remote.con commit fmt-merge-msg: refactor merge title formatting (403994e)
   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
  11static struct refspec s_tag_refspec = {
  12        0,
  13        1,
  14        0,
  15        "refs/tags/*",
  16        "refs/tags/*"
  17};
  18
  19const struct refspec *tag_refspec = &s_tag_refspec;
  20
  21struct counted_string {
  22        size_t len;
  23        const char *s;
  24};
  25struct rewrite {
  26        const char *base;
  27        size_t baselen;
  28        struct counted_string *instead_of;
  29        int instead_of_nr;
  30        int instead_of_alloc;
  31};
  32struct rewrites {
  33        struct rewrite **rewrite;
  34        int rewrite_alloc;
  35        int rewrite_nr;
  36};
  37
  38static struct remote **remotes;
  39static int remotes_alloc;
  40static int remotes_nr;
  41
  42static struct branch **branches;
  43static int branches_alloc;
  44static int branches_nr;
  45
  46static struct branch *current_branch;
  47static const char *default_remote_name;
  48static int explicit_default_remote_name;
  49
  50static struct rewrites rewrites;
  51static struct rewrites rewrites_push;
  52
  53#define BUF_SIZE (2048)
  54static char buffer[BUF_SIZE];
  55
  56static int valid_remote(const struct remote *remote)
  57{
  58        return (!!remote->url) || (!!remote->foreign_vcs);
  59}
  60
  61static const char *alias_url(const char *url, struct rewrites *r)
  62{
  63        int i, j;
  64        char *ret;
  65        struct counted_string *longest;
  66        int longest_i;
  67
  68        longest = NULL;
  69        longest_i = -1;
  70        for (i = 0; i < r->rewrite_nr; i++) {
  71                if (!r->rewrite[i])
  72                        continue;
  73                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  74                        if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  75                            (!longest ||
  76                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  77                                longest = &(r->rewrite[i]->instead_of[j]);
  78                                longest_i = i;
  79                        }
  80                }
  81        }
  82        if (!longest)
  83                return url;
  84
  85        ret = xmalloc(r->rewrite[longest_i]->baselen +
  86                     (strlen(url) - longest->len) + 1);
  87        strcpy(ret, r->rewrite[longest_i]->base);
  88        strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  89        return ret;
  90}
  91
  92static void add_push_refspec(struct remote *remote, const char *ref)
  93{
  94        ALLOC_GROW(remote->push_refspec,
  95                   remote->push_refspec_nr + 1,
  96                   remote->push_refspec_alloc);
  97        remote->push_refspec[remote->push_refspec_nr++] = ref;
  98}
  99
 100static void add_fetch_refspec(struct remote *remote, const char *ref)
 101{
 102        ALLOC_GROW(remote->fetch_refspec,
 103                   remote->fetch_refspec_nr + 1,
 104                   remote->fetch_refspec_alloc);
 105        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 106}
 107
 108static void add_url(struct remote *remote, const char *url)
 109{
 110        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 111        remote->url[remote->url_nr++] = url;
 112}
 113
 114static void add_pushurl(struct remote *remote, const char *pushurl)
 115{
 116        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 117        remote->pushurl[remote->pushurl_nr++] = pushurl;
 118}
 119
 120static void add_pushurl_alias(struct remote *remote, const char *url)
 121{
 122        const char *pushurl = alias_url(url, &rewrites_push);
 123        if (pushurl != url)
 124                add_pushurl(remote, pushurl);
 125}
 126
 127static void add_url_alias(struct remote *remote, const char *url)
 128{
 129        add_url(remote, alias_url(url, &rewrites));
 130        add_pushurl_alias(remote, url);
 131}
 132
 133static struct remote *make_remote(const char *name, int len)
 134{
 135        struct remote *ret;
 136        int i;
 137
 138        for (i = 0; i < remotes_nr; i++) {
 139                if (len ? (!strncmp(name, remotes[i]->name, len) &&
 140                           !remotes[i]->name[len]) :
 141                    !strcmp(name, remotes[i]->name))
 142                        return remotes[i];
 143        }
 144
 145        ret = xcalloc(1, sizeof(struct remote));
 146        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 147        remotes[remotes_nr++] = ret;
 148        if (len)
 149                ret->name = xstrndup(name, len);
 150        else
 151                ret->name = xstrdup(name);
 152        return ret;
 153}
 154
 155static void add_merge(struct branch *branch, const char *name)
 156{
 157        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 158                   branch->merge_alloc);
 159        branch->merge_name[branch->merge_nr++] = name;
 160}
 161
 162static struct branch *make_branch(const char *name, int len)
 163{
 164        struct branch *ret;
 165        int i;
 166        char *refname;
 167
 168        for (i = 0; i < branches_nr; i++) {
 169                if (len ? (!strncmp(name, branches[i]->name, len) &&
 170                           !branches[i]->name[len]) :
 171                    !strcmp(name, branches[i]->name))
 172                        return branches[i];
 173        }
 174
 175        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 176        ret = xcalloc(1, sizeof(struct branch));
 177        branches[branches_nr++] = ret;
 178        if (len)
 179                ret->name = xstrndup(name, len);
 180        else
 181                ret->name = xstrdup(name);
 182        refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 183        strcpy(refname, "refs/heads/");
 184        strcpy(refname + strlen("refs/heads/"), ret->name);
 185        ret->refname = refname;
 186
 187        return ret;
 188}
 189
 190static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 191{
 192        struct rewrite *ret;
 193        int i;
 194
 195        for (i = 0; i < r->rewrite_nr; i++) {
 196                if (len
 197                    ? (len == r->rewrite[i]->baselen &&
 198                       !strncmp(base, r->rewrite[i]->base, len))
 199                    : !strcmp(base, r->rewrite[i]->base))
 200                        return r->rewrite[i];
 201        }
 202
 203        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 204        ret = xcalloc(1, sizeof(struct rewrite));
 205        r->rewrite[r->rewrite_nr++] = ret;
 206        if (len) {
 207                ret->base = xstrndup(base, len);
 208                ret->baselen = len;
 209        }
 210        else {
 211                ret->base = xstrdup(base);
 212                ret->baselen = strlen(base);
 213        }
 214        return ret;
 215}
 216
 217static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 218{
 219        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 220        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 221        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 222        rewrite->instead_of_nr++;
 223}
 224
 225static void read_remotes_file(struct remote *remote)
 226{
 227        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 228
 229        if (!f)
 230                return;
 231        remote->origin = REMOTE_REMOTES;
 232        while (fgets(buffer, BUF_SIZE, f)) {
 233                int value_list;
 234                char *s, *p;
 235
 236                if (!prefixcmp(buffer, "URL:")) {
 237                        value_list = 0;
 238                        s = buffer + 4;
 239                } else if (!prefixcmp(buffer, "Push:")) {
 240                        value_list = 1;
 241                        s = buffer + 5;
 242                } else if (!prefixcmp(buffer, "Pull:")) {
 243                        value_list = 2;
 244                        s = buffer + 5;
 245                } else
 246                        continue;
 247
 248                while (isspace(*s))
 249                        s++;
 250                if (!*s)
 251                        continue;
 252
 253                p = s + strlen(s);
 254                while (isspace(p[-1]))
 255                        *--p = 0;
 256
 257                switch (value_list) {
 258                case 0:
 259                        add_url_alias(remote, xstrdup(s));
 260                        break;
 261                case 1:
 262                        add_push_refspec(remote, xstrdup(s));
 263                        break;
 264                case 2:
 265                        add_fetch_refspec(remote, xstrdup(s));
 266                        break;
 267                }
 268        }
 269        fclose(f);
 270}
 271
 272static void read_branches_file(struct remote *remote)
 273{
 274        const char *slash = strchr(remote->name, '/');
 275        char *frag;
 276        struct strbuf branch = STRBUF_INIT;
 277        int n = slash ? slash - remote->name : 1000;
 278        FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 279        char *s, *p;
 280        int len;
 281
 282        if (!f)
 283                return;
 284        s = fgets(buffer, BUF_SIZE, f);
 285        fclose(f);
 286        if (!s)
 287                return;
 288        while (isspace(*s))
 289                s++;
 290        if (!*s)
 291                return;
 292        remote->origin = REMOTE_BRANCHES;
 293        p = s + strlen(s);
 294        while (isspace(p[-1]))
 295                *--p = 0;
 296        len = p - s;
 297        if (slash)
 298                len += strlen(slash);
 299        p = xmalloc(len + 1);
 300        strcpy(p, s);
 301        if (slash)
 302                strcat(p, slash);
 303
 304        /*
 305         * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 306         * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 307         * the partial URL obtained from the branches file plus
 308         * "/netdev-2.6" and does not store it in any tracking ref.
