remote.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "remote.h"
   4 #include "refs.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "revision.h"
   8 #include "dir.h"
   9 #include "tag.h"
  10 #include "string-list.h"
  11 #include "mergesort.h"
  12 #include "argv-array.h"
  13
  14 enum map_direction { FROM_SRC, FROM_DST };
  15
  16 static struct refspec s_tag_refspec = {
  17         0,
  18         1,
  19         0,
  20         0,
  21         "refs/tags/*",
  22         "refs/tags/*"
  23 };
  24
  25 const struct refspec *tag_refspec = &s_tag_refspec;
  26
  27 struct counted_string {
  28         size_t len;
  29         const char *s;
  30 };
  31 struct rewrite {
  32         const char *base;
  33         size_t baselen;
  34         struct counted_string *instead_of;
  35         int instead_of_nr;
  36         int instead_of_alloc;
  37 };
  38 struct rewrites {
  39         struct rewrite **rewrite;
  40         int rewrite_alloc;
  41         int rewrite_nr;
  42 };
  43
  44 static struct remote **remotes;
  45 static int remotes_alloc;
  46 static int remotes_nr;
  47 static struct hashmap remotes_hash;
  48
  49 static struct branch **branches;
  50 static int branches_alloc;
  51 static int branches_nr;
  52
  53 static struct branch *current_branch;
  54 static const char *pushremote_name;
  55
  56 static struct rewrites rewrites;
  57 static struct rewrites rewrites_push;
  58
  59 static int valid_remote(const struct remote *remote)
  60 {
  61         return (!!remote->url) || (!!remote->foreign_vcs);
  62 }
  63
  64 static const char *alias_url(const char *url, struct rewrites *r)
  65 {
  66         int i, j;
  67         struct counted_string *longest;
  68         int longest_i;
  69
  70         longest = NULL;
  71         longest_i = -1;
  72         for (i = 0; i < r->rewrite_nr; i++) {
  73                 if (!r->rewrite[i])
  74                         continue;
  75                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  76                         if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  77                             (!longest ||
  78                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  79                                 longest = &(r->rewrite[i]->instead_of[j]);
  80                                 longest_i = i;
  81                         }
  82                 }
  83         }
  84         if (!longest)
  85                 return url;
  86
  87         return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  88 }
  89
  90 static void add_push_refspec(struct remote *remote, const char *ref)
  91 {
  92         ALLOC_GROW(remote->push_refspec,
  93                    remote->push_refspec_nr + 1,
  94                    remote->push_refspec_alloc);
  95         remote->push_refspec[remote->push_refspec_nr++] = ref;
  96 }
  97
  98 static void add_fetch_refspec(struct remote *remote, const char *ref)
  99 {
 100         ALLOC_GROW(remote->fetch_refspec,
 101                    remote->fetch_refspec_nr + 1,
 102                    remote->fetch_refspec_alloc);
 103         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 104 }
 105
 106 static void add_url(struct remote *remote, const char *url)
 107 {
 108         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 109         remote->url[remote->url_nr++] = url;
 110 }
 111
 112 static void add_pushurl(struct remote *remote, const char *pushurl)
 113 {
 114         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 115         remote->pushurl[remote->pushurl_nr++] = pushurl;
 116 }
 117
 118 static void add_pushurl_alias(struct remote *remote, const char *url)
 119 {
 120         const char *pushurl = alias_url(url, &rewrites_push);
 121         if (pushurl != url)
 122                 add_pushurl(remote, pushurl);
 123 }
 124
 125 static void add_url_alias(struct remote *remote, const char *url)
 126 {
 127         add_url(remote, alias_url(url, &rewrites));
 128         add_pushurl_alias(remote, url);
 129 }
 130
 131 struct remotes_hash_key {
 132         const char *str;
 133         int len;
 134 };
 135
 136 static int remotes_hash_cmp(const void *unused_cmp_data,
 137                             const void *entry,
 138                             const void *entry_or_key,
 139                             const void *keydata)
 140 {
 141         const struct remote *a = entry;
 142         const struct remote *b = entry_or_key;
 143         const struct remotes_hash_key *key = keydata;
 144
 145         if (key)
 146                 return strncmp(a->name, key->str, key->len) || a->name[key->len];
 147         else
 148                 return strcmp(a->name, b->name);
 149 }
 150
 151 static inline void init_remotes_hash(void)
 152 {
 153         if (!remotes_hash.cmpfn)
 154                 hashmap_init(&remotes_hash, remotes_hash_cmp, NULL, 0);
 155 }
 156
 157 static struct remote *make_remote(const char *name, int len)
 158 {
 159         struct remote *ret, *replaced;
 160         struct remotes_hash_key lookup;
 161         struct hashmap_entry lookup_entry;
 162
 163         if (!len)
 164                 len = strlen(name);
 165
 166         init_remotes_hash();
 167         lookup.str = name;
 168         lookup.len = len;
 169         hashmap_entry_init(&lookup_entry, memhash(name, len));
 170
 171         if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 172                 return ret;
 173
 174         ret = xcalloc(1, sizeof(struct remote));
 175         ret->prune = -1;  /* unspecified */
 176         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 177         remotes[remotes_nr++] = ret;
 178         ret->name = xstrndup(name, len);
 179
 180         hashmap_entry_init(ret, lookup_entry.hash);
 181         replaced = hashmap_put(&remotes_hash, ret);
 182         assert(replaced == NULL);  /* no previous entry overwritten */
 183         return ret;
 184 }
 185
 186 static void add_merge(struct branch *branch, const char *name)
 187 {
 188         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 189                    branch->merge_alloc);
 190         branch->merge_name[branch->merge_nr++] = name;
 191 }
 192
 193 static struct branch *make_branch(const char *name, int len)
 194 {
 195         struct branch *ret;
 196         int i;
 197
 198         for (i = 0; i < branches_nr; i++) {
 199                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 200                            !branches[i]->name[len]) :
 201                     !strcmp(name, branches[i]->name))
 202                         return branches[i];
 203         }
 204
 205         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 206         ret = xcalloc(1, sizeof(struct branch));
 207         branches[branches_nr++] = ret;
 208         if (len)
 209                 ret->name = xstrndup(name, len);
 210         else
 211                 ret->name = xstrdup(name);
 212         ret->refname = xstrfmt("refs/heads/%s", ret->name);
 213
 214         return ret;
 215 }
 216
 217 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 218 {
 219         struct rewrite *ret;
 220         int i;
 221
 222         for (i = 0; i < r->rewrite_nr; i++) {
 223                 if (len
 224                     ? (len == r->rewrite[i]->baselen &&
 225                        !strncmp(base, r->rewrite[i]->base, len))
 226                     : !strcmp(base, r->rewrite[i]->base))
 227                         return r->rewrite[i];
 228         }
 229
 230         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 231         ret = xcalloc(1, sizeof(struct rewrite));
 232         r->rewrite[r->rewrite_nr++] = ret;
 233         if (len) {
 234                 ret->base = xstrndup(base, len);
 235                 ret->baselen = len;
 236         }
 237         else {
 238                 ret->base = xstrdup(base);
 239                 ret->baselen = strlen(base);
 240         }
 241         return ret;
 242 }
 243
 244 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 245 {
 246         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 247         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 248         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 249         rewrite->instead_of_nr++;
 250 }
 251
 252 static const char *skip_spaces(const char *s)
 253 {
 254         while (isspace(*s))
 255                 s++;
 256         return s;
 257 }
 258
 259 static void read_remotes_file(struct remote *remote)
 260 {
 261         struct strbuf buf = STRBUF_INIT;
 262         FILE *f = fopen_or_warn(git_path("remotes/%s", remote->name), "r");
 263
 264         if (!f)
 265                 return;
 266         remote->configured_in_repo = 1;
 267         remote->origin = REMOTE_REMOTES;
 268         while (strbuf_getline(&buf, f) != EOF) {
 269                 const char *v;
 270
 271                 strbuf_rtrim(&buf);
 272
 273                 if (skip_prefix(buf.buf, "URL:", &v))
 274                         add_url_alias(remote, xstrdup(skip_spaces(v)));
 275                 else if (skip_prefix(buf.buf, "Push:", &v))
 276                         add_push_refspec(remote, xstrdup(skip_spaces(v)));
 277                 else if (skip_prefix(buf.buf, "Pull:", &v))
 278                         add_fetch_refspec(remote, xstrdup(skip_spaces(v)));
 279         }
 280         strbuf_release(&buf);
 281         fclose(f);
 282 }
 283
 284 static void read_branches_file(struct remote *remote)
 285 {
 286         char *frag;
 287         struct strbuf buf = STRBUF_INIT;
 288         FILE *f = fopen_or_warn(git_path("branches/%s", remote->name), "r");
 289
 290         if (!f)
 291                 return;
 292
 293         strbuf_getline_lf(&buf, f);
 294         fclose(f);
 295         strbuf_trim(&buf);
 296         if (!buf.len) {
 297                 strbuf_release(&buf);
 298                 return;
 299         }
 300
 301         remote->configured_in_repo = 1;
 302         remote->origin = REMOTE_BRANCHES;
 303
 304         /*
 305          * The branches file would have URL and optionally
 306          * #branch specified.  The "master" (or specified) branch is
 307          * fetched and stored in the local branch matching the
 308          * remote name.
