remote.con commit ref-filter: fill empty fields with empty values (20a9c15)
   1#include "cache.h"
   2#include "config.h"
   3#include "remote.h"
   4#include "refs.h"
   5#include "refspec.h"
   6#include "commit.h"
   7#include "diff.h"
   8#include "revision.h"
   9#include "dir.h"
  10#include "tag.h"
  11#include "string-list.h"
  12#include "mergesort.h"
  13#include "argv-array.h"
  14
  15enum map_direction { FROM_SRC, FROM_DST };
  16
  17struct counted_string {
  18        size_t len;
  19        const char *s;
  20};
  21struct rewrite {
  22        const char *base;
  23        size_t baselen;
  24        struct counted_string *instead_of;
  25        int instead_of_nr;
  26        int instead_of_alloc;
  27};
  28struct rewrites {
  29        struct rewrite **rewrite;
  30        int rewrite_alloc;
  31        int rewrite_nr;
  32};
  33
  34static struct remote **remotes;
  35static int remotes_alloc;
  36static int remotes_nr;
  37static struct hashmap remotes_hash;
  38
  39static struct branch **branches;
  40static int branches_alloc;
  41static int branches_nr;
  42
  43static struct branch *current_branch;
  44static const char *pushremote_name;
  45
  46static struct rewrites rewrites;
  47static struct rewrites rewrites_push;
  48
  49static int valid_remote(const struct remote *remote)
  50{
  51        return (!!remote->url) || (!!remote->foreign_vcs);
  52}
  53
  54static const char *alias_url(const char *url, struct rewrites *r)
  55{
  56        int i, j;
  57        struct counted_string *longest;
  58        int longest_i;
  59
  60        longest = NULL;
  61        longest_i = -1;
  62        for (i = 0; i < r->rewrite_nr; i++) {
  63                if (!r->rewrite[i])
  64                        continue;
  65                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  66                        if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  67                            (!longest ||
  68                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  69                                longest = &(r->rewrite[i]->instead_of[j]);
  70                                longest_i = i;
  71                        }
  72                }
  73        }
  74        if (!longest)
  75                return url;
  76
  77        return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
  78}
  79
  80static void add_url(struct remote *remote, const char *url)
  81{
  82        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
  83        remote->url[remote->url_nr++] = url;
  84}
  85
  86static void add_pushurl(struct remote *remote, const char *pushurl)
  87{
  88        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
  89        remote->pushurl[remote->pushurl_nr++] = pushurl;
  90}
  91
  92static void add_pushurl_alias(struct remote *remote, const char *url)
  93{
  94        const char *pushurl = alias_url(url, &rewrites_push);
  95        if (pushurl != url)
  96                add_pushurl(remote, pushurl);
  97}
  98
  99static void add_url_alias(struct remote *remote, const char *url)
 100{
 101        add_url(remote, alias_url(url, &rewrites));
 102        add_pushurl_alias(remote, url);
 103}
 104
 105struct remotes_hash_key {
 106        const char *str;
 107        int len;
 108};
 109
 110static int remotes_hash_cmp(const void *unused_cmp_data,
 111                            const void *entry,
 112                            const void *entry_or_key,
 113                            const void *keydata)
 114{
 115        const struct remote *a = entry;
 116        const struct remote *b = entry_or_key;
 117        const struct remotes_hash_key *key = keydata;
 118
 119        if (key)
 120                return strncmp(a->name, key->str, key->len) || a->name[key->len];
 121        else
 122                return strcmp(a->name, b->name);
 123}
 124
 125static inline void init_remotes_hash(void)
 126{
 127        if (!remotes_hash.cmpfn)
 128                hashmap_init(&remotes_hash, remotes_hash_cmp, NULL, 0);
 129}
 130
 131static struct remote *make_remote(const char *name, int len)
 132{
 133        struct remote *ret, *replaced;
 134        struct remotes_hash_key lookup;
 135        struct hashmap_entry lookup_entry;
 136
 137        if (!len)
 138                len = strlen(name);
 139
 140        init_remotes_hash();
 141        lookup.str = name;
 142        lookup.len = len;
 143        hashmap_entry_init(&lookup_entry, memhash(name, len));
 144
 145        if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
 146                return ret;
 147
 148        ret = xcalloc(1, sizeof(struct remote));
 149        ret->prune = -1;  /* unspecified */
 150        ret->prune_tags = -1;  /* unspecified */
 151        ret->name = xstrndup(name, len);
 152        refspec_init(&ret->push, REFSPEC_PUSH);
 153        refspec_init(&ret->fetch, REFSPEC_FETCH);
 154
 155        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 156        remotes[remotes_nr++] = ret;
 157
 158        hashmap_entry_init(ret, lookup_entry.hash);
 159        replaced = hashmap_put(&remotes_hash, ret);
 160        assert(replaced == NULL);  /* no previous entry overwritten */
 161        return ret;
 162}
 163
 164static void add_merge(struct branch *branch, const char *name)
 165{
 166        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 167                   branch->merge_alloc);
 168        branch->merge_name[branch->merge_nr++] = name;
 169}
 170
 171static struct branch *make_branch(const char *name, int len)
 172{
 173        struct branch *ret;
 174        int i;
 175
 176        for (i = 0; i < branches_nr; i++) {
 177                if (len ? (!strncmp(name, branches[i]->name, len) &&
 178                           !branches[i]->name[len]) :
 179                    !strcmp(name, branches[i]->name))
 180                        return branches[i];
 181        }
 182
 183        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 184        ret = xcalloc(1, sizeof(struct branch));
 185        branches[branches_nr++] = ret;
 186        if (len)
 187                ret->name = xstrndup(name, len);
 188        else
 189                ret->name = xstrdup(name);
 190        ret->refname = xstrfmt("refs/heads/%s", ret->name);
 191
 192        return ret;
 193}
 194
 195static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 196{
 197        struct rewrite *ret;
 198        int i;
 199
 200        for (i = 0; i < r->rewrite_nr; i++) {
 201                if (len
 202                    ? (len == r->rewrite[i]->baselen &&
 203                       !strncmp(base, r->rewrite[i]->base, len))
 204                    : !strcmp(base, r->rewrite[i]->base))
 205                        return r->rewrite[i];
 206        }
 207
 208        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 209        ret = xcalloc(1, sizeof(struct rewrite));
 210        r->rewrite[r->rewrite_nr++] = ret;
 211        if (len) {
 212                ret->base = xstrndup(base, len);
 213                ret->baselen = len;
 214        }
 215        else {
 216                ret->base = xstrdup(base);
 217                ret->baselen = strlen(base);
 218        }
 219        return ret;
 220}
 221
 222static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 223{
 224        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 225        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 226        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 227        rewrite->instead_of_nr++;
 228}
 229
 230static const char *skip_spaces(const char *s)
 231{
 232        while (isspace(*s))
 233                s++;
 234        return s;
 235}
 236
 237static void read_remotes_file(struct remote *remote)
 238{
 239        struct strbuf buf = STRBUF_INIT;
 240        FILE *f = fopen_or_warn(git_path("remotes/%s", remote->name), "r");
 241
 242        if (!f)
 243                return;
 244        remote->configured_in_repo = 1;
 245        remote->origin = REMOTE_REMOTES;
 246        while (strbuf_getline(&buf, f) != EOF) {
 247                const char *v;
 248
 249                strbuf_rtrim(&buf);
 250
 251                if (skip_prefix(buf.buf, "URL:", &v))
 252                        add_url_alias(remote, xstrdup(skip_spaces(v)));
 253                else if (skip_prefix(buf.buf, "Push:", &v))
 254                        refspec_append(&remote->push, skip_spaces(v));
 255                else if (skip_prefix(buf.buf, "Pull:", &v))
 256                        refspec_append(&remote->fetch, skip_spaces(v));
 257        }
 258        strbuf_release(&buf);
 259        fclose(f);
 260}
 261
 262static void read_branches_file(struct remote *remote)
 263{
 264        char *frag;
 265        struct strbuf buf = STRBUF_INIT;
 266        FILE *f = fopen_or_warn(git_path("branches/%s", remote->name), "r");
 267
 268        if (!f)
 269                return;
 270
 271        strbuf_getline_lf(&buf, f);
 272        fclose(f);
 273        strbuf_trim(&buf);
 274        if (!buf.len) {
 275                strbuf_release(&buf);
 276                return;
 277        }
 278
 279        remote->configured_in_repo = 1;
 280        remote->origin = REMOTE_BRANCHES;
 281
 282        /*
 283         * The branches file would have URL and optionally
 284         * #branch specified.  The "master" (or specified) branch is
 285         * fetched and stored in the local branch matching the
 286         * remote name.
