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->configured_in_repo = 1;
 259         remote->origin = REMOTE_REMOTES;
 260         while (strbuf_getline(&buf, f) != EOF) {
 261                 const char *v;
 262
 263                 strbuf_rtrim(&buf);
 264
 265                 if (skip_prefix(buf.buf, "URL:", &v))
 266                         add_url_alias(remote, xstrdup(skip_spaces(v)));
 267                 else if (skip_prefix(buf.buf, "Push:", &v))
 268                         add_push_refspec(remote, xstrdup(skip_spaces(v)));
 269                 else if (skip_prefix(buf.buf, "Pull:", &v))
 270                         add_fetch_refspec(remote, xstrdup(skip_spaces(v)));
 271         }
 272         strbuf_release(&buf);
 273         fclose(f);
 274 }
 275
 276 static void read_branches_file(struct remote *remote)
 277 {
 278         char *frag;
 279         struct strbuf buf = STRBUF_INIT;
 280         FILE *f = fopen(git_path("branches/%s", remote->name), "r");
 281
 282         if (!f)
 283                 return;
 284
 285         strbuf_getline_lf(&buf, f);
 286         fclose(f);
 287         strbuf_trim(&buf);
 288         if (!buf.len) {
 289                 strbuf_release(&buf);
 290                 return;
 291         }
 292
 293         remote->configured_in_repo = 1;
 294         remote->origin = REMOTE_BRANCHES;
 295
 296         /*
 297          * The branches file would have URL and optionally
 298          * #branch specified.  The "master" (or specified) branch is
 299          * fetched and stored in the local branch matching the
 300          * remote name.
 301          */
 302         frag = strchr(buf.buf, '#');
 303         if (frag)
 304                 *(frag++) = '\0';
 305         else
 306                 frag = "master";
 307
 308         add_url_alias(remote, strbuf_detach(&buf, NULL));
 309         add_fetch_refspec(remote, xstrfmt("refs/heads/%s:refs/heads/%s",
 310                                           frag, remote->name));
 311
 312         /*
 313          * Cogito compatible push: push current HEAD to remote #branch
 314          * (master if missing)
 315          */
 316         add_push_refspec(remote, xstrfmt("HEAD:refs/heads/%s", frag));
 317         remote->fetch_tags = 1; /* always auto-follow */
 318 }
 319
 320 static int handle_config(const char *key, const char *value, void *cb)
 321 {
 322         const char *name;
 323         int namelen;
 324         const char *subkey;
 325         struct remote *remote;
 326         struct branch *branch;
 327         if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
 328                 if (!name)
 329                         return 0;
 330                 branch = make_branch(name, namelen);
 331                 if (!strcmp(subkey, "remote")) {
 332                         return git_config_string(&branch->remote_name, key, value);
 333                 } else if (!strcmp(subkey, "pushremote")) {
 334                         return git_config_string(&branch->pushremote_name, key, value);
 335                 } else if (!strcmp(subkey, "merge")) {
 336                         if (!value)
 337                                 return config_error_nonbool(key);
 338                         add_merge(branch, xstrdup(value));
 339                 }
 340                 return 0;
 341         }
 342         if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
 343                 struct rewrite *rewrite;
 344                 if (!name)
 345                         return 0;
 346                 if (!strcmp(subkey, "insteadof")) {
 347                         rewrite = make_rewrite(&rewrites, name, namelen);
 348                         if (!value)
 349                                 return config_error_nonbool(key);
 350                         add_instead_of(rewrite, xstrdup(value));
 351                 } else if (!strcmp(subkey, "pushinsteadof")) {
 352                         rewrite = make_rewrite(&rewrites_push, name, namelen);
 353                         if (!value)
 354                                 return config_error_nonbool(key);
 355                         add_instead_of(rewrite, xstrdup(value));
 356                 }
 357         }
 358
 359         if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
 360                 return 0;
 361
 362         /* Handle remote.* variables */
 363         if (!name && !strcmp(subkey, "pushdefault"))
 364                 return git_config_string(&pushremote_name, key, value);
 365
 366         if (!name)
 367                 return 0;
 368         /* Handle remote.<name>.* variables */
 369         if (*name == '/') {
 370                 warning("Config remote shorthand cannot begin with '/': %s",
 371                         name);
 372                 return 0;
 373         }
 374         remote = make_remote(name, namelen);
 375         remote->origin = REMOTE_CONFIG;
 376         if (current_config_scope() == CONFIG_SCOPE_REPO)
 377                 remote->configured_in_repo = 1;
 378         if (!strcmp(subkey, "mirror"))
 379                 remote->mirror = git_config_bool(key, value);
 380         else if (!strcmp(subkey, "skipdefaultupdate"))
 381                 remote->skip_default_update = git_config_bool(key, value);
 382         else if (!strcmp(subkey, "skipfetchall"))
 383                 remote->skip_default_update = git_config_bool(key, value);
 384         else if (!strcmp(subkey, "prune"))
 385                 remote->prune = git_config_bool(key, value);
 386         else if (!strcmp(subkey, "url")) {
 387                 const char *v;
 388                 if (git_config_string(&v, key, value))
 389                         return -1;
 390                 add_url(remote, v);
 391         } else if (!strcmp(subkey, "pushurl")) {
 392                 const char *v;
 393                 if (git_config_string(&v, key, value))
 394                         return -1;
 395                 add_pushurl(remote, v);
 396         } else if (!strcmp(subkey, "push")) {
 397                 const char *v;
 398                 if (git_config_string(&v, key, value))
 399                         return -1;
 400                 add_push_refspec(remote, v);
 401         } else if (!strcmp(subkey, "fetch")) {
 402                 const char *v;
 403                 if (git_config_string(&v, key, value))
 404                         return -1;
 405                 add_fetch_refspec(remote, v);
 406         } else if (!strcmp(subkey, "receivepack")) {
 407                 const char *v;
 408                 if (git_config_string(&v, key, value))
 409                         return -1;
 410                 if (!remote->receivepack)
 411                         remote->receivepack = v;
 412                 else
 413                         error("more than one receivepack given, using the first");
 414         } else if (!strcmp(subkey, "uploadpack")) {
 415                 const char *v;
 416                 if (git_config_string(&v, key, value))
 417                         return -1;
 418                 if (!remote->uploadpack)
 419                         remote->uploadpack = v;
 420                 else
 421                         error("more than one uploadpack given, using the first");
 422         } else if (!strcmp(subkey, "tagopt")) {
 423                 if (!strcmp(value, "--no-tags"))
 424                         remote->fetch_tags = -1;
 425                 else if (!strcmp(value, "--tags"))
 426                         remote->fetch_tags = 2;
 427         } else if (!strcmp(subkey, "proxy")) {
 428                 return git_config_string((const char **)&remote->http_proxy,
 429                                          key, value);
 430         } else if (!strcmp(subkey, "proxyauthmethod")) {
 431                 return git_config_string((const char **)&remote->http_proxy_authmethod,
 432                                          key, value);
 433         } else if (!strcmp(subkey, "vcs")) {
 434                 return git_config_string(&remote->foreign_vcs, key, value);
 435         }
 436         return 0;
 437 }
 438
 439 static void alias_all_urls(void)
 440 {
 441         int i, j;
 442         for (i = 0; i < remotes_nr; i++) {
 443                 int add_pushurl_aliases;
 444                 if (!remotes[i])
 445                         continue;
 446                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 447                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 448                 }
 449                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 450                 for (j = 0; j < remotes[i]->url_nr; j++) {
 451                         if (add_pushurl_aliases)
 452                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 453                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 454                 }
 455         }
 456 }
 457
 458 static void read_config(void)
 459 {
 460         static int loaded;
 461         struct object_id oid;
 462         int flag;
 463
 464         if (loaded)
 465                 return;
 466         loaded = 1;
 467
 468         current_branch = NULL;
 469         if (startup_info->have_repository) {
 470                 const char *head_ref = resolve_ref_unsafe("HEAD", 0, oid.hash, &flag);
 471                 if (head_ref && (flag & REF_ISSYMREF) &&
 472                     skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 473                         current_branch = make_branch(head_ref, 0);
 474                 }
 475         }
 476         git_config(handle_config, NULL);
 477         alias_all_urls();
 478 }
 479
 480 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 481 {
 482         int i;
 483         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 484
 485         for (i = 0; i < nr_refspec; i++) {
 486                 size_t llen;
 487                 int is_glob;
 488                 const char *lhs, *rhs;
 489                 int flags;
 490
 491                 is_glob = 0;
 492
 493                 lhs = refspec[i];
 494                 if (*lhs == '+') {
 495                         rs[i].force = 1;
 496                         lhs++;
 497                 }
 498
 499                 rhs = strrchr(lhs, ':');
 500
 501                 /*
 502                  * Before going on, special case ":" (or "+:") as a refspec
 503                  * for pushing matching refs.
