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
   8 static struct refspec s_tag_refspec = {
   9         0,
  10         1,
  11         0,
  12         "refs/tags/",
  13         "refs/tags/"
  14 };
  15
  16 const struct refspec *tag_refspec = &s_tag_refspec;
  17
  18 struct counted_string {
  19         size_t len;
  20         const char *s;
  21 };
  22 struct rewrite {
  23         const char *base;
  24         size_t baselen;
  25         struct counted_string *instead_of;
  26         int instead_of_nr;
  27         int instead_of_alloc;
  28 };
  29
  30 static struct remote **remotes;
  31 static int remotes_alloc;
  32 static int remotes_nr;
  33
  34 static struct branch **branches;
  35 static int branches_alloc;
  36 static int branches_nr;
  37
  38 static struct branch *current_branch;
  39 static const char *default_remote_name;
  40
  41 static struct rewrite **rewrite;
  42 static int rewrite_alloc;
  43 static int rewrite_nr;
  44
  45 #define BUF_SIZE (2048)
  46 static char buffer[BUF_SIZE];
  47
  48 static const char *alias_url(const char *url)
  49 {
  50         int i, j;
  51         char *ret;
  52         struct counted_string *longest;
  53         int longest_i;
  54
  55         longest = NULL;
  56         longest_i = -1;
  57         for (i = 0; i < rewrite_nr; i++) {
  58                 if (!rewrite[i])
  59                         continue;
  60                 for (j = 0; j < rewrite[i]->instead_of_nr; j++) {
  61                         if (!prefixcmp(url, rewrite[i]->instead_of[j].s) &&
  62                             (!longest ||
  63                              longest->len < rewrite[i]->instead_of[j].len)) {
  64                                 longest = &(rewrite[i]->instead_of[j]);
  65                                 longest_i = i;
  66                         }
  67                 }
  68         }
  69         if (!longest)
  70                 return url;
  71
  72         ret = malloc(rewrite[longest_i]->baselen +
  73                      (strlen(url) - longest->len) + 1);
  74         strcpy(ret, rewrite[longest_i]->base);
  75         strcpy(ret + rewrite[longest_i]->baselen, url + longest->len);
  76         return ret;
  77 }
  78
  79 static void add_push_refspec(struct remote *remote, const char *ref)
  80 {
  81         ALLOC_GROW(remote->push_refspec,
  82                    remote->push_refspec_nr + 1,
  83                    remote->push_refspec_alloc);
  84         remote->push_refspec[remote->push_refspec_nr++] = ref;
  85 }
  86
  87 static void add_fetch_refspec(struct remote *remote, const char *ref)
  88 {
  89         ALLOC_GROW(remote->fetch_refspec,
  90                    remote->fetch_refspec_nr + 1,
  91                    remote->fetch_refspec_alloc);
  92         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
  93 }
  94
  95 static void add_url(struct remote *remote, const char *url)
  96 {
  97         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
  98         remote->url[remote->url_nr++] = url;
  99 }
 100
 101 static void add_url_alias(struct remote *remote, const char *url)
 102 {
 103         add_url(remote, alias_url(url));
 104 }
 105
 106 static struct remote *make_remote(const char *name, int len)
 107 {
 108         struct remote *ret;
 109         int i;
 110
 111         for (i = 0; i < remotes_nr; i++) {
 112                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
 113                            !remotes[i]->name[len]) :
 114                     !strcmp(name, remotes[i]->name))
 115                         return remotes[i];
 116         }
 117
 118         ret = xcalloc(1, sizeof(struct remote));
 119         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 120         remotes[remotes_nr++] = ret;
 121         if (len)
 122                 ret->name = xstrndup(name, len);
 123         else
 124                 ret->name = xstrdup(name);
 125         return ret;
 126 }
 127
 128 static void add_merge(struct branch *branch, const char *name)
 129 {
 130         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 131                    branch->merge_alloc);
 132         branch->merge_name[branch->merge_nr++] = name;
 133 }
 134
 135 static struct branch *make_branch(const char *name, int len)
 136 {
 137         struct branch *ret;
 138         int i;
 139         char *refname;
 140
 141         for (i = 0; i < branches_nr; i++) {
 142                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 143                            !branches[i]->name[len]) :
 144                     !strcmp(name, branches[i]->name))
 145                         return branches[i];
 146         }
 147
 148         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 149         ret = xcalloc(1, sizeof(struct branch));
 150         branches[branches_nr++] = ret;
 151         if (len)
 152                 ret->name = xstrndup(name, len);
 153         else
 154                 ret->name = xstrdup(name);
 155         refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
 156         strcpy(refname, "refs/heads/");
 157         strcpy(refname + strlen("refs/heads/"), ret->name);
 158         ret->refname = refname;
 159
 160         return ret;
 161 }
 162
 163 static struct rewrite *make_rewrite(const char *base, int len)
 164 {
 165         struct rewrite *ret;
 166         int i;
 167
 168         for (i = 0; i < rewrite_nr; i++) {
 169                 if (len
 170                     ? (len == rewrite[i]->baselen &&
 171                        !strncmp(base, rewrite[i]->base, len))
 172                     : !strcmp(base, rewrite[i]->base))
 173                         return rewrite[i];
 174         }
 175
 176         ALLOC_GROW(rewrite, rewrite_nr + 1, rewrite_alloc);
 177         ret = xcalloc(1, sizeof(struct rewrite));
 178         rewrite[rewrite_nr++] = ret;
 179         if (len) {
 180                 ret->base = xstrndup(base, len);
 181                 ret->baselen = len;
 182         }
 183         else {
 184                 ret->base = xstrdup(base);
