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 static struct hashmap remotes_hash;
  46
  47 static struct branch **branches;
  48 static int branches_alloc;
  49 static int branches_nr;
  50
  51 static struct branch *current_branch;
  52 static const char *default_remote_name;
  53 static const char *branch_pushremote_name;
  54 static const char *pushremote_name;
  55 static int explicit_default_remote_name;
  56
  57 static struct rewrites rewrites;
  58 static struct rewrites rewrites_push;
  59
  60 #define BUF_SIZE (2048)
  61 static char buffer[BUF_SIZE];
  62
  63 static int valid_remote(const struct remote *remote)
  64 {
  65         return (!!remote->url) || (!!remote->foreign_vcs);
  66 }
  67
  68 static const char *alias_url(const char *url, struct rewrites *r)
  69 {
  70         int i, j;
  71         char *ret;
  72         struct counted_string *longest;
  73         int longest_i;
  74
  75         longest = NULL;
  76         longest_i = -1;
  77         for (i = 0; i < r->rewrite_nr; i++) {
  78                 if (!r->rewrite[i])
  79                         continue;
  80                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  81                         if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  82                             (!longest ||
  83                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  84                                 longest = &(r->rewrite[i]->instead_of[j]);
  85                                 longest_i = i;
  86                         }
  87                 }
  88         }
  89         if (!longest)
  90                 return url;
  91
  92         ret = xmalloc(r->rewrite[longest_i]->baselen +
  93                      (strlen(url) - longest->len) + 1);
  94         strcpy(ret, r->rewrite[longest_i]->base);
  95         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  96         return ret;
  97 }
  98
  99 static void add_push_refspec(struct remote *remote, const char *ref)
 100 {
 101         ALLOC_GROW(remote->push_refspec,
 102                    remote->push_refspec_nr + 1,
 103                    remote->push_refspec_alloc);
 104         remote->push_refspec[remote->push_refspec_nr++] = ref;
 105 }
 106
 107 static void add_fetch_refspec(struct remote *remote, const char *ref)
 108 {
 109         ALLOC_GROW(remote->fetch_refspec,
 110                    remote->fetch_refspec_nr + 1,
 111                    remote->fetch_refspec_alloc);
 112         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 113 }
 114
 115 static void add_url(struct remote *remote, const char *url)
 116 {
 117         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 118         remote->url[remote->url_nr++] = url;
 119 }
 120
 121 static void add_pushurl(struct remote *remote, const char *pushurl)
 122 {
 123         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 124         remote->pushurl[remote->pushurl_nr++] = pushurl;
 125 }
 126
 127 static void add_pushurl_alias(struct remote *remote, const char *url)
 128 {
 129         const char *pushurl = alias_url(url, &rewrites_push);
 130         if (pushurl != url)
 131                 add_pushurl(remote, pushurl);
 132 }
 133
 134 static void add_url_alias(struct remote *remote, const char *url)
 135 {
 136         add_url(remote, alias_url(url, &rewrites));
 137         add_pushurl_alias(remote, url);
 138 }
 139
 140 struct remotes_hash_key {
 141         const char *str;
 142         int len;
 143 };
 144
 145 static int remotes_hash_cmp(const struct remote *a, const struct remote *b, const struct remotes_hash_key *key)
 146 {
 147         if (key)
 148                 return strncmp(a->name, key->str, key->len) || a->name[key->len];
 149         else
 150                 return strcmp(a->name, b->name);
 151 }
 152
 153 static inline void init_remotes_hash(void)
 154 {
 155         if (!remotes_hash.cmpfn)
 156                 hashmap_init(&remotes_hash, (hashmap_cmp_fn)remotes_hash_cmp, 0);
 157 }
 158
 159 static struct remote *make_remote(const char *name, int len)
 160 {
 161         struct remote *ret, *replaced;
 162         struct remotes_hash_key lookup;
 163         struct hashmap_entry lookup_entry;
 164
 165         if (!len)
 166                 len = strlen(name);
 167
 168         init_remotes_hash();
 169         lookup.str = name;
 170         lookup.len = len;
 171         hashmap_entry_init(&lookup_entry, memhash(name, len));
 172
 173         if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 174                 return ret;
 175
 176         ret = xcalloc(1, sizeof(struct remote));
 177         ret->prune = -1;  /* unspecified */
 178         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 179         remotes[remotes_nr++] = ret;
 180         ret->name = xstrndup(name, len);
 181
 182         hashmap_entry_init(ret, lookup_entry.hash);
 183         replaced = hashmap_put(&remotes_hash, ret);
 184         assert(replaced == NULL);  /* no previous entry overwritten */
 185         return ret;
 186 }
 187
 188 static void add_merge(struct branch *branch, const char *name)
 189 {
 190         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 191                    branch->merge_alloc);
 192         branch->merge_name[branch->merge_nr++] = name;
 193 }
 194
 195 static struct branch *make_branch(const char *name, int len)
 196 {
 197         struct branch *ret;
 198         int i;
 199
 200         for (i = 0; i < branches_nr; i++) {
 201                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 202                            !branches[i]->name[len]) :
 203                     !strcmp(name, branches[i]->name))
 204                         return branches[i];
 205         }
 206
 207         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 208         ret = xcalloc(1, sizeof(struct branch));
 209         branches[branches_nr++] = ret;
 210         if (len)
 211                 ret->name = xstrndup(name, len);
 212         else
 213                 ret->name = xstrdup(name);
 214         ret->refname = xstrfmt("refs/heads/%s", ret->name);
 215
 216         return ret;
 217 }
 218
 219 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 220 {
 221         struct rewrite *ret;
 222         int i;
 223
 224         for (i = 0; i < r->rewrite_nr; i++) {
 225                 if (len
 226                     ? (len == r->rewrite[i]->baselen &&
 227                        !strncmp(base, r->rewrite[i]->base, len))
 228                     : !strcmp(base, r->rewrite[i]->base))
 229                         return r->rewrite[i];
 230         }
 231
 232         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 233         ret = xcalloc(1, sizeof(struct rewrite));
 234         r->rewrite[r->rewrite_nr++] = ret;
 235         if (len) {
 236                 ret->base = xstrndup(base, len);
 237                 ret->baselen = len;
 238         }
 239         else {
 240                 ret->base = xstrdup(base);
 241                 ret->baselen = strlen(base);
 242         }
 243         return ret;
 244 }
 245
 246 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 247 {
 248         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 249         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 250         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 251         rewrite->instead_of_nr++;
 252 }
 253
 254 static void read_remotes_file(struct remote *remote)
 255 {
 256         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 257
 258         if (!f)
 259                 return;
 260         remote->origin = REMOTE_REMOTES;
 261         while (fgets(buffer, BUF_SIZE, f)) {
 262                 int value_list;
 263                 char *s, *p;
 264
 265                 if (starts_with(buffer, "URL:")) {
 266                         value_list = 0;
 267                         s = buffer + 4;
 268                 } else if (starts_with(buffer, "Push:")) {
 269                         value_list = 1;
 270                         s = buffer + 5;
 271                 } else if (starts_with(buffer, "Pull:")) {
 272                         value_list = 2;
 273                         s = buffer + 5;
 274                 } else
 275                         continue;
 276
 277                 while (isspace(*s))
 278                         s++;
 279                 if (!*s)
 280                         continue;
 281
 282                 p = s + strlen(s);
 283                 while (isspace(p[-1]))
 284                         *--p = 0;
 285
 286                 switch (value_list) {
 287                 case 0:
 288                         add_url_alias(remote, xstrdup(s));
 289                         break;
 290                 case 1:
 291                         add_push_refspec(remote, xstrdup(s));
 292                         break;
 293                 case 2:
 294                         add_fetch_refspec(remote, xstrdup(s));
 295                         break;
 296                 }
 297         }
 298         fclose(f);
 299 }
 300
 301 static void read_branches_file(struct remote *remote)
 302 {
 303         char *frag;
 304         struct strbuf branch = STRBUF_INIT;
 305         int n = 1000;
 306         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 307         char *s, *p;
 308         int len;
 309
 310         if (!f)
 311                 return;
 312         s = fgets(buffer, BUF_SIZE, f);
 313         fclose(f);
 314         if (!s)
 315                 return;
 316         while (isspace(*s))
 317                 s++;
 318         if (!*s)
 319                 return;
 320         remote->origin = REMOTE_BRANCHES;
 321         p = s + strlen(s);
 322         while (isspace(p[-1]))
 323                 *--p = 0;
 324         len = p - s;
 325         p = xmalloc(len + 1);
 326         strcpy(p, s);
 327
 328         /*
 329          * The branches file would have URL and optionally
 330          * #branch specified.  The "master" (or specified) branch is
 331          * fetched and stored in the local branch of the same name.