 309         * #branch specifier in the file is ignored.
 310         *
 311         * Otherwise, the branches file would have URL and optionally
 312         * #branch specified.  The "master" (or specified) branch is
 313         * fetched and stored in the local branch of the same name.
 314         */
 315        frag = strchr(p, '#');
 316        if (frag) {
 317                *(frag++) = '\0';
 318                strbuf_addf(&branch, "refs/heads/%s", frag);
 319        } else
 320                strbuf_addstr(&branch, "refs/heads/master");
 321        if (!slash) {
 322                strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 323        } else {
 324                strbuf_reset(&branch);
 325                strbuf_addstr(&branch, "HEAD:");
 326        }
 327        add_url_alias(remote, p);
 328        add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 329        /*
 330         * Cogito compatible push: push current HEAD to remote #branch
 331         * (master if missing)
 332         */
 333        strbuf_init(&branch, 0);
 334        strbuf_addstr(&branch, "HEAD");
 335        if (frag)
 336                strbuf_addf(&branch, ":refs/heads/%s", frag);
 337        else
 338                strbuf_addstr(&branch, ":refs/heads/master");
 339        add_push_refspec(remote, strbuf_detach(&branch, NULL));
 340        remote->fetch_tags = 1; /* always auto-follow */
 341}
 342
 343static int handle_config(const char *key, const char *value, void *cb)
 344{
 345        const char *name;
 346        const char *subkey;
 347        struct remote *remote;
 348        struct branch *branch;
 349        if (!prefixcmp(key, "branch.")) {
 350                name = key + 7;
 351                subkey = strrchr(name, '.');
 352                if (!subkey)
 353                        return 0;
 354                branch = make_branch(name, subkey - name);
 355                if (!strcmp(subkey, ".remote")) {
 356                        if (!value)
 357                                return config_error_nonbool(key);
 358                        branch->remote_name = xstrdup(value);
 359                        if (branch == current_branch) {
 360                                default_remote_name = branch->remote_name;
 361                                explicit_default_remote_name = 1;
 362                        }
 363                } else if (!strcmp(subkey, ".merge")) {
 364                        if (!value)
 365                                return config_error_nonbool(key);
 366                        add_merge(branch, xstrdup(value));
 367                }
 368                return 0;
 369        }
 370        if (!prefixcmp(key, "url.")) {
 371                struct rewrite *rewrite;
 372                name = key + 4;
 373                subkey = strrchr(name, '.');
 374                if (!subkey)
 375                        return 0;
 376                if (!strcmp(subkey, ".insteadof")) {
 377                        rewrite = make_rewrite(&rewrites, name, subkey - name);
 378                        if (!value)
 379                                return config_error_nonbool(key);
 380                        add_instead_of(rewrite, xstrdup(value));
 381                } else if (!strcmp(subkey, ".pushinsteadof")) {
 382                        rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 383                        if (!value)
 384                                return config_error_nonbool(key);
 385                        add_instead_of(rewrite, xstrdup(value));
 386                }
 387        }
 388        if (prefixcmp(key,  "remote."))