 504                  */
 505                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 506                         rs[i].matching = 1;
 507                         continue;
 508                 }
 509
 510                 if (rhs) {
 511                         size_t rlen = strlen(++rhs);
 512                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 513                         rs[i].dst = xstrndup(rhs, rlen);
 514                 }
 515
 516                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 517                 if (1 <= llen && memchr(lhs, '*', llen)) {
 518                         if ((rhs && !is_glob) || (!rhs && fetch))
 519                                 goto invalid;
 520                         is_glob = 1;
 521                 } else if (rhs && is_glob) {
 522                         goto invalid;
 523                 }
 524
 525                 rs[i].pattern = is_glob;
 526                 rs[i].src = xstrndup(lhs, llen);
 527                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 528
 529                 if (fetch) {
 530                         struct object_id unused;
 531
 532                         /* LHS */
 533                         if (!*rs[i].src)
 534                                 ; /* empty is ok; it means "HEAD" */
 535                         else if (llen == GIT_SHA1_HEXSZ && !get_oid_hex(rs[i].src, &unused))
 536                                 rs[i].exact_sha1 = 1; /* ok */
 537                         else if (!check_refname_format(rs[i].src, flags))
 538                                 ; /* valid looking ref is ok */
 539                         else
 540                                 goto invalid;
 541                         /* RHS */
 542                         if (!rs[i].dst)
 543                                 ; /* missing is ok; it is the same as empty */
 544                         else if (!*rs[i].dst)
 545                                 ; /* empty is ok; it means "do not store" */
 546                         else if (!check_refname_format(rs[i].dst, flags))
 547                                 ; /* valid looking ref is ok */
 548                         else
 549                                 goto invalid;
 550                 } else {
 551                         /*
 552                          * LHS
 553                          * - empty is allowed; it means delete.
 554                          * - when wildcarded, it must be a valid looking ref.
 555                          * - otherwise, it must be an extended SHA-1, but
 556                          *   there is no existing way to validate this.
 557                          */
 558                         if (!*rs[i].src)
 559                                 ; /* empty is ok */
 560                         else if (is_glob) {
 561                                 if (check_refname_format(rs[i].src, flags))
 562                                         goto invalid;
 563                         }
 564                         else
 565                                 ; /* anything goes, for now */
 566                         /*
 567                          * RHS
 568                          * - missing is allowed, but LHS then must be a
 569                          *   valid looking ref.
 570                          * - empty is not allowed.
 571                          * - otherwise it must be a valid looking ref.
 572                          */
 573                         if (!rs[i].dst) {
 574                                 if (check_refname_format(rs[i].src, flags))
 575                                         goto invalid;
 576                         } else if (!*rs[i].dst) {
 577                                 goto invalid;
 578                         } else {
 579                                 if (check_refname_format(rs[i].dst, flags))
 580                                         goto invalid;
 581                         }
 582                 }
 583         }
 584         return rs;
 585
 586  invalid:
 587         if (verify) {
 588                 /*
 589                  * nr_refspec must be greater than zero and i must be valid
 590                  * since it is only possible to reach this point from within
 591                  * the for loop above.
 592                  */
 593                 free_refspec(i+1, rs);
 594                 return NULL;
 595         }
 596         die("Invalid refspec '%s'", refspec[i]);
 597 }
 598
 599 int valid_fetch_refspec(const char *fetch_refspec_str)
 600 {
 601         struct refspec *refspec;
 602
 603         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 604         free_refspec(1, refspec);
 605         return !!refspec;
 606 }
 607
 608 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 609 {
 610         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 611 }
 612
 613 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 614 {
 615         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 616 }
 617
 618 void free_refspec(int nr_refspec, struct refspec *refspec)
 619 {
 620         int i;
 621
 622         if (!refspec)
 623                 return;
 624
 625         for (i = 0; i < nr_refspec; i++) {
 626                 free(refspec[i].src);
 627                 free(refspec[i].dst);
 628         }
 629         free(refspec);
 630 }
 631
 632 static int valid_remote_nick(const char *name)
 633 {
 634         if (!name[0] || is_dot_or_dotdot(name))
 635                 return 0;
 636
 637         /* remote nicknames cannot contain slashes */
 638         while (*name)
 639                 if (is_dir_sep(*name++))
 640                         return 0;
 641         return 1;
 642 }
 643
 644 const char *remote_for_branch(struct branch *branch, int *explicit)
 645 {
 646         if (branch && branch->remote_name) {
 647                 if (explicit)
 648                         *explicit = 1;
 649                 return branch->remote_name;
 650         }
 651         if (explicit)
 652                 *explicit = 0;
 653         return "origin";
 654 }
 655
 656 const char *pushremote_for_branch(struct branch *branch, int *explicit)
 657 {
 658         if (branch && branch->pushremote_name) {
 659                 if (explicit)
 660                         *explicit = 1;
 661                 return branch->pushremote_name;
 662         }
 663         if (pushremote_name) {
 664                 if (explicit)
 665                         *explicit = 1;
 666                 return pushremote_name;
 667         }
 668         return remote_for_branch(branch, explicit);
 669 }
 670
 671 static struct remote *remote_get_1(const char *name,
 672                                    const char *(*get_default)(struct branch *, int *))
 673 {
 674         struct remote *ret;
 675         int name_given = 0;
 676
 677         read_config();
 678
 679         if (name)
 680                 name_given = 1;
 681         else
 682                 name = get_default(current_branch, &name_given);
 683
 684         ret = make_remote(name, 0);
 685         if (valid_remote_nick(name) && have_git_dir()) {
 686                 if (!valid_remote(ret))
 687                         read_remotes_file(ret);
 688                 if (!valid_remote(ret))
 689                         read_branches_file(ret);
 690         }
 691         if (name_given && !valid_remote(ret))
 692                 add_url_alias(ret, name);
 693         if (!valid_remote(ret))
 694                 return NULL;
 695         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 696         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 697         return ret;
 698 }
 699
 700 struct remote *remote_get(const char *name)
 701 {
 702         return remote_get_1(name, remote_for_branch);
 703 }
 704
 705 struct remote *pushremote_get(const char *name)
 706 {
 707         return remote_get_1(name, pushremote_for_branch);
 708 }
 709
 710 int remote_is_configured(struct remote *remote, int in_repo)
 711 {
 712         if (!remote)
 713                 return 0;
 714         if (in_repo)
 715                 return remote->configured_in_repo;
 716         return !!remote->origin;
 717 }
 718
 719 int for_each_remote(each_remote_fn fn, void *priv)
 720 {
 721         int i, result = 0;
 722         read_config();
 723         for (i = 0; i < remotes_nr && !result; i++) {
 724                 struct remote *r = remotes[i];
 725                 if (!r)
 726                         continue;
 727                 if (!r->fetch)
 728                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 729                                                        r->fetch_refspec);
 730                 if (!r->push)
 731                         r->push = parse_push_refspec(r->push_refspec_nr,
 732                                                      r->push_refspec);
 733                 result = fn(r, priv);
 734         }
 735         return result;
 736 }
 737
 738 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 739 {
 740         if (strcmp(ref1->name, ref2->name)) {
 741                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 742                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 743                         die(_("Cannot fetch both %s and %s to %s"),
 744                             ref1->name, ref2->name, ref2->peer_ref->name);
 745                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 746                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 747                         warning(_("%s usually tracks %s, not %s"),
 748                                 ref2->peer_ref->name, ref2->name, ref1->name);
 749                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 750                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 751                         die(_("%s tracks both %s and %s"),
 752                             ref2->peer_ref->name, ref1->name, ref2->name);
 753                 } else {
 754                         /*
 755                          * This last possibility doesn't occur because
 756                          * FETCH_HEAD_IGNORE entries always appear at
 757                          * the end of the list.
