remote.con commit Merge branch 'ab/sha1dc-maint' into maint (d0506fc)
   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#include "argv-array.h"
  12
  13enum map_direction { FROM_SRC, FROM_DST };
  14
  15static struct refspec s_tag_refspec = {
  16        0,
  17        1,
  18        0,
  19        0,
  20        "refs/tags/*",
  21        "refs/tags/*"
  22};
  23
  24const struct refspec *tag_refspec = &s_tag_refspec;
  25
  26struct counted_string {
  27        size_t len;
  28        const char *s;
  29};
  30struct rewrite {
  31        const char *base;
  32        size_t baselen;
  33        struct counted_string *instead_of;
  34        int instead_of_nr;
  35        int instead_of_alloc;
  36};
  37struct rewrites {
  38        struct rewrite **rewrite;
  39        int rewrite_alloc;
  40        int rewrite_nr;
  41};
  42
  43static struct remote **remotes;
  44static int remotes_alloc;
  45static int remotes_nr;
  46static struct hashmap remotes_hash;
  47
  48static struct branch **branches;
  49static int branches_alloc;
  50static int branches_nr;
  51
  52static struct branch *current_branch;
  53static const char *pushremote_name;
  54
  55static struct rewrites rewrites;
  56static struct rewrites rewrites_push;
  57
  58static int valid_remote(const struct remote *remote)
  59{
  60        return (!!remote->url) || (!!remote->foreign_vcs);
  61}
  62
  63static const char *alias_url(const char *url, struct rewrites *r)
  64{
  65        int i, j;
  66        struct counted_string *longest;
  67        int longest_i;
  68
  69        longest = NULL;
  70        longest_i = -1;
  71        for (i = 0; i < r->rewrite_nr; i++) {
  72                if (!r->rewrite[i])
  73                        continue;
  74                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  75                        if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  76                            (!longest ||
  77                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  78                                longest = &(r->rewrite[i]->instead_of[j]);
  79                                longest_i = i;
  80                        }
  81                }
  82        }
  83        if (!longest)
  84                return url;
  85
  86        return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  87}
  88
  89static void add_push_refspec(struct remote *remote, const char *ref)
  90{
  91        ALLOC_GROW(remote->push_refspec,
  92                   remote->push_refspec_nr + 1,
  93                   remote->push_refspec_alloc);
  94        remote->push_refspec[remote->push_refspec_nr++] = ref;
  95}
  96
  97static void add_fetch_refspec(struct remote *remote, const char *ref)
  98{
  99        ALLOC_GROW(remote->fetch_refspec,
 100                   remote->fetch_refspec_nr + 1,
 101                   remote->fetch_refspec_alloc);
 102        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 103}
 104
 105static void add_url(struct remote *remote, const char *url)
 106{
 107        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 108        remote->url[remote->url_nr++] = url;
 109}
 110
 111static void add_pushurl(struct remote *remote, const char *pushurl)
 112{
 113        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 114        remote->pushurl[remote->pushurl_nr++] = pushurl;
 115}
 116
 117static void add_pushurl_alias(struct remote *remote, const char *url)
 118{
 119        const char *pushurl = alias_url(url, &rewrites_push);
 120        if (pushurl != url)
 121                add_pushurl(remote, pushurl);
 122}
 123
 124static void add_url_alias(struct remote *remote, const char *url)
 125{
 126        add_url(remote, alias_url(url, &rewrites));
 127        add_pushurl_alias(remote, url);
 128}
 129
 130struct remotes_hash_key {
 131        const char *str;
 132        int len;
 133};
 134
 135static int remotes_hash_cmp(const struct remote *a, const struct remote *b, const struct remotes_hash_key *key)
 136{
 137        if (key)
 138                return strncmp(a->name, key->str, key->len) || a->name[key->len];
 139        else
 140                return strcmp(a->name, b->name);
 141}
 142
 143static inline void init_remotes_hash(void)
 144{
 145        if (!remotes_hash.cmpfn)
 146                hashmap_init(&remotes_hash, (hashmap_cmp_fn)remotes_hash_cmp, 0);
 147}
 148
 149static struct remote *make_remote(const char *name, int len)
 150{
 151        struct remote *ret, *replaced;
 152        struct remotes_hash_key lookup;
 153        struct hashmap_entry lookup_entry;
 154
 155        if (!len)
 156                len = strlen(name);
 157
 158        init_remotes_hash();
 159        lookup.str = name;
 160        lookup.len = len;
 161        hashmap_entry_init(&lookup_entry, memhash(name, len));
 162
 163        if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 164                return ret;
 165
 166        ret = xcalloc(1, sizeof(struct remote));
 167        ret->prune = -1;  /* unspecified */
 168        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 169        remotes[remotes_nr++] = ret;
 170        ret->name = xstrndup(name, len);
 171
 172        hashmap_entry_init(ret, lookup_entry.hash);
 173        replaced = hashmap_put(&remotes_hash, ret);
 174        assert(replaced == NULL);  /* no previous entry overwritten */
 175        return ret;
 176}
 177
 178static void add_merge(struct branch *branch, const char *name)
 179{
 180        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 181                   branch->merge_alloc);
 182        branch->merge_name[branch->merge_nr++] = name;
 183}
 184
 185static struct branch *make_branch(const char *name, int len)
 186{
 187        struct branch *ret;
 188        int i;
 189
 190        for (i = 0; i < branches_nr; i++) {
 191                if (len ? (!strncmp(name, branches[i]->name, len) &&
 192                           !branches[i]->name[len]) :
 193                    !strcmp(name, branches[i]->name))
 194                        return branches[i];
 195        }
 196
 197        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 198        ret = xcalloc(1, sizeof(struct branch));
 199        branches[branches_nr++] = ret;
 200        if (len)
 201                ret->name = xstrndup(name, len);
 202        else
 203                ret->name = xstrdup(name);
 204        ret->refname = xstrfmt("refs/heads/%s", ret->name);
 205
 206        return ret;
 207}
 208
 209static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 210{
 211        struct rewrite *ret;
 212        int i;
 213
 214        for (i = 0; i < r->rewrite_nr; i++) {
 215                if (len
 216                    ? (len == r->rewrite[i]->baselen &&
 217                       !strncmp(base, r->rewrite[i]->base, len))
 218                    : !strcmp(base, r->rewrite[i]->base))
 219                        return r->rewrite[i];
 220        }
 221
 222        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 223        ret = xcalloc(1, sizeof(struct rewrite));
 224        r->rewrite[r->rewrite_nr++] = ret;
 225        if (len) {
 226                ret->base = xstrndup(base, len);
 227                ret->baselen = len;
 228        }
 229        else {
 230                ret->base = xstrdup(base);
 231                ret->baselen = strlen(base);
 232        }
 233        return ret;
 234}
 235
 236static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 237{
 238        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 239        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 240        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 241        rewrite->instead_of_nr++;
 242}
 243
 244static const char *skip_spaces(const char *s)
 245{
 246        while (isspace(*s))
 247                s++;
 248        return s;
 249}
 250
 251static void read_remotes_file(struct remote *remote)
 252{
 253        struct strbuf buf = STRBUF_INIT;
 254        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 255
 256        if (!f)
 257                return;
 258        remote->configured_in_repo = 1;
 259        remote->origin = REMOTE_REMOTES;
 260        while (strbuf_getline(&buf, f) != EOF) {
 261                const char *v;
 262
 263                strbuf_rtrim(&buf);
 264
 265                if (skip_prefix(buf.buf, "URL:", &v))
 266                        add_url_alias(remote, xstrdup(skip_spaces(v)));
 267                else if (skip_prefix(buf.buf, "Push:", &v))
 268                        add_push_refspec(remote, xstrdup(skip_spaces(v)));
 269                else if (skip_prefix(buf.buf, "Pull:", &v))
 270                        add_fetch_refspec(remote, xstrdup(skip_spaces(v)));
 271        }
 272        strbuf_release(&buf);
 273        fclose(f);
 274}
 275
 276static void read_branches_file(struct remote *remote)
 277{
 278        char *frag;
 279        struct strbuf buf = STRBUF_INIT;
 280        FILE *f = fopen(git_path("branches/%s", remote->name), "r");
 281
 282        if (!f)
 283                return;
 284
 285        strbuf_getline_lf(&buf, f);
 286        fclose(f);
 287        strbuf_trim(&buf);
 288        if (!buf.len) {
 289                strbuf_release(&buf);
 290                return;
 291        }
 292
 293        remote->configured_in_repo = 1;
 294        remote->origin = REMOTE_BRANCHES;
 295
 296        /*
 297         * The branches file would have URL and optionally
 298         * #branch specified.  The "master" (or specified) branch is
 299         * fetched and stored in the local branch matching the
 300         * remote name.
