
1006                         matched_weak = refs;
1007                         weak_match++;
1008                 }
1009                 else {
1010                         matched = refs;
1011                         match++;
1012                 }
1013         }
1014         if (!matched) {
1015                 *matched_ref = matched_weak;
1016                 return weak_match;
1017         }
1018         else {
1019                 *matched_ref = matched;
1020                 return match;
1021         }
1022 }
1023
1024 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1025 {
1026         **tail = ref;
1027         while (ref->next)
1028                 ref = ref->next;
1029         *tail = &ref->next;
1030 }
1031
1032 static struct ref *alloc_delete_ref(void)
1033 {
1034         struct ref *ref = alloc_ref("(delete)");
1035         hashclr(ref->new_sha1);
1036         return ref;
1037 }
1038
1039 static struct ref *try_explicit_object_name(const char *name)
1040 {
1041         unsigned char sha1[20];
1042         struct ref *ref;
1043
1044         if (!*name)
1045                 return alloc_delete_ref();
1046         if (get_sha1(name, sha1))
1047                 return NULL;
1048         ref = alloc_ref(name);
1049         hashcpy(ref->new_sha1, sha1);
1050         return ref;
1051 }
1052
1053 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1054 {
1055         struct ref *ret = alloc_ref(name);
1056         tail_link_ref(ret, tail);
1057         return ret;
1058 }
1059
1060 static char *guess_ref(const char *name, struct ref *peer)
1061 {
1062         struct strbuf buf = STRBUF_INIT;
1063         unsigned char sha1[20];
1064
1065         const char *r = resolve_ref_unsafe(peer->name, sha1, 1, NULL);
1066         if (!r)
1067                 return NULL;
1068
1069         if (!prefixcmp(r, "refs/heads/"))
1070                 strbuf_addstr(&buf, "refs/heads/");
1071         else if (!prefixcmp(r, "refs/tags/"))
1072                 strbuf_addstr(&buf, "refs/tags/");
1073         else
1074                 return NULL;
1075
1076         strbuf_addstr(&buf, name);
1077         return strbuf_detach(&buf, NULL);
1078 }
1079
1080 static int match_explicit(struct ref *src, struct ref *dst,
1081                           struct ref ***dst_tail,
1082                           struct refspec *rs)
1083 {
1084         struct ref *matched_src, *matched_dst;
1085         int copy_src;
1086
1087         const char *dst_value = rs->dst;
1088         char *dst_guess;
1089
1090         if (rs->pattern || rs->matching)
1091                 return 0;
1092
1093         matched_src = matched_dst = NULL;
1094         switch (count_refspec_match(rs->src, src, &matched_src)) {
1095         case 1:
1096                 copy_src = 1;
1097                 break;
1098         case 0:
1099                 /* The source could be in the get_sha1() format
1100                  * not a reference name.  :refs/other is a
1101                  * way to delete 'other' ref at the remote end.
1102                  */
1103                 matched_src = try_explicit_object_name(rs->src);
1104                 if (!matched_src)
1105                         return error("src refspec %s does not match any.", rs->src);
1106                 copy_src = 0;
1107                 break;
1108         default:
1109                 return error("src refspec %s matches more than one.", rs->src);
1110         }
1111
1112         if (!dst_value) {
1113                 unsigned char sha1[20];
1114                 int flag;
1115
1116                 dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag);
1117                 if (!dst_value ||
1118                     ((flag & REF_ISSYMREF) &&
1119                      prefixcmp(dst_value, "refs/heads/")))
1120                         die("%s cannot be resolved to branch.",
1121                             matched_src->name);
1122         }
1123
1124         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1125         case 1:
1126                 break;
1127         case 0:
1128                 if (!memcmp(dst_value, "refs/", 5))
1129                         matched_dst = make_linked_ref(dst_value, dst_tail);
1130                 else if (is_null_sha1(matched_src->new_sha1))
1131                         error("unable to delete '%s': remote ref does not exist",
1132                               dst_value);
1133                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1134                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1135                 else
1136                         error("unable to push to unqualified destination: %s\n"
1137                               "The destination refspec neither matches an "
1138                               "existing ref on the remote nor\n"
1139                               "begins with refs/, and we are unable to "
1140                               "guess a prefix based on the source ref.",
1141                               dst_value);
1142                 break;
1143         default:
1144                 matched_dst = NULL;
1145                 error("dst refspec %s matches more than one.",
1146                       dst_value);
1147                 break;
1148         }
1149         if (!matched_dst)
1150                 return -1;
1151         if (matched_dst->peer_ref)
1152                 return error("dst ref %s receives from more than one src.",
