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 *pushremote_name;
  53
  54 static struct rewrites rewrites;
  55 static struct rewrites rewrites_push;
  56
  57 #define BUF_SIZE (2048)
  58 static char buffer[BUF_SIZE];
  59
  60 static int valid_remote(const struct remote *remote)
  61 {
  62         return (!!remote->url) || (!!remote->foreign_vcs);
  63 }
  64
  65 static const char *alias_url(const char *url, struct rewrites *r)
  66 {
  67         int i, j;
  68         struct counted_string *longest;
  69         int longest_i;
  70
  71         longest = NULL;
  72         longest_i = -1;
  73         for (i = 0; i < r->rewrite_nr; i++) {
  74                 if (!r->rewrite[i])
  75                         continue;
  76                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  77                         if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  78                             (!longest ||
  79                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  80                                 longest = &(r->rewrite[i]->instead_of[j]);
  81                                 longest_i = i;
  82                         }
  83                 }
  84         }
  85         if (!longest)
  86                 return url;
  87
  88         return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  89 }
  90
  91 static void add_push_refspec(struct remote *remote, const char *ref)
  92 {
  93         ALLOC_GROW(remote->push_refspec,
  94                    remote->push_refspec_nr + 1,
  95                    remote->push_refspec_alloc);
  96         remote->push_refspec[remote->push_refspec_nr++] = ref;
  97 }
  98
  99 static void add_fetch_refspec(struct remote *remote, const char *ref)
 100 {
 101         ALLOC_GROW(remote->fetch_refspec,
 102                    remote->fetch_refspec_nr + 1,
 103                    remote->fetch_refspec_alloc);
 104         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 105 }
 106
 107 static void add_url(struct remote *remote, const char *url)
 108 {
 109         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 110         remote->url[remote->url_nr++] = url;
 111 }
 112
 113 static void add_pushurl(struct remote *remote, const char *pushurl)
 114 {
 115         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 116         remote->pushurl[remote->pushurl_nr++] = pushurl;
 117 }
 118
 119 static void add_pushurl_alias(struct remote *remote, const char *url)
 120 {
 121         const char *pushurl = alias_url(url, &rewrites_push);
 122         if (pushurl != url)
 123                 add_pushurl(remote, pushurl);
 124 }
 125
 126 static void add_url_alias(struct remote *remote, const char *url)
 127 {
 128         add_url(remote, alias_url(url, &rewrites));
 129         add_pushurl_alias(remote, url);
 130 }
 131
 132 struct remotes_hash_key {
 133         const char *str;
 134         int len;
 135 };
 136
 137 static int remotes_hash_cmp(const struct remote *a, const struct remote *b, const struct remotes_hash_key *key)
 138 {
 139         if (key)
 140                 return strncmp(a->name, key->str, key->len) || a->name[key->len];
 141         else
 142                 return strcmp(a->name, b->name);
 143 }
 144
 145 static inline void init_remotes_hash(void)
 146 {
 147         if (!remotes_hash.cmpfn)
 148                 hashmap_init(&remotes_hash, (hashmap_cmp_fn)remotes_hash_cmp, 0);
 149 }
 150
 151 static struct remote *make_remote(const char *name, int len)
 152 {
 153         struct remote *ret, *replaced;
 154         struct remotes_hash_key lookup;
 155         struct hashmap_entry lookup_entry;
 156
 157         if (!len)
 158                 len = strlen(name);
 159
 160         init_remotes_hash();
 161         lookup.str = name;
 162         lookup.len = len;
 163         hashmap_entry_init(&lookup_entry, memhash(name, len));
 164
 165         if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 166                 return ret;
 167
 168         ret = xcalloc(1, sizeof(struct remote));
 169         ret->prune = -1;  /* unspecified */
 170         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 171         remotes[remotes_nr++] = ret;
 172         ret->name = xstrndup(name, len);
 173
 174         hashmap_entry_init(ret, lookup_entry.hash);
 175         replaced = hashmap_put(&remotes_hash, ret);
 176         assert(replaced == NULL);  /* no previous entry overwritten */
 177         return ret;
 178 }
 179
 180 static void add_merge(struct branch *branch, const char *name)
 181 {
 182         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 183                    branch->merge_alloc);
 184         branch->merge_name[branch->merge_nr++] = name;
 185 }
 186
 187 static struct branch *make_branch(const char *name, int len)
 188 {
 189         struct branch *ret;
 190         int i;
 191
 192         for (i = 0; i < branches_nr; i++) {
 193                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 194                            !branches[i]->name[len]) :
 195                     !strcmp(name, branches[i]->name))
 196                         return branches[i];
 197         }
 198
 199         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 200         ret = xcalloc(1, sizeof(struct branch));
 201         branches[branches_nr++] = ret;
 202         if (len)
 203                 ret->name = xstrndup(name, len);
 204         else
 205                 ret->name = xstrdup(name);
 206         ret->refname = xstrfmt("refs/heads/%s", ret->name);
 207
 208         return ret;
 209 }
 210
 211 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 212 {
 213         struct rewrite *ret;
 214         int i;
 215
 216         for (i = 0; i < r->rewrite_nr; i++) {
 217                 if (len
 218                     ? (len == r->rewrite[i]->baselen &&
 219                        !strncmp(base, r->rewrite[i]->base, len))
 220                     : !strcmp(base, r->rewrite[i]->base))
 221                         return r->rewrite[i];
 222         }
 223
 224         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 225         ret = xcalloc(1, sizeof(struct rewrite));
 226         r->rewrite[r->rewrite_nr++] = ret;
 227         if (len) {
 228                 ret->base = xstrndup(base, len);
 229                 ret->baselen = len;
 230         }
 231         else {
 232                 ret->base = xstrdup(base);
 233                 ret->baselen = strlen(base);
 234         }
 235         return ret;
 236 }
 237
 238 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 239 {
 240         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 241         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 242         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 243         rewrite->instead_of_nr++;
 244 }
 245
 246 static void read_remotes_file(struct remote *remote)
 247 {
 248         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 249
 250         if (!f)
 251                 return;
 252         remote->origin = REMOTE_REMOTES;
 253         while (fgets(buffer, BUF_SIZE, f)) {
 254                 int value_list;
 255                 char *s, *p;
 256
 257                 if (starts_with(buffer, "URL:")) {
 258                         value_list = 0;
 259                         s = buffer + 4;
 260                 } else if (starts_with(buffer, "Push:")) {
 261                         value_list = 1;
 262                         s = buffer + 5;
 263                 } else if (starts_with(buffer, "Pull:")) {
 264                         value_list = 2;
 265                         s = buffer + 5;
 266                 } else
 267                         continue;
 268
 269                 while (isspace(*s))
 270                         s++;
 271                 if (!*s)
 272                         continue;
 273
 274                 p = s + strlen(s);
 275                 while (isspace(p[-1]))
 276                         *--p = 0;
 277
 278                 switch (value_list) {
 279                 case 0:
 280                         add_url_alias(remote, xstrdup(s));
 281                         break;
 282                 case 1:
 283                         add_push_refspec(remote, xstrdup(s));
 284                         break;
 285                 case 2:
 286                         add_fetch_refspec(remote, xstrdup(s));
 287                         break;
 288                 }
 289         }
 290         fclose(f);
 291 }
 292
 293 static void read_branches_file(struct remote *remote)
 294 {
 295         char *frag;
 296         struct strbuf buf = STRBUF_INIT;
 297         FILE *f = fopen(git_path("branches/%s", remote->name), "r");
 298
 299         if (!f)
 300                 return;
 301
 302         strbuf_getline(&buf, f, '\n');
 303         strbuf_trim(&buf);
 304         if (!buf.len) {
 305                 strbuf_release(&buf);
 306                 return;
 307         }
 308
 309         remote->origin = REMOTE_BRANCHES;
 310
 311         /*
 312          * The branches file would have URL and optionally
 313          * #branch specified.  The "master" (or specified) branch is
 314          * fetched and stored in the local branch matching the
 315          * remote name.
 316          */
 317         frag = strchr(buf.buf, '#');
 318         if (frag)
 319                 *(frag++) = '\0';
 320         else
 321                 frag = "master";
 322
 323         add_url_alias(remote, strbuf_detach(&buf, NULL));
 324         add_fetch_refspec(remote, xstrfmt("refs/heads/%s:refs/heads/%s",
 325                                           frag, remote->name));
 326
 327         /*
 328          * Cogito compatible push: push current HEAD to remote #branch
 329          * (master if missing)
 330          */
 331         add_push_refspec(remote, xstrfmt("HEAD:refs/heads/%s", frag));
 332         remote->fetch_tags = 1; /* always auto-follow */
 333 }
 334
 335 static int handle_config(const char *key, const char *value, void *cb)
 336 {
 337         const char *name;
 338         const char *subkey;
 339         struct remote *remote;
 340         struct branch *branch;
 341         if (starts_with(key, "branch.")) {
 342                 name = key + 7;
 343                 subkey = strrchr(name, '.');
 344                 if (!subkey)
 345                         return 0;
 346                 branch = make_branch(name, subkey - name);
 347                 if (!strcmp(subkey, ".remote")) {
 348                         return git_config_string(&branch->remote_name, key, value);
 349                 } else if (!strcmp(subkey, ".pushremote")) {
 350                         return git_config_string(&branch->pushremote_name, key, value);
 351                 } else if (!strcmp(subkey, ".merge")) {
 352                         if (!value)
 353                                 return config_error_nonbool(key);
 354                         add_merge(branch, xstrdup(value));
 355                 }
 356                 return 0;
 357         }
 358         if (starts_with(key, "url.")) {
 359                 struct rewrite *rewrite;
 360                 name = key + 4;
 361                 subkey = strrchr(name, '.');
 362                 if (!subkey)
 363                         return 0;
 364                 if (!strcmp(subkey, ".insteadof")) {
 365                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 366                         if (!value)
 367                                 return config_error_nonbool(key);
 368                         add_instead_of(rewrite, xstrdup(value));
 369                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 370                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 371                         if (!value)
 372                                 return config_error_nonbool(key);
 373                         add_instead_of(rewrite, xstrdup(value));
 374                 }
 375         }
 376
 377         if (!starts_with(key,  "remote."))
