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
 653         /* remote nicknames cannot contain slashes */
 654         while (*name)
 655                 if (is_dir_sep(*name++))
 656                         return 0;
 657         return 1;
 658 }
 659
 660 const char *remote_for_branch(struct branch *branch, int *explicit)
 661 {
 662         if (branch && branch->remote_name) {
 663                 if (explicit)
 664                         *explicit = 1;
 665                 return branch->remote_name;
 666         }
 667         if (explicit)
 668                 *explicit = 0;
 669         return "origin";
 670 }
 671
 672 const char *pushremote_for_branch(struct branch *branch, int *explicit)
 673 {
 674         if (branch && branch->pushremote_name) {
 675                 if (explicit)
 676                         *explicit = 1;
 677                 return branch->pushremote_name;
 678         }
 679         if (pushremote_name) {
 680                 if (explicit)
 681                         *explicit = 1;
 682                 return pushremote_name;
 683         }
 684         return remote_for_branch(branch, explicit);
 685 }
 686
 687 static struct remote *remote_get_1(const char *name,
 688                                    const char *(*get_default)(struct branch *, int *))
 689 {
 690         struct remote *ret;
 691         int name_given = 0;
 692
 693         read_config();
 694
 695         if (name)
 696                 name_given = 1;
 697         else
 698                 name = get_default(current_branch, &name_given);
 699
 700         ret = make_remote(name, 0);
 701         if (valid_remote_nick(name) && have_git_dir()) {
 702                 if (!valid_remote(ret))
 703                         read_remotes_file(ret);
 704                 if (!valid_remote(ret))
 705                         read_branches_file(ret);
 706         }
 707         if (name_given && !valid_remote(ret))
 708                 add_url_alias(ret, name);
 709         if (!valid_remote(ret))
 710                 return NULL;
 711         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 712         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 713         return ret;
 714 }
 715
 716 struct remote *remote_get(const char *name)
 717 {
 718         return remote_get_1(name, remote_for_branch);
 719 }
 720
 721 struct remote *pushremote_get(const char *name)
 722 {
 723         return remote_get_1(name, pushremote_for_branch);
 724 }
 725
 726 int remote_is_configured(struct remote *remote, int in_repo)
 727 {
 728         if (!remote)
 729                 return 0;
 730         if (in_repo)
 731                 return remote->configured_in_repo;
 732         return !!remote->origin;
 733 }
 734
 735 int for_each_remote(each_remote_fn fn, void *priv)
 736 {
 737         int i, result = 0;
 738         read_config();
 739         for (i = 0; i < remotes_nr && !result; i++) {
 740                 struct remote *r = remotes[i];
 741                 if (!r)
 742                         continue;
 743                 if (!r->fetch)
 744                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 745                                                        r->fetch_refspec);
 746                 if (!r->push)
 747                         r->push = parse_push_refspec(r->push_refspec_nr,
 748                                                      r->push_refspec);
 749                 result = fn(r, priv);
 750         }
 751         return result;
 752 }
 753
 754 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 755 {
 756         if (strcmp(ref1->name, ref2->name)) {
 757                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 758                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 759                         die(_("Cannot fetch both %s and %s to %s"),
 760                             ref1->name, ref2->name, ref2->peer_ref->name);
 761                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 762                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 763                         warning(_("%s usually tracks %s, not %s"),
 764                                 ref2->peer_ref->name, ref2->name, ref1->name);
 765                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 766                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 767                         die(_("%s tracks both %s and %s"),
 768                             ref2->peer_ref->name, ref1->name, ref2->name);
 769                 } else {
 770                         /*
 771                          * This last possibility doesn't occur because
 772                          * FETCH_HEAD_IGNORE entries always appear at
 773                          * the end of the list.
 774                          */
 775                         die(_("Internal error"));
 776                 }
 777         }
 778         free(ref2->peer_ref);
 779         free(ref2);
 780 }
 781
 782 struct ref *ref_remove_duplicates(struct ref *ref_map)
 783 {
 784         struct string_list refs = STRING_LIST_INIT_NODUP;
 785         struct ref *retval = NULL;
 786         struct ref **p = &retval;
 787
 788         while (ref_map) {
 789                 struct ref *ref = ref_map;
 790
 791                 ref_map = ref_map->next;
 792                 ref->next = NULL;
 793
 794                 if (!ref->peer_ref) {
 795                         *p = ref;
 796                         p = &ref->next;
 797                 } else {
 798                         struct string_list_item *item =
 799                                 string_list_insert(&refs, ref->peer_ref->name);
 800
 801                         if (item->util) {
 802                                 /* Entry already existed */
 803                                 handle_duplicate((struct ref *)item->util, ref);
 804                         } else {
 805                                 *p = ref;
 806                                 p = &ref->next;
 807                                 item->util = ref;
 808                         }
 809                 }
 810         }
 811
 812         string_list_clear(&refs, 0);
 813         return retval;
 814 }
 815
 816 int remote_has_url(struct remote *remote, const char *url)
 817 {
 818         int i;
 819         for (i = 0; i < remote->url_nr; i++) {
 820                 if (!strcmp(remote->url[i], url))
 821                         return 1;
 822         }
 823         return 0;
 824 }
 825
 826 static int match_name_with_pattern(const char *key, const char *name,
 827                                    const char *value, char **result)
 828 {
 829         const char *kstar = strchr(key, '*');
 830         size_t klen;
 831         size_t ksuffixlen;
 832         size_t namelen;
 833         int ret;
 834         if (!kstar)
 835                 die("Key '%s' of pattern had no '*'", key);
 836         klen = kstar - key;
 837         ksuffixlen = strlen(kstar + 1);
 838         namelen = strlen(name);
 839         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 840                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 841         if (ret && value) {
 842                 struct strbuf sb = STRBUF_INIT;
 843                 const char *vstar = strchr(value, '*');
 844                 if (!vstar)
 845                         die("Value '%s' of pattern has no '*'", value);
 846                 strbuf_add(&sb, value, vstar - value);
 847                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 848                 strbuf_addstr(&sb, vstar + 1);
 849                 *result = strbuf_detach(&sb, NULL);
 850         }
 851         return ret;
 852 }
 853
 854 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 855 {
 856         int i;
 857         int find_src = !query->src;
 858
 859         if (find_src && !query->dst)
 860                 error("query_refspecs_multiple: need either src or dst");
 861
 862         for (i = 0; i < ref_count; i++) {
 863                 struct refspec *refspec = &refs[i];
 864                 const char *key = find_src ? refspec->dst : refspec->src;
 865                 const char *value = find_src ? refspec->src : refspec->dst;
 866                 const char *needle = find_src ? query->dst : query->src;
 867                 char **result = find_src ? &query->src : &query->dst;
 868
 869                 if (!refspec->dst)
 870                         continue;
 871                 if (refspec->pattern) {
 872                         if (match_name_with_pattern(key, needle, value, result))
 873                                 string_list_append_nodup(results, *result);
 874                 } else if (!strcmp(needle, key)) {
 875                         string_list_append(results, value);
 876                 }
 877         }
 878 }
 879
 880 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 881 {
 882         int i;
 883         int find_src = !query->src;
 884         const char *needle = find_src ? query->dst : query->src;