 389                return 0;
 390        name = key + 7;
 391        if (*name == '/') {
 392                warning("Config remote shorthand cannot begin with '/': %s",
 393                        name);
 394                return 0;
 395        }
 396        subkey = strrchr(name, '.');
 397        if (!subkey)
 398                return 0;
 399        remote = make_remote(name, subkey - name);
 400        remote->origin = REMOTE_CONFIG;
 401        if (!strcmp(subkey, ".mirror"))
 402                remote->mirror = git_config_bool(key, value);
 403        else if (!strcmp(subkey, ".skipdefaultupdate"))
 404                remote->skip_default_update = git_config_bool(key, value);
 405        else if (!strcmp(subkey, ".skipfetchall"))
 406                remote->skip_default_update = git_config_bool(key, value);
 407        else if (!strcmp(subkey, ".url")) {
 408                const char *v;
 409                if (git_config_string(&v, key, value))
 410                        return -1;
 411                add_url(remote, v);
 412        } else if (!strcmp(subkey, ".pushurl")) {
 413                const char *v;
 414                if (git_config_string(&v, key, value))
 415                        return -1;
 416                add_pushurl(remote, v);
 417        } else if (!strcmp(subkey, ".push")) {
 418                const char *v;
 419                if (git_config_string(&v, key, value))
 420                        return -1;
 421                add_push_refspec(remote, v);
 422        } else if (!strcmp(subkey, ".fetch")) {
 423                const char *v;
 424                if (git_config_string(&v, key, value))
 425                        return -1;
 426                add_fetch_refspec(remote, v);
 427        } else if (!strcmp(subkey, ".receivepack")) {
 428                const char *v;
 429                if (git_config_string(&v, key, value))
 430                        return -1;
 431                if (!remote->receivepack)
 432                        remote->receivepack = v;
 433                else
 434                        error("more than one receivepack given, using the first");
 435        } else if (!strcmp(subkey, ".uploadpack")) {
 436                const char *v;
 437                if (git_config_string(&v, key, value))
 438                        return -1;
 439                if (!remote->uploadpack)
 440                        remote->uploadpack = v;
 441                else
 442                        error("more than one uploadpack given, using the first");
 443        } else if (!strcmp(subkey, ".tagopt")) {
 444                if (!strcmp(value, "--no-tags"))
 445                        remote->fetch_tags = -1;
 446        } else if (!strcmp(subkey, ".proxy")) {
 447                return git_config_string((const char **)&remote->http_proxy,
 448                                         key, value);
 449        } else if (!strcmp(subkey, ".vcs")) {
 450                return git_config_string(&remote->foreign_vcs, key, value);
 451        }
 452        return 0;
 453}
 454
 455static void alias_all_urls(void)
 456{
 457        int i, j;
 458        for (i = 0; i < remotes_nr; i++) {
 459                int add_pushurl_aliases;
 460                if (!remotes[i])
 461                        continue;
 462                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 463                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 464                }
 465                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 466                for (j = 0; j < remotes[i]->url_nr; j++) {
 467                        if (add_pushurl_aliases)
 468                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 469                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 470                }
 471        }
 472}
 473
 474static void read_config(void)
 475{
 476        unsigned char sha1[20];
 477        const char *head_ref;
 478        int flag;
 479        if (default_remote_name) // did this already
 480                return;
 481        default_remote_name = xstrdup("origin");
 482        current_branch = NULL;
 483        head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 484        if (head_ref && (flag & REF_ISSYMREF) &&
 485            !prefixcmp(head_ref, "refs/heads/")) {
 486                current_branch =
 487                        make_branch(head_ref + strlen("refs/heads/"), 0);
 488        }
 489        git_config(handle_config, NULL);
 490        alias_all_urls();
 491}
 492
 493/*
 494 * We need to make sure the tracking branches are well formed, but a
 495 * wildcard refspec in "struct refspec" must have a trailing slash. We
 496 * temporarily drop the trailing '/' while calling check_ref_format(),
 497 * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 498 * error return is Ok for a wildcard refspec.
 499 */
 500static int verify_refname(char *name, int is_glob)
 501{
 502        int result;
 503
 504        result = check_ref_format(name);
 505        if (is_glob && result == CHECK_REF_FORMAT_WILDCARD)
 506                result = CHECK_REF_FORMAT_OK;
 507        return result;
 508}
 509
 510/*
 511 * This function frees a refspec array.
 512 * Warning: code paths should be checked to ensure that the src
 513 *          and dst pointers are always freeable pointers as well
 514 *          as the refspec pointer itself.
 515 */
 516static void free_refspecs(struct refspec *refspec, int nr_refspec)
 517{
 518        int i;
 519
 520        if (!refspec)
 521                return;
 522
 523        for (i = 0; i < nr_refspec; i++) {
 524                free(refspec[i].src);
 525                free(refspec[i].dst);
 526        }
 527        free(refspec);
 528}
 529
 530static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 531{
 532        int i;
 533        int st;
 534        struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 535
 536        for (i = 0; i < nr_refspec; i++) {
 537                size_t llen;
 538                int is_glob;
 539                const char *lhs, *rhs;
 540
 541                is_glob = 0;
 542
 543                lhs = refspec[i];
 544                if (*lhs == '+') {
 545                        rs[i].force = 1;
 546                        lhs++;
 547                }
 548
 549                rhs = strrchr(lhs, ':');
 550
 551                /*
 552                 * Before going on, special case ":" (or "+:") as a refspec
 553                 * for matching refs.
 554                 */
 555                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 556                        rs[i].matching = 1;
 557                        continue;
 558                }
 559
 560                if (rhs) {
 561                        size_t rlen = strlen(++rhs);
 562                        is_glob = (1 <= rlen && strchr(rhs, '*'));
 563                        rs[i].dst = xstrndup(rhs, rlen);
 564                }
 565
 566                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 567                if (1 <= llen && memchr(lhs, '*', llen)) {
 568                        if ((rhs && !is_glob) || (!rhs && fetch))
 569                                goto invalid;
 570                        is_glob = 1;
 571                } else if (rhs && is_glob) {
 572                        goto invalid;
 573                }
 574
 575                rs[i].pattern = is_glob;
 576                rs[i].src = xstrndup(lhs, llen);
 577
 578                if (fetch) {
 579                        /*
 580                         * LHS
 581                         * - empty is allowed; it means HEAD.
 582                         * - otherwise it must be a valid looking ref.
 583                         */
 584                        if (!*rs[i].src)
 585                                ; /* empty is ok */
 586                        else {
 587                                st = verify_refname(rs[i].src, is_glob);
 588                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 589                                        goto invalid;
 590                        }
 591                        /*
 592                         * RHS
 593                         * - missing is ok, and is same as empty.
 594                         * - empty is ok; it means not to store.
 595                         * - otherwise it must be a valid looking ref.
 596                         */
 597                        if (!rs[i].dst) {
 598                                ; /* ok */
 599                        } else if (!*rs[i].dst) {
 600                                ; /* ok */
 601                        } else {
 602                                st = verify_refname(rs[i].dst, is_glob);
 603                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 604                                        goto invalid;
 605                        }
 606                } else {
 607                        /*
 608                         * LHS
 609                         * - empty is allowed; it means delete.
 610                         * - when wildcarded, it must be a valid looking ref.
 611                         * - otherwise, it must be an extended SHA-1, but
 612                         *   there is no existing way to validate this.
 613                         */
 614                        if (!*rs[i].src)
 615                                ; /* empty is ok */
 616                        else if (is_glob) {
 617                                st = verify_refname(rs[i].src, is_glob);
 618                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 619                                        goto invalid;
 620                        }
 621                        else
 622                                ; /* anything goes, for now */
 623                        /*
 624                         * RHS
 625                         * - missing is allowed, but LHS then must be a
 626                         *   valid looking ref.
 627                         * - empty is not allowed.
 628                         * - otherwise it must be a valid looking ref.
 629                         */
 630                        if (!rs[i].dst) {
 631                                st = verify_refname(rs[i].src, is_glob);
 632                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 633                                        goto invalid;
 634                        } else if (!*rs[i].dst) {
 635                                goto invalid;
 636                        } else {
 637                                st = verify_refname(rs[i].dst, is_glob);
 638                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 639                                        goto invalid;
 640                        }
 641                }
 642        }
 643        return rs;
 644
 645 invalid:
 646        if (verify) {
 647                /*
 648                 * nr_refspec must be greater than zero and i must be valid
 649                 * since it is only possible to reach this point from within
 650                 * the for loop above.
