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

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