 287         */
 288        frag = strchr(buf.buf, '#');
 289        if (frag)
 290                *(frag++) = '\0';
 291        else
 292                frag = "master";
 293
 294        add_url_alias(remote, strbuf_detach(&buf, NULL));
 295        strbuf_addf(&buf, "refs/heads/%s:refs/heads/%s",
 296                    frag, remote->name);
 297        refspec_append(&remote->fetch, buf.buf);
 298
 299        /*
 300         * Cogito compatible push: push current HEAD to remote #branch
 301         * (master if missing)
 302         */
 303        strbuf_reset(&buf);
 304        strbuf_addf(&buf, "HEAD:refs/heads/%s", frag);
 305        refspec_append(&remote->push, buf.buf);
 306        remote->fetch_tags = 1; /* always auto-follow */
 307        strbuf_release(&buf);
 308}
 309
 310static int handle_config(const char *key, const char *value, void *cb)
 311{
 312        const char *name;
 313        int namelen;
 314        const char *subkey;
 315        struct remote *remote;
 316        struct branch *branch;
 317        if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
 318                if (!name)
 319                        return 0;
 320                branch = make_branch(name, namelen);
 321                if (!strcmp(subkey, "remote")) {
 322                        return git_config_string(&branch->remote_name, key, value);
 323                } else if (!strcmp(subkey, "pushremote")) {
 324                        return git_config_string(&branch->pushremote_name, key, value);
 325                } else if (!strcmp(subkey, "merge")) {
 326                        if (!value)
 327                                return config_error_nonbool(key);
 328                        add_merge(branch, xstrdup(value));
 329                }
 330                return 0;
 331        }
 332        if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
 333                struct rewrite *rewrite;
 334                if (!name)
 335                        return 0;
 336                if (!strcmp(subkey, "insteadof")) {
 337                        rewrite = make_rewrite(&rewrites, name, namelen);
 338                        if (!value)
 339                                return config_error_nonbool(key);
 340                        add_instead_of(rewrite, xstrdup(value));
 341                } else if (!strcmp(subkey, "pushinsteadof")) {
 342                        rewrite = make_rewrite(&rewrites_push, name, namelen);
 343                        if (!value)
 344                                return config_error_nonbool(key);
 345                        add_instead_of(rewrite, xstrdup(value));
 346                }
 347        }
 348
 349        if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
 350                return 0;
 351
 352        /* Handle remote.* variables */
 353        if (!name && !strcmp(subkey, "pushdefault"))
 354                return git_config_string(&pushremote_name, key, value);
 355
 356        if (!name)
 357                return 0;
 358        /* Handle remote.<name>.* variables */
 359        if (*name == '/') {
 360                warning("Config remote shorthand cannot begin with '/': %s",
 361                        name);
 362                return 0;
 363        }
 364        remote = make_remote(name, namelen);
 365        remote->origin = REMOTE_CONFIG;
 366        if (current_config_scope() == CONFIG_SCOPE_REPO)
 367                remote->configured_in_repo = 1;
 368        if (!strcmp(subkey, "mirror"))
 369                remote->mirror = git_config_bool(key, value);
 370        else if (!strcmp(subkey, "skipdefaultupdate"))
 371                remote->skip_default_update = git_config_bool(key, value);
 372        else if (!strcmp(subkey, "skipfetchall"))
 373                remote->skip_default_update = git_config_bool(key, value);
 374        else if (!strcmp(subkey, "prune"))
 375                remote->prune = git_config_bool(key, value);
 376        else if (!strcmp(subkey, "prunetags"))
 377                remote->prune_tags = git_config_bool(key, value);
 378        else if (!strcmp(subkey, "url")) {
 379                const char *v;
 380                if (git_config_string(&v, key, value))
 381                        return -1;
 382                add_url(remote, v);
 383        } else if (!strcmp(subkey, "pushurl")) {
 384                const char *v;
 385                if (git_config_string(&v, key, value))
 386                        return -1;
 387                add_pushurl(remote, v);
 388        } else if (!strcmp(subkey, "push")) {
 389                const char *v;
 390                if (git_config_string(&v, key, value))
 391                        return -1;
 392                refspec_append(&remote->push, v);
 393                free((char *)v);
 394        } else if (!strcmp(subkey, "fetch")) {
 395                const char *v;
 396                if (git_config_string(&v, key, value))
 397                        return -1;
 398                refspec_append(&remote->fetch, v);
 399                free((char *)v);
 400        } else if (!strcmp(subkey, "receivepack")) {
 401                const char *v;
 402                if (git_config_string(&v, key, value))
 403                        return -1;
 404                if (!remote->receivepack)
 405                        remote->receivepack = v;
 406                else
 407                        error("more than one receivepack given, using the first");
 408        } else if (!strcmp(subkey, "uploadpack")) {
 409                const char *v;
 410                if (git_config_string(&v, key, value))
 411                        return -1;
 412                if (!remote->uploadpack)
 413                        remote->uploadpack = v;
 414                else
 415                        error("more than one uploadpack given, using the first");
 416        } else if (!strcmp(subkey, "tagopt")) {
 417                if (!strcmp(value, "--no-tags"))
 418                        remote->fetch_tags = -1;
 419                else if (!strcmp(value, "--tags"))
 420                        remote->fetch_tags = 2;
 421        } else if (!strcmp(subkey, "proxy")) {
 422                return git_config_string((const char **)&remote->http_proxy,
 423                                         key, value);
 424        } else if (!strcmp(subkey, "proxyauthmethod")) {
 425                return git_config_string((const char **)&remote->http_proxy_authmethod,
 426                                         key, value);
 427        } else if (!strcmp(subkey, "vcs")) {
 428                return git_config_string(&remote->foreign_vcs, key, value);
 429        }
 430        return 0;
 431}
 432
 433static void alias_all_urls(void)
 434{
 435        int i, j;
 436        for (i = 0; i < remotes_nr; i++) {