 651                 */
 652                free_refspecs(rs, i+1);
 653                return NULL;
 654        }
 655        die("Invalid refspec '%s'", refspec[i]);
 656}
 657
 658int valid_fetch_refspec(const char *fetch_refspec_str)
 659{
 660        const char *fetch_refspec[] = { fetch_refspec_str };
 661        struct refspec *refspec;
 662
 663        refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 664        free_refspecs(refspec, 1);
 665        return !!refspec;
 666}
 667
 668struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 669{
 670        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 671}
 672
 673static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 674{
 675        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 676}
 677
 678void free_refspec(int nr_refspec, struct refspec *refspec)
 679{
 680        int i;
 681        for (i = 0; i < nr_refspec; i++) {
 682                free(refspec[i].src);
 683                free(refspec[i].dst);
 684        }
 685        free(refspec);
 686}
 687
 688static int valid_remote_nick(const char *name)
 689{
 690        if (!name[0] || is_dot_or_dotdot(name))
 691                return 0;
 692        return !strchr(name, '/'); /* no slash */
 693}
 694
 695struct remote *remote_get(const char *name)
 696{
 697        struct remote *ret;
 698        int name_given = 0;
 699
 700        read_config();
 701        if (name)
 702                name_given = 1;
 703        else {
 704                name = default_remote_name;
 705                name_given = explicit_default_remote_name;
 706        }
 707
 708        ret = make_remote(name, 0);
 709        if (valid_remote_nick(name)) {
 710                if (!valid_remote(ret))
 711                        read_remotes_file(ret);
 712                if (!valid_remote(ret))
 713                        read_branches_file(ret);
 714        }
 715        if (name_given && !valid_remote(ret))
 716                add_url_alias(ret, name);
 717        if (!valid_remote(ret))
 718                return NULL;
 719        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 720        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 721        return ret;
 722}
 723
 724int remote_is_configured(const char *name)
 725{
 726        int i;
 727        read_config();
 728
 729        for (i = 0; i < remotes_nr; i++)
 730                if (!strcmp(name, remotes[i]->name))
 731                        return 1;
 732        return 0;
 733}
 734
 735int for_each_remote(each_remote_fn fn, void *priv)
 736{
 737        int i, result = 0;
 738        read_config();
 739        for (i = 0; i < remotes_nr && !result; i++) {
 740                struct remote *r = remotes[i];
 741                if (!r)
 742                        continue;
 743                if (!r->fetch)
 744                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 745                                                       r->fetch_refspec);
 746                if (!r->push)
 747                        r->push = parse_push_refspec(r->push_refspec_nr,
 748                                                     r->push_refspec);
 749                result = fn(r, priv);
 750        }
 751        return result;
 752}
 753
 754void ref_remove_duplicates(struct ref *ref_map)
 755{
 756        struct string_list refs = { NULL, 0, 0, 0 };
 757        struct string_list_item *item = NULL;
 758        struct ref *prev = NULL, *next = NULL;
 759        for (; ref_map; prev = ref_map, ref_map = next) {
 760                next = ref_map->next;
 761                if (!ref_map->peer_ref)
 762                        continue;
 763
 764                item = string_list_lookup(ref_map->peer_ref->name, &refs);
 765                if (item) {
 766                        if (strcmp(((struct ref *)item->util)->name,
 767                                   ref_map->name))
 768                                die("%s tracks both %s and %s",
 769                                    ref_map->peer_ref->name,
 770                                    ((struct ref *)item->util)->name,
 771                                    ref_map->name);
 772                        prev->next = ref_map->next;
 773                        free(ref_map->peer_ref);
 774                        free(ref_map);
 775                        ref_map = prev; /* skip this; we freed it */
 776                        continue;
 777                }
 778
 779                item = string_list_insert(ref_map->peer_ref->name, &refs);
 780                item->util = ref_map;
 781        }
 782        string_list_clear(&refs, 0);
 783}
 784
 785int remote_has_url(struct remote *remote, const char *url)
 786{
 787        int i;
 788        for (i = 0; i < remote->url_nr; i++) {
 789                if (!strcmp(remote->url[i], url))
 790                        return 1;
 791        }
 792        return 0;
 793}
 794
 795static int match_name_with_pattern(const char *key, const char *name,
 796                                   const char *value, char **result)
 797{
 798        const char *kstar = strchr(key, '*');
 799        size_t klen;
 800        size_t ksuffixlen;
 801        size_t namelen;
 802        int ret;
 803        if (!kstar)
 804                die("Key '%s' of pattern had no '*'", key);
 805        klen = kstar - key;
 806        ksuffixlen = strlen(kstar + 1);
 807        namelen = strlen(name);
 808        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 809                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 810        if (ret && value) {
 811                const char *vstar = strchr(value, '*');
 812                size_t vlen;
 813                size_t vsuffixlen;
 814                if (!vstar)
 815                        die("Value '%s' of pattern has no '*'", value);
 816                vlen = vstar - value;
 817                vsuffixlen = strlen(vstar + 1);
 818                *result = xmalloc(vlen + vsuffixlen +
 819                                  strlen(name) -
 820                                  klen - ksuffixlen + 1);
 821                strncpy(*result, value, vlen);
 822                strncpy(*result + vlen,
 823                        name + klen, namelen - klen - ksuffixlen);
 824                strcpy(*result + vlen + namelen - klen - ksuffixlen,
 825                       vstar + 1);
 826        }
 827        return ret;
 828}
 829
 830char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 831                     const char *name)
 832{
 833        int i;
 834        char *ret = NULL;
 835        for (i = 0; i < nr_refspec; i++) {
 836                struct refspec *refspec = refspecs + i;
 837                if (refspec->pattern) {
 838                        if (match_name_with_pattern(refspec->src, name,
 839                                                    refspec->dst, &ret))
 840                                return ret;
 841                } else if (!strcmp(refspec->src, name))
 842                        return strdup(refspec->dst);
 843        }
 844        return NULL;
 845}
 846
 847int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 848{
 849        int find_src = refspec->src == NULL;
 850        char *needle, **result;
 851        int i;
 852
 853        if (find_src) {
 854                if (!refspec->dst)
 855                        return error("find_tracking: need either src or dst");
 856                needle = refspec->dst;
 857                result = &refspec->src;
 858        } else {