 378                 return 0;
 379         name = key + 7;
 380
 381         /* Handle remote.* variables */
 382         if (!strcmp(name, "pushdefault"))
 383                 return git_config_string(&pushremote_name, key, value);
 384
 385         /* Handle remote.<name>.* variables */
 386         if (*name == '/') {
 387                 warning("Config remote shorthand cannot begin with '/': %s",
 388                         name);
 389                 return 0;
 390         }
 391         subkey = strrchr(name, '.');
 392         if (!subkey)
 393                 return 0;
 394         remote = make_remote(name, subkey - name);
 395         remote->origin = REMOTE_CONFIG;
 396         if (!strcmp(subkey, ".mirror"))
 397                 remote->mirror = git_config_bool(key, value);
 398         else if (!strcmp(subkey, ".skipdefaultupdate"))
 399                 remote->skip_default_update = git_config_bool(key, value);
 400         else if (!strcmp(subkey, ".skipfetchall"))
 401                 remote->skip_default_update = git_config_bool(key, value);
 402         else if (!strcmp(subkey, ".prune"))
 403                 remote->prune = git_config_bool(key, value);
 404         else if (!strcmp(subkey, ".url")) {
 405                 const char *v;
 406                 if (git_config_string(&v, key, value))
 407                         return -1;
 408                 add_url(remote, v);
 409         } else if (!strcmp(subkey, ".pushurl")) {
 410                 const char *v;
 411                 if (git_config_string(&v, key, value))
 412                         return -1;
 413                 add_pushurl(remote, v);
 414         } else if (!strcmp(subkey, ".push")) {
 415                 const char *v;
 416                 if (git_config_string(&v, key, value))
 417                         return -1;
 418                 add_push_refspec(remote, v);
 419         } else if (!strcmp(subkey, ".fetch")) {
 420                 const char *v;
 421                 if (git_config_string(&v, key, value))
 422                         return -1;
 423                 add_fetch_refspec(remote, v);
 424         } else if (!strcmp(subkey, ".receivepack")) {
 425                 const char *v;
 426                 if (git_config_string(&v, key, value))
 427                         return -1;
 428                 if (!remote->receivepack)
 429                         remote->receivepack = v;
 430                 else
 431                         error("more than one receivepack given, using the first");
 432         } else if (!strcmp(subkey, ".uploadpack")) {
 433                 const char *v;
 434                 if (git_config_string(&v, key, value))
 435                         return -1;
 436                 if (!remote->uploadpack)
 437                         remote->uploadpack = v;
 438                 else
 439                         error("more than one uploadpack given, using the first");
 440         } else if (!strcmp(subkey, ".tagopt")) {
 441                 if (!strcmp(value, "--no-tags"))
 442                         remote->fetch_tags = -1;
 443                 else if (!strcmp(value, "--tags"))
 444                         remote->fetch_tags = 2;
 445         } else if (!strcmp(subkey, ".proxy")) {
 446                 return git_config_string((const char **)&remote->http_proxy,
 447                                          key, value);
 448         } else if (!strcmp(subkey, ".vcs")) {
 449                 return git_config_string(&remote->foreign_vcs, key, value);
 450         }
 451         return 0;
 452 }
 453
 454 static void alias_all_urls(void)
 455 {
 456         int i, j;
 457         for (i = 0; i < remotes_nr; i++) {
 458                 int add_pushurl_aliases;
 459                 if (!remotes[i])
 460                         continue;
 461                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 462                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 463                 }
 464                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 465                 for (j = 0; j < remotes[i]->url_nr; j++) {
 466                         if (add_pushurl_aliases)
 467                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 468                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 469                 }
 470         }
 471 }
 472
 473 static void read_config(void)
 474 {
 475         static int loaded;
 476         unsigned char sha1[20];
 477         const char *head_ref;
 478         int flag;
 479
 480         if (loaded)
 481                 return;
 482         loaded = 1;
 483
 484         current_branch = NULL;
 485         head_ref = resolve_ref_unsafe("HEAD", 0, sha1, &flag);
 486         if (head_ref && (flag & REF_ISSYMREF) &&
 487             skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 488                 current_branch = make_branch(head_ref, 0);
 489         }
 490         git_config(handle_config, NULL);
 491         alias_all_urls();
 492 }
 493
 494 /*
 495  * This function frees a refspec array.
 496  * Warning: code paths should be checked to ensure that the src
 497  *          and dst pointers are always freeable pointers as well
 498  *          as the refspec pointer itself.
 499  */
 500 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 501 {
 502         int i;
 503
 504         if (!refspec)
 505                 return;
 506
 507         for (i = 0; i < nr_refspec; i++) {
 508                 free(refspec[i].src);
 509                 free(refspec[i].dst);
 510         }
 511         free(refspec);
 512 }
 513
 514 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 515 {
 516         int i;
 517         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 518
 519         for (i = 0; i < nr_refspec; i++) {
 520                 size_t llen;
 521                 int is_glob;
 522                 const char *lhs, *rhs;
 523                 int flags;
 524
 525                 is_glob = 0;
 526
 527                 lhs = refspec[i];
 528                 if (*lhs == '+') {
 529                         rs[i].force = 1;
 530                         lhs++;
 531                 }
 532
 533                 rhs = strrchr(lhs, ':');
 534
 535                 /*
 536                  * Before going on, special case ":" (or "+:") as a refspec
 537                  * for pushing matching refs.
 538                  */
 539                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 540                         rs[i].matching = 1;
 541                         continue;
 542                 }
 543
 544                 if (rhs) {
 545                         size_t rlen = strlen(++rhs);
 546                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 547                         rs[i].dst = xstrndup(rhs, rlen);
 548                 }
 549
 550                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 551                 if (1 <= llen && memchr(lhs, '*', llen)) {
 552                         if ((rhs && !is_glob) || (!rhs && fetch))
 553                                 goto invalid;
 554                         is_glob = 1;
 555                 } else if (rhs && is_glob) {
 556                         goto invalid;
 557                 }
 558
 559                 rs[i].pattern = is_glob;
 560                 rs[i].src = xstrndup(lhs, llen);
 561                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 562
 563                 if (fetch) {
 564                         unsigned char unused[40];
 565
 566                         /* LHS */
 567                         if (!*rs[i].src)
 568                                 ; /* empty is ok; it means "HEAD" */
 569                         else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 570                                 rs[i].exact_sha1 = 1; /* ok */
 571                         else if (!check_refname_format(rs[i].src, flags))
 572                                 ; /* valid looking ref is ok */
 573                         else
 574                                 goto invalid;
 575                         /* RHS */
 576                         if (!rs[i].dst)
 577                                 ; /* missing is ok; it is the same as empty */
 578                         else if (!*rs[i].dst)
 579                                 ; /* empty is ok; it means "do not store" */
 580                         else if (!check_refname_format(rs[i].dst, flags))
 581                                 ; /* valid looking ref is ok */
 582                         else
 583                                 goto invalid;
 584                 } else {
 585                         /*
 586                          * LHS
 587                          * - empty is allowed; it means delete.
 588                          * - when wildcarded, it must be a valid looking ref.
 589                          * - otherwise, it must be an extended SHA-1, but
 590                          *   there is no existing way to validate this.
 591                          */
 592                         if (!*rs[i].src)
 593                                 ; /* empty is ok */
 594                         else if (is_glob) {
 595                                 if (check_refname_format(rs[i].src, flags))
 596                                         goto invalid;
 597                         }
 598                         else
 599                                 ; /* anything goes, for now */
 600                         /*
 601                          * RHS
 602                          * - missing is allowed, but LHS then must be a
 603                          *   valid looking ref.
 604                          * - empty is not allowed.
 605                          * - otherwise it must be a valid looking ref.
 606                          */
 607                         if (!rs[i].dst) {
 608                                 if (check_refname_format(rs[i].src, flags))
 609                                         goto invalid;
 610                         } else if (!*rs[i].dst) {
 611                                 goto invalid;
 612                         } else {
 613                                 if (check_refname_format(rs[i].dst, flags))
 614                                         goto invalid;
 615                         }
 616                 }
 617         }
 618         return rs;
 619
 620  invalid:
 621         if (verify) {
 622                 /*
 623                  * nr_refspec must be greater than zero and i must be valid
 624                  * since it is only possible to reach this point from within
 625                  * the for loop above.