 885         char **result = find_src ? &query->src : &query->dst;
 886
 887         if (find_src && !query->dst)
 888                 return error("query_refspecs: need either src or dst");
 889
 890         for (i = 0; i < ref_count; i++) {
 891                 struct refspec *refspec = &refs[i];
 892                 const char *key = find_src ? refspec->dst : refspec->src;
 893                 const char *value = find_src ? refspec->src : refspec->dst;
 894
 895                 if (!refspec->dst)
 896                         continue;
 897                 if (refspec->pattern) {
 898                         if (match_name_with_pattern(key, needle, value, result)) {
 899                                 query->force = refspec->force;
 900                                 return 0;
 901                         }
 902                 } else if (!strcmp(needle, key)) {
 903                         *result = xstrdup(value);
 904                         query->force = refspec->force;
 905                         return 0;
 906                 }
 907         }
 908         return -1;
 909 }
 910
 911 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 912                      const char *name)
 913 {
 914         struct refspec query;
 915
 916         memset(&query, 0, sizeof(struct refspec));
 917         query.src = (char *)name;
 918
 919         if (query_refspecs(refspecs, nr_refspec, &query))
 920                 return NULL;
 921
 922         return query.dst;
 923 }
 924
 925 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 926 {
 927         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 928 }
 929
 930 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 931                 const char *name)
 932 {
 933         size_t len = strlen(name);
 934         struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 935         memcpy(ref->name, prefix, prefixlen);
 936         memcpy(ref->name + prefixlen, name, len);
 937         return ref;
 938 }
 939
 940 struct ref *alloc_ref(const char *name)
 941 {
 942         return alloc_ref_with_prefix("", 0, name);
 943 }
 944
 945 struct ref *copy_ref(const struct ref *ref)
 946 {
 947         struct ref *cpy;
 948         size_t len;
 949         if (!ref)
 950                 return NULL;
 951         len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 952         cpy = xmalloc(len);
 953         memcpy(cpy, ref, len);
 954         cpy->next = NULL;
 955         cpy->symref = xstrdup_or_null(ref->symref);
 956         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 957         cpy->peer_ref = copy_ref(ref->peer_ref);
 958         return cpy;
 959 }
 960
 961 struct ref *copy_ref_list(const struct ref *ref)
 962 {
 963         struct ref *ret = NULL;
 964         struct ref **tail = &ret;
 965         while (ref) {
 966                 *tail = copy_ref(ref);
 967                 ref = ref->next;
 968                 tail = &((*tail)->next);
 969         }
 970         return ret;
 971 }
 972
 973 static void free_ref(struct ref *ref)
 974 {
 975         if (!ref)
 976                 return;
 977         free_ref(ref->peer_ref);
 978         free(ref->remote_status);
 979         free(ref->symref);
 980         free(ref);
 981 }
 982
 983 void free_refs(struct ref *ref)
 984 {
 985         struct ref *next;
 986         while (ref) {
 987                 next = ref->next;
 988                 free_ref(ref);
 989                 ref = next;
 990         }
 991 }
 992
 993 int ref_compare_name(const void *va, const void *vb)
 994 {
 995         const struct ref *a = va, *b = vb;
 996         return strcmp(a->name, b->name);
 997 }
 998
 999 static void *ref_list_get_next(const void *a)
1000 {
1001         return ((const struct ref *)a)->next;
1002 }
1003
1004 static void ref_list_set_next(void *a, void *next)
1005 {
1006         ((struct ref *)a)->next = next;
1007 }
1008
1009 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1010 {
1011         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1012 }
1013
1014 int count_refspec_match(const char *pattern,
1015                         struct ref *refs,
1016                         struct ref **matched_ref)
1017 {
1018         int patlen = strlen(pattern);
1019         struct ref *matched_weak = NULL;
1020         struct ref *matched = NULL;
1021         int weak_match = 0;
1022         int match = 0;
1023
1024         for (weak_match = match = 0; refs; refs = refs->next) {
1025                 char *name = refs->name;
1026                 int namelen = strlen(name);
1027
1028                 if (!refname_match(pattern, name))
1029                         continue;
1030
1031                 /* A match is "weak" if it is with refs outside
1032                  * heads or tags, and did not specify the pattern
1033                  * in full (e.g. "refs/remotes/origin/master") or at
1034                  * least from the toplevel (e.g. "remotes/origin/master");
1035                  * otherwise "git push $URL master" would result in
1036                  * ambiguity between remotes/origin/master and heads/master
1037                  * at the remote site.
1038                  */
1039                 if (namelen != patlen &&
1040                     patlen != namelen - 5 &&
1041                     !starts_with(name, "refs/heads/") &&
1042                     !starts_with(name, "refs/tags/")) {
1043                         /* We want to catch the case where only weak
1044                          * matches are found and there are multiple
1045                          * matches, and where more than one strong
1046                          * matches are found, as ambiguous.  One
1047                          * strong match with zero or more weak matches
1048                          * are acceptable as a unique match.
1049                          */
1050                         matched_weak = refs;
1051                         weak_match++;
1052                 }
1053                 else {
1054                         matched = refs;
1055                         match++;
1056                 }
1057         }
1058         if (!matched) {
1059                 if (matched_ref)
1060                         *matched_ref = matched_weak;
1061                 return weak_match;
1062         }
1063         else {
1064                 if (matched_ref)
1065                         *matched_ref = matched;
1066                 return match;
1067         }
1068 }
1069
1070 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1071 {
1072         **tail = ref;
1073         while (ref->next)
1074                 ref = ref->next;
1075         *tail = &ref->next;
1076 }
1077
1078 static struct ref *alloc_delete_ref(void)
1079 {
1080         struct ref *ref = alloc_ref("(delete)");
1081         oidclr(&ref->new_oid);
1082         return ref;
1083 }
1084
1085 static int try_explicit_object_name(const char *name,
1086                                     struct ref **match)
1087 {
1088         struct object_id oid;
1089
1090         if (!*name) {
1091                 if (match)
1092                         *match = alloc_delete_ref();
1093                 return 0;
1094         }
1095
1096         if (get_sha1(name, oid.hash))
1097                 return -1;
1098
1099         if (match) {
1100                 *match = alloc_ref(name);
1101                 oidcpy(&(*match)->new_oid, &oid);
1102         }
1103         return 0;
1104 }
1105
1106 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1107 {
1108         struct ref *ret = alloc_ref(name);
1109         tail_link_ref(ret, tail);
1110         return ret;
1111 }
1112
1113 static char *guess_ref(const char *name, struct ref *peer)
1114 {
1115         struct strbuf buf = STRBUF_INIT;
1116         struct object_id oid;
1117
1118         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1119                                            oid.hash, NULL);
1120         if (!r)
1121                 return NULL;
1122
1123         if (starts_with(r, "refs/heads/"))
1124                 strbuf_addstr(&buf, "refs/heads/");
1125         else if (starts_with(r, "refs/tags/"))
1126                 strbuf_addstr(&buf, "refs/tags/");
1127         else
1128                 return NULL;
1129
1130         strbuf_addstr(&buf, name);
1131         return strbuf_detach(&buf, NULL);
1132 }
1133
1134 static int match_explicit_lhs(struct ref *src,
1135                               struct refspec *rs,
1136                               struct ref **match,
1137                               int *allocated_match)
1138 {
1139         switch (count_refspec_match(rs->src, src, match)) {
1140         case 1:
1141                 if (allocated_match)
1142                         *allocated_match = 0;
1143                 return 0;
1144         case 0:
1145                 /* The source could be in the get_sha1() format
1146                  * not a reference name.  :refs/other is a
1147                  * way to delete 'other' ref at the remote end.
