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 struct ref *ref_remove_duplicates(struct ref *ref_map)
 749 {
 750         struct string_list refs = STRING_LIST_INIT_NODUP;
 751         struct ref *retval = NULL;
 752         struct ref **p = &retval;
 753
 754         while (ref_map) {
 755                 struct ref *ref = ref_map;
 756
 757                 ref_map = ref_map->next;
 758                 ref->next = NULL;
 759
 760                 if (!ref->peer_ref) {
 761                         *p = ref;
 762                         p = &ref->next;
 763                 } else {
 764                         struct string_list_item *item =
 765                                 string_list_insert(&refs, ref->peer_ref->name);
 766
 767                         if (item->util) {
 768                                 /* Entry already existed */
 769                                 if (strcmp(((struct ref *)item->util)->name,
 770                                            ref->name))
 771                                         die("%s tracks both %s and %s",
 772                                             ref->peer_ref->name,
 773                                             ((struct ref *)item->util)->name,
 774                                             ref->name);
 775                                 free(ref->peer_ref);
 776                                 free(ref);
 777                         } else {
 778                                 *p = ref;
 779                                 p = &ref->next;
 780                                 item->util = ref;
 781                         }
 782                 }
 783         }
 784
 785         string_list_clear(&refs, 0);
 786         return retval;
 787 }
 788
 789 int remote_has_url(struct remote *remote, const char *url)
 790 {
 791         int i;
 792         for (i = 0; i < remote->url_nr; i++) {
 793                 if (!strcmp(remote->url[i], url))
 794                         return 1;
 795         }
 796         return 0;
 797 }
 798
 799 static int match_name_with_pattern(const char *key, const char *name,
 800                                    const char *value, char **result)
 801 {
 802         const char *kstar = strchr(key, '*');
 803         size_t klen;
 804         size_t ksuffixlen;
 805         size_t namelen;
 806         int ret;
 807         if (!kstar)
 808                 die("Key '%s' of pattern had no '*'", key);
 809         klen = kstar - key;
 810         ksuffixlen = strlen(kstar + 1);
 811         namelen = strlen(name);
 812         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 813                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 814         if (ret && value) {
 815                 const char *vstar = strchr(value, '*');
 816                 size_t vlen;
 817                 size_t vsuffixlen;
 818                 if (!vstar)
 819                         die("Value '%s' of pattern has no '*'", value);
 820                 vlen = vstar - value;
 821                 vsuffixlen = strlen(vstar + 1);
 822                 *result = xmalloc(vlen + vsuffixlen +
 823                                   strlen(name) -
 824                                   klen - ksuffixlen + 1);
 825                 strncpy(*result, value, vlen);
 826                 strncpy(*result + vlen,
 827                         name + klen, namelen - klen - ksuffixlen);
 828                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 829                        vstar + 1);
 830         }
 831         return ret;
 832 }
 833
 834 static int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 835 {
 836         int i;
 837         int find_src = !query->src;
 838         const char *needle = find_src ? query->dst : query->src;
 839         char **result = find_src ? &query->src : &query->dst;
 840
 841         if (find_src && !query->dst)
 842                 return error("query_refspecs: need either src or dst");
 843
 844         for (i = 0; i < ref_count; i++) {
 845                 struct refspec *refspec = &refs[i];
 846                 const char *key = find_src ? refspec->dst : refspec->src;
 847                 const char *value = find_src ? refspec->src : refspec->dst;
 848
 849                 if (!refspec->dst)
 850                         continue;
 851                 if (refspec->pattern) {
 852                         if (match_name_with_pattern(key, needle, value, result)) {
 853                                 query->force = refspec->force;
 854                                 return 0;
 855                         }
 856                 } else if (!strcmp(needle, key)) {
 857                         *result = xstrdup(value);
 858                         query->force = refspec->force;
 859                         return 0;
 860                 }
 861         }
 862         return -1;
 863 }
 864
 865 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 866                      const char *name)
 867 {
 868         struct refspec query;
 869
 870         memset(&query, 0, sizeof(struct refspec));
 871         query.src = (char *)name;
 872
 873         if (query_refspecs(refspecs, nr_refspec, &query))
 874                 return NULL;
 875
 876         return query.dst;
 877 }
 878
 879 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 880 {
 881         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 882 }
 883
 884 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 885                 const char *name)
 886 {
 887         size_t len = strlen(name);
 888         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 889         memcpy(ref->name, prefix, prefixlen);
 890         memcpy(ref->name + prefixlen, name, len);
 891         return ref;
 892 }
 893
 894 struct ref *alloc_ref(const char *name)
 895 {
 896         return alloc_ref_with_prefix("", 0, name);
 897 }
 898
 899 struct ref *copy_ref(const struct ref *ref)
 900 {
 901         struct ref *cpy;
 902         size_t len;
 903         if (!ref)
 904                 return NULL;
 905         len = strlen(ref->name);
 906         cpy = xmalloc(sizeof(struct ref) + len + 1);
 907         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 908         cpy->next = NULL;
 909         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 910         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 911         cpy->peer_ref = copy_ref(ref->peer_ref);