 758                          */
 759                         die(_("Internal error"));
 760                 }
 761         }
 762         free(ref2->peer_ref);
 763         free(ref2);
 764 }
 765
 766 struct ref *ref_remove_duplicates(struct ref *ref_map)
 767 {
 768         struct string_list refs = STRING_LIST_INIT_NODUP;
 769         struct ref *retval = NULL;
 770         struct ref **p = &retval;
 771
 772         while (ref_map) {
 773                 struct ref *ref = ref_map;
 774
 775                 ref_map = ref_map->next;
 776                 ref->next = NULL;
 777
 778                 if (!ref->peer_ref) {
 779                         *p = ref;
 780                         p = &ref->next;
 781                 } else {
 782                         struct string_list_item *item =
 783                                 string_list_insert(&refs, ref->peer_ref->name);
 784
 785                         if (item->util) {
 786                                 /* Entry already existed */
 787                                 handle_duplicate((struct ref *)item->util, ref);
 788                         } else {
 789                                 *p = ref;
 790                                 p = &ref->next;
 791                                 item->util = ref;
 792                         }
 793                 }
 794         }
 795
 796         string_list_clear(&refs, 0);
 797         return retval;
 798 }
 799
 800 int remote_has_url(struct remote *remote, const char *url)
 801 {
 802         int i;
 803         for (i = 0; i < remote->url_nr; i++) {
 804                 if (!strcmp(remote->url[i], url))
 805                         return 1;
 806         }
 807         return 0;
 808 }
 809
 810 static int match_name_with_pattern(const char *key, const char *name,
 811                                    const char *value, char **result)
 812 {
 813         const char *kstar = strchr(key, '*');
 814         size_t klen;
 815         size_t ksuffixlen;
 816         size_t namelen;
 817         int ret;
 818         if (!kstar)
 819                 die("Key '%s' of pattern had no '*'", key);
 820         klen = kstar - key;
 821         ksuffixlen = strlen(kstar + 1);
 822         namelen = strlen(name);
 823         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 824                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 825         if (ret && value) {
 826                 struct strbuf sb = STRBUF_INIT;
 827                 const char *vstar = strchr(value, '*');
 828                 if (!vstar)
 829                         die("Value '%s' of pattern has no '*'", value);
 830                 strbuf_add(&sb, value, vstar - value);
 831                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 832                 strbuf_addstr(&sb, vstar + 1);
 833                 *result = strbuf_detach(&sb, NULL);
 834         }
 835         return ret;
 836 }
 837
 838 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 839 {
 840         int i;
 841         int find_src = !query->src;
 842
 843         if (find_src && !query->dst)
 844                 error("query_refspecs_multiple: need either src or dst");
 845
 846         for (i = 0; i < ref_count; i++) {
 847                 struct refspec *refspec = &refs[i];
 848                 const char *key = find_src ? refspec->dst : refspec->src;
 849                 const char *value = find_src ? refspec->src : refspec->dst;
 850                 const char *needle = find_src ? query->dst : query->src;
 851                 char **result = find_src ? &query->src : &query->dst;
 852
 853                 if (!refspec->dst)
 854                         continue;
 855                 if (refspec->pattern) {
 856                         if (match_name_with_pattern(key, needle, value, result))
 857                                 string_list_append_nodup(results, *result);
 858                 } else if (!strcmp(needle, key)) {
 859                         string_list_append(results, value);
 860                 }
 861         }
 862 }
 863
 864 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 865 {
 866         int i;
 867         int find_src = !query->src;
 868         const char *needle = find_src ? query->dst : query->src;
 869         char **result = find_src ? &query->src : &query->dst;
 870
 871         if (find_src && !query->dst)
 872                 return error("query_refspecs: need either src or dst");
 873
 874         for (i = 0; i < ref_count; i++) {
 875                 struct refspec *refspec = &refs[i];
 876                 const char *key = find_src ? refspec->dst : refspec->src;
 877                 const char *value = find_src ? refspec->src : refspec->dst;
 878
 879                 if (!refspec->dst)
 880                         continue;
 881                 if (refspec->pattern) {
 882                         if (match_name_with_pattern(key, needle, value, result)) {
 883                                 query->force = refspec->force;
 884                                 return 0;
 885                         }
 886                 } else if (!strcmp(needle, key)) {
 887                         *result = xstrdup(value);
 888                         query->force = refspec->force;
 889                         return 0;
 890                 }
 891         }
 892         return -1;
 893 }
 894
 895 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 896                      const char *name)
 897 {
 898         struct refspec query;
 899
 900         memset(&query, 0, sizeof(struct refspec));
 901         query.src = (char *)name;
 902
 903         if (query_refspecs(refspecs, nr_refspec, &query))
 904                 return NULL;
 905
 906         return query.dst;
 907 }
 908
 909 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 910 {
 911         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 912 }
 913
 914 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 915                 const char *name)
 916 {
 917         size_t len = strlen(name);
 918         struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 919         memcpy(ref->name, prefix, prefixlen);
 920         memcpy(ref->name + prefixlen, name, len);
 921         return ref;
 922 }
 923
 924 struct ref *alloc_ref(const char *name)
 925 {
 926         return alloc_ref_with_prefix("", 0, name);
 927 }
 928
 929 struct ref *copy_ref(const struct ref *ref)
 930 {
 931         struct ref *cpy;
 932         size_t len;
 933         if (!ref)
 934                 return NULL;
 935         len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 936         cpy = xmalloc(len);
 937         memcpy(cpy, ref, len);
 938         cpy->next = NULL;
 939         cpy->symref = xstrdup_or_null(ref->symref);
 940         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 941         cpy->peer_ref = copy_ref(ref->peer_ref);
 942         return cpy;
 943 }
 944
 945 struct ref *copy_ref_list(const struct ref *ref)
 946 {
 947         struct ref *ret = NULL;
 948         struct ref **tail = &ret;
 949         while (ref) {
 950                 *tail = copy_ref(ref);
 951                 ref = ref->next;
 952                 tail = &((*tail)->next);
 953         }
 954         return ret;
 955 }
 956
 957 static void free_ref(struct ref *ref)
 958 {
 959         if (!ref)
 960                 return;
 961         free_ref(ref->peer_ref);
 962         free(ref->remote_status);
 963         free(ref->symref);
 964         free(ref);
 965 }
 966
 967 void free_refs(struct ref *ref)
 968 {
 969         struct ref *next;
 970         while (ref) {
 971                 next = ref->next;
 972                 free_ref(ref);
 973                 ref = next;
 974         }
 975 }
 976
 977 int ref_compare_name(const void *va, const void *vb)
 978 {
 979         const struct ref *a = va, *b = vb;
 980         return strcmp(a->name, b->name);
 981 }
 982
 983 static void *ref_list_get_next(const void *a)
 984 {
 985         return ((const struct ref *)a)->next;
 986 }
 987
 988 static void ref_list_set_next(void *a, void *next)
 989 {
 990         ((struct ref *)a)->next = next;
 991 }
 992
 993 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 994 {
 995         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 996 }
 997
 998 int count_refspec_match(const char *pattern,
 999                         struct ref *refs,
1000                         struct ref **matched_ref)
1001 {
1002         int patlen = strlen(pattern);
1003         struct ref *matched_weak = NULL;
1004         struct ref *matched = NULL;
1005         int weak_match = 0;
1006         int match = 0;
1007
1008         for (weak_match = match = 0; refs; refs = refs->next) {
1009                 char *name = refs->name;
1010                 int namelen = strlen(name);
1011
1012                 if (!refname_match(pattern, name))
1013                         continue;
1014
1015                 /* A match is "weak" if it is with refs outside
1016                  * heads or tags, and did not specify the pattern
1017                  * in full (e.g. "refs/remotes/origin/master") or at
1018                  * least from the toplevel (e.g. "remotes/origin/master");
1019                  * otherwise "git push $URL master" would result in
1020                  * ambiguity between remotes/origin/master and heads/master
1021                  * at the remote site.
1022                  */
1023                 if (namelen != patlen &&
1024                     patlen != namelen - 5 &&
1025                     !starts_with(name, "refs/heads/") &&
1026                     !starts_with(name, "refs/tags/")) {
1027                         /* We want to catch the case where only weak
1028                          * matches are found and there are multiple
1029                          * matches, and where more than one strong
1030                          * matches are found, as ambiguous.  One
1031                          * strong match with zero or more weak matches
1032                          * are acceptable as a unique match.
