git.oblomov.eu Git - git/blob - remote.c

   1 #include "cache.h"
   2 #include "remote.h"
   3 #include "refs.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "dir.h"
   8 #include "tag.h"
   9 #include "string-list.h"
  10 #include "mergesort.h"
  11
  12 enum map_direction { FROM_SRC, FROM_DST };
  13
  14 static struct refspec s_tag_refspec = {
  15         0,
  16         1,
  17         0,
  18         0,
  19         "refs/tags/*",
  20         "refs/tags/*"
  21 };
  22
  23 const struct refspec *tag_refspec = &s_tag_refspec;
  24
  25 struct counted_string {
  26         size_t len;
  27         const char *s;
  28 };
  29 struct rewrite {
  30         const char *base;
  31         size_t baselen;
  32         struct counted_string *instead_of;
  33         int instead_of_nr;
  34         int instead_of_alloc;
  35 };
  36 struct rewrites {
  37         struct rewrite **rewrite;
  38         int rewrite_alloc;
  39         int rewrite_nr;
  40 };
  41
  42 static struct remote **remotes;
  43 static int remotes_alloc;
  44 static int remotes_nr;
  45 static struct hashmap remotes_hash;
  46
  47 static struct branch **branches;
  48 static int branches_alloc;
  49 static int branches_nr;
  50
  51 static struct branch *current_branch;
  52 static const char *pushremote_name;
  53
  54 static struct rewrites rewrites;
  55 static struct rewrites rewrites_push;
  56
  57 #define BUF_SIZE (2048)
  58 static char buffer[BUF_SIZE];
  59
  60 static int valid_remote(const struct remote *remote)
  61 {
  62         return (!!remote->url) || (!!remote->foreign_vcs);
  63 }
  64
  65 static const char *alias_url(const char *url, struct rewrites *r)
  66 {
  67         int i, j;
  68         struct counted_string *longest;
  69         int longest_i;
  70
  71         longest = NULL;
  72         longest_i = -1;
  73         for (i = 0; i < r->rewrite_nr; i++) {
  74                 if (!r->rewrite[i])
  75                         continue;
  76                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  77                         if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  78                             (!longest ||
  79                              longest->len < r->rewrite[i]->instead_of[j].len)) {
  80                                 longest = &(r->rewrite[i]->instead_of[j]);
  81                                 longest_i = i;
  82                         }
  83                 }
  84         }
  85         if (!longest)
  86                 return url;
  87
  88         return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  89 }
  90
  91 static void add_push_refspec(struct remote *remote, const char *ref)
  92 {
  93         ALLOC_GROW(remote->push_refspec,
  94                    remote->push_refspec_nr + 1,
  95                    remote->push_refspec_alloc);
  96         remote->push_refspec[remote->push_refspec_nr++] = ref;
  97 }
  98
  99 static void add_fetch_refspec(struct remote *remote, const char *ref)
 100 {
 101         ALLOC_GROW(remote->fetch_refspec,
 102                    remote->fetch_refspec_nr + 1,
 103                    remote->fetch_refspec_alloc);
 104         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 105 }
 106
 107 static void add_url(struct remote *remote, const char *url)
 108 {
 109         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 110         remote->url[remote->url_nr++] = url;
 111 }
 112
 113 static void add_pushurl(struct remote *remote, const char *pushurl)
 114 {
 115         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 116         remote->pushurl[remote->pushurl_nr++] = pushurl;
 117 }
 118
 119 static void add_pushurl_alias(struct remote *remote, const char *url)
 120 {
 121         const char *pushurl = alias_url(url, &rewrites_push);
 122         if (pushurl != url)
 123                 add_pushurl(remote, pushurl);
 124 }
 125
 126 static void add_url_alias(struct remote *remote, const char *url)
 127 {
 128         add_url(remote, alias_url(url, &rewrites));
 129         add_pushurl_alias(remote, url);
 130 }
 131
 132 struct remotes_hash_key {
 133         const char *str;
 134         int len;
 135 };
 136
 137 static int remotes_hash_cmp(const struct remote *a, const struct remote *b, const struct remotes_hash_key *key)
 138 {
 139         if (key)
 140                 return strncmp(a->name, key->str, key->len) || a->name[key->len];
 141         else
 142                 return strcmp(a->name, b->name);
 143 }
 144
 145 static inline void init_remotes_hash(void)
 146 {
 147         if (!remotes_hash.cmpfn)
 148                 hashmap_init(&remotes_hash, (hashmap_cmp_fn)remotes_hash_cmp, 0);
 149 }
 150
 151 static struct remote *make_remote(const char *name, int len)
 152 {
 153         struct remote *ret, *replaced;
 154         struct remotes_hash_key lookup;
 155         struct hashmap_entry lookup_entry;
 156
 157         if (!len)
 158                 len = strlen(name);
 159
 160         init_remotes_hash();
 161         lookup.str = name;
 162         lookup.len = len;
 163         hashmap_entry_init(&lookup_entry, memhash(name, len));
 164
 165         if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 166                 return ret;
 167
 168         ret = xcalloc(1, sizeof(struct remote));
 169         ret->prune = -1;  /* unspecified */
 170         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 171         remotes[remotes_nr++] = ret;
 172         ret->name = xstrndup(name, len);
 173
 174         hashmap_entry_init(ret, lookup_entry.hash);
 175         replaced = hashmap_put(&remotes_hash, ret);
 176         assert(replaced == NULL);  /* no previous entry overwritten */
 177         return ret;
 178 }
 179
 180 static void add_merge(struct branch *branch, const char *name)
 181 {
 182         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 183                    branch->merge_alloc);
 184         branch->merge_name[branch->merge_nr++] = name;
 185 }
 186
 187 static struct branch *make_branch(const char *name, int len)
 188 {
 189         struct branch *ret;
 190         int i;
 191
 192         for (i = 0; i < branches_nr; i++) {
 193                 if (len ? (!strncmp(name, branches[i]->name, len) &&
 194                            !branches[i]->name[len]) :
 195                     !strcmp(name, branches[i]->name))
 196                         return branches[i];
 197         }
 198
 199         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 200         ret = xcalloc(1, sizeof(struct branch));
 201         branches[branches_nr++] = ret;
 202         if (len)
 203                 ret->name = xstrndup(name, len);
 204         else
 205                 ret->name = xstrdup(name);
 206         ret->refname = xstrfmt("refs/heads/%s", ret->name);
 207
 208         return ret;
 209 }
 210
 211 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 212 {
 213         struct rewrite *ret;
 214         int i;
 215
 216         for (i = 0; i < r->rewrite_nr; i++) {
 217                 if (len
 218                     ? (len == r->rewrite[i]->baselen &&
 219                        !strncmp(base, r->rewrite[i]->base, len))
 220                     : !strcmp(base, r->rewrite[i]->base))
 221                         return r->rewrite[i];
 222         }
 223
 224         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 225         ret = xcalloc(1, sizeof(struct rewrite));
 226         r->rewrite[r->rewrite_nr++] = ret;
 227         if (len) {
 228                 ret->base = xstrndup(base, len);
 229                 ret->baselen = len;
 230         }
 231         else {
 232                 ret->base = xstrdup(base);
 233                 ret->baselen = strlen(base);
 234         }
 235         return ret;
 236 }
 237
 238 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 239 {
 240         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 241         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 242         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 243         rewrite->instead_of_nr++;
 244 }
 245
 246 static void read_remotes_file(struct remote *remote)
 247 {
 248         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 249
 250         if (!f)
 251                 return;
 252         remote->origin = REMOTE_REMOTES;
 253         while (fgets(buffer, BUF_SIZE, f)) {
 254                 int value_list;
 255                 char *s, *p;
 256
 257                 if (starts_with(buffer, "URL:")) {
 258                         value_list = 0;
 259                         s = buffer + 4;
 260                 } else if (starts_with(buffer, "Push:")) {
 261                         value_list = 1;
 262                         s = buffer + 5;
 263                 } else if (starts_with(buffer, "Pull:")) {
 264                         value_list = 2;
 265                         s = buffer + 5;
 266                 } else
 267                         continue;
 268
 269                 while (isspace(*s))
 270                         s++;
 271                 if (!*s)
 272                         continue;
 273
 274                 p = s + strlen(s);
 275                 while (isspace(p[-1]))
 276                         *--p = 0;
 277
 278                 switch (value_list) {
 279                 case 0:
 280                         add_url_alias(remote, xstrdup(s));
 281                         break;
 282                 case 1:
 283                         add_push_refspec(remote, xstrdup(s));
 284                         break;
 285                 case 2:
 286                         add_fetch_refspec(remote, xstrdup(s));
 287                         break;
 288                 }
 289         }
 290         fclose(f);
 291 }
 292
 293 static void read_branches_file(struct remote *remote)
 294 {
 295         char *frag;
 296         struct strbuf branch = STRBUF_INIT;
 297         int n = 1000;
 298         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 299         char *s, *p;
 300         int len;
 301
 302         if (!f)
 303                 return;
 304         s = fgets(buffer, BUF_SIZE, f);
 305         fclose(f);
 306         if (!s)
 307                 return;
 308         while (isspace(*s))
 309                 s++;
 310         if (!*s)
 311                 return;
 312         remote->origin = REMOTE_BRANCHES;
 313         p = s + strlen(s);
 314         while (isspace(p[-1]))
 315                 *--p = 0;
 316         len = p - s;
 317         p = xmalloc(len + 1);
 318         strcpy(p, s);
 319
 320         /*
 321          * The branches file would have URL and optionally
 322          * #branch specified.  The "master" (or specified) branch is
 323          * fetched and stored in the local branch of the same name.
