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 *pushremote_name;
  53 static int explicit_default_remote_name;
  54
  55 static struct rewrites rewrites;
  56 static struct rewrites rewrites_push;
  57
  58 #define BUF_SIZE (2048)
  59 static char buffer[BUF_SIZE];
  60
  61 static int valid_remote(const struct remote *remote)
  62 {
  63         return (!!remote->url) || (!!remote->foreign_vcs);
  64 }
  65
  66 static const char *alias_url(const char *url, struct rewrites *r)
  67 {
  68         int i, j;
  69         char *ret;
  70         struct counted_string *longest;
  71         int longest_i;
  72
  73         longest = NULL;
  74         longest_i = -1;
  75         for (i = 0; i < r->rewrite_nr; i++) {
  76                 if (!r->rewrite[i])
  77                         continue;
  78                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  79                         if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  80                             (!longest ||
  81                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  82                                 longest = &(r->rewrite[i]->instead_of[j]);
  83                                 longest_i = i;
  84                         }
  85                 }
  86         }
  87         if (!longest)
  88                 return url;
  89
  90         ret = xmalloc(r->rewrite[longest_i]->baselen +
  91                      (strlen(url) - longest->len) + 1);
  92         strcpy(ret, r->rewrite[longest_i]->base);
  93         strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  94         return ret;
  95 }
  96
  97 static void add_push_refspec(struct remote *remote, const char *ref)
  98 {
  99         ALLOC_GROW(remote->push_refspec,
 100                    remote->push_refspec_nr + 1,
 101                    remote->push_refspec_alloc);
 102         remote->push_refspec[remote->push_refspec_nr++] = ref;
 103 }
 104
 105 static void add_fetch_refspec(struct remote *remote, const char *ref)
 106 {
 107         ALLOC_GROW(remote->fetch_refspec,
 108                    remote->fetch_refspec_nr + 1,
 109                    remote->fetch_refspec_alloc);
 110         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 111 }
 112
 113 static void add_url(struct remote *remote, const char *url)
 114 {
 115         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 116         remote->url[remote->url_nr++] = url;
 117 }
 118
 119 static void add_pushurl(struct remote *remote, const char *pushurl)
 120 {
 121         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 122         remote->pushurl[remote->pushurl_nr++] = pushurl;
 123 }
 124
 125 static void add_pushurl_alias(struct remote *remote, const char *url)
 126 {
 127         const char *pushurl = alias_url(url, &rewrites_push);
 128         if (pushurl != url)
 129                 add_pushurl(remote, pushurl);
 130 }
 131
 132 static void add_url_alias(struct remote *remote, const char *url)
 133 {
 134         add_url(remote, alias_url(url, &rewrites));
 135         add_pushurl_alias(remote, url);
 136 }
 137
 138 static struct remote *make_remote(const char *name, int len)
 139 {
 140         struct remote *ret;
 141         int i;
 142
 143         for (i = 0; i < remotes_nr; i++) {
 144                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 145                            !remotes[i]->name[len]) :
 146                     !strcmp(name, remotes[i]->name))
 147                         return remotes[i];
 148         }
 149
 150         ret = xcalloc(1, sizeof(struct remote));
 151         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 152         remotes[remotes_nr++] = ret;
 153         if (len)
 154                 ret->name = xstrndup(name, len);
 155         else
 156                 ret->name = xstrdup(name);
 157         return ret;
 158 }
 159
 160 static void add_merge(struct branch *branch, const char *name)
 161 {
 162         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 163                    branch->merge_alloc);
 164         branch->merge_name[branch->merge_nr++] = name;
 165 }
 166
 167 static struct branch *make_branch(const char *name, int len)
 168 {
 169         struct branch *ret;
 170         int i;
 171         char *refname;
 172
 173         for (i = 0; i < branches_nr; i++) {
 174                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 175                            !branches[i]->name[len]) :
 176                     !strcmp(name, branches[i]->name))
 177                         return branches[i];
 178         }
 179
 180         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 181         ret = xcalloc(1, sizeof(struct branch));
 182         branches[branches_nr++] = ret;
 183         if (len)
 184                 ret->name = xstrndup(name, len);
 185         else
 186                 ret->name = xstrdup(name);
 187         refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 188         strcpy(refname, "refs/heads/");
 189         strcpy(refname + strlen("refs/heads/"), ret->name);
 190         ret->refname = refname;
 191
 192         return ret;
 193 }
 194
 195 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 196 {
 197         struct rewrite *ret;
 198         int i;
 199
 200         for (i = 0; i < r->rewrite_nr; i++) {
 201                 if (len
 202                     ? (len == r->rewrite[i]->baselen &&
 203                        !strncmp(base, r->rewrite[i]->base, len))
 204                     : !strcmp(base, r->rewrite[i]->base))
 205                         return r->rewrite[i];
 206         }
 207
 208         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 209         ret = xcalloc(1, sizeof(struct rewrite));
 210         r->rewrite[r->rewrite_nr++] = ret;
 211         if (len) {
 212                 ret->base = xstrndup(base, len);
 213                 ret->baselen = len;
 214         }
 215         else {
 216                 ret->base = xstrdup(base);
 217                 ret->baselen = strlen(base);
 218         }
 219         return ret;
 220 }
 221
 222 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 223 {
 224         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 225         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 226         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 227         rewrite->instead_of_nr++;
 228 }
 229
 230 static void read_remotes_file(struct remote *remote)
 231 {
 232         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 233
 234         if (!f)
 235                 return;
 236         remote->origin = REMOTE_REMOTES;
 237         while (fgets(buffer, BUF_SIZE, f)) {
 238                 int value_list;
 239                 char *s, *p;
 240
 241                 if (!prefixcmp(buffer, "URL:")) {
 242                         value_list = 0;
 243                         s = buffer + 4;
 244                 } else if (!prefixcmp(buffer, "Push:")) {
 245                         value_list = 1;
 246                         s = buffer + 5;
 247                 } else if (!prefixcmp(buffer, "Pull:")) {
 248                         value_list = 2;
 249                         s = buffer + 5;
 250                 } else
 251                         continue;
 252
 253                 while (isspace(*s))
 254                         s++;
 255                 if (!*s)
 256                         continue;
 257
 258                 p = s + strlen(s);
 259                 while (isspace(p[-1]))
 260                         *--p = 0;
 261
 262                 switch (value_list) {
 263                 case 0:
 264                         add_url_alias(remote, xstrdup(s));
 265                         break;
 266                 case 1:
 267                         add_push_refspec(remote, xstrdup(s));
 268                         break;
 269                 case 2:
 270                         add_fetch_refspec(remote, xstrdup(s));
 271                         break;
 272                 }
 273         }
 274         fclose(f);
 275 }
 276
 277 static void read_branches_file(struct remote *remote)
 278 {
 279         const char *slash = strchr(remote->name, '/');
 280         char *frag;
 281         struct strbuf branch = STRBUF_INIT;
 282         int n = slash ? slash - remote->name : 1000;
 283         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 284         char *s, *p;
 285         int len;
 286
 287         if (!f)
 288                 return;
 289         s = fgets(buffer, BUF_SIZE, f);
 290         fclose(f);
 291         if (!s)
 292                 return;
 293         while (isspace(*s))
 294                 s++;
 295         if (!*s)
 296                 return;
 297         remote->origin = REMOTE_BRANCHES;
 298         p = s + strlen(s);
 299         while (isspace(p[-1]))
 300                 *--p = 0;
 301         len = p - s;
 302         if (slash)
 303                 len += strlen(slash);
 304         p = xmalloc(len + 1);
 305         strcpy(p, s);
 306         if (slash)
 307                 strcat(p, slash);
 308
 309         /*
 310          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 311          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 312          * the partial URL obtained from the branches file plus
 313          * "/netdev-2.6" and does not store it in any tracking ref.
