beaf9fb5b2ac37db11f11175ec89a0df5fba425b
   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
  10static struct refspec s_tag_refspec = {
  11        0,
  12        1,
  13        0,
  14        "refs/tags/*",
  15        "refs/tags/*"
  16};
  17
  18const struct refspec *tag_refspec = &s_tag_refspec;
  19
  20struct counted_string {
  21        size_t len;
  22        const char *s;
  23};
  24struct rewrite {
  25        const char *base;
  26        size_t baselen;
  27        struct counted_string *instead_of;
  28        int instead_of_nr;
  29        int instead_of_alloc;
  30};
  31struct rewrites {
  32        struct rewrite **rewrite;
  33        int rewrite_alloc;
  34        int rewrite_nr;
  35};
  36
  37static struct remote **remotes;
  38static int remotes_alloc;
  39static int remotes_nr;
  40
  41static struct branch **branches;
  42static int branches_alloc;
  43static int branches_nr;
  44
  45static struct branch *current_branch;
  46static const char *default_remote_name;
  47static int explicit_default_remote_name;
  48
  49static struct rewrites rewrites;
  50static struct rewrites rewrites_push;
  51
  52#define BUF_SIZE (2048)
  53static char buffer[BUF_SIZE];
  54
  55static const char *alias_url(const char *url, struct rewrites *r)
  56{
  57        int i, j;
  58        char *ret;
  59        struct counted_string *longest;
  60        int longest_i;
  61
  62        longest = NULL;
  63        longest_i = -1;
  64        for (i = 0; i < r->rewrite_nr; i++) {
  65                if (!r->rewrite[i])
  66                        continue;
  67                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  68                        if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  69                            (!longest ||
  70                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  71                                longest = &(r->rewrite[i]->instead_of[j]);
  72                                longest_i = i;
  73                        }
  74                }
  75        }
  76        if (!longest)
  77                return url;
  78
  79        ret = xmalloc(r->rewrite[longest_i]->baselen +
  80                     (strlen(url) - longest->len) + 1);
  81        strcpy(ret, r->rewrite[longest_i]->base);
  82        strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  83        return ret;
  84}
  85
  86static void add_push_refspec(struct remote *remote, const char *ref)
  87{
  88        ALLOC_GROW(remote->push_refspec,
  89                   remote->push_refspec_nr + 1,
  90                   remote->push_refspec_alloc);
  91        remote->push_refspec[remote->push_refspec_nr++] = ref;
  92}
  93
  94static void add_fetch_refspec(struct remote *remote, const char *ref)
  95{
  96        ALLOC_GROW(remote->fetch_refspec,
  97                   remote->fetch_refspec_nr + 1,
  98                   remote->fetch_refspec_alloc);
  99        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 100}
 101
 102static void add_url(struct remote *remote, const char *url)
 103{
 104        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 105        remote->url[remote->url_nr++] = url;
 106}
 107
 108static void add_pushurl(struct remote *remote, const char *pushurl)
 109{
 110        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 111        remote->pushurl[remote->pushurl_nr++] = pushurl;
 112}
 113
 114static void add_pushurl_alias(struct remote *remote, const char *url)
 115{
 116        const char *pushurl = alias_url(url, &rewrites_push);
 117        if (pushurl != url)
 118                add_pushurl(remote, pushurl);
 119}
 120
 121static void add_url_alias(struct remote *remote, const char *url)
 122{
 123        add_url(remote, alias_url(url, &rewrites));
 124        add_pushurl_alias(remote, url);
 125}
 126
 127static struct remote *make_remote(const char *name, int len)
 128{
 129        struct remote *ret;
 130        int i;
 131
 132        for (i = 0; i < remotes_nr; i++) {
 133                if (len ? (!strncmp(name, remotes[i]->name, len) &&
 134                           !remotes[i]->name[len]) :
 135                    !strcmp(name, remotes[i]->name))
 136                        return remotes[i];
 137        }
 138
 139        ret = xcalloc(1, sizeof(struct remote));
 140        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 141        remotes[remotes_nr++] = ret;
 142        if (len)
 143                ret->name = xstrndup(name, len);
 144        else
 145                ret->name = xstrdup(name);
 146        return ret;
 147}
 148
 149static void add_merge(struct branch *branch, const char *name)
 150{
 151        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 152                   branch->merge_alloc);
 153        branch->merge_name[branch->merge_nr++] = name;
 154}
 155
 156static struct branch *make_branch(const char *name, int len)
 157{
 158        struct branch *ret;
 159        int i;
 160        char *refname;
 161
 162        for (i = 0; i < branches_nr; i++) {
 163                if (len ? (!strncmp(name, branches[i]->name, len) &&
 164                           !branches[i]->name[len]) :
 165                    !strcmp(name, branches[i]->name))
 166                        return branches[i];
 167        }
 168
 169        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 170        ret = xcalloc(1, sizeof(struct branch));
 171        branches[branches_nr++] = ret;
 172        if (len)
 173                ret->name = xstrndup(name, len);
 174        else
 175                ret->name = xstrdup(name);
 176        refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 177        strcpy(refname, "refs/heads/");
 178        strcpy(refname + strlen("refs/heads/"), ret->name);
 179        ret->refname = refname;
 180
 181        return ret;
 182}
 183
 184static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 185{
 186        struct rewrite *ret;
 187        int i;
 188
 189        for (i = 0; i < r->rewrite_nr; i++) {
 190                if (len
 191                    ? (len == r->rewrite[i]->baselen &&
 192                       !strncmp(base, r->rewrite[i]->base, len))
 193                    : !strcmp(base, r->rewrite[i]->base))
 194                        return r->rewrite[i];
 195        }
 196
 197        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 198        ret = xcalloc(1, sizeof(struct rewrite));
 199        r->rewrite[r->rewrite_nr++] = ret;
 200        if (len) {
 201                ret->base = xstrndup(base, len);
 202                ret->baselen = len;
 203        }
 204        else {
 205                ret->base = xstrdup(base);
 206                ret->baselen = strlen(base);
 207        }
 208        return ret;
 209}
 210
 211static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 212{
