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

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "dir.h"
   8 #include "tag.h"
   9 #include "string-list.h"
  10 #include "mergesort.h"
  11
  12 enum map_direction { FROM_SRC, FROM_DST };
  13
  14 static struct refspec s_tag_refspec = {
  15         0,
  16         1,
  17         0,
  18         0,
  19         "refs/tags/*",
  20         "refs/tags/*"
  21 };
  22
  23 const struct refspec *tag_refspec = &s_tag_refspec;
  24
  25 struct counted_string {
  26         size_t len;
  27         const char *s;
  28 };
  29 struct rewrite {
  30         const char *base;
  31         size_t baselen;
  32         struct counted_string *instead_of;
  33         int instead_of_nr;
  34         int instead_of_alloc;
  35 };
  36 struct rewrites {
  37         struct rewrite **rewrite;
  38         int rewrite_alloc;
  39         int rewrite_nr;
  40 };
  41
  42 static struct remote **remotes;
  43 static int remotes_alloc;
  44 static int remotes_nr;
  45 static struct hashmap remotes_hash;
  46
  47 static struct branch **branches;
  48 static int branches_alloc;
  49 static int branches_nr;
  50
  51 static struct branch *current_branch;
  52 static const char *pushremote_name;
  53
  54 static struct rewrites rewrites;
  55 static struct rewrites rewrites_push;
  56
  57 #define BUF_SIZE (2048)
  58 static char buffer[BUF_SIZE];
  59
  60 static int valid_remote(const struct remote *remote)
  61 {
  62         return (!!remote->url) || (!!remote->foreign_vcs);
  63 }
  64
  65 static const char *alias_url(const char *url, struct rewrites *r)
  66 {
  67         int i, j;
  68         char *ret;
  69         struct counted_string *longest;
  70         int longest_i;
  71
  72         longest = NULL;
  73         longest_i = -1;
  74         for (i = 0; i < r->rewrite_nr; i++) {
  75                 if (!r->rewrite[i])
  76                         continue;
  77                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  78                         if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  79                             (!longest ||
  80                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  81                                 longest = &(r->rewrite[i]->instead_of[j]);
  82                                 longest_i = i;
  83                         }
  84                 }
  85         }
  86         if (!longest)
  87                 return url;
  88
  89         ret = xmalloc(r->rewrite[longest_i]->baselen +
  90                      (strlen(url) - longest->len) + 1);
  91         strcpy(ret, r->rewrite[longest_i]->base);
  92         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  93         return ret;
  94 }
  95
  96 static void add_push_refspec(struct remote *remote, const char *ref)
  97 {
  98         ALLOC_GROW(remote->push_refspec,
  99                    remote->push_refspec_nr + 1,
 100                    remote->push_refspec_alloc);
 101         remote->push_refspec[remote->push_refspec_nr++] = ref;
 102 }
 103
 104 static void add_fetch_refspec(struct remote *remote, const char *ref)
 105 {
 106         ALLOC_GROW(remote->fetch_refspec,
 107                    remote->fetch_refspec_nr + 1,
 108                    remote->fetch_refspec_alloc);
 109         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 110 }
 111
 112 static void add_url(struct remote *remote, const char *url)
 113 {
 114         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 115         remote->url[remote->url_nr++] = url;
 116 }
 117
 118 static void add_pushurl(struct remote *remote, const char *pushurl)
 119 {
 120         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 121         remote->pushurl[remote->pushurl_nr++] = pushurl;
 122 }
 123
 124 static void add_pushurl_alias(struct remote *remote, const char *url)
 125 {
 126         const char *pushurl = alias_url(url, &rewrites_push);
 127         if (pushurl != url)
 128                 add_pushurl(remote, pushurl);
 129 }
 130
 131 static void add_url_alias(struct remote *remote, const char *url)
 132 {
 133         add_url(remote, alias_url(url, &rewrites));
 134         add_pushurl_alias(remote, url);
 135 }
 136
 137 struct remotes_hash_key {
 138         const char *str;
 139         int len;
 140 };
 141
 142 static int remotes_hash_cmp(const struct remote *a, const struct remote *b, const struct remotes_hash_key *key)
 143 {
 144         if (key)
 145                 return strncmp(a->name, key->str, key->len) || a->name[key->len];
 146         else
 147                 return strcmp(a->name, b->name);
 148 }
 149
 150 static inline void init_remotes_hash(void)
 151 {
 152         if (!remotes_hash.cmpfn)
 153                 hashmap_init(&remotes_hash, (hashmap_cmp_fn)remotes_hash_cmp, 0);
 154 }
 155
 156 static struct remote *make_remote(const char *name, int len)
 157 {
 158         struct remote *ret, *replaced;
 159         struct remotes_hash_key lookup;
 160         struct hashmap_entry lookup_entry;
 161
 162         if (!len)
 163                 len = strlen(name);
 164
 165         init_remotes_hash();
 166         lookup.str = name;
 167         lookup.len = len;
 168         hashmap_entry_init(&lookup_entry, memhash(name, len));
 169
 170         if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 171                 return ret;
 172
 173         ret = xcalloc(1, sizeof(struct remote));
 174         ret->prune = -1;  /* unspecified */
 175         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 176         remotes[remotes_nr++] = ret;
 177         ret->name = xstrndup(name, len);
 178
 179         hashmap_entry_init(ret, lookup_entry.hash);
 180         replaced = hashmap_put(&remotes_hash, ret);
 181         assert(replaced == NULL);  /* no previous entry overwritten */
 182         return ret;
 183 }
 184
 185 static void add_merge(struct branch *branch, const char *name)
 186 {
 187         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 188                    branch->merge_alloc);
 189         branch->merge_name[branch->merge_nr++] = name;
 190 }
 191
 192 static struct branch *make_branch(const char *name, int len)
 193 {
 194         struct branch *ret;
 195         int i;
 196
 197         for (i = 0; i < branches_nr; i++) {
 198                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 199                            !branches[i]->name[len]) :
 200                     !strcmp(name, branches[i]->name))
 201                         return branches[i];
 202         }
 203
 204         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 205         ret = xcalloc(1, sizeof(struct branch));
 206         branches[branches_nr++] = ret;
 207         if (len)
 208                 ret->name = xstrndup(name, len);
 209         else
 210                 ret->name = xstrdup(name);
 211         ret->refname = xstrfmt("refs/heads/%s", ret->name);
 212
 213         return ret;
 214 }
 215
 216 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 217 {
 218         struct rewrite *ret;
 219         int i;
 220
 221         for (i = 0; i < r->rewrite_nr; i++) {
 222                 if (len
 223                     ? (len == r->rewrite[i]->baselen &&
 224                        !strncmp(base, r->rewrite[i]->base, len))
 225                     : !strcmp(base, r->rewrite[i]->base))
 226                         return r->rewrite[i];
 227         }
 228
 229         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 230         ret = xcalloc(1, sizeof(struct rewrite));
 231         r->rewrite[r->rewrite_nr++] = ret;
 232         if (len) {
 233                 ret->base = xstrndup(base, len);
 234                 ret->baselen = len;
 235         }
 236         else {
 237                 ret->base = xstrdup(base);
 238                 ret->baselen = strlen(base);
 239         }
 240         return ret;
 241 }
 242
 243 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 244 {
 245         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 246         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 247         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 248         rewrite->instead_of_nr++;
 249 }
 250
 251 static void read_remotes_file(struct remote *remote)
 252 {
 253         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 254
 255         if (!f)
 256                 return;
 257         remote->origin = REMOTE_REMOTES;
 258         while (fgets(buffer, BUF_SIZE, f)) {
 259                 int value_list;
 260                 char *s, *p;
 261
 262                 if (starts_with(buffer, "URL:")) {
 263                         value_list = 0;
 264                         s = buffer + 4;
 265                 } else if (starts_with(buffer, "Push:")) {
 266                         value_list = 1;
 267                         s = buffer + 5;
 268                 } else if (starts_with(buffer, "Pull:")) {
 269                         value_list = 2;
 270                         s = buffer + 5;
 271                 } else
 272                         continue;
 273
 274                 while (isspace(*s))
 275                         s++;
 276                 if (!*s)
 277                         continue;
 278
 279                 p = s + strlen(s);
 280                 while (isspace(p[-1]))
 281                         *--p = 0;
 282
 283                 switch (value_list) {
 284                 case 0:
 285                         add_url_alias(remote, xstrdup(s));
 286                         break;
 287                 case 1:
 288                         add_push_refspec(remote, xstrdup(s));
 289                         break;
 290                 case 2:
 291                         add_fetch_refspec(remote, xstrdup(s));
 292                         break;
 293                 }
 294         }
 295         fclose(f);
 296 }
 297
 298 static void read_branches_file(struct remote *remote)
 299 {
 300         char *frag;
 301         struct strbuf branch = STRBUF_INIT;
 302         int n = 1000;
 303         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 304         char *s, *p;
 305         int len;
 306
 307         if (!f)
 308                 return;
 309         s = fgets(buffer, BUF_SIZE, f);
 310         fclose(f);
 311         if (!s)
 312                 return;
 313         while (isspace(*s))
 314                 s++;
 315         if (!*s)
 316                 return;
 317         remote->origin = REMOTE_BRANCHES;
 318         p = s + strlen(s);
 319         while (isspace(p[-1]))
 320                 *--p = 0;
 321         len = p - s;
 322         p = xmalloc(len + 1);
 323         strcpy(p, s);
 324
 325         /*
 326          * The branches file would have URL and optionally
 327          * #branch specified.  The "master" (or specified) branch is
 328          * fetched and stored in the local branch of the same name.