 324          */
 325         frag = strchr(p, '#');
 326         if (frag) {
 327                 *(frag++) = '\0';
 328                 strbuf_addf(&branch, "refs/heads/%s", frag);
 329         } else
 330                 strbuf_addstr(&branch, "refs/heads/master");
 331
 332         strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 333         add_url_alias(remote, p);
 334         add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 335         /*
 336          * Cogito compatible push: push current HEAD to remote #branch
 337          * (master if missing)
 338          */
 339         strbuf_init(&branch, 0);
 340         strbuf_addstr(&branch, "HEAD");
 341         if (frag)
 342                 strbuf_addf(&branch, ":refs/heads/%s", frag);
 343         else
 344                 strbuf_addstr(&branch, ":refs/heads/master");
 345         add_push_refspec(remote, strbuf_detach(&branch, NULL));
 346         remote->fetch_tags = 1; /* always auto-follow */
 347 }
 348
 349 static int handle_config(const char *key, const char *value, void *cb)
 350 {
 351         const char *name;
 352         const char *subkey;
 353         struct remote *remote;
 354         struct branch *branch;
 355         if (starts_with(key, "branch.")) {
 356                 name = key + 7;
 357                 subkey = strrchr(name, '.');
 358                 if (!subkey)
 359                         return 0;
 360                 branch = make_branch(name, subkey - name);
 361                 if (!strcmp(subkey, ".remote")) {
 362                         return git_config_string(&branch->remote_name, key, value);
 363                 } else if (!strcmp(subkey, ".pushremote")) {
 364                         return git_config_string(&branch->pushremote_name, key, value);
 365                 } else if (!strcmp(subkey, ".merge")) {
 366                         if (!value)
 367                                 return config_error_nonbool(key);
 368                         add_merge(branch, xstrdup(value));
 369                 }
 370                 return 0;
 371         }
 372         if (starts_with(key, "url.")) {
 373                 struct rewrite *rewrite;
 374                 name = key + 4;
 375                 subkey = strrchr(name, '.');
 376                 if (!subkey)
 377                         return 0;
 378                 if (!strcmp(subkey, ".insteadof")) {
 379                         rewrite = make_rewrite(&rewrites, name, subkey - name);
 380                         if (!value)
 381                                 return config_error_nonbool(key);
 382                         add_instead_of(rewrite, xstrdup(value));
 383                 } else if (!strcmp(subkey, ".pushinsteadof")) {
 384                         rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 385                         if (!value)
 386                                 return config_error_nonbool(key);
 387                         add_instead_of(rewrite, xstrdup(value));
 388                 }
 389         }
 390
 391         if (!starts_with(key,  "remote."))
 392                 return 0;
 393         name = key + 7;
 394
 395         /* Handle remote.* variables */
 396         if (!strcmp(name, "pushdefault"))
 397                 return git_config_string(&pushremote_name, key, value);
 398
 399         /* Handle remote.<name>.* variables */
 400         if (*name == '/') {
 401                 warning("Config remote shorthand cannot begin with '/': %s",
 402                         name);
 403                 return 0;
 404         }
 405         subkey = strrchr(name, '.');
 406         if (!subkey)
 407                 return 0;
 408         remote = make_remote(name, subkey - name);
 409         remote->origin = REMOTE_CONFIG;
 410         if (!strcmp(subkey, ".mirror"))
 411                 remote->mirror = git_config_bool(key, value);
 412         else if (!strcmp(subkey, ".skipdefaultupdate"))
 413                 remote->skip_default_update = git_config_bool(key, value);
 414         else if (!strcmp(subkey, ".skipfetchall"))
 415                 remote->skip_default_update = git_config_bool(key, value);
 416         else if (!strcmp(subkey, ".prune"))
 417                 remote->prune = git_config_bool(key, value);
 418         else if (!strcmp(subkey, ".url")) {
 419                 const char *v;
 420                 if (git_config_string(&v, key, value))
 421                         return -1;
 422                 add_url(remote, v);
 423         } else if (!strcmp(subkey, ".pushurl")) {
 424                 const char *v;
 425                 if (git_config_string(&v, key, value))
 426                         return -1;
 427                 add_pushurl(remote, v);
 428         } else if (!strcmp(subkey, ".push")) {
 429                 const char *v;
 430                 if (git_config_string(&v, key, value))
 431                         return -1;
 432                 add_push_refspec(remote, v);
 433         } else if (!strcmp(subkey, ".fetch")) {
 434                 const char *v;
 435                 if (git_config_string(&v, key, value))
 436                         return -1;
 437                 add_fetch_refspec(remote, v);
 438         } else if (!strcmp(subkey, ".receivepack")) {
 439                 const char *v;
 440                 if (git_config_string(&v, key, value))
 441                         return -1;
 442                 if (!remote->receivepack)
 443                         remote->receivepack = v;
 444                 else
 445                         error("more than one receivepack given, using the first");
 446         } else if (!strcmp(subkey, ".uploadpack")) {
 447                 const char *v;
 448                 if (git_config_string(&v, key, value))
 449                         return -1;
 450                 if (!remote->uploadpack)
 451                         remote->uploadpack = v;
 452                 else
 453                         error("more than one uploadpack given, using the first");
 454         } else if (!strcmp(subkey, ".tagopt")) {
 455                 if (!strcmp(value, "--no-tags"))
 456                         remote->fetch_tags = -1;
 457                 else if (!strcmp(value, "--tags"))
 458                         remote->fetch_tags = 2;
 459         } else if (!strcmp(subkey, ".proxy")) {
 460                 return git_config_string((const char **)&remote->http_proxy,
 461                                          key, value);
 462         } else if (!strcmp(subkey, ".vcs")) {
 463                 return git_config_string(&remote->foreign_vcs, key, value);
 464         }
 465         return 0;
 466 }
 467
 468 static void alias_all_urls(void)
 469 {
 470         int i, j;
 471         for (i = 0; i < remotes_nr; i++) {
 472                 int add_pushurl_aliases;
 473                 if (!remotes[i])
 474                         continue;
 475                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 476                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 477                 }
 478                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 479                 for (j = 0; j < remotes[i]->url_nr; j++) {
 480                         if (add_pushurl_aliases)
 481                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 482                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 483                 }
 484         }
 485 }
 486
 487 static void read_config(void)
 488 {
 489         static int loaded;
 490         unsigned char sha1[20];
 491         const char *head_ref;
 492         int flag;
 493
 494         if (loaded)
 495                 return;
 496         loaded = 1;
 497
 498         current_branch = NULL;
 499         head_ref = resolve_ref_unsafe("HEAD", 0, sha1, &flag);
 500         if (head_ref && (flag & REF_ISSYMREF) &&
 501             skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 502                 current_branch = make_branch(head_ref, 0);
 503         }
 504         git_config(handle_config, NULL);
 505         alias_all_urls();
 506 }
 507
 508 /*
 509  * This function frees a refspec array.
 510  * Warning: code paths should be checked to ensure that the src
 511  *          and dst pointers are always freeable pointers as well
 512  *          as the refspec pointer itself.
 513  */
 514 static void free_refspecs(struct refspec *refspec, int nr_refspec)
 515 {
 516         int i;
 517
 518         if (!refspec)
 519                 return;
 520
 521         for (i = 0; i < nr_refspec; i++) {
 522                 free(refspec[i].src);
 523                 free(refspec[i].dst);
 524         }
 525         free(refspec);
 526 }
 527
 528 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 529 {
 530         int i;
 531         struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 532
 533         for (i = 0; i < nr_refspec; i++) {
 534                 size_t llen;
 535                 int is_glob;
 536                 const char *lhs, *rhs;
 537                 int flags;
 538
 539                 is_glob = 0;
 540
 541                 lhs = refspec[i];
 542                 if (*lhs == '+') {
 543                         rs[i].force = 1;
 544                         lhs++;
 545                 }
 546
 547                 rhs = strrchr(lhs, ':');
 548
 549                 /*
 550                  * Before going on, special case ":" (or "+:") as a refspec
 551                  * for pushing matching refs.
 552                  */
 553                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
 554                         rs[i].matching = 1;
 555                         continue;
 556                 }
 557
 558                 if (rhs) {
 559                         size_t rlen = strlen(++rhs);
 560                         is_glob = (1 <= rlen && strchr(rhs, '*'));
 561                         rs[i].dst = xstrndup(rhs, rlen);
 562                 }
 563
 564                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 565                 if (1 <= llen && memchr(lhs, '*', llen)) {
 566                         if ((rhs && !is_glob) || (!rhs && fetch))
 567                                 goto invalid;
 568                         is_glob = 1;
 569                 } else if (rhs && is_glob) {
 570                         goto invalid;
 571                 }
 572
 573                 rs[i].pattern = is_glob;
 574                 rs[i].src = xstrndup(lhs, llen);
 575                 flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 576
 577                 if (fetch) {
 578                         unsigned char unused[40];
 579
 580                         /* LHS */
 581                         if (!*rs[i].src)
 582                                 ; /* empty is ok; it means "HEAD" */
 583                         else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 584                                 rs[i].exact_sha1 = 1; /* ok */
 585                         else if (!check_refname_format(rs[i].src, flags))
 586                                 ; /* valid looking ref is ok */
 587                         else
 588                                 goto invalid;
 589                         /* RHS */
 590                         if (!rs[i].dst)
 591                                 ; /* missing is ok; it is the same as empty */
 592                         else if (!*rs[i].dst)
 593                                 ; /* empty is ok; it means "do not store" */
 594                         else if (!check_refname_format(rs[i].dst, flags))
 595                                 ; /* valid looking ref is ok */
 596                         else
 597                                 goto invalid;
 598                 } else {
 599                         /*
 600                          * LHS
 601                          * - empty is allowed; it means delete.
