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 static struct remote *remote_get_1(const char *name, const char *pushremote_name)
 696 {
 697         struct remote *ret;
 698         int name_given = 0;
 699
 700         if (name)
 701                 name_given = 1;
 702         else {
 703                 if (pushremote_name) {
 704                         name = pushremote_name;
 705                         name_given = 1;
 706                 } else {
 707                         if (current_branch && current_branch->remote_name) {
 708                                 name = current_branch->remote_name;
 709                                 name_given = 1;
 710                         } else
 711                                 name = "origin";
 712                 }
 713         }
 714
 715         ret = make_remote(name, 0);
 716         if (valid_remote_nick(name)) {
 717                 if (!valid_remote(ret))
 718                         read_remotes_file(ret);
 719                 if (!valid_remote(ret))
 720                         read_branches_file(ret);
 721         }
 722         if (name_given && !valid_remote(ret))
 723                 add_url_alias(ret, name);
 724         if (!valid_remote(ret))
 725                 return NULL;
 726         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 727         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 728         return ret;
 729 }
 730
 731 struct remote *remote_get(const char *name)
 732 {
 733         read_config();
 734         return remote_get_1(name, NULL);
 735 }
 736
 737 struct remote *pushremote_get(const char *name)
 738 {
 739         read_config();
 740         return remote_get_1(name, pushremote_name);
 741 }
 742
 743 int remote_is_configured(const char *name)
 744 {
 745         struct remotes_hash_key lookup;
 746         struct hashmap_entry lookup_entry;
 747         read_config();
 748
 749         init_remotes_hash();
 750         lookup.str = name;
 751         lookup.len = strlen(name);
 752         hashmap_entry_init(&lookup_entry, memhash(name, lookup.len));
 753
 754         return hashmap_get(&remotes_hash, &lookup_entry, &lookup) != NULL;
 755 }
 756
 757 int for_each_remote(each_remote_fn fn, void *priv)
 758 {
 759         int i, result = 0;
 760         read_config();
 761         for (i = 0; i < remotes_nr && !result; i++) {
 762                 struct remote *r = remotes[i];
 763                 if (!r)
 764                         continue;
 765                 if (!r->fetch)
 766                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 767                                                        r->fetch_refspec);
 768                 if (!r->push)
 769                         r->push = parse_push_refspec(r->push_refspec_nr,
 770                                                      r->push_refspec);
 771                 result = fn(r, priv);
 772         }
 773         return result;
 774 }
 775
 776 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 777 {
 778         if (strcmp(ref1->name, ref2->name)) {
 779                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 780                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 781                         die(_("Cannot fetch both %s and %s to %s"),
 782                             ref1->name, ref2->name, ref2->peer_ref->name);
 783                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 784                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 785                         warning(_("%s usually tracks %s, not %s"),
 786                                 ref2->peer_ref->name, ref2->name, ref1->name);
 787                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 788                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 789                         die(_("%s tracks both %s and %s"),
 790                             ref2->peer_ref->name, ref1->name, ref2->name);
 791                 } else {
 792                         /*
 793                          * This last possibility doesn't occur because
 794                          * FETCH_HEAD_IGNORE entries always appear at
 795                          * the end of the list.
 796                          */
 797                         die(_("Internal error"));
 798                 }
 799         }
 800         free(ref2->peer_ref);
 801         free(ref2);
 802 }
 803
 804 struct ref *ref_remove_duplicates(struct ref *ref_map)
 805 {
 806         struct string_list refs = STRING_LIST_INIT_NODUP;
 807         struct ref *retval = NULL;
 808         struct ref **p = &retval;
 809
 810         while (ref_map) {
 811                 struct ref *ref = ref_map;
 812
 813                 ref_map = ref_map->next;
 814                 ref->next = NULL;
 815
 816                 if (!ref->peer_ref) {
 817                         *p = ref;
 818                         p = &ref->next;
 819                 } else {
 820                         struct string_list_item *item =
 821                                 string_list_insert(&refs, ref->peer_ref->name);
 822
 823                         if (item->util) {
 824                                 /* Entry already existed */
 825                                 handle_duplicate((struct ref *)item->util, ref);
 826                         } else {
 827                                 *p = ref;
 828                                 p = &ref->next;
 829                                 item->util = ref;
 830                         }
 831                 }
 832         }
 833
 834         string_list_clear(&refs, 0);
 835         return retval;
 836 }
 837
 838 int remote_has_url(struct remote *remote, const char *url)
 839 {
 840         int i;
 841         for (i = 0; i < remote->url_nr; i++) {
 842                 if (!strcmp(remote->url[i], url))
 843                         return 1;
 844         }
 845         return 0;
 846 }
 847
 848 static int match_name_with_pattern(const char *key, const char *name,
 849                                    const char *value, char **result)
 850 {
 851         const char *kstar = strchr(key, '*');
 852         size_t klen;
 853         size_t ksuffixlen;
 854         size_t namelen;
 855         int ret;
 856         if (!kstar)
 857                 die("Key '%s' of pattern had no '*'", key);
 858         klen = kstar - key;
 859         ksuffixlen = strlen(kstar + 1);
 860         namelen = strlen(name);
 861         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 862                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 863         if (ret && value) {
 864                 struct strbuf sb = STRBUF_INIT;
 865                 const char *vstar = strchr(value, '*');
 866                 if (!vstar)
 867                         die("Value '%s' of pattern has no '*'", value);
 868                 strbuf_add(&sb, value, vstar - value);
 869                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 870                 strbuf_addstr(&sb, vstar + 1);
 871                 *result = strbuf_detach(&sb, NULL);
 872         }
 873         return ret;
 874 }
 875