1153                       matched_dst->name);
1154         else {
1155                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1156                 matched_dst->force = rs->force;
1157         }
1158         return 0;
1159 }
1160
1161 static int match_explicit_refs(struct ref *src, struct ref *dst,
1162                                struct ref ***dst_tail, struct refspec *rs,
1163                                int rs_nr)
1164 {
1165         int i, errs;
1166         for (i = errs = 0; i < rs_nr; i++)
1167                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1168         return errs;
1169 }
1170
1171 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1172                 int send_mirror, int direction, const struct refspec **ret_pat)
1173 {
1174         const struct refspec *pat;
1175         char *name;
1176         int i;
1177         int matching_refs = -1;
1178         for (i = 0; i < rs_nr; i++) {
1179                 if (rs[i].matching &&
1180                     (matching_refs == -1 || rs[i].force)) {
1181                         matching_refs = i;
1182                         continue;
1183                 }
1184
1185                 if (rs[i].pattern) {
1186                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1187                         int match;
1188                         if (direction == FROM_SRC)
1189                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1190                         else
1191                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1192                         if (match) {
1193                                 matching_refs = i;
1194                                 break;
1195                         }
1196                 }
1197         }
1198         if (matching_refs == -1)
1199                 return NULL;
1200
1201         pat = rs + matching_refs;
1202         if (pat->matching) {
1203                 /*
1204                  * "matching refs"; traditionally we pushed everything
1205                  * including refs outside refs/heads/ hierarchy, but
1206                  * that does not make much sense these days.
1207                  */
1208                 if (!send_mirror && prefixcmp(ref->name, "refs/heads/"))
1209                         return NULL;
1210                 name = xstrdup(ref->name);
1211         }
1212         if (ret_pat)
1213                 *ret_pat = pat;
1214         return name;
1215 }
1216
1217 static struct ref **tail_ref(struct ref **head)
1218 {
1219         struct ref **tail = head;
1220         while (*tail)
1221                 tail = &((*tail)->next);
1222         return tail;
1223 }
1224
1225 struct tips {
1226         struct commit **tip;
1227         int nr, alloc;
1228 };
1229
1230 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1231 {
1232         struct commit *commit;
1233
1234         if (is_null_sha1(sha1))
1235                 return;
1236         commit = lookup_commit_reference_gently(sha1, 1);
1237         if (!commit || (commit->object.flags & TMP_MARK))
1238                 return;
1239         commit->object.flags |= TMP_MARK;
1240         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1241         tips->tip[tips->nr++] = commit;
1242 }
1243
1244 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1245 {
1246         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1247         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1248         struct string_list_item *item;
1249         struct ref *ref;
1250         struct tips sent_tips;
1251
1252         /*
1253          * Collect everything we know they would have at the end of
1254          * this push, and collect all tags they have.
1255          */
1256         memset(&sent_tips, 0, sizeof(sent_tips));
1257         for (ref = *dst; ref; ref = ref->next) {
1258                 if (ref->peer_ref &&
1259                     !is_null_sha1(ref->peer_ref->new_sha1))
1260                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1261                 else
1262                         add_to_tips(&sent_tips, ref->old_sha1);
1263                 if (!prefixcmp(ref->name, "refs/tags/"))
1264                         string_list_append(&dst_tag, ref->name);
1265         }
1266         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1267
1268         sort_string_list(&dst_tag);
1269
1270         /* Collect tags they do not have. */
1271         for (ref = src; ref; ref = ref->next) {
1272                 if (prefixcmp(ref->name, "refs/tags/"))
1273                         continue; /* not a tag */
1274                 if (string_list_has_string(&dst_tag, ref->name))
1275                         continue; /* they already have it */
1276                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1277                         continue; /* be conservative */
1278                 item = string_list_append(&src_tag, ref->name);
1279                 item->util = ref;
1280         }
1281         string_list_clear(&dst_tag, 0);
1282
1283         /*
1284          * At this point, src_tag lists tags that are missing from
1285          * dst, and sent_tips lists the tips we are pushing or those
1286          * that we know they already have. An element in the src_tag
1287          * that is an ancestor of any of the sent_tips needs to be
1288          * sent to the other side.