1148                  */
1149                 if (try_explicit_object_name(rs->src, match) < 0)
1150                         return error("src refspec %s does not match any.", rs->src);
1151                 if (allocated_match)
1152                         *allocated_match = 1;
1153                 return 0;
1154         default:
1155                 return error("src refspec %s matches more than one.", rs->src);
1156         }
1157 }
1158
1159 static int match_explicit(struct ref *src, struct ref *dst,
1160                           struct ref ***dst_tail,
1161                           struct refspec *rs)
1162 {
1163         struct ref *matched_src, *matched_dst;
1164         int allocated_src;
1165
1166         const char *dst_value = rs->dst;
1167         char *dst_guess;
1168
1169         if (rs->pattern || rs->matching)
1170                 return 0;
1171
1172         matched_src = matched_dst = NULL;
1173         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1174                 return -1;
1175
1176         if (!dst_value) {
1177                 struct object_id oid;
1178                 int flag;
1179
1180                 dst_value = resolve_ref_unsafe(matched_src->name,
1181                                                RESOLVE_REF_READING,
1182                                                oid.hash, &flag);
1183                 if (!dst_value ||
1184                     ((flag & REF_ISSYMREF) &&
1185                      !starts_with(dst_value, "refs/heads/")))
1186                         die("%s cannot be resolved to branch.",
1187                             matched_src->name);
1188         }
1189
1190         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1191         case 1:
1192                 break;
1193         case 0:
1194                 if (starts_with(dst_value, "refs/"))
1195                         matched_dst = make_linked_ref(dst_value, dst_tail);
1196                 else if (is_null_oid(&matched_src->new_oid))
1197                         error("unable to delete '%s': remote ref does not exist",
1198                               dst_value);
1199                 else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1200                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1201                         free(dst_guess);
1202                 } else
1203                         error("unable to push to unqualified destination: %s\n"
1204                               "The destination refspec neither matches an "
1205                               "existing ref on the remote nor\n"
1206                               "begins with refs/, and we are unable to "
1207                               "guess a prefix based on the source ref.",
1208                               dst_value);
1209                 break;
1210         default:
1211                 matched_dst = NULL;
1212                 error("dst refspec %s matches more than one.",
1213                       dst_value);
1214                 break;
1215         }
1216         if (!matched_dst)
1217                 return -1;
1218         if (matched_dst->peer_ref)
1219                 return error("dst ref %s receives from more than one src.",
1220                       matched_dst->name);
1221         else {
1222                 matched_dst->peer_ref = allocated_src ?
1223                                         matched_src :
1224                                         copy_ref(matched_src);
1225                 matched_dst->force = rs->force;
1226         }
1227         return 0;
1228 }
1229
1230 static int match_explicit_refs(struct ref *src, struct ref *dst,
1231                                struct ref ***dst_tail, struct refspec *rs,
1232                                int rs_nr)
1233 {
1234         int i, errs;
1235         for (i = errs = 0; i < rs_nr; i++)
1236                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1237         return errs;
1238 }
1239
1240 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1241                 int send_mirror, int direction, const struct refspec **ret_pat)
1242 {
1243         const struct refspec *pat;
1244         char *name;
1245         int i;
1246         int matching_refs = -1;
1247         for (i = 0; i < rs_nr; i++) {
1248                 if (rs[i].matching &&
1249                     (matching_refs == -1 || rs[i].force)) {
1250                         matching_refs = i;
1251                         continue;
1252                 }
1253
1254                 if (rs[i].pattern) {
1255                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1256                         int match;
1257                         if (direction == FROM_SRC)
1258                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1259                         else
1260                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1261                         if (match) {
1262                                 matching_refs = i;
1263                                 break;
1264                         }
1265                 }
1266         }
1267         if (matching_refs == -1)
1268                 return NULL;
1269
1270         pat = rs + matching_refs;
1271         if (pat->matching) {
1272                 /*
1273                  * "matching refs"; traditionally we pushed everything
1274                  * including refs outside refs/heads/ hierarchy, but
1275                  * that does not make much sense these days.
1276                  */
1277                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1278                         return NULL;
1279                 name = xstrdup(ref->name);
1280         }
1281         if (ret_pat)
1282                 *ret_pat = pat;
1283         return name;
1284 }
1285
1286 static struct ref **tail_ref(struct ref **head)
1287 {
1288         struct ref **tail = head;
1289         while (*tail)
1290                 tail = &((*tail)->next);
1291         return tail;
1292 }
1293
1294 struct tips {
1295         struct commit **tip;
1296         int nr, alloc;
1297 };
1298
1299 static void add_to_tips(struct tips *tips, const struct object_id *oid)
1300 {
1301         struct commit *commit;
1302
1303         if (is_null_oid(oid))
1304                 return;
1305         commit = lookup_commit_reference_gently(oid->hash, 1);
1306         if (!commit || (commit->object.flags & TMP_MARK))
1307                 return;
1308         commit->object.flags |= TMP_MARK;
1309         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1310         tips->tip[tips->nr++] = commit;
1311 }
1312
1313 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1314 {
1315         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1316         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1317         struct string_list_item *item;
1318         struct ref *ref;
1319         struct tips sent_tips;
1320
1321         /*
1322          * Collect everything we know they would have at the end of
1323          * this push, and collect all tags they have.