 876 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 877 {
 878         int i;
 879         int find_src = !query->src;
 880
 881         if (find_src && !query->dst)
 882                 error("query_refspecs_multiple: need either src or dst");
 883
 884         for (i = 0; i < ref_count; i++) {
 885                 struct refspec *refspec = &refs[i];
 886                 const char *key = find_src ? refspec->dst : refspec->src;
 887                 const char *value = find_src ? refspec->src : refspec->dst;
 888                 const char *needle = find_src ? query->dst : query->src;
 889                 char **result = find_src ? &query->src : &query->dst;
 890
 891                 if (!refspec->dst)
 892                         continue;
 893                 if (refspec->pattern) {
 894                         if (match_name_with_pattern(key, needle, value, result))
 895                                 string_list_append_nodup(results, *result);
 896                 } else if (!strcmp(needle, key)) {
 897                         string_list_append(results, value);
 898                 }
 899         }
 900 }
 901
 902 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 903 {
 904         int i;
 905         int find_src = !query->src;
 906         const char *needle = find_src ? query->dst : query->src;
 907         char **result = find_src ? &query->src : &query->dst;
 908
 909         if (find_src && !query->dst)
 910                 return error("query_refspecs: need either src or dst");
 911
 912         for (i = 0; i < ref_count; i++) {
 913                 struct refspec *refspec = &refs[i];
 914                 const char *key = find_src ? refspec->dst : refspec->src;
 915                 const char *value = find_src ? refspec->src : refspec->dst;
 916
 917                 if (!refspec->dst)
 918                         continue;
 919                 if (refspec->pattern) {
 920                         if (match_name_with_pattern(key, needle, value, result)) {
 921                                 query->force = refspec->force;
 922                                 return 0;
 923                         }
 924                 } else if (!strcmp(needle, key)) {
 925                         *result = xstrdup(value);
 926                         query->force = refspec->force;
 927                         return 0;
 928                 }
 929         }
 930         return -1;
 931 }
 932
 933 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 934                      const char *name)
 935 {
 936         struct refspec query;
 937
 938         memset(&query, 0, sizeof(struct refspec));
 939         query.src = (char *)name;
 940
 941         if (query_refspecs(refspecs, nr_refspec, &query))
 942                 return NULL;
 943
 944         return query.dst;
 945 }
 946
 947 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 948 {
 949         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 950 }
 951
 952 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 953                 const char *name)
 954 {
 955         size_t len = strlen(name);
 956         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 957         memcpy(ref->name, prefix, prefixlen);
 958         memcpy(ref->name + prefixlen, name, len);
 959         return ref;
 960 }
 961
 962 struct ref *alloc_ref(const char *name)
 963 {
 964         return alloc_ref_with_prefix("", 0, name);
 965 }
 966
 967 struct ref *copy_ref(const struct ref *ref)
 968 {
 969         struct ref *cpy;
 970         size_t len;
 971         if (!ref)
 972                 return NULL;
 973         len = strlen(ref->name);
 974         cpy = xmalloc(sizeof(struct ref) + len + 1);
 975         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 976         cpy->next = NULL;
 977         cpy->symref = xstrdup_or_null(ref->symref);
 978         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 979         cpy->peer_ref = copy_ref(ref->peer_ref);
 980         return cpy;
 981 }
 982
 983 struct ref *copy_ref_list(const struct ref *ref)
 984 {
 985         struct ref *ret = NULL;
 986         struct ref **tail = &ret;
 987         while (ref) {
 988                 *tail = copy_ref(ref);
 989                 ref = ref->next;
 990                 tail = &((*tail)->next);
 991         }
 992         return ret;
 993 }
 994
 995 static void free_ref(struct ref *ref)
 996 {
 997         if (!ref)
 998                 return;
 999         free_ref(ref->peer_ref);
1000         free(ref->remote_status);
1001         free(ref->symref);
1002         free(ref);
1003 }
1004
1005 void free_refs(struct ref *ref)
1006 {
1007         struct ref *next;
1008         while (ref) {
1009                 next = ref->next;
1010                 free_ref(ref);
1011                 ref = next;
1012         }
1013 }
1014
1015 int ref_compare_name(const void *va, const void *vb)
1016 {
1017         const struct ref *a = va, *b = vb;
1018         return strcmp(a->name, b->name);
1019 }
1020
1021 static void *ref_list_get_next(const void *a)
1022 {
1023         return ((const struct ref *)a)->next;
1024 }
1025
1026 static void ref_list_set_next(void *a, void *next)
1027 {
1028         ((struct ref *)a)->next = next;
1029 }
1030
1031 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1032 {
1033         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1034 }
1035
1036 int count_refspec_match(const char *pattern,
1037                         struct ref *refs,
1038                         struct ref **matched_ref)
1039 {
1040         int patlen = strlen(pattern);
1041         struct ref *matched_weak = NULL;
1042         struct ref *matched = NULL;
1043         int weak_match = 0;
1044         int match = 0;
1045
1046         for (weak_match = match = 0; refs; refs = refs->next) {
1047                 char *name = refs->name;
1048                 int namelen = strlen(name);
1049
1050                 if (!refname_match(pattern, name))
1051                         continue;
1052
1053                 /* A match is "weak" if it is with refs outside
1054                  * heads or tags, and did not specify the pattern
1055                  * in full (e.g. "refs/remotes/origin/master") or at
1056                  * least from the toplevel (e.g. "remotes/origin/master");
1057                  * otherwise "git push $URL master" would result in
1058                  * ambiguity between remotes/origin/master and heads/master
1059                  * at the remote site.
1060                  */
1061                 if (namelen != patlen &&
1062                     patlen != namelen - 5 &&
1063                     !starts_with(name, "refs/heads/") &&
1064                     !starts_with(name, "refs/tags/")) {
1065                         /* We want to catch the case where only weak
1066                          * matches are found and there are multiple
1067                          * matches, and where more than one strong
1068                          * matches are found, as ambiguous.  One
1069                          * strong match with zero or more weak matches
1070                          * are acceptable as a unique match.