1033                          */
1034                         matched_weak = refs;
1035                         weak_match++;
1036                 }
1037                 else {
1038                         matched = refs;
1039                         match++;
1040                 }
1041         }
1042         if (!matched) {
1043                 if (matched_ref)
1044                         *matched_ref = matched_weak;
1045                 return weak_match;
1046         }
1047         else {
1048                 if (matched_ref)
1049                         *matched_ref = matched;
1050                 return match;
1051         }
1052 }
1053
1054 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1055 {
1056         **tail = ref;
1057         while (ref->next)
1058                 ref = ref->next;
1059         *tail = &ref->next;
1060 }
1061
1062 static struct ref *alloc_delete_ref(void)
1063 {
1064         struct ref *ref = alloc_ref("(delete)");
1065         oidclr(&ref->new_oid);
1066         return ref;
1067 }
1068
1069 static int try_explicit_object_name(const char *name,
1070                                     struct ref **match)
1071 {
1072         struct object_id oid;
1073
1074         if (!*name) {
1075                 if (match)
1076                         *match = alloc_delete_ref();
1077                 return 0;
1078         }
1079
1080         if (get_sha1(name, oid.hash))
1081                 return -1;
1082
1083         if (match) {
1084                 *match = alloc_ref(name);
1085                 oidcpy(&(*match)->new_oid, &oid);
1086         }
1087         return 0;
1088 }
1089
1090 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1091 {
1092         struct ref *ret = alloc_ref(name);
1093         tail_link_ref(ret, tail);
1094         return ret;
1095 }
1096
1097 static char *guess_ref(const char *name, struct ref *peer)
1098 {
1099         struct strbuf buf = STRBUF_INIT;
1100         struct object_id oid;
1101
1102         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1103                                            oid.hash, NULL);
1104         if (!r)
1105                 return NULL;
1106
1107         if (starts_with(r, "refs/heads/"))
1108                 strbuf_addstr(&buf, "refs/heads/");
1109         else if (starts_with(r, "refs/tags/"))
1110                 strbuf_addstr(&buf, "refs/tags/");
1111         else
1112                 return NULL;
1113
1114         strbuf_addstr(&buf, name);
1115         return strbuf_detach(&buf, NULL);
1116 }
1117
1118 static int match_explicit_lhs(struct ref *src,
1119                               struct refspec *rs,
1120                               struct ref **match,
1121                               int *allocated_match)
1122 {
1123         switch (count_refspec_match(rs->src, src, match)) {
1124         case 1:
1125                 if (allocated_match)
1126                         *allocated_match = 0;
1127                 return 0;
1128         case 0:
1129                 /* The source could be in the get_sha1() format
1130                  * not a reference name.  :refs/other is a
1131                  * way to delete 'other' ref at the remote end.
1132                  */
1133                 if (try_explicit_object_name(rs->src, match) < 0)
1134                         return error("src refspec %s does not match any.", rs->src);
1135                 if (allocated_match)
1136                         *allocated_match = 1;
1137                 return 0;
1138         default:
1139                 return error("src refspec %s matches more than one.", rs->src);
1140         }
1141 }
1142
1143 static int match_explicit(struct ref *src, struct ref *dst,
1144                           struct ref ***dst_tail,
1145                           struct refspec *rs)
1146 {
1147         struct ref *matched_src, *matched_dst;
1148         int allocated_src;
1149
1150         const char *dst_value = rs->dst;
1151         char *dst_guess;
1152
1153         if (rs->pattern || rs->matching)
1154                 return 0;
1155
1156         matched_src = matched_dst = NULL;
1157         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1158                 return -1;
1159
1160         if (!dst_value) {
1161                 struct object_id oid;
1162                 int flag;
1163
1164                 dst_value = resolve_ref_unsafe(matched_src->name,
1165                                                RESOLVE_REF_READING,
1166                                                oid.hash, &flag);
1167                 if (!dst_value ||
1168                     ((flag & REF_ISSYMREF) &&
1169                      !starts_with(dst_value, "refs/heads/")))
1170                         die("%s cannot be resolved to branch.",
1171                             matched_src->name);
1172         }
1173
1174         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1175         case 1:
1176                 break;
1177         case 0:
1178                 if (starts_with(dst_value, "refs/"))
1179                         matched_dst = make_linked_ref(dst_value, dst_tail);
1180                 else if (is_null_oid(&matched_src->new_oid))
1181                         error("unable to delete '%s': remote ref does not exist",
1182                               dst_value);
1183                 else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1184                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1185                         free(dst_guess);
1186                 } else
1187                         error("unable to push to unqualified destination: %s\n"
1188                               "The destination refspec neither matches an "
1189                               "existing ref on the remote nor\n"
1190                               "begins with refs/, and we are unable to "
1191                               "guess a prefix based on the source ref.",
1192                               dst_value);
1193                 break;
1194         default:
1195                 matched_dst = NULL;
1196                 error("dst refspec %s matches more than one.",
1197                       dst_value);
1198                 break;
1199         }
1200         if (!matched_dst)
1201                 return -1;
1202         if (matched_dst->peer_ref)
1203                 return error("dst ref %s receives from more than one src.",
1204                       matched_dst->name);
1205         else {
1206                 matched_dst->peer_ref = allocated_src ?
1207                                         matched_src :
1208                                         copy_ref(matched_src);
1209                 matched_dst->force = rs->force;
1210         }
1211         return 0;
1212 }
1213
1214 static int match_explicit_refs(struct ref *src, struct ref *dst,
1215                                struct ref ***dst_tail, struct refspec *rs,
1216                                int rs_nr)
1217 {
1218         int i, errs;
1219         for (i = errs = 0; i < rs_nr; i++)
1220                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1221         return errs;
1222 }
1223
1224 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1225                 int send_mirror, int direction, const struct refspec **ret_pat)
1226 {
1227         const struct refspec *pat;
1228         char *name;
1229         int i;
1230         int matching_refs = -1;
1231         for (i = 0; i < rs_nr; i++) {
1232                 if (rs[i].matching &&
1233                     (matching_refs == -1 || rs[i].force)) {
1234                         matching_refs = i;
1235                         continue;
1236                 }
1237
1238                 if (rs[i].pattern) {
1239                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1240                         int match;
1241                         if (direction == FROM_SRC)
1242                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1243                         else
1244                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1245                         if (match) {
1246                                 matching_refs = i;
1247                                 break;
1248                         }
1249                 }
1250         }
1251         if (matching_refs == -1)
1252                 return NULL;
1253
1254         pat = rs + matching_refs;
1255         if (pat->matching) {
1256                 /*
1257                  * "matching refs"; traditionally we pushed everything
1258                  * including refs outside refs/heads/ hierarchy, but
1259                  * that does not make much sense these days.
1260                  */
1261                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1262                         return NULL;
1263                 name = xstrdup(ref->name);
1264         }
1265         if (ret_pat)
1266                 *ret_pat = pat;
1267         return name;
1268 }
1269
1270 static struct ref **tail_ref(struct ref **head)
1271 {
1272         struct ref **tail = head;
1273         while (*tail)
1274                 tail = &((*tail)->next);
1275         return tail;
1276 }
1277
1278 struct tips {
1279         struct commit **tip;
1280         int nr, alloc;
1281 };
1282
1283 static void add_to_tips(struct tips *tips, const struct object_id *oid)
1284 {
1285         struct commit *commit;
1286
1287         if (is_null_oid(oid))
1288                 return;
1289         commit = lookup_commit_reference_gently(oid->hash, 1);
1290         if (!commit || (commit->object.flags & TMP_MARK))
1291                 return;
1292         commit->object.flags |= TMP_MARK;
1293         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1294         tips->tip[tips->nr++] = commit;
1295 }
1296
1297 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1298 {
1299         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1300         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1301         struct string_list_item *item;
1302         struct ref *ref;
1303         struct tips sent_tips;
1304
1305         /*
1306          * Collect everything we know they would have at the end of
1307          * this push, and collect all tags they have.
