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

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "dir.h"
   8 #include "tag.h"
   9 #include "string-list.h"
  10 #include "mergesort.h"
  11 #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->origin = REMOTE_REMOTES;
 259         while (strbuf_getline(&buf, f, '\n') != EOF) {
 260                 const char *v;
 261
 262                 strbuf_rtrim(&buf);
 263
 264                 if (skip_prefix(buf.buf, "URL:", &v))
 265                         add_url_alias(remote, xstrdup(skip_spaces(v)));
 266                 else if (skip_prefix(buf.buf, "Push:", &v))
 267                         add_push_refspec(remote, xstrdup(skip_spaces(v)));
 268                 else if (skip_prefix(buf.buf, "Pull:", &v))
 269                         add_fetch_refspec(remote, xstrdup(skip_spaces(v)));
 270         }
 271         strbuf_release(&buf);
 272         fclose(f);
 273 }
 274
 275 static void read_branches_file(struct remote *remote)
 276 {
 277         char *frag;
 278         struct strbuf buf = STRBUF_INIT;
 279         FILE *f = fopen(git_path("branches/%s", remote->name), "r");
 280
 281         if (!f)
 282                 return;
 283
 284         strbuf_getline(&buf, f, '\n');
 285         fclose(f);
 286         strbuf_trim(&buf);
 287         if (!buf.len) {
 288                 strbuf_release(&buf);
 289                 return;
 290         }
 291
 292         remote->origin = REMOTE_BRANCHES;
 293
 294         /*
 295          * The branches file would have URL and optionally
 296          * #branch specified.  The "master" (or specified) branch is
 297          * fetched and stored in the local branch matching the
 298          * remote name.
 299          */
 300         frag = strchr(buf.buf, '#');
 301         if (frag)
 302                 *(frag++) = '\0';
 303         else
 304                 frag = "master";
 305
 306         add_url_alias(remote, strbuf_detach(&buf, NULL));
 307         add_fetch_refspec(remote, xstrfmt("refs/heads/%s:refs/heads/%s",
 308                                           frag, remote->name));
 309
 310         /*
 311          * Cogito compatible push: push current HEAD to remote #branch
 312          * (master if missing)
 313          */
 314         add_push_refspec(remote, xstrfmt("HEAD:refs/heads/%s", frag));
 315         remote->fetch_tags = 1; /* always auto-follow */
 316 }
 317
 318 static int handle_config(const char *key, const char *value, void *cb)
 319 {
 320         const char *name;
 321         const char *subkey;
 322         struct remote *remote;
 323         struct branch *branch;
 324         if (starts_with(key, "branch.")) {
 325                 name = key + 7;
 326                 subkey = strrchr(name, '.');
 327                 if (!subkey)
 328                         return 0;
 329                 branch = make_branch(name, subkey - name);
 330                 if (!strcmp(subkey, ".remote")) {
 331                         return git_config_string(&branch->remote_name, key, value);
 332                 } else if (!strcmp(subkey, ".pushremote")) {
 333                         return git_config_string(&branch->pushremote_name, key, value);
 334                 } else if (!strcmp(subkey, ".merge")) {
 335                         if (!value)
 336                                 return config_error_nonbool(key);
 337                         add_merge(branch, xstrdup(value));
 338                 } else if (!strcmp(subkey, ".push"))
 339                         return git_config_string(&branch->push_name, key, value);
 340                 return 0;
 341         }
 342         if (starts_with(key, "url.")) {
 343                 struct rewrite *rewrite;
 344                 name = key + 4;
 345                 subkey = strrchr(name, '.');
 346                 if (!subkey)
 347                         return 0;
 348                 if (!strcmp(subkey, ".insteadof")) {
 349                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 350                         if (!value)
 351                                 return config_error_nonbool(key);
 352                         add_instead_of(rewrite, xstrdup(value));
 353                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 354                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 355                         if (!value)
 356                                 return config_error_nonbool(key);
 357                         add_instead_of(rewrite, xstrdup(value));
 358                 }
 359         }
 360
 361         if (!starts_with(key,  "remote."))
 362                 return 0;
 363         name = key + 7;
 364
 365         /* Handle remote.* variables */
 366         if (!strcmp(name, "pushdefault"))
 367                 return git_config_string(&pushremote_name, key, value);
 368
 369         /* Handle remote.<name>.* variables */
 370         if (*name == '/') {
 371                 warning("Config remote shorthand cannot begin with '/': %s",
 372                         name);
 373                 return 0;
 374         }
 375         subkey = strrchr(name, '.');
 376         if (!subkey)
 377                 return 0;
 378         remote = make_remote(name, subkey - name);
 379         remote->origin = REMOTE_CONFIG;
 380         if (!strcmp(subkey, ".mirror"))
 381                 remote->mirror = git_config_bool(key, value);
 382         else if (!strcmp(subkey, ".skipdefaultupdate"))
 383                 remote->skip_default_update = git_config_bool(key, value);
 384         else if (!strcmp(subkey, ".skipfetchall"))
 385                 remote->skip_default_update = git_config_bool(key, value);
 386         else if (!strcmp(subkey, ".prune"))
 387                 remote->prune = git_config_bool(key, value);
 388         else if (!strcmp(subkey, ".url")) {
 389                 const char *v;
 390                 if (git_config_string(&v, key, value))
 391                         return -1;
 392                 add_url(remote, v);
 393         } else if (!strcmp(subkey, ".pushurl")) {
 394                 const char *v;
 395                 if (git_config_string(&v, key, value))
 396                         return -1;
 397                 add_pushurl(remote, v);
 398         } else if (!strcmp(subkey, ".push")) {
 399                 const char *v;
 400                 if (git_config_string(&v, key, value))
 401                         return -1;
 402                 add_push_refspec(remote, v);
 403         } else if (!strcmp(subkey, ".fetch")) {
 404                 const char *v;
 405                 if (git_config_string(&v, key, value))
 406                         return -1;
 407                 add_fetch_refspec(remote, v);
 408         } else if (!strcmp(subkey, ".receivepack")) {
 409                 const char *v;
 410                 if (git_config_string(&v, key, value))
 411                         return -1;
 412                 if (!remote->receivepack)
 413                         remote->receivepack = v;
 414                 else
 415                         error("more than one receivepack given, using the first");
 416         } else if (!strcmp(subkey, ".uploadpack")) {
 417                 const char *v;
 418                 if (git_config_string(&v, key, value))
 419                         return -1;
 420                 if (!remote->uploadpack)
 421                         remote->uploadpack = v;
 422                 else
 423                         error("more than one uploadpack given, using the first");
 424         } else if (!strcmp(subkey, ".tagopt")) {
 425                 if (!strcmp(value, "--no-tags"))
 426                         remote->fetch_tags = -1;
 427                 else if (!strcmp(value, "--tags"))
 428                         remote->fetch_tags = 2;
 429         } else if (!strcmp(subkey, ".proxy")) {
 430                 return git_config_string((const char **)&remote->http_proxy,
 431                                          key, value);
 432         } else if (!strcmp(subkey, ".vcs")) {
 433                 return git_config_string(&remote->foreign_vcs, key, value);
 434         }
 435         return 0;
 436 }
 437
 438 static void alias_all_urls(void)
 439 {
 440         int i, j;
 441         for (i = 0; i < remotes_nr; i++) {
 442                 int add_pushurl_aliases;
 443                 if (!remotes[i])
 444                         continue;
 445                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 446                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 447                 }
 448                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 449                 for (j = 0; j < remotes[i]->url_nr; j++) {
 450                         if (add_pushurl_aliases)
 451                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 452                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 453                 }
 454         }
 455 }
 456
 457 static void read_config(void)
 458 {
 459         static int loaded;
 460         struct object_id oid;
 461         const char *head_ref;
 462         int flag;
 463
 464         if (loaded)
 465                 return;
 466         loaded = 1;
 467
 468         current_branch = NULL;
 469         head_ref = resolve_ref_unsafe("HEAD", 0, oid.hash, &flag);
 470         if (head_ref && (flag & REF_ISSYMREF) &&
 471             skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 472                 current_branch = make_branch(head_ref, 0);
 473         }
 474         git_config(handle_config, NULL);
 475         alias_all_urls();
 476 }
 477
 478 /*
 479  * This function frees a refspec array.
 480  * Warning: code paths should be checked to ensure that the src
 481  *          and dst pointers are always freeable pointers as well
 482  *          as the refspec pointer itself.