 213        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 214        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 215        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 216        rewrite->instead_of_nr++;
 217}
 218
 219static void read_remotes_file(struct remote *remote)
 220{
 221        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 222
 223        if (!f)
 224                return;
 225        remote->origin = REMOTE_REMOTES;
 226        while (fgets(buffer, BUF_SIZE, f)) {
 227                int value_list;
 228                char *s, *p;
 229
 230                if (!prefixcmp(buffer, "URL:")) {
 231                        value_list = 0;
 232                        s = buffer + 4;
 233                } else if (!prefixcmp(buffer, "Push:")) {
 234                        value_list = 1;
 235                        s = buffer + 5;
 236                } else if (!prefixcmp(buffer, "Pull:")) {
 237                        value_list = 2;
 238                        s = buffer + 5;
 239                } else
 240                        continue;
 241
 242                while (isspace(*s))
 243                        s++;
 244                if (!*s)
 245                        continue;
 246
 247                p = s + strlen(s);
 248                while (isspace(p[-1]))
 249                        *--p = 0;
 250
 251                switch (value_list) {
 252                case 0:
 253                        add_url_alias(remote, xstrdup(s));
 254                        break;
 255                case 1:
 256                        add_push_refspec(remote, xstrdup(s));
 257                        break;
 258                case 2:
 259                        add_fetch_refspec(remote, xstrdup(s));
 260                        break;
 261                }
 262        }
 263        fclose(f);
 264}
 265
 266static void read_branches_file(struct remote *remote)
 267{
 268        const char *slash = strchr(remote->name, '/');
 269        char *frag;
 270        struct strbuf branch = STRBUF_INIT;
 271        int n = slash ? slash - remote->name : 1000;
 272        FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 273        char *s, *p;
 274        int len;
 275
 276        if (!f)
 277                return;
 278        s = fgets(buffer, BUF_SIZE, f);
 279        fclose(f);
 280        if (!s)
 281                return;
 282        while (isspace(*s))
 283                s++;
 284        if (!*s)
 285                return;
 286        remote->origin = REMOTE_BRANCHES;
 287        p = s + strlen(s);
 288        while (isspace(p[-1]))
 289                *--p = 0;
 290        len = p - s;
 291        if (slash)
 292                len += strlen(slash);
 293        p = xmalloc(len + 1);
 294        strcpy(p, s);
 295        if (slash)
 296                strcat(p, slash);
 297
 298        /*
 299         * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 300         * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 301         * the partial URL obtained from the branches file plus
 302         * "/netdev-2.6" and does not store it in any tracking ref.
 303         * #branch specifier in the file is ignored.
 304         *
 305         * Otherwise, the branches file would have URL and optionally
 306         * #branch specified.  The "master" (or specified) branch is
 307         * fetched and stored in the local branch of the same name.
 308         */
 309        frag = strchr(p, '#');
 310        if (frag) {
 311                *(frag++) = '\0';
 312                strbuf_addf(&branch, "refs/heads/%s", frag);
 313        } else
 314                strbuf_addstr(&branch, "refs/heads/master");
 315        if (!slash) {
 316                strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 317        } else {
 318                strbuf_reset(&branch);
 319                strbuf_addstr(&branch, "HEAD:");
 320        }
 321        add_url_alias(remote, p);
 322        add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 323        /*
 324         * Cogito compatible push: push current HEAD to remote #branch
 325         * (master if missing)
 326         */
 327        strbuf_init(&branch, 0);
 328        strbuf_addstr(&branch, "HEAD");
 329        if (frag)
 330                strbuf_addf(&branch, ":refs/heads/%s", frag);
 331        else
 332                strbuf_addstr(&branch, ":refs/heads/master");
 333        add_push_refspec(remote, strbuf_detach(&branch, NULL));
 334        remote->fetch_tags = 1; /* always auto-follow */
 335}
 336
 337static int handle_config(const char *key, const char *value, void *cb)
 338{
 339        const char *name;
 340        const char *subkey;
 341        struct remote *remote;
 342        struct branch *branch;
 343        if (!prefixcmp(key, "branch.")) {
 344                name = key + 7;
 345                subkey = strrchr(name, '.');
 346                if (!subkey)
 347                        return 0;
 348                branch = make_branch(name, subkey - name);
 349                if (!strcmp(subkey, ".remote")) {
 350                        if (!value)
 351                                return config_error_nonbool(key);
 352                        branch->remote_name = xstrdup(value);
 353                        if (branch == current_branch) {
 354                                default_remote_name = branch->remote_name;
 355                                explicit_default_remote_name = 1;
 356                        }
 357                } else if (!strcmp(subkey, ".merge")) {
 358                        if (!value)
 359                                return config_error_nonbool(key);
 360                        add_merge(branch, xstrdup(value));
 361                }
 362                return 0;
 363        }
 364        if (!prefixcmp(key, "url.")) {
 365                struct rewrite *rewrite;
 366                name = key + 4;
 367                subkey = strrchr(name, '.');
 368                if (!subkey)
 369                        return 0;
 370                if (!strcmp(subkey, ".insteadof")) {
 371                        rewrite = make_rewrite(&rewrites, name, subkey - name);
 372                        if (!value)
 373                                return config_error_nonbool(key);
 374                        add_instead_of(rewrite, xstrdup(value));
 375                } else if (!strcmp(subkey, ".pushinsteadof")) {
 376                        rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 377                        if (!value)
 378                                return config_error_nonbool(key);
 379                        add_instead_of(rewrite, xstrdup(value));
 380                }
 381        }
 382        if (prefixcmp(key,  "remote."))