1289          */
1290         if (sent_tips.nr) {
1291                 for_each_string_list_item(item, &src_tag) {
1292                         struct ref *ref = item->util;
1293                         struct ref *dst_ref;
1294                         struct commit *commit;
1295
1296                         if (is_null_sha1(ref->new_sha1))
1297                                 continue;
1298                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1299                         if (!commit)
1300                                 /* not pushing a commit, which is not an error */
1301                                 continue;
1302
1303                         /*
1304                          * Is this tag, which they do not have, reachable from
1305                          * any of the commits we are sending?
1306                          */
1307                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1308                                 continue;
1309
1310                         /* Add it in */
1311                         dst_ref = make_linked_ref(ref->name, dst_tail);
1312                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1313                         dst_ref->peer_ref = copy_ref(ref);
1314                 }
1315         }
1316         string_list_clear(&src_tag, 0);
1317         free(sent_tips.tip);
1318 }
1319
1320 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1321 {
1322         for ( ; list; list = list->next)
1323                 if (!strcmp(list->name, name))
1324                         return (struct ref *)list;
1325         return NULL;
1326 }
1327
1328 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1329 {
1330         for ( ; ref; ref = ref->next)
1331                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1332
1333         sort_string_list(ref_index);
1334 }
1335
1336 /*
1337  * Given the set of refs the local repository has, the set of refs the
1338  * remote repository has, and the refspec used for push, determine
1339  * what remote refs we will update and with what value by setting
1340  * peer_ref (which object is being pushed) and force (if the push is
1341  * forced) in elements of "dst". The function may add new elements to
1342  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1343  */
1344 int match_push_refs(struct ref *src, struct ref **dst,
1345                     int nr_refspec, const char **refspec, int flags)
1346 {
1347         struct refspec *rs;
1348         int send_all = flags & MATCH_REFS_ALL;
1349         int send_mirror = flags & MATCH_REFS_MIRROR;
1350         int send_prune = flags & MATCH_REFS_PRUNE;
1351         int errs;
1352         static const char *default_refspec[] = { ":", NULL };
1353         struct ref *ref, **dst_tail = tail_ref(dst);
1354         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1355
1356         if (!nr_refspec) {
1357                 nr_refspec = 1;
1358                 refspec = default_refspec;
1359         }
1360         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1361         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1362
1363         /* pick the remainder */
1364         for (ref = src; ref; ref = ref->next) {
1365                 struct string_list_item *dst_item;
1366                 struct ref *dst_peer;
1367                 const struct refspec *pat = NULL;
1368                 char *dst_name;
1369
1370                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1371                 if (!dst_name)
1372                         continue;
1373
1374                 if (!dst_ref_index.nr)
1375                         prepare_ref_index(&dst_ref_index, *dst);
1376
1377                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1378                 dst_peer = dst_item ? dst_item->util : NULL;
1379                 if (dst_peer) {
1380                         if (dst_peer->peer_ref)
1381                                 /* We're already sending something to this ref. */
1382                                 goto free_name;
1383                 } else {
1384                         if (pat->matching && !(send_all || send_mirror))
1385                                 /*
1386                                  * Remote doesn't have it, and we have no
1387                                  * explicit pattern, and we don't have
1388                                  * --all nor --mirror.
1389                                  */
1390                                 goto free_name;
1391
1392                         /* Create a new one and link it */
1393                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1394                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1395                         string_list_insert(&dst_ref_index,
1396                                 dst_peer->name)->util = dst_peer;
1397                 }
1398                 dst_peer->peer_ref = copy_ref(ref);
1399                 dst_peer->force = pat->force;
1400         free_name:
1401                 free(dst_name);
1402         }
1403
1404         string_list_clear(&dst_ref_index, 0);
1405
1406         if (flags & MATCH_REFS_FOLLOW_TAGS)
1407                 add_missing_tags(src, dst, &dst_tail);
1408
1409         if (send_prune) {
1410                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1411                 /* check for missing refs on the remote */
1412                 for (ref = *dst; ref; ref = ref->next) {
1413                         char *src_name;
1414
1415                         if (ref->peer_ref)
1416                                 /* We're already sending something to this ref. */
1417                                 continue;
1418
1419                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1420                         if (src_name) {
1421                                 if (!src_ref_index.nr)
1422                                         prepare_ref_index(&src_ref_index, src);
1423                                 if (!string_list_has_string(&src_ref_index,
1424                                             src_name))
1425                                         ref->peer_ref = alloc_delete_ref();
1426                                 free(src_name);
1427                         }
1428                 }
1429                 string_list_clear(&src_ref_index, 0);
1430         }
1431         if (errs)
1432                 return -1;
1433         return 0;
1434 }
1435
1436 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1437                              int force_update)
1438 {
1439         struct ref *ref;
1440
1441         for (ref = remote_refs; ref; ref = ref->next) {
1442                 int force_ref_update = ref->force || force_update;
1443                 int reject_reason = 0;
1444
1445                 if (ref->peer_ref)
1446                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1447                 else if (!send_mirror)
1448                         continue;
1449
1450                 ref->deletion = is_null_sha1(ref->new_sha1);
1451                 if (!ref->deletion &&
1452                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1453                         ref->status = REF_STATUS_UPTODATE;
1454                         continue;
1455                 }
1456
1457                 /*
1458                  * Bypass the usual "must fast-forward" check but
1459                  * replace it with a weaker "the old value must be
1460                  * this value we observed".  If the remote ref has
1461                  * moved and is now different from what we expect,
1462                  * reject any push.