 301         */
 302        frag = strchr(buf.buf, '#');
 303        if (frag)
 304                *(frag++) = '\0';
 305        else
 306                frag = "master";
 307
 308        add_url_alias(remote, strbuf_detach(&buf, NULL));
 309        add_fetch_refspec(remote, xstrfmt("refs/heads/%s:refs/heads/%s",
 310                                          frag, remote->name));
 311
 312        /*
 313         * Cogito compatible push: push current HEAD to remote #branch
 314         * (master if missing)
 315         */
 316        add_push_refspec(remote, xstrfmt("HEAD:refs/heads/%s", frag));
 317        remote->fetch_tags = 1; /* always auto-follow */
 318}
 319
 320static int handle_config(const char *key, const char *value, void *cb)
 321{
 322        const char *name;
 323        int namelen;
 324        const char *subkey;
 325        struct remote *remote;
 326        struct branch *branch;
 327        if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
 328                if (!name)
 329                        return 0;
 330                branch = make_branch(name, namelen);
 331                if (!strcmp(subkey, "remote")) {
 332                        return git_config_string(&branch->remote_name, key, value);
 333                } else if (!strcmp(subkey, "pushremote")) {
 334                        return git_config_string(&branch->pushremote_name, key, value);
 335                } else if (!strcmp(subkey, "merge")) {
 336                        if (!value)
 337                                return config_error_nonbool(key);
 338                        add_merge(branch, xstrdup(value));
 339                }
 340                return 0;
 341        }
 342        if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
 343                struct rewrite *rewrite;
 344                if (!name)
 345                        return 0;
 346                if (!strcmp(subkey, "insteadof")) {
 347                        rewrite = make_rewrite(&rewrites, name, namelen);
 348                        if (!value)
 349                                return config_error_nonbool(key);
 350                        add_instead_of(rewrite, xstrdup(value));
 351                } else if (!strcmp(subkey, "pushinsteadof")) {
 352                        rewrite = make_rewrite(&rewrites_push, name, namelen);
 353                        if (!value)
 354                                return config_error_nonbool(key);
 355                        add_instead_of(rewrite, xstrdup(value));
 356                }
 357        }
 358
 359        if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
 360                return 0;
 361
 362        /* Handle remote.* variables */
 363        if (!name && !strcmp(subkey, "pushdefault"))
 364                return git_config_string(&pushremote_name, key, value);
 365
 366        if (!name)
 367                return 0;
 368        /* Handle remote.<name>.* variables */
 369        if (*name == '/') {
 370                warning("Config remote shorthand cannot begin with '/': %s",
 371                        name);
 372                return 0;
 373        }
 374        remote = make_remote(name, namelen);
 375        remote->origin = REMOTE_CONFIG;
 376        if (current_config_scope() == CONFIG_SCOPE_REPO)
 377                remote->configured_in_repo = 1;
 378        if (!strcmp(subkey, "mirror"))
 379                remote->mirror = git_config_bool(key, value);
 380        else if (!strcmp(subkey, "skipdefaultupdate"))
 381                remote->skip_default_update = git_config_bool(key, value);
 382        else if (!strcmp(subkey, "skipfetchall"))
 383                remote->skip_default_update = git_config_bool(key, value);
 384        else if (!strcmp(subkey, "prune"))
 385                remote->prune = git_config_bool(key, value);
 386        else if (!strcmp(subkey, "url")) {
 387                const char *v;
 388                if (git_config_string(&v, key, value))
 389                        return -1;
 390                add_url(remote, v);
 391        } else if (!strcmp(subkey, "pushurl")) {
 392                const char *v;
 393                if (git_config_string(&v, key, value))
 394                        return -1;
 395                add_pushurl(remote, v);
 396        } else if (!strcmp(subkey, "push")) {
 397                const char *v;
 398                if (git_config_string(&v, key, value))
 399                        return -1;
 400                add_push_refspec(remote, v);
 401        } else if (!strcmp(subkey, "fetch")) {
 402                const char *v;
 403                if (git_config_string(&v, key, value))
 404                        return -1;
 405                add_fetch_refspec(remote, v);
 406        } else if (!strcmp(subkey, "receivepack")) {
 407                const char *v;
 408                if (git_config_string(&v, key, value))
 409                        return -1;
 410                if (!remote->receivepack)
 411                        remote->receivepack = v;
 412                else
 413                        error("more than one receivepack given, using the first");
 414        } else if (!strcmp(subkey, "uploadpack")) {
 415                const char *v;
 416                if (git_config_string(&v, key, value))
 417                        return -1;
 418                if (!remote->uploadpack)
 419                        remote->uploadpack = v;
 420                else
 421                        error("more than one uploadpack given, using the first");
 422        } else if (!strcmp(subkey, "tagopt")) {
 423                if (!strcmp(value, "--no-tags"))
 424                        remote->fetch_tags = -1;
 425                else if (!strcmp(value, "--tags"))
 426                        remote->fetch_tags = 2;
 427        } else if (!strcmp(subkey, "proxy")) {
 428                return git_config_string((const char **)&remote->http_proxy,
 429                                         key, value);
 430        } else if (!strcmp(subkey, "proxyauthmethod")) {
 431                return git_config_string((const char **)&remote->http_proxy_authmethod,
 432                                         key, value);
 433        } else if (!strcmp(subkey, "vcs")) {
 434                return git_config_string(&remote->foreign_vcs, key, value);
 435        }
 436        return 0;
 437}
 438
 439static void alias_all_urls(void)
 440{
 441        int i, j;
 442        for (i = 0; i < remotes_nr; i++) {
 443                int add_pushurl_aliases;
 444                if (!remotes[i])
 445                        continue;
 446                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 447                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 448                }
 449                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 450                for (j = 0; j < remotes[i]->url_nr; j++) {
 451                        if (add_pushurl_aliases)
 452                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 453                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 454                }
 455        }
 456}
 457
 458static void read_config(void)
 459{
 460        static int loaded;
 461        struct object_id oid;
 462        int flag;
 463
 464        if (loaded)
 465                return;
 466        loaded = 1;
 467
 468        current_branch = NULL;
 469        if (startup_info->have_repository) {
 470                const char *head_ref = resolve_ref_unsafe("HEAD", 0, oid.hash, &flag);
 471                if (head_ref && (flag & REF_ISSYMREF) &&
 472                    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 473                        current_branch = make_branch(head_ref, 0);
 474                }
 475        }
 476        git_config(handle_config, NULL);
 477        alias_all_urls();
 478}
 479
 480/*
 481 * This function frees a refspec array.
 482 * Warning: code paths should be checked to ensure that the src
 483 *          and dst pointers are always freeable pointers as well
 484 *          as the refspec pointer itself.
 485 */
 486static void free_refspecs(struct refspec *refspec, int nr_refspec)
 487{
 488        int i;
 489
 490        if (!refspec)
 491                return;
 492
 493        for (i = 0; i < nr_refspec; i++) {
 494                free(refspec[i].src);
 495                free(refspec[i].dst);
 496        }
 497        free(refspec);
 498}
 499
 500static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 501{
 502        int i;
 503        struct refspec *rs = xcalloc(nr_refspec, sizeof(*rs));
 504
 505        for (i = 0; i < nr_refspec; i++) {
 506                size_t llen;
 507                int is_glob;
 508                const char *lhs, *rhs;
 509                int flags;
 510
 511                is_glob = 0;
 512
 513                lhs = refspec[i];
 514                if (*lhs == '+') {
 515                        rs[i].force = 1;
 516                        lhs++;
 517                }
 518
 519                rhs = strrchr(lhs, ':');
 520
 521                /*
 522                 * Before going on, special case ":" (or "+:") as a refspec
 523                 * for pushing matching refs.
 524                 */
 525                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 526                        rs[i].matching = 1;
 527                        continue;
 528                }
 529
 530                if (rhs) {
 531                        size_t rlen = strlen(++rhs);
 532                        is_glob = (1 <= rlen && strchr(rhs, '*'));
 533                        rs[i].dst = xstrndup(rhs, rlen);
 534                }
 535
 536                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 537                if (1 <= llen && memchr(lhs, '*', llen)) {
 538                        if ((rhs && !is_glob) || (!rhs && fetch))
 539                                goto invalid;
 540                        is_glob = 1;
 541                } else if (rhs && is_glob) {
 542                        goto invalid;
 543                }
 544
 545                rs[i].pattern = is_glob;
 546                rs[i].src = xstrndup(lhs, llen);
 547                flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 548
 549                if (fetch) {
 550                        struct object_id unused;
 551
 552                        /* LHS */
 553                        if (!*rs[i].src)
 554                                ; /* empty is ok; it means "HEAD" */
 555                        else if (llen == GIT_SHA1_HEXSZ && !get_oid_hex(rs[i].src, &unused))
 556                                rs[i].exact_sha1 = 1; /* ok */
 557                        else if (!check_refname_format(rs[i].src, flags))
 558                                ; /* valid looking ref is ok */
 559                        else
 560                                goto invalid;
 561                        /* RHS */
 562                        if (!rs[i].dst)
 563                                ; /* missing is ok; it is the same as empty */
 564                        else if (!*rs[i].dst)
 565                                ; /* empty is ok; it means "do not store" */
 566                        else if (!check_refname_format(rs[i].dst, flags))
 567                                ; /* valid looking ref is ok */
 568                        else
 569                                goto invalid;
 570                } else {
 571                        /*
 572                         * LHS
 573                         * - empty is allowed; it means delete.
 574                         * - when wildcarded, it must be a valid looking ref.
 575                         * - otherwise, it must be an extended SHA-1, but
 576                         *   there is no existing way to validate this.