 626                  */
 627                 free_refspecs(rs, i+1);
 628                 return NULL;
 629         }
 630         die("Invalid refspec '%s'", refspec[i]);
 631 }
 632
 633 int valid_fetch_refspec(const char *fetch_refspec_str)
 634 {
 635         struct refspec *refspec;
 636
 637         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 638         free_refspecs(refspec, 1);
 639         return !!refspec;
 640 }
 641
 642 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 643 {
 644         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 645 }
 646
 647 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 648 {
 649         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 650 }
 651
 652 void free_refspec(int nr_refspec, struct refspec *refspec)
 653 {
 654         int i;
 655         for (i = 0; i < nr_refspec; i++) {
 656                 free(refspec[i].src);
 657                 free(refspec[i].dst);
 658         }
 659         free(refspec);
 660 }
 661
 662 static int valid_remote_nick(const char *name)
 663 {
 664         if (!name[0] || is_dot_or_dotdot(name))
 665                 return 0;
 666         return !strchr(name, '/'); /* no slash */
 667 }
 668
 669 const char *remote_for_branch(struct branch *branch, int *explicit)
 670 {
 671         if (branch && branch->remote_name) {
 672                 if (explicit)
 673                         *explicit = 1;
 674                 return branch->remote_name;
 675         }
 676         if (explicit)
 677                 *explicit = 0;
 678         return "origin";
 679 }
 680
 681 const char *pushremote_for_branch(struct branch *branch, int *explicit)
 682 {
 683         if (branch && branch->pushremote_name) {
 684                 if (explicit)
 685                         *explicit = 1;
 686                 return branch->pushremote_name;
 687         }
 688         if (pushremote_name) {
 689                 if (explicit)
 690                         *explicit = 1;
 691                 return pushremote_name;
 692         }
 693         return remote_for_branch(branch, explicit);
 694 }
 695
 696 static struct remote *remote_get_1(const char *name,
 697                                    const char *(*get_default)(struct branch *, int *))
 698 {
 699         struct remote *ret;
 700         int name_given = 0;
 701
 702         read_config();
 703
 704         if (name)
 705                 name_given = 1;
 706         else
 707                 name = get_default(current_branch, &name_given);
 708
 709         ret = make_remote(name, 0);
 710         if (valid_remote_nick(name)) {
 711                 if (!valid_remote(ret))
 712                         read_remotes_file(ret);
 713                 if (!valid_remote(ret))
 714                         read_branches_file(ret);
 715         }
 716         if (name_given && !valid_remote(ret))
 717                 add_url_alias(ret, name);
 718         if (!valid_remote(ret))
 719                 return NULL;
 720         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 721         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 722         return ret;
 723 }
 724
 725 struct remote *remote_get(const char *name)
 726 {
 727         return remote_get_1(name, remote_for_branch);
 728 }
 729
 730 struct remote *pushremote_get(const char *name)
 731 {
 732         return remote_get_1(name, pushremote_for_branch);
 733 }
 734
 735 int remote_is_configured(const char *name)
 736 {
 737         struct remotes_hash_key lookup;
 738         struct hashmap_entry lookup_entry;
 739         read_config();
 740
 741         init_remotes_hash();
 742         lookup.str = name;
 743         lookup.len = strlen(name);
 744         hashmap_entry_init(&lookup_entry, memhash(name, lookup.len));
 745
 746         return hashmap_get(&remotes_hash, &lookup_entry, &lookup) != NULL;
 747 }
 748
 749 int for_each_remote(each_remote_fn fn, void *priv)
 750 {
 751         int i, result = 0;
 752         read_config();
 753         for (i = 0; i < remotes_nr && !result; i++) {
 754                 struct remote *r = remotes[i];
 755                 if (!r)
 756                         continue;
 757                 if (!r->fetch)
 758                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 759                                                        r->fetch_refspec);
 760                 if (!r->push)
 761                         r->push = parse_push_refspec(r->push_refspec_nr,
 762                                                      r->push_refspec);
 763                 result = fn(r, priv);
 764         }
 765         return result;
 766 }
 767
 768 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 769 {
 770         if (strcmp(ref1->name, ref2->name)) {
 771                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 772                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 773                         die(_("Cannot fetch both %s and %s to %s"),
 774                             ref1->name, ref2->name, ref2->peer_ref->name);
 775                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 776                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 777                         warning(_("%s usually tracks %s, not %s"),
 778                                 ref2->peer_ref->name, ref2->name, ref1->name);
 779                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 780                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 781                         die(_("%s tracks both %s and %s"),
 782                             ref2->peer_ref->name, ref1->name, ref2->name);
 783                 } else {
 784                         /*
 785                          * This last possibility doesn't occur because
 786                          * FETCH_HEAD_IGNORE entries always appear at
 787                          * the end of the list.
 788                          */
 789                         die(_("Internal error"));
 790                 }
 791         }
 792         free(ref2->peer_ref);
 793         free(ref2);
 794 }
 795
 796 struct ref *ref_remove_duplicates(struct ref *ref_map)
 797 {
 798         struct string_list refs = STRING_LIST_INIT_NODUP;
 799         struct ref *retval = NULL;
 800         struct ref **p = &retval;
 801
 802         while (ref_map) {
 803                 struct ref *ref = ref_map;
 804
 805                 ref_map = ref_map->next;
 806                 ref->next = NULL;
 807
 808                 if (!ref->peer_ref) {
 809                         *p = ref;
 810                         p = &ref->next;
 811                 } else {
 812                         struct string_list_item *item =
 813                                 string_list_insert(&refs, ref->peer_ref->name);
 814
 815                         if (item->util) {
 816                                 /* Entry already existed */
 817                                 handle_duplicate((struct ref *)item->util, ref);
 818                         } else {
 819                                 *p = ref;
 820                                 p = &ref->next;
 821                                 item->util = ref;
 822                         }
 823                 }
 824         }
 825
 826         string_list_clear(&refs, 0);
 827         return retval;
 828 }
 829
 830 int remote_has_url(struct remote *remote, const char *url)
 831 {
 832         int i;
 833         for (i = 0; i < remote->url_nr; i++) {
 834                 if (!strcmp(remote->url[i], url))
 835                         return 1;
 836         }
 837         return 0;
 838 }
 839
 840 static int match_name_with_pattern(const char *key, const char *name,
 841                                    const char *value, char **result)
 842 {
 843         const char *kstar = strchr(key, '*');
 844         size_t klen;
 845         size_t ksuffixlen;
 846         size_t namelen;
 847         int ret;
 848         if (!kstar)
 849                 die("Key '%s' of pattern had no '*'", key);
 850         klen = kstar - key;
 851         ksuffixlen = strlen(kstar + 1);
 852         namelen = strlen(name);
 853         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 854                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 855         if (ret && value) {
 856                 struct strbuf sb = STRBUF_INIT;
 857                 const char *vstar = strchr(value, '*');
 858                 if (!vstar)
 859                         die("Value '%s' of pattern has no '*'", value);
 860                 strbuf_add(&sb, value, vstar - value);
 861                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 862                 strbuf_addstr(&sb, vstar + 1);
 863                 *result = strbuf_detach(&sb, NULL);
 864         }
 865         return ret;
 866 }
 867
 868 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 869 {
 870         int i;
 871         int find_src = !query->src;
 872
 873         if (find_src && !query->dst)
 874                 error("query_refspecs_multiple: need either src or dst");
 875
 876         for (i = 0; i < ref_count; i++) {
 877                 struct refspec *refspec = &refs[i];
 878                 const char *key = find_src ? refspec->dst : refspec->src;
 879                 const char *value = find_src ? refspec->src : refspec->dst;
 880                 const char *needle = find_src ? query->dst : query->src;
 881                 char **result = find_src ? &query->src : &query->dst;
 882
 883                 if (!refspec->dst)
 884                         continue;
 885                 if (refspec->pattern) {
 886                         if (match_name_with_pattern(key, needle, value, result))
 887                                 string_list_append_nodup(results, *result);
 888                 } else if (!strcmp(needle, key)) {
 889                         string_list_append(results, value);
 890                 }
 891         }
 892 }
 893
 894 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 895 {
 896         int i;
 897         int find_src = !query->src;
 898         const char *needle = find_src ? query->dst : query->src;
 899         char **result = find_src ? &query->src : &query->dst;
 900
 901         if (find_src && !query->dst)
 902                 return error("query_refspecs: need either src or dst");
 903
 904         for (i = 0; i < ref_count; i++) {
 905                 struct refspec *refspec = &refs[i];
 906                 const char *key = find_src ? refspec->dst : refspec->src;
 907                 const char *value = find_src ? refspec->src : refspec->dst;
 908
 909                 if (!refspec->dst)
 910                         continue;
 911                 if (refspec->pattern) {
 912                         if (match_name_with_pattern(key, needle, value, result)) {
 913                                 query->force = refspec->force;
 914                                 return 0;
 915                         }
 916                 } else if (!strcmp(needle, key)) {
 917                         *result = xstrdup(value);
 918                         query->force = refspec->force;
 919                         return 0;
 920                 }
