git.oblomov.eu Git - git/blob - remote.c

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