1071                          */
1072                         matched_weak = refs;
1073                         weak_match++;
1074                 }
1075                 else {
1076                         matched = refs;
1077                         match++;
1078                 }
1079         }
1080         if (!matched) {
1081                 if (matched_ref)
1082                         *matched_ref = matched_weak;
1083                 return weak_match;
1084         }
1085         else {
1086                 if (matched_ref)
1087                         *matched_ref = matched;
1088                 return match;
1089         }
1090 }
1091
1092 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1093 {
1094         **tail = ref;
1095         while (ref->next)
1096                 ref = ref->next;
1097         *tail = &ref->next;
1098 }
1099
1100 static struct ref *alloc_delete_ref(void)
1101 {
1102         struct ref *ref = alloc_ref("(delete)");
1103         hashclr(ref->new_sha1);
1104         return ref;
1105 }
1106
1107 static int try_explicit_object_name(const char *name,
1108                                     struct ref **match)
1109 {
1110         unsigned char sha1[20];
1111
1112         if (!*name) {
1113                 if (match)
1114                         *match = alloc_delete_ref();
1115                 return 0;
1116         }
1117
1118         if (get_sha1(name, sha1))
1119                 return -1;
1120
1121         if (match) {
1122                 *match = alloc_ref(name);
1123                 hashcpy((*match)->new_sha1, sha1);
1124         }
1125         return 0;
1126 }
1127
1128 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1129 {
1130         struct ref *ret = alloc_ref(name);
1131         tail_link_ref(ret, tail);
1132         return ret;
1133 }
1134
1135 static char *guess_ref(const char *name, struct ref *peer)
1136 {
1137         struct strbuf buf = STRBUF_INIT;
1138         unsigned char sha1[20];
1139
1140         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1141                                            sha1, NULL);
1142         if (!r)
1143                 return NULL;
1144
1145         if (starts_with(r, "refs/heads/"))
1146                 strbuf_addstr(&buf, "refs/heads/");
1147         else if (starts_with(r, "refs/tags/"))
1148                 strbuf_addstr(&buf, "refs/tags/");
1149         else
1150                 return NULL;
1151
1152         strbuf_addstr(&buf, name);
1153         return strbuf_detach(&buf, NULL);
1154 }
1155
1156 static int match_explicit_lhs(struct ref *src,
1157                               struct refspec *rs,
1158                               struct ref **match,
1159                               int *allocated_match)
1160 {
1161         switch (count_refspec_match(rs->src, src, match)) {
1162         case 1:
1163                 if (allocated_match)
1164                         *allocated_match = 0;
1165                 return 0;
1166         case 0:
1167                 /* The source could be in the get_sha1() format
1168                  * not a reference name.  :refs/other is a
1169                  * way to delete 'other' ref at the remote end.
1170                  */
1171                 if (try_explicit_object_name(rs->src, match) < 0)
1172                         return error("src refspec %s does not match any.", rs->src);
1173                 if (allocated_match)
1174                         *allocated_match = 1;
1175                 return 0;
1176         default:
1177                 return error("src refspec %s matches more than one.", rs->src);
1178         }
1179 }
1180
1181 static int match_explicit(struct ref *src, struct ref *dst,
1182                           struct ref ***dst_tail,
1183                           struct refspec *rs)
1184 {
1185         struct ref *matched_src, *matched_dst;
1186         int allocated_src;
1187
1188         const char *dst_value = rs->dst;
1189         char *dst_guess;
1190
1191         if (rs->pattern || rs->matching)
1192                 return 0;
1193
1194         matched_src = matched_dst = NULL;
1195         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1196                 return -1;
1197
1198         if (!dst_value) {
1199                 unsigned char sha1[20];
1200                 int flag;
1201
1202                 dst_value = resolve_ref_unsafe(matched_src->name,
1203                                                RESOLVE_REF_READING,
1204                                                sha1, &flag);
1205                 if (!dst_value ||
1206                     ((flag & REF_ISSYMREF) &&
1207                      !starts_with(dst_value, "refs/heads/")))
1208                         die("%s cannot be resolved to branch.",
1209                             matched_src->name);
1210         }
1211
1212         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1213         case 1:
1214                 break;
1215         case 0:
1216                 if (starts_with(dst_value, "refs/"))
1217                         matched_dst = make_linked_ref(dst_value, dst_tail);
1218                 else if (is_null_sha1(matched_src->new_sha1))
1219                         error("unable to delete '%s': remote ref does not exist",
1220                               dst_value);
1221                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1222                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1223                 else
1224                         error("unable to push to unqualified destination: %s\n"
1225                               "The destination refspec neither matches an "
1226                               "existing ref on the remote nor\n"
1227                               "begins with refs/, and we are unable to "
1228                               "guess a prefix based on the source ref.",
1229                               dst_value);
1230                 break;
1231         default:
1232                 matched_dst = NULL;
1233                 error("dst refspec %s matches more than one.",
1234                       dst_value);
1235                 break;
1236         }
1237         if (!matched_dst)
1238                 return -1;
1239         if (matched_dst->peer_ref)
1240                 return error("dst ref %s receives from more than one src.",
1241                       matched_dst->name);
1242         else {
1243                 matched_dst->peer_ref = allocated_src ?
1244                                         matched_src :
1245                                         copy_ref(matched_src);
1246                 matched_dst->force = rs->force;
1247         }
1248         return 0;
1249 }
1250
1251 static int match_explicit_refs(struct ref *src, struct ref *dst,
1252                                struct ref ***dst_tail, struct refspec *rs,
1253                                int rs_nr)
1254 {
1255         int i, errs;
1256         for (i = errs = 0; i < rs_nr; i++)
1257                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1258         return errs;
1259 }
1260
1261 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1262                 int send_mirror, int direction, const struct refspec **ret_pat)
1263 {
1264         const struct refspec *pat;
1265         char *name;
1266         int i;
1267         int matching_refs = -1;
1268         for (i = 0; i < rs_nr; i++) {
1269                 if (rs[i].matching &&
1270                     (matching_refs == -1 || rs[i].force)) {
1271                         matching_refs = i;
1272                         continue;
1273                 }
1274
1275                 if (rs[i].pattern) {
1276                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1277                         int match;
1278                         if (direction == FROM_SRC)
1279                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1280                         else
1281                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1282                         if (match) {
1283                                 matching_refs = i;
1284                                 break;
1285                         }
1286                 }
1287         }
1288         if (matching_refs == -1)
1289                 return NULL;
1290
1291         pat = rs + matching_refs;
1292         if (pat->matching) {
1293                 /*
1294                  * "matching refs"; traditionally we pushed everything
1295                  * including refs outside refs/heads/ hierarchy, but
1296                  * that does not make much sense these days.
