remote.con commit Merge branch 'cb/mkstemps-uint-type-fix' (aa5bec8)
   1#include "cache.h"
   2#include "config.h"
   3#include "remote.h"
   4#include "refs.h"
   5#include "refspec.h"
   6#include "object-store.h"
   7#include "commit.h"
   8#include "diff.h"
   9#include "revision.h"
  10#include "dir.h"
  11#include "tag.h"
  12#include "string-list.h"
  13#include "mergesort.h"
  14#include "argv-array.h"
  15#include "commit-reach.h"
  16#include "advice.h"
  17
  18enum map_direction { FROM_SRC, FROM_DST };
  19
  20struct counted_string {
  21        size_t len;
  22        const char *s;
  23};
  24struct rewrite {
  25        const char *base;
  26        size_t baselen;
  27        struct counted_string *instead_of;
  28        int instead_of_nr;
  29        int instead_of_alloc;
  30};
  31struct rewrites {
  32        struct rewrite **rewrite;
  33        int rewrite_alloc;
  34        int rewrite_nr;
  35};
  36
  37static struct remote **remotes;
  38static int remotes_alloc;
  39static int remotes_nr;
  40static struct hashmap remotes_hash;
  41
  42static struct branch **branches;
  43static int branches_alloc;
  44static int branches_nr;
  45
  46static struct branch *current_branch;
  47static const char *pushremote_name;
  48
  49static struct rewrites rewrites;
  50static struct rewrites rewrites_push;
  51
  52static int valid_remote(const struct remote *remote)
  53{
  54        return (!!remote->url) || (!!remote->foreign_vcs);
  55}
  56
  57static const char *alias_url(const char *url, struct rewrites *r)
  58{
  59        int i, j;
  60        struct counted_string *longest;
  61        int longest_i;
  62
  63        longest = NULL;
  64        longest_i = -1;
  65        for (i = 0; i < r->rewrite_nr; i++) {
  66                if (!r->rewrite[i])
  67                        continue;
  68                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  69                        if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  70                            (!longest ||
  71                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  72                                longest = &(r->rewrite[i]->instead_of[j]);
  73                                longest_i = i;
  74                        }
  75                }
  76        }
  77        if (!longest)
  78                return url;
  79
  80        return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  81}
  82
  83static void add_url(struct remote *remote, const char *url)
  84{
  85        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
  86        remote->url[remote->url_nr++] = url;
  87}
  88
  89static void add_pushurl(struct remote *remote, const char *pushurl)
  90{
  91        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
  92        remote->pushurl[remote->pushurl_nr++] = pushurl;
  93}
  94
  95static void add_pushurl_alias(struct remote *remote, const char *url)
  96{
  97        const char *pushurl = alias_url(url, &rewrites_push);
  98        if (pushurl != url)
  99                add_pushurl(remote, pushurl);
 100}
 101
 102static void add_url_alias(struct remote *remote, const char *url)
 103{
 104        add_url(remote, alias_url(url, &rewrites));
 105        add_pushurl_alias(remote, url);
 106}
 107
 108struct remotes_hash_key {
 109        const char *str;
 110        int len;
 111};
 112
 113static int remotes_hash_cmp(const void *unused_cmp_data,
 114                            const void *entry,
 115                            const void *entry_or_key,
 116                            const void *keydata)
 117{
 118        const struct remote *a = entry;
 119        const struct remote *b = entry_or_key;
 120        const struct remotes_hash_key *key = keydata;
 121
 122        if (key)
 123                return strncmp(a->name, key->str, key->len) || a->name[key->len];
 124        else
 125                return strcmp(a->name, b->name);
 126}
 127
 128static inline void init_remotes_hash(void)
 129{
 130        if (!remotes_hash.cmpfn)
 131                hashmap_init(&remotes_hash, remotes_hash_cmp, NULL, 0);
 132}
 133
 134static struct remote *make_remote(const char *name, int len)
 135{
 136        struct remote *ret, *replaced;
 137        struct remotes_hash_key lookup;
 138        struct hashmap_entry lookup_entry;
 139
 140        if (!len)
 141                len = strlen(name);
 142
 143        init_remotes_hash();
 144        lookup.str = name;
 145        lookup.len = len;
 146        hashmap_entry_init(&lookup_entry, memhash(name, len));
 147
 148        if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 149                return ret;
 150
 151        ret = xcalloc(1, sizeof(struct remote));
 152        ret->prune = -1;  /* unspecified */
 153        ret->prune_tags = -1;  /* unspecified */
 154        ret->name = xstrndup(name, len);
 155        refspec_init(&ret->push, REFSPEC_PUSH);
 156        refspec_init(&ret->fetch, REFSPEC_FETCH);
 157
 158        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 159        remotes[remotes_nr++] = ret;
 160
 161        hashmap_entry_init(ret, lookup_entry.hash);
 162        replaced = hashmap_put(&remotes_hash, ret);
 163        assert(replaced == NULL);  /* no previous entry overwritten */
 164        return ret;
 165}
 166
 167static void add_merge(struct branch *branch, const char *name)
 168{
 169        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 170                   branch->merge_alloc);
 171        branch->merge_name[branch->merge_nr++] = name;
 172}
 173
 174static struct branch *make_branch(const char *name, int len)
 175{
 176        struct branch *ret;
 177        int i;
 178
 179        for (i = 0; i < branches_nr; i++) {
 180                if (len ? (!strncmp(name, branches[i]->name, len) &&
 181                           !branches[i]->name[len]) :
 182                    !strcmp(name, branches[i]->name))
 183                        return branches[i];
 184        }
 185
 186        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 187        ret = xcalloc(1, sizeof(struct branch));
 188        branches[branches_nr++] = ret;
 189        if (len)
 190                ret->name = xstrndup(name, len);
 191        else
 192                ret->name = xstrdup(name);
 193        ret->refname = xstrfmt("refs/heads/%s", ret->name);
 194
 195        return ret;
 196}
 197
 198static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 199{
 200        struct rewrite *ret;
 201        int i;
 202
 203        for (i = 0; i < r->rewrite_nr; i++) {
 204                if (len
 205                    ? (len == r->rewrite[i]->baselen &&
 206                       !strncmp(base, r->rewrite[i]->base, len))
 207                    : !strcmp(base, r->rewrite[i]->base))
 208                        return r->rewrite[i];
 209        }
 210
 211        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 212        ret = xcalloc(1, sizeof(struct rewrite));
 213        r->rewrite[r->rewrite_nr++] = ret;
 214        if (len) {
 215                ret->base = xstrndup(base, len);
 216                ret->baselen = len;
 217        }
 218        else {
 219                ret->base = xstrdup(base);
 220                ret->baselen = strlen(base);
 221        }
 222        return ret;
 223}
 224
 225static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 226{
 227        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 228        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 229        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 230        rewrite->instead_of_nr++;
 231}
 232
 233static const char *skip_spaces(const char *s)
 234{
 235        while (isspace(*s))
 236                s++;
 237        return s;
 238}
 239
 240static void read_remotes_file(struct remote *remote)
 241{
 242        struct strbuf buf = STRBUF_INIT;
 243        FILE *f = fopen_or_warn(git_path("remotes/%s", remote->name), "r");
 244
 245        if (!f)
 246                return;
 247        remote->configured_in_repo = 1;
 248        remote->origin = REMOTE_REMOTES;
 249        while (strbuf_getline(&buf, f) != EOF) {
 250                const char *v;
 251
 252                strbuf_rtrim(&buf);
 253
 254                if (skip_prefix(buf.buf, "URL:", &v))
 255                        add_url_alias(remote, xstrdup(skip_spaces(v)));
 256                else if (skip_prefix(buf.buf, "Push:", &v))
 257                        refspec_append(&remote->push, skip_spaces(v));
 258                else if (skip_prefix(buf.buf, "Pull:", &v))
 259                        refspec_append(&remote->fetch, skip_spaces(v));
 260        }
 261        strbuf_release(&buf);
 262        fclose(f);
 263}
 264
 265static void read_branches_file(struct remote *remote)
 266{
 267        char *frag;
 268        struct strbuf buf = STRBUF_INIT;
 269        FILE *f = fopen_or_warn(git_path("branches/%s", remote->name), "r");
 270
 271        if (!f)
 272                return;
 273
 274        strbuf_getline_lf(&buf, f);
 275        fclose(f);
 276        strbuf_trim(&buf);
 277        if (!buf.len) {
 278                strbuf_release(&buf);
 279                return;
 280        }
 281
 282        remote->configured_in_repo = 1;
 283        remote->origin = REMOTE_BRANCHES;
 284
 285        /*
 286         * The branches file would have URL and optionally
 287         * #branch specified.  The "master" (or specified) branch is
 288         * fetched and stored in the local branch matching the
 289         * remote name.