 383                return 0;
 384        name = key + 7;
 385        if (*name == '/') {
 386                warning("Config remote shorthand cannot begin with '/': %s",
 387                        name);
 388                return 0;
 389        }
 390        subkey = strrchr(name, '.');
 391        if (!subkey)
 392                return 0;
 393        remote = make_remote(name, subkey - name);
 394        remote->origin = REMOTE_CONFIG;
 395        if (!strcmp(subkey, ".mirror"))
 396                remote->mirror = git_config_bool(key, value);
 397        else if (!strcmp(subkey, ".skipdefaultupdate"))
 398                remote->skip_default_update = git_config_bool(key, value);
 399        else if (!strcmp(subkey, ".skipfetchall"))
 400                remote->skip_default_update = git_config_bool(key, value);
 401        else if (!strcmp(subkey, ".url")) {
 402                const char *v;
 403                if (git_config_string(&v, key, value))
 404                        return -1;
 405                add_url(remote, v);
 406        } else if (!strcmp(subkey, ".pushurl")) {
 407                const char *v;
 408                if (git_config_string(&v, key, value))
 409                        return -1;
 410                add_pushurl(remote, v);
 411        } else if (!strcmp(subkey, ".push")) {
 412                const char *v;
 413                if (git_config_string(&v, key, value))
 414                        return -1;
 415                add_push_refspec(remote, v);
 416        } else if (!strcmp(subkey, ".fetch")) {
 417                const char *v;
 418                if (git_config_string(&v, key, value))
 419                        return -1;
 420                add_fetch_refspec(remote, v);
 421        } else if (!strcmp(subkey, ".receivepack")) {
 422                const char *v;
 423                if (git_config_string(&v, key, value))
 424                        return -1;
 425                if (!remote->receivepack)
 426                        remote->receivepack = v;
 427                else
 428                        error("more than one receivepack given, using the first");
 429        } else if (!strcmp(subkey, ".uploadpack")) {
 430                const char *v;
 431                if (git_config_string(&v, key, value))
 432                        return -1;
 433                if (!remote->uploadpack)
 434                        remote->uploadpack = v;
 435                else
 436                        error("more than one uploadpack given, using the first");
 437        } else if (!strcmp(subkey, ".tagopt")) {
 438                if (!strcmp(value, "--no-tags"))
 439                        remote->fetch_tags = -1;
 440        } else if (!strcmp(subkey, ".proxy")) {
 441                return git_config_string((const char **)&remote->http_proxy,
 442                                         key, value);
 443        }
 444        return 0;
 445}
 446
 447static void alias_all_urls(void)
 448{
 449        int i, j;
 450        for (i = 0; i < remotes_nr; i++) {
 451                int add_pushurl_aliases;
 452                if (!remotes[i])
 453                        continue;
 454                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 455                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 456                }
 457                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 458                for (j = 0; j < remotes[i]->url_nr; j++) {
 459                        if (add_pushurl_aliases)
 460                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 461                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 462                }
 463        }
 464}
 465
 466static void read_config(void)
 467{
 468        unsigned char sha1[20];
 469        const char *head_ref;
 470        int flag;
 471        if (default_remote_name) // did this already
 472                return;
 473        default_remote_name = xstrdup("origin");
 474        current_branch = NULL;
 475        head_ref = resolve_ref("HEAD", sha1, 0, &flag);
 476        if (head_ref && (flag & REF_ISSYMREF) &&
 477            !prefixcmp(head_ref, "refs/heads/")) {
 478                current_branch =
 479                        make_branch(head_ref + strlen("refs/heads/"), 0);
 480        }
 481        git_config(handle_config, NULL);
 482        alias_all_urls();
 483}
 484
 485/*
 486 * We need to make sure the tracking branches are well formed, but a
 487 * wildcard refspec in "struct refspec" must have a trailing slash. We
 488 * temporarily drop the trailing '/' while calling check_ref_format(),
 489 * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
 490 * error return is Ok for a wildcard refspec.
 491 */
 492static int verify_refname(char *name, int is_glob)
 493{
 494        int result;
 495
 496        result = check_ref_format(name);
 497        if (is_glob && result == CHECK_REF_FORMAT_WILDCARD)
 498                result = CHECK_REF_FORMAT_OK;
 499        return result;
 500}
 501
 502/*
 503 * This function frees a refspec array.
 504 * Warning: code paths should be checked to ensure that the src
 505 *          and dst pointers are always freeable pointers as well
 506 *          as the refspec pointer itself.
 507 */
 508static void free_refspecs(struct refspec *refspec, int nr_refspec)
 509{
 510        int i;
 511
 512        if (!refspec)
 513                return;
 514
 515        for (i = 0; i < nr_refspec; i++) {
 516                free(refspec[i].src);
 517                free(refspec[i].dst);
 518        }
 519        free(refspec);
 520}
 521
 522static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 523{
 524        int i;
 525        int st;
 526        struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 527
 528        for (i = 0; i < nr_refspec; i++) {
 529                size_t llen;
 530                int is_glob;
 531                const char *lhs, *rhs;
 532
 533                is_glob = 0;
 534
 535                lhs = refspec[i];
 536                if (*lhs == '+') {
 537                        rs[i].force = 1;
 538                        lhs++;
 539                }
 540
 541                rhs = strrchr(lhs, ':');
 542
 543                /*
 544                 * Before going on, special case ":" (or "+:") as a refspec
 545                 * for matching refs.
 546                 */
 547                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 548                        rs[i].matching = 1;
 549                        continue;
 550                }
 551
 552                if (rhs) {
 553                        size_t rlen = strlen(++rhs);
 554                        is_glob = (1 <= rlen && strchr(rhs, '*'));
 555                        rs[i].dst = xstrndup(rhs, rlen);
 556                }
 557
 558                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 559                if (1 <= llen && memchr(lhs, '*', llen)) {
 560                        if ((rhs && !is_glob) || (!rhs && fetch))
 561                                goto invalid;
 562                        is_glob = 1;
 563                } else if (rhs && is_glob) {
 564                        goto invalid;
 565                }
 566
 567                rs[i].pattern = is_glob;
 568                rs[i].src = xstrndup(lhs, llen);
 569
 570                if (fetch) {
 571                        /*
 572                         * LHS
 573                         * - empty is allowed; it means HEAD.
 574                         * - otherwise it must be a valid looking ref.
 575                         */
 576                        if (!*rs[i].src)
 577                                ; /* empty is ok */
 578                        else {
 579                                st = verify_refname(rs[i].src, is_glob);
 580                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 581                                        goto invalid;
 582                        }
 583                        /*
 584                         * RHS
 585                         * - missing is ok, and is same as empty.
 586                         * - empty is ok; it means not to store.
 587                         * - otherwise it must be a valid looking ref.
