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 #include "argv-array.h"
  12
  13 enum map_direction { FROM_SRC, FROM_DST };
  14
  15 static struct refspec s_tag_refspec = {
  16         0,
  17         1,
  18         0,
  19         0,
  20         "refs/tags/*",
  21         "refs/tags/*"
  22 };
  23
  24 const struct refspec *tag_refspec = &s_tag_refspec;
  25
  26 struct counted_string {
  27         size_t len;
  28         const char *s;
  29 };
  30 struct rewrite {
  31         const char *base;
  32         size_t baselen;
  33         struct counted_string *instead_of;
  34         int instead_of_nr;
  35         int instead_of_alloc;
  36 };
  37 struct rewrites {
  38         struct rewrite **rewrite;
  39         int rewrite_alloc;
  40         int rewrite_nr;
  41 };
  42
  43 static struct remote **remotes;
  44 static int remotes_alloc;
  45 static int remotes_nr;
  46 static struct hashmap remotes_hash;
  47
  48 static struct branch **branches;
  49 static int branches_alloc;
  50 static int branches_nr;
  51
  52 static struct branch *current_branch;
  53 static const char *pushremote_name;
  54
  55 static struct rewrites rewrites;
  56 static struct rewrites rewrites_push;
  57
  58 static int valid_remote(const struct remote *remote)
  59 {
  60         return (!!remote->url) || (!!remote->foreign_vcs);
  61 }
  62
  63 static const char *alias_url(const char *url, struct rewrites *r)
  64 {
  65         int i, j;
  66         struct counted_string *longest;
  67         int longest_i;
  68
  69         longest = NULL;
  70         longest_i = -1;
  71         for (i = 0; i < r->rewrite_nr; i++) {
  72                 if (!r->rewrite[i])
  73                         continue;
  74                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  75                         if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  76                             (!longest ||
  77                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  78                                 longest = &(r->rewrite[i]->instead_of[j]);
  79                                 longest_i = i;
  80                         }
  81                 }
  82         }
  83         if (!longest)
  84                 return url;
  85
  86         return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  87 }
  88
  89 static void add_push_refspec(struct remote *remote, const char *ref)
  90 {
  91         ALLOC_GROW(remote->push_refspec,
  92                    remote->push_refspec_nr + 1,
  93                    remote->push_refspec_alloc);
  94         remote->push_refspec[remote->push_refspec_nr++] = ref;
  95 }
  96
  97 static void add_fetch_refspec(struct remote *remote, const char *ref)
  98 {
  99         ALLOC_GROW(remote->fetch_refspec,
 100                    remote->fetch_refspec_nr + 1,
 101                    remote->fetch_refspec_alloc);
 102         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 103 }
 104
 105 static void add_url(struct remote *remote, const char *url)
 106 {
 107         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 108         remote->url[remote->url_nr++] = url;
 109 }
 110
 111 static void add_pushurl(struct remote *remote, const char *pushurl)
 112 {
 113         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 114         remote->pushurl[remote->pushurl_nr++] = pushurl;
 115 }
 116
 117 static void add_pushurl_alias(struct remote *remote, const char *url)
 118 {
 119         const char *pushurl = alias_url(url, &rewrites_push);
 120         if (pushurl != url)
 121                 add_pushurl(remote, pushurl);
 122 }
 123
 124 static void add_url_alias(struct remote *remote, const char *url)
 125 {
 126         add_url(remote, alias_url(url, &rewrites));
 127         add_pushurl_alias(remote, url);
 128 }
 129
 130 struct remotes_hash_key {
 131         const char *str;
 132         int len;
 133 };
 134
 135 static int remotes_hash_cmp(const struct remote *a, const struct remote *b, const struct remotes_hash_key *key)
 136 {
 137         if (key)
 138                 return strncmp(a->name, key->str, key->len) || a->name[key->len];
 139         else
 140                 return strcmp(a->name, b->name);
 141 }
 142
 143 static inline void init_remotes_hash(void)
 144 {
 145         if (!remotes_hash.cmpfn)
 146                 hashmap_init(&remotes_hash, (hashmap_cmp_fn)remotes_hash_cmp, 0);
 147 }
 148
 149 static struct remote *make_remote(const char *name, int len)
 150 {
 151         struct remote *ret, *replaced;
 152         struct remotes_hash_key lookup;
 153         struct hashmap_entry lookup_entry;
 154
 155         if (!len)
 156                 len = strlen(name);
 157
 158         init_remotes_hash();
 159         lookup.str = name;
 160         lookup.len = len;
 161         hashmap_entry_init(&lookup_entry, memhash(name, len));
 162
 163         if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 164                 return ret;
 165
 166         ret = xcalloc(1, sizeof(struct remote));
 167         ret->prune = -1;  /* unspecified */
 168         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 169         remotes[remotes_nr++] = ret;
 170         ret->name = xstrndup(name, len);
 171
 172         hashmap_entry_init(ret, lookup_entry.hash);
 173         replaced = hashmap_put(&remotes_hash, ret);
 174         assert(replaced == NULL);  /* no previous entry overwritten */
 175         return ret;
 176 }
 177
 178 static void add_merge(struct branch *branch, const char *name)
 179 {
 180         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 181                    branch->merge_alloc);
 182         branch->merge_name[branch->merge_nr++] = name;
 183 }
 184
 185 static struct branch *make_branch(const char *name, int len)
 186 {
 187         struct branch *ret;
 188         int i;
 189
 190         for (i = 0; i < branches_nr; i++) {
 191                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 192                            !branches[i]->name[len]) :
 193                     !strcmp(name, branches[i]->name))
 194                         return branches[i];
 195         }
 196
 197         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 198         ret = xcalloc(1, sizeof(struct branch));
 199         branches[branches_nr++] = ret;
 200         if (len)
 201                 ret->name = xstrndup(name, len);
 202         else
 203                 ret->name = xstrdup(name);
 204         ret->refname = xstrfmt("refs/heads/%s", ret->name);
 205
 206         return ret;
 207 }
 208
 209 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 210 {
 211         struct rewrite *ret;
 212         int i;
 213
 214         for (i = 0; i < r->rewrite_nr; i++) {
 215                 if (len
 216                     ? (len == r->rewrite[i]->baselen &&
 217                        !strncmp(base, r->rewrite[i]->base, len))
 218                     : !strcmp(base, r->rewrite[i]->base))
 219                         return r->rewrite[i];
 220         }
 221
 222         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 223         ret = xcalloc(1, sizeof(struct rewrite));
 224         r->rewrite[r->rewrite_nr++] = ret;
 225         if (len) {
 226                 ret->base = xstrndup(base, len);
 227                 ret->baselen = len;
 228         }
 229         else {
 230                 ret->base = xstrdup(base);
 231                 ret->baselen = strlen(base);
 232         }
 233         return ret;
 234 }
 235
 236 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 237 {
 238         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 239         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 240         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 241         rewrite->instead_of_nr++;
 242 }
 243
 244 static const char *skip_spaces(const char *s)
 245 {
 246         while (isspace(*s))
 247                 s++;
 248         return s;
 249 }
 250
 251 static void read_remotes_file(struct remote *remote)
 252 {
 253         struct strbuf buf = STRBUF_INIT;
 254         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 255
 256         if (!f)
 257                 return;
 258         remote->origin = REMOTE_REMOTES;
 259         while (strbuf_getline(&buf, f) != EOF) {
 260                 const char *v;
 261
 262                 strbuf_rtrim(&buf);
 263
 264                 if (skip_prefix(buf.buf, "URL:", &v))
 265                         add_url_alias(remote, xstrdup(skip_spaces(v)));
 266                 else if (skip_prefix(buf.buf, "Push:", &v))
 267                         add_push_refspec(remote, xstrdup(skip_spaces(v)));
 268                 else if (skip_prefix(buf.buf, "Pull:", &v))
 269                         add_fetch_refspec(remote, xstrdup(skip_spaces(v)));
 270         }
 271         strbuf_release(&buf);
 272         fclose(f);
 273 }
 274
 275 static void read_branches_file(struct remote *remote)
 276 {
 277         char *frag;
 278         struct strbuf buf = STRBUF_INIT;
 279         FILE *f = fopen(git_path("branches/%s", remote->name), "r");
 280
 281         if (!f)
 282                 return;
 283
 284         strbuf_getline_lf(&buf, f);
 285         fclose(f);
 286         strbuf_trim(&buf);
 287         if (!buf.len) {
 288                 strbuf_release(&buf);
 289                 return;
 290         }
 291
 292         remote->origin = REMOTE_BRANCHES;
 293
 294         /*
 295          * The branches file would have URL and optionally
 296          * #branch specified.  The "master" (or specified) branch is
 297          * fetched and stored in the local branch matching the
 298          * remote name.