 921         }
 922         return -1;
 923 }
 924
 925 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 926                      const char *name)
 927 {
 928         struct refspec query;
 929
 930         memset(&query, 0, sizeof(struct refspec));
 931         query.src = (char *)name;
 932
 933         if (query_refspecs(refspecs, nr_refspec, &query))
 934                 return NULL;
 935
 936         return query.dst;
 937 }
 938
 939 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 940 {
 941         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 942 }
 943
 944 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 945                 const char *name)
 946 {
 947         size_t len = strlen(name);
 948         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 949         memcpy(ref->name, prefix, prefixlen);
 950         memcpy(ref->name + prefixlen, name, len);
 951         return ref;
 952 }
 953
 954 struct ref *alloc_ref(const char *name)
 955 {
 956         return alloc_ref_with_prefix("", 0, name);
 957 }
 958
 959 struct ref *copy_ref(const struct ref *ref)
 960 {
 961         struct ref *cpy;
 962         size_t len;
 963         if (!ref)
 964                 return NULL;
 965         len = strlen(ref->name);
 966         cpy = xmalloc(sizeof(struct ref) + len + 1);
 967         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 968         cpy->next = NULL;
 969         cpy->symref = xstrdup_or_null(ref->symref);
 970         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 971         cpy->peer_ref = copy_ref(ref->peer_ref);
 972         return cpy;
 973 }
 974
 975 struct ref *copy_ref_list(const struct ref *ref)
 976 {
 977         struct ref *ret = NULL;
 978         struct ref **tail = &ret;
 979         while (ref) {
 980                 *tail = copy_ref(ref);
 981                 ref = ref->next;
 982                 tail = &((*tail)->next);
 983         }
 984         return ret;
 985 }
 986
 987 static void free_ref(struct ref *ref)
 988 {
 989         if (!ref)
 990                 return;
 991         free_ref(ref->peer_ref);
 992         free(ref->remote_status);
 993         free(ref->symref);
 994         free(ref);
 995 }
 996
 997 void free_refs(struct ref *ref)
 998 {
 999         struct ref *next;
1000         while (ref) {
1001                 next = ref->next;
1002                 free_ref(ref);
1003                 ref = next;
1004         }
1005 }
1006
1007 int ref_compare_name(const void *va, const void *vb)
1008 {
1009         const struct ref *a = va, *b = vb;
1010         return strcmp(a->name, b->name);
1011 }
1012
1013 static void *ref_list_get_next(const void *a)
1014 {
1015         return ((const struct ref *)a)->next;
1016 }
1017
1018 static void ref_list_set_next(void *a, void *next)
1019 {
1020         ((struct ref *)a)->next = next;
1021 }
1022
1023 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1024 {
1025         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1026 }
1027
1028 int count_refspec_match(const char *pattern,
1029                         struct ref *refs,
1030                         struct ref **matched_ref)
1031 {
1032         int patlen = strlen(pattern);
1033         struct ref *matched_weak = NULL;
1034         struct ref *matched = NULL;
1035         int weak_match = 0;
1036         int match = 0;
1037
1038         for (weak_match = match = 0; refs; refs = refs->next) {
1039                 char *name = refs->name;
1040                 int namelen = strlen(name);
1041
1042                 if (!refname_match(pattern, name))
1043                         continue;
1044
1045                 /* A match is "weak" if it is with refs outside
1046                  * heads or tags, and did not specify the pattern
1047                  * in full (e.g. "refs/remotes/origin/master") or at
1048                  * least from the toplevel (e.g. "remotes/origin/master");
1049                  * otherwise "git push $URL master" would result in
1050                  * ambiguity between remotes/origin/master and heads/master
1051                  * at the remote site.
1052                  */
1053                 if (namelen != patlen &&
1054                     patlen != namelen - 5 &&
1055                     !starts_with(name, "refs/heads/") &&
1056                     !starts_with(name, "refs/tags/")) {
1057                         /* We want to catch the case where only weak
1058                          * matches are found and there are multiple
1059                          * matches, and where more than one strong
1060                          * matches are found, as ambiguous.  One
1061                          * strong match with zero or more weak matches
1062                          * are acceptable as a unique match.
1063                          */
1064                         matched_weak = refs;
1065                         weak_match++;
1066                 }
1067                 else {
1068                         matched = refs;
1069                         match++;
1070                 }
1071         }
1072         if (!matched) {
1073                 if (matched_ref)
1074                         *matched_ref = matched_weak;
1075                 return weak_match;
1076         }
1077         else {
1078                 if (matched_ref)
1079                         *matched_ref = matched;
1080                 return match;
1081         }
1082 }
1083
1084 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1085 {
1086         **tail = ref;
1087         while (ref->next)
1088                 ref = ref->next;
1089         *tail = &ref->next;
1090 }
1091
1092 static struct ref *alloc_delete_ref(void)
1093 {
1094         struct ref *ref = alloc_ref("(delete)");
1095         hashclr(ref->new_sha1);
1096         return ref;
1097 }
1098
1099 static int try_explicit_object_name(const char *name,
1100                                     struct ref **match)
1101 {
1102         unsigned char sha1[20];
1103
1104         if (!*name) {
1105                 if (match)
1106                         *match = alloc_delete_ref();
1107                 return 0;
1108         }
1109
1110         if (get_sha1(name, sha1))
1111                 return -1;
1112
1113         if (match) {
1114                 *match = alloc_ref(name);
1115                 hashcpy((*match)->new_sha1, sha1);
1116         }
1117         return 0;
1118 }
1119
1120 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1121 {
1122         struct ref *ret = alloc_ref(name);
1123         tail_link_ref(ret, tail);
1124         return ret;
1125 }
1126
1127 static char *guess_ref(const char *name, struct ref *peer)
1128 {
1129         struct strbuf buf = STRBUF_INIT;
1130         unsigned char sha1[20];
1131
1132         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1133                                            sha1, NULL);
1134         if (!r)
1135                 return NULL;
1136
1137         if (starts_with(r, "refs/heads/"))
1138                 strbuf_addstr(&buf, "refs/heads/");
1139         else if (starts_with(r, "refs/tags/"))
1140                 strbuf_addstr(&buf, "refs/tags/");
1141         else
1142                 return NULL;
1143
1144         strbuf_addstr(&buf, name);
1145         return strbuf_detach(&buf, NULL);
1146 }
1147
1148 static int match_explicit_lhs(struct ref *src,
1149                               struct refspec *rs,
1150                               struct ref **match,
1151                               int *allocated_match)
1152 {
1153         switch (count_refspec_match(rs->src, src, match)) {
1154         case 1:
1155                 if (allocated_match)
1156                         *allocated_match = 0;
1157                 return 0;
1158         case 0:
1159                 /* The source could be in the get_sha1() format
1160                  * not a reference name.  :refs/other is a
1161                  * way to delete 'other' ref at the remote end.
1162                  */
1163                 if (try_explicit_object_name(rs->src, match) < 0)
1164                         return error("src refspec %s does not match any.", rs->src);
1165                 if (allocated_match)
1166                         *allocated_match = 1;
1167                 return 0;
1168         default:
1169                 return error("src refspec %s matches more than one.", rs->src);
1170         }
1171 }
1172
1173 static int match_explicit(struct ref *src, struct ref *dst,
1174                           struct ref ***dst_tail,
1175                           struct refspec *rs)
1176 {
1177         struct ref *matched_src, *matched_dst;
1178         int allocated_src;
1179
1180         const char *dst_value = rs->dst;
1181         char *dst_guess;
1182
1183         if (rs->pattern || rs->matching)
1184                 return 0;
1185
1186         matched_src = matched_dst = NULL;
1187         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1188                 return -1;
1189
1190         if (!dst_value) {
1191                 unsigned char sha1[20];
1192                 int flag;
1193
1194                 dst_value = resolve_ref_unsafe(matched_src->name,
1195                                                RESOLVE_REF_READING,
1196                                                sha1, &flag);
1197                 if (!dst_value ||
1198                     ((flag & REF_ISSYMREF) &&
1199                      !starts_with(dst_value, "refs/heads/")))
1200                         die("%s cannot be resolved to branch.",
1201                             matched_src->name);
1202         }
1203
1204         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1205         case 1:
1206                 break;
1207         case 0:
1208                 if (starts_with(dst_value, "refs/"))
1209                         matched_dst = make_linked_ref(dst_value, dst_tail);
1210                 else if (is_null_sha1(matched_src->new_sha1))
1211                         error("unable to delete '%s': remote ref does not exist",
1212                               dst_value);
1213                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1214                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1215                 else
1216                         error("unable to push to unqualified destination: %s\n"
1217                               "The destination refspec neither matches an "
1218                               "existing ref on the remote nor\n"
1219                               "begins with refs/, and we are unable to "
1220                               "guess a prefix based on the source ref.",
1221                               dst_value);
1222                 break;
1223         default:
1224                 matched_dst = NULL;
1225                 error("dst refspec %s matches more than one.",
1226                       dst_value);
1227                 break;
1228         }
1229         if (!matched_dst)
1230                 return -1;
1231         if (matched_dst->peer_ref)
1232                 return error("dst ref %s receives from more than one src.",
1233                       matched_dst->name);
1234         else {
1235                 matched_dst->peer_ref = allocated_src ?