1297                  */
1298                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1299                         return NULL;
1300                 name = xstrdup(ref->name);
1301         }
1302         if (ret_pat)
1303                 *ret_pat = pat;
1304         return name;
1305 }
1306
1307 static struct ref **tail_ref(struct ref **head)
1308 {
1309         struct ref **tail = head;
1310         while (*tail)
1311                 tail = &((*tail)->next);
1312         return tail;
1313 }
1314
1315 struct tips {
1316         struct commit **tip;
1317         int nr, alloc;
1318 };
1319
1320 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1321 {
1322         struct commit *commit;
1323
1324         if (is_null_sha1(sha1))
1325                 return;
1326         commit = lookup_commit_reference_gently(sha1, 1);
1327         if (!commit || (commit->object.flags & TMP_MARK))
1328                 return;
1329         commit->object.flags |= TMP_MARK;
1330         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1331         tips->tip[tips->nr++] = commit;
1332 }
1333
1334 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1335 {
1336         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1337         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1338         struct string_list_item *item;
1339         struct ref *ref;
1340         struct tips sent_tips;
1341
1342         /*
1343          * Collect everything we know they would have at the end of
1344          * this push, and collect all tags they have.
1345          */
1346         memset(&sent_tips, 0, sizeof(sent_tips));
1347         for (ref = *dst; ref; ref = ref->next) {
1348                 if (ref->peer_ref &&
1349                     !is_null_sha1(ref->peer_ref->new_sha1))
1350                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1351                 else
1352                         add_to_tips(&sent_tips, ref->old_sha1);
1353                 if (starts_with(ref->name, "refs/tags/"))
1354                         string_list_append(&dst_tag, ref->name);
1355         }
1356         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1357
1358         string_list_sort(&dst_tag);
1359
1360         /* Collect tags they do not have. */
1361         for (ref = src; ref; ref = ref->next) {
1362                 if (!starts_with(ref->name, "refs/tags/"))
1363                         continue; /* not a tag */
1364                 if (string_list_has_string(&dst_tag, ref->name))
1365                         continue; /* they already have it */
1366                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1367                         continue; /* be conservative */
1368                 item = string_list_append(&src_tag, ref->name);
1369                 item->util = ref;
1370         }
1371         string_list_clear(&dst_tag, 0);
1372
1373         /*
1374          * At this point, src_tag lists tags that are missing from
1375          * dst, and sent_tips lists the tips we are pushing or those
1376          * that we know they already have. An element in the src_tag
1377          * that is an ancestor of any of the sent_tips needs to be
1378          * sent to the other side.
1379          */
1380         if (sent_tips.nr) {
1381                 for_each_string_list_item(item, &src_tag) {
1382                         struct ref *ref = item->util;
1383                         struct ref *dst_ref;
1384                         struct commit *commit;
1385
1386                         if (is_null_sha1(ref->new_sha1))
1387                                 continue;
1388                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1389                         if (!commit)
1390                                 /* not pushing a commit, which is not an error */
1391                                 continue;
1392
1393                         /*
1394                          * Is this tag, which they do not have, reachable from
1395                          * any of the commits we are sending?
1396                          */
1397                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1398                                 continue;
1399
1400                         /* Add it in */
1401                         dst_ref = make_linked_ref(ref->name, dst_tail);
1402                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1403                         dst_ref->peer_ref = copy_ref(ref);
1404                 }
1405         }
1406         string_list_clear(&src_tag, 0);
1407         free(sent_tips.tip);
1408 }
1409
1410 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1411 {
1412         for ( ; list; list = list->next)
1413                 if (!strcmp(list->name, name))
1414                         return (struct ref *)list;
1415         return NULL;
1416 }
1417
1418 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1419 {
1420         for ( ; ref; ref = ref->next)
1421                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1422
1423         string_list_sort(ref_index);
1424 }
1425
1426 /*
1427  * Given only the set of local refs, sanity-check the set of push
1428  * refspecs. We can't catch all errors that match_push_refs would,
1429  * but we can catch some errors early before even talking to the
1430  * remote side.
1431  */
1432 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1433 {
1434         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1435         int ret = 0;
1436         int i;
1437
1438         for (i = 0; i < nr_refspec; i++) {
1439                 struct refspec *rs = refspec + i;
1440
1441                 if (rs->pattern || rs->matching)
1442                         continue;
1443
1444                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1445         }
1446
1447         free_refspec(nr_refspec, refspec);
1448         return ret;
1449 }
1450
1451 /*
1452  * Given the set of refs the local repository has, the set of refs the
1453  * remote repository has, and the refspec used for push, determine
1454  * what remote refs we will update and with what value by setting
1455  * peer_ref (which object is being pushed) and force (if the push is
1456  * forced) in elements of "dst". The function may add new elements to
1457  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1458  */
1459 int match_push_refs(struct ref *src, struct ref **dst,
1460                     int nr_refspec, const char **refspec, int flags)
1461 {
1462         struct refspec *rs;
1463         int send_all = flags & MATCH_REFS_ALL;
1464         int send_mirror = flags & MATCH_REFS_MIRROR;
1465         int send_prune = flags & MATCH_REFS_PRUNE;
1466         int errs;
1467         static const char *default_refspec[] = { ":", NULL };
1468         struct ref *ref, **dst_tail = tail_ref(dst);
1469         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1470
1471         if (!nr_refspec) {
1472                 nr_refspec = 1;
1473                 refspec = default_refspec;
1474         }
1475         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1476         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1477
1478         /* pick the remainder */
1479         for (ref = src; ref; ref = ref->next) {
1480                 struct string_list_item *dst_item;
1481                 struct ref *dst_peer;
1482                 const struct refspec *pat = NULL;
1483                 char *dst_name;
1484
1485                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1486                 if (!dst_name)
1487                         continue;
1488
1489                 if (!dst_ref_index.nr)
1490                         prepare_ref_index(&dst_ref_index, *dst);
1491
1492                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1493                 dst_peer = dst_item ? dst_item->util : NULL;
1494                 if (dst_peer) {
1495                         if (dst_peer->peer_ref)
1496                                 /* We're already sending something to this ref. */
1497                                 goto free_name;
1498                 } else {
1499                         if (pat->matching && !(send_all || send_mirror))
1500                                 /*
1501                                  * Remote doesn't have it, and we have no
1502                                  * explicit pattern, and we don't have
1503                                  * --all or --mirror.