 299          */
 300         frag = strchr(buf.buf, '#');
 301         if (frag)
 302                 *(frag++) = '\0';
 303         else
 304                 frag = "master";
 305
 306         add_url_alias(remote, strbuf_detach(&buf, NULL));
 307         add_fetch_refspec(remote, xstrfmt("refs/heads/%s:refs/heads/%s",
 308                                           frag, remote->name));
 309
 310         /*
 311          * Cogito compatible push: push current HEAD to remote #branch
 312          * (master if missing)
 313          */
 314         add_push_refspec(remote, xstrfmt("HEAD:refs/heads/%s", frag));
 315         remote->fetch_tags = 1; /* always auto-follow */
 316 }
 317
 318 static int handle_config(const char *key, const char *value, void *cb)
 319 {
 320         const char *name;
 321         const char *subkey;
 322         struct remote *remote;
 323         struct branch *branch;
 324         if (starts_with(key, "branch.")) {
 325                 name = key + 7;
 326                 subkey = strrchr(name, '.');
 327                 if (!subkey)
 328                         return 0;
 329                 branch = make_branch(name, subkey - name);
 330                 if (!strcmp(subkey, ".remote")) {
 331                         return git_config_string(&branch->remote_name, key, value);
 332                 } else if (!strcmp(subkey, ".pushremote")) {
 333                         return git_config_string(&branch->pushremote_name, key, value);
 334                 } else if (!strcmp(subkey, ".merge")) {
 335                         if (!value)
 336                                 return config_error_nonbool(key);
 337                         add_merge(branch, xstrdup(value));
 338                 }
 339                 return 0;
 340         }
 341         if (starts_with(key, "url.")) {
 342                 struct rewrite *rewrite;
 343                 name = key + 4;
 344                 subkey = strrchr(name, '.');
 345                 if (!subkey)
 346                         return 0;
 347                 if (!strcmp(subkey, ".insteadof")) {
 348                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 349                         if (!value)
 350                                 return config_error_nonbool(key);
 351                         add_instead_of(rewrite, xstrdup(value));
 352                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 353                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 354                         if (!value)
 355                                 return config_error_nonbool(key);
 356                         add_instead_of(rewrite, xstrdup(value));
 357                 }
 358         }
 359
 360         if (!starts_with(key,  "remote."))
 361                 return 0;
 362         name = key + 7;
 363
 364         /* Handle remote.* variables */
 365         if (!strcmp(name, "pushdefault"))
 366                 return git_config_string(&pushremote_name, key, value);
 367
 368         /* Handle remote.<name>.* variables */
 369         if (*name == '/') {
 370                 warning("Config remote shorthand cannot begin with '/': %s",
 371                         name);
 372                 return 0;
 373         }
 374         subkey = strrchr(name, '.');
 375         if (!subkey)
 376                 return 0;
 377         remote = make_remote(name, subkey - name);
 378         remote->origin = REMOTE_CONFIG;
 379         if (!strcmp(subkey, ".mirror"))
 380                 remote->mirror = git_config_bool(key, value);
 381         else if (!strcmp(subkey, ".skipdefaultupdate"))
 382                 remote->skip_default_update = git_config_bool(key, value);
 383         else if (!strcmp(subkey, ".skipfetchall"))
 384                 remote->skip_default_update = git_config_bool(key, value);
 385         else if (!strcmp(subkey, ".prune"))
 386                 remote->prune = git_config_bool(key, value);
 387         else if (!strcmp(subkey, ".url")) {
 388                 const char *v;
 389                 if (git_config_string(&v, key, value))
 390                         return -1;
 391                 add_url(remote, v);
 392         } else if (!strcmp(subkey, ".pushurl")) {
 393                 const char *v;
 394                 if (git_config_string(&v, key, value))
 395                         return -1;
 396                 add_pushurl(remote, v);
 397         } else if (!strcmp(subkey, ".push")) {
 398                 const char *v;
 399                 if (git_config_string(&v, key, value))
 400                         return -1;
 401                 add_push_refspec(remote, v);
 402         } else if (!strcmp(subkey, ".fetch")) {
 403                 const char *v;
 404                 if (git_config_string(&v, key, value))
 405                         return -1;
 406                 add_fetch_refspec(remote, v);
 407         } else if (!strcmp(subkey, ".receivepack")) {
 408                 const char *v;
 409                 if (git_config_string(&v, key, value))
 410                         return -1;
 411                 if (!remote->receivepack)
 412                         remote->receivepack = v;
 413                 else
 414                         error("more than one receivepack given, using the first");
 415         } else if (!strcmp(subkey, ".uploadpack")) {
 416                 const char *v;
 417                 if (git_config_string(&v, key, value))
 418                         return -1;
 419                 if (!remote->uploadpack)
 420                         remote->uploadpack = v;
 421                 else
 422                         error("more than one uploadpack given, using the first");
 423         } else if (!strcmp(subkey, ".tagopt")) {
 424                 if (!strcmp(value, "--no-tags"))
 425                         remote->fetch_tags = -1;
 426                 else if (!strcmp(value, "--tags"))
 427                         remote->fetch_tags = 2;
 428         } else if (!strcmp(subkey, ".proxy")) {
 429                 return git_config_string((const char **)&remote->http_proxy,
 430                                          key, value);
 431         } else if (!strcmp(subkey, ".proxyauthmethod")) {
 432                 return git_config_string((const char **)&remote->http_proxy_authmethod,
 433                                          key, value);
 434         } else if (!strcmp(subkey, ".vcs")) {
 435                 return git_config_string(&remote->foreign_vcs, key, value);
 436         }
 437         return 0;
 438 }
 439
 440 static void alias_all_urls(void)
 441 {
 442         int i, j;
 443         for (i = 0; i < remotes_nr; i++) {
 444                 int add_pushurl_aliases;
 445                 if (!remotes[i])
 446                         continue;
 447                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 448                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 449                 }
 450                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 451                 for (j = 0; j < remotes[i]->url_nr; j++) {
 452                         if (add_pushurl_aliases)
 453                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 454                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 455                 }
 456         }
 457 }
 458
 459 static void read_config(void)
 460 {
 461         static int loaded;
 462         struct object_id oid;
 463         const char *head_ref;
 464         int flag;
 465
 466         if (loaded)
 467                 return;
 468         loaded = 1;
 469
 470         current_branch = NULL;
 471         head_ref = resolve_ref_unsafe("HEAD", 0, oid.hash, &flag);
 472         if (head_ref && (flag & REF_ISSYMREF) &&
 473             skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 474                 current_branch = make_branch(head_ref, 0);
 475         }
 476         git_config(handle_config, NULL);
 477         alias_all_urls();
 478 }
 479
 480 /*
 481  * This function frees a refspec array.
 482  * Warning: code paths should be checked to ensure that the src
 483  *          and dst pointers are always freeable pointers as well
 484  *          as the refspec pointer itself.
 485  */
 486 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 487 {
 488         int i;
 489
 490         if (!refspec)
 491                 return;
 492
 493         for (i = 0; i < nr_refspec; i++) {
 494                 free(refspec[i].src);
 495                 free(refspec[i].dst);
 496         }
 497         free(refspec);
 498 }
 499
 500 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 501 {
 502         int i;
 503         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 504
 505         for (i = 0; i < nr_refspec; i++) {
 506                 size_t llen;
 507                 int is_glob;
 508                 const char *lhs, *rhs;
 509                 int flags;
 510
 511                 is_glob = 0;
 512
 513                 lhs = refspec[i];
 514                 if (*lhs == '+') {
 515                         rs[i].force = 1;
 516                         lhs++;
 517                 }
 518
 519                 rhs = strrchr(lhs, ':');
 520
 521                 /*
 522                  * Before going on, special case ":" (or "+:") as a refspec
 523                  * for pushing matching refs.
 524                  */
 525                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 526                         rs[i].matching = 1;
 527                         continue;
 528                 }
 529
 530                 if (rhs) {
 531                         size_t rlen = strlen(++rhs);
 532                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 533                         rs[i].dst = xstrndup(rhs, rlen);
 534                 }
 535
 536                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 537                 if (1 <= llen && memchr(lhs, '*', llen)) {
 538                         if ((rhs && !is_glob) || (!rhs && fetch))
 539                                 goto invalid;
 540                         is_glob = 1;
 541                 } else if (rhs && is_glob) {
 542                         goto invalid;
 543                 }
 544
 545                 rs[i].pattern = is_glob;
 546                 rs[i].src = xstrndup(lhs, llen);
 547                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 548
 549                 if (fetch) {
 550                         struct object_id unused;
 551
 552                         /* LHS */
 553                         if (!*rs[i].src)
 554                                 ; /* empty is ok; it means "HEAD" */
 555                         else if (llen == GIT_SHA1_HEXSZ && !get_oid_hex(rs[i].src, &unused))
 556                                 rs[i].exact_sha1 = 1; /* ok */
 557                         else if (!check_refname_format(rs[i].src, flags))
 558                                 ; /* valid looking ref is ok */
 559                         else
 560                                 goto invalid;
 561                         /* RHS */
 562                         if (!rs[i].dst)
 563                                 ; /* missing is ok; it is the same as empty */
 564                         else if (!*rs[i].dst)
 565                                 ; /* empty is ok; it means "do not store" */
 566                         else if (!check_refname_format(rs[i].dst, flags))
 567                                 ; /* valid looking ref is ok */
 568                         else
 569                                 goto invalid;
 570                 } else {
 571                         /*
 572                          * LHS
 573                          * - empty is allowed; it means delete.
 574                          * - when wildcarded, it must be a valid looking ref.
 575                          * - otherwise, it must be an extended SHA-1, but
 576                          *   there is no existing way to validate this.
 577                          */
 578                         if (!*rs[i].src)
 579                                 ; /* empty is ok */
 580                         else if (is_glob) {
 581                                 if (check_refname_format(rs[i].src, flags))
 582                                         goto invalid;
 583                         }
 584                         else
 585                                 ; /* anything goes, for now */
 586                         /*
 587                          * RHS
 588                          * - missing is allowed, but LHS then must be a
 589                          *   valid looking ref.
