remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "dir.h"
   8 #include "tag.h"
   9 #include "string-list.h"
  10 #include "mergesort.h"
  11 #include "argv-array.h"
  12
  13 enum map_direction { FROM_SRC, FROM_DST };
  14
  15 static struct refspec s_tag_refspec = {
  16         0,
  17         1,
  18         0,
  19         0,
  20         "refs/tags/*",
  21         "refs/tags/*"
  22 };
  23
  24 const struct refspec *tag_refspec = &s_tag_refspec;
  25
  26 struct counted_string {
  27         size_t len;
  28         const char *s;
  29 };
  30 struct rewrite {
  31         const char *base;
  32         size_t baselen;
  33         struct counted_string *instead_of;
  34         int instead_of_nr;
  35         int instead_of_alloc;
  36 };
  37 struct rewrites {
  38         struct rewrite **rewrite;
  39         int rewrite_alloc;
  40         int rewrite_nr;
  41 };
  42
  43 static struct remote **remotes;
  44 static int remotes_alloc;
  45 static int remotes_nr;
  46 static struct hashmap remotes_hash;
  47
  48 static struct branch **branches;
  49 static int branches_alloc;
  50 static int branches_nr;
  51
  52 static struct branch *current_branch;
  53 static const char *pushremote_name;
  54
  55 static struct rewrites rewrites;
  56 static struct rewrites rewrites_push;
  57
  58 static int valid_remote(const struct remote *remote)
  59 {
  60         return (!!remote->url) || (!!remote->foreign_vcs);
  61 }
  62
  63 static const char *alias_url(const char *url, struct rewrites *r)
  64 {
  65         int i, j;
  66         struct counted_string *longest;
  67         int longest_i;
  68
  69         longest = NULL;
  70         longest_i = -1;
  71         for (i = 0; i < r->rewrite_nr; i++) {
  72                 if (!r->rewrite[i])
  73                         continue;
  74                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  75                         if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  76                             (!longest ||
  77                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  78                                 longest = &(r->rewrite[i]->instead_of[j]);
  79                                 longest_i = i;
  80                         }
  81                 }
  82         }
  83         if (!longest)
  84                 return url;
  85
  86         return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  87 }
  88
  89 static void add_push_refspec(struct remote *remote, const char *ref)
  90 {
  91         ALLOC_GROW(remote->push_refspec,
  92                    remote->push_refspec_nr + 1,
  93                    remote->push_refspec_alloc);
  94         remote->push_refspec[remote->push_refspec_nr++] = ref;
  95 }
  96
  97 static void add_fetch_refspec(struct remote *remote, const char *ref)
  98 {
  99         ALLOC_GROW(remote->fetch_refspec,
 100                    remote->fetch_refspec_nr + 1,
 101                    remote->fetch_refspec_alloc);
 102         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 103 }
 104
 105 static void add_url(struct remote *remote, const char *url)
 106 {
 107         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 108         remote->url[remote->url_nr++] = url;
 109 }
 110
 111 static void add_pushurl(struct remote *remote, const char *pushurl)
 112 {
 113         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 114         remote->pushurl[remote->pushurl_nr++] = pushurl;
 115 }
 116
 117 static void add_pushurl_alias(struct remote *remote, const char *url)
 118 {
 119         const char *pushurl = alias_url(url, &rewrites_push);
 120         if (pushurl != url)
 121                 add_pushurl(remote, pushurl);
 122 }
 123
 124 static void add_url_alias(struct remote *remote, const char *url)
 125 {
 126         add_url(remote, alias_url(url, &rewrites));
 127         add_pushurl_alias(remote, url);
 128 }
 129
 130 struct remotes_hash_key {
 131         const char *str;
 132         int len;
 133 };
 134
 135 static int remotes_hash_cmp(const struct remote *a, const struct remote *b, const struct remotes_hash_key *key)
 136 {
 137         if (key)
 138                 return strncmp(a->name, key->str, key->len) || a->name[key->len];
 139         else
 140                 return strcmp(a->name, b->name);
 141 }
 142
 143 static inline void init_remotes_hash(void)
 144 {
 145         if (!remotes_hash.cmpfn)
 146                 hashmap_init(&remotes_hash, (hashmap_cmp_fn)remotes_hash_cmp, 0);
 147 }
 148
 149 static struct remote *make_remote(const char *name, int len)
 150 {
 151         struct remote *ret, *replaced;
 152         struct remotes_hash_key lookup;
 153         struct hashmap_entry lookup_entry;
 154
 155         if (!len)
 156                 len = strlen(name);
 157
 158         init_remotes_hash();
 159         lookup.str = name;
 160         lookup.len = len;
 161         hashmap_entry_init(&lookup_entry, memhash(name, len));
 162
 163         if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 164                 return ret;
 165
 166         ret = xcalloc(1, sizeof(struct remote));
 167         ret->prune = -1;  /* unspecified */
 168         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 169         remotes[remotes_nr++] = ret;
 170         ret->name = xstrndup(name, len);
 171
 172         hashmap_entry_init(ret, lookup_entry.hash);
 173         replaced = hashmap_put(&remotes_hash, ret);
 174         assert(replaced == NULL);  /* no previous entry overwritten */
 175         return ret;
 176 }
 177
 178 static void add_merge(struct branch *branch, const char *name)
 179 {
 180         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 181                    branch->merge_alloc);
 182         branch->merge_name[branch->merge_nr++] = name;
 183 }
 184
 185 static struct branch *make_branch(const char *name, int len)
 186 {
 187         struct branch *ret;
 188         int i;
 189
 190         for (i = 0; i < branches_nr; i++) {
 191                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 192                            !branches[i]->name[len]) :
 193                     !strcmp(name, branches[i]->name))
 194                         return branches[i];
 195         }
 196
 197         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 198         ret = xcalloc(1, sizeof(struct branch));
 199         branches[branches_nr++] = ret;
 200         if (len)
 201                 ret->name = xstrndup(name, len);
 202         else
 203                 ret->name = xstrdup(name);
 204         ret->refname = xstrfmt("refs/heads/%s", ret->name);
 205
 206         return ret;
 207 }
 208
 209 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 210 {
 211         struct rewrite *ret;
 212         int i;
 213
 214         for (i = 0; i < r->rewrite_nr; i++) {
 215                 if (len
 216                     ? (len == r->rewrite[i]->baselen &&
 217                        !strncmp(base, r->rewrite[i]->base, len))
 218                     : !strcmp(base, r->rewrite[i]->base))
 219                         return r->rewrite[i];
 220         }
 221
 222         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 223         ret = xcalloc(1, sizeof(struct rewrite));
 224         r->rewrite[r->rewrite_nr++] = ret;
 225         if (len) {
 226                 ret->base = xstrndup(base, len);
 227                 ret->baselen = len;
 228         }
 229         else {
 230                 ret->base = xstrdup(base);
 231                 ret->baselen = strlen(base);
 232         }
 233         return ret;
 234 }
 235
 236 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 237 {
 238         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 239         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 240         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 241         rewrite->instead_of_nr++;
 242 }
 243
 244 static const char *skip_spaces(const char *s)
 245 {
 246         while (isspace(*s))
 247                 s++;
 248         return s;
 249 }
 250
 251 static void read_remotes_file(struct remote *remote)
 252 {
 253         struct strbuf buf = STRBUF_INIT;
 254         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 255
 256         if (!f)
 257                 return;
 258         remote->configured_in_repo = 1;
 259         remote->origin = REMOTE_REMOTES;
 260         while (strbuf_getline(&buf, f) != EOF) {
 261                 const char *v;
 262
 263                 strbuf_rtrim(&buf);
 264
 265                 if (skip_prefix(buf.buf, "URL:", &v))
 266                         add_url_alias(remote, xstrdup(skip_spaces(v)));
 267                 else if (skip_prefix(buf.buf, "Push:", &v))
 268                         add_push_refspec(remote, xstrdup(skip_spaces(v)));
 269                 else if (skip_prefix(buf.buf, "Pull:", &v))
 270                         add_fetch_refspec(remote, xstrdup(skip_spaces(v)));
 271         }
 272         strbuf_release(&buf);
 273         fclose(f);
 274 }
 275
 276 static void read_branches_file(struct remote *remote)
 277 {
 278         char *frag;
 279         struct strbuf buf = STRBUF_INIT;
 280         FILE *f = fopen(git_path("branches/%s", remote->name), "r");
 281
 282         if (!f)
 283                 return;
 284
 285         strbuf_getline_lf(&buf, f);
 286         fclose(f);
 287         strbuf_trim(&buf);
 288         if (!buf.len) {
 289                 strbuf_release(&buf);
 290                 return;
 291         }
 292
 293         remote->configured_in_repo = 1;
 294         remote->origin = REMOTE_BRANCHES;
 295
 296         /*
 297          * The branches file would have URL and optionally
 298          * #branch specified.  The "master" (or specified) branch is
 299          * fetched and stored in the local branch matching the
 300          * remote name.