1504                                  */
1505                                 goto free_name;
1506
1507                         /* Create a new one and link it */
1508                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1509                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1510                         string_list_insert(&dst_ref_index,
1511                                 dst_peer->name)->util = dst_peer;
1512                 }
1513                 dst_peer->peer_ref = copy_ref(ref);
1514                 dst_peer->force = pat->force;
1515         free_name:
1516                 free(dst_name);
1517         }
1518
1519         string_list_clear(&dst_ref_index, 0);
1520
1521         if (flags & MATCH_REFS_FOLLOW_TAGS)
1522                 add_missing_tags(src, dst, &dst_tail);
1523
1524         if (send_prune) {
1525                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1526                 /* check for missing refs on the remote */
1527                 for (ref = *dst; ref; ref = ref->next) {
1528                         char *src_name;
1529
1530                         if (ref->peer_ref)
1531                                 /* We're already sending something to this ref. */
1532                                 continue;
1533
1534                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1535                         if (src_name) {
1536                                 if (!src_ref_index.nr)
1537                                         prepare_ref_index(&src_ref_index, src);
1538                                 if (!string_list_has_string(&src_ref_index,
1539                                             src_name))
1540                                         ref->peer_ref = alloc_delete_ref();
1541                                 free(src_name);
1542                         }
1543                 }
1544                 string_list_clear(&src_ref_index, 0);
1545         }
1546         if (errs)
1547                 return -1;
1548         return 0;
1549 }
1550
1551 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1552                              int force_update)
1553 {
1554         struct ref *ref;
1555
1556         for (ref = remote_refs; ref; ref = ref->next) {
1557                 int force_ref_update = ref->force || force_update;
1558                 int reject_reason = 0;
1559
1560                 if (ref->peer_ref)
1561                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1562                 else if (!send_mirror)
1563                         continue;
1564
1565                 ref->deletion = is_null_sha1(ref->new_sha1);
1566                 if (!ref->deletion &&
1567                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1568                         ref->status = REF_STATUS_UPTODATE;
1569                         continue;
1570                 }
1571
1572                 /*
1573                  * Bypass the usual "must fast-forward" check but
1574                  * replace it with a weaker "the old value must be
1575                  * this value we observed".  If the remote ref has
1576                  * moved and is now different from what we expect,
1577                  * reject any push.
1578                  *
1579                  * It also is an error if the user told us to check
1580                  * with the remote-tracking branch to find the value
1581                  * to expect, but we did not have such a tracking
1582                  * branch.
1583                  */
1584                 if (ref->expect_old_sha1) {
1585                         if (ref->expect_old_no_trackback ||
1586                             hashcmp(ref->old_sha1, ref->old_sha1_expect))
1587                                 reject_reason = REF_STATUS_REJECT_STALE;
1588                 }
1589
1590                 /*
1591                  * The usual "must fast-forward" rules.
1592                  *
1593                  * Decide whether an individual refspec A:B can be
1594                  * pushed.  The push will succeed if any of the
1595                  * following are true:
1596                  *
1597                  * (1) the remote reference B does not exist
1598                  *
1599                  * (2) the remote reference B is being removed (i.e.,
1600                  *     pushing :B where no source is specified)
1601                  *
1602                  * (3) the destination is not under refs/tags/, and
1603                  *     if the old and new value is a commit, the new
1604                  *     is a descendant of the old.
1605                  *
1606                  * (4) it is forced using the +A:B notation, or by
1607                  *     passing the --force argument
1608                  */
1609
1610                 else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1611                         if (starts_with(ref->name, "refs/tags/"))
1612                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1613                         else if (!has_sha1_file(ref->old_sha1))
1614                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1615                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1616                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1617                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1618                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1619                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1620                 }
1621
1622                 /*
1623                  * "--force" will defeat any rejection implemented
1624                  * by the rules above.
1625                  */
1626                 if (!force_ref_update)
1627                         ref->status = reject_reason;
1628                 else if (reject_reason)
1629                         ref->forced_update = 1;
1630         }
1631 }
1632
1633 static void set_merge(struct branch *ret)
1634 {
1635         char *ref;
1636         unsigned char sha1[20];
1637         int i;
1638
1639         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1640         for (i = 0; i < ret->merge_nr; i++) {
1641                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1642                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1643                 if (!remote_find_tracking(ret->remote, ret->merge[i]) ||
1644                     strcmp(ret->remote_name, "."))
1645                         continue;
1646                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1647                              sha1, &ref) == 1)
1648                         ret->merge[i]->dst = ref;
1649                 else
1650                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1651         }
1652 }
1653
1654 struct branch *branch_get(const char *name)
1655 {
1656         struct branch *ret;
1657
1658         read_config();
1659         if (!name || !*name || !strcmp(name, "HEAD"))
1660                 ret = current_branch;
1661         else
1662                 ret = make_branch(name, 0);
1663         if (ret && ret->remote_name) {
1664                 ret->remote = remote_get(ret->remote_name);
1665                 if (ret->merge_nr)
1666                         set_merge(ret);
1667         }
1668         return ret;
1669 }
1670
1671 int branch_has_merge_config(struct branch *branch)
1672 {
1673         return branch && !!branch->merge;
1674 }
1675
1676 int branch_merge_matches(struct branch *branch,
1677                                  int i,
1678                                  const char *refname)
1679 {
1680         if (!branch || i < 0 || i >= branch->merge_nr)
1681                 return 0;
1682         return refname_match(branch->merge[i]->src, refname);
1683 }
1684
1685 static int ignore_symref_update(const char *refname)
1686 {
1687         unsigned char sha1[20];
1688         int flag;
1689
1690         if (!resolve_ref_unsafe(refname, 0, sha1, &flag))
1691                 return 0; /* non-existing refs are OK */
1692         return (flag & REF_ISSYMREF);
1693 }
1694
1695 /*
1696  * Create and return a list of (struct ref) consisting of copies of
1697  * each remote_ref that matches refspec.  refspec must be a pattern.