 590                          * - empty is not allowed.
 591                          * - otherwise it must be a valid looking ref.
 592                          */
 593                         if (!rs[i].dst) {
 594                                 if (check_refname_format(rs[i].src, flags))
 595                                         goto invalid;
 596                         } else if (!*rs[i].dst) {
 597                                 goto invalid;
 598                         } else {
 599                                 if (check_refname_format(rs[i].dst, flags))
 600                                         goto invalid;
 601                         }
 602                 }
 603         }
 604         return rs;
 605
 606  invalid:
 607         if (verify) {
 608                 /*
 609                  * nr_refspec must be greater than zero and i must be valid
 610                  * since it is only possible to reach this point from within
 611                  * the for loop above.
 612                  */
 613                 free_refspecs(rs, i+1);
 614                 return NULL;
 615         }
 616         die("Invalid refspec '%s'", refspec[i]);
 617 }
 618
 619 int valid_fetch_refspec(const char *fetch_refspec_str)
 620 {
 621         struct refspec *refspec;
 622
 623         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 624         free_refspecs(refspec, 1);
 625         return !!refspec;
 626 }
 627
 628 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 629 {
 630         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 631 }
 632
 633 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 634 {
 635         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 636 }
 637
 638 void free_refspec(int nr_refspec, struct refspec *refspec)
 639 {
 640         int i;
 641         for (i = 0; i < nr_refspec; i++) {
 642                 free(refspec[i].src);
 643                 free(refspec[i].dst);
 644         }
 645         free(refspec);
 646 }
 647
 648 static int valid_remote_nick(const char *name)
 649 {
 650         if (!name[0] || is_dot_or_dotdot(name))
 651                 return 0;
 652         return !strchr(name, '/'); /* no slash */
 653 }
 654
 655 const char *remote_for_branch(struct branch *branch, int *explicit)
 656 {
 657         if (branch && branch->remote_name) {
 658                 if (explicit)
 659                         *explicit = 1;
 660                 return branch->remote_name;
 661         }
 662         if (explicit)
 663                 *explicit = 0;
 664         return "origin";
 665 }
 666
 667 const char *pushremote_for_branch(struct branch *branch, int *explicit)
 668 {
 669         if (branch && branch->pushremote_name) {
 670                 if (explicit)
 671                         *explicit = 1;
 672                 return branch->pushremote_name;
 673         }
 674         if (pushremote_name) {
 675                 if (explicit)
 676                         *explicit = 1;
 677                 return pushremote_name;
 678         }
 679         return remote_for_branch(branch, explicit);
 680 }
 681
 682 static struct remote *remote_get_1(const char *name,
 683                                    const char *(*get_default)(struct branch *, int *))
 684 {
 685         struct remote *ret;
 686         int name_given = 0;
 687
 688         read_config();
 689
 690         if (name)
 691                 name_given = 1;
 692         else
 693                 name = get_default(current_branch, &name_given);
 694
 695         ret = make_remote(name, 0);
 696         if (valid_remote_nick(name)) {
 697                 if (!valid_remote(ret))
 698                         read_remotes_file(ret);
 699                 if (!valid_remote(ret))
 700                         read_branches_file(ret);
 701         }
 702         if (name_given && !valid_remote(ret))
 703                 add_url_alias(ret, name);
 704         if (!valid_remote(ret))
 705                 return NULL;
 706         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 707         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 708         return ret;
 709 }
 710
 711 struct remote *remote_get(const char *name)
 712 {
 713         return remote_get_1(name, remote_for_branch);
 714 }
 715
 716 struct remote *pushremote_get(const char *name)
 717 {
 718         return remote_get_1(name, pushremote_for_branch);
 719 }
 720
 721 int remote_is_configured(const char *name)
 722 {
 723         struct remotes_hash_key lookup;
 724         struct hashmap_entry lookup_entry;
 725         read_config();
 726
 727         init_remotes_hash();
 728         lookup.str = name;
 729         lookup.len = strlen(name);
 730         hashmap_entry_init(&lookup_entry, memhash(name, lookup.len));
 731
 732         return hashmap_get(&remotes_hash, &lookup_entry, &lookup) != NULL;
 733 }
 734
 735 int for_each_remote(each_remote_fn fn, void *priv)
 736 {
 737         int i, result = 0;
 738         read_config();
 739         for (i = 0; i < remotes_nr && !result; i++) {
 740                 struct remote *r = remotes[i];
 741                 if (!r)
 742                         continue;
 743                 if (!r->fetch)
 744                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 745                                                        r->fetch_refspec);
 746                 if (!r->push)
 747                         r->push = parse_push_refspec(r->push_refspec_nr,
 748                                                      r->push_refspec);
 749                 result = fn(r, priv);
 750         }
 751         return result;
 752 }
 753
 754 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 755 {
 756         if (strcmp(ref1->name, ref2->name)) {
 757                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 758                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 759                         die(_("Cannot fetch both %s and %s to %s"),
 760                             ref1->name, ref2->name, ref2->peer_ref->name);
 761                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 762                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 763                         warning(_("%s usually tracks %s, not %s"),
 764                                 ref2->peer_ref->name, ref2->name, ref1->name);
 765                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 766                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 767                         die(_("%s tracks both %s and %s"),
 768                             ref2->peer_ref->name, ref1->name, ref2->name);
 769                 } else {
 770                         /*
 771                          * This last possibility doesn't occur because
 772                          * FETCH_HEAD_IGNORE entries always appear at
 773                          * the end of the list.
 774                          */
 775                         die(_("Internal error"));
 776                 }
 777         }
 778         free(ref2->peer_ref);
 779         free(ref2);
 780 }
 781
 782 struct ref *ref_remove_duplicates(struct ref *ref_map)
 783 {
 784         struct string_list refs = STRING_LIST_INIT_NODUP;
 785         struct ref *retval = NULL;
 786         struct ref **p = &retval;
 787
 788         while (ref_map) {
 789                 struct ref *ref = ref_map;
 790
 791                 ref_map = ref_map->next;
 792                 ref->next = NULL;
 793
 794                 if (!ref->peer_ref) {
 795                         *p = ref;
 796                         p = &ref->next;
 797                 } else {
 798                         struct string_list_item *item =
 799                                 string_list_insert(&refs, ref->peer_ref->name);
 800
 801                         if (item->util) {
 802                                 /* Entry already existed */
 803                                 handle_duplicate((struct ref *)item->util, ref);
 804                         } else {
 805                                 *p = ref;
 806                                 p = &ref->next;
 807                                 item->util = ref;
 808                         }
 809                 }
 810         }
 811
 812         string_list_clear(&refs, 0);
 813         return retval;
 814 }
 815
 816 int remote_has_url(struct remote *remote, const char *url)
 817 {
 818         int i;
 819         for (i = 0; i < remote->url_nr; i++) {
 820                 if (!strcmp(remote->url[i], url))
 821                         return 1;
 822         }
 823         return 0;
 824 }
 825
 826 static int match_name_with_pattern(const char *key, const char *name,
 827                                    const char *value, char **result)
 828 {
 829         const char *kstar = strchr(key, '*');
 830         size_t klen;
 831         size_t ksuffixlen;
 832         size_t namelen;
 833         int ret;
 834         if (!kstar)
 835                 die("Key '%s' of pattern had no '*'", key);
 836         klen = kstar - key;
 837         ksuffixlen = strlen(kstar + 1);
 838         namelen = strlen(name);
 839         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 840                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 841         if (ret && value) {
 842                 struct strbuf sb = STRBUF_INIT;
 843                 const char *vstar = strchr(value, '*');
 844                 if (!vstar)
 845                         die("Value '%s' of pattern has no '*'", value);
 846                 strbuf_add(&sb, value, vstar - value);
 847                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 848                 strbuf_addstr(&sb, vstar + 1);
 849                 *result = strbuf_detach(&sb, NULL);
 850         }
 851         return ret;
 852 }
 853
 854 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 855 {
 856         int i;
 857         int find_src = !query->src;
 858
 859         if (find_src && !query->dst)
 860                 error("query_refspecs_multiple: need either src or dst");
 861
 862         for (i = 0; i < ref_count; i++) {
 863                 struct refspec *refspec = &refs[i];
 864                 const char *key = find_src ? refspec->dst : refspec->src;
 865                 const char *value = find_src ? refspec->src : refspec->dst;
 866                 const char *needle = find_src ? query->dst : query->src;
 867                 char **result = find_src ? &query->src : &query->dst;
 868
 869                 if (!refspec->dst)
 870                         continue;
 871                 if (refspec->pattern) {
 872                         if (match_name_with_pattern(key, needle, value, result))
 873                                 string_list_append_nodup(results, *result);
 874                 } else if (!strcmp(needle, key)) {
 875                         string_list_append(results, value);
 876                 }
 877         }
 878 }
 879
 880 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 881 {
 882         int i;
 883         int find_src = !query->src;
 884         const char *needle = find_src ? query->dst : query->src;
 885         char **result = find_src ? &query->src : &query->dst;
 886
 887         if (find_src && !query->dst)
 888                 return error("query_refspecs: need either src or dst");
 889
 890         for (i = 0; i < ref_count; i++) {
 891                 struct refspec *refspec = &refs[i];
 892                 const char *key = find_src ? refspec->dst : refspec->src;
 893                 const char *value = find_src ? refspec->src : refspec->dst;
 894
 895                 if (!refspec->dst)
 896                         continue;