 332          */
 333         frag = strchr(p, '#');
 334         if (frag) {
 335                 *(frag++) = '\0';
 336                 strbuf_addf(&branch, "refs/heads/%s", frag);
 337         } else
 338                 strbuf_addstr(&branch, "refs/heads/master");
 339
 340         strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 341         add_url_alias(remote, p);
 342         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 343         /*
 344          * Cogito compatible push: push current HEAD to remote #branch
 345          * (master if missing)
 346          */
 347         strbuf_init(&branch, 0);
 348         strbuf_addstr(&branch, "HEAD");
 349         if (frag)
 350                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 351         else
 352                 strbuf_addstr(&branch, ":refs/heads/master");
 353         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 354         remote->fetch_tags = 1; /* always auto-follow */
 355 }
 356
 357 static int handle_config(const char *key, const char *value, void *cb)
 358 {
 359         const char *name;
 360         const char *subkey;
 361         struct remote *remote;
 362         struct branch *branch;
 363         if (starts_with(key, "branch.")) {
 364                 name = key + 7;
 365                 subkey = strrchr(name, '.');
 366                 if (!subkey)
 367                         return 0;
 368                 branch = make_branch(name, subkey - name);
 369                 if (!strcmp(subkey, ".remote")) {
 370                         if (git_config_string(&branch->remote_name, key, value))
 371                                 return -1;
 372                         if (branch == current_branch) {
 373                                 default_remote_name = branch->remote_name;
 374                                 explicit_default_remote_name = 1;
 375                         }
 376                 } else if (!strcmp(subkey, ".pushremote")) {
 377                         if (branch == current_branch)
 378                                 if (git_config_string(&branch_pushremote_name, key, value))
 379                                         return -1;
 380                 } else if (!strcmp(subkey, ".merge")) {
 381                         if (!value)
 382                                 return config_error_nonbool(key);
 383                         add_merge(branch, xstrdup(value));
 384                 }
 385                 return 0;
 386         }
 387         if (starts_with(key, "url.")) {
 388                 struct rewrite *rewrite;
 389                 name = key + 4;
 390                 subkey = strrchr(name, '.');
 391                 if (!subkey)
 392                         return 0;
 393                 if (!strcmp(subkey, ".insteadof")) {
 394                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 395                         if (!value)
 396                                 return config_error_nonbool(key);
 397                         add_instead_of(rewrite, xstrdup(value));
 398                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 399                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 400                         if (!value)
 401                                 return config_error_nonbool(key);
 402                         add_instead_of(rewrite, xstrdup(value));
 403                 }
 404         }
 405
 406         if (!starts_with(key,  "remote."))
 407                 return 0;
 408         name = key + 7;
 409
 410         /* Handle remote.* variables */
 411         if (!strcmp(name, "pushdefault"))
 412                 return git_config_string(&pushremote_name, key, value);
 413
 414         /* Handle remote.<name>.* variables */
 415         if (*name == '/') {
 416                 warning("Config remote shorthand cannot begin with '/': %s",
 417                         name);
 418                 return 0;
 419         }
 420         subkey = strrchr(name, '.');
 421         if (!subkey)
 422                 return 0;
 423         remote = make_remote(name, subkey - name);
 424         remote->origin = REMOTE_CONFIG;
 425         if (!strcmp(subkey, ".mirror"))
 426                 remote->mirror = git_config_bool(key, value);
 427         else if (!strcmp(subkey, ".skipdefaultupdate"))
 428                 remote->skip_default_update = git_config_bool(key, value);
 429         else if (!strcmp(subkey, ".skipfetchall"))
 430                 remote->skip_default_update = git_config_bool(key, value);
 431         else if (!strcmp(subkey, ".prune"))
 432                 remote->prune = git_config_bool(key, value);
 433         else if (!strcmp(subkey, ".url")) {
 434                 const char *v;
 435                 if (git_config_string(&v, key, value))
 436                         return -1;
 437                 add_url(remote, v);
 438         } else if (!strcmp(subkey, ".pushurl")) {
 439                 const char *v;
 440                 if (git_config_string(&v, key, value))
 441                         return -1;
 442                 add_pushurl(remote, v);
 443         } else if (!strcmp(subkey, ".push")) {
 444                 const char *v;
 445                 if (git_config_string(&v, key, value))
 446                         return -1;
 447                 add_push_refspec(remote, v);
 448         } else if (!strcmp(subkey, ".fetch")) {
 449                 const char *v;
 450                 if (git_config_string(&v, key, value))
 451                         return -1;
 452                 add_fetch_refspec(remote, v);
 453         } else if (!strcmp(subkey, ".receivepack")) {
 454                 const char *v;
 455                 if (git_config_string(&v, key, value))
 456                         return -1;
 457                 if (!remote->receivepack)
 458                         remote->receivepack = v;
 459                 else
 460                         error("more than one receivepack given, using the first");
 461         } else if (!strcmp(subkey, ".uploadpack")) {
 462                 const char *v;
 463                 if (git_config_string(&v, key, value))
 464                         return -1;
 465                 if (!remote->uploadpack)
 466                         remote->uploadpack = v;
 467                 else
 468                         error("more than one uploadpack given, using the first");
 469         } else if (!strcmp(subkey, ".tagopt")) {
 470                 if (!strcmp(value, "--no-tags"))
 471                         remote->fetch_tags = -1;
 472                 else if (!strcmp(value, "--tags"))
 473                         remote->fetch_tags = 2;
 474         } else if (!strcmp(subkey, ".proxy")) {
 475                 return git_config_string((const char **)&remote->http_proxy,
 476                                          key, value);
 477         } else if (!strcmp(subkey, ".vcs")) {
 478                 return git_config_string(&remote->foreign_vcs, key, value);
 479         }
 480         return 0;
 481 }
 482
 483 static void alias_all_urls(void)
 484 {
 485         int i, j;
 486         for (i = 0; i < remotes_nr; i++) {
 487                 int add_pushurl_aliases;
 488                 if (!remotes[i])
 489                         continue;
 490                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 491                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 492                 }
 493                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 494                 for (j = 0; j < remotes[i]->url_nr; j++) {
 495                         if (add_pushurl_aliases)
 496                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 497                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 498                 }
 499         }
 500 }
 501
 502 static void read_config(void)
 503 {
 504         unsigned char sha1[20];
 505         const char *head_ref;
 506         int flag;
 507         if (default_remote_name) /* did this already */
 508                 return;
 509         default_remote_name = "origin";
 510         current_branch = NULL;
 511         head_ref = resolve_ref_unsafe("HEAD", 0, sha1, &flag);
 512         if (head_ref && (flag & REF_ISSYMREF) &&
 513             skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 514                 current_branch = make_branch(head_ref, 0);
 515         }
 516         git_config(handle_config, NULL);
 517         if (branch_pushremote_name) {
 518                 free((char *)pushremote_name);
 519                 pushremote_name = branch_pushremote_name;
 520         }
 521         alias_all_urls();
 522 }
 523
 524 /*
 525  * This function frees a refspec array.
 526  * Warning: code paths should be checked to ensure that the src
 527  *          and dst pointers are always freeable pointers as well
 528  *          as the refspec pointer itself.
 529  */
 530 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 531 {
 532         int i;
 533
 534         if (!refspec)
 535                 return;
 536
 537         for (i = 0; i < nr_refspec; i++) {
 538                 free(refspec[i].src);
 539                 free(refspec[i].dst);
 540         }
 541         free(refspec);
 542 }
 543
 544 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 545 {
 546         int i;
 547         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 548
 549         for (i = 0; i < nr_refspec; i++) {
 550                 size_t llen;
 551                 int is_glob;
 552                 const char *lhs, *rhs;
 553                 int flags;
 554
 555                 is_glob = 0;
 556
 557                 lhs = refspec[i];
 558                 if (*lhs == '+') {
 559                         rs[i].force = 1;
 560                         lhs++;
 561                 }
 562
 563                 rhs = strrchr(lhs, ':');
 564
 565                 /*
 566                  * Before going on, special case ":" (or "+:") as a refspec
 567                  * for pushing matching refs.