1698  * Fill in the copies' peer_ref to describe the local tracking refs to
1699  * which they map.  Omit any references that would map to an existing
1700  * local symbolic ref.
1701  */
1702 static struct ref *get_expanded_map(const struct ref *remote_refs,
1703                                     const struct refspec *refspec)
1704 {
1705         const struct ref *ref;
1706         struct ref *ret = NULL;
1707         struct ref **tail = &ret;
1708
1709         for (ref = remote_refs; ref; ref = ref->next) {
1710                 char *expn_name = NULL;
1711
1712                 if (strchr(ref->name, '^'))
1713                         continue; /* a dereference item */
1714                 if (match_name_with_pattern(refspec->src, ref->name,
1715                                             refspec->dst, &expn_name) &&
1716                     !ignore_symref_update(expn_name)) {
1717                         struct ref *cpy = copy_ref(ref);
1718
1719                         cpy->peer_ref = alloc_ref(expn_name);
1720                         if (refspec->force)
1721                                 cpy->peer_ref->force = 1;
1722                         *tail = cpy;
1723                         tail = &cpy->next;
1724                 }
1725                 free(expn_name);
1726         }
1727
1728         return ret;
1729 }
1730
1731 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1732 {
1733         const struct ref *ref;
1734         for (ref = refs; ref; ref = ref->next) {
1735                 if (refname_match(name, ref->name))
1736                         return ref;
1737         }
1738         return NULL;
1739 }
1740
1741 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1742 {
1743         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1744
1745         if (!ref)
1746                 return NULL;
1747
1748         return copy_ref(ref);
1749 }
1750
1751 static struct ref *get_local_ref(const char *name)
1752 {
1753         if (!name || name[0] == '\0')
1754                 return NULL;
1755
1756         if (starts_with(name, "refs/"))
1757                 return alloc_ref(name);
1758
1759         if (starts_with(name, "heads/") ||
1760             starts_with(name, "tags/") ||
1761             starts_with(name, "remotes/"))
1762                 return alloc_ref_with_prefix("refs/", 5, name);
1763
1764         return alloc_ref_with_prefix("refs/heads/", 11, name);
1765 }
1766
1767 int get_fetch_map(const struct ref *remote_refs,
1768                   const struct refspec *refspec,
1769                   struct ref ***tail,
1770                   int missing_ok)
1771 {
1772         struct ref *ref_map, **rmp;
1773
1774         if (refspec->pattern) {
1775                 ref_map = get_expanded_map(remote_refs, refspec);
1776         } else {
1777                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1778
1779                 if (refspec->exact_sha1) {
1780                         ref_map = alloc_ref(name);
1781                         get_sha1_hex(name, ref_map->old_sha1);
1782                 } else {
1783                         ref_map = get_remote_ref(remote_refs, name);
1784                 }
1785                 if (!missing_ok && !ref_map)
1786                         die("Couldn't find remote ref %s", name);
1787                 if (ref_map) {
1788                         ref_map->peer_ref = get_local_ref(refspec->dst);
1789                         if (ref_map->peer_ref && refspec->force)
1790                                 ref_map->peer_ref->force = 1;
1791                 }
1792         }
1793
1794         for (rmp = &ref_map; *rmp; ) {
1795                 if ((*rmp)->peer_ref) {
1796                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1797                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1798                                 struct ref *ignore = *rmp;
1799                                 error("* Ignoring funny ref '%s' locally",
1800                                       (*rmp)->peer_ref->name);
1801                                 *rmp = (*rmp)->next;
1802                                 free(ignore->peer_ref);
1803                                 free(ignore);
1804                                 continue;
1805                         }
1806                 }
1807                 rmp = &((*rmp)->next);
1808         }
1809
1810         if (ref_map)
1811                 tail_link_ref(ref_map, tail);
1812
1813         return 0;
1814 }
1815
1816 int resolve_remote_symref(struct ref *ref, struct ref *list)
1817 {
1818         if (!ref->symref)
1819                 return 0;
1820         for (; list; list = list->next)
1821                 if (!strcmp(ref->symref, list->name)) {
1822                         hashcpy(ref->old_sha1, list->old_sha1);
1823                         return 0;
1824                 }
1825         return 1;
1826 }
1827
1828 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1829 {
1830         while (list) {
1831                 struct commit_list *temp = list;
1832                 temp->item->object.flags &= ~mark;
1833                 list = temp->next;
1834                 free(temp);
1835         }
1836 }
1837
1838 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1839 {
1840         struct object *o;
1841         struct commit *old, *new;
1842         struct commit_list *list, *used;
1843         int found = 0;
1844
1845         /*
1846          * Both new and old must be commit-ish and new is descendant of
1847          * old.  Otherwise we require --force.
1848          */
1849         o = deref_tag(parse_object(old_sha1), NULL, 0);
1850         if (!o || o->type != OBJ_COMMIT)
1851                 return 0;
1852         old = (struct commit *) o;
1853
1854         o = deref_tag(parse_object(new_sha1), NULL, 0);
1855         if (!o || o->type != OBJ_COMMIT)
1856                 return 0;
1857         new = (struct commit *) o;
1858
1859         if (parse_commit(new) < 0)
1860                 return 0;
1861
1862         used = list = NULL;
1863         commit_list_insert(new, &list);
1864         while (list) {
1865                 new = pop_most_recent_commit(&list, TMP_MARK);
1866                 commit_list_insert(new, &used);
1867                 if (new == old) {
1868                         found = 1;
1869                         break;
1870                 }
1871         }
1872         unmark_and_free(list, TMP_MARK);
1873         unmark_and_free(used, TMP_MARK);
1874         return found;
1875 }
1876
1877 /*
1878  * Compare a branch with its upstream, and save their differences (number
1879  * of commits) in *num_ours and *num_theirs.
1880  *
1881  * Return 0 if branch has no upstream (no base), -1 if upstream is missing
1882  * (with "gone" base), otherwise 1 (with base).