 314          * #branch specifier in the file is ignored.
 315          *
 316          * Otherwise, the branches file would have URL and optionally
 317          * #branch specified.  The "master" (or specified) branch is
 318          * fetched and stored in the local branch of the same name.
 319          */
 320         frag = strchr(p, '#');
 321         if (frag) {
 322                 *(frag++) = '\0';
 323                 strbuf_addf(&branch, "refs/heads/%s", frag);
 324         } else
 325                 strbuf_addstr(&branch, "refs/heads/master");
 326         if (!slash) {
 327                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 328         } else {
 329                 strbuf_reset(&branch);
 330                 strbuf_addstr(&branch, "HEAD:");
 331         }
 332         add_url_alias(remote, p);
 333         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 334         /*
 335          * Cogito compatible push: push current HEAD to remote #branch
 336          * (master if missing)
 337          */
 338         strbuf_init(&branch, 0);
 339         strbuf_addstr(&branch, "HEAD");
 340         if (frag)
 341                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 342         else
 343                 strbuf_addstr(&branch, ":refs/heads/master");
 344         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 345         remote->fetch_tags = 1; /* always auto-follow */
 346 }
 347
 348 static int handle_config(const char *key, const char *value, void *cb)
 349 {
 350         const char *name;
 351         const char *subkey;
 352         struct remote *remote;
 353         struct branch *branch;
 354         if (!prefixcmp(key, "branch.")) {
 355                 name = key + 7;
 356                 subkey = strrchr(name, '.');
 357                 if (!subkey)
 358                         return 0;
 359                 branch = make_branch(name, subkey - name);
 360                 if (!strcmp(subkey, ".remote")) {
 361                         if (git_config_string(&branch->remote_name, key, value))
 362                                 return -1;
 363                         if (branch == current_branch) {
 364                                 default_remote_name = branch->remote_name;
 365                                 explicit_default_remote_name = 1;
 366                         }
 367                 } else if (!strcmp(subkey, ".pushremote")) {
 368                         if (branch == current_branch)
 369                                 if (git_config_string(&pushremote_name, key, value))
 370                                         return -1;
 371                 } else if (!strcmp(subkey, ".merge")) {
 372                         if (!value)
 373                                 return config_error_nonbool(key);
 374                         add_merge(branch, xstrdup(value));
 375                 }
 376                 return 0;
 377         }
 378         if (!prefixcmp(key, "url.")) {
 379                 struct rewrite *rewrite;
 380                 name = key + 4;
 381                 subkey = strrchr(name, '.');
 382                 if (!subkey)
 383                         return 0;
 384                 if (!strcmp(subkey, ".insteadof")) {
 385                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 386                         if (!value)
 387                                 return config_error_nonbool(key);
 388                         add_instead_of(rewrite, xstrdup(value));
 389                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 390                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 391                         if (!value)
 392                                 return config_error_nonbool(key);
 393                         add_instead_of(rewrite, xstrdup(value));
 394                 }
 395         }
 396
 397         if (prefixcmp(key,  "remote."))
 398                 return 0;
 399         name = key + 7;
 400
 401         /* Handle remote.* variables */
 402         if (!strcmp(name, "pushdefault"))
 403                 return git_config_string(&pushremote_name, key, value);
 404
 405         /* Handle remote.<name>.* variables */
 406         if (*name == '/') {
 407                 warning("Config remote shorthand cannot begin with '/': %s",
 408                         name);
 409                 return 0;
 410         }
 411         subkey = strrchr(name, '.');
 412         if (!subkey)
 413                 return 0;
 414         remote = make_remote(name, subkey - name);
 415         remote->origin = REMOTE_CONFIG;
 416         if (!strcmp(subkey, ".mirror"))
 417                 remote->mirror = git_config_bool(key, value);
 418         else if (!strcmp(subkey, ".skipdefaultupdate"))
 419                 remote->skip_default_update = git_config_bool(key, value);
 420         else if (!strcmp(subkey, ".skipfetchall"))
 421                 remote->skip_default_update = git_config_bool(key, value);
 422         else if (!strcmp(subkey, ".url")) {
 423                 const char *v;
 424                 if (git_config_string(&v, key, value))
 425                         return -1;
 426                 add_url(remote, v);
 427         } else if (!strcmp(subkey, ".pushurl")) {
 428                 const char *v;
 429                 if (git_config_string(&v, key, value))
 430                         return -1;
 431                 add_pushurl(remote, v);
 432         } else if (!strcmp(subkey, ".push")) {
 433                 const char *v;
 434                 if (git_config_string(&v, key, value))
 435                         return -1;
 436                 add_push_refspec(remote, v);
 437         } else if (!strcmp(subkey, ".fetch")) {
 438                 const char *v;
 439                 if (git_config_string(&v, key, value))
 440                         return -1;
 441                 add_fetch_refspec(remote, v);
 442         } else if (!strcmp(subkey, ".receivepack")) {
 443                 const char *v;
 444                 if (git_config_string(&v, key, value))
 445                         return -1;
 446                 if (!remote->receivepack)
 447                         remote->receivepack = v;
 448                 else
 449                         error("more than one receivepack given, using the first");
 450         } else if (!strcmp(subkey, ".uploadpack")) {
 451                 const char *v;
 452                 if (git_config_string(&v, key, value))
 453                         return -1;
 454                 if (!remote->uploadpack)
 455                         remote->uploadpack = v;
 456                 else
 457                         error("more than one uploadpack given, using the first");
 458         } else if (!strcmp(subkey, ".tagopt")) {
 459                 if (!strcmp(value, "--no-tags"))
 460                         remote->fetch_tags = -1;
 461                 else if (!strcmp(value, "--tags"))
 462                         remote->fetch_tags = 2;
 463         } else if (!strcmp(subkey, ".proxy")) {
 464                 return git_config_string((const char **)&remote->http_proxy,
 465                                          key, value);
 466         } else if (!strcmp(subkey, ".vcs")) {
 467                 return git_config_string(&remote->foreign_vcs, key, value);
 468         }
 469         return 0;
 470 }
 471
 472 static void alias_all_urls(void)
 473 {
 474         int i, j;
 475         for (i = 0; i < remotes_nr; i++) {
 476                 int add_pushurl_aliases;
 477                 if (!remotes[i])
 478                         continue;
 479                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 480                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 481                 }
 482                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 483                 for (j = 0; j < remotes[i]->url_nr; j++) {
 484                         if (add_pushurl_aliases)
 485                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 486                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 487                 }
 488         }
 489 }
 490
 491 static void read_config(void)
 492 {
 493         unsigned char sha1[20];
 494         const char *head_ref;
 495         int flag;
 496         if (default_remote_name) /* did this already */
 497                 return;
 498         default_remote_name = xstrdup("origin");
 499         current_branch = NULL;
 500         head_ref = resolve_ref_unsafe("HEAD", sha1, 0, &flag);
 501         if (head_ref && (flag & REF_ISSYMREF) &&
 502             !prefixcmp(head_ref, "refs/heads/")) {
 503                 current_branch =
 504                         make_branch(head_ref + strlen("refs/heads/"), 0);
 505         }
 506         git_config(handle_config, NULL);
 507         alias_all_urls();
 508 }
 509
 510 /*
 511  * This function frees a refspec array.