 437                int add_pushurl_aliases;
 438                if (!remotes[i])
 439                        continue;
 440                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 441                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 442                }
 443                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 444                for (j = 0; j < remotes[i]->url_nr; j++) {
 445                        if (add_pushurl_aliases)
 446                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 447                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 448                }
 449        }
 450}
 451
 452static void read_config(void)
 453{
 454        static int loaded;
 455        int flag;
 456
 457        if (loaded)
 458                return;
 459        loaded = 1;
 460
 461        current_branch = NULL;
 462        if (startup_info->have_repository) {
 463                const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
 464                if (head_ref && (flag & REF_ISSYMREF) &&
 465                    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
 466                        current_branch = make_branch(head_ref, 0);
 467                }
 468        }
 469        git_config(handle_config, NULL);
 470        alias_all_urls();
 471}
 472
 473static int valid_remote_nick(const char *name)
 474{
 475        if (!name[0] || is_dot_or_dotdot(name))
 476                return 0;
 477
 478        /* remote nicknames cannot contain slashes */
 479        while (*name)
 480                if (is_dir_sep(*name++))
 481                        return 0;
 482        return 1;
 483}
 484
 485const char *remote_for_branch(struct branch *branch, int *explicit)
 486{
 487        if (branch && branch->remote_name) {
 488                if (explicit)
 489                        *explicit = 1;
 490                return branch->remote_name;
 491        }
 492        if (explicit)
 493                *explicit = 0;
 494        return "origin";
 495}
 496
 497const char *pushremote_for_branch(struct branch *branch, int *explicit)
 498{
 499        if (branch && branch->pushremote_name) {
 500                if (explicit)
 501                        *explicit = 1;
 502                return branch->pushremote_name;
 503        }
 504        if (pushremote_name) {
 505                if (explicit)
 506                        *explicit = 1;
 507                return pushremote_name;
 508        }
 509        return remote_for_branch(branch, explicit);
 510}
 511
 512const char *remote_ref_for_branch(struct branch *branch, int for_push,
 513                                  int *explicit)
 514{
 515        if (branch) {
 516                if (!for_push) {
 517                        if (branch->merge_nr) {
 518                                if (explicit)
 519                                        *explicit = 1;
 520                                return branch->merge_name[0];
 521                        }
 522                } else {
 523                        const char *dst, *remote_name =
 524                                pushremote_for_branch(branch, NULL);
 525                        struct remote *remote = remote_get(remote_name);
 526
 527                        if (remote && remote->push.nr &&
 528                            (dst = apply_refspecs(&remote->push,
 529                                                  branch->refname))) {
 530                                if (explicit)
 531                                        *explicit = 1;
 532                                return dst;
 533                        }
 534                }
 535        }
 536        if (explicit)
 537                *explicit = 0;
 538        return "";
 539}
 540
 541static struct remote *remote_get_1(const char *name,
 542                                   const char *(*get_default)(struct branch *, int *))
 543{
 544        struct remote *ret;
 545        int name_given = 0;
 546
 547        read_config();
 548
 549        if (name)
 550                name_given = 1;
 551        else
 552                name = get_default(current_branch, &name_given);
 553
 554        ret = make_remote(name, 0);
 555        if (valid_remote_nick(name) && have_git_dir()) {
 556                if (!valid_remote(ret))
 557                        read_remotes_file(ret);
 558                if (!valid_remote(ret))
 559                        read_branches_file(ret);
 560        }
 561        if (name_given && !valid_remote(ret))
 562                add_url_alias(ret, name);
 563        if (!valid_remote(ret))
 564                return NULL;
 565        return ret;
 566}
 567
 568struct remote *remote_get(const char *name)
 569{
 570        return remote_get_1(name, remote_for_branch);
 571}
 572
 573struct remote *pushremote_get(const char *name)
 574{
 575        return remote_get_1(name, pushremote_for_branch);
 576}
 577
 578int remote_is_configured(struct remote *remote, int in_repo)
 579{
 580        if (!remote)
 581                return 0;
 582        if (in_repo)
 583                return remote->configured_in_repo;
 584        return !!remote->origin;
 585}
 586
 587int for_each_remote(each_remote_fn fn, void *priv)
 588{
 589        int i, result = 0;
 590        read_config();
 591        for (i = 0; i < remotes_nr && !result; i++) {
 592                struct remote *r = remotes[i];
 593                if (!r)
 594                        continue;
 595                result = fn(r, priv);
 596        }
 597        return result;
 598}
 599
 600static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 601{
 602        if (strcmp(ref1->name, ref2->name)) {
 603                if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 604                    ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 605                        die(_("Cannot fetch both %s and %s to %s"),
 606                            ref1->name, ref2->name, ref2->peer_ref->name);
 607                } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 608                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 609                        warning(_("%s usually tracks %s, not %s"),
 610                                ref2->peer_ref->name, ref2->name, ref1->name);
 611                } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 612                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 613                        die(_("%s tracks both %s and %s"),
 614                            ref2->peer_ref->name, ref1->name, ref2->name);
 615                } else {
 616                        /*
 617                         * This last possibility doesn't occur because
 618                         * FETCH_HEAD_IGNORE entries always appear at
 619                         * the end of the list.