 483  */
 484 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 485 {
 486         int i;
 487
 488         if (!refspec)
 489                 return;
 490
 491         for (i = 0; i < nr_refspec; i++) {
 492                 free(refspec[i].src);
 493                 free(refspec[i].dst);
 494         }
 495         free(refspec);
 496 }
 497
 498 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 499 {
 500         int i;
 501         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 502
 503         for (i = 0; i < nr_refspec; i++) {
 504                 size_t llen;
 505                 int is_glob;
 506                 const char *lhs, *rhs;
 507                 int flags;
 508
 509                 is_glob = 0;
 510
 511                 lhs = refspec[i];
 512                 if (*lhs == '+') {
 513                         rs[i].force = 1;
 514                         lhs++;
 515                 }
 516
 517                 rhs = strrchr(lhs, ':');
 518
 519                 /*
 520                  * Before going on, special case ":" (or "+:") as a refspec
 521                  * for pushing matching refs.
 522                  */
 523                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 524                         rs[i].matching = 1;
 525                         continue;
 526                 }
 527
 528                 if (rhs) {
 529                         size_t rlen = strlen(++rhs);
 530                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 531                         rs[i].dst = xstrndup(rhs, rlen);
 532                 }
 533
 534                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 535                 if (1 <= llen && memchr(lhs, '*', llen)) {
 536                         if ((rhs && !is_glob) || (!rhs && fetch))
 537                                 goto invalid;
 538                         is_glob = 1;
 539                 } else if (rhs && is_glob) {
 540                         goto invalid;
 541                 }
 542
 543                 rs[i].pattern = is_glob;
 544                 rs[i].src = xstrndup(lhs, llen);
 545                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 546
 547                 if (fetch) {
 548                         struct object_id unused;
 549
 550                         /* LHS */
 551                         if (!*rs[i].src)
 552                                 ; /* empty is ok; it means "HEAD" */
 553                         else if (llen == GIT_SHA1_HEXSZ && !get_oid_hex(rs[i].src, &unused))
 554                                 rs[i].exact_sha1 = 1; /* ok */
 555                         else if (!check_refname_format(rs[i].src, flags))
 556                                 ; /* valid looking ref is ok */
 557                         else
 558                                 goto invalid;
 559                         /* RHS */
 560                         if (!rs[i].dst)
 561                                 ; /* missing is ok; it is the same as empty */
 562                         else if (!*rs[i].dst)
 563                                 ; /* empty is ok; it means "do not store" */
 564                         else if (!check_refname_format(rs[i].dst, flags))
 565                                 ; /* valid looking ref is ok */
 566                         else
 567                                 goto invalid;
 568                 } else {
 569                         /*
 570                          * LHS
 571                          * - empty is allowed; it means delete.
 572                          * - when wildcarded, it must be a valid looking ref.
 573                          * - otherwise, it must be an extended SHA-1, but
 574                          *   there is no existing way to validate this.
 575                          */
 576                         if (!*rs[i].src)
 577                                 ; /* empty is ok */
 578                         else if (is_glob) {
 579                                 if (check_refname_format(rs[i].src, flags))
 580                                         goto invalid;
 581                         }
 582                         else
 583                                 ; /* anything goes, for now */
 584                         /*
 585                          * RHS
 586                          * - missing is allowed, but LHS then must be a
 587                          *   valid looking ref.
 588                          * - empty is not allowed.
 589                          * - otherwise it must be a valid looking ref.
 590                          */
 591                         if (!rs[i].dst) {
 592                                 if (check_refname_format(rs[i].src, flags))
 593                                         goto invalid;
 594                         } else if (!*rs[i].dst) {
 595                                 goto invalid;
 596                         } else {
 597                                 if (check_refname_format(rs[i].dst, flags))
 598                                         goto invalid;
 599                         }
 600                 }
 601         }
 602         return rs;
 603
 604  invalid:
 605         if (verify) {
 606                 /*
 607                  * nr_refspec must be greater than zero and i must be valid
 608                  * since it is only possible to reach this point from within
 609                  * the for loop above.
 610                  */
 611                 free_refspecs(rs, i+1);
 612                 return NULL;
 613         }
 614         die("Invalid refspec '%s'", refspec[i]);
 615 }
 616
 617 int valid_fetch_refspec(const char *fetch_refspec_str)
 618 {
 619         struct refspec *refspec;
 620
 621         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 622         free_refspecs(refspec, 1);
 623         return !!refspec;
 624 }
 625
 626 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 627 {
 628         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 629 }
 630
 631 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 632 {
 633         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 634 }
 635
 636 void free_refspec(int nr_refspec, struct refspec *refspec)
 637 {
 638         int i;
 639         for (i = 0; i < nr_refspec; i++) {
 640                 free(refspec[i].src);
 641                 free(refspec[i].dst);
 642         }
 643         free(refspec);
 644 }
 645
 646 static int valid_remote_nick(const char *name)
 647 {
 648         if (!name[0] || is_dot_or_dotdot(name))
 649                 return 0;
 650         return !strchr(name, '/'); /* no slash */
 651 }
 652
 653 const char *remote_for_branch(struct branch *branch, int *explicit)
 654 {
 655         if (branch && branch->remote_name) {
 656                 if (explicit)
 657                         *explicit = 1;
 658                 return branch->remote_name;
 659         }
 660         if (explicit)
 661                 *explicit = 0;
 662         return "origin";
 663 }
 664
 665 const char *pushremote_for_branch(struct branch *branch, int *explicit)
 666 {
 667         if (branch && branch->pushremote_name) {
 668                 if (explicit)
 669                         *explicit = 1;
 670                 return branch->pushremote_name;
 671         }
 672         if (pushremote_name) {
 673                 if (explicit)
 674                         *explicit = 1;
 675                 return pushremote_name;
 676         }
 677         return remote_for_branch(branch, explicit);
 678 }
 679
 680 static struct remote *remote_get_1(const char *name,
 681                                    const char *(*get_default)(struct branch *, int *))
 682 {
 683         struct remote *ret;
 684         int name_given = 0;
 685
 686         read_config();
 687
 688         if (name)
 689                 name_given = 1;
 690         else
 691                 name = get_default(current_branch, &name_given);
 692
 693         ret = make_remote(name, 0);
 694         if (valid_remote_nick(name)) {
 695                 if (!valid_remote(ret))
 696                         read_remotes_file(ret);
 697                 if (!valid_remote(ret))
 698                         read_branches_file(ret);
 699         }
 700         if (name_given && !valid_remote(ret))
 701                 add_url_alias(ret, name);
 702         if (!valid_remote(ret))
 703                 return NULL;
 704         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 705         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 706         return ret;
 707 }
 708
 709 struct remote *remote_get(const char *name)
 710 {
 711         return remote_get_1(name, remote_for_branch);
 712 }
 713
 714 struct remote *pushremote_get(const char *name)
 715 {
 716         return remote_get_1(name, pushremote_for_branch);
 717 }
 718
 719 int remote_is_configured(const char *name)
 720 {
 721         struct remotes_hash_key lookup;
 722         struct hashmap_entry lookup_entry;
 723         read_config();
 724
 725         init_remotes_hash();
 726         lookup.str = name;
 727         lookup.len = strlen(name);
 728         hashmap_entry_init(&lookup_entry, memhash(name, lookup.len));
 729
 730         return hashmap_get(&remotes_hash, &lookup_entry, &lookup) != NULL;
 731 }
 732
 733 int for_each_remote(each_remote_fn fn, void *priv)
 734 {
 735         int i, result = 0;
 736         read_config();
 737         for (i = 0; i < remotes_nr && !result; i++) {
 738                 struct remote *r = remotes[i];
 739                 if (!r)
 740                         continue;
 741                 if (!r->fetch)
 742                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 743                                                        r->fetch_refspec);
 744                 if (!r->push)
 745                         r->push = parse_push_refspec(r->push_refspec_nr,
 746                                                      r->push_refspec);
 747                 result = fn(r, priv);
 748         }
 749         return result;
 750 }
 751
 752 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 753 {
 754         if (strcmp(ref1->name, ref2->name)) {
 755                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 756                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 757                         die(_("Cannot fetch both %s and %s to %s"),
 758                             ref1->name, ref2->name, ref2->peer_ref->name);
 759                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 760                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 761                         warning(_("%s usually tracks %s, not %s"),
 762                                 ref2->peer_ref->name, ref2->name, ref1->name);
 763                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 764                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 765                         die(_("%s tracks both %s and %s"),
 766                             ref2->peer_ref->name, ref1->name, ref2->name);
 767                 } else {
 768                         /*
 769                          * This last possibility doesn't occur because
 770                          * FETCH_HEAD_IGNORE entries always appear at
 771                          * the end of the list.
