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