 309          */
 310         frag = strchr(buf.buf, '#');
 311         if (frag)
 312                 *(frag++) = '\0';
 313         else
 314                 frag = "master";
 315
 316         add_url_alias(remote, strbuf_detach(&buf, NULL));
 317         add_fetch_refspec(remote, xstrfmt("refs/heads/%s:refs/heads/%s",
 318                                           frag, remote->name));
 319
 320         /*
 321          * Cogito compatible push: push current HEAD to remote #branch
 322          * (master if missing)
 323          */
 324         add_push_refspec(remote, xstrfmt("HEAD:refs/heads/%s", frag));
 325         remote->fetch_tags = 1; /* always auto-follow */
 326 }
 327
 328 static int handle_config(const char *key, const char *value, void *cb)
 329 {
 330         const char *name;
 331         int namelen;
 332         const char *subkey;
 333         struct remote *remote;
 334         struct branch *branch;
 335         if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
 336                 if (!name)
 337                         return 0;
 338                 branch = make_branch(name, namelen);
 339                 if (!strcmp(subkey, "remote")) {
 340                         return git_config_string(&branch->remote_name, key, value);
 341                 } else if (!strcmp(subkey, "pushremote")) {
 342                         return git_config_string(&branch->pushremote_name, key, value);
 343                 } else if (!strcmp(subkey, "merge")) {
 344                         if (!value)
 345                                 return config_error_nonbool(key);
 346                         add_merge(branch, xstrdup(value));
 347                 }
 348                 return 0;
 349         }
 350         if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
 351                 struct rewrite *rewrite;
 352                 if (!name)
 353                         return 0;
 354                 if (!strcmp(subkey, "insteadof")) {
 355                         rewrite = make_rewrite(&rewrites, name, namelen);
 356                         if (!value)
 357                                 return config_error_nonbool(key);
 358                         add_instead_of(rewrite, xstrdup(value));
 359                 } else if (!strcmp(subkey, "pushinsteadof")) {
 360                         rewrite = make_rewrite(&rewrites_push, name, namelen);
 361                         if (!value)
 362                                 return config_error_nonbool(key);
 363                         add_instead_of(rewrite, xstrdup(value));
 364                 }
 365         }
 366
 367         if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
 368                 return 0;
 369
 370         /* Handle remote.* variables */
 371         if (!name && !strcmp(subkey, "pushdefault"))
 372                 return git_config_string(&pushremote_name, key, value);
 373
 374         if (!name)
 375                 return 0;
 376         /* Handle remote.<name>.* variables */
 377         if (*name == '/') {
 378                 warning("Config remote shorthand cannot begin with '/': %s",
 379                         name);
 380                 return 0;
 381         }
 382         remote = make_remote(name, namelen);
 383         remote->origin = REMOTE_CONFIG;
 384         if (current_config_scope() == CONFIG_SCOPE_REPO)
 385                 remote->configured_in_repo = 1;
 386         if (!strcmp(subkey, "mirror"))
 387                 remote->mirror = git_config_bool(key, value);
 388         else if (!strcmp(subkey, "skipdefaultupdate"))
 389                 remote->skip_default_update = git_config_bool(key, value);
 390         else if (!strcmp(subkey, "skipfetchall"))
 391                 remote->skip_default_update = git_config_bool(key, value);
 392         else if (!strcmp(subkey, "prune"))
 393                 remote->prune = git_config_bool(key, value);
 394         else if (!strcmp(subkey, "url")) {
 395                 const char *v;
 396                 if (git_config_string(&v, key, value))
 397                         return -1;
 398                 add_url(remote, v);
 399         } else if (!strcmp(subkey, "pushurl")) {
 400                 const char *v;
 401                 if (git_config_string(&v, key, value))
 402                         return -1;
 403                 add_pushurl(remote, v);
 404         } else if (!strcmp(subkey, "push")) {
 405                 const char *v;
 406                 if (git_config_string(&v, key, value))
 407                         return -1;
 408                 add_push_refspec(remote, v);
 409         } else if (!strcmp(subkey, "fetch")) {
 410                 const char *v;
 411                 if (git_config_string(&v, key, value))
 412                         return -1;
 413                 add_fetch_refspec(remote, v);
 414         } else if (!strcmp(subkey, "receivepack")) {
 415                 const char *v;
 416                 if (git_config_string(&v, key, value))
 417                         return -1;
 418                 if (!remote->receivepack)
 419                         remote->receivepack = v;
 420                 else
 421                         error("more than one receivepack given, using the first");
 422         } else if (!strcmp(subkey, "uploadpack")) {
 423                 const char *v;
 424                 if (git_config_string(&v, key, value))
 425                         return -1;
 426                 if (!remote->uploadpack)
 427                         remote->uploadpack = v;
 428                 else
 429                         error("more than one uploadpack given, using the first");
 430         } else if (!strcmp(subkey, "tagopt")) {
 431                 if (!strcmp(value, "--no-tags"))
 432                         remote->fetch_tags = -1;
 433                 else if (!strcmp(value, "--tags"))
 434                         remote->fetch_tags = 2;
 435         } else if (!strcmp(subkey, "proxy")) {
 436                 return git_config_string((const char **)&remote->http_proxy,
 437                                          key, value);
 438         } else if (!strcmp(subkey, "proxyauthmethod")) {
 439                 return git_config_string((const char **)&remote->http_proxy_authmethod,
 440                                          key, value);
 441         } else if (!strcmp(subkey, "vcs")) {
 442                 return git_config_string(&remote->foreign_vcs, key, value);
 443         }
 444         return 0;
 445 }
 446
 447 static void alias_all_urls(void)
 448 {
 449         int i, j;
 450         for (i = 0; i < remotes_nr; i++) {
 451                 int add_pushurl_aliases;
 452                 if (!remotes[i])
 453                         continue;
 454                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 455                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 456                 }
 457                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 458                 for (j = 0; j < remotes[i]->url_nr; j++) {
 459                         if (add_pushurl_aliases)
 460                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 461                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 462                 }
 463         }
 464 }
 465
 466 static void read_config(void)
 467 {
 468         static int loaded;
 469         int flag;
 470
 471         if (loaded)
 472                 return;
 473         loaded = 1;
 474
 475         current_branch = NULL;
 476         if (startup_info->have_repository) {
 477                 const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
 478                 if (head_ref && (flag & REF_ISSYMREF) &&
 479                     skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 480                         current_branch = make_branch(head_ref, 0);
 481                 }
 482         }
 483         git_config(handle_config, NULL);
 484         alias_all_urls();
 485 }
 486
 487 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 488 {
 489         int i;
 490         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 491
 492         for (i = 0; i < nr_refspec; i++) {
 493                 size_t llen;
 494                 int is_glob;
 495                 const char *lhs, *rhs;
 496                 int flags;
 497
 498                 is_glob = 0;
 499
 500                 lhs = refspec[i];
 501                 if (*lhs == '+') {
 502                         rs[i].force = 1;
 503                         lhs++;
 504                 }
 505
 506                 rhs = strrchr(lhs, ':');
 507
 508                 /*
 509                  * Before going on, special case ":" (or "+:") as a refspec
 510                  * for pushing matching refs.
 511                  */
 512                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 513                         rs[i].matching = 1;
 514                         continue;
 515                 }
 516
 517                 if (rhs) {
 518                         size_t rlen = strlen(++rhs);
 519                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 520                         rs[i].dst = xstrndup(rhs, rlen);
 521                 }
 522
 523                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 524                 if (1 <= llen && memchr(lhs, '*', llen)) {
 525                         if ((rhs && !is_glob) || (!rhs && fetch))
 526                                 goto invalid;
 527                         is_glob = 1;
 528                 } else if (rhs && is_glob) {
 529                         goto invalid;
 530                 }
 531
 532                 rs[i].pattern = is_glob;
 533                 rs[i].src = xstrndup(lhs, llen);
 534                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 535
 536                 if (fetch) {
 537                         struct object_id unused;
 538
 539                         /* LHS */
 540                         if (!*rs[i].src)
 541                                 ; /* empty is ok; it means "HEAD" */
 542                         else if (llen == GIT_SHA1_HEXSZ && !get_oid_hex(rs[i].src, &unused))
 543                                 rs[i].exact_sha1 = 1; /* ok */
 544                         else if (!check_refname_format(rs[i].src, flags))
 545                                 ; /* valid looking ref is ok */
 546                         else
 547                                 goto invalid;
 548                         /* RHS */
 549                         if (!rs[i].dst)
 550                                 ; /* missing is ok; it is the same as empty */
 551                         else if (!*rs[i].dst)
 552                                 ; /* empty is ok; it means "do not store" */
 553                         else if (!check_refname_format(rs[i].dst, flags))
 554                                 ; /* valid looking ref is ok */
 555                         else
 556                                 goto invalid;
 557                 } else {
 558                         /*
 559                          * LHS
 560                          * - empty is allowed; it means delete.
 561                          * - when wildcarded, it must be a valid looking ref.
 562                          * - otherwise, it must be an extended SHA-1, but
 563                          *   there is no existing way to validate this.
 564                          */
 565                         if (!*rs[i].src)
 566                                 ; /* empty is ok */
 567                         else if (is_glob) {
 568                                 if (check_refname_format(rs[i].src, flags))
 569                                         goto invalid;
 570                         }
 571                         else
 572                                 ; /* anything goes, for now */
 573                         /*
 574                          * RHS
 575                          * - missing is allowed, but LHS then must be a
 576                          *   valid looking ref.