1883  */
1884 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1885 {
1886         unsigned char sha1[20];
1887         struct commit *ours, *theirs;
1888         char symmetric[84];
1889         struct rev_info revs;
1890         const char *rev_argv[10], *base;
1891         int rev_argc;
1892
1893         /* Cannot stat unless we are marked to build on top of somebody else. */
1894         if (!branch ||
1895             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1896                 return 0;
1897
1898         /* Cannot stat if what we used to build on no longer exists */
1899         base = branch->merge[0]->dst;
1900         if (read_ref(base, sha1))
1901                 return -1;
1902         theirs = lookup_commit_reference(sha1);
1903         if (!theirs)
1904                 return -1;
1905
1906         if (read_ref(branch->refname, sha1))
1907                 return -1;
1908         ours = lookup_commit_reference(sha1);
1909         if (!ours)
1910                 return -1;
1911
1912         /* are we the same? */
1913         if (theirs == ours) {
1914                 *num_theirs = *num_ours = 0;
1915                 return 1;
1916         }
1917
1918         /* Run "rev-list --left-right ours...theirs" internally... */
1919         rev_argc = 0;
1920         rev_argv[rev_argc++] = NULL;
1921         rev_argv[rev_argc++] = "--left-right";
1922         rev_argv[rev_argc++] = symmetric;
1923         rev_argv[rev_argc++] = "--";
1924         rev_argv[rev_argc] = NULL;
1925
1926         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1927         strcpy(symmetric + 40, "...");
1928         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1929
1930         init_revisions(&revs, NULL);
1931         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1932         if (prepare_revision_walk(&revs))
1933                 die("revision walk setup failed");
1934
1935         /* ... and count the commits on each side. */
1936         *num_ours = 0;
1937         *num_theirs = 0;
1938         while (1) {
1939                 struct commit *c = get_revision(&revs);
1940                 if (!c)
1941                         break;
1942                 if (c->object.flags & SYMMETRIC_LEFT)
1943                         (*num_ours)++;
1944                 else
1945                         (*num_theirs)++;
1946         }
1947
1948         /* clear object flags smudged by the above traversal */
1949         clear_commit_marks(ours, ALL_REV_FLAGS);
1950         clear_commit_marks(theirs, ALL_REV_FLAGS);
1951         return 1;
1952 }
1953
1954 /*
1955  * Return true when there is anything to report, otherwise false.
1956  */
1957 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1958 {
1959         int ours, theirs;
1960         char *base;
1961         int upstream_is_gone = 0;
1962
1963         switch (stat_tracking_info(branch, &ours, &theirs)) {
1964         case 0:
1965                 /* no base */
1966                 return 0;
1967         case -1:
1968                 /* with "gone" base */
1969                 upstream_is_gone = 1;
1970                 break;
1971         default:
1972                 /* with base */
1973                 break;
1974         }
1975
1976         base = shorten_unambiguous_ref(branch->merge[0]->dst, 0);
1977         if (upstream_is_gone) {
1978                 strbuf_addf(sb,
1979                         _("Your branch is based on '%s', but the upstream is gone.\n"),
1980                         base);
1981                 if (advice_status_hints)
1982                         strbuf_addf(sb,
1983                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1984         } else if (!ours && !theirs) {
1985                 strbuf_addf(sb,
1986                         _("Your branch is up-to-date with '%s'.\n"),
1987                         base);
1988         } else if (!theirs) {
1989                 strbuf_addf(sb,
1990                         Q_("Your branch is ahead of '%s' by %d commit.\n",
1991                            "Your branch is ahead of '%s' by %d commits.\n",
1992                            ours),
1993                         base, ours);
1994                 if (advice_status_hints)
1995                         strbuf_addf(sb,
1996                                 _("  (use \"git push\" to publish your local commits)\n"));
1997         } else if (!ours) {
1998                 strbuf_addf(sb,
1999                         Q_("Your branch is behind '%s' by %d commit, "
2000                                "and can be fast-forwarded.\n",
2001                            "Your branch is behind '%s' by %d commits, "
2002                                "and can be fast-forwarded.\n",
2003                            theirs),
2004                         base, theirs);
2005                 if (advice_status_hints)
2006                         strbuf_addf(sb,
2007                                 _("  (use \"git pull\" to update your local branch)\n"));
2008         } else {
2009                 strbuf_addf(sb,
2010                         Q_("Your branch and '%s' have diverged,\n"
2011                                "and have %d and %d different commit each, "
2012                                "respectively.\n",
2013                            "Your branch and '%s' have diverged,\n"
2014                                "and have %d and %d different commits each, "
2015                                "respectively.\n",
2016                            theirs),
2017                         base, ours, theirs);
2018                 if (advice_status_hints)
2019                         strbuf_addf(sb,
2020                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2021         }
2022         free(base);
2023         return 1;
2024 }
2025
2026 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
2027 {
2028         struct ref ***local_tail = cb_data;
2029         struct ref *ref;
2030         int len;
2031
2032         /* we already know it starts with refs/ to get here */
2033         if (check_refname_format(refname + 5, 0))
2034                 return 0;
2035
2036         len = strlen(refname) + 1;
2037         ref = xcalloc(1, sizeof(*ref) + len);
2038         hashcpy(ref->new_sha1, sha1);
2039         memcpy(ref->name, refname, len);
2040         **local_tail = ref;
2041         *local_tail = &ref->next;
2042         return 0;
2043 }
2044
2045 struct ref *get_local_heads(void)
2046 {
2047         struct ref *local_refs = NULL, **local_tail = &local_refs;
2048         for_each_ref(one_local_ref, &local_tail);
2049         return local_refs;
2050 }
2051
2052 struct ref *guess_remote_head(const struct ref *head,
2053                               const struct ref *refs,
2054                               int all)
2055 {
2056         const struct ref *r;
2057         struct ref *list = NULL;
2058         struct ref **tail = &list;
2059
2060         if (!head)
2061                 return NULL;
2062
2063         /*
2064          * Some transports support directly peeking at
2065          * where HEAD points; if that is the case, then
2066          * we don't have to guess.