 512  * Warning: code paths should be checked to ensure that the src
 513  *          and dst pointers are always freeable pointers as well
 514  *          as the refspec pointer itself.
 515  */
 516 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 517 {
 518         int i;
 519
 520         if (!refspec)
 521                 return;
 522
 523         for (i = 0; i < nr_refspec; i++) {
 524                 free(refspec[i].src);
 525                 free(refspec[i].dst);
 526         }
 527         free(refspec);
 528 }
 529
 530 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 531 {
 532         int i;
 533         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 534
 535         for (i = 0; i < nr_refspec; i++) {
 536                 size_t llen;
 537                 int is_glob;
 538                 const char *lhs, *rhs;
 539                 int flags;
 540
 541                 is_glob = 0;
 542
 543                 lhs = refspec[i];
 544                 if (*lhs == '+') {
 545                         rs[i].force = 1;
 546                         lhs++;
 547                 }
 548
 549                 rhs = strrchr(lhs, ':');
 550
 551                 /*
 552                  * Before going on, special case ":" (or "+:") as a refspec
 553                  * for pushing matching refs.
 554                  */
 555                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 556                         rs[i].matching = 1;
 557                         continue;
 558                 }
 559
 560                 if (rhs) {
 561                         size_t rlen = strlen(++rhs);
 562                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 563                         rs[i].dst = xstrndup(rhs, rlen);
 564                 }
 565
 566                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 567                 if (1 <= llen && memchr(lhs, '*', llen)) {
 568                         if ((rhs && !is_glob) || (!rhs && fetch))
 569                                 goto invalid;
 570                         is_glob = 1;
 571                 } else if (rhs && is_glob) {
 572                         goto invalid;
 573                 }
 574
 575                 rs[i].pattern = is_glob;
 576                 rs[i].src = xstrndup(lhs, llen);
 577                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 578
 579                 if (fetch) {
 580                         unsigned char unused[40];
 581
 582                         /* LHS */
 583                         if (!*rs[i].src)
 584                                 ; /* empty is ok; it means "HEAD" */
 585                         else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 586                                 rs[i].exact_sha1 = 1; /* ok */
 587                         else if (!check_refname_format(rs[i].src, flags))
 588                                 ; /* valid looking ref is ok */
 589                         else
 590                                 goto invalid;
 591                         /* RHS */
 592                         if (!rs[i].dst)
 593                                 ; /* missing is ok; it is the same as empty */
 594                         else if (!*rs[i].dst)
 595                                 ; /* empty is ok; it means "do not store" */
 596                         else if (!check_refname_format(rs[i].dst, flags))
 597                                 ; /* valid looking ref is ok */
 598                         else
 599                                 goto invalid;
 600                 } else {
 601                         /*
 602                          * LHS
 603                          * - empty is allowed; it means delete.
 604                          * - when wildcarded, it must be a valid looking ref.
 605                          * - otherwise, it must be an extended SHA-1, but
 606                          *   there is no existing way to validate this.
 607                          */
 608                         if (!*rs[i].src)
 609                                 ; /* empty is ok */
 610                         else if (is_glob) {
 611                                 if (check_refname_format(rs[i].src, flags))
 612                                         goto invalid;
 613                         }
 614                         else
 615                                 ; /* anything goes, for now */
 616                         /*
 617                          * RHS
 618                          * - missing is allowed, but LHS then must be a
 619                          *   valid looking ref.
 620                          * - empty is not allowed.
 621                          * - otherwise it must be a valid looking ref.
 622                          */
 623                         if (!rs[i].dst) {
 624                                 if (check_refname_format(rs[i].src, flags))
 625                                         goto invalid;
 626                         } else if (!*rs[i].dst) {
 627                                 goto invalid;
 628                         } else {
 629                                 if (check_refname_format(rs[i].dst, flags))
 630                                         goto invalid;
 631                         }
 632                 }
 633         }
 634         return rs;
 635
 636  invalid:
 637         if (verify) {
 638                 /*
 639                  * nr_refspec must be greater than zero and i must be valid
 640                  * since it is only possible to reach this point from within
 641                  * the for loop above.
 642                  */
 643                 free_refspecs(rs, i+1);
 644                 return NULL;
 645         }
 646         die("Invalid refspec '%s'", refspec[i]);
 647 }
 648
 649 int valid_fetch_refspec(const char *fetch_refspec_str)
 650 {
 651         struct refspec *refspec;
 652
 653         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 654         free_refspecs(refspec, 1);
 655         return !!refspec;
 656 }
 657
 658 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 659 {
 660         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 661 }
 662
 663 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 664 {
 665         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 666 }
 667
 668 void free_refspec(int nr_refspec, struct refspec *refspec)
 669 {
 670         int i;
 671         for (i = 0; i < nr_refspec; i++) {
 672                 free(refspec[i].src);
 673                 free(refspec[i].dst);
 674         }
 675         free(refspec);
 676 }
 677
 678 static int valid_remote_nick(const char *name)
 679 {
 680         if (!name[0] || is_dot_or_dotdot(name))
 681                 return 0;
 682         return !strchr(name, '/'); /* no slash */
 683 }
 684
 685 static struct remote *remote_get_1(const char *name, const char *pushremote_name)
 686 {
 687         struct remote *ret;
 688         int name_given = 0;
 689
 690         if (name)
 691                 name_given = 1;
 692         else {
 693                 if (pushremote_name) {
 694                         name = pushremote_name;
 695                         name_given = 1;
 696                 } else {
 697                         name = default_remote_name;
 698                         name_given = explicit_default_remote_name;
 699                 }
 700         }
 701
 702         ret = make_remote(name, 0);
 703         if (valid_remote_nick(name)) {
 704                 if (!valid_remote(ret))
 705                         read_remotes_file(ret);
 706                 if (!valid_remote(ret))
 707                         read_branches_file(ret);
 708         }
 709         if (name_given && !valid_remote(ret))
 710                 add_url_alias(ret, name);
 711         if (!valid_remote(ret))
 712                 return NULL;
 713         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 714         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 715         return ret;
 716 }
 717
 718 struct remote *remote_get(const char *name)
 719 {
 720         read_config();
 721         return remote_get_1(name, NULL);
 722 }
 723
 724 struct remote *pushremote_get(const char *name)
 725 {
 726         read_config();
 727         return remote_get_1(name, pushremote_name);
 728 }
 729
 730 int remote_is_configured(const char *name)
 731 {
 732         int i;
 733         read_config();
 734
 735         for (i = 0; i < remotes_nr; i++)
 736                 if (!strcmp(name, remotes[i]->name))
 737                         return 1;
 738         return 0;
 739 }
 740
 741 int for_each_remote(each_remote_fn fn, void *priv)
 742 {
 743         int i, result = 0;
 744         read_config();
 745         for (i = 0; i < remotes_nr && !result; i++) {
 746                 struct remote *r = remotes[i];
 747                 if (!r)
 748                         continue;
 749                 if (!r->fetch)