1236                                         matched_src :
1237                                         copy_ref(matched_src);
1238                 matched_dst->force = rs->force;
1239         }
1240         return 0;
1241 }
1242
1243 static int match_explicit_refs(struct ref *src, struct ref *dst,
1244                                struct ref ***dst_tail, struct refspec *rs,
1245                                int rs_nr)
1246 {
1247         int i, errs;
1248         for (i = errs = 0; i < rs_nr; i++)
1249                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1250         return errs;
1251 }
1252
1253 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1254                 int send_mirror, int direction, const struct refspec **ret_pat)
1255 {
1256         const struct refspec *pat;
1257         char *name;
1258         int i;
1259         int matching_refs = -1;
1260         for (i = 0; i < rs_nr; i++) {
1261                 if (rs[i].matching &&
1262                     (matching_refs == -1 || rs[i].force)) {
1263                         matching_refs = i;
1264                         continue;
1265                 }
1266
1267                 if (rs[i].pattern) {
1268                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1269                         int match;
1270                         if (direction == FROM_SRC)
1271                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1272                         else
1273                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1274                         if (match) {
1275                                 matching_refs = i;
1276                                 break;
1277                         }
1278                 }
1279         }
1280         if (matching_refs == -1)
1281                 return NULL;
1282
1283         pat = rs + matching_refs;
1284         if (pat->matching) {
1285                 /*
1286                  * "matching refs"; traditionally we pushed everything
1287                  * including refs outside refs/heads/ hierarchy, but
1288                  * that does not make much sense these days.
1289                  */
1290                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1291                         return NULL;
1292                 name = xstrdup(ref->name);
1293         }
1294         if (ret_pat)
1295                 *ret_pat = pat;
1296         return name;
1297 }
1298
1299 static struct ref **tail_ref(struct ref **head)
1300 {
1301         struct ref **tail = head;
1302         while (*tail)
1303                 tail = &((*tail)->next);
1304         return tail;
1305 }
1306
1307 struct tips {
1308         struct commit **tip;
1309         int nr, alloc;
1310 };
1311
1312 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1313 {
1314         struct commit *commit;
1315
1316         if (is_null_sha1(sha1))
1317                 return;
1318         commit = lookup_commit_reference_gently(sha1, 1);
1319         if (!commit || (commit->object.flags & TMP_MARK))
1320                 return;
1321         commit->object.flags |= TMP_MARK;
1322         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1323         tips->tip[tips->nr++] = commit;
1324 }
1325
1326 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1327 {
1328         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1329         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1330         struct string_list_item *item;
1331         struct ref *ref;
1332         struct tips sent_tips;
1333
1334         /*
1335          * Collect everything we know they would have at the end of
1336          * this push, and collect all tags they have.
1337          */
1338         memset(&sent_tips, 0, sizeof(sent_tips));
1339         for (ref = *dst; ref; ref = ref->next) {
1340                 if (ref->peer_ref &&
1341                     !is_null_sha1(ref->peer_ref->new_sha1))
1342                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1343                 else
1344                         add_to_tips(&sent_tips, ref->old_sha1);
1345                 if (starts_with(ref->name, "refs/tags/"))
1346                         string_list_append(&dst_tag, ref->name);
1347         }
1348         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1349
1350         string_list_sort(&dst_tag);
1351
1352         /* Collect tags they do not have. */
1353         for (ref = src; ref; ref = ref->next) {
1354                 if (!starts_with(ref->name, "refs/tags/"))
1355                         continue; /* not a tag */
1356                 if (string_list_has_string(&dst_tag, ref->name))
1357                         continue; /* they already have it */
1358                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1359                         continue; /* be conservative */
1360                 item = string_list_append(&src_tag, ref->name);
1361                 item->util = ref;
1362         }
1363         string_list_clear(&dst_tag, 0);
1364
1365         /*
1366          * At this point, src_tag lists tags that are missing from
1367          * dst, and sent_tips lists the tips we are pushing or those
1368          * that we know they already have. An element in the src_tag
1369          * that is an ancestor of any of the sent_tips needs to be
1370          * sent to the other side.
1371          */
1372         if (sent_tips.nr) {
1373                 for_each_string_list_item(item, &src_tag) {
1374                         struct ref *ref = item->util;
1375                         struct ref *dst_ref;
1376                         struct commit *commit;
1377
1378                         if (is_null_sha1(ref->new_sha1))
1379                                 continue;
1380                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1381                         if (!commit)
1382                                 /* not pushing a commit, which is not an error */
1383                                 continue;
1384
1385                         /*
1386                          * Is this tag, which they do not have, reachable from
1387                          * any of the commits we are sending?
1388                          */
1389                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1390                                 continue;
1391
1392                         /* Add it in */
1393                         dst_ref = make_linked_ref(ref->name, dst_tail);
1394                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1395                         dst_ref->peer_ref = copy_ref(ref);
1396                 }
1397         }
1398         string_list_clear(&src_tag, 0);
1399         free(sent_tips.tip);
1400 }
1401
1402 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1403 {
1404         for ( ; list; list = list->next)
1405                 if (!strcmp(list->name, name))
1406                         return (struct ref *)list;
1407         return NULL;
1408 }
1409
1410 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1411 {
1412         for ( ; ref; ref = ref->next)
1413                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1414
1415         string_list_sort(ref_index);
1416 }
1417
1418 /*
1419  * Given only the set of local refs, sanity-check the set of push
1420  * refspecs. We can't catch all errors that match_push_refs would,
1421  * but we can catch some errors early before even talking to the
1422  * remote side.
1423  */
1424 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1425 {
1426         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1427         int ret = 0;
1428         int i;
1429
1430         for (i = 0; i < nr_refspec; i++) {
1431                 struct refspec *rs = refspec + i;
1432
1433                 if (rs->pattern || rs->matching)
1434                         continue;
1435
1436                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1437         }
1438
1439         free_refspec(nr_refspec, refspec);
1440         return ret;
1441 }
1442
1443 /*
1444  * Given the set of refs the local repository has, the set of refs the
1445  * remote repository has, and the refspec used for push, determine
1446  * what remote refs we will update and with what value by setting
1447  * peer_ref (which object is being pushed) and force (if the push is
1448  * forced) in elements of "dst". The function may add new elements to
1449  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1450  */
1451 int match_push_refs(struct ref *src, struct ref **dst,
1452                     int nr_refspec, const char **refspec, int flags)
1453 {
1454         struct refspec *rs;
1455         int send_all = flags & MATCH_REFS_ALL;
1456         int send_mirror = flags & MATCH_REFS_MIRROR;
1457         int send_prune = flags & MATCH_REFS_PRUNE;
1458         int errs;
1459         static const char *default_refspec[] = { ":", NULL };
1460         struct ref *ref, **dst_tail = tail_ref(dst);
1461         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1462
1463         if (!nr_refspec) {
1464                 nr_refspec = 1;
1465                 refspec = default_refspec;
1466         }
1467         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1468         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1469
1470         /* pick the remainder */
1471         for (ref = src; ref; ref = ref->next) {
1472                 struct string_list_item *dst_item;
1473                 struct ref *dst_peer;
1474                 const struct refspec *pat = NULL;
1475                 char *dst_name;
1476
1477                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1478                 if (!dst_name)
1479                         continue;
1480
1481                 if (!dst_ref_index.nr)
1482                         prepare_ref_index(&dst_ref_index, *dst);
1483
1484                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1485                 dst_peer = dst_item ? dst_item->util : NULL;
1486                 if (dst_peer) {
1487                         if (dst_peer->peer_ref)
1488                                 /* We're already sending something to this ref. */
1489                                 goto free_name;
1490                 } else {
1491                         if (pat->matching && !(send_all || send_mirror))
1492                                 /*
1493                                  * Remote doesn't have it, and we have no
1494                                  * explicit pattern, and we don't have
1495                                  * --all or --mirror.