 577                          * - empty is not allowed.
 578                          * - otherwise it must be a valid looking ref.
 579                          */
 580                         if (!rs[i].dst) {
 581                                 if (check_refname_format(rs[i].src, flags))
 582                                         goto invalid;
 583                         } else if (!*rs[i].dst) {
 584                                 goto invalid;
 585                         } else {
 586                                 if (check_refname_format(rs[i].dst, flags))
 587                                         goto invalid;
 588                         }
 589                 }
 590         }
 591         return rs;
 592
 593  invalid:
 594         if (verify) {
 595                 /*
 596                  * nr_refspec must be greater than zero and i must be valid
 597                  * since it is only possible to reach this point from within
 598                  * the for loop above.
 599                  */
 600                 free_refspec(i+1, rs);
 601                 return NULL;
 602         }
 603         die("Invalid refspec '%s'", refspec[i]);
 604 }
 605
 606 int valid_fetch_refspec(const char *fetch_refspec_str)
 607 {
 608         struct refspec *refspec;
 609
 610         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 611         free_refspec(1, refspec);
 612         return !!refspec;
 613 }
 614
 615 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 616 {
 617         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 618 }
 619
 620 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 621 {
 622         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 623 }
 624
 625 void free_refspec(int nr_refspec, struct refspec *refspec)
 626 {
 627         int i;
 628
 629         if (!refspec)
 630                 return;
 631
 632         for (i = 0; i < nr_refspec; i++) {
 633                 free(refspec[i].src);
 634                 free(refspec[i].dst);
 635         }
 636         free(refspec);
 637 }
 638
 639 static int valid_remote_nick(const char *name)
 640 {
 641         if (!name[0] || is_dot_or_dotdot(name))
 642                 return 0;
 643
 644         /* remote nicknames cannot contain slashes */
 645         while (*name)
 646                 if (is_dir_sep(*name++))
 647                         return 0;
 648         return 1;
 649 }
 650
 651 const char *remote_for_branch(struct branch *branch, int *explicit)
 652 {
 653         if (branch && branch->remote_name) {
 654                 if (explicit)
 655                         *explicit = 1;
 656                 return branch->remote_name;
 657         }
 658         if (explicit)
 659                 *explicit = 0;
 660         return "origin";
 661 }
 662
 663 const char *pushremote_for_branch(struct branch *branch, int *explicit)
 664 {
 665         if (branch && branch->pushremote_name) {
 666                 if (explicit)
 667                         *explicit = 1;
 668                 return branch->pushremote_name;
 669         }
 670         if (pushremote_name) {
 671                 if (explicit)
 672                         *explicit = 1;
 673                 return pushremote_name;
 674         }
 675         return remote_for_branch(branch, explicit);
 676 }
 677
 678 static struct remote *remote_get_1(const char *name,
 679                                    const char *(*get_default)(struct branch *, int *))
 680 {
 681         struct remote *ret;
 682         int name_given = 0;
 683
 684         read_config();
 685
 686         if (name)
 687                 name_given = 1;
 688         else
 689                 name = get_default(current_branch, &name_given);
 690
 691         ret = make_remote(name, 0);
 692         if (valid_remote_nick(name) && have_git_dir()) {
 693                 if (!valid_remote(ret))
 694                         read_remotes_file(ret);
 695                 if (!valid_remote(ret))
 696                         read_branches_file(ret);
 697         }
 698         if (name_given && !valid_remote(ret))
 699                 add_url_alias(ret, name);
 700         if (!valid_remote(ret))
 701                 return NULL;
 702         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 703         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 704         return ret;
 705 }
 706
 707 struct remote *remote_get(const char *name)
 708 {
 709         return remote_get_1(name, remote_for_branch);
 710 }
 711
 712 struct remote *pushremote_get(const char *name)
 713 {
 714         return remote_get_1(name, pushremote_for_branch);
 715 }
 716
 717 int remote_is_configured(struct remote *remote, int in_repo)
 718 {
 719         if (!remote)
 720                 return 0;
 721         if (in_repo)
 722                 return remote->configured_in_repo;
 723         return !!remote->origin;
 724 }
 725
 726 int for_each_remote(each_remote_fn fn, void *priv)
 727 {
 728         int i, result = 0;
 729         read_config();
 730         for (i = 0; i < remotes_nr && !result; i++) {
 731                 struct remote *r = remotes[i];
 732                 if (!r)
 733                         continue;
 734                 if (!r->fetch)
 735                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 736                                                        r->fetch_refspec);
 737                 if (!r->push)
 738                         r->push = parse_push_refspec(r->push_refspec_nr,
 739                                                      r->push_refspec);
 740                 result = fn(r, priv);
 741         }
 742         return result;
 743 }
 744
 745 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 746 {
 747         if (strcmp(ref1->name, ref2->name)) {
 748                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 749                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 750                         die(_("Cannot fetch both %s and %s to %s"),
 751                             ref1->name, ref2->name, ref2->peer_ref->name);
 752                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 753                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 754                         warning(_("%s usually tracks %s, not %s"),
 755                                 ref2->peer_ref->name, ref2->name, ref1->name);
 756                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 757                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 758                         die(_("%s tracks both %s and %s"),
 759                             ref2->peer_ref->name, ref1->name, ref2->name);
 760                 } else {
 761                         /*
 762                          * This last possibility doesn't occur because
 763                          * FETCH_HEAD_IGNORE entries always appear at
 764                          * the end of the list.
 765                          */
 766                         die(_("Internal error"));
 767                 }
 768         }
 769         free(ref2->peer_ref);
 770         free(ref2);
 771 }
 772
 773 struct ref *ref_remove_duplicates(struct ref *ref_map)
 774 {
 775         struct string_list refs = STRING_LIST_INIT_NODUP;
 776         struct ref *retval = NULL;
 777         struct ref **p = &retval;
 778
 779         while (ref_map) {
 780                 struct ref *ref = ref_map;
 781
 782                 ref_map = ref_map->next;
 783                 ref->next = NULL;
 784
 785                 if (!ref->peer_ref) {
 786                         *p = ref;
 787                         p = &ref->next;
 788                 } else {
 789                         struct string_list_item *item =
 790                                 string_list_insert(&refs, ref->peer_ref->name);
 791
 792                         if (item->util) {
 793                                 /* Entry already existed */
 794                                 handle_duplicate((struct ref *)item->util, ref);
 795                         } else {
 796                                 *p = ref;
 797                                 p = &ref->next;
 798                                 item->util = ref;
 799                         }
 800                 }
 801         }
 802
 803         string_list_clear(&refs, 0);
 804         return retval;
 805 }
 806
 807 int remote_has_url(struct remote *remote, const char *url)
 808 {
 809         int i;
 810         for (i = 0; i < remote->url_nr; i++) {
 811                 if (!strcmp(remote->url[i], url))
 812                         return 1;
 813         }
 814         return 0;
 815 }
 816
 817 static int match_name_with_pattern(const char *key, const char *name,
 818                                    const char *value, char **result)
 819 {
 820         const char *kstar = strchr(key, '*');
 821         size_t klen;
 822         size_t ksuffixlen;
 823         size_t namelen;
 824         int ret;
 825         if (!kstar)
 826                 die("Key '%s' of pattern had no '*'", key);
 827         klen = kstar - key;
 828         ksuffixlen = strlen(kstar + 1);
 829         namelen = strlen(name);
 830         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 831                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 832         if (ret && value) {
 833                 struct strbuf sb = STRBUF_INIT;
 834                 const char *vstar = strchr(value, '*');
 835                 if (!vstar)
 836                         die("Value '%s' of pattern has no '*'", value);
 837                 strbuf_add(&sb, value, vstar - value);
 838                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 839                 strbuf_addstr(&sb, vstar + 1);
 840                 *result = strbuf_detach(&sb, NULL);
 841         }
 842         return ret;
 843 }
 844
 845 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 846 {
 847         int i;
 848         int find_src = !query->src;
 849
 850         if (find_src && !query->dst)
 851                 error("query_refspecs_multiple: need either src or dst");
 852
 853         for (i = 0; i < ref_count; i++) {
 854                 struct refspec *refspec = &refs[i];
 855                 const char *key = find_src ? refspec->dst : refspec->src;
 856                 const char *value = find_src ? refspec->src : refspec->dst;
 857                 const char *needle = find_src ? query->dst : query->src;
 858                 char **result = find_src ? &query->src : &query->dst;
 859
 860                 if (!refspec->dst)
 861                         continue;
 862                 if (refspec->pattern) {
 863                         if (match_name_with_pattern(key, needle, value, result))
 864                                 string_list_append_nodup(results, *result);
 865                 } else if (!strcmp(needle, key)) {
 866                         string_list_append(results, value);
 867                 }
 868         }
 869 }
 870
 871 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 872 {
 873         int i;
 874         int find_src = !query->src;
 875         const char *needle = find_src ? query->dst : query->src;
 876         char **result = find_src ? &query->src : &query->dst;
 877
 878         if (find_src && !query->dst)
 879                 return error("query_refspecs: need either src or dst");
 880
 881         for (i = 0; i < ref_count; i++) {
 882                 struct refspec *refspec = &refs[i];
 883                 const char *key = find_src ? refspec->dst : refspec->src;
 884                 const char *value = find_src ? refspec->src : refspec->dst;
 885
 886                 if (!refspec->dst)