 329          */
 330         frag = strchr(p, '#');
 331         if (frag) {
 332                 *(frag++) = '\0';
 333                 strbuf_addf(&branch, "refs/heads/%s", frag);
 334         } else
 335                 strbuf_addstr(&branch, "refs/heads/master");
 336
 337         strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 338         add_url_alias(remote, p);
 339         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 340         /*
 341          * Cogito compatible push: push current HEAD to remote #branch
 342          * (master if missing)
 343          */
 344         strbuf_init(&branch, 0);
 345         strbuf_addstr(&branch, "HEAD");
 346         if (frag)
 347                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 348         else
 349                 strbuf_addstr(&branch, ":refs/heads/master");
 350         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 351         remote->fetch_tags = 1; /* always auto-follow */
 352 }
 353
 354 static int handle_config(const char *key, const char *value, void *cb)
 355 {
 356         const char *name;
 357         const char *subkey;
 358         struct remote *remote;
 359         struct branch *branch;
 360         if (starts_with(key, "branch.")) {
 361                 name = key + 7;
 362                 subkey = strrchr(name, '.');
 363                 if (!subkey)
 364                         return 0;
 365                 branch = make_branch(name, subkey - name);
 366                 if (!strcmp(subkey, ".remote")) {
 367                         return git_config_string(&branch->remote_name, key, value);
 368                 } else if (!strcmp(subkey, ".pushremote")) {
 369                         return git_config_string(&branch->pushremote_name, key, value);
 370                 } else if (!strcmp(subkey, ".merge")) {
 371                         if (!value)
 372                                 return config_error_nonbool(key);
 373                         add_merge(branch, xstrdup(value));
 374                 }
 375                 return 0;
 376         }
 377         if (starts_with(key, "url.")) {
 378                 struct rewrite *rewrite;
 379                 name = key + 4;
 380                 subkey = strrchr(name, '.');
 381                 if (!subkey)
 382                         return 0;
 383                 if (!strcmp(subkey, ".insteadof")) {
 384                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 385                         if (!value)
 386                                 return config_error_nonbool(key);
 387                         add_instead_of(rewrite, xstrdup(value));
 388                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 389                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 390                         if (!value)
 391                                 return config_error_nonbool(key);
 392                         add_instead_of(rewrite, xstrdup(value));
 393                 }
 394         }
 395
 396         if (!starts_with(key,  "remote."))
 397                 return 0;
 398         name = key + 7;
 399
 400         /* Handle remote.* variables */
 401         if (!strcmp(name, "pushdefault"))
 402                 return git_config_string(&pushremote_name, key, value);
 403
 404         /* Handle remote.<name>.* variables */
 405         if (*name == '/') {
 406                 warning("Config remote shorthand cannot begin with '/': %s",
 407                         name);
 408                 return 0;
 409         }
 410         subkey = strrchr(name, '.');
 411         if (!subkey)
 412                 return 0;
 413         remote = make_remote(name, subkey - name);
 414         remote->origin = REMOTE_CONFIG;
 415         if (!strcmp(subkey, ".mirror"))
 416                 remote->mirror = git_config_bool(key, value);
 417         else if (!strcmp(subkey, ".skipdefaultupdate"))
 418                 remote->skip_default_update = git_config_bool(key, value);
 419         else if (!strcmp(subkey, ".skipfetchall"))
 420                 remote->skip_default_update = git_config_bool(key, value);
 421         else if (!strcmp(subkey, ".prune"))
 422                 remote->prune = git_config_bool(key, value);
 423         else if (!strcmp(subkey, ".url")) {
 424                 const char *v;
 425                 if (git_config_string(&v, key, value))
 426                         return -1;
 427                 add_url(remote, v);
 428         } else if (!strcmp(subkey, ".pushurl")) {
 429                 const char *v;
 430                 if (git_config_string(&v, key, value))
 431                         return -1;
 432                 add_pushurl(remote, v);
 433         } else if (!strcmp(subkey, ".push")) {
 434                 const char *v;
 435                 if (git_config_string(&v, key, value))
 436                         return -1;
 437                 add_push_refspec(remote, v);
 438         } else if (!strcmp(subkey, ".fetch")) {
 439                 const char *v;
 440                 if (git_config_string(&v, key, value))
 441                         return -1;
 442                 add_fetch_refspec(remote, v);
 443         } else if (!strcmp(subkey, ".receivepack")) {
 444                 const char *v;
 445                 if (git_config_string(&v, key, value))
 446                         return -1;
 447                 if (!remote->receivepack)
 448                         remote->receivepack = v;
 449                 else
 450                         error("more than one receivepack given, using the first");
 451         } else if (!strcmp(subkey, ".uploadpack")) {
 452                 const char *v;
 453                 if (git_config_string(&v, key, value))
 454                         return -1;
 455                 if (!remote->uploadpack)
 456                         remote->uploadpack = v;
 457                 else
 458                         error("more than one uploadpack given, using the first");
 459         } else if (!strcmp(subkey, ".tagopt")) {
 460                 if (!strcmp(value, "--no-tags"))
 461                         remote->fetch_tags = -1;
 462                 else if (!strcmp(value, "--tags"))
 463                         remote->fetch_tags = 2;
 464         } else if (!strcmp(subkey, ".proxy")) {
 465                 return git_config_string((const char **)&remote->http_proxy,
 466                                          key, value);
 467         } else if (!strcmp(subkey, ".vcs")) {
 468                 return git_config_string(&remote->foreign_vcs, key, value);
 469         }
 470         return 0;
 471 }
 472
 473 static void alias_all_urls(void)
 474 {
 475         int i, j;
 476         for (i = 0; i < remotes_nr; i++) {
 477                 int add_pushurl_aliases;
 478                 if (!remotes[i])
 479                         continue;
 480                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 481                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 482                 }
 483                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 484                 for (j = 0; j < remotes[i]->url_nr; j++) {
 485                         if (add_pushurl_aliases)
 486                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 487                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 488                 }
 489         }
 490 }
 491
 492 static void read_config(void)
 493 {
 494         static int loaded;
 495         unsigned char sha1[20];
 496         const char *head_ref;
 497         int flag;
 498
 499         if (loaded)
 500                 return;
 501         loaded = 1;
 502
 503         current_branch = NULL;
 504         head_ref = resolve_ref_unsafe("HEAD", 0, sha1, &flag);
 505         if (head_ref && (flag & REF_ISSYMREF) &&
 506             skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 507                 current_branch = make_branch(head_ref, 0);
 508         }
 509         git_config(handle_config, NULL);
 510         alias_all_urls();
 511 }
 512
 513 /*
 514  * This function frees a refspec array.
 515  * Warning: code paths should be checked to ensure that the src
 516  *          and dst pointers are always freeable pointers as well
 517  *          as the refspec pointer itself.
 518  */
 519 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 520 {
 521         int i;
 522
 523         if (!refspec)
 524                 return;
 525
 526         for (i = 0; i < nr_refspec; i++) {
 527                 free(refspec[i].src);
 528                 free(refspec[i].dst);
 529         }
 530         free(refspec);
 531 }
 532
 533 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 534 {
 535         int i;
 536         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 537
 538         for (i = 0; i < nr_refspec; i++) {
 539                 size_t llen;
 540                 int is_glob;
 541                 const char *lhs, *rhs;
 542                 int flags;
 543
 544                 is_glob = 0;
 545
 546                 lhs = refspec[i];
 547                 if (*lhs == '+') {
 548                         rs[i].force = 1;
 549                         lhs++;
 550                 }
 551
 552                 rhs = strrchr(lhs, ':');
 553
 554                 /*
 555                  * Before going on, special case ":" (or "+:") as a refspec
 556                  * for pushing matching refs.