 588                         */
 589                        if (!rs[i].dst) {
 590                                ; /* ok */
 591                        } else if (!*rs[i].dst) {
 592                                ; /* ok */
 593                        } else {
 594                                st = verify_refname(rs[i].dst, is_glob);
 595                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 596                                        goto invalid;
 597                        }
 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                                st = verify_refname(rs[i].src, is_glob);
 610                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 611                                        goto invalid;
 612                        }
 613                        else
 614                                ; /* anything goes, for now */
 615                        /*
 616                         * RHS
 617                         * - missing is allowed, but LHS then must be a
 618                         *   valid looking ref.
 619                         * - empty is not allowed.
 620                         * - otherwise it must be a valid looking ref.
 621                         */
 622                        if (!rs[i].dst) {
 623                                st = verify_refname(rs[i].src, is_glob);
 624                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 625                                        goto invalid;
 626                        } else if (!*rs[i].dst) {
 627                                goto invalid;
 628                        } else {
 629                                st = verify_refname(rs[i].dst, is_glob);
 630                                if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 631                                        goto invalid;
 632                        }
 633                }
 634        }
 635        return rs;
 636
 637 invalid:
 638        if (verify) {
 639                /*
 640                 * nr_refspec must be greater than zero and i must be valid
 641                 * since it is only possible to reach this point from within
 642                 * the for loop above.
 643                 */
 644                free_refspecs(rs, i+1);
 645                return NULL;
 646        }
 647        die("Invalid refspec '%s'", refspec[i]);
 648}
 649
 650int valid_fetch_refspec(const char *fetch_refspec_str)
 651{
 652        const char *fetch_refspec[] = { fetch_refspec_str };
 653        struct refspec *refspec;
 654
 655        refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
 656        free_refspecs(refspec, 1);
 657        return !!refspec;
 658}
 659
 660struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 661{
 662        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 663}
 664
 665static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 666{
 667        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 668}
 669
 670static int valid_remote_nick(const char *name)
 671{
 672        if (!name[0] || is_dot_or_dotdot(name))
 673                return 0;
 674        return !strchr(name, '/'); /* no slash */
 675}
 676
 677struct remote *remote_get(const char *name)
 678{
 679        struct remote *ret;
 680        int name_given = 0;
 681
 682        read_config();
 683        if (name)
 684                name_given = 1;
 685        else {
 686                name = default_remote_name;
 687                name_given = explicit_default_remote_name;
 688        }
 689
 690        ret = make_remote(name, 0);
 691        if (valid_remote_nick(name)) {
 692                if (!ret->url)
 693                        read_remotes_file(ret);
 694                if (!ret->url)
 695                        read_branches_file(ret);
 696        }
 697        if (name_given && !ret->url)
 698                add_url_alias(ret, name);
 699        if (!ret->url)
 700                return NULL;
 701        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 702        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 703        return ret;
 704}
 705
 706int remote_is_configured(const char *name)
 707{
 708        int i;
 709        read_config();
 710
 711        for (i = 0; i < remotes_nr; i++)
 712                if (!strcmp(name, remotes[i]->name))
 713                        return 1;
 714        return 0;
 715}
 716
 717int for_each_remote(each_remote_fn fn, void *priv)
 718{
 719        int i, result = 0;
 720        read_config();
 721        for (i = 0; i < remotes_nr && !result; i++) {
 722                struct remote *r = remotes[i];
 723                if (!r)
 724                        continue;
 725                if (!r->fetch)
 726                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 727                                                       r->fetch_refspec);
 728                if (!r->push)
 729                        r->push = parse_push_refspec(r->push_refspec_nr,
 730                                                     r->push_refspec);
 731                result = fn(r, priv);
 732        }
 733        return result;
 734}
 735
 736void ref_remove_duplicates(struct ref *ref_map)
 737{
 738        struct ref **posn;
 739        struct ref *next;
 740        for (; ref_map; ref_map = ref_map->next) {
 741                if (!ref_map->peer_ref)
 742                        continue;
 743                posn = &ref_map->next;
 744                while (*posn) {
 745                        if ((*posn)->peer_ref &&
 746                            !strcmp((*posn)->peer_ref->name,
 747                                    ref_map->peer_ref->name)) {
 748                                if (strcmp((*posn)->name, ref_map->name))
 749                                        die("%s tracks both %s and %s",
 750                                            ref_map->peer_ref->name,
 751                                            (*posn)->name, ref_map->name);
 752                                next = (*posn)->next;
 753                                free((*posn)->peer_ref);
 754                                free(*posn);
 755                                *posn = next;
 756                        } else {
 757                                posn = &(*posn)->next;
 758                        }
 759                }
 760        }
 761}
 762
 763int remote_has_url(struct remote *remote, const char *url)
 764{
 765        int i;
 766        for (i = 0; i < remote->url_nr; i++) {
 767                if (!strcmp(remote->url[i], url))
 768                        return 1;
 769        }
 770        return 0;
 771}
 772
 773static int match_name_with_pattern(const char *key, const char *name,
 774                                   const char *value, char **result)
 775{
 776        const char *kstar = strchr(key, '*');
 777        size_t klen;
 778        size_t ksuffixlen;
 779        size_t namelen;
 780        int ret;
 781        if (!kstar)
 782                die("Key '%s' of pattern had no '*'", key);
 783        klen = kstar - key;
 784        ksuffixlen = strlen(kstar + 1);
 785        namelen = strlen(name);
 786        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 787                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 788        if (ret && value) {
 789                const char *vstar = strchr(value, '*');
 790                size_t vlen;
 791                size_t vsuffixlen;
 792                if (!vstar)
 793                        die("Value '%s' of pattern has no '*'", value);
 794                vlen = vstar - value;
 795                vsuffixlen = strlen(vstar + 1);
 796                *result = xmalloc(vlen + vsuffixlen +
 797                                  strlen(name) -
 798                                  klen - ksuffixlen + 1);
 799                strncpy(*result, value, vlen);
 800                strncpy(*result + vlen,
 801                        name + klen, namelen - klen - ksuffixlen);
 802                strcpy(*result + vlen + namelen - klen - ksuffixlen,