 887                         continue;
 888                 if (refspec->pattern) {
 889                         if (match_name_with_pattern(key, needle, value, result)) {
 890                                 query->force = refspec->force;
 891                                 return 0;
 892                         }
 893                 } else if (!strcmp(needle, key)) {
 894                         *result = xstrdup(value);
 895                         query->force = refspec->force;
 896                         return 0;
 897                 }
 898         }
 899         return -1;
 900 }
 901
 902 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 903                      const char *name)
 904 {
 905         struct refspec query;
 906
 907         memset(&query, 0, sizeof(struct refspec));
 908         query.src = (char *)name;
 909
 910         if (query_refspecs(refspecs, nr_refspec, &query))
 911                 return NULL;
 912
 913         return query.dst;
 914 }
 915
 916 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 917 {
 918         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 919 }
 920
 921 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 922                 const char *name)
 923 {
 924         size_t len = strlen(name);
 925         struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 926         memcpy(ref->name, prefix, prefixlen);
 927         memcpy(ref->name + prefixlen, name, len);
 928         return ref;
 929 }
 930
 931 struct ref *alloc_ref(const char *name)
 932 {
 933         return alloc_ref_with_prefix("", 0, name);
 934 }
 935
 936 struct ref *copy_ref(const struct ref *ref)
 937 {
 938         struct ref *cpy;
 939         size_t len;
 940         if (!ref)
 941                 return NULL;
 942         len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 943         cpy = xmalloc(len);
 944         memcpy(cpy, ref, len);
 945         cpy->next = NULL;
 946         cpy->symref = xstrdup_or_null(ref->symref);
 947         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 948         cpy->peer_ref = copy_ref(ref->peer_ref);
 949         return cpy;
 950 }
 951
 952 struct ref *copy_ref_list(const struct ref *ref)
 953 {
 954         struct ref *ret = NULL;
 955         struct ref **tail = &ret;
 956         while (ref) {
 957                 *tail = copy_ref(ref);
 958                 ref = ref->next;
 959                 tail = &((*tail)->next);
 960         }
 961         return ret;
 962 }
 963
 964 static void free_ref(struct ref *ref)
 965 {
 966         if (!ref)
 967                 return;
 968         free_ref(ref->peer_ref);
 969         free(ref->remote_status);
 970         free(ref->symref);
 971         free(ref);
 972 }
 973
 974 void free_refs(struct ref *ref)
 975 {
 976         struct ref *next;
 977         while (ref) {
 978                 next = ref->next;
 979                 free_ref(ref);
 980                 ref = next;
 981         }
 982 }
 983
 984 int ref_compare_name(const void *va, const void *vb)
 985 {
 986         const struct ref *a = va, *b = vb;
 987         return strcmp(a->name, b->name);
 988 }
 989
 990 static void *ref_list_get_next(const void *a)
 991 {
 992         return ((const struct ref *)a)->next;
 993 }
 994
 995 static void ref_list_set_next(void *a, void *next)
 996 {
 997         ((struct ref *)a)->next = next;
 998 }
 999
1000 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1001 {
1002         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1003 }
1004
1005 int count_refspec_match(const char *pattern,
1006                         struct ref *refs,
1007                         struct ref **matched_ref)
1008 {
1009         int patlen = strlen(pattern);
1010         struct ref *matched_weak = NULL;
1011         struct ref *matched = NULL;
1012         int weak_match = 0;
1013         int match = 0;
1014
1015         for (weak_match = match = 0; refs; refs = refs->next) {
1016                 char *name = refs->name;
1017                 int namelen = strlen(name);
1018
1019                 if (!refname_match(pattern, name))
1020                         continue;
1021
1022                 /* A match is "weak" if it is with refs outside
1023                  * heads or tags, and did not specify the pattern
1024                  * in full (e.g. "refs/remotes/origin/master") or at
1025                  * least from the toplevel (e.g. "remotes/origin/master");
1026                  * otherwise "git push $URL master" would result in
1027                  * ambiguity between remotes/origin/master and heads/master
1028                  * at the remote site.
1029                  */
1030                 if (namelen != patlen &&
1031                     patlen != namelen - 5 &&
1032                     !starts_with(name, "refs/heads/") &&
1033                     !starts_with(name, "refs/tags/")) {
1034                         /* We want to catch the case where only weak
1035                          * matches are found and there are multiple
1036                          * matches, and where more than one strong
1037                          * matches are found, as ambiguous.  One
1038                          * strong match with zero or more weak matches
1039                          * are acceptable as a unique match.
1040                          */
1041                         matched_weak = refs;
1042                         weak_match++;
1043                 }
1044                 else {
1045                         matched = refs;
1046                         match++;
1047                 }
1048         }
1049         if (!matched) {
1050                 if (matched_ref)
1051                         *matched_ref = matched_weak;
1052                 return weak_match;
1053         }
1054         else {
1055                 if (matched_ref)
1056                         *matched_ref = matched;
1057                 return match;
1058         }
1059 }
1060
1061 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1062 {
1063         **tail = ref;
1064         while (ref->next)
1065                 ref = ref->next;
1066         *tail = &ref->next;
1067 }
1068
1069 static struct ref *alloc_delete_ref(void)
1070 {
1071         struct ref *ref = alloc_ref("(delete)");
1072         oidclr(&ref->new_oid);
1073         return ref;
1074 }
1075
1076 static int try_explicit_object_name(const char *name,
1077                                     struct ref **match)
1078 {
1079         struct object_id oid;
1080
1081         if (!*name) {
1082                 if (match)
1083                         *match = alloc_delete_ref();
1084                 return 0;
1085         }
1086
1087         if (get_oid(name, &oid))
1088                 return -1;
1089
1090         if (match) {
1091                 *match = alloc_ref(name);
1092                 oidcpy(&(*match)->new_oid, &oid);
1093         }
1094         return 0;
1095 }
1096
1097 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1098 {
1099         struct ref *ret = alloc_ref(name);
1100         tail_link_ref(ret, tail);
1101         return ret;
1102 }
1103
1104 static char *guess_ref(const char *name, struct ref *peer)
1105 {
1106         struct strbuf buf = STRBUF_INIT;
1107
1108         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1109                                            NULL, NULL);
1110         if (!r)
1111                 return NULL;
1112
1113         if (starts_with(r, "refs/heads/"))
1114                 strbuf_addstr(&buf, "refs/heads/");
1115         else if (starts_with(r, "refs/tags/"))
1116                 strbuf_addstr(&buf, "refs/tags/");
1117         else
1118                 return NULL;
1119
1120         strbuf_addstr(&buf, name);
1121         return strbuf_detach(&buf, NULL);
1122 }
1123
1124 static int match_explicit_lhs(struct ref *src,
1125                               struct refspec *rs,
1126                               struct ref **match,
1127                               int *allocated_match)
1128 {
1129         switch (count_refspec_match(rs->src, src, match)) {
1130         case 1:
1131                 if (allocated_match)
1132                         *allocated_match = 0;
1133                 return 0;
1134         case 0:
1135                 /* The source could be in the get_sha1() format
1136                  * not a reference name.  :refs/other is a
1137                  * way to delete 'other' ref at the remote end.
1138                  */
1139                 if (try_explicit_object_name(rs->src, match) < 0)
1140                         return error("src refspec %s does not match any.", rs->src);
1141                 if (allocated_match)
1142                         *allocated_match = 1;
1143                 return 0;
1144         default:
1145                 return error("src refspec %s matches more than one.", rs->src);
1146         }
1147 }
1148
1149 static int match_explicit(struct ref *src, struct ref *dst,
1150                           struct ref ***dst_tail,
1151                           struct refspec *rs)
1152 {
1153         struct ref *matched_src, *matched_dst;
1154         int allocated_src;
1155
1156         const char *dst_value = rs->dst;
1157         char *dst_guess;
1158
1159         if (rs->pattern || rs->matching)
1160                 return 0;
1161
1162         matched_src = matched_dst = NULL;
1163         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1164                 return -1;
1165
1166         if (!dst_value) {
1167                 int flag;
1168
1169                 dst_value = resolve_ref_unsafe(matched_src->name,
1170                                                RESOLVE_REF_READING,
1171                                                NULL, &flag);
1172                 if (!dst_value ||
1173                     ((flag & REF_ISSYMREF) &&
1174                      !starts_with(dst_value, "refs/heads/")))
1175                         die("%s cannot be resolved to branch.",
1176                             matched_src->name);
1177         }
1178
1179         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1180         case 1:
1181                 break;
1182         case 0:
1183                 if (starts_with(dst_value, "refs/"))
1184                         matched_dst = make_linked_ref(dst_value, dst_tail);
1185                 else if (is_null_oid(&matched_src->new_oid))
1186                         error("unable to delete '%s': remote ref does not exist",
1187                               dst_value);
1188                 else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1189                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1190                         free(dst_guess);
1191                 } else
1192                         error("unable to push to unqualified destination: %s\n"
1193                               "The destination refspec neither matches an "
1194                               "existing ref on the remote nor\n"
1195                               "begins with refs/, and we are unable to "
1196                               "guess a prefix based on the source ref.",
1197                               dst_value);
1198                 break;
1199         default:
1200                 matched_dst = NULL;
1201                 error("dst refspec %s matches more than one.",
1202                       dst_value);
1203                 break;
1204         }
1205         if (!matched_dst)
1206                 return -1;
1207         if (matched_dst->peer_ref)
1208                 return error("dst ref %s receives from more than one src.",
1209                       matched_dst->name);
1210         else {
1211                 matched_dst->peer_ref = allocated_src ?