 602                          * - when wildcarded, it must be a valid looking ref.
 603                          * - otherwise, it must be an extended SHA-1, but
 604                          *   there is no existing way to validate this.
 605                          */
 606                         if (!*rs[i].src)
 607                                 ; /* empty is ok */
 608                         else if (is_glob) {
 609                                 if (check_refname_format(rs[i].src, flags))
 610                                         goto invalid;
 611                         }
 612                         else
 613                                 ; /* anything goes, for now */
 614                         /*
 615                          * RHS
 616                          * - missing is allowed, but LHS then must be a
 617                          *   valid looking ref.
 618                          * - empty is not allowed.
 619                          * - otherwise it must be a valid looking ref.
 620                          */
 621                         if (!rs[i].dst) {
 622                                 if (check_refname_format(rs[i].src, flags))
 623                                         goto invalid;
 624                         } else if (!*rs[i].dst) {
 625                                 goto invalid;
 626                         } else {
 627                                 if (check_refname_format(rs[i].dst, flags))
 628                                         goto invalid;
 629                         }
 630                 }
 631         }
 632         return rs;
 633
 634  invalid:
 635         if (verify) {
 636                 /*
 637                  * nr_refspec must be greater than zero and i must be valid
 638                  * since it is only possible to reach this point from within
 639                  * the for loop above.
 640                  */
 641                 free_refspecs(rs, i+1);
 642                 return NULL;
 643         }
 644         die("Invalid refspec '%s'", refspec[i]);
 645 }
 646
 647 int valid_fetch_refspec(const char *fetch_refspec_str)
 648 {
 649         struct refspec *refspec;
 650
 651         refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 652         free_refspecs(refspec, 1);
 653         return !!refspec;
 654 }
 655
 656 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 657 {
 658         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 659 }
 660
 661 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 662 {
 663         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 664 }
 665
 666 void free_refspec(int nr_refspec, struct refspec *refspec)
 667 {
 668         int i;
 669         for (i = 0; i < nr_refspec; i++) {
 670                 free(refspec[i].src);
 671                 free(refspec[i].dst);
 672         }
 673         free(refspec);
 674 }
 675
 676 static int valid_remote_nick(const char *name)
 677 {
 678         if (!name[0] || is_dot_or_dotdot(name))
 679                 return 0;
 680         return !strchr(name, '/'); /* no slash */
 681 }
 682
 683 const char *remote_for_branch(struct branch *branch, int *explicit)
 684 {
 685         if (branch && branch->remote_name) {
 686                 if (explicit)
 687                         *explicit = 1;
 688                 return branch->remote_name;
 689         }
 690         if (explicit)
 691                 *explicit = 0;
 692         return "origin";
 693 }
 694
 695 const char *pushremote_for_branch(struct branch *branch, int *explicit)
 696 {
 697         if (branch && branch->pushremote_name) {
 698                 if (explicit)
 699                         *explicit = 1;
 700                 return branch->pushremote_name;
 701         }
 702         if (pushremote_name) {
 703                 if (explicit)
 704                         *explicit = 1;
 705                 return pushremote_name;
 706         }
 707         return remote_for_branch(branch, explicit);
 708 }
 709
 710 static struct remote *remote_get_1(const char *name,
 711                                    const char *(*get_default)(struct branch *, int *))
 712 {
 713         struct remote *ret;
 714         int name_given = 0;
 715
 716         read_config();
 717
 718         if (name)
 719                 name_given = 1;
 720         else
 721                 name = get_default(current_branch, &name_given);
 722
 723         ret = make_remote(name, 0);
 724         if (valid_remote_nick(name)) {
 725                 if (!valid_remote(ret))
 726                         read_remotes_file(ret);
 727                 if (!valid_remote(ret))
 728                         read_branches_file(ret);
 729         }
 730         if (name_given && !valid_remote(ret))
 731                 add_url_alias(ret, name);
 732         if (!valid_remote(ret))
 733                 return NULL;
 734         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 735         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 736         return ret;
 737 }
 738
 739 struct remote *remote_get(const char *name)
 740 {
 741         return remote_get_1(name, remote_for_branch);
 742 }
 743
 744 struct remote *pushremote_get(const char *name)
 745 {
 746         return remote_get_1(name, pushremote_for_branch);
 747 }
 748
 749 int remote_is_configured(const char *name)
 750 {
 751         struct remotes_hash_key lookup;
 752         struct hashmap_entry lookup_entry;
 753         read_config();
 754
 755         init_remotes_hash();
 756         lookup.str = name;
 757         lookup.len = strlen(name);
 758         hashmap_entry_init(&lookup_entry, memhash(name, lookup.len));
 759
 760         return hashmap_get(&remotes_hash, &lookup_entry, &lookup) != NULL;
 761 }
 762
 763 int for_each_remote(each_remote_fn fn, void *priv)
 764 {
 765         int i, result = 0;
 766         read_config();
 767         for (i = 0; i < remotes_nr && !result; i++) {
 768                 struct remote *r = remotes[i];
 769                 if (!r)
 770                         continue;
 771                 if (!r->fetch)
 772                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 773                                                        r->fetch_refspec);
 774                 if (!r->push)
 775                         r->push = parse_push_refspec(r->push_refspec_nr,
 776                                                      r->push_refspec);
 777                 result = fn(r, priv);
 778         }
 779         return result;
 780 }
 781
 782 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 783 {
 784         if (strcmp(ref1->name, ref2->name)) {
 785                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 786                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 787                         die(_("Cannot fetch both %s and %s to %s"),
 788                             ref1->name, ref2->name, ref2->peer_ref->name);
 789                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 790                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 791                         warning(_("%s usually tracks %s, not %s"),
 792                                 ref2->peer_ref->name, ref2->name, ref1->name);
 793                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 794                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 795                         die(_("%s tracks both %s and %s"),
 796                             ref2->peer_ref->name, ref1->name, ref2->name);
 797                 } else {
 798                         /*
 799                          * This last possibility doesn't occur because
 800                          * FETCH_HEAD_IGNORE entries always appear at
 801                          * the end of the list.
 802                          */
 803                         die(_("Internal error"));
 804                 }
 805         }
 806         free(ref2->peer_ref);
 807         free(ref2);
 808 }
 809
 810 struct ref *ref_remove_duplicates(struct ref *ref_map)
 811 {
 812         struct string_list refs = STRING_LIST_INIT_NODUP;
 813         struct ref *retval = NULL;
 814         struct ref **p = &retval;
 815
 816         while (ref_map) {
 817                 struct ref *ref = ref_map;
 818
 819                 ref_map = ref_map->next;
 820                 ref->next = NULL;
 821
 822                 if (!ref->peer_ref) {
 823                         *p = ref;
 824                         p = &ref->next;
 825                 } else {
 826                         struct string_list_item *item =
 827                                 string_list_insert(&refs, ref->peer_ref->name);
 828
 829                         if (item->util) {
 830                                 /* Entry already existed */
 831                                 handle_duplicate((struct ref *)item->util, ref);
 832                         } else {
 833                                 *p = ref;
 834                                 p = &ref->next;
 835                                 item->util = ref;
 836                         }
 837                 }
 838         }
 839
 840         string_list_clear(&refs, 0);
 841         return retval;
 842 }
 843
 844 int remote_has_url(struct remote *remote, const char *url)
 845 {
 846         int i;
 847         for (i = 0; i < remote->url_nr; i++) {
 848                 if (!strcmp(remote->url[i], url))
 849                         return 1;
 850         }
 851         return 0;
 852 }
 853
 854 static int match_name_with_pattern(const char *key, const char *name,
 855                                    const char *value, char **result)
 856 {
 857         const char *kstar = strchr(key, '*');
 858         size_t klen;
 859         size_t ksuffixlen;
 860         size_t namelen;
 861         int ret;
 862         if (!kstar)
 863                 die("Key '%s' of pattern had no '*'", key);
 864         klen = kstar - key;
 865         ksuffixlen = strlen(kstar + 1);
 866         namelen = strlen(name);
 867         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 868                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 869         if (ret && value) {
 870                 struct strbuf sb = STRBUF_INIT;
 871                 const char *vstar = strchr(value, '*');
 872                 if (!vstar)
 873                         die("Value '%s' of pattern has no '*'", value);
 874                 strbuf_add(&sb, value, vstar - value);
 875                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 876                 strbuf_addstr(&sb, vstar + 1);
 877                 *result = strbuf_detach(&sb, NULL);
 878         }
 879         return ret;
 880 }
 881
 882 static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 883 {
 884         int i;
 885         int find_src = !query->src;
 886
 887         if (find_src && !query->dst)
 888                 error("query_refspecs_multiple: need either src or dst");
 889
 890         for (i = 0; i < ref_count; i++) {
 891                 struct refspec *refspec = &refs[i];
 892                 const char *key = find_src ? refspec->dst : refspec->src;
 893                 const char *value = find_src ? refspec->src : refspec->dst;
 894                 const char *needle = find_src ? query->dst : query->src;
 895                 char **result = find_src ? &query->src : &query->dst;
 896
 897                 if (!refspec->dst)
 898                         continue;
 899                 if (refspec->pattern) {
 900                         if (match_name_with_pattern(key, needle, value, result))
 901                                 string_list_append_nodup(results, *result);
 902                 } else if (!strcmp(needle, key)) {
 903                         string_list_append(results, value);
 904                 }
 905         }
 906 }
 907
 908 int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 909 {
 910         int i;
 911         int find_src = !query->src;
 912         const char *needle = find_src ? query->dst : query->src;
 913         char **result = find_src ? &query->src : &query->dst;
 914
 915         if (find_src && !query->dst)