 185                 ret->baselen = strlen(base);
 186         }
 187         return ret;
 188 }
 189
 190 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 191 {
 192         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 193         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 194         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 195         rewrite->instead_of_nr++;
 196 }
 197
 198 static void read_remotes_file(struct remote *remote)
 199 {
 200         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 201
 202         if (!f)
 203                 return;
 204         while (fgets(buffer, BUF_SIZE, f)) {
 205                 int value_list;
 206                 char *s, *p;
 207
 208                 if (!prefixcmp(buffer, "URL:")) {
 209                         value_list = 0;
 210                         s = buffer + 4;
 211                 } else if (!prefixcmp(buffer, "Push:")) {
 212                         value_list = 1;
 213                         s = buffer + 5;
 214                 } else if (!prefixcmp(buffer, "Pull:")) {
 215                         value_list = 2;
 216                         s = buffer + 5;
 217                 } else
 218                         continue;
 219
 220                 while (isspace(*s))
 221                         s++;
 222                 if (!*s)
 223                         continue;
 224
 225                 p = s + strlen(s);
 226                 while (isspace(p[-1]))
 227                         *--p = 0;
 228
 229                 switch (value_list) {
 230                 case 0:
 231                         add_url_alias(remote, xstrdup(s));
 232                         break;
 233                 case 1:
 234                         add_push_refspec(remote, xstrdup(s));
 235                         break;
 236                 case 2:
 237                         add_fetch_refspec(remote, xstrdup(s));
 238                         break;
 239                 }
 240         }
 241         fclose(f);
 242 }
 243
 244 static void read_branches_file(struct remote *remote)
 245 {
 246         const char *slash = strchr(remote->name, '/');
 247         char *frag;
 248         struct strbuf branch;
 249         int n = slash ? slash - remote->name : 1000;
 250         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 251         char *s, *p;
 252         int len;
 253
 254         if (!f)
 255                 return;
 256         s = fgets(buffer, BUF_SIZE, f);
 257         fclose(f);
 258         if (!s)
 259                 return;
 260         while (isspace(*s))
 261                 s++;
 262         if (!*s)
 263                 return;
 264         p = s + strlen(s);
 265         while (isspace(p[-1]))
 266                 *--p = 0;
 267         len = p - s;
 268         if (slash)
 269                 len += strlen(slash);
 270         p = xmalloc(len + 1);
 271         strcpy(p, s);
 272         if (slash)
 273                 strcat(p, slash);
 274
 275         /*
 276          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 277          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 278          * the partial URL obtained from the branches file plus
 279          * "/netdev-2.6" and does not store it in any tracking ref.
 280          * #branch specifier in the file is ignored.
 281          *
 282          * Otherwise, the branches file would have URL and optionally
 283          * #branch specified.  The "master" (or specified) branch is
 284          * fetched and stored in the local branch of the same name.
 285          */
 286         strbuf_init(&branch, 0);
 287         frag = strchr(p, '#');
 288         if (frag) {
 289                 *(frag++) = '\0';
 290                 strbuf_addf(&branch, "refs/heads/%s", frag);
 291         } else
 292                 strbuf_addstr(&branch, "refs/heads/master");
 293         if (!slash) {
 294                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 295         } else {
 296                 strbuf_reset(&branch);
 297                 strbuf_addstr(&branch, "HEAD:");
 298         }
 299         add_url_alias(remote, p);
 300         add_fetch_refspec(remote, strbuf_detach(&branch, 0));
 301         remote->fetch_tags = 1; /* always auto-follow */
 302 }
 303
 304 static int handle_config(const char *key, const char *value, void *cb)
 305 {
 306         const char *name;
 307         const char *subkey;
 308         struct remote *remote;
 309         struct branch *branch;
 310         if (!prefixcmp(key, "branch.")) {
 311                 name = key + 7;
 312                 subkey = strrchr(name, '.');
 313                 if (!subkey)
 314                         return 0;
 315                 branch = make_branch(name, subkey - name);
 316                 if (!strcmp(subkey, ".remote")) {
 317                         if (!value)
 318                                 return config_error_nonbool(key);
 319                         branch->remote_name = xstrdup(value);
 320                         if (branch == current_branch)
 321                                 default_remote_name = branch->remote_name;
 322                 } else if (!strcmp(subkey, ".merge")) {
 323                         if (!value)
 324                                 return config_error_nonbool(key);
 325                         add_merge(branch, xstrdup(value));
 326                 }
 327                 return 0;
 328         }
 329         if (!prefixcmp(key, "url.")) {
 330                 struct rewrite *rewrite;
 331                 name = key + 4;
 332                 subkey = strrchr(name, '.');
 333                 if (!subkey)
 334                         return 0;
 335                 rewrite = make_rewrite(name, subkey - name);
 336                 if (!strcmp(subkey, ".insteadof")) {
 337                         if (!value)
 338                                 return config_error_nonbool(key);
 339                         add_instead_of(rewrite, xstrdup(value));
 340                 }
 341         }
 342         if (prefixcmp(key,  "remote."))