 290         */
 291        frag = strchr(buf.buf, '#');
 292        if (frag)
 293                *(frag++) = '\0';
 294        else
 295                frag = "master";
 296
 297        add_url_alias(remote, strbuf_detach(&buf, NULL));
 298        strbuf_addf(&buf, "refs/heads/%s:refs/heads/%s",
 299                    frag, remote->name);
 300        refspec_append(&remote->fetch, buf.buf);
 301
 302        /*
 303         * Cogito compatible push: push current HEAD to remote #branch
 304         * (master if missing)
 305         */
 306        strbuf_reset(&buf);
 307        strbuf_addf(&buf, "HEAD:refs/heads/%s", frag);
 308        refspec_append(&remote->push, buf.buf);
 309        remote->fetch_tags = 1; /* always auto-follow */
 310        strbuf_release(&buf);
 311}
 312
 313static int handle_config(const char *key, const char *value, void *cb)
 314{
 315        const char *name;
 316        int namelen;
 317        const char *subkey;
 318        struct remote *remote;
 319        struct branch *branch;
 320        if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
 321                if (!name)
 322                        return 0;
 323                branch = make_branch(name, namelen);
 324                if (!strcmp(subkey, "remote")) {
 325                        return git_config_string(&branch->remote_name, key, value);
 326                } else if (!strcmp(subkey, "pushremote")) {
 327                        return git_config_string(&branch->pushremote_name, key, value);
 328                } else if (!strcmp(subkey, "merge")) {
 329                        if (!value)
 330                                return config_error_nonbool(key);
 331                        add_merge(branch, xstrdup(value));
 332                }
 333                return 0;
 334        }
 335        if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
 336                struct rewrite *rewrite;
 337                if (!name)
 338                        return 0;
 339                if (!strcmp(subkey, "insteadof")) {
 340                        if (!value)
 341                                return config_error_nonbool(key);
 342                        rewrite = make_rewrite(&rewrites, name, namelen);
 343                        add_instead_of(rewrite, xstrdup(value));
 344                } else if (!strcmp(subkey, "pushinsteadof")) {
 345                        if (!value)
 346                                return config_error_nonbool(key);
 347                        rewrite = make_rewrite(&rewrites_push, name, namelen);
 348                        add_instead_of(rewrite, xstrdup(value));
 349                }
 350        }
 351
 352        if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
 353                return 0;
 354
 355        /* Handle remote.* variables */
 356        if (!name && !strcmp(subkey, "pushdefault"))
 357                return git_config_string(&pushremote_name, key, value);
 358
 359        if (!name)
 360                return 0;
 361        /* Handle remote.<name>.* variables */
 362        if (*name == '/') {
 363                warning(_("config remote shorthand cannot begin with '/': %s"),
 364                        name);
 365                return 0;
 366        }
 367        remote = make_remote(name, namelen);
 368        remote->origin = REMOTE_CONFIG;
 369        if (current_config_scope() == CONFIG_SCOPE_REPO)
 370                remote->configured_in_repo = 1;
 371        if (!strcmp(subkey, "mirror"))
 372                remote->mirror = git_config_bool(key, value);
 373        else if (!strcmp(subkey, "skipdefaultupdate"))
 374                remote->skip_default_update = git_config_bool(key, value);
 375        else if (!strcmp(subkey, "skipfetchall"))
 376                remote->skip_default_update = git_config_bool(key, value);
 377        else if (!strcmp(subkey, "prune"))
 378                remote->prune = git_config_bool(key, value);
 379        else if (!strcmp(subkey, "prunetags"))
 380                remote->prune_tags = git_config_bool(key, value);
 381        else if (!strcmp(subkey, "url")) {
 382                const char *v;
 383                if (git_config_string(&v, key, value))
 384                        return -1;
 385                add_url(remote, v);
 386        } else if (!strcmp(subkey, "pushurl")) {
 387                const char *v;
 388                if (git_config_string(&v, key, value))
 389                        return -1;
 390                add_pushurl(remote, v);
 391        } else if (!strcmp(subkey, "push")) {
 392                const char *v;
 393                if (git_config_string(&v, key, value))
 394                        return -1;
 395                refspec_append(&remote->push, v);
 396                free((char *)v);
 397        } else if (!strcmp(subkey, "fetch")) {
 398                const char *v;
 399                if (git_config_string(&v, key, value))
 400                        return -1;
 401                refspec_append(&remote->fetch, v);
 402                free((char *)v);
 403        } else if (!strcmp(subkey, "receivepack")) {
 404                const char *v;
 405                if (git_config_string(&v, key, value))
 406                        return -1;
 407                if (!remote->receivepack)
 408                        remote->receivepack = v;
 409                else
 410                        error(_("more than one receivepack given, using the first"));
 411        } else if (!strcmp(subkey, "uploadpack")) {
 412                const char *v;
 413                if (git_config_string(&v, key, value))
 414                        return -1;
 415                if (!remote->uploadpack)
 416                        remote->uploadpack = v;
 417                else
 418                        error(_("more than one uploadpack given, using the first"));
 419        } else if (!strcmp(subkey, "tagopt")) {
 420                if (!strcmp(value, "--no-tags"))
 421                        remote->fetch_tags = -1;
 422                else if (!strcmp(value, "--tags"))
 423                        remote->fetch_tags = 2;
 424        } else if (!strcmp(subkey, "proxy")) {
 425                return git_config_string((const char **)&remote->http_proxy,
 426                                         key, value);
 427        } else if (!strcmp(subkey, "proxyauthmethod")) {
 428                return git_config_string((const char **)&remote->http_proxy_authmethod,
 429                                         key, value);
 430        } else if (!strcmp(subkey, "vcs")) {
 431                return git_config_string(&remote->foreign_vcs, key, value);
 432        }
 433        return 0;
 434}
 435
 436static void alias_all_urls(void)
 437{
 438        int i, j;
 439        for (i = 0; i < remotes_nr; i++) {
 440                int add_pushurl_aliases;
 441                if (!remotes[i])
 442                        continue;
 443                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 444                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 445                }
 446                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 447                for (j = 0; j < remotes[i]->url_nr; j++) {
 448                        if (add_pushurl_aliases)
 449                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 450                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 451                }
 452        }
 453}
 454
 455static void read_config(void)
 456{
 457        static int loaded;
 458        int flag;
 459
 460        if (loaded)
 461                return;
 462        loaded = 1;
 463
 464        current_branch = NULL;
 465        if (startup_info->have_repository) {
 466                const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
 467                if (head_ref && (flag & REF_ISSYMREF) &&
 468                    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 469                        current_branch = make_branch(head_ref, 0);
 470                }
 471        }
 472        git_config(handle_config, NULL);
 473        alias_all_urls();
 474}
 475
 476static int valid_remote_nick(const char *name)
 477{
 478        if (!name[0] || is_dot_or_dotdot(name))
 479                return 0;
 480
 481        /* remote nicknames cannot contain slashes */
 482        while (*name)
 483                if (is_dir_sep(*name++))
 484                        return 0;
 485        return 1;
 486}
 487
 488const char *remote_for_branch(struct branch *branch, int *explicit)
 489{
 490        if (branch && branch->remote_name) {
 491                if (explicit)
 492                        *explicit = 1;
 493                return branch->remote_name;
 494        }
 495        if (explicit)
 496                *explicit = 0;
 497        return "origin";
 498}
 499
 500const char *pushremote_for_branch(struct branch *branch, int *explicit)
 501{
 502        if (branch && branch->pushremote_name) {
 503                if (explicit)
 504                        *explicit = 1;
 505                return branch->pushremote_name;
 506        }
 507        if (pushremote_name) {
 508                if (explicit)
 509                        *explicit = 1;
 510                return pushremote_name;
 511        }
 512        return remote_for_branch(branch, explicit);
 513}
 514
 515const char *remote_ref_for_branch(struct branch *branch, int for_push,
 516                                  int *explicit)
 517{
 518        if (branch) {
 519                if (!for_push) {
 520                        if (branch->merge_nr) {
 521                                if (explicit)
 522                                        *explicit = 1;
 523                                return branch->merge_name[0];
 524                        }
 525                } else {
 526                        const char *dst, *remote_name =
 527                                pushremote_for_branch(branch, NULL);
 528                        struct remote *remote = remote_get(remote_name);
 529
 530                        if (remote && remote->push.nr &&
 531                            (dst = apply_refspecs(&remote->push,
 532                                                  branch->refname))) {
 533                                if (explicit)
 534                                        *explicit = 1;
 535                                return dst;
 536                        }
 537                }
 538        }
 539        if (explicit)
 540                *explicit = 0;
 541        return "";
 542}
 543
 544static struct remote *remote_get_1(const char *name,
 545                                   const char *(*get_default)(struct branch *, int *))
 546{
 547        struct remote *ret;
 548        int name_given = 0;
 549
 550        read_config();
 551
 552        if (name)
 553                name_given = 1;
 554        else
 555                name = get_default(current_branch, &name_given);
 556
 557        ret = make_remote(name, 0);
 558        if (valid_remote_nick(name) && have_git_dir()) {
 559                if (!valid_remote(ret))
 560                        read_remotes_file(ret);
 561                if (!valid_remote(ret))
 562                        read_branches_file(ret);
 563        }
 564        if (name_given && !valid_remote(ret))
 565                add_url_alias(ret, name);
 566        if (!valid_remote(ret))
 567                return NULL;
 568        return ret;
 569}
 570
 571struct remote *remote_get(const char *name)
 572{
 573        return remote_get_1(name, remote_for_branch);
 574}
 575
 576struct remote *pushremote_get(const char *name)
 577{
 578        return remote_get_1(name, pushremote_for_branch);
 579}
 580
 581int remote_is_configured(struct remote *remote, int in_repo)
 582{
 583        if (!remote)
 584                return 0;
 585        if (in_repo)
 586                return remote->configured_in_repo;
 587        return !!remote->origin;
 588}
 589
 590int for_each_remote(each_remote_fn fn, void *priv)
 591{
 592        int i, result = 0;
 593        read_config();
 594        for (i = 0; i < remotes_nr && !result; i++) {
 595                struct remote *r = remotes[i];
 596                if (!r)
 597                        continue;
 598                result = fn(r, priv);
 599        }
 600        return result;
 601}
 602
 603static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 604{
 605        if (strcmp(ref1->name, ref2->name)) {
 606                if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 607                    ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 608                        die(_("Cannot fetch both %s and %s to %s"),
 609                            ref1->name, ref2->name, ref2->peer_ref->name);
 610                } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 611                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 612                        warning(_("%s usually tracks %s, not %s"),
 613                                ref2->peer_ref->name, ref2->name, ref1->name);
 614                } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 615                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 616                        die(_("%s tracks both %s and %s"),
 617                            ref2->peer_ref->name, ref1->name, ref2->name);
 618                } else {
 619                        /*
 620                         * This last possibility doesn't occur because
 621                         * FETCH_HEAD_IGNORE entries always appear at
 622                         * the end of the list.