1308          */
1309         memset(&sent_tips, 0, sizeof(sent_tips));
1310         for (ref = *dst; ref; ref = ref->next) {
1311                 if (ref->peer_ref &&
1312                     !is_null_oid(&ref->peer_ref->new_oid))
1313                         add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1314                 else
1315                         add_to_tips(&sent_tips, &ref->old_oid);
1316                 if (starts_with(ref->name, "refs/tags/"))
1317                         string_list_append(&dst_tag, ref->name);
1318         }
1319         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1320
1321         string_list_sort(&dst_tag);
1322
1323         /* Collect tags they do not have. */
1324         for (ref = src; ref; ref = ref->next) {
1325                 if (!starts_with(ref->name, "refs/tags/"))
1326                         continue; /* not a tag */
1327                 if (string_list_has_string(&dst_tag, ref->name))
1328                         continue; /* they already have it */
1329                 if (sha1_object_info(ref->new_oid.hash, NULL) != OBJ_TAG)
1330                         continue; /* be conservative */
1331                 item = string_list_append(&src_tag, ref->name);
1332                 item->util = ref;
1333         }
1334         string_list_clear(&dst_tag, 0);
1335
1336         /*
1337          * At this point, src_tag lists tags that are missing from
1338          * dst, and sent_tips lists the tips we are pushing or those
1339          * that we know they already have. An element in the src_tag
1340          * that is an ancestor of any of the sent_tips needs to be
1341          * sent to the other side.
1342          */
1343         if (sent_tips.nr) {
1344                 for_each_string_list_item(item, &src_tag) {
1345                         struct ref *ref = item->util;
1346                         struct ref *dst_ref;
1347                         struct commit *commit;
1348
1349                         if (is_null_oid(&ref->new_oid))
1350                                 continue;
1351                         commit = lookup_commit_reference_gently(ref->new_oid.hash, 1);
1352                         if (!commit)
1353                                 /* not pushing a commit, which is not an error */
1354                                 continue;
1355
1356                         /*
1357                          * Is this tag, which they do not have, reachable from
1358                          * any of the commits we are sending?
1359                          */
1360                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1361                                 continue;
1362
1363                         /* Add it in */
1364                         dst_ref = make_linked_ref(ref->name, dst_tail);
1365                         oidcpy(&dst_ref->new_oid, &ref->new_oid);
1366                         dst_ref->peer_ref = copy_ref(ref);
1367                 }
1368         }
1369         string_list_clear(&src_tag, 0);
1370         free(sent_tips.tip);
1371 }
1372
1373 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1374 {
1375         for ( ; list; list = list->next)
1376                 if (!strcmp(list->name, name))
1377                         return (struct ref *)list;
1378         return NULL;
1379 }
1380
1381 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1382 {
1383         for ( ; ref; ref = ref->next)
1384                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1385
1386         string_list_sort(ref_index);
1387 }
1388
1389 /*
1390  * Given only the set of local refs, sanity-check the set of push
1391  * refspecs. We can't catch all errors that match_push_refs would,
1392  * but we can catch some errors early before even talking to the
1393  * remote side.
1394  */
1395 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1396 {
1397         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1398         int ret = 0;
1399         int i;
1400
1401         for (i = 0; i < nr_refspec; i++) {
1402                 struct refspec *rs = refspec + i;
1403
1404                 if (rs->pattern || rs->matching)
1405                         continue;
1406
1407                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1408         }
1409
1410         free_refspec(nr_refspec, refspec);
1411         return ret;
1412 }
1413
1414 /*
1415  * Given the set of refs the local repository has, the set of refs the
1416  * remote repository has, and the refspec used for push, determine
1417  * what remote refs we will update and with what value by setting
1418  * peer_ref (which object is being pushed) and force (if the push is
1419  * forced) in elements of "dst". The function may add new elements to
1420  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1421  */
1422 int match_push_refs(struct ref *src, struct ref **dst,
1423                     int nr_refspec, const char **refspec, int flags)
1424 {
1425         struct refspec *rs;
1426         int send_all = flags & MATCH_REFS_ALL;
1427         int send_mirror = flags & MATCH_REFS_MIRROR;
1428         int send_prune = flags & MATCH_REFS_PRUNE;
1429         int errs;
1430         static const char *default_refspec[] = { ":", NULL };
1431         struct ref *ref, **dst_tail = tail_ref(dst);
1432         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1433
1434         if (!nr_refspec) {
1435                 nr_refspec = 1;
1436                 refspec = default_refspec;
1437         }
1438         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1439         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1440
1441         /* pick the remainder */
1442         for (ref = src; ref; ref = ref->next) {
1443                 struct string_list_item *dst_item;
1444                 struct ref *dst_peer;
1445                 const struct refspec *pat = NULL;
1446                 char *dst_name;
1447
1448                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1449                 if (!dst_name)
1450                         continue;
1451
1452                 if (!dst_ref_index.nr)
1453                         prepare_ref_index(&dst_ref_index, *dst);
1454
1455                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1456                 dst_peer = dst_item ? dst_item->util : NULL;
1457                 if (dst_peer) {
1458                         if (dst_peer->peer_ref)
1459                                 /* We're already sending something to this ref. */
1460                                 goto free_name;
1461                 } else {
1462                         if (pat->matching && !(send_all || send_mirror))
1463                                 /*
1464                                  * Remote doesn't have it, and we have no
1465                                  * explicit pattern, and we don't have
1466                                  * --all or --mirror.
1467                                  */
1468                                 goto free_name;
1469
1470                         /* Create a new one and link it */
1471                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1472                         oidcpy(&dst_peer->new_oid, &ref->new_oid);
1473                         string_list_insert(&dst_ref_index,
1474                                 dst_peer->name)->util = dst_peer;
1475                 }
1476                 dst_peer->peer_ref = copy_ref(ref);
1477                 dst_peer->force = pat->force;
1478         free_name:
1479                 free(dst_name);
1480         }
1481
1482         string_list_clear(&dst_ref_index, 0);
1483
1484         if (flags & MATCH_REFS_FOLLOW_TAGS)
1485                 add_missing_tags(src, dst, &dst_tail);
1486
1487         if (send_prune) {
1488                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1489                 /* check for missing refs on the remote */
1490                 for (ref = *dst; ref; ref = ref->next) {
1491                         char *src_name;
1492
1493                         if (ref->peer_ref)
1494                                 /* We're already sending something to this ref. */
1495                                 continue;
1496
1497                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1498                         if (src_name) {
1499                                 if (!src_ref_index.nr)
1500                                         prepare_ref_index(&src_ref_index, src);
1501                                 if (!string_list_has_string(&src_ref_index,
1502                                             src_name))
1503                                         ref->peer_ref = alloc_delete_ref();
1504                                 free(src_name);
1505                         }
1506                 }
1507                 string_list_clear(&src_ref_index, 0);
1508         }
1509         if (errs)
1510                 return -1;
1511         return 0;
1512 }
1513
1514 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1515                              int force_update)
1516 {
1517         struct ref *ref;
1518
1519         for (ref = remote_refs; ref; ref = ref->next) {
1520                 int force_ref_update = ref->force || force_update;
1521                 int reject_reason = 0;
1522
1523                 if (ref->peer_ref)
1524                         oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1525                 else if (!send_mirror)
1526                         continue;
1527
1528                 ref->deletion = is_null_oid(&ref->new_oid);
1529                 if (!ref->deletion &&
1530                         !oidcmp(&ref->old_oid, &ref->new_oid)) {
1531                         ref->status = REF_STATUS_UPTODATE;
1532                         continue;
1533                 }
1534
1535                 /*
1536                  * If the remote ref has moved and is now different
1537                  * from what we expect, reject any push.
1538                  *
1539                  * It also is an error if the user told us to check
1540                  * with the remote-tracking branch to find the value
1541                  * to expect, but we did not have such a tracking
1542                  * branch.
1543                  */
1544                 if (ref->expect_old_sha1) {
1545                         if (oidcmp(&ref->old_oid, &ref->old_oid_expect))
1546                                 reject_reason = REF_STATUS_REJECT_STALE;
1547                         else
1548                                 /* If the ref isn't stale then force the update. */
1549                                 force_ref_update = 1;
1550                 }
1551
1552                 /*
1553                  * If the update isn't already rejected then check
1554                  * the usual "must fast-forward" rules.
1555                  *
1556                  * Decide whether an individual refspec A:B can be
1557                  * pushed.  The push will succeed if any of the
1558                  * following are true:
1559                  *
1560                  * (1) the remote reference B does not exist
1561                  *
1562                  * (2) the remote reference B is being removed (i.e.,
1563                  *     pushing :B where no source is specified)
1564                  *
1565                  * (3) the destination is not under refs/tags/, and
1566                  *     if the old and new value is a commit, the new
1567                  *     is a descendant of the old.