 750                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 751                                                        r->fetch_refspec);
 752                 if (!r->push)
 753                         r->push = parse_push_refspec(r->push_refspec_nr,
 754                                                      r->push_refspec);
 755                 result = fn(r, priv);
 756         }
 757         return result;
 758 }
 759
 760 void ref_remove_duplicates(struct ref *ref_map)
 761 {
 762         struct string_list refs = STRING_LIST_INIT_NODUP;
 763         struct string_list_item *item = NULL;
 764         struct ref *prev = NULL, *next = NULL;
 765         for (; ref_map; prev = ref_map, ref_map = next) {
 766                 next = ref_map->next;
 767                 if (!ref_map->peer_ref)
 768                         continue;
 769
 770                 item = string_list_lookup(&refs, ref_map->peer_ref->name);
 771                 if (item) {
 772                         if (strcmp(((struct ref *)item->util)->name,
 773                                    ref_map->name))
 774                                 die("%s tracks both %s and %s",
 775                                     ref_map->peer_ref->name,
 776                                     ((struct ref *)item->util)->name,
 777                                     ref_map->name);
 778                         prev->next = ref_map->next;
 779                         free(ref_map->peer_ref);
 780                         free(ref_map);
 781                         ref_map = prev; /* skip this; we freed it */
 782                         continue;
 783                 }
 784
 785                 item = string_list_insert(&refs, ref_map->peer_ref->name);
 786                 item->util = ref_map;
 787         }
 788         string_list_clear(&refs, 0);
 789 }
 790
 791 int remote_has_url(struct remote *remote, const char *url)
 792 {
 793         int i;
 794         for (i = 0; i < remote->url_nr; i++) {
 795                 if (!strcmp(remote->url[i], url))
 796                         return 1;
 797         }
 798         return 0;
 799 }
 800
 801 static int match_name_with_pattern(const char *key, const char *name,
 802                                    const char *value, char **result)
 803 {
 804         const char *kstar = strchr(key, '*');
 805         size_t klen;
 806         size_t ksuffixlen;
 807         size_t namelen;
 808         int ret;
 809         if (!kstar)
 810                 die("Key '%s' of pattern had no '*'", key);
 811         klen = kstar - key;
 812         ksuffixlen = strlen(kstar + 1);
 813         namelen = strlen(name);
 814         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 815                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 816         if (ret && value) {
 817                 const char *vstar = strchr(value, '*');
 818                 size_t vlen;
 819                 size_t vsuffixlen;
 820                 if (!vstar)
 821                         die("Value '%s' of pattern has no '*'", value);
 822                 vlen = vstar - value;
 823                 vsuffixlen = strlen(vstar + 1);
 824                 *result = xmalloc(vlen + vsuffixlen +
 825                                   strlen(name) -
 826                                   klen - ksuffixlen + 1);
 827                 strncpy(*result, value, vlen);
 828                 strncpy(*result + vlen,
 829                         name + klen, namelen - klen - ksuffixlen);
 830                 strcpy(*result + vlen + namelen - klen - ksuffixlen,
 831                        vstar + 1);
 832         }
 833         return ret;
 834 }
 835
 836 static int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 837 {
 838         int i;
 839         int find_src = !query->src;
 840
 841         if (find_src && !query->dst)
 842                 return error("query_refspecs: need either src or dst");
 843
 844         for (i = 0; i < ref_count; i++) {
 845                 struct refspec *refspec = &refs[i];
 846                 const char *key = find_src ? refspec->dst : refspec->src;
 847                 const char *value = find_src ? refspec->src : refspec->dst;
 848                 const char *needle = find_src ? query->dst : query->src;
 849                 char **result = find_src ? &query->src : &query->dst;
 850
 851                 if (!refspec->dst)
 852                         continue;
 853                 if (refspec->pattern) {
 854                         if (match_name_with_pattern(key, needle, value, result)) {
 855                                 query->force = refspec->force;
 856                                 return 0;
 857                         }
 858                 } else if (!strcmp(needle, key)) {
 859                         *result = xstrdup(value);
 860                         query->force = refspec->force;
 861                         return 0;
 862                 }
 863         }
 864         return -1;
 865 }
 866
 867 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 868                      const char *name)
 869 {
 870         struct refspec query;
 871
 872         memset(&query, 0, sizeof(struct refspec));
 873         query.src = (char *)name;
 874
 875         if (query_refspecs(refspecs, nr_refspec, &query))
 876                 return NULL;
 877
 878         return query.dst;
 879 }
 880
 881 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 882 {
 883         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 884 }
 885
 886 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 887                 const char *name)
 888 {
 889         size_t len = strlen(name);
 890         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 891         memcpy(ref->name, prefix, prefixlen);
 892         memcpy(ref->name + prefixlen, name, len);
 893         return ref;
 894 }
 895
 896 struct ref *alloc_ref(const char *name)
 897 {
 898         return alloc_ref_with_prefix("", 0, name);
 899 }
 900
 901 struct ref *copy_ref(const struct ref *ref)
 902 {
 903         struct ref *cpy;
 904         size_t len;
 905         if (!ref)
 906                 return NULL;
 907         len = strlen(ref->name);
 908         cpy = xmalloc(sizeof(struct ref) + len + 1);
 909         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 910         cpy->next = NULL;
 911         cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 912         cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 913         cpy->peer_ref = copy_ref(ref->peer_ref);
 914         return cpy;
 915 }
 916
 917 struct ref *copy_ref_list(const struct ref *ref)
 918 {
 919         struct ref *ret = NULL;
 920         struct ref **tail = &ret;
 921         while (ref) {
 922                 *tail = copy_ref(ref);
 923                 ref = ref->next;
 924                 tail = &((*tail)->next);
 925         }
 926         return ret;
 927 }
 928
 929 static void free_ref(struct ref *ref)
 930 {
 931         if (!ref)
 932                 return;
 933         free_ref(ref->peer_ref);
 934         free(ref->remote_status);
 935         free(ref->symref);
 936         free(ref);
 937 }
 938
 939 void free_refs(struct ref *ref)
 940 {
 941         struct ref *next;
 942         while (ref) {
 943                 next = ref->next;
 944                 free_ref(ref);
 945                 ref = next;
 946         }
 947 }
 948
 949 int ref_compare_name(const void *va, const void *vb)
 950 {
 951         const struct ref *a = va, *b = vb;
 952         return strcmp(a->name, b->name);
 953 }
 954
 955 static void *ref_list_get_next(const void *a)
 956 {
 957         return ((const struct ref *)a)->next;
 958 }
 959
 960 static void ref_list_set_next(void *a, void *next)
 961 {
 962         ((struct ref *)a)->next = next;
 963 }
 964
 965 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 966 {
 967         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 968 }
 969
 970 static int count_refspec_match(const char *pattern,
 971                                struct ref *refs,
 972                                struct ref **matched_ref)
 973 {
 974         int patlen = strlen(pattern);
 975         struct ref *matched_weak = NULL;
 976         struct ref *matched = NULL;
 977         int weak_match = 0;
 978         int match = 0;
 979
 980         for (weak_match = match = 0; refs; refs = refs->next) {
 981                 char *name = refs->name;
 982                 int namelen = strlen(name);
 983
 984                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 985                         continue;
 986
 987                 /* A match is "weak" if it is with refs outside
 988                  * heads or tags, and did not specify the pattern
 989                  * in full (e.g. "refs/remotes/origin/master") or at
 990                  * least from the toplevel (e.g. "remotes/origin/master");
 991                  * otherwise "git push $URL master" would result in
 992                  * ambiguity between remotes/origin/master and heads/master
 993                  * at the remote site.