1463                  *
1464                  * It also is an error if the user told us to check
1465                  * with the remote-tracking branch to find the value
1466                  * to expect, but we did not have such a tracking
1467                  * branch.
1468                  */
1469                 if (ref->expect_old_sha1) {
1470                         if (ref->expect_old_no_trackback ||
1471                             hashcmp(ref->old_sha1, ref->old_sha1_expect))
1472                                 reject_reason = REF_STATUS_REJECT_STALE;
1473                 }
1474
1475                 /*
1476                  * The usual "must fast-forward" rules.
1477                  *
1478                  * Decide whether an individual refspec A:B can be
1479                  * pushed.  The push will succeed if any of the
1480                  * following are true:
1481                  *
1482                  * (1) the remote reference B does not exist
1483                  *
1484                  * (2) the remote reference B is being removed (i.e.,
1485                  *     pushing :B where no source is specified)
1486                  *
1487                  * (3) the destination is not under refs/tags/, and
1488                  *     if the old and new value is a commit, the new
1489                  *     is a descendant of the old.
1490                  *
1491                  * (4) it is forced using the +A:B notation, or by
1492                  *     passing the --force argument
1493                  */
1494
1495                 else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1496                         if (!prefixcmp(ref->name, "refs/tags/"))
1497                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1498                         else if (!has_sha1_file(ref->old_sha1))
1499                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1500                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1501                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1502                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1503                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1504                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1505                 }
1506
1507                 /*
1508                  * "--force" will defeat any rejection implemented
1509                  * by the rules above.
1510                  */
1511                 if (!force_ref_update)
1512                         ref->status = reject_reason;
1513                 else if (reject_reason)
1514                         ref->forced_update = 1;
1515         }
1516 }
1517
1518 struct branch *branch_get(const char *name)
1519 {
1520         struct branch *ret;
1521
1522         read_config();
1523         if (!name || !*name || !strcmp(name, "HEAD"))
1524                 ret = current_branch;
1525         else
1526                 ret = make_branch(name, 0);
1527         if (ret && ret->remote_name) {
1528                 ret->remote = remote_get(ret->remote_name);
1529                 if (ret->merge_nr) {
1530                         int i;
1531                         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1532                         for (i = 0; i < ret->merge_nr; i++) {
1533                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1534                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1535                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1536                                     && !strcmp(ret->remote_name, "."))
1537                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1538                         }
1539                 }
1540         }
1541         return ret;
1542 }
1543
1544 int branch_has_merge_config(struct branch *branch)
1545 {
1546         return branch && !!branch->merge;
1547 }
1548
1549 int branch_merge_matches(struct branch *branch,
1550                                  int i,
1551                                  const char *refname)
1552 {
1553         if (!branch || i < 0 || i >= branch->merge_nr)
1554                 return 0;
1555         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1556 }
1557
1558 static int ignore_symref_update(const char *refname)
1559 {
1560         unsigned char sha1[20];
1561         int flag;
1562
1563         if (!resolve_ref_unsafe(refname, sha1, 0, &flag))
1564                 return 0; /* non-existing refs are OK */
1565         return (flag & REF_ISSYMREF);
1566 }
1567
1568 /*
1569  * Create and return a list of (struct ref) consisting of copies of
1570  * each remote_ref that matches refspec.  refspec must be a pattern.
1571  * Fill in the copies' peer_ref to describe the local tracking refs to
1572  * which they map.  Omit any references that would map to an existing
1573  * local symbolic ref.