1212                                         matched_src :
1213                                         copy_ref(matched_src);
1214                 matched_dst->force = rs->force;
1215         }
1216         return 0;
1217 }
1218
1219 static int match_explicit_refs(struct ref *src, struct ref *dst,
1220                                struct ref ***dst_tail, struct refspec *rs,
1221                                int rs_nr)
1222 {
1223         int i, errs;
1224         for (i = errs = 0; i < rs_nr; i++)
1225                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1226         return errs;
1227 }
1228
1229 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1230                 int send_mirror, int direction, const struct refspec **ret_pat)
1231 {
1232         const struct refspec *pat;
1233         char *name;
1234         int i;
1235         int matching_refs = -1;
1236         for (i = 0; i < rs_nr; i++) {
1237                 if (rs[i].matching &&
1238                     (matching_refs == -1 || rs[i].force)) {
1239                         matching_refs = i;
1240                         continue;
1241                 }
1242
1243                 if (rs[i].pattern) {
1244                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1245                         int match;
1246                         if (direction == FROM_SRC)
1247                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1248                         else
1249                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1250                         if (match) {
1251                                 matching_refs = i;
1252                                 break;
1253                         }
1254                 }
1255         }
1256         if (matching_refs == -1)
1257                 return NULL;
1258
1259         pat = rs + matching_refs;
1260         if (pat->matching) {
1261                 /*
1262                  * "matching refs"; traditionally we pushed everything
1263                  * including refs outside refs/heads/ hierarchy, but
1264                  * that does not make much sense these days.
1265                  */
1266                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1267                         return NULL;
1268                 name = xstrdup(ref->name);
1269         }
1270         if (ret_pat)
1271                 *ret_pat = pat;
1272         return name;
1273 }
1274
1275 static struct ref **tail_ref(struct ref **head)
1276 {
1277         struct ref **tail = head;
1278         while (*tail)
1279                 tail = &((*tail)->next);
1280         return tail;
1281 }
1282
1283 struct tips {
1284         struct commit **tip;
1285         int nr, alloc;
1286 };
1287
1288 static void add_to_tips(struct tips *tips, const struct object_id *oid)
1289 {
1290         struct commit *commit;
1291
1292         if (is_null_oid(oid))
1293                 return;
1294         commit = lookup_commit_reference_gently(oid, 1);
1295         if (!commit || (commit->object.flags & TMP_MARK))
1296                 return;
1297         commit->object.flags |= TMP_MARK;
1298         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1299         tips->tip[tips->nr++] = commit;
1300 }
1301
1302 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1303 {
1304         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1305         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1306         struct string_list_item *item;
1307         struct ref *ref;
1308         struct tips sent_tips;
1309
1310         /*
1311          * Collect everything we know they would have at the end of
1312          * this push, and collect all tags they have.
1313          */
1314         memset(&sent_tips, 0, sizeof(sent_tips));
1315         for (ref = *dst; ref; ref = ref->next) {
1316                 if (ref->peer_ref &&
1317                     !is_null_oid(&ref->peer_ref->new_oid))
1318                         add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1319                 else
1320                         add_to_tips(&sent_tips, &ref->old_oid);
1321                 if (starts_with(ref->name, "refs/tags/"))
1322                         string_list_append(&dst_tag, ref->name);
1323         }
1324         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1325
1326         string_list_sort(&dst_tag);
1327
1328         /* Collect tags they do not have. */
1329         for (ref = src; ref; ref = ref->next) {
1330                 if (!starts_with(ref->name, "refs/tags/"))
1331                         continue; /* not a tag */
1332                 if (string_list_has_string(&dst_tag, ref->name))
1333                         continue; /* they already have it */
1334                 if (sha1_object_info(ref->new_oid.hash, NULL) != OBJ_TAG)
1335                         continue; /* be conservative */
1336                 item = string_list_append(&src_tag, ref->name);
1337                 item->util = ref;
1338         }
1339         string_list_clear(&dst_tag, 0);
1340
1341         /*
1342          * At this point, src_tag lists tags that are missing from
1343          * dst, and sent_tips lists the tips we are pushing or those
1344          * that we know they already have. An element in the src_tag
1345          * that is an ancestor of any of the sent_tips needs to be
1346          * sent to the other side.
1347          */
1348         if (sent_tips.nr) {
1349                 for_each_string_list_item(item, &src_tag) {
1350                         struct ref *ref = item->util;
1351                         struct ref *dst_ref;
1352                         struct commit *commit;
1353
1354                         if (is_null_oid(&ref->new_oid))
1355                                 continue;
1356                         commit = lookup_commit_reference_gently(&ref->new_oid,
1357                                                                 1);
1358                         if (!commit)
1359                                 /* not pushing a commit, which is not an error */
1360                                 continue;
1361
1362                         /*
1363                          * Is this tag, which they do not have, reachable from
1364                          * any of the commits we are sending?
1365                          */
1366                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1367                                 continue;
1368
1369                         /* Add it in */
1370                         dst_ref = make_linked_ref(ref->name, dst_tail);
1371                         oidcpy(&dst_ref->new_oid, &ref->new_oid);
1372                         dst_ref->peer_ref = copy_ref(ref);
1373                 }
1374         }
1375         string_list_clear(&src_tag, 0);
1376         free(sent_tips.tip);
1377 }
1378
1379 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1380 {
1381         for ( ; list; list = list->next)
1382                 if (!strcmp(list->name, name))
1383                         return (struct ref *)list;
1384         return NULL;
1385 }
1386
1387 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1388 {
1389         for ( ; ref; ref = ref->next)
1390                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1391
1392         string_list_sort(ref_index);
1393 }
1394
1395 /*
1396  * Given only the set of local refs, sanity-check the set of push
1397  * refspecs. We can't catch all errors that match_push_refs would,
1398  * but we can catch some errors early before even talking to the
1399  * remote side.
1400  */
1401 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1402 {
1403         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1404         int ret = 0;
1405         int i;
1406
1407         for (i = 0; i < nr_refspec; i++) {
1408                 struct refspec *rs = refspec + i;
1409
1410                 if (rs->pattern || rs->matching)
1411                         continue;
1412
1413                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1414         }
1415
1416         free_refspec(nr_refspec, refspec);
1417         return ret;
1418 }
1419
1420 /*
1421  * Given the set of refs the local repository has, the set of refs the
1422  * remote repository has, and the refspec used for push, determine
1423  * what remote refs we will update and with what value by setting
1424  * peer_ref (which object is being pushed) and force (if the push is
1425  * forced) in elements of "dst". The function may add new elements to
1426  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1427  */
1428 int match_push_refs(struct ref *src, struct ref **dst,
1429                     int nr_refspec, const char **refspec, int flags)
1430 {
1431         struct refspec *rs;
1432         int send_all = flags & MATCH_REFS_ALL;
1433         int send_mirror = flags & MATCH_REFS_MIRROR;
1434         int send_prune = flags & MATCH_REFS_PRUNE;
1435         int errs;
1436         static const char *default_refspec[] = { ":", NULL };
1437         struct ref *ref, **dst_tail = tail_ref(dst);
1438         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1439
1440         if (!nr_refspec) {
1441                 nr_refspec = 1;
1442                 refspec = default_refspec;
1443         }
1444         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1445         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1446
1447         /* pick the remainder */
1448         for (ref = src; ref; ref = ref->next) {
1449                 struct string_list_item *dst_item;
1450                 struct ref *dst_peer;
1451                 const struct refspec *pat = NULL;
1452                 char *dst_name;
1453
1454                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1455                 if (!dst_name)
1456                         continue;
1457
1458                 if (!dst_ref_index.nr)
1459                         prepare_ref_index(&dst_ref_index, *dst);
1460
1461                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1462                 dst_peer = dst_item ? dst_item->util : NULL;
1463                 if (dst_peer) {
1464                         if (dst_peer->peer_ref)
1465                                 /* We're already sending something to this ref. */
1466                                 goto free_name;
1467                 } else {
1468                         if (pat->matching && !(send_all || send_mirror))
1469                                 /*
1470                                  * Remote doesn't have it, and we have no
1471                                  * explicit pattern, and we don't have
1472                                  * --all or --mirror.