 994                  */
 995                 if (namelen != patlen &&
 996                     patlen != namelen - 5 &&
 997                     prefixcmp(name, "refs/heads/") &&
 998                     prefixcmp(name, "refs/tags/")) {
 999                         /* We want to catch the case where only weak
1000                          * matches are found and there are multiple
1001                          * matches, and where more than one strong
1002                          * matches are found, as ambiguous.  One
1003                          * strong match with zero or more weak matches
1004                          * are acceptable as a unique match.
1005                          */
1006                         matched_weak = refs;
1007                         weak_match++;
1008                 }
1009                 else {
1010                         matched = refs;
1011                         match++;
1012                 }
1013         }
1014         if (!matched) {
1015                 *matched_ref = matched_weak;
1016                 return weak_match;
1017         }
1018         else {
1019                 *matched_ref = matched;
1020                 return match;
1021         }
1022 }
1023
1024 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1025 {
1026         **tail = ref;
1027         while (ref->next)
1028                 ref = ref->next;
1029         *tail = &ref->next;
1030 }
1031
1032 static struct ref *alloc_delete_ref(void)
1033 {
1034         struct ref *ref = alloc_ref("(delete)");
1035         hashclr(ref->new_sha1);
1036         return ref;
1037 }
1038
1039 static struct ref *try_explicit_object_name(const char *name)
1040 {
1041         unsigned char sha1[20];
1042         struct ref *ref;
1043
1044         if (!*name)
1045                 return alloc_delete_ref();
1046         if (get_sha1(name, sha1))
1047                 return NULL;
1048         ref = alloc_ref(name);
1049         hashcpy(ref->new_sha1, sha1);
1050         return ref;
1051 }
1052
1053 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1054 {
1055         struct ref *ret = alloc_ref(name);
1056         tail_link_ref(ret, tail);
1057         return ret;
1058 }
1059
1060 static char *guess_ref(const char *name, struct ref *peer)
1061 {
1062         struct strbuf buf = STRBUF_INIT;
1063         unsigned char sha1[20];
1064
1065         const char *r = resolve_ref_unsafe(peer->name, sha1, 1, NULL);
1066         if (!r)
1067                 return NULL;
1068
1069         if (!prefixcmp(r, "refs/heads/"))
1070                 strbuf_addstr(&buf, "refs/heads/");
1071         else if (!prefixcmp(r, "refs/tags/"))
1072                 strbuf_addstr(&buf, "refs/tags/");
1073         else
1074                 return NULL;
1075
1076         strbuf_addstr(&buf, name);
1077         return strbuf_detach(&buf, NULL);
1078 }
1079
1080 static int match_explicit(struct ref *src, struct ref *dst,
1081                           struct ref ***dst_tail,
1082                           struct refspec *rs)
1083 {
1084         struct ref *matched_src, *matched_dst;
1085         int copy_src;
1086
1087         const char *dst_value = rs->dst;
1088         char *dst_guess;
1089
1090         if (rs->pattern || rs->matching)
1091                 return 0;
1092
1093         matched_src = matched_dst = NULL;
1094         switch (count_refspec_match(rs->src, src, &matched_src)) {
1095         case 1:
1096                 copy_src = 1;
1097                 break;
1098         case 0:
1099                 /* The source could be in the get_sha1() format
1100                  * not a reference name.  :refs/other is a
1101                  * way to delete 'other' ref at the remote end.
1102                  */
1103                 matched_src = try_explicit_object_name(rs->src);
1104                 if (!matched_src)
1105                         return error("src refspec %s does not match any.", rs->src);
1106                 copy_src = 0;
1107                 break;
1108         default:
1109                 return error("src refspec %s matches more than one.", rs->src);
1110         }
1111
1112         if (!dst_value) {
1113                 unsigned char sha1[20];
1114                 int flag;
1115
1116                 dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag);
1117                 if (!dst_value ||
1118                     ((flag & REF_ISSYMREF) &&
1119                      prefixcmp(dst_value, "refs/heads/")))
1120                         die("%s cannot be resolved to branch.",
1121                             matched_src->name);
1122         }
1123
1124         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1125         case 1:
1126                 break;
1127         case 0:
1128                 if (!memcmp(dst_value, "refs/", 5))
1129                         matched_dst = make_linked_ref(dst_value, dst_tail);
1130                 else if (is_null_sha1(matched_src->new_sha1))
1131                         error("unable to delete '%s': remote ref does not exist",
1132                               dst_value);
1133                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1134                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1135                 else
1136                         error("unable to push to unqualified destination: %s\n"
1137                               "The destination refspec neither matches an "
1138                               "existing ref on the remote nor\n"
1139                               "begins with refs/, and we are unable to "
1140                               "guess a prefix based on the source ref.",
1141                               dst_value);
1142                 break;
1143         default:
1144                 matched_dst = NULL;
1145                 error("dst refspec %s matches more than one.",
1146                       dst_value);
1147                 break;
1148         }
1149         if (!matched_dst)
1150                 return -1;
1151         if (matched_dst->peer_ref)
1152                 return error("dst ref %s receives from more than one src.",
1153                       matched_dst->name);
1154         else {
1155                 matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1156                 matched_dst->force = rs->force;
1157         }
1158         return 0;
1159 }
1160
1161 static int match_explicit_refs(struct ref *src, struct ref *dst,
1162                                struct ref ***dst_tail, struct refspec *rs,
1163                                int rs_nr)
1164 {
1165         int i, errs;
1166         for (i = errs = 0; i < rs_nr; i++)
1167                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1168         return errs;
1169 }
1170
1171 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1172                 int send_mirror, int direction, const struct refspec **ret_pat)
1173 {
1174         const struct refspec *pat;
1175         char *name;
1176         int i;
1177         int matching_refs = -1;
1178         for (i = 0; i < rs_nr; i++) {
1179                 if (rs[i].matching &&
1180                     (matching_refs == -1 || rs[i].force)) {
1181                         matching_refs = i;
1182                         continue;
1183                 }
1184
1185                 if (rs[i].pattern) {
1186                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1187                         int match;
1188                         if (direction == FROM_SRC)
1189                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1190                         else
1191                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1192                         if (match) {
1193                                 matching_refs = i;
1194                                 break;
1195                         }
1196                 }
1197         }
1198         if (matching_refs == -1)
1199                 return NULL;
1200
1201         pat = rs + matching_refs;
1202         if (pat->matching) {
1203                 /*
1204                  * "matching refs"; traditionally we pushed everything
1205                  * including refs outside refs/heads/ hierarchy, but
1206                  * that does not make much sense these days.
1207                  */
1208                 if (!send_mirror && prefixcmp(ref->name, "refs/heads/"))
1209                         return NULL;
1210                 name = xstrdup(ref->name);
1211         }
1212         if (ret_pat)
1213                 *ret_pat = pat;
1214         return name;
1215 }
1216
1217 static struct ref **tail_ref(struct ref **head)
1218 {
1219         struct ref **tail = head;
1220         while (*tail)
1221                 tail = &((*tail)->next);
1222         return tail;
1223 }
1224
1225 struct tips {
1226         struct commit **tip;
1227         int nr, alloc;
1228 };
1229
1230 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1231 {
1232         struct commit *commit;
1233
1234         if (is_null_sha1(sha1))
1235                 return;
1236         commit = lookup_commit_reference_gently(sha1, 1);
1237         if (!commit || (commit->object.flags & TMP_MARK))
1238                 return;
1239         commit->object.flags |= TMP_MARK;
1240         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1241         tips->tip[tips->nr++] = commit;
1242 }
1243
1244 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1245 {
1246         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1247         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1248         struct string_list_item *item;
1249         struct ref *ref;
1250         struct tips sent_tips;
1251
1252         /*
1253          * Collect everything we know they would have at the end of
1254          * this push, and collect all tags they have.