 557                  */
 558                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 559                         rs[i].matching = 1;
 560                         continue;
 561                 }
 562
 563                 if (rhs) {
 564                         size_t rlen = strlen(++rhs);
 565                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 566                         rs[i].dst = xstrndup(rhs, rlen);
 567                 }
 568
 569                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 570                 if (1 <= llen && memchr(lhs, '*', llen)) {
 571                         if ((rhs && !is_glob) || (!rhs && fetch))
 572                                 goto invalid;
 573                         is_glob = 1;
 574                 } else if (rhs && is_glob) {
 575                         goto invalid;
 576                 }
 577
 578                 rs[i].pattern = is_glob;
 579                 rs[i].src = xstrndup(lhs, llen);
 580                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 581
 582                 if (fetch) {
 583                         unsigned char unused[40];
 584
 585                         /* LHS */
 586                         if (!*rs[i].src)
 587                                 ; /* empty is ok; it means "HEAD" */
 588                         else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 589                                 rs[i].exact_sha1 = 1; /* ok */
 590                         else if (!check_refname_format(rs[i].src, flags))
 591                                 ; /* valid looking ref is ok */
 592                         else
 593                                 goto invalid;
 594                         /* RHS */
 595                         if (!rs[i].dst)
 596                                 ; /* missing is ok; it is the same as empty */
 597                         else if (!*rs[i].dst)
 598                                 ; /* empty is ok; it means "do not store" */
 599                         else if (!check_refname_format(rs[i].dst, flags))
 600                                 ; /* valid looking ref is ok */
 601                         else
 602                                 goto invalid;
 603                 } else {
 604                         /*
 605                          * LHS
 606                          * - empty is allowed; it means delete.
 607                          * - when wildcarded, it must be a valid looking ref.
 608                          * - otherwise, it must be an extended SHA-1, but
 609                          *   there is no existing way to validate this.
 610                          */
 611                         if (!*rs[i].src)
 612                                 ; /* empty is ok */
 613                         else if (is_glob) {
 614                                 if (check_refname_format(rs[i].src, flags))
 615                                         goto invalid;
 616                         }
 617                         else
 618                                 ; /* anything goes, for now */
 619                         /*
 620                          * RHS
 621                          * - missing is allowed, but LHS then must be a
 622                          *   valid looking ref.
 623                          * - empty is not allowed.
 624                          * - otherwise it must be a valid looking ref.
 625                          */
 626                         if (!rs[i].dst) {
 627                                 if (check_refname_format(rs[i].src, flags))
 628                                         goto invalid;
 629                         } else if (!*rs[i].dst) {
 630                                 goto invalid;
 631                         } else {
 632                                 if (check_refname_format(rs[i].dst, flags))
 633                                         goto invalid;
 634                         }
 635                 }
 636         }
 637         return rs;
 638
 639  invalid:
 640         if (verify) {
 641                 /*
 642                  * nr_refspec must be greater than zero and i must be valid
 643                  * since it is only possible to reach this point from within
 644                  * the for loop above.
 645                  */
 646                 free_refspecs(rs, i+1);
 647                 return NULL;
 648         }
 649         die("Invalid refspec '%s'", refspec[i]);
 650 }
 651
 652 int valid_fetch_refspec(const char *fetch_refspec_str)
 653 {
 654         struct refspec *refspec;
 655
 656         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 657         free_refspecs(refspec, 1);
 658         return !!refspec;
 659 }
 660
 661 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 662 {
 663         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 664 }
 665
 666 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 667 {
 668         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 669 }
 670
 671 void free_refspec(int nr_refspec, struct refspec *refspec)
 672 {
 673         int i;
 674         for (i = 0; i < nr_refspec; i++) {
 675                 free(refspec[i].src);
 676                 free(refspec[i].dst);
 677         }
 678         free(refspec);
 679 }
 680
 681 static int valid_remote_nick(const char *name)
 682 {
 683         if (!name[0] || is_dot_or_dotdot(name))
 684                 return 0;
 685         return !strchr(name, '/'); /* no slash */
 686 }
 687
 688 const char *remote_for_branch(struct branch *branch, int *explicit)
 689 {
 690         if (branch && branch->remote_name) {
 691                 if (explicit)
 692                         *explicit = 1;
 693                 return branch->remote_name;
 694         }
 695         if (explicit)
 696                 *explicit = 0;
 697         return "origin";
 698 }
 699
 700 const char *pushremote_for_branch(struct branch *branch, int *explicit)
 701 {
 702         if (branch && branch->pushremote_name) {
 703                 if (explicit)
 704                         *explicit = 1;
 705                 return branch->pushremote_name;
 706         }
 707         if (pushremote_name) {
 708                 if (explicit)
 709                         *explicit = 1;
 710                 return pushremote_name;
 711         }
 712         return remote_for_branch(branch, explicit);
 713 }
 714
 715 static struct remote *remote_get_1(const char *name,
 716                                    const char *(*get_default)(struct branch *, int *))
 717 {
 718         struct remote *ret;
 719         int name_given = 0;
 720
 721         read_config();
 722
 723         if (name)
 724                 name_given = 1;
 725         else
 726                 name = get_default(current_branch, &name_given);
 727
 728         ret = make_remote(name, 0);
 729         if (valid_remote_nick(name)) {
 730                 if (!valid_remote(ret))
 731                         read_remotes_file(ret);
 732                 if (!valid_remote(ret))
 733                         read_branches_file(ret);
 734         }
 735         if (name_given && !valid_remote(ret))
 736                 add_url_alias(ret, name);
 737         if (!valid_remote(ret))
 738                 return NULL;
 739         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 740         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 741         return ret;
 742 }
 743
 744 struct remote *remote_get(const char *name)
 745 {
 746         return remote_get_1(name, remote_for_branch);
 747 }
 748
 749 struct remote *pushremote_get(const char *name)
 750 {
 751         return remote_get_1(name, pushremote_for_branch);
 752 }
 753
 754 int remote_is_configured(const char *name)
 755 {
 756         struct remotes_hash_key lookup;
 757         struct hashmap_entry lookup_entry;
 758         read_config();
 759
 760         init_remotes_hash();
 761         lookup.str = name;
 762         lookup.len = strlen(name);
 763         hashmap_entry_init(&lookup_entry, memhash(name, lookup.len));
 764
 765         return hashmap_get(&remotes_hash, &lookup_entry, &lookup) != NULL;
 766 }
 767
 768 int for_each_remote(each_remote_fn fn, void *priv)
 769 {
 770         int i, result = 0;
 771         read_config();
 772         for (i = 0; i < remotes_nr && !result; i++) {
 773                 struct remote *r = remotes[i];
 774                 if (!r)
 775                         continue;
 776                 if (!r->fetch)
 777                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 778                                                        r->fetch_refspec);
 779                 if (!r->push)
 780                         r->push = parse_push_refspec(r->push_refspec_nr,
 781                                                      r->push_refspec);
 782                 result = fn(r, priv);
 783         }
 784         return result;
 785 }
 786
 787 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 788 {
 789         if (strcmp(ref1->name, ref2->name)) {
 790                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 791                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 792                         die(_("Cannot fetch both %s and %s to %s"),
 793                             ref1->name, ref2->name, ref2->peer_ref->name);
 794                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 795                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 796                         warning(_("%s usually tracks %s, not %s"),
 797                                 ref2->peer_ref->name, ref2->name, ref1->name);
 798                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 799                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 800                         die(_("%s tracks both %s and %s"),
 801                             ref2->peer_ref->name, ref1->name, ref2->name);
 802                 } else {
 803                         /*
 804                          * This last possibility doesn't occur because
 805                          * FETCH_HEAD_IGNORE entries always appear at
 806                          * the end of the list.