1473                                  */
1474                                 goto free_name;
1475
1476                         /* Create a new one and link it */
1477                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1478                         oidcpy(&dst_peer->new_oid, &ref->new_oid);
1479                         string_list_insert(&dst_ref_index,
1480                                 dst_peer->name)->util = dst_peer;
1481                 }
1482                 dst_peer->peer_ref = copy_ref(ref);
1483                 dst_peer->force = pat->force;
1484         free_name:
1485                 free(dst_name);
1486         }
1487
1488         string_list_clear(&dst_ref_index, 0);
1489
1490         if (flags & MATCH_REFS_FOLLOW_TAGS)
1491                 add_missing_tags(src, dst, &dst_tail);
1492
1493         if (send_prune) {
1494                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1495                 /* check for missing refs on the remote */
1496                 for (ref = *dst; ref; ref = ref->next) {
1497                         char *src_name;
1498
1499                         if (ref->peer_ref)
1500                                 /* We're already sending something to this ref. */
1501                                 continue;
1502
1503                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1504                         if (src_name) {
1505                                 if (!src_ref_index.nr)
1506                                         prepare_ref_index(&src_ref_index, src);
1507                                 if (!string_list_has_string(&src_ref_index,
1508                                             src_name))
1509                                         ref->peer_ref = alloc_delete_ref();
1510                                 free(src_name);
1511                         }
1512                 }
1513                 string_list_clear(&src_ref_index, 0);
1514         }
1515         if (errs)
1516                 return -1;
1517         return 0;
1518 }
1519
1520 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1521                              int force_update)
1522 {
1523         struct ref *ref;
1524
1525         for (ref = remote_refs; ref; ref = ref->next) {
1526                 int force_ref_update = ref->force || force_update;
1527                 int reject_reason = 0;
1528
1529                 if (ref->peer_ref)
1530                         oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1531                 else if (!send_mirror)
1532                         continue;
1533
1534                 ref->deletion = is_null_oid(&ref->new_oid);
1535                 if (!ref->deletion &&
1536                         !oidcmp(&ref->old_oid, &ref->new_oid)) {
1537                         ref->status = REF_STATUS_UPTODATE;
1538                         continue;
1539                 }
1540
1541                 /*
1542                  * If the remote ref has moved and is now different
1543                  * from what we expect, reject any push.
1544                  *
1545                  * It also is an error if the user told us to check
1546                  * with the remote-tracking branch to find the value
1547                  * to expect, but we did not have such a tracking
1548                  * branch.
1549                  */
1550                 if (ref->expect_old_sha1) {
1551                         if (oidcmp(&ref->old_oid, &ref->old_oid_expect))
1552                                 reject_reason = REF_STATUS_REJECT_STALE;
1553                         else
1554                                 /* If the ref isn't stale then force the update. */
1555                                 force_ref_update = 1;
1556                 }
1557
1558                 /*
1559                  * If the update isn't already rejected then check
1560                  * the usual "must fast-forward" rules.
1561                  *
1562                  * Decide whether an individual refspec A:B can be
1563                  * pushed.  The push will succeed if any of the
1564                  * following are true:
1565                  *
1566                  * (1) the remote reference B does not exist
1567                  *
1568                  * (2) the remote reference B is being removed (i.e.,
1569                  *     pushing :B where no source is specified)
1570                  *
1571                  * (3) the destination is not under refs/tags/, and
1572                  *     if the old and new value is a commit, the new
1573                  *     is a descendant of the old.
1574                  *
1575                  * (4) it is forced using the +A:B notation, or by
1576                  *     passing the --force argument
1577                  */
1578
1579                 if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1580                         if (starts_with(ref->name, "refs/tags/"))
1581                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1582                         else if (!has_object_file(&ref->old_oid))
1583                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1584                         else if (!lookup_commit_reference_gently(&ref->old_oid, 1) ||
1585                                  !lookup_commit_reference_gently(&ref->new_oid, 1))
1586                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1587                         else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1588                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1589                 }
1590
1591                 /*
1592                  * "--force" will defeat any rejection implemented
1593                  * by the rules above.
1594                  */
1595                 if (!force_ref_update)
1596                         ref->status = reject_reason;
1597                 else if (reject_reason)
1598                         ref->forced_update = 1;
1599         }
1600 }
1601
1602 static void set_merge(struct branch *ret)
1603 {
1604         struct remote *remote;
1605         char *ref;
1606         struct object_id oid;
1607         int i;
1608
1609         if (!ret)
1610                 return; /* no branch */
1611         if (ret->merge)
1612                 return; /* already run */
1613         if (!ret->remote_name || !ret->merge_nr) {
1614                 /*
1615                  * no merge config; let's make sure we don't confuse callers
1616                  * with a non-zero merge_nr but a NULL merge
1617                  */
1618                 ret->merge_nr = 0;
1619                 return;
1620         }
1621
1622         remote = remote_get(ret->remote_name);
1623
1624         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1625         for (i = 0; i < ret->merge_nr; i++) {
1626                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1627                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1628                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1629                     strcmp(ret->remote_name, "."))
1630                         continue;
1631                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1632                              &oid, &ref) == 1)
1633                         ret->merge[i]->dst = ref;
1634                 else
1635                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1636         }
1637 }
1638
1639 struct branch *branch_get(const char *name)
1640 {
1641         struct branch *ret;
1642
1643         read_config();
1644         if (!name || !*name || !strcmp(name, "HEAD"))
1645                 ret = current_branch;
1646         else
1647                 ret = make_branch(name, 0);
1648         set_merge(ret);
1649         return ret;
1650 }
1651
1652 int branch_has_merge_config(struct branch *branch)
1653 {
1654         return branch && !!branch->merge;
1655 }
1656
1657 int branch_merge_matches(struct branch *branch,
1658                                  int i,
1659                                  const char *refname)
1660 {
1661         if (!branch || i < 0 || i >= branch->merge_nr)
1662                 return 0;
1663         return refname_match(branch->merge[i]->src, refname);
1664 }
1665
1666 __attribute__((format (printf,2,3)))
1667 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1668 {
1669         if (err) {
1670                 va_list ap;
1671                 va_start(ap, fmt);
1672                 strbuf_vaddf(err, fmt, ap);
1673                 va_end(ap);
1674         }
1675         return NULL;
1676 }
1677
1678 const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1679 {
1680         if (!branch)
1681                 return error_buf(err, _("HEAD does not point to a branch"));
1682
1683         if (!branch->merge || !branch->merge[0]) {
1684                 /*
1685                  * no merge config; is it because the user didn't define any,
1686                  * or because it is not a real branch, and get_branch
1687                  * auto-vivified it?
1688                  */
1689                 if (!ref_exists(branch->refname))
1690                         return error_buf(err, _("no such branch: '%s'"),
1691                                          branch->name);
1692                 return error_buf(err,
1693                                  _("no upstream configured for branch '%s'"),
1694                                  branch->name);
1695         }
1696
1697         if (!branch->merge[0]->dst)
1698                 return error_buf(err,
1699                                  _("upstream branch '%s' not stored as a remote-tracking branch"),
1700                                  branch->merge[0]->src);
1701
1702         return branch->merge[0]->dst;
1703 }
1704
1705 static const char *tracking_for_push_dest(struct remote *remote,
1706                                           const char *refname,
1707                                           struct strbuf *err)
1708 {
1709         char *ret;
1710
1711         ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1712         if (!ret)
1713                 return error_buf(err,
1714                                  _("push destination '%s' on remote '%s' has no local tracking branch"),
1715                                  refname, remote->name);
1716         return ret;
1717 }
1718
1719 static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1720 {
1721         struct remote *remote;
1722
1723         remote = remote_get(pushremote_for_branch(branch, NULL));
1724         if (!remote)
1725                 return error_buf(err,
1726                                  _("branch '%s' has no remote for pushing"),
1727                                  branch->name);
1728
1729         if (remote->push_refspec_nr) {
1730                 char *dst;
1731                 const char *ret;
1732
1733                 dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1734                                      branch->refname);
1735                 if (!dst)
1736                         return error_buf(err,
1737                                          _("push refspecs for '%s' do not include '%s'"),
1738                                          remote->name, branch->name);
1739
1740                 ret = tracking_for_push_dest(remote, dst, err);
1741                 free(dst);
1742                 return ret;
1743         }
1744
1745         if (remote->mirror)
1746                 return tracking_for_push_dest(remote, branch->refname, err);
1747
1748         switch (push_default) {
1749         case PUSH_DEFAULT_NOTHING:
1750                 return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1751
1752         case PUSH_DEFAULT_MATCHING:
1753         case PUSH_DEFAULT_CURRENT:
1754                 return tracking_for_push_dest(remote, branch->refname, err);
1755
1756         case PUSH_DEFAULT_UPSTREAM:
1757                 return branch_get_upstream(branch, err);
1758
1759         case PUSH_DEFAULT_UNSPECIFIED:
1760         case PUSH_DEFAULT_SIMPLE:
1761                 {
1762                         const char *up, *cur;
1763
1764                         up = branch_get_upstream(branch, err);
1765                         if (!up)
1766                                 return NULL;
1767                         cur = tracking_for_push_dest(remote, branch->refname, err);
1768                         if (!cur)
1769                                 return NULL;
1770                         if (strcmp(cur, up))
1771                                 return error_buf(err,
1772                                                  _("cannot resolve 'simple' push to a single destination"));
1773                         return cur;
1774                 }
1775         }
1776
1777         die("BUG: unhandled push situation");
1778 }
1779
1780 const char *branch_get_push(struct branch *branch, struct strbuf *err)
1781 {
1782         if (!branch)
1783                 return error_buf(err, _("HEAD does not point to a branch"));
1784
1785         if (!branch->push_tracking_ref)
1786                 branch->push_tracking_ref = branch_get_push_1(branch, err);
1787         return branch->push_tracking_ref;
1788 }
1789
1790 static int ignore_symref_update(const char *refname)
1791 {
1792         int flag;
1793
1794         if (!resolve_ref_unsafe(refname, 0, NULL, &flag))
1795                 return 0; /* non-existing refs are OK */
1796         return (flag & REF_ISSYMREF);
1797 }
1798
1799 /*
1800  * Create and return a list of (struct ref) consisting of copies of
1801  * each remote_ref that matches refspec.  refspec must be a pattern.