 916                 return error("query_refspecs: need either src or dst");
 917
 918         for (i = 0; i < ref_count; i++) {
 919                 struct refspec *refspec = &refs[i];
 920                 const char *key = find_src ? refspec->dst : refspec->src;
 921                 const char *value = find_src ? refspec->src : refspec->dst;
 922
 923                 if (!refspec->dst)
 924                         continue;
 925                 if (refspec->pattern) {
 926                         if (match_name_with_pattern(key, needle, value, result)) {
 927                                 query->force = refspec->force;
 928                                 return 0;
 929                         }
 930                 } else if (!strcmp(needle, key)) {
 931                         *result = xstrdup(value);
 932                         query->force = refspec->force;
 933                         return 0;
 934                 }
 935         }
 936         return -1;
 937 }
 938
 939 char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 940                      const char *name)
 941 {
 942         struct refspec query;
 943
 944         memset(&query, 0, sizeof(struct refspec));
 945         query.src = (char *)name;
 946
 947         if (query_refspecs(refspecs, nr_refspec, &query))
 948                 return NULL;
 949
 950         return query.dst;
 951 }
 952
 953 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 954 {
 955         return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 956 }
 957
 958 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 959                 const char *name)
 960 {
 961         size_t len = strlen(name);
 962         struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 963         memcpy(ref->name, prefix, prefixlen);
 964         memcpy(ref->name + prefixlen, name, len);
 965         return ref;
 966 }
 967
 968 struct ref *alloc_ref(const char *name)
 969 {
 970         return alloc_ref_with_prefix("", 0, name);
 971 }
 972
 973 struct ref *copy_ref(const struct ref *ref)
 974 {
 975         struct ref *cpy;
 976         size_t len;
 977         if (!ref)
 978                 return NULL;
 979         len = strlen(ref->name);
 980         cpy = xmalloc(sizeof(struct ref) + len + 1);
 981         memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 982         cpy->next = NULL;
 983         cpy->symref = xstrdup_or_null(ref->symref);
 984         cpy->remote_status = xstrdup_or_null(ref->remote_status);
 985         cpy->peer_ref = copy_ref(ref->peer_ref);
 986         return cpy;
 987 }
 988
 989 struct ref *copy_ref_list(const struct ref *ref)
 990 {
 991         struct ref *ret = NULL;
 992         struct ref **tail = &ret;
 993         while (ref) {
 994                 *tail = copy_ref(ref);
 995                 ref = ref->next;
 996                 tail = &((*tail)->next);
 997         }
 998         return ret;
 999 }
1000
1001 static void free_ref(struct ref *ref)
1002 {
1003         if (!ref)
1004                 return;
1005         free_ref(ref->peer_ref);
1006         free(ref->remote_status);
1007         free(ref->symref);
1008         free(ref);
1009 }
1010
1011 void free_refs(struct ref *ref)
1012 {
1013         struct ref *next;
1014         while (ref) {
1015                 next = ref->next;
1016                 free_ref(ref);
1017                 ref = next;
1018         }
1019 }
1020
1021 int ref_compare_name(const void *va, const void *vb)
1022 {
1023         const struct ref *a = va, *b = vb;
1024         return strcmp(a->name, b->name);
1025 }
1026
1027 static void *ref_list_get_next(const void *a)
1028 {
1029         return ((const struct ref *)a)->next;
1030 }
1031
1032 static void ref_list_set_next(void *a, void *next)
1033 {
1034         ((struct ref *)a)->next = next;
1035 }
1036
1037 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1038 {
1039         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1040 }
1041
1042 int count_refspec_match(const char *pattern,
1043                         struct ref *refs,
1044                         struct ref **matched_ref)
1045 {
1046         int patlen = strlen(pattern);
1047         struct ref *matched_weak = NULL;
1048         struct ref *matched = NULL;
1049         int weak_match = 0;
1050         int match = 0;
1051
1052         for (weak_match = match = 0; refs; refs = refs->next) {
1053                 char *name = refs->name;
1054                 int namelen = strlen(name);
1055
1056                 if (!refname_match(pattern, name))
1057                         continue;
1058
1059                 /* A match is "weak" if it is with refs outside
1060                  * heads or tags, and did not specify the pattern
1061                  * in full (e.g. "refs/remotes/origin/master") or at
1062                  * least from the toplevel (e.g. "remotes/origin/master");
1063                  * otherwise "git push $URL master" would result in
1064                  * ambiguity between remotes/origin/master and heads/master
1065                  * at the remote site.
1066                  */
1067                 if (namelen != patlen &&
1068                     patlen != namelen - 5 &&
1069                     !starts_with(name, "refs/heads/") &&
1070                     !starts_with(name, "refs/tags/")) {
1071                         /* We want to catch the case where only weak
1072                          * matches are found and there are multiple
1073                          * matches, and where more than one strong
1074                          * matches are found, as ambiguous.  One
1075                          * strong match with zero or more weak matches
1076                          * are acceptable as a unique match.
1077                          */
1078                         matched_weak = refs;
1079                         weak_match++;
1080                 }
1081                 else {
1082                         matched = refs;
1083                         match++;
1084                 }
1085         }
1086         if (!matched) {
1087                 if (matched_ref)
1088                         *matched_ref = matched_weak;
1089                 return weak_match;
1090         }
1091         else {
1092                 if (matched_ref)
1093                         *matched_ref = matched;
1094                 return match;
1095         }
1096 }
1097
1098 static void tail_link_ref(struct ref *ref, struct ref ***tail)
1099 {
1100         **tail = ref;
1101         while (ref->next)
1102                 ref = ref->next;
1103         *tail = &ref->next;
1104 }
1105
1106 static struct ref *alloc_delete_ref(void)
1107 {
1108         struct ref *ref = alloc_ref("(delete)");
1109         hashclr(ref->new_sha1);
1110         return ref;
1111 }
1112
1113 static int try_explicit_object_name(const char *name,
1114                                     struct ref **match)
1115 {
1116         unsigned char sha1[20];
1117
1118         if (!*name) {
1119                 if (match)
1120                         *match = alloc_delete_ref();
1121                 return 0;
1122         }
1123
1124         if (get_sha1(name, sha1))
1125                 return -1;
1126
1127         if (match) {
1128                 *match = alloc_ref(name);
1129                 hashcpy((*match)->new_sha1, sha1);
1130         }
1131         return 0;
1132 }
1133
1134 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1135 {
1136         struct ref *ret = alloc_ref(name);
1137         tail_link_ref(ret, tail);
1138         return ret;
1139 }
1140
1141 static char *guess_ref(const char *name, struct ref *peer)
1142 {
1143         struct strbuf buf = STRBUF_INIT;
1144         unsigned char sha1[20];
1145
1146         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1147                                            sha1, NULL);
1148         if (!r)
1149                 return NULL;
1150
1151         if (starts_with(r, "refs/heads/"))
1152                 strbuf_addstr(&buf, "refs/heads/");
1153         else if (starts_with(r, "refs/tags/"))
1154                 strbuf_addstr(&buf, "refs/tags/");
1155         else
1156                 return NULL;
1157
1158         strbuf_addstr(&buf, name);
1159         return strbuf_detach(&buf, NULL);
1160 }
1161
1162 static int match_explicit_lhs(struct ref *src,
1163                               struct refspec *rs,
1164                               struct ref **match,
1165                               int *allocated_match)
1166 {
1167         switch (count_refspec_match(rs->src, src, match)) {
1168         case 1:
1169                 if (allocated_match)
1170                         *allocated_match = 0;
1171                 return 0;
1172         case 0:
1173                 /* The source could be in the get_sha1() format
1174                  * not a reference name.  :refs/other is a
1175                  * way to delete 'other' ref at the remote end.
1176                  */
1177                 if (try_explicit_object_name(rs->src, match) < 0)
1178                         return error("src refspec %s does not match any.", rs->src);
1179                 if (allocated_match)
1180                         *allocated_match = 1;
1181                 return 0;
1182         default:
1183                 return error("src refspec %s matches more than one.", rs->src);
1184         }
1185 }
1186
1187 static int match_explicit(struct ref *src, struct ref *dst,
1188                           struct ref ***dst_tail,
1189                           struct refspec *rs)
1190 {
1191         struct ref *matched_src, *matched_dst;
1192         int allocated_src;
1193
1194         const char *dst_value = rs->dst;
1195         char *dst_guess;
1196
1197         if (rs->pattern || rs->matching)
1198                 return 0;
1199
1200         matched_src = matched_dst = NULL;
1201         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1202                 return -1;
1203
1204         if (!dst_value) {
1205                 unsigned char sha1[20];
1206                 int flag;
1207
1208                 dst_value = resolve_ref_unsafe(matched_src->name,
1209                                                RESOLVE_REF_READING,
1210                                                sha1, &flag);
1211                 if (!dst_value ||
1212                     ((flag & REF_ISSYMREF) &&
1213                      !starts_with(dst_value, "refs/heads/")))
1214                         die("%s cannot be resolved to branch.",
1215                             matched_src->name);
1216         }
1217
1218         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1219         case 1:
1220                 break;
1221         case 0:
1222                 if (starts_with(dst_value, "refs/"))
1223                         matched_dst = make_linked_ref(dst_value, dst_tail);
1224                 else if (is_null_sha1(matched_src->new_sha1))
1225                         error("unable to delete '%s': remote ref does not exist",
1226                               dst_value);
1227                 else if ((dst_guess = guess_ref(dst_value, matched_src)))
1228                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1229                 else
1230                         error("unable to push to unqualified destination: %s\n"
1231                               "The destination refspec neither matches an "
1232                               "existing ref on the remote nor\n"
1233                               "begins with refs/, and we are unable to "
1234                               "guess a prefix based on the source ref.",
1235                               dst_value);
1236                 break;
1237         default:
1238                 matched_dst = NULL;
1239                 error("dst refspec %s matches more than one.",
1240                       dst_value);
1241                 break;
1242         }
1243         if (!matched_dst)
1244                 return -1;
1245         if (matched_dst->peer_ref)
1246                 return error("dst ref %s receives from more than one src.",
1247                       matched_dst->name);
1248         else {
1249                 matched_dst->peer_ref = allocated_src ?
