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