1255          */
1256         memset(&sent_tips, 0, sizeof(sent_tips));
1257         for (ref = *dst; ref; ref = ref->next) {
1258                 if (ref->peer_ref &&
1259                     !is_null_sha1(ref->peer_ref->new_sha1))
1260                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1261                 else
1262                         add_to_tips(&sent_tips, ref->old_sha1);
1263                 if (!prefixcmp(ref->name, "refs/tags/"))
1264                         string_list_append(&dst_tag, ref->name);
1265         }
1266         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1267
1268         sort_string_list(&dst_tag);
1269
1270         /* Collect tags they do not have. */
1271         for (ref = src; ref; ref = ref->next) {
1272                 if (prefixcmp(ref->name, "refs/tags/"))
1273                         continue; /* not a tag */
1274                 if (string_list_has_string(&dst_tag, ref->name))
1275                         continue; /* they already have it */
1276                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1277                         continue; /* be conservative */
1278                 item = string_list_append(&src_tag, ref->name);
1279                 item->util = ref;
1280         }
1281         string_list_clear(&dst_tag, 0);
1282
1283         /*
1284          * At this point, src_tag lists tags that are missing from
1285          * dst, and sent_tips lists the tips we are pushing or those
1286          * that we know they already have. An element in the src_tag
1287          * that is an ancestor of any of the sent_tips needs to be
1288          * sent to the other side.
1289          */
1290         if (sent_tips.nr) {
1291                 for_each_string_list_item(item, &src_tag) {
1292                         struct ref *ref = item->util;
1293                         struct ref *dst_ref;
1294                         struct commit *commit;
1295
1296                         if (is_null_sha1(ref->new_sha1))
1297                                 continue;
1298                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1299                         if (!commit)
1300                                 /* not pushing a commit, which is not an error */
1301                                 continue;
1302
1303                         /*
1304                          * Is this tag, which they do not have, reachable from
1305                          * any of the commits we are sending?
1306                          */
1307                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1308                                 continue;
1309
1310                         /* Add it in */
1311                         dst_ref = make_linked_ref(ref->name, dst_tail);
1312                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1313                         dst_ref->peer_ref = copy_ref(ref);
1314                 }
1315         }
1316         string_list_clear(&src_tag, 0);
1317         free(sent_tips.tip);
1318 }
1319
1320 /*
1321  * Given the set of refs the local repository has, the set of refs the
1322  * remote repository has, and the refspec used for push, determine
1323  * what remote refs we will update and with what value by setting
1324  * peer_ref (which object is being pushed) and force (if the push is
1325  * forced) in elements of "dst". The function may add new elements to
1326  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1327  */
1328 int match_push_refs(struct ref *src, struct ref **dst,
1329                     int nr_refspec, const char **refspec, int flags)
1330 {
1331         struct refspec *rs;
1332         int send_all = flags & MATCH_REFS_ALL;
1333         int send_mirror = flags & MATCH_REFS_MIRROR;
1334         int send_prune = flags & MATCH_REFS_PRUNE;
1335         int errs;
1336         static const char *default_refspec[] = { ":", NULL };
1337         struct ref *ref, **dst_tail = tail_ref(dst);
1338
1339         if (!nr_refspec) {
1340                 nr_refspec = 1;
1341                 refspec = default_refspec;
1342         }
1343         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1344         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1345
1346         /* pick the remainder */
1347         for (ref = src; ref; ref = ref->next) {
1348                 struct ref *dst_peer;
1349                 const struct refspec *pat = NULL;
1350                 char *dst_name;
1351
1352                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1353                 if (!dst_name)
1354                         continue;
1355
1356                 dst_peer = find_ref_by_name(*dst, dst_name);
1357                 if (dst_peer) {
1358                         if (dst_peer->peer_ref)
1359                                 /* We're already sending something to this ref. */
1360                                 goto free_name;
1361                 } else {
1362                         if (pat->matching && !(send_all || send_mirror))
1363                                 /*
1364                                  * Remote doesn't have it, and we have no
1365                                  * explicit pattern, and we don't have
1366                                  * --all nor --mirror.
1367                                  */
1368                                 goto free_name;
1369
1370                         /* Create a new one and link it */
1371                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1372                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1373                 }
1374                 dst_peer->peer_ref = copy_ref(ref);
1375                 dst_peer->force = pat->force;
1376         free_name:
1377                 free(dst_name);
1378         }
1379
1380         if (flags & MATCH_REFS_FOLLOW_TAGS)
1381                 add_missing_tags(src, dst, &dst_tail);
1382
1383         if (send_prune) {
1384                 /* check for missing refs on the remote */
1385                 for (ref = *dst; ref; ref = ref->next) {
1386                         char *src_name;
1387
1388                         if (ref->peer_ref)
1389                                 /* We're already sending something to this ref. */
1390                                 continue;
1391
1392                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1393                         if (src_name) {
1394                                 if (!find_ref_by_name(src, src_name))
1395                                         ref->peer_ref = alloc_delete_ref();
1396                                 free(src_name);
1397                         }
1398                 }
1399         }
1400         if (errs)
1401                 return -1;
1402         return 0;
1403 }
1404
1405 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1406         int force_update)
1407 {
1408         struct ref *ref;
1409
1410         for (ref = remote_refs; ref; ref = ref->next) {
1411                 int force_ref_update = ref->force || force_update;
1412
1413                 if (ref->peer_ref)
1414                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1415                 else if (!send_mirror)
1416                         continue;
1417
1418                 ref->deletion = is_null_sha1(ref->new_sha1);
1419                 if (!ref->deletion &&
1420                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1421                         ref->status = REF_STATUS_UPTODATE;
1422                         continue;
1423                 }
1424
1425                 /*
1426                  * Decide whether an individual refspec A:B can be
1427                  * pushed.  The push will succeed if any of the
1428                  * following are true:
1429                  *
1430                  * (1) the remote reference B does not exist
1431                  *
1432                  * (2) the remote reference B is being removed (i.e.,
1433                  *     pushing :B where no source is specified)
1434                  *
1435                  * (3) the destination is not under refs/tags/, and
1436                  *     if the old and new value is a commit, the new
1437                  *     is a descendant of the old.
1438                  *
1439                  * (4) it is forced using the +A:B notation, or by
1440                  *     passing the --force argument
1441                  */
1442
1443                 if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1444                         int why = 0; /* why would this push require --force? */
1445
1446                         if (!prefixcmp(ref->name, "refs/tags/"))
1447                                 why = REF_STATUS_REJECT_ALREADY_EXISTS;
1448                         else if (!has_sha1_file(ref->old_sha1))
1449                                 why = REF_STATUS_REJECT_FETCH_FIRST;
1450                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1451                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1452                                 why = REF_STATUS_REJECT_NEEDS_FORCE;
1453                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1454                                 why = REF_STATUS_REJECT_NONFASTFORWARD;
1455
1456                         if (!force_ref_update)
1457                                 ref->status = why;
1458                         else if (why)
1459                                 ref->forced_update = 1;
1460                 }
1461         }
1462 }
1463
1464 struct branch *branch_get(const char *name)
1465 {
1466         struct branch *ret;
1467
1468         read_config();
1469         if (!name || !*name || !strcmp(name, "HEAD"))
1470                 ret = current_branch;
1471         else
1472                 ret = make_branch(name, 0);
1473         if (ret && ret->remote_name) {
1474                 ret->remote = remote_get(ret->remote_name);
1475                 if (ret->merge_nr) {
1476                         int i;
1477                         ret->merge = xcalloc(sizeof(*ret->merge),
1478                                              ret->merge_nr);
1479                         for (i = 0; i < ret->merge_nr; i++) {
1480                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1481                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1482                                 if (remote_find_tracking(ret->remote, ret->merge[i])
1483                                     && !strcmp(ret->remote_name, "."))