1574  */
1575 static struct ref *get_expanded_map(const struct ref *remote_refs,
1576                                     const struct refspec *refspec)
1577 {
1578         const struct ref *ref;
1579         struct ref *ret = NULL;
1580         struct ref **tail = &ret;
1581
1582         for (ref = remote_refs; ref; ref = ref->next) {
1583                 char *expn_name = NULL;
1584
1585                 if (strchr(ref->name, '^'))
1586                         continue; /* a dereference item */
1587                 if (match_name_with_pattern(refspec->src, ref->name,
1588                                             refspec->dst, &expn_name) &&
1589                     !ignore_symref_update(expn_name)) {
1590                         struct ref *cpy = copy_ref(ref);
1591
1592                         cpy->peer_ref = alloc_ref(expn_name);
1593                         if (refspec->force)
1594                                 cpy->peer_ref->force = 1;
1595                         *tail = cpy;
1596                         tail = &cpy->next;
1597                 }
1598                 free(expn_name);
1599         }
1600
1601         return ret;
1602 }
1603
1604 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1605 {
1606         const struct ref *ref;
1607         for (ref = refs; ref; ref = ref->next) {
1608                 if (refname_match(name, ref->name, ref_fetch_rules))
1609                         return ref;
1610         }
1611         return NULL;
1612 }
1613
1614 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1615 {
1616         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1617
1618         if (!ref)
1619                 return NULL;
1620
1621         return copy_ref(ref);
1622 }
1623
1624 static struct ref *get_local_ref(const char *name)
1625 {
1626         if (!name || name[0] == '\0')
1627                 return NULL;
1628
1629         if (!prefixcmp(name, "refs/"))
1630                 return alloc_ref(name);
1631
1632         if (!prefixcmp(name, "heads/") ||
1633             !prefixcmp(name, "tags/") ||
1634             !prefixcmp(name, "remotes/"))
1635                 return alloc_ref_with_prefix("refs/", 5, name);
1636
1637         return alloc_ref_with_prefix("refs/heads/", 11, name);
1638 }
1639
1640 int get_fetch_map(const struct ref *remote_refs,
1641                   const struct refspec *refspec,
1642                   struct ref ***tail,
1643                   int missing_ok)
1644 {
1645         struct ref *ref_map, **rmp;
1646
1647         if (refspec->pattern) {
1648                 ref_map = get_expanded_map(remote_refs, refspec);
1649         } else {
1650                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1651
1652                 if (refspec->exact_sha1) {
1653                         ref_map = alloc_ref(name);
1654                         get_sha1_hex(name, ref_map->old_sha1);
1655                 } else {
1656                         ref_map = get_remote_ref(remote_refs, name);
1657                 }
1658                 if (!missing_ok && !ref_map)
1659                         die("Couldn't find remote ref %s", name);
1660                 if (ref_map) {
1661                         ref_map->peer_ref = get_local_ref(refspec->dst);
1662                         if (ref_map->peer_ref && refspec->force)
1663                                 ref_map->peer_ref->force = 1;
1664                 }
1665         }
1666
1667         for (rmp = &ref_map; *rmp; ) {
1668                 if ((*rmp)->peer_ref) {
1669                         if (prefixcmp((*rmp)->peer_ref->name, "refs/") ||
1670                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1671                                 struct ref *ignore = *rmp;
1672                                 error("* Ignoring funny ref '%s' locally",
1673                                       (*rmp)->peer_ref->name);
1674                                 *rmp = (*rmp)->next;
1675                                 free(ignore->peer_ref);
1676                                 free(ignore);
1677                                 continue;
1678                         }
1679                 }
1680                 rmp = &((*rmp)->next);
1681         }
1682
1683         if (ref_map)
1684                 tail_link_ref(ref_map, tail);
1685
1686         return 0;
1687 }
1688
1689 int resolve_remote_symref(struct ref *ref, struct ref *list)
1690 {
1691         if (!ref->symref)
1692                 return 0;
1693         for (; list; list = list->next)
1694                 if (!strcmp(ref->symref, list->name)) {
1695                         hashcpy(ref->old_sha1, list->old_sha1);
1696                         return 0;
1697                 }
1698         return 1;
1699 }
1700
1701 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1702 {
1703         while (list) {
1704                 struct commit_list *temp = list;
1705                 temp->item->object.flags &= ~mark;
1706                 list = temp->next;
1707                 free(temp);
1708         }
1709 }
1710
1711 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1712 {
1713         struct object *o;
1714         struct commit *old, *new;
1715         struct commit_list *list, *used;
1716         int found = 0;
1717
1718         /*
1719          * Both new and old must be commit-ish and new is descendant of
1720          * old.  Otherwise we require --force.