1568                  *
1569                  * (4) it is forced using the +A:B notation, or by
1570                  *     passing the --force argument
1571                  */
1572
1573                 if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1574                         if (starts_with(ref->name, "refs/tags/"))
1575                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1576                         else if (!has_object_file(&ref->old_oid))
1577                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1578                         else if (!lookup_commit_reference_gently(ref->old_oid.hash, 1) ||
1579                                  !lookup_commit_reference_gently(ref->new_oid.hash, 1))
1580                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1581                         else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1582                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1583                 }
1584
1585                 /*
1586                  * "--force" will defeat any rejection implemented
1587                  * by the rules above.
1588                  */
1589                 if (!force_ref_update)
1590                         ref->status = reject_reason;
1591                 else if (reject_reason)
1592                         ref->forced_update = 1;
1593         }
1594 }
1595
1596 static void set_merge(struct branch *ret)
1597 {
1598         struct remote *remote;
1599         char *ref;
1600         struct object_id oid;
1601         int i;
1602
1603         if (!ret)
1604                 return; /* no branch */
1605         if (ret->merge)
1606                 return; /* already run */
1607         if (!ret->remote_name || !ret->merge_nr) {
1608                 /*
1609                  * no merge config; let's make sure we don't confuse callers
1610                  * with a non-zero merge_nr but a NULL merge
1611                  */
1612                 ret->merge_nr = 0;
1613                 return;
1614         }
1615
1616         remote = remote_get(ret->remote_name);
1617
1618         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1619         for (i = 0; i < ret->merge_nr; i++) {
1620                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1621                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1622                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1623                     strcmp(ret->remote_name, "."))
1624                         continue;
1625                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1626                              oid.hash, &ref) == 1)
1627                         ret->merge[i]->dst = ref;
1628                 else
1629                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1630         }
1631 }
1632
1633 struct branch *branch_get(const char *name)
1634 {
1635         struct branch *ret;
1636
1637         read_config();
1638         if (!name || !*name || !strcmp(name, "HEAD"))
1639                 ret = current_branch;
1640         else
1641                 ret = make_branch(name, 0);
1642         set_merge(ret);
1643         return ret;
1644 }
1645
1646 int branch_has_merge_config(struct branch *branch)
1647 {
1648         return branch && !!branch->merge;
1649 }
1650
1651 int branch_merge_matches(struct branch *branch,
1652                                  int i,
1653                                  const char *refname)
1654 {
1655         if (!branch || i < 0 || i >= branch->merge_nr)
1656                 return 0;
1657         return refname_match(branch->merge[i]->src, refname);
1658 }
1659
1660 __attribute__((format (printf,2,3)))
1661 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1662 {
1663         if (err) {
1664                 va_list ap;
1665                 va_start(ap, fmt);
1666                 strbuf_vaddf(err, fmt, ap);
1667                 va_end(ap);
1668         }
1669         return NULL;
1670 }
1671
1672 const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1673 {
1674         if (!branch)
1675                 return error_buf(err, _("HEAD does not point to a branch"));
1676
1677         if (!branch->merge || !branch->merge[0]) {
1678                 /*
1679                  * no merge config; is it because the user didn't define any,
1680                  * or because it is not a real branch, and get_branch
1681                  * auto-vivified it?
1682                  */
1683                 if (!ref_exists(branch->refname))
1684                         return error_buf(err, _("no such branch: '%s'"),
1685                                          branch->name);
1686                 return error_buf(err,
1687                                  _("no upstream configured for branch '%s'"),
1688                                  branch->name);
1689         }
1690
1691         if (!branch->merge[0]->dst)
1692                 return error_buf(err,
1693                                  _("upstream branch '%s' not stored as a remote-tracking branch"),
1694                                  branch->merge[0]->src);
1695
1696         return branch->merge[0]->dst;
1697 }
1698
1699 static const char *tracking_for_push_dest(struct remote *remote,
1700                                           const char *refname,
1701                                           struct strbuf *err)
1702 {
1703         char *ret;
1704
1705         ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1706         if (!ret)
1707                 return error_buf(err,
1708                                  _("push destination '%s' on remote '%s' has no local tracking branch"),
1709                                  refname, remote->name);
1710         return ret;
1711 }
1712
1713 static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1714 {
1715         struct remote *remote;
1716
1717         remote = remote_get(pushremote_for_branch(branch, NULL));
1718         if (!remote)
1719                 return error_buf(err,
1720                                  _("branch '%s' has no remote for pushing"),
1721                                  branch->name);
1722
1723         if (remote->push_refspec_nr) {
1724                 char *dst;
1725                 const char *ret;
1726
1727                 dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1728                                      branch->refname);
1729                 if (!dst)
1730                         return error_buf(err,
1731                                          _("push refspecs for '%s' do not include '%s'"),
1732                                          remote->name, branch->name);
1733
1734                 ret = tracking_for_push_dest(remote, dst, err);
1735                 free(dst);
1736                 return ret;
1737         }
1738
1739         if (remote->mirror)
1740                 return tracking_for_push_dest(remote, branch->refname, err);
1741
1742         switch (push_default) {
1743         case PUSH_DEFAULT_NOTHING:
1744                 return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1745
1746         case PUSH_DEFAULT_MATCHING:
1747         case PUSH_DEFAULT_CURRENT:
1748                 return tracking_for_push_dest(remote, branch->refname, err);
1749
1750         case PUSH_DEFAULT_UPSTREAM:
1751                 return branch_get_upstream(branch, err);
1752
1753         case PUSH_DEFAULT_UNSPECIFIED:
1754         case PUSH_DEFAULT_SIMPLE:
1755                 {
1756                         const char *up, *cur;
1757
1758                         up = branch_get_upstream(branch, err);
1759                         if (!up)
1760                                 return NULL;
1761                         cur = tracking_for_push_dest(remote, branch->refname, err);
1762                         if (!cur)
1763                                 return NULL;
1764                         if (strcmp(cur, up))
1765                                 return error_buf(err,
1766                                                  _("cannot resolve 'simple' push to a single destination"));
1767                         return cur;
1768                 }
1769         }
1770
1771         die("BUG: unhandled push situation");
1772 }
1773
1774 const char *branch_get_push(struct branch *branch, struct strbuf *err)
1775 {
1776         if (!branch)
1777                 return error_buf(err, _("HEAD does not point to a branch"));
1778
1779         if (!branch->push_tracking_ref)
1780                 branch->push_tracking_ref = branch_get_push_1(branch, err);
1781         return branch->push_tracking_ref;
1782 }
1783
1784 static int ignore_symref_update(const char *refname)
1785 {
1786         struct object_id oid;
1787         int flag;
1788
1789         if (!resolve_ref_unsafe(refname, 0, oid.hash, &flag))
1790                 return 0; /* non-existing refs are OK */
1791         return (flag & REF_ISSYMREF);
1792 }
1793
1794 /*
1795  * Create and return a list of (struct ref) consisting of copies of
1796  * each remote_ref that matches refspec.  refspec must be a pattern.
1797  * Fill in the copies' peer_ref to describe the local tracking refs to
1798  * which they map.  Omit any references that would map to an existing
1799  * local symbolic ref.