1324          */
1325         memset(&sent_tips, 0, sizeof(sent_tips));
1326         for (ref = *dst; ref; ref = ref->next) {
1327                 if (ref->peer_ref &&
1328                     !is_null_oid(&ref->peer_ref->new_oid))
1329                         add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1330                 else
1331                         add_to_tips(&sent_tips, &ref->old_oid);
1332                 if (starts_with(ref->name, "refs/tags/"))
1333                         string_list_append(&dst_tag, ref->name);
1334         }
1335         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1336
1337         string_list_sort(&dst_tag);
1338
1339         /* Collect tags they do not have. */
1340         for (ref = src; ref; ref = ref->next) {
1341                 if (!starts_with(ref->name, "refs/tags/"))
1342                         continue; /* not a tag */
1343                 if (string_list_has_string(&dst_tag, ref->name))
1344                         continue; /* they already have it */
1345                 if (sha1_object_info(ref->new_oid.hash, NULL) != OBJ_TAG)
1346                         continue; /* be conservative */
1347                 item = string_list_append(&src_tag, ref->name);
1348                 item->util = ref;
1349         }
1350         string_list_clear(&dst_tag, 0);
1351
1352         /*
1353          * At this point, src_tag lists tags that are missing from
1354          * dst, and sent_tips lists the tips we are pushing or those
1355          * that we know they already have. An element in the src_tag
1356          * that is an ancestor of any of the sent_tips needs to be
1357          * sent to the other side.
1358          */
1359         if (sent_tips.nr) {
1360                 for_each_string_list_item(item, &src_tag) {
1361                         struct ref *ref = item->util;
1362                         struct ref *dst_ref;
1363                         struct commit *commit;
1364
1365                         if (is_null_oid(&ref->new_oid))
1366                                 continue;
1367                         commit = lookup_commit_reference_gently(ref->new_oid.hash, 1);
1368                         if (!commit)
1369                                 /* not pushing a commit, which is not an error */
1370                                 continue;
1371
1372                         /*
1373                          * Is this tag, which they do not have, reachable from
1374                          * any of the commits we are sending?
1375                          */
1376                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1377                                 continue;
1378
1379                         /* Add it in */
1380                         dst_ref = make_linked_ref(ref->name, dst_tail);
1381                         oidcpy(&dst_ref->new_oid, &ref->new_oid);
1382                         dst_ref->peer_ref = copy_ref(ref);
1383                 }
1384         }
1385         string_list_clear(&src_tag, 0);
1386         free(sent_tips.tip);
1387 }
1388
1389 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1390 {
1391         for ( ; list; list = list->next)
1392                 if (!strcmp(list->name, name))
1393                         return (struct ref *)list;
1394         return NULL;
1395 }
1396
1397 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1398 {
1399         for ( ; ref; ref = ref->next)
1400                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1401
1402         string_list_sort(ref_index);
1403 }
1404
1405 /*
1406  * Given only the set of local refs, sanity-check the set of push
1407  * refspecs. We can't catch all errors that match_push_refs would,
1408  * but we can catch some errors early before even talking to the
1409  * remote side.
1410  */
1411 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1412 {
1413         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1414         int ret = 0;
1415         int i;
1416
1417         for (i = 0; i < nr_refspec; i++) {
1418                 struct refspec *rs = refspec + i;
1419
1420                 if (rs->pattern || rs->matching)
1421                         continue;
1422
1423                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1424         }
1425
1426         free_refspec(nr_refspec, refspec);
1427         return ret;
1428 }
1429
1430 /*
1431  * Given the set of refs the local repository has, the set of refs the
1432  * remote repository has, and the refspec used for push, determine
1433  * what remote refs we will update and with what value by setting
1434  * peer_ref (which object is being pushed) and force (if the push is
1435  * forced) in elements of "dst". The function may add new elements to
1436  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1437  */
1438 int match_push_refs(struct ref *src, struct ref **dst,
1439                     int nr_refspec, const char **refspec, int flags)
1440 {
1441         struct refspec *rs;
1442         int send_all = flags & MATCH_REFS_ALL;
1443         int send_mirror = flags & MATCH_REFS_MIRROR;
1444         int send_prune = flags & MATCH_REFS_PRUNE;
1445         int errs;
1446         static const char *default_refspec[] = { ":", NULL };
1447         struct ref *ref, **dst_tail = tail_ref(dst);
1448         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1449
1450         if (!nr_refspec) {
1451                 nr_refspec = 1;
1452                 refspec = default_refspec;
1453         }
1454         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1455         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1456
1457         /* pick the remainder */
1458         for (ref = src; ref; ref = ref->next) {
1459                 struct string_list_item *dst_item;
1460                 struct ref *dst_peer;
1461                 const struct refspec *pat = NULL;
1462                 char *dst_name;
1463
1464                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1465                 if (!dst_name)
1466                         continue;
1467
1468                 if (!dst_ref_index.nr)
1469                         prepare_ref_index(&dst_ref_index, *dst);
1470
1471                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1472                 dst_peer = dst_item ? dst_item->util : NULL;
1473                 if (dst_peer) {
1474                         if (dst_peer->peer_ref)
1475                                 /* We're already sending something to this ref. */
1476                                 goto free_name;
1477                 } else {
1478                         if (pat->matching && !(send_all || send_mirror))
1479                                 /*
1480                                  * Remote doesn't have it, and we have no
1481                                  * explicit pattern, and we don't have
1482                                  * --all or --mirror.
1483                                  */
1484                                 goto free_name;
1485
1486                         /* Create a new one and link it */
1487                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1488                         oidcpy(&dst_peer->new_oid, &ref->new_oid);
1489                         string_list_insert(&dst_ref_index,
1490                                 dst_peer->name)->util = dst_peer;
1491                 }
1492                 dst_peer->peer_ref = copy_ref(ref);
1493                 dst_peer->force = pat->force;
1494         free_name:
1495                 free(dst_name);
1496         }
1497
1498         string_list_clear(&dst_ref_index, 0);
1499
1500         if (flags & MATCH_REFS_FOLLOW_TAGS)
1501                 add_missing_tags(src, dst, &dst_tail);
1502
1503         if (send_prune) {
1504                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1505                 /* check for missing refs on the remote */
1506                 for (ref = *dst; ref; ref = ref->next) {
1507                         char *src_name;
1508
1509                         if (ref->peer_ref)
1510                                 /* We're already sending something to this ref. */
1511                                 continue;
1512
1513                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1514                         if (src_name) {
1515                                 if (!src_ref_index.nr)
1516                                         prepare_ref_index(&src_ref_index, src);
1517                                 if (!string_list_has_string(&src_ref_index,
1518                                             src_name))
1519                                         ref->peer_ref = alloc_delete_ref();
1520                                 free(src_name);
1521                         }
1522                 }
1523                 string_list_clear(&src_ref_index, 0);
1524         }
1525         if (errs)
1526                 return -1;
1527         return 0;
1528 }
1529
1530 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1531                              int force_update)
1532 {
1533         struct ref *ref;
1534
1535         for (ref = remote_refs; ref; ref = ref->next) {
1536                 int force_ref_update = ref->force || force_update;
1537                 int reject_reason = 0;
1538
1539                 if (ref->peer_ref)
1540                         oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1541                 else if (!send_mirror)
1542                         continue;
1543
1544                 ref->deletion = is_null_oid(&ref->new_oid);
1545                 if (!ref->deletion &&
1546                         !oidcmp(&ref->old_oid, &ref->new_oid)) {
1547                         ref->status = REF_STATUS_UPTODATE;
1548                         continue;
1549                 }
1550
1551                 /*
1552                  * If the remote ref has moved and is now different
1553                  * from what we expect, reject any push.