1496                                  */
1497                                 goto free_name;
1498
1499                         /* Create a new one and link it */
1500                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1501                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1502                         string_list_insert(&dst_ref_index,
1503                                 dst_peer->name)->util = dst_peer;
1504                 }
1505                 dst_peer->peer_ref = copy_ref(ref);
1506                 dst_peer->force = pat->force;
1507         free_name:
1508                 free(dst_name);
1509         }
1510
1511         string_list_clear(&dst_ref_index, 0);
1512
1513         if (flags & MATCH_REFS_FOLLOW_TAGS)
1514                 add_missing_tags(src, dst, &dst_tail);
1515
1516         if (send_prune) {
1517                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1518                 /* check for missing refs on the remote */
1519                 for (ref = *dst; ref; ref = ref->next) {
1520                         char *src_name;
1521
1522                         if (ref->peer_ref)
1523                                 /* We're already sending something to this ref. */
1524                                 continue;
1525
1526                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1527                         if (src_name) {
1528                                 if (!src_ref_index.nr)
1529                                         prepare_ref_index(&src_ref_index, src);
1530                                 if (!string_list_has_string(&src_ref_index,
1531                                             src_name))
1532                                         ref->peer_ref = alloc_delete_ref();
1533                                 free(src_name);
1534                         }
1535                 }
1536                 string_list_clear(&src_ref_index, 0);
1537         }
1538         if (errs)
1539                 return -1;
1540         return 0;
1541 }
1542
1543 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1544                              int force_update)
1545 {
1546         struct ref *ref;
1547
1548         for (ref = remote_refs; ref; ref = ref->next) {
1549                 int force_ref_update = ref->force || force_update;
1550                 int reject_reason = 0;
1551
1552                 if (ref->peer_ref)
1553                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1554                 else if (!send_mirror)
1555                         continue;
1556
1557                 ref->deletion = is_null_sha1(ref->new_sha1);
1558                 if (!ref->deletion &&
1559                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1560                         ref->status = REF_STATUS_UPTODATE;
1561                         continue;
1562                 }
1563
1564                 /*
1565                  * Bypass the usual "must fast-forward" check but
1566                  * replace it with a weaker "the old value must be
1567                  * this value we observed".  If the remote ref has
1568                  * moved and is now different from what we expect,
1569                  * reject any push.
1570                  *
1571                  * It also is an error if the user told us to check
1572                  * with the remote-tracking branch to find the value
1573                  * to expect, but we did not have such a tracking
1574                  * branch.
1575                  */
1576                 if (ref->expect_old_sha1) {
1577                         if (ref->expect_old_no_trackback ||
1578                             hashcmp(ref->old_sha1, ref->old_sha1_expect))
1579                                 reject_reason = REF_STATUS_REJECT_STALE;
1580                 }
1581
1582                 /*
1583                  * The usual "must fast-forward" rules.
1584                  *
1585                  * Decide whether an individual refspec A:B can be
1586                  * pushed.  The push will succeed if any of the
1587                  * following are true:
1588                  *
1589                  * (1) the remote reference B does not exist
1590                  *
1591                  * (2) the remote reference B is being removed (i.e.,
1592                  *     pushing :B where no source is specified)
1593                  *
1594                  * (3) the destination is not under refs/tags/, and
1595                  *     if the old and new value is a commit, the new
1596                  *     is a descendant of the old.
1597                  *
1598                  * (4) it is forced using the +A:B notation, or by
1599                  *     passing the --force argument
1600                  */
1601
1602                 else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1603                         if (starts_with(ref->name, "refs/tags/"))
1604                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1605                         else if (!has_sha1_file(ref->old_sha1))
1606                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1607                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1608                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1609                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1610                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1611                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1612                 }
1613
1614                 /*
1615                  * "--force" will defeat any rejection implemented
1616                  * by the rules above.
1617                  */
1618                 if (!force_ref_update)
1619                         ref->status = reject_reason;
1620                 else if (reject_reason)
1621                         ref->forced_update = 1;
1622         }
1623 }
1624
1625 static void set_merge(struct branch *ret)
1626 {
1627         struct remote *remote;
1628         char *ref;
1629         unsigned char sha1[20];
1630         int i;
1631
1632         if (!ret)
1633                 return; /* no branch */
1634         if (ret->merge)
1635                 return; /* already run */
1636         if (!ret->remote_name || !ret->merge_nr) {
1637                 /*
1638                  * no merge config; let's make sure we don't confuse callers
1639                  * with a non-zero merge_nr but a NULL merge
1640                  */
1641                 ret->merge_nr = 0;
1642                 return;
1643         }
1644
1645         remote = remote_get(ret->remote_name);
1646
1647         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1648         for (i = 0; i < ret->merge_nr; i++) {
1649                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1650                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1651                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1652                     strcmp(ret->remote_name, "."))
1653                         continue;
1654                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1655                              sha1, &ref) == 1)
1656                         ret->merge[i]->dst = ref;
1657                 else
1658                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1659         }
1660 }
1661
1662 struct branch *branch_get(const char *name)
1663 {
1664         struct branch *ret;
1665
1666         read_config();
1667         if (!name || !*name || !strcmp(name, "HEAD"))
1668                 ret = current_branch;
1669         else
1670                 ret = make_branch(name, 0);
1671         set_merge(ret);
1672         return ret;
1673 }
1674
1675 int branch_has_merge_config(struct branch *branch)
1676 {
1677         return branch && !!branch->merge;
1678 }
1679
1680 int branch_merge_matches(struct branch *branch,
1681                                  int i,
1682                                  const char *refname)
1683 {
1684         if (!branch || i < 0 || i >= branch->merge_nr)
1685                 return 0;
1686         return refname_match(branch->merge[i]->src, refname);
1687 }
1688
1689 __attribute((format (printf,2,3)))
1690 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1691 {
1692         if (err) {
1693                 va_list ap;
1694                 va_start(ap, fmt);
1695                 strbuf_vaddf(err, fmt, ap);
1696                 va_end(ap);
1697         }
1698         return NULL;
1699 }
1700
1701 const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1702 {
1703         if (!branch)
1704                 return error_buf(err, _("HEAD does not point to a branch"));
1705
1706         if (!branch->merge || !branch->merge[0]) {
1707                 /*
1708                  * no merge config; is it because the user didn't define any,
1709                  * or because it is not a real branch, and get_branch
1710                  * auto-vivified it?
1711                  */
1712                 if (!ref_exists(branch->refname))
1713                         return error_buf(err, _("no such branch: '%s'"),
1714                                          branch->name);
1715                 return error_buf(err,
1716                                  _("no upstream configured for branch '%s'"),
1717                                  branch->name);
1718         }
1719
1720         if (!branch->merge[0]->dst)
1721                 return error_buf(err,
1722                                  _("upstream branch '%s' not stored as a remote-tracking branch"),
1723                                  branch->merge[0]->src);
1724
1725         return branch->merge[0]->dst;
1726 }
1727
1728 static const char *tracking_for_push_dest(struct remote *remote,
1729                                           const char *refname,
1730                                           struct strbuf *err)
1731 {
1732         char *ret;
1733
1734         ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1735         if (!ret)
1736                 return error_buf(err,
1737                                  _("push destination '%s' on remote '%s' has no local tracking branch"),
1738                                  refname, remote->name);
1739         return ret;
1740 }
1741
1742 static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1743 {
1744         struct remote *remote;
1745
1746         if (!branch)
1747                 return error_buf(err, _("HEAD does not point to a branch"));
1748
1749         remote = remote_get(pushremote_for_branch(branch, NULL));
1750         if (!remote)
1751                 return error_buf(err,
1752                                  _("branch '%s' has no remote for pushing"),
1753                                  branch->name);
1754
1755         if (remote->push_refspec_nr) {
1756                 char *dst;
1757                 const char *ret;
1758
1759                 dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1760                                      branch->refname);
1761                 if (!dst)
1762                         return error_buf(err,
1763                                          _("push refspecs for '%s' do not include '%s'"),
1764                                          remote->name, branch->name);
1765
1766                 ret = tracking_for_push_dest(remote, dst, err);
1767                 free(dst);
1768                 return ret;
1769         }
1770
1771         if (remote->mirror)
1772                 return tracking_for_push_dest(remote, branch->refname, err);
1773
1774         switch (push_default) {
1775         case PUSH_DEFAULT_NOTHING:
1776                 return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1777
1778         case PUSH_DEFAULT_MATCHING:
1779         case PUSH_DEFAULT_CURRENT:
1780                 return tracking_for_push_dest(remote, branch->refname, err);
1781
1782         case PUSH_DEFAULT_UPSTREAM:
1783                 return branch_get_upstream(branch, err);
1784
1785         case PUSH_DEFAULT_UNSPECIFIED:
1786         case PUSH_DEFAULT_SIMPLE:
1787                 {
1788                         const char *up, *cur;
1789
1790                         up = branch_get_upstream(branch, err);
1791                         if (!up)
1792                                 return NULL;
1793                         cur = tracking_for_push_dest(remote, branch->refname, err);
1794                         if (!cur)
1795                                 return NULL;
1796                         if (strcmp(cur, up))
1797                                 return error_buf(err,
1798                                                  _("cannot resolve 'simple' push to a single destination"));
1799                         return cur;
1800                 }
1801         }
1802
1803         die("BUG: unhandled push situation");
1804 }
1805
1806 const char *branch_get_push(struct branch *branch, struct strbuf *err)
1807 {
1808         if (!branch->push_tracking_ref)
1809                 branch->push_tracking_ref = branch_get_push_1(branch, err);
1810         return branch->push_tracking_ref;
1811 }
1812
1813 static int ignore_symref_update(const char *refname)
1814 {
1815         unsigned char sha1[20];
1816         int flag;
1817
1818         if (!resolve_ref_unsafe(refname, 0, sha1, &flag))
1819                 return 0; /* non-existing refs are OK */
1820         return (flag & REF_ISSYMREF);
1821 }
1822
1823 /*
1824  * Create and return a list of (struct ref) consisting of copies of
1825  * each remote_ref that matches refspec.  refspec must be a pattern.
1826  * Fill in the copies' peer_ref to describe the local tracking refs to
1827  * which they map.  Omit any references that would map to an existing
1828  * local symbolic ref.