1800  */
1801 static struct ref *get_expanded_map(const struct ref *remote_refs,
1802                                     const struct refspec *refspec)
1803 {
1804         const struct ref *ref;
1805         struct ref *ret = NULL;
1806         struct ref **tail = &ret;
1807
1808         for (ref = remote_refs; ref; ref = ref->next) {
1809                 char *expn_name = NULL;
1810
1811                 if (strchr(ref->name, '^'))
1812                         continue; /* a dereference item */
1813                 if (match_name_with_pattern(refspec->src, ref->name,
1814                                             refspec->dst, &expn_name) &&
1815                     !ignore_symref_update(expn_name)) {
1816                         struct ref *cpy = copy_ref(ref);
1817
1818                         cpy->peer_ref = alloc_ref(expn_name);
1819                         if (refspec->force)
1820                                 cpy->peer_ref->force = 1;
1821                         *tail = cpy;
1822                         tail = &cpy->next;
1823                 }
1824                 free(expn_name);
1825         }
1826
1827         return ret;
1828 }
1829
1830 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1831 {
1832         const struct ref *ref;
1833         for (ref = refs; ref; ref = ref->next) {
1834                 if (refname_match(name, ref->name))
1835                         return ref;
1836         }
1837         return NULL;
1838 }
1839
1840 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1841 {
1842         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1843
1844         if (!ref)
1845                 return NULL;
1846
1847         return copy_ref(ref);
1848 }
1849
1850 static struct ref *get_local_ref(const char *name)
1851 {
1852         if (!name || name[0] == '\0')
1853                 return NULL;
1854
1855         if (starts_with(name, "refs/"))
1856                 return alloc_ref(name);
1857
1858         if (starts_with(name, "heads/") ||
1859             starts_with(name, "tags/") ||
1860             starts_with(name, "remotes/"))
1861                 return alloc_ref_with_prefix("refs/", 5, name);
1862
1863         return alloc_ref_with_prefix("refs/heads/", 11, name);
1864 }
1865
1866 int get_fetch_map(const struct ref *remote_refs,
1867                   const struct refspec *refspec,
1868                   struct ref ***tail,
1869                   int missing_ok)
1870 {
1871         struct ref *ref_map, **rmp;
1872
1873         if (refspec->pattern) {
1874                 ref_map = get_expanded_map(remote_refs, refspec);
1875         } else {
1876                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1877
1878                 if (refspec->exact_sha1) {
1879                         ref_map = alloc_ref(name);
1880                         get_oid_hex(name, &ref_map->old_oid);
1881                 } else {
1882                         ref_map = get_remote_ref(remote_refs, name);
1883                 }
1884                 if (!missing_ok && !ref_map)
1885                         die("Couldn't find remote ref %s", name);
1886                 if (ref_map) {
1887                         ref_map->peer_ref = get_local_ref(refspec->dst);
1888                         if (ref_map->peer_ref && refspec->force)
1889                                 ref_map->peer_ref->force = 1;
1890                 }
1891         }
1892
1893         for (rmp = &ref_map; *rmp; ) {
1894                 if ((*rmp)->peer_ref) {
1895                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1896                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1897                                 struct ref *ignore = *rmp;
1898                                 error("* Ignoring funny ref '%s' locally",
1899                                       (*rmp)->peer_ref->name);
1900                                 *rmp = (*rmp)->next;
1901                                 free(ignore->peer_ref);
1902                                 free(ignore);
1903                                 continue;
1904                         }
1905                 }
1906                 rmp = &((*rmp)->next);
1907         }
1908
1909         if (ref_map)
1910                 tail_link_ref(ref_map, tail);
1911
1912         return 0;
1913 }
1914
1915 int resolve_remote_symref(struct ref *ref, struct ref *list)
1916 {
1917         if (!ref->symref)
1918                 return 0;
1919         for (; list; list = list->next)
1920                 if (!strcmp(ref->symref, list->name)) {
1921                         oidcpy(&ref->old_oid, &list->old_oid);
1922                         return 0;
1923                 }
1924         return 1;
1925 }
1926
1927 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1928 {
1929         while (list) {
1930                 struct commit *commit = pop_commit(&list);
1931                 commit->object.flags &= ~mark;
1932         }
1933 }
1934
1935 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1936 {
1937         struct object *o;
1938         struct commit *old, *new;
1939         struct commit_list *list, *used;
1940         int found = 0;
1941
1942         /*
1943          * Both new and old must be commit-ish and new is descendant of
1944          * old.  Otherwise we require --force.
1945          */
1946         o = deref_tag(parse_object(old_oid->hash), NULL, 0);
1947         if (!o || o->type != OBJ_COMMIT)
1948                 return 0;
1949         old = (struct commit *) o;
1950
1951         o = deref_tag(parse_object(new_oid->hash), NULL, 0);
1952         if (!o || o->type != OBJ_COMMIT)
1953                 return 0;
1954         new = (struct commit *) o;
1955
1956         if (parse_commit(new) < 0)
1957                 return 0;
1958
1959         used = list = NULL;
1960         commit_list_insert(new, &list);
1961         while (list) {
1962                 new = pop_most_recent_commit(&list, TMP_MARK);
1963                 commit_list_insert(new, &used);
1964                 if (new == old) {
1965                         found = 1;
1966                         break;
1967                 }
1968         }
1969         unmark_and_free(list, TMP_MARK);
1970         unmark_and_free(used, TMP_MARK);
1971         return found;
1972 }
1973
1974 /*
1975  * Compare a branch with its upstream, and save their differences (number
1976  * of commits) in *num_ours and *num_theirs. The name of the upstream branch
1977  * (or NULL if no upstream is defined) is returned via *upstream_name, if it
1978  * is not itself NULL.
1979  *
1980  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1981  * upstream defined, or ref does not exist), 0 otherwise.
1982  */
1983 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
1984                        const char **upstream_name)
1985 {
1986         struct object_id oid;
1987         struct commit *ours, *theirs;
1988         struct rev_info revs;
1989         const char *base;
1990         struct argv_array argv = ARGV_ARRAY_INIT;
1991
1992         /* Cannot stat unless we are marked to build on top of somebody else. */
1993         base = branch_get_upstream(branch, NULL);
1994         if (upstream_name)
1995                 *upstream_name = base;
1996         if (!base)
1997                 return -1;
1998
1999         /* Cannot stat if what we used to build on no longer exists */
2000         if (read_ref(base, oid.hash))
2001                 return -1;
2002         theirs = lookup_commit_reference(oid.hash);
2003         if (!theirs)
2004                 return -1;
2005
2006         if (read_ref(branch->refname, oid.hash))
2007                 return -1;
2008         ours = lookup_commit_reference(oid.hash);
2009         if (!ours)
2010                 return -1;
2011
2012         /* are we the same? */
2013         if (theirs == ours) {
2014                 *num_theirs = *num_ours = 0;
2015                 return 0;
2016         }
2017
2018         /* Run "rev-list --left-right ours...theirs" internally... */
2019         argv_array_push(&argv, ""); /* ignored */
2020         argv_array_push(&argv, "--left-right");
2021         argv_array_pushf(&argv, "%s...%s",
2022                          oid_to_hex(&ours->object.oid),
2023                          oid_to_hex(&theirs->object.oid));
2024         argv_array_push(&argv, "--");
2025
2026         init_revisions(&revs, NULL);
2027         setup_revisions(argv.argc, argv.argv, &revs, NULL);
2028         if (prepare_revision_walk(&revs))
2029                 die("revision walk setup failed");
2030
2031         /* ... and count the commits on each side. */
2032         *num_ours = 0;
2033         *num_theirs = 0;
2034         while (1) {
2035                 struct commit *c = get_revision(&revs);
2036                 if (!c)
2037                         break;
2038                 if (c->object.flags & SYMMETRIC_LEFT)
2039                         (*num_ours)++;
2040                 else
2041                         (*num_theirs)++;
2042         }
2043
2044         /* clear object flags smudged by the above traversal */
2045         clear_commit_marks(ours, ALL_REV_FLAGS);
2046         clear_commit_marks(theirs, ALL_REV_FLAGS);
2047
2048         argv_array_clear(&argv);
2049         return 0;
2050 }
2051
2052 /*
2053  * Return true when there is anything to report, otherwise false.