1802  * Fill in the copies' peer_ref to describe the local tracking refs to
1803  * which they map.  Omit any references that would map to an existing
1804  * local symbolic ref.
1805  */
1806 static struct ref *get_expanded_map(const struct ref *remote_refs,
1807                                     const struct refspec *refspec)
1808 {
1809         const struct ref *ref;
1810         struct ref *ret = NULL;
1811         struct ref **tail = &ret;
1812
1813         for (ref = remote_refs; ref; ref = ref->next) {
1814                 char *expn_name = NULL;
1815
1816                 if (strchr(ref->name, '^'))
1817                         continue; /* a dereference item */
1818                 if (match_name_with_pattern(refspec->src, ref->name,
1819                                             refspec->dst, &expn_name) &&
1820                     !ignore_symref_update(expn_name)) {
1821                         struct ref *cpy = copy_ref(ref);
1822
1823                         cpy->peer_ref = alloc_ref(expn_name);
1824                         if (refspec->force)
1825                                 cpy->peer_ref->force = 1;
1826                         *tail = cpy;
1827                         tail = &cpy->next;
1828                 }
1829                 free(expn_name);
1830         }
1831
1832         return ret;
1833 }
1834
1835 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1836 {
1837         const struct ref *ref;
1838         for (ref = refs; ref; ref = ref->next) {
1839                 if (refname_match(name, ref->name))
1840                         return ref;
1841         }
1842         return NULL;
1843 }
1844
1845 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1846 {
1847         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1848
1849         if (!ref)
1850                 return NULL;
1851
1852         return copy_ref(ref);
1853 }
1854
1855 static struct ref *get_local_ref(const char *name)
1856 {
1857         if (!name || name[0] == '\0')
1858                 return NULL;
1859
1860         if (starts_with(name, "refs/"))
1861                 return alloc_ref(name);
1862
1863         if (starts_with(name, "heads/") ||
1864             starts_with(name, "tags/") ||
1865             starts_with(name, "remotes/"))
1866                 return alloc_ref_with_prefix("refs/", 5, name);
1867
1868         return alloc_ref_with_prefix("refs/heads/", 11, name);
1869 }
1870
1871 int get_fetch_map(const struct ref *remote_refs,
1872                   const struct refspec *refspec,
1873                   struct ref ***tail,
1874                   int missing_ok)
1875 {
1876         struct ref *ref_map, **rmp;
1877
1878         if (refspec->pattern) {
1879                 ref_map = get_expanded_map(remote_refs, refspec);
1880         } else {
1881                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1882
1883                 if (refspec->exact_sha1) {
1884                         ref_map = alloc_ref(name);
1885                         get_oid_hex(name, &ref_map->old_oid);
1886                 } else {
1887                         ref_map = get_remote_ref(remote_refs, name);
1888                 }
1889                 if (!missing_ok && !ref_map)
1890                         die("Couldn't find remote ref %s", name);
1891                 if (ref_map) {
1892                         ref_map->peer_ref = get_local_ref(refspec->dst);
1893                         if (ref_map->peer_ref && refspec->force)
1894                                 ref_map->peer_ref->force = 1;
1895                 }
1896         }
1897
1898         for (rmp = &ref_map; *rmp; ) {
1899                 if ((*rmp)->peer_ref) {
1900                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1901                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1902                                 struct ref *ignore = *rmp;
1903                                 error("* Ignoring funny ref '%s' locally",
1904                                       (*rmp)->peer_ref->name);
1905                                 *rmp = (*rmp)->next;
1906                                 free(ignore->peer_ref);
1907                                 free(ignore);
1908                                 continue;
1909                         }
1910                 }
1911                 rmp = &((*rmp)->next);
1912         }
1913
1914         if (ref_map)
1915                 tail_link_ref(ref_map, tail);
1916
1917         return 0;
1918 }
1919
1920 int resolve_remote_symref(struct ref *ref, struct ref *list)
1921 {
1922         if (!ref->symref)
1923                 return 0;
1924         for (; list; list = list->next)
1925                 if (!strcmp(ref->symref, list->name)) {
1926                         oidcpy(&ref->old_oid, &list->old_oid);
1927                         return 0;
1928                 }
1929         return 1;
1930 }
1931
1932 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1933 {
1934         while (list) {
1935                 struct commit *commit = pop_commit(&list);
1936                 commit->object.flags &= ~mark;
1937         }
1938 }
1939
1940 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1941 {
1942         struct object *o;
1943         struct commit *old, *new;
1944         struct commit_list *list, *used;
1945         int found = 0;
1946
1947         /*
1948          * Both new and old must be commit-ish and new is descendant of
1949          * old.  Otherwise we require --force.
1950          */
1951         o = deref_tag(parse_object(old_oid), NULL, 0);
1952         if (!o || o->type != OBJ_COMMIT)
1953                 return 0;
1954         old = (struct commit *) o;
1955
1956         o = deref_tag(parse_object(new_oid), NULL, 0);
1957         if (!o || o->type != OBJ_COMMIT)
1958                 return 0;
1959         new = (struct commit *) o;
1960
1961         if (parse_commit(new) < 0)
1962                 return 0;
1963
1964         used = list = NULL;
1965         commit_list_insert(new, &list);
1966         while (list) {
1967                 new = pop_most_recent_commit(&list, TMP_MARK);
1968                 commit_list_insert(new, &used);
1969                 if (new == old) {
1970                         found = 1;
1971                         break;
1972                 }
1973         }
1974         unmark_and_free(list, TMP_MARK);
1975         unmark_and_free(used, TMP_MARK);
1976         return found;
1977 }
1978
1979 /*
1980  * Compare a branch with its upstream, and save their differences (number
1981  * of commits) in *num_ours and *num_theirs. The name of the upstream branch
1982  * (or NULL if no upstream is defined) is returned via *upstream_name, if it
1983  * is not itself NULL.
1984  *
1985  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1986  * upstream defined, or ref does not exist), 0 otherwise.
1987  */
1988 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
1989                        const char **upstream_name)
1990 {
1991         struct object_id oid;
1992         struct commit *ours, *theirs;
1993         struct rev_info revs;
1994         const char *base;
1995         struct argv_array argv = ARGV_ARRAY_INIT;
1996
1997         /* Cannot stat unless we are marked to build on top of somebody else. */
1998         base = branch_get_upstream(branch, NULL);
1999         if (upstream_name)
2000                 *upstream_name = base;
2001         if (!base)
2002                 return -1;
2003
2004         /* Cannot stat if what we used to build on no longer exists */
2005         if (read_ref(base, &oid))
2006                 return -1;
2007         theirs = lookup_commit_reference(&oid);
2008         if (!theirs)
2009                 return -1;
2010
2011         if (read_ref(branch->refname, &oid))
2012                 return -1;
2013         ours = lookup_commit_reference(&oid);
2014         if (!ours)
2015                 return -1;
2016
2017         /* are we the same? */
2018         if (theirs == ours) {
2019                 *num_theirs = *num_ours = 0;
2020                 return 0;
2021         }
2022
2023         /* Run "rev-list --left-right ours...theirs" internally... */
2024         argv_array_push(&argv, ""); /* ignored */
2025         argv_array_push(&argv, "--left-right");
2026         argv_array_pushf(&argv, "%s...%s",
2027                          oid_to_hex(&ours->object.oid),
2028                          oid_to_hex(&theirs->object.oid));
2029         argv_array_push(&argv, "--");
2030
2031         init_revisions(&revs, NULL);
2032         setup_revisions(argv.argc, argv.argv, &revs, NULL);
2033         if (prepare_revision_walk(&revs))
2034                 die("revision walk setup failed");
2035
2036         /* ... and count the commits on each side. */
2037         *num_ours = 0;
2038         *num_theirs = 0;
2039         while (1) {
2040                 struct commit *c = get_revision(&revs);
2041                 if (!c)
2042                         break;
2043                 if (c->object.flags & SYMMETRIC_LEFT)
2044                         (*num_ours)++;
2045                 else
2046                         (*num_theirs)++;
2047         }
2048
2049         /* clear object flags smudged by the above traversal */
2050         clear_commit_marks(ours, ALL_REV_FLAGS);
2051         clear_commit_marks(theirs, ALL_REV_FLAGS);
2052
2053         argv_array_clear(&argv);
2054         return 0;
2055 }
2056
2057 /*
2058  * Return true when there is anything to report, otherwise false.