 343                 return 0;
 344         name = key + 7;
 345         subkey = strrchr(name, '.');
 346         if (!subkey)
 347                 return error("Config with no key for remote %s", name);
 348         if (*subkey == '/') {
 349                 warning("Config remote shorthand cannot begin with '/': %s", name);
 350                 return 0;
 351         }
 352         remote = make_remote(name, subkey - name);
 353         if (!strcmp(subkey, ".mirror"))
 354                 remote->mirror = git_config_bool(key, value);
 355         else if (!strcmp(subkey, ".skipdefaultupdate"))
 356                 remote->skip_default_update = git_config_bool(key, value);
 357
 358         else if (!strcmp(subkey, ".url")) {
 359                 const char *v;
 360                 if (git_config_string(&v, key, value))
 361                         return -1;
 362                 add_url(remote, v);
 363         } else if (!strcmp(subkey, ".push")) {
 364                 const char *v;
 365                 if (git_config_string(&v, key, value))
 366                         return -1;
 367                 add_push_refspec(remote, v);
 368         } else if (!strcmp(subkey, ".fetch")) {
 369                 const char *v;
 370                 if (git_config_string(&v, key, value))
 371                         return -1;
 372                 add_fetch_refspec(remote, v);
 373         } else if (!strcmp(subkey, ".receivepack")) {
 374                 const char *v;
 375                 if (git_config_string(&v, key, value))
 376                         return -1;
 377                 if (!remote->receivepack)
 378                         remote->receivepack = v;
 379                 else
 380                         error("more than one receivepack given, using the first");
 381         } else if (!strcmp(subkey, ".uploadpack")) {
 382                 const char *v;
 383                 if (git_config_string(&v, key, value))
 384                         return -1;
 385                 if (!remote->uploadpack)
 386                         remote->uploadpack = v;
 387                 else
 388                         error("more than one uploadpack given, using the first");
 389         } else if (!strcmp(subkey, ".tagopt")) {
 390                 if (!strcmp(value, "--no-tags"))
 391                         remote->fetch_tags = -1;
 392         } else if (!strcmp(subkey, ".proxy")) {
 393                 return git_config_string((const char **)&remote->http_proxy,
 394                                          key, value);
 395         }
 396         return 0;
 397 }
 398
 399 static void alias_all_urls(void)
 400 {
 401         int i, j;
 402         for (i = 0; i < remotes_nr; i++) {
 403                 if (!remotes[i])
 404                         continue;
 405                 for (j = 0; j < remotes[i]->url_nr; j++) {
 406                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 407                 }
 408         }
 409 }
 410
 411 static void read_config(void)
 412 {
 413         unsigned char sha1[20];
 414         const char *head_ref;
 415         int flag;
 416         if (default_remote_name) // did this already
 417                 return;
 418         default_remote_name = xstrdup("origin");
 419         current_branch = NULL;
 420         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 421         if (head_ref && (flag & REF_ISSYMREF) &&
 422             !prefixcmp(head_ref, "refs/heads/")) {
 423                 current_branch =
 424                         make_branch(head_ref + strlen("refs/heads/"), 0);
 425         }
 426         git_config(handle_config, NULL);
 427         alias_all_urls();
 428 }
 429
 430 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 431 {
 432         int i;
 433         int st;
 434         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 435
 436         for (i = 0; i < nr_refspec; i++) {
 437                 size_t llen, rlen;
 438                 int is_glob;
 439                 const char *lhs, *rhs;
 440
 441                 llen = rlen = is_glob = 0;
 442
 443                 lhs = refspec[i];
 444                 if (*lhs == '+') {
 445                         rs[i].force = 1;
 446                         lhs++;
 447                 }
 448
 449                 rhs = strrchr(lhs, ':');
 450
 451                 /*
 452                  * Before going on, special case ":" (or "+:") as a refspec
 453                  * for matching refs.
 454                  */
 455                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 456                         rs[i].matching = 1;
 457                         continue;
 458                 }
 459
 460                 if (rhs) {
 461                         rhs++;
 462                         rlen = strlen(rhs);
 463                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
 464                         if (is_glob)
 465                                 rlen -= 2;
 466                         rs[i].dst = xstrndup(rhs, rlen);
 467                 }
 468
 469                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 470                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
 471                         if ((rhs && !is_glob) || (!rhs && fetch))
 472                                 goto invalid;
 473                         is_glob = 1;
 474                         llen -= 2;
 475                 } else if (rhs && is_glob) {
 476                         goto invalid;
 477                 }
 478
 479                 rs[i].pattern = is_glob;
 480                 rs[i].src = xstrndup(lhs, llen);
 481
 482                 if (fetch) {
 483                         /*
 484                          * LHS
 485                          * - empty is allowed; it means HEAD.
 486                          * - otherwise it must be a valid looking ref.
 487                          */
 488                         if (!*rs[i].src)
 489                                 ; /* empty is ok */
 490                         else {
 491                                 st = check_ref_format(rs[i].src);
 492                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 493                                         goto invalid;
 494                         }
 495                         /*
 496                          * RHS
 497                          * - missing is ok, and is same as empty.
 498                          * - empty is ok; it means not to store.
 499                          * - otherwise it must be a valid looking ref.