 803                       vstar + 1);
 804        }
 805        return ret;
 806}
 807
 808int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 809{
 810        int find_src = refspec->src == NULL;
 811        char *needle, **result;
 812        int i;
 813
 814        if (find_src) {
 815                if (!refspec->dst)
 816                        return error("find_tracking: need either src or dst");
 817                needle = refspec->dst;
 818                result = &refspec->src;
 819        } else {
 820                needle = refspec->src;
 821                result = &refspec->dst;
 822        }
 823
 824        for (i = 0; i < remote->fetch_refspec_nr; i++) {
 825                struct refspec *fetch = &remote->fetch[i];
 826                const char *key = find_src ? fetch->dst : fetch->src;
 827                const char *value = find_src ? fetch->src : fetch->dst;
 828                if (!fetch->dst)
 829                        continue;
 830                if (fetch->pattern) {
 831                        if (match_name_with_pattern(key, needle, value, result)) {
 832                                refspec->force = fetch->force;
 833                                return 0;
 834                        }
 835                } else if (!strcmp(needle, key)) {
 836                        *result = xstrdup(value);
 837                        refspec->force = fetch->force;
 838                        return 0;
 839                }
 840        }
 841        return -1;
 842}
 843
 844static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 845                const char *name)
 846{
 847        size_t len = strlen(name);
 848        struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 849        memcpy(ref->name, prefix, prefixlen);
 850        memcpy(ref->name + prefixlen, name, len);
 851        return ref;
 852}
 853
 854struct ref *alloc_ref(const char *name)
 855{
 856        return alloc_ref_with_prefix("", 0, name);
 857}
 858
 859static struct ref *copy_ref(const struct ref *ref)
 860{
 861        struct ref *cpy;
 862        size_t len;
 863        if (!ref)
 864                return NULL;
 865        len = strlen(ref->name);
 866        cpy = xmalloc(sizeof(struct ref) + len + 1);
 867        memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 868        cpy->next = NULL;
 869        cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 870        cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 871        cpy->peer_ref = copy_ref(ref->peer_ref);
 872        return cpy;
 873}
 874
 875struct ref *copy_ref_list(const struct ref *ref)
 876{
 877        struct ref *ret = NULL;
 878        struct ref **tail = &ret;
 879        while (ref) {
 880                *tail = copy_ref(ref);
 881                ref = ref->next;
 882                tail = &((*tail)->next);
 883        }
 884        return ret;
 885}
 886
 887static void free_ref(struct ref *ref)
 888{
 889        if (!ref)
 890                return;
 891        free_ref(ref->peer_ref);
 892        free(ref->remote_status);
 893        free(ref->symref);
 894        free(ref);
 895}
 896
 897void free_refs(struct ref *ref)
 898{
 899        struct ref *next;
 900        while (ref) {
 901                next = ref->next;
 902                free_ref(ref);
 903                ref = next;
 904        }
 905}
 906
 907static int count_refspec_match(const char *pattern,
 908                               struct ref *refs,
 909                               struct ref **matched_ref)
 910{
 911        int patlen = strlen(pattern);
 912        struct ref *matched_weak = NULL;
 913        struct ref *matched = NULL;
 914        int weak_match = 0;
 915        int match = 0;
 916
 917        for (weak_match = match = 0; refs; refs = refs->next) {
 918                char *name = refs->name;
 919                int namelen = strlen(name);
 920
 921                if (!refname_match(pattern, name, ref_rev_parse_rules))
 922                        continue;
 923
 924                /* A match is "weak" if it is with refs outside
 925                 * heads or tags, and did not specify the pattern
 926                 * in full (e.g. "refs/remotes/origin/master") or at
 927                 * least from the toplevel (e.g. "remotes/origin/master");
 928                 * otherwise "git push $URL master" would result in
 929                 * ambiguity between remotes/origin/master and heads/master
 930                 * at the remote site.
 931                 */
 932                if (namelen != patlen &&
 933                    patlen != namelen - 5 &&
 934                    prefixcmp(name, "refs/heads/") &&
 935                    prefixcmp(name, "refs/tags/")) {
 936                        /* We want to catch the case where only weak
 937                         * matches are found and there are multiple
 938                         * matches, and where more than one strong
 939                         * matches are found, as ambiguous.  One
 940                         * strong match with zero or more weak matches
 941                         * are acceptable as a unique match.
 942                         */
 943                        matched_weak = refs;
 944                        weak_match++;
 945                }
 946                else {
 947                        matched = refs;
 948                        match++;
 949                }
 950        }
 951        if (!matched) {
 952                *matched_ref = matched_weak;
 953                return weak_match;
 954        }
 955        else {
 956                *matched_ref = matched;
 957                return match;
 958        }
 959}
 960
 961static void tail_link_ref(struct ref *ref, struct ref ***tail)
 962{
 963        **tail = ref;
 964        while (ref->next)
 965                ref = ref->next;
 966        *tail = &ref->next;
 967}
 968
 969static struct ref *try_explicit_object_name(const char *name)
 970{
 971        unsigned char sha1[20];
 972        struct ref *ref;
 973
 974        if (!*name) {
 975                ref = alloc_ref("(delete)");
 976                hashclr(ref->new_sha1);
 977                return ref;
 978        }
 979        if (get_sha1(name, sha1))
 980                return NULL;
 981        ref = alloc_ref(name);
 982        hashcpy(ref->new_sha1, sha1);
 983        return ref;
 984}
 985
 986static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 987{
 988        struct ref *ret = alloc_ref(name);
 989        tail_link_ref(ret, tail);
 990        return ret;
 991}
 992
 993static char *guess_ref(const char *name, struct ref *peer)
 994{
 995        struct strbuf buf = STRBUF_INIT;
 996        unsigned char sha1[20];
 997
 998        const char *r = resolve_ref(peer->name, sha1, 1, NULL);
 999        if (!r)
1000                return NULL;
1001
1002        if (!prefixcmp(r, "refs/heads/"))
1003                strbuf_addstr(&buf, "refs/heads/");
1004        else if (!prefixcmp(r, "refs/tags/"))
1005                strbuf_addstr(&buf, "refs/tags/");
1006        else
1007                return NULL;
1008
1009        strbuf_addstr(&buf, name);
1010        return strbuf_detach(&buf, NULL);
1011}
1012
1013static int match_explicit(struct ref *src, struct ref *dst,
1014                          struct ref ***dst_tail,
1015                          struct refspec *rs)
1016{
1017        struct ref *matched_src, *matched_dst;
1018        int copy_src;
1019
1020        const char *dst_value = rs->dst;
1021        char *dst_guess;
1022
1023        if (rs->pattern || rs->matching)
1024                return 0;
1025
1026        matched_src = matched_dst = NULL;
1027        switch (count_refspec_match(rs->src, src, &matched_src)) {
1028        case 1:
1029                copy_src = 1;
1030                break;
1031        case 0:
1032                /* The source could be in the get_sha1() format
1033                 * not a reference name.  :refs/other is a
1034                 * way to delete 'other' ref at the remote end.