 620                         */
 621                        die(_("Internal error"));
 622                }
 623        }
 624        free(ref2->peer_ref);
 625        free(ref2);
 626}
 627
 628struct ref *ref_remove_duplicates(struct ref *ref_map)
 629{
 630        struct string_list refs = STRING_LIST_INIT_NODUP;
 631        struct ref *retval = NULL;
 632        struct ref **p = &retval;
 633
 634        while (ref_map) {
 635                struct ref *ref = ref_map;
 636
 637                ref_map = ref_map->next;
 638                ref->next = NULL;
 639
 640                if (!ref->peer_ref) {
 641                        *p = ref;
 642                        p = &ref->next;
 643                } else {
 644                        struct string_list_item *item =
 645                                string_list_insert(&refs, ref->peer_ref->name);
 646
 647                        if (item->util) {
 648                                /* Entry already existed */
 649                                handle_duplicate((struct ref *)item->util, ref);
 650                        } else {
 651                                *p = ref;
 652                                p = &ref->next;
 653                                item->util = ref;
 654                        }
 655                }
 656        }
 657
 658        string_list_clear(&refs, 0);
 659        return retval;
 660}
 661
 662int remote_has_url(struct remote *remote, const char *url)
 663{
 664        int i;
 665        for (i = 0; i < remote->url_nr; i++) {
 666                if (!strcmp(remote->url[i], url))
 667                        return 1;
 668        }
 669        return 0;
 670}
 671
 672static int match_name_with_pattern(const char *key, const char *name,
 673                                   const char *value, char **result)
 674{
 675        const char *kstar = strchr(key, '*');
 676        size_t klen;
 677        size_t ksuffixlen;
 678        size_t namelen;
 679        int ret;
 680        if (!kstar)
 681                die("Key '%s' of pattern had no '*'", key);
 682        klen = kstar - key;
 683        ksuffixlen = strlen(kstar + 1);
 684        namelen = strlen(name);
 685        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 686                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 687        if (ret && value) {
 688                struct strbuf sb = STRBUF_INIT;
 689                const char *vstar = strchr(value, '*');
 690                if (!vstar)
 691                        die("Value '%s' of pattern has no '*'", value);
 692                strbuf_add(&sb, value, vstar - value);
 693                strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
 694                strbuf_addstr(&sb, vstar + 1);
 695                *result = strbuf_detach(&sb, NULL);
 696        }
 697        return ret;
 698}
 699
 700static void query_refspecs_multiple(struct refspec *rs,
 701                                    struct refspec_item *query,
 702                                    struct string_list *results)
 703{
 704        int i;
 705        int find_src = !query->src;
 706
 707        if (find_src && !query->dst)
 708                error("query_refspecs_multiple: need either src or dst");
 709
 710        for (i = 0; i < rs->nr; i++) {
 711                struct refspec_item *refspec = &rs->items[i];
 712                const char *key = find_src ? refspec->dst : refspec->src;
 713                const char *value = find_src ? refspec->src : refspec->dst;
 714                const char *needle = find_src ? query->dst : query->src;
 715                char **result = find_src ? &query->src : &query->dst;
 716
 717                if (!refspec->dst)
 718                        continue;
 719                if (refspec->pattern) {
 720                        if (match_name_with_pattern(key, needle, value, result))
 721                                string_list_append_nodup(results, *result);
 722                } else if (!strcmp(needle, key)) {
 723                        string_list_append(results, value);
 724                }
 725        }
 726}
 727
 728int query_refspecs(struct refspec *rs, struct refspec_item *query)
 729{
 730        int i;
 731        int find_src = !query->src;
 732        const char *needle = find_src ? query->dst : query->src;
 733        char **result = find_src ? &query->src : &query->dst;
 734
 735        if (find_src && !query->dst)
 736                return error("query_refspecs: need either src or dst");
 737
 738        for (i = 0; i < rs->nr; i++) {
 739                struct refspec_item *refspec = &rs->items[i];
 740                const char *key = find_src ? refspec->dst : refspec->src;
 741                const char *value = find_src ? refspec->src : refspec->dst;
 742
 743                if (!refspec->dst)
 744                        continue;
 745                if (refspec->pattern) {
 746                        if (match_name_with_pattern(key, needle, value, result)) {
 747                                query->force = refspec->force;
 748                                return 0;
 749                        }
 750                } else if (!strcmp(needle, key)) {
 751                        *result = xstrdup(value);
 752                        query->force = refspec->force;
 753                        return 0;
 754                }
 755        }
 756        return -1;
 757}
 758
 759char *apply_refspecs(struct refspec *rs, const char *name)
 760{
 761        struct refspec_item query;
 762
 763        memset(&query, 0, sizeof(struct refspec_item));
 764        query.src = (char *)name;
 765
 766        if (query_refspecs(rs, &query))
 767                return NULL;
 768
 769        return query.dst;
 770}
 771
 772int remote_find_tracking(struct remote *remote, struct refspec_item *refspec)
 773{
 774        return query_refspecs(&remote->fetch, refspec);
 775}
 776
 777static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 778                const char *name)
 779{
 780        size_t len = strlen(name);
 781        struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
 782        memcpy(ref->name, prefix, prefixlen);
 783        memcpy(ref->name + prefixlen, name, len);
 784        return ref;
 785}
 786
 787struct ref *alloc_ref(const char *name)
 788{
 789        return alloc_ref_with_prefix("", 0, name);
 790}
 791
 792struct ref *copy_ref(const struct ref *ref)
 793{
 794        struct ref *cpy;
 795        size_t len;
 796        if (!ref)
 797                return NULL;
 798        len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
 799        cpy = xmalloc(len);
 800        memcpy(cpy, ref, len);
 801        cpy->next = NULL;
 802        cpy->symref = xstrdup_or_null(ref->symref);
 803        cpy->remote_status = xstrdup_or_null(ref->remote_status);
 804        cpy->peer_ref = copy_ref(ref->peer_ref);
 805        return cpy;
 806}
 807
 808struct ref *copy_ref_list(const struct ref *ref)
 809{
 810        struct ref *ret = NULL;
 811        struct ref **tail = &ret;
 812        while (ref) {
 813                *tail = copy_ref(ref);
 814                ref = ref->next;
 815                tail = &((*tail)->next);
 816        }
 817        return ret;
 818}
 819
 820static void free_ref(struct ref *ref)
 821{
 822        if (!ref)
 823                return;
 824        free_ref(ref->peer_ref);
 825        free(ref->remote_status);
 826        free(ref->symref);
 827        free(ref);
 828}
 829
 830void free_refs(struct ref *ref)
 831{
 832        struct ref *next;
 833        while (ref) {
 834                next = ref->next;
 835                free_ref(ref);
 836                ref = next;
 837        }
 838}
 839
 840int ref_compare_name(const void *va, const void *vb)
 841{
 842        const struct ref *a = va, *b = vb;
 843        return strcmp(a->name, b->name);
 844}
 845
 846static void *ref_list_get_next(const void *a)
 847{
 848        return ((const struct ref *)a)->next;
 849}
 850
 851static void ref_list_set_next(void *a, void *next)
 852{
 853        ((struct ref *)a)->next = next;
 854}
 855
 856void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 857{
 858        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 859}
 860
 861int count_refspec_match(const char *pattern,
 862                        struct ref *refs,
 863                        struct ref **matched_ref)
 864{
 865        int patlen = strlen(pattern);
 866        struct ref *matched_weak = NULL;
 867        struct ref *matched = NULL;
 868        int weak_match = 0;
 869        int match = 0;
 870
 871        for (weak_match = match = 0; refs; refs = refs->next) {
 872                char *name = refs->name;
 873                int namelen = strlen(name);
 874
 875                if (!refname_match(pattern, name))
 876                        continue;
 877
 878                /* A match is "weak" if it is with refs outside
 879                 * heads or tags, and did not specify the pattern
 880                 * in full (e.g. "refs/remotes/origin/master") or at
 881                 * least from the toplevel (e.g. "remotes/origin/master");
 882                 * otherwise "git push $URL master" would result in
 883                 * ambiguity between remotes/origin/master and heads/master
 884                 * at the remote site.