1721          */
1722         o = deref_tag(parse_object(old_sha1), NULL, 0);
1723         if (!o || o->type != OBJ_COMMIT)
1724                 return 0;
1725         old = (struct commit *) o;
1726
1727         o = deref_tag(parse_object(new_sha1), NULL, 0);
1728         if (!o || o->type != OBJ_COMMIT)
1729                 return 0;
1730         new = (struct commit *) o;
1731
1732         if (parse_commit(new) < 0)
1733                 return 0;
1734
1735         used = list = NULL;
1736         commit_list_insert(new, &list);
1737         while (list) {
1738                 new = pop_most_recent_commit(&list, TMP_MARK);
1739                 commit_list_insert(new, &used);
1740                 if (new == old) {
1741                         found = 1;
1742                         break;
1743                 }
1744         }
1745         unmark_and_free(list, TMP_MARK);
1746         unmark_and_free(used, TMP_MARK);
1747         return found;
1748 }
1749
1750 /*
1751  * Compare a branch with its upstream, and save their differences (number
1752  * of commits) in *num_ours and *num_theirs.
1753  *
1754  * Return 0 if branch has no upstream (no base), -1 if upstream is missing
1755  * (with "gone" base), otherwise 1 (with base).
1756  */
1757 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1758 {
1759         unsigned char sha1[20];
1760         struct commit *ours, *theirs;
1761         char symmetric[84];
1762         struct rev_info revs;
1763         const char *rev_argv[10], *base;
1764         int rev_argc;
1765
1766         /* Cannot stat unless we are marked to build on top of somebody else. */
1767         if (!branch ||
1768             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1769                 return 0;
1770
1771         /* Cannot stat if what we used to build on no longer exists */
1772         base = branch->merge[0]->dst;
1773         if (read_ref(base, sha1))
1774                 return -1;
1775         theirs = lookup_commit_reference(sha1);
1776         if (!theirs)
1777                 return -1;
1778
1779         if (read_ref(branch->refname, sha1))
1780                 return -1;
1781         ours = lookup_commit_reference(sha1);
1782         if (!ours)
1783                 return -1;
1784
1785         /* are we the same? */
1786         if (theirs == ours) {
1787                 *num_theirs = *num_ours = 0;
1788                 return 1;
1789         }
1790
1791         /* Run "rev-list --left-right ours...theirs" internally... */
1792         rev_argc = 0;
1793         rev_argv[rev_argc++] = NULL;
1794         rev_argv[rev_argc++] = "--left-right";
1795         rev_argv[rev_argc++] = symmetric;
1796         rev_argv[rev_argc++] = "--";
1797         rev_argv[rev_argc] = NULL;
1798
1799         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1800         strcpy(symmetric + 40, "...");
1801         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1802
1803         init_revisions(&revs, NULL);
1804         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1805         prepare_revision_walk(&revs);
1806
1807         /* ... and count the commits on each side. */
1808         *num_ours = 0;
1809         *num_theirs = 0;
1810         while (1) {
1811                 struct commit *c = get_revision(&revs);
1812                 if (!c)
1813                         break;
1814                 if (c->object.flags & SYMMETRIC_LEFT)
1815                         (*num_ours)++;
1816                 else
1817                         (*num_theirs)++;
1818         }
1819
1820         /* clear object flags smudged by the above traversal */
1821         clear_commit_marks(ours, ALL_REV_FLAGS);
1822         clear_commit_marks(theirs, ALL_REV_FLAGS);
1823         return 1;
1824 }
1825
1826 /*
1827  * Return true when there is anything to report, otherwise false.