 912         return cpy;
 913 }
 914
 915 struct ref *copy_ref_list(const struct ref *ref)
 916 {
 917         struct ref *ret = NULL;
 918         struct ref **tail = &ret;
 919         while (ref) {
 920                 *tail = copy_ref(ref);
 921                 ref = ref->next;
 922                 tail = &((*tail)->next);
 923         }
 924         return ret;
 925 }
 926
 927 static void free_ref(struct ref *ref)
 928 {
 929         if (!ref)
 930                 return;
 931         free_ref(ref->peer_ref);
 932         free(ref->remote_status);
 933         free(ref->symref);
 934         free(ref);
 935 }
 936
 937 void free_refs(struct ref *ref)
 938 {
 939         struct ref *next;
 940         while (ref) {
 941                 next = ref->next;
 942                 free_ref(ref);
 943                 ref = next;
 944         }
 945 }
 946
 947 int ref_compare_name(const void *va, const void *vb)
 948 {
 949         const struct ref *a = va, *b = vb;
 950         return strcmp(a->name, b->name);
 951 }
 952
 953 static void *ref_list_get_next(const void *a)
 954 {
 955         return ((const struct ref *)a)->next;
 956 }
 957
 958 static void ref_list_set_next(void *a, void *next)
 959 {
 960         ((struct ref *)a)->next = next;
 961 }
 962
 963 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 964 {
 965         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 966 }
 967
 968 static int count_refspec_match(const char *pattern,
 969                                struct ref *refs,
 970                                struct ref **matched_ref)
 971 {
 972         int patlen = strlen(pattern);
 973         struct ref *matched_weak = NULL;
 974         struct ref *matched = NULL;
 975         int weak_match = 0;
 976         int match = 0;
 977
 978         for (weak_match = match = 0; refs; refs = refs->next) {
 979                 char *name = refs->name;
 980                 int namelen = strlen(name);
 981
 982                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 983                         continue;
 984
 985                 /* A match is "weak" if it is with refs outside
 986                  * heads or tags, and did not specify the pattern
 987                  * in full (e.g. "refs/remotes/origin/master") or at
 988                  * least from the toplevel (e.g. "remotes/origin/master");
 989                  * otherwise "git push $URL master" would result in
 990                  * ambiguity between remotes/origin/master and heads/master
 991                  * at the remote site.
 992                  */
 993                 if (namelen != patlen &&
 994                     patlen != namelen - 5 &&
 995                     prefixcmp(name, "refs/heads/") &&
 996                     prefixcmp(name, "refs/tags/")) {
 997                         /* We want to catch the case where only weak
 998                          * matches are found and there are multiple
 999                          * matches, and where more than one strong
1000                          * matches are found, as ambiguous.  One
1001                          * strong match with zero or more weak matches
1002                          * are acceptable as a unique match.
1003                          */
1004                         matched_weak = refs;
1005                         weak_match++;
1006                 }
1007                 else {
1008                         matched = refs;
1009                         match++;
1010                 }
1011         }
1012         if (!matched) {
1013                 *matched_ref = matched_weak;
1014                 return weak_match;
1015         }
1016         else {
1017                 *matched_ref = matched;
1018                 return match;
1019         }
1020 }
1021
1022 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1023 {
1024         **tail = ref;
1025         while (ref->next)
1026                 ref = ref->next;
1027         *tail = &ref->next;
1028 }
1029
1030 static struct ref *alloc_delete_ref(void)
1031 {
1032         struct ref *ref = alloc_ref("(delete)");
1033         hashclr(ref->new_sha1);
1034         return ref;
1035 }
1036
1037 static struct ref *try_explicit_object_name(const char *name)
1038 {
1039         unsigned char sha1[20];
1040         struct ref *ref;
1041
1042         if (!*name)
1043                 return alloc_delete_ref();
1044         if (get_sha1(name, sha1))
1045                 return NULL;
1046         ref = alloc_ref(name);
1047         hashcpy(ref->new_sha1, sha1);
1048         return ref;
1049 }
1050
1051 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1052 {
1053         struct ref *ret = alloc_ref(name);
1054         tail_link_ref(ret, tail);
1055         return ret;
1056 }
1057
1058 static char *guess_ref(const char *name, struct ref *peer)
1059 {
1060         struct strbuf buf = STRBUF_INIT;
1061         unsigned char sha1[20];
1062
1063         const char *r = resolve_ref_unsafe(peer->name, sha1, 1, NULL);
1064         if (!r)
1065                 return NULL;
1066
1067         if (!prefixcmp(r, "refs/heads/"))
1068                 strbuf_addstr(&buf, "refs/heads/");
1069         else if (!prefixcmp(r, "refs/tags/"))
1070                 strbuf_addstr(&buf, "refs/tags/");
1071         else
1072                 return NULL;
1073
1074         strbuf_addstr(&buf, name);
1075         return strbuf_detach(&buf, NULL);
1076 }
1077
1078 static int match_explicit(struct ref *src, struct ref *dst,
1079                           struct ref ***dst_tail,
1080                           struct refspec *rs)
1081 {
1082         struct ref *matched_src, *matched_dst;
1083         int copy_src;
1084
1085         const char *dst_value = rs->dst;
1086         char *dst_guess;
1087
1088         if (rs->pattern || rs->matching)
1089                 return 0;
1090
1091         matched_src = matched_dst = NULL;
1092         switch (count_refspec_match(rs->src, src, &matched_src)) {
1093         case 1:
1094                 copy_src = 1;
1095                 break;
1096         case 0:
1097                 /* The source could be in the get_sha1() format
1098                  * not a reference name.  :refs/other is a
1099                  * way to delete 'other' ref at the remote end.