 885                 */
 886                if (namelen != patlen &&
 887                    patlen != namelen - 5 &&
 888                    !starts_with(name, "refs/heads/") &&
 889                    !starts_with(name, "refs/tags/")) {
 890                        /* We want to catch the case where only weak
 891                         * matches are found and there are multiple
 892                         * matches, and where more than one strong
 893                         * matches are found, as ambiguous.  One
 894                         * strong match with zero or more weak matches
 895                         * are acceptable as a unique match.
 896                         */
 897                        matched_weak = refs;
 898                        weak_match++;
 899                }
 900                else {
 901                        matched = refs;
 902                        match++;
 903                }
 904        }
 905        if (!matched) {
 906                if (matched_ref)
 907                        *matched_ref = matched_weak;
 908                return weak_match;
 909        }
 910        else {
 911                if (matched_ref)
 912                        *matched_ref = matched;
 913                return match;
 914        }
 915}
 916
 917static void tail_link_ref(struct ref *ref, struct ref ***tail)
 918{
 919        **tail = ref;
 920        while (ref->next)
 921                ref = ref->next;
 922        *tail = &ref->next;
 923}
 924
 925static struct ref *alloc_delete_ref(void)
 926{
 927        struct ref *ref = alloc_ref("(delete)");
 928        oidclr(&ref->new_oid);
 929        return ref;
 930}
 931
 932static int try_explicit_object_name(const char *name,
 933                                    struct ref **match)
 934{
 935        struct object_id oid;
 936
 937        if (!*name) {
 938                if (match)
 939                        *match = alloc_delete_ref();
 940                return 0;
 941        }
 942
 943        if (get_oid(name, &oid))
 944                return -1;
 945
 946        if (match) {
 947                *match = alloc_ref(name);
 948                oidcpy(&(*match)->new_oid, &oid);
 949        }
 950        return 0;
 951}
 952
 953static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 954{
 955        struct ref *ret = alloc_ref(name);
 956        tail_link_ref(ret, tail);
 957        return ret;
 958}
 959
 960static char *guess_ref(const char *name, struct ref *peer)
 961{
 962        struct strbuf buf = STRBUF_INIT;
 963
 964        const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
 965                                           NULL, NULL);
 966        if (!r)
 967                return NULL;
 968
 969        if (starts_with(r, "refs/heads/"))
 970                strbuf_addstr(&buf, "refs/heads/");
 971        else if (starts_with(r, "refs/tags/"))
 972                strbuf_addstr(&buf, "refs/tags/");
 973        else
 974                return NULL;
 975
 976        strbuf_addstr(&buf, name);
 977        return strbuf_detach(&buf, NULL);
 978}
 979
 980static int match_explicit_lhs(struct ref *src,
 981                              struct refspec_item *rs,
 982                              struct ref **match,
 983                              int *allocated_match)
 984{
 985        switch (count_refspec_match(rs->src, src, match)) {
 986        case 1:
 987                if (allocated_match)
 988                        *allocated_match = 0;
 989                return 0;
 990        case 0:
 991                /* The source could be in the get_sha1() format
 992                 * not a reference name.  :refs/other is a
 993                 * way to delete 'other' ref at the remote end.
 994                 */
 995                if (try_explicit_object_name(rs->src, match) < 0)
 996                        return error("src refspec %s does not match any.", rs->src);
 997                if (allocated_match)
 998                        *allocated_match = 1;
 999                return 0;
1000        default:
1001                return error("src refspec %s matches more than one.", rs->src);
1002        }
1003}
1004
1005static int match_explicit(struct ref *src, struct ref *dst,
1006                          struct ref ***dst_tail,
1007                          struct refspec_item *rs)
1008{
1009        struct ref *matched_src, *matched_dst;
1010        int allocated_src;
1011
1012        const char *dst_value = rs->dst;
1013        char *dst_guess;
1014
1015        if (rs->pattern || rs->matching)
1016                return 0;
1017
1018        matched_src = matched_dst = NULL;
1019        if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1020                return -1;
1021
1022        if (!dst_value) {
1023                int flag;
1024
1025                dst_value = resolve_ref_unsafe(matched_src->name,
1026                                               RESOLVE_REF_READING,
1027                                               NULL, &flag);
1028                if (!dst_value ||
1029                    ((flag & REF_ISSYMREF) &&
1030                     !starts_with(dst_value, "refs/heads/")))
1031                        die("%s cannot be resolved to branch.",
1032                            matched_src->name);
1033        }
1034
1035        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1036        case 1:
1037                break;
1038        case 0:
1039                if (starts_with(dst_value, "refs/"))
1040                        matched_dst = make_linked_ref(dst_value, dst_tail);
1041                else if (is_null_oid(&matched_src->new_oid))
1042                        error("unable to delete '%s': remote ref does not exist",
1043                              dst_value);
1044                else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1045                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1046                        free(dst_guess);
1047                } else
1048                        error("unable to push to unqualified destination: %s\n"
1049                              "The destination refspec neither matches an "
1050                              "existing ref on the remote nor\n"
1051                              "begins with refs/, and we are unable to "
1052                              "guess a prefix based on the source ref.",
1053                              dst_value);
1054                break;
1055        default:
1056                matched_dst = NULL;
1057                error("dst refspec %s matches more than one.",
1058                      dst_value);
1059                break;
1060        }
1061        if (!matched_dst)
1062                return -1;
1063        if (matched_dst->peer_ref)
1064                return error("dst ref %s receives from more than one src.",
1065                      matched_dst->name);
1066        else {
1067                matched_dst->peer_ref = allocated_src ?
1068                                        matched_src :
1069                                        copy_ref(matched_src);
1070                matched_dst->force = rs->force;
1071        }
1072        return 0;
1073}
1074
1075static int match_explicit_refs(struct ref *src, struct ref *dst,
1076                               struct ref ***dst_tail, struct refspec *rs)
1077{
1078        int i, errs;
1079        for (i = errs = 0; i < rs->nr; i++)
1080                errs += match_explicit(src, dst, dst_tail, &rs->items[i]);
1081        return errs;
1082}
1083
1084static char *get_ref_match(const struct refspec *rs, const struct ref *ref,
1085                           int send_mirror, int direction,
1086                           const struct refspec_item **ret_pat)
1087{
1088        const struct refspec_item *pat;
1089        char *name;
1090        int i;
1091        int matching_refs = -1;
1092        for (i = 0; i < rs->nr; i++) {
1093                const struct refspec_item *item = &rs->items[i];
1094                if (item->matching &&
1095                    (matching_refs == -1 || item->force)) {
1096                        matching_refs = i;
1097                        continue;
1098                }
1099
1100                if (item->pattern) {
1101                        const char *dst_side = item->dst ? item->dst : item->src;
1102                        int match;
1103                        if (direction == FROM_SRC)
1104                                match = match_name_with_pattern(item->src, ref->name, dst_side, &name);
1105                        else
1106                                match = match_name_with_pattern(dst_side, ref->name, item->src, &name);
1107                        if (match) {
1108                                matching_refs = i;
1109                                break;
1110                        }
1111                }
1112        }
1113        if (matching_refs == -1)
1114                return NULL;
1115
1116        pat = &rs->items[matching_refs];
1117        if (pat->matching) {
1118                /*
1119                 * "matching refs"; traditionally we pushed everything
1120                 * including refs outside refs/heads/ hierarchy, but
1121                 * that does not make much sense these days.
