34ddc5b8d8731cf31103df03faccc9b821fe4acc
   1#include "cache.h"
   2#include "remote.h"
   3#include "refs.h"
   4#include "commit.h"
   5#include "diff.h"
   6#include "revision.h"
   7#include "dir.h"
   8#include "tag.h"
   9#include "string-list.h"
  10#include "mergesort.h"
  11
  12enum map_direction { FROM_SRC, FROM_DST };
  13
  14static struct refspec s_tag_refspec = {
  15        0,
  16        1,
  17        0,
  18        0,
  19        "refs/tags/*",
  20        "refs/tags/*"
  21};
  22
  23const struct refspec *tag_refspec = &s_tag_refspec;
  24
  25struct counted_string {
  26        size_t len;
  27        const char *s;
  28};
  29struct rewrite {
  30        const char *base;
  31        size_t baselen;
  32        struct counted_string *instead_of;
  33        int instead_of_nr;
  34        int instead_of_alloc;
  35};
  36struct rewrites {
  37        struct rewrite **rewrite;
  38        int rewrite_alloc;
  39        int rewrite_nr;
  40};
  41
  42static struct remote **remotes;
  43static int remotes_alloc;
  44static int remotes_nr;
  45
  46static struct branch **branches;
  47static int branches_alloc;
  48static int branches_nr;
  49
  50static struct branch *current_branch;
  51static const char *default_remote_name;
  52static int explicit_default_remote_name;
  53
  54static struct rewrites rewrites;
  55static struct rewrites rewrites_push;
  56
  57#define BUF_SIZE (2048)
  58static char buffer[BUF_SIZE];
  59
  60static int valid_remote(const struct remote *remote)
  61{
  62        return (!!remote->url) || (!!remote->foreign_vcs);
  63}
  64
  65static const char *alias_url(const char *url, struct rewrites *r)
  66{
  67        int i, j;
  68        char *ret;
  69        struct counted_string *longest;
  70        int longest_i;
  71
  72        longest = NULL;
  73        longest_i = -1;
  74        for (i = 0; i < r->rewrite_nr; i++) {
  75                if (!r->rewrite[i])
  76                        continue;
  77                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  78                        if (!prefixcmp(url, r->rewrite[i]->instead_of[j].s) &&
  79                            (!longest ||
  80                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  81                                longest = &(r->rewrite[i]->instead_of[j]);
  82                                longest_i = i;
  83                        }
  84                }
  85        }
  86        if (!longest)
  87                return url;
  88
  89        ret = xmalloc(r->rewrite[longest_i]->baselen +
  90                     (strlen(url) - longest->len) + 1);
  91        strcpy(ret, r->rewrite[longest_i]->base);
  92        strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  93        return ret;
  94}
  95
  96static void add_push_refspec(struct remote *remote, const char *ref)
  97{
  98        ALLOC_GROW(remote->push_refspec,
  99                   remote->push_refspec_nr + 1,
 100                   remote->push_refspec_alloc);
 101        remote->push_refspec[remote->push_refspec_nr++] = ref;
 102}
 103
 104static void add_fetch_refspec(struct remote *remote, const char *ref)
 105{
 106        ALLOC_GROW(remote->fetch_refspec,
 107                   remote->fetch_refspec_nr + 1,
 108                   remote->fetch_refspec_alloc);
 109        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 110}
 111
 112static void add_url(struct remote *remote, const char *url)
 113{
 114        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 115        remote->url[remote->url_nr++] = url;
 116}
 117
 118static void add_pushurl(struct remote *remote, const char *pushurl)
 119{
 120        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 121        remote->pushurl[remote->pushurl_nr++] = pushurl;
 122}
 123
 124static void add_pushurl_alias(struct remote *remote, const char *url)
 125{
 126        const char *pushurl = alias_url(url, &rewrites_push);
 127        if (pushurl != url)
 128                add_pushurl(remote, pushurl);
 129}
 130
 131static void add_url_alias(struct remote *remote, const char *url)
 132{
 133        add_url(remote, alias_url(url, &rewrites));
 134        add_pushurl_alias(remote, url);
 135}
 136
 137static struct remote *make_remote(const char *name, int len)
 138{
 139        struct remote *ret;
 140        int i;
 141
 142        for (i = 0; i < remotes_nr; i++) {
 143                if (len ? (!strncmp(name, remotes[i]->name, len) &&
 144                           !remotes[i]->name[len]) :
 145                    !strcmp(name, remotes[i]->name))
 146                        return remotes[i];
 147        }
 148
 149        ret = xcalloc(1, sizeof(struct remote));
 150        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 151        remotes[remotes_nr++] = ret;
 152        if (len)
 153                ret->name = xstrndup(name, len);
 154        else
 155                ret->name = xstrdup(name);
 156        return ret;
 157}
 158
 159static void add_merge(struct branch *branch, const char *name)
 160{
 161        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 162                   branch->merge_alloc);
 163        branch->merge_name[branch->merge_nr++] = name;
 164}
 165
 166static struct branch *make_branch(const char *name, int len)
 167{
 168        struct branch *ret;
 169        int i;
 170        char *refname;
 171
 172        for (i = 0; i < branches_nr; i++) {
 173                if (len ? (!strncmp(name, branches[i]->name, len) &&
 174                           !branches[i]->name[len]) :
 175                    !strcmp(name, branches[i]->name))
 176                        return branches[i];
 177        }
 178
 179        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 180        ret = xcalloc(1, sizeof(struct branch));
 181        branches[branches_nr++] = ret;
 182        if (len)
 183                ret->name = xstrndup(name, len);
 184        else
 185                ret->name = xstrdup(name);
 186        refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 187        strcpy(refname, "refs/heads/");
 188        strcpy(refname + strlen("refs/heads/"), ret->name);
 189        ret->refname = refname;
 190
 191        return ret;
 192}
 193
 194static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 195{
 196        struct rewrite *ret;
 197        int i;
 198
 199        for (i = 0; i < r->rewrite_nr; i++) {
 200                if (len
 201                    ? (len == r->rewrite[i]->baselen &&
 202                       !strncmp(base, r->rewrite[i]->base, len))
 203                    : !strcmp(base, r->rewrite[i]->base))
 204                        return r->rewrite[i];
 205        }
 206
 207        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 208        ret = xcalloc(1, sizeof(struct rewrite));
 209        r->rewrite[r->rewrite_nr++] = ret;
 210        if (len) {
 211                ret->base = xstrndup(base, len);
 212                ret->baselen = len;