1100                  */
1101                 matched_src = try_explicit_object_name(rs->src);
1102                 if (!matched_src)
1103                         return error("src refspec %s does not match any.", rs->src);
1104                 copy_src = 0;
1105                 break;
1106         default:
1107                 return error("src refspec %s matches more than one.", rs->src);
1108         }
1109
1110         if (!dst_value) {
1111                 unsigned char sha1[20];
1112                 int flag;
1113
1114                 dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag);
1115                 if (!dst_value ||
1116                     ((flag & REF_ISSYMREF) &&
1117                      prefixcmp(dst_value, "refs/heads/")))
1118                         die("%s cannot be resolved to branch.",
1119                             matched_src->name);
1120         }
1121
1122         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1123         case 1:
1124                 break;
1125         case 0:
1126                 if (!memcmp(dst_value, "refs/", 5))
1127                         matched_dst = make_linked_ref(dst_value, dst_tail);
1128                 else if (is_null_sha1(matched_src->new_sha1))
1129                         error("unable to delete '%s': remote ref does not exist",
1130                               dst_value);
1131                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1132                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1133                 else
1134                         error("unable to push to unqualified destination: %s\n"
1135                               "The destination refspec neither matches an "
1136                               "existing ref on the remote nor\n"
1137                               "begins with refs/, and we are unable to "
1138                               "guess a prefix based on the source ref.",
1139                               dst_value);
1140                 break;
1141         default:
1142                 matched_dst = NULL;
1143                 error("dst refspec %s matches more than one.",
1144                       dst_value);
1145                 break;
1146         }
1147         if (!matched_dst)
1148                 return -1;
1149         if (matched_dst->peer_ref)
1150                 return error("dst ref %s receives from more than one src.",
1151                       matched_dst->name);
1152         else {
1153                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1154                 matched_dst->force = rs->force;
1155         }
1156         return 0;
1157 }
1158
1159 static int match_explicit_refs(struct ref *src, struct ref *dst,
1160                                struct ref ***dst_tail, struct refspec *rs,
1161                                int rs_nr)
1162 {
1163         int i, errs;
1164         for (i = errs = 0; i < rs_nr; i++)
1165                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1166         return errs;
1167 }
1168
1169 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1170                 int send_mirror, int direction, const struct refspec **ret_pat)
1171 {
1172         const struct refspec *pat;
1173         char *name;
1174         int i;
1175         int matching_refs = -1;
1176         for (i = 0; i < rs_nr; i++) {
1177                 if (rs[i].matching &&
1178                     (matching_refs == -1 || rs[i].force)) {
1179                         matching_refs = i;
1180                         continue;
1181                 }
1182
1183                 if (rs[i].pattern) {
1184                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1185                         int match;
1186                         if (direction == FROM_SRC)
1187                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1188                         else
1189                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1190                         if (match) {
1191                                 matching_refs = i;
1192                                 break;
1193                         }
1194                 }
1195         }
1196         if (matching_refs == -1)
1197                 return NULL;
1198
1199         pat = rs + matching_refs;
1200         if (pat->matching) {
1201                 /*
1202                  * "matching refs"; traditionally we pushed everything
1203                  * including refs outside refs/heads/ hierarchy, but
1204                  * that does not make much sense these days.
1205                  */
1206                 if (!send_mirror && prefixcmp(ref->name, "refs/heads/"))
1207                         return NULL;
1208                 name = xstrdup(ref->name);
1209         }
1210         if (ret_pat)
1211                 *ret_pat = pat;
1212         return name;
1213 }
1214
1215 static struct ref **tail_ref(struct ref **head)
1216 {
1217         struct ref **tail = head;
1218         while (*tail)
1219                 tail = &((*tail)->next);
1220         return tail;
1221 }
1222
1223 struct tips {
1224         struct commit **tip;
1225         int nr, alloc;
1226 };
1227
1228 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1229 {
1230         struct commit *commit;
1231
1232         if (is_null_sha1(sha1))
1233                 return;
1234         commit = lookup_commit_reference_gently(sha1, 1);
1235         if (!commit || (commit->object.flags & TMP_MARK))
1236                 return;
1237         commit->object.flags |= TMP_MARK;
1238         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1239         tips->tip[tips->nr++] = commit;
1240 }
1241
1242 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1243 {
1244         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1245         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1246         struct string_list_item *item;
1247         struct ref *ref;
1248         struct tips sent_tips;
1249
1250         /*
1251          * Collect everything we know they would have at the end of
1252          * this push, and collect all tags they have.
1253          */
1254         memset(&sent_tips, 0, sizeof(sent_tips));
1255         for (ref = *dst; ref; ref = ref->next) {
1256                 if (ref->peer_ref &&
1257                     !is_null_sha1(ref->peer_ref->new_sha1))
1258                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1259                 else
1260                         add_to_tips(&sent_tips, ref->old_sha1);
1261                 if (!prefixcmp(ref->name, "refs/tags/"))
1262                         string_list_append(&dst_tag, ref->name);
1263         }
1264         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1265
1266         sort_string_list(&dst_tag);
1267
1268         /* Collect tags they do not have. */
1269         for (ref = src; ref; ref = ref->next) {
1270                 if (prefixcmp(ref->name, "refs/tags/"))
1271                         continue; /* not a tag */
1272                 if (string_list_has_string(&dst_tag, ref->name))
1273                         continue; /* they already have it */
1274                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1275                         continue; /* be conservative */
1276                 item = string_list_append(&src_tag, ref->name);
1277                 item->util = ref;
1278         }
1279         string_list_clear(&dst_tag, 0);
1280
1281         /*
1282          * At this point, src_tag lists tags that are missing from
1283          * dst, and sent_tips lists the tips we are pushing or those
1284          * that we know they already have. An element in the src_tag
1285          * that is an ancestor of any of the sent_tips needs to be
1286          * sent to the other side.
