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