1484                                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1485                         }
1486                 }
1487         }
1488         return ret;
1489 }
1490
1491 int branch_has_merge_config(struct branch *branch)
1492 {
1493         return branch && !!branch->merge;
1494 }
1495
1496 int branch_merge_matches(struct branch *branch,
1497                                  int i,
1498                                  const char *refname)
1499 {
1500         if (!branch || i < 0 || i >= branch->merge_nr)
1501                 return 0;
1502         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1503 }
1504
1505 static int ignore_symref_update(const char *refname)
1506 {
1507         unsigned char sha1[20];
1508         int flag;
1509
1510         if (!resolve_ref_unsafe(refname, sha1, 0, &flag))
1511                 return 0; /* non-existing refs are OK */
1512         return (flag & REF_ISSYMREF);
1513 }
1514
1515 static struct ref *get_expanded_map(const struct ref *remote_refs,
1516                                     const struct refspec *refspec)
1517 {
1518         const struct ref *ref;
1519         struct ref *ret = NULL;
1520         struct ref **tail = &ret;
1521
1522         char *expn_name;
1523
1524         for (ref = remote_refs; ref; ref = ref->next) {
1525                 if (strchr(ref->name, '^'))
1526                         continue; /* a dereference item */
1527                 if (match_name_with_pattern(refspec->src, ref->name,
1528                                             refspec->dst, &expn_name) &&
1529                     !ignore_symref_update(expn_name)) {
1530                         struct ref *cpy = copy_ref(ref);
1531
1532                         cpy->peer_ref = alloc_ref(expn_name);
1533                         free(expn_name);
1534                         if (refspec->force)
1535                                 cpy->peer_ref->force = 1;
1536                         *tail = cpy;
1537                         tail = &cpy->next;
1538                 }
1539         }
1540
1541         return ret;
1542 }
1543
1544 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1545 {
1546         const struct ref *ref;
1547         for (ref = refs; ref; ref = ref->next) {
1548                 if (refname_match(name, ref->name, ref_fetch_rules))
1549                         return ref;
1550         }
1551         return NULL;
1552 }
1553
1554 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1555 {
1556         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1557
1558         if (!ref)
1559                 return NULL;
1560
1561         return copy_ref(ref);
1562 }
1563
1564 static struct ref *get_local_ref(const char *name)
1565 {
1566         if (!name || name[0] == '\0')
1567                 return NULL;
1568
1569         if (!prefixcmp(name, "refs/"))
1570                 return alloc_ref(name);
1571
1572         if (!prefixcmp(name, "heads/") ||
1573             !prefixcmp(name, "tags/") ||
1574             !prefixcmp(name, "remotes/"))
1575                 return alloc_ref_with_prefix("refs/", 5, name);
1576
1577         return alloc_ref_with_prefix("refs/heads/", 11, name);
1578 }
1579
1580 int get_fetch_map(const struct ref *remote_refs,
1581                   const struct refspec *refspec,
1582                   struct ref ***tail,
1583                   int missing_ok)
1584 {
1585         struct ref *ref_map, **rmp;
1586
1587         if (refspec->pattern) {
1588                 ref_map = get_expanded_map(remote_refs, refspec);
1589         } else {
1590                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1591
1592                 if (refspec->exact_sha1) {
1593                         ref_map = alloc_ref(name);
1594                         get_sha1_hex(name, ref_map->old_sha1);
1595                 } else {
1596                         ref_map = get_remote_ref(remote_refs, name);
1597                 }
1598                 if (!missing_ok && !ref_map)
1599                         die("Couldn't find remote ref %s", name);
1600                 if (ref_map) {
1601                         ref_map->peer_ref = get_local_ref(refspec->dst);
1602                         if (ref_map->peer_ref && refspec->force)
1603                                 ref_map->peer_ref->force = 1;
1604                 }
1605         }
1606
1607         for (rmp = &ref_map; *rmp; ) {
1608                 if ((*rmp)->peer_ref) {
1609                         if (prefixcmp((*rmp)->peer_ref->name, "refs/") ||
1610                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1611                                 struct ref *ignore = *rmp;
1612                                 error("* Ignoring funny ref '%s' locally",
1613                                       (*rmp)->peer_ref->name);
1614                                 *rmp = (*rmp)->next;
1615                                 free(ignore->peer_ref);
1616                                 free(ignore);
1617                                 continue;
1618                         }
1619                 }
1620                 rmp = &((*rmp)->next);
1621         }
1622
1623         if (ref_map)
1624                 tail_link_ref(ref_map, tail);
1625
1626         return 0;
1627 }
1628
1629 int resolve_remote_symref(struct ref *ref, struct ref *list)
1630 {
1631         if (!ref->symref)
1632                 return 0;
1633         for (; list; list = list->next)
1634                 if (!strcmp(ref->symref, list->name)) {
1635                         hashcpy(ref->old_sha1, list->old_sha1);
1636                         return 0;
1637                 }
1638         return 1;
1639 }
1640
1641 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1642 {
1643         while (list) {
1644                 struct commit_list *temp = list;
1645                 temp->item->object.flags &= ~mark;
1646                 list = temp->next;
1647                 free(temp);
1648         }
1649 }
1650
1651 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1652 {
1653         struct object *o;
1654         struct commit *old, *new;
1655         struct commit_list *list, *used;
1656         int found = 0;
1657
1658         /*
1659          * Both new and old must be commit-ish and new is descendant of
1660          * old.  Otherwise we require --force.
1661          */
1662         o = deref_tag(parse_object(old_sha1), NULL, 0);
1663         if (!o || o->type != OBJ_COMMIT)
1664                 return 0;
1665         old = (struct commit *) o;
1666
1667         o = deref_tag(parse_object(new_sha1), NULL, 0);
1668         if (!o || o->type != OBJ_COMMIT)
1669                 return 0;
1670         new = (struct commit *) o;
1671
1672         if (parse_commit(new) < 0)
1673                 return 0;
1674
1675         used = list = NULL;
1676         commit_list_insert(new, &list);
1677         while (list) {
1678                 new = pop_most_recent_commit(&list, TMP_MARK);
1679                 commit_list_insert(new, &used);
1680                 if (new == old) {
1681                         found = 1;
1682                         break;
1683                 }
1684         }
1685         unmark_and_free(list, TMP_MARK);
1686         unmark_and_free(used, TMP_MARK);
1687         return found;
1688 }
1689
1690 /*
1691  * Return true if there is anything to report, otherwise false.
1692  */
1693 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1694 {
1695         unsigned char sha1[20];
1696         struct commit *ours, *theirs;
1697         char symmetric[84];
1698         struct rev_info revs;
1699         const char *rev_argv[10], *base;
1700         int rev_argc;
1701
1702         /*
1703          * Nothing to report unless we are marked to build on top of
1704          * somebody else.