2067          */
2068         if (head->symref)
2069                 return copy_ref(find_ref_by_name(refs, head->symref));
2070
2071         /* If refs/heads/master could be right, it is. */
2072         if (!all) {
2073                 r = find_ref_by_name(refs, "refs/heads/master");
2074                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
2075                         return copy_ref(r);
2076         }
2077
2078         /* Look for another ref that points there */
2079         for (r = refs; r; r = r->next) {
2080                 if (r != head &&
2081                     starts_with(r->name, "refs/heads/") &&
2082                     !hashcmp(r->old_sha1, head->old_sha1)) {
2083                         *tail = copy_ref(r);
2084                         tail = &((*tail)->next);
2085                         if (!all)
2086                                 break;
2087                 }
2088         }
2089
2090         return list;
2091 }
2092
2093 struct stale_heads_info {
2094         struct string_list *ref_names;
2095         struct ref **stale_refs_tail;
2096         struct refspec *refs;
2097         int ref_count;
2098 };
2099
2100 static int get_stale_heads_cb(const char *refname,
2101         const unsigned char *sha1, int flags, void *cb_data)
2102 {
2103         struct stale_heads_info *info = cb_data;
2104         struct string_list matches = STRING_LIST_INIT_DUP;
2105         struct refspec query;
2106         int i, stale = 1;
2107         memset(&query, 0, sizeof(struct refspec));
2108         query.dst = (char *)refname;
2109
2110         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2111         if (matches.nr == 0)
2112                 goto clean_exit; /* No matches */
2113
2114         /*
2115          * If we did find a suitable refspec and it's not a symref and
2116          * it's not in the list of refs that currently exist in that
2117          * remote, we consider it to be stale. In order to deal with
2118          * overlapping refspecs, we need to go over all of the
2119          * matching refs.
2120          */
2121         if (flags & REF_ISSYMREF)
2122                 goto clean_exit;
2123
2124         for (i = 0; stale && i < matches.nr; i++)
2125                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2126                         stale = 0;
2127
2128         if (stale) {
2129                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2130                 hashcpy(ref->new_sha1, sha1);
2131         }
2132
2133 clean_exit:
2134         string_list_clear(&matches, 0);
2135         return 0;
2136 }
2137
2138 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2139 {
2140         struct ref *ref, *stale_refs = NULL;
2141         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2142         struct stale_heads_info info;
2143         info.ref_names = &ref_names;
2144         info.stale_refs_tail = &stale_refs;
2145         info.refs = refs;
2146         info.ref_count = ref_count;
2147         for (ref = fetch_map; ref; ref = ref->next)
2148                 string_list_append(&ref_names, ref->name);
2149         string_list_sort(&ref_names);
2150         for_each_ref(get_stale_heads_cb, &info);
2151         string_list_clear(&ref_names, 0);
2152         return stale_refs;
2153 }
2154
2155 /*
2156  * Compare-and-swap
2157  */
2158 static void clear_cas_option(struct push_cas_option *cas)
2159 {
2160         int i;
2161
2162         for (i = 0; i < cas->nr; i++)
2163                 free(cas->entry[i].refname);
2164         free(cas->entry);
2165         memset(cas, 0, sizeof(*cas));
2166 }
2167
2168 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2169                                       const char *refname,
2170                                       size_t refnamelen)
2171 {
2172         struct push_cas *entry;
2173         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2174         entry = &cas->entry[cas->nr++];
2175         memset(entry, 0, sizeof(*entry));
2176         entry->refname = xmemdupz(refname, refnamelen);
2177         return entry;
2178 }
2179
2180 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2181 {
2182         const char *colon;
2183         struct push_cas *entry;
2184
2185         if (unset) {
2186                 /* "--no-<option>" */
2187                 clear_cas_option(cas);
2188                 return 0;
2189         }
2190
2191         if (!arg) {
2192                 /* just "--<option>" */
2193                 cas->use_tracking_for_rest = 1;
2194                 return 0;
2195         }
2196
2197         /* "--<option>=refname" or "--<option>=refname:value" */
2198         colon = strchrnul(arg, ':');
2199         entry = add_cas_entry(cas, arg, colon - arg);
2200         if (!*colon)
2201                 entry->use_tracking = 1;
2202         else if (get_sha1(colon + 1, entry->expect))
2203                 return error("cannot parse expected object name '%s'", colon + 1);
2204         return 0;
2205 }
2206
2207 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2208 {
2209         return parse_push_cas_option(opt->value, arg, unset);
2210 }
2211
2212 int is_empty_cas(const struct push_cas_option *cas)
2213 {
2214         return !cas->use_tracking_for_rest && !cas->nr;
2215 }
2216
2217 /*
2218  * Look at remote.fetch refspec and see if we have a remote
2219  * tracking branch for the refname there.  Fill its current
2220  * value in sha1[].
2221  * If we cannot do so, return negative to signal an error.
2222  */
2223 static int remote_tracking(struct remote *remote, const char *refname,
2224                            unsigned char sha1[20])
2225 {
2226         char *dst;
2227
2228         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2229         if (!dst)
2230                 return -1; /* no tracking ref for refname at remote */
2231         if (read_ref(dst, sha1))
2232                 return -1; /* we know what the tracking ref is but we cannot read it */
2233         return 0;
2234 }
2235
2236 static void apply_cas(struct push_cas_option *cas,
2237                       struct remote *remote,
2238                       struct ref *ref)
2239 {
2240         int i;
2241
2242         /* Find an explicit --<option>=<name>[:<value>] entry */
2243         for (i = 0; i < cas->nr; i++) {
2244                 struct push_cas *entry = &cas->entry[i];
2245                 if (!refname_match(entry->refname, ref->name))
2246                         continue;
2247                 ref->expect_old_sha1 = 1;
2248                 if (!entry->use_tracking)
2249                         hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2250                 else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2251                         ref->expect_old_no_trackback = 1;
2252                 return;
2253         }
2254
2255         /* Are we using "--<option>" to cover all? */
2256         if (!cas->use_tracking_for_rest)
2257                 return;
2258
2259         ref->expect_old_sha1 = 1;
2260         if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2261                 ref->expect_old_no_trackback = 1;
2262 }
2263
2264 void apply_push_cas(struct push_cas_option *cas,
2265                     struct remote *remote,
2266                     struct ref *remote_refs)
2267 {
2268         struct ref *ref;
2269         for (ref = remote_refs; ref; ref = ref->next)
2270                 apply_cas(cas, remote, ref);
2271 }