 623                         */
 624                        BUG("Internal error");
 625                }
 626        }
 627        free(ref2->peer_ref);
 628        free(ref2);
 629}
 630
 631struct ref *ref_remove_duplicates(struct ref *ref_map)
 632{
 633        struct string_list refs = STRING_LIST_INIT_NODUP;
 634        struct ref *retval = NULL;
 635        struct ref **p = &retval;
 636
 637        while (ref_map) {
 638                struct ref *ref = ref_map;
 639
 640                ref_map = ref_map->next;
 641                ref->next = NULL;
 642
 643                if (!ref->peer_ref) {
 644                        *p = ref;
 645                        p = &ref->next;
 646                } else {
 647                        struct string_list_item *item =
 648                                string_list_insert(&refs, ref->peer_ref->name);
 649
 650                        if (item->util) {
 651                                /* Entry already existed */
 652                                handle_duplicate((struct ref *)item->util, ref);
 653                        } else {
 654                                *p = ref;
 655                                p = &ref->next;
 656                                item->util = ref;
 657                        }
 658                }
 659        }
 660
 661        string_list_clear(&refs, 0);
 662        return retval;
 663}
 664
 665int remote_has_url(struct remote *remote, const char *url)
 666{
 667        int i;
 668        for (i = 0; i < remote->url_nr; i++) {
 669                if (!strcmp(remote->url[i], url))
 670                        return 1;
 671        }
 672        return 0;
 673}
 674
 675static int match_name_with_pattern(const char *key, const char *name,
 676                                   const char *value, char **result)
 677{
 678        const char *kstar = strchr(key, '*');
 679        size_t klen;
 680        size_t ksuffixlen;
 681        size_t namelen;
 682        int ret;
 683        if (!kstar)
 684                die(_("key '%s' of pattern had no '*'"), key);
 685        klen = kstar - key;
 686        ksuffixlen = strlen(kstar + 1);
 687        namelen = strlen(name);
 688        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 689                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 690        if (ret && value) {
 691                struct strbuf sb = STRBUF_INIT;
 692                const char *vstar = strchr(value, '*');
 693                if (!vstar)
 694                        die(_("value '%s' of pattern has no '*'"), value);
 695                strbuf_add(&sb, value, vstar - value);
 696                strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 697                strbuf_addstr(&sb, vstar + 1);
 698                *result = strbuf_detach(&sb, NULL);
 699        }
 700        return ret;
 701}
 702
 703static void query_refspecs_multiple(struct refspec *rs,
 704                                    struct refspec_item *query,
 705                                    struct string_list *results)
 706{
 707        int i;
 708        int find_src = !query->src;
 709
 710        if (find_src && !query->dst)
 711                BUG("query_refspecs_multiple: need either src or dst");
 712
 713        for (i = 0; i < rs->nr; i++) {
 714                struct refspec_item *refspec = &rs->items[i];
 715                const char *key = find_src ? refspec->dst : refspec->src;
 716                const char *value = find_src ? refspec->src : refspec->dst;
 717                const char *needle = find_src ? query->dst : query->src;
 718                char **result = find_src ? &query->src : &query->dst;
 719
 720                if (!refspec->dst)
 721                        continue;
 722                if (refspec->pattern) {
 723                        if (match_name_with_pattern(key, needle, value, result))
 724                                string_list_append_nodup(results, *result);
 725                } else if (!strcmp(needle, key)) {
 726                        string_list_append(results, value);
 727                }
 728        }
 729}
 730
 731int query_refspecs(struct refspec *rs, struct refspec_item *query)
 732{
 733        int i;
 734        int find_src = !query->src;
 735        const char *needle = find_src ? query->dst : query->src;
 736        char **result = find_src ? &query->src : &query->dst;
 737
 738        if (find_src && !query->dst)
 739                BUG("query_refspecs: need either src or dst");
 740
 741        for (i = 0; i < rs->nr; i++) {
 742                struct refspec_item *refspec = &rs->items[i];
 743                const char *key = find_src ? refspec->dst : refspec->src;
 744                const char *value = find_src ? refspec->src : refspec->dst;
 745
 746                if (!refspec->dst)
 747                        continue;
 748                if (refspec->pattern) {
 749                        if (match_name_with_pattern(key, needle, value, result)) {
 750                                query->force = refspec->force;
 751                                return 0;
 752                        }
 753                } else if (!strcmp(needle, key)) {
 754                        *result = xstrdup(value);
 755                        query->force = refspec->force;
 756                        return 0;
 757                }
 758        }
 759        return -1;
 760}
 761
 762char *apply_refspecs(struct refspec *rs, const char *name)
 763{
 764        struct refspec_item query;
 765
 766        memset(&query, 0, sizeof(struct refspec_item));
 767        query.src = (char *)name;
 768
 769        if (query_refspecs(rs, &query))
 770                return NULL;
 771
 772        return query.dst;
 773}
 774
 775int remote_find_tracking(struct remote *remote, struct refspec_item *refspec)
 776{
 777        return query_refspecs(&remote->fetch, refspec);
 778}
 779
 780static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 781                const char *name)
 782{
 783        size_t len = strlen(name);
 784        struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 785        memcpy(ref->name, prefix, prefixlen);
 786        memcpy(ref->name + prefixlen, name, len);
 787        return ref;
 788}
 789
 790struct ref *alloc_ref(const char *name)
 791{
 792        return alloc_ref_with_prefix("", 0, name);
 793}
 794
 795struct ref *copy_ref(const struct ref *ref)
 796{
 797        struct ref *cpy;
 798        size_t len;
 799        if (!ref)
 800                return NULL;
 801        len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 802        cpy = xmalloc(len);
 803        memcpy(cpy, ref, len);
 804        cpy->next = NULL;
 805        cpy->symref = xstrdup_or_null(ref->symref);
 806        cpy->remote_status = xstrdup_or_null(ref->remote_status);
 807        cpy->peer_ref = copy_ref(ref->peer_ref);
 808        return cpy;
 809}
 810
 811struct ref *copy_ref_list(const struct ref *ref)
 812{
 813        struct ref *ret = NULL;
 814        struct ref **tail = &ret;
 815        while (ref) {
 816                *tail = copy_ref(ref);
 817                ref = ref->next;
 818                tail = &((*tail)->next);
 819        }
 820        return ret;
 821}
 822
 823void free_one_ref(struct ref *ref)
 824{
 825        if (!ref)
 826                return;
 827        free_one_ref(ref->peer_ref);
 828        free(ref->remote_status);
 829        free(ref->symref);
 830        free(ref);
 831}
 832
 833void free_refs(struct ref *ref)
 834{
 835        struct ref *next;
 836        while (ref) {
 837                next = ref->next;
 838                free_one_ref(ref);
 839                ref = next;
 840        }
 841}
 842
 843int ref_compare_name(const void *va, const void *vb)
 844{
 845        const struct ref *a = va, *b = vb;
 846        return strcmp(a->name, b->name);
 847}
 848
 849static void *ref_list_get_next(const void *a)
 850{
 851        return ((const struct ref *)a)->next;
 852}
 853
 854static void ref_list_set_next(void *a, void *next)
 855{
 856        ((struct ref *)a)->next = next;
 857}
 858
 859void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 860{
 861        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 862}
 863
 864int count_refspec_match(const char *pattern,
 865                        struct ref *refs,
 866                        struct ref **matched_ref)
 867{
 868        int patlen = strlen(pattern);
 869        struct ref *matched_weak = NULL;
 870        struct ref *matched = NULL;
 871        int weak_match = 0;
 872        int match = 0;
 873
 874        for (weak_match = match = 0; refs; refs = refs->next) {
 875                char *name = refs->name;
 876                int namelen = strlen(name);
 877
 878                if (!refname_match(pattern, name))
 879                        continue;
 880
 881                /* A match is "weak" if it is with refs outside
 882                 * heads or tags, and did not specify the pattern
 883                 * in full (e.g. "refs/remotes/origin/master") or at
 884                 * least from the toplevel (e.g. "remotes/origin/master");
 885                 * otherwise "git push $URL master" would result in
 886                 * ambiguity between remotes/origin/master and heads/master
 887                 * at the remote site.
 888                 */
 889                if (namelen != patlen &&
 890                    patlen != namelen - 5 &&
 891                    !starts_with(name, "refs/heads/") &&
 892                    !starts_with(name, "refs/tags/")) {
 893                        /* We want to catch the case where only weak
 894                         * matches are found and there are multiple
 895                         * matches, and where more than one strong
 896                         * matches are found, as ambiguous.  One
 897                         * strong match with zero or more weak matches
 898                         * are acceptable as a unique match.