1554                  *
1555                  * It also is an error if the user told us to check
1556                  * with the remote-tracking branch to find the value
1557                  * to expect, but we did not have such a tracking
1558                  * branch.
1559                  */
1560                 if (ref->expect_old_sha1) {
1561                         if (oidcmp(&ref->old_oid, &ref->old_oid_expect))
1562                                 reject_reason = REF_STATUS_REJECT_STALE;
1563                         else
1564                                 /* If the ref isn't stale then force the update. */
1565                                 force_ref_update = 1;
1566                 }
1567
1568                 /*
1569                  * If the update isn't already rejected then check
1570                  * the usual "must fast-forward" rules.
1571                  *
1572                  * Decide whether an individual refspec A:B can be
1573                  * pushed.  The push will succeed if any of the
1574                  * following are true:
1575                  *
1576                  * (1) the remote reference B does not exist
1577                  *
1578                  * (2) the remote reference B is being removed (i.e.,
1579                  *     pushing :B where no source is specified)
1580                  *
1581                  * (3) the destination is not under refs/tags/, and
1582                  *     if the old and new value is a commit, the new
1583                  *     is a descendant of the old.
1584                  *
1585                  * (4) it is forced using the +A:B notation, or by
1586                  *     passing the --force argument
1587                  */
1588
1589                 if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1590                         if (starts_with(ref->name, "refs/tags/"))
1591                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1592                         else if (!has_object_file(&ref->old_oid))
1593                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1594                         else if (!lookup_commit_reference_gently(ref->old_oid.hash, 1) ||
1595                                  !lookup_commit_reference_gently(ref->new_oid.hash, 1))
1596                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1597                         else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1598                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1599                 }
1600
1601                 /*
1602                  * "--force" will defeat any rejection implemented
1603                  * by the rules above.
1604                  */
1605                 if (!force_ref_update)
1606                         ref->status = reject_reason;
1607                 else if (reject_reason)
1608                         ref->forced_update = 1;
1609         }
1610 }
1611
1612 static void set_merge(struct branch *ret)
1613 {
1614         struct remote *remote;
1615         char *ref;
1616         struct object_id oid;
1617         int i;
1618
1619         if (!ret)
1620                 return; /* no branch */
1621         if (ret->merge)
1622                 return; /* already run */
1623         if (!ret->remote_name || !ret->merge_nr) {
1624                 /*
1625                  * no merge config; let's make sure we don't confuse callers
1626                  * with a non-zero merge_nr but a NULL merge
1627                  */
1628                 ret->merge_nr = 0;
1629                 return;
1630         }
1631
1632         remote = remote_get(ret->remote_name);
1633
1634         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1635         for (i = 0; i < ret->merge_nr; i++) {
1636                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1637                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1638                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1639                     strcmp(ret->remote_name, "."))
1640                         continue;
1641                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1642                              oid.hash, &ref) == 1)
1643                         ret->merge[i]->dst = ref;
1644                 else
1645                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1646         }
1647 }
1648
1649 struct branch *branch_get(const char *name)
1650 {
1651         struct branch *ret;
1652
1653         read_config();
1654         if (!name || !*name || !strcmp(name, "HEAD"))
1655                 ret = current_branch;
1656         else
1657                 ret = make_branch(name, 0);
1658         set_merge(ret);
1659         return ret;
1660 }
1661
1662 int branch_has_merge_config(struct branch *branch)
1663 {
1664         return branch && !!branch->merge;
1665 }
1666
1667 int branch_merge_matches(struct branch *branch,
1668                                  int i,
1669                                  const char *refname)
1670 {
1671         if (!branch || i < 0 || i >= branch->merge_nr)
1672                 return 0;
1673         return refname_match(branch->merge[i]->src, refname);
1674 }
1675
1676 __attribute__((format (printf,2,3)))
1677 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1678 {
1679         if (err) {
1680                 va_list ap;
1681                 va_start(ap, fmt);
1682                 strbuf_vaddf(err, fmt, ap);
1683                 va_end(ap);
1684         }
1685         return NULL;
1686 }
1687
1688 const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1689 {
1690         if (!branch)
1691                 return error_buf(err, _("HEAD does not point to a branch"));
1692
1693         if (!branch->merge || !branch->merge[0]) {
1694                 /*
1695                  * no merge config; is it because the user didn't define any,
1696                  * or because it is not a real branch, and get_branch
1697                  * auto-vivified it?
1698                  */
1699                 if (!ref_exists(branch->refname))
1700                         return error_buf(err, _("no such branch: '%s'"),
1701                                          branch->name);
1702                 return error_buf(err,
1703                                  _("no upstream configured for branch '%s'"),
1704                                  branch->name);
1705         }
1706
1707         if (!branch->merge[0]->dst)
1708                 return error_buf(err,
1709                                  _("upstream branch '%s' not stored as a remote-tracking branch"),
1710                                  branch->merge[0]->src);
1711
1712         return branch->merge[0]->dst;
1713 }
1714
1715 static const char *tracking_for_push_dest(struct remote *remote,
1716                                           const char *refname,
1717                                           struct strbuf *err)
1718 {
1719         char *ret;
1720
1721         ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1722         if (!ret)
1723                 return error_buf(err,
1724                                  _("push destination '%s' on remote '%s' has no local tracking branch"),
1725                                  refname, remote->name);
1726         return ret;
1727 }
1728
1729 static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1730 {
1731         struct remote *remote;
1732
1733         remote = remote_get(pushremote_for_branch(branch, NULL));
1734         if (!remote)
1735                 return error_buf(err,
1736                                  _("branch '%s' has no remote for pushing"),
1737                                  branch->name);
1738
1739         if (remote->push_refspec_nr) {
1740                 char *dst;
1741                 const char *ret;
1742
1743                 dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1744                                      branch->refname);
1745                 if (!dst)
1746                         return error_buf(err,
1747                                          _("push refspecs for '%s' do not include '%s'"),
1748                                          remote->name, branch->name);
1749
1750                 ret = tracking_for_push_dest(remote, dst, err);
1751                 free(dst);
1752                 return ret;
1753         }
1754
1755         if (remote->mirror)
1756                 return tracking_for_push_dest(remote, branch->refname, err);
1757
1758         switch (push_default) {
1759         case PUSH_DEFAULT_NOTHING:
1760                 return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1761
1762         case PUSH_DEFAULT_MATCHING:
1763         case PUSH_DEFAULT_CURRENT:
1764                 return tracking_for_push_dest(remote, branch->refname, err);
1765
1766         case PUSH_DEFAULT_UPSTREAM:
1767                 return branch_get_upstream(branch, err);
1768
1769         case PUSH_DEFAULT_UNSPECIFIED:
1770         case PUSH_DEFAULT_SIMPLE:
1771                 {
1772                         const char *up, *cur;
1773
1774                         up = branch_get_upstream(branch, err);
1775                         if (!up)
1776                                 return NULL;
1777                         cur = tracking_for_push_dest(remote, branch->refname, err);
1778                         if (!cur)
1779                                 return NULL;
1780                         if (strcmp(cur, up))
1781                                 return error_buf(err,
1782                                                  _("cannot resolve 'simple' push to a single destination"));
1783                         return cur;
1784                 }
1785         }
1786
1787         die("BUG: unhandled push situation");
1788 }
1789
1790 const char *branch_get_push(struct branch *branch, struct strbuf *err)
1791 {
1792         if (!branch)
1793                 return error_buf(err, _("HEAD does not point to a branch"));
1794
1795         if (!branch->push_tracking_ref)
1796                 branch->push_tracking_ref = branch_get_push_1(branch, err);
1797         return branch->push_tracking_ref;
1798 }
1799
1800 static int ignore_symref_update(const char *refname)
1801 {
1802         struct object_id oid;
1803         int flag;
1804
1805         if (!resolve_ref_unsafe(refname, 0, oid.hash, &flag))
1806                 return 0; /* non-existing refs are OK */
1807         return (flag & REF_ISSYMREF);
1808 }
1809
1810 /*
1811  * Create and return a list of (struct ref) consisting of copies of
1812  * each remote_ref that matches refspec.  refspec must be a pattern.