2054  */
2055 int format_tracking_info(struct branch *branch, struct strbuf *sb)
2056 {
2057         int ours, theirs;
2058         const char *full_base;
2059         char *base;
2060         int upstream_is_gone = 0;
2061
2062         if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2063                 if (!full_base)
2064                         return 0;
2065                 upstream_is_gone = 1;
2066         }
2067
2068         base = shorten_unambiguous_ref(full_base, 0);
2069         if (upstream_is_gone) {
2070                 strbuf_addf(sb,
2071                         _("Your branch is based on '%s', but the upstream is gone.\n"),
2072                         base);
2073                 if (advice_status_hints)
2074                         strbuf_addstr(sb,
2075                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2076         } else if (!ours && !theirs) {
2077                 strbuf_addf(sb,
2078                         _("Your branch is up-to-date with '%s'.\n"),
2079                         base);
2080         } else if (!theirs) {
2081                 strbuf_addf(sb,
2082                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2083                            "Your branch is ahead of '%s' by %d commits.\n",
2084                            ours),
2085                         base, ours);
2086                 if (advice_status_hints)
2087                         strbuf_addstr(sb,
2088                                 _("  (use \"git push\" to publish your local commits)\n"));
2089         } else if (!ours) {
2090                 strbuf_addf(sb,
2091                         Q_("Your branch is behind '%s' by %d commit, "
2092                                "and can be fast-forwarded.\n",
2093                            "Your branch is behind '%s' by %d commits, "
2094                                "and can be fast-forwarded.\n",
2095                            theirs),
2096                         base, theirs);
2097                 if (advice_status_hints)
2098                         strbuf_addstr(sb,
2099                                 _("  (use \"git pull\" to update your local branch)\n"));
2100         } else {
2101                 strbuf_addf(sb,
2102                         Q_("Your branch and '%s' have diverged,\n"
2103                                "and have %d and %d different commit each, "
2104                                "respectively.\n",
2105                            "Your branch and '%s' have diverged,\n"
2106                                "and have %d and %d different commits each, "
2107                                "respectively.\n",
2108                            ours + theirs),
2109                         base, ours, theirs);
2110                 if (advice_status_hints)
2111                         strbuf_addstr(sb,
2112                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2113         }
2114         free(base);
2115         return 1;
2116 }
2117
2118 static int one_local_ref(const char *refname, const struct object_id *oid,
2119                          int flag, void *cb_data)
2120 {
2121         struct ref ***local_tail = cb_data;
2122         struct ref *ref;
2123
2124         /* we already know it starts with refs/ to get here */
2125         if (check_refname_format(refname + 5, 0))
2126                 return 0;
2127
2128         ref = alloc_ref(refname);
2129         oidcpy(&ref->new_oid, oid);
2130         **local_tail = ref;
2131         *local_tail = &ref->next;
2132         return 0;
2133 }
2134
2135 struct ref *get_local_heads(void)
2136 {
2137         struct ref *local_refs = NULL, **local_tail = &local_refs;
2138
2139         for_each_ref(one_local_ref, &local_tail);
2140         return local_refs;
2141 }
2142
2143 struct ref *guess_remote_head(const struct ref *head,
2144                               const struct ref *refs,
2145                               int all)
2146 {
2147         const struct ref *r;
2148         struct ref *list = NULL;
2149         struct ref **tail = &list;
2150
2151         if (!head)
2152                 return NULL;
2153
2154         /*
2155          * Some transports support directly peeking at
2156          * where HEAD points; if that is the case, then
2157          * we don't have to guess.
2158          */
2159         if (head->symref)
2160                 return copy_ref(find_ref_by_name(refs, head->symref));
2161
2162         /* If refs/heads/master could be right, it is. */
2163         if (!all) {
2164                 r = find_ref_by_name(refs, "refs/heads/master");
2165                 if (r && !oidcmp(&r->old_oid, &head->old_oid))
2166                         return copy_ref(r);
2167         }
2168
2169         /* Look for another ref that points there */
2170         for (r = refs; r; r = r->next) {
2171                 if (r != head &&
2172                     starts_with(r->name, "refs/heads/") &&
2173                     !oidcmp(&r->old_oid, &head->old_oid)) {
2174                         *tail = copy_ref(r);
2175                         tail = &((*tail)->next);
2176                         if (!all)
2177                                 break;
2178                 }
2179         }
2180
2181         return list;
2182 }
2183
2184 struct stale_heads_info {
2185         struct string_list *ref_names;
2186         struct ref **stale_refs_tail;
2187         struct refspec *refs;
2188         int ref_count;
2189 };
2190
2191 static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2192                               int flags, void *cb_data)
2193 {
2194         struct stale_heads_info *info = cb_data;
2195         struct string_list matches = STRING_LIST_INIT_DUP;
2196         struct refspec query;
2197         int i, stale = 1;
2198         memset(&query, 0, sizeof(struct refspec));
2199         query.dst = (char *)refname;
2200
2201         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2202         if (matches.nr == 0)
2203                 goto clean_exit; /* No matches */
2204
2205         /*
2206          * If we did find a suitable refspec and it's not a symref and
2207          * it's not in the list of refs that currently exist in that
2208          * remote, we consider it to be stale. In order to deal with
2209          * overlapping refspecs, we need to go over all of the
2210          * matching refs.
2211          */
2212         if (flags & REF_ISSYMREF)
2213                 goto clean_exit;
2214
2215         for (i = 0; stale && i < matches.nr; i++)
2216                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2217                         stale = 0;
2218
2219         if (stale) {
2220                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2221                 oidcpy(&ref->new_oid, oid);
2222         }
2223
2224 clean_exit:
2225         string_list_clear(&matches, 0);
2226         return 0;
2227 }
2228
2229 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2230 {
2231         struct ref *ref, *stale_refs = NULL;
2232         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2233         struct stale_heads_info info;
2234
2235         info.ref_names = &ref_names;
2236         info.stale_refs_tail = &stale_refs;
2237         info.refs = refs;
2238         info.ref_count = ref_count;
2239         for (ref = fetch_map; ref; ref = ref->next)
2240                 string_list_append(&ref_names, ref->name);
2241         string_list_sort(&ref_names);
2242         for_each_ref(get_stale_heads_cb, &info);
2243         string_list_clear(&ref_names, 0);
2244         return stale_refs;
2245 }
2246
2247 /*
2248  * Compare-and-swap
2249  */
2250 static void clear_cas_option(struct push_cas_option *cas)
2251 {
2252         int i;
2253
2254         for (i = 0; i < cas->nr; i++)
2255                 free(cas->entry[i].refname);
2256         free(cas->entry);
2257         memset(cas, 0, sizeof(*cas));
2258 }
2259
2260 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2261                                       const char *refname,
2262                                       size_t refnamelen)
2263 {
2264         struct push_cas *entry;
2265         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2266         entry = &cas->entry[cas->nr++];
2267         memset(entry, 0, sizeof(*entry));
2268         entry->refname = xmemdupz(refname, refnamelen);
2269         return entry;
2270 }
2271
2272 static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2273 {
2274         const char *colon;
2275         struct push_cas *entry;
2276
2277         if (unset) {
2278                 /* "--no-<option>" */
2279                 clear_cas_option(cas);
2280                 return 0;
2281         }
2282
2283         if (!arg) {
2284                 /* just "--<option>" */
2285                 cas->use_tracking_for_rest = 1;
2286                 return 0;
2287         }
2288
2289         /* "--<option>=refname" or "--<option>=refname:value" */
2290         colon = strchrnul(arg, ':');
2291         entry = add_cas_entry(cas, arg, colon - arg);
2292         if (!*colon)
2293                 entry->use_tracking = 1;
2294         else if (!colon[1])
2295                 hashclr(entry->expect);
2296         else if (get_sha1(colon + 1, entry->expect))
2297                 return error("cannot parse expected object name '%s'", colon + 1);
2298         return 0;
2299 }
2300
2301 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2302 {
2303         return parse_push_cas_option(opt->value, arg, unset);
2304 }
2305
2306 int is_empty_cas(const struct push_cas_option *cas)
2307 {
2308         return !cas->use_tracking_for_rest && !cas->nr;
2309 }
2310
2311 /*
2312  * Look at remote.fetch refspec and see if we have a remote
2313  * tracking branch for the refname there.  Fill its current
2314  * value in sha1[].
2315  * If we cannot do so, return negative to signal an error.
2316  */
2317 static int remote_tracking(struct remote *remote, const char *refname,
2318                            struct object_id *oid)
2319 {
2320         char *dst;
2321
2322         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2323         if (!dst)
2324                 return -1; /* no tracking ref for refname at remote */
2325         if (read_ref(dst, oid->hash))
2326                 return -1; /* we know what the tracking ref is but we cannot read it */
2327         return 0;
2328 }
2329
2330 static void apply_cas(struct push_cas_option *cas,
2331                       struct remote *remote,
2332                       struct ref *ref)
2333 {
2334         int i;
2335
2336         /* Find an explicit --<option>=<name>[:<value>] entry */
2337         for (i = 0; i < cas->nr; i++) {
2338                 struct push_cas *entry = &cas->entry[i];
2339                 if (!refname_match(entry->refname, ref->name))
2340                         continue;
2341                 ref->expect_old_sha1 = 1;
2342                 if (!entry->use_tracking)
2343                         hashcpy(ref->old_oid_expect.hash, cas->entry[i].expect);
2344                 else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2345                         oidclr(&ref->old_oid_expect);
2346                 return;
2347         }
2348
2349         /* Are we using "--<option>" to cover all? */
2350         if (!cas->use_tracking_for_rest)
2351                 return;
2352
2353         ref->expect_old_sha1 = 1;
2354         if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2355                 oidclr(&ref->old_oid_expect);
2356 }
2357
2358 void apply_push_cas(struct push_cas_option *cas,
2359                     struct remote *remote,
2360                     struct ref *remote_refs)
2361 {
2362         struct ref *ref;
2363         for (ref = remote_refs; ref; ref = ref->next)
2364                 apply_cas(cas, remote, ref);
2365 }