 568                  */
 569                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 570                         rs[i].matching = 1;
 571                         continue;
 572                 }
 573
 574                 if (rhs) {
 575                         size_t rlen = strlen(++rhs);
 576                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 577                         rs[i].dst = xstrndup(rhs, rlen);
 578                 }
 579
 580                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 581                 if (1 <= llen && memchr(lhs, '*', llen)) {
 582                         if ((rhs && !is_glob) || (!rhs && fetch))
 583                                 goto invalid;
 584                         is_glob = 1;
 585                 } else if (rhs && is_glob) {
 586                         goto invalid;
 587                 }
 588
 589                 rs[i].pattern = is_glob;
 590                 rs[i].src = xstrndup(lhs, llen);
 591                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 592
 593                 if (fetch) {
 594                         unsigned char unused[40];
 595
 596                         /* LHS */
 597                         if (!*rs[i].src)
 598                                 ; /* empty is ok; it means "HEAD" */
 599                         else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 600                                 rs[i].exact_sha1 = 1; /* ok */
 601                         else if (!check_refname_format(rs[i].src, flags))
 602                                 ; /* valid looking ref is ok */
 603                         else
 604                                 goto invalid;
 605                         /* RHS */
 606                         if (!rs[i].dst)
 607                                 ; /* missing is ok; it is the same as empty */
 608                         else if (!*rs[i].dst)
 609                                 ; /* empty is ok; it means "do not store" */
 610                         else if (!check_refname_format(rs[i].dst, flags))
 611                                 ; /* valid looking ref is ok */
 612                         else
 613                                 goto invalid;
 614                 } else {
 615                         /*
 616                          * LHS
 617                          * - empty is allowed; it means delete.
 618                          * - when wildcarded, it must be a valid looking ref.
 619                          * - otherwise, it must be an extended SHA-1, but
 620                          *   there is no existing way to validate this.
 621                          */
 622                         if (!*rs[i].src)
 623                                 ; /* empty is ok */
 624                         else if (is_glob) {
 625                                 if (check_refname_format(rs[i].src, flags))
 626                                         goto invalid;
 627                         }
 628                         else
 629                                 ; /* anything goes, for now */
 630                         /*
 631                          * RHS
 632                          * - missing is allowed, but LHS then must be a
 633                          *   valid looking ref.
 634                          * - empty is not allowed.
 635                          * - otherwise it must be a valid looking ref.
 636                          */
 637                         if (!rs[i].dst) {
 638                                 if (check_refname_format(rs[i].src, flags))
 639                                         goto invalid;
 640                         } else if (!*rs[i].dst) {
 641                                 goto invalid;
 642                         } else {
 643                                 if (check_refname_format(rs[i].dst, flags))
 644                                         goto invalid;
 645                         }
 646                 }
 647         }
 648         return rs;
 649
 650  invalid:
 651         if (verify) {
 652                 /*
 653                  * nr_refspec must be greater than zero and i must be valid
 654                  * since it is only possible to reach this point from within
 655                  * the for loop above.
 656                  */
 657                 free_refspecs(rs, i+1);
 658                 return NULL;
 659         }
 660         die("Invalid refspec '%s'", refspec[i]);
 661 }
 662
 663 int valid_fetch_refspec(const char *fetch_refspec_str)
 664 {
 665         struct refspec *refspec;
 666
 667         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 668         free_refspecs(refspec, 1);
 669         return !!refspec;
 670 }
 671
 672 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 673 {
 674         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 675 }
 676
 677 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 678 {
 679         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 680 }
 681
 682 void free_refspec(int nr_refspec, struct refspec *refspec)
 683 {
 684         int i;
 685         for (i = 0; i < nr_refspec; i++) {
 686                 free(refspec[i].src);
 687                 free(refspec[i].dst);
 688         }
 689         free(refspec);
 690 }
 691
 692 static int valid_remote_nick(const char *name)
 693 {
 694         if (!name[0] || is_dot_or_dotdot(name))
 695                 return 0;
 696         return !strchr(name, '/'); /* no slash */
 697 }
 698
 699 static struct remote *remote_get_1(const char *name, const char *pushremote_name)
 700 {
 701         struct remote *ret;
 702         int name_given = 0;
 703
 704         if (name)
 705                 name_given = 1;
 706         else {
 707                 if (pushremote_name) {
 708                         name = pushremote_name;
 709                         name_given = 1;
 710                 } else {
 711                         name = default_remote_name;
 712                         name_given = explicit_default_remote_name;
 713                 }
 714         }
 715
 716         ret = make_remote(name, 0);
 717         if (valid_remote_nick(name)) {
 718                 if (!valid_remote(ret))
 719                         read_remotes_file(ret);
 720                 if (!valid_remote(ret))
 721                         read_branches_file(ret);
 722         }
 723         if (name_given && !valid_remote(ret))
 724                 add_url_alias(ret, name);
 725         if (!valid_remote(ret))
 726                 return NULL;
 727         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 728         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 729         return ret;
 730 }
 731
 732 struct remote *remote_get(const char *name)
 733 {
 734         read_config();
 735         return remote_get_1(name, NULL);
 736 }
 737
 738 struct remote *pushremote_get(const char *name)
 739 {
 740         read_config();
 741         return remote_get_1(name, pushremote_name);
 742 }
 743
 744 int remote_is_configured(const char *name)
 745 {
 746         struct remotes_hash_key lookup;
 747         struct hashmap_entry lookup_entry;
 748         read_config();
 749
 750         init_remotes_hash();
 751         lookup.str = name;
 752         lookup.len = strlen(name);
 753         hashmap_entry_init(&lookup_entry, memhash(name, lookup.len));
 754
 755         return hashmap_get(&remotes_hash, &lookup_entry, &lookup) != NULL;
 756 }
 757
 758 int for_each_remote(each_remote_fn fn, void *priv)
 759 {
 760         int i, result = 0;
 761         read_config();
 762         for (i = 0; i < remotes_nr && !result; i++) {
 763                 struct remote *r = remotes[i];
 764                 if (!r)
 765                         continue;
 766                 if (!r->fetch)
 767                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 768                                                        r->fetch_refspec);
 769                 if (!r->push)
 770                         r->push = parse_push_refspec(r->push_refspec_nr,
 771                                                      r->push_refspec);
 772                 result = fn(r, priv);
 773         }
 774         return result;
 775 }
 776
 777 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 778 {
 779         if (strcmp(ref1->name, ref2->name)) {
 780                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 781                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 782                         die(_("Cannot fetch both %s and %s to %s"),
 783                             ref1->name, ref2->name, ref2->peer_ref->name);
 784                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 785                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 786                         warning(_("%s usually tracks %s, not %s"),
 787                                 ref2->peer_ref->name, ref2->name, ref1->name);
 788                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 789                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 790                         die(_("%s tracks both %s and %s"),
 791                             ref2->peer_ref->name, ref1->name, ref2->name);
 792                 } else {
 793                         /*
 794                          * This last possibility doesn't occur because
 795                          * FETCH_HEAD_IGNORE entries always appear at
 796                          * the end of the list.