 807                          */
 808                         die(_("Internal error"));
 809                 }
 810         }
 811         free(ref2->peer_ref);
 812         free(ref2);
 813 }
 814
 815 struct ref *ref_remove_duplicates(struct ref *ref_map)
 816 {
 817         struct string_list refs = STRING_LIST_INIT_NODUP;
 818         struct ref *retval = NULL;
 819         struct ref **p = &retval;
 820
 821         while (ref_map) {
 822                 struct ref *ref = ref_map;
 823
 824                 ref_map = ref_map->next;
 825                 ref->next = NULL;
 826
 827                 if (!ref->peer_ref) {
 828                         *p = ref;
 829                         p = &ref->next;
 830                 } else {
 831                         struct string_list_item *item =
 832                                 string_list_insert(&refs, ref->peer_ref->name);
 833
 834                         if (item->util) {
 835                                 /* Entry already existed */
 836                                 handle_duplicate((struct ref *)item->util, ref);
 837                         } else {
 838                                 *p = ref;
 839                                 p = &ref->next;
 840                                 item->util = ref;
 841                         }
 842                 }
 843         }
 844
 845         string_list_clear(&refs, 0);
 846         return retval;
 847 }
 848
 849 int remote_has_url(struct remote *remote, const char *url)
 850 {
 851         int i;
 852         for (i = 0; i < remote->url_nr; i++) {
 853                 if (!strcmp(remote->url[i], url))
 854                         return 1;
 855         }
 856         return 0;
 857 }
 858
 859 static int match_name_with_pattern(const char *key, const char *name,
 860                                    const char *value, char **result)
 861 {
 862         const char *kstar = strchr(key, '*');
 863         size_t klen;
 864         size_t ksuffixlen;
 865         size_t namelen;
 866         int ret;
 867         if (!kstar)
 868                 die("Key '%s' of pattern had no '*'", key);
 869         klen = kstar - key;
 870         ksuffixlen = strlen(kstar + 1);
 871         namelen = strlen(name);
 872         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 873                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 874         if (ret && value) {
 875                 struct strbuf sb = STRBUF_INIT;
 876                 const char *vstar = strchr(value, '*');
 877                 if (!vstar)
 878                         die("Value '%s' of pattern has no '*'", value);
 879                 strbuf_add(&sb, value, vstar - value);
 880                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 881                 strbuf_addstr(&sb, vstar + 1);
 882                 *result = strbuf_detach(&sb, NULL);
 883         }
 884         return ret;
 885 }
 886
 887 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 888 {
 889         int i;
 890         int find_src = !query->src;
 891
 892         if (find_src && !query->dst)
 893                 error("query_refspecs_multiple: need either src or dst");
 894
 895         for (i = 0; i < ref_count; i++) {
 896                 struct refspec *refspec = &refs[i];
 897                 const char *key = find_src ? refspec->dst : refspec->src;
 898                 const char *value = find_src ? refspec->src : refspec->dst;
 899                 const char *needle = find_src ? query->dst : query->src;
 900                 char **result = find_src ? &query->src : &query->dst;
 901
 902                 if (!refspec->dst)
 903                         continue;
 904                 if (refspec->pattern) {
 905                         if (match_name_with_pattern(key, needle, value, result))
 906                                 string_list_append_nodup(results, *result);
 907                 } else if (!strcmp(needle, key)) {
 908                         string_list_append(results, value);
 909                 }
 910         }
 911 }
 912
 913 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 914 {
 915         int i;
 916         int find_src = !query->src;
 917         const char *needle = find_src ? query->dst : query->src;
 918         char **result = find_src ? &query->src : &query->dst;
 919
 920         if (find_src && !query->dst)
 921                 return error("query_refspecs: need either src or dst");
 922
 923         for (i = 0; i < ref_count; i++) {
 924                 struct refspec *refspec = &refs[i];
 925                 const char *key = find_src ? refspec->dst : refspec->src;
 926                 const char *value = find_src ? refspec->src : refspec->dst;
 927
 928                 if (!refspec->dst)
 929                         continue;
 930                 if (refspec->pattern) {
 931                         if (match_name_with_pattern(key, needle, value, result)) {
 932                                 query->force = refspec->force;
 933                                 return 0;
 934                         }
 935                 } else if (!strcmp(needle, key)) {
 936                         *result = xstrdup(value);
 937                         query->force = refspec->force;
 938                         return 0;
 939                 }
 940         }
 941         return -1;
 942 }
 943
 944 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 945                      const char *name)
 946 {
 947         struct refspec query;
 948
 949         memset(&query, 0, sizeof(struct refspec));
 950         query.src = (char *)name;
 951
 952         if (query_refspecs(refspecs, nr_refspec, &query))
 953                 return NULL;
 954
 955         return query.dst;
 956 }
 957
 958 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 959 {
 960         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 961 }
 962
 963 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 964                 const char *name)
 965 {
 966         size_t len = strlen(name);
 967         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 968         memcpy(ref->name, prefix, prefixlen);
 969         memcpy(ref->name + prefixlen, name, len);
 970         return ref;
 971 }
 972
 973 struct ref *alloc_ref(const char *name)
 974 {
 975         return alloc_ref_with_prefix("", 0, name);
 976 }
 977
 978 struct ref *copy_ref(const struct ref *ref)
 979 {
 980         struct ref *cpy;
 981         size_t len;
 982         if (!ref)
 983                 return NULL;
 984         len = strlen(ref->name);
 985         cpy = xmalloc(sizeof(struct ref) + len + 1);
 986         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 987         cpy->next = NULL;
 988         cpy->symref = xstrdup_or_null(ref->symref);
 989         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 990         cpy->peer_ref = copy_ref(ref->peer_ref);
 991         return cpy;
 992 }
 993
 994 struct ref *copy_ref_list(const struct ref *ref)
 995 {
 996         struct ref *ret = NULL;
 997         struct ref **tail = &ret;
 998         while (ref) {
 999                 *tail = copy_ref(ref);
1000                 ref = ref->next;
1001                 tail = &((*tail)->next);
1002         }
1003         return ret;
1004 }
1005
1006 static void free_ref(struct ref *ref)
1007 {
1008         if (!ref)
1009                 return;
1010         free_ref(ref->peer_ref);
1011         free(ref->remote_status);
1012         free(ref->symref);
1013         free(ref);
1014 }
1015
1016 void free_refs(struct ref *ref)
1017 {
1018         struct ref *next;
1019         while (ref) {
1020                 next = ref->next;
1021                 free_ref(ref);
1022                 ref = next;
1023         }
1024 }
1025
1026 int ref_compare_name(const void *va, const void *vb)
1027 {
1028         const struct ref *a = va, *b = vb;
1029         return strcmp(a->name, b->name);
1030 }
1031
1032 static void *ref_list_get_next(const void *a)
1033 {
1034         return ((const struct ref *)a)->next;
1035 }
1036
1037 static void ref_list_set_next(void *a, void *next)
1038 {
1039         ((struct ref *)a)->next = next;
1040 }
1041
1042 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1043 {
1044         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1045 }
1046
1047 int count_refspec_match(const char *pattern,
1048                         struct ref *refs,
1049                         struct ref **matched_ref)
1050 {
1051         int patlen = strlen(pattern);
1052         struct ref *matched_weak = NULL;
1053         struct ref *matched = NULL;
1054         int weak_match = 0;
1055         int match = 0;
1056
1057         for (weak_match = match = 0; refs; refs = refs->next) {
1058                 char *name = refs->name;
1059                 int namelen = strlen(name);
1060
1061                 if (!refname_match(pattern, name))
1062                         continue;
1063
1064                 /* A match is "weak" if it is with refs outside
1065                  * heads or tags, and did not specify the pattern
1066                  * in full (e.g. "refs/remotes/origin/master") or at
1067                  * least from the toplevel (e.g. "remotes/origin/master");
1068                  * otherwise "git push $URL master" would result in
1069                  * ambiguity between remotes/origin/master and heads/master
1070                  * at the remote site.
1071                  */
1072                 if (namelen != patlen &&
1073                     patlen != namelen - 5 &&
1074                     !starts_with(name, "refs/heads/") &&
1075                     !starts_with(name, "refs/tags/")) {
1076                         /* We want to catch the case where only weak
1077                          * matches are found and there are multiple
1078                          * matches, and where more than one strong
1079                          * matches are found, as ambiguous.  One
1080                          * strong match with zero or more weak matches
1081                          * are acceptable as a unique match.
1082                          */
1083                         matched_weak = refs;
1084                         weak_match++;
1085                 }
1086                 else {
1087                         matched = refs;
1088                         match++;
1089                 }
1090         }
1091         if (!matched) {
1092                 if (matched_ref)
1093                         *matched_ref = matched_weak;
1094                 return weak_match;
1095         }
1096         else {
1097                 if (matched_ref)
1098                         *matched_ref = matched;
1099                 return match;
1100         }
1101 }
1102
1103 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1104 {
1105         **tail = ref;
1106         while (ref->next)
1107                 ref = ref->next;
1108         *tail = &ref->next;
1109 }
1110
1111 static struct ref *alloc_delete_ref(void)
1112 {
1113         struct ref *ref = alloc_ref("(delete)");
1114         hashclr(ref->new_sha1);
1115         return ref;
1116 }
1117
1118 static int try_explicit_object_name(const char *name,
1119                                     struct ref **match)
1120 {
1121         unsigned char sha1[20];
1122
1123         if (!*name) {
1124                 if (match)
1125                         *match = alloc_delete_ref();
1126                 return 0;
1127         }
1128
1129         if (get_sha1(name, sha1))
1130                 return -1;
1131
1132         if (match) {
1133                 *match = alloc_ref(name);
1134                 hashcpy((*match)->new_sha1, sha1);
1135         }
1136         return 0;
1137 }
1138
1139 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1140 {
1141         struct ref *ret = alloc_ref(name);
1142         tail_link_ref(ret, tail);
1143         return ret;
1144 }
1145
1146 static char *guess_ref(const char *name, struct ref *peer)
1147 {
1148         struct strbuf buf = STRBUF_INIT;
1149         unsigned char sha1[20];
1150
1151         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1152                                            sha1, NULL);
1153         if (!r)
1154                 return NULL;
1155
1156         if (starts_with(r, "refs/heads/"))
1157                 strbuf_addstr(&buf, "refs/heads/");
1158         else if (starts_with(r, "refs/tags/"))
1159                 strbuf_addstr(&buf, "refs/tags/");
1160         else
1161                 return NULL;
1162
1163         strbuf_addstr(&buf, name);
1164         return strbuf_detach(&buf, NULL);
1165 }
1166
1167 static int match_explicit_lhs(struct ref *src,
1168                               struct refspec *rs,
1169                               struct ref **match,
1170                               int *allocated_match)
1171 {
1172         switch (count_refspec_match(rs->src, src, match)) {
1173         case 1:
1174                 if (allocated_match)
1175                         *allocated_match = 0;
1176                 return 0;
1177         case 0:
1178                 /* The source could be in the get_sha1() format
1179                  * not a reference name.  :refs/other is a
1180                  * way to delete 'other' ref at the remote end.