 500                          */
 501                         if (!rs[i].dst) {
 502                                 ; /* ok */
 503                         } else if (!*rs[i].dst) {
 504                                 ; /* ok */
 505                         } else {
 506                                 st = check_ref_format(rs[i].dst);
 507                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 508                                         goto invalid;
 509                         }
 510                 } else {
 511                         /*
 512                          * LHS
 513                          * - empty is allowed; it means delete.
 514                          * - when wildcarded, it must be a valid looking ref.
 515                          * - otherwise, it must be an extended SHA-1, but
 516                          *   there is no existing way to validate this.
 517                          */
 518                         if (!*rs[i].src)
 519                                 ; /* empty is ok */
 520                         else if (is_glob) {
 521                                 st = check_ref_format(rs[i].src);
 522                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 523                                         goto invalid;
 524                         }
 525                         else
 526                                 ; /* anything goes, for now */
 527                         /*
 528                          * RHS
 529                          * - missing is allowed, but LHS then must be a
 530                          *   valid looking ref.
 531                          * - empty is not allowed.
 532                          * - otherwise it must be a valid looking ref.
 533                          */
 534                         if (!rs[i].dst) {
 535                                 st = check_ref_format(rs[i].src);
 536                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 537                                         goto invalid;
 538                         } else if (!*rs[i].dst) {
 539                                 goto invalid;
 540                         } else {
 541                                 st = check_ref_format(rs[i].dst);
 542                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 543                                         goto invalid;
 544                         }
 545                 }
 546         }
 547         return rs;
 548
 549  invalid:
 550         if (verify) {
 551                 free(rs);
 552                 return NULL;
 553         }
 554         die("Invalid refspec '%s'", refspec[i]);
 555 }
 556
 557 int valid_fetch_refspec(const char *fetch_refspec_str)
 558 {
 559         const char *fetch_refspec[] = { fetch_refspec_str };
 560         struct refspec *refspec;
 561
 562         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 563         if (refspec)
 564                 free(refspec);
 565         return !!refspec;
 566 }
 567
 568 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 569 {
 570         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 571 }
 572
 573 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 574 {
 575         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 576 }
 577
 578 static int valid_remote_nick(const char *name)
 579 {
 580         if (!name[0] || /* not empty */
 581             (name[0] == '.' && /* not "." */
 582              (!name[1] || /* not ".." */
 583               (name[1] == '.' && !name[2]))))
 584                 return 0;
 585         return !strchr(name, '/'); /* no slash */
 586 }
 587
 588 struct remote *remote_get(const char *name)
 589 {
 590         struct remote *ret;
 591
 592         read_config();
 593         if (!name)
 594                 name = default_remote_name;
 595         ret = make_remote(name, 0);
 596         if (valid_remote_nick(name)) {
 597                 if (!ret->url)
 598                         read_remotes_file(ret);
 599                 if (!ret->url)
 600                         read_branches_file(ret);
 601         }
 602         if (!ret->url)
 603                 add_url_alias(ret, name);
 604         if (!ret->url)
 605                 return NULL;
 606         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 607         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 608         return ret;
 609 }
 610
 611 int for_each_remote(each_remote_fn fn, void *priv)
 612 {
 613         int i, result = 0;
 614         read_config();
 615         for (i = 0; i < remotes_nr && !result; i++) {
 616                 struct remote *r = remotes[i];
 617                 if (!r)
 618                         continue;
 619                 if (!r->fetch)
 620                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 621                                                        r->fetch_refspec);
 622                 if (!r->push)
 623                         r->push = parse_push_refspec(r->push_refspec_nr,
 624                                                      r->push_refspec);
 625                 result = fn(r, priv);
 626         }
 627         return result;
 628 }
 629
 630 void ref_remove_duplicates(struct ref *ref_map)
 631 {
 632         struct ref **posn;
 633         struct ref *next;
 634         for (; ref_map; ref_map = ref_map->next) {
 635                 if (!ref_map->peer_ref)
 636                         continue;
 637                 posn = &ref_map->next;
 638                 while (*posn) {
 639                         if ((*posn)->peer_ref &&
 640                             !strcmp((*posn)->peer_ref->name,
 641                                     ref_map->peer_ref->name)) {
 642                                 if (strcmp((*posn)->name, ref_map->name))
 643                                         die("%s tracks both %s and %s",
 644                                             ref_map->peer_ref->name,
 645                                             (*posn)->name, ref_map->name);
 646                                 next = (*posn)->next;
 647                                 free((*posn)->peer_ref);
 648                                 free(*posn);
 649                                 *posn = next;
 650                         } else {
 651                                 posn = &(*posn)->next;
 652                         }
 653                 }
 654         }
 655 }
 656
 657 int remote_has_url(struct remote *remote, const char *url)
 658 {
 659         int i;
 660         for (i = 0; i < remote->url_nr; i++) {
 661                 if (!strcmp(remote->url[i], url))
 662                         return 1;
 663         }
 664         return 0;
 665 }
 666
 667 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 668 {
 669         int find_src = refspec->src == NULL;
 670         char *needle, **result;
 671         int i;
 672
 673         if (find_src) {
 674                 if (!refspec->dst)
 675                         return error("find_tracking: need either src or dst");
 676                 needle = refspec->dst;
 677                 result = &refspec->src;
 678         } else {
 679                 needle = refspec->src;
 680                 result = &refspec->dst;
 681         }
 682
 683         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 684                 struct refspec *fetch = &remote->fetch[i];
 685                 const char *key = find_src ? fetch->dst : fetch->src;