 301          */
 302         frag = strchr(buf.buf, '#');
 303         if (frag)
 304                 *(frag++) = '\0';
 305         else
 306                 frag = "master";
 307
 308         add_url_alias(remote, strbuf_detach(&buf, NULL));
 309         add_fetch_refspec(remote, xstrfmt("refs/heads/%s:refs/heads/%s",
 310                                           frag, remote->name));
 311
 312         /*
 313          * Cogito compatible push: push current HEAD to remote #branch
 314          * (master if missing)
 315          */
 316         add_push_refspec(remote, xstrfmt("HEAD:refs/heads/%s", frag));
 317         remote->fetch_tags = 1; /* always auto-follow */
 318 }
 319
 320 static int handle_config(const char *key, const char *value, void *cb)
 321 {
 322         const char *name;
 323         int namelen;
 324         const char *subkey;
 325         struct remote *remote;
 326         struct branch *branch;
 327         if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
 328                 if (!name)
 329                         return 0;
 330                 branch = make_branch(name, namelen);
 331                 if (!strcmp(subkey, "remote")) {
 332                         return git_config_string(&branch->remote_name, key, value);
 333                 } else if (!strcmp(subkey, "pushremote")) {
 334                         return git_config_string(&branch->pushremote_name, key, value);
 335                 } else if (!strcmp(subkey, "merge")) {
 336                         if (!value)
 337                                 return config_error_nonbool(key);
 338                         add_merge(branch, xstrdup(value));
 339                 }
 340                 return 0;
 341         }
 342         if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
 343                 struct rewrite *rewrite;
 344                 if (!name)
 345                         return 0;
 346                 if (!strcmp(subkey, "insteadof")) {
 347                         rewrite = make_rewrite(&rewrites, name, namelen);
 348                         if (!value)
 349                                 return config_error_nonbool(key);
 350                         add_instead_of(rewrite, xstrdup(value));
 351                 } else if (!strcmp(subkey, "pushinsteadof")) {
 352                         rewrite = make_rewrite(&rewrites_push, name, namelen);
 353                         if (!value)
 354                                 return config_error_nonbool(key);
 355                         add_instead_of(rewrite, xstrdup(value));
 356                 }
 357         }
 358
 359         if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
 360                 return 0;
 361
 362         /* Handle remote.* variables */
 363         if (!name && !strcmp(subkey, "pushdefault"))
 364                 return git_config_string(&pushremote_name, key, value);
 365
 366         if (!name)
 367                 return 0;
 368         /* Handle remote.<name>.* variables */
 369         if (*name == '/') {
 370                 warning("Config remote shorthand cannot begin with '/': %s",
 371                         name);
 372                 return 0;
 373         }
 374         remote = make_remote(name, namelen);
 375         remote->origin = REMOTE_CONFIG;
 376         if (current_config_scope() == CONFIG_SCOPE_REPO)
 377                 remote->configured_in_repo = 1;
 378         if (!strcmp(subkey, "mirror"))
 379                 remote->mirror = git_config_bool(key, value);
 380         else if (!strcmp(subkey, "skipdefaultupdate"))
 381                 remote->skip_default_update = git_config_bool(key, value);
 382         else if (!strcmp(subkey, "skipfetchall"))
 383                 remote->skip_default_update = git_config_bool(key, value);
 384         else if (!strcmp(subkey, "prune"))
 385                 remote->prune = git_config_bool(key, value);
 386         else if (!strcmp(subkey, "url")) {
 387                 const char *v;
 388                 if (git_config_string(&v, key, value))
 389                         return -1;
 390                 add_url(remote, v);
 391         } else if (!strcmp(subkey, "pushurl")) {
 392                 const char *v;
 393                 if (git_config_string(&v, key, value))
 394                         return -1;
 395                 add_pushurl(remote, v);
 396         } else if (!strcmp(subkey, "push")) {
 397                 const char *v;
 398                 if (git_config_string(&v, key, value))
 399                         return -1;
 400                 add_push_refspec(remote, v);
 401         } else if (!strcmp(subkey, "fetch")) {
 402                 const char *v;
 403                 if (git_config_string(&v, key, value))
 404                         return -1;
 405                 add_fetch_refspec(remote, v);
 406         } else if (!strcmp(subkey, "receivepack")) {
 407                 const char *v;
 408                 if (git_config_string(&v, key, value))
 409                         return -1;
 410                 if (!remote->receivepack)
 411                         remote->receivepack = v;
 412                 else
 413                         error("more than one receivepack given, using the first");
 414         } else if (!strcmp(subkey, "uploadpack")) {
 415                 const char *v;
 416                 if (git_config_string(&v, key, value))
 417                         return -1;
 418                 if (!remote->uploadpack)
 419                         remote->uploadpack = v;
 420                 else
 421                         error("more than one uploadpack given, using the first");
 422         } else if (!strcmp(subkey, "tagopt")) {
 423                 if (!strcmp(value, "--no-tags"))
 424                         remote->fetch_tags = -1;
 425                 else if (!strcmp(value, "--tags"))
 426                         remote->fetch_tags = 2;
 427         } else if (!strcmp(subkey, "proxy")) {
 428                 return git_config_string((const char **)&remote->http_proxy,
 429                                          key, value);
 430         } else if (!strcmp(subkey, "proxyauthmethod")) {
 431                 return git_config_string((const char **)&remote->http_proxy_authmethod,
 432                                          key, value);
 433         } else if (!strcmp(subkey, "vcs")) {
 434                 return git_config_string(&remote->foreign_vcs, key, value);
 435         }
 436         return 0;
 437 }
 438
 439 static void alias_all_urls(void)
 440 {
 441         int i, j;
 442         for (i = 0; i < remotes_nr; i++) {
 443                 int add_pushurl_aliases;
 444                 if (!remotes[i])
 445                         continue;
 446                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 447                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 448                 }
 449                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 450                 for (j = 0; j < remotes[i]->url_nr; j++) {
 451                         if (add_pushurl_aliases)
 452                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 453                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 454                 }
 455         }
 456 }
 457
 458 static void read_config(void)
 459 {
 460         static int loaded;
 461         struct object_id oid;
 462         int flag;
 463
 464         if (loaded)
 465                 return;
 466         loaded = 1;
 467
 468         current_branch = NULL;
 469         if (startup_info->have_repository) {
 470                 const char *head_ref = resolve_ref_unsafe("HEAD", 0, oid.hash, &flag);
 471                 if (head_ref && (flag & REF_ISSYMREF) &&
 472                     skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 473                         current_branch = make_branch(head_ref, 0);
 474                 }
 475         }
 476         git_config(handle_config, NULL);
 477         alias_all_urls();
 478 }
 479
 480 /*
 481  * This function frees a refspec array.
 482  * Warning: code paths should be checked to ensure that the src
 483  *          and dst pointers are always freeable pointers as well
 484  *          as the refspec pointer itself.
 485  */
 486 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 487 {
 488         int i;
 489
 490         if (!refspec)
 491                 return;
 492
 493         for (i = 0; i < nr_refspec; i++) {
 494                 free(refspec[i].src);
 495                 free(refspec[i].dst);
 496         }
 497         free(refspec);
 498 }
 499
 500 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 501 {
 502         int i;
 503         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 504
 505         for (i = 0; i < nr_refspec; i++) {
 506                 size_t llen;
 507                 int is_glob;
 508                 const char *lhs, *rhs;
 509                 int flags;
 510
 511                 is_glob = 0;
 512
 513                 lhs = refspec[i];
 514                 if (*lhs == '+') {
 515                         rs[i].force = 1;
 516                         lhs++;
 517                 }
 518
 519                 rhs = strrchr(lhs, ':');
 520
 521                 /*
 522                  * Before going on, special case ":" (or "+:") as a refspec
 523                  * for pushing matching refs.
 524                  */
 525                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 526                         rs[i].matching = 1;
 527                         continue;
 528                 }
 529
 530                 if (rhs) {
 531                         size_t rlen = strlen(++rhs);
 532                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 533                         rs[i].dst = xstrndup(rhs, rlen);
 534                 }
 535
 536                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 537                 if (1 <= llen && memchr(lhs, '*', llen)) {
 538                         if ((rhs && !is_glob) || (!rhs && fetch))
 539                                 goto invalid;
 540                         is_glob = 1;
 541                 } else if (rhs && is_glob) {
 542                         goto invalid;
 543                 }
 544
 545                 rs[i].pattern = is_glob;
 546                 rs[i].src = xstrndup(lhs, llen);
 547                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 548
 549                 if (fetch) {
 550                         struct object_id unused;
 551
 552                         /* LHS */
 553                         if (!*rs[i].src)
 554                                 ; /* empty is ok; it means "HEAD" */
 555                         else if (llen == GIT_SHA1_HEXSZ && !get_oid_hex(rs[i].src, &unused))
 556                                 rs[i].exact_sha1 = 1; /* ok */
 557                         else if (!check_refname_format(rs[i].src, flags))
 558                                 ; /* valid looking ref is ok */
 559                         else
 560                                 goto invalid;
 561                         /* RHS */
 562                         if (!rs[i].dst)
 563                                 ; /* missing is ok; it is the same as empty */
 564                         else if (!*rs[i].dst)
 565                                 ; /* empty is ok; it means "do not store" */
 566                         else if (!check_refname_format(rs[i].dst, flags))
 567                                 ; /* valid looking ref is ok */
 568                         else
 569                                 goto invalid;
 570                 } else {
 571                         /*
 572                          * LHS
 573                          * - empty is allowed; it means delete.
 574                          * - when wildcarded, it must be a valid looking ref.
 575                          * - otherwise, it must be an extended SHA-1, but
 576                          *   there is no existing way to validate this.