 577                         */
 578                        if (!*rs[i].src)
 579                                ; /* empty is ok */
 580                        else if (is_glob) {
 581                                if (check_refname_format(rs[i].src, flags))
 582                                        goto invalid;
 583                        }
 584                        else
 585                                ; /* anything goes, for now */
 586                        /*
 587                         * RHS
 588                         * - missing is allowed, but LHS then must be a
 589                         *   valid looking ref.
 590                         * - empty is not allowed.
 591                         * - otherwise it must be a valid looking ref.
 592                         */
 593                        if (!rs[i].dst) {
 594                                if (check_refname_format(rs[i].src, flags))
 595                                        goto invalid;
 596                        } else if (!*rs[i].dst) {
 597                                goto invalid;
 598                        } else {
 599                                if (check_refname_format(rs[i].dst, flags))
 600                                        goto invalid;
 601                        }
 602                }
 603        }
 604        return rs;
 605
 606 invalid:
 607        if (verify) {
 608                /*
 609                 * nr_refspec must be greater than zero and i must be valid
 610                 * since it is only possible to reach this point from within
 611                 * the for loop above.
 612                 */
 613                free_refspecs(rs, i+1);
 614                return NULL;
 615        }
 616        die("Invalid refspec '%s'", refspec[i]);
 617}
 618
 619int valid_fetch_refspec(const char *fetch_refspec_str)
 620{
 621        struct refspec *refspec;
 622
 623        refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 624        free_refspecs(refspec, 1);
 625        return !!refspec;
 626}
 627
 628struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 629{
 630        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 631}
 632
 633struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 634{
 635        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 636}
 637
 638void free_refspec(int nr_refspec, struct refspec *refspec)
 639{
 640        int i;
 641        for (i = 0; i < nr_refspec; i++) {
 642                free(refspec[i].src);
 643                free(refspec[i].dst);
 644        }
 645        free(refspec);
 646}
 647
 648static int valid_remote_nick(const char *name)
 649{
 650        if (!name[0] || is_dot_or_dotdot(name))
 651                return 0;
 652
 653        /* remote nicknames cannot contain slashes */
 654        while (*name)
 655                if (is_dir_sep(*name++))
 656                        return 0;
 657        return 1;
 658}
 659
 660const char *remote_for_branch(struct branch *branch, int *explicit)
 661{
 662        if (branch && branch->remote_name) {
 663                if (explicit)
 664                        *explicit = 1;
 665                return branch->remote_name;
 666        }
 667        if (explicit)
 668                *explicit = 0;
 669        return "origin";
 670}
 671
 672const char *pushremote_for_branch(struct branch *branch, int *explicit)
 673{
 674        if (branch && branch->pushremote_name) {
 675                if (explicit)
 676                        *explicit = 1;
 677                return branch->pushremote_name;
 678        }
 679        if (pushremote_name) {
 680                if (explicit)
 681                        *explicit = 1;
 682                return pushremote_name;
 683        }
 684        return remote_for_branch(branch, explicit);
 685}
 686
 687static struct remote *remote_get_1(const char *name,
 688                                   const char *(*get_default)(struct branch *, int *))
 689{
 690        struct remote *ret;
 691        int name_given = 0;
 692
 693        read_config();
 694
 695        if (name)
 696                name_given = 1;
 697        else
 698                name = get_default(current_branch, &name_given);
 699
 700        ret = make_remote(name, 0);
 701        if (valid_remote_nick(name) && have_git_dir()) {
 702                if (!valid_remote(ret))
 703                        read_remotes_file(ret);
 704                if (!valid_remote(ret))
 705                        read_branches_file(ret);
 706        }
 707        if (name_given && !valid_remote(ret))
 708                add_url_alias(ret, name);
 709        if (!valid_remote(ret))
 710                return NULL;
 711        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 712        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 713        return ret;
 714}
 715
 716struct remote *remote_get(const char *name)
 717{
 718        return remote_get_1(name, remote_for_branch);
 719}
 720
 721struct remote *pushremote_get(const char *name)
 722{
 723        return remote_get_1(name, pushremote_for_branch);
 724}
 725
 726int remote_is_configured(struct remote *remote, int in_repo)
 727{
 728        if (!remote)
 729                return 0;
 730        if (in_repo)
 731                return remote->configured_in_repo;
 732        return !!remote->origin;
 733}
 734
 735int for_each_remote(each_remote_fn fn, void *priv)
 736{
 737        int i, result = 0;
 738        read_config();
 739        for (i = 0; i < remotes_nr && !result; i++) {
 740                struct remote *r = remotes[i];
 741                if (!r)
 742                        continue;
 743                if (!r->fetch)
 744                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 745                                                       r->fetch_refspec);
 746                if (!r->push)
 747                        r->push = parse_push_refspec(r->push_refspec_nr,
 748                                                     r->push_refspec);
 749                result = fn(r, priv);
 750        }
 751        return result;
 752}
 753
 754static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 755{
 756        if (strcmp(ref1->name, ref2->name)) {
 757                if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 758                    ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 759                        die(_("Cannot fetch both %s and %s to %s"),
 760                            ref1->name, ref2->name, ref2->peer_ref->name);
 761                } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 762                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 763                        warning(_("%s usually tracks %s, not %s"),
 764                                ref2->peer_ref->name, ref2->name, ref1->name);
 765                } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 766                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 767                        die(_("%s tracks both %s and %s"),
 768                            ref2->peer_ref->name, ref1->name, ref2->name);
 769                } else {
 770                        /*
 771                         * This last possibility doesn't occur because
 772                         * FETCH_HEAD_IGNORE entries always appear at
 773                         * the end of the list.
 774                         */
 775                        die(_("Internal error"));
 776                }
 777        }
 778        free(ref2->peer_ref);
 779        free(ref2);
 780}
 781
 782struct ref *ref_remove_duplicates(struct ref *ref_map)
 783{
 784        struct string_list refs = STRING_LIST_INIT_NODUP;
 785        struct ref *retval = NULL;
 786        struct ref **p = &retval;
 787
 788        while (ref_map) {
 789                struct ref *ref = ref_map;
 790
 791                ref_map = ref_map->next;
 792                ref->next = NULL;
 793
 794                if (!ref->peer_ref) {
 795                        *p = ref;
 796                        p = &ref->next;
 797                } else {
 798                        struct string_list_item *item =
 799                                string_list_insert(&refs, ref->peer_ref->name);
 800
 801                        if (item->util) {
 802                                /* Entry already existed */
 803                                handle_duplicate((struct ref *)item->util, ref);
 804                        } else {
 805                                *p = ref;
 806                                p = &ref->next;
 807                                item->util = ref;
 808                        }
 809                }
 810        }
 811
 812        string_list_clear(&refs, 0);
 813        return retval;
 814}
 815
 816int remote_has_url(struct remote *remote, const char *url)
 817{
 818        int i;
 819        for (i = 0; i < remote->url_nr; i++) {
 820                if (!strcmp(remote->url[i], url))
 821                        return 1;
 822        }
 823        return 0;
 824}
 825
 826static int match_name_with_pattern(const char *key, const char *name,
 827                                   const char *value, char **result)
 828{
 829        const char *kstar = strchr(key, '*');
 830        size_t klen;
 831        size_t ksuffixlen;
 832        size_t namelen;
 833        int ret;
 834        if (!kstar)
 835                die("Key '%s' of pattern had no '*'", key);
 836        klen = kstar - key;
 837        ksuffixlen = strlen(kstar + 1);
 838        namelen = strlen(name);
 839        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 840                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 841        if (ret && value) {
 842                struct strbuf sb = STRBUF_INIT;
 843                const char *vstar = strchr(value, '*');
 844                if (!vstar)
 845                        die("Value '%s' of pattern has no '*'", value);
 846                strbuf_add(&sb, value, vstar - value);
 847                strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 848                strbuf_addstr(&sb, vstar + 1);
 849                *result = strbuf_detach(&sb, NULL);
 850        }
 851        return ret;
 852}
 853
 854static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 855{
 856        int i;
 857        int find_src = !query->src;
 858
 859        if (find_src && !query->dst)
 860                error("query_refspecs_multiple: need either src or dst");
 861
 862        for (i = 0; i < ref_count; i++) {
 863                struct refspec *refspec = &refs[i];
 864                const char *key = find_src ? refspec->dst : refspec->src;
 865                const char *value = find_src ? refspec->src : refspec->dst;
 866                const char *needle = find_src ? query->dst : query->src;
 867                char **result = find_src ? &query->src : &query->dst;
 868
 869                if (!refspec->dst)
 870                        continue;
 871                if (refspec->pattern) {
 872                        if (match_name_with_pattern(key, needle, value, result))
 873                                string_list_append_nodup(results, *result);
 874                } else if (!strcmp(needle, key)) {
 875                        string_list_append(results, value);
 876                }
 877        }
 878}
 879
 880int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 881{
 882        int i;
 883        int find_src = !query->src;
 884        const char *needle = find_src ? query->dst : query->src;
 885        char **result = find_src ? &query->src : &query->dst;
 886
 887        if (find_src && !query->dst)
 888                return error("query_refspecs: need either src or dst");
 889
 890        for (i = 0; i < ref_count; i++) {