1829  */
1830 static struct ref *get_expanded_map(const struct ref *remote_refs,
1831                                     const struct refspec *refspec)
1832 {
1833         const struct ref *ref;
1834         struct ref *ret = NULL;
1835         struct ref **tail = &ret;
1836
1837         for (ref = remote_refs; ref; ref = ref->next) {
1838                 char *expn_name = NULL;
1839
1840                 if (strchr(ref->name, '^'))
1841                         continue; /* a dereference item */
1842                 if (match_name_with_pattern(refspec->src, ref->name,
1843                                             refspec->dst, &expn_name) &&
1844                     !ignore_symref_update(expn_name)) {
1845                         struct ref *cpy = copy_ref(ref);
1846
1847                         cpy->peer_ref = alloc_ref(expn_name);
1848                         if (refspec->force)
1849                                 cpy->peer_ref->force = 1;
1850                         *tail = cpy;
1851                         tail = &cpy->next;
1852                 }
1853                 free(expn_name);
1854         }
1855
1856         return ret;
1857 }
1858
1859 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1860 {
1861         const struct ref *ref;
1862         for (ref = refs; ref; ref = ref->next) {
1863                 if (refname_match(name, ref->name))
1864                         return ref;
1865         }
1866         return NULL;
1867 }
1868
1869 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1870 {
1871         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1872
1873         if (!ref)
1874                 return NULL;
1875
1876         return copy_ref(ref);
1877 }
1878
1879 static struct ref *get_local_ref(const char *name)
1880 {
1881         if (!name || name[0] == '\0')
1882                 return NULL;
1883
1884         if (starts_with(name, "refs/"))
1885                 return alloc_ref(name);
1886
1887         if (starts_with(name, "heads/") ||
1888             starts_with(name, "tags/") ||
1889             starts_with(name, "remotes/"))
1890                 return alloc_ref_with_prefix("refs/", 5, name);
1891
1892         return alloc_ref_with_prefix("refs/heads/", 11, name);
1893 }
1894
1895 int get_fetch_map(const struct ref *remote_refs,
1896                   const struct refspec *refspec,
1897                   struct ref ***tail,
1898                   int missing_ok)
1899 {
1900         struct ref *ref_map, **rmp;
1901
1902         if (refspec->pattern) {
1903                 ref_map = get_expanded_map(remote_refs, refspec);
1904         } else {
1905                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1906
1907                 if (refspec->exact_sha1) {
1908                         ref_map = alloc_ref(name);
1909                         get_sha1_hex(name, ref_map->old_sha1);
1910                 } else {
1911                         ref_map = get_remote_ref(remote_refs, name);
1912                 }
1913                 if (!missing_ok && !ref_map)
1914                         die("Couldn't find remote ref %s", name);
1915                 if (ref_map) {
1916                         ref_map->peer_ref = get_local_ref(refspec->dst);
1917                         if (ref_map->peer_ref && refspec->force)
1918                                 ref_map->peer_ref->force = 1;
1919                 }
1920         }
1921
1922         for (rmp = &ref_map; *rmp; ) {
1923                 if ((*rmp)->peer_ref) {
1924                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1925                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1926                                 struct ref *ignore = *rmp;
1927                                 error("* Ignoring funny ref '%s' locally",
1928                                       (*rmp)->peer_ref->name);
1929                                 *rmp = (*rmp)->next;
1930                                 free(ignore->peer_ref);
1931                                 free(ignore);
1932                                 continue;
1933                         }
1934                 }
1935                 rmp = &((*rmp)->next);
1936         }
1937
1938         if (ref_map)
1939                 tail_link_ref(ref_map, tail);
1940
1941         return 0;
1942 }
1943
1944 int resolve_remote_symref(struct ref *ref, struct ref *list)
1945 {
1946         if (!ref->symref)
1947                 return 0;
1948         for (; list; list = list->next)
1949                 if (!strcmp(ref->symref, list->name)) {
1950                         hashcpy(ref->old_sha1, list->old_sha1);
1951                         return 0;
1952                 }
1953         return 1;
1954 }
1955
1956 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1957 {
1958         while (list) {
1959                 struct commit_list *temp = list;
1960                 temp->item->object.flags &= ~mark;
1961                 list = temp->next;
1962                 free(temp);
1963         }
1964 }
1965
1966 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1967 {
1968         struct object *o;
1969         struct commit *old, *new;
1970         struct commit_list *list, *used;
1971         int found = 0;
1972
1973         /*
1974          * Both new and old must be commit-ish and new is descendant of
1975          * old.  Otherwise we require --force.
1976          */
1977         o = deref_tag(parse_object(old_sha1), NULL, 0);
1978         if (!o || o->type != OBJ_COMMIT)
1979                 return 0;
1980         old = (struct commit *) o;
1981
1982         o = deref_tag(parse_object(new_sha1), NULL, 0);
1983         if (!o || o->type != OBJ_COMMIT)
1984                 return 0;
1985         new = (struct commit *) o;
1986
1987         if (parse_commit(new) < 0)
1988                 return 0;
1989
1990         used = list = NULL;
1991         commit_list_insert(new, &list);
1992         while (list) {
1993                 new = pop_most_recent_commit(&list, TMP_MARK);
1994                 commit_list_insert(new, &used);
1995                 if (new == old) {
1996                         found = 1;
1997                         break;
1998                 }
1999         }
2000         unmark_and_free(list, TMP_MARK);
2001         unmark_and_free(used, TMP_MARK);
2002         return found;
2003 }
2004
2005 /*
2006  * Compare a branch with its upstream, and save their differences (number
2007  * of commits) in *num_ours and *num_theirs. The name of the upstream branch
2008  * (or NULL if no upstream is defined) is returned via *upstream_name, if it
2009  * is not itself NULL.
2010  *
2011  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
2012  * upstream defined, or ref does not exist), 0 otherwise.
2013  */
2014 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
2015                        const char **upstream_name)
2016 {
2017         unsigned char sha1[20];
2018         struct commit *ours, *theirs;
2019         char symmetric[84];
2020         struct rev_info revs;
2021         const char *rev_argv[10], *base;
2022         int rev_argc;
2023
2024         /* Cannot stat unless we are marked to build on top of somebody else. */
2025         base = branch_get_upstream(branch, NULL);
2026         if (upstream_name)
2027                 *upstream_name = base;
2028         if (!base)
2029                 return -1;
2030
2031         /* Cannot stat if what we used to build on no longer exists */
2032         if (read_ref(base, sha1))
2033                 return -1;
2034         theirs = lookup_commit_reference(sha1);
2035         if (!theirs)
2036                 return -1;
2037
2038         if (read_ref(branch->refname, sha1))
2039                 return -1;
2040         ours = lookup_commit_reference(sha1);
2041         if (!ours)
2042                 return -1;
2043
2044         /* are we the same? */
2045         if (theirs == ours) {
2046                 *num_theirs = *num_ours = 0;
2047                 return 0;
2048         }
2049
2050         /* Run "rev-list --left-right ours...theirs" internally... */
2051         rev_argc = 0;
2052         rev_argv[rev_argc++] = NULL;
2053         rev_argv[rev_argc++] = "--left-right";
2054         rev_argv[rev_argc++] = symmetric;
2055         rev_argv[rev_argc++] = "--";
2056         rev_argv[rev_argc] = NULL;
2057
2058         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
2059         strcpy(symmetric + 40, "...");
2060         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
2061
2062         init_revisions(&revs, NULL);
2063         setup_revisions(rev_argc, rev_argv, &revs, NULL);
2064         if (prepare_revision_walk(&revs))
2065                 die("revision walk setup failed");
2066
2067         /* ... and count the commits on each side. */
2068         *num_ours = 0;
2069         *num_theirs = 0;
2070         while (1) {
2071                 struct commit *c = get_revision(&revs);
2072                 if (!c)
2073                         break;
2074                 if (c->object.flags & SYMMETRIC_LEFT)
2075                         (*num_ours)++;
2076                 else
2077                         (*num_theirs)++;
2078         }
2079
2080         /* clear object flags smudged by the above traversal */
2081         clear_commit_marks(ours, ALL_REV_FLAGS);
2082         clear_commit_marks(theirs, ALL_REV_FLAGS);
2083         return 0;
2084 }
2085
2086 /*
2087  * Return true when there is anything to report, otherwise false.