1828  */
1829 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1830 {
1831         int ours, theirs;
1832         const char *base;
1833         int upstream_is_gone = 0;
1834
1835         switch (stat_tracking_info(branch, &ours, &theirs)) {
1836         case 0:
1837                 /* no base */
1838                 return 0;
1839         case -1:
1840                 /* with "gone" base */
1841                 upstream_is_gone = 1;
1842                 break;
1843         default:
1844                 /* with base */
1845                 break;
1846         }
1847
1848         base = branch->merge[0]->dst;
1849         base = shorten_unambiguous_ref(base, 0);
1850         if (upstream_is_gone) {
1851                 strbuf_addf(sb,
1852                         _("Your branch is based on '%s', but the upstream is gone.\n"),
1853                         base);
1854                 if (advice_status_hints)
1855                         strbuf_addf(sb,
1856                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1857         } else if (!ours && !theirs) {
1858                 strbuf_addf(sb,
1859                         _("Your branch is up-to-date with '%s'.\n"),
1860                         base);
1861         } else if (!theirs) {
1862                 strbuf_addf(sb,
1863                         Q_("Your branch is ahead of '%s' by %d commit.\n",
1864                            "Your branch is ahead of '%s' by %d commits.\n",
1865                            ours),
1866                         base, ours);
1867                 if (advice_status_hints)
1868                         strbuf_addf(sb,
1869                                 _("  (use \"git push\" to publish your local commits)\n"));
1870         } else if (!ours) {
1871                 strbuf_addf(sb,
1872                         Q_("Your branch is behind '%s' by %d commit, "
1873                                "and can be fast-forwarded.\n",
1874                            "Your branch is behind '%s' by %d commits, "
1875                                "and can be fast-forwarded.\n",
1876                            theirs),
1877                         base, theirs);
1878                 if (advice_status_hints)
1879                         strbuf_addf(sb,
1880                                 _("  (use \"git pull\" to update your local branch)\n"));
1881         } else {
1882                 strbuf_addf(sb,
1883                         Q_("Your branch and '%s' have diverged,\n"
1884                                "and have %d and %d different commit each, "
1885                                "respectively.\n",
1886                            "Your branch and '%s' have diverged,\n"
1887                                "and have %d and %d different commits each, "
1888                                "respectively.\n",
1889                            theirs),
1890                         base, ours, theirs);
1891                 if (advice_status_hints)
1892                         strbuf_addf(sb,
1893                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1894         }
1895         return 1;
1896 }
1897
1898 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1899 {
1900         struct ref ***local_tail = cb_data;
1901         struct ref *ref;
1902         int len;
1903
1904         /* we already know it starts with refs/ to get here */
1905         if (check_refname_format(refname + 5, 0))
1906                 return 0;
1907
1908         len = strlen(refname) + 1;
1909         ref = xcalloc(1, sizeof(*ref) + len);
1910         hashcpy(ref->new_sha1, sha1);
1911         memcpy(ref->name, refname, len);
1912         **local_tail = ref;
1913         *local_tail = &ref->next;
1914         return 0;
1915 }
1916
1917 struct ref *get_local_heads(void)
1918 {
1919         struct ref *local_refs = NULL, **local_tail = &local_refs;
1920         for_each_ref(one_local_ref, &local_tail);
1921         return local_refs;
1922 }
1923
1924 struct ref *guess_remote_head(const struct ref *head,
1925                               const struct ref *refs,
1926                               int all)
1927 {
1928         const struct ref *r;
1929         struct ref *list = NULL;
1930         struct ref **tail = &list;
1931
1932         if (!head)
1933                 return NULL;
1934
1935         /*
1936          * Some transports support directly peeking at
1937          * where HEAD points; if that is the case, then
1938          * we don't have to guess.
1939          */
1940         if (head->symref)
1941                 return copy_ref(find_ref_by_name(refs, head->symref));
1942
1943         /* If refs/heads/master could be right, it is. */
1944         if (!all) {
1945                 r = find_ref_by_name(refs, "refs/heads/master");
1946                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1947                         return copy_ref(r);
1948         }
1949
1950         /* Look for another ref that points there */
1951         for (r = refs; r; r = r->next) {
1952                 if (r != head &&
1953                     !prefixcmp(r->name, "refs/heads/") &&
1954                     !hashcmp(r->old_sha1, head->old_sha1)) {
1955                         *tail = copy_ref(r);
1956                         tail = &((*tail)->next);
1957                         if (!all)
1958                                 break;
1959                 }
1960         }
1961
1962         return list;
1963 }
1964
1965 struct stale_heads_info {
1966         struct string_list *ref_names;
1967         struct ref **stale_refs_tail;
1968         struct refspec *refs;
1969         int ref_count;
1970 };
1971
1972 static int get_stale_heads_cb(const char *refname,
1973         const unsigned char *sha1, int flags, void *cb_data)
1974 {
1975         struct stale_heads_info *info = cb_data;
1976         struct refspec query;
1977         memset(&query, 0, sizeof(struct refspec));
1978         query.dst = (char *)refname;
1979
1980         if (query_refspecs(info->refs, info->ref_count, &query))
1981                 return 0; /* No matches */
1982
1983         /*
1984          * If we did find a suitable refspec and it's not a symref and
1985          * it's not in the list of refs that currently exist in that
1986          * remote we consider it to be stale.