 891                struct refspec *refspec = &refs[i];
 892                const char *key = find_src ? refspec->dst : refspec->src;
 893                const char *value = find_src ? refspec->src : refspec->dst;
 894
 895                if (!refspec->dst)
 896                        continue;
 897                if (refspec->pattern) {
 898                        if (match_name_with_pattern(key, needle, value, result)) {
 899                                query->force = refspec->force;
 900                                return 0;
 901                        }
 902                } else if (!strcmp(needle, key)) {
 903                        *result = xstrdup(value);
 904                        query->force = refspec->force;
 905                        return 0;
 906                }
 907        }
 908        return -1;
 909}
 910
 911char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 912                     const char *name)
 913{
 914        struct refspec query;
 915
 916        memset(&query, 0, sizeof(struct refspec));
 917        query.src = (char *)name;
 918
 919        if (query_refspecs(refspecs, nr_refspec, &query))
 920                return NULL;
 921
 922        return query.dst;
 923}
 924
 925int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 926{
 927        return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 928}
 929
 930static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 931                const char *name)
 932{
 933        size_t len = strlen(name);
 934        struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 935        memcpy(ref->name, prefix, prefixlen);
 936        memcpy(ref->name + prefixlen, name, len);
 937        return ref;
 938}
 939
 940struct ref *alloc_ref(const char *name)
 941{
 942        return alloc_ref_with_prefix("", 0, name);
 943}
 944
 945struct ref *copy_ref(const struct ref *ref)
 946{
 947        struct ref *cpy;
 948        size_t len;
 949        if (!ref)
 950                return NULL;
 951        len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 952        cpy = xmalloc(len);
 953        memcpy(cpy, ref, len);
 954        cpy->next = NULL;
 955        cpy->symref = xstrdup_or_null(ref->symref);
 956        cpy->remote_status = xstrdup_or_null(ref->remote_status);
 957        cpy->peer_ref = copy_ref(ref->peer_ref);
 958        return cpy;
 959}
 960
 961struct ref *copy_ref_list(const struct ref *ref)
 962{
 963        struct ref *ret = NULL;
 964        struct ref **tail = &ret;
 965        while (ref) {
 966                *tail = copy_ref(ref);
 967                ref = ref->next;
 968                tail = &((*tail)->next);
 969        }
 970        return ret;
 971}
 972
 973static void free_ref(struct ref *ref)
 974{
 975        if (!ref)
 976                return;
 977        free_ref(ref->peer_ref);
 978        free(ref->remote_status);
 979        free(ref->symref);
 980        free(ref);
 981}
 982
 983void free_refs(struct ref *ref)
 984{
 985        struct ref *next;
 986        while (ref) {
 987                next = ref->next;
 988                free_ref(ref);
 989                ref = next;
 990        }
 991}
 992
 993int ref_compare_name(const void *va, const void *vb)
 994{
 995        const struct ref *a = va, *b = vb;
 996        return strcmp(a->name, b->name);
 997}
 998
 999static void *ref_list_get_next(const void *a)
1000{
1001        return ((const struct ref *)a)->next;
1002}
1003
1004static void ref_list_set_next(void *a, void *next)
1005{
1006        ((struct ref *)a)->next = next;
1007}
1008
1009void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1010{
1011        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1012}
1013
1014int count_refspec_match(const char *pattern,
1015                        struct ref *refs,
1016                        struct ref **matched_ref)
1017{
1018        int patlen = strlen(pattern);
1019        struct ref *matched_weak = NULL;
1020        struct ref *matched = NULL;
1021        int weak_match = 0;
1022        int match = 0;
1023
1024        for (weak_match = match = 0; refs; refs = refs->next) {
1025                char *name = refs->name;
1026                int namelen = strlen(name);
1027
1028                if (!refname_match(pattern, name))
1029                        continue;
1030
1031                /* A match is "weak" if it is with refs outside
1032                 * heads or tags, and did not specify the pattern
1033                 * in full (e.g. "refs/remotes/origin/master") or at
1034                 * least from the toplevel (e.g. "remotes/origin/master");
1035                 * otherwise "git push $URL master" would result in
1036                 * ambiguity between remotes/origin/master and heads/master
1037                 * at the remote site.
1038                 */
1039                if (namelen != patlen &&
1040                    patlen != namelen - 5 &&
1041                    !starts_with(name, "refs/heads/") &&
1042                    !starts_with(name, "refs/tags/")) {
1043                        /* We want to catch the case where only weak
1044                         * matches are found and there are multiple
1045                         * matches, and where more than one strong
1046                         * matches are found, as ambiguous.  One
1047                         * strong match with zero or more weak matches
1048                         * are acceptable as a unique match.
1049                         */
1050                        matched_weak = refs;
1051                        weak_match++;
1052                }
1053                else {
1054                        matched = refs;
1055                        match++;
1056                }
1057        }
1058        if (!matched) {
1059                if (matched_ref)
1060                        *matched_ref = matched_weak;
1061                return weak_match;
1062        }
1063        else {
1064                if (matched_ref)
1065                        *matched_ref = matched;
1066                return match;
1067        }
1068}
1069
1070static void tail_link_ref(struct ref *ref, struct ref ***tail)
1071{
1072        **tail = ref;
1073        while (ref->next)
1074                ref = ref->next;
1075        *tail = &ref->next;
1076}
1077
1078static struct ref *alloc_delete_ref(void)
1079{
1080        struct ref *ref = alloc_ref("(delete)");
1081        oidclr(&ref->new_oid);
1082        return ref;
1083}
1084
1085static int try_explicit_object_name(const char *name,
1086                                    struct ref **match)
1087{
1088        struct object_id oid;
1089
1090        if (!*name) {
1091                if (match)
1092                        *match = alloc_delete_ref();
1093                return 0;
1094        }
1095
1096        if (get_sha1(name, oid.hash))
1097                return -1;
1098
1099        if (match) {
1100                *match = alloc_ref(name);
1101                oidcpy(&(*match)->new_oid, &oid);
1102        }
1103        return 0;
1104}
1105
1106static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1107{
1108        struct ref *ret = alloc_ref(name);
1109        tail_link_ref(ret, tail);
1110        return ret;
1111}
1112
1113static char *guess_ref(const char *name, struct ref *peer)
1114{
1115        struct strbuf buf = STRBUF_INIT;
1116        struct object_id oid;
1117
1118        const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
1119                                           oid.hash, NULL);
1120        if (!r)
1121                return NULL;
1122
1123        if (starts_with(r, "refs/heads/"))
1124                strbuf_addstr(&buf, "refs/heads/");
1125        else if (starts_with(r, "refs/tags/"))
1126                strbuf_addstr(&buf, "refs/tags/");
1127        else
1128                return NULL;
1129
1130        strbuf_addstr(&buf, name);
1131        return strbuf_detach(&buf, NULL);
1132}
1133
1134static int match_explicit_lhs(struct ref *src,
1135                              struct refspec *rs,
1136                              struct ref **match,
1137                              int *allocated_match)
1138{
1139        switch (count_refspec_match(rs->src, src, match)) {
1140        case 1:
1141                if (allocated_match)
1142                        *allocated_match = 0;
1143                return 0;
1144        case 0:
1145                /* The source could be in the get_sha1() format
1146                 * not a reference name.  :refs/other is a
1147                 * way to delete 'other' ref at the remote end.
1148                 */
1149                if (try_explicit_object_name(rs->src, match) < 0)
1150                        return error("src refspec %s does not match any.", rs->src);
1151                if (allocated_match)
1152                        *allocated_match = 1;
1153                return 0;
1154        default:
1155                return error("src refspec %s matches more than one.", rs->src);
1156        }
1157}
1158
1159static int match_explicit(struct ref *src, struct ref *dst,
1160                          struct ref ***dst_tail,
1161                          struct refspec *rs)
1162{
1163        struct ref *matched_src, *matched_dst;
1164        int allocated_src;
1165
1166        const char *dst_value = rs->dst;
1167        char *dst_guess;
1168
1169        if (rs->pattern || rs->matching)
1170                return 0;
1171
1172        matched_src = matched_dst = NULL;
1173        if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1174                return -1;
1175
1176        if (!dst_value) {
1177                struct object_id oid;
1178                int flag;
1179
1180                dst_value = resolve_ref_unsafe(matched_src->name,
1181                                               RESOLVE_REF_READING,
1182                                               oid.hash, &flag);
1183                if (!dst_value ||
1184                    ((flag & REF_ISSYMREF) &&
1185                     !starts_with(dst_value, "refs/heads/")))
1186                        die("%s cannot be resolved to branch.",
1187                            matched_src->name);
1188        }
1189
1190        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1191        case 1:
1192                break;
1193        case 0:
1194                if (starts_with(dst_value, "refs/"))
1195                        matched_dst = make_linked_ref(dst_value, dst_tail);
1196                else if (is_null_oid(&matched_src->new_oid))
1197                        error("unable to delete '%s': remote ref does not exist",
1198                              dst_value);
1199                else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1200                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1201                        free(dst_guess);
1202                } else
1203                        error("unable to push to unqualified destination: %s\n"
1204                              "The destination refspec neither matches an "
1205                              "existing ref on the remote nor\n"
1206                              "begins with refs/, and we are unable to "
1207                              "guess a prefix based on the source ref.",
1208                              dst_value);
1209                break;
1210        default:
1211                matched_dst = NULL;
1212                error("dst refspec %s matches more than one.",
1213                      dst_value);
1214                break;
1215        }
1216        if (!matched_dst)
1217                return -1;
1218        if (matched_dst->peer_ref)
1219                return error("dst ref %s receives from more than one src.",
1220                      matched_dst->name);
1221        else {
1222                matched_dst->peer_ref = allocated_src ?