1035                 */
1036                matched_src = try_explicit_object_name(rs->src);
1037                if (!matched_src)
1038                        return error("src refspec %s does not match any.", rs->src);
1039                copy_src = 0;
1040                break;
1041        default:
1042                return error("src refspec %s matches more than one.", rs->src);
1043        }
1044
1045        if (!dst_value) {
1046                unsigned char sha1[20];
1047                int flag;
1048
1049                dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
1050                if (!dst_value ||
1051                    ((flag & REF_ISSYMREF) &&
1052                     prefixcmp(dst_value, "refs/heads/")))
1053                        die("%s cannot be resolved to branch.",
1054                            matched_src->name);
1055        }
1056
1057        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1058        case 1:
1059                break;
1060        case 0:
1061                if (!memcmp(dst_value, "refs/", 5))
1062                        matched_dst = make_linked_ref(dst_value, dst_tail);
1063                else if ((dst_guess = guess_ref(dst_value, matched_src)))
1064                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1065                else
1066                        error("unable to push to unqualified destination: %s\n"
1067                              "The destination refspec neither matches an "
1068                              "existing ref on the remote nor\n"
1069                              "begins with refs/, and we are unable to "
1070                              "guess a prefix based on the source ref.",
1071                              dst_value);
1072                break;
1073        default:
1074                matched_dst = NULL;
1075                error("dst refspec %s matches more than one.",
1076                      dst_value);
1077                break;
1078        }
1079        if (!matched_dst)
1080                return -1;
1081        if (matched_dst->peer_ref)
1082                return error("dst ref %s receives from more than one src.",
1083                      matched_dst->name);
1084        else {
1085                matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1086                matched_dst->force = rs->force;
1087        }
1088        return 0;
1089}
1090
1091static int match_explicit_refs(struct ref *src, struct ref *dst,
1092                               struct ref ***dst_tail, struct refspec *rs,
1093                               int rs_nr)
1094{
1095        int i, errs;
1096        for (i = errs = 0; i < rs_nr; i++)
1097                errs += match_explicit(src, dst, dst_tail, &rs[i]);
1098        return errs;
1099}
1100
1101static const struct refspec *check_pattern_match(const struct refspec *rs,
1102                                                 int rs_nr,
1103                                                 const struct ref *src)
1104{
1105        int i;
1106        int matching_refs = -1;
1107        for (i = 0; i < rs_nr; i++) {
1108                if (rs[i].matching &&
1109                    (matching_refs == -1 || rs[i].force)) {
1110                        matching_refs = i;
1111                        continue;
1112                }
1113
1114                if (rs[i].pattern && match_name_with_pattern(rs[i].src, src->name,
1115                                                             NULL, NULL))
1116                        return rs + i;
1117        }
1118        if (matching_refs != -1)
1119                return rs + matching_refs;
1120        else
1121                return NULL;
1122}
1123
1124static struct ref **tail_ref(struct ref **head)
1125{
1126        struct ref **tail = head;
1127        while (*tail)
1128                tail = &((*tail)->next);
1129        return tail;
1130}
1131
1132/*
1133 * Note. This is used only by "push"; refspec matching rules for
1134 * push and fetch are subtly different, so do not try to reuse it
1135 * without thinking.
1136 */
1137int match_refs(struct ref *src, struct ref **dst,
1138               int nr_refspec, const char **refspec, int flags)
1139{
1140        struct refspec *rs;
1141        int send_all = flags & MATCH_REFS_ALL;
1142        int send_mirror = flags & MATCH_REFS_MIRROR;
1143        int errs;
1144        static const char *default_refspec[] = { ":", NULL };
1145        struct ref **dst_tail = tail_ref(dst);
1146
1147        if (!nr_refspec) {
1148                nr_refspec = 1;
1149                refspec = default_refspec;
1150        }
1151        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1152        errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1153
1154        /* pick the remainder */
1155        for ( ; src; src = src->next) {
1156                struct ref *dst_peer;
1157                const struct refspec *pat = NULL;
1158                char *dst_name;
1159                if (src->peer_ref)
1160                        continue;
1161
1162                pat = check_pattern_match(rs, nr_refspec, src);
1163                if (!pat)
1164                        continue;
1165
1166                if (pat->matching) {
1167                        /*
1168                         * "matching refs"; traditionally we pushed everything
1169                         * including refs outside refs/heads/ hierarchy, but
1170                         * that does not make much sense these days.
1171                         */
1172                        if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1173                                continue;
1174                        dst_name = xstrdup(src->name);
1175
1176                } else {
1177                        const char *dst_side = pat->dst ? pat->dst : pat->src;
1178                        if (!match_name_with_pattern(pat->src, src->name,
1179                                                     dst_side, &dst_name))
1180                                die("Didn't think it matches any more");
1181                }
1182                dst_peer = find_ref_by_name(*dst, dst_name);
1183                if (dst_peer) {
1184                        if (dst_peer->peer_ref)
1185                                /* We're already sending something to this ref. */
1186                                goto free_name;
1187
1188                } else {
1189                        if (pat->matching && !(send_all || send_mirror))
1190                                /*
1191                                 * Remote doesn't have it, and we have no
1192                                 * explicit pattern, and we don't have
1193                                 * --all nor --mirror.