 899                         */
 900                        matched_weak = refs;
 901                        weak_match++;
 902                }
 903                else {
 904                        matched = refs;
 905                        match++;
 906                }
 907        }
 908        if (!matched) {
 909                if (matched_ref)
 910                        *matched_ref = matched_weak;
 911                return weak_match;
 912        }
 913        else {
 914                if (matched_ref)
 915                        *matched_ref = matched;
 916                return match;
 917        }
 918}
 919
 920static void tail_link_ref(struct ref *ref, struct ref ***tail)
 921{
 922        **tail = ref;
 923        while (ref->next)
 924                ref = ref->next;
 925        *tail = &ref->next;
 926}
 927
 928static struct ref *alloc_delete_ref(void)
 929{
 930        struct ref *ref = alloc_ref("(delete)");
 931        oidclr(&ref->new_oid);
 932        return ref;
 933}
 934
 935static int try_explicit_object_name(const char *name,
 936                                    struct ref **match)
 937{
 938        struct object_id oid;
 939
 940        if (!*name) {
 941                if (match)
 942                        *match = alloc_delete_ref();
 943                return 0;
 944        }
 945
 946        if (get_oid(name, &oid))
 947                return -1;
 948
 949        if (match) {
 950                *match = alloc_ref(name);
 951                oidcpy(&(*match)->new_oid, &oid);
 952        }
 953        return 0;
 954}
 955
 956static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 957{
 958        struct ref *ret = alloc_ref(name);
 959        tail_link_ref(ret, tail);
 960        return ret;
 961}
 962
 963static char *guess_ref(const char *name, struct ref *peer)
 964{
 965        struct strbuf buf = STRBUF_INIT;
 966
 967        const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
 968                                           NULL, NULL);
 969        if (!r)
 970                return NULL;
 971
 972        if (starts_with(r, "refs/heads/")) {
 973                strbuf_addstr(&buf, "refs/heads/");
 974        } else if (starts_with(r, "refs/tags/")) {
 975                strbuf_addstr(&buf, "refs/tags/");
 976        } else {
 977                return NULL;
 978        }
 979
 980        strbuf_addstr(&buf, name);
 981        return strbuf_detach(&buf, NULL);
 982}
 983
 984static int match_explicit_lhs(struct ref *src,
 985                              struct refspec_item *rs,
 986                              struct ref **match,
 987                              int *allocated_match)
 988{
 989        switch (count_refspec_match(rs->src, src, match)) {
 990        case 1:
 991                if (allocated_match)
 992                        *allocated_match = 0;
 993                return 0;
 994        case 0:
 995                /* The source could be in the get_sha1() format
 996                 * not a reference name.  :refs/other is a
 997                 * way to delete 'other' ref at the remote end.
 998                 */
 999                if (try_explicit_object_name(rs->src, match) < 0)
1000                        return error(_("src refspec %s does not match any"), rs->src);
1001                if (allocated_match)
1002                        *allocated_match = 1;
1003                return 0;
1004        default:
1005                return error(_("src refspec %s matches more than one"), rs->src);
1006        }
1007}
1008
1009static void show_push_unqualified_ref_name_error(const char *dst_value,
1010                                                 const char *matched_src_name)
1011{
1012        struct object_id oid;
1013        enum object_type type;
1014
1015        /*
1016         * TRANSLATORS: "matches '%s'%" is the <dst> part of "git push
1017         * <remote> <src>:<dst>" push, and "being pushed ('%s')" is
1018         * the <src>.
1019         */
1020        error(_("The destination you provided is not a full refname (i.e.,\n"
1021                "starting with \"refs/\"). We tried to guess what you meant by:\n"
1022                "\n"
1023                "- Looking for a ref that matches '%s' on the remote side.\n"
1024                "- Checking if the <src> being pushed ('%s')\n"
1025                "  is a ref in \"refs/{heads,tags}/\". If so we add a corresponding\n"
1026                "  refs/{heads,tags}/ prefix on the remote side.\n"
1027                "\n"
1028                "Neither worked, so we gave up. You must fully qualify the ref."),
1029              dst_value, matched_src_name);
1030
1031        if (!advice_push_unqualified_ref_name)
1032                return;
1033
1034        if (get_oid(matched_src_name, &oid))
1035                BUG("'%s' is not a valid object, "
1036                    "match_explicit_lhs() should catch this!",
1037                    matched_src_name);
1038        type = oid_object_info(the_repository, &oid, NULL);
1039        if (type == OBJ_COMMIT) {
1040                advise(_("The <src> part of the refspec is a commit object.\n"
1041                         "Did you mean to create a new branch by pushing to\n"
1042                         "'%s:refs/heads/%s'?"),
1043                       matched_src_name, dst_value);
1044        } else if (type == OBJ_TAG) {
1045                advise(_("The <src> part of the refspec is a tag object.\n"
1046                         "Did you mean to create a new tag by pushing to\n"
1047                         "'%s:refs/tags/%s'?"),
1048                       matched_src_name, dst_value);
1049        } else if (type == OBJ_TREE) {
1050                advise(_("The <src> part of the refspec is a tree object.\n"
1051                         "Did you mean to tag a new tree by pushing to\n"
1052                         "'%s:refs/tags/%s'?"),
1053                       matched_src_name, dst_value);
1054        } else if (type == OBJ_BLOB) {
1055                advise(_("The <src> part of the refspec is a blob object.\n"
1056                         "Did you mean to tag a new blob by pushing to\n"
1057                         "'%s:refs/tags/%s'?"),
1058                       matched_src_name, dst_value);
1059        } else {
1060                BUG("'%s' should be commit/tag/tree/blob, is '%d'",
1061                    matched_src_name, type);
1062        }
1063}
1064
1065static int match_explicit(struct ref *src, struct ref *dst,
1066                          struct ref ***dst_tail,
1067                          struct refspec_item *rs)
1068{
1069        struct ref *matched_src, *matched_dst;
1070        int allocated_src;
1071
1072        const char *dst_value = rs->dst;
1073        char *dst_guess;
1074
1075        if (rs->pattern || rs->matching)
1076                return 0;
1077
1078        matched_src = matched_dst = NULL;
1079        if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1080                return -1;
1081
1082        if (!dst_value) {
1083                int flag;
1084
1085                dst_value = resolve_ref_unsafe(matched_src->name,
1086                                               RESOLVE_REF_READING,
1087                                               NULL, &flag);
1088                if (!dst_value ||
1089                    ((flag & REF_ISSYMREF) &&
1090                     !starts_with(dst_value, "refs/heads/")))
1091                        die(_("%s cannot be resolved to branch"),
1092                            matched_src->name);
1093        }
1094
1095        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1096        case 1:
1097                break;
1098        case 0:
1099                if (starts_with(dst_value, "refs/")) {
1100                        matched_dst = make_linked_ref(dst_value, dst_tail);
1101                } else if (is_null_oid(&matched_src->new_oid)) {
1102                        error(_("unable to delete '%s': remote ref does not exist"),
1103                              dst_value);
1104                } else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1105                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1106                        free(dst_guess);
1107                } else {
1108                        show_push_unqualified_ref_name_error(dst_value,
1109                                                             matched_src->name);
1110                }
1111                break;
1112        default:
1113                matched_dst = NULL;
1114                error(_("dst refspec %s matches more than one"),
1115                      dst_value);
1116                break;
1117        }
1118        if (!matched_dst)
1119                return -1;
1120        if (matched_dst->peer_ref)
1121                return error(_("dst ref %s receives from more than one src"),
1122                             matched_dst->name);
1123        else {
1124                matched_dst->peer_ref = allocated_src ?
1125                                        matched_src :
1126                                        copy_ref(matched_src);
1127                matched_dst->force = rs->force;
1128        }
1129        return 0;
1130}
1131
1132static int match_explicit_refs(struct ref *src, struct ref *dst,
1133                               struct ref ***dst_tail, struct refspec *rs)
1134{
1135        int i, errs;
1136        for (i = errs = 0; i < rs->nr; i++)
1137                errs += match_explicit(src, dst, dst_tail, &rs->items[i]);
1138        return errs;
1139}
1140
1141static char *get_ref_match(const struct refspec *rs, const struct ref *ref,
1142                           int send_mirror, int direction,
1143                           const struct refspec_item **ret_pat)
1144{
1145        const struct refspec_item *pat;
1146        char *name;
1147        int i;
1148        int matching_refs = -1;
1149        for (i = 0; i < rs->nr; i++) {
1150                const struct refspec_item *item = &rs->items[i];
1151                if (item->matching &&
1152                    (matching_refs == -1 || item->force)) {
1153                        matching_refs = i;
1154                        continue;
1155                }
1156
1157                if (item->pattern) {
1158                        const char *dst_side = item->dst ? item->dst : item->src;
1159                        int match;
1160                        if (direction == FROM_SRC)
1161                                match = match_name_with_pattern(item->src, ref->name, dst_side, &name);
1162                        else
1163                                match = match_name_with_pattern(dst_side, ref->name, item->src, &name);
1164                        if (match) {
1165                                matching_refs = i;
1166                                break;
1167                        }
1168                }
1169        }
1170        if (matching_refs == -1)
1171                return NULL;
1172
1173        pat = &rs->items[matching_refs];
1174        if (pat->matching) {
1175                /*
1176                 * "matching refs"; traditionally we pushed everything
1177                 * including refs outside refs/heads/ hierarchy, but
1178                 * that does not make much sense these days.