1223                                        matched_src :
1224                                        copy_ref(matched_src);
1225                matched_dst->force = rs->force;
1226        }
1227        return 0;
1228}
1229
1230static int match_explicit_refs(struct ref *src, struct ref *dst,
1231                               struct ref ***dst_tail, struct refspec *rs,
1232                               int rs_nr)
1233{
1234        int i, errs;
1235        for (i = errs = 0; i < rs_nr; i++)
1236                errs += match_explicit(src, dst, dst_tail, &rs[i]);
1237        return errs;
1238}
1239
1240static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1241                int send_mirror, int direction, const struct refspec **ret_pat)
1242{
1243        const struct refspec *pat;
1244        char *name;
1245        int i;
1246        int matching_refs = -1;
1247        for (i = 0; i < rs_nr; i++) {
1248                if (rs[i].matching &&
1249                    (matching_refs == -1 || rs[i].force)) {
1250                        matching_refs = i;
1251                        continue;
1252                }
1253
1254                if (rs[i].pattern) {
1255                        const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1256                        int match;
1257                        if (direction == FROM_SRC)
1258                                match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1259                        else
1260                                match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1261                        if (match) {
1262                                matching_refs = i;
1263                                break;
1264                        }
1265                }
1266        }
1267        if (matching_refs == -1)
1268                return NULL;
1269
1270        pat = rs + matching_refs;
1271        if (pat->matching) {
1272                /*
1273                 * "matching refs"; traditionally we pushed everything
1274                 * including refs outside refs/heads/ hierarchy, but
1275                 * that does not make much sense these days.
1276                 */
1277                if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1278                        return NULL;
1279                name = xstrdup(ref->name);
1280        }
1281        if (ret_pat)
1282                *ret_pat = pat;
1283        return name;
1284}
1285
1286static struct ref **tail_ref(struct ref **head)
1287{
1288        struct ref **tail = head;
1289        while (*tail)
1290                tail = &((*tail)->next);
1291        return tail;
1292}
1293
1294struct tips {
1295        struct commit **tip;
1296        int nr, alloc;
1297};
1298
1299static void add_to_tips(struct tips *tips, const struct object_id *oid)
1300{
1301        struct commit *commit;
1302
1303        if (is_null_oid(oid))
1304                return;
1305        commit = lookup_commit_reference_gently(oid->hash, 1);
1306        if (!commit || (commit->object.flags & TMP_MARK))
1307                return;
1308        commit->object.flags |= TMP_MARK;
1309        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1310        tips->tip[tips->nr++] = commit;
1311}
1312
1313static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1314{
1315        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1316        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1317        struct string_list_item *item;
1318        struct ref *ref;
1319        struct tips sent_tips;
1320
1321        /*
1322         * Collect everything we know they would have at the end of
1323         * this push, and collect all tags they have.
1324         */
1325        memset(&sent_tips, 0, sizeof(sent_tips));
1326        for (ref = *dst; ref; ref = ref->next) {
1327                if (ref->peer_ref &&
1328                    !is_null_oid(&ref->peer_ref->new_oid))
1329                        add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1330                else
1331                        add_to_tips(&sent_tips, &ref->old_oid);
1332                if (starts_with(ref->name, "refs/tags/"))
1333                        string_list_append(&dst_tag, ref->name);
1334        }
1335        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1336
1337        string_list_sort(&dst_tag);
1338
1339        /* Collect tags they do not have. */
1340        for (ref = src; ref; ref = ref->next) {
1341                if (!starts_with(ref->name, "refs/tags/"))
1342                        continue; /* not a tag */
1343                if (string_list_has_string(&dst_tag, ref->name))
1344                        continue; /* they already have it */
1345                if (sha1_object_info(ref->new_oid.hash, NULL) != OBJ_TAG)
1346                        continue; /* be conservative */
1347                item = string_list_append(&src_tag, ref->name);
1348                item->util = ref;
1349        }
1350        string_list_clear(&dst_tag, 0);
1351
1352        /*
1353         * At this point, src_tag lists tags that are missing from
1354         * dst, and sent_tips lists the tips we are pushing or those
1355         * that we know they already have. An element in the src_tag
1356         * that is an ancestor of any of the sent_tips needs to be
1357         * sent to the other side.
1358         */
1359        if (sent_tips.nr) {
1360                for_each_string_list_item(item, &src_tag) {
1361                        struct ref *ref = item->util;
1362                        struct ref *dst_ref;
1363                        struct commit *commit;
1364
1365                        if (is_null_oid(&ref->new_oid))
1366                                continue;
1367                        commit = lookup_commit_reference_gently(ref->new_oid.hash, 1);
1368                        if (!commit)
1369                                /* not pushing a commit, which is not an error */
1370                                continue;
1371
1372                        /*
1373                         * Is this tag, which they do not have, reachable from
1374                         * any of the commits we are sending?
1375                         */
1376                        if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1377                                continue;
1378
1379                        /* Add it in */
1380                        dst_ref = make_linked_ref(ref->name, dst_tail);
1381                        oidcpy(&dst_ref->new_oid, &ref->new_oid);
1382                        dst_ref->peer_ref = copy_ref(ref);
1383                }
1384        }
1385        string_list_clear(&src_tag, 0);
1386        free(sent_tips.tip);
1387}
1388
1389struct ref *find_ref_by_name(const struct ref *list, const char *name)
1390{
1391        for ( ; list; list = list->next)
1392                if (!strcmp(list->name, name))
1393                        return (struct ref *)list;
1394        return NULL;
1395}
1396
1397static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1398{
1399        for ( ; ref; ref = ref->next)
1400                string_list_append_nodup(ref_index, ref->name)->util = ref;
1401
1402        string_list_sort(ref_index);
1403}
1404
1405/*
1406 * Given only the set of local refs, sanity-check the set of push
1407 * refspecs. We can't catch all errors that match_push_refs would,
1408 * but we can catch some errors early before even talking to the
1409 * remote side.
1410 */
1411int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1412{
1413        struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1414        int ret = 0;
1415        int i;
1416
1417        for (i = 0; i < nr_refspec; i++) {
1418                struct refspec *rs = refspec + i;
1419
1420                if (rs->pattern || rs->matching)
1421                        continue;
1422
1423                ret |= match_explicit_lhs(src, rs, NULL, NULL);
1424        }
1425
1426        free_refspec(nr_refspec, refspec);
1427        return ret;
1428}
1429
1430/*
1431 * Given the set of refs the local repository has, the set of refs the
1432 * remote repository has, and the refspec used for push, determine
1433 * what remote refs we will update and with what value by setting
1434 * peer_ref (which object is being pushed) and force (if the push is
1435 * forced) in elements of "dst". The function may add new elements to
1436 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1437 */
1438int match_push_refs(struct ref *src, struct ref **dst,
1439                    int nr_refspec, const char **refspec, int flags)
1440{
1441        struct refspec *rs;
1442        int send_all = flags & MATCH_REFS_ALL;
1443        int send_mirror = flags & MATCH_REFS_MIRROR;
1444        int send_prune = flags & MATCH_REFS_PRUNE;
1445        int errs;
1446        static const char *default_refspec[] = { ":", NULL };
1447        struct ref *ref, **dst_tail = tail_ref(dst);
1448        struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1449
1450        if (!nr_refspec) {
1451                nr_refspec = 1;
1452                refspec = default_refspec;
1453        }
1454        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1455        errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1456
1457        /* pick the remainder */
1458        for (ref = src; ref; ref = ref->next) {
1459                struct string_list_item *dst_item;
1460                struct ref *dst_peer;
1461                const struct refspec *pat = NULL;
1462                char *dst_name;
1463
1464                dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1465                if (!dst_name)
1466                        continue;
1467
1468                if (!dst_ref_index.nr)
1469                        prepare_ref_index(&dst_ref_index, *dst);
1470
1471                dst_item = string_list_lookup(&dst_ref_index, dst_name);
1472                dst_peer = dst_item ? dst_item->util : NULL;
1473                if (dst_peer) {
1474                        if (dst_peer->peer_ref)
1475                                /* We're already sending something to this ref. */
1476                                goto free_name;
1477                } else {
1478                        if (pat->matching && !(send_all || send_mirror))
1479                                /*
1480                                 * Remote doesn't have it, and we have no
1481                                 * explicit pattern, and we don't have
1482                                 * --all or --mirror.