1987          */
1988         if (!((flags & REF_ISSYMREF) ||
1989               string_list_has_string(info->ref_names, query.src))) {
1990                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1991                 hashcpy(ref->new_sha1, sha1);
1992         }
1993
1994         free(query.src);
1995         return 0;
1996 }
1997
1998 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
1999 {
2000         struct ref *ref, *stale_refs = NULL;
2001         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2002         struct stale_heads_info info;
2003         info.ref_names = &ref_names;
2004         info.stale_refs_tail = &stale_refs;
2005         info.refs = refs;
2006         info.ref_count = ref_count;
2007         for (ref = fetch_map; ref; ref = ref->next)
2008                 string_list_append(&ref_names, ref->name);
2009         sort_string_list(&ref_names);
2010         for_each_ref(get_stale_heads_cb, &info);
2011         string_list_clear(&ref_names, 0);
2012         return stale_refs;
2013 }
2014
2015 /*
2016  * Compare-and-swap
2017  */
2018 void clear_cas_option(struct push_cas_option *cas)
2019 {
2020         int i;
2021
2022         for (i = 0; i < cas->nr; i++)
2023                 free(cas->entry[i].refname);
2024         free(cas->entry);
2025         memset(cas, 0, sizeof(*cas));
2026 }
2027
2028 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2029                                       const char *refname,
2030                                       size_t refnamelen)
2031 {
2032         struct push_cas *entry;
2033         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2034         entry = &cas->entry[cas->nr++];
2035         memset(entry, 0, sizeof(*entry));
2036         entry->refname = xmemdupz(refname, refnamelen);
2037         return entry;
2038 }
2039
2040 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2041 {
2042         const char *colon;
2043         struct push_cas *entry;
2044
2045         if (unset) {
2046                 /* "--no-<option>" */
2047                 clear_cas_option(cas);
2048                 return 0;
2049         }
2050
2051         if (!arg) {
2052                 /* just "--<option>" */
2053                 cas->use_tracking_for_rest = 1;
2054                 return 0;
2055         }
2056
2057         /* "--<option>=refname" or "--<option>=refname:value" */
2058         colon = strchrnul(arg, ':');
2059         entry = add_cas_entry(cas, arg, colon - arg);
2060         if (!*colon)
2061                 entry->use_tracking = 1;
2062         else if (get_sha1(colon + 1, entry->expect))
2063                 return error("cannot parse expected object name '%s'", colon + 1);
2064         return 0;
2065 }
2066
2067 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2068 {
2069         return parse_push_cas_option(opt->value, arg, unset);
2070 }
2071
2072 int is_empty_cas(const struct push_cas_option *cas)
2073 {
2074         return !cas->use_tracking_for_rest && !cas->nr;
2075 }
2076
2077 /*
2078  * Look at remote.fetch refspec and see if we have a remote
2079  * tracking branch for the refname there.  Fill its current
2080  * value in sha1[].
2081  * If we cannot do so, return negative to signal an error.
2082  */
2083 static int remote_tracking(struct remote *remote, const char *refname,
2084                            unsigned char sha1[20])
2085 {
2086         char *dst;
2087
2088         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2089         if (!dst)
2090                 return -1; /* no tracking ref for refname at remote */
2091         if (read_ref(dst, sha1))
2092                 return -1; /* we know what the tracking ref is but we cannot read it */
2093         return 0;
2094 }
2095
2096 static void apply_cas(struct push_cas_option *cas,
2097                       struct remote *remote,
2098                       struct ref *ref)
2099 {
2100         int i;
2101
2102         /* Find an explicit --<option>=<name>[:<value>] entry */
2103         for (i = 0; i < cas->nr; i++) {
2104                 struct push_cas *entry = &cas->entry[i];
2105                 if (!refname_match(entry->refname, ref->name, ref_rev_parse_rules))
2106                         continue;
2107                 ref->expect_old_sha1 = 1;
2108                 if (!entry->use_tracking)
2109                         hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2110                 else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2111                         ref->expect_old_no_trackback = 1;
2112                 return;
2113         }
2114
2115         /* Are we using "--<option>" to cover all? */
2116         if (!cas->use_tracking_for_rest)
2117                 return;
2118
2119         ref->expect_old_sha1 = 1;
2120         if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2121                 ref->expect_old_no_trackback = 1;
2122 }
2123
2124 void apply_push_cas(struct push_cas_option *cas,
2125                     struct remote *remote,
2126                     struct ref *remote_refs)
2127 {
2128         struct ref *ref;
2129         for (ref = remote_refs; ref; ref = ref->next)
2130                 apply_cas(cas, remote, ref);
2131 }