1179                 */
1180                if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1181                        return NULL;
1182                name = xstrdup(ref->name);
1183        }
1184        if (ret_pat)
1185                *ret_pat = pat;
1186        return name;
1187}
1188
1189static struct ref **tail_ref(struct ref **head)
1190{
1191        struct ref **tail = head;
1192        while (*tail)
1193                tail = &((*tail)->next);
1194        return tail;
1195}
1196
1197struct tips {
1198        struct commit **tip;
1199        int nr, alloc;
1200};
1201
1202static void add_to_tips(struct tips *tips, const struct object_id *oid)
1203{
1204        struct commit *commit;
1205
1206        if (is_null_oid(oid))
1207                return;
1208        commit = lookup_commit_reference_gently(the_repository, oid, 1);
1209        if (!commit || (commit->object.flags & TMP_MARK))
1210                return;
1211        commit->object.flags |= TMP_MARK;
1212        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1213        tips->tip[tips->nr++] = commit;
1214}
1215
1216static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1217{
1218        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1219        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1220        struct string_list_item *item;
1221        struct ref *ref;
1222        struct tips sent_tips;
1223
1224        /*
1225         * Collect everything we know they would have at the end of
1226         * this push, and collect all tags they have.
1227         */
1228        memset(&sent_tips, 0, sizeof(sent_tips));
1229        for (ref = *dst; ref; ref = ref->next) {
1230                if (ref->peer_ref &&
1231                    !is_null_oid(&ref->peer_ref->new_oid))
1232                        add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1233                else
1234                        add_to_tips(&sent_tips, &ref->old_oid);
1235                if (starts_with(ref->name, "refs/tags/"))
1236                        string_list_append(&dst_tag, ref->name);
1237        }
1238        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1239
1240        string_list_sort(&dst_tag);
1241
1242        /* Collect tags they do not have. */
1243        for (ref = src; ref; ref = ref->next) {
1244                if (!starts_with(ref->name, "refs/tags/"))
1245                        continue; /* not a tag */
1246                if (string_list_has_string(&dst_tag, ref->name))
1247                        continue; /* they already have it */
1248                if (oid_object_info(the_repository, &ref->new_oid, NULL) != OBJ_TAG)
1249                        continue; /* be conservative */
1250                item = string_list_append(&src_tag, ref->name);
1251                item->util = ref;
1252        }
1253        string_list_clear(&dst_tag, 0);
1254
1255        /*
1256         * At this point, src_tag lists tags that are missing from
1257         * dst, and sent_tips lists the tips we are pushing or those
1258         * that we know they already have. An element in the src_tag
1259         * that is an ancestor of any of the sent_tips needs to be
1260         * sent to the other side.
1261         */
1262        if (sent_tips.nr) {
1263                const int reachable_flag = 1;
1264                struct commit_list *found_commits;
1265                struct commit **src_commits;
1266                int nr_src_commits = 0, alloc_src_commits = 16;
1267                ALLOC_ARRAY(src_commits, alloc_src_commits);
1268
1269                for_each_string_list_item(item, &src_tag) {
1270                        struct ref *ref = item->util;
1271                        struct commit *commit;
1272
1273                        if (is_null_oid(&ref->new_oid))
1274                                continue;
1275                        commit = lookup_commit_reference_gently(the_repository,
1276                                                                &ref->new_oid,
1277                                                                1);
1278                        if (!commit)
1279                                /* not pushing a commit, which is not an error */
1280                                continue;
1281
1282                        ALLOC_GROW(src_commits, nr_src_commits + 1, alloc_src_commits);
1283                        src_commits[nr_src_commits++] = commit;
1284                }
1285
1286                found_commits = get_reachable_subset(sent_tips.tip, sent_tips.nr,
1287                                                     src_commits, nr_src_commits,
1288                                                     reachable_flag);
1289
1290                for_each_string_list_item(item, &src_tag) {
1291                        struct ref *dst_ref;
1292                        struct ref *ref = item->util;
1293                        struct commit *commit;
1294
1295                        if (is_null_oid(&ref->new_oid))
1296                                continue;
1297                        commit = lookup_commit_reference_gently(the_repository,
1298                                                                &ref->new_oid,
1299                                                                1);
1300                        if (!commit)
1301                                /* not pushing a commit, which is not an error */
1302                                continue;
1303
1304                        /*
1305                         * Is this tag, which they do not have, reachable from
1306                         * any of the commits we are sending?
1307                         */
1308                        if (!(commit->object.flags & reachable_flag))
1309                                continue;
1310
1311                        /* Add it in */
1312                        dst_ref = make_linked_ref(ref->name, dst_tail);
1313                        oidcpy(&dst_ref->new_oid, &ref->new_oid);
1314                        dst_ref->peer_ref = copy_ref(ref);
1315                }
1316
1317                clear_commit_marks_many(nr_src_commits, src_commits, reachable_flag);
1318                free(src_commits);
1319                free_commit_list(found_commits);
1320        }
1321
1322        string_list_clear(&src_tag, 0);
1323        free(sent_tips.tip);
1324}
1325
1326struct ref *find_ref_by_name(const struct ref *list, const char *name)
1327{
1328        for ( ; list; list = list->next)
1329                if (!strcmp(list->name, name))
1330                        return (struct ref *)list;
1331        return NULL;
1332}
1333
1334static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1335{
1336        for ( ; ref; ref = ref->next)
1337                string_list_append_nodup(ref_index, ref->name)->util = ref;
1338
1339        string_list_sort(ref_index);
1340}
1341
1342/*
1343 * Given only the set of local refs, sanity-check the set of push
1344 * refspecs. We can't catch all errors that match_push_refs would,
1345 * but we can catch some errors early before even talking to the
1346 * remote side.
1347 */
1348int check_push_refs(struct ref *src, struct refspec *rs)
1349{
1350        int ret = 0;
1351        int i;
1352
1353        for (i = 0; i < rs->nr; i++) {
1354                struct refspec_item *item = &rs->items[i];
1355
1356                if (item->pattern || item->matching)
1357                        continue;
1358
1359                ret |= match_explicit_lhs(src, item, NULL, NULL);
1360        }
1361
1362        return ret;
1363}
1364
1365/*
1366 * Given the set of refs the local repository has, the set of refs the
1367 * remote repository has, and the refspec used for push, determine
1368 * what remote refs we will update and with what value by setting
1369 * peer_ref (which object is being pushed) and force (if the push is
1370 * forced) in elements of "dst". The function may add new elements to
1371 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1372 */
1373int match_push_refs(struct ref *src, struct ref **dst,
1374                    struct refspec *rs, int flags)
1375{
1376        int send_all = flags & MATCH_REFS_ALL;
1377        int send_mirror = flags & MATCH_REFS_MIRROR;
1378        int send_prune = flags & MATCH_REFS_PRUNE;
1379        int errs;
1380        struct ref *ref, **dst_tail = tail_ref(dst);
1381        struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1382
1383        /* If no refspec is provided, use the default ":" */
1384        if (!rs->nr)
1385                refspec_append(rs, ":");
1386
1387        errs = match_explicit_refs(src, *dst, &dst_tail, rs);
1388
1389        /* pick the remainder */
1390        for (ref = src; ref; ref = ref->next) {
1391                struct string_list_item *dst_item;
1392                struct ref *dst_peer;
1393                const struct refspec_item *pat = NULL;
1394                char *dst_name;
1395
1396                dst_name = get_ref_match(rs, ref, send_mirror, FROM_SRC, &pat);
1397                if (!dst_name)
1398                        continue;
1399
1400                if (!dst_ref_index.nr)
1401                        prepare_ref_index(&dst_ref_index, *dst);
1402
1403                dst_item = string_list_lookup(&dst_ref_index, dst_name);
1404                dst_peer = dst_item ? dst_item->util : NULL;
1405                if (dst_peer) {
1406                        if (dst_peer->peer_ref)
1407                                /* We're already sending something to this ref. */
1408                                goto free_name;
1409                } else {
1410                        if (pat->matching && !(send_all || send_mirror))
1411                                /*
1412                                 * Remote doesn't have it, and we have no
1413                                 * explicit pattern, and we don't have
1414                                 * --all or --mirror.