 577                          */
 578                         if (!*rs[i].src)
 579                                 ; /* empty is ok */
 580                         else if (is_glob) {
 581                                 if (check_refname_format(rs[i].src, flags))
 582                                         goto invalid;
 583                         }
 584                         else
 585                                 ; /* anything goes, for now */
 586                         /*
 587                          * RHS
 588                          * - missing is allowed, but LHS then must be a
 589                          *   valid looking ref.
 590                          * - empty is not allowed.
 591                          * - otherwise it must be a valid looking ref.
 592                          */
 593                         if (!rs[i].dst) {
 594                                 if (check_refname_format(rs[i].src, flags))
 595                                         goto invalid;
 596                         } else if (!*rs[i].dst) {
 597                                 goto invalid;
 598                         } else {
 599                                 if (check_refname_format(rs[i].dst, flags))
 600                                         goto invalid;
 601                         }
 602                 }
 603         }
 604         return rs;
 605
 606  invalid:
 607         if (verify) {
 608                 /*
 609                  * nr_refspec must be greater than zero and i must be valid
 610                  * since it is only possible to reach this point from within
 611                  * the for loop above.
 612                  */
 613                 free_refspecs(rs, i+1);
 614                 return NULL;
 615         }
 616         die("Invalid refspec '%s'", refspec[i]);
 617 }
 618
 619 int valid_fetch_refspec(const char *fetch_refspec_str)
 620 {
 621         struct refspec *refspec;
 622
 623         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 624         free_refspecs(refspec, 1);
 625         return !!refspec;
 626 }
 627
 628 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 629 {
 630         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 631 }
 632
 633 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 634 {
 635         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 636 }
 637
 638 void free_refspec(int nr_refspec, struct refspec *refspec)
 639 {
 640         int i;
 641         for (i = 0; i < nr_refspec; i++) {
 642                 free(refspec[i].src);
 643                 free(refspec[i].dst);
 644         }
 645         free(refspec);
 646 }
 647
 648 static int valid_remote_nick(const char *name)
 649 {
 650         if (!name[0] || is_dot_or_dotdot(name))
 651                 return 0;
 652         return !strchr(name, '/'); /* no slash */
 653 }
 654
 655 const char *remote_for_branch(struct branch *branch, int *explicit)
 656 {
 657         if (branch && branch->remote_name) {
 658                 if (explicit)
 659                         *explicit = 1;
 660                 return branch->remote_name;
 661         }
 662         if (explicit)
 663                 *explicit = 0;
 664         return "origin";
 665 }
 666
 667 const char *pushremote_for_branch(struct branch *branch, int *explicit)
 668 {
 669         if (branch && branch->pushremote_name) {
 670                 if (explicit)
 671                         *explicit = 1;
 672                 return branch->pushremote_name;
 673         }
 674         if (pushremote_name) {
 675                 if (explicit)
 676                         *explicit = 1;
 677                 return pushremote_name;
 678         }
 679         return remote_for_branch(branch, explicit);
 680 }
 681
 682 static struct remote *remote_get_1(const char *name,
 683                                    const char *(*get_default)(struct branch *, int *))
 684 {
 685         struct remote *ret;
 686         int name_given = 0;
 687
 688         read_config();
 689
 690         if (name)
 691                 name_given = 1;
 692         else
 693                 name = get_default(current_branch, &name_given);
 694
 695         ret = make_remote(name, 0);
 696         if (valid_remote_nick(name) && have_git_dir()) {
 697                 if (!valid_remote(ret))
 698                         read_remotes_file(ret);
 699                 if (!valid_remote(ret))
 700                         read_branches_file(ret);
 701         }
 702         if (name_given && !valid_remote(ret))
 703                 add_url_alias(ret, name);
 704         if (!valid_remote(ret))
 705                 return NULL;
 706         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 707         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 708         return ret;
 709 }
 710
 711 struct remote *remote_get(const char *name)
 712 {
 713         return remote_get_1(name, remote_for_branch);
 714 }
 715
 716 struct remote *pushremote_get(const char *name)
 717 {
 718         return remote_get_1(name, pushremote_for_branch);
 719 }
 720
 721 int remote_is_configured(struct remote *remote, int in_repo)
 722 {
 723         if (!remote)
 724                 return 0;
 725         if (in_repo)
 726                 return remote->configured_in_repo;
 727         return !!remote->origin;
 728 }
 729
 730 int for_each_remote(each_remote_fn fn, void *priv)
 731 {
 732         int i, result = 0;
 733         read_config();
 734         for (i = 0; i < remotes_nr && !result; i++) {
 735                 struct remote *r = remotes[i];
 736                 if (!r)
 737                         continue;
 738                 if (!r->fetch)
 739                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 740                                                        r->fetch_refspec);
 741                 if (!r->push)
 742                         r->push = parse_push_refspec(r->push_refspec_nr,
 743                                                      r->push_refspec);
 744                 result = fn(r, priv);
 745         }
 746         return result;
 747 }
 748
 749 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 750 {
 751         if (strcmp(ref1->name, ref2->name)) {
 752                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 753                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 754                         die(_("Cannot fetch both %s and %s to %s"),
 755                             ref1->name, ref2->name, ref2->peer_ref->name);
 756                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 757                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 758                         warning(_("%s usually tracks %s, not %s"),
 759                                 ref2->peer_ref->name, ref2->name, ref1->name);
 760                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 761                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 762                         die(_("%s tracks both %s and %s"),
 763                             ref2->peer_ref->name, ref1->name, ref2->name);
 764                 } else {
 765                         /*
 766                          * This last possibility doesn't occur because
 767                          * FETCH_HEAD_IGNORE entries always appear at
 768                          * the end of the list.
 769                          */
 770                         die(_("Internal error"));
 771                 }
 772         }
 773         free(ref2->peer_ref);
 774         free(ref2);
 775 }
 776
 777 struct ref *ref_remove_duplicates(struct ref *ref_map)
 778 {
 779         struct string_list refs = STRING_LIST_INIT_NODUP;
 780         struct ref *retval = NULL;
 781         struct ref **p = &retval;
 782
 783         while (ref_map) {
 784                 struct ref *ref = ref_map;
 785
 786                 ref_map = ref_map->next;
 787                 ref->next = NULL;
 788
 789                 if (!ref->peer_ref) {
 790                         *p = ref;
 791                         p = &ref->next;
 792                 } else {
 793                         struct string_list_item *item =
 794                                 string_list_insert(&refs, ref->peer_ref->name);
 795
 796                         if (item->util) {
 797                                 /* Entry already existed */
 798                                 handle_duplicate((struct ref *)item->util, ref);
 799                         } else {
 800                                 *p = ref;
 801                                 p = &ref->next;
 802                                 item->util = ref;
 803                         }
 804                 }
 805         }
 806
 807         string_list_clear(&refs, 0);
 808         return retval;
 809 }
 810
 811 int remote_has_url(struct remote *remote, const char *url)
 812 {
 813         int i;
 814         for (i = 0; i < remote->url_nr; i++) {
 815                 if (!strcmp(remote->url[i], url))
 816                         return 1;
 817         }
 818         return 0;
 819 }
 820
 821 static int match_name_with_pattern(const char *key, const char *name,
 822                                    const char *value, char **result)
 823 {
 824         const char *kstar = strchr(key, '*');
 825         size_t klen;
 826         size_t ksuffixlen;
 827         size_t namelen;
 828         int ret;
 829         if (!kstar)
 830                 die("Key '%s' of pattern had no '*'", key);
 831         klen = kstar - key;
 832         ksuffixlen = strlen(kstar + 1);
 833         namelen = strlen(name);
 834         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 835                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 836         if (ret && value) {
 837                 struct strbuf sb = STRBUF_INIT;
 838                 const char *vstar = strchr(value, '*');
 839                 if (!vstar)
 840                         die("Value '%s' of pattern has no '*'", value);
 841                 strbuf_add(&sb, value, vstar - value);
 842                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 843                 strbuf_addstr(&sb, vstar + 1);
 844                 *result = strbuf_detach(&sb, NULL);
 845         }
 846         return ret;
 847 }
 848
 849 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 850 {
 851         int i;
 852         int find_src = !query->src;
 853
 854         if (find_src && !query->dst)
 855                 error("query_refspecs_multiple: need either src or dst");
 856
 857         for (i = 0; i < ref_count; i++) {
 858                 struct refspec *refspec = &refs[i];
 859                 const char *key = find_src ? refspec->dst : refspec->src;
 860                 const char *value = find_src ? refspec->src : refspec->dst;
 861                 const char *needle = find_src ? query->dst : query->src;
 862                 char **result = find_src ? &query->src : &query->dst;
 863
 864                 if (!refspec->dst)
 865                         continue;
 866                 if (refspec->pattern) {
 867                         if (match_name_with_pattern(key, needle, value, result))
 868                                 string_list_append_nodup(results, *result);
 869                 } else if (!strcmp(needle, key)) {
 870                         string_list_append(results, value);
 871                 }
 872         }
 873 }
 874
 875 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 876 {
 877         int i;
 878         int find_src = !query->src;
 879         const char *needle = find_src ? query->dst : query->src;
 880         char **result = find_src ? &query->src : &query->dst;
 881
 882         if (find_src && !query->dst)
 883                 return error("query_refspecs: need either src or dst");
 884
 885         for (i = 0; i < ref_count; i++) {
 886                 struct refspec *refspec = &refs[i];