 897                 if (refspec->pattern) {
 898                         if (match_name_with_pattern(key, needle, value, result)) {
 899                                 query->force = refspec->force;
 900                                 return 0;
 901                         }
 902                 } else if (!strcmp(needle, key)) {
 903                         *result = xstrdup(value);
 904                         query->force = refspec->force;
 905                         return 0;
 906                 }
 907         }
 908         return -1;
 909 }
 910
 911 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 912                      const char *name)
 913 {
 914         struct refspec query;
 915
 916         memset(&query, 0, sizeof(struct refspec));
 917         query.src = (char *)name;
 918
 919         if (query_refspecs(refspecs, nr_refspec, &query))
 920                 return NULL;
 921
 922         return query.dst;
 923 }
 924
 925 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 926 {
 927         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 928 }
 929
 930 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 931                 const char *name)
 932 {
 933         size_t len = strlen(name);
 934         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 935         memcpy(ref->name, prefix, prefixlen);
 936         memcpy(ref->name + prefixlen, name, len);
 937         return ref;
 938 }
 939
 940 struct ref *alloc_ref(const char *name)
 941 {
 942         return alloc_ref_with_prefix("", 0, name);
 943 }
 944
 945 struct ref *copy_ref(const struct ref *ref)
 946 {
 947         struct ref *cpy;
 948         size_t len;
 949         if (!ref)
 950                 return NULL;
 951         len = strlen(ref->name);
 952         cpy = xmalloc(sizeof(struct ref) + len + 1);
 953         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 954         cpy->next = NULL;
 955         cpy->symref = xstrdup_or_null(ref->symref);
 956         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 957         cpy->peer_ref = copy_ref(ref->peer_ref);
 958         return cpy;
 959 }
 960
 961 struct ref *copy_ref_list(const struct ref *ref)
 962 {
 963         struct ref *ret = NULL;
 964         struct ref **tail = &ret;
 965         while (ref) {
 966                 *tail = copy_ref(ref);
 967                 ref = ref->next;
 968                 tail = &((*tail)->next);
 969         }
 970         return ret;
 971 }
 972
 973 static void free_ref(struct ref *ref)
 974 {
 975         if (!ref)
 976                 return;
 977         free_ref(ref->peer_ref);
 978         free(ref->remote_status);
 979         free(ref->symref);
 980         free(ref);
 981 }
 982
 983 void free_refs(struct ref *ref)
 984 {
 985         struct ref *next;
 986         while (ref) {
 987                 next = ref->next;
 988                 free_ref(ref);
 989                 ref = next;
 990         }
 991 }
 992
 993 int ref_compare_name(const void *va, const void *vb)
 994 {
 995         const struct ref *a = va, *b = vb;
 996         return strcmp(a->name, b->name);
 997 }
 998
 999 static void *ref_list_get_next(const void *a)
1000 {
1001         return ((const struct ref *)a)->next;
1002 }
1003
1004 static void ref_list_set_next(void *a, void *next)
1005 {
1006         ((struct ref *)a)->next = next;
1007 }
1008
1009 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1010 {
1011         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1012 }
1013
1014 int count_refspec_match(const char *pattern,
1015                         struct ref *refs,
1016                         struct ref **matched_ref)
1017 {
1018         int patlen = strlen(pattern);
1019         struct ref *matched_weak = NULL;
1020         struct ref *matched = NULL;
1021         int weak_match = 0;
1022         int match = 0;
1023
1024         for (weak_match = match = 0; refs; refs = refs->next) {
1025                 char *name = refs->name;
1026                 int namelen = strlen(name);
1027
1028                 if (!refname_match(pattern, name))
1029                         continue;
1030
1031                 /* A match is "weak" if it is with refs outside
1032                  * heads or tags, and did not specify the pattern
1033                  * in full (e.g. "refs/remotes/origin/master") or at
1034                  * least from the toplevel (e.g. "remotes/origin/master");
1035                  * otherwise "git push $URL master" would result in
1036                  * ambiguity between remotes/origin/master and heads/master
1037                  * at the remote site.
1038                  */
1039                 if (namelen != patlen &&
1040                     patlen != namelen - 5 &&
1041                     !starts_with(name, "refs/heads/") &&
1042                     !starts_with(name, "refs/tags/")) {
1043                         /* We want to catch the case where only weak
1044                          * matches are found and there are multiple
1045                          * matches, and where more than one strong
1046                          * matches are found, as ambiguous.  One
1047                          * strong match with zero or more weak matches
1048                          * are acceptable as a unique match.
1049                          */
1050                         matched_weak = refs;
1051                         weak_match++;
1052                 }
1053                 else {
1054                         matched = refs;
1055                         match++;
1056                 }
1057         }
1058         if (!matched) {
1059                 if (matched_ref)
1060                         *matched_ref = matched_weak;
1061                 return weak_match;
1062         }
1063         else {
1064                 if (matched_ref)
1065                         *matched_ref = matched;
1066                 return match;
1067         }
1068 }
1069
1070 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1071 {
1072         **tail = ref;
1073         while (ref->next)
1074                 ref = ref->next;
1075         *tail = &ref->next;
1076 }
1077
1078 static struct ref *alloc_delete_ref(void)
1079 {
1080         struct ref *ref = alloc_ref("(delete)");
1081         oidclr(&ref->new_oid);
1082         return ref;
1083 }
1084
1085 static int try_explicit_object_name(const char *name,
1086                                     struct ref **match)
1087 {
1088         struct object_id oid;
1089
1090         if (!*name) {
1091                 if (match)
1092                         *match = alloc_delete_ref();
1093                 return 0;
1094         }
1095
1096         if (get_sha1(name, oid.hash))
1097                 return -1;
1098
1099         if (match) {
1100                 *match = alloc_ref(name);
1101                 oidcpy(&(*match)->new_oid, &oid);
1102         }
1103         return 0;
1104 }
1105
1106 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1107 {
1108         struct ref *ret = alloc_ref(name);
1109         tail_link_ref(ret, tail);
1110         return ret;
1111 }
1112
1113 static char *guess_ref(const char *name, struct ref *peer)
1114 {
1115         struct strbuf buf = STRBUF_INIT;
1116         struct object_id oid;
1117
1118         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1119                                            oid.hash, NULL);
1120         if (!r)
1121                 return NULL;
1122
1123         if (starts_with(r, "refs/heads/"))
1124                 strbuf_addstr(&buf, "refs/heads/");
1125         else if (starts_with(r, "refs/tags/"))
1126                 strbuf_addstr(&buf, "refs/tags/");
1127         else
1128                 return NULL;
1129
1130         strbuf_addstr(&buf, name);
1131         return strbuf_detach(&buf, NULL);
1132 }
1133
1134 static int match_explicit_lhs(struct ref *src,
1135                               struct refspec *rs,
1136                               struct ref **match,
1137                               int *allocated_match)
1138 {
1139         switch (count_refspec_match(rs->src, src, match)) {
1140         case 1:
1141                 if (allocated_match)
1142                         *allocated_match = 0;
1143                 return 0;
1144         case 0:
1145                 /* The source could be in the get_sha1() format
1146                  * not a reference name.  :refs/other is a
1147                  * way to delete 'other' ref at the remote end.
1148                  */
1149                 if (try_explicit_object_name(rs->src, match) < 0)
1150                         return error("src refspec %s does not match any.", rs->src);
1151                 if (allocated_match)
1152                         *allocated_match = 1;
1153                 return 0;
1154         default:
1155                 return error("src refspec %s matches more than one.", rs->src);
1156         }
1157 }
1158
1159 static int match_explicit(struct ref *src, struct ref *dst,
1160                           struct ref ***dst_tail,
1161                           struct refspec *rs)
1162 {
1163         struct ref *matched_src, *matched_dst;
1164         int allocated_src;
1165
1166         const char *dst_value = rs->dst;
1167         char *dst_guess;
1168
1169         if (rs->pattern || rs->matching)
1170                 return 0;
1171
1172         matched_src = matched_dst = NULL;
1173         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1174                 return -1;
1175
1176         if (!dst_value) {
1177                 struct object_id oid;
1178                 int flag;
1179
1180                 dst_value = resolve_ref_unsafe(matched_src->name,
1181                                                RESOLVE_REF_READING,
1182                                                oid.hash, &flag);
1183                 if (!dst_value ||
1184                     ((flag & REF_ISSYMREF) &&
1185                      !starts_with(dst_value, "refs/heads/")))
1186                         die("%s cannot be resolved to branch.",
1187                             matched_src->name);
1188         }
1189
1190         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1191         case 1:
1192                 break;
1193         case 0:
1194                 if (starts_with(dst_value, "refs/"))
1195                         matched_dst = make_linked_ref(dst_value, dst_tail);
1196                 else if (is_null_oid(&matched_src->new_oid))
1197                         error("unable to delete '%s': remote ref does not exist",
1198                               dst_value);
1199                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1200                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1201                 else
1202                         error("unable to push to unqualified destination: %s\n"
1203                               "The destination refspec neither matches an "
1204                               "existing ref on the remote nor\n"
1205                               "begins with refs/, and we are unable to "
1206                               "guess a prefix based on the source ref.",
1207                               dst_value);
1208                 break;
1209         default:
1210                 matched_dst = NULL;
1211                 error("dst refspec %s matches more than one.",
1212                       dst_value);
1213                 break;
1214         }
1215         if (!matched_dst)
1216                 return -1;
1217         if (matched_dst->peer_ref)
1218                 return error("dst ref %s receives from more than one src.",
1219                       matched_dst->name);
1220         else {
1221                 matched_dst->peer_ref = allocated_src ?