 772                          */
 773                         die(_("Internal error"));
 774                 }
 775         }
 776         free(ref2->peer_ref);
 777         free(ref2);
 778 }
 779
 780 struct ref *ref_remove_duplicates(struct ref *ref_map)
 781 {
 782         struct string_list refs = STRING_LIST_INIT_NODUP;
 783         struct ref *retval = NULL;
 784         struct ref **p = &retval;
 785
 786         while (ref_map) {
 787                 struct ref *ref = ref_map;
 788
 789                 ref_map = ref_map->next;
 790                 ref->next = NULL;
 791
 792                 if (!ref->peer_ref) {
 793                         *p = ref;
 794                         p = &ref->next;
 795                 } else {
 796                         struct string_list_item *item =
 797                                 string_list_insert(&refs, ref->peer_ref->name);
 798
 799                         if (item->util) {
 800                                 /* Entry already existed */
 801                                 handle_duplicate((struct ref *)item->util, ref);
 802                         } else {
 803                                 *p = ref;
 804                                 p = &ref->next;
 805                                 item->util = ref;
 806                         }
 807                 }
 808         }
 809
 810         string_list_clear(&refs, 0);
 811         return retval;
 812 }
 813
 814 int remote_has_url(struct remote *remote, const char *url)
 815 {
 816         int i;
 817         for (i = 0; i < remote->url_nr; i++) {
 818                 if (!strcmp(remote->url[i], url))
 819                         return 1;
 820         }
 821         return 0;
 822 }
 823
 824 static int match_name_with_pattern(const char *key, const char *name,
 825                                    const char *value, char **result)
 826 {
 827         const char *kstar = strchr(key, '*');
 828         size_t klen;
 829         size_t ksuffixlen;
 830         size_t namelen;
 831         int ret;
 832         if (!kstar)
 833                 die("Key '%s' of pattern had no '*'", key);
 834         klen = kstar - key;
 835         ksuffixlen = strlen(kstar + 1);
 836         namelen = strlen(name);
 837         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 838                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 839         if (ret && value) {
 840                 struct strbuf sb = STRBUF_INIT;
 841                 const char *vstar = strchr(value, '*');
 842                 if (!vstar)
 843                         die("Value '%s' of pattern has no '*'", value);
 844                 strbuf_add(&sb, value, vstar - value);
 845                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 846                 strbuf_addstr(&sb, vstar + 1);
 847                 *result = strbuf_detach(&sb, NULL);
 848         }
 849         return ret;
 850 }
 851
 852 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 853 {
 854         int i;
 855         int find_src = !query->src;
 856
 857         if (find_src && !query->dst)
 858                 error("query_refspecs_multiple: need either src or dst");
 859
 860         for (i = 0; i < ref_count; i++) {
 861                 struct refspec *refspec = &refs[i];
 862                 const char *key = find_src ? refspec->dst : refspec->src;
 863                 const char *value = find_src ? refspec->src : refspec->dst;
 864                 const char *needle = find_src ? query->dst : query->src;
 865                 char **result = find_src ? &query->src : &query->dst;
 866
 867                 if (!refspec->dst)
 868                         continue;
 869                 if (refspec->pattern) {
 870                         if (match_name_with_pattern(key, needle, value, result))
 871                                 string_list_append_nodup(results, *result);
 872                 } else if (!strcmp(needle, key)) {
 873                         string_list_append(results, value);
 874                 }
 875         }
 876 }
 877
 878 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 879 {
 880         int i;
 881         int find_src = !query->src;
 882         const char *needle = find_src ? query->dst : query->src;
 883         char **result = find_src ? &query->src : &query->dst;
 884
 885         if (find_src && !query->dst)
 886                 return error("query_refspecs: need either src or dst");
 887
 888         for (i = 0; i < ref_count; i++) {
 889                 struct refspec *refspec = &refs[i];
 890                 const char *key = find_src ? refspec->dst : refspec->src;
 891                 const char *value = find_src ? refspec->src : refspec->dst;
 892
 893                 if (!refspec->dst)
 894                         continue;
 895                 if (refspec->pattern) {
 896                         if (match_name_with_pattern(key, needle, value, result)) {
 897                                 query->force = refspec->force;
 898                                 return 0;
 899                         }
 900                 } else if (!strcmp(needle, key)) {
 901                         *result = xstrdup(value);
 902                         query->force = refspec->force;
 903                         return 0;
 904                 }
 905         }
 906         return -1;
 907 }
 908
 909 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 910                      const char *name)
 911 {
 912         struct refspec query;
 913
 914         memset(&query, 0, sizeof(struct refspec));
 915         query.src = (char *)name;
 916
 917         if (query_refspecs(refspecs, nr_refspec, &query))
 918                 return NULL;
 919
 920         return query.dst;
 921 }
 922
 923 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 924 {
 925         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 926 }
 927
 928 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 929                 const char *name)
 930 {
 931         size_t len = strlen(name);
 932         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 933         memcpy(ref->name, prefix, prefixlen);
 934         memcpy(ref->name + prefixlen, name, len);
 935         return ref;
 936 }
 937
 938 struct ref *alloc_ref(const char *name)
 939 {
 940         return alloc_ref_with_prefix("", 0, name);
 941 }
 942
 943 struct ref *copy_ref(const struct ref *ref)
 944 {
 945         struct ref *cpy;
 946         size_t len;
 947         if (!ref)
 948                 return NULL;
 949         len = strlen(ref->name);
 950         cpy = xmalloc(sizeof(struct ref) + len + 1);
 951         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 952         cpy->next = NULL;
 953         cpy->symref = xstrdup_or_null(ref->symref);
 954         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 955         cpy->peer_ref = copy_ref(ref->peer_ref);
 956         return cpy;
 957 }
 958
 959 struct ref *copy_ref_list(const struct ref *ref)
 960 {
 961         struct ref *ret = NULL;
 962         struct ref **tail = &ret;
 963         while (ref) {
 964                 *tail = copy_ref(ref);
 965                 ref = ref->next;
 966                 tail = &((*tail)->next);
 967         }
 968         return ret;
 969 }
 970
 971 static void free_ref(struct ref *ref)
 972 {
 973         if (!ref)
 974                 return;
 975         free_ref(ref->peer_ref);
 976         free(ref->remote_status);
 977         free(ref->symref);
 978         free(ref);
 979 }
 980
 981 void free_refs(struct ref *ref)
 982 {
 983         struct ref *next;
 984         while (ref) {
 985                 next = ref->next;
 986                 free_ref(ref);
 987                 ref = next;
 988         }
 989 }
 990
 991 int ref_compare_name(const void *va, const void *vb)
 992 {
 993         const struct ref *a = va, *b = vb;
 994         return strcmp(a->name, b->name);
 995 }
 996
 997 static void *ref_list_get_next(const void *a)
 998 {
 999         return ((const struct ref *)a)->next;
1000 }
1001
1002 static void ref_list_set_next(void *a, void *next)
1003 {
1004         ((struct ref *)a)->next = next;
1005 }
1006
1007 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1008 {
1009         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1010 }
1011
1012 int count_refspec_match(const char *pattern,
1013                         struct ref *refs,
1014                         struct ref **matched_ref)
1015 {
1016         int patlen = strlen(pattern);
1017         struct ref *matched_weak = NULL;
1018         struct ref *matched = NULL;
1019         int weak_match = 0;
1020         int match = 0;
1021
1022         for (weak_match = match = 0; refs; refs = refs->next) {
1023                 char *name = refs->name;
1024                 int namelen = strlen(name);
1025
1026                 if (!refname_match(pattern, name))
1027                         continue;
1028
1029                 /* A match is "weak" if it is with refs outside
1030                  * heads or tags, and did not specify the pattern
1031                  * in full (e.g. "refs/remotes/origin/master") or at
1032                  * least from the toplevel (e.g. "remotes/origin/master");
1033                  * otherwise "git push $URL master" would result in
1034                  * ambiguity between remotes/origin/master and heads/master
1035                  * at the remote site.
1036                  */
1037                 if (namelen != patlen &&
1038                     patlen != namelen - 5 &&
1039                     !starts_with(name, "refs/heads/") &&
1040                     !starts_with(name, "refs/tags/")) {
1041                         /* We want to catch the case where only weak
1042                          * matches are found and there are multiple
1043                          * matches, and where more than one strong
1044                          * matches are found, as ambiguous.  One
1045                          * strong match with zero or more weak matches
1046                          * are acceptable as a unique match.