1250                                         matched_src :
1251                                         copy_ref(matched_src);
1252                 matched_dst->force = rs->force;
1253         }
1254         return 0;
1255 }
1256
1257 static int match_explicit_refs(struct ref *src, struct ref *dst,
1258                                struct ref ***dst_tail, struct refspec *rs,
1259                                int rs_nr)
1260 {
1261         int i, errs;
1262         for (i = errs = 0; i < rs_nr; i++)
1263                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
1264         return errs;
1265 }
1266
1267 static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1268                 int send_mirror, int direction, const struct refspec **ret_pat)
1269 {
1270         const struct refspec *pat;
1271         char *name;
1272         int i;
1273         int matching_refs = -1;
1274         for (i = 0; i < rs_nr; i++) {
1275                 if (rs[i].matching &&
1276                     (matching_refs == -1 || rs[i].force)) {
1277                         matching_refs = i;
1278                         continue;
1279                 }
1280
1281                 if (rs[i].pattern) {
1282                         const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1283                         int match;
1284                         if (direction == FROM_SRC)
1285                                 match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1286                         else
1287                                 match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1288                         if (match) {
1289                                 matching_refs = i;
1290                                 break;
1291                         }
1292                 }
1293         }
1294         if (matching_refs == -1)
1295                 return NULL;
1296
1297         pat = rs + matching_refs;
1298         if (pat->matching) {
1299                 /*
1300                  * "matching refs"; traditionally we pushed everything
1301                  * including refs outside refs/heads/ hierarchy, but
1302                  * that does not make much sense these days.
1303                  */
1304                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1305                         return NULL;
1306                 name = xstrdup(ref->name);
1307         }
1308         if (ret_pat)
1309                 *ret_pat = pat;
1310         return name;
1311 }
1312
1313 static struct ref **tail_ref(struct ref **head)
1314 {
1315         struct ref **tail = head;
1316         while (*tail)
1317                 tail = &((*tail)->next);
1318         return tail;
1319 }
1320
1321 struct tips {
1322         struct commit **tip;
1323         int nr, alloc;
1324 };
1325
1326 static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1327 {
1328         struct commit *commit;
1329
1330         if (is_null_sha1(sha1))
1331                 return;
1332         commit = lookup_commit_reference_gently(sha1, 1);
1333         if (!commit || (commit->object.flags & TMP_MARK))
1334                 return;
1335         commit->object.flags |= TMP_MARK;
1336         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1337         tips->tip[tips->nr++] = commit;
1338 }
1339
1340 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1341 {
1342         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1343         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1344         struct string_list_item *item;
1345         struct ref *ref;
1346         struct tips sent_tips;
1347
1348         /*
1349          * Collect everything we know they would have at the end of
1350          * this push, and collect all tags they have.
1351          */
1352         memset(&sent_tips, 0, sizeof(sent_tips));
1353         for (ref = *dst; ref; ref = ref->next) {
1354                 if (ref->peer_ref &&
1355                     !is_null_sha1(ref->peer_ref->new_sha1))
1356                         add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1357                 else
1358                         add_to_tips(&sent_tips, ref->old_sha1);
1359                 if (starts_with(ref->name, "refs/tags/"))
1360                         string_list_append(&dst_tag, ref->name);
1361         }
1362         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1363
1364         string_list_sort(&dst_tag);
1365
1366         /* Collect tags they do not have. */
1367         for (ref = src; ref; ref = ref->next) {
1368                 if (!starts_with(ref->name, "refs/tags/"))
1369                         continue; /* not a tag */
1370                 if (string_list_has_string(&dst_tag, ref->name))
1371                         continue; /* they already have it */
1372                 if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1373                         continue; /* be conservative */
1374                 item = string_list_append(&src_tag, ref->name);
1375                 item->util = ref;
1376         }
1377         string_list_clear(&dst_tag, 0);
1378
1379         /*
1380          * At this point, src_tag lists tags that are missing from
1381          * dst, and sent_tips lists the tips we are pushing or those
1382          * that we know they already have. An element in the src_tag
1383          * that is an ancestor of any of the sent_tips needs to be
1384          * sent to the other side.
1385          */
1386         if (sent_tips.nr) {
1387                 for_each_string_list_item(item, &src_tag) {
1388                         struct ref *ref = item->util;
1389                         struct ref *dst_ref;
1390                         struct commit *commit;
1391
1392                         if (is_null_sha1(ref->new_sha1))
1393                                 continue;
1394                         commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1395                         if (!commit)
1396                                 /* not pushing a commit, which is not an error */
1397                                 continue;
1398
1399                         /*
1400                          * Is this tag, which they do not have, reachable from
1401                          * any of the commits we are sending?
1402                          */
1403                         if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1404                                 continue;
1405
1406                         /* Add it in */
1407                         dst_ref = make_linked_ref(ref->name, dst_tail);
1408                         hashcpy(dst_ref->new_sha1, ref->new_sha1);
1409                         dst_ref->peer_ref = copy_ref(ref);
1410                 }
1411         }
1412         string_list_clear(&src_tag, 0);
1413         free(sent_tips.tip);
1414 }
1415
1416 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1417 {
1418         for ( ; list; list = list->next)
1419                 if (!strcmp(list->name, name))
1420                         return (struct ref *)list;
1421         return NULL;
1422 }
1423
1424 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1425 {
1426         for ( ; ref; ref = ref->next)
1427                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1428
1429         string_list_sort(ref_index);
1430 }
1431
1432 /*
1433  * Given only the set of local refs, sanity-check the set of push
1434  * refspecs. We can't catch all errors that match_push_refs would,
1435  * but we can catch some errors early before even talking to the
1436  * remote side.
1437  */
1438 int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1439 {
1440         struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1441         int ret = 0;
1442         int i;
1443
1444         for (i = 0; i < nr_refspec; i++) {
1445                 struct refspec *rs = refspec + i;
1446
1447                 if (rs->pattern || rs->matching)
1448                         continue;
1449
1450                 ret |= match_explicit_lhs(src, rs, NULL, NULL);
1451         }
1452
1453         free_refspec(nr_refspec, refspec);
1454         return ret;
1455 }
1456
1457 /*
1458  * Given the set of refs the local repository has, the set of refs the
1459  * remote repository has, and the refspec used for push, determine
1460  * what remote refs we will update and with what value by setting
1461  * peer_ref (which object is being pushed) and force (if the push is
1462  * forced) in elements of "dst". The function may add new elements to
1463  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1464  */
1465 int match_push_refs(struct ref *src, struct ref **dst,
1466                     int nr_refspec, const char **refspec, int flags)
1467 {
1468         struct refspec *rs;
1469         int send_all = flags & MATCH_REFS_ALL;
1470         int send_mirror = flags & MATCH_REFS_MIRROR;
1471         int send_prune = flags & MATCH_REFS_PRUNE;
1472         int errs;
1473         static const char *default_refspec[] = { ":", NULL };
1474         struct ref *ref, **dst_tail = tail_ref(dst);
1475         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1476
1477         if (!nr_refspec) {
1478                 nr_refspec = 1;
1479                 refspec = default_refspec;
1480         }
1481         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1482         errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1483
1484         /* pick the remainder */
1485         for (ref = src; ref; ref = ref->next) {
1486                 struct string_list_item *dst_item;
1487                 struct ref *dst_peer;
1488                 const struct refspec *pat = NULL;
1489                 char *dst_name;
1490
1491                 dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1492                 if (!dst_name)
1493                         continue;
1494
1495                 if (!dst_ref_index.nr)
1496                         prepare_ref_index(&dst_ref_index, *dst);
1497
1498                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1499                 dst_peer = dst_item ? dst_item->util : NULL;
1500                 if (dst_peer) {
1501                         if (dst_peer->peer_ref)
1502                                 /* We're already sending something to this ref. */
1503                                 goto free_name;
1504                 } else {
1505                         if (pat->matching && !(send_all || send_mirror))
1506                                 /*
1507                                  * Remote doesn't have it, and we have no
1508                                  * explicit pattern, and we don't have
1509                                  * --all or --mirror.