1181                  */
1182                 if (try_explicit_object_name(rs->src, match) < 0)
1183                         return error("src refspec %s does not match any.", rs->src);
1184                 if (allocated_match)
1185                         *allocated_match = 1;
1186                 return 0;
1187         default:
1188                 return error("src refspec %s matches more than one.", rs->src);
1189         }
1190 }
1191
1192 static int match_explicit(struct ref *src, struct ref *dst,
1193                           struct ref ***dst_tail,
1194                           struct refspec *rs)
1195 {
1196         struct ref *matched_src, *matched_dst;
1197         int allocated_src;
1198
1199         const char *dst_value = rs->dst;
1200         char *dst_guess;
1201
1202         if (rs->pattern || rs->matching)
1203                 return 0;
1204
1205         matched_src = matched_dst = NULL;
1206         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1207                 return -1;
1208
1209         if (!dst_value) {
1210                 unsigned char sha1[20];
1211                 int flag;
1212
1213                 dst_value = resolve_ref_unsafe(matched_src->name,
1214                                                RESOLVE_REF_READING,
1215                                                sha1, &flag);
1216                 if (!dst_value ||
1217                     ((flag & REF_ISSYMREF) &&
1218                      !starts_with(dst_value, "refs/heads/")))
1219                         die("%s cannot be resolved to branch.",
1220                             matched_src->name);
1221         }
1222
1223         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1224         case 1:
1225                 break;
1226         case 0:
1227                 if (starts_with(dst_value, "refs/"))
1228                         matched_dst = make_linked_ref(dst_value, dst_tail);
1229                 else if (is_null_sha1(matched_src->new_sha1))
1230                         error("unable to delete '%s': remote ref does not exist",
1231                               dst_value);
1232                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1233                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1234                 else
1235                         error("unable to push to unqualified destination: %s\n"
1236                               "The destination refspec neither matches an "
1237                               "existing ref on the remote nor\n"
1238                               "begins with refs/, and we are unable to "
1239                               "guess a prefix based on the source ref.",
1240                               dst_value);
1241                 break;
1242         default:
1243                 matched_dst = NULL;
1244                 error("dst refspec %s matches more than one.",
1245                       dst_value);
1246                 break;
1247         }
1248         if (!matched_dst)
1249                 return -1;
1250         if (matched_dst->peer_ref)
1251                 return error("dst ref %s receives from more than one src.",
1252                       matched_dst->name);
1253         else {
1254                 matched_dst->peer_ref = allocated_src ?
1255                                         matched_src :
1256                                         copy_ref(matched_src);
1257                 matched_dst->force = rs->force;
1258         }
1259         return 0;
1260 }
1261
1262 static int match_explicit_refs(struct ref *src, struct ref *dst,
1263                                struct ref ***dst_tail, struct refspec *rs,
1264                                int rs_nr)
1265 {
1266         int i, errs;
1267         for (i = errs = 0; i < rs_nr; i++)
1268                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1269         return errs;
1270 }
1271
1272 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1273                 int send_mirror, int direction, const struct refspec **ret_pat)
1274 {
1275         const struct refspec *pat;
1276         char *name;
1277         int i;
1278         int matching_refs = -1;
1279         for (i = 0; i < rs_nr; i++) {
1280                 if (rs[i].matching &&
1281                     (matching_refs == -1 || rs[i].force)) {
1282                         matching_refs = i;
1283                         continue;
1284                 }
1285
1286                 if (rs[i].pattern) {
1287                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1288                         int match;
1289                         if (direction == FROM_SRC)
1290                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1291                         else
1292                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1293                         if (match) {
1294                                 matching_refs = i;
1295                                 break;
1296                         }
1297                 }
1298         }
1299         if (matching_refs == -1)
1300                 return NULL;
1301
1302         pat = rs + matching_refs;
1303         if (pat->matching) {
1304                 /*
1305                  * "matching refs"; traditionally we pushed everything
1306                  * including refs outside refs/heads/ hierarchy, but
1307                  * that does not make much sense these days.
1308                  */
1309                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1310                         return NULL;
1311                 name = xstrdup(ref->name);
1312         }
1313         if (ret_pat)
1314                 *ret_pat = pat;
1315         return name;
1316 }
1317
1318 static struct ref **tail_ref(struct ref **head)
1319 {
1320         struct ref **tail = head;
1321         while (*tail)
1322                 tail = &((*tail)->next);
1323         return tail;
1324 }
1325
1326 struct tips {
1327         struct commit **tip;
1328         int nr, alloc;
1329 };
1330
1331 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1332 {
1333         struct commit *commit;
1334
1335         if (is_null_sha1(sha1))
1336                 return;
1337         commit = lookup_commit_reference_gently(sha1, 1);
1338         if (!commit || (commit->object.flags & TMP_MARK))
1339                 return;
1340         commit->object.flags |= TMP_MARK;
1341         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1342         tips->tip[tips->nr++] = commit;
1343 }
1344
1345 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1346 {
1347         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1348         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1349         struct string_list_item *item;
1350         struct ref *ref;
1351         struct tips sent_tips;
1352
1353         /*
1354          * Collect everything we know they would have at the end of
1355          * this push, and collect all tags they have.
1356          */
1357         memset(&sent_tips, 0, sizeof(sent_tips));
1358         for (ref = *dst; ref; ref = ref->next) {
1359                 if (ref->peer_ref &&
1360                     !is_null_sha1(ref->peer_ref->new_sha1))
1361                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1362                 else
1363                         add_to_tips(&sent_tips, ref->old_sha1);
1364                 if (starts_with(ref->name, "refs/tags/"))
1365                         string_list_append(&dst_tag, ref->name);
1366         }
1367         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1368
1369         string_list_sort(&dst_tag);
1370
1371         /* Collect tags they do not have. */
1372         for (ref = src; ref; ref = ref->next) {
1373                 if (!starts_with(ref->name, "refs/tags/"))
1374                         continue; /* not a tag */
1375                 if (string_list_has_string(&dst_tag, ref->name))
1376                         continue; /* they already have it */
1377                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1378                         continue; /* be conservative */
1379                 item = string_list_append(&src_tag, ref->name);
1380                 item->util = ref;
1381         }
1382         string_list_clear(&dst_tag, 0);
1383
1384         /*
1385          * At this point, src_tag lists tags that are missing from
1386          * dst, and sent_tips lists the tips we are pushing or those
1387          * that we know they already have. An element in the src_tag
1388          * that is an ancestor of any of the sent_tips needs to be
1389          * sent to the other side.
1390          */
1391         if (sent_tips.nr) {
1392                 for_each_string_list_item(item, &src_tag) {
1393                         struct ref *ref = item->util;
1394                         struct ref *dst_ref;
1395                         struct commit *commit;
1396
1397                         if (is_null_sha1(ref->new_sha1))
1398                                 continue;
1399                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1400                         if (!commit)
1401                                 /* not pushing a commit, which is not an error */
1402                                 continue;
1403
1404                         /*
1405                          * Is this tag, which they do not have, reachable from
1406                          * any of the commits we are sending?
1407                          */
1408                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1409                                 continue;
1410
1411                         /* Add it in */
1412                         dst_ref = make_linked_ref(ref->name, dst_tail);
1413                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1414                         dst_ref->peer_ref = copy_ref(ref);
1415                 }
1416         }
1417         string_list_clear(&src_tag, 0);
1418         free(sent_tips.tip);
1419 }
1420
1421 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1422 {
1423         for ( ; list; list = list->next)
1424                 if (!strcmp(list->name, name))
1425                         return (struct ref *)list;
1426         return NULL;
1427 }
1428
1429 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1430 {
1431         for ( ; ref; ref = ref->next)
1432                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1433
1434         string_list_sort(ref_index);
1435 }
1436
1437 /*
1438  * Given only the set of local refs, sanity-check the set of push
1439  * refspecs. We can't catch all errors that match_push_refs would,
1440  * but we can catch some errors early before even talking to the
1441  * remote side.
