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