1813  * Fill in the copies' peer_ref to describe the local tracking refs to
1814  * which they map.  Omit any references that would map to an existing
1815  * local symbolic ref.
1816  */
1817 static struct ref *get_expanded_map(const struct ref *remote_refs,
1818                                     const struct refspec *refspec)
1819 {
1820         const struct ref *ref;
1821         struct ref *ret = NULL;
1822         struct ref **tail = &ret;
1823
1824         for (ref = remote_refs; ref; ref = ref->next) {
1825                 char *expn_name = NULL;
1826
1827                 if (strchr(ref->name, '^'))
1828                         continue; /* a dereference item */
1829                 if (match_name_with_pattern(refspec->src, ref->name,
1830                                             refspec->dst, &expn_name) &&
1831                     !ignore_symref_update(expn_name)) {
1832                         struct ref *cpy = copy_ref(ref);
1833
1834                         cpy->peer_ref = alloc_ref(expn_name);
1835                         if (refspec->force)
1836                                 cpy->peer_ref->force = 1;
1837                         *tail = cpy;
1838                         tail = &cpy->next;
1839                 }
1840                 free(expn_name);
1841         }
1842
1843         return ret;
1844 }
1845
1846 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1847 {
1848         const struct ref *ref;
1849         for (ref = refs; ref; ref = ref->next) {
1850                 if (refname_match(name, ref->name))
1851                         return ref;
1852         }
1853         return NULL;
1854 }
1855
1856 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1857 {
1858         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1859
1860         if (!ref)
1861                 return NULL;
1862
1863         return copy_ref(ref);
1864 }
1865
1866 static struct ref *get_local_ref(const char *name)
1867 {
1868         if (!name || name[0] == '\0')
1869                 return NULL;
1870
1871         if (starts_with(name, "refs/"))
1872                 return alloc_ref(name);
1873
1874         if (starts_with(name, "heads/") ||
1875             starts_with(name, "tags/") ||
1876             starts_with(name, "remotes/"))
1877                 return alloc_ref_with_prefix("refs/", 5, name);
1878
1879         return alloc_ref_with_prefix("refs/heads/", 11, name);
1880 }
1881
1882 int get_fetch_map(const struct ref *remote_refs,
1883                   const struct refspec *refspec,
1884                   struct ref ***tail,
1885                   int missing_ok)
1886 {
1887         struct ref *ref_map, **rmp;
1888
1889         if (refspec->pattern) {
1890                 ref_map = get_expanded_map(remote_refs, refspec);
1891         } else {
1892                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1893
1894                 if (refspec->exact_sha1) {
1895                         ref_map = alloc_ref(name);
1896                         get_oid_hex(name, &ref_map->old_oid);
1897                 } else {
1898                         ref_map = get_remote_ref(remote_refs, name);
1899                 }
1900                 if (!missing_ok && !ref_map)
1901                         die("Couldn't find remote ref %s", name);
1902                 if (ref_map) {
1903                         ref_map->peer_ref = get_local_ref(refspec->dst);
1904                         if (ref_map->peer_ref && refspec->force)
1905                                 ref_map->peer_ref->force = 1;
1906                 }
1907         }
1908
1909         for (rmp = &ref_map; *rmp; ) {
1910                 if ((*rmp)->peer_ref) {
1911                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1912                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1913                                 struct ref *ignore = *rmp;
1914                                 error("* Ignoring funny ref '%s' locally",
1915                                       (*rmp)->peer_ref->name);
1916                                 *rmp = (*rmp)->next;
1917                                 free(ignore->peer_ref);
1918                                 free(ignore);
1919                                 continue;
1920                         }
1921                 }
1922                 rmp = &((*rmp)->next);
1923         }
1924
1925         if (ref_map)
1926                 tail_link_ref(ref_map, tail);
1927
1928         return 0;
1929 }
1930
1931 int resolve_remote_symref(struct ref *ref, struct ref *list)
1932 {
1933         if (!ref->symref)
1934                 return 0;
1935         for (; list; list = list->next)
1936                 if (!strcmp(ref->symref, list->name)) {
1937                         oidcpy(&ref->old_oid, &list->old_oid);
1938                         return 0;
1939                 }
1940         return 1;
1941 }
1942
1943 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1944 {
1945         while (list) {
1946                 struct commit *commit = pop_commit(&list);
1947                 commit->object.flags &= ~mark;
1948         }
1949 }
1950
1951 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1952 {
1953         struct object *o;
1954         struct commit *old, *new;
1955         struct commit_list *list, *used;
1956         int found = 0;
1957
1958         /*
1959          * Both new and old must be commit-ish and new is descendant of
1960          * old.  Otherwise we require --force.