1047                          */
1048                         matched_weak = refs;
1049                         weak_match++;
1050                 }
1051                 else {
1052                         matched = refs;
1053                         match++;
1054                 }
1055         }
1056         if (!matched) {
1057                 if (matched_ref)
1058                         *matched_ref = matched_weak;
1059                 return weak_match;
1060         }
1061         else {
1062                 if (matched_ref)
1063                         *matched_ref = matched;
1064                 return match;
1065         }
1066 }
1067
1068 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1069 {
1070         **tail = ref;
1071         while (ref->next)
1072                 ref = ref->next;
1073         *tail = &ref->next;
1074 }
1075
1076 static struct ref *alloc_delete_ref(void)
1077 {
1078         struct ref *ref = alloc_ref("(delete)");
1079         oidclr(&ref->new_oid);
1080         return ref;
1081 }
1082
1083 static int try_explicit_object_name(const char *name,
1084                                     struct ref **match)
1085 {
1086         struct object_id oid;
1087
1088         if (!*name) {
1089                 if (match)
1090                         *match = alloc_delete_ref();
1091                 return 0;
1092         }
1093
1094         if (get_sha1(name, oid.hash))
1095                 return -1;
1096
1097         if (match) {
1098                 *match = alloc_ref(name);
1099                 oidcpy(&(*match)->new_oid, &oid);
1100         }
1101         return 0;
1102 }
1103
1104 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1105 {
1106         struct ref *ret = alloc_ref(name);
1107         tail_link_ref(ret, tail);
1108         return ret;
1109 }
1110
1111 static char *guess_ref(const char *name, struct ref *peer)
1112 {
1113         struct strbuf buf = STRBUF_INIT;
1114         struct object_id oid;
1115
1116         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1117                                            oid.hash, NULL);
1118         if (!r)
1119                 return NULL;
1120
1121         if (starts_with(r, "refs/heads/"))
1122                 strbuf_addstr(&buf, "refs/heads/");
1123         else if (starts_with(r, "refs/tags/"))
1124                 strbuf_addstr(&buf, "refs/tags/");
1125         else
1126                 return NULL;
1127
1128         strbuf_addstr(&buf, name);
1129         return strbuf_detach(&buf, NULL);
1130 }
1131
1132 static int match_explicit_lhs(struct ref *src,
1133                               struct refspec *rs,
1134                               struct ref **match,
1135                               int *allocated_match)
1136 {
1137         switch (count_refspec_match(rs->src, src, match)) {
1138         case 1:
1139                 if (allocated_match)
1140                         *allocated_match = 0;
1141                 return 0;
1142         case 0:
1143                 /* The source could be in the get_sha1() format
1144                  * not a reference name.  :refs/other is a
1145                  * way to delete 'other' ref at the remote end.
1146                  */
1147                 if (try_explicit_object_name(rs->src, match) < 0)
1148                         return error("src refspec %s does not match any.", rs->src);
1149                 if (allocated_match)
1150                         *allocated_match = 1;
1151                 return 0;
1152         default:
1153                 return error("src refspec %s matches more than one.", rs->src);
1154         }
1155 }
1156
1157 static int match_explicit(struct ref *src, struct ref *dst,
1158                           struct ref ***dst_tail,
1159                           struct refspec *rs)
1160 {
1161         struct ref *matched_src, *matched_dst;
1162         int allocated_src = 0;
1163
1164         const char *dst_value = rs->dst;
1165         char *dst_guess;
1166
1167         if (rs->pattern || rs->matching)
1168                 return 0;
1169
1170         matched_src = matched_dst = NULL;
1171         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1172                 return -1;
1173
1174         if (!dst_value) {
1175                 struct object_id oid;
1176                 int flag;
1177
1178                 dst_value = resolve_ref_unsafe(matched_src->name,
1179                                                RESOLVE_REF_READING,
1180                                                oid.hash, &flag);
1181                 if (!dst_value ||
1182                     ((flag & REF_ISSYMREF) &&
1183                      !starts_with(dst_value, "refs/heads/")))
1184                         die("%s cannot be resolved to branch.",
1185                             matched_src->name);
1186         }
1187
1188         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1189         case 1:
1190                 break;
1191         case 0:
1192                 if (starts_with(dst_value, "refs/"))
1193                         matched_dst = make_linked_ref(dst_value, dst_tail);
1194                 else if (is_null_oid(&matched_src->new_oid))
1195                         error("unable to delete '%s': remote ref does not exist",
1196                               dst_value);
1197                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1198                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1199                 else
1200                         error("unable to push to unqualified destination: %s\n"
1201                               "The destination refspec neither matches an "
1202                               "existing ref on the remote nor\n"
1203                               "begins with refs/, and we are unable to "
1204                               "guess a prefix based on the source ref.",
1205                               dst_value);
1206                 break;
1207         default:
1208                 matched_dst = NULL;
1209                 error("dst refspec %s matches more than one.",
1210                       dst_value);
1211                 break;
1212         }
1213         if (!matched_dst)
1214                 return -1;
1215         if (matched_dst->peer_ref)
1216                 return error("dst ref %s receives from more than one src.",
1217                       matched_dst->name);
1218         else {
1219                 matched_dst->peer_ref = allocated_src ?
1220                                         matched_src :
1221                                         copy_ref(matched_src);
1222                 matched_dst->force = rs->force;
1223         }
1224         return 0;
1225 }
1226
1227 static int match_explicit_refs(struct ref *src, struct ref *dst,
1228                                struct ref ***dst_tail, struct refspec *rs,
1229                                int rs_nr)
1230 {
1231         int i, errs;
1232         for (i = errs = 0; i < rs_nr; i++)
1233                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1234         return errs;
1235 }
1236
1237 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1238                 int send_mirror, int direction, const struct refspec **ret_pat)
1239 {
1240         const struct refspec *pat;
1241         char *name;
1242         int i;
1243         int matching_refs = -1;
1244         for (i = 0; i < rs_nr; i++) {
1245                 if (rs[i].matching &&
1246                     (matching_refs == -1 || rs[i].force)) {
1247                         matching_refs = i;
1248                         continue;
1249                 }
1250
1251                 if (rs[i].pattern) {
1252                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1253                         int match;
1254                         if (direction == FROM_SRC)
1255                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1256                         else
1257                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1258                         if (match) {
1259                                 matching_refs = i;
1260                                 break;
1261                         }
1262                 }
1263         }
1264         if (matching_refs == -1)
1265                 return NULL;
1266
1267         pat = rs + matching_refs;
1268         if (pat->matching) {
1269                 /*
1270                  * "matching refs"; traditionally we pushed everything
1271                  * including refs outside refs/heads/ hierarchy, but
1272                  * that does not make much sense these days.
1273                  */
1274                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1275                         return NULL;
1276                 name = xstrdup(ref->name);
1277         }
1278         if (ret_pat)
1279                 *ret_pat = pat;
1280         return name;
1281 }
1282
1283 static struct ref **tail_ref(struct ref **head)
1284 {
1285         struct ref **tail = head;
1286         while (*tail)
1287                 tail = &((*tail)->next);
1288         return tail;
1289 }
1290
1291 struct tips {
1292         struct commit **tip;
1293         int nr, alloc;
1294 };
1295
1296 static void add_to_tips(struct tips *tips, const struct object_id *oid)
1297 {
1298         struct commit *commit;
1299
1300         if (is_null_oid(oid))
1301                 return;
1302         commit = lookup_commit_reference_gently(oid->hash, 1);
1303         if (!commit || (commit->object.flags & TMP_MARK))
1304                 return;
1305         commit->object.flags |= TMP_MARK;
1306         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1307         tips->tip[tips->nr++] = commit;
1308 }
1309
1310 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1311 {
1312         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1313         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1314         struct string_list_item *item;
1315         struct ref *ref;
1316         struct tips sent_tips;
1317
1318         /*
1319          * Collect everything we know they would have at the end of
1320          * this push, and collect all tags they have.
1321          */
1322         memset(&sent_tips, 0, sizeof(sent_tips));
1323         for (ref = *dst; ref; ref = ref->next) {
1324                 if (ref->peer_ref &&
1325                     !is_null_oid(&ref->peer_ref->new_oid))
1326                         add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1327                 else
1328                         add_to_tips(&sent_tips, &ref->old_oid);
1329                 if (starts_with(ref->name, "refs/tags/"))
1330                         string_list_append(&dst_tag, ref->name);
1331         }
1332         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1333
1334         string_list_sort(&dst_tag);
1335
1336         /* Collect tags they do not have. */
1337         for (ref = src; ref; ref = ref->next) {
1338                 if (!starts_with(ref->name, "refs/tags/"))
1339                         continue; /* not a tag */
1340                 if (string_list_has_string(&dst_tag, ref->name))
1341                         continue; /* they already have it */
1342                 if (sha1_object_info(ref->new_oid.hash, NULL) != OBJ_TAG)
1343                         continue; /* be conservative */
1344                 item = string_list_append(&src_tag, ref->name);
1345                 item->util = ref;
1346         }
1347         string_list_clear(&dst_tag, 0);
1348
1349         /*
1350          * At this point, src_tag lists tags that are missing from
1351          * dst, and sent_tips lists the tips we are pushing or those
1352          * that we know they already have. An element in the src_tag
1353          * that is an ancestor of any of the sent_tips needs to be
1354          * sent to the other side.