 859                needle = refspec->src;
 860                result = &refspec->dst;
 861        }
 862
 863        for (i = 0; i < remote->fetch_refspec_nr; i++) {
 864                struct refspec *fetch = &remote->fetch[i];
 865                const char *key = find_src ? fetch->dst : fetch->src;
 866                const char *value = find_src ? fetch->src : fetch->dst;
 867                if (!fetch->dst)
 868                        continue;
 869                if (fetch->pattern) {
 870                        if (match_name_with_pattern(key, needle, value, result)) {
 871                                refspec->force = fetch->force;
 872                                return 0;
 873                        }
 874                } else if (!strcmp(needle, key)) {
 875                        *result = xstrdup(value);
 876                        refspec->force = fetch->force;
 877                        return 0;
 878                }
 879        }
 880        return -1;
 881}
 882
 883static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 884                const char *name)
 885{
 886        size_t len = strlen(name);
 887        struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 888        memcpy(ref->name, prefix, prefixlen);
 889        memcpy(ref->name + prefixlen, name, len);
 890        return ref;
 891}
 892
 893struct ref *alloc_ref(const char *name)
 894{
 895        return alloc_ref_with_prefix("", 0, name);
 896}
 897
 898static struct ref *copy_ref(const struct ref *ref)
 899{
 900        struct ref *cpy;
 901        size_t len;
 902        if (!ref)
 903                return NULL;
 904        len = strlen(ref->name);
 905        cpy = xmalloc(sizeof(struct ref) + len + 1);
 906        memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 907        cpy->next = NULL;
 908        cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 909        cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 910        cpy->peer_ref = copy_ref(ref->peer_ref);
 911        return cpy;
 912}
 913
 914struct ref *copy_ref_list(const struct ref *ref)
 915{
 916        struct ref *ret = NULL;
 917        struct ref **tail = &ret;
 918        while (ref) {
 919                *tail = copy_ref(ref);
 920                ref = ref->next;
 921                tail = &((*tail)->next);
 922        }
 923        return ret;
 924}
 925
 926static void free_ref(struct ref *ref)
 927{
 928        if (!ref)
 929                return;
 930        free_ref(ref->peer_ref);
 931        free(ref->remote_status);
 932        free(ref->symref);
 933        free(ref);
 934}
 935
 936void free_refs(struct ref *ref)
 937{
 938        struct ref *next;
 939        while (ref) {
 940                next = ref->next;
 941                free_ref(ref);
 942                ref = next;
 943        }
 944}
 945
 946static int count_refspec_match(const char *pattern,
 947                               struct ref *refs,
 948                               struct ref **matched_ref)
 949{
 950        int patlen = strlen(pattern);
 951        struct ref *matched_weak = NULL;
 952        struct ref *matched = NULL;
 953        int weak_match = 0;
 954        int match = 0;
 955
 956        for (weak_match = match = 0; refs; refs = refs->next) {
 957                char *name = refs->name;
 958                int namelen = strlen(name);
 959
 960                if (!refname_match(pattern, name, ref_rev_parse_rules))
 961                        continue;
 962
 963                /* A match is "weak" if it is with refs outside
 964                 * heads or tags, and did not specify the pattern
 965                 * in full (e.g. "refs/remotes/origin/master") or at
 966                 * least from the toplevel (e.g. "remotes/origin/master");
 967                 * otherwise "git push $URL master" would result in
 968                 * ambiguity between remotes/origin/master and heads/master
 969                 * at the remote site.
 970                 */
 971                if (namelen != patlen &&
 972                    patlen != namelen - 5 &&
 973                    prefixcmp(name, "refs/heads/") &&
 974                    prefixcmp(name, "refs/tags/")) {
 975                        /* We want to catch the case where only weak
 976                         * matches are found and there are multiple
 977                         * matches, and where more than one strong
 978                         * matches are found, as ambiguous.  One
 979                         * strong match with zero or more weak matches
 980                         * are acceptable as a unique match.
 981                         */
 982                        matched_weak = refs;
 983                        weak_match++;
 984                }
 985                else {
 986                        matched = refs;
 987                        match++;
 988                }
 989        }
 990        if (!matched) {
 991                *matched_ref = matched_weak;
 992                return weak_match;
 993        }
 994        else {
 995                *matched_ref = matched;
 996                return match;
 997        }
 998}
 999
1000static void tail_link_ref(struct ref *ref, struct ref ***tail)
1001{
1002        **tail = ref;
1003        while (ref->next)
1004                ref = ref->next;
1005        *tail = &ref->next;
1006}
1007
1008static struct ref *try_explicit_object_name(const char *name)
1009{
1010        unsigned char sha1[20];
1011        struct ref *ref;
1012
1013        if (!*name) {
1014                ref = alloc_ref("(delete)");
1015                hashclr(ref->new_sha1);
1016                return ref;
1017        }
1018        if (get_sha1(name, sha1))
1019                return NULL;
1020        ref = alloc_ref(name);
1021        hashcpy(ref->new_sha1, sha1);
1022        return ref;
1023}
1024
1025static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1026{
1027        struct ref *ret = alloc_ref(name);
1028        tail_link_ref(ret, tail);
1029        return ret;
1030}
1031
1032static char *guess_ref(const char *name, struct ref *peer)
1033{
1034        struct strbuf buf = STRBUF_INIT;
1035        unsigned char sha1[20];
1036
1037        const char *r = resolve_ref(peer->name, sha1, 1, NULL);
1038        if (!r)
1039                return NULL;
1040
1041        if (!prefixcmp(r, "refs/heads/"))
1042                strbuf_addstr(&buf, "refs/heads/");
1043        else if (!prefixcmp(r, "refs/tags/"))
1044                strbuf_addstr(&buf, "refs/tags/");
1045        else
1046                return NULL;
1047
1048        strbuf_addstr(&buf, name);
1049        return strbuf_detach(&buf, NULL);
1050}
1051
1052static int match_explicit(struct ref *src, struct ref *dst,
1053                          struct ref ***dst_tail,
1054                          struct refspec *rs)
1055{
1056        struct ref *matched_src, *matched_dst;
1057        int copy_src;
1058
1059        const char *dst_value = rs->dst;
1060        char *dst_guess;
1061
1062        if (rs->pattern || rs->matching)
1063                return 0;
1064
1065        matched_src = matched_dst = NULL;
1066        switch (count_refspec_match(rs->src, src, &matched_src)) {
1067        case 1:
1068                copy_src = 1;
1069                break;
1070        case 0:
1071                /* The source could be in the get_sha1() format
1072                 * not a reference name.  :refs/other is a
1073                 * way to delete 'other' ref at the remote end.