1961          */
1962         o = deref_tag(parse_object(old_oid->hash), NULL, 0);
1963         if (!o || o->type != OBJ_COMMIT)
1964                 return 0;
1965         old = (struct commit *) o;
1966
1967         o = deref_tag(parse_object(new_oid->hash), NULL, 0);
1968         if (!o || o->type != OBJ_COMMIT)
1969                 return 0;
1970         new = (struct commit *) o;
1971
1972         if (parse_commit(new) < 0)
1973                 return 0;
1974
1975         used = list = NULL;
1976         commit_list_insert(new, &list);
1977         while (list) {
1978                 new = pop_most_recent_commit(&list, TMP_MARK);
1979                 commit_list_insert(new, &used);
1980                 if (new == old) {
1981                         found = 1;
1982                         break;
1983                 }
1984         }
1985         unmark_and_free(list, TMP_MARK);
1986         unmark_and_free(used, TMP_MARK);
1987         return found;
1988 }
1989
1990 /*
1991  * Compare a branch with its upstream, and save their differences (number
1992  * of commits) in *num_ours and *num_theirs. The name of the upstream branch
1993  * (or NULL if no upstream is defined) is returned via *upstream_name, if it
1994  * is not itself NULL.
1995  *
1996  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1997  * upstream defined, or ref does not exist), 0 otherwise.
1998  */
1999 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
2000                        const char **upstream_name)
2001 {
2002         struct object_id oid;
2003         struct commit *ours, *theirs;
2004         struct rev_info revs;
2005         const char *base;
2006         struct argv_array argv = ARGV_ARRAY_INIT;
2007
2008         /* Cannot stat unless we are marked to build on top of somebody else. */
2009         base = branch_get_upstream(branch, NULL);
2010         if (upstream_name)
2011                 *upstream_name = base;
2012         if (!base)
2013                 return -1;
2014
2015         /* Cannot stat if what we used to build on no longer exists */
2016         if (read_ref(base, oid.hash))
2017                 return -1;
2018         theirs = lookup_commit_reference(oid.hash);
2019         if (!theirs)
2020                 return -1;
2021
2022         if (read_ref(branch->refname, oid.hash))
2023                 return -1;
2024         ours = lookup_commit_reference(oid.hash);
2025         if (!ours)
2026                 return -1;
2027
2028         /* are we the same? */
2029         if (theirs == ours) {
2030                 *num_theirs = *num_ours = 0;
2031                 return 0;
2032         }
2033
2034         /* Run "rev-list --left-right ours...theirs" internally... */
2035         argv_array_push(&argv, ""); /* ignored */
2036         argv_array_push(&argv, "--left-right");
2037         argv_array_pushf(&argv, "%s...%s",
2038                          oid_to_hex(&ours->object.oid),
2039                          oid_to_hex(&theirs->object.oid));
2040         argv_array_push(&argv, "--");
2041
2042         init_revisions(&revs, NULL);
2043         setup_revisions(argv.argc, argv.argv, &revs, NULL);
2044         if (prepare_revision_walk(&revs))
2045                 die("revision walk setup failed");
2046
2047         /* ... and count the commits on each side. */
2048         *num_ours = 0;
2049         *num_theirs = 0;
2050         while (1) {
2051                 struct commit *c = get_revision(&revs);
2052                 if (!c)
2053                         break;
2054                 if (c->object.flags & SYMMETRIC_LEFT)
2055                         (*num_ours)++;
2056                 else
2057                         (*num_theirs)++;
2058         }
2059
2060         /* clear object flags smudged by the above traversal */
2061         clear_commit_marks(ours, ALL_REV_FLAGS);
2062         clear_commit_marks(theirs, ALL_REV_FLAGS);
2063
2064         argv_array_clear(&argv);
2065         return 0;
2066 }
2067
2068 /*
2069  * Return true when there is anything to report, otherwise false.
2070  */
2071 int format_tracking_info(struct branch *branch, struct strbuf *sb)
2072 {
2073         int ours, theirs;
2074         const char *full_base;
2075         char *base;
2076         int upstream_is_gone = 0;
2077
2078         if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2079                 if (!full_base)
2080                         return 0;
2081                 upstream_is_gone = 1;
2082         }
2083
2084         base = shorten_unambiguous_ref(full_base, 0);
2085         if (upstream_is_gone) {
2086                 strbuf_addf(sb,
2087                         _("Your branch is based on '%s', but the upstream is gone.\n"),
2088                         base);
2089                 if (advice_status_hints)
2090                         strbuf_addstr(sb,
2091                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2092         } else if (!ours && !theirs) {
2093                 strbuf_addf(sb,
2094                         _("Your branch is up-to-date with '%s'.\n"),
2095                         base);
2096         } else if (!theirs) {
2097                 strbuf_addf(sb,
2098                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2099                            "Your branch is ahead of '%s' by %d commits.\n",
2100                            ours),
2101                         base, ours);
2102                 if (advice_status_hints)
2103                         strbuf_addstr(sb,
2104                                 _("  (use \"git push\" to publish your local commits)\n"));
2105         } else if (!ours) {
2106                 strbuf_addf(sb,
2107                         Q_("Your branch is behind '%s' by %d commit, "
2108                                "and can be fast-forwarded.\n",
2109                            "Your branch is behind '%s' by %d commits, "
2110                                "and can be fast-forwarded.\n",
2111                            theirs),
2112                         base, theirs);
2113                 if (advice_status_hints)
2114                         strbuf_addstr(sb,
2115                                 _("  (use \"git pull\" to update your local branch)\n"));
2116         } else {
2117                 strbuf_addf(sb,
2118                         Q_("Your branch and '%s' have diverged,\n"
2119                                "and have %d and %d different commit each, "
2120                                "respectively.\n",
2121                            "Your branch and '%s' have diverged,\n"
2122                                "and have %d and %d different commits each, "
2123                                "respectively.\n",
2124                            ours + theirs),
2125                         base, ours, theirs);
2126                 if (advice_status_hints)
2127                         strbuf_addstr(sb,
2128                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2129         }
2130         free(base);
2131         return 1;
2132 }
2133
2134 static int one_local_ref(const char *refname, const struct object_id *oid,
2135                          int flag, void *cb_data)
2136 {
2137         struct ref ***local_tail = cb_data;
2138         struct ref *ref;
2139
2140         /* we already know it starts with refs/ to get here */
2141         if (check_refname_format(refname + 5, 0))
2142                 return 0;
2143
2144         ref = alloc_ref(refname);
2145         oidcpy(&ref->new_oid, oid);
2146         **local_tail = ref;
2147         *local_tail = &ref->next;
2148         return 0;
2149 }
2150
2151 struct ref *get_local_heads(void)
2152 {
2153         struct ref *local_refs = NULL, **local_tail = &local_refs;
2154
2155         for_each_ref(one_local_ref, &local_tail);
2156         return local_refs;
2157 }
2158
2159 struct ref *guess_remote_head(const struct ref *head,
2160                               const struct ref *refs,
2161                               int all)
2162 {
2163         const struct ref *r;
2164         struct ref *list = NULL;
2165         struct ref **tail = &list;
2166
2167         if (!head)
2168                 return NULL;
2169
2170         /*
2171          * Some transports support directly peeking at
2172          * where HEAD points; if that is the case, then
2173          * we don't have to guess.