1222                                         matched_src :
1223                                         copy_ref(matched_src);
1224                 matched_dst->force = rs->force;
1225         }
1226         return 0;
1227 }
1228
1229 static int match_explicit_refs(struct ref *src, struct ref *dst,
1230                                struct ref ***dst_tail, struct refspec *rs,
1231                                int rs_nr)
1232 {
1233         int i, errs;
1234         for (i = errs = 0; i < rs_nr; i++)
1235                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1236         return errs;
1237 }
1238
1239 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1240                 int send_mirror, int direction, const struct refspec **ret_pat)
1241 {
1242         const struct refspec *pat;
1243         char *name;
1244         int i;
1245         int matching_refs = -1;
1246         for (i = 0; i < rs_nr; i++) {
1247                 if (rs[i].matching &&
1248                     (matching_refs == -1 || rs[i].force)) {
1249                         matching_refs = i;
1250                         continue;
1251                 }
1252
1253                 if (rs[i].pattern) {
1254                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1255                         int match;
1256                         if (direction == FROM_SRC)
1257                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1258                         else
1259                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1260                         if (match) {
1261                                 matching_refs = i;
1262                                 break;
1263                         }
1264                 }
1265         }
1266         if (matching_refs == -1)
1267                 return NULL;
1268
1269         pat = rs + matching_refs;
1270         if (pat->matching) {
1271                 /*
1272                  * "matching refs"; traditionally we pushed everything
1273                  * including refs outside refs/heads/ hierarchy, but
1274                  * that does not make much sense these days.
1275                  */
1276                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1277                         return NULL;
1278                 name = xstrdup(ref->name);
1279         }
1280         if (ret_pat)
1281                 *ret_pat = pat;
1282         return name;
1283 }
1284
1285 static struct ref **tail_ref(struct ref **head)
1286 {
1287         struct ref **tail = head;
1288         while (*tail)
1289                 tail = &((*tail)->next);
1290         return tail;
1291 }
1292
1293 struct tips {
1294         struct commit **tip;
1295         int nr, alloc;
1296 };
1297
1298 static void add_to_tips(struct tips *tips, const struct object_id *oid)
1299 {
1300         struct commit *commit;
1301
1302         if (is_null_oid(oid))
1303                 return;
1304         commit = lookup_commit_reference_gently(oid->hash, 1);
1305         if (!commit || (commit->object.flags & TMP_MARK))
1306                 return;
1307         commit->object.flags |= TMP_MARK;
1308         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1309         tips->tip[tips->nr++] = commit;
1310 }
1311
1312 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1313 {
1314         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1315         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1316         struct string_list_item *item;
1317         struct ref *ref;
1318         struct tips sent_tips;
1319
1320         /*
1321          * Collect everything we know they would have at the end of
1322          * this push, and collect all tags they have.
1323          */
1324         memset(&sent_tips, 0, sizeof(sent_tips));
1325         for (ref = *dst; ref; ref = ref->next) {
1326                 if (ref->peer_ref &&
1327                     !is_null_oid(&ref->peer_ref->new_oid))
1328                         add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1329                 else
1330                         add_to_tips(&sent_tips, &ref->old_oid);
1331                 if (starts_with(ref->name, "refs/tags/"))
1332                         string_list_append(&dst_tag, ref->name);
1333         }
1334         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1335
1336         string_list_sort(&dst_tag);
1337
1338         /* Collect tags they do not have. */
1339         for (ref = src; ref; ref = ref->next) {
1340                 if (!starts_with(ref->name, "refs/tags/"))
1341                         continue; /* not a tag */
1342                 if (string_list_has_string(&dst_tag, ref->name))
1343                         continue; /* they already have it */
1344                 if (sha1_object_info(ref->new_oid.hash, NULL) != OBJ_TAG)
1345                         continue; /* be conservative */
1346                 item = string_list_append(&src_tag, ref->name);
1347                 item->util = ref;
1348         }
1349         string_list_clear(&dst_tag, 0);
1350
1351         /*
1352          * At this point, src_tag lists tags that are missing from
1353          * dst, and sent_tips lists the tips we are pushing or those
1354          * that we know they already have. An element in the src_tag
1355          * that is an ancestor of any of the sent_tips needs to be
1356          * sent to the other side.
1357          */
1358         if (sent_tips.nr) {
1359                 for_each_string_list_item(item, &src_tag) {
1360                         struct ref *ref = item->util;
1361                         struct ref *dst_ref;
1362                         struct commit *commit;
1363
1364                         if (is_null_oid(&ref->new_oid))
1365                                 continue;
1366                         commit = lookup_commit_reference_gently(ref->new_oid.hash, 1);
1367                         if (!commit)
1368                                 /* not pushing a commit, which is not an error */
1369                                 continue;
1370
1371                         /*
1372                          * Is this tag, which they do not have, reachable from
1373                          * any of the commits we are sending?
1374                          */
1375                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1376                                 continue;
1377
1378                         /* Add it in */
1379                         dst_ref = make_linked_ref(ref->name, dst_tail);
1380                         oidcpy(&dst_ref->new_oid, &ref->new_oid);
1381                         dst_ref->peer_ref = copy_ref(ref);
1382                 }
1383         }
1384         string_list_clear(&src_tag, 0);
1385         free(sent_tips.tip);
1386 }
1387
1388 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1389 {
1390         for ( ; list; list = list->next)
1391                 if (!strcmp(list->name, name))
1392                         return (struct ref *)list;
1393         return NULL;
1394 }
1395
1396 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1397 {
1398         for ( ; ref; ref = ref->next)
1399                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1400
1401         string_list_sort(ref_index);
1402 }
1403
1404 /*
1405  * Given only the set of local refs, sanity-check the set of push
1406  * refspecs. We can't catch all errors that match_push_refs would,
1407  * but we can catch some errors early before even talking to the
1408  * remote side.
1409  */
1410 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1411 {
1412         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1413         int ret = 0;
1414         int i;
1415
1416         for (i = 0; i < nr_refspec; i++) {
1417                 struct refspec *rs = refspec + i;
1418
1419                 if (rs->pattern || rs->matching)
1420                         continue;
1421
1422                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1423         }
1424
1425         free_refspec(nr_refspec, refspec);
1426         return ret;
1427 }
1428
1429 /*
1430  * Given the set of refs the local repository has, the set of refs the
1431  * remote repository has, and the refspec used for push, determine
1432  * what remote refs we will update and with what value by setting
1433  * peer_ref (which object is being pushed) and force (if the push is
1434  * forced) in elements of "dst". The function may add new elements to
1435  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1436  */
1437 int match_push_refs(struct ref *src, struct ref **dst,
1438                     int nr_refspec, const char **refspec, int flags)
1439 {
1440         struct refspec *rs;
1441         int send_all = flags & MATCH_REFS_ALL;
1442         int send_mirror = flags & MATCH_REFS_MIRROR;
1443         int send_prune = flags & MATCH_REFS_PRUNE;
1444         int errs;
1445         static const char *default_refspec[] = { ":", NULL };
1446         struct ref *ref, **dst_tail = tail_ref(dst);
1447         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1448
1449         if (!nr_refspec) {
1450                 nr_refspec = 1;
1451                 refspec = default_refspec;
1452         }
1453         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1454         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1455
1456         /* pick the remainder */
1457         for (ref = src; ref; ref = ref->next) {
1458                 struct string_list_item *dst_item;
1459                 struct ref *dst_peer;
1460                 const struct refspec *pat = NULL;
1461                 char *dst_name;
1462
1463                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1464                 if (!dst_name)
1465                         continue;
1466
1467                 if (!dst_ref_index.nr)
1468                         prepare_ref_index(&dst_ref_index, *dst);
1469
1470                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1471                 dst_peer = dst_item ? dst_item->util : NULL;
1472                 if (dst_peer) {
1473                         if (dst_peer->peer_ref)
1474                                 /* We're already sending something to this ref. */
1475                                 goto free_name;
1476                 } else {
1477                         if (pat->matching && !(send_all || send_mirror))
1478                                 /*
1479                                  * Remote doesn't have it, and we have no
1480                                  * explicit pattern, and we don't have
1481                                  * --all or --mirror.