 797                          */
 798                         die(_("Internal error"));
 799                 }
 800         }
 801         free(ref2->peer_ref);
 802         free(ref2);
 803 }
 804
 805 struct ref *ref_remove_duplicates(struct ref *ref_map)
 806 {
 807         struct string_list refs = STRING_LIST_INIT_NODUP;
 808         struct ref *retval = NULL;
 809         struct ref **p = &retval;
 810
 811         while (ref_map) {
 812                 struct ref *ref = ref_map;
 813
 814                 ref_map = ref_map->next;
 815                 ref->next = NULL;
 816
 817                 if (!ref->peer_ref) {
 818                         *p = ref;
 819                         p = &ref->next;
 820                 } else {
 821                         struct string_list_item *item =
 822                                 string_list_insert(&refs, ref->peer_ref->name);
 823
 824                         if (item->util) {
 825                                 /* Entry already existed */
 826                                 handle_duplicate((struct ref *)item->util, ref);
 827                         } else {
 828                                 *p = ref;
 829                                 p = &ref->next;
 830                                 item->util = ref;
 831                         }
 832                 }
 833         }
 834
 835         string_list_clear(&refs, 0);
 836         return retval;
 837 }
 838
 839 int remote_has_url(struct remote *remote, const char *url)
 840 {
 841         int i;
 842         for (i = 0; i < remote->url_nr; i++) {
 843                 if (!strcmp(remote->url[i], url))
 844                         return 1;
 845         }
 846         return 0;
 847 }
 848
 849 static int match_name_with_pattern(const char *key, const char *name,
 850                                    const char *value, char **result)
 851 {
 852         const char *kstar = strchr(key, '*');
 853         size_t klen;
 854         size_t ksuffixlen;
 855         size_t namelen;
 856         int ret;
 857         if (!kstar)
 858                 die("Key '%s' of pattern had no '*'", key);
 859         klen = kstar - key;
 860         ksuffixlen = strlen(kstar + 1);
 861         namelen = strlen(name);
 862         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 863                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 864         if (ret && value) {
 865                 struct strbuf sb = STRBUF_INIT;
 866                 const char *vstar = strchr(value, '*');
 867                 if (!vstar)
 868                         die("Value '%s' of pattern has no '*'", value);
 869                 strbuf_add(&sb, value, vstar - value);
 870                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 871                 strbuf_addstr(&sb, vstar + 1);
 872                 *result = strbuf_detach(&sb, NULL);
 873         }
 874         return ret;
 875 }
 876
 877 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 878 {
 879         int i;
 880         int find_src = !query->src;
 881
 882         if (find_src && !query->dst)
 883                 error("query_refspecs_multiple: need either src or dst");
 884
 885         for (i = 0; i < ref_count; i++) {
 886                 struct refspec *refspec = &refs[i];
 887                 const char *key = find_src ? refspec->dst : refspec->src;
 888                 const char *value = find_src ? refspec->src : refspec->dst;
 889                 const char *needle = find_src ? query->dst : query->src;
 890                 char **result = find_src ? &query->src : &query->dst;
 891
 892                 if (!refspec->dst)
 893                         continue;
 894                 if (refspec->pattern) {
 895                         if (match_name_with_pattern(key, needle, value, result))
 896                                 string_list_append_nodup(results, *result);
 897                 } else if (!strcmp(needle, key)) {
 898                         string_list_append(results, value);
 899                 }
 900         }
 901 }
 902
 903 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 904 {
 905         int i;
 906         int find_src = !query->src;
 907         const char *needle = find_src ? query->dst : query->src;
 908         char **result = find_src ? &query->src : &query->dst;
 909
 910         if (find_src && !query->dst)
 911                 return error("query_refspecs: need either src or dst");
 912
 913         for (i = 0; i < ref_count; i++) {
 914                 struct refspec *refspec = &refs[i];
 915                 const char *key = find_src ? refspec->dst : refspec->src;
 916                 const char *value = find_src ? refspec->src : refspec->dst;
 917
 918                 if (!refspec->dst)
 919                         continue;
 920                 if (refspec->pattern) {
 921                         if (match_name_with_pattern(key, needle, value, result)) {
 922                                 query->force = refspec->force;
 923                                 return 0;
 924                         }
 925                 } else if (!strcmp(needle, key)) {
 926                         *result = xstrdup(value);
 927                         query->force = refspec->force;
 928                         return 0;
 929                 }
 930         }
 931         return -1;
 932 }
 933
 934 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 935                      const char *name)
 936 {
 937         struct refspec query;
 938
 939         memset(&query, 0, sizeof(struct refspec));
 940         query.src = (char *)name;
 941
 942         if (query_refspecs(refspecs, nr_refspec, &query))
 943                 return NULL;
 944
 945         return query.dst;
 946 }
 947
 948 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 949 {
 950         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 951 }
 952
 953 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 954                 const char *name)
 955 {
 956         size_t len = strlen(name);
 957         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 958         memcpy(ref->name, prefix, prefixlen);
 959         memcpy(ref->name + prefixlen, name, len);
 960         return ref;
 961 }
 962
 963 struct ref *alloc_ref(const char *name)
 964 {
 965         return alloc_ref_with_prefix("", 0, name);
 966 }
 967
 968 struct ref *copy_ref(const struct ref *ref)
 969 {
 970         struct ref *cpy;
 971         size_t len;
 972         if (!ref)
 973                 return NULL;
 974         len = strlen(ref->name);
 975         cpy = xmalloc(sizeof(struct ref) + len + 1);
 976         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 977         cpy->next = NULL;
 978         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 979         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 980         cpy->peer_ref = copy_ref(ref->peer_ref);
 981         return cpy;
 982 }
 983
 984 struct ref *copy_ref_list(const struct ref *ref)
 985 {
 986         struct ref *ret = NULL;
 987         struct ref **tail = &ret;
 988         while (ref) {
 989                 *tail = copy_ref(ref);
 990                 ref = ref->next;
 991                 tail = &((*tail)->next);
 992         }
 993         return ret;
 994 }
 995
 996 static void free_ref(struct ref *ref)
 997 {
 998         if (!ref)
 999                 return;
1000         free_ref(ref->peer_ref);
1001         free(ref->remote_status);
1002         free(ref->symref);
1003         free(ref);
1004 }
1005
1006 void free_refs(struct ref *ref)
1007 {
1008         struct ref *next;
1009         while (ref) {
1010                 next = ref->next;
1011                 free_ref(ref);
1012                 ref = next;
1013         }
1014 }
1015
1016 int ref_compare_name(const void *va, const void *vb)
1017 {
1018         const struct ref *a = va, *b = vb;
1019         return strcmp(a->name, b->name);
1020 }
1021
1022 static void *ref_list_get_next(const void *a)
1023 {
1024         return ((const struct ref *)a)->next;
1025 }
1026
1027 static void ref_list_set_next(void *a, void *next)
1028 {
1029         ((struct ref *)a)->next = next;
1030 }
1031
1032 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1033 {
1034         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1035 }
1036
1037 int count_refspec_match(const char *pattern,
1038                         struct ref *refs,
1039                         struct ref **matched_ref)
1040 {
1041         int patlen = strlen(pattern);
1042         struct ref *matched_weak = NULL;
1043         struct ref *matched = NULL;
1044         int weak_match = 0;
1045         int match = 0;
1046
1047         for (weak_match = match = 0; refs; refs = refs->next) {
1048                 char *name = refs->name;
1049                 int namelen = strlen(name);
1050
1051                 if (!refname_match(pattern, name))
1052                         continue;
1053
1054                 /* A match is "weak" if it is with refs outside
1055                  * heads or tags, and did not specify the pattern
1056                  * in full (e.g. "refs/remotes/origin/master") or at
1057                  * least from the toplevel (e.g. "remotes/origin/master");
1058                  * otherwise "git push $URL master" would result in
1059                  * ambiguity between remotes/origin/master and heads/master
1060                  * at the remote site.
1061                  */
1062                 if (namelen != patlen &&
1063                     patlen != namelen - 5 &&
1064                     !starts_with(name, "refs/heads/") &&
1065                     !starts_with(name, "refs/tags/")) {
1066                         /* We want to catch the case where only weak
1067                          * matches are found and there are multiple
1068                          * matches, and where more than one strong
1069                          * matches are found, as ambiguous.  One
1070                          * strong match with zero or more weak matches
1071                          * are acceptable as a unique match.
1072                          */
1073                         matched_weak = refs;
1074                         weak_match++;
1075                 }
1076                 else {
1077                         matched = refs;
1078                         match++;
1079                 }
1080         }
1081         if (!matched) {
1082                 if (matched_ref)
1083                         *matched_ref = matched_weak;
1084                 return weak_match;
1085         }
1086         else {
1087                 if (matched_ref)
1088                         *matched_ref = matched;
1089                 return match;
1090         }
1091 }
1092
1093 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1094 {
1095         **tail = ref;
1096         while (ref->next)
1097                 ref = ref->next;
1098         *tail = &ref->next;
1099 }
1100
1101 static struct ref *alloc_delete_ref(void)
1102 {
1103         struct ref *ref = alloc_ref("(delete)");
1104         hashclr(ref->new_sha1);
1105         return ref;
1106 }
1107
1108 static int try_explicit_object_name(const char *name,
1109                                     struct ref **match)
1110 {
1111         unsigned char sha1[20];
1112
1113         if (!*name) {
1114                 if (match)
1115                         *match = alloc_delete_ref();
1116                 return 0;
1117         }
1118
1119         if (get_sha1(name, sha1))
1120                 return -1;
1121
1122         if (match) {
1123                 *match = alloc_ref(name);
1124                 hashcpy((*match)->new_sha1, sha1);
1125         }
1126         return 0;
1127 }
1128
1129 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1130 {
1131         struct ref *ret = alloc_ref(name);
1132         tail_link_ref(ret, tail);
1133         return ret;
1134 }
1135
1136 static char *guess_ref(const char *name, struct ref *peer)
1137 {
1138         struct strbuf buf = STRBUF_INIT;
1139         unsigned char sha1[20];
1140
1141         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1142                                            sha1, NULL);
1143         if (!r)
1144                 return NULL;
1145
1146         if (starts_with(r, "refs/heads/"))
1147                 strbuf_addstr(&buf, "refs/heads/");
1148         else if (starts_with(r, "refs/tags/"))
1149                 strbuf_addstr(&buf, "refs/tags/");
1150         else
1151                 return NULL;
1152
1153         strbuf_addstr(&buf, name);
1154         return strbuf_detach(&buf, NULL);
1155 }
1156
1157 static int match_explicit_lhs(struct ref *src,
1158                               struct refspec *rs,
1159                               struct ref **match,
1160                               int *allocated_match)
1161 {
1162         switch (count_refspec_match(rs->src, src, match)) {
1163         case 1:
1164                 if (allocated_match)
1165                         *allocated_match = 0;
1166                 return 0;
1167         case 0:
1168                 /* The source could be in the get_sha1() format
1169                  * not a reference name.  :refs/other is a
1170                  * way to delete 'other' ref at the remote end.