1194                                 */
1195                                goto free_name;
1196
1197                        /* Create a new one and link it */
1198                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1199                        hashcpy(dst_peer->new_sha1, src->new_sha1);
1200                }
1201                dst_peer->peer_ref = copy_ref(src);
1202                dst_peer->force = pat->force;
1203        free_name:
1204                free(dst_name);
1205        }
1206        if (errs)
1207                return -1;
1208        return 0;
1209}
1210
1211struct branch *branch_get(const char *name)
1212{
1213        struct branch *ret;
1214
1215        read_config();
1216        if (!name || !*name || !strcmp(name, "HEAD"))
1217                ret = current_branch;
1218        else
1219                ret = make_branch(name, 0);
1220        if (ret && ret->remote_name) {
1221                ret->remote = remote_get(ret->remote_name);
1222                if (ret->merge_nr) {
1223                        int i;
1224                        ret->merge = xcalloc(sizeof(*ret->merge),
1225                                             ret->merge_nr);
1226                        for (i = 0; i < ret->merge_nr; i++) {
1227                                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1228                                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1229                                if (remote_find_tracking(ret->remote, ret->merge[i])
1230                                    && !strcmp(ret->remote_name, "."))
1231                                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1232                        }
1233                }
1234        }
1235        return ret;
1236}
1237
1238int branch_has_merge_config(struct branch *branch)
1239{
1240        return branch && !!branch->merge;
1241}
1242
1243int branch_merge_matches(struct branch *branch,
1244                                 int i,
1245                                 const char *refname)
1246{
1247        if (!branch || i < 0 || i >= branch->merge_nr)
1248                return 0;
1249        return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1250}
1251
1252static struct ref *get_expanded_map(const struct ref *remote_refs,
1253                                    const struct refspec *refspec)
1254{
1255        const struct ref *ref;
1256        struct ref *ret = NULL;
1257        struct ref **tail = &ret;
1258
1259        char *expn_name;
1260
1261        for (ref = remote_refs; ref; ref = ref->next) {
1262                if (strchr(ref->name, '^'))
1263                        continue; /* a dereference item */
1264                if (match_name_with_pattern(refspec->src, ref->name,
1265                                            refspec->dst, &expn_name)) {
1266                        struct ref *cpy = copy_ref(ref);
1267
1268                        cpy->peer_ref = alloc_ref(expn_name);
1269                        free(expn_name);
1270                        if (refspec->force)
1271                                cpy->peer_ref->force = 1;
1272                        *tail = cpy;
1273                        tail = &cpy->next;
1274                }
1275        }
1276
1277        return ret;
1278}
1279
1280static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1281{
1282        const struct ref *ref;
1283        for (ref = refs; ref; ref = ref->next) {
1284                if (refname_match(name, ref->name, ref_fetch_rules))
1285                        return ref;
1286        }
1287        return NULL;
1288}
1289
1290struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1291{
1292        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1293
1294        if (!ref)
1295                return NULL;
1296
1297        return copy_ref(ref);
1298}
1299
1300static struct ref *get_local_ref(const char *name)
1301{
1302        if (!name || name[0] == '\0')
1303                return NULL;
1304
1305        if (!prefixcmp(name, "refs/"))
1306                return alloc_ref(name);
1307
1308        if (!prefixcmp(name, "heads/") ||
1309            !prefixcmp(name, "tags/") ||
1310            !prefixcmp(name, "remotes/"))
1311                return alloc_ref_with_prefix("refs/", 5, name);
1312
1313        return alloc_ref_with_prefix("refs/heads/", 11, name);
1314}
1315
1316int get_fetch_map(const struct ref *remote_refs,
1317                  const struct refspec *refspec,
1318                  struct ref ***tail,
1319                  int missing_ok)
1320{
1321        struct ref *ref_map, **rmp;
1322
1323        if (refspec->pattern) {
1324                ref_map = get_expanded_map(remote_refs, refspec);
1325        } else {
1326                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1327
1328                ref_map = get_remote_ref(remote_refs, name);
1329                if (!missing_ok && !ref_map)
1330                        die("Couldn't find remote ref %s", name);
1331                if (ref_map) {
1332                        ref_map->peer_ref = get_local_ref(refspec->dst);
1333                        if (ref_map->peer_ref && refspec->force)
1334                                ref_map->peer_ref->force = 1;
1335                }
1336        }
1337
1338        for (rmp = &ref_map; *rmp; ) {
1339                if ((*rmp)->peer_ref) {
1340                        int st = check_ref_format((*rmp)->peer_ref->name + 5);
1341                        if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1342                                struct ref *ignore = *rmp;
1343                                error("* Ignoring funny ref '%s' locally",
1344                                      (*rmp)->peer_ref->name);
1345                                *rmp = (*rmp)->next;
1346                                free(ignore->peer_ref);
1347                                free(ignore);
1348                                continue;
1349                        }
1350                }
1351                rmp = &((*rmp)->next);
1352        }
1353
1354        if (ref_map)
1355                tail_link_ref(ref_map, tail);
1356
1357        return 0;
1358}
1359
1360int resolve_remote_symref(struct ref *ref, struct ref *list)
1361{
1362        if (!ref->symref)
1363                return 0;
1364        for (; list; list = list->next)
1365                if (!strcmp(ref->symref, list->name)) {
1366                        hashcpy(ref->old_sha1, list->old_sha1);
1367                        return 0;
1368                }
1369        return 1;
1370}
1371
1372static void unmark_and_free(struct commit_list *list, unsigned int mark)
1373{
1374        while (list) {
1375                struct commit_list *temp = list;
1376                temp->item->object.flags &= ~mark;
1377                list = temp->next;
1378                free(temp);
1379        }
1380}
1381
1382int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1383{
1384        struct object *o;
1385        struct commit *old, *new;
1386        struct commit_list *list, *used;
1387        int found = 0;
1388
1389        /* Both new and old must be commit-ish and new is descendant of
1390         * old.  Otherwise we require --force.