 213        }
 214        else {
 215                ret->base = xstrdup(base);
 216                ret->baselen = strlen(base);
 217        }
 218        return ret;
 219}
 220
 221static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 222{
 223        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 224        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 225        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 226        rewrite->instead_of_nr++;
 227}
 228
 229static void read_remotes_file(struct remote *remote)
 230{
 231        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 232
 233        if (!f)
 234                return;
 235        remote->origin = REMOTE_REMOTES;
 236        while (fgets(buffer, BUF_SIZE, f)) {
 237                int value_list;
 238                char *s, *p;
 239
 240                if (!prefixcmp(buffer, "URL:")) {
 241                        value_list = 0;
 242                        s = buffer + 4;
 243                } else if (!prefixcmp(buffer, "Push:")) {
 244                        value_list = 1;
 245                        s = buffer + 5;
 246                } else if (!prefixcmp(buffer, "Pull:")) {
 247                        value_list = 2;
 248                        s = buffer + 5;
 249                } else
 250                        continue;
 251
 252                while (isspace(*s))
 253                        s++;
 254                if (!*s)
 255                        continue;
 256
 257                p = s + strlen(s);
 258                while (isspace(p[-1]))
 259                        *--p = 0;
 260
 261                switch (value_list) {
 262                case 0:
 263                        add_url_alias(remote, xstrdup(s));
 264                        break;
 265                case 1:
 266                        add_push_refspec(remote, xstrdup(s));
 267                        break;
 268                case 2:
 269                        add_fetch_refspec(remote, xstrdup(s));
 270                        break;
 271                }
 272        }
 273        fclose(f);
 274}
 275
 276static void read_branches_file(struct remote *remote)
 277{
 278        const char *slash = strchr(remote->name, '/');
 279        char *frag;
 280        struct strbuf branch = STRBUF_INIT;
 281        int n = slash ? slash - remote->name : 1000;
 282        FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 283        char *s, *p;
 284        int len;
 285
 286        if (!f)
 287                return;
 288        s = fgets(buffer, BUF_SIZE, f);
 289        fclose(f);
 290        if (!s)
 291                return;
 292        while (isspace(*s))
 293                s++;
 294        if (!*s)
 295                return;
 296        remote->origin = REMOTE_BRANCHES;
 297        p = s + strlen(s);
 298        while (isspace(p[-1]))
 299                *--p = 0;
 300        len = p - s;
 301        if (slash)
 302                len += strlen(slash);
 303        p = xmalloc(len + 1);
 304        strcpy(p, s);
 305        if (slash)
 306                strcat(p, slash);
 307
 308        /*
 309         * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
 310         * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
 311         * the partial URL obtained from the branches file plus
 312         * "/netdev-2.6" and does not store it in any tracking ref.
 313         * #branch specifier in the file is ignored.
 314         *
 315         * Otherwise, the branches file would have URL and optionally
 316         * #branch specified.  The "master" (or specified) branch is
 317         * fetched and stored in the local branch of the same name.
 318         */
 319        frag = strchr(p, '#');
 320        if (frag) {
 321                *(frag++) = '\0';
 322                strbuf_addf(&branch, "refs/heads/%s", frag);
 323        } else
 324                strbuf_addstr(&branch, "refs/heads/master");
 325        if (!slash) {
 326                strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 327        } else {
 328                strbuf_reset(&branch);
 329                strbuf_addstr(&branch, "HEAD:");
 330        }
 331        add_url_alias(remote, p);
 332        add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 333        /*
 334         * Cogito compatible push: push current HEAD to remote #branch
 335         * (master if missing)
 336         */
 337        strbuf_init(&branch, 0);
 338        strbuf_addstr(&branch, "HEAD");
 339        if (frag)
 340                strbuf_addf(&branch, ":refs/heads/%s", frag);
 341        else
 342                strbuf_addstr(&branch, ":refs/heads/master");
 343        add_push_refspec(remote, strbuf_detach(&branch, NULL));
 344        remote->fetch_tags = 1; /* always auto-follow */
 345}
 346
 347static int handle_config(const char *key, const char *value, void *cb)
 348{
 349        const char *name;
 350        const char *subkey;
 351        struct remote *remote;
 352        struct branch *branch;
 353        if (!prefixcmp(key, "branch.")) {
 354                name = key + 7;
 355                subkey = strrchr(name, '.');
 356                if (!subkey)
 357                        return 0;
 358                branch = make_branch(name, subkey - name);
 359                if (!strcmp(subkey, ".remote")) {
 360                        if (git_config_string(&branch->remote_name, key, value))
 361                                return -1;
 362                        if (branch == current_branch) {
 363                                default_remote_name = branch->remote_name;
 364                                explicit_default_remote_name = 1;
 365                        }
 366                } else if (!strcmp(subkey, ".merge")) {
 367                        if (!value)
 368                                return config_error_nonbool(key);
 369                        add_merge(branch, xstrdup(value));
 370                }
 371                return 0;
 372        }
 373        if (!prefixcmp(key, "url.")) {
 374                struct rewrite *rewrite;
 375                name = key + 4;
 376                subkey = strrchr(name, '.');
 377                if (!subkey)
 378                        return 0;
 379                if (!strcmp(subkey, ".insteadof")) {
 380                        rewrite = make_rewrite(&rewrites, name, subkey - name);
 381                        if (!value)
 382                                return config_error_nonbool(key);
 383                        add_instead_of(rewrite, xstrdup(value));
 384                } else if (!strcmp(subkey, ".pushinsteadof")) {
 385                        rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 386                        if (!value)
 387                                return config_error_nonbool(key);
 388                        add_instead_of(rewrite, xstrdup(value));
 389                }
 390        }
 391        if (prefixcmp(key,  "remote."))