1482                                  */
1483                                 goto free_name;
1484
1485                         /* Create a new one and link it */
1486                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1487                         oidcpy(&dst_peer->new_oid, &ref->new_oid);
1488                         string_list_insert(&dst_ref_index,
1489                                 dst_peer->name)->util = dst_peer;
1490                 }
1491                 dst_peer->peer_ref = copy_ref(ref);
1492                 dst_peer->force = pat->force;
1493         free_name:
1494                 free(dst_name);
1495         }
1496
1497         string_list_clear(&dst_ref_index, 0);
1498
1499         if (flags & MATCH_REFS_FOLLOW_TAGS)
1500                 add_missing_tags(src, dst, &dst_tail);
1501
1502         if (send_prune) {
1503                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1504                 /* check for missing refs on the remote */
1505                 for (ref = *dst; ref; ref = ref->next) {
1506                         char *src_name;
1507
1508                         if (ref->peer_ref)
1509                                 /* We're already sending something to this ref. */
1510                                 continue;
1511
1512                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1513                         if (src_name) {
1514                                 if (!src_ref_index.nr)
1515                                         prepare_ref_index(&src_ref_index, src);
1516                                 if (!string_list_has_string(&src_ref_index,
1517                                             src_name))
1518                                         ref->peer_ref = alloc_delete_ref();
1519                                 free(src_name);
1520                         }
1521                 }
1522                 string_list_clear(&src_ref_index, 0);
1523         }
1524         if (errs)
1525                 return -1;
1526         return 0;
1527 }
1528
1529 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1530                              int force_update)
1531 {
1532         struct ref *ref;
1533
1534         for (ref = remote_refs; ref; ref = ref->next) {
1535                 int force_ref_update = ref->force || force_update;
1536                 int reject_reason = 0;
1537
1538                 if (ref->peer_ref)
1539                         oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1540                 else if (!send_mirror)
1541                         continue;
1542
1543                 ref->deletion = is_null_oid(&ref->new_oid);
1544                 if (!ref->deletion &&
1545                         !oidcmp(&ref->old_oid, &ref->new_oid)) {
1546                         ref->status = REF_STATUS_UPTODATE;
1547                         continue;
1548                 }
1549
1550                 /*
1551                  * Bypass the usual "must fast-forward" check but
1552                  * replace it with a weaker "the old value must be
1553                  * this value we observed".  If the remote ref has
1554                  * moved and is now different from what we expect,
1555                  * reject any push.
1556                  *
1557                  * It also is an error if the user told us to check
1558                  * with the remote-tracking branch to find the value
1559                  * to expect, but we did not have such a tracking
1560                  * branch.
1561                  */
1562                 if (ref->expect_old_sha1) {
1563                         if (ref->expect_old_no_trackback ||
1564                             oidcmp(&ref->old_oid, &ref->old_oid_expect))
1565                                 reject_reason = REF_STATUS_REJECT_STALE;
1566                 }
1567
1568                 /*
1569                  * The usual "must fast-forward" rules.
1570                  *
1571                  * Decide whether an individual refspec A:B can be
1572                  * pushed.  The push will succeed if any of the
1573                  * following are true:
1574                  *
1575                  * (1) the remote reference B does not exist
1576                  *
1577                  * (2) the remote reference B is being removed (i.e.,
1578                  *     pushing :B where no source is specified)
1579                  *
1580                  * (3) the destination is not under refs/tags/, and
1581                  *     if the old and new value is a commit, the new
1582                  *     is a descendant of the old.
1583                  *
1584                  * (4) it is forced using the +A:B notation, or by
1585                  *     passing the --force argument
1586                  */
1587
1588                 else if (!ref->deletion && !is_null_oid(&ref->old_oid)) {
1589                         if (starts_with(ref->name, "refs/tags/"))
1590                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1591                         else if (!has_object_file(&ref->old_oid))
1592                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1593                         else if (!lookup_commit_reference_gently(ref->old_oid.hash, 1) ||
1594                                  !lookup_commit_reference_gently(ref->new_oid.hash, 1))
1595                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1596                         else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1597                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1598                 }
1599
1600                 /*
1601                  * "--force" will defeat any rejection implemented
1602                  * by the rules above.
1603                  */
1604                 if (!force_ref_update)
1605                         ref->status = reject_reason;
1606                 else if (reject_reason)
1607                         ref->forced_update = 1;
1608         }
1609 }
1610
1611 static void set_merge(struct branch *ret)
1612 {
1613         struct remote *remote;
1614         char *ref;
1615         struct object_id oid;
1616         int i;
1617
1618         if (!ret)
1619                 return; /* no branch */
1620         if (ret->merge)
1621                 return; /* already run */
1622         if (!ret->remote_name || !ret->merge_nr) {
1623                 /*
1624                  * no merge config; let's make sure we don't confuse callers
1625                  * with a non-zero merge_nr but a NULL merge
1626                  */
1627                 ret->merge_nr = 0;
1628                 return;
1629         }
1630
1631         remote = remote_get(ret->remote_name);
1632
1633         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1634         for (i = 0; i < ret->merge_nr; i++) {
1635                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1636                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1637                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1638                     strcmp(ret->remote_name, "."))
1639                         continue;
1640                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1641                              oid.hash, &ref) == 1)
1642                         ret->merge[i]->dst = ref;
1643                 else
1644                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1645         }
1646 }
1647
1648 struct branch *branch_get(const char *name)
1649 {
1650         struct branch *ret;
1651
1652         read_config();
1653         if (!name || !*name || !strcmp(name, "HEAD"))
1654                 ret = current_branch;
1655         else
1656                 ret = make_branch(name, 0);
1657         set_merge(ret);
1658         return ret;
1659 }
1660
1661 int branch_has_merge_config(struct branch *branch)
1662 {
1663         return branch && !!branch->merge;
1664 }
1665
1666 int branch_merge_matches(struct branch *branch,
1667                                  int i,
1668                                  const char *refname)
1669 {
1670         if (!branch || i < 0 || i >= branch->merge_nr)
1671                 return 0;
1672         return refname_match(branch->merge[i]->src, refname);
1673 }
1674
1675 __attribute((format (printf,2,3)))
1676 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1677 {
1678         if (err) {
1679                 va_list ap;
1680                 va_start(ap, fmt);
1681                 strbuf_vaddf(err, fmt, ap);
1682                 va_end(ap);
1683         }
1684         return NULL;
1685 }
1686
1687 const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1688 {
1689         if (!branch)
1690                 return error_buf(err, _("HEAD does not point to a branch"));
1691
1692         if (!branch->merge || !branch->merge[0]) {
1693                 /*
1694                  * no merge config; is it because the user didn't define any,
1695                  * or because it is not a real branch, and get_branch
1696                  * auto-vivified it?
1697                  */
1698                 if (!ref_exists(branch->refname))
1699                         return error_buf(err, _("no such branch: '%s'"),
1700                                          branch->name);
1701                 return error_buf(err,
1702                                  _("no upstream configured for branch '%s'"),
1703                                  branch->name);
1704         }
1705
1706         if (!branch->merge[0]->dst)
1707                 return error_buf(err,
1708                                  _("upstream branch '%s' not stored as a remote-tracking branch"),
1709                                  branch->merge[0]->src);
1710
1711         return branch->merge[0]->dst;
1712 }
1713
1714 static const char *tracking_for_push_dest(struct remote *remote,
1715                                           const char *refname,
1716                                           struct strbuf *err)
1717 {
1718         char *ret;
1719
1720         ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1721         if (!ret)
1722                 return error_buf(err,
1723                                  _("push destination '%s' on remote '%s' has no local tracking branch"),
1724                                  refname, remote->name);
1725         return ret;
1726 }
1727
1728 static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1729 {
1730         struct remote *remote;
1731
1732         if (!branch)
1733                 return error_buf(err, _("HEAD does not point to a branch"));
1734
1735         remote = remote_get(pushremote_for_branch(branch, NULL));
1736         if (!remote)
1737                 return error_buf(err,
1738                                  _("branch '%s' has no remote for pushing"),
1739                                  branch->name);
1740
1741         if (remote->push_refspec_nr) {
1742                 char *dst;
1743                 const char *ret;
1744
1745                 dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1746                                      branch->refname);
1747                 if (!dst)
1748                         return error_buf(err,
1749                                          _("push refspecs for '%s' do not include '%s'"),
1750                                          remote->name, branch->name);
1751
1752                 ret = tracking_for_push_dest(remote, dst, err);
1753                 free(dst);
1754                 return ret;
1755         }
1756
1757         if (remote->mirror)
1758                 return tracking_for_push_dest(remote, branch->refname, err);
1759
1760         switch (push_default) {
1761         case PUSH_DEFAULT_NOTHING:
1762                 return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1763
1764         case PUSH_DEFAULT_MATCHING:
1765         case PUSH_DEFAULT_CURRENT:
1766                 return tracking_for_push_dest(remote, branch->refname, err);
1767
1768         case PUSH_DEFAULT_UPSTREAM:
1769                 return branch_get_upstream(branch, err);
1770
1771         case PUSH_DEFAULT_UNSPECIFIED:
1772         case PUSH_DEFAULT_SIMPLE:
1773                 {
1774                         const char *up, *cur;
1775
1776                         up = branch_get_upstream(branch, err);
1777                         if (!up)
1778                                 return NULL;
1779                         cur = tracking_for_push_dest(remote, branch->refname, err);
1780                         if (!cur)
1781                                 return NULL;
1782                         if (strcmp(cur, up))
1783                                 return error_buf(err,
1784                                                  _("cannot resolve 'simple' push to a single destination"));
1785                         return cur;
1786                 }
1787         }
1788
1789         die("BUG: unhandled push situation");
1790 }
1791
1792 const char *branch_get_push(struct branch *branch, struct strbuf *err)
1793 {
1794         if (!branch->push_tracking_ref)
1795                 branch->push_tracking_ref = branch_get_push_1(branch, err);
1796         return branch->push_tracking_ref;
1797 }
1798
1799 static int ignore_symref_update(const char *refname)
1800 {
1801         struct object_id oid;
1802         int flag;
1803
1804         if (!resolve_ref_unsafe(refname, 0, oid.hash, &flag))
1805                 return 0; /* non-existing refs are OK */
1806         return (flag & REF_ISSYMREF);
1807 }
1808
1809 /*
1810  * Create and return a list of (struct ref) consisting of copies of
1811  * each remote_ref that matches refspec.  refspec must be a pattern.