1510                                  */
1511                                 goto free_name;
1512
1513                         /* Create a new one and link it */
1514                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1515                         hashcpy(dst_peer->new_sha1, ref->new_sha1);
1516                         string_list_insert(&dst_ref_index,
1517                                 dst_peer->name)->util = dst_peer;
1518                 }
1519                 dst_peer->peer_ref = copy_ref(ref);
1520                 dst_peer->force = pat->force;
1521         free_name:
1522                 free(dst_name);
1523         }
1524
1525         string_list_clear(&dst_ref_index, 0);
1526
1527         if (flags & MATCH_REFS_FOLLOW_TAGS)
1528                 add_missing_tags(src, dst, &dst_tail);
1529
1530         if (send_prune) {
1531                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1532                 /* check for missing refs on the remote */
1533                 for (ref = *dst; ref; ref = ref->next) {
1534                         char *src_name;
1535
1536                         if (ref->peer_ref)
1537                                 /* We're already sending something to this ref. */
1538                                 continue;
1539
1540                         src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1541                         if (src_name) {
1542                                 if (!src_ref_index.nr)
1543                                         prepare_ref_index(&src_ref_index, src);
1544                                 if (!string_list_has_string(&src_ref_index,
1545                                             src_name))
1546                                         ref->peer_ref = alloc_delete_ref();
1547                                 free(src_name);
1548                         }
1549                 }
1550                 string_list_clear(&src_ref_index, 0);
1551         }
1552         if (errs)
1553                 return -1;
1554         return 0;
1555 }
1556
1557 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1558                              int force_update)
1559 {
1560         struct ref *ref;
1561
1562         for (ref = remote_refs; ref; ref = ref->next) {
1563                 int force_ref_update = ref->force || force_update;
1564                 int reject_reason = 0;
1565
1566                 if (ref->peer_ref)
1567                         hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1568                 else if (!send_mirror)
1569                         continue;
1570
1571                 ref->deletion = is_null_sha1(ref->new_sha1);
1572                 if (!ref->deletion &&
1573                         !hashcmp(ref->old_sha1, ref->new_sha1)) {
1574                         ref->status = REF_STATUS_UPTODATE;
1575                         continue;
1576                 }
1577
1578                 /*
1579                  * Bypass the usual "must fast-forward" check but
1580                  * replace it with a weaker "the old value must be
1581                  * this value we observed".  If the remote ref has
1582                  * moved and is now different from what we expect,
1583                  * reject any push.
1584                  *
1585                  * It also is an error if the user told us to check
1586                  * with the remote-tracking branch to find the value
1587                  * to expect, but we did not have such a tracking
1588                  * branch.
1589                  */
1590                 if (ref->expect_old_sha1) {
1591                         if (ref->expect_old_no_trackback ||
1592                             hashcmp(ref->old_sha1, ref->old_sha1_expect))
1593                                 reject_reason = REF_STATUS_REJECT_STALE;
1594                 }
1595
1596                 /*
1597                  * The usual "must fast-forward" rules.
1598                  *
1599                  * Decide whether an individual refspec A:B can be
1600                  * pushed.  The push will succeed if any of the
1601                  * following are true:
1602                  *
1603                  * (1) the remote reference B does not exist
1604                  *
1605                  * (2) the remote reference B is being removed (i.e.,
1606                  *     pushing :B where no source is specified)
1607                  *
1608                  * (3) the destination is not under refs/tags/, and
1609                  *     if the old and new value is a commit, the new
1610                  *     is a descendant of the old.
1611                  *
1612                  * (4) it is forced using the +A:B notation, or by
1613                  *     passing the --force argument
1614                  */
1615
1616                 else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1617                         if (starts_with(ref->name, "refs/tags/"))
1618                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1619                         else if (!has_sha1_file(ref->old_sha1))
1620                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1621                         else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1622                                  !lookup_commit_reference_gently(ref->new_sha1, 1))
1623                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1624                         else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1625                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1626                 }
1627
1628                 /*
1629                  * "--force" will defeat any rejection implemented
1630                  * by the rules above.
1631                  */
1632                 if (!force_ref_update)
1633                         ref->status = reject_reason;
1634                 else if (reject_reason)
1635                         ref->forced_update = 1;
1636         }
1637 }
1638
1639 static void set_merge(struct branch *ret)
1640 {
1641         struct remote *remote;
1642         char *ref;
1643         unsigned char sha1[20];
1644         int i;
1645
1646         if (!ret)
1647                 return; /* no branch */
1648         if (ret->merge)
1649                 return; /* already run */
1650         if (!ret->remote_name || !ret->merge_nr) {
1651                 /*
1652                  * no merge config; let's make sure we don't confuse callers
1653                  * with a non-zero merge_nr but a NULL merge
1654                  */
1655                 ret->merge_nr = 0;
1656                 return;
1657         }
1658
1659         remote = remote_get(ret->remote_name);
1660
1661         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1662         for (i = 0; i < ret->merge_nr; i++) {
1663                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1664                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1665                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1666                     strcmp(ret->remote_name, "."))
1667                         continue;
1668                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1669                              sha1, &ref) == 1)
1670                         ret->merge[i]->dst = ref;
1671                 else
1672                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1673         }
1674 }
1675
1676 struct branch *branch_get(const char *name)
1677 {
1678         struct branch *ret;
1679
1680         read_config();
1681         if (!name || !*name || !strcmp(name, "HEAD"))
1682                 ret = current_branch;
1683         else
1684                 ret = make_branch(name, 0);
1685         set_merge(ret);
1686         return ret;
1687 }
1688
1689 int branch_has_merge_config(struct branch *branch)
1690 {
1691         return branch && !!branch->merge;
1692 }
1693
1694 int branch_merge_matches(struct branch *branch,
1695                                  int i,
1696                                  const char *refname)
1697 {
1698         if (!branch || i < 0 || i >= branch->merge_nr)
1699                 return 0;
1700         return refname_match(branch->merge[i]->src, refname);
1701 }
1702
1703 __attribute((format (printf,2,3)))
1704 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1705 {
1706         if (err) {
1707                 va_list ap;
1708                 va_start(ap, fmt);
1709                 strbuf_vaddf(err, fmt, ap);
1710                 va_end(ap);
1711         }
1712         return NULL;
1713 }
1714
1715 const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1716 {
1717         if (!branch)
1718                 return error_buf(err, _("HEAD does not point to a branch"));
1719
1720         if (!branch->merge || !branch->merge[0]) {
1721                 /*
1722                  * no merge config; is it because the user didn't define any,
1723                  * or because it is not a real branch, and get_branch
1724                  * auto-vivified it?
1725                  */
1726                 if (!ref_exists(branch->refname))
1727                         return error_buf(err, _("no such branch: '%s'"),
1728                                          branch->name);
1729                 return error_buf(err,
1730                                  _("no upstream configured for branch '%s'"),
1731                                  branch->name);
1732         }
1733
1734         if (!branch->merge[0]->dst)
1735                 return error_buf(err,
1736                                  _("upstream branch '%s' not stored as a remote-tracking branch"),
1737                                  branch->merge[0]->src);
1738
1739         return branch->merge[0]->dst;
1740 }
1741
1742 static const char *tracking_for_push_dest(struct remote *remote,
1743                                           const char *refname,
1744                                           struct strbuf *err)
1745 {
1746         char *ret;
1747
1748         ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1749         if (!ret)
1750                 return error_buf(err,
1751                                  _("push destination '%s' on remote '%s' has no local tracking branch"),
1752                                  refname, remote->name);
1753         return ret;
1754 }
1755
1756 static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1757 {
1758         struct remote *remote;
1759
1760         if (!branch)
1761                 return error_buf(err, _("HEAD does not point to a branch"));
1762
1763         remote = remote_get(pushremote_for_branch(branch, NULL));
1764         if (!remote)
1765                 return error_buf(err,
1766                                  _("branch '%s' has no remote for pushing"),
1767                                  branch->name);
1768
1769         if (remote->push_refspec_nr) {
1770                 char *dst;
1771                 const char *ret;
1772
1773                 dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1774                                      branch->refname);
1775                 if (!dst)
1776                         return error_buf(err,
1777                                          _("push refspecs for '%s' do not include '%s'"),
1778                                          remote->name, branch->name);
1779
1780                 ret = tracking_for_push_dest(remote, dst, err);
1781                 free(dst);
1782                 return ret;
1783         }
1784
1785         if (remote->mirror)
1786                 return tracking_for_push_dest(remote, branch->refname, err);
1787
1788         switch (push_default) {
1789         case PUSH_DEFAULT_NOTHING:
1790                 return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1791
1792         case PUSH_DEFAULT_MATCHING:
1793         case PUSH_DEFAULT_CURRENT:
1794                 return tracking_for_push_dest(remote, branch->refname, err);
1795
1796         case PUSH_DEFAULT_UPSTREAM:
1797                 return branch_get_upstream(branch, err);
1798
1799         case PUSH_DEFAULT_UNSPECIFIED:
1800         case PUSH_DEFAULT_SIMPLE:
1801                 {
1802                         const char *up, *cur;
1803
1804                         up = branch_get_upstream(branch, err);
1805                         if (!up)
1806                                 return NULL;
1807                         cur = tracking_for_push_dest(remote, branch->refname, err);
1808                         if (!cur)
1809                                 return NULL;
1810                         if (strcmp(cur, up))
1811                                 return error_buf(err,
1812                                                  _("cannot resolve 'simple' push to a single destination"));
1813                         return cur;
1814                 }
1815         }
1816
1817         die("BUG: unhandled push situation");
1818 }
1819
1820 const char *branch_get_push(struct branch *branch, struct strbuf *err)
1821 {
1822         if (!branch->push_tracking_ref)
1823                 branch->push_tracking_ref = branch_get_push_1(branch, err);
1824         return branch->push_tracking_ref;
1825 }
1826
1827 static int ignore_symref_update(const char *refname)
1828 {
1829         unsigned char sha1[20];
1830         int flag;
1831
1832         if (!resolve_ref_unsafe(refname, 0, sha1, &flag))
1833                 return 0; /* non-existing refs are OK */
1834         return (flag & REF_ISSYMREF);
1835 }
1836
1837 /*
1838  * Create and return a list of (struct ref) consisting of copies of
1839  * each remote_ref that matches refspec.  refspec must be a pattern.