1171                  */
1172                 if (try_explicit_object_name(rs->src, match) < 0)
1173                         return error("src refspec %s does not match any.", rs->src);
1174                 if (allocated_match)
1175                         *allocated_match = 1;
1176                 return 0;
1177         default:
1178                 return error("src refspec %s matches more than one.", rs->src);
1179         }
1180 }
1181
1182 static int match_explicit(struct ref *src, struct ref *dst,
1183                           struct ref ***dst_tail,
1184                           struct refspec *rs)
1185 {
1186         struct ref *matched_src, *matched_dst;
1187         int allocated_src;
1188
1189         const char *dst_value = rs->dst;
1190         char *dst_guess;
1191
1192         if (rs->pattern || rs->matching)
1193                 return 0;
1194
1195         matched_src = matched_dst = NULL;
1196         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1197                 return -1;
1198
1199         if (!dst_value) {
1200                 unsigned char sha1[20];
1201                 int flag;
1202
1203                 dst_value = resolve_ref_unsafe(matched_src->name,
1204                                                RESOLVE_REF_READING,
1205                                                sha1, &flag);
1206                 if (!dst_value ||
1207                     ((flag & REF_ISSYMREF) &&
1208                      !starts_with(dst_value, "refs/heads/")))
1209                         die("%s cannot be resolved to branch.",
1210                             matched_src->name);
1211         }
1212
1213         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1214         case 1:
1215                 break;
1216         case 0:
1217                 if (starts_with(dst_value, "refs/"))
1218                         matched_dst = make_linked_ref(dst_value, dst_tail);
1219                 else if (is_null_sha1(matched_src->new_sha1))
1220                         error("unable to delete '%s': remote ref does not exist",
1221                               dst_value);
1222                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1223                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1224                 else
1225                         error("unable to push to unqualified destination: %s\n"
1226                               "The destination refspec neither matches an "
1227                               "existing ref on the remote nor\n"
1228                               "begins with refs/, and we are unable to "
1229                               "guess a prefix based on the source ref.",
1230                               dst_value);
1231                 break;
1232         default:
1233                 matched_dst = NULL;
1234                 error("dst refspec %s matches more than one.",
1235                       dst_value);
1236                 break;
1237         }
1238         if (!matched_dst)
1239                 return -1;
1240         if (matched_dst->peer_ref)
1241                 return error("dst ref %s receives from more than one src.",
1242                       matched_dst->name);
1243         else {
1244                 matched_dst->peer_ref = allocated_src ?
1245                                         matched_src :
1246                                         copy_ref(matched_src);
1247                 matched_dst->force = rs->force;
1248         }
1249         return 0;
1250 }
1251
1252 static int match_explicit_refs(struct ref *src, struct ref *dst,
1253                                struct ref ***dst_tail, struct refspec *rs,
1254                                int rs_nr)
1255 {
1256         int i, errs;
1257         for (i = errs = 0; i < rs_nr; i++)
1258                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1259         return errs;
1260 }
1261
1262 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1263                 int send_mirror, int direction, const struct refspec **ret_pat)
1264 {
1265         const struct refspec *pat;
1266         char *name;
1267         int i;
1268         int matching_refs = -1;
1269         for (i = 0; i < rs_nr; i++) {
1270                 if (rs[i].matching &&
1271                     (matching_refs == -1 || rs[i].force)) {
1272                         matching_refs = i;
1273                         continue;
1274                 }
1275
1276                 if (rs[i].pattern) {
1277                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1278                         int match;
1279                         if (direction == FROM_SRC)
1280                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1281                         else
1282                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1283                         if (match) {
1284                                 matching_refs = i;
1285                                 break;
1286                         }
1287                 }
1288         }
1289         if (matching_refs == -1)
1290                 return NULL;
1291
1292         pat = rs + matching_refs;
1293         if (pat->matching) {
1294                 /*
1295                  * "matching refs"; traditionally we pushed everything
1296                  * including refs outside refs/heads/ hierarchy, but
1297                  * that does not make much sense these days.
1298                  */
1299                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1300                         return NULL;
1301                 name = xstrdup(ref->name);
1302         }
1303         if (ret_pat)
1304                 *ret_pat = pat;
1305         return name;
1306 }
1307
1308 static struct ref **tail_ref(struct ref **head)
1309 {
1310         struct ref **tail = head;
1311         while (*tail)
1312                 tail = &((*tail)->next);
1313         return tail;
1314 }
1315
1316 struct tips {
1317         struct commit **tip;
1318         int nr, alloc;
1319 };
1320
1321 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1322 {
1323         struct commit *commit;
1324
1325         if (is_null_sha1(sha1))
1326                 return;
1327         commit = lookup_commit_reference_gently(sha1, 1);
1328         if (!commit || (commit->object.flags & TMP_MARK))
1329                 return;
1330         commit->object.flags |= TMP_MARK;
1331         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1332         tips->tip[tips->nr++] = commit;
1333 }
1334
1335 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1336 {
1337         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1338         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1339         struct string_list_item *item;
1340         struct ref *ref;
1341         struct tips sent_tips;
1342
1343         /*
1344          * Collect everything we know they would have at the end of
1345          * this push, and collect all tags they have.
1346          */
1347         memset(&sent_tips, 0, sizeof(sent_tips));
1348         for (ref = *dst; ref; ref = ref->next) {
1349                 if (ref->peer_ref &&
1350                     !is_null_sha1(ref->peer_ref->new_sha1))
1351                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1352                 else
1353                         add_to_tips(&sent_tips, ref->old_sha1);
1354                 if (starts_with(ref->name, "refs/tags/"))
1355                         string_list_append(&dst_tag, ref->name);
1356         }
1357         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1358
1359         string_list_sort(&dst_tag);
1360
1361         /* Collect tags they do not have. */
1362         for (ref = src; ref; ref = ref->next) {
1363                 if (!starts_with(ref->name, "refs/tags/"))
1364                         continue; /* not a tag */
1365                 if (string_list_has_string(&dst_tag, ref->name))
1366                         continue; /* they already have it */
1367                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1368                         continue; /* be conservative */
1369                 item = string_list_append(&src_tag, ref->name);
1370                 item->util = ref;
1371         }
1372         string_list_clear(&dst_tag, 0);
1373
1374         /*
1375          * At this point, src_tag lists tags that are missing from
1376          * dst, and sent_tips lists the tips we are pushing or those
1377          * that we know they already have. An element in the src_tag
1378          * that is an ancestor of any of the sent_tips needs to be
1379          * sent to the other side.
1380          */
1381         if (sent_tips.nr) {
1382                 for_each_string_list_item(item, &src_tag) {
1383                         struct ref *ref = item->util;
1384                         struct ref *dst_ref;
1385                         struct commit *commit;
1386
1387                         if (is_null_sha1(ref->new_sha1))
1388                                 continue;
1389                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1390                         if (!commit)
1391                                 /* not pushing a commit, which is not an error */
1392                                 continue;
1393
1394                         /*
1395                          * Is this tag, which they do not have, reachable from
1396                          * any of the commits we are sending?
1397                          */
1398                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1399                                 continue;
1400
1401                         /* Add it in */
1402                         dst_ref = make_linked_ref(ref->name, dst_tail);
1403                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1404                         dst_ref->peer_ref = copy_ref(ref);
1405                 }
1406         }
1407         string_list_clear(&src_tag, 0);
1408         free(sent_tips.tip);
1409 }
1410
1411 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1412 {
1413         for ( ; list; list = list->next)
1414                 if (!strcmp(list->name, name))
1415                         return (struct ref *)list;
1416         return NULL;
1417 }
1418
1419 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1420 {
1421         for ( ; ref; ref = ref->next)
1422                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1423
1424         string_list_sort(ref_index);
1425 }
1426
1427 /*
1428  * Given only the set of local refs, sanity-check the set of push
1429  * refspecs. We can't catch all errors that match_push_refs would,
1430  * but we can catch some errors early before even talking to the
1431  * remote side.