1812  * Fill in the copies' peer_ref to describe the local tracking refs to
1813  * which they map.  Omit any references that would map to an existing
1814  * local symbolic ref.
1815  */
1816 static struct ref *get_expanded_map(const struct ref *remote_refs,
1817                                     const struct refspec *refspec)
1818 {
1819         const struct ref *ref;
1820         struct ref *ret = NULL;
1821         struct ref **tail = &ret;
1822
1823         for (ref = remote_refs; ref; ref = ref->next) {
1824                 char *expn_name = NULL;
1825
1826                 if (strchr(ref->name, '^'))
1827                         continue; /* a dereference item */
1828                 if (match_name_with_pattern(refspec->src, ref->name,
1829                                             refspec->dst, &expn_name) &&
1830                     !ignore_symref_update(expn_name)) {
1831                         struct ref *cpy = copy_ref(ref);
1832
1833                         cpy->peer_ref = alloc_ref(expn_name);
1834                         if (refspec->force)
1835                                 cpy->peer_ref->force = 1;
1836                         *tail = cpy;
1837                         tail = &cpy->next;
1838                 }
1839                 free(expn_name);
1840         }
1841
1842         return ret;
1843 }
1844
1845 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1846 {
1847         const struct ref *ref;
1848         for (ref = refs; ref; ref = ref->next) {
1849                 if (refname_match(name, ref->name))
1850                         return ref;
1851         }
1852         return NULL;
1853 }
1854
1855 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1856 {
1857         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1858
1859         if (!ref)
1860                 return NULL;
1861
1862         return copy_ref(ref);
1863 }
1864
1865 static struct ref *get_local_ref(const char *name)
1866 {
1867         if (!name || name[0] == '\0')
1868                 return NULL;
1869
1870         if (starts_with(name, "refs/"))
1871                 return alloc_ref(name);
1872
1873         if (starts_with(name, "heads/") ||
1874             starts_with(name, "tags/") ||
1875             starts_with(name, "remotes/"))
1876                 return alloc_ref_with_prefix("refs/", 5, name);
1877
1878         return alloc_ref_with_prefix("refs/heads/", 11, name);
1879 }
1880
1881 int get_fetch_map(const struct ref *remote_refs,
1882                   const struct refspec *refspec,
1883                   struct ref ***tail,
1884                   int missing_ok)
1885 {
1886         struct ref *ref_map, **rmp;
1887
1888         if (refspec->pattern) {
1889                 ref_map = get_expanded_map(remote_refs, refspec);
1890         } else {
1891                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1892
1893                 if (refspec->exact_sha1) {
1894                         ref_map = alloc_ref(name);
1895                         get_oid_hex(name, &ref_map->old_oid);
1896                 } else {
1897                         ref_map = get_remote_ref(remote_refs, name);
1898                 }
1899                 if (!missing_ok && !ref_map)
1900                         die("Couldn't find remote ref %s", name);
1901                 if (ref_map) {
1902                         ref_map->peer_ref = get_local_ref(refspec->dst);
1903                         if (ref_map->peer_ref && refspec->force)
1904                                 ref_map->peer_ref->force = 1;
1905                 }
1906         }
1907
1908         for (rmp = &ref_map; *rmp; ) {
1909                 if ((*rmp)->peer_ref) {
1910                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1911                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1912                                 struct ref *ignore = *rmp;
1913                                 error("* Ignoring funny ref '%s' locally",
1914                                       (*rmp)->peer_ref->name);
1915                                 *rmp = (*rmp)->next;
1916                                 free(ignore->peer_ref);
1917                                 free(ignore);
1918                                 continue;
1919                         }
1920                 }
1921                 rmp = &((*rmp)->next);
1922         }
1923
1924         if (ref_map)
1925                 tail_link_ref(ref_map, tail);
1926
1927         return 0;
1928 }
1929
1930 int resolve_remote_symref(struct ref *ref, struct ref *list)
1931 {
1932         if (!ref->symref)
1933                 return 0;
1934         for (; list; list = list->next)
1935                 if (!strcmp(ref->symref, list->name)) {
1936                         oidcpy(&ref->old_oid, &list->old_oid);
1937                         return 0;
1938                 }
1939         return 1;
1940 }
1941
1942 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1943 {
1944         while (list) {
1945                 struct commit *commit = pop_commit(&list);
1946                 commit->object.flags &= ~mark;
1947         }
1948 }
1949
1950 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1951 {
1952         struct object *o;
1953         struct commit *old, *new;
1954         struct commit_list *list, *used;
1955         int found = 0;
1956
1957         /*
1958          * Both new and old must be commit-ish and new is descendant of
1959          * old.  Otherwise we require --force.
1960          */
1961         o = deref_tag(parse_object(old_oid->hash), NULL, 0);
1962         if (!o || o->type != OBJ_COMMIT)
1963                 return 0;
1964         old = (struct commit *) o;
1965
1966         o = deref_tag(parse_object(new_oid->hash), NULL, 0);
1967         if (!o || o->type != OBJ_COMMIT)
1968                 return 0;
1969         new = (struct commit *) o;
1970
1971         if (parse_commit(new) < 0)
1972                 return 0;
1973
1974         used = list = NULL;
1975         commit_list_insert(new, &list);
1976         while (list) {
1977                 new = pop_most_recent_commit(&list, TMP_MARK);
1978                 commit_list_insert(new, &used);
1979                 if (new == old) {
1980                         found = 1;
1981                         break;
1982                 }
1983         }
1984         unmark_and_free(list, TMP_MARK);
1985         unmark_and_free(used, TMP_MARK);
1986         return found;
1987 }
1988
1989 /*
1990  * Compare a branch with its upstream, and save their differences (number
1991  * of commits) in *num_ours and *num_theirs. The name of the upstream branch
1992  * (or NULL if no upstream is defined) is returned via *upstream_name, if it
1993  * is not itself NULL.
1994  *
1995  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1996  * upstream defined, or ref does not exist), 0 otherwise.
1997  */
1998 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
1999                        const char **upstream_name)
2000 {
2001         struct object_id oid;
2002         struct commit *ours, *theirs;
2003         struct rev_info revs;
2004         const char *base;
2005         struct argv_array argv = ARGV_ARRAY_INIT;
2006
2007         /* Cannot stat unless we are marked to build on top of somebody else. */
2008         base = branch_get_upstream(branch, NULL);
2009         if (upstream_name)
2010                 *upstream_name = base;
2011         if (!base)
2012                 return -1;
2013
2014         /* Cannot stat if what we used to build on no longer exists */
2015         if (read_ref(base, oid.hash))
2016                 return -1;
2017         theirs = lookup_commit_reference(oid.hash);
2018         if (!theirs)
2019                 return -1;
2020
2021         if (read_ref(branch->refname, oid.hash))
2022                 return -1;
2023         ours = lookup_commit_reference(oid.hash);
2024         if (!ours)
2025                 return -1;
2026
2027         /* are we the same? */
2028         if (theirs == ours) {
2029                 *num_theirs = *num_ours = 0;
2030                 return 0;
2031         }
2032
2033         /* Run "rev-list --left-right ours...theirs" internally... */
2034         argv_array_push(&argv, ""); /* ignored */
2035         argv_array_push(&argv, "--left-right");
2036         argv_array_pushf(&argv, "%s...%s",
2037                          oid_to_hex(&ours->object.oid),
2038                          oid_to_hex(&theirs->object.oid));
2039         argv_array_push(&argv, "--");
2040
2041         init_revisions(&revs, NULL);
2042         setup_revisions(argv.argc, argv.argv, &revs, NULL);
2043         if (prepare_revision_walk(&revs))
2044                 die("revision walk setup failed");
2045
2046         /* ... and count the commits on each side. */
2047         *num_ours = 0;
2048         *num_theirs = 0;
2049         while (1) {
2050                 struct commit *c = get_revision(&revs);
2051                 if (!c)
2052                         break;
2053                 if (c->object.flags & SYMMETRIC_LEFT)
2054                         (*num_ours)++;
2055                 else
2056                         (*num_theirs)++;
2057         }
2058
2059         /* clear object flags smudged by the above traversal */
2060         clear_commit_marks(ours, ALL_REV_FLAGS);
2061         clear_commit_marks(theirs, ALL_REV_FLAGS);
2062
2063         argv_array_clear(&argv);
2064         return 0;
2065 }
2066
2067 /*
2068  * Return true when there is anything to report, otherwise false.