1287          */
1288         if (sent_tips.nr) {
1289                 for_each_string_list_item(item, &src_tag) {
1290                         struct ref *ref = item->util;
1291                         struct ref *dst_ref;
1292                         struct commit *commit;
1293
1294                         if (is_null_sha1(ref->new_sha1))
1295                                 continue;
1296                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1297                         if (!commit)
1298                                 /* not pushing a commit, which is not an error */
1299                                 continue;
1300
1301                         /*
1302                          * Is this tag, which they do not have, reachable from
1303                          * any of the commits we are sending?
1304                          */
1305                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1306                                 continue;
1307
1308                         /* Add it in */
1309                         dst_ref = make_linked_ref(ref->name, dst_tail);
1310                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1311                         dst_ref->peer_ref = copy_ref(ref);
1312                 }
1313         }
1314         string_list_clear(&src_tag, 0);
1315         free(sent_tips.tip);
1316 }
1317
1318 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1319 {
1320         for ( ; list; list = list->next)
1321                 if (!strcmp(list->name, name))
1322                         return (struct ref *)list;
1323         return NULL;
1324 }
1325
1326 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1327 {
1328         for ( ; ref; ref = ref->next)
1329                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1330
1331         sort_string_list(ref_index);
1332 }
1333
1334 /*
1335  * Given the set of refs the local repository has, the set of refs the
1336  * remote repository has, and the refspec used for push, determine
1337  * what remote refs we will update and with what value by setting
1338  * peer_ref (which object is being pushed) and force (if the push is
1339  * forced) in elements of "dst". The function may add new elements to
1340  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1341  */
1342 int match_push_refs(struct ref *src, struct ref **dst,
1343                     int nr_refspec, const char **refspec, int flags)
1344 {
1345         struct refspec *rs;
1346         int send_all = flags & MATCH_REFS_ALL;
1347         int send_mirror = flags & MATCH_REFS_MIRROR;
1348         int send_prune = flags & MATCH_REFS_PRUNE;
1349         int errs;
1350         static const char *default_refspec[] = { ":", NULL };
1351         struct ref *ref, **dst_tail = tail_ref(dst);
1352         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1353
1354         if (!nr_refspec) {
1355                 nr_refspec = 1;
1356                 refspec = default_refspec;
1357         }
1358         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1359         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1360
1361         /* pick the remainder */
1362         for (ref = src; ref; ref = ref->next) {
1363                 struct string_list_item *dst_item;
1364                 struct ref *dst_peer;
1365                 const struct refspec *pat = NULL;
1366                 char *dst_name;
1367
1368                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1369                 if (!dst_name)
1370                         continue;
1371
1372                 if (!dst_ref_index.nr)
1373                         prepare_ref_index(&dst_ref_index, *dst);
1374
1375                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1376                 dst_peer = dst_item ? dst_item->util : NULL;
1377                 if (dst_peer) {
1378                         if (dst_peer->peer_ref)
1379                                 /* We're already sending something to this ref. */
1380                                 goto free_name;
1381                 } else {
1382                         if (pat->matching && !(send_all || send_mirror))
1383                                 /*
1384                                  * Remote doesn't have it, and we have no
1385                                  * explicit pattern, and we don't have
1386                                  * --all nor --mirror.
1387                                  */
1388                                 goto free_name;
1389
1390                         /* Create a new one and link it */
1391                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1392                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1393                         string_list_insert(&dst_ref_index,
1394                                 dst_peer->name)->util = dst_peer;
1395                 }
1396                 dst_peer->peer_ref = copy_ref(ref);
1397                 dst_peer->force = pat->force;
1398         free_name:
1399                 free(dst_name);
1400         }
1401
1402         string_list_clear(&dst_ref_index, 0);
1403
1404         if (flags & MATCH_REFS_FOLLOW_TAGS)
1405                 add_missing_tags(src, dst, &dst_tail);
1406
1407         if (send_prune) {
1408                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1409                 /* check for missing refs on the remote */
1410                 for (ref = *dst; ref; ref = ref->next) {
1411                         char *src_name;
1412
1413                         if (ref->peer_ref)
1414                                 /* We're already sending something to this ref. */
1415                                 continue;
1416
1417                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1418                         if (src_name) {
1419                                 if (!src_ref_index.nr)
1420                                         prepare_ref_index(&src_ref_index, src);
1421                                 if (!string_list_has_string(&src_ref_index,
1422                                             src_name))
1423                                         ref->peer_ref = alloc_delete_ref();
1424                                 free(src_name);
1425                         }
1426                 }
1427                 string_list_clear(&src_ref_index, 0);
1428         }
1429         if (errs)
1430                 return -1;
1431         return 0;
1432 }
1433
1434 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1435                              int force_update)
1436 {
1437         struct ref *ref;
1438
1439         for (ref = remote_refs; ref; ref = ref->next) {
1440                 int force_ref_update = ref->force || force_update;
1441                 int reject_reason = 0;
1442
1443                 if (ref->peer_ref)
1444                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1445                 else if (!send_mirror)
1446                         continue;
1447
1448                 ref->deletion = is_null_sha1(ref->new_sha1);
1449                 if (!ref->deletion &&
1450                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1451                         ref->status = REF_STATUS_UPTODATE;
1452                         continue;
1453                 }
1454
1455                 /*
1456                  * Bypass the usual "must fast-forward" check but
1457                  * replace it with a weaker "the old value must be
1458                  * this value we observed".  If the remote ref has
1459                  * moved and is now different from what we expect,
1460                  * reject any push.