 887                 const char *key = find_src ? refspec->dst : refspec->src;
 888                 const char *value = find_src ? refspec->src : refspec->dst;
 889
 890                 if (!refspec->dst)
 891                         continue;
 892                 if (refspec->pattern) {
 893                         if (match_name_with_pattern(key, needle, value, result)) {
 894                                 query->force = refspec->force;
 895                                 return 0;
 896                         }
 897                 } else if (!strcmp(needle, key)) {
 898                         *result = xstrdup(value);
 899                         query->force = refspec->force;
 900                         return 0;
 901                 }
 902         }
 903         return -1;
 904 }
 905
 906 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 907                      const char *name)
 908 {
 909         struct refspec query;
 910
 911         memset(&query, 0, sizeof(struct refspec));
 912         query.src = (char *)name;
 913
 914         if (query_refspecs(refspecs, nr_refspec, &query))
 915                 return NULL;
 916
 917         return query.dst;
 918 }
 919
 920 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 921 {
 922         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 923 }
 924
 925 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 926                 const char *name)
 927 {
 928         size_t len = strlen(name);
 929         struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 930         memcpy(ref->name, prefix, prefixlen);
 931         memcpy(ref->name + prefixlen, name, len);
 932         return ref;
 933 }
 934
 935 struct ref *alloc_ref(const char *name)
 936 {
 937         return alloc_ref_with_prefix("", 0, name);
 938 }
 939
 940 struct ref *copy_ref(const struct ref *ref)
 941 {
 942         struct ref *cpy;
 943         size_t len;
 944         if (!ref)
 945                 return NULL;
 946         len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 947         cpy = xmalloc(len);
 948         memcpy(cpy, ref, len);
 949         cpy->next = NULL;
 950         cpy->symref = xstrdup_or_null(ref->symref);
 951         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 952         cpy->peer_ref = copy_ref(ref->peer_ref);
 953         return cpy;
 954 }
 955
 956 struct ref *copy_ref_list(const struct ref *ref)
 957 {
 958         struct ref *ret = NULL;
 959         struct ref **tail = &ret;
 960         while (ref) {
 961                 *tail = copy_ref(ref);
 962                 ref = ref->next;
 963                 tail = &((*tail)->next);
 964         }
 965         return ret;
 966 }
 967
 968 static void free_ref(struct ref *ref)
 969 {
 970         if (!ref)
 971                 return;
 972         free_ref(ref->peer_ref);
 973         free(ref->remote_status);
 974         free(ref->symref);
 975         free(ref);
 976 }
 977
 978 void free_refs(struct ref *ref)
 979 {
 980         struct ref *next;
 981         while (ref) {
 982                 next = ref->next;
 983                 free_ref(ref);
 984                 ref = next;
 985         }
 986 }
 987
 988 int ref_compare_name(const void *va, const void *vb)
 989 {
 990         const struct ref *a = va, *b = vb;
 991         return strcmp(a->name, b->name);
 992 }
 993
 994 static void *ref_list_get_next(const void *a)
 995 {
 996         return ((const struct ref *)a)->next;
 997 }
 998
 999 static void ref_list_set_next(void *a, void *next)
1000 {
1001         ((struct ref *)a)->next = next;
1002 }
1003
1004 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1005 {
1006         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1007 }
1008
1009 int count_refspec_match(const char *pattern,
1010                         struct ref *refs,
1011                         struct ref **matched_ref)
1012 {
1013         int patlen = strlen(pattern);
1014         struct ref *matched_weak = NULL;
1015         struct ref *matched = NULL;
1016         int weak_match = 0;
1017         int match = 0;
1018
1019         for (weak_match = match = 0; refs; refs = refs->next) {
1020                 char *name = refs->name;
1021                 int namelen = strlen(name);
1022
1023                 if (!refname_match(pattern, name))
1024                         continue;
1025
1026                 /* A match is "weak" if it is with refs outside
1027                  * heads or tags, and did not specify the pattern
1028                  * in full (e.g. "refs/remotes/origin/master") or at
1029                  * least from the toplevel (e.g. "remotes/origin/master");
1030                  * otherwise "git push $URL master" would result in
1031                  * ambiguity between remotes/origin/master and heads/master
1032                  * at the remote site.
1033                  */
1034                 if (namelen != patlen &&
1035                     patlen != namelen - 5 &&
1036                     !starts_with(name, "refs/heads/") &&
1037                     !starts_with(name, "refs/tags/")) {
1038                         /* We want to catch the case where only weak
1039                          * matches are found and there are multiple
1040                          * matches, and where more than one strong
1041                          * matches are found, as ambiguous.  One
1042                          * strong match with zero or more weak matches
1043                          * are acceptable as a unique match.
1044                          */
1045                         matched_weak = refs;
1046                         weak_match++;
1047                 }
1048                 else {
1049                         matched = refs;
1050                         match++;
1051                 }
1052         }
1053         if (!matched) {
1054                 if (matched_ref)
1055                         *matched_ref = matched_weak;
1056                 return weak_match;
1057         }
1058         else {
1059                 if (matched_ref)
1060                         *matched_ref = matched;
1061                 return match;
1062         }
1063 }
1064
1065 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1066 {
1067         **tail = ref;
1068         while (ref->next)
1069                 ref = ref->next;
1070         *tail = &ref->next;
1071 }
1072
1073 static struct ref *alloc_delete_ref(void)
1074 {
1075         struct ref *ref = alloc_ref("(delete)");
1076         oidclr(&ref->new_oid);
1077         return ref;
1078 }
1079
1080 static int try_explicit_object_name(const char *name,
1081                                     struct ref **match)
1082 {
1083         struct object_id oid;
1084
1085         if (!*name) {
1086                 if (match)
1087                         *match = alloc_delete_ref();
1088                 return 0;
1089         }
1090
1091         if (get_sha1(name, oid.hash))
1092                 return -1;
1093
1094         if (match) {
1095                 *match = alloc_ref(name);
1096                 oidcpy(&(*match)->new_oid, &oid);
1097         }
1098         return 0;
1099 }
1100
1101 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1102 {
1103         struct ref *ret = alloc_ref(name);
1104         tail_link_ref(ret, tail);
1105         return ret;
1106 }
1107
1108 static char *guess_ref(const char *name, struct ref *peer)
1109 {
1110         struct strbuf buf = STRBUF_INIT;
1111         struct object_id oid;
1112
1113         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1114                                            oid.hash, NULL);
1115         if (!r)
1116                 return NULL;
1117
1118         if (starts_with(r, "refs/heads/"))
1119                 strbuf_addstr(&buf, "refs/heads/");
1120         else if (starts_with(r, "refs/tags/"))
1121                 strbuf_addstr(&buf, "refs/tags/");
1122         else
1123                 return NULL;
1124
1125         strbuf_addstr(&buf, name);
1126         return strbuf_detach(&buf, NULL);
1127 }
1128
1129 static int match_explicit_lhs(struct ref *src,
1130                               struct refspec *rs,
1131                               struct ref **match,
1132                               int *allocated_match)
1133 {
1134         switch (count_refspec_match(rs->src, src, match)) {
1135         case 1:
1136                 if (allocated_match)
1137                         *allocated_match = 0;
1138                 return 0;
1139         case 0:
1140                 /* The source could be in the get_sha1() format
1141                  * not a reference name.  :refs/other is a
1142                  * way to delete 'other' ref at the remote end.
1143                  */
1144                 if (try_explicit_object_name(rs->src, match) < 0)
1145                         return error("src refspec %s does not match any.", rs->src);
1146                 if (allocated_match)
1147                         *allocated_match = 1;
1148                 return 0;
1149         default:
1150                 return error("src refspec %s matches more than one.", rs->src);
1151         }
1152 }
1153
1154 static int match_explicit(struct ref *src, struct ref *dst,
1155                           struct ref ***dst_tail,
1156                           struct refspec *rs)
1157 {
1158         struct ref *matched_src, *matched_dst;
1159         int allocated_src;
1160
1161         const char *dst_value = rs->dst;
1162         char *dst_guess;
1163
1164         if (rs->pattern || rs->matching)
1165                 return 0;
1166
1167         matched_src = matched_dst = NULL;
1168         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1169                 return -1;
1170
1171         if (!dst_value) {
1172                 struct object_id oid;
1173                 int flag;
1174
1175                 dst_value = resolve_ref_unsafe(matched_src->name,
1176                                                RESOLVE_REF_READING,
1177                                                oid.hash, &flag);
1178                 if (!dst_value ||
1179                     ((flag & REF_ISSYMREF) &&
1180                      !starts_with(dst_value, "refs/heads/")))
1181                         die("%s cannot be resolved to branch.",
1182                             matched_src->name);
1183         }
1184
1185         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1186         case 1:
1187                 break;
1188         case 0:
1189                 if (starts_with(dst_value, "refs/"))
1190                         matched_dst = make_linked_ref(dst_value, dst_tail);
1191                 else if (is_null_oid(&matched_src->new_oid))
1192                         error("unable to delete '%s': remote ref does not exist",
1193                               dst_value);
1194                 else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1195                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1196                         free(dst_guess);
1197                 } else
1198                         error("unable to push to unqualified destination: %s\n"
1199                               "The destination refspec neither matches an "
1200                               "existing ref on the remote nor\n"
1201                               "begins with refs/, and we are unable to "
1202                               "guess a prefix based on the source ref.",
1203                               dst_value);
1204                 break;
1205         default:
1206                 matched_dst = NULL;
1207                 error("dst refspec %s matches more than one.",
1208                       dst_value);
1209                 break;
1210         }
1211         if (!matched_dst)
1212                 return -1;
1213         if (matched_dst->peer_ref)
1214                 return error("dst ref %s receives from more than one src.",
1215                       matched_dst->name);
1216         else {
1217                 matched_dst->peer_ref = allocated_src ?