2069  */
2070 int format_tracking_info(struct branch *branch, struct strbuf *sb)
2071 {
2072         int ours, theirs;
2073         const char *full_base;
2074         char *base;
2075         int upstream_is_gone = 0;
2076
2077         if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2078                 if (!full_base)
2079                         return 0;
2080                 upstream_is_gone = 1;
2081         }
2082
2083         base = shorten_unambiguous_ref(full_base, 0);
2084         if (upstream_is_gone) {
2085                 strbuf_addf(sb,
2086                         _("Your branch is based on '%s', but the upstream is gone.\n"),
2087                         base);
2088                 if (advice_status_hints)
2089                         strbuf_addf(sb,
2090                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2091         } else if (!ours && !theirs) {
2092                 strbuf_addf(sb,
2093                         _("Your branch is up-to-date with '%s'.\n"),
2094                         base);
2095         } else if (!theirs) {
2096                 strbuf_addf(sb,
2097                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2098                            "Your branch is ahead of '%s' by %d commits.\n",
2099                            ours),
2100                         base, ours);
2101                 if (advice_status_hints)
2102                         strbuf_addf(sb,
2103                                 _("  (use \"git push\" to publish your local commits)\n"));
2104         } else if (!ours) {
2105                 strbuf_addf(sb,
2106                         Q_("Your branch is behind '%s' by %d commit, "
2107                                "and can be fast-forwarded.\n",
2108                            "Your branch is behind '%s' by %d commits, "
2109                                "and can be fast-forwarded.\n",
2110                            theirs),
2111                         base, theirs);
2112                 if (advice_status_hints)
2113                         strbuf_addf(sb,
2114                                 _("  (use \"git pull\" to update your local branch)\n"));
2115         } else {
2116                 strbuf_addf(sb,
2117                         Q_("Your branch and '%s' have diverged,\n"
2118                                "and have %d and %d different commit each, "
2119                                "respectively.\n",
2120                            "Your branch and '%s' have diverged,\n"
2121                                "and have %d and %d different commits each, "
2122                                "respectively.\n",
2123                            theirs),
2124                         base, ours, theirs);
2125                 if (advice_status_hints)
2126                         strbuf_addf(sb,
2127                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2128         }
2129         free(base);
2130         return 1;
2131 }
2132
2133 static int one_local_ref(const char *refname, const struct object_id *oid,
2134                          int flag, void *cb_data)
2135 {
2136         struct ref ***local_tail = cb_data;
2137         struct ref *ref;
2138         int len;
2139
2140         /* we already know it starts with refs/ to get here */
2141         if (check_refname_format(refname + 5, 0))
2142                 return 0;
2143
2144         len = strlen(refname) + 1;
2145         ref = xcalloc(1, sizeof(*ref) + len);
2146         oidcpy(&ref->new_oid, oid);
2147         memcpy(ref->name, refname, len);
2148         **local_tail = ref;
2149         *local_tail = &ref->next;
2150         return 0;
2151 }
2152
2153 struct ref *get_local_heads(void)
2154 {
2155         struct ref *local_refs = NULL, **local_tail = &local_refs;
2156
2157         for_each_ref(one_local_ref, &local_tail);
2158         return local_refs;
2159 }
2160
2161 struct ref *guess_remote_head(const struct ref *head,
2162                               const struct ref *refs,
2163                               int all)
2164 {
2165         const struct ref *r;
2166         struct ref *list = NULL;
2167         struct ref **tail = &list;
2168
2169         if (!head)
2170                 return NULL;
2171
2172         /*
2173          * Some transports support directly peeking at
2174          * where HEAD points; if that is the case, then
2175          * we don't have to guess.
2176          */
2177         if (head->symref)
2178                 return copy_ref(find_ref_by_name(refs, head->symref));
2179
2180         /* If refs/heads/master could be right, it is. */
2181         if (!all) {
2182                 r = find_ref_by_name(refs, "refs/heads/master");
2183                 if (r && !oidcmp(&r->old_oid, &head->old_oid))
2184                         return copy_ref(r);
2185         }
2186
2187         /* Look for another ref that points there */
2188         for (r = refs; r; r = r->next) {
2189                 if (r != head &&
2190                     starts_with(r->name, "refs/heads/") &&
2191                     !oidcmp(&r->old_oid, &head->old_oid)) {
2192                         *tail = copy_ref(r);
2193                         tail = &((*tail)->next);
2194                         if (!all)
2195                                 break;
2196                 }
2197         }
2198
2199         return list;
2200 }
2201
2202 struct stale_heads_info {
2203         struct string_list *ref_names;
2204         struct ref **stale_refs_tail;
2205         struct refspec *refs;
2206         int ref_count;
2207 };
2208
2209 static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2210                               int flags, void *cb_data)
2211 {
2212         struct stale_heads_info *info = cb_data;
2213         struct string_list matches = STRING_LIST_INIT_DUP;
2214         struct refspec query;
2215         int i, stale = 1;
2216         memset(&query, 0, sizeof(struct refspec));
2217         query.dst = (char *)refname;
2218
2219         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2220         if (matches.nr == 0)
2221                 goto clean_exit; /* No matches */
2222
2223         /*
2224          * If we did find a suitable refspec and it's not a symref and
2225          * it's not in the list of refs that currently exist in that
2226          * remote, we consider it to be stale. In order to deal with
2227          * overlapping refspecs, we need to go over all of the
2228          * matching refs.
2229          */
2230         if (flags & REF_ISSYMREF)
2231                 goto clean_exit;
2232
2233         for (i = 0; stale && i < matches.nr; i++)
2234                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2235                         stale = 0;
2236
2237         if (stale) {
2238                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2239                 oidcpy(&ref->new_oid, oid);
2240         }
2241
2242 clean_exit:
2243         string_list_clear(&matches, 0);
2244         return 0;
2245 }
2246
2247 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2248 {
2249         struct ref *ref, *stale_refs = NULL;
2250         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2251         struct stale_heads_info info;
2252
2253         info.ref_names = &ref_names;
2254         info.stale_refs_tail = &stale_refs;
2255         info.refs = refs;
2256         info.ref_count = ref_count;
2257         for (ref = fetch_map; ref; ref = ref->next)
2258                 string_list_append(&ref_names, ref->name);
2259         string_list_sort(&ref_names);
2260         for_each_ref(get_stale_heads_cb, &info);
2261         string_list_clear(&ref_names, 0);
2262         return stale_refs;
2263 }
2264
2265 /*
2266  * Compare-and-swap
2267  */
2268 static void clear_cas_option(struct push_cas_option *cas)
2269 {
2270         int i;
2271
2272         for (i = 0; i < cas->nr; i++)
2273                 free(cas->entry[i].refname);
2274         free(cas->entry);
2275         memset(cas, 0, sizeof(*cas));
2276 }
2277
2278 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2279                                       const char *refname,
2280                                       size_t refnamelen)
2281 {
2282         struct push_cas *entry;
2283         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2284         entry = &cas->entry[cas->nr++];
2285         memset(entry, 0, sizeof(*entry));
2286         entry->refname = xmemdupz(refname, refnamelen);
2287         return entry;
2288 }
2289
2290 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2291 {
2292         const char *colon;
2293         struct push_cas *entry;
2294
2295         if (unset) {
2296                 /* "--no-<option>" */
2297                 clear_cas_option(cas);
2298                 return 0;
2299         }
2300
2301         if (!arg) {
2302                 /* just "--<option>" */
2303                 cas->use_tracking_for_rest = 1;
2304                 return 0;
2305         }
2306
2307         /* "--<option>=refname" or "--<option>=refname:value" */
2308         colon = strchrnul(arg, ':');
2309         entry = add_cas_entry(cas, arg, colon - arg);
2310         if (!*colon)
2311                 entry->use_tracking = 1;
2312         else if (get_sha1(colon + 1, entry->expect))
2313                 return error("cannot parse expected object name '%s'", colon + 1);
2314         return 0;
2315 }
2316
2317 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2318 {
2319         return parse_push_cas_option(opt->value, arg, unset);
2320 }
2321
2322 int is_empty_cas(const struct push_cas_option *cas)
2323 {
2324         return !cas->use_tracking_for_rest && !cas->nr;
2325 }
2326
2327 /*
2328  * Look at remote.fetch refspec and see if we have a remote
2329  * tracking branch for the refname there.  Fill its current
2330  * value in sha1[].
2331  * If we cannot do so, return negative to signal an error.
2332  */
2333 static int remote_tracking(struct remote *remote, const char *refname,
2334                            struct object_id *oid)
2335 {
2336         char *dst;
2337
2338         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2339         if (!dst)
2340                 return -1; /* no tracking ref for refname at remote */
2341         if (read_ref(dst, oid->hash))
2342                 return -1; /* we know what the tracking ref is but we cannot read it */
2343         return 0;
2344 }
2345
2346 static void apply_cas(struct push_cas_option *cas,
2347                       struct remote *remote,
2348                       struct ref *ref)
2349 {
2350         int i;
2351
2352         /* Find an explicit --<option>=<name>[:<value>] entry */
2353         for (i = 0; i < cas->nr; i++) {
2354                 struct push_cas *entry = &cas->entry[i];
2355                 if (!refname_match(entry->refname, ref->name))
2356                         continue;
2357                 ref->expect_old_sha1 = 1;
2358                 if (!entry->use_tracking)
2359                         hashcpy(ref->old_oid_expect.hash, cas->entry[i].expect);
2360                 else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2361                         ref->expect_old_no_trackback = 1;
2362                 return;
2363         }
2364
2365         /* Are we using "--<option>" to cover all? */
2366         if (!cas->use_tracking_for_rest)
2367                 return;
2368
2369         ref->expect_old_sha1 = 1;
2370         if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2371                 ref->expect_old_no_trackback = 1;
2372 }
2373
2374 void apply_push_cas(struct push_cas_option *cas,
2375                     struct remote *remote,
2376                     struct ref *remote_refs)
2377 {
2378         struct ref *ref;
2379         for (ref = remote_refs; ref; ref = ref->next)
2380                 apply_cas(cas, remote, ref);
2381 }