1074                 */
1075                matched_src = try_explicit_object_name(rs->src);
1076                if (!matched_src)
1077                        return error("src refspec %s does not match any.", rs->src);
1078                copy_src = 0;
1079                break;
1080        default:
1081                return error("src refspec %s matches more than one.", rs->src);
1082        }
1083
1084        if (!dst_value) {
1085                unsigned char sha1[20];
1086                int flag;
1087
1088                dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
1089                if (!dst_value ||
1090                    ((flag & REF_ISSYMREF) &&
1091                     prefixcmp(dst_value, "refs/heads/")))
1092                        die("%s cannot be resolved to branch.",
1093                            matched_src->name);
1094        }
1095
1096        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1097        case 1:
1098                break;
1099        case 0:
1100                if (!memcmp(dst_value, "refs/", 5))
1101                        matched_dst = make_linked_ref(dst_value, dst_tail);
1102                else if ((dst_guess = guess_ref(dst_value, matched_src)))
1103                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1104                else
1105                        error("unable to push to unqualified destination: %s\n"
1106                              "The destination refspec neither matches an "
1107                              "existing ref on the remote nor\n"
1108                              "begins with refs/, and we are unable to "
1109                              "guess a prefix based on the source ref.",
1110                              dst_value);
1111                break;
1112        default:
1113                matched_dst = NULL;
1114                error("dst refspec %s matches more than one.",
1115                      dst_value);
1116                break;
1117        }
1118        if (!matched_dst)
1119                return -1;
1120        if (matched_dst->peer_ref)
1121                return error("dst ref %s receives from more than one src.",
1122                      matched_dst->name);
1123        else {
1124                matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1125                matched_dst->force = rs->force;
1126        }
1127        return 0;
1128}
1129
1130static int match_explicit_refs(struct ref *src, struct ref *dst,
1131                               struct ref ***dst_tail, struct refspec *rs,
1132                               int rs_nr)
1133{
1134        int i, errs;
1135        for (i = errs = 0; i < rs_nr; i++)
1136                errs += match_explicit(src, dst, dst_tail, &rs[i]);
1137        return errs;
1138}
1139
1140static const struct refspec *check_pattern_match(const struct refspec *rs,
1141                                                 int rs_nr,
1142                                                 const struct ref *src)
1143{
1144        int i;
1145        int matching_refs = -1;
1146        for (i = 0; i < rs_nr; i++) {
1147                if (rs[i].matching &&
1148                    (matching_refs == -1 || rs[i].force)) {
1149                        matching_refs = i;
1150                        continue;
1151                }
1152
1153                if (rs[i].pattern && match_name_with_pattern(rs[i].src, src->name,
1154                                                             NULL, NULL))
1155                        return rs + i;
1156        }
1157        if (matching_refs != -1)
1158                return rs + matching_refs;
1159        else
1160                return NULL;
1161}
1162
1163static struct ref **tail_ref(struct ref **head)
1164{
1165        struct ref **tail = head;
1166        while (*tail)
1167                tail = &((*tail)->next);
1168        return tail;
1169}
1170
1171/*
1172 * Note. This is used only by "push"; refspec matching rules for
1173 * push and fetch are subtly different, so do not try to reuse it
1174 * without thinking.
1175 */
1176int match_refs(struct ref *src, struct ref **dst,
1177               int nr_refspec, const char **refspec, int flags)
1178{
1179        struct refspec *rs;
1180        int send_all = flags & MATCH_REFS_ALL;
1181        int send_mirror = flags & MATCH_REFS_MIRROR;
1182        int errs;
1183        static const char *default_refspec[] = { ":", NULL };
1184        struct ref **dst_tail = tail_ref(dst);
1185
1186        if (!nr_refspec) {
1187                nr_refspec = 1;
1188                refspec = default_refspec;
1189        }
1190        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1191        errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1192
1193        /* pick the remainder */
1194        for ( ; src; src = src->next) {
1195                struct ref *dst_peer;
1196                const struct refspec *pat = NULL;
1197                char *dst_name;
1198                if (src->peer_ref)
1199                        continue;
1200
1201                pat = check_pattern_match(rs, nr_refspec, src);
1202                if (!pat)
1203                        continue;
1204
1205                if (pat->matching) {
1206                        /*
1207                         * "matching refs"; traditionally we pushed everything
1208                         * including refs outside refs/heads/ hierarchy, but
1209                         * that does not make much sense these days.
1210                         */
1211                        if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1212                                continue;
1213                        dst_name = xstrdup(src->name);
1214
1215                } else {
1216                        const char *dst_side = pat->dst ? pat->dst : pat->src;
1217                        if (!match_name_with_pattern(pat->src, src->name,
1218                                                     dst_side, &dst_name))
1219                                die("Didn't think it matches any more");
1220                }
1221                dst_peer = find_ref_by_name(*dst, dst_name);
1222                if (dst_peer) {
1223                        if (dst_peer->peer_ref)
1224                                /* We're already sending something to this ref. */
1225                                goto free_name;
1226
1227                } else {
1228                        if (pat->matching && !(send_all || send_mirror))
1229                                /*
1230                                 * Remote doesn't have it, and we have no
1231                                 * explicit pattern, and we don't have
1232                                 * --all nor --mirror.
1233                                 */
1234                                goto free_name;
1235
1236                        /* Create a new one and link it */
1237                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1238                        hashcpy(dst_peer->new_sha1, src->new_sha1);
1239                }
1240                dst_peer->peer_ref = copy_ref(src);
1241                dst_peer->force = pat->force;
1242        free_name:
1243                free(dst_name);
1244        }
1245        if (errs)
1246                return -1;
1247        return 0;
1248}
1249
1250void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1251        int force_update)
1252{
1253        struct ref *ref;
1254
1255        for (ref = remote_refs; ref; ref = ref->next) {
1256                if (ref->peer_ref)
1257                        hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1258                else if (!send_mirror)
1259                        continue;
1260
1261                ref->deletion = is_null_sha1(ref->new_sha1);
1262                if (!ref->deletion &&
1263                        !hashcmp(ref->old_sha1, ref->new_sha1)) {
1264                        ref->status = REF_STATUS_UPTODATE;
1265                        continue;
1266                }
1267
1268                /* This part determines what can overwrite what.
1269                 * The rules are:
1270                 *
1271                 * (0) you can always use --force or +A:B notation to
1272                 *     selectively force individual ref pairs.
1273                 *
1274                 * (1) if the old thing does not exist, it is OK.
1275                 *
1276                 * (2) if you do not have the old thing, you are not allowed
1277                 *     to overwrite it; you would not know what you are losing
1278                 *     otherwise.
1279                 *
1280                 * (3) if both new and old are commit-ish, and new is a
1281                 *     descendant of old, it is OK.
1282                 *
1283                 * (4) regardless of all of the above, removing :B is
1284                 *     always allowed.