1483                                 */
1484                                goto free_name;
1485
1486                        /* Create a new one and link it */
1487                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1488                        oidcpy(&dst_peer->new_oid, &ref->new_oid);
1489                        string_list_insert(&dst_ref_index,
1490                                dst_peer->name)->util = dst_peer;
1491                }
1492                dst_peer->peer_ref = copy_ref(ref);
1493                dst_peer->force = pat->force;
1494        free_name:
1495                free(dst_name);
1496        }
1497
1498        string_list_clear(&dst_ref_index, 0);
1499
1500        if (flags & MATCH_REFS_FOLLOW_TAGS)
1501                add_missing_tags(src, dst, &dst_tail);
1502
1503        if (send_prune) {
1504                struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1505                /* check for missing refs on the remote */
1506                for (ref = *dst; ref; ref = ref->next) {
1507                        char *src_name;
1508
1509                        if (ref->peer_ref)
1510                                /* We're already sending something to this ref. */
1511                                continue;
1512
1513                        src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1514                        if (src_name) {
1515                                if (!src_ref_index.nr)
1516                                        prepare_ref_index(&src_ref_index, src);
1517                                if (!string_list_has_string(&src_ref_index,
1518                                            src_name))
1519                                        ref->peer_ref = alloc_delete_ref();
1520                                free(src_name);
1521                        }
1522                }
1523                string_list_clear(&src_ref_index, 0);
1524        }
1525        if (errs)
1526                return -1;
1527        return 0;
1528}
1529
1530void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1531                             int force_update)
1532{
1533        struct ref *ref;
1534
1535        for (ref = remote_refs; ref; ref = ref->next) {
1536                int force_ref_update = ref->force || force_update;
1537                int reject_reason = 0;
1538
1539                if (ref->peer_ref)
1540                        oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1541                else if (!send_mirror)
1542                        continue;
1543
1544                ref->deletion = is_null_oid(&ref->new_oid);
1545                if (!ref->deletion &&
1546                        !oidcmp(&ref->old_oid, &ref->new_oid)) {
1547                        ref->status = REF_STATUS_UPTODATE;
1548                        continue;
1549                }
1550
1551                /*
1552                 * If the remote ref has moved and is now different
1553                 * from what we expect, reject any push.
1554                 *
1555                 * It also is an error if the user told us to check
1556                 * with the remote-tracking branch to find the value
1557                 * to expect, but we did not have such a tracking
1558                 * branch.
1559                 */
1560                if (ref->expect_old_sha1) {
1561                        if (oidcmp(&ref->old_oid, &ref->old_oid_expect))
1562                                reject_reason = REF_STATUS_REJECT_STALE;
1563                        else
1564                                /* If the ref isn't stale then force the update. */
1565                                force_ref_update = 1;
1566                }
1567
1568                /*
1569                 * If the update isn't already rejected then check
1570                 * the usual "must fast-forward" rules.
1571                 *
1572                 * Decide whether an individual refspec A:B can be
1573                 * pushed.  The push will succeed if any of the
1574                 * following are true:
1575                 *
1576                 * (1) the remote reference B does not exist
1577                 *
1578                 * (2) the remote reference B is being removed (i.e.,
1579                 *     pushing :B where no source is specified)
1580                 *
1581                 * (3) the destination is not under refs/tags/, and
1582                 *     if the old and new value is a commit, the new
1583                 *     is a descendant of the old.
1584                 *
1585                 * (4) it is forced using the +A:B notation, or by
1586                 *     passing the --force argument
1587                 */
1588
1589                if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1590                        if (starts_with(ref->name, "refs/tags/"))
1591                                reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1592                        else if (!has_object_file(&ref->old_oid))
1593                                reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1594                        else if (!lookup_commit_reference_gently(ref->old_oid.hash, 1) ||
1595                                 !lookup_commit_reference_gently(ref->new_oid.hash, 1))
1596                                reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1597                        else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1598                                reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1599                }
1600
1601                /*
1602                 * "--force" will defeat any rejection implemented
1603                 * by the rules above.
1604                 */
1605                if (!force_ref_update)
1606                        ref->status = reject_reason;
1607                else if (reject_reason)
1608                        ref->forced_update = 1;
1609        }
1610}
1611
1612static void set_merge(struct branch *ret)
1613{
1614        struct remote *remote;
1615        char *ref;
1616        struct object_id oid;
1617        int i;
1618
1619        if (!ret)
1620                return; /* no branch */
1621        if (ret->merge)
1622                return; /* already run */
1623        if (!ret->remote_name || !ret->merge_nr) {
1624                /*
1625                 * no merge config; let's make sure we don't confuse callers
1626                 * with a non-zero merge_nr but a NULL merge
1627                 */
1628                ret->merge_nr = 0;
1629                return;
1630        }
1631
1632        remote = remote_get(ret->remote_name);
1633
1634        ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1635        for (i = 0; i < ret->merge_nr; i++) {
1636                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1637                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1638                if (!remote_find_tracking(remote, ret->merge[i]) ||
1639                    strcmp(ret->remote_name, "."))
1640                        continue;
1641                if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1642                             oid.hash, &ref) == 1)
1643                        ret->merge[i]->dst = ref;
1644                else
1645                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1646        }
1647}
1648
1649struct branch *branch_get(const char *name)
1650{
1651        struct branch *ret;
1652
1653        read_config();
1654        if (!name || !*name || !strcmp(name, "HEAD"))
1655                ret = current_branch;
1656        else
1657                ret = make_branch(name, 0);
1658        set_merge(ret);
1659        return ret;
1660}
1661
1662int branch_has_merge_config(struct branch *branch)
1663{
1664        return branch && !!branch->merge;
1665}
1666
1667int branch_merge_matches(struct branch *branch,
1668                                 int i,
1669                                 const char *refname)
1670{
1671        if (!branch || i < 0 || i >= branch->merge_nr)
1672                return 0;
1673        return refname_match(branch->merge[i]->src, refname);
1674}
1675
1676__attribute__((format (printf,2,3)))
1677static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1678{
1679        if (err) {
1680                va_list ap;
1681                va_start(ap, fmt);
1682                strbuf_vaddf(err, fmt, ap);
1683                va_end(ap);
1684        }
1685        return NULL;
1686}
1687
1688const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1689{
1690        if (!branch)
1691                return error_buf(err, _("HEAD does not point to a branch"));
1692
1693        if (!branch->merge || !branch->merge[0]) {
1694                /*
1695                 * no merge config; is it because the user didn't define any,
1696                 * or because it is not a real branch, and get_branch
1697                 * auto-vivified it?
1698                 */
1699                if (!ref_exists(branch->refname))
1700                        return error_buf(err, _("no such branch: '%s'"),
1701                                         branch->name);
1702                return error_buf(err,
1703                                 _("no upstream configured for branch '%s'"),
1704                                 branch->name);
1705        }
1706
1707        if (!branch->merge[0]->dst)
1708                return error_buf(err,
1709                                 _("upstream branch '%s' not stored as a remote-tracking branch"),
1710                                 branch->merge[0]->src);
1711
1712        return branch->merge[0]->dst;
1713}
1714
1715static const char *tracking_for_push_dest(struct remote *remote,
1716                                          const char *refname,
1717                                          struct strbuf *err)
1718{
1719        char *ret;
1720
1721        ret = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
1722        if (!ret)
1723                return error_buf(err,
1724                                 _("push destination '%s' on remote '%s' has no local tracking branch"),
1725                                 refname, remote->name);
1726        return ret;
1727}
1728
1729static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1730{
1731        struct remote *remote;
1732
1733        remote = remote_get(pushremote_for_branch(branch, NULL));
1734        if (!remote)
1735                return error_buf(err,
1736                                 _("branch '%s' has no remote for pushing"),
1737                                 branch->name);
1738
1739        if (remote->push_refspec_nr) {
1740                char *dst;
1741                const char *ret;
1742
1743                dst = apply_refspecs(remote->push, remote->push_refspec_nr,
1744                                     branch->refname);
1745                if (!dst)
1746                        return error_buf(err,
1747                                         _("push refspecs for '%s' do not include '%s'"),
1748                                         remote->name, branch->name);
1749
1750                ret = tracking_for_push_dest(remote, dst, err);
1751                free(dst);
1752                return ret;
1753        }
1754
1755        if (remote->mirror)
1756                return tracking_for_push_dest(remote, branch->refname, err);
1757
1758        switch (push_default) {
1759        case PUSH_DEFAULT_NOTHING:
1760                return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1761
1762        case PUSH_DEFAULT_MATCHING:
1763        case PUSH_DEFAULT_CURRENT:
1764                return tracking_for_push_dest(remote, branch->refname, err);
1765
1766        case PUSH_DEFAULT_UPSTREAM:
1767                return branch_get_upstream(branch, err);
1768
1769        case PUSH_DEFAULT_UNSPECIFIED:
1770        case PUSH_DEFAULT_SIMPLE:
1771                {
1772                        const char *up, *cur;
1773
1774                        up = branch_get_upstream(branch, err);
1775                        if (!up)
1776                                return NULL;
1777                        cur = tracking_for_push_dest(remote, branch->refname, err);
1778                        if (!cur)
1779                                return NULL;
1780                        if (strcmp(cur, up))
1781                                return error_buf(err,
1782                                                 _("cannot resolve 'simple' push to a single destination"));
1783                        return cur;
1784                }
1785        }
1786
1787        die("BUG: unhandled push situation");
1788}
1789
1790const char *branch_get_push(struct branch *branch, struct strbuf *err)
1791{
1792        if (!branch)
1793                return error_buf(err, _("HEAD does not point to a branch"));
1794
1795        if (!branch->push_tracking_ref)
1796                branch->push_tracking_ref = branch_get_push_1(branch, err);
1797        return branch->push_tracking_ref;
1798}
1799
1800static int ignore_symref_update(const char *refname)
1801{
1802        struct object_id oid;
1803        int flag;
1804
1805        if (!resolve_ref_unsafe(refname, 0, oid.hash, &flag))
1806                return 0; /* non-existing refs are OK */
1807        return (flag & REF_ISSYMREF);
1808}
1809
1810/*
1811 * Create and return a list of (struct ref) consisting of copies of
1812 * each remote_ref that matches refspec.  refspec must be a pattern.