1415                                 */
1416                                goto free_name;
1417
1418                        /* Create a new one and link it */
1419                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1420                        oidcpy(&dst_peer->new_oid, &ref->new_oid);
1421                        string_list_insert(&dst_ref_index,
1422                                dst_peer->name)->util = dst_peer;
1423                }
1424                dst_peer->peer_ref = copy_ref(ref);
1425                dst_peer->force = pat->force;
1426        free_name:
1427                free(dst_name);
1428        }
1429
1430        string_list_clear(&dst_ref_index, 0);
1431
1432        if (flags & MATCH_REFS_FOLLOW_TAGS)
1433                add_missing_tags(src, dst, &dst_tail);
1434
1435        if (send_prune) {
1436                struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1437                /* check for missing refs on the remote */
1438                for (ref = *dst; ref; ref = ref->next) {
1439                        char *src_name;
1440
1441                        if (ref->peer_ref)
1442                                /* We're already sending something to this ref. */
1443                                continue;
1444
1445                        src_name = get_ref_match(rs, ref, send_mirror, FROM_DST, NULL);
1446                        if (src_name) {
1447                                if (!src_ref_index.nr)
1448                                        prepare_ref_index(&src_ref_index, src);
1449                                if (!string_list_has_string(&src_ref_index,
1450                                            src_name))
1451                                        ref->peer_ref = alloc_delete_ref();
1452                                free(src_name);
1453                        }
1454                }
1455                string_list_clear(&src_ref_index, 0);
1456        }
1457
1458        if (errs)
1459                return -1;
1460        return 0;
1461}
1462
1463void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1464                             int force_update)
1465{
1466        struct ref *ref;
1467
1468        for (ref = remote_refs; ref; ref = ref->next) {
1469                int force_ref_update = ref->force || force_update;
1470                int reject_reason = 0;
1471
1472                if (ref->peer_ref)
1473                        oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1474                else if (!send_mirror)
1475                        continue;
1476
1477                ref->deletion = is_null_oid(&ref->new_oid);
1478                if (!ref->deletion &&
1479                        oideq(&ref->old_oid, &ref->new_oid)) {
1480                        ref->status = REF_STATUS_UPTODATE;
1481                        continue;
1482                }
1483
1484                /*
1485                 * If the remote ref has moved and is now different
1486                 * from what we expect, reject any push.
1487                 *
1488                 * It also is an error if the user told us to check
1489                 * with the remote-tracking branch to find the value
1490                 * to expect, but we did not have such a tracking
1491                 * branch.
1492                 */
1493                if (ref->expect_old_sha1) {
1494                        if (!oideq(&ref->old_oid, &ref->old_oid_expect))
1495                                reject_reason = REF_STATUS_REJECT_STALE;
1496                        else
1497                                /* If the ref isn't stale then force the update. */
1498                                force_ref_update = 1;
1499                }
1500
1501                /*
1502                 * If the update isn't already rejected then check
1503                 * the usual "must fast-forward" rules.
1504                 *
1505                 * Decide whether an individual refspec A:B can be
1506                 * pushed.  The push will succeed if any of the
1507                 * following are true:
1508                 *
1509                 * (1) the remote reference B does not exist
1510                 *
1511                 * (2) the remote reference B is being removed (i.e.,
1512                 *     pushing :B where no source is specified)
1513                 *
1514                 * (3) the destination is not under refs/tags/, and
1515                 *     if the old and new value is a commit, the new
1516                 *     is a descendant of the old.
1517                 *
1518                 * (4) it is forced using the +A:B notation, or by
1519                 *     passing the --force argument
1520                 */
1521
1522                if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1523                        if (starts_with(ref->name, "refs/tags/"))
1524                                reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1525                        else if (!has_object_file(&ref->old_oid))
1526                                reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1527                        else if (!lookup_commit_reference_gently(the_repository, &ref->old_oid, 1) ||
1528                                 !lookup_commit_reference_gently(the_repository, &ref->new_oid, 1))
1529                                reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1530                        else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1531                                reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1532                }
1533
1534                /*
1535                 * "--force" will defeat any rejection implemented
1536                 * by the rules above.
1537                 */
1538                if (!force_ref_update)
1539                        ref->status = reject_reason;
1540                else if (reject_reason)
1541                        ref->forced_update = 1;
1542        }
1543}
1544
1545static void set_merge(struct branch *ret)
1546{
1547        struct remote *remote;
1548        char *ref;
1549        struct object_id oid;
1550        int i;
1551
1552        if (!ret)
1553                return; /* no branch */
1554        if (ret->merge)
1555                return; /* already run */
1556        if (!ret->remote_name || !ret->merge_nr) {
1557                /*
1558                 * no merge config; let's make sure we don't confuse callers
1559                 * with a non-zero merge_nr but a NULL merge
1560                 */
1561                ret->merge_nr = 0;
1562                return;
1563        }
1564
1565        remote = remote_get(ret->remote_name);
1566
1567        ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1568        for (i = 0; i < ret->merge_nr; i++) {
1569                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1570                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1571                if (!remote_find_tracking(remote, ret->merge[i]) ||
1572                    strcmp(ret->remote_name, "."))
1573                        continue;
1574                if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1575                             &oid, &ref) == 1)
1576                        ret->merge[i]->dst = ref;
1577                else
1578                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1579        }
1580}
1581
1582struct branch *branch_get(const char *name)
1583{
1584        struct branch *ret;
1585
1586        read_config();
1587        if (!name || !*name || !strcmp(name, "HEAD"))
1588                ret = current_branch;
1589        else
1590                ret = make_branch(name, 0);
1591        set_merge(ret);
1592        return ret;
1593}
1594
1595int branch_has_merge_config(struct branch *branch)
1596{
1597        return branch && !!branch->merge;
1598}
1599
1600int branch_merge_matches(struct branch *branch,
1601                                 int i,
1602                                 const char *refname)
1603{
1604        if (!branch || i < 0 || i >= branch->merge_nr)
1605                return 0;
1606        return refname_match(branch->merge[i]->src, refname);
1607}
1608
1609__attribute__((format (printf,2,3)))
1610static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1611{
1612        if (err) {
1613                va_list ap;
1614                va_start(ap, fmt);
1615                strbuf_vaddf(err, fmt, ap);
1616                va_end(ap);
1617        }
1618        return NULL;
1619}
1620
1621const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1622{
1623        if (!branch)
1624                return error_buf(err, _("HEAD does not point to a branch"));
1625
1626        if (!branch->merge || !branch->merge[0]) {
1627                /*
1628                 * no merge config; is it because the user didn't define any,
1629                 * or because it is not a real branch, and get_branch
1630                 * auto-vivified it?
1631                 */
1632                if (!ref_exists(branch->refname))
1633                        return error_buf(err, _("no such branch: '%s'"),
1634                                         branch->name);
1635                return error_buf(err,
1636                                 _("no upstream configured for branch '%s'"),
1637                                 branch->name);
1638        }
1639
1640        if (!branch->merge[0]->dst)
1641                return error_buf(err,
1642                                 _("upstream branch '%s' not stored as a remote-tracking branch"),
1643                                 branch->merge[0]->src);
1644
1645        return branch->merge[0]->dst;
1646}
1647
1648static const char *tracking_for_push_dest(struct remote *remote,
1649                                          const char *refname,
1650                                          struct strbuf *err)
1651{
1652        char *ret;
1653
1654        ret = apply_refspecs(&remote->fetch, refname);
1655        if (!ret)
1656                return error_buf(err,
1657                                 _("push destination '%s' on remote '%s' has no local tracking branch"),
1658                                 refname, remote->name);
1659        return ret;
1660}
1661
1662static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1663{
1664        struct remote *remote;
1665
1666        remote = remote_get(pushremote_for_branch(branch, NULL));
1667        if (!remote)
1668                return error_buf(err,
1669                                 _("branch '%s' has no remote for pushing"),
1670                                 branch->name);
1671
1672        if (remote->push.nr) {
1673                char *dst;
1674                const char *ret;
1675
1676                dst = apply_refspecs(&remote->push, branch->refname);
1677                if (!dst)
1678                        return error_buf(err,
1679                                         _("push refspecs for '%s' do not include '%s'"),
1680                                         remote->name, branch->name);
1681
1682                ret = tracking_for_push_dest(remote, dst, err);
1683                free(dst);
1684                return ret;
1685        }
1686
1687        if (remote->mirror)
1688                return tracking_for_push_dest(remote, branch->refname, err);
1689
1690        switch (push_default) {
1691        case PUSH_DEFAULT_NOTHING:
1692                return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1693
1694        case PUSH_DEFAULT_MATCHING:
1695        case PUSH_DEFAULT_CURRENT:
1696                return tracking_for_push_dest(remote, branch->refname, err);
1697
1698        case PUSH_DEFAULT_UPSTREAM:
1699                return branch_get_upstream(branch, err);
1700
1701        case PUSH_DEFAULT_UNSPECIFIED:
1702        case PUSH_DEFAULT_SIMPLE:
1703                {
1704                        const char *up, *cur;
1705
1706                        up = branch_get_upstream(branch, err);
1707                        if (!up)
1708                                return NULL;
1709                        cur = tracking_for_push_dest(remote, branch->refname, err);
1710                        if (!cur)
1711                                return NULL;
1712                        if (strcmp(cur, up))
1713                                return error_buf(err,
1714                                                 _("cannot resolve 'simple' push to a single destination"));
1715                        return cur;
1716                }
1717        }
1718
1719        BUG("unhandled push situation");
1720}
1721
1722const char *branch_get_push(struct branch *branch, struct strbuf *err)
1723{
1724        if (!branch)
1725                return error_buf(err, _("HEAD does not point to a branch"));
1726
1727        if (!branch->push_tracking_ref)
1728                branch->push_tracking_ref = branch_get_push_1(branch, err);
1729        return branch->push_tracking_ref;
1730}
1731
1732static int ignore_symref_update(const char *refname)
1733{
1734        int flag;
1735
1736        if (!resolve_ref_unsafe(refname, 0, NULL, &flag))
1737                return 0; /* non-existing refs are OK */
1738        return (flag & REF_ISSYMREF);
1739}
1740
1741/*
1742 * Create and return a list of (struct ref) consisting of copies of
1743 * each remote_ref that matches refspec.  refspec must be a pattern.
1744 * Fill in the copies' peer_ref to describe the local tracking refs to
1745 * which they map.  Omit any references that would map to an existing
1746 * local symbolic ref.