1705          */
1706         if (!branch ||
1707             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1708                 return 0;
1709
1710         /*
1711          * If what we used to build on no longer exists, there is
1712          * nothing to report.
1713          */
1714         base = branch->merge[0]->dst;
1715         if (read_ref(base, sha1))
1716                 return 0;
1717         theirs = lookup_commit_reference(sha1);
1718         if (!theirs)
1719                 return 0;
1720
1721         if (read_ref(branch->refname, sha1))
1722                 return 0;
1723         ours = lookup_commit_reference(sha1);
1724         if (!ours)
1725                 return 0;
1726
1727         /* are we the same? */
1728         if (theirs == ours)
1729                 return 0;
1730
1731         /* Run "rev-list --left-right ours...theirs" internally... */
1732         rev_argc = 0;
1733         rev_argv[rev_argc++] = NULL;
1734         rev_argv[rev_argc++] = "--left-right";
1735         rev_argv[rev_argc++] = symmetric;
1736         rev_argv[rev_argc++] = "--";
1737         rev_argv[rev_argc] = NULL;
1738
1739         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1740         strcpy(symmetric + 40, "...");
1741         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1742
1743         init_revisions(&revs, NULL);
1744         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1745         prepare_revision_walk(&revs);
1746
1747         /* ... and count the commits on each side. */
1748         *num_ours = 0;
1749         *num_theirs = 0;
1750         while (1) {
1751                 struct commit *c = get_revision(&revs);
1752                 if (!c)
1753                         break;
1754                 if (c->object.flags & SYMMETRIC_LEFT)
1755                         (*num_ours)++;
1756                 else
1757                         (*num_theirs)++;
1758         }
1759
1760         /* clear object flags smudged by the above traversal */
1761         clear_commit_marks(ours, ALL_REV_FLAGS);
1762         clear_commit_marks(theirs, ALL_REV_FLAGS);
1763         return 1;
1764 }
1765
1766 /*
1767  * Return true when there is anything to report, otherwise false.
1768  */
1769 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1770 {
1771         int num_ours, num_theirs;
1772         const char *base;
1773
1774         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1775                 return 0;
1776
1777         base = branch->merge[0]->dst;
1778         base = shorten_unambiguous_ref(base, 0);
1779         if (!num_theirs) {
1780                 strbuf_addf(sb,
1781                         Q_("Your branch is ahead of '%s' by %d commit.\n",
1782                            "Your branch is ahead of '%s' by %d commits.\n",
1783                            num_ours),
1784                         base, num_ours);
1785                 if (advice_status_hints)
1786                         strbuf_addf(sb,
1787                                 _("  (use \"git push\" to publish your local commits)\n"));
1788         } else if (!num_ours) {
1789                 strbuf_addf(sb,
1790                         Q_("Your branch is behind '%s' by %d commit, "
1791                                "and can be fast-forwarded.\n",
1792                            "Your branch is behind '%s' by %d commits, "
1793                                "and can be fast-forwarded.\n",
1794                            num_theirs),
1795                         base, num_theirs);
1796                 if (advice_status_hints)
1797                         strbuf_addf(sb,
1798                                 _("  (use \"git pull\" to update your local branch)\n"));
1799         } else {
1800                 strbuf_addf(sb,
1801                         Q_("Your branch and '%s' have diverged,\n"
1802                                "and have %d and %d different commit each, "
1803                                "respectively.\n",
1804                            "Your branch and '%s' have diverged,\n"
1805                                "and have %d and %d different commits each, "
1806                                "respectively.\n",
1807                            num_theirs),
1808                         base, num_ours, num_theirs);
1809                 if (advice_status_hints)
1810                         strbuf_addf(sb,
1811                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1812         }
1813         return 1;
1814 }
1815
1816 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1817 {
1818         struct ref ***local_tail = cb_data;
1819         struct ref *ref;
1820         int len;
1821
1822         /* we already know it starts with refs/ to get here */
1823         if (check_refname_format(refname + 5, 0))
1824                 return 0;
1825
1826         len = strlen(refname) + 1;
1827         ref = xcalloc(1, sizeof(*ref) + len);
1828         hashcpy(ref->new_sha1, sha1);
1829         memcpy(ref->name, refname, len);
1830         **local_tail = ref;
1831         *local_tail = &ref->next;
1832         return 0;
1833 }
1834
1835 struct ref *get_local_heads(void)
1836 {
1837         struct ref *local_refs = NULL, **local_tail = &local_refs;
1838         for_each_ref(one_local_ref, &local_tail);
1839         return local_refs;
1840 }
1841
1842 struct ref *guess_remote_head(const struct ref *head,
1843                               const struct ref *refs,
1844                               int all)
1845 {
1846         const struct ref *r;
1847         struct ref *list = NULL;
1848         struct ref **tail = &list;
1849
1850         if (!head)
1851                 return NULL;
1852
1853         /*
1854          * Some transports support directly peeking at
1855          * where HEAD points; if that is the case, then
1856          * we don't have to guess.
1857          */
1858         if (head->symref)
1859                 return copy_ref(find_ref_by_name(refs, head->symref));
1860
1861         /* If refs/heads/master could be right, it is. */
1862         if (!all) {
1863                 r = find_ref_by_name(refs, "refs/heads/master");
1864                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
1865                         return copy_ref(r);
1866         }
1867
1868         /* Look for another ref that points there */
1869         for (r = refs; r; r = r->next) {
1870                 if (r != head &&
1871                     !prefixcmp(r->name, "refs/heads/") &&
1872                     !hashcmp(r->old_sha1, head->old_sha1)) {
1873                         *tail = copy_ref(r);
1874                         tail = &((*tail)->next);
1875                         if (!all)
1876                                 break;
1877                 }
1878         }
1879
1880         return list;
1881 }
1882
1883 struct stale_heads_info {
1884         struct string_list *ref_names;
1885         struct ref **stale_refs_tail;
1886         struct refspec *refs;
1887         int ref_count;
1888 };
1889
1890 static int get_stale_heads_cb(const char *refname,
1891         const unsigned char *sha1, int flags, void *cb_data)
1892 {
1893         struct stale_heads_info *info = cb_data;
1894         struct refspec query;
1895         memset(&query, 0, sizeof(struct refspec));
1896         query.dst = (char *)refname;
1897
1898         if (query_refspecs(info->refs, info->ref_count, &query))
1899                 return 0; /* No matches */
1900
1901         /*
1902          * If we did find a suitable refspec and it's not a symref and
1903          * it's not in the list of refs that currently exist in that
1904          * remote we consider it to be stale.
1905          */
1906         if (!((flags & REF_ISSYMREF) ||
1907               string_list_has_string(info->ref_names, query.src))) {
1908                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1909                 hashcpy(ref->new_sha1, sha1);
1910         }
1911
1912         free(query.src);
1913         return 0;
1914 }
1915
1916 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
1917 {
1918         struct ref *ref, *stale_refs = NULL;
1919         struct string_list ref_names = STRING_LIST_INIT_NODUP;
1920         struct stale_heads_info info;
1921         info.ref_names = &ref_names;
1922         info.stale_refs_tail = &stale_refs;
1923         info.refs = refs;
1924         info.ref_count = ref_count;
1925         for (ref = fetch_map; ref; ref = ref->next)
1926                 string_list_append(&ref_names, ref->name);
1927         sort_string_list(&ref_names);
1928         for_each_ref(get_stale_heads_cb, &info);
1929         string_list_clear(&ref_names, 0);
1930         return stale_refs;
1931 }