 392                return 0;
 393        name = key + 7;
 394        if (*name == '/') {
 395                warning("Config remote shorthand cannot begin with '/': %s",
 396                        name);
 397                return 0;
 398        }
 399        subkey = strrchr(name, '.');
 400        if (!subkey)
 401                return 0;
 402        remote = make_remote(name, subkey - name);
 403        remote->origin = REMOTE_CONFIG;
 404        if (!strcmp(subkey, ".mirror"))
 405                remote->mirror = git_config_bool(key, value);
 406        else if (!strcmp(subkey, ".skipdefaultupdate"))
 407                remote->skip_default_update = git_config_bool(key, value);
 408        else if (!strcmp(subkey, ".skipfetchall"))
 409                remote->skip_default_update = git_config_bool(key, value);
 410        else if (!strcmp(subkey, ".url")) {
 411                const char *v;
 412                if (git_config_string(&v, key, value))
 413                        return -1;
 414                add_url(remote, v);
 415        } else if (!strcmp(subkey, ".pushurl")) {
 416                const char *v;
 417                if (git_config_string(&v, key, value))
 418                        return -1;
 419                add_pushurl(remote, v);
 420        } else if (!strcmp(subkey, ".push")) {
 421                const char *v;
 422                if (git_config_string(&v, key, value))
 423                        return -1;
 424                add_push_refspec(remote, v);
 425        } else if (!strcmp(subkey, ".fetch")) {
 426                const char *v;
 427                if (git_config_string(&v, key, value))
 428                        return -1;
 429                add_fetch_refspec(remote, v);
 430        } else if (!strcmp(subkey, ".receivepack")) {
 431                const char *v;
 432                if (git_config_string(&v, key, value))
 433                        return -1;
 434                if (!remote->receivepack)
 435                        remote->receivepack = v;
 436                else
 437                        error("more than one receivepack given, using the first");
 438        } else if (!strcmp(subkey, ".uploadpack")) {
 439                const char *v;
 440                if (git_config_string(&v, key, value))
 441                        return -1;
 442                if (!remote->uploadpack)
 443                        remote->uploadpack = v;
 444                else
 445                        error("more than one uploadpack given, using the first");
 446        } else if (!strcmp(subkey, ".tagopt")) {
 447                if (!strcmp(value, "--no-tags"))
 448                        remote->fetch_tags = -1;
 449                else if (!strcmp(value, "--tags"))
 450                        remote->fetch_tags = 2;
 451        } else if (!strcmp(subkey, ".proxy")) {
 452                return git_config_string((const char **)&remote->http_proxy,
 453                                         key, value);
 454        } else if (!strcmp(subkey, ".vcs")) {
 455                return git_config_string(&remote->foreign_vcs, key, value);
 456        }
 457        return 0;
 458}
 459
 460static void alias_all_urls(void)
 461{
 462        int i, j;
 463        for (i = 0; i < remotes_nr; i++) {
 464                int add_pushurl_aliases;
 465                if (!remotes[i])
 466                        continue;
 467                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 468                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 469                }
 470                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 471                for (j = 0; j < remotes[i]->url_nr; j++) {
 472                        if (add_pushurl_aliases)
 473                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 474                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 475                }
 476        }
 477}
 478
 479static void read_config(void)
 480{
 481        unsigned char sha1[20];
 482        const char *head_ref;
 483        int flag;
 484        if (default_remote_name) /* did this already */
 485                return;
 486        default_remote_name = xstrdup("origin");
 487        current_branch = NULL;
 488        head_ref = resolve_ref_unsafe("HEAD", sha1, 0, &flag);
 489        if (head_ref && (flag & REF_ISSYMREF) &&
 490            !prefixcmp(head_ref, "refs/heads/")) {
 491                current_branch =
 492                        make_branch(head_ref + strlen("refs/heads/"), 0);
 493        }
 494        git_config(handle_config, NULL);
 495        alias_all_urls();
 496}
 497
 498/*
 499 * This function frees a refspec array.
 500 * Warning: code paths should be checked to ensure that the src
 501 *          and dst pointers are always freeable pointers as well
 502 *          as the refspec pointer itself.
 503 */
 504static void free_refspecs(struct refspec *refspec, int nr_refspec)
 505{
 506        int i;
 507
 508        if (!refspec)
 509                return;
 510
 511        for (i = 0; i < nr_refspec; i++) {
 512                free(refspec[i].src);
 513                free(refspec[i].dst);
 514        }
 515        free(refspec);
 516}
 517
 518static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 519{
 520        int i;
 521        struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 522
 523        for (i = 0; i < nr_refspec; i++) {
 524                size_t llen;
 525                int is_glob;
 526                const char *lhs, *rhs;
 527                int flags;
 528
 529                is_glob = 0;
 530
 531                lhs = refspec[i];
 532                if (*lhs == '+') {
 533                        rs[i].force = 1;
 534                        lhs++;
 535                }
 536
 537                rhs = strrchr(lhs, ':');
 538
 539                /*
 540                 * Before going on, special case ":" (or "+:") as a refspec
 541                 * for pushing matching refs.
 542                 */
 543                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 544                        rs[i].matching = 1;
 545                        continue;
 546                }
 547
 548                if (rhs) {
 549                        size_t rlen = strlen(++rhs);
 550                        is_glob = (1 <= rlen && strchr(rhs, '*'));
 551                        rs[i].dst = xstrndup(rhs, rlen);
 552                }
 553
 554                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 555                if (1 <= llen && memchr(lhs, '*', llen)) {
 556                        if ((rhs && !is_glob) || (!rhs && fetch))
 557                                goto invalid;
 558                        is_glob = 1;
 559                } else if (rhs && is_glob) {
 560                        goto invalid;
 561                }
 562
 563                rs[i].pattern = is_glob;
 564                rs[i].src = xstrndup(lhs, llen);
 565                flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 566
 567                if (fetch) {
 568                        unsigned char unused[40];
 569
 570                        /* LHS */
 571                        if (!*rs[i].src)
 572                                ; /* empty is ok; it means "HEAD" */
 573                        else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 574                                rs[i].exact_sha1 = 1; /* ok */
 575                        else if (!check_refname_format(rs[i].src, flags))
 576                                ; /* valid looking ref is ok */
 577                        else
 578                                goto invalid;
 579                        /* RHS */
 580                        if (!rs[i].dst)
 581                                ; /* missing is ok; it is the same as empty */
 582                        else if (!*rs[i].dst)
 583                                ; /* empty is ok; it means "do not store" */
 584                        else if (!check_refname_format(rs[i].dst, flags))
 585                                ; /* valid looking ref is ok */
 586                        else
 587                                goto invalid;
 588                } else {
 589                        /*
 590                         * LHS
 591                         * - empty is allowed; it means delete.
 592                         * - when wildcarded, it must be a valid looking ref.
 593                         * - otherwise, it must be an extended SHA-1, but
 594                         *   there is no existing way to validate this.
 595                         */
 596                        if (!*rs[i].src)
 597                                ; /* empty is ok */
 598                        else if (is_glob) {
 599                                if (check_refname_format(rs[i].src, flags))
 600                                        goto invalid;
 601                        }
 602                        else
 603                                ; /* anything goes, for now */
 604                        /*
 605                         * RHS
 606                         * - missing is allowed, but LHS then must be a
 607                         *   valid looking ref.
 608                         * - empty is not allowed.
 609                         * - otherwise it must be a valid looking ref.
 610                         */
 611                        if (!rs[i].dst) {
 612                                if (check_refname_format(rs[i].src, flags))
 613                                        goto invalid;
 614                        } else if (!*rs[i].dst) {
 615                                goto invalid;
 616                        } else {
 617                                if (check_refname_format(rs[i].dst, flags))
 618                                        goto invalid;
 619                        }
 620                }
 621        }
 622        return rs;
 623
 624 invalid:
 625        if (verify) {
 626                /*
 627                 * nr_refspec must be greater than zero and i must be valid
 628                 * since it is only possible to reach this point from within
 629                 * the for loop above.