1122                 */
1123                if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1124                        return NULL;
1125                name = xstrdup(ref->name);
1126        }
1127        if (ret_pat)
1128                *ret_pat = pat;
1129        return name;
1130}
1131
1132static struct ref **tail_ref(struct ref **head)
1133{
1134        struct ref **tail = head;
1135        while (*tail)
1136                tail = &((*tail)->next);
1137        return tail;
1138}
1139
1140struct tips {
1141        struct commit **tip;
1142        int nr, alloc;
1143};
1144
1145static void add_to_tips(struct tips *tips, const struct object_id *oid)
1146{
1147        struct commit *commit;
1148
1149        if (is_null_oid(oid))
1150                return;
1151        commit = lookup_commit_reference_gently(oid, 1);
1152        if (!commit || (commit->object.flags & TMP_MARK))
1153                return;
1154        commit->object.flags |= TMP_MARK;
1155        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1156        tips->tip[tips->nr++] = commit;
1157}
1158
1159static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1160{
1161        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1162        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1163        struct string_list_item *item;
1164        struct ref *ref;
1165        struct tips sent_tips;
1166
1167        /*
1168         * Collect everything we know they would have at the end of
1169         * this push, and collect all tags they have.
1170         */
1171        memset(&sent_tips, 0, sizeof(sent_tips));
1172        for (ref = *dst; ref; ref = ref->next) {
1173                if (ref->peer_ref &&
1174                    !is_null_oid(&ref->peer_ref->new_oid))
1175                        add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1176                else
1177                        add_to_tips(&sent_tips, &ref->old_oid);
1178                if (starts_with(ref->name, "refs/tags/"))
1179                        string_list_append(&dst_tag, ref->name);
1180        }
1181        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1182
1183        string_list_sort(&dst_tag);
1184
1185        /* Collect tags they do not have. */
1186        for (ref = src; ref; ref = ref->next) {
1187                if (!starts_with(ref->name, "refs/tags/"))
1188                        continue; /* not a tag */
1189                if (string_list_has_string(&dst_tag, ref->name))
1190                        continue; /* they already have it */
1191                if (oid_object_info(the_repository, &ref->new_oid, NULL) != OBJ_TAG)
1192                        continue; /* be conservative */
1193                item = string_list_append(&src_tag, ref->name);
1194                item->util = ref;
1195        }
1196        string_list_clear(&dst_tag, 0);
1197
1198        /*
1199         * At this point, src_tag lists tags that are missing from
1200         * dst, and sent_tips lists the tips we are pushing or those
1201         * that we know they already have. An element in the src_tag
1202         * that is an ancestor of any of the sent_tips needs to be
1203         * sent to the other side.
1204         */
1205        if (sent_tips.nr) {
1206                for_each_string_list_item(item, &src_tag) {
1207                        struct ref *ref = item->util;
1208                        struct ref *dst_ref;
1209                        struct commit *commit;
1210
1211                        if (is_null_oid(&ref->new_oid))
1212                                continue;
1213                        commit = lookup_commit_reference_gently(&ref->new_oid,
1214                                                                1);
1215                        if (!commit)
1216                                /* not pushing a commit, which is not an error */
1217                                continue;
1218
1219                        /*
1220                         * Is this tag, which they do not have, reachable from
1221                         * any of the commits we are sending?
1222                         */
1223                        if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1224                                continue;
1225
1226                        /* Add it in */
1227                        dst_ref = make_linked_ref(ref->name, dst_tail);
1228                        oidcpy(&dst_ref->new_oid, &ref->new_oid);
1229                        dst_ref->peer_ref = copy_ref(ref);
1230                }
1231        }
1232        string_list_clear(&src_tag, 0);
1233        free(sent_tips.tip);
1234}
1235
1236struct ref *find_ref_by_name(const struct ref *list, const char *name)
1237{
1238        for ( ; list; list = list->next)
1239                if (!strcmp(list->name, name))
1240                        return (struct ref *)list;
1241        return NULL;
1242}
1243
1244static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1245{
1246        for ( ; ref; ref = ref->next)
1247                string_list_append_nodup(ref_index, ref->name)->util = ref;
1248
1249        string_list_sort(ref_index);
1250}
1251
1252/*
1253 * Given only the set of local refs, sanity-check the set of push
1254 * refspecs. We can't catch all errors that match_push_refs would,
1255 * but we can catch some errors early before even talking to the
1256 * remote side.
1257 */
1258int check_push_refs(struct ref *src, struct refspec *rs)
1259{
1260        int ret = 0;
1261        int i;
1262
1263        for (i = 0; i < rs->nr; i++) {
1264                struct refspec_item *item = &rs->items[i];
1265
1266                if (item->pattern || item->matching)
1267                        continue;
1268
1269                ret |= match_explicit_lhs(src, item, NULL, NULL);
1270        }
1271
1272        return ret;
1273}
1274
1275/*
1276 * Given the set of refs the local repository has, the set of refs the
1277 * remote repository has, and the refspec used for push, determine
1278 * what remote refs we will update and with what value by setting
1279 * peer_ref (which object is being pushed) and force (if the push is
1280 * forced) in elements of "dst". The function may add new elements to
1281 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1282 */
1283int match_push_refs(struct ref *src, struct ref **dst,
1284                    struct refspec *rs, int flags)
1285{
1286        int send_all = flags & MATCH_REFS_ALL;
1287        int send_mirror = flags & MATCH_REFS_MIRROR;
1288        int send_prune = flags & MATCH_REFS_PRUNE;
1289        int errs;
1290        struct ref *ref, **dst_tail = tail_ref(dst);
1291        struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1292
1293        /* If no refspec is provided, use the default ":" */
1294        if (!rs->nr)
1295                refspec_append(rs, ":");
1296
1297        errs = match_explicit_refs(src, *dst, &dst_tail, rs);
1298
1299        /* pick the remainder */
1300        for (ref = src; ref; ref = ref->next) {
1301                struct string_list_item *dst_item;
1302                struct ref *dst_peer;
1303                const struct refspec_item *pat = NULL;
1304                char *dst_name;
1305
1306                dst_name = get_ref_match(rs, ref, send_mirror, FROM_SRC, &pat);
1307                if (!dst_name)
1308                        continue;
1309
1310                if (!dst_ref_index.nr)
1311                        prepare_ref_index(&dst_ref_index, *dst);
1312
1313                dst_item = string_list_lookup(&dst_ref_index, dst_name);
1314                dst_peer = dst_item ? dst_item->util : NULL;
1315                if (dst_peer) {
1316                        if (dst_peer->peer_ref)
1317                                /* We're already sending something to this ref. */
1318                                goto free_name;
1319                } else {
1320                        if (pat->matching && !(send_all || send_mirror))
1321                                /*
1322                                 * Remote doesn't have it, and we have no
1323                                 * explicit pattern, and we don't have
1324                                 * --all or --mirror.