1813 * Fill in the copies' peer_ref to describe the local tracking refs to
1814 * which they map.  Omit any references that would map to an existing
1815 * local symbolic ref.
1816 */
1817static struct ref *get_expanded_map(const struct ref *remote_refs,
1818                                    const struct refspec *refspec)
1819{
1820        const struct ref *ref;
1821        struct ref *ret = NULL;
1822        struct ref **tail = &ret;
1823
1824        for (ref = remote_refs; ref; ref = ref->next) {
1825                char *expn_name = NULL;
1826
1827                if (strchr(ref->name, '^'))
1828                        continue; /* a dereference item */
1829                if (match_name_with_pattern(refspec->src, ref->name,
1830                                            refspec->dst, &expn_name) &&
1831                    !ignore_symref_update(expn_name)) {
1832                        struct ref *cpy = copy_ref(ref);
1833
1834                        cpy->peer_ref = alloc_ref(expn_name);
1835                        if (refspec->force)
1836                                cpy->peer_ref->force = 1;
1837                        *tail = cpy;
1838                        tail = &cpy->next;
1839                }
1840                free(expn_name);
1841        }
1842
1843        return ret;
1844}
1845
1846static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1847{
1848        const struct ref *ref;
1849        for (ref = refs; ref; ref = ref->next) {
1850                if (refname_match(name, ref->name))
1851                        return ref;
1852        }
1853        return NULL;
1854}
1855
1856struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1857{
1858        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1859
1860        if (!ref)
1861                return NULL;
1862
1863        return copy_ref(ref);
1864}
1865
1866static struct ref *get_local_ref(const char *name)
1867{
1868        if (!name || name[0] == '\0')
1869                return NULL;
1870
1871        if (starts_with(name, "refs/"))
1872                return alloc_ref(name);
1873
1874        if (starts_with(name, "heads/") ||
1875            starts_with(name, "tags/") ||
1876            starts_with(name, "remotes/"))
1877                return alloc_ref_with_prefix("refs/", 5, name);
1878
1879        return alloc_ref_with_prefix("refs/heads/", 11, name);
1880}
1881
1882int get_fetch_map(const struct ref *remote_refs,
1883                  const struct refspec *refspec,
1884                  struct ref ***tail,
1885                  int missing_ok)
1886{
1887        struct ref *ref_map, **rmp;
1888
1889        if (refspec->pattern) {
1890                ref_map = get_expanded_map(remote_refs, refspec);
1891        } else {
1892                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1893
1894                if (refspec->exact_sha1) {
1895                        ref_map = alloc_ref(name);
1896                        get_oid_hex(name, &ref_map->old_oid);
1897                } else {
1898                        ref_map = get_remote_ref(remote_refs, name);
1899                }
1900                if (!missing_ok && !ref_map)
1901                        die("Couldn't find remote ref %s", name);
1902                if (ref_map) {
1903                        ref_map->peer_ref = get_local_ref(refspec->dst);
1904                        if (ref_map->peer_ref && refspec->force)
1905                                ref_map->peer_ref->force = 1;
1906                }
1907        }
1908
1909        for (rmp = &ref_map; *rmp; ) {
1910                if ((*rmp)->peer_ref) {
1911                        if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1912                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1913                                struct ref *ignore = *rmp;
1914                                error("* Ignoring funny ref '%s' locally",
1915                                      (*rmp)->peer_ref->name);
1916                                *rmp = (*rmp)->next;
1917                                free(ignore->peer_ref);
1918                                free(ignore);
1919                                continue;
1920                        }
1921                }
1922                rmp = &((*rmp)->next);
1923        }
1924
1925        if (ref_map)
1926                tail_link_ref(ref_map, tail);
1927
1928        return 0;
1929}
1930
1931int resolve_remote_symref(struct ref *ref, struct ref *list)
1932{
1933        if (!ref->symref)
1934                return 0;
1935        for (; list; list = list->next)
1936                if (!strcmp(ref->symref, list->name)) {
1937                        oidcpy(&ref->old_oid, &list->old_oid);
1938                        return 0;
1939                }
1940        return 1;
1941}
1942
1943static void unmark_and_free(struct commit_list *list, unsigned int mark)
1944{
1945        while (list) {
1946                struct commit *commit = pop_commit(&list);
1947                commit->object.flags &= ~mark;
1948        }
1949}
1950
1951int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1952{
1953        struct object *o;
1954        struct commit *old, *new;
1955        struct commit_list *list, *used;
1956        int found = 0;
1957
1958        /*
1959         * Both new and old must be commit-ish and new is descendant of
1960         * old.  Otherwise we require --force.
1961         */
1962        o = deref_tag(parse_object(old_oid->hash), NULL, 0);
1963        if (!o || o->type != OBJ_COMMIT)
1964                return 0;
1965        old = (struct commit *) o;
1966
1967        o = deref_tag(parse_object(new_oid->hash), NULL, 0);
1968        if (!o || o->type != OBJ_COMMIT)
1969                return 0;
1970        new = (struct commit *) o;
1971
1972        if (parse_commit(new) < 0)
1973                return 0;
1974
1975        used = list = NULL;
1976        commit_list_insert(new, &list);
1977        while (list) {
1978                new = pop_most_recent_commit(&list, TMP_MARK);
1979                commit_list_insert(new, &used);
1980                if (new == old) {
1981                        found = 1;
1982                        break;
1983                }
1984        }
1985        unmark_and_free(list, TMP_MARK);
1986        unmark_and_free(used, TMP_MARK);
1987        return found;
1988}
1989
1990/*
1991 * Compare a branch with its upstream, and save their differences (number
1992 * of commits) in *num_ours and *num_theirs. The name of the upstream branch
1993 * (or NULL if no upstream is defined) is returned via *upstream_name, if it
1994 * is not itself NULL.
1995 *
1996 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1997 * upstream defined, or ref does not exist), 0 otherwise.
1998 */
1999int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
2000                       const char **upstream_name)
2001{
2002        struct object_id oid;
2003        struct commit *ours, *theirs;
2004        struct rev_info revs;
2005        const char *base;
2006        struct argv_array argv = ARGV_ARRAY_INIT;
2007
2008        /* Cannot stat unless we are marked to build on top of somebody else. */
2009        base = branch_get_upstream(branch, NULL);
2010        if (upstream_name)
2011                *upstream_name = base;
2012        if (!base)
2013                return -1;
2014
2015        /* Cannot stat if what we used to build on no longer exists */
2016        if (read_ref(base, oid.hash))
2017                return -1;
2018        theirs = lookup_commit_reference(oid.hash);
2019        if (!theirs)
2020                return -1;
2021
2022        if (read_ref(branch->refname, oid.hash))
2023                return -1;
2024        ours = lookup_commit_reference(oid.hash);
2025        if (!ours)
2026                return -1;
2027
2028        /* are we the same? */
2029        if (theirs == ours) {
2030                *num_theirs = *num_ours = 0;
2031                return 0;
2032        }
2033
2034        /* Run "rev-list --left-right ours...theirs" internally... */
2035        argv_array_push(&argv, ""); /* ignored */
2036        argv_array_push(&argv, "--left-right");
2037        argv_array_pushf(&argv, "%s...%s",
2038                         oid_to_hex(&ours->object.oid),
2039                         oid_to_hex(&theirs->object.oid));
2040        argv_array_push(&argv, "--");
2041
2042        init_revisions(&revs, NULL);
2043        setup_revisions(argv.argc, argv.argv, &revs, NULL);
2044        if (prepare_revision_walk(&revs))
2045                die("revision walk setup failed");
2046
2047        /* ... and count the commits on each side. */
2048        *num_ours = 0;
2049        *num_theirs = 0;
2050        while (1) {
2051                struct commit *c = get_revision(&revs);
2052                if (!c)
2053                        break;
2054                if (c->object.flags & SYMMETRIC_LEFT)
2055                        (*num_ours)++;
2056                else
2057                        (*num_theirs)++;
2058        }
2059
2060        /* clear object flags smudged by the above traversal */
2061        clear_commit_marks(ours, ALL_REV_FLAGS);
2062        clear_commit_marks(theirs, ALL_REV_FLAGS);
2063
2064        argv_array_clear(&argv);
2065        return 0;
2066}
2067
2068/*
2069 * Return true when there is anything to report, otherwise false.