 630                 */
 631                free_refspecs(rs, i+1);
 632                return NULL;
 633        }
 634        die("Invalid refspec '%s'", refspec[i]);
 635}
 636
 637int valid_fetch_refspec(const char *fetch_refspec_str)
 638{
 639        struct refspec *refspec;
 640
 641        refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 642        free_refspecs(refspec, 1);
 643        return !!refspec;
 644}
 645
 646struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 647{
 648        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 649}
 650
 651static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 652{
 653        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 654}
 655
 656void free_refspec(int nr_refspec, struct refspec *refspec)
 657{
 658        int i;
 659        for (i = 0; i < nr_refspec; i++) {
 660                free(refspec[i].src);
 661                free(refspec[i].dst);
 662        }
 663        free(refspec);
 664}
 665
 666static int valid_remote_nick(const char *name)
 667{
 668        if (!name[0] || is_dot_or_dotdot(name))
 669                return 0;
 670        return !strchr(name, '/'); /* no slash */
 671}
 672
 673struct remote *remote_get(const char *name)
 674{
 675        struct remote *ret;
 676        int name_given = 0;
 677
 678        read_config();
 679        if (name)
 680                name_given = 1;
 681        else {
 682                name = default_remote_name;
 683                name_given = explicit_default_remote_name;
 684        }
 685
 686        ret = make_remote(name, 0);
 687        if (valid_remote_nick(name)) {
 688                if (!valid_remote(ret))
 689                        read_remotes_file(ret);
 690                if (!valid_remote(ret))
 691                        read_branches_file(ret);
 692        }
 693        if (name_given && !valid_remote(ret))
 694                add_url_alias(ret, name);
 695        if (!valid_remote(ret))
 696                return NULL;
 697        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 698        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 699        return ret;
 700}
 701
 702int remote_is_configured(const char *name)
 703{
 704        int i;
 705        read_config();
 706
 707        for (i = 0; i < remotes_nr; i++)
 708                if (!strcmp(name, remotes[i]->name))
 709                        return 1;
 710        return 0;
 711}
 712
 713int for_each_remote(each_remote_fn fn, void *priv)
 714{
 715        int i, result = 0;
 716        read_config();
 717        for (i = 0; i < remotes_nr && !result; i++) {
 718                struct remote *r = remotes[i];
 719                if (!r)
 720                        continue;
 721                if (!r->fetch)
 722                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 723                                                       r->fetch_refspec);
 724                if (!r->push)
 725                        r->push = parse_push_refspec(r->push_refspec_nr,
 726                                                     r->push_refspec);
 727                result = fn(r, priv);
 728        }
 729        return result;
 730}
 731
 732void ref_remove_duplicates(struct ref *ref_map)
 733{
 734        struct string_list refs = STRING_LIST_INIT_NODUP;
 735        struct string_list_item *item = NULL;
 736        struct ref *prev = NULL, *next = NULL;
 737        for (; ref_map; prev = ref_map, ref_map = next) {
 738                next = ref_map->next;
 739                if (!ref_map->peer_ref)
 740                        continue;
 741
 742                item = string_list_lookup(&refs, ref_map->peer_ref->name);
 743                if (item) {
 744                        if (strcmp(((struct ref *)item->util)->name,
 745                                   ref_map->name))
 746                                die("%s tracks both %s and %s",
 747                                    ref_map->peer_ref->name,
 748                                    ((struct ref *)item->util)->name,
 749                                    ref_map->name);
 750                        prev->next = ref_map->next;
 751                        free(ref_map->peer_ref);
 752                        free(ref_map);
 753                        ref_map = prev; /* skip this; we freed it */
 754                        continue;
 755                }
 756
 757                item = string_list_insert(&refs, ref_map->peer_ref->name);
 758                item->util = ref_map;
 759        }
 760        string_list_clear(&refs, 0);
 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
 808static int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 809{
 810        int i;
 811        int find_src = !query->src;
 812
 813        if (find_src && !query->dst)
 814                return error("query_refspecs: need either src or dst");
 815
 816        for (i = 0; i < ref_count; i++) {
 817                struct refspec *refspec = &refs[i];
 818                const char *key = find_src ? refspec->dst : refspec->src;
 819                const char *value = find_src ? refspec->src : refspec->dst;
 820                const char *needle = find_src ? query->dst : query->src;
 821                char **result = find_src ? &query->src : &query->dst;
 822
 823                if (!refspec->dst)
 824                        continue;
 825                if (refspec->pattern) {
 826                        if (match_name_with_pattern(key, needle, value, result)) {
 827                                query->force = refspec->force;
 828                                return 0;
 829                        }
 830                } else if (!strcmp(needle, key)) {
 831                        *result = xstrdup(value);
 832                        query->force = refspec->force;
 833                        return 0;
 834                }
 835        }
 836        return -1;
 837}
 838
 839char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 840                     const char *name)
 841{
 842        struct refspec query;
 843
 844        memset(&query, 0, sizeof(struct refspec));
 845        query.src = (char *)name;
 846
 847        if (query_refspecs(refspecs, nr_refspec, &query))
 848                return NULL;
 849
 850        return query.dst;
 851}
 852
 853int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 854{
 855        return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 856}
 857
 858static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 859                const char *name)
 860{
 861        size_t len = strlen(name);
 862        struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 863        memcpy(ref->name, prefix, prefixlen);
 864        memcpy(ref->name + prefixlen, name, len);
 865        return ref;
 866}
 867
 868struct ref *alloc_ref(const char *name)
 869{
 870        return alloc_ref_with_prefix("", 0, name);
 871}
 872
 873struct ref *copy_ref(const struct ref *ref)
 874{
 875        struct ref *cpy;
 876        size_t len;
 877        if (!ref)
 878                return NULL;
 879        len = strlen(ref->name);
 880        cpy = xmalloc(sizeof(struct ref) + len + 1);
 881        memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 882        cpy->next = NULL;
 883        cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 884        cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 885        cpy->peer_ref = copy_ref(ref->peer_ref);
 886        return cpy;
 887}
 888
 889struct ref *copy_ref_list(const struct ref *ref)
 890{
 891        struct ref *ret = NULL;
 892        struct ref **tail = &ret;
 893        while (ref) {
 894                *tail = copy_ref(ref);
 895                ref = ref->next;
 896                tail = &((*tail)->next);
 897        }
 898        return ret;
 899}
 900
 901static void free_ref(struct ref *ref)
 902{
 903        if (!ref)
 904                return;
 905        free_ref(ref->peer_ref);
 906        free(ref->remote_status);
 907        free(ref->symref);
 908        free(ref);
 909}
 910
 911void free_refs(struct ref *ref)
 912{
 913        struct ref *next;
 914        while (ref) {
 915                next = ref->next;
 916                free_ref(ref);
 917                ref = next;
 918        }
 919}
 920
 921int ref_compare_name(const void *va, const void *vb)
 922{
 923        const struct ref *a = va, *b = vb;
 924        return strcmp(a->name, b->name);
 925}
 926
 927static void *ref_list_get_next(const void *a)
 928{
 929        return ((const struct ref *)a)->next;
 930}
 931
 932static void ref_list_set_next(void *a, void *next)
 933{
 934        ((struct ref *)a)->next = next;
 935}
 936
 937void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 938{
 939        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 940}
 941
 942static int count_refspec_match(const char *pattern,
 943                               struct ref *refs,
 944                               struct ref **matched_ref)
 945{
 946        int patlen = strlen(pattern);
 947        struct ref *matched_weak = NULL;
 948        struct ref *matched = NULL;
 949        int weak_match = 0;
 950        int match = 0;
 951
 952        for (weak_match = match = 0; refs; refs = refs->next) {
 953                char *name = refs->name;
 954                int namelen = strlen(name);
 955
 956                if (!refname_match(pattern, name, ref_rev_parse_rules))
 957                        continue;
 958
 959                /* A match is "weak" if it is with refs outside
 960                 * heads or tags, and did not specify the pattern
 961                 * in full (e.g. "refs/remotes/origin/master") or at
 962                 * least from the toplevel (e.g. "remotes/origin/master");
 963                 * otherwise "git push $URL master" would result in
 964                 * ambiguity between remotes/origin/master and heads/master
 965                 * at the remote site.