1325                                 */
1326                                goto free_name;
1327
1328                        /* Create a new one and link it */
1329                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1330                        oidcpy(&dst_peer->new_oid, &ref->new_oid);
1331                        string_list_insert(&dst_ref_index,
1332                                dst_peer->name)->util = dst_peer;
1333                }
1334                dst_peer->peer_ref = copy_ref(ref);
1335                dst_peer->force = pat->force;
1336        free_name:
1337                free(dst_name);
1338        }
1339
1340        string_list_clear(&dst_ref_index, 0);
1341
1342        if (flags & MATCH_REFS_FOLLOW_TAGS)
1343                add_missing_tags(src, dst, &dst_tail);
1344
1345        if (send_prune) {
1346                struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1347                /* check for missing refs on the remote */
1348                for (ref = *dst; ref; ref = ref->next) {
1349                        char *src_name;
1350
1351                        if (ref->peer_ref)
1352                                /* We're already sending something to this ref. */
1353                                continue;
1354
1355                        src_name = get_ref_match(rs, ref, send_mirror, FROM_DST, NULL);
1356                        if (src_name) {
1357                                if (!src_ref_index.nr)
1358                                        prepare_ref_index(&src_ref_index, src);
1359                                if (!string_list_has_string(&src_ref_index,
1360                                            src_name))
1361                                        ref->peer_ref = alloc_delete_ref();
1362                                free(src_name);
1363                        }
1364                }
1365                string_list_clear(&src_ref_index, 0);
1366        }
1367
1368        if (errs)
1369                return -1;
1370        return 0;
1371}
1372
1373void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1374                             int force_update)
1375{
1376        struct ref *ref;
1377
1378        for (ref = remote_refs; ref; ref = ref->next) {
1379                int force_ref_update = ref->force || force_update;
1380                int reject_reason = 0;
1381
1382                if (ref->peer_ref)
1383                        oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1384                else if (!send_mirror)
1385                        continue;
1386
1387                ref->deletion = is_null_oid(&ref->new_oid);
1388                if (!ref->deletion &&
1389                        !oidcmp(&ref->old_oid, &ref->new_oid)) {
1390                        ref->status = REF_STATUS_UPTODATE;
1391                        continue;
1392                }
1393
1394                /*
1395                 * If the remote ref has moved and is now different
1396                 * from what we expect, reject any push.
1397                 *
1398                 * It also is an error if the user told us to check
1399                 * with the remote-tracking branch to find the value
1400                 * to expect, but we did not have such a tracking
1401                 * branch.
1402                 */
1403                if (ref->expect_old_sha1) {
1404                        if (oidcmp(&ref->old_oid, &ref->old_oid_expect))
1405                                reject_reason = REF_STATUS_REJECT_STALE;
1406                        else
1407                                /* If the ref isn't stale then force the update. */
1408                                force_ref_update = 1;
1409                }
1410
1411                /*
1412                 * If the update isn't already rejected then check
1413                 * the usual "must fast-forward" rules.
1414                 *
1415                 * Decide whether an individual refspec A:B can be
1416                 * pushed.  The push will succeed if any of the
1417                 * following are true:
1418                 *
1419                 * (1) the remote reference B does not exist
1420                 *
1421                 * (2) the remote reference B is being removed (i.e.,
1422                 *     pushing :B where no source is specified)
1423                 *
1424                 * (3) the destination is not under refs/tags/, and
1425                 *     if the old and new value is a commit, the new
1426                 *     is a descendant of the old.
1427                 *
1428                 * (4) it is forced using the +A:B notation, or by
1429                 *     passing the --force argument
1430                 */
1431
1432                if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1433                        if (starts_with(ref->name, "refs/tags/"))
1434                                reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1435                        else if (!has_object_file(&ref->old_oid))
1436                                reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1437                        else if (!lookup_commit_reference_gently(&ref->old_oid, 1) ||
1438                                 !lookup_commit_reference_gently(&ref->new_oid, 1))
1439                                reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1440                        else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1441                                reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1442                }
1443
1444                /*
1445                 * "--force" will defeat any rejection implemented
1446                 * by the rules above.
1447                 */
1448                if (!force_ref_update)
1449                        ref->status = reject_reason;
1450                else if (reject_reason)
1451                        ref->forced_update = 1;
1452        }
1453}
1454
1455static void set_merge(struct branch *ret)
1456{
1457        struct remote *remote;
1458        char *ref;
1459        struct object_id oid;
1460        int i;
1461
1462        if (!ret)
1463                return; /* no branch */
1464        if (ret->merge)
1465                return; /* already run */
1466        if (!ret->remote_name || !ret->merge_nr) {
1467                /*
1468                 * no merge config; let's make sure we don't confuse callers
1469                 * with a non-zero merge_nr but a NULL merge
1470                 */
1471                ret->merge_nr = 0;
1472                return;
1473        }
1474
1475        remote = remote_get(ret->remote_name);
1476
1477        ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1478        for (i = 0; i < ret->merge_nr; i++) {
1479                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1480                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1481                if (!remote_find_tracking(remote, ret->merge[i]) ||
1482                    strcmp(ret->remote_name, "."))
1483                        continue;
1484                if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1485                             &oid, &ref) == 1)
1486                        ret->merge[i]->dst = ref;
1487                else
1488                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1489        }
1490}
1491
1492struct branch *branch_get(const char *name)
1493{
1494        struct branch *ret;
1495
1496        read_config();
1497        if (!name || !*name || !strcmp(name, "HEAD"))
1498                ret = current_branch;
1499        else
1500                ret = make_branch(name, 0);
1501        set_merge(ret);
1502        return ret;
1503}
1504
1505int branch_has_merge_config(struct branch *branch)
1506{
1507        return branch && !!branch->merge;
1508}
1509
1510int branch_merge_matches(struct branch *branch,
1511                                 int i,
1512                                 const char *refname)
1513{
1514        if (!branch || i < 0 || i >= branch->merge_nr)
1515                return 0;
1516        return refname_match(branch->merge[i]->src, refname);
1517}
1518
1519__attribute__((format (printf,2,3)))
1520static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1521{
1522        if (err) {
1523                va_list ap;
1524                va_start(ap, fmt);
1525                strbuf_vaddf(err, fmt, ap);
1526                va_end(ap);
1527        }
1528        return NULL;
1529}
1530
1531const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1532{
1533        if (!branch)
1534                return error_buf(err, _("HEAD does not point to a branch"));
1535
1536        if (!branch->merge || !branch->merge[0]) {
1537                /*
1538                 * no merge config; is it because the user didn't define any,
1539                 * or because it is not a real branch, and get_branch
1540                 * auto-vivified it?