1285                 */
1286
1287                ref->nonfastforward =
1288                        !ref->deletion &&
1289                        !is_null_sha1(ref->old_sha1) &&
1290                        (!has_sha1_file(ref->old_sha1)
1291                          || !ref_newer(ref->new_sha1, ref->old_sha1));
1292
1293                if (ref->nonfastforward && !ref->force && !force_update) {
1294                        ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
1295                        continue;
1296                }
1297        }
1298}
1299
1300struct branch *branch_get(const char *name)
1301{
1302        struct branch *ret;
1303
1304        read_config();
1305        if (!name || !*name || !strcmp(name, "HEAD"))
1306                ret = current_branch;
1307        else
1308                ret = make_branch(name, 0);
1309        if (ret && ret->remote_name) {
1310                ret->remote = remote_get(ret->remote_name);
1311                if (ret->merge_nr) {
1312                        int i;
1313                        ret->merge = xcalloc(sizeof(*ret->merge),
1314                                             ret->merge_nr);
1315                        for (i = 0; i < ret->merge_nr; i++) {
1316                                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1317                                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1318                                if (remote_find_tracking(ret->remote, ret->merge[i])
1319                                    && !strcmp(ret->remote_name, "."))
1320                                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1321                        }
1322                }
1323        }
1324        return ret;
1325}
1326
1327int branch_has_merge_config(struct branch *branch)
1328{
1329        return branch && !!branch->merge;
1330}
1331
1332int branch_merge_matches(struct branch *branch,
1333                                 int i,
1334                                 const char *refname)
1335{
1336        if (!branch || i < 0 || i >= branch->merge_nr)
1337                return 0;
1338        return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1339}
1340
1341static struct ref *get_expanded_map(const struct ref *remote_refs,
1342                                    const struct refspec *refspec)
1343{
1344        const struct ref *ref;
1345        struct ref *ret = NULL;
1346        struct ref **tail = &ret;
1347
1348        char *expn_name;
1349
1350        for (ref = remote_refs; ref; ref = ref->next) {
1351                if (strchr(ref->name, '^'))
1352                        continue; /* a dereference item */
1353                if (match_name_with_pattern(refspec->src, ref->name,
1354                                            refspec->dst, &expn_name)) {
1355                        struct ref *cpy = copy_ref(ref);
1356
1357                        cpy->peer_ref = alloc_ref(expn_name);
1358                        free(expn_name);
1359                        if (refspec->force)
1360                                cpy->peer_ref->force = 1;
1361                        *tail = cpy;
1362                        tail = &cpy->next;
1363                }
1364        }
1365
1366        return ret;
1367}
1368
1369static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1370{
1371        const struct ref *ref;
1372        for (ref = refs; ref; ref = ref->next) {
1373                if (refname_match(name, ref->name, ref_fetch_rules))
1374                        return ref;
1375        }
1376        return NULL;
1377}
1378
1379struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1380{
1381        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1382
1383        if (!ref)
1384                return NULL;
1385
1386        return copy_ref(ref);
1387}
1388
1389static struct ref *get_local_ref(const char *name)
1390{
1391        if (!name || name[0] == '\0')
1392                return NULL;
1393
1394        if (!prefixcmp(name, "refs/"))
1395                return alloc_ref(name);
1396
1397        if (!prefixcmp(name, "heads/") ||
1398            !prefixcmp(name, "tags/") ||
1399            !prefixcmp(name, "remotes/"))
1400                return alloc_ref_with_prefix("refs/", 5, name);
1401
1402        return alloc_ref_with_prefix("refs/heads/", 11, name);
1403}
1404
1405int get_fetch_map(const struct ref *remote_refs,
1406                  const struct refspec *refspec,
1407                  struct ref ***tail,
1408                  int missing_ok)
1409{
1410        struct ref *ref_map, **rmp;
1411
1412        if (refspec->pattern) {
1413                ref_map = get_expanded_map(remote_refs, refspec);
1414        } else {
1415                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1416
1417                ref_map = get_remote_ref(remote_refs, name);
1418                if (!missing_ok && !ref_map)
1419                        die("Couldn't find remote ref %s", name);
1420                if (ref_map) {
1421                        ref_map->peer_ref = get_local_ref(refspec->dst);
1422                        if (ref_map->peer_ref && refspec->force)
1423                                ref_map->peer_ref->force = 1;
1424                }
1425        }
1426
1427        for (rmp = &ref_map; *rmp; ) {
1428                if ((*rmp)->peer_ref) {
1429                        int st = check_ref_format((*rmp)->peer_ref->name + 5);
1430                        if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1431                                struct ref *ignore = *rmp;
1432                                error("* Ignoring funny ref '%s' locally",
1433                                      (*rmp)->peer_ref->name);
1434                                *rmp = (*rmp)->next;
1435                                free(ignore->peer_ref);
1436                                free(ignore);
1437                                continue;
1438                        }
1439                }
1440                rmp = &((*rmp)->next);
1441        }
1442
1443        if (ref_map)
1444                tail_link_ref(ref_map, tail);
1445
1446        return 0;
1447}
1448
1449int resolve_remote_symref(struct ref *ref, struct ref *list)
1450{
1451        if (!ref->symref)
1452                return 0;
1453        for (; list; list = list->next)
1454                if (!strcmp(ref->symref, list->name)) {
1455                        hashcpy(ref->old_sha1, list->old_sha1);
1456                        return 0;
1457                }
1458        return 1;
1459}
1460
1461static void unmark_and_free(struct commit_list *list, unsigned int mark)
1462{
1463        while (list) {
1464                struct commit_list *temp = list;
1465                temp->item->object.flags &= ~mark;
1466                list = temp->next;
1467                free(temp);
1468        }
1469}
1470
1471int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1472{
1473        struct object *o;
1474        struct commit *old, *new;
1475        struct commit_list *list, *used;
1476        int found = 0;
1477
1478        /* Both new and old must be commit-ish and new is descendant of
1479         * old.  Otherwise we require --force.
1480         */
1481        o = deref_tag(parse_object(old_sha1), NULL, 0);
1482        if (!o || o->type != OBJ_COMMIT)
1483                return 0;
1484        old = (struct commit *) o;
1485
1486        o = deref_tag(parse_object(new_sha1), NULL, 0);
1487        if (!o || o->type != OBJ_COMMIT)
1488                return 0;
1489        new = (struct commit *) o;
1490
1491        if (parse_commit(new) < 0)
1492                return 0;
1493
1494        used = list = NULL;
1495        commit_list_insert(new, &list);
1496        while (list) {
1497                new = pop_most_recent_commit(&list, TMP_MARK);
1498                commit_list_insert(new, &used);
1499                if (new == old) {
1500                        found = 1;
1501                        break;
1502                }
1503        }
1504        unmark_and_free(list, TMP_MARK);
1505        unmark_and_free(used, TMP_MARK);
1506        return found;
1507}
1508
1509/*
1510 * Return true if there is anything to report, otherwise false.