1218                                         matched_src :
1219                                         copy_ref(matched_src);
1220                 matched_dst->force = rs->force;
1221         }
1222         return 0;
1223 }
1224
1225 static int match_explicit_refs(struct ref *src, struct ref *dst,
1226                                struct ref ***dst_tail, struct refspec *rs,
1227                                int rs_nr)
1228 {
1229         int i, errs;
1230         for (i = errs = 0; i < rs_nr; i++)
1231                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1232         return errs;
1233 }
1234
1235 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1236                 int send_mirror, int direction, const struct refspec **ret_pat)
1237 {
1238         const struct refspec *pat;
1239         char *name;
1240         int i;
1241         int matching_refs = -1;
1242         for (i = 0; i < rs_nr; i++) {
1243                 if (rs[i].matching &&
1244                     (matching_refs == -1 || rs[i].force)) {
1245                         matching_refs = i;
1246                         continue;
1247                 }
1248
1249                 if (rs[i].pattern) {
1250                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1251                         int match;
1252                         if (direction == FROM_SRC)
1253                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1254                         else
1255                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1256                         if (match) {
1257                                 matching_refs = i;
1258                                 break;
1259                         }
1260                 }
1261         }
1262         if (matching_refs == -1)
1263                 return NULL;
1264
1265         pat = rs + matching_refs;
1266         if (pat->matching) {
1267                 /*
1268                  * "matching refs"; traditionally we pushed everything
1269                  * including refs outside refs/heads/ hierarchy, but
1270                  * that does not make much sense these days.
1271                  */
1272                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1273                         return NULL;
1274                 name = xstrdup(ref->name);
1275         }
1276         if (ret_pat)
1277                 *ret_pat = pat;
1278         return name;
1279 }
1280
1281 static struct ref **tail_ref(struct ref **head)
1282 {
1283         struct ref **tail = head;
1284         while (*tail)
1285                 tail = &((*tail)->next);
1286         return tail;
1287 }
1288
1289 struct tips {
1290         struct commit **tip;
1291         int nr, alloc;
1292 };
1293
1294 static void add_to_tips(struct tips *tips, const struct object_id *oid)
1295 {
1296         struct commit *commit;
1297
1298         if (is_null_oid(oid))
1299                 return;
1300         commit = lookup_commit_reference_gently(oid, 1);
1301         if (!commit || (commit->object.flags & TMP_MARK))
1302                 return;
1303         commit->object.flags |= TMP_MARK;
1304         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1305         tips->tip[tips->nr++] = commit;
1306 }
1307
1308 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1309 {
1310         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1311         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1312         struct string_list_item *item;
1313         struct ref *ref;
1314         struct tips sent_tips;
1315
1316         /*
1317          * Collect everything we know they would have at the end of
1318          * this push, and collect all tags they have.
1319          */
1320         memset(&sent_tips, 0, sizeof(sent_tips));
1321         for (ref = *dst; ref; ref = ref->next) {
1322                 if (ref->peer_ref &&
1323                     !is_null_oid(&ref->peer_ref->new_oid))
1324                         add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1325                 else
1326                         add_to_tips(&sent_tips, &ref->old_oid);
1327                 if (starts_with(ref->name, "refs/tags/"))
1328                         string_list_append(&dst_tag, ref->name);
1329         }
1330         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1331
1332         string_list_sort(&dst_tag);
1333
1334         /* Collect tags they do not have. */
1335         for (ref = src; ref; ref = ref->next) {
1336                 if (!starts_with(ref->name, "refs/tags/"))
1337                         continue; /* not a tag */
1338                 if (string_list_has_string(&dst_tag, ref->name))
1339                         continue; /* they already have it */
1340                 if (sha1_object_info(ref->new_oid.hash, NULL) != OBJ_TAG)
1341                         continue; /* be conservative */
1342                 item = string_list_append(&src_tag, ref->name);
1343                 item->util = ref;
1344         }
1345         string_list_clear(&dst_tag, 0);
1346
1347         /*
1348          * At this point, src_tag lists tags that are missing from
1349          * dst, and sent_tips lists the tips we are pushing or those
1350          * that we know they already have. An element in the src_tag
1351          * that is an ancestor of any of the sent_tips needs to be
1352          * sent to the other side.
1353          */
1354         if (sent_tips.nr) {
1355                 for_each_string_list_item(item, &src_tag) {
1356                         struct ref *ref = item->util;
1357                         struct ref *dst_ref;
1358                         struct commit *commit;
1359
1360                         if (is_null_oid(&ref->new_oid))
1361                                 continue;
1362                         commit = lookup_commit_reference_gently(&ref->new_oid,
1363                                                                 1);
1364                         if (!commit)
1365                                 /* not pushing a commit, which is not an error */
1366                                 continue;
1367
1368                         /*
1369                          * Is this tag, which they do not have, reachable from
1370                          * any of the commits we are sending?
1371                          */
1372                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1373                                 continue;
1374
1375                         /* Add it in */
1376                         dst_ref = make_linked_ref(ref->name, dst_tail);
1377                         oidcpy(&dst_ref->new_oid, &ref->new_oid);
1378                         dst_ref->peer_ref = copy_ref(ref);
1379                 }
1380         }
1381         string_list_clear(&src_tag, 0);
1382         free(sent_tips.tip);
1383 }
1384
1385 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1386 {
1387         for ( ; list; list = list->next)
1388                 if (!strcmp(list->name, name))
1389                         return (struct ref *)list;
1390         return NULL;
1391 }
1392
1393 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1394 {
1395         for ( ; ref; ref = ref->next)
1396                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1397
1398         string_list_sort(ref_index);
1399 }
1400
1401 /*
1402  * Given only the set of local refs, sanity-check the set of push
1403  * refspecs. We can't catch all errors that match_push_refs would,
1404  * but we can catch some errors early before even talking to the
1405  * remote side.
1406  */
1407 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1408 {
1409         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1410         int ret = 0;
1411         int i;
1412
1413         for (i = 0; i < nr_refspec; i++) {
1414                 struct refspec *rs = refspec + i;
1415
1416                 if (rs->pattern || rs->matching)
1417                         continue;
1418
1419                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1420         }
1421
1422         free_refspec(nr_refspec, refspec);
1423         return ret;
1424 }
1425
1426 /*
1427  * Given the set of refs the local repository has, the set of refs the
1428  * remote repository has, and the refspec used for push, determine
1429  * what remote refs we will update and with what value by setting
1430  * peer_ref (which object is being pushed) and force (if the push is
1431  * forced) in elements of "dst". The function may add new elements to
1432  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1433  */
1434 int match_push_refs(struct ref *src, struct ref **dst,
1435                     int nr_refspec, const char **refspec, int flags)
1436 {
1437         struct refspec *rs;
1438         int send_all = flags & MATCH_REFS_ALL;
1439         int send_mirror = flags & MATCH_REFS_MIRROR;
1440         int send_prune = flags & MATCH_REFS_PRUNE;
1441         int errs;
1442         static const char *default_refspec[] = { ":", NULL };
1443         struct ref *ref, **dst_tail = tail_ref(dst);
1444         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1445
1446         if (!nr_refspec) {
1447                 nr_refspec = 1;
1448                 refspec = default_refspec;
1449         }
1450         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1451         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1452
1453         /* pick the remainder */
1454         for (ref = src; ref; ref = ref->next) {
1455                 struct string_list_item *dst_item;
1456                 struct ref *dst_peer;
1457                 const struct refspec *pat = NULL;
1458                 char *dst_name;
1459
1460                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1461                 if (!dst_name)
1462                         continue;
1463
1464                 if (!dst_ref_index.nr)
1465                         prepare_ref_index(&dst_ref_index, *dst);
1466
1467                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1468                 dst_peer = dst_item ? dst_item->util : NULL;
1469                 if (dst_peer) {
1470                         if (dst_peer->peer_ref)
1471                                 /* We're already sending something to this ref. */
1472                                 goto free_name;
1473                 } else {
1474                         if (pat->matching && !(send_all || send_mirror))
1475                                 /*
1476                                  * Remote doesn't have it, and we have no
1477                                  * explicit pattern, and we don't have
1478                                  * --all or --mirror.