1442  */
1443 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1444 {
1445         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1446         int ret = 0;
1447         int i;
1448
1449         for (i = 0; i < nr_refspec; i++) {
1450                 struct refspec *rs = refspec + i;
1451
1452                 if (rs->pattern || rs->matching)
1453                         continue;
1454
1455                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1456         }
1457
1458         free_refspec(nr_refspec, refspec);
1459         return ret;
1460 }
1461
1462 /*
1463  * Given the set of refs the local repository has, the set of refs the
1464  * remote repository has, and the refspec used for push, determine
1465  * what remote refs we will update and with what value by setting
1466  * peer_ref (which object is being pushed) and force (if the push is
1467  * forced) in elements of "dst". The function may add new elements to
1468  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1469  */
1470 int match_push_refs(struct ref *src, struct ref **dst,
1471                     int nr_refspec, const char **refspec, int flags)
1472 {
1473         struct refspec *rs;
1474         int send_all = flags & MATCH_REFS_ALL;
1475         int send_mirror = flags & MATCH_REFS_MIRROR;
1476         int send_prune = flags & MATCH_REFS_PRUNE;
1477         int errs;
1478         static const char *default_refspec[] = { ":", NULL };
1479         struct ref *ref, **dst_tail = tail_ref(dst);
1480         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1481
1482         if (!nr_refspec) {
1483                 nr_refspec = 1;
1484                 refspec = default_refspec;
1485         }
1486         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1487         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1488
1489         /* pick the remainder */
1490         for (ref = src; ref; ref = ref->next) {
1491                 struct string_list_item *dst_item;
1492                 struct ref *dst_peer;
1493                 const struct refspec *pat = NULL;
1494                 char *dst_name;
1495
1496                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1497                 if (!dst_name)
1498                         continue;
1499
1500                 if (!dst_ref_index.nr)
1501                         prepare_ref_index(&dst_ref_index, *dst);
1502
1503                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1504                 dst_peer = dst_item ? dst_item->util : NULL;
1505                 if (dst_peer) {
1506                         if (dst_peer->peer_ref)
1507                                 /* We're already sending something to this ref. */
1508                                 goto free_name;
1509                 } else {
1510                         if (pat->matching && !(send_all || send_mirror))
1511                                 /*
1512                                  * Remote doesn't have it, and we have no
1513                                  * explicit pattern, and we don't have
1514                                  * --all or --mirror.
1515                                  */
1516                                 goto free_name;
1517
1518                         /* Create a new one and link it */
1519                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1520                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1521                         string_list_insert(&dst_ref_index,
1522                                 dst_peer->name)->util = dst_peer;
1523                 }
1524                 dst_peer->peer_ref = copy_ref(ref);
1525                 dst_peer->force = pat->force;
1526         free_name:
1527                 free(dst_name);
1528         }
1529
1530         string_list_clear(&dst_ref_index, 0);
1531
1532         if (flags & MATCH_REFS_FOLLOW_TAGS)
1533                 add_missing_tags(src, dst, &dst_tail);
1534
1535         if (send_prune) {
1536                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1537                 /* check for missing refs on the remote */
1538                 for (ref = *dst; ref; ref = ref->next) {
1539                         char *src_name;
1540
1541                         if (ref->peer_ref)
1542                                 /* We're already sending something to this ref. */
1543                                 continue;
1544
1545                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1546                         if (src_name) {
1547                                 if (!src_ref_index.nr)
1548                                         prepare_ref_index(&src_ref_index, src);
1549                                 if (!string_list_has_string(&src_ref_index,
1550                                             src_name))
1551                                         ref->peer_ref = alloc_delete_ref();
1552                                 free(src_name);
1553                         }
1554                 }
1555                 string_list_clear(&src_ref_index, 0);
1556         }
1557         if (errs)
1558                 return -1;
1559         return 0;
1560 }
1561
1562 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1563                              int force_update)
1564 {
1565         struct ref *ref;
1566
1567         for (ref = remote_refs; ref; ref = ref->next) {
1568                 int force_ref_update = ref->force || force_update;
1569                 int reject_reason = 0;
1570
1571                 if (ref->peer_ref)
1572                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1573                 else if (!send_mirror)
1574                         continue;
1575
1576                 ref->deletion = is_null_sha1(ref->new_sha1);
1577                 if (!ref->deletion &&
1578                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1579                         ref->status = REF_STATUS_UPTODATE;
1580                         continue;
1581                 }
1582
1583                 /*
1584                  * Bypass the usual "must fast-forward" check but
1585                  * replace it with a weaker "the old value must be
1586                  * this value we observed".  If the remote ref has
1587                  * moved and is now different from what we expect,
1588                  * reject any push.
1589                  *
1590                  * It also is an error if the user told us to check
1591                  * with the remote-tracking branch to find the value
1592                  * to expect, but we did not have such a tracking
1593                  * branch.
1594                  */
1595                 if (ref->expect_old_sha1) {
1596                         if (ref->expect_old_no_trackback ||
1597                             hashcmp(ref->old_sha1, ref->old_sha1_expect))
1598                                 reject_reason = REF_STATUS_REJECT_STALE;
1599                 }
1600
1601                 /*
1602                  * The usual "must fast-forward" rules.
1603                  *
1604                  * Decide whether an individual refspec A:B can be
1605                  * pushed.  The push will succeed if any of the
1606                  * following are true:
1607                  *
1608                  * (1) the remote reference B does not exist
1609                  *
1610                  * (2) the remote reference B is being removed (i.e.,
1611                  *     pushing :B where no source is specified)
1612                  *
1613                  * (3) the destination is not under refs/tags/, and
1614                  *     if the old and new value is a commit, the new
1615                  *     is a descendant of the old.
1616                  *
1617                  * (4) it is forced using the +A:B notation, or by
1618                  *     passing the --force argument
1619                  */
1620
1621                 else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1622                         if (starts_with(ref->name, "refs/tags/"))
1623                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1624                         else if (!has_sha1_file(ref->old_sha1))
1625                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1626                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1627                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1628                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1629                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1630                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1631                 }
1632
1633                 /*
1634                  * "--force" will defeat any rejection implemented
1635                  * by the rules above.
1636                  */
1637                 if (!force_ref_update)
1638                         ref->status = reject_reason;
1639                 else if (reject_reason)
1640                         ref->forced_update = 1;
1641         }
1642 }
1643
1644 static void set_merge(struct branch *ret)
1645 {
1646         struct remote *remote;
1647         char *ref;
1648         unsigned char sha1[20];
1649         int i;
1650
1651         if (!ret)
1652                 return; /* no branch */
1653         if (ret->merge)
1654                 return; /* already run */
1655         if (!ret->remote_name || !ret->merge_nr) {
1656                 /*
1657                  * no merge config; let's make sure we don't confuse callers
1658                  * with a non-zero merge_nr but a NULL merge
1659                  */
1660                 ret->merge_nr = 0;
1661                 return;
1662         }
1663
1664         remote = remote_get(ret->remote_name);
1665
1666         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1667         for (i = 0; i < ret->merge_nr; i++) {
1668                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1669                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1670                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1671                     strcmp(ret->remote_name, "."))
1672                         continue;
1673                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1674                              sha1, &ref) == 1)
1675                         ret->merge[i]->dst = ref;
1676                 else
1677                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1678         }
1679 }
1680
1681 struct branch *branch_get(const char *name)
1682 {
1683         struct branch *ret;
1684
1685         read_config();
1686         if (!name || !*name || !strcmp(name, "HEAD"))
1687                 ret = current_branch;
1688         else
1689                 ret = make_branch(name, 0);
1690         set_merge(ret);
1691         return ret;
1692 }
1693
1694 int branch_has_merge_config(struct branch *branch)
1695 {
1696         return branch && !!branch->merge;
1697 }
1698
1699 int branch_merge_matches(struct branch *branch,
1700                                  int i,
1701                                  const char *refname)
1702 {
1703         if (!branch || i < 0 || i >= branch->merge_nr)
1704                 return 0;
1705         return refname_match(branch->merge[i]->src, refname);
1706 }
1707
1708 const char *branch_get_upstream(struct branch *branch)
1709 {
1710         if (!branch || !branch->merge || !branch->merge[0])
1711                 return NULL;
1712         return branch->merge[0]->dst;
1713 }
1714
1715 static int ignore_symref_update(const char *refname)
1716 {
1717         unsigned char sha1[20];
1718         int flag;
1719
1720         if (!resolve_ref_unsafe(refname, 0, sha1, &flag))
1721                 return 0; /* non-existing refs are OK */
1722         return (flag & REF_ISSYMREF);
1723 }
1724
1725 /*
1726  * Create and return a list of (struct ref) consisting of copies of
1727  * each remote_ref that matches refspec.  refspec must be a pattern.
1728  * Fill in the copies' peer_ref to describe the local tracking refs to
1729  * which they map.  Omit any references that would map to an existing
1730  * local symbolic ref.