2088  */
2089 int format_tracking_info(struct branch *branch, struct strbuf *sb)
2090 {
2091         int ours, theirs;
2092         const char *full_base;
2093         char *base;
2094         int upstream_is_gone = 0;
2095
2096         if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2097                 if (!full_base)
2098                         return 0;
2099                 upstream_is_gone = 1;
2100         }
2101
2102         base = shorten_unambiguous_ref(full_base, 0);
2103         if (upstream_is_gone) {
2104                 strbuf_addf(sb,
2105                         _("Your branch is based on '%s', but the upstream is gone.\n"),
2106                         base);
2107                 if (advice_status_hints)
2108                         strbuf_addf(sb,
2109                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2110         } else if (!ours && !theirs) {
2111                 strbuf_addf(sb,
2112                         _("Your branch is up-to-date with '%s'.\n"),
2113                         base);
2114         } else if (!theirs) {
2115                 strbuf_addf(sb,
2116                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2117                            "Your branch is ahead of '%s' by %d commits.\n",
2118                            ours),
2119                         base, ours);
2120                 if (advice_status_hints)
2121                         strbuf_addf(sb,
2122                                 _("  (use \"git push\" to publish your local commits)\n"));
2123         } else if (!ours) {
2124                 strbuf_addf(sb,
2125                         Q_("Your branch is behind '%s' by %d commit, "
2126                                "and can be fast-forwarded.\n",
2127                            "Your branch is behind '%s' by %d commits, "
2128                                "and can be fast-forwarded.\n",
2129                            theirs),
2130                         base, theirs);
2131                 if (advice_status_hints)
2132                         strbuf_addf(sb,
2133                                 _("  (use \"git pull\" to update your local branch)\n"));
2134         } else {
2135                 strbuf_addf(sb,
2136                         Q_("Your branch and '%s' have diverged,\n"
2137                                "and have %d and %d different commit each, "
2138                                "respectively.\n",
2139                            "Your branch and '%s' have diverged,\n"
2140                                "and have %d and %d different commits each, "
2141                                "respectively.\n",
2142                            theirs),
2143                         base, ours, theirs);
2144                 if (advice_status_hints)
2145                         strbuf_addf(sb,
2146                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2147         }
2148         free(base);
2149         return 1;
2150 }
2151
2152 static int one_local_ref(const char *refname, const struct object_id *oid,
2153                          int flag, void *cb_data)
2154 {
2155         struct ref ***local_tail = cb_data;
2156         struct ref *ref;
2157         int len;
2158
2159         /* we already know it starts with refs/ to get here */
2160         if (check_refname_format(refname + 5, 0))
2161                 return 0;
2162
2163         len = strlen(refname) + 1;
2164         ref = xcalloc(1, sizeof(*ref) + len);
2165         hashcpy(ref->new_sha1, oid->hash);
2166         memcpy(ref->name, refname, len);
2167         **local_tail = ref;
2168         *local_tail = &ref->next;
2169         return 0;
2170 }
2171
2172 struct ref *get_local_heads(void)
2173 {
2174         struct ref *local_refs = NULL, **local_tail = &local_refs;
2175
2176         for_each_ref(one_local_ref, &local_tail);
2177         return local_refs;
2178 }
2179
2180 struct ref *guess_remote_head(const struct ref *head,
2181                               const struct ref *refs,
2182                               int all)
2183 {
2184         const struct ref *r;
2185         struct ref *list = NULL;
2186         struct ref **tail = &list;
2187
2188         if (!head)
2189                 return NULL;
2190
2191         /*
2192          * Some transports support directly peeking at
2193          * where HEAD points; if that is the case, then
2194          * we don't have to guess.
2195          */
2196         if (head->symref)
2197                 return copy_ref(find_ref_by_name(refs, head->symref));
2198
2199         /* If refs/heads/master could be right, it is. */
2200         if (!all) {
2201                 r = find_ref_by_name(refs, "refs/heads/master");
2202                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
2203                         return copy_ref(r);
2204         }
2205
2206         /* Look for another ref that points there */
2207         for (r = refs; r; r = r->next) {
2208                 if (r != head &&
2209                     starts_with(r->name, "refs/heads/") &&
2210                     !hashcmp(r->old_sha1, head->old_sha1)) {
2211                         *tail = copy_ref(r);
2212                         tail = &((*tail)->next);
2213                         if (!all)
2214                                 break;
2215                 }
2216         }
2217
2218         return list;
2219 }
2220
2221 struct stale_heads_info {
2222         struct string_list *ref_names;
2223         struct ref **stale_refs_tail;
2224         struct refspec *refs;
2225         int ref_count;
2226 };
2227
2228 static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2229                               int flags, void *cb_data)
2230 {
2231         struct stale_heads_info *info = cb_data;
2232         struct string_list matches = STRING_LIST_INIT_DUP;
2233         struct refspec query;
2234         int i, stale = 1;
2235         memset(&query, 0, sizeof(struct refspec));
2236         query.dst = (char *)refname;
2237
2238         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2239         if (matches.nr == 0)
2240                 goto clean_exit; /* No matches */
2241
2242         /*
2243          * If we did find a suitable refspec and it's not a symref and
2244          * it's not in the list of refs that currently exist in that
2245          * remote, we consider it to be stale. In order to deal with
2246          * overlapping refspecs, we need to go over all of the
2247          * matching refs.
2248          */
2249         if (flags & REF_ISSYMREF)
2250                 goto clean_exit;
2251
2252         for (i = 0; stale && i < matches.nr; i++)
2253                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2254                         stale = 0;
2255
2256         if (stale) {
2257                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2258                 hashcpy(ref->new_sha1, oid->hash);
2259         }
2260
2261 clean_exit:
2262         string_list_clear(&matches, 0);
2263         return 0;
2264 }
2265
2266 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2267 {
2268         struct ref *ref, *stale_refs = NULL;
2269         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2270         struct stale_heads_info info;
2271
2272         info.ref_names = &ref_names;
2273         info.stale_refs_tail = &stale_refs;
2274         info.refs = refs;
2275         info.ref_count = ref_count;
2276         for (ref = fetch_map; ref; ref = ref->next)
2277                 string_list_append(&ref_names, ref->name);
2278         string_list_sort(&ref_names);
2279         for_each_ref(get_stale_heads_cb, &info);
2280         string_list_clear(&ref_names, 0);
2281         return stale_refs;
2282 }
2283
2284 /*
2285  * Compare-and-swap
2286  */
2287 static void clear_cas_option(struct push_cas_option *cas)
2288 {
2289         int i;
2290
2291         for (i = 0; i < cas->nr; i++)
2292                 free(cas->entry[i].refname);
2293         free(cas->entry);
2294         memset(cas, 0, sizeof(*cas));
2295 }
2296
2297 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2298                                       const char *refname,
2299                                       size_t refnamelen)
2300 {
2301         struct push_cas *entry;
2302         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2303         entry = &cas->entry[cas->nr++];
2304         memset(entry, 0, sizeof(*entry));
2305         entry->refname = xmemdupz(refname, refnamelen);
2306         return entry;
2307 }
2308
2309 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2310 {
2311         const char *colon;
2312         struct push_cas *entry;
2313
2314         if (unset) {
2315                 /* "--no-<option>" */
2316                 clear_cas_option(cas);
2317                 return 0;
2318         }
2319
2320         if (!arg) {
2321                 /* just "--<option>" */
2322                 cas->use_tracking_for_rest = 1;
2323                 return 0;
2324         }
2325
2326         /* "--<option>=refname" or "--<option>=refname:value" */
2327         colon = strchrnul(arg, ':');
2328         entry = add_cas_entry(cas, arg, colon - arg);
2329         if (!*colon)
2330                 entry->use_tracking = 1;
2331         else if (get_sha1(colon + 1, entry->expect))
2332                 return error("cannot parse expected object name '%s'", colon + 1);
2333         return 0;
2334 }
2335
2336 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2337 {
2338         return parse_push_cas_option(opt->value, arg, unset);
2339 }
2340
2341 int is_empty_cas(const struct push_cas_option *cas)
2342 {
2343         return !cas->use_tracking_for_rest && !cas->nr;
2344 }
2345
2346 /*
2347  * Look at remote.fetch refspec and see if we have a remote
2348  * tracking branch for the refname there.  Fill its current
2349  * value in sha1[].
2350  * If we cannot do so, return negative to signal an error.
2351  */
2352 static int remote_tracking(struct remote *remote, const char *refname,
2353                            unsigned char sha1[20])
2354 {
2355         char *dst;
2356
2357         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2358         if (!dst)
2359                 return -1; /* no tracking ref for refname at remote */
2360         if (read_ref(dst, sha1))
2361                 return -1; /* we know what the tracking ref is but we cannot read it */
2362         return 0;
2363 }
2364
2365 static void apply_cas(struct push_cas_option *cas,
2366                       struct remote *remote,
2367                       struct ref *ref)
2368 {
2369         int i;
2370
2371         /* Find an explicit --<option>=<name>[:<value>] entry */
2372         for (i = 0; i < cas->nr; i++) {
2373                 struct push_cas *entry = &cas->entry[i];
2374                 if (!refname_match(entry->refname, ref->name))
2375                         continue;
2376                 ref->expect_old_sha1 = 1;
2377                 if (!entry->use_tracking)
2378                         hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2379                 else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2380                         ref->expect_old_no_trackback = 1;
2381                 return;
2382         }
2383
2384         /* Are we using "--<option>" to cover all? */
2385         if (!cas->use_tracking_for_rest)
2386                 return;
2387
2388         ref->expect_old_sha1 = 1;
2389         if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2390                 ref->expect_old_no_trackback = 1;
2391 }
2392
2393 void apply_push_cas(struct push_cas_option *cas,
2394                     struct remote *remote,
2395                     struct ref *remote_refs)
2396 {
2397         struct ref *ref;
2398         for (ref = remote_refs; ref; ref = ref->next)
2399                 apply_cas(cas, remote, ref);
2400 }