 686                 const char *value = find_src ? fetch->src : fetch->dst;
 687                 if (!fetch->dst)
 688                         continue;
 689                 if (fetch->pattern) {
 690                         if (!prefixcmp(needle, key) &&
 691                             needle[strlen(key)] == '/') {
 692                                 *result = xmalloc(strlen(value) +
 693                                                   strlen(needle) -
 694                                                   strlen(key) + 1);
 695                                 strcpy(*result, value);
 696                                 strcpy(*result + strlen(value),
 697                                        needle + strlen(key));
 698                                 refspec->force = fetch->force;
 699                                 return 0;
 700                         }
 701                 } else if (!strcmp(needle, key)) {
 702                         *result = xstrdup(value);
 703                         refspec->force = fetch->force;
 704                         return 0;
 705                 }
 706         }
 707         return -1;
 708 }
 709
 710 struct ref *alloc_ref(unsigned namelen)
 711 {
 712         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
 713         memset(ret, 0, sizeof(struct ref) + namelen);
 714         return ret;
 715 }
 716
 717 struct ref *alloc_ref_from_str(const char* str)
 718 {
 719         struct ref *ret = alloc_ref(strlen(str) + 1);
 720         strcpy(ret->name, str);
 721         return ret;
 722 }
 723
 724 static struct ref *copy_ref(const struct ref *ref)
 725 {
 726         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
 727         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
 728         ret->next = NULL;
 729         return ret;
 730 }
 731
 732 struct ref *copy_ref_list(const struct ref *ref)
 733 {
 734         struct ref *ret = NULL;
 735         struct ref **tail = &ret;
 736         while (ref) {
 737                 *tail = copy_ref(ref);
 738                 ref = ref->next;
 739                 tail = &((*tail)->next);
 740         }
 741         return ret;
 742 }
 743
 744 void free_ref(struct ref *ref)
 745 {
 746         if (!ref)
 747                 return;
 748         free(ref->remote_status);
 749         free(ref->symref);
 750         free(ref);
 751 }
 752
 753 void free_refs(struct ref *ref)
 754 {
 755         struct ref *next;
 756         while (ref) {
 757                 next = ref->next;
 758                 free(ref->peer_ref);
 759                 free_ref(ref);
 760                 ref = next;
 761         }
 762 }
 763
 764 static int count_refspec_match(const char *pattern,
 765                                struct ref *refs,
 766                                struct ref **matched_ref)
 767 {
 768         int patlen = strlen(pattern);
 769         struct ref *matched_weak = NULL;
 770         struct ref *matched = NULL;
 771         int weak_match = 0;
 772         int match = 0;
 773
 774         for (weak_match = match = 0; refs; refs = refs->next) {
 775                 char *name = refs->name;
 776                 int namelen = strlen(name);
 777
 778                 if (!refname_match(pattern, name, ref_rev_parse_rules))
 779                         continue;
 780
 781                 /* A match is "weak" if it is with refs outside
 782                  * heads or tags, and did not specify the pattern
 783                  * in full (e.g. "refs/remotes/origin/master") or at
 784                  * least from the toplevel (e.g. "remotes/origin/master");
 785                  * otherwise "git push $URL master" would result in
 786                  * ambiguity between remotes/origin/master and heads/master
 787                  * at the remote site.
 788                  */
 789                 if (namelen != patlen &&
 790                     patlen != namelen - 5 &&
 791                     prefixcmp(name, "refs/heads/") &&
 792                     prefixcmp(name, "refs/tags/")) {
 793                         /* We want to catch the case where only weak
 794                          * matches are found and there are multiple
 795                          * matches, and where more than one strong
 796                          * matches are found, as ambiguous.  One
 797                          * strong match with zero or more weak matches
 798                          * are acceptable as a unique match.
 799                          */
 800                         matched_weak = refs;
 801                         weak_match++;
 802                 }
 803                 else {
 804                         matched = refs;
 805                         match++;
 806                 }
 807         }
 808         if (!matched) {
 809                 *matched_ref = matched_weak;
 810                 return weak_match;
 811         }
 812         else {
 813                 *matched_ref = matched;
 814                 return match;
 815         }
 816 }
 817
 818 static void tail_link_ref(struct ref *ref, struct ref ***tail)
 819 {
 820         **tail = ref;
 821         while (ref->next)
 822                 ref = ref->next;
 823         *tail = &ref->next;
 824 }
 825
 826 static struct ref *try_explicit_object_name(const char *name)
 827 {
 828         unsigned char sha1[20];
 829         struct ref *ref;
 830
 831         if (!*name) {
 832                 ref = alloc_ref(20);
 833                 strcpy(ref->name, "(delete)");
 834                 hashclr(ref->new_sha1);
 835                 return ref;
 836         }
 837         if (get_sha1(name, sha1))
 838                 return NULL;
 839         ref = alloc_ref_from_str(name);
 840         hashcpy(ref->new_sha1, sha1);
 841         return ref;
 842 }
 843
 844 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 845 {
 846         struct ref *ret = alloc_ref_from_str(name);
 847         tail_link_ref(ret, tail);
 848         return ret;
 849 }
 850
 851 static char *guess_ref(const char *name, struct ref *peer)
 852 {
 853         struct strbuf buf = STRBUF_INIT;
 854         unsigned char sha1[20];
 855
 856         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
 857         if (!r)
 858                 return NULL;
 859
 860         if (!prefixcmp(r, "refs/heads/"))
 861                 strbuf_addstr(&buf, "refs/heads/");
 862         else if (!prefixcmp(r, "refs/tags/"))
 863                 strbuf_addstr(&buf, "refs/tags/");
 864         else
 865                 return NULL;
 866
 867         strbuf_addstr(&buf, name);
 868         return strbuf_detach(&buf, NULL);
 869 }
 870
 871 static int match_explicit(struct ref *src, struct ref *dst,
 872                           struct ref ***dst_tail,
 873                           struct refspec *rs)
 874 {
 875         struct ref *matched_src, *matched_dst;
 876
 877         const char *dst_value = rs->dst;
 878         char *dst_guess;
 879
 880         if (rs->pattern || rs->matching)
 881                 return 0;
 882
 883         matched_src = matched_dst = NULL;
 884         switch (count_refspec_match(rs->src, src, &matched_src)) {
 885         case 1:
 886                 break;
 887         case 0:
 888                 /* The source could be in the get_sha1() format
 889                  * not a reference name.  :refs/other is a
 890                  * way to delete 'other' ref at the remote end.