 966                 */
 967                if (namelen != patlen &&
 968                    patlen != namelen - 5 &&
 969                    prefixcmp(name, "refs/heads/") &&
 970                    prefixcmp(name, "refs/tags/")) {
 971                        /* We want to catch the case where only weak
 972                         * matches are found and there are multiple
 973                         * matches, and where more than one strong
 974                         * matches are found, as ambiguous.  One
 975                         * strong match with zero or more weak matches
 976                         * are acceptable as a unique match.
 977                         */
 978                        matched_weak = refs;
 979                        weak_match++;
 980                }
 981                else {
 982                        matched = refs;
 983                        match++;
 984                }
 985        }
 986        if (!matched) {
 987                *matched_ref = matched_weak;
 988                return weak_match;
 989        }
 990        else {
 991                *matched_ref = matched;
 992                return match;
 993        }
 994}
 995
 996static void tail_link_ref(struct ref *ref, struct ref ***tail)
 997{
 998        **tail = ref;
 999        while (ref->next)
1000                ref = ref->next;
1001        *tail = &ref->next;
1002}
1003
1004static struct ref *alloc_delete_ref(void)
1005{
1006        struct ref *ref = alloc_ref("(delete)");
1007        hashclr(ref->new_sha1);
1008        return ref;
1009}
1010
1011static struct ref *try_explicit_object_name(const char *name)
1012{
1013        unsigned char sha1[20];
1014        struct ref *ref;
1015
1016        if (!*name)
1017                return alloc_delete_ref();
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_unsafe(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_unsafe(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 (is_null_sha1(matched_src->new_sha1))
1103                        error("unable to delete '%s': remote ref does not exist",
1104                              dst_value);
1105                else if ((dst_guess = guess_ref(dst_value, matched_src)))
1106                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1107                else
1108                        error("unable to push to unqualified destination: %s\n"
1109                              "The destination refspec neither matches an "
1110                              "existing ref on the remote nor\n"
1111                              "begins with refs/, and we are unable to "
1112                              "guess a prefix based on the source ref.",
1113                              dst_value);
1114                break;
1115        default:
1116                matched_dst = NULL;
1117                error("dst refspec %s matches more than one.",
1118                      dst_value);
1119                break;
1120        }
1121        if (!matched_dst)
1122                return -1;
1123        if (matched_dst->peer_ref)
1124                return error("dst ref %s receives from more than one src.",
1125                      matched_dst->name);
1126        else {
1127                matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
1128                matched_dst->force = rs->force;
1129        }
1130        return 0;
1131}
1132
1133static int match_explicit_refs(struct ref *src, struct ref *dst,
1134                               struct ref ***dst_tail, struct refspec *rs,
1135                               int rs_nr)
1136{
1137        int i, errs;
1138        for (i = errs = 0; i < rs_nr; i++)
1139                errs += match_explicit(src, dst, dst_tail, &rs[i]);
1140        return errs;
1141}
1142
1143static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1144                int send_mirror, int direction, const struct refspec **ret_pat)
1145{
1146        const struct refspec *pat;
1147        char *name;
1148        int i;
1149        int matching_refs = -1;
1150        for (i = 0; i < rs_nr; i++) {
1151                if (rs[i].matching &&
1152                    (matching_refs == -1 || rs[i].force)) {
1153                        matching_refs = i;
1154                        continue;
1155                }
1156
1157                if (rs[i].pattern) {
1158                        const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1159                        int match;
1160                        if (direction == FROM_SRC)
1161                                match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1162                        else
1163                                match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1164                        if (match) {
1165                                matching_refs = i;
1166                                break;
1167                        }
1168                }
1169        }
1170        if (matching_refs == -1)
1171                return NULL;
1172
1173        pat = rs + matching_refs;
1174        if (pat->matching) {
1175                /*
1176                 * "matching refs"; traditionally we pushed everything
1177                 * including refs outside refs/heads/ hierarchy, but
1178                 * that does not make much sense these days.
1179                 */
1180                if (!send_mirror && prefixcmp(ref->name, "refs/heads/"))
1181                        return NULL;
1182                name = xstrdup(ref->name);
1183        }
1184        if (ret_pat)
1185                *ret_pat = pat;
1186        return name;
1187}
1188
1189static struct ref **tail_ref(struct ref **head)
1190{
1191        struct ref **tail = head;
1192        while (*tail)
1193                tail = &((*tail)->next);
1194        return tail;
1195}
1196
1197struct tips {
1198        struct commit **tip;
1199        int nr, alloc;
1200};
1201
1202static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1203{
1204        struct commit *commit;
1205
1206        if (is_null_sha1(sha1))
1207                return;
1208        commit = lookup_commit_reference_gently(sha1, 1);
1209        if (!commit || (commit->object.flags & TMP_MARK))
1210                return;
1211        commit->object.flags |= TMP_MARK;
1212        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1213        tips->tip[tips->nr++] = commit;
1214}
1215
1216static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1217{
1218        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1219        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1220        struct string_list_item *item;
1221        struct ref *ref;
1222        struct tips sent_tips;
1223
1224        /*
1225         * Collect everything we know they would have at the end of
1226         * this push, and collect all tags they have.
1227         */
1228        memset(&sent_tips, 0, sizeof(sent_tips));
1229        for (ref = *dst; ref; ref = ref->next) {
1230                if (ref->peer_ref &&
1231                    !is_null_sha1(ref->peer_ref->new_sha1))
1232                        add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1233                else
1234                        add_to_tips(&sent_tips, ref->old_sha1);
1235                if (!prefixcmp(ref->name, "refs/tags/"))
1236                        string_list_append(&dst_tag, ref->name);
1237        }
1238        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1239
1240        sort_string_list(&dst_tag);
1241
1242        /* Collect tags they do not have. */
1243        for (ref = src; ref; ref = ref->next) {
1244                if (prefixcmp(ref->name, "refs/tags/"))
1245                        continue; /* not a tag */
1246                if (string_list_has_string(&dst_tag, ref->name))
1247                        continue; /* they already have it */
1248                if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1249                        continue; /* be conservative */
1250                item = string_list_append(&src_tag, ref->name);
1251                item->util = ref;
1252        }
1253        string_list_clear(&dst_tag, 0);
1254
1255        /*
1256         * At this point, src_tag lists tags that are missing from
1257         * dst, and sent_tips lists the tips we are pushing or those
1258         * that we know they already have. An element in the src_tag
1259         * that is an ancestor of any of the sent_tips needs to be
1260         * sent to the other side.