1479                                  */
1480                                 goto free_name;
1481
1482                         /* Create a new one and link it */
1483                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1484                         oidcpy(&dst_peer->new_oid, &ref->new_oid);
1485                         string_list_insert(&dst_ref_index,
1486                                 dst_peer->name)->util = dst_peer;
1487                 }
1488                 dst_peer->peer_ref = copy_ref(ref);
1489                 dst_peer->force = pat->force;
1490         free_name:
1491                 free(dst_name);
1492         }
1493
1494         string_list_clear(&dst_ref_index, 0);
1495
1496         if (flags & MATCH_REFS_FOLLOW_TAGS)
1497                 add_missing_tags(src, dst, &dst_tail);
1498
1499         if (send_prune) {
1500                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1501                 /* check for missing refs on the remote */
1502                 for (ref = *dst; ref; ref = ref->next) {
1503                         char *src_name;
1504
1505                         if (ref->peer_ref)
1506                                 /* We're already sending something to this ref. */
1507                                 continue;
1508
1509                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1510                         if (src_name) {
1511                                 if (!src_ref_index.nr)
1512                                         prepare_ref_index(&src_ref_index, src);
1513                                 if (!string_list_has_string(&src_ref_index,
1514                                             src_name))
1515                                         ref->peer_ref = alloc_delete_ref();
1516                                 free(src_name);
1517                         }
1518                 }
1519                 string_list_clear(&src_ref_index, 0);
1520         }
1521         if (errs)
1522                 return -1;
1523         return 0;
1524 }
1525
1526 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1527                              int force_update)
1528 {
1529         struct ref *ref;
1530
1531         for (ref = remote_refs; ref; ref = ref->next) {
1532                 int force_ref_update = ref->force || force_update;
1533                 int reject_reason = 0;
1534
1535                 if (ref->peer_ref)
1536                         oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1537                 else if (!send_mirror)
1538                         continue;
1539
1540                 ref->deletion = is_null_oid(&ref->new_oid);
1541                 if (!ref->deletion &&
1542                         !oidcmp(&ref->old_oid, &ref->new_oid)) {
1543                         ref->status = REF_STATUS_UPTODATE;
1544                         continue;
1545                 }
1546
1547                 /*
1548                  * If the remote ref has moved and is now different
1549                  * from what we expect, reject any push.
1550                  *
1551                  * It also is an error if the user told us to check
1552                  * with the remote-tracking branch to find the value
1553                  * to expect, but we did not have such a tracking
1554                  * branch.
1555                  */
1556                 if (ref->expect_old_sha1) {
1557                         if (oidcmp(&ref->old_oid, &ref->old_oid_expect))
1558                                 reject_reason = REF_STATUS_REJECT_STALE;
1559                         else
1560                                 /* If the ref isn't stale then force the update. */
1561                                 force_ref_update = 1;
1562                 }
1563
1564                 /*
1565                  * If the update isn't already rejected then check
1566                  * the usual "must fast-forward" rules.
1567                  *
1568                  * Decide whether an individual refspec A:B can be
1569                  * pushed.  The push will succeed if any of the
1570                  * following are true:
1571                  *
1572                  * (1) the remote reference B does not exist
1573                  *
1574                  * (2) the remote reference B is being removed (i.e.,
1575                  *     pushing :B where no source is specified)
1576                  *
1577                  * (3) the destination is not under refs/tags/, and
1578                  *     if the old and new value is a commit, the new
1579                  *     is a descendant of the old.
1580                  *
1581                  * (4) it is forced using the +A:B notation, or by
1582                  *     passing the --force argument
1583                  */
1584
1585                 if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1586                         if (starts_with(ref->name, "refs/tags/"))
1587                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1588                         else if (!has_object_file(&ref->old_oid))
1589                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1590                         else if (!lookup_commit_reference_gently(&ref->old_oid, 1) ||
1591                                  !lookup_commit_reference_gently(&ref->new_oid, 1))
1592                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1593                         else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1594                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1595                 }
1596
1597                 /*
1598                  * "--force" will defeat any rejection implemented
1599                  * by the rules above.
1600                  */
1601                 if (!force_ref_update)
1602                         ref->status = reject_reason;
1603                 else if (reject_reason)
1604                         ref->forced_update = 1;
1605         }
1606 }
1607
1608 static void set_merge(struct branch *ret)
1609 {
1610         struct remote *remote;
1611         char *ref;
1612         struct object_id oid;
1613         int i;
1614
1615         if (!ret)
1616                 return; /* no branch */
1617         if (ret->merge)
1618                 return; /* already run */
1619         if (!ret->remote_name || !ret->merge_nr) {
1620                 /*
1621                  * no merge config; let's make sure we don't confuse callers
1622                  * with a non-zero merge_nr but a NULL merge
1623                  */
1624                 ret->merge_nr = 0;
1625                 return;
1626         }
1627
1628         remote = remote_get(ret->remote_name);
1629
1630         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1631         for (i = 0; i < ret->merge_nr; i++) {
1632                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1633                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1634                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1635                     strcmp(ret->remote_name, "."))
1636                         continue;
1637                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1638                              oid.hash, &ref) == 1)
1639                         ret->merge[i]->dst = ref;
1640                 else
1641                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1642         }
1643 }
1644
1645 struct branch *branch_get(const char *name)
1646 {
1647         struct branch *ret;
1648
1649         read_config();
1650         if (!name || !*name || !strcmp(name, "HEAD"))
1651                 ret = current_branch;
1652         else
1653                 ret = make_branch(name, 0);
1654         set_merge(ret);
1655         return ret;
1656 }
1657
1658 int branch_has_merge_config(struct branch *branch)
1659 {
1660         return branch && !!branch->merge;
1661 }
1662
1663 int branch_merge_matches(struct branch *branch,
1664                                  int i,
1665                                  const char *refname)
1666 {
1667         if (!branch || i < 0 || i >= branch->merge_nr)
1668                 return 0;
1669         return refname_match(branch->merge[i]->src, refname);
1670 }
1671
1672 __attribute__((format (printf,2,3)))
1673 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1674 {
1675         if (err) {
1676                 va_list ap;
1677                 va_start(ap, fmt);
1678                 strbuf_vaddf(err, fmt, ap);
1679                 va_end(ap);
1680         }
1681         return NULL;
1682 }
1683
1684 const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1685 {
1686         if (!branch)
1687                 return error_buf(err, _("HEAD does not point to a branch"));
1688
1689         if (!branch->merge || !branch->merge[0]) {
1690                 /*
1691                  * no merge config; is it because the user didn't define any,
1692                  * or because it is not a real branch, and get_branch
1693                  * auto-vivified it?
1694                  */
1695                 if (!ref_exists(branch->refname))
1696                         return error_buf(err, _("no such branch: '%s'"),
1697                                          branch->name);
1698                 return error_buf(err,
1699                                  _("no upstream configured for branch '%s'"),
1700                                  branch->name);
1701         }
1702
1703         if (!branch->merge[0]->dst)
1704                 return error_buf(err,
1705                                  _("upstream branch '%s' not stored as a remote-tracking branch"),
1706                                  branch->merge[0]->src);
1707
1708         return branch->merge[0]->dst;
1709 }
1710
1711 static const char *tracking_for_push_dest(struct remote *remote,
1712                                           const char *refname,
1713                                           struct strbuf *err)
1714 {
1715         char *ret;
1716
1717         ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1718         if (!ret)
1719                 return error_buf(err,
1720                                  _("push destination '%s' on remote '%s' has no local tracking branch"),
1721                                  refname, remote->name);
1722         return ret;
1723 }
1724
1725 static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1726 {
1727         struct remote *remote;
1728
1729         remote = remote_get(pushremote_for_branch(branch, NULL));
1730         if (!remote)
1731                 return error_buf(err,
1732                                  _("branch '%s' has no remote for pushing"),
1733                                  branch->name);
1734
1735         if (remote->push_refspec_nr) {
1736                 char *dst;
1737                 const char *ret;
1738
1739                 dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1740                                      branch->refname);
1741                 if (!dst)
1742                         return error_buf(err,
1743                                          _("push refspecs for '%s' do not include '%s'"),
1744                                          remote->name, branch->name);
1745
1746                 ret = tracking_for_push_dest(remote, dst, err);
1747                 free(dst);
1748                 return ret;
1749         }
1750
1751         if (remote->mirror)
1752                 return tracking_for_push_dest(remote, branch->refname, err);
1753
1754         switch (push_default) {
1755         case PUSH_DEFAULT_NOTHING:
1756                 return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1757
1758         case PUSH_DEFAULT_MATCHING:
1759         case PUSH_DEFAULT_CURRENT:
1760                 return tracking_for_push_dest(remote, branch->refname, err);
1761
1762         case PUSH_DEFAULT_UPSTREAM:
1763                 return branch_get_upstream(branch, err);
1764
1765         case PUSH_DEFAULT_UNSPECIFIED:
1766         case PUSH_DEFAULT_SIMPLE:
1767                 {
1768                         const char *up, *cur;
1769
1770                         up = branch_get_upstream(branch, err);
1771                         if (!up)
1772                                 return NULL;
1773                         cur = tracking_for_push_dest(remote, branch->refname, err);
1774                         if (!cur)
1775                                 return NULL;
1776                         if (strcmp(cur, up))
1777                                 return error_buf(err,
1778                                                  _("cannot resolve 'simple' push to a single destination"));
1779                         return cur;
1780                 }
1781         }
1782
1783         die("BUG: unhandled push situation");
1784 }
1785
1786 const char *branch_get_push(struct branch *branch, struct strbuf *err)
1787 {
1788         if (!branch)
1789                 return error_buf(err, _("HEAD does not point to a branch"));
1790
1791         if (!branch->push_tracking_ref)
1792                 branch->push_tracking_ref = branch_get_push_1(branch, err);
1793         return branch->push_tracking_ref;
1794 }
1795
1796 static int ignore_symref_update(const char *refname)
1797 {
1798         struct object_id oid;
1799         int flag;
1800
1801         if (!resolve_ref_unsafe(refname, 0, oid.hash, &flag))
1802                 return 0; /* non-existing refs are OK */
1803         return (flag & REF_ISSYMREF);
1804 }
1805
1806 /*
1807  * Create and return a list of (struct ref) consisting of copies of
1808  * each remote_ref that matches refspec.  refspec must be a pattern.