 891                  */
 892                 matched_src = try_explicit_object_name(rs->src);
 893                 if (!matched_src)
 894                         return error("src refspec %s does not match any.", rs->src);
 895                 break;
 896         default:
 897                 return error("src refspec %s matches more than one.", rs->src);
 898         }
 899
 900         if (!dst_value) {
 901                 unsigned char sha1[20];
 902                 int flag;
 903
 904                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 905                 if (!dst_value ||
 906                     ((flag & REF_ISSYMREF) &&
 907                      prefixcmp(dst_value, "refs/heads/")))
 908                         die("%s cannot be resolved to branch.",
 909                             matched_src->name);
 910         }
 911
 912         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
 913         case 1:
 914                 break;
 915         case 0:
 916                 if (!memcmp(dst_value, "refs/", 5))
 917                         matched_dst = make_linked_ref(dst_value, dst_tail);
 918                 else if((dst_guess = guess_ref(dst_value, matched_src)))
 919                         matched_dst = make_linked_ref(dst_guess, dst_tail);
 920                 else
 921                         error("unable to push to unqualified destination: %s\n"
 922                               "The destination refspec neither matches an "
 923                               "existing ref on the remote nor\n"
 924                               "begins with refs/, and we are unable to "
 925                               "guess a prefix based on the source ref.",
 926                               dst_value);
 927                 break;
 928         default:
 929                 matched_dst = NULL;
 930                 error("dst refspec %s matches more than one.",
 931                       dst_value);
 932                 break;
 933         }
 934         if (!matched_dst)
 935                 return -1;
 936         if (matched_dst->peer_ref)
 937                 return error("dst ref %s receives from more than one src.",
 938                       matched_dst->name);
 939         else {
 940                 matched_dst->peer_ref = matched_src;
 941                 matched_dst->force = rs->force;
 942         }
 943         return 0;
 944 }
 945
 946 static int match_explicit_refs(struct ref *src, struct ref *dst,
 947                                struct ref ***dst_tail, struct refspec *rs,
 948                                int rs_nr)
 949 {
 950         int i, errs;
 951         for (i = errs = 0; i < rs_nr; i++)
 952                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
 953         return errs;
 954 }
 955
 956 static const struct refspec *check_pattern_match(const struct refspec *rs,
 957                                                  int rs_nr,
 958                                                  const struct ref *src)
 959 {
 960         int i;
 961         int matching_refs = -1;
 962         for (i = 0; i < rs_nr; i++) {
 963                 if (rs[i].matching &&
 964                     (matching_refs == -1 || rs[i].force)) {
 965                         matching_refs = i;
 966                         continue;
 967                 }
 968
 969                 if (rs[i].pattern &&
 970                     !prefixcmp(src->name, rs[i].src) &&
 971                     src->name[strlen(rs[i].src)] == '/')
 972                         return rs + i;
 973         }
 974         if (matching_refs != -1)
 975                 return rs + matching_refs;
 976         else
 977                 return NULL;
 978 }
 979
 980 /*
 981  * Note. This is used only by "push"; refspec matching rules for
 982  * push and fetch are subtly different, so do not try to reuse it
 983  * without thinking.
 984  */
 985 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 986                int nr_refspec, const char **refspec, int flags)
 987 {
 988         struct refspec *rs;
 989         int send_all = flags & MATCH_REFS_ALL;
 990         int send_mirror = flags & MATCH_REFS_MIRROR;
 991         static const char *default_refspec[] = { ":", 0 };
 992
 993         if (!nr_refspec) {
 994                 nr_refspec = 1;
 995                 refspec = default_refspec;
 996         }
 997         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
 998         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
 999                 return -1;
1000
1001         /* pick the remainder */
1002         for ( ; src; src = src->next) {
1003                 struct ref *dst_peer;
1004                 const struct refspec *pat = NULL;
1005                 char *dst_name;
1006                 if (src->peer_ref)
1007                         continue;
1008
1009                 pat = check_pattern_match(rs, nr_refspec, src);
1010                 if (!pat)
1011                         continue;
1012
1013                 if (pat->matching) {
1014                         /*
1015                          * "matching refs"; traditionally we pushed everything
1016                          * including refs outside refs/heads/ hierarchy, but
1017                          * that does not make much sense these days.