1261         */
1262        if (sent_tips.nr) {
1263                for_each_string_list_item(item, &src_tag) {
1264                        struct ref *ref = item->util;
1265                        struct ref *dst_ref;
1266                        struct commit *commit;
1267
1268                        if (is_null_sha1(ref->new_sha1))
1269                                continue;
1270                        commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1271                        if (!commit)
1272                                /* not pushing a commit, which is not an error */
1273                                continue;
1274
1275                        /*
1276                         * Is this tag, which they do not have, reachable from
1277                         * any of the commits we are sending?
1278                         */
1279                        if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1280                                continue;
1281
1282                        /* Add it in */
1283                        dst_ref = make_linked_ref(ref->name, dst_tail);
1284                        hashcpy(dst_ref->new_sha1, ref->new_sha1);
1285                        dst_ref->peer_ref = copy_ref(ref);
1286                }
1287        }
1288        string_list_clear(&src_tag, 0);
1289        free(sent_tips.tip);
1290}
1291
1292/*
1293 * Given the set of refs the local repository has, the set of refs the
1294 * remote repository has, and the refspec used for push, determine
1295 * what remote refs we will update and with what value by setting
1296 * peer_ref (which object is being pushed) and force (if the push is
1297 * forced) in elements of "dst". The function may add new elements to
1298 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1299 */
1300int match_push_refs(struct ref *src, struct ref **dst,
1301                    int nr_refspec, const char **refspec, int flags)
1302{
1303        struct refspec *rs;
1304        int send_all = flags & MATCH_REFS_ALL;
1305        int send_mirror = flags & MATCH_REFS_MIRROR;
1306        int send_prune = flags & MATCH_REFS_PRUNE;
1307        int errs;
1308        static const char *default_refspec[] = { ":", NULL };
1309        struct ref *ref, **dst_tail = tail_ref(dst);
1310
1311        if (!nr_refspec) {
1312                nr_refspec = 1;
1313                refspec = default_refspec;
1314        }
1315        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1316        errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1317
1318        /* pick the remainder */
1319        for (ref = src; ref; ref = ref->next) {
1320                struct ref *dst_peer;
1321                const struct refspec *pat = NULL;
1322                char *dst_name;
1323
1324                dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1325                if (!dst_name)
1326                        continue;
1327
1328                dst_peer = find_ref_by_name(*dst, dst_name);
1329                if (dst_peer) {
1330                        if (dst_peer->peer_ref)
1331                                /* We're already sending something to this ref. */
1332                                goto free_name;
1333                } else {
1334                        if (pat->matching && !(send_all || send_mirror))
1335                                /*
1336                                 * Remote doesn't have it, and we have no
1337                                 * explicit pattern, and we don't have
1338                                 * --all nor --mirror.
1339                                 */
1340                                goto free_name;
1341
1342                        /* Create a new one and link it */
1343                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1344                        hashcpy(dst_peer->new_sha1, ref->new_sha1);
1345                }
1346                dst_peer->peer_ref = copy_ref(ref);
1347                dst_peer->force = pat->force;
1348        free_name:
1349                free(dst_name);
1350        }
1351
1352        if (flags & MATCH_REFS_FOLLOW_TAGS)
1353                add_missing_tags(src, dst, &dst_tail);
1354
1355        if (send_prune) {
1356                /* check for missing refs on the remote */
1357                for (ref = *dst; ref; ref = ref->next) {
1358                        char *src_name;
1359
1360                        if (ref->peer_ref)
1361                                /* We're already sending something to this ref. */
1362                                continue;
1363
1364                        src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1365                        if (src_name) {
1366                                if (!find_ref_by_name(src, src_name))
1367                                        ref->peer_ref = alloc_delete_ref();
1368                                free(src_name);
1369                        }
1370                }
1371        }
1372        if (errs)
1373                return -1;
1374        return 0;
1375}
1376
1377void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1378        int force_update)
1379{
1380        struct ref *ref;
1381
1382        for (ref = remote_refs; ref; ref = ref->next) {
1383                int force_ref_update = ref->force || force_update;
1384
1385                if (ref->peer_ref)
1386                        hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1387                else if (!send_mirror)
1388                        continue;
1389
1390                ref->deletion = is_null_sha1(ref->new_sha1);
1391                if (!ref->deletion &&
1392                        !hashcmp(ref->old_sha1, ref->new_sha1)) {
1393                        ref->status = REF_STATUS_UPTODATE;
1394                        continue;
1395                }
1396
1397                /*
1398                 * Decide whether an individual refspec A:B can be
1399                 * pushed.  The push will succeed if any of the
1400                 * following are true:
1401                 *
1402                 * (1) the remote reference B does not exist
1403                 *
1404                 * (2) the remote reference B is being removed (i.e.,
1405                 *     pushing :B where no source is specified)
1406                 *
1407                 * (3) the destination is not under refs/tags/, and
1408                 *     if the old and new value is a commit, the new
1409                 *     is a descendant of the old.
1410                 *
1411                 * (4) it is forced using the +A:B notation, or by
1412                 *     passing the --force argument
1413                 */
1414
1415                if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1416                        int why = 0; /* why would this push require --force? */
1417
1418                        if (!prefixcmp(ref->name, "refs/tags/"))
1419                                why = REF_STATUS_REJECT_ALREADY_EXISTS;
1420                        else if (!has_sha1_file(ref->old_sha1))
1421                                why = REF_STATUS_REJECT_FETCH_FIRST;
1422                        else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1423                                 !lookup_commit_reference_gently(ref->new_sha1, 1))
1424                                why = REF_STATUS_REJECT_NEEDS_FORCE;
1425                        else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1426                                why = REF_STATUS_REJECT_NONFASTFORWARD;
1427
1428                        if (!force_ref_update)
1429                                ref->status = why;
1430                        else if (why)
1431                                ref->forced_update = 1;
1432                }
1433        }
1434}
1435
1436struct branch *branch_get(const char *name)
1437{
1438        struct branch *ret;
1439
1440        read_config();
1441        if (!name || !*name || !strcmp(name, "HEAD"))
1442                ret = current_branch;
1443        else
1444                ret = make_branch(name, 0);
1445        if (ret && ret->remote_name) {
1446                ret->remote = remote_get(ret->remote_name);
1447                if (ret->merge_nr) {
1448                        int i;
1449                        ret->merge = xcalloc(sizeof(*ret->merge),
1450                                             ret->merge_nr);
1451                        for (i = 0; i < ret->merge_nr; i++) {
1452                                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1453                                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1454                                if (remote_find_tracking(ret->remote, ret->merge[i])
1455                                    && !strcmp(ret->remote_name, "."))