1355          */
1356         if (sent_tips.nr) {
1357                 for_each_string_list_item(item, &src_tag) {
1358                         struct ref *ref = item->util;
1359                         struct ref *dst_ref;
1360                         struct commit *commit;
1361
1362                         if (is_null_oid(&ref->new_oid))
1363                                 continue;
1364                         commit = lookup_commit_reference_gently(ref->new_oid.hash, 1);
1365                         if (!commit)
1366                                 /* not pushing a commit, which is not an error */
1367                                 continue;
1368
1369                         /*
1370                          * Is this tag, which they do not have, reachable from
1371                          * any of the commits we are sending?
1372                          */
1373                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1374                                 continue;
1375
1376                         /* Add it in */
1377                         dst_ref = make_linked_ref(ref->name, dst_tail);
1378                         oidcpy(&dst_ref->new_oid, &ref->new_oid);
1379                         dst_ref->peer_ref = copy_ref(ref);
1380                 }
1381         }
1382         string_list_clear(&src_tag, 0);
1383         free(sent_tips.tip);
1384 }
1385
1386 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1387 {
1388         for ( ; list; list = list->next)
1389                 if (!strcmp(list->name, name))
1390                         return (struct ref *)list;
1391         return NULL;
1392 }
1393
1394 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1395 {
1396         for ( ; ref; ref = ref->next)
1397                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1398
1399         string_list_sort(ref_index);
1400 }
1401
1402 /*
1403  * Given only the set of local refs, sanity-check the set of push
1404  * refspecs. We can't catch all errors that match_push_refs would,
1405  * but we can catch some errors early before even talking to the
1406  * remote side.
1407  */
1408 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1409 {
1410         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1411         int ret = 0;
1412         int i;
1413
1414         for (i = 0; i < nr_refspec; i++) {
1415                 struct refspec *rs = refspec + i;
1416
1417                 if (rs->pattern || rs->matching)
1418                         continue;
1419
1420                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1421         }
1422
1423         free_refspec(nr_refspec, refspec);
1424         return ret;
1425 }
1426
1427 /*
1428  * Given the set of refs the local repository has, the set of refs the
1429  * remote repository has, and the refspec used for push, determine
1430  * what remote refs we will update and with what value by setting
1431  * peer_ref (which object is being pushed) and force (if the push is
1432  * forced) in elements of "dst". The function may add new elements to
1433  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1434  */
1435 int match_push_refs(struct ref *src, struct ref **dst,
1436                     int nr_refspec, const char **refspec, int flags)
1437 {
1438         struct refspec *rs;
1439         int send_all = flags & MATCH_REFS_ALL;
1440         int send_mirror = flags & MATCH_REFS_MIRROR;
1441         int send_prune = flags & MATCH_REFS_PRUNE;
1442         int errs;
1443         static const char *default_refspec[] = { ":", NULL };
1444         struct ref *ref, **dst_tail = tail_ref(dst);
1445         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1446
1447         if (!nr_refspec) {
1448                 nr_refspec = 1;
1449                 refspec = default_refspec;
1450         }
1451         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1452         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1453
1454         /* pick the remainder */
1455         for (ref = src; ref; ref = ref->next) {
1456                 struct string_list_item *dst_item;
1457                 struct ref *dst_peer;
1458                 const struct refspec *pat = NULL;
1459                 char *dst_name;
1460
1461                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1462                 if (!dst_name)
1463                         continue;
1464
1465                 if (!dst_ref_index.nr)
1466                         prepare_ref_index(&dst_ref_index, *dst);
1467
1468                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1469                 dst_peer = dst_item ? dst_item->util : NULL;
1470                 if (dst_peer) {
1471                         if (dst_peer->peer_ref)
1472                                 /* We're already sending something to this ref. */
1473                                 goto free_name;
1474                 } else {
1475                         if (pat->matching && !(send_all || send_mirror))
1476                                 /*
1477                                  * Remote doesn't have it, and we have no
1478                                  * explicit pattern, and we don't have
1479                                  * --all or --mirror.
1480                                  */
1481                                 goto free_name;
1482
1483                         /* Create a new one and link it */
1484                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1485                         oidcpy(&dst_peer->new_oid, &ref->new_oid);
1486                         string_list_insert(&dst_ref_index,
1487                                 dst_peer->name)->util = dst_peer;
1488                 }
1489                 dst_peer->peer_ref = copy_ref(ref);
1490                 dst_peer->force = pat->force;
1491         free_name:
1492                 free(dst_name);
1493         }
1494
1495         string_list_clear(&dst_ref_index, 0);
1496
1497         if (flags & MATCH_REFS_FOLLOW_TAGS)
1498                 add_missing_tags(src, dst, &dst_tail);
1499
1500         if (send_prune) {
1501                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1502                 /* check for missing refs on the remote */
1503                 for (ref = *dst; ref; ref = ref->next) {
1504                         char *src_name;
1505
1506                         if (ref->peer_ref)
1507                                 /* We're already sending something to this ref. */
1508                                 continue;
1509
1510                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1511                         if (src_name) {
1512                                 if (!src_ref_index.nr)
1513                                         prepare_ref_index(&src_ref_index, src);
1514                                 if (!string_list_has_string(&src_ref_index,
1515                                             src_name))
1516                                         ref->peer_ref = alloc_delete_ref();
1517                                 free(src_name);
1518                         }
1519                 }
1520                 string_list_clear(&src_ref_index, 0);
1521         }
1522         if (errs)
1523                 return -1;
1524         return 0;
1525 }
1526
1527 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1528                              int force_update)
1529 {
1530         struct ref *ref;
1531
1532         for (ref = remote_refs; ref; ref = ref->next) {
1533                 int force_ref_update = ref->force || force_update;
1534                 int reject_reason = 0;
1535
1536                 if (ref->peer_ref)
1537                         oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1538                 else if (!send_mirror)
1539                         continue;
1540
1541                 ref->deletion = is_null_oid(&ref->new_oid);
1542                 if (!ref->deletion &&
1543                         !oidcmp(&ref->old_oid, &ref->new_oid)) {
1544                         ref->status = REF_STATUS_UPTODATE;
1545                         continue;
1546                 }
1547
1548                 /*
1549                  * Bypass the usual "must fast-forward" check but
1550                  * replace it with a weaker "the old value must be
1551                  * this value we observed".  If the remote ref has
1552                  * moved and is now different from what we expect,
1553                  * 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 (ref->expect_old_no_trackback ||
1562                             oidcmp(&ref->old_oid, &ref->old_oid_expect))
1563                                 reject_reason = REF_STATUS_REJECT_STALE;
1564                 }
1565
1566                 /*
1567                  * The usual "must fast-forward" rules.
1568                  *
1569                  * Decide whether an individual refspec A:B can be
1570                  * pushed.  The push will succeed if any of the
1571                  * following are true:
1572                  *
1573                  * (1) the remote reference B does not exist
1574                  *
1575                  * (2) the remote reference B is being removed (i.e.,
1576                  *     pushing :B where no source is specified)
1577                  *
1578                  * (3) the destination is not under refs/tags/, and
1579                  *     if the old and new value is a commit, the new
1580                  *     is a descendant of the old.
1581                  *
1582                  * (4) it is forced using the +A:B notation, or by
1583                  *     passing the --force argument
1584                  */
1585
1586                 else if (!ref->deletion && !is_null_oid(&ref->old_oid)) {
1587                         if (starts_with(ref->name, "refs/tags/"))
1588                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1589                         else if (!has_object_file(&ref->old_oid))
1590                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1591                         else if (!lookup_commit_reference_gently(ref->old_oid.hash, 1) ||
1592                                  !lookup_commit_reference_gently(ref->new_oid.hash, 1))
1593                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1594                         else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1595                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1596                 }
1597
1598                 /*
1599                  * "--force" will defeat any rejection implemented
1600                  * by the rules above.
1601                  */
1602                 if (!force_ref_update)
1603                         ref->status = reject_reason;
1604                 else if (reject_reason)
1605                         ref->forced_update = 1;
1606         }
1607 }
1608
1609 static void set_merge(struct branch *ret)
1610 {
1611         struct remote *remote;
1612         char *ref;
1613         struct object_id oid;
1614         int i;
1615
1616         if (!ret)
1617                 return; /* no branch */
1618         if (ret->merge)
1619                 return; /* already run */
1620         if (!ret->remote_name || !ret->merge_nr) {
1621                 /*
1622                  * no merge config; let's make sure we don't confuse callers
1623                  * with a non-zero merge_nr but a NULL merge
1624                  */
1625                 ret->merge_nr = 0;
1626                 return;
1627         }
1628
1629         remote = remote_get(ret->remote_name);
1630
1631         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1632         for (i = 0; i < ret->merge_nr; i++) {
1633                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1634                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1635                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1636                     strcmp(ret->remote_name, "."))