1461                  *
1462                  * It also is an error if the user told us to check
1463                  * with the remote-tracking branch to find the value
1464                  * to expect, but we did not have such a tracking
1465                  * branch.
1466                  */
1467                 if (ref->expect_old_sha1) {
1468                         if (ref->expect_old_no_trackback ||
1469                             hashcmp(ref->old_sha1, ref->old_sha1_expect))
1470                                 reject_reason = REF_STATUS_REJECT_STALE;
1471                 }
1472
1473                 /*
1474                  * The usual "must fast-forward" rules.
1475                  *
1476                  * Decide whether an individual refspec A:B can be
1477                  * pushed.  The push will succeed if any of the
1478                  * following are true:
1479                  *
1480                  * (1) the remote reference B does not exist
1481                  *
1482                  * (2) the remote reference B is being removed (i.e.,
1483                  *     pushing :B where no source is specified)
1484                  *
1485                  * (3) the destination is not under refs/tags/, and
1486                  *     if the old and new value is a commit, the new
1487                  *     is a descendant of the old.
1488                  *
1489                  * (4) it is forced using the +A:B notation, or by
1490                  *     passing the --force argument
1491                  */
1492
1493                 else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1494                         if (!prefixcmp(ref->name, "refs/tags/"))
1495                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1496                         else if (!has_sha1_file(ref->old_sha1))
1497                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1498                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1499                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1500                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1501                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1502                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1503                 }
1504
1505                 /*
1506                  * "--force" will defeat any rejection implemented
1507                  * by the rules above.
1508                  */
1509                 if (!force_ref_update)
1510                         ref->status = reject_reason;
1511                 else if (reject_reason)
1512                         ref->forced_update = 1;
1513         }
1514 }
1515
1516 struct branch *branch_get(const char *name)
1517 {
1518         struct branch *ret;
1519
1520         read_config();
1521         if (!name || !*name || !strcmp(name, "HEAD"))
1522                 ret = current_branch;
1523         else
1524                 ret = make_branch(name, 0);
1525         if (ret && ret->remote_name) {
1526                 ret->remote = remote_get(ret->remote_name);
1527                 if (ret->merge_nr) {
1528                         int i;
1529                         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1530                         for (i = 0; i < ret->merge_nr; i++) {
1531                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1532                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1533                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1534                                     && !strcmp(ret->remote_name, "."))
1535                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1536                         }
1537                 }
1538         }
1539         return ret;
1540 }
1541
1542 int branch_has_merge_config(struct branch *branch)
1543 {
1544         return branch && !!branch->merge;
1545 }
1546
1547 int branch_merge_matches(struct branch *branch,
1548                                  int i,
1549                                  const char *refname)
1550 {
1551         if (!branch || i < 0 || i >= branch->merge_nr)
1552                 return 0;
1553         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1554 }
1555
1556 static int ignore_symref_update(const char *refname)
1557 {
1558         unsigned char sha1[20];
1559         int flag;
1560
1561         if (!resolve_ref_unsafe(refname, sha1, 0, &flag))
1562                 return 0; /* non-existing refs are OK */
1563         return (flag & REF_ISSYMREF);
1564 }
1565
1566 /*
1567  * Create and return a list of (struct ref) consisting of copies of
1568  * each remote_ref that matches refspec.  refspec must be a pattern.
1569  * Fill in the copies' peer_ref to describe the local tracking refs to
1570  * which they map.  Omit any references that would map to an existing
1571  * local symbolic ref.
1572  */
1573 static struct ref *get_expanded_map(const struct ref *remote_refs,
1574                                     const struct refspec *refspec)
1575 {
1576         const struct ref *ref;
1577         struct ref *ret = NULL;
1578         struct ref **tail = &ret;
1579
1580         for (ref = remote_refs; ref; ref = ref->next) {
1581                 char *expn_name = NULL;
1582
1583                 if (strchr(ref->name, '^'))
1584                         continue; /* a dereference item */
1585                 if (match_name_with_pattern(refspec->src, ref->name,
1586                                             refspec->dst, &expn_name) &&
1587                     !ignore_symref_update(expn_name)) {
1588                         struct ref *cpy = copy_ref(ref);
1589
1590                         cpy->peer_ref = alloc_ref(expn_name);
1591                         if (refspec->force)
1592                                 cpy->peer_ref->force = 1;
1593                         *tail = cpy;
1594                         tail = &cpy->next;
1595                 }
1596                 free(expn_name);
1597         }
1598
1599         return ret;
1600 }
1601
1602 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1603 {
1604         const struct ref *ref;
1605         for (ref = refs; ref; ref = ref->next) {
1606                 if (refname_match(name, ref->name, ref_fetch_rules))
1607                         return ref;
1608         }
1609         return NULL;
1610 }
1611
1612 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1613 {
1614         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1615
1616         if (!ref)
1617                 return NULL;
1618
1619         return copy_ref(ref);
1620 }
1621
1622 static struct ref *get_local_ref(const char *name)
1623 {
1624         if (!name || name[0] == '\0')
1625                 return NULL;
1626
1627         if (!prefixcmp(name, "refs/"))
1628                 return alloc_ref(name);
1629
1630         if (!prefixcmp(name, "heads/") ||
1631             !prefixcmp(name, "tags/") ||
1632             !prefixcmp(name, "remotes/"))
1633                 return alloc_ref_with_prefix("refs/", 5, name);