1456                                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1457                        }
1458                }
1459        }
1460        return ret;
1461}
1462
1463int branch_has_merge_config(struct branch *branch)
1464{
1465        return branch && !!branch->merge;
1466}
1467
1468int branch_merge_matches(struct branch *branch,
1469                                 int i,
1470                                 const char *refname)
1471{
1472        if (!branch || i < 0 || i >= branch->merge_nr)
1473                return 0;
1474        return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1475}
1476
1477static int ignore_symref_update(const char *refname)
1478{
1479        unsigned char sha1[20];
1480        int flag;
1481
1482        if (!resolve_ref_unsafe(refname, sha1, 0, &flag))
1483                return 0; /* non-existing refs are OK */
1484        return (flag & REF_ISSYMREF);
1485}
1486
1487static struct ref *get_expanded_map(const struct ref *remote_refs,
1488                                    const struct refspec *refspec)
1489{
1490        const struct ref *ref;
1491        struct ref *ret = NULL;
1492        struct ref **tail = &ret;
1493
1494        char *expn_name;
1495
1496        for (ref = remote_refs; ref; ref = ref->next) {
1497                if (strchr(ref->name, '^'))
1498                        continue; /* a dereference item */
1499                if (match_name_with_pattern(refspec->src, ref->name,
1500                                            refspec->dst, &expn_name) &&
1501                    !ignore_symref_update(expn_name)) {
1502                        struct ref *cpy = copy_ref(ref);
1503
1504                        cpy->peer_ref = alloc_ref(expn_name);
1505                        free(expn_name);
1506                        if (refspec->force)
1507                                cpy->peer_ref->force = 1;
1508                        *tail = cpy;
1509                        tail = &cpy->next;
1510                }
1511        }
1512
1513        return ret;
1514}
1515
1516static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1517{
1518        const struct ref *ref;
1519        for (ref = refs; ref; ref = ref->next) {
1520                if (refname_match(name, ref->name, ref_fetch_rules))
1521                        return ref;
1522        }
1523        return NULL;
1524}
1525
1526struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1527{
1528        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1529
1530        if (!ref)
1531                return NULL;
1532
1533        return copy_ref(ref);
1534}
1535
1536static struct ref *get_local_ref(const char *name)
1537{
1538        if (!name || name[0] == '\0')
1539                return NULL;
1540
1541        if (!prefixcmp(name, "refs/"))
1542                return alloc_ref(name);
1543
1544        if (!prefixcmp(name, "heads/") ||
1545            !prefixcmp(name, "tags/") ||
1546            !prefixcmp(name, "remotes/"))
1547                return alloc_ref_with_prefix("refs/", 5, name);
1548
1549        return alloc_ref_with_prefix("refs/heads/", 11, name);
1550}
1551
1552int get_fetch_map(const struct ref *remote_refs,
1553                  const struct refspec *refspec,
1554                  struct ref ***tail,
1555                  int missing_ok)
1556{
1557        struct ref *ref_map, **rmp;
1558
1559        if (refspec->pattern) {
1560                ref_map = get_expanded_map(remote_refs, refspec);
1561        } else {
1562                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1563
1564                if (refspec->exact_sha1) {
1565                        ref_map = alloc_ref(name);
1566                        get_sha1_hex(name, ref_map->old_sha1);
1567                } else {
1568                        ref_map = get_remote_ref(remote_refs, name);
1569                }
1570                if (!missing_ok && !ref_map)
1571                        die("Couldn't find remote ref %s", name);
1572                if (ref_map) {
1573                        ref_map->peer_ref = get_local_ref(refspec->dst);
1574                        if (ref_map->peer_ref && refspec->force)
1575                                ref_map->peer_ref->force = 1;
1576                }
1577        }
1578
1579        for (rmp = &ref_map; *rmp; ) {
1580                if ((*rmp)->peer_ref) {
1581                        if (prefixcmp((*rmp)->peer_ref->name, "refs/") ||
1582                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1583                                struct ref *ignore = *rmp;
1584                                error("* Ignoring funny ref '%s' locally",
1585                                      (*rmp)->peer_ref->name);
1586                                *rmp = (*rmp)->next;
1587                                free(ignore->peer_ref);
1588                                free(ignore);
1589                                continue;
1590                        }
1591                }
1592                rmp = &((*rmp)->next);
1593        }
1594
1595        if (ref_map)
1596                tail_link_ref(ref_map, tail);
1597
1598        return 0;
1599}
1600
1601int resolve_remote_symref(struct ref *ref, struct ref *list)
1602{
1603        if (!ref->symref)
1604                return 0;
1605        for (; list; list = list->next)
1606                if (!strcmp(ref->symref, list->name)) {
1607                        hashcpy(ref->old_sha1, list->old_sha1);
1608                        return 0;
1609                }
1610        return 1;
1611}
1612
1613static void unmark_and_free(struct commit_list *list, unsigned int mark)
1614{
1615        while (list) {
1616                struct commit_list *temp = list;
1617                temp->item->object.flags &= ~mark;
1618                list = temp->next;
1619                free(temp);
1620        }
1621}
1622
1623int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1624{
1625        struct object *o;
1626        struct commit *old, *new;
1627        struct commit_list *list, *used;
1628        int found = 0;
1629
1630        /*
1631         * Both new and old must be commit-ish and new is descendant of
1632         * old.  Otherwise we require --force.
1633         */
1634        o = deref_tag(parse_object(old_sha1), NULL, 0);
1635        if (!o || o->type != OBJ_COMMIT)
1636                return 0;
1637        old = (struct commit *) o;
1638
1639        o = deref_tag(parse_object(new_sha1), NULL, 0);
1640        if (!o || o->type != OBJ_COMMIT)
1641                return 0;
1642        new = (struct commit *) o;
1643
1644        if (parse_commit(new) < 0)
1645                return 0;
1646
1647        used = list = NULL;
1648        commit_list_insert(new, &list);
1649        while (list) {
1650                new = pop_most_recent_commit(&list, TMP_MARK);
1651                commit_list_insert(new, &used);
1652                if (new == old) {
1653                        found = 1;
1654                        break;
1655                }
1656        }
1657        unmark_and_free(list, TMP_MARK);
1658        unmark_and_free(used, TMP_MARK);
1659        return found;
1660}
1661
1662/*
1663 * Return true if there is anything to report, otherwise false.
1664 */
1665int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1666{
1667        unsigned char sha1[20];
1668        struct commit *ours, *theirs;
1669        char symmetric[84];
1670        struct rev_info revs;
1671        const char *rev_argv[10], *base;
1672        int rev_argc;
1673
1674        /*
1675         * Nothing to report unless we are marked to build on top of
1676         * somebody else.
1677         */
1678        if (!branch ||
1679            !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1680                return 0;
1681
1682        /*
1683         * If what we used to build on no longer exists, there is
1684         * nothing to report.