2059  */
2060 int format_tracking_info(struct branch *branch, struct strbuf *sb)
2061 {
2062         int ours, theirs;
2063         const char *full_base;
2064         char *base;
2065         int upstream_is_gone = 0;
2066
2067         if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2068                 if (!full_base)
2069                         return 0;
2070                 upstream_is_gone = 1;
2071         }
2072
2073         base = shorten_unambiguous_ref(full_base, 0);
2074         if (upstream_is_gone) {
2075                 strbuf_addf(sb,
2076                         _("Your branch is based on '%s', but the upstream is gone.\n"),
2077                         base);
2078                 if (advice_status_hints)
2079                         strbuf_addstr(sb,
2080                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2081         } else if (!ours && !theirs) {
2082                 strbuf_addf(sb,
2083                         _("Your branch is up to date with '%s'.\n"),
2084                         base);
2085         } else if (!theirs) {
2086                 strbuf_addf(sb,
2087                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2088                            "Your branch is ahead of '%s' by %d commits.\n",
2089                            ours),
2090                         base, ours);
2091                 if (advice_status_hints)
2092                         strbuf_addstr(sb,
2093                                 _("  (use \"git push\" to publish your local commits)\n"));
2094         } else if (!ours) {
2095                 strbuf_addf(sb,
2096                         Q_("Your branch is behind '%s' by %d commit, "
2097                                "and can be fast-forwarded.\n",
2098                            "Your branch is behind '%s' by %d commits, "
2099                                "and can be fast-forwarded.\n",
2100                            theirs),
2101                         base, theirs);
2102                 if (advice_status_hints)
2103                         strbuf_addstr(sb,
2104                                 _("  (use \"git pull\" to update your local branch)\n"));
2105         } else {
2106                 strbuf_addf(sb,
2107                         Q_("Your branch and '%s' have diverged,\n"
2108                                "and have %d and %d different commit each, "
2109                                "respectively.\n",
2110                            "Your branch and '%s' have diverged,\n"
2111                                "and have %d and %d different commits each, "
2112                                "respectively.\n",
2113                            ours + theirs),
2114                         base, ours, theirs);
2115                 if (advice_status_hints)
2116                         strbuf_addstr(sb,
2117                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2118         }
2119         free(base);
2120         return 1;
2121 }
2122
2123 static int one_local_ref(const char *refname, const struct object_id *oid,
2124                          int flag, void *cb_data)
2125 {
2126         struct ref ***local_tail = cb_data;
2127         struct ref *ref;
2128
2129         /* we already know it starts with refs/ to get here */
2130         if (check_refname_format(refname + 5, 0))
2131                 return 0;
2132
2133         ref = alloc_ref(refname);
2134         oidcpy(&ref->new_oid, oid);
2135         **local_tail = ref;
2136         *local_tail = &ref->next;
2137         return 0;
2138 }
2139
2140 struct ref *get_local_heads(void)
2141 {
2142         struct ref *local_refs = NULL, **local_tail = &local_refs;
2143
2144         for_each_ref(one_local_ref, &local_tail);
2145         return local_refs;
2146 }
2147
2148 struct ref *guess_remote_head(const struct ref *head,
2149                               const struct ref *refs,
2150                               int all)
2151 {
2152         const struct ref *r;
2153         struct ref *list = NULL;
2154         struct ref **tail = &list;
2155
2156         if (!head)
2157                 return NULL;
2158
2159         /*
2160          * Some transports support directly peeking at
2161          * where HEAD points; if that is the case, then
2162          * we don't have to guess.
2163          */
2164         if (head->symref)
2165                 return copy_ref(find_ref_by_name(refs, head->symref));
2166
2167         /* If refs/heads/master could be right, it is. */
2168         if (!all) {
2169                 r = find_ref_by_name(refs, "refs/heads/master");
2170                 if (r && !oidcmp(&r->old_oid, &head->old_oid))
2171                         return copy_ref(r);
2172         }
2173
2174         /* Look for another ref that points there */
2175         for (r = refs; r; r = r->next) {
2176                 if (r != head &&
2177                     starts_with(r->name, "refs/heads/") &&
2178                     !oidcmp(&r->old_oid, &head->old_oid)) {
2179                         *tail = copy_ref(r);
2180                         tail = &((*tail)->next);
2181                         if (!all)
2182                                 break;
2183                 }
2184         }
2185
2186         return list;
2187 }
2188
2189 struct stale_heads_info {
2190         struct string_list *ref_names;
2191         struct ref **stale_refs_tail;
2192         struct refspec *refs;
2193         int ref_count;
2194 };
2195
2196 static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2197                               int flags, void *cb_data)
2198 {
2199         struct stale_heads_info *info = cb_data;
2200         struct string_list matches = STRING_LIST_INIT_DUP;
2201         struct refspec query;
2202         int i, stale = 1;
2203         memset(&query, 0, sizeof(struct refspec));
2204         query.dst = (char *)refname;
2205
2206         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2207         if (matches.nr == 0)
2208                 goto clean_exit; /* No matches */
2209
2210         /*
2211          * If we did find a suitable refspec and it's not a symref and
2212          * it's not in the list of refs that currently exist in that
2213          * remote, we consider it to be stale. In order to deal with
2214          * overlapping refspecs, we need to go over all of the
2215          * matching refs.
2216          */
2217         if (flags & REF_ISSYMREF)
2218                 goto clean_exit;
2219
2220         for (i = 0; stale && i < matches.nr; i++)
2221                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2222                         stale = 0;
2223
2224         if (stale) {
2225                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2226                 oidcpy(&ref->new_oid, oid);
2227         }
2228
2229 clean_exit:
2230         string_list_clear(&matches, 0);
2231         return 0;
2232 }
2233
2234 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2235 {
2236         struct ref *ref, *stale_refs = NULL;
2237         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2238         struct stale_heads_info info;
2239
2240         info.ref_names = &ref_names;
2241         info.stale_refs_tail = &stale_refs;
2242         info.refs = refs;
2243         info.ref_count = ref_count;
2244         for (ref = fetch_map; ref; ref = ref->next)
2245                 string_list_append(&ref_names, ref->name);
2246         string_list_sort(&ref_names);
2247         for_each_ref(get_stale_heads_cb, &info);
2248         string_list_clear(&ref_names, 0);
2249         return stale_refs;
2250 }
2251
2252 /*
2253  * Compare-and-swap
2254  */
2255 static void clear_cas_option(struct push_cas_option *cas)
2256 {
2257         int i;
2258
2259         for (i = 0; i < cas->nr; i++)
2260                 free(cas->entry[i].refname);
2261         free(cas->entry);
2262         memset(cas, 0, sizeof(*cas));
2263 }
2264
2265 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2266                                       const char *refname,
2267                                       size_t refnamelen)
2268 {
2269         struct push_cas *entry;
2270         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2271         entry = &cas->entry[cas->nr++];
2272         memset(entry, 0, sizeof(*entry));
2273         entry->refname = xmemdupz(refname, refnamelen);
2274         return entry;
2275 }
2276
2277 static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2278 {
2279         const char *colon;
2280         struct push_cas *entry;
2281
2282         if (unset) {
2283                 /* "--no-<option>" */
2284                 clear_cas_option(cas);
2285                 return 0;
2286         }
2287
2288         if (!arg) {
2289                 /* just "--<option>" */
2290                 cas->use_tracking_for_rest = 1;
2291                 return 0;
2292         }
2293
2294         /* "--<option>=refname" or "--<option>=refname:value" */
2295         colon = strchrnul(arg, ':');
2296         entry = add_cas_entry(cas, arg, colon - arg);
2297         if (!*colon)
2298                 entry->use_tracking = 1;
2299         else if (!colon[1])
2300                 oidclr(&entry->expect);
2301         else if (get_oid(colon + 1, &entry->expect))
2302                 return error("cannot parse expected object name '%s'", colon + 1);
2303         return 0;
2304 }
2305
2306 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2307 {
2308         return parse_push_cas_option(opt->value, arg, unset);
2309 }
2310
2311 int is_empty_cas(const struct push_cas_option *cas)
2312 {
2313         return !cas->use_tracking_for_rest && !cas->nr;
2314 }
2315
2316 /*
2317  * Look at remote.fetch refspec and see if we have a remote
2318  * tracking branch for the refname there.  Fill its current
2319  * value in sha1[].
2320  * If we cannot do so, return negative to signal an error.
2321  */
2322 static int remote_tracking(struct remote *remote, const char *refname,
2323                            struct object_id *oid)
2324 {
2325         char *dst;
2326
2327         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2328         if (!dst)
2329                 return -1; /* no tracking ref for refname at remote */
2330         if (read_ref(dst, oid))
2331                 return -1; /* we know what the tracking ref is but we cannot read it */
2332         return 0;
2333 }
2334
2335 static void apply_cas(struct push_cas_option *cas,
2336                       struct remote *remote,
2337                       struct ref *ref)
2338 {
2339         int i;
2340
2341         /* Find an explicit --<option>=<name>[:<value>] entry */
2342         for (i = 0; i < cas->nr; i++) {
2343                 struct push_cas *entry = &cas->entry[i];
2344                 if (!refname_match(entry->refname, ref->name))
2345                         continue;
2346                 ref->expect_old_sha1 = 1;
2347                 if (!entry->use_tracking)
2348                         oidcpy(&ref->old_oid_expect, &entry->expect);
2349                 else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2350                         oidclr(&ref->old_oid_expect);
2351                 return;
2352         }
2353
2354         /* Are we using "--<option>" to cover all? */
2355         if (!cas->use_tracking_for_rest)
2356                 return;
2357
2358         ref->expect_old_sha1 = 1;
2359         if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2360                 oidclr(&ref->old_oid_expect);
2361 }
2362
2363 void apply_push_cas(struct push_cas_option *cas,
2364                     struct remote *remote,
2365                     struct ref *remote_refs)
2366 {
2367         struct ref *ref;
2368         for (ref = remote_refs; ref; ref = ref->next)
2369                 apply_cas(cas, remote, ref);
2370 }