1637                         continue;
1638                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1639                              oid.hash, &ref) == 1)
1640                         ret->merge[i]->dst = ref;
1641                 else
1642                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1643         }
1644 }
1645
1646 struct branch *branch_get(const char *name)
1647 {
1648         struct branch *ret;
1649
1650         read_config();
1651         if (!name || !*name || !strcmp(name, "HEAD"))
1652                 ret = current_branch;
1653         else
1654                 ret = make_branch(name, 0);
1655         set_merge(ret);
1656         if (ret && ret->pushremote_name && ret->push_name) {
1657                 struct remote *pushremote;
1658                 pushremote = pushremote_get(ret->pushremote_name);
1659                 ret->push.src = xstrdup(ret->push_name);
1660                 if (remote_find_tracking(pushremote, &ret->push)
1661                     && !strcmp(ret->pushremote_name, "."))
1662                         ret->push.dst = xstrdup(ret->push_name);
1663         }
1664         return ret;
1665 }
1666
1667 int branch_has_merge_config(struct branch *branch)
1668 {
1669         return branch && !!branch->merge;
1670 }
1671
1672 int branch_merge_matches(struct branch *branch,
1673                                  int i,
1674                                  const char *refname)
1675 {
1676         if (!branch || i < 0 || i >= branch->merge_nr)
1677                 return 0;
1678         return refname_match(branch->merge[i]->src, refname);
1679 }
1680
1681 __attribute((format (printf,2,3)))
1682 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1683 {
1684         if (err) {
1685                 va_list ap;
1686                 va_start(ap, fmt);
1687                 strbuf_vaddf(err, fmt, ap);
1688                 va_end(ap);
1689         }
1690         return NULL;
1691 }
1692
1693 const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1694 {
1695         if (!branch)
1696                 return error_buf(err, _("HEAD does not point to a branch"));
1697
1698         if (!branch->merge || !branch->merge[0]) {
1699                 /*
1700                  * no merge config; is it because the user didn't define any,
1701                  * or because it is not a real branch, and get_branch
1702                  * auto-vivified it?
1703                  */
1704                 if (!ref_exists(branch->refname))
1705                         return error_buf(err, _("no such branch: '%s'"),
1706                                          branch->name);
1707                 return error_buf(err,
1708                                  _("no upstream configured for branch '%s'"),
1709                                  branch->name);
1710         }
1711
1712         if (!branch->merge[0]->dst)
1713                 return error_buf(err,
1714                                  _("upstream branch '%s' not stored as a remote-tracking branch"),
1715                                  branch->merge[0]->src);
1716
1717         return branch->merge[0]->dst;
1718 }
1719
1720 static const char *tracking_for_push_dest(struct remote *remote,
1721                                           const char *refname,
1722                                           struct strbuf *err)
1723 {
1724         char *ret;
1725
1726         ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1727         if (!ret)
1728                 return error_buf(err,
1729                                  _("push destination '%s' on remote '%s' has no local tracking branch"),
1730                                  refname, remote->name);
1731         return ret;
1732 }
1733
1734 static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1735 {
1736         struct remote *remote;
1737
1738         if (!branch)
1739                 return error_buf(err, _("HEAD does not point to a branch"));
1740
1741         remote = remote_get(pushremote_for_branch(branch, NULL));
1742         if (!remote)
1743                 return error_buf(err,
1744                                  _("branch '%s' has no remote for pushing"),
1745                                  branch->name);
1746
1747         if (remote->push_refspec_nr) {
1748                 char *dst;
1749                 const char *ret;
1750
1751                 dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1752                                      branch->refname);
1753                 if (!dst)
1754                         return error_buf(err,
1755                                          _("push refspecs for '%s' do not include '%s'"),
1756                                          remote->name, branch->name);
1757
1758                 ret = tracking_for_push_dest(remote, dst, err);
1759                 free(dst);
1760                 return ret;
1761         }
1762
1763         if (remote->mirror)
1764                 return tracking_for_push_dest(remote, branch->refname, err);
1765
1766         switch (push_default) {
1767         case PUSH_DEFAULT_NOTHING:
1768                 return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1769
1770         case PUSH_DEFAULT_MATCHING:
1771         case PUSH_DEFAULT_CURRENT:
1772                 return tracking_for_push_dest(remote, branch->refname, err);
1773
1774         case PUSH_DEFAULT_UPSTREAM:
1775                 return branch_get_upstream(branch, err);
1776
1777         case PUSH_DEFAULT_UNSPECIFIED:
1778         case PUSH_DEFAULT_SIMPLE:
1779                 {
1780                         const char *up, *cur;
1781
1782                         up = branch_get_upstream(branch, err);
1783                         if (!up)
1784                                 return NULL;
1785                         cur = tracking_for_push_dest(remote, branch->refname, err);
1786                         if (!cur)
1787                                 return NULL;
1788                         if (strcmp(cur, up))
1789                                 return error_buf(err,
1790                                                  _("cannot resolve 'simple' push to a single destination"));
1791                         return cur;
1792                 }
1793         }
1794
1795         die("BUG: unhandled push situation");
1796 }
1797
1798 const char *branch_get_push(struct branch *branch, struct strbuf *err)
1799 {
1800         if (!branch->push_tracking_ref)
1801                 branch->push_tracking_ref = branch_get_push_1(branch, err);
1802         return branch->push_tracking_ref;
1803 }
1804
1805 const char *branch_get_publish(struct branch *branch, struct strbuf *err)
1806 {
1807         if (!branch)
1808                 return error_buf(err, _("HEAD does not point to a branch"));
1809         if (!branch->push.dst)
1810                 return error_buf(err, _("No publish configured for branch '%s'"), branch->name);
1811         return branch->push.dst;
1812 }
1813
1814 static int ignore_symref_update(const char *refname)
1815 {
1816         struct object_id oid;
1817         int flag;
1818
1819         if (!resolve_ref_unsafe(refname, 0, oid.hash, &flag))
1820                 return 0; /* non-existing refs are OK */
1821         return (flag & REF_ISSYMREF);
1822 }
1823
1824 /*
1825  * Create and return a list of (struct ref) consisting of copies of
1826  * each remote_ref that matches refspec.  refspec must be a pattern.
1827  * Fill in the copies' peer_ref to describe the local tracking refs to
1828  * which they map.  Omit any references that would map to an existing
1829  * local symbolic ref.
