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