2174          */
2175         if (head->symref)
2176                 return copy_ref(find_ref_by_name(refs, head->symref));
2177
2178         /* If refs/heads/master could be right, it is. */
2179         if (!all) {
2180                 r = find_ref_by_name(refs, "refs/heads/master");
2181                 if (r && !oidcmp(&r->old_oid, &head->old_oid))
2182                         return copy_ref(r);
2183         }
2184
2185         /* Look for another ref that points there */
2186         for (r = refs; r; r = r->next) {
2187                 if (r != head &&
2188                     starts_with(r->name, "refs/heads/") &&
2189                     !oidcmp(&r->old_oid, &head->old_oid)) {
2190                         *tail = copy_ref(r);
2191                         tail = &((*tail)->next);
2192                         if (!all)
2193                                 break;
2194                 }
2195         }
2196
2197         return list;
2198 }
2199
2200 struct stale_heads_info {
2201         struct string_list *ref_names;
2202         struct ref **stale_refs_tail;
2203         struct refspec *refs;
2204         int ref_count;
2205 };
2206
2207 static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2208                               int flags, void *cb_data)
2209 {
2210         struct stale_heads_info *info = cb_data;
2211         struct string_list matches = STRING_LIST_INIT_DUP;
2212         struct refspec query;
2213         int i, stale = 1;
2214         memset(&query, 0, sizeof(struct refspec));
2215         query.dst = (char *)refname;
2216
2217         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2218         if (matches.nr == 0)
2219                 goto clean_exit; /* No matches */
2220
2221         /*
2222          * If we did find a suitable refspec and it's not a symref and
2223          * it's not in the list of refs that currently exist in that
2224          * remote, we consider it to be stale. In order to deal with
2225          * overlapping refspecs, we need to go over all of the
2226          * matching refs.
2227          */
2228         if (flags & REF_ISSYMREF)
2229                 goto clean_exit;
2230
2231         for (i = 0; stale && i < matches.nr; i++)
2232                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2233                         stale = 0;
2234
2235         if (stale) {
2236                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2237                 oidcpy(&ref->new_oid, oid);
2238         }
2239
2240 clean_exit:
2241         string_list_clear(&matches, 0);
2242         return 0;
2243 }
2244
2245 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2246 {
2247         struct ref *ref, *stale_refs = NULL;
2248         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2249         struct stale_heads_info info;
2250
2251         info.ref_names = &ref_names;
2252         info.stale_refs_tail = &stale_refs;
2253         info.refs = refs;
2254         info.ref_count = ref_count;
2255         for (ref = fetch_map; ref; ref = ref->next)
2256                 string_list_append(&ref_names, ref->name);
2257         string_list_sort(&ref_names);
2258         for_each_ref(get_stale_heads_cb, &info);
2259         string_list_clear(&ref_names, 0);
2260         return stale_refs;
2261 }
2262
2263 /*
2264  * Compare-and-swap
2265  */
2266 static void clear_cas_option(struct push_cas_option *cas)
2267 {
2268         int i;
2269
2270         for (i = 0; i < cas->nr; i++)
2271                 free(cas->entry[i].refname);
2272         free(cas->entry);
2273         memset(cas, 0, sizeof(*cas));
2274 }
2275
2276 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2277                                       const char *refname,
2278                                       size_t refnamelen)
2279 {
2280         struct push_cas *entry;
2281         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2282         entry = &cas->entry[cas->nr++];
2283         memset(entry, 0, sizeof(*entry));
2284         entry->refname = xmemdupz(refname, refnamelen);
2285         return entry;
2286 }
2287
2288 static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2289 {
2290         const char *colon;
2291         struct push_cas *entry;
2292
2293         if (unset) {
2294                 /* "--no-<option>" */
2295                 clear_cas_option(cas);
2296                 return 0;
2297         }
2298
2299         if (!arg) {
2300                 /* just "--<option>" */
2301                 cas->use_tracking_for_rest = 1;
2302                 return 0;
2303         }
2304
2305         /* "--<option>=refname" or "--<option>=refname:value" */
2306         colon = strchrnul(arg, ':');
2307         entry = add_cas_entry(cas, arg, colon - arg);
2308         if (!*colon)
2309                 entry->use_tracking = 1;
2310         else if (!colon[1])
2311                 hashclr(entry->expect);
2312         else if (get_sha1(colon + 1, entry->expect))
2313                 return error("cannot parse expected object name '%s'", colon + 1);
2314         return 0;
2315 }
2316
2317 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2318 {
2319         return parse_push_cas_option(opt->value, arg, unset);
2320 }
2321
2322 int is_empty_cas(const struct push_cas_option *cas)
2323 {
2324         return !cas->use_tracking_for_rest && !cas->nr;
2325 }
2326
2327 /*
2328  * Look at remote.fetch refspec and see if we have a remote
2329  * tracking branch for the refname there.  Fill its current
2330  * value in sha1[].
2331  * If we cannot do so, return negative to signal an error.
2332  */
2333 static int remote_tracking(struct remote *remote, const char *refname,
2334                            struct object_id *oid)
2335 {
2336         char *dst;
2337
2338         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2339         if (!dst)
2340                 return -1; /* no tracking ref for refname at remote */
2341         if (read_ref(dst, oid->hash))
2342                 return -1; /* we know what the tracking ref is but we cannot read it */
2343         return 0;
2344 }
2345
2346 static void apply_cas(struct push_cas_option *cas,
2347                       struct remote *remote,
2348                       struct ref *ref)
2349 {
2350         int i;
2351
2352         /* Find an explicit --<option>=<name>[:<value>] entry */
2353         for (i = 0; i < cas->nr; i++) {
2354                 struct push_cas *entry = &cas->entry[i];
2355                 if (!refname_match(entry->refname, ref->name))
2356                         continue;
2357                 ref->expect_old_sha1 = 1;
2358                 if (!entry->use_tracking)
2359                         hashcpy(ref->old_oid_expect.hash, cas->entry[i].expect);
2360                 else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2361                         oidclr(&ref->old_oid_expect);
2362                 return;
2363         }
2364
2365         /* Are we using "--<option>" to cover all? */
2366         if (!cas->use_tracking_for_rest)
2367                 return;
2368
2369         ref->expect_old_sha1 = 1;
2370         if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2371                 oidclr(&ref->old_oid_expect);
2372 }
2373
2374 void apply_push_cas(struct push_cas_option *cas,
2375                     struct remote *remote,
2376                     struct ref *remote_refs)
2377 {
2378         struct ref *ref;
2379         for (ref = remote_refs; ref; ref = ref->next)
2380                 apply_cas(cas, remote, ref);
2381 }