1432  */
1433 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1434 {
1435         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1436         int ret = 0;
1437         int i;
1438
1439         for (i = 0; i < nr_refspec; i++) {
1440                 struct refspec *rs = refspec + i;
1441
1442                 if (rs->pattern || rs->matching)
1443                         continue;
1444
1445                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1446         }
1447
1448         free_refspec(nr_refspec, refspec);
1449         return ret;
1450 }
1451
1452 /*
1453  * Given the set of refs the local repository has, the set of refs the
1454  * remote repository has, and the refspec used for push, determine
1455  * what remote refs we will update and with what value by setting
1456  * peer_ref (which object is being pushed) and force (if the push is
1457  * forced) in elements of "dst". The function may add new elements to
1458  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1459  */
1460 int match_push_refs(struct ref *src, struct ref **dst,
1461                     int nr_refspec, const char **refspec, int flags)
1462 {
1463         struct refspec *rs;
1464         int send_all = flags & MATCH_REFS_ALL;
1465         int send_mirror = flags & MATCH_REFS_MIRROR;
1466         int send_prune = flags & MATCH_REFS_PRUNE;
1467         int errs;
1468         static const char *default_refspec[] = { ":", NULL };
1469         struct ref *ref, **dst_tail = tail_ref(dst);
1470         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1471
1472         if (!nr_refspec) {
1473                 nr_refspec = 1;
1474                 refspec = default_refspec;
1475         }
1476         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1477         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1478
1479         /* pick the remainder */
1480         for (ref = src; ref; ref = ref->next) {
1481                 struct string_list_item *dst_item;
1482                 struct ref *dst_peer;
1483                 const struct refspec *pat = NULL;
1484                 char *dst_name;
1485
1486                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1487                 if (!dst_name)
1488                         continue;
1489
1490                 if (!dst_ref_index.nr)
1491                         prepare_ref_index(&dst_ref_index, *dst);
1492
1493                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1494                 dst_peer = dst_item ? dst_item->util : NULL;
1495                 if (dst_peer) {
1496                         if (dst_peer->peer_ref)
1497                                 /* We're already sending something to this ref. */
1498                                 goto free_name;
1499                 } else {
1500                         if (pat->matching && !(send_all || send_mirror))
1501                                 /*
1502                                  * Remote doesn't have it, and we have no
1503                                  * explicit pattern, and we don't have
1504                                  * --all or --mirror.
1505                                  */
1506                                 goto free_name;
1507
1508                         /* Create a new one and link it */
1509                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1510                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1511                         string_list_insert(&dst_ref_index,
1512                                 dst_peer->name)->util = dst_peer;
1513                 }
1514                 dst_peer->peer_ref = copy_ref(ref);
1515                 dst_peer->force = pat->force;
1516         free_name:
1517                 free(dst_name);
1518         }
1519
1520         string_list_clear(&dst_ref_index, 0);
1521
1522         if (flags & MATCH_REFS_FOLLOW_TAGS)
1523                 add_missing_tags(src, dst, &dst_tail);
1524
1525         if (send_prune) {
1526                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1527                 /* check for missing refs on the remote */
1528                 for (ref = *dst; ref; ref = ref->next) {
1529                         char *src_name;
1530
1531                         if (ref->peer_ref)
1532                                 /* We're already sending something to this ref. */
1533                                 continue;
1534
1535                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1536                         if (src_name) {
1537                                 if (!src_ref_index.nr)
1538                                         prepare_ref_index(&src_ref_index, src);
1539                                 if (!string_list_has_string(&src_ref_index,
1540                                             src_name))
1541                                         ref->peer_ref = alloc_delete_ref();
1542                                 free(src_name);
1543                         }
1544                 }
1545                 string_list_clear(&src_ref_index, 0);
1546         }
1547         if (errs)
1548                 return -1;
1549         return 0;
1550 }
1551
1552 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1553                              int force_update)
1554 {
1555         struct ref *ref;
1556
1557         for (ref = remote_refs; ref; ref = ref->next) {
1558                 int force_ref_update = ref->force || force_update;
1559                 int reject_reason = 0;
1560
1561                 if (ref->peer_ref)
1562                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1563                 else if (!send_mirror)
1564                         continue;
1565
1566                 ref->deletion = is_null_sha1(ref->new_sha1);
1567                 if (!ref->deletion &&
1568                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1569                         ref->status = REF_STATUS_UPTODATE;
1570                         continue;
1571                 }
1572
1573                 /*
1574                  * Bypass the usual "must fast-forward" check but
1575                  * replace it with a weaker "the old value must be
1576                  * this value we observed".  If the remote ref has
1577                  * moved and is now different from what we expect,
1578                  * reject any push.
1579                  *
1580                  * It also is an error if the user told us to check
1581                  * with the remote-tracking branch to find the value
1582                  * to expect, but we did not have such a tracking
1583                  * branch.
1584                  */
1585                 if (ref->expect_old_sha1) {
1586                         if (ref->expect_old_no_trackback ||
1587                             hashcmp(ref->old_sha1, ref->old_sha1_expect))
1588                                 reject_reason = REF_STATUS_REJECT_STALE;
1589                 }
1590
1591                 /*
1592                  * The usual "must fast-forward" rules.
1593                  *
1594                  * Decide whether an individual refspec A:B can be
1595                  * pushed.  The push will succeed if any of the
1596                  * following are true:
1597                  *
1598                  * (1) the remote reference B does not exist
1599                  *
1600                  * (2) the remote reference B is being removed (i.e.,
1601                  *     pushing :B where no source is specified)
1602                  *
1603                  * (3) the destination is not under refs/tags/, and
1604                  *     if the old and new value is a commit, the new
1605                  *     is a descendant of the old.
1606                  *
1607                  * (4) it is forced using the +A:B notation, or by
1608                  *     passing the --force argument
1609                  */
1610
1611                 else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1612                         if (starts_with(ref->name, "refs/tags/"))
1613                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1614                         else if (!has_sha1_file(ref->old_sha1))
1615                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1616                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1617                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1618                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1619                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1620                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1621                 }
1622
1623                 /*
1624                  * "--force" will defeat any rejection implemented
1625                  * by the rules above.
1626                  */
1627                 if (!force_ref_update)
1628                         ref->status = reject_reason;
1629                 else if (reject_reason)
1630                         ref->forced_update = 1;
1631         }
1632 }
1633
1634 static void set_merge(struct branch *ret)
1635 {
1636         char *ref;
1637         unsigned char sha1[20];
1638         int i;
1639
1640         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1641         for (i = 0; i < ret->merge_nr; i++) {
1642                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1643                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1644                 if (!remote_find_tracking(ret->remote, ret->merge[i]) ||
1645                     strcmp(ret->remote_name, "."))
1646                         continue;
1647                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1648                              sha1, &ref) == 1)
1649                         ret->merge[i]->dst = ref;
1650                 else
1651                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1652         }
1653 }
1654
1655 struct branch *branch_get(const char *name)
1656 {
1657         struct branch *ret;
1658
1659         read_config();
1660         if (!name || !*name || !strcmp(name, "HEAD"))
1661                 ret = current_branch;
1662         else
1663                 ret = make_branch(name, 0);
1664         if (ret && ret->remote_name) {
1665                 ret->remote = remote_get(ret->remote_name);
1666                 if (ret->merge_nr)
1667                         set_merge(ret);
1668         }
1669         return ret;
1670 }
1671
1672 int branch_has_merge_config(struct branch *branch)
1673 {
1674         return branch && !!branch->merge;
1675 }
1676
1677 int branch_merge_matches(struct branch *branch,
1678                                  int i,
1679                                  const char *refname)
1680 {
1681         if (!branch || i < 0 || i >= branch->merge_nr)
1682                 return 0;
1683         return refname_match(branch->merge[i]->src, refname);
1684 }
1685
1686 static int ignore_symref_update(const char *refname)
1687 {
1688         unsigned char sha1[20];
1689         int flag;
1690
1691         if (!resolve_ref_unsafe(refname, 0, sha1, &flag))
1692                 return 0; /* non-existing refs are OK */
1693         return (flag & REF_ISSYMREF);
1694 }
1695
1696 /*
1697  * Create and return a list of (struct ref) consisting of copies of
1698  * each remote_ref that matches refspec.  refspec must be a pattern.
1699  * Fill in the copies' peer_ref to describe the local tracking refs to
1700  * which they map.  Omit any references that would map to an existing
1701  * local symbolic ref.