1830  */
1831 static struct ref *get_expanded_map(const struct ref *remote_refs,
1832                                     const struct refspec *refspec)
1833 {
1834         const struct ref *ref;
1835         struct ref *ret = NULL;
1836         struct ref **tail = &ret;
1837
1838         for (ref = remote_refs; ref; ref = ref->next) {
1839                 char *expn_name = NULL;
1840
1841                 if (strchr(ref->name, '^'))
1842                         continue; /* a dereference item */
1843                 if (match_name_with_pattern(refspec->src, ref->name,
1844                                             refspec->dst, &expn_name) &&
1845                     !ignore_symref_update(expn_name)) {
1846                         struct ref *cpy = copy_ref(ref);
1847
1848                         cpy->peer_ref = alloc_ref(expn_name);
1849                         if (refspec->force)
1850                                 cpy->peer_ref->force = 1;
1851                         *tail = cpy;
1852                         tail = &cpy->next;
1853                 }
1854                 free(expn_name);
1855         }
1856
1857         return ret;
1858 }
1859
1860 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1861 {
1862         const struct ref *ref;
1863         for (ref = refs; ref; ref = ref->next) {
1864                 if (refname_match(name, ref->name))
1865                         return ref;
1866         }
1867         return NULL;
1868 }
1869
1870 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1871 {
1872         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1873
1874         if (!ref)
1875                 return NULL;
1876
1877         return copy_ref(ref);
1878 }
1879
1880 static struct ref *get_local_ref(const char *name)
1881 {
1882         if (!name || name[0] == '\0')
1883                 return NULL;
1884
1885         if (starts_with(name, "refs/"))
1886                 return alloc_ref(name);
1887
1888         if (starts_with(name, "heads/") ||
1889             starts_with(name, "tags/") ||
1890             starts_with(name, "remotes/"))
1891                 return alloc_ref_with_prefix("refs/", 5, name);
1892
1893         return alloc_ref_with_prefix("refs/heads/", 11, name);
1894 }
1895
1896 int get_fetch_map(const struct ref *remote_refs,
1897                   const struct refspec *refspec,
1898                   struct ref ***tail,
1899                   int missing_ok)
1900 {
1901         struct ref *ref_map, **rmp;
1902
1903         if (refspec->pattern) {
1904                 ref_map = get_expanded_map(remote_refs, refspec);
1905         } else {
1906                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1907
1908                 if (refspec->exact_sha1) {
1909                         ref_map = alloc_ref(name);
1910                         get_oid_hex(name, &ref_map->old_oid);
1911                 } else {
1912                         ref_map = get_remote_ref(remote_refs, name);
1913                 }
1914                 if (!missing_ok && !ref_map)
1915                         die("Couldn't find remote ref %s", name);
1916                 if (ref_map) {
1917                         ref_map->peer_ref = get_local_ref(refspec->dst);
1918                         if (ref_map->peer_ref && refspec->force)
1919                                 ref_map->peer_ref->force = 1;
1920                 }
1921         }
1922
1923         for (rmp = &ref_map; *rmp; ) {
1924                 if ((*rmp)->peer_ref) {
1925                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1926                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1927                                 struct ref *ignore = *rmp;
1928                                 error("* Ignoring funny ref '%s' locally",
1929                                       (*rmp)->peer_ref->name);
1930                                 *rmp = (*rmp)->next;
1931                                 free(ignore->peer_ref);
1932                                 free(ignore);
1933                                 continue;
1934                         }
1935                 }
1936                 rmp = &((*rmp)->next);
1937         }
1938
1939         if (ref_map)
1940                 tail_link_ref(ref_map, tail);
1941
1942         return 0;
1943 }
1944
1945 int resolve_remote_symref(struct ref *ref, struct ref *list)
1946 {
1947         if (!ref->symref)
1948                 return 0;
1949         for (; list; list = list->next)
1950                 if (!strcmp(ref->symref, list->name)) {
1951                         oidcpy(&ref->old_oid, &list->old_oid);
1952                         return 0;
1953                 }
1954         return 1;
1955 }
1956
1957 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1958 {
1959         while (list) {
1960                 struct commit *commit = pop_commit(&list);
1961                 commit->object.flags &= ~mark;
1962         }
1963 }
1964
1965 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1966 {
1967         struct object *o;
1968         struct commit *old, *new;
1969         struct commit_list *list, *used;
1970         int found = 0;
1971
1972         /*
1973          * Both new and old must be commit-ish and new is descendant of
1974          * old.  Otherwise we require --force.
1975          */
1976         o = deref_tag(parse_object(old_oid->hash), NULL, 0);
1977         if (!o || o->type != OBJ_COMMIT)
1978                 return 0;
1979         old = (struct commit *) o;
1980
1981         o = deref_tag(parse_object(new_oid->hash), NULL, 0);
1982         if (!o || o->type != OBJ_COMMIT)
1983                 return 0;
1984         new = (struct commit *) o;
1985
1986         if (parse_commit(new) < 0)
1987                 return 0;
1988
1989         used = list = NULL;
1990         commit_list_insert(new, &list);
1991         while (list) {
1992                 new = pop_most_recent_commit(&list, TMP_MARK);
1993                 commit_list_insert(new, &used);
1994                 if (new == old) {
1995                         found = 1;
1996                         break;
1997                 }
1998         }
1999         unmark_and_free(list, TMP_MARK);
2000         unmark_and_free(used, TMP_MARK);
2001         return found;
2002 }
2003
2004 /*
2005  * Compare a branch with its upstream, and save their differences (number
2006  * of commits) in *num_ours and *num_theirs. The name of the upstream branch
2007  * (or NULL if no upstream is defined) is returned via *upstream_name, if it
2008  * is not itself NULL.
2009  *
2010  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
2011  * upstream defined, or ref does not exist), 0 otherwise.
2012  */
2013 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
2014                        const char **upstream_name)
2015 {
2016         struct object_id oid;
2017         struct commit *ours, *theirs;
2018         struct rev_info revs;
2019         const char *base;
2020         struct argv_array argv = ARGV_ARRAY_INIT;
2021
2022         /* Cannot stat unless we are marked to build on top of somebody else. */
2023         base = branch_get_upstream(branch, NULL);
2024         if (upstream_name)
2025                 *upstream_name = base;
2026         if (!base)
2027                 return -1;
2028
2029         /* Cannot stat if what we used to build on no longer exists */
2030         if (read_ref(base, oid.hash))
2031                 return -1;
2032         theirs = lookup_commit_reference(oid.hash);
2033         if (!theirs)
2034                 return -1;
2035
2036         if (read_ref(branch->refname, oid.hash))
2037                 return -1;
2038         ours = lookup_commit_reference(oid.hash);
2039         if (!ours)
2040                 return -1;
2041
2042         /* are we the same? */
2043         if (theirs == ours) {
2044                 *num_theirs = *num_ours = 0;
2045                 return 0;
2046         }
2047
2048         /* Run "rev-list --left-right ours...theirs" internally... */
2049         argv_array_push(&argv, ""); /* ignored */
2050         argv_array_push(&argv, "--left-right");
2051         argv_array_pushf(&argv, "%s...%s",
2052                          oid_to_hex(&ours->object.oid),
2053                          oid_to_hex(&theirs->object.oid));
2054         argv_array_push(&argv, "--");
2055
2056         init_revisions(&revs, NULL);
2057         setup_revisions(argv.argc, argv.argv, &revs, NULL);
2058         if (prepare_revision_walk(&revs))
2059                 die("revision walk setup failed");
2060
2061         /* ... and count the commits on each side. */
2062         *num_ours = 0;
2063         *num_theirs = 0;
2064         while (1) {
2065                 struct commit *c = get_revision(&revs);
2066                 if (!c)
2067                         break;
2068                 if (c->object.flags & SYMMETRIC_LEFT)
2069                         (*num_ours)++;
2070                 else
2071                         (*num_theirs)++;
2072         }
2073
2074         /* clear object flags smudged by the above traversal */
2075         clear_commit_marks(ours, ALL_REV_FLAGS);
2076         clear_commit_marks(theirs, ALL_REV_FLAGS);
2077
2078         argv_array_clear(&argv);
2079         return 0;
2080 }
2081
2082 /*
2083  * Return true when there is anything to report, otherwise false.
2084  */
2085 int format_tracking_info(struct branch *branch, struct strbuf *sb)
2086 {
2087         int ours, theirs;
2088         const char *full_base;
2089         char *base;
2090         int upstream_is_gone = 0;
2091
2092         if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2093                 if (!full_base)
2094                         return 0;
2095                 upstream_is_gone = 1;
2096         }
2097
2098         base = shorten_unambiguous_ref(full_base, 0);
2099         if (upstream_is_gone) {
2100                 strbuf_addf(sb,
2101                         _("Your branch is based on '%s', but the upstream is gone.\n"),
2102                         base);
2103                 if (advice_status_hints)
2104                         strbuf_addf(sb,
2105                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2106         } else if (!ours && !theirs) {
2107                 strbuf_addf(sb,
2108                         _("Your branch is up-to-date with '%s'.\n"),
2109                         base);
2110         } else if (!theirs) {
2111                 strbuf_addf(sb,
2112                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2113                            "Your branch is ahead of '%s' by %d commits.\n",
2114                            ours),
2115                         base, ours);
2116                 if (advice_status_hints && !branch->push.dst)
2117                         strbuf_addf(sb,
2118                                 _("  (use \"git push\" to publish your local commits)\n"));
2119         } else if (!ours) {
2120                 strbuf_addf(sb,
2121                         Q_("Your branch is behind '%s' by %d commit, "
2122                                "and can be fast-forwarded.\n",
2123                            "Your branch is behind '%s' by %d commits, "
2124                                "and can be fast-forwarded.\n",
2125                            theirs),
2126                         base, theirs);
2127                 if (advice_status_hints)
2128                         strbuf_addf(sb,
2129                                 _("  (use \"git pull\" to update your local branch)\n"));
2130         } else {
2131                 strbuf_addf(sb,
2132                         Q_("Your branch and '%s' have diverged,\n"
2133                                "and have %d and %d different commit each, "
2134                                "respectively.\n",
2135                            "Your branch and '%s' have diverged,\n"
2136                                "and have %d and %d different commits each, "
2137                                "respectively.\n",
2138                            theirs),
2139                         base, ours, theirs);
2140                 if (advice_status_hints)
2141                         strbuf_addf(sb,
2142                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2143         }
2144         if (branch->push.dst) {
2145                 unsigned char local_sha1[20];
2146                 unsigned char remote_sha1[20];
2147                 const char *pub;
2148
2149                 pub = shorten_unambiguous_ref(branch->push.dst, 0);
2150
2151                 /* Is it published? */
2152                 if (!read_ref(branch->refname, local_sha1) &&
2153                                 !read_ref(branch->push.dst, remote_sha1)) {
2154                         if (hashcmp(local_sha1, remote_sha1)) {
2155                                 strbuf_addf(sb, _("Some commits haven't been published to '%s'.\n"), pub);
2156                                 if (advice_status_hints)
2157                                         strbuf_addf(sb, _("  (use \"git push\" to publish your local commits)\n"));
2158                         }
2159                 }
2160         }
2161         free(base);
2162         return 1;
2163 }
2164
2165 static int one_local_ref(const char *refname, const struct object_id *oid,
2166                          int flag, void *cb_data)
2167 {
2168         struct ref ***local_tail = cb_data;
2169         struct ref *ref;
2170         int len;
2171
2172         /* we already know it starts with refs/ to get here */
2173         if (check_refname_format(refname + 5, 0))
2174                 return 0;
2175
2176         len = strlen(refname) + 1;
2177         ref = xcalloc(1, sizeof(*ref) + len);
2178         oidcpy(&ref->new_oid, oid);
2179         memcpy(ref->name, refname, len);
2180         **local_tail = ref;
2181         *local_tail = &ref->next;
2182         return 0;
2183 }
2184
2185 struct ref *get_local_heads(void)
2186 {
2187         struct ref *local_refs = NULL, **local_tail = &local_refs;
2188
2189         for_each_ref(one_local_ref, &local_tail);
2190         return local_refs;
2191 }
2192
2193 struct ref *guess_remote_head(const struct ref *head,
2194                               const struct ref *refs,
2195                               int all)
2196 {
2197         const struct ref *r;
2198         struct ref *list = NULL;
2199         struct ref **tail = &list;
2200
2201         if (!head)
2202                 return NULL;
2203
2204         /*
2205          * Some transports support directly peeking at
2206          * where HEAD points; if that is the case, then
2207          * we don't have to guess.