1018                          */
1019                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1020                                 continue;
1021                         dst_name = xstrdup(src->name);
1022
1023                 } else {
1024                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1025                         dst_name = xmalloc(strlen(dst_side) +
1026                                            strlen(src->name) -
1027                                            strlen(pat->src) + 2);
1028                         strcpy(dst_name, dst_side);
1029                         strcat(dst_name, src->name + strlen(pat->src));
1030                 }
1031                 dst_peer = find_ref_by_name(dst, dst_name);
1032                 if (dst_peer) {
1033                         if (dst_peer->peer_ref)
1034                                 /* We're already sending something to this ref. */
1035                                 goto free_name;
1036
1037                 } else {
1038                         if (pat->matching && !(send_all || send_mirror))
1039                                 /*
1040                                  * Remote doesn't have it, and we have no
1041                                  * explicit pattern, and we don't have
1042                                  * --all nor --mirror.
1043                                  */
1044                                 goto free_name;
1045
1046                         /* Create a new one and link it */
1047                         dst_peer = make_linked_ref(dst_name, dst_tail);
1048                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1049                 }
1050                 dst_peer->peer_ref = src;
1051                 dst_peer->force = pat->force;
1052         free_name:
1053                 free(dst_name);
1054         }
1055         return 0;
1056 }
1057
1058 struct branch *branch_get(const char *name)
1059 {
1060         struct branch *ret;
1061
1062         read_config();
1063         if (!name || !*name || !strcmp(name, "HEAD"))
1064                 ret = current_branch;
1065         else
1066                 ret = make_branch(name, 0);
1067         if (ret && ret->remote_name) {
1068                 ret->remote = remote_get(ret->remote_name);
1069                 if (ret->merge_nr) {
1070                         int i;
1071                         ret->merge = xcalloc(sizeof(*ret->merge),
1072                                              ret->merge_nr);
1073                         for (i = 0; i < ret->merge_nr; i++) {
1074                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1075                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1076                                 remote_find_tracking(ret->remote,
1077                                                      ret->merge[i]);
1078                         }
1079                 }
1080         }
1081         return ret;
1082 }
1083
1084 int branch_has_merge_config(struct branch *branch)
1085 {
1086         return branch && !!branch->merge;
1087 }
1088
1089 int branch_merge_matches(struct branch *branch,
1090                                  int i,
1091                                  const char *refname)
1092 {
1093         if (!branch || i < 0 || i >= branch->merge_nr)
1094                 return 0;
1095         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1096 }
1097
1098 static struct ref *get_expanded_map(const struct ref *remote_refs,
1099                                     const struct refspec *refspec)
1100 {
1101         const struct ref *ref;
1102         struct ref *ret = NULL;
1103         struct ref **tail = &ret;
1104
1105         int remote_prefix_len = strlen(refspec->src);
1106         int local_prefix_len = strlen(refspec->dst);
1107
1108         for (ref = remote_refs; ref; ref = ref->next) {
1109                 if (strchr(ref->name, '^'))
1110                         continue; /* a dereference item */
1111                 if (!prefixcmp(ref->name, refspec->src)) {
1112                         const char *match;
1113                         struct ref *cpy = copy_ref(ref);
1114                         match = ref->name + remote_prefix_len;
1115
1116                         cpy->peer_ref = alloc_ref(local_prefix_len +
1117                                                   strlen(match) + 1);
1118                         sprintf(cpy->peer_ref->name, "%s%s",
1119                                 refspec->dst, match);
1120                         if (refspec->force)
1121                                 cpy->peer_ref->force = 1;
1122                         *tail = cpy;
1123                         tail = &cpy->next;
1124                 }
1125         }
1126
1127         return ret;
1128 }
1129
1130 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1131 {
1132         const struct ref *ref;
1133         for (ref = refs; ref; ref = ref->next) {
1134                 if (refname_match(name, ref->name, ref_fetch_rules))
1135                         return ref;
1136         }
1137         return NULL;
1138 }
1139
1140 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1141 {
1142         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1143
1144         if (!ref)
1145                 return NULL;
1146
1147         return copy_ref(ref);
1148 }
1149
1150 static struct ref *get_local_ref(const char *name)
1151 {
1152         struct ref *ret;
1153         if (!name)
1154                 return NULL;
1155
1156         if (!prefixcmp(name, "refs/")) {
1157                 return alloc_ref_from_str(name);
1158         }
1159
1160         if (!prefixcmp(name, "heads/") ||
1161             !prefixcmp(name, "tags/") ||
1162             !prefixcmp(name, "remotes/")) {
1163                 ret = alloc_ref(strlen(name) + 6);
1164                 sprintf(ret->name, "refs/%s", name);
1165                 return ret;
1166         }
1167
1168         ret = alloc_ref(strlen(name) + 12);
1169         sprintf(ret->name, "refs/heads/%s", name);
1170         return ret;
1171 }
1172
1173 int get_fetch_map(const struct ref *remote_refs,
1174                   const struct refspec *refspec,
1175                   struct ref ***tail,
1176                   int missing_ok)
1177 {
1178         struct ref *ref_map, **rmp;