1840  * Fill in the copies' peer_ref to describe the local tracking refs to
1841  * which they map.  Omit any references that would map to an existing
1842  * local symbolic ref.
1843  */
1844 static struct ref *get_expanded_map(const struct ref *remote_refs,
1845                                     const struct refspec *refspec)
1846 {
1847         const struct ref *ref;
1848         struct ref *ret = NULL;
1849         struct ref **tail = &ret;
1850
1851         for (ref = remote_refs; ref; ref = ref->next) {
1852                 char *expn_name = NULL;
1853
1854                 if (strchr(ref->name, '^'))
1855                         continue; /* a dereference item */
1856                 if (match_name_with_pattern(refspec->src, ref->name,
1857                                             refspec->dst, &expn_name) &&
1858                     !ignore_symref_update(expn_name)) {
1859                         struct ref *cpy = copy_ref(ref);
1860
1861                         cpy->peer_ref = alloc_ref(expn_name);
1862                         if (refspec->force)
1863                                 cpy->peer_ref->force = 1;
1864                         *tail = cpy;
1865                         tail = &cpy->next;
1866                 }
1867                 free(expn_name);
1868         }
1869
1870         return ret;
1871 }
1872
1873 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1874 {
1875         const struct ref *ref;
1876         for (ref = refs; ref; ref = ref->next) {
1877                 if (refname_match(name, ref->name))
1878                         return ref;
1879         }
1880         return NULL;
1881 }
1882
1883 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1884 {
1885         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1886
1887         if (!ref)
1888                 return NULL;
1889
1890         return copy_ref(ref);
1891 }
1892
1893 static struct ref *get_local_ref(const char *name)
1894 {
1895         if (!name || name[0] == '\0')
1896                 return NULL;
1897
1898         if (starts_with(name, "refs/"))
1899                 return alloc_ref(name);
1900
1901         if (starts_with(name, "heads/") ||
1902             starts_with(name, "tags/") ||
1903             starts_with(name, "remotes/"))
1904                 return alloc_ref_with_prefix("refs/", 5, name);
1905
1906         return alloc_ref_with_prefix("refs/heads/", 11, name);
1907 }
1908
1909 int get_fetch_map(const struct ref *remote_refs,
1910                   const struct refspec *refspec,
1911                   struct ref ***tail,
1912                   int missing_ok)
1913 {
1914         struct ref *ref_map, **rmp;
1915
1916         if (refspec->pattern) {
1917                 ref_map = get_expanded_map(remote_refs, refspec);
1918         } else {
1919                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1920
1921                 if (refspec->exact_sha1) {
1922                         ref_map = alloc_ref(name);
1923                         get_sha1_hex(name, ref_map->old_sha1);
1924                 } else {
1925                         ref_map = get_remote_ref(remote_refs, name);
1926                 }
1927                 if (!missing_ok && !ref_map)
1928                         die("Couldn't find remote ref %s", name);
1929                 if (ref_map) {
1930                         ref_map->peer_ref = get_local_ref(refspec->dst);
1931                         if (ref_map->peer_ref && refspec->force)
1932                                 ref_map->peer_ref->force = 1;
1933                 }
1934         }
1935
1936         for (rmp = &ref_map; *rmp; ) {
1937                 if ((*rmp)->peer_ref) {
1938                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1939                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1940                                 struct ref *ignore = *rmp;
1941                                 error("* Ignoring funny ref '%s' locally",
1942                                       (*rmp)->peer_ref->name);
1943                                 *rmp = (*rmp)->next;
1944                                 free(ignore->peer_ref);
1945                                 free(ignore);
1946                                 continue;
1947                         }
1948                 }
1949                 rmp = &((*rmp)->next);
1950         }
1951
1952         if (ref_map)
1953                 tail_link_ref(ref_map, tail);
1954
1955         return 0;
1956 }
1957
1958 int resolve_remote_symref(struct ref *ref, struct ref *list)
1959 {
1960         if (!ref->symref)
1961                 return 0;
1962         for (; list; list = list->next)
1963                 if (!strcmp(ref->symref, list->name)) {
1964                         hashcpy(ref->old_sha1, list->old_sha1);
1965                         return 0;
1966                 }
1967         return 1;
1968 }
1969
1970 static void unmark_and_free(struct commit_list *list, unsigned int mark)
1971 {
1972         while (list) {
1973                 struct commit_list *temp = list;
1974                 temp->item->object.flags &= ~mark;
1975                 list = temp->next;
1976                 free(temp);
1977         }
1978 }
1979
1980 int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1981 {
1982         struct object *o;
1983         struct commit *old, *new;
1984         struct commit_list *list, *used;
1985         int found = 0;
1986
1987         /*
1988          * Both new and old must be commit-ish and new is descendant of
1989          * old.  Otherwise we require --force.
1990          */
1991         o = deref_tag(parse_object(old_sha1), NULL, 0);
1992         if (!o || o->type != OBJ_COMMIT)
1993                 return 0;
1994         old = (struct commit *) o;
1995
1996         o = deref_tag(parse_object(new_sha1), NULL, 0);
1997         if (!o || o->type != OBJ_COMMIT)
1998                 return 0;
1999         new = (struct commit *) o;
2000
2001         if (parse_commit(new) < 0)
2002                 return 0;
2003
2004         used = list = NULL;
2005         commit_list_insert(new, &list);
2006         while (list) {
2007                 new = pop_most_recent_commit(&list, TMP_MARK);
2008                 commit_list_insert(new, &used);
2009                 if (new == old) {
2010                         found = 1;
2011                         break;
2012                 }
2013         }
2014         unmark_and_free(list, TMP_MARK);
2015         unmark_and_free(used, TMP_MARK);
2016         return found;
2017 }
2018
2019 /*
2020  * Compare a branch with its upstream, and save their differences (number
2021  * of commits) in *num_ours and *num_theirs. The name of the upstream branch
2022  * (or NULL if no upstream is defined) is returned via *upstream_name, if it
2023  * is not itself NULL.
2024  *
2025  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
2026  * upstream defined, or ref does not exist), 0 otherwise.
2027  */
2028 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
2029                        const char **upstream_name)
2030 {
2031         unsigned char sha1[20];
2032         struct commit *ours, *theirs;
2033         char symmetric[84];
2034         struct rev_info revs;
2035         const char *rev_argv[10], *base;
2036         int rev_argc;
2037
2038         /* Cannot stat unless we are marked to build on top of somebody else. */
2039         base = branch_get_upstream(branch, NULL);
2040         if (upstream_name)
2041                 *upstream_name = base;
2042         if (!base)
2043                 return -1;
2044
2045         /* Cannot stat if what we used to build on no longer exists */
2046         if (read_ref(base, sha1))
2047                 return -1;
2048         theirs = lookup_commit_reference(sha1);
2049         if (!theirs)
2050                 return -1;
2051
2052         if (read_ref(branch->refname, sha1))
2053                 return -1;
2054         ours = lookup_commit_reference(sha1);
2055         if (!ours)
2056                 return -1;
2057
2058         /* are we the same? */
2059         if (theirs == ours) {
2060                 *num_theirs = *num_ours = 0;
2061                 return 0;
2062         }
2063
2064         /* Run "rev-list --left-right ours...theirs" internally... */
2065         rev_argc = 0;
2066         rev_argv[rev_argc++] = NULL;
2067         rev_argv[rev_argc++] = "--left-right";
2068         rev_argv[rev_argc++] = symmetric;
2069         rev_argv[rev_argc++] = "--";
2070         rev_argv[rev_argc] = NULL;
2071
2072         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
2073         strcpy(symmetric + 40, "...");
2074         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
2075
2076         init_revisions(&revs, NULL);
2077         setup_revisions(rev_argc, rev_argv, &revs, NULL);
2078         if (prepare_revision_walk(&revs))
2079                 die("revision walk setup failed");
2080
2081         /* ... and count the commits on each side. */
2082         *num_ours = 0;
2083         *num_theirs = 0;
2084         while (1) {
2085                 struct commit *c = get_revision(&revs);
2086                 if (!c)
2087                         break;
2088                 if (c->object.flags & SYMMETRIC_LEFT)
2089                         (*num_ours)++;
2090                 else
2091                         (*num_theirs)++;
2092         }
2093
2094         /* clear object flags smudged by the above traversal */
2095         clear_commit_marks(ours, ALL_REV_FLAGS);
2096         clear_commit_marks(theirs, ALL_REV_FLAGS);
2097         return 0;
2098 }
2099
2100 /*
2101  * Return true when there is anything to report, otherwise false.