2070 */
2071int format_tracking_info(struct branch *branch, struct strbuf *sb)
2072{
2073        int ours, theirs;
2074        const char *full_base;
2075        char *base;
2076        int upstream_is_gone = 0;
2077
2078        if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
2079                if (!full_base)
2080                        return 0;
2081                upstream_is_gone = 1;
2082        }
2083
2084        base = shorten_unambiguous_ref(full_base, 0);
2085        if (upstream_is_gone) {
2086                strbuf_addf(sb,
2087                        _("Your branch is based on '%s', but the upstream is gone.\n"),
2088                        base);
2089                if (advice_status_hints)
2090                        strbuf_addstr(sb,
2091                                _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2092        } else if (!ours && !theirs) {
2093                strbuf_addf(sb,
2094                        _("Your branch is up-to-date with '%s'.\n"),
2095                        base);
2096        } else if (!theirs) {
2097                strbuf_addf(sb,
2098                        Q_("Your branch is ahead of '%s' by %d commit.\n",
2099                           "Your branch is ahead of '%s' by %d commits.\n",
2100                           ours),
2101                        base, ours);
2102                if (advice_status_hints)
2103                        strbuf_addstr(sb,
2104                                _("  (use \"git push\" to publish your local commits)\n"));
2105        } else if (!ours) {
2106                strbuf_addf(sb,
2107                        Q_("Your branch is behind '%s' by %d commit, "
2108                               "and can be fast-forwarded.\n",
2109                           "Your branch is behind '%s' by %d commits, "
2110                               "and can be fast-forwarded.\n",
2111                           theirs),
2112                        base, theirs);
2113                if (advice_status_hints)
2114                        strbuf_addstr(sb,
2115                                _("  (use \"git pull\" to update your local branch)\n"));
2116        } else {
2117                strbuf_addf(sb,
2118                        Q_("Your branch and '%s' have diverged,\n"
2119                               "and have %d and %d different commit each, "
2120                               "respectively.\n",
2121                           "Your branch and '%s' have diverged,\n"
2122                               "and have %d and %d different commits each, "
2123                               "respectively.\n",
2124                           ours + theirs),
2125                        base, ours, theirs);
2126                if (advice_status_hints)
2127                        strbuf_addstr(sb,
2128                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2129        }
2130        free(base);
2131        return 1;
2132}
2133
2134static int one_local_ref(const char *refname, const struct object_id *oid,
2135                         int flag, void *cb_data)
2136{
2137        struct ref ***local_tail = cb_data;
2138        struct ref *ref;
2139
2140        /* we already know it starts with refs/ to get here */
2141        if (check_refname_format(refname + 5, 0))
2142                return 0;
2143
2144        ref = alloc_ref(refname);
2145        oidcpy(&ref->new_oid, oid);
2146        **local_tail = ref;
2147        *local_tail = &ref->next;
2148        return 0;
2149}
2150
2151struct ref *get_local_heads(void)
2152{
2153        struct ref *local_refs = NULL, **local_tail = &local_refs;
2154
2155        for_each_ref(one_local_ref, &local_tail);
2156        return local_refs;
2157}
2158
2159struct ref *guess_remote_head(const struct ref *head,
2160                              const struct ref *refs,
2161                              int all)
2162{
2163        const struct ref *r;
2164        struct ref *list = NULL;
2165        struct ref **tail = &list;
2166
2167        if (!head)
2168                return NULL;
2169
2170        /*
2171         * Some transports support directly peeking at
2172         * where HEAD points; if that is the case, then
2173         * we don't have to guess.
2174         */
2175        if (head->symref)
2176                return copy_ref(find_ref_by_name(refs, head->symref));
2177
2178        /* If refs/heads/master could be right, it is. */
2179        if (!all) {
2180                r = find_ref_by_name(refs, "refs/heads/master");
2181                if (r && !oidcmp(&r->old_oid, &head->old_oid))
2182                        return copy_ref(r);
2183        }
2184
2185        /* Look for another ref that points there */
2186        for (r = refs; r; r = r->next) {
2187                if (r != head &&
2188                    starts_with(r->name, "refs/heads/") &&
2189                    !oidcmp(&r->old_oid, &head->old_oid)) {
2190                        *tail = copy_ref(r);
2191                        tail = &((*tail)->next);
2192                        if (!all)
2193                                break;
2194                }
2195        }
2196
2197        return list;
2198}
2199
2200struct stale_heads_info {
2201        struct string_list *ref_names;
2202        struct ref **stale_refs_tail;
2203        struct refspec *refs;
2204        int ref_count;
2205};
2206
2207static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2208                              int flags, void *cb_data)
2209{
2210        struct stale_heads_info *info = cb_data;
2211        struct string_list matches = STRING_LIST_INIT_DUP;
2212        struct refspec query;
2213        int i, stale = 1;
2214        memset(&query, 0, sizeof(struct refspec));
2215        query.dst = (char *)refname;
2216
2217        query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2218        if (matches.nr == 0)
2219                goto clean_exit; /* No matches */
2220
2221        /*
2222         * If we did find a suitable refspec and it's not a symref and
2223         * it's not in the list of refs that currently exist in that
2224         * remote, we consider it to be stale. In order to deal with
2225         * overlapping refspecs, we need to go over all of the
2226         * matching refs.
2227         */
2228        if (flags & REF_ISSYMREF)
2229                goto clean_exit;
2230
2231        for (i = 0; stale && i < matches.nr; i++)
2232                if (string_list_has_string(info->ref_names, matches.items[i].string))
2233                        stale = 0;
2234
2235        if (stale) {
2236                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2237                oidcpy(&ref->new_oid, oid);
2238        }
2239
2240clean_exit:
2241        string_list_clear(&matches, 0);
2242        return 0;
2243}
2244
2245struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2246{
2247        struct ref *ref, *stale_refs = NULL;
2248        struct string_list ref_names = STRING_LIST_INIT_NODUP;
2249        struct stale_heads_info info;
2250
2251        info.ref_names = &ref_names;
2252        info.stale_refs_tail = &stale_refs;
2253        info.refs = refs;
2254        info.ref_count = ref_count;
2255        for (ref = fetch_map; ref; ref = ref->next)
2256                string_list_append(&ref_names, ref->name);
2257        string_list_sort(&ref_names);
2258        for_each_ref(get_stale_heads_cb, &info);
2259        string_list_clear(&ref_names, 0);
2260        return stale_refs;
2261}
2262
2263/*
2264 * Compare-and-swap
2265 */
2266static void clear_cas_option(struct push_cas_option *cas)
2267{
2268        int i;
2269
2270        for (i = 0; i < cas->nr; i++)
2271                free(cas->entry[i].refname);
2272        free(cas->entry);
2273        memset(cas, 0, sizeof(*cas));
2274}
2275
2276static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2277                                      const char *refname,
2278                                      size_t refnamelen)
2279{
2280        struct push_cas *entry;
2281        ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2282        entry = &cas->entry[cas->nr++];
2283        memset(entry, 0, sizeof(*entry));
2284        entry->refname = xmemdupz(refname, refnamelen);
2285        return entry;
2286}
2287
2288static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2289{
2290        const char *colon;
2291        struct push_cas *entry;
2292
2293        if (unset) {
2294                /* "--no-<option>" */
2295                clear_cas_option(cas);
2296                return 0;
2297        }
2298
2299        if (!arg) {
2300                /* just "--<option>" */
2301                cas->use_tracking_for_rest = 1;
2302                return 0;
2303        }
2304
2305        /* "--<option>=refname" or "--<option>=refname:value" */
2306        colon = strchrnul(arg, ':');
2307        entry = add_cas_entry(cas, arg, colon - arg);
2308        if (!*colon)
2309                entry->use_tracking = 1;
2310        else if (!colon[1])
2311                hashclr(entry->expect);
2312        else if (get_sha1(colon + 1, entry->expect))
2313                return error("cannot parse expected object name '%s'", colon + 1);
2314        return 0;
2315}
2316
2317int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2318{
2319        return parse_push_cas_option(opt->value, arg, unset);
2320}
2321
2322int is_empty_cas(const struct push_cas_option *cas)
2323{
2324        return !cas->use_tracking_for_rest && !cas->nr;
2325}
2326
2327/*
2328 * Look at remote.fetch refspec and see if we have a remote
2329 * tracking branch for the refname there.  Fill its current
2330 * value in sha1[].
2331 * If we cannot do so, return negative to signal an error.
2332 */
2333static int remote_tracking(struct remote *remote, const char *refname,
2334                           struct object_id *oid)
2335{
2336        char *dst;
2337
2338        dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2339        if (!dst)
2340                return -1; /* no tracking ref for refname at remote */
2341        if (read_ref(dst, oid->hash))
2342                return -1; /* we know what the tracking ref is but we cannot read it */
2343        return 0;
2344}
2345
2346static void apply_cas(struct push_cas_option *cas,
2347                      struct remote *remote,
2348                      struct ref *ref)
2349{
2350        int i;
2351
2352        /* Find an explicit --<option>=<name>[:<value>] entry */
2353        for (i = 0; i < cas->nr; i++) {
2354                struct push_cas *entry = &cas->entry[i];
2355                if (!refname_match(entry->refname, ref->name))
2356                        continue;
2357                ref->expect_old_sha1 = 1;
2358                if (!entry->use_tracking)
2359                        hashcpy(ref->old_oid_expect.hash, cas->entry[i].expect);
2360                else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2361                        oidclr(&ref->old_oid_expect);
2362                return;
2363        }
2364
2365        /* Are we using "--<option>" to cover all? */
2366        if (!cas->use_tracking_for_rest)
2367                return;
2368
2369        ref->expect_old_sha1 = 1;
2370        if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2371                oidclr(&ref->old_oid_expect);
2372}
2373
2374void apply_push_cas(struct push_cas_option *cas,
2375                    struct remote *remote,
2376                    struct ref *remote_refs)
2377{
2378        struct ref *ref;
2379        for (ref = remote_refs; ref; ref = ref->next)
2380                apply_cas(cas, remote, ref);
2381}