1809  * Fill in the copies' peer_ref to describe the local tracking refs to
1810  * which they map.  Omit any references that would map to an existing
1811  * local symbolic ref.
1812  */
1813 static struct ref *get_expanded_map(const struct ref *remote_refs,
1814                                     const struct refspec *refspec)
1815 {
1816         const struct ref *ref;
1817         struct ref *ret = NULL;
1818         struct ref **tail = &ret;
1819
1820         for (ref = remote_refs; ref; ref = ref->next) {
1821                 char *expn_name = NULL;
1822
1823                 if (strchr(ref->name, '^'))
1824                         continue; /* a dereference item */
1825                 if (match_name_with_pattern(refspec->src, ref->name,
1826                                             refspec->dst, &expn_name) &&
1827                     !ignore_symref_update(expn_name)) {
1828                         struct ref *cpy = copy_ref(ref);
1829
1830                         cpy->peer_ref = alloc_ref(expn_name);
1831                         if (refspec->force)
1832                                 cpy->peer_ref->force = 1;
1833                         *tail = cpy;
1834                         tail = &cpy->next;
1835                 }
1836                 free(expn_name);
1837         }
1838
1839         return ret;
1840 }
1841
1842 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1843 {
1844         const struct ref *ref;
1845         for (ref = refs; ref; ref = ref->next) {
1846                 if (refname_match(name, ref->name))
1847                         return ref;
1848         }
1849         return NULL;
1850 }
1851
1852 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1853 {
1854         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1855
1856         if (!ref)
1857                 return NULL;
1858
1859         return copy_ref(ref);
1860 }
1861
1862 static struct ref *get_local_ref(const char *name)
1863 {
1864         if (!name || name[0] == '\0')
1865                 return NULL;
1866
1867         if (starts_with(name, "refs/"))
1868                 return alloc_ref(name);
1869
1870         if (starts_with(name, "heads/") ||
1871             starts_with(name, "tags/") ||
1872             starts_with(name, "remotes/"))
1873                 return alloc_ref_with_prefix("refs/", 5, name);
1874
1875         return alloc_ref_with_prefix("refs/heads/", 11, name);
1876 }
1877
1878 int get_fetch_map(const struct ref *remote_refs,
1879                   const struct refspec *refspec,
1880                   struct ref ***tail,
1881                   int missing_ok)
1882 {
1883         struct ref *ref_map, **rmp;
1884
1885         if (refspec->pattern) {
1886                 ref_map = get_expanded_map(remote_refs, refspec);
1887         } else {
1888                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1889
1890                 if (refspec->exact_sha1) {
1891                         ref_map = alloc_ref(name);
1892                         get_oid_hex(name, &ref_map->old_oid);
1893                 } else {
1894                         ref_map = get_remote_ref(remote_refs, name);
1895                 }
1896                 if (!missing_ok && !ref_map)
1897                         die("Couldn't find remote ref %s", name);
1898                 if (ref_map) {
1899                         ref_map->peer_ref = get_local_ref(refspec->dst);
1900                         if (ref_map->peer_ref && refspec->force)
1901                                 ref_map->peer_ref->force = 1;
1902                 }
1903         }
1904
1905         for (rmp = &ref_map; *rmp; ) {
1906                 if ((*rmp)->peer_ref) {
1907                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1908                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1909                                 struct ref *ignore = *rmp;
1910                                 error("* Ignoring funny ref '%s' locally",
1911                                       (*rmp)->peer_ref->name);
1912                                 *rmp = (*rmp)->next;
1913                                 free(ignore->peer_ref);
1914                                 free(ignore);
1915                                 continue;
1916                         }
1917                 }
1918                 rmp = &((*rmp)->next);
1919         }
1920
1921         if (ref_map)
1922                 tail_link_ref(ref_map, tail);
1923
1924         return 0;
1925 }
1926
1927 int resolve_remote_symref(struct ref *ref, struct ref *list)
1928 {
1929         if (!ref->symref)
1930                 return 0;
1931         for (; list; list = list->next)
1932                 if (!strcmp(ref->symref, list->name)) {
1933                         oidcpy(&ref->old_oid, &list->old_oid);
1934                         return 0;
1935                 }
1936         return 1;
1937 }
1938
1939 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1940 {
1941         while (list) {
1942                 struct commit *commit = pop_commit(&list);
1943                 commit->object.flags &= ~mark;
1944         }
1945 }
1946
1947 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1948 {
1949         struct object *o;
1950         struct commit *old, *new;
1951         struct commit_list *list, *used;
1952         int found = 0;
1953
1954         /*
1955          * Both new and old must be commit-ish and new is descendant of
1956          * old.  Otherwise we require --force.
1957          */
1958         o = deref_tag(parse_object(old_oid), NULL, 0);
1959         if (!o || o->type != OBJ_COMMIT)
1960                 return 0;
1961         old = (struct commit *) o;
1962
1963         o = deref_tag(parse_object(new_oid), NULL, 0);
1964         if (!o || o->type != OBJ_COMMIT)
1965                 return 0;
1966         new = (struct commit *) o;
1967
1968         if (parse_commit(new) < 0)
1969                 return 0;
1970
1971         used = list = NULL;
1972         commit_list_insert(new, &list);
1973         while (list) {
1974                 new = pop_most_recent_commit(&list, TMP_MARK);
1975                 commit_list_insert(new, &used);
1976                 if (new == old) {
1977                         found = 1;
1978                         break;
1979                 }
1980         }
1981         unmark_and_free(list, TMP_MARK);
1982         unmark_and_free(used, TMP_MARK);
1983         return found;
1984 }
1985
1986 /*
1987  * Compare a branch with its upstream, and save their differences (number
1988  * of commits) in *num_ours and *num_theirs. The name of the upstream branch
1989  * (or NULL if no upstream is defined) is returned via *upstream_name, if it
1990  * is not itself NULL.
1991  *
1992  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1993  * upstream defined, or ref does not exist), 0 otherwise.
1994  */
1995 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
1996                        const char **upstream_name)
1997 {
1998         struct object_id oid;
1999         struct commit *ours, *theirs;
2000         struct rev_info revs;
2001         const char *base;
2002         struct argv_array argv = ARGV_ARRAY_INIT;
2003
2004         /* Cannot stat unless we are marked to build on top of somebody else. */
2005         base = branch_get_upstream(branch, NULL);
2006         if (upstream_name)
2007                 *upstream_name = base;
2008         if (!base)
2009                 return -1;
2010
2011         /* Cannot stat if what we used to build on no longer exists */
2012         if (read_ref(base, oid.hash))
2013                 return -1;
2014         theirs = lookup_commit_reference(&oid);
2015         if (!theirs)
2016                 return -1;
2017
2018         if (read_ref(branch->refname, oid.hash))
2019                 return -1;
2020         ours = lookup_commit_reference(&oid);
2021         if (!ours)
2022                 return -1;
2023
2024         /* are we the same? */
2025         if (theirs == ours) {
2026                 *num_theirs = *num_ours = 0;
2027                 return 0;
2028         }
2029
2030         /* Run "rev-list --left-right ours...theirs" internally... */
2031         argv_array_push(&argv, ""); /* ignored */
2032         argv_array_push(&argv, "--left-right");
2033         argv_array_pushf(&argv, "%s...%s",
2034                          oid_to_hex(&ours->object.oid),
2035                          oid_to_hex(&theirs->object.oid));
2036         argv_array_push(&argv, "--");
2037
2038         init_revisions(&revs, NULL);
2039         setup_revisions(argv.argc, argv.argv, &revs, NULL);
2040         if (prepare_revision_walk(&revs))
2041                 die("revision walk setup failed");
2042
2043         /* ... and count the commits on each side. */
2044         *num_ours = 0;
2045         *num_theirs = 0;
2046         while (1) {
2047                 struct commit *c = get_revision(&revs);
2048                 if (!c)
2049                         break;
2050                 if (c->object.flags & SYMMETRIC_LEFT)
2051                         (*num_ours)++;
2052                 else
2053                         (*num_theirs)++;
2054         }
2055
2056         /* clear object flags smudged by the above traversal */
2057         clear_commit_marks(ours, ALL_REV_FLAGS);
2058         clear_commit_marks(theirs, ALL_REV_FLAGS);
2059
2060         argv_array_clear(&argv);
2061         return 0;
2062 }
2063
2064 /*
2065  * Return true when there is anything to report, otherwise false.