1747 */
1748static struct ref *get_expanded_map(const struct ref *remote_refs,
1749                                    const struct refspec_item *refspec)
1750{
1751        const struct ref *ref;
1752        struct ref *ret = NULL;
1753        struct ref **tail = &ret;
1754
1755        for (ref = remote_refs; ref; ref = ref->next) {
1756                char *expn_name = NULL;
1757
1758                if (strchr(ref->name, '^'))
1759                        continue; /* a dereference item */
1760                if (match_name_with_pattern(refspec->src, ref->name,
1761                                            refspec->dst, &expn_name) &&
1762                    !ignore_symref_update(expn_name)) {
1763                        struct ref *cpy = copy_ref(ref);
1764
1765                        cpy->peer_ref = alloc_ref(expn_name);
1766                        if (refspec->force)
1767                                cpy->peer_ref->force = 1;
1768                        *tail = cpy;
1769                        tail = &cpy->next;
1770                }
1771                free(expn_name);
1772        }
1773
1774        return ret;
1775}
1776
1777static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1778{
1779        const struct ref *ref;
1780        const struct ref *best_match = NULL;
1781        int best_score = 0;
1782
1783        for (ref = refs; ref; ref = ref->next) {
1784                int score = refname_match(name, ref->name);
1785
1786                if (best_score < score) {
1787                        best_match = ref;
1788                        best_score = score;
1789                }
1790        }
1791        return best_match;
1792}
1793
1794struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1795{
1796        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1797
1798        if (!ref)
1799                return NULL;
1800
1801        return copy_ref(ref);
1802}
1803
1804static struct ref *get_local_ref(const char *name)
1805{
1806        if (!name || name[0] == '\0')
1807                return NULL;
1808
1809        if (starts_with(name, "refs/"))
1810                return alloc_ref(name);
1811
1812        if (starts_with(name, "heads/") ||
1813            starts_with(name, "tags/") ||
1814            starts_with(name, "remotes/"))
1815                return alloc_ref_with_prefix("refs/", 5, name);
1816
1817        return alloc_ref_with_prefix("refs/heads/", 11, name);
1818}
1819
1820int get_fetch_map(const struct ref *remote_refs,
1821                  const struct refspec_item *refspec,
1822                  struct ref ***tail,
1823                  int missing_ok)
1824{
1825        struct ref *ref_map, **rmp;
1826
1827        if (refspec->pattern) {
1828                ref_map = get_expanded_map(remote_refs, refspec);
1829        } else {
1830                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1831
1832                if (refspec->exact_sha1) {
1833                        ref_map = alloc_ref(name);
1834                        get_oid_hex(name, &ref_map->old_oid);
1835                        ref_map->exact_oid = 1;
1836                } else {
1837                        ref_map = get_remote_ref(remote_refs, name);
1838                }
1839                if (!missing_ok && !ref_map)
1840                        die(_("couldn't find remote ref %s"), name);
1841                if (ref_map) {
1842                        ref_map->peer_ref = get_local_ref(refspec->dst);
1843                        if (ref_map->peer_ref && refspec->force)
1844                                ref_map->peer_ref->force = 1;
1845                }
1846        }
1847
1848        for (rmp = &ref_map; *rmp; ) {
1849                if ((*rmp)->peer_ref) {
1850                        if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1851                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1852                                struct ref *ignore = *rmp;
1853                                error(_("* Ignoring funny ref '%s' locally"),
1854                                      (*rmp)->peer_ref->name);
1855                                *rmp = (*rmp)->next;
1856                                free(ignore->peer_ref);
1857                                free(ignore);
1858                                continue;
1859                        }
1860                }
1861                rmp = &((*rmp)->next);
1862        }
1863
1864        if (ref_map)
1865                tail_link_ref(ref_map, tail);
1866
1867        return 0;
1868}
1869
1870int resolve_remote_symref(struct ref *ref, struct ref *list)
1871{
1872        if (!ref->symref)
1873                return 0;
1874        for (; list; list = list->next)
1875                if (!strcmp(ref->symref, list->name)) {
1876                        oidcpy(&ref->old_oid, &list->old_oid);
1877                        return 0;
1878                }
1879        return 1;
1880}
1881
1882/*
1883 * Compute the commit ahead/behind values for the pair branch_name, base.
1884 *
1885 * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
1886 * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
1887 * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
1888 * set to zero).
1889 *
1890 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., ref
1891 * does not exist).  Returns 0 if the commits are identical.  Returns 1 if
1892 * commits are different.
1893 */
1894
1895static int stat_branch_pair(const char *branch_name, const char *base,
1896                             int *num_ours, int *num_theirs,
1897                             enum ahead_behind_flags abf)
1898{
1899        struct object_id oid;
1900        struct commit *ours, *theirs;
1901        struct rev_info revs;
1902        struct argv_array argv = ARGV_ARRAY_INIT;
1903
1904        /* Cannot stat if what we used to build on no longer exists */
1905        if (read_ref(base, &oid))
1906                return -1;
1907        theirs = lookup_commit_reference(the_repository, &oid);
1908        if (!theirs)
1909                return -1;
1910
1911        if (read_ref(branch_name, &oid))
1912                return -1;
1913        ours = lookup_commit_reference(the_repository, &oid);
1914        if (!ours)
1915                return -1;
1916
1917        *num_theirs = *num_ours = 0;
1918
1919        /* are we the same? */
1920        if (theirs == ours)
1921                return 0;
1922        if (abf == AHEAD_BEHIND_QUICK)
1923                return 1;
1924        if (abf != AHEAD_BEHIND_FULL)
1925                BUG("stat_branch_pair: invalid abf '%d'", abf);
1926
1927        /* Run "rev-list --left-right ours...theirs" internally... */
1928        argv_array_push(&argv, ""); /* ignored */
1929        argv_array_push(&argv, "--left-right");
1930        argv_array_pushf(&argv, "%s...%s",
1931                         oid_to_hex(&ours->object.oid),
1932                         oid_to_hex(&theirs->object.oid));
1933        argv_array_push(&argv, "--");
1934
1935        repo_init_revisions(the_repository, &revs, NULL);
1936        setup_revisions(argv.argc, argv.argv, &revs, NULL);
1937        if (prepare_revision_walk(&revs))
1938                die(_("revision walk setup failed"));
1939
1940        /* ... and count the commits on each side. */
1941        while (1) {
1942                struct commit *c = get_revision(&revs);
1943                if (!c)
1944                        break;
1945                if (c->object.flags & SYMMETRIC_LEFT)
1946                        (*num_ours)++;
1947                else
1948                        (*num_theirs)++;
1949        }
1950
1951        /* clear object flags smudged by the above traversal */
1952        clear_commit_marks(ours, ALL_REV_FLAGS);
1953        clear_commit_marks(theirs, ALL_REV_FLAGS);
1954
1955        argv_array_clear(&argv);
1956        return 1;
1957}
1958
1959/*
1960 * Lookup the tracking branch for the given branch and if present, optionally
1961 * compute the commit ahead/behind values for the pair.
1962 *
1963 * If for_push is true, the tracking branch refers to the push branch,
1964 * otherwise it refers to the upstream branch.
1965 *
1966 * The name of the tracking branch (or NULL if it is not defined) is
1967 * returned via *tracking_name, if it is not itself NULL.
1968 *
1969 * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
1970 * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
1971 * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
1972 * set to zero).
1973 *
1974 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1975 * upstream defined, or ref does not exist).  Returns 0 if the commits are
1976 * identical.  Returns 1 if commits are different.
1977 */
1978int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
1979                       const char **tracking_name, int for_push,
1980                       enum ahead_behind_flags abf)
1981{
1982        const char *base;
1983
1984        /* Cannot stat unless we are marked to build on top of somebody else. */
1985        base = for_push ? branch_get_push(branch, NULL) :
1986                branch_get_upstream(branch, NULL);
1987        if (tracking_name)
1988                *tracking_name = base;
1989        if (!base)
1990                return -1;
1991
1992        return stat_branch_pair(branch->refname, base, num_ours, num_theirs, abf);
1993}
1994
1995/*
1996 * Return true when there is anything to report, otherwise false.