1634
1635         return alloc_ref_with_prefix("refs/heads/", 11, name);
1636 }
1637
1638 int get_fetch_map(const struct ref *remote_refs,
1639                   const struct refspec *refspec,
1640                   struct ref ***tail,
1641                   int missing_ok)
1642 {
1643         struct ref *ref_map, **rmp;
1644
1645         if (refspec->pattern) {
1646                 ref_map = get_expanded_map(remote_refs, refspec);
1647         } else {
1648                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1649
1650                 if (refspec->exact_sha1) {
1651                         ref_map = alloc_ref(name);
1652                         get_sha1_hex(name, ref_map->old_sha1);
1653                 } else {
1654                         ref_map = get_remote_ref(remote_refs, name);
1655                 }
1656                 if (!missing_ok && !ref_map)
1657                         die("Couldn't find remote ref %s", name);
1658                 if (ref_map) {
1659                         ref_map->peer_ref = get_local_ref(refspec->dst);
1660                         if (ref_map->peer_ref && refspec->force)
1661                                 ref_map->peer_ref->force = 1;
1662                 }
1663         }
1664
1665         for (rmp = &ref_map; *rmp; ) {
1666                 if ((*rmp)->peer_ref) {
1667                         if (prefixcmp((*rmp)->peer_ref->name, "refs/") ||
1668                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1669                                 struct ref *ignore = *rmp;
1670                                 error("* Ignoring funny ref '%s' locally",
1671                                       (*rmp)->peer_ref->name);
1672                                 *rmp = (*rmp)->next;
1673                                 free(ignore->peer_ref);
1674                                 free(ignore);
1675                                 continue;
1676                         }
1677                 }
1678                 rmp = &((*rmp)->next);
1679         }
1680
1681         if (ref_map)
1682                 tail_link_ref(ref_map, tail);
1683
1684         return 0;
1685 }
1686
1687 int resolve_remote_symref(struct ref *ref, struct ref *list)
1688 {
1689         if (!ref->symref)
1690                 return 0;
1691         for (; list; list = list->next)
1692                 if (!strcmp(ref->symref, list->name)) {
1693                         hashcpy(ref->old_sha1, list->old_sha1);
1694                         return 0;
1695                 }
1696         return 1;
1697 }
1698
1699 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1700 {
1701         while (list) {
1702                 struct commit_list *temp = list;
1703                 temp->item->object.flags &= ~mark;
1704                 list = temp->next;
1705                 free(temp);
1706         }
1707 }
1708
1709 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1710 {
1711         struct object *o;
1712         struct commit *old, *new;
1713         struct commit_list *list, *used;
1714         int found = 0;
1715
1716         /*
1717          * Both new and old must be commit-ish and new is descendant of
1718          * old.  Otherwise we require --force.
1719          */
1720         o = deref_tag(parse_object(old_sha1), NULL, 0);
1721         if (!o || o->type != OBJ_COMMIT)
1722                 return 0;
1723         old = (struct commit *) o;
1724
1725         o = deref_tag(parse_object(new_sha1), NULL, 0);
1726         if (!o || o->type != OBJ_COMMIT)
1727                 return 0;
1728         new = (struct commit *) o;
1729
1730         if (parse_commit(new) < 0)
1731                 return 0;
1732
1733         used = list = NULL;
1734         commit_list_insert(new, &list);
1735         while (list) {
1736                 new = pop_most_recent_commit(&list, TMP_MARK);
1737                 commit_list_insert(new, &used);
1738                 if (new == old) {
1739                         found = 1;
1740                         break;
1741                 }
1742         }
1743         unmark_and_free(list, TMP_MARK);
1744         unmark_and_free(used, TMP_MARK);
1745         return found;
1746 }
1747
1748 /*
1749  * Compare a branch with its upstream, and save their differences (number
1750  * of commits) in *num_ours and *num_theirs.
1751  *
1752  * Return 0 if branch has no upstream (no base), -1 if upstream is missing
1753  * (with "gone" base), otherwise 1 (with base).
1754  */
1755 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1756 {
1757         unsigned char sha1[20];
1758         struct commit *ours, *theirs;
1759         char symmetric[84];
1760         struct rev_info revs;
1761         const char *rev_argv[10], *base;
1762         int rev_argc;
1763
1764         /* Cannot stat unless we are marked to build on top of somebody else. */
1765         if (!branch ||
1766             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1767                 return 0;
1768
1769         /* Cannot stat if what we used to build on no longer exists */
1770         base = branch->merge[0]->dst;
1771         if (read_ref(base, sha1))
1772                 return -1;
1773         theirs = lookup_commit_reference(sha1);
1774         if (!theirs)
1775                 return -1;
1776
1777         if (read_ref(branch->refname, sha1))
1778                 return -1;
1779         ours = lookup_commit_reference(sha1);
1780         if (!ours)
1781                 return -1;
1782
1783         /* are we the same? */
1784         if (theirs == ours) {
1785                 *num_theirs = *num_ours = 0;
1786                 return 1;
1787         }
1788
1789         /* Run "rev-list --left-right ours...theirs" internally... */
1790         rev_argc = 0;
1791         rev_argv[rev_argc++] = NULL;
1792         rev_argv[rev_argc++] = "--left-right";
1793         rev_argv[rev_argc++] = symmetric;
1794         rev_argv[rev_argc++] = "--";
1795         rev_argv[rev_argc] = NULL;
1796
1797         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1798         strcpy(symmetric + 40, "...");
1799         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1800
1801         init_revisions(&revs, NULL);
1802         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1803         prepare_revision_walk(&revs);
1804
1805         /* ... and count the commits on each side. */
1806         *num_ours = 0;
1807         *num_theirs = 0;
1808         while (1) {
1809                 struct commit *c = get_revision(&revs);
1810                 if (!c)
1811                         break;
1812                 if (c->object.flags & SYMMETRIC_LEFT)
1813                         (*num_ours)++;
1814                 else
1815                         (*num_theirs)++;
1816         }
1817
1818         /* clear object flags smudged by the above traversal */
1819         clear_commit_marks(ours, ALL_REV_FLAGS);
1820         clear_commit_marks(theirs, ALL_REV_FLAGS);
1821         return 1;
1822 }
1823
1824 /*
1825  * Return true when there is anything to report, otherwise false.