2066  */
2067 int format_tracking_info(struct branch *branch, struct strbuf *sb)
2068 {
2069         int ours, theirs;
2070         const char *full_base;
2071         char *base;
2072         int upstream_is_gone = 0;
2073
2074         if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2075                 if (!full_base)
2076                         return 0;
2077                 upstream_is_gone = 1;
2078         }
2079
2080         base = shorten_unambiguous_ref(full_base, 0);
2081         if (upstream_is_gone) {
2082                 strbuf_addf(sb,
2083                         _("Your branch is based on '%s', but the upstream is gone.\n"),
2084                         base);
2085                 if (advice_status_hints)
2086                         strbuf_addstr(sb,
2087                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2088         } else if (!ours && !theirs) {
2089                 strbuf_addf(sb,
2090                         _("Your branch is up-to-date with '%s'.\n"),
2091                         base);
2092         } else if (!theirs) {
2093                 strbuf_addf(sb,
2094                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2095                            "Your branch is ahead of '%s' by %d commits.\n",
2096                            ours),
2097                         base, ours);
2098                 if (advice_status_hints)
2099                         strbuf_addstr(sb,
2100                                 _("  (use \"git push\" to publish your local commits)\n"));
2101         } else if (!ours) {
2102                 strbuf_addf(sb,
2103                         Q_("Your branch is behind '%s' by %d commit, "
2104                                "and can be fast-forwarded.\n",
2105                            "Your branch is behind '%s' by %d commits, "
2106                                "and can be fast-forwarded.\n",
2107                            theirs),
2108                         base, theirs);
2109                 if (advice_status_hints)
2110                         strbuf_addstr(sb,
2111                                 _("  (use \"git pull\" to update your local branch)\n"));
2112         } else {
2113                 strbuf_addf(sb,
2114                         Q_("Your branch and '%s' have diverged,\n"
2115                                "and have %d and %d different commit each, "
2116                                "respectively.\n",
2117                            "Your branch and '%s' have diverged,\n"
2118                                "and have %d and %d different commits each, "
2119                                "respectively.\n",
2120                            ours + theirs),
2121                         base, ours, theirs);
2122                 if (advice_status_hints)
2123                         strbuf_addstr(sb,
2124                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2125         }
2126         free(base);
2127         return 1;
2128 }
2129
2130 static int one_local_ref(const char *refname, const struct object_id *oid,
2131                          int flag, void *cb_data)
2132 {
2133         struct ref ***local_tail = cb_data;
2134         struct ref *ref;
2135
2136         /* we already know it starts with refs/ to get here */
2137         if (check_refname_format(refname + 5, 0))
2138                 return 0;
2139
2140         ref = alloc_ref(refname);
2141         oidcpy(&ref->new_oid, oid);
2142         **local_tail = ref;
2143         *local_tail = &ref->next;
2144         return 0;
2145 }
2146
2147 struct ref *get_local_heads(void)
2148 {
2149         struct ref *local_refs = NULL, **local_tail = &local_refs;
2150
2151         for_each_ref(one_local_ref, &local_tail);
2152         return local_refs;
2153 }
2154
2155 struct ref *guess_remote_head(const struct ref *head,
2156                               const struct ref *refs,
2157                               int all)
2158 {
2159         const struct ref *r;
2160         struct ref *list = NULL;
2161         struct ref **tail = &list;
2162
2163         if (!head)
2164                 return NULL;
2165
2166         /*
2167          * Some transports support directly peeking at
2168          * where HEAD points; if that is the case, then
2169          * we don't have to guess.
2170          */
2171         if (head->symref)
2172                 return copy_ref(find_ref_by_name(refs, head->symref));
2173
2174         /* If refs/heads/master could be right, it is. */
2175         if (!all) {
2176                 r = find_ref_by_name(refs, "refs/heads/master");
2177                 if (r && !oidcmp(&r->old_oid, &head->old_oid))
2178                         return copy_ref(r);
2179         }
2180
2181         /* Look for another ref that points there */
2182         for (r = refs; r; r = r->next) {
2183                 if (r != head &&
2184                     starts_with(r->name, "refs/heads/") &&
2185                     !oidcmp(&r->old_oid, &head->old_oid)) {
2186                         *tail = copy_ref(r);
2187                         tail = &((*tail)->next);
2188                         if (!all)
2189                                 break;
2190                 }
2191         }
2192
2193         return list;
2194 }
2195
2196 struct stale_heads_info {
2197         struct string_list *ref_names;
2198         struct ref **stale_refs_tail;
2199         struct refspec *refs;
2200         int ref_count;
2201 };
2202
2203 static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2204                               int flags, void *cb_data)
2205 {
2206         struct stale_heads_info *info = cb_data;
2207         struct string_list matches = STRING_LIST_INIT_DUP;
2208         struct refspec query;
2209         int i, stale = 1;
2210         memset(&query, 0, sizeof(struct refspec));
2211         query.dst = (char *)refname;
2212
2213         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2214         if (matches.nr == 0)
2215                 goto clean_exit; /* No matches */
2216
2217         /*
2218          * If we did find a suitable refspec and it's not a symref and
2219          * it's not in the list of refs that currently exist in that
2220          * remote, we consider it to be stale. In order to deal with
2221          * overlapping refspecs, we need to go over all of the
2222          * matching refs.
2223          */
2224         if (flags & REF_ISSYMREF)
2225                 goto clean_exit;
2226
2227         for (i = 0; stale && i < matches.nr; i++)
2228                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2229                         stale = 0;
2230
2231         if (stale) {
2232                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2233                 oidcpy(&ref->new_oid, oid);
2234         }
2235
2236 clean_exit:
2237         string_list_clear(&matches, 0);
2238         return 0;
2239 }
2240
2241 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2242 {
2243         struct ref *ref, *stale_refs = NULL;
2244         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2245         struct stale_heads_info info;
2246
2247         info.ref_names = &ref_names;
2248         info.stale_refs_tail = &stale_refs;
2249         info.refs = refs;
2250         info.ref_count = ref_count;
2251         for (ref = fetch_map; ref; ref = ref->next)
2252                 string_list_append(&ref_names, ref->name);
2253         string_list_sort(&ref_names);
2254         for_each_ref(get_stale_heads_cb, &info);
2255         string_list_clear(&ref_names, 0);
2256         return stale_refs;
2257 }
2258
2259 /*
2260  * Compare-and-swap
2261  */
2262 static void clear_cas_option(struct push_cas_option *cas)
2263 {
2264         int i;
2265
2266         for (i = 0; i < cas->nr; i++)
2267                 free(cas->entry[i].refname);
2268         free(cas->entry);
2269         memset(cas, 0, sizeof(*cas));
2270 }
2271
2272 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2273                                       const char *refname,
2274                                       size_t refnamelen)
2275 {
2276         struct push_cas *entry;
2277         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2278         entry = &cas->entry[cas->nr++];
2279         memset(entry, 0, sizeof(*entry));
2280         entry->refname = xmemdupz(refname, refnamelen);
2281         return entry;
2282 }
2283
2284 static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2285 {
2286         const char *colon;
2287         struct push_cas *entry;
2288
2289         if (unset) {
2290                 /* "--no-<option>" */
2291                 clear_cas_option(cas);
2292                 return 0;
2293         }
2294
2295         if (!arg) {
2296                 /* just "--<option>" */
2297                 cas->use_tracking_for_rest = 1;
2298                 return 0;
2299         }
2300
2301         /* "--<option>=refname" or "--<option>=refname:value" */
2302         colon = strchrnul(arg, ':');
2303         entry = add_cas_entry(cas, arg, colon - arg);
2304         if (!*colon)
2305                 entry->use_tracking = 1;
2306         else if (!colon[1])
2307                 hashclr(entry->expect);
2308         else if (get_sha1(colon + 1, entry->expect))
2309                 return error("cannot parse expected object name '%s'", colon + 1);
2310         return 0;
2311 }
2312
2313 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2314 {
2315         return parse_push_cas_option(opt->value, arg, unset);
2316 }
2317
2318 int is_empty_cas(const struct push_cas_option *cas)
2319 {
2320         return !cas->use_tracking_for_rest && !cas->nr;
2321 }
2322
2323 /*
2324  * Look at remote.fetch refspec and see if we have a remote
2325  * tracking branch for the refname there.  Fill its current
2326  * value in sha1[].
2327  * If we cannot do so, return negative to signal an error.
2328  */
2329 static int remote_tracking(struct remote *remote, const char *refname,
2330                            struct object_id *oid)
2331 {
2332         char *dst;
2333
2334         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2335         if (!dst)
2336                 return -1; /* no tracking ref for refname at remote */
2337         if (read_ref(dst, oid->hash))
2338                 return -1; /* we know what the tracking ref is but we cannot read it */
2339         return 0;
2340 }
2341
2342 static void apply_cas(struct push_cas_option *cas,
2343                       struct remote *remote,
2344                       struct ref *ref)
2345 {
2346         int i;
2347
2348         /* Find an explicit --<option>=<name>[:<value>] entry */
2349         for (i = 0; i < cas->nr; i++) {
2350                 struct push_cas *entry = &cas->entry[i];
2351                 if (!refname_match(entry->refname, ref->name))
2352                         continue;
2353                 ref->expect_old_sha1 = 1;
2354                 if (!entry->use_tracking)
2355                         hashcpy(ref->old_oid_expect.hash, cas->entry[i].expect);
2356                 else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2357                         oidclr(&ref->old_oid_expect);
2358                 return;
2359         }
2360
2361         /* Are we using "--<option>" to cover all? */
2362         if (!cas->use_tracking_for_rest)
2363                 return;
2364
2365         ref->expect_old_sha1 = 1;
2366         if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2367                 oidclr(&ref->old_oid_expect);
2368 }
2369
2370 void apply_push_cas(struct push_cas_option *cas,
2371                     struct remote *remote,
2372                     struct ref *remote_refs)
2373 {
2374         struct ref *ref;
2375         for (ref = remote_refs; ref; ref = ref->next)
2376                 apply_cas(cas, remote, ref);
2377 }