1997 */
1998int format_tracking_info(struct branch *branch, struct strbuf *sb,
1999                         enum ahead_behind_flags abf)
2000{
2001        int ours, theirs, sti;
2002        const char *full_base;
2003        char *base;
2004        int upstream_is_gone = 0;
2005
2006        sti = stat_tracking_info(branch, &ours, &theirs, &full_base, 0, abf);
2007        if (sti < 0) {
2008                if (!full_base)
2009                        return 0;
2010                upstream_is_gone = 1;
2011        }
2012
2013        base = shorten_unambiguous_ref(full_base, 0);
2014        if (upstream_is_gone) {
2015                strbuf_addf(sb,
2016                        _("Your branch is based on '%s', but the upstream is gone.\n"),
2017                        base);
2018                if (advice_status_hints)
2019                        strbuf_addstr(sb,
2020                                _("  (use \"git branch --unset-upstream\" to fixup)\n"));
2021        } else if (!sti) {
2022                strbuf_addf(sb,
2023                        _("Your branch is up to date with '%s'.\n"),
2024                        base);
2025        } else if (abf == AHEAD_BEHIND_QUICK) {
2026                strbuf_addf(sb,
2027                            _("Your branch and '%s' refer to different commits.\n"),
2028                            base);
2029                if (advice_status_hints)
2030                        strbuf_addf(sb, _("  (use \"%s\" for details)\n"),
2031                                    "git status --ahead-behind");
2032        } else if (!theirs) {
2033                strbuf_addf(sb,
2034                        Q_("Your branch is ahead of '%s' by %d commit.\n",
2035                           "Your branch is ahead of '%s' by %d commits.\n",
2036                           ours),
2037                        base, ours);
2038                if (advice_status_hints)
2039                        strbuf_addstr(sb,
2040                                _("  (use \"git push\" to publish your local commits)\n"));
2041        } else if (!ours) {
2042                strbuf_addf(sb,
2043                        Q_("Your branch is behind '%s' by %d commit, "
2044                               "and can be fast-forwarded.\n",
2045                           "Your branch is behind '%s' by %d commits, "
2046                               "and can be fast-forwarded.\n",
2047                           theirs),
2048                        base, theirs);
2049                if (advice_status_hints)
2050                        strbuf_addstr(sb,
2051                                _("  (use \"git pull\" to update your local branch)\n"));
2052        } else {
2053                strbuf_addf(sb,
2054                        Q_("Your branch and '%s' have diverged,\n"
2055                               "and have %d and %d different commit each, "
2056                               "respectively.\n",
2057                           "Your branch and '%s' have diverged,\n"
2058                               "and have %d and %d different commits each, "
2059                               "respectively.\n",
2060                           ours + theirs),
2061                        base, ours, theirs);
2062                if (advice_status_hints)
2063                        strbuf_addstr(sb,
2064                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2065        }
2066        free(base);
2067        return 1;
2068}
2069
2070static int one_local_ref(const char *refname, const struct object_id *oid,
2071                         int flag, void *cb_data)
2072{
2073        struct ref ***local_tail = cb_data;
2074        struct ref *ref;
2075
2076        /* we already know it starts with refs/ to get here */
2077        if (check_refname_format(refname + 5, 0))
2078                return 0;
2079
2080        ref = alloc_ref(refname);
2081        oidcpy(&ref->new_oid, oid);
2082        **local_tail = ref;
2083        *local_tail = &ref->next;
2084        return 0;
2085}
2086
2087struct ref *get_local_heads(void)
2088{
2089        struct ref *local_refs = NULL, **local_tail = &local_refs;
2090
2091        for_each_ref(one_local_ref, &local_tail);
2092        return local_refs;
2093}
2094
2095struct ref *guess_remote_head(const struct ref *head,
2096                              const struct ref *refs,
2097                              int all)
2098{
2099        const struct ref *r;
2100        struct ref *list = NULL;
2101        struct ref **tail = &list;
2102
2103        if (!head)
2104                return NULL;
2105
2106        /*
2107         * Some transports support directly peeking at
2108         * where HEAD points; if that is the case, then
2109         * we don't have to guess.
2110         */
2111        if (head->symref)
2112                return copy_ref(find_ref_by_name(refs, head->symref));
2113
2114        /* If refs/heads/master could be right, it is. */
2115        if (!all) {
2116                r = find_ref_by_name(refs, "refs/heads/master");
2117                if (r && oideq(&r->old_oid, &head->old_oid))
2118                        return copy_ref(r);
2119        }
2120
2121        /* Look for another ref that points there */
2122        for (r = refs; r; r = r->next) {
2123                if (r != head &&
2124                    starts_with(r->name, "refs/heads/") &&
2125                    oideq(&r->old_oid, &head->old_oid)) {
2126                        *tail = copy_ref(r);
2127                        tail = &((*tail)->next);
2128                        if (!all)
2129                                break;
2130                }
2131        }
2132
2133        return list;
2134}
2135
2136struct stale_heads_info {
2137        struct string_list *ref_names;
2138        struct ref **stale_refs_tail;
2139        struct refspec *rs;
2140};
2141
2142static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2143                              int flags, void *cb_data)
2144{
2145        struct stale_heads_info *info = cb_data;
2146        struct string_list matches = STRING_LIST_INIT_DUP;
2147        struct refspec_item query;
2148        int i, stale = 1;
2149        memset(&query, 0, sizeof(struct refspec_item));
2150        query.dst = (char *)refname;
2151
2152        query_refspecs_multiple(info->rs, &query, &matches);
2153        if (matches.nr == 0)
2154                goto clean_exit; /* No matches */
2155
2156        /*
2157         * If we did find a suitable refspec and it's not a symref and
2158         * it's not in the list of refs that currently exist in that
2159         * remote, we consider it to be stale. In order to deal with
2160         * overlapping refspecs, we need to go over all of the
2161         * matching refs.
2162         */
2163        if (flags & REF_ISSYMREF)
2164                goto clean_exit;
2165
2166        for (i = 0; stale && i < matches.nr; i++)
2167                if (string_list_has_string(info->ref_names, matches.items[i].string))
2168                        stale = 0;
2169
2170        if (stale) {
2171                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2172                oidcpy(&ref->new_oid, oid);
2173        }
2174
2175clean_exit:
2176        string_list_clear(&matches, 0);
2177        return 0;
2178}
2179
2180struct ref *get_stale_heads(struct refspec *rs, struct ref *fetch_map)
2181{
2182        struct ref *ref, *stale_refs = NULL;
2183        struct string_list ref_names = STRING_LIST_INIT_NODUP;
2184        struct stale_heads_info info;
2185
2186        info.ref_names = &ref_names;
2187        info.stale_refs_tail = &stale_refs;
2188        info.rs = rs;
2189        for (ref = fetch_map; ref; ref = ref->next)
2190                string_list_append(&ref_names, ref->name);
2191        string_list_sort(&ref_names);
2192        for_each_ref(get_stale_heads_cb, &info);
2193        string_list_clear(&ref_names, 0);
2194        return stale_refs;
2195}
2196
2197/*
2198 * Compare-and-swap
2199 */
2200static void clear_cas_option(struct push_cas_option *cas)
2201{
2202        int i;
2203
2204        for (i = 0; i < cas->nr; i++)
2205                free(cas->entry[i].refname);
2206        free(cas->entry);
2207        memset(cas, 0, sizeof(*cas));
2208}
2209
2210static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2211                                      const char *refname,
2212                                      size_t refnamelen)
2213{
2214        struct push_cas *entry;
2215        ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2216        entry = &cas->entry[cas->nr++];
2217        memset(entry, 0, sizeof(*entry));
2218        entry->refname = xmemdupz(refname, refnamelen);
2219        return entry;
2220}
2221
2222static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2223{
2224        const char *colon;
2225        struct push_cas *entry;
2226
2227        if (unset) {
2228                /* "--no-<option>" */
2229                clear_cas_option(cas);
2230                return 0;
2231        }
2232
2233        if (!arg) {
2234                /* just "--<option>" */
2235                cas->use_tracking_for_rest = 1;
2236                return 0;
2237        }
2238
2239        /* "--<option>=refname" or "--<option>=refname:value" */
2240        colon = strchrnul(arg, ':');
2241        entry = add_cas_entry(cas, arg, colon - arg);
2242        if (!*colon)
2243                entry->use_tracking = 1;
2244        else if (!colon[1])
2245                oidclr(&entry->expect);
2246        else if (get_oid(colon + 1, &entry->expect))
2247                return error(_("cannot parse expected object name '%s'"),
2248                             colon + 1);
2249        return 0;
2250}
2251
2252int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2253{
2254        return parse_push_cas_option(opt->value, arg, unset);
2255}
2256
2257int is_empty_cas(const struct push_cas_option *cas)
2258{
2259        return !cas->use_tracking_for_rest && !cas->nr;
2260}
2261
2262/*
2263 * Look at remote.fetch refspec and see if we have a remote
2264 * tracking branch for the refname there.  Fill its current
2265 * value in sha1[].
2266 * If we cannot do so, return negative to signal an error.
2267 */
2268static int remote_tracking(struct remote *remote, const char *refname,
2269                           struct object_id *oid)
2270{
2271        char *dst;
2272
2273        dst = apply_refspecs(&remote->fetch, refname);
2274        if (!dst)
2275                return -1; /* no tracking ref for refname at remote */
2276        if (read_ref(dst, oid))
2277                return -1; /* we know what the tracking ref is but we cannot read it */
2278        return 0;
2279}
2280
2281static void apply_cas(struct push_cas_option *cas,
2282                      struct remote *remote,
2283                      struct ref *ref)
2284{
2285        int i;
2286
2287        /* Find an explicit --<option>=<name>[:<value>] entry */
2288        for (i = 0; i < cas->nr; i++) {
2289                struct push_cas *entry = &cas->entry[i];
2290                if (!refname_match(entry->refname, ref->name))
2291                        continue;
2292                ref->expect_old_sha1 = 1;
2293                if (!entry->use_tracking)
2294                        oidcpy(&ref->old_oid_expect, &entry->expect);
2295                else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2296                        oidclr(&ref->old_oid_expect);
2297                return;
2298        }
2299
2300        /* Are we using "--<option>" to cover all? */
2301        if (!cas->use_tracking_for_rest)
2302                return;
2303
2304        ref->expect_old_sha1 = 1;
2305        if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2306                oidclr(&ref->old_oid_expect);
2307}
2308
2309void apply_push_cas(struct push_cas_option *cas,
2310                    struct remote *remote,
2311                    struct ref *remote_refs)
2312{
2313        struct ref *ref;
2314        for (ref = remote_refs; ref; ref = ref->next)
2315                apply_cas(cas, remote, ref);
2316}