1702  */
1703 static struct ref *get_expanded_map(const struct ref *remote_refs,
1704                                     const struct refspec *refspec)
1705 {
1706         const struct ref *ref;
1707         struct ref *ret = NULL;
1708         struct ref **tail = &ret;
1709
1710         for (ref = remote_refs; ref; ref = ref->next) {
1711                 char *expn_name = NULL;
1712
1713                 if (strchr(ref->name, '^'))
1714                         continue; /* a dereference item */
1715                 if (match_name_with_pattern(refspec->src, ref->name,
1716                                             refspec->dst, &expn_name) &&
1717                     !ignore_symref_update(expn_name)) {
1718                         struct ref *cpy = copy_ref(ref);
1719
1720                         cpy->peer_ref = alloc_ref(expn_name);
1721                         if (refspec->force)
1722                                 cpy->peer_ref->force = 1;
1723                         *tail = cpy;
1724                         tail = &cpy->next;
1725                 }
1726                 free(expn_name);
1727         }
1728
1729         return ret;
1730 }
1731
1732 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1733 {
1734         const struct ref *ref;
1735         for (ref = refs; ref; ref = ref->next) {
1736                 if (refname_match(name, ref->name))
1737                         return ref;
1738         }
1739         return NULL;
1740 }
1741
1742 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1743 {
1744         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1745
1746         if (!ref)
1747                 return NULL;
1748
1749         return copy_ref(ref);
1750 }
1751
1752 static struct ref *get_local_ref(const char *name)
1753 {
1754         if (!name || name[0] == '\0')
1755                 return NULL;
1756
1757         if (starts_with(name, "refs/"))
1758                 return alloc_ref(name);
1759
1760         if (starts_with(name, "heads/") ||
1761             starts_with(name, "tags/") ||
1762             starts_with(name, "remotes/"))
1763                 return alloc_ref_with_prefix("refs/", 5, name);
1764
1765         return alloc_ref_with_prefix("refs/heads/", 11, name);
1766 }
1767
1768 int get_fetch_map(const struct ref *remote_refs,
1769                   const struct refspec *refspec,
1770                   struct ref ***tail,
1771                   int missing_ok)
1772 {
1773         struct ref *ref_map, **rmp;
1774
1775         if (refspec->pattern) {
1776                 ref_map = get_expanded_map(remote_refs, refspec);
1777         } else {
1778                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1779
1780                 if (refspec->exact_sha1) {
1781                         ref_map = alloc_ref(name);
1782                         get_sha1_hex(name, ref_map->old_sha1);
1783                 } else {
1784                         ref_map = get_remote_ref(remote_refs, name);
1785                 }
1786                 if (!missing_ok && !ref_map)
1787                         die("Couldn't find remote ref %s", name);
1788                 if (ref_map) {
1789                         ref_map->peer_ref = get_local_ref(refspec->dst);
1790                         if (ref_map->peer_ref && refspec->force)
1791                                 ref_map->peer_ref->force = 1;
1792                 }
1793         }
1794
1795         for (rmp = &ref_map; *rmp; ) {
1796                 if ((*rmp)->peer_ref) {
1797                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1798                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1799                                 struct ref *ignore = *rmp;
1800                                 error("* Ignoring funny ref '%s' locally",
1801                                       (*rmp)->peer_ref->name);
1802                                 *rmp = (*rmp)->next;
1803                                 free(ignore->peer_ref);
1804                                 free(ignore);
1805                                 continue;
1806                         }
1807                 }
1808                 rmp = &((*rmp)->next);
1809         }
1810
1811         if (ref_map)
1812                 tail_link_ref(ref_map, tail);
1813
1814         return 0;
1815 }
1816
1817 int resolve_remote_symref(struct ref *ref, struct ref *list)
1818 {
1819         if (!ref->symref)
1820                 return 0;
1821         for (; list; list = list->next)
1822                 if (!strcmp(ref->symref, list->name)) {
1823                         hashcpy(ref->old_sha1, list->old_sha1);
1824                         return 0;
1825                 }
1826         return 1;
1827 }
1828
1829 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1830 {
1831         while (list) {
1832                 struct commit_list *temp = list;
1833                 temp->item->object.flags &= ~mark;
1834                 list = temp->next;
1835                 free(temp);
1836         }
1837 }
1838
1839 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1840 {
1841         struct object *o;
1842         struct commit *old, *new;
1843         struct commit_list *list, *used;
1844         int found = 0;
1845
1846         /*
1847          * Both new and old must be commit-ish and new is descendant of
1848          * old.  Otherwise we require --force.
1849          */
1850         o = deref_tag(parse_object(old_sha1), NULL, 0);
1851         if (!o || o->type != OBJ_COMMIT)
1852                 return 0;
1853         old = (struct commit *) o;
1854
1855         o = deref_tag(parse_object(new_sha1), NULL, 0);
1856         if (!o || o->type != OBJ_COMMIT)
1857                 return 0;
1858         new = (struct commit *) o;
1859
1860         if (parse_commit(new) < 0)
1861                 return 0;
1862
1863         used = list = NULL;
1864         commit_list_insert(new, &list);
1865         while (list) {
1866                 new = pop_most_recent_commit(&list, TMP_MARK);
1867                 commit_list_insert(new, &used);
1868                 if (new == old) {
1869                         found = 1;
1870                         break;
1871                 }
1872         }
1873         unmark_and_free(list, TMP_MARK);
1874         unmark_and_free(used, TMP_MARK);
1875         return found;
1876 }
1877
1878 /*
1879  * Compare a branch with its upstream, and save their differences (number
1880  * of commits) in *num_ours and *num_theirs.
1881  *
1882  * Return 0 if branch has no upstream (no base), -1 if upstream is missing
1883  * (with "gone" base), otherwise 1 (with base).
1884  */
1885 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1886 {
1887         unsigned char sha1[20];
1888         struct commit *ours, *theirs;
1889         char symmetric[84];
1890         struct rev_info revs;
1891         const char *rev_argv[10], *base;
1892         int rev_argc;
1893
1894         /* Cannot stat unless we are marked to build on top of somebody else. */
1895         if (!branch ||
1896             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1897                 return 0;
1898
1899         /* Cannot stat if what we used to build on no longer exists */
1900         base = branch->merge[0]->dst;
1901         if (read_ref(base, sha1))
1902                 return -1;
1903         theirs = lookup_commit_reference(sha1);
1904         if (!theirs)
1905                 return -1;
1906
1907         if (read_ref(branch->refname, sha1))
1908                 return -1;
1909         ours = lookup_commit_reference(sha1);
1910         if (!ours)
1911                 return -1;
1912
1913         /* are we the same? */
1914         if (theirs == ours) {
1915                 *num_theirs = *num_ours = 0;
1916                 return 1;
1917         }
1918
1919         /* Run "rev-list --left-right ours...theirs" internally... */
1920         rev_argc = 0;
1921         rev_argv[rev_argc++] = NULL;
1922         rev_argv[rev_argc++] = "--left-right";
1923         rev_argv[rev_argc++] = symmetric;
1924         rev_argv[rev_argc++] = "--";
1925         rev_argv[rev_argc] = NULL;
1926
1927         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1928         strcpy(symmetric + 40, "...");
1929         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1930
1931         init_revisions(&revs, NULL);
1932         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1933         if (prepare_revision_walk(&revs))
1934                 die("revision walk setup failed");
1935
1936         /* ... and count the commits on each side. */
1937         *num_ours = 0;
1938         *num_theirs = 0;
1939         while (1) {
1940                 struct commit *c = get_revision(&revs);
1941                 if (!c)
1942                         break;
1943                 if (c->object.flags & SYMMETRIC_LEFT)
1944                         (*num_ours)++;
1945                 else
1946                         (*num_theirs)++;
1947         }
1948
1949         /* clear object flags smudged by the above traversal */
1950         clear_commit_marks(ours, ALL_REV_FLAGS);
1951         clear_commit_marks(theirs, ALL_REV_FLAGS);
1952         return 1;
1953 }
1954
1955 /*
1956  * Return true when there is anything to report, otherwise false.