1731  */
1732 static struct ref *get_expanded_map(const struct ref *remote_refs,
1733                                     const struct refspec *refspec)
1734 {
1735         const struct ref *ref;
1736         struct ref *ret = NULL;
1737         struct ref **tail = &ret;
1738
1739         for (ref = remote_refs; ref; ref = ref->next) {
1740                 char *expn_name = NULL;
1741
1742                 if (strchr(ref->name, '^'))
1743                         continue; /* a dereference item */
1744                 if (match_name_with_pattern(refspec->src, ref->name,
1745                                             refspec->dst, &expn_name) &&
1746                     !ignore_symref_update(expn_name)) {
1747                         struct ref *cpy = copy_ref(ref);
1748
1749                         cpy->peer_ref = alloc_ref(expn_name);
1750                         if (refspec->force)
1751                                 cpy->peer_ref->force = 1;
1752                         *tail = cpy;
1753                         tail = &cpy->next;
1754                 }
1755                 free(expn_name);
1756         }
1757
1758         return ret;
1759 }
1760
1761 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1762 {
1763         const struct ref *ref;
1764         for (ref = refs; ref; ref = ref->next) {
1765                 if (refname_match(name, ref->name))
1766                         return ref;
1767         }
1768         return NULL;
1769 }
1770
1771 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1772 {
1773         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1774
1775         if (!ref)
1776                 return NULL;
1777
1778         return copy_ref(ref);
1779 }
1780
1781 static struct ref *get_local_ref(const char *name)
1782 {
1783         if (!name || name[0] == '\0')
1784                 return NULL;
1785
1786         if (starts_with(name, "refs/"))
1787                 return alloc_ref(name);
1788
1789         if (starts_with(name, "heads/") ||
1790             starts_with(name, "tags/") ||
1791             starts_with(name, "remotes/"))
1792                 return alloc_ref_with_prefix("refs/", 5, name);
1793
1794         return alloc_ref_with_prefix("refs/heads/", 11, name);
1795 }
1796
1797 int get_fetch_map(const struct ref *remote_refs,
1798                   const struct refspec *refspec,
1799                   struct ref ***tail,
1800                   int missing_ok)
1801 {
1802         struct ref *ref_map, **rmp;
1803
1804         if (refspec->pattern) {
1805                 ref_map = get_expanded_map(remote_refs, refspec);
1806         } else {
1807                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1808
1809                 if (refspec->exact_sha1) {
1810                         ref_map = alloc_ref(name);
1811                         get_sha1_hex(name, ref_map->old_sha1);
1812                 } else {
1813                         ref_map = get_remote_ref(remote_refs, name);
1814                 }
1815                 if (!missing_ok && !ref_map)
1816                         die("Couldn't find remote ref %s", name);
1817                 if (ref_map) {
1818                         ref_map->peer_ref = get_local_ref(refspec->dst);
1819                         if (ref_map->peer_ref && refspec->force)
1820                                 ref_map->peer_ref->force = 1;
1821                 }
1822         }
1823
1824         for (rmp = &ref_map; *rmp; ) {
1825                 if ((*rmp)->peer_ref) {
1826                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1827                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1828                                 struct ref *ignore = *rmp;
1829                                 error("* Ignoring funny ref '%s' locally",
1830                                       (*rmp)->peer_ref->name);
1831                                 *rmp = (*rmp)->next;
1832                                 free(ignore->peer_ref);
1833                                 free(ignore);
1834                                 continue;
1835                         }
1836                 }
1837                 rmp = &((*rmp)->next);
1838         }
1839
1840         if (ref_map)
1841                 tail_link_ref(ref_map, tail);
1842
1843         return 0;
1844 }
1845
1846 int resolve_remote_symref(struct ref *ref, struct ref *list)
1847 {
1848         if (!ref->symref)
1849                 return 0;
1850         for (; list; list = list->next)
1851                 if (!strcmp(ref->symref, list->name)) {
1852                         hashcpy(ref->old_sha1, list->old_sha1);
1853                         return 0;
1854                 }
1855         return 1;
1856 }
1857
1858 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1859 {
1860         while (list) {
1861                 struct commit_list *temp = list;
1862                 temp->item->object.flags &= ~mark;
1863                 list = temp->next;
1864                 free(temp);
1865         }
1866 }
1867
1868 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1869 {
1870         struct object *o;
1871         struct commit *old, *new;
1872         struct commit_list *list, *used;
1873         int found = 0;
1874
1875         /*
1876          * Both new and old must be commit-ish and new is descendant of
1877          * old.  Otherwise we require --force.
1878          */
1879         o = deref_tag(parse_object(old_sha1), NULL, 0);
1880         if (!o || o->type != OBJ_COMMIT)
1881                 return 0;
1882         old = (struct commit *) o;
1883
1884         o = deref_tag(parse_object(new_sha1), NULL, 0);
1885         if (!o || o->type != OBJ_COMMIT)
1886                 return 0;
1887         new = (struct commit *) o;
1888
1889         if (parse_commit(new) < 0)
1890                 return 0;
1891
1892         used = list = NULL;
1893         commit_list_insert(new, &list);
1894         while (list) {
1895                 new = pop_most_recent_commit(&list, TMP_MARK);
1896                 commit_list_insert(new, &used);
1897                 if (new == old) {
1898                         found = 1;
1899                         break;
1900                 }
1901         }
1902         unmark_and_free(list, TMP_MARK);
1903         unmark_and_free(used, TMP_MARK);
1904         return found;
1905 }
1906
1907 /*
1908  * Compare a branch with its upstream, and save their differences (number
1909  * of commits) in *num_ours and *num_theirs.
1910  *
1911  * Return 0 if branch has no upstream (no base), -1 if upstream is missing
1912  * (with "gone" base), otherwise 1 (with base).
1913  */
1914 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1915 {
1916         unsigned char sha1[20];
1917         struct commit *ours, *theirs;
1918         char symmetric[84];
1919         struct rev_info revs;
1920         const char *rev_argv[10], *base;
1921         int rev_argc;
1922
1923         /* Cannot stat unless we are marked to build on top of somebody else. */
1924         base = branch_get_upstream(branch);
1925         if (!base)
1926                 return 0;
1927
1928         /* Cannot stat if what we used to build on no longer exists */
1929         if (read_ref(base, sha1))
1930                 return -1;
1931         theirs = lookup_commit_reference(sha1);
1932         if (!theirs)
1933                 return -1;
1934
1935         if (read_ref(branch->refname, sha1))
1936                 return -1;
1937         ours = lookup_commit_reference(sha1);
1938         if (!ours)
1939                 return -1;
1940
1941         /* are we the same? */
1942         if (theirs == ours) {
1943                 *num_theirs = *num_ours = 0;
1944                 return 1;
1945         }
1946
1947         /* Run "rev-list --left-right ours...theirs" internally... */
1948         rev_argc = 0;
1949         rev_argv[rev_argc++] = NULL;
1950         rev_argv[rev_argc++] = "--left-right";
1951         rev_argv[rev_argc++] = symmetric;
1952         rev_argv[rev_argc++] = "--";
1953         rev_argv[rev_argc] = NULL;
1954
1955         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1956         strcpy(symmetric + 40, "...");
1957         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1958
1959         init_revisions(&revs, NULL);
1960         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1961         if (prepare_revision_walk(&revs))
1962                 die("revision walk setup failed");
1963
1964         /* ... and count the commits on each side. */
1965         *num_ours = 0;
1966         *num_theirs = 0;
1967         while (1) {
1968                 struct commit *c = get_revision(&revs);
1969                 if (!c)
1970                         break;
1971                 if (c->object.flags & SYMMETRIC_LEFT)
1972                         (*num_ours)++;
1973                 else
1974                         (*num_theirs)++;
1975         }
1976
1977         /* clear object flags smudged by the above traversal */
1978         clear_commit_marks(ours, ALL_REV_FLAGS);
1979         clear_commit_marks(theirs, ALL_REV_FLAGS);
1980         return 1;
1981 }
1982
1983 /*
1984  * Return true when there is anything to report, otherwise false.