2102  */
2103 int format_tracking_info(struct branch *branch, struct strbuf *sb)
2104 {
2105         int ours, theirs;
2106         const char *full_base;
2107         char *base;
2108         int upstream_is_gone = 0;
2109
2110         if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2111                 if (!full_base)
2112                         return 0;
2113                 upstream_is_gone = 1;
2114         }
2115
2116         base = shorten_unambiguous_ref(full_base, 0);
2117         if (upstream_is_gone) {
2118                 strbuf_addf(sb,
2119                         _("Your branch is based on '%s', but the upstream is gone.\n"),
2120                         base);
2121                 if (advice_status_hints)
2122                         strbuf_addf(sb,
2123                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2124         } else if (!ours && !theirs) {
2125                 strbuf_addf(sb,
2126                         _("Your branch is up-to-date with '%s'.\n"),
2127                         base);
2128         } else if (!theirs) {
2129                 strbuf_addf(sb,
2130                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2131                            "Your branch is ahead of '%s' by %d commits.\n",
2132                            ours),
2133                         base, ours);
2134                 if (advice_status_hints)
2135                         strbuf_addf(sb,
2136                                 _("  (use \"git push\" to publish your local commits)\n"));
2137         } else if (!ours) {
2138                 strbuf_addf(sb,
2139                         Q_("Your branch is behind '%s' by %d commit, "
2140                                "and can be fast-forwarded.\n",
2141                            "Your branch is behind '%s' by %d commits, "
2142                                "and can be fast-forwarded.\n",
2143                            theirs),
2144                         base, theirs);
2145                 if (advice_status_hints)
2146                         strbuf_addf(sb,
2147                                 _("  (use \"git pull\" to update your local branch)\n"));
2148         } else {
2149                 strbuf_addf(sb,
2150                         Q_("Your branch and '%s' have diverged,\n"
2151                                "and have %d and %d different commit each, "
2152                                "respectively.\n",
2153                            "Your branch and '%s' have diverged,\n"
2154                                "and have %d and %d different commits each, "
2155                                "respectively.\n",
2156                            theirs),
2157                         base, ours, theirs);
2158                 if (advice_status_hints)
2159                         strbuf_addf(sb,
2160                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2161         }
2162         free(base);
2163         return 1;
2164 }
2165
2166 static int one_local_ref(const char *refname, const struct object_id *oid,
2167                          int flag, void *cb_data)
2168 {
2169         struct ref ***local_tail = cb_data;
2170         struct ref *ref;
2171         int len;
2172
2173         /* we already know it starts with refs/ to get here */
2174         if (check_refname_format(refname + 5, 0))
2175                 return 0;
2176
2177         len = strlen(refname) + 1;
2178         ref = xcalloc(1, sizeof(*ref) + len);
2179         hashcpy(ref->new_sha1, oid->hash);
2180         memcpy(ref->name, refname, len);
2181         **local_tail = ref;
2182         *local_tail = &ref->next;
2183         return 0;
2184 }
2185
2186 struct ref *get_local_heads(void)
2187 {
2188         struct ref *local_refs = NULL, **local_tail = &local_refs;
2189
2190         for_each_ref(one_local_ref, &local_tail);
2191         return local_refs;
2192 }
2193
2194 struct ref *guess_remote_head(const struct ref *head,
2195                               const struct ref *refs,
2196                               int all)
2197 {
2198         const struct ref *r;
2199         struct ref *list = NULL;
2200         struct ref **tail = &list;
2201
2202         if (!head)
2203                 return NULL;
2204
2205         /*
2206          * Some transports support directly peeking at
2207          * where HEAD points; if that is the case, then
2208          * we don't have to guess.
2209          */
2210         if (head->symref)
2211                 return copy_ref(find_ref_by_name(refs, head->symref));
2212
2213         /* If refs/heads/master could be right, it is. */
2214         if (!all) {
2215                 r = find_ref_by_name(refs, "refs/heads/master");
2216                 if (r && !hashcmp(r->old_sha1, head->old_sha1))
2217                         return copy_ref(r);
2218         }
2219
2220         /* Look for another ref that points there */
2221         for (r = refs; r; r = r->next) {
2222                 if (r != head &&
2223                     starts_with(r->name, "refs/heads/") &&
2224                     !hashcmp(r->old_sha1, head->old_sha1)) {
2225                         *tail = copy_ref(r);
2226                         tail = &((*tail)->next);
2227                         if (!all)
2228                                 break;
2229                 }
2230         }
2231
2232         return list;
2233 }
2234
2235 struct stale_heads_info {
2236         struct string_list *ref_names;
2237         struct ref **stale_refs_tail;
2238         struct refspec *refs;
2239         int ref_count;
2240 };
2241
2242 static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2243                               int flags, void *cb_data)
2244 {
2245         struct stale_heads_info *info = cb_data;
2246         struct string_list matches = STRING_LIST_INIT_DUP;
2247         struct refspec query;
2248         int i, stale = 1;
2249         memset(&query, 0, sizeof(struct refspec));
2250         query.dst = (char *)refname;
2251
2252         query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2253         if (matches.nr == 0)
2254                 goto clean_exit; /* No matches */
2255
2256         /*
2257          * If we did find a suitable refspec and it's not a symref and
2258          * it's not in the list of refs that currently exist in that
2259          * remote, we consider it to be stale. In order to deal with
2260          * overlapping refspecs, we need to go over all of the
2261          * matching refs.
2262          */
2263         if (flags & REF_ISSYMREF)
2264                 goto clean_exit;
2265
2266         for (i = 0; stale && i < matches.nr; i++)
2267                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2268                         stale = 0;
2269
2270         if (stale) {
2271                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2272                 hashcpy(ref->new_sha1, oid->hash);
2273         }
2274
2275 clean_exit:
2276         string_list_clear(&matches, 0);
2277         return 0;
2278 }
2279
2280 struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2281 {
2282         struct ref *ref, *stale_refs = NULL;
2283         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2284         struct stale_heads_info info;
2285
2286         info.ref_names = &ref_names;
2287         info.stale_refs_tail = &stale_refs;
2288         info.refs = refs;
2289         info.ref_count = ref_count;
2290         for (ref = fetch_map; ref; ref = ref->next)
2291                 string_list_append(&ref_names, ref->name);
2292         string_list_sort(&ref_names);
2293         for_each_ref(get_stale_heads_cb, &info);
2294         string_list_clear(&ref_names, 0);
2295         return stale_refs;
2296 }
2297
2298 /*
2299  * Compare-and-swap
2300  */
2301 static void clear_cas_option(struct push_cas_option *cas)
2302 {
2303         int i;
2304
2305         for (i = 0; i < cas->nr; i++)
2306                 free(cas->entry[i].refname);
2307         free(cas->entry);
2308         memset(cas, 0, sizeof(*cas));
2309 }
2310
2311 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2312                                       const char *refname,
2313                                       size_t refnamelen)
2314 {
2315         struct push_cas *entry;
2316         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2317         entry = &cas->entry[cas->nr++];
2318         memset(entry, 0, sizeof(*entry));
2319         entry->refname = xmemdupz(refname, refnamelen);
2320         return entry;
2321 }
2322
2323 int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2324 {
2325         const char *colon;
2326         struct push_cas *entry;
2327
2328         if (unset) {
2329                 /* "--no-<option>" */
2330                 clear_cas_option(cas);
2331                 return 0;
2332         }
2333
2334         if (!arg) {
2335                 /* just "--<option>" */
2336                 cas->use_tracking_for_rest = 1;
2337                 return 0;
2338         }
2339
2340         /* "--<option>=refname" or "--<option>=refname:value" */
2341         colon = strchrnul(arg, ':');
2342         entry = add_cas_entry(cas, arg, colon - arg);
2343         if (!*colon)
2344                 entry->use_tracking = 1;
2345         else if (get_sha1(colon + 1, entry->expect))
2346                 return error("cannot parse expected object name '%s'", colon + 1);
2347         return 0;
2348 }
2349
2350 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2351 {
2352         return parse_push_cas_option(opt->value, arg, unset);
2353 }
2354
2355 int is_empty_cas(const struct push_cas_option *cas)
2356 {
2357         return !cas->use_tracking_for_rest && !cas->nr;
2358 }
2359
2360 /*
2361  * Look at remote.fetch refspec and see if we have a remote
2362  * tracking branch for the refname there.  Fill its current
2363  * value in sha1[].
2364  * If we cannot do so, return negative to signal an error.
2365  */
2366 static int remote_tracking(struct remote *remote, const char *refname,
2367                            unsigned char sha1[20])
2368 {
2369         char *dst;
2370
2371         dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2372         if (!dst)
2373                 return -1; /* no tracking ref for refname at remote */
2374         if (read_ref(dst, sha1))
2375                 return -1; /* we know what the tracking ref is but we cannot read it */
2376         return 0;
2377 }
2378
2379 static void apply_cas(struct push_cas_option *cas,
2380                       struct remote *remote,
2381                       struct ref *ref)
2382 {
2383         int i;
2384
2385         /* Find an explicit --<option>=<name>[:<value>] entry */
2386         for (i = 0; i < cas->nr; i++) {
2387                 struct push_cas *entry = &cas->entry[i];
2388                 if (!refname_match(entry->refname, ref->name))
2389                         continue;
2390                 ref->expect_old_sha1 = 1;
2391                 if (!entry->use_tracking)
2392                         hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2393                 else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2394                         ref->expect_old_no_trackback = 1;
2395                 return;
2396         }
2397
2398         /* Are we using "--<option>" to cover all? */
2399         if (!cas->use_tracking_for_rest)
2400                 return;
2401
2402         ref->expect_old_sha1 = 1;
2403         if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2404                 ref->expect_old_no_trackback = 1;
2405 }
2406
2407 void apply_push_cas(struct push_cas_option *cas,
2408                     struct remote *remote,
2409                     struct ref *remote_refs)
2410 {
2411         struct ref *ref;
2412         for (ref = remote_refs; ref; ref = ref->next)
2413                 apply_cas(cas, remote, ref);
2414 }