1826  */
1827 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1828 {
1829         int ours, theirs;
1830         const char *base;
1831         int upstream_is_gone = 0;
1832
1833         switch (stat_tracking_info(branch, &ours, &theirs)) {
1834         case 0:
1835                 /* no base */
1836                 return 0;
1837         case -1:
1838                 /* with "gone" base */
1839                 upstream_is_gone = 1;
1840                 break;
1841         default:
1842                 /* with base */
1843                 break;
1844         }
1845
1846         base = branch->merge[0]->dst;
1847         base = shorten_unambiguous_ref(base, 0);
1848         if (upstream_is_gone) {
1849                 strbuf_addf(sb,
1850                         _("Your branch is based on '%s', but the upstream is gone.\n"),
1851                         base);
1852                 if (advice_status_hints)
1853                         strbuf_addf(sb,
1854                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1855         } else if (!ours && !theirs) {
1856                 strbuf_addf(sb,
1857                         _("Your branch is up-to-date with '%s'.\n"),
1858                         base);
1859         } else if (!theirs) {
1860                 strbuf_addf(sb,
1861                         Q_("Your branch is ahead of '%s' by %d commit.\n",
1862                            "Your branch is ahead of '%s' by %d commits.\n",
1863                            ours),
1864                         base, ours);
1865                 if (advice_status_hints)
1866                         strbuf_addf(sb,
1867                                 _("  (use \"git push\" to publish your local commits)\n"));
1868         } else if (!ours) {
1869                 strbuf_addf(sb,
1870                         Q_("Your branch is behind '%s' by %d commit, "
1871                                "and can be fast-forwarded.\n",
1872                            "Your branch is behind '%s' by %d commits, "
1873                                "and can be fast-forwarded.\n",
1874                            theirs),
1875                         base, theirs);
1876                 if (advice_status_hints)
1877                         strbuf_addf(sb,
1878                                 _("  (use \"git pull\" to update your local branch)\n"));
1879         } else {
1880                 strbuf_addf(sb,
1881                         Q_("Your branch and '%s' have diverged,\n"
1882                                "and have %d and %d different commit each, "
1883                                "respectively.\n",
1884                            "Your branch and '%s' have diverged,\n"
1885                                "and have %d and %d different commits each, "
1886                                "respectively.\n",
1887                            theirs),
1888                         base, ours, theirs);
1889                 if (advice_status_hints)
1890                         strbuf_addf(sb,
1891                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1892         }
1893         return 1;
1894 }
1895
1896 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1897 {
1898         struct ref ***local_tail = cb_data;
1899         struct ref *ref;
1900         int len;
1901
1902         /* we already know it starts with refs/ to get here */
1903         if (check_refname_format(refname + 5, 0))
1904                 return 0;
1905
1906         len = strlen(refname) + 1;
1907         ref = xcalloc(1, sizeof(*ref) + len);
1908         hashcpy(ref->new_sha1, sha1);
1909         memcpy(ref->name, refname, len);
1910         **local_tail = ref;
1911         *local_tail = &ref->next;
1912         return 0;
1913 }
1914
1915 struct ref *get_local_heads(void)
1916 {
1917         struct ref *local_refs = NULL, **local_tail = &local_refs;
1918         for_each_ref(one_local_ref, &local_tail);
1919         return local_refs;
1920 }
1921
1922 struct ref *guess_remote_head(const struct ref *head,
1923                               const struct ref *refs,
1924                               int all)
1925 {
1926         const struct ref *r;
1927         struct ref *list = NULL;
1928         struct ref **tail = &list;
1929
1930         if (!head)
1931                 return NULL;
1932
1933         /*
1934          * Some transports support directly peeking at
1935          * where HEAD points; if that is the case, then
1936          * we don't have to guess.