1179
1180         if (refspec->pattern) {
1181                 ref_map = get_expanded_map(remote_refs, refspec);
1182         } else {
1183                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1184
1185                 ref_map = get_remote_ref(remote_refs, name);
1186                 if (!missing_ok && !ref_map)
1187                         die("Couldn't find remote ref %s", name);
1188                 if (ref_map) {
1189                         ref_map->peer_ref = get_local_ref(refspec->dst);
1190                         if (ref_map->peer_ref && refspec->force)
1191                                 ref_map->peer_ref->force = 1;
1192                 }
1193         }
1194
1195         for (rmp = &ref_map; *rmp; ) {
1196                 if ((*rmp)->peer_ref) {
1197                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1198                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1199                                 struct ref *ignore = *rmp;
1200                                 error("* Ignoring funny ref '%s' locally",
1201                                       (*rmp)->peer_ref->name);
1202                                 *rmp = (*rmp)->next;
1203                                 free(ignore->peer_ref);
1204                                 free(ignore);
1205                                 continue;
1206                         }
1207                 }
1208                 rmp = &((*rmp)->next);
1209         }
1210
1211         if (ref_map)
1212                 tail_link_ref(ref_map, tail);
1213
1214         return 0;
1215 }
1216
1217 int resolve_remote_symref(struct ref *ref, struct ref *list)
1218 {
1219         if (!ref->symref)
1220                 return 0;
1221         for (; list; list = list->next)
1222                 if (!strcmp(ref->symref, list->name)) {
1223                         hashcpy(ref->old_sha1, list->old_sha1);
1224                         return 0;
1225                 }
1226         return 1;
1227 }
1228
1229 /*
1230  * Return true if there is anything to report, otherwise false.
1231  */
1232 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1233 {
1234         unsigned char sha1[20];
1235         struct commit *ours, *theirs;
1236         char symmetric[84];
1237         struct rev_info revs;
1238         const char *rev_argv[10], *base;
1239         int rev_argc;
1240
1241         /*
1242          * Nothing to report unless we are marked to build on top of
1243          * somebody else.
1244          */
1245         if (!branch ||
1246             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1247                 return 0;
1248
1249         /*
1250          * If what we used to build on no longer exists, there is
1251          * nothing to report.
1252          */
1253         base = branch->merge[0]->dst;
1254         if (!resolve_ref(base, sha1, 1, NULL))
1255                 return 0;
1256         theirs = lookup_commit(sha1);
1257         if (!theirs)
1258                 return 0;
1259
1260         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1261                 return 0;
1262         ours = lookup_commit(sha1);
1263         if (!ours)
1264                 return 0;
1265
1266         /* are we the same? */
1267         if (theirs == ours)
1268                 return 0;
1269
1270         /* Run "rev-list --left-right ours...theirs" internally... */
1271         rev_argc = 0;
1272         rev_argv[rev_argc++] = NULL;
1273         rev_argv[rev_argc++] = "--left-right";
1274         rev_argv[rev_argc++] = symmetric;
1275         rev_argv[rev_argc++] = "--";
1276         rev_argv[rev_argc] = NULL;
1277
1278         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1279         strcpy(symmetric + 40, "...");
1280         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1281
1282         init_revisions(&revs, NULL);
1283         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1284         prepare_revision_walk(&revs);
1285
1286         /* ... and count the commits on each side. */
1287         *num_ours = 0;
1288         *num_theirs = 0;
1289         while (1) {
1290                 struct commit *c = get_revision(&revs);
1291                 if (!c)
1292                         break;
1293                 if (c->object.flags & SYMMETRIC_LEFT)
1294                         (*num_ours)++;
1295                 else
1296                         (*num_theirs)++;
1297         }
1298
1299         /* clear object flags smudged by the above traversal */
1300         clear_commit_marks(ours, ALL_REV_FLAGS);
1301         clear_commit_marks(theirs, ALL_REV_FLAGS);
1302         return 1;
1303 }
1304
1305 /*
1306  * Return true when there is anything to report, otherwise false.
1307  */
1308 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1309 {
1310         int num_ours, num_theirs;
1311         const char *base, *remote_msg;
1312
1313         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1314                 return 0;
1315
1316         base = branch->merge[0]->dst;
1317         if (!prefixcmp(base, "refs/remotes/")) {
1318                 remote_msg = " remote";
1319                 base += strlen("refs/remotes/");
1320         } else {
1321                 remote_msg = "";
1322         }
1323         if (!num_theirs)
1324                 strbuf_addf(sb, "Your branch is ahead of the tracked%s branch '%s' "
1325                             "by %d commit%s.\n",
1326                             remote_msg, base,
1327                             num_ours, (num_ours == 1) ? "" : "s");
1328         else if (!num_ours)
1329                 strbuf_addf(sb, "Your branch is behind the tracked%s branch '%s' "
1330                             "by %d commit%s,\n"
1331                             "and can be fast-forwarded.\n",
1332                             remote_msg, base,
1333                             num_theirs, (num_theirs == 1) ? "" : "s");
1334         else
1335                 strbuf_addf(sb, "Your branch and the tracked%s branch '%s' "
1336                             "have diverged,\nand respectively "
1337                             "have %d and %d different commit(s) each.\n",
1338                             remote_msg, base,
1339                             num_ours, num_theirs);
1340         return 1;
1341 }