1957  */
1958 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1959 {
1960         int ours, theirs;
1961         char *base;
1962         int upstream_is_gone = 0;
1963
1964         switch (stat_tracking_info(branch, &ours, &theirs)) {
1965         case 0:
1966                 /* no base */
1967                 return 0;
1968         case -1:
1969                 /* with "gone" base */
1970                 upstream_is_gone = 1;
1971                 break;
1972         default:
1973                 /* with base */
1974                 break;
1975         }
1976
1977         base = shorten_unambiguous_ref(branch->merge[0]->dst, 0);
1978         if (upstream_is_gone) {
1979                 strbuf_addf(sb,
1980                         _("Your branch is based on '%s', but the upstream is gone.\n"),
1981                         base);
1982                 if (advice_status_hints)
1983                         strbuf_addf(sb,
1984                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1985         } else if (!ours && !theirs) {
1986                 strbuf_addf(sb,
1987                         _("Your branch is up-to-date with '%s'.\n"),
1988                         base);
1989         } else if (!theirs) {
1990                 strbuf_addf(sb,
1991                         Q_("Your branch is ahead of '%s' by %d commit.\n",
1992                            "Your branch is ahead of '%s' by %d commits.\n",
1993                            ours),
1994                         base, ours);
1995                 if (advice_status_hints)
1996                         strbuf_addf(sb,
1997                                 _("  (use \"git push\" to publish your local commits)\n"));
1998         } else if (!ours) {
1999                 strbuf_addf(sb,
2000                         Q_("Your branch is behind '%s' by %d commit, "
2001                                "and can be fast-forwarded.\n",
2002                            "Your branch is behind '%s' by %d commits, "
2003                                "and can be fast-forwarded.\n",
2004                            theirs),
2005                         base, theirs);
2006                 if (advice_status_hints)
2007                         strbuf_addf(sb,
2008                                 _("  (use \"git pull\" to update your local branch)\n"));
2009         } else {
2010                 strbuf_addf(sb,
2011                         Q_("Your branch and '%s' have diverged,\n"
2012                                "and have %d and %d different commit each, "
2013                                "respectively.\n",
2014                            "Your branch and '%s' have diverged,\n"
2015                                "and have %d and %d different commits each, "
2016                                "respectively.\n",
2017                            theirs),
2018                         base, ours, theirs);
2019                 if (advice_status_hints)
2020                         strbuf_addf(sb,
2021                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2022         }
2023         free(base);
2024         return 1;
2025 }
2026
2027 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
2028 {
2029         struct ref ***local_tail = cb_data;
2030         struct ref *ref;
2031         int len;
2032
2033         /* we already know it starts with refs/ to get here */
2034         if (check_refname_format(refname + 5, 0))
2035                 return 0;
2036
2037         len = strlen(refname) + 1;
2038         ref = xcalloc(1, sizeof(*ref) + len);
2039         hashcpy(ref->new_sha1, sha1);
2040         memcpy(ref->name, refname, len);
2041         **local_tail = ref;
2042         *local_tail = &ref->next;
2043         return 0;
2044 }
2045
2046 struct ref *get_local_heads(void)
2047 {
2048         struct ref *local_refs = NULL, **local_tail = &local_refs;
2049         for_each_ref(one_local_ref, &local_tail);
2050         return local_refs;
2051 }
2052
2053 struct ref *guess_remote_head(const struct ref *head,
2054                               const struct ref *refs,
2055                               int all)
2056 {
2057         const struct ref *r;
2058         struct ref *list = NULL;
2059         struct ref **tail = &list;
2060
2061         if (!head)
2062                 return NULL;
2063
2064         /*
2065          * Some transports support directly peeking at
2066          * where HEAD points; if that is the case, then
2067          * we don't have to guess.
2068          */
2069         if (head->symref)
2070                 return copy_ref(find_ref_by_name(refs, head->symref));
2071
2072         /* If refs/heads/master could be right, it is. */
2073         if (!all) {
2074                 r = find_ref_by_name(refs, "refs/heads/master");
2075                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
2076                         return copy_ref(r);
2077         }
2078
2079         /* Look for another ref that points there */
2080         for (r = refs; r; r = r->next) {
2081                 if (r != head &&
2082                     starts_with(r->name, "refs/heads/") &&
2083                     !hashcmp(r->old_sha1, head->old_sha1)) {
2084                         *tail = copy_ref(r);
2085                         tail = &((*tail)->next);
2086                         if (!all)
2087                                 break;
2088                 }
2089         }
2090
2091         return list;
2092 }
2093
2094 struct stale_heads_info {
2095         struct string_list *ref_names;
2096         struct ref **stale_refs_tail;
2097         struct refspec *refs;
2098         int ref_count;
2099 };
2100
2101 static int get_stale_heads_cb(const char *refname,
2102         const unsigned char *sha1, int flags, void *cb_data)
2103 {
2104         struct stale_heads_info *info = cb_data;
2105         struct string_list matches = STRING_LIST_INIT_DUP;
2106         struct refspec query;
2107         int i, stale = 1;
2108         memset(&query, 0, sizeof(struct refspec));
2109         query.dst = (char *)refname;
2110
2111         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2112         if (matches.nr == 0)
2113                 goto clean_exit; /* No matches */
2114
2115         /*
2116          * If we did find a suitable refspec and it's not a symref and
2117          * it's not in the list of refs that currently exist in that
2118          * remote, we consider it to be stale. In order to deal with
2119          * overlapping refspecs, we need to go over all of the
2120          * matching refs.
2121          */
2122         if (flags & REF_ISSYMREF)
2123                 goto clean_exit;
2124
2125         for (i = 0; stale && i < matches.nr; i++)
2126                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2127                         stale = 0;
2128
2129         if (stale) {
2130                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2131                 hashcpy(ref->new_sha1, sha1);
2132         }
2133
2134 clean_exit:
2135         string_list_clear(&matches, 0);
2136         return 0;
2137 }
2138
2139 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2140 {
2141         struct ref *ref, *stale_refs = NULL;
2142         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2143         struct stale_heads_info info;
2144         info.ref_names = &ref_names;
2145         info.stale_refs_tail = &stale_refs;
2146         info.refs = refs;
2147         info.ref_count = ref_count;
2148         for (ref = fetch_map; ref; ref = ref->next)
2149                 string_list_append(&ref_names, ref->name);
2150         string_list_sort(&ref_names);
2151         for_each_ref(get_stale_heads_cb, &info);
2152         string_list_clear(&ref_names, 0);
2153         return stale_refs;
2154 }
2155
2156 /*
2157  * Compare-and-swap
2158  */
2159 void clear_cas_option(struct push_cas_option *cas)
2160 {
2161         int i;
2162
2163         for (i = 0; i < cas->nr; i++)
2164                 free(cas->entry[i].refname);
2165         free(cas->entry);
2166         memset(cas, 0, sizeof(*cas));
2167 }
2168
2169 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2170                                       const char *refname,
2171                                       size_t refnamelen)
2172 {
2173         struct push_cas *entry;
2174         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2175         entry = &cas->entry[cas->nr++];
2176         memset(entry, 0, sizeof(*entry));
2177         entry->refname = xmemdupz(refname, refnamelen);
2178         return entry;
2179 }
2180
2181 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2182 {
2183         const char *colon;
2184         struct push_cas *entry;
2185
2186         if (unset) {
2187                 /* "--no-<option>" */
2188                 clear_cas_option(cas);
2189                 return 0;
2190         }
2191
2192         if (!arg) {
2193                 /* just "--<option>" */
2194                 cas->use_tracking_for_rest = 1;
2195                 return 0;
2196         }
2197
2198         /* "--<option>=refname" or "--<option>=refname:value" */
2199         colon = strchrnul(arg, ':');
2200         entry = add_cas_entry(cas, arg, colon - arg);
2201         if (!*colon)
2202                 entry->use_tracking = 1;
2203         else if (get_sha1(colon + 1, entry->expect))
2204                 return error("cannot parse expected object name '%s'", colon + 1);
2205         return 0;
2206 }
2207
2208 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2209 {
2210         return parse_push_cas_option(opt->value, arg, unset);
2211 }
2212
2213 int is_empty_cas(const struct push_cas_option *cas)
2214 {
2215         return !cas->use_tracking_for_rest && !cas->nr;
2216 }
2217
2218 /*
2219  * Look at remote.fetch refspec and see if we have a remote
2220  * tracking branch for the refname there.  Fill its current
2221  * value in sha1[].
2222  * If we cannot do so, return negative to signal an error.
2223  */
2224 static int remote_tracking(struct remote *remote, const char *refname,
2225                            unsigned char sha1[20])
2226 {
2227         char *dst;
2228
2229         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2230         if (!dst)
2231                 return -1; /* no tracking ref for refname at remote */
2232         if (read_ref(dst, sha1))
2233                 return -1; /* we know what the tracking ref is but we cannot read it */
2234         return 0;
2235 }
2236
2237 static void apply_cas(struct push_cas_option *cas,
2238                       struct remote *remote,
2239                       struct ref *ref)
2240 {
2241         int i;
2242
2243         /* Find an explicit --<option>=<name>[:<value>] entry */
2244         for (i = 0; i < cas->nr; i++) {
2245                 struct push_cas *entry = &cas->entry[i];
2246                 if (!refname_match(entry->refname, ref->name))
2247                         continue;
2248                 ref->expect_old_sha1 = 1;
2249                 if (!entry->use_tracking)
2250                         hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2251                 else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2252                         ref->expect_old_no_trackback = 1;
2253                 return;
2254         }
2255
2256         /* Are we using "--<option>" to cover all? */
2257         if (!cas->use_tracking_for_rest)
2258                 return;
2259
2260         ref->expect_old_sha1 = 1;
2261         if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2262                 ref->expect_old_no_trackback = 1;
2263 }
2264
2265 void apply_push_cas(struct push_cas_option *cas,
2266                     struct remote *remote,
2267                     struct ref *remote_refs)
2268 {
2269         struct ref *ref;
2270         for (ref = remote_refs; ref; ref = ref->next)
2271                 apply_cas(cas, remote, ref);
2272 }