1511 */
1512int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1513{
1514        unsigned char sha1[20];
1515        struct commit *ours, *theirs;
1516        char symmetric[84];
1517        struct rev_info revs;
1518        const char *rev_argv[10], *base;
1519        int rev_argc;
1520
1521        /*
1522         * Nothing to report unless we are marked to build on top of
1523         * somebody else.
1524         */
1525        if (!branch ||
1526            !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1527                return 0;
1528
1529        /*
1530         * If what we used to build on no longer exists, there is
1531         * nothing to report.
1532         */
1533        base = branch->merge[0]->dst;
1534        if (!resolve_ref(base, sha1, 1, NULL))
1535                return 0;
1536        theirs = lookup_commit_reference(sha1);
1537        if (!theirs)
1538                return 0;
1539
1540        if (!resolve_ref(branch->refname, sha1, 1, NULL))
1541                return 0;
1542        ours = lookup_commit_reference(sha1);
1543        if (!ours)
1544                return 0;
1545
1546        /* are we the same? */
1547        if (theirs == ours)
1548                return 0;
1549
1550        /* Run "rev-list --left-right ours...theirs" internally... */
1551        rev_argc = 0;
1552        rev_argv[rev_argc++] = NULL;
1553        rev_argv[rev_argc++] = "--left-right";
1554        rev_argv[rev_argc++] = symmetric;
1555        rev_argv[rev_argc++] = "--";
1556        rev_argv[rev_argc] = NULL;
1557
1558        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1559        strcpy(symmetric + 40, "...");
1560        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1561
1562        init_revisions(&revs, NULL);
1563        setup_revisions(rev_argc, rev_argv, &revs, NULL);
1564        prepare_revision_walk(&revs);
1565
1566        /* ... and count the commits on each side. */
1567        *num_ours = 0;
1568        *num_theirs = 0;
1569        while (1) {
1570                struct commit *c = get_revision(&revs);
1571                if (!c)
1572                        break;
1573                if (c->object.flags & SYMMETRIC_LEFT)
1574                        (*num_ours)++;
1575                else
1576                        (*num_theirs)++;
1577        }
1578
1579        /* clear object flags smudged by the above traversal */
1580        clear_commit_marks(ours, ALL_REV_FLAGS);
1581        clear_commit_marks(theirs, ALL_REV_FLAGS);
1582        return 1;
1583}
1584
1585/*
1586 * Return true when there is anything to report, otherwise false.
1587 */
1588int format_tracking_info(struct branch *branch, struct strbuf *sb)
1589{
1590        int num_ours, num_theirs;
1591        const char *base;
1592
1593        if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1594                return 0;
1595
1596        base = branch->merge[0]->dst;
1597        base = shorten_unambiguous_ref(base, 0);
1598        if (!num_theirs)
1599                strbuf_addf(sb, "Your branch is ahead of '%s' "
1600                            "by %d commit%s.\n",
1601                            base, num_ours, (num_ours == 1) ? "" : "s");
1602        else if (!num_ours)
1603                strbuf_addf(sb, "Your branch is behind '%s' "
1604                            "by %d commit%s, "
1605                            "and can be fast-forwarded.\n",
1606                            base, num_theirs, (num_theirs == 1) ? "" : "s");
1607        else
1608                strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1609                            "and have %d and %d different commit(s) each, "
1610                            "respectively.\n",
1611                            base, num_ours, num_theirs);
1612        return 1;
1613}
1614
1615static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1616{
1617        struct ref ***local_tail = cb_data;
1618        struct ref *ref;
1619        int len;
1620
1621        /* we already know it starts with refs/ to get here */
1622        if (check_ref_format(refname + 5))
1623                return 0;
1624
1625        len = strlen(refname) + 1;
1626        ref = xcalloc(1, sizeof(*ref) + len);
1627        hashcpy(ref->new_sha1, sha1);
1628        memcpy(ref->name, refname, len);
1629        **local_tail = ref;
1630        *local_tail = &ref->next;
1631        return 0;
1632}
1633
1634struct ref *get_local_heads(void)
1635{
1636        struct ref *local_refs = NULL, **local_tail = &local_refs;
1637        for_each_ref(one_local_ref, &local_tail);
1638        return local_refs;
1639}
1640
1641struct ref *guess_remote_head(const struct ref *head,
1642                              const struct ref *refs,
1643                              int all)
1644{
1645        const struct ref *r;
1646        struct ref *list = NULL;
1647        struct ref **tail = &list;
1648
1649        if (!head)
1650                return NULL;
1651
1652        /*
1653         * Some transports support directly peeking at
1654         * where HEAD points; if that is the case, then
1655         * we don't have to guess.
1656         */
1657        if (head->symref)
1658                return copy_ref(find_ref_by_name(refs, head->symref));
1659
1660        /* If refs/heads/master could be right, it is. */
1661        if (!all) {
1662                r = find_ref_by_name(refs, "refs/heads/master");
1663                if (r && !hashcmp(r->old_sha1, head->old_sha1))
1664                        return copy_ref(r);
1665        }
1666
1667        /* Look for another ref that points there */
1668        for (r = refs; r; r = r->next) {
1669                if (r != head && !hashcmp(r->old_sha1, head->old_sha1)) {
1670                        *tail = copy_ref(r);
1671                        tail = &((*tail)->next);
1672                        if (!all)
1673                                break;
1674                }
1675        }
1676
1677        return list;
1678}
1679
1680struct stale_heads_info {
1681        struct remote *remote;
1682        struct string_list *ref_names;
1683        struct ref **stale_refs_tail;
1684};
1685
1686static int get_stale_heads_cb(const char *refname,
1687        const unsigned char *sha1, int flags, void *cb_data)
1688{
1689        struct stale_heads_info *info = cb_data;
1690        struct refspec refspec;
1691        memset(&refspec, 0, sizeof(refspec));
1692        refspec.dst = (char *)refname;
1693        if (!remote_find_tracking(info->remote, &refspec)) {
1694                if (!((flags & REF_ISSYMREF) ||
1695                    string_list_has_string(info->ref_names, refspec.src))) {
1696                        struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1697                        hashcpy(ref->new_sha1, sha1);
1698                }
1699        }
1700        return 0;
1701}
1702
1703struct ref *get_stale_heads(struct remote *remote, struct ref *fetch_map)
1704{
1705        struct ref *ref, *stale_refs = NULL;
1706        struct string_list ref_names = { NULL, 0, 0, 0 };
1707        struct stale_heads_info info;
1708        info.remote = remote;
1709        info.ref_names = &ref_names;
1710        info.stale_refs_tail = &stale_refs;
1711        for (ref = fetch_map; ref; ref = ref->next)
1712                string_list_append(ref->name, &ref_names);
1713        sort_string_list(&ref_names);
1714        for_each_ref(get_stale_heads_cb, &info);
1715        string_list_clear(&ref_names, 0);
1716        return stale_refs;
1717}