2208          */
2209         if (head->symref)
2210                 return copy_ref(find_ref_by_name(refs, head->symref));
2211
2212         /* If refs/heads/master could be right, it is. */
2213         if (!all) {
2214                 r = find_ref_by_name(refs, "refs/heads/master");
2215                 if (r && !oidcmp(&r->old_oid, &head->old_oid))
2216                         return copy_ref(r);
2217         }
2218
2219         /* Look for another ref that points there */
2220         for (r = refs; r; r = r->next) {
2221                 if (r != head &&
2222                     starts_with(r->name, "refs/heads/") &&
2223                     !oidcmp(&r->old_oid, &head->old_oid)) {
2224                         *tail = copy_ref(r);
2225                         tail = &((*tail)->next);
2226                         if (!all)
2227                                 break;
2228                 }
2229         }
2230
2231         return list;
2232 }
2233
2234 struct stale_heads_info {
2235         struct string_list *ref_names;
2236         struct ref **stale_refs_tail;
2237         struct refspec *refs;
2238         int ref_count;
2239 };
2240
2241 static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2242                               int flags, void *cb_data)
2243 {
2244         struct stale_heads_info *info = cb_data;
2245         struct string_list matches = STRING_LIST_INIT_DUP;
2246         struct refspec query;
2247         int i, stale = 1;
2248         memset(&query, 0, sizeof(struct refspec));
2249         query.dst = (char *)refname;
2250
2251         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2252         if (matches.nr == 0)
2253                 goto clean_exit; /* No matches */
2254
2255         /*
2256          * If we did find a suitable refspec and it's not a symref and
2257          * it's not in the list of refs that currently exist in that
2258          * remote, we consider it to be stale. In order to deal with
2259          * overlapping refspecs, we need to go over all of the
2260          * matching refs.
2261          */
2262         if (flags & REF_ISSYMREF)
2263                 goto clean_exit;
2264
2265         for (i = 0; stale && i < matches.nr; i++)
2266                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2267                         stale = 0;
2268
2269         if (stale) {
2270                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2271                 oidcpy(&ref->new_oid, oid);
2272         }
2273
2274 clean_exit:
2275         string_list_clear(&matches, 0);
2276         return 0;
2277 }
2278
2279 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2280 {
2281         struct ref *ref, *stale_refs = NULL;
2282         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2283         struct stale_heads_info info;
2284
2285         info.ref_names = &ref_names;
2286         info.stale_refs_tail = &stale_refs;
2287         info.refs = refs;
2288         info.ref_count = ref_count;
2289         for (ref = fetch_map; ref; ref = ref->next)
2290                 string_list_append(&ref_names, ref->name);
2291         string_list_sort(&ref_names);
2292         for_each_ref(get_stale_heads_cb, &info);
2293         string_list_clear(&ref_names, 0);
2294         return stale_refs;
2295 }
2296
2297 /*
2298  * Compare-and-swap
2299  */
2300 static void clear_cas_option(struct push_cas_option *cas)
2301 {
2302         int i;
2303
2304         for (i = 0; i < cas->nr; i++)
2305                 free(cas->entry[i].refname);
2306         free(cas->entry);
2307         memset(cas, 0, sizeof(*cas));
2308 }
2309
2310 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2311                                       const char *refname,
2312                                       size_t refnamelen)
2313 {
2314         struct push_cas *entry;
2315         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2316         entry = &cas->entry[cas->nr++];
2317         memset(entry, 0, sizeof(*entry));
2318         entry->refname = xmemdupz(refname, refnamelen);
2319         return entry;
2320 }
2321
2322 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2323 {
2324         const char *colon;
2325         struct push_cas *entry;
2326
2327         if (unset) {
2328                 /* "--no-<option>" */
2329                 clear_cas_option(cas);
2330                 return 0;
2331         }
2332
2333         if (!arg) {
2334                 /* just "--<option>" */
2335                 cas->use_tracking_for_rest = 1;
2336                 return 0;
2337         }
2338
2339         /* "--<option>=refname" or "--<option>=refname:value" */
2340         colon = strchrnul(arg, ':');
2341         entry = add_cas_entry(cas, arg, colon - arg);
2342         if (!*colon)
2343                 entry->use_tracking = 1;
2344         else if (get_sha1(colon + 1, entry->expect))
2345                 return error("cannot parse expected object name '%s'", colon + 1);
2346         return 0;
2347 }
2348
2349 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2350 {
2351         return parse_push_cas_option(opt->value, arg, unset);
2352 }
2353
2354 int is_empty_cas(const struct push_cas_option *cas)
2355 {
2356         return !cas->use_tracking_for_rest && !cas->nr;
2357 }
2358
2359 /*
2360  * Look at remote.fetch refspec and see if we have a remote
2361  * tracking branch for the refname there.  Fill its current
2362  * value in sha1[].
2363  * If we cannot do so, return negative to signal an error.
2364  */
2365 static int remote_tracking(struct remote *remote, const char *refname,
2366                            struct object_id *oid)
2367 {
2368         char *dst;
2369
2370         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2371         if (!dst)
2372                 return -1; /* no tracking ref for refname at remote */
2373         if (read_ref(dst, oid->hash))
2374                 return -1; /* we know what the tracking ref is but we cannot read it */
2375         return 0;
2376 }
2377
2378 static void apply_cas(struct push_cas_option *cas,
2379                       struct remote *remote,
2380                       struct ref *ref)
2381 {
2382         int i;
2383
2384         /* Find an explicit --<option>=<name>[:<value>] entry */
2385         for (i = 0; i < cas->nr; i++) {
2386                 struct push_cas *entry = &cas->entry[i];
2387                 if (!refname_match(entry->refname, ref->name))
2388                         continue;
2389                 ref->expect_old_sha1 = 1;
2390                 if (!entry->use_tracking)
2391                         hashcpy(ref->old_oid_expect.hash, cas->entry[i].expect);
2392                 else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2393                         ref->expect_old_no_trackback = 1;
2394                 return;
2395         }
2396
2397         /* Are we using "--<option>" to cover all? */
2398         if (!cas->use_tracking_for_rest)
2399                 return;
2400
2401         ref->expect_old_sha1 = 1;
2402         if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2403                 ref->expect_old_no_trackback = 1;
2404 }
2405
2406 void apply_push_cas(struct push_cas_option *cas,
2407                     struct remote *remote,
2408                     struct ref *remote_refs)
2409 {
2410         struct ref *ref;
2411         for (ref = remote_refs; ref; ref = ref->next)
2412                 apply_cas(cas, remote, ref);
2413 }