1985  */
1986 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1987 {
1988         int ours, theirs;
1989         char *base;
1990         int upstream_is_gone = 0;
1991
1992         switch (stat_tracking_info(branch, &ours, &theirs)) {
1993         case 0:
1994                 /* no base */
1995                 return 0;
1996         case -1:
1997                 /* with "gone" base */
1998                 upstream_is_gone = 1;
1999                 break;
2000         default:
2001                 /* with base */
2002                 break;
2003         }
2004
2005         base = shorten_unambiguous_ref(branch->merge[0]->dst, 0);
2006         if (upstream_is_gone) {
2007                 strbuf_addf(sb,
2008                         _("Your branch is based on '%s', but the upstream is gone.\n"),
2009                         base);
2010                 if (advice_status_hints)
2011                         strbuf_addf(sb,
2012                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2013         } else if (!ours && !theirs) {
2014                 strbuf_addf(sb,
2015                         _("Your branch is up-to-date with '%s'.\n"),
2016                         base);
2017         } else if (!theirs) {
2018                 strbuf_addf(sb,
2019                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2020                            "Your branch is ahead of '%s' by %d commits.\n",
2021                            ours),
2022                         base, ours);
2023                 if (advice_status_hints)
2024                         strbuf_addf(sb,
2025                                 _("  (use \"git push\" to publish your local commits)\n"));
2026         } else if (!ours) {
2027                 strbuf_addf(sb,
2028                         Q_("Your branch is behind '%s' by %d commit, "
2029                                "and can be fast-forwarded.\n",
2030                            "Your branch is behind '%s' by %d commits, "
2031                                "and can be fast-forwarded.\n",
2032                            theirs),
2033                         base, theirs);
2034                 if (advice_status_hints)
2035                         strbuf_addf(sb,
2036                                 _("  (use \"git pull\" to update your local branch)\n"));
2037         } else {
2038                 strbuf_addf(sb,
2039                         Q_("Your branch and '%s' have diverged,\n"
2040                                "and have %d and %d different commit each, "
2041                                "respectively.\n",
2042                            "Your branch and '%s' have diverged,\n"
2043                                "and have %d and %d different commits each, "
2044                                "respectively.\n",
2045                            theirs),
2046                         base, ours, theirs);
2047                 if (advice_status_hints)
2048                         strbuf_addf(sb,
2049                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2050         }
2051         free(base);
2052         return 1;
2053 }
2054
2055 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
2056 {
2057         struct ref ***local_tail = cb_data;
2058         struct ref *ref;
2059         int len;
2060
2061         /* we already know it starts with refs/ to get here */
2062         if (check_refname_format(refname + 5, 0))
2063                 return 0;
2064
2065         len = strlen(refname) + 1;
2066         ref = xcalloc(1, sizeof(*ref) + len);
2067         hashcpy(ref->new_sha1, sha1);
2068         memcpy(ref->name, refname, len);
2069         **local_tail = ref;
2070         *local_tail = &ref->next;
2071         return 0;
2072 }
2073
2074 struct ref *get_local_heads(void)
2075 {
2076         struct ref *local_refs = NULL, **local_tail = &local_refs;
2077         for_each_ref(one_local_ref, &local_tail);
2078         return local_refs;
2079 }
2080
2081 struct ref *guess_remote_head(const struct ref *head,
2082                               const struct ref *refs,
2083                               int all)
2084 {
2085         const struct ref *r;
2086         struct ref *list = NULL;
2087         struct ref **tail = &list;
2088
2089         if (!head)
2090                 return NULL;
2091
2092         /*
2093          * Some transports support directly peeking at
2094          * where HEAD points; if that is the case, then
2095          * we don't have to guess.
2096          */
2097         if (head->symref)
2098                 return copy_ref(find_ref_by_name(refs, head->symref));
2099
2100         /* If refs/heads/master could be right, it is. */
2101         if (!all) {
2102                 r = find_ref_by_name(refs, "refs/heads/master");
2103                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
2104                         return copy_ref(r);
2105         }
2106
2107         /* Look for another ref that points there */
2108         for (r = refs; r; r = r->next) {
2109                 if (r != head &&
2110                     starts_with(r->name, "refs/heads/") &&
2111                     !hashcmp(r->old_sha1, head->old_sha1)) {
2112                         *tail = copy_ref(r);
2113                         tail = &((*tail)->next);
2114                         if (!all)
2115                                 break;
2116                 }
2117         }
2118
2119         return list;
2120 }
2121
2122 struct stale_heads_info {
2123         struct string_list *ref_names;
2124         struct ref **stale_refs_tail;
2125         struct refspec *refs;
2126         int ref_count;
2127 };
2128
2129 static int get_stale_heads_cb(const char *refname,
2130         const unsigned char *sha1, int flags, void *cb_data)
2131 {
2132         struct stale_heads_info *info = cb_data;
2133         struct string_list matches = STRING_LIST_INIT_DUP;
2134         struct refspec query;
2135         int i, stale = 1;
2136         memset(&query, 0, sizeof(struct refspec));
2137         query.dst = (char *)refname;
2138
2139         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2140         if (matches.nr == 0)
2141                 goto clean_exit; /* No matches */
2142
2143         /*
2144          * If we did find a suitable refspec and it's not a symref and
2145          * it's not in the list of refs that currently exist in that
2146          * remote, we consider it to be stale. In order to deal with
2147          * overlapping refspecs, we need to go over all of the
2148          * matching refs.
2149          */
2150         if (flags & REF_ISSYMREF)
2151                 goto clean_exit;
2152
2153         for (i = 0; stale && i < matches.nr; i++)
2154                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2155                         stale = 0;
2156
2157         if (stale) {
2158                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2159                 hashcpy(ref->new_sha1, sha1);
2160         }
2161
2162 clean_exit:
2163         string_list_clear(&matches, 0);
2164         return 0;
2165 }
2166
2167 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2168 {
2169         struct ref *ref, *stale_refs = NULL;
2170         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2171         struct stale_heads_info info;
2172         info.ref_names = &ref_names;
2173         info.stale_refs_tail = &stale_refs;
2174         info.refs = refs;
2175         info.ref_count = ref_count;
2176         for (ref = fetch_map; ref; ref = ref->next)
2177                 string_list_append(&ref_names, ref->name);
2178         string_list_sort(&ref_names);
2179         for_each_ref(get_stale_heads_cb, &info);
2180         string_list_clear(&ref_names, 0);
2181         return stale_refs;
2182 }
2183
2184 /*
2185  * Compare-and-swap
2186  */
2187 static void clear_cas_option(struct push_cas_option *cas)
2188 {
2189         int i;
2190
2191         for (i = 0; i < cas->nr; i++)
2192                 free(cas->entry[i].refname);
2193         free(cas->entry);
2194         memset(cas, 0, sizeof(*cas));
2195 }
2196
2197 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2198                                       const char *refname,
2199                                       size_t refnamelen)
2200 {
2201         struct push_cas *entry;
2202         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2203         entry = &cas->entry[cas->nr++];
2204         memset(entry, 0, sizeof(*entry));
2205         entry->refname = xmemdupz(refname, refnamelen);
2206         return entry;
2207 }
2208
2209 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2210 {
2211         const char *colon;
2212         struct push_cas *entry;
2213
2214         if (unset) {
2215                 /* "--no-<option>" */
2216                 clear_cas_option(cas);
2217                 return 0;
2218         }
2219
2220         if (!arg) {
2221                 /* just "--<option>" */
2222                 cas->use_tracking_for_rest = 1;
2223                 return 0;
2224         }
2225
2226         /* "--<option>=refname" or "--<option>=refname:value" */
2227         colon = strchrnul(arg, ':');
2228         entry = add_cas_entry(cas, arg, colon - arg);
2229         if (!*colon)
2230                 entry->use_tracking = 1;
2231         else if (get_sha1(colon + 1, entry->expect))
2232                 return error("cannot parse expected object name '%s'", colon + 1);
2233         return 0;
2234 }
2235
2236 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2237 {
2238         return parse_push_cas_option(opt->value, arg, unset);
2239 }
2240
2241 int is_empty_cas(const struct push_cas_option *cas)
2242 {
2243         return !cas->use_tracking_for_rest && !cas->nr;
2244 }
2245
2246 /*
2247  * Look at remote.fetch refspec and see if we have a remote
2248  * tracking branch for the refname there.  Fill its current
2249  * value in sha1[].
2250  * If we cannot do so, return negative to signal an error.
2251  */
2252 static int remote_tracking(struct remote *remote, const char *refname,
2253                            unsigned char sha1[20])
2254 {
2255         char *dst;
2256
2257         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2258         if (!dst)
2259                 return -1; /* no tracking ref for refname at remote */
2260         if (read_ref(dst, sha1))
2261                 return -1; /* we know what the tracking ref is but we cannot read it */
2262         return 0;
2263 }
2264
2265 static void apply_cas(struct push_cas_option *cas,
2266                       struct remote *remote,
2267                       struct ref *ref)
2268 {
2269         int i;
2270
2271         /* Find an explicit --<option>=<name>[:<value>] entry */
2272         for (i = 0; i < cas->nr; i++) {
2273                 struct push_cas *entry = &cas->entry[i];
2274                 if (!refname_match(entry->refname, ref->name))
2275                         continue;
2276                 ref->expect_old_sha1 = 1;
2277                 if (!entry->use_tracking)
2278                         hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2279                 else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2280                         ref->expect_old_no_trackback = 1;
2281                 return;
2282         }
2283
2284         /* Are we using "--<option>" to cover all? */
2285         if (!cas->use_tracking_for_rest)
2286                 return;
2287
2288         ref->expect_old_sha1 = 1;
2289         if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2290                 ref->expect_old_no_trackback = 1;
2291 }
2292
2293 void apply_push_cas(struct push_cas_option *cas,
2294                     struct remote *remote,
2295                     struct ref *remote_refs)
2296 {
2297         struct ref *ref;
2298         for (ref = remote_refs; ref; ref = ref->next)
2299                 apply_cas(cas, remote, ref);
2300 }