1391         */
1392        o = deref_tag(parse_object(old_sha1), NULL, 0);
1393        if (!o || o->type != OBJ_COMMIT)
1394                return 0;
1395        old = (struct commit *) o;
1396
1397        o = deref_tag(parse_object(new_sha1), NULL, 0);
1398        if (!o || o->type != OBJ_COMMIT)
1399                return 0;
1400        new = (struct commit *) o;
1401
1402        if (parse_commit(new) < 0)
1403                return 0;
1404
1405        used = list = NULL;
1406        commit_list_insert(new, &list);
1407        while (list) {
1408                new = pop_most_recent_commit(&list, TMP_MARK);
1409                commit_list_insert(new, &used);
1410                if (new == old) {
1411                        found = 1;
1412                        break;
1413                }
1414        }
1415        unmark_and_free(list, TMP_MARK);
1416        unmark_and_free(used, TMP_MARK);
1417        return found;
1418}
1419
1420/*
1421 * Return true if there is anything to report, otherwise false.
1422 */
1423int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1424{
1425        unsigned char sha1[20];
1426        struct commit *ours, *theirs;
1427        char symmetric[84];
1428        struct rev_info revs;
1429        const char *rev_argv[10], *base;
1430        int rev_argc;
1431
1432        /*
1433         * Nothing to report unless we are marked to build on top of
1434         * somebody else.
1435         */
1436        if (!branch ||
1437            !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1438                return 0;
1439
1440        /*
1441         * If what we used to build on no longer exists, there is
1442         * nothing to report.
1443         */
1444        base = branch->merge[0]->dst;
1445        if (!resolve_ref(base, sha1, 1, NULL))
1446                return 0;
1447        theirs = lookup_commit_reference(sha1);
1448        if (!theirs)
1449                return 0;
1450
1451        if (!resolve_ref(branch->refname, sha1, 1, NULL))
1452                return 0;
1453        ours = lookup_commit_reference(sha1);
1454        if (!ours)
1455                return 0;
1456
1457        /* are we the same? */
1458        if (theirs == ours)
1459                return 0;
1460
1461        /* Run "rev-list --left-right ours...theirs" internally... */
1462        rev_argc = 0;
1463        rev_argv[rev_argc++] = NULL;
1464        rev_argv[rev_argc++] = "--left-right";
1465        rev_argv[rev_argc++] = symmetric;
1466        rev_argv[rev_argc++] = "--";
1467        rev_argv[rev_argc] = NULL;
1468
1469        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1470        strcpy(symmetric + 40, "...");
1471        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1472
1473        init_revisions(&revs, NULL);
1474        setup_revisions(rev_argc, rev_argv, &revs, NULL);
1475        prepare_revision_walk(&revs);
1476
1477        /* ... and count the commits on each side. */
1478        *num_ours = 0;
1479        *num_theirs = 0;
1480        while (1) {
1481                struct commit *c = get_revision(&revs);
1482                if (!c)
1483                        break;
1484                if (c->object.flags & SYMMETRIC_LEFT)
1485                        (*num_ours)++;
1486                else
1487                        (*num_theirs)++;
1488        }
1489
1490        /* clear object flags smudged by the above traversal */
1491        clear_commit_marks(ours, ALL_REV_FLAGS);
1492        clear_commit_marks(theirs, ALL_REV_FLAGS);
1493        return 1;
1494}
1495
1496/*
1497 * Return true when there is anything to report, otherwise false.
1498 */
1499int format_tracking_info(struct branch *branch, struct strbuf *sb)
1500{
1501        int num_ours, num_theirs;
1502        const char *base;
1503
1504        if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1505                return 0;
1506
1507        base = branch->merge[0]->dst;
1508        base = shorten_unambiguous_ref(base, 0);
1509        if (!num_theirs)
1510                strbuf_addf(sb, "Your branch is ahead of '%s' "
1511                            "by %d commit%s.\n",
1512                            base, num_ours, (num_ours == 1) ? "" : "s");
1513        else if (!num_ours)
1514                strbuf_addf(sb, "Your branch is behind '%s' "
1515                            "by %d commit%s, "
1516                            "and can be fast-forwarded.\n",
1517                            base, num_theirs, (num_theirs == 1) ? "" : "s");
1518        else
1519                strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1520                            "and have %d and %d different commit(s) each, "
1521                            "respectively.\n",
1522                            base, num_ours, num_theirs);
1523        return 1;
1524}
1525
1526static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1527{
1528        struct ref ***local_tail = cb_data;
1529        struct ref *ref;
1530        int len;
1531
1532        /* we already know it starts with refs/ to get here */
1533        if (check_ref_format(refname + 5))
1534                return 0;
1535
1536        len = strlen(refname) + 1;
1537        ref = xcalloc(1, sizeof(*ref) + len);
1538        hashcpy(ref->new_sha1, sha1);
1539        memcpy(ref->name, refname, len);
1540        **local_tail = ref;
1541        *local_tail = &ref->next;
1542        return 0;
1543}
1544
1545struct ref *get_local_heads(void)
1546{
1547        struct ref *local_refs = NULL, **local_tail = &local_refs;
1548        for_each_ref(one_local_ref, &local_tail);
1549        return local_refs;
1550}
1551
1552struct ref *guess_remote_head(const struct ref *head,
1553                              const struct ref *refs,
1554                              int all)
1555{
1556        const struct ref *r;
1557        struct ref *list = NULL;
1558        struct ref **tail = &list;
1559
1560        if (!head)
1561                return NULL;
1562
1563        /*
1564         * Some transports support directly peeking at
1565         * where HEAD points; if that is the case, then
1566         * we don't have to guess.
1567         */
1568        if (head->symref)
1569                return copy_ref(find_ref_by_name(refs, head->symref));
1570
1571        /* If refs/heads/master could be right, it is. */
1572        if (!all) {
1573                r = find_ref_by_name(refs, "refs/heads/master");
1574                if (r && !hashcmp(r->old_sha1, head->old_sha1))
1575                        return copy_ref(r);
1576        }
1577
1578        /* Look for another ref that points there */
1579        for (r = refs; r; r = r->next) {
1580                if (r != head && !hashcmp(r->old_sha1, head->old_sha1)) {
1581                        *tail = copy_ref(r);
1582                        tail = &((*tail)->next);
1583                        if (!all)
1584                                break;
1585                }
1586        }
1587
1588        return list;
1589}