1937          */
1938         if (head->symref)
1939                 return copy_ref(find_ref_by_name(refs, head->symref));
1940
1941         /* If refs/heads/master could be right, it is. */
1942         if (!all) {
1943                 r = find_ref_by_name(refs, "refs/heads/master");
1944                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1945                         return copy_ref(r);
1946         }
1947
1948         /* Look for another ref that points there */
1949         for (r = refs; r; r = r->next) {
1950                 if (r != head &&
1951                     !prefixcmp(r->name, "refs/heads/") &&
1952                     !hashcmp(r->old_sha1, head->old_sha1)) {
1953                         *tail = copy_ref(r);
1954                         tail = &((*tail)->next);
1955                         if (!all)
1956                                 break;
1957                 }
1958         }
1959
1960         return list;
1961 }
1962
1963 struct stale_heads_info {
1964         struct string_list *ref_names;
1965         struct ref **stale_refs_tail;
1966         struct refspec *refs;
1967         int ref_count;
1968 };
1969
1970 static int get_stale_heads_cb(const char *refname,
1971         const unsigned char *sha1, int flags, void *cb_data)
1972 {
1973         struct stale_heads_info *info = cb_data;
1974         struct refspec query;
1975         memset(&query, 0, sizeof(struct refspec));
1976         query.dst = (char *)refname;
1977
1978         if (query_refspecs(info->refs, info->ref_count, &query))
1979                 return 0; /* No matches */
1980
1981         /*
1982          * If we did find a suitable refspec and it's not a symref and
1983          * it's not in the list of refs that currently exist in that
1984          * remote we consider it to be stale.
1985          */
1986         if (!((flags & REF_ISSYMREF) ||
1987               string_list_has_string(info->ref_names, query.src))) {
1988                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1989                 hashcpy(ref->new_sha1, sha1);
1990         }
1991
1992         free(query.src);
1993         return 0;
1994 }
1995
1996 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
1997 {
1998         struct ref *ref, *stale_refs = NULL;
1999         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2000         struct stale_heads_info info;
2001         info.ref_names = &ref_names;
2002         info.stale_refs_tail = &stale_refs;
2003         info.refs = refs;
2004         info.ref_count = ref_count;
2005         for (ref = fetch_map; ref; ref = ref->next)
2006                 string_list_append(&ref_names, ref->name);
2007         sort_string_list(&ref_names);
2008         for_each_ref(get_stale_heads_cb, &info);
2009         string_list_clear(&ref_names, 0);
2010         return stale_refs;
2011 }
2012
2013 /*
2014  * Compare-and-swap
2015  */
2016 void clear_cas_option(struct push_cas_option *cas)
2017 {
2018         int i;
2019
2020         for (i = 0; i < cas->nr; i++)
2021                 free(cas->entry[i].refname);
2022         free(cas->entry);
2023         memset(cas, 0, sizeof(*cas));
2024 }
2025
2026 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2027                                       const char *refname,
2028                                       size_t refnamelen)
2029 {
2030         struct push_cas *entry;
2031         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2032         entry = &cas->entry[cas->nr++];
2033         memset(entry, 0, sizeof(*entry));
2034         entry->refname = xmemdupz(refname, refnamelen);
2035         return entry;
2036 }
2037
2038 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2039 {
2040         const char *colon;
2041         struct push_cas *entry;
2042
2043         if (unset) {
2044                 /* "--no-<option>" */
2045                 clear_cas_option(cas);
2046                 return 0;
2047         }
2048
2049         if (!arg) {
2050                 /* just "--<option>" */
2051                 cas->use_tracking_for_rest = 1;
2052                 return 0;
2053         }
2054
2055         /* "--<option>=refname" or "--<option>=refname:value" */
2056         colon = strchrnul(arg, ':');
2057         entry = add_cas_entry(cas, arg, colon - arg);
2058         if (!*colon)
2059                 entry->use_tracking = 1;
2060         else if (get_sha1(colon + 1, entry->expect))
2061                 return error("cannot parse expected object name '%s'", colon + 1);
2062         return 0;
2063 }
2064
2065 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2066 {
2067         return parse_push_cas_option(opt->value, arg, unset);
2068 }
2069
2070 int is_empty_cas(const struct push_cas_option *cas)
2071 {
2072         return !cas->use_tracking_for_rest && !cas->nr;
2073 }
2074
2075 /*
2076  * Look at remote.fetch refspec and see if we have a remote
2077  * tracking branch for the refname there.  Fill its current
2078  * value in sha1[].
2079  * If we cannot do so, return negative to signal an error.
2080  */
2081 static int remote_tracking(struct remote *remote, const char *refname,
2082                            unsigned char sha1[20])
2083 {
2084         char *dst;
2085
2086         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2087         if (!dst)
2088                 return -1; /* no tracking ref for refname at remote */
2089         if (read_ref(dst, sha1))
2090                 return -1; /* we know what the tracking ref is but we cannot read it */
2091         return 0;
2092 }
2093
2094 static void apply_cas(struct push_cas_option *cas,
2095                       struct remote *remote,
2096                       struct ref *ref)
2097 {
2098         int i;
2099
2100         /* Find an explicit --<option>=<name>[:<value>] entry */
2101         for (i = 0; i < cas->nr; i++) {
2102                 struct push_cas *entry = &cas->entry[i];
2103                 if (!refname_match(entry->refname, ref->name, ref_rev_parse_rules))
2104                         continue;
2105                 ref->expect_old_sha1 = 1;
2106                 if (!entry->use_tracking)
2107                         hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2108                 else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2109                         ref->expect_old_no_trackback = 1;
2110                 return;
2111         }
2112
2113         /* Are we using "--<option>" to cover all? */
2114         if (!cas->use_tracking_for_rest)
2115                 return;
2116
2117         ref->expect_old_sha1 = 1;
2118         if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2119                 ref->expect_old_no_trackback = 1;
2120 }
2121
2122 void apply_push_cas(struct push_cas_option *cas,
2123                     struct remote *remote,
2124                     struct ref *remote_refs)
2125 {
2126         struct ref *ref;
2127         for (ref = remote_refs; ref; ref = ref->next)
2128                 apply_cas(cas, remote, ref);
2129 }