1685         */
1686        base = branch->merge[0]->dst;
1687        if (read_ref(base, sha1))
1688                return 0;
1689        theirs = lookup_commit_reference(sha1);
1690        if (!theirs)
1691                return 0;
1692
1693        if (read_ref(branch->refname, sha1))
1694                return 0;
1695        ours = lookup_commit_reference(sha1);
1696        if (!ours)
1697                return 0;
1698
1699        /* are we the same? */
1700        if (theirs == ours)
1701                return 0;
1702
1703        /* Run "rev-list --left-right ours...theirs" internally... */
1704        rev_argc = 0;
1705        rev_argv[rev_argc++] = NULL;
1706        rev_argv[rev_argc++] = "--left-right";
1707        rev_argv[rev_argc++] = symmetric;
1708        rev_argv[rev_argc++] = "--";
1709        rev_argv[rev_argc] = NULL;
1710
1711        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1712        strcpy(symmetric + 40, "...");
1713        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1714
1715        init_revisions(&revs, NULL);
1716        setup_revisions(rev_argc, rev_argv, &revs, NULL);
1717        prepare_revision_walk(&revs);
1718
1719        /* ... and count the commits on each side. */
1720        *num_ours = 0;
1721        *num_theirs = 0;
1722        while (1) {
1723                struct commit *c = get_revision(&revs);
1724                if (!c)
1725                        break;
1726                if (c->object.flags & SYMMETRIC_LEFT)
1727                        (*num_ours)++;
1728                else
1729                        (*num_theirs)++;
1730        }
1731
1732        /* clear object flags smudged by the above traversal */
1733        clear_commit_marks(ours, ALL_REV_FLAGS);
1734        clear_commit_marks(theirs, ALL_REV_FLAGS);
1735        return 1;
1736}
1737
1738/*
1739 * Return true when there is anything to report, otherwise false.
1740 */
1741int format_tracking_info(struct branch *branch, struct strbuf *sb)
1742{
1743        int num_ours, num_theirs;
1744        const char *base;
1745
1746        if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1747                return 0;
1748
1749        base = branch->merge[0]->dst;
1750        base = shorten_unambiguous_ref(base, 0);
1751        if (!num_theirs) {
1752                strbuf_addf(sb,
1753                        Q_("Your branch is ahead of '%s' by %d commit.\n",
1754                           "Your branch is ahead of '%s' by %d commits.\n",
1755                           num_ours),
1756                        base, num_ours);
1757                if (advice_status_hints)
1758                        strbuf_addf(sb,
1759                                _("  (use \"git push\" to publish your local commits)\n"));
1760        } else if (!num_ours) {
1761                strbuf_addf(sb,
1762                        Q_("Your branch is behind '%s' by %d commit, "
1763                               "and can be fast-forwarded.\n",
1764                           "Your branch is behind '%s' by %d commits, "
1765                               "and can be fast-forwarded.\n",
1766                           num_theirs),
1767                        base, num_theirs);
1768                if (advice_status_hints)
1769                        strbuf_addf(sb,
1770                                _("  (use \"git pull\" to update your local branch)\n"));
1771        } else {
1772                strbuf_addf(sb,
1773                        Q_("Your branch and '%s' have diverged,\n"
1774                               "and have %d and %d different commit each, "
1775                               "respectively.\n",
1776                           "Your branch and '%s' have diverged,\n"
1777                               "and have %d and %d different commits each, "
1778                               "respectively.\n",
1779                           num_theirs),
1780                        base, num_ours, num_theirs);
1781                if (advice_status_hints)
1782                        strbuf_addf(sb,
1783                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1784        }
1785        return 1;
1786}
1787
1788static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1789{
1790        struct ref ***local_tail = cb_data;
1791        struct ref *ref;
1792        int len;
1793
1794        /* we already know it starts with refs/ to get here */
1795        if (check_refname_format(refname + 5, 0))
1796                return 0;
1797
1798        len = strlen(refname) + 1;
1799        ref = xcalloc(1, sizeof(*ref) + len);
1800        hashcpy(ref->new_sha1, sha1);
1801        memcpy(ref->name, refname, len);
1802        **local_tail = ref;
1803        *local_tail = &ref->next;
1804        return 0;
1805}
1806
1807struct ref *get_local_heads(void)
1808{
1809        struct ref *local_refs = NULL, **local_tail = &local_refs;
1810        for_each_ref(one_local_ref, &local_tail);
1811        return local_refs;
1812}
1813
1814struct ref *guess_remote_head(const struct ref *head,
1815                              const struct ref *refs,
1816                              int all)
1817{
1818        const struct ref *r;
1819        struct ref *list = NULL;
1820        struct ref **tail = &list;
1821
1822        if (!head)
1823                return NULL;
1824
1825        /*
1826         * Some transports support directly peeking at
1827         * where HEAD points; if that is the case, then
1828         * we don't have to guess.
1829         */
1830        if (head->symref)
1831                return copy_ref(find_ref_by_name(refs, head->symref));
1832
1833        /* If refs/heads/master could be right, it is. */
1834        if (!all) {
1835                r = find_ref_by_name(refs, "refs/heads/master");
1836                if (r && !hashcmp(r->old_sha1, head->old_sha1))
1837                        return copy_ref(r);
1838        }
1839
1840        /* Look for another ref that points there */
1841        for (r = refs; r; r = r->next) {
1842                if (r != head &&
1843                    !prefixcmp(r->name, "refs/heads/") &&
1844                    !hashcmp(r->old_sha1, head->old_sha1)) {
1845                        *tail = copy_ref(r);
1846                        tail = &((*tail)->next);
1847                        if (!all)
1848                                break;
1849                }
1850        }
1851
1852        return list;
1853}
1854
1855struct stale_heads_info {
1856        struct string_list *ref_names;
1857        struct ref **stale_refs_tail;
1858        struct refspec *refs;
1859        int ref_count;
1860};
1861
1862static int get_stale_heads_cb(const char *refname,
1863        const unsigned char *sha1, int flags, void *cb_data)
1864{
1865        struct stale_heads_info *info = cb_data;
1866        struct refspec query;
1867        memset(&query, 0, sizeof(struct refspec));
1868        query.dst = (char *)refname;
1869
1870        if (query_refspecs(info->refs, info->ref_count, &query))
1871                return 0; /* No matches */
1872
1873        /*
1874         * If we did find a suitable refspec and it's not a symref and
1875         * it's not in the list of refs that currently exist in that
1876         * remote we consider it to be stale.
1877         */
1878        if (!((flags & REF_ISSYMREF) ||
1879              string_list_has_string(info->ref_names, query.src))) {
1880                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
1881                hashcpy(ref->new_sha1, sha1);
1882        }
1883
1884        free(query.src);
1885        return 0;
1886}
1887
1888struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
1889{
1890        struct ref *ref, *stale_refs = NULL;
1891        struct string_list ref_names = STRING_LIST_INIT_NODUP;
1892        struct stale_heads_info info;
1893        info.ref_names = &ref_names;
1894        info.stale_refs_tail = &stale_refs;
1895        info.refs = refs;
1896        info.ref_count = ref_count;
1897        for (ref = fetch_map; ref; ref = ref->next)
1898                string_list_append(&ref_names, ref->name);
1899        sort_string_list(&ref_names);
1900        for_each_ref(get_stale_heads_cb, &info);
1901        string_list_clear(&ref_names, 0);
1902        return stale_refs;
1903}