1541                 */
1542                if (!ref_exists(branch->refname))
1543                        return error_buf(err, _("no such branch: '%s'"),
1544                                         branch->name);
1545                return error_buf(err,
1546                                 _("no upstream configured for branch '%s'"),
1547                                 branch->name);
1548        }
1549
1550        if (!branch->merge[0]->dst)
1551                return error_buf(err,
1552                                 _("upstream branch '%s' not stored as a remote-tracking branch"),
1553                                 branch->merge[0]->src);
1554
1555        return branch->merge[0]->dst;
1556}
1557
1558static const char *tracking_for_push_dest(struct remote *remote,
1559                                          const char *refname,
1560                                          struct strbuf *err)
1561{
1562        char *ret;
1563
1564        ret = apply_refspecs(&remote->fetch, refname);
1565        if (!ret)
1566                return error_buf(err,
1567                                 _("push destination '%s' on remote '%s' has no local tracking branch"),
1568                                 refname, remote->name);
1569        return ret;
1570}
1571
1572static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1573{
1574        struct remote *remote;
1575
1576        remote = remote_get(pushremote_for_branch(branch, NULL));
1577        if (!remote)
1578                return error_buf(err,
1579                                 _("branch '%s' has no remote for pushing"),
1580                                 branch->name);
1581
1582        if (remote->push.nr) {
1583                char *dst;
1584                const char *ret;
1585
1586                dst = apply_refspecs(&remote->push, branch->refname);
1587                if (!dst)
1588                        return error_buf(err,
1589                                         _("push refspecs for '%s' do not include '%s'"),
1590                                         remote->name, branch->name);
1591
1592                ret = tracking_for_push_dest(remote, dst, err);
1593                free(dst);
1594                return ret;
1595        }
1596
1597        if (remote->mirror)
1598                return tracking_for_push_dest(remote, branch->refname, err);
1599
1600        switch (push_default) {
1601        case PUSH_DEFAULT_NOTHING:
1602                return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1603
1604        case PUSH_DEFAULT_MATCHING:
1605        case PUSH_DEFAULT_CURRENT:
1606                return tracking_for_push_dest(remote, branch->refname, err);
1607
1608        case PUSH_DEFAULT_UPSTREAM:
1609                return branch_get_upstream(branch, err);
1610
1611        case PUSH_DEFAULT_UNSPECIFIED:
1612        case PUSH_DEFAULT_SIMPLE:
1613                {
1614                        const char *up, *cur;
1615
1616                        up = branch_get_upstream(branch, err);
1617                        if (!up)
1618                                return NULL;
1619                        cur = tracking_for_push_dest(remote, branch->refname, err);
1620                        if (!cur)
1621                                return NULL;
1622                        if (strcmp(cur, up))
1623                                return error_buf(err,
1624                                                 _("cannot resolve 'simple' push to a single destination"));
1625                        return cur;
1626                }
1627        }
1628
1629        BUG("unhandled push situation");
1630}
1631
1632const char *branch_get_push(struct branch *branch, struct strbuf *err)
1633{
1634        if (!branch)
1635                return error_buf(err, _("HEAD does not point to a branch"));
1636
1637        if (!branch->push_tracking_ref)
1638                branch->push_tracking_ref = branch_get_push_1(branch, err);
1639        return branch->push_tracking_ref;
1640}
1641
1642static int ignore_symref_update(const char *refname)
1643{
1644        int flag;
1645
1646        if (!resolve_ref_unsafe(refname, 0, NULL, &flag))
1647                return 0; /* non-existing refs are OK */
1648        return (flag & REF_ISSYMREF);
1649}
1650
1651/*
1652 * Create and return a list of (struct ref) consisting of copies of
1653 * each remote_ref that matches refspec.  refspec must be a pattern.
1654 * Fill in the copies' peer_ref to describe the local tracking refs to
1655 * which they map.  Omit any references that would map to an existing
1656 * local symbolic ref.
1657 */
1658static struct ref *get_expanded_map(const struct ref *remote_refs,
1659                                    const struct refspec_item *refspec)
1660{
1661        const struct ref *ref;
1662        struct ref *ret = NULL;
1663        struct ref **tail = &ret;
1664
1665        for (ref = remote_refs; ref; ref = ref->next) {
1666                char *expn_name = NULL;
1667
1668                if (strchr(ref->name, '^'))
1669                        continue; /* a dereference item */
1670                if (match_name_with_pattern(refspec->src, ref->name,
1671                                            refspec->dst, &expn_name) &&
1672                    !ignore_symref_update(expn_name)) {
1673                        struct ref *cpy = copy_ref(ref);
1674
1675                        cpy->peer_ref = alloc_ref(expn_name);
1676                        if (refspec->force)
1677                                cpy->peer_ref->force = 1;
1678                        *tail = cpy;
1679                        tail = &cpy->next;
1680                }
1681                free(expn_name);
1682        }
1683
1684        return ret;
1685}
1686
1687static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1688{
1689        const struct ref *ref;
1690        for (ref = refs; ref; ref = ref->next) {
1691                if (refname_match(name, ref->name))
1692                        return ref;
1693        }
1694        return NULL;
1695}
1696
1697struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1698{
1699        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1700
1701        if (!ref)
1702                return NULL;
1703
1704        return copy_ref(ref);
1705}
1706
1707static struct ref *get_local_ref(const char *name)
1708{
1709        if (!name || name[0] == '\0')
1710                return NULL;
1711
1712        if (starts_with(name, "refs/"))
1713                return alloc_ref(name);
1714
1715        if (starts_with(name, "heads/") ||
1716            starts_with(name, "tags/") ||
1717            starts_with(name, "remotes/"))
1718                return alloc_ref_with_prefix("refs/", 5, name);
1719
1720        return alloc_ref_with_prefix("refs/heads/", 11, name);
1721}
1722
1723int get_fetch_map(const struct ref *remote_refs,
1724                  const struct refspec_item *refspec,
1725                  struct ref ***tail,
1726                  int missing_ok)
1727{
1728        struct ref *ref_map, **rmp;
1729
1730        if (refspec->pattern) {
1731                ref_map = get_expanded_map(remote_refs, refspec);
1732        } else {
1733                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1734
1735                if (refspec->exact_sha1) {
1736                        ref_map = alloc_ref(name);
1737                        get_oid_hex(name, &ref_map->old_oid);
1738                } else {
1739                        ref_map = get_remote_ref(remote_refs, name);
1740                }
1741                if (!missing_ok && !ref_map)
1742                        die("Couldn't find remote ref %s", name);
1743                if (ref_map) {
1744                        ref_map->peer_ref = get_local_ref(refspec->dst);
1745                        if (ref_map->peer_ref && refspec->force)
1746                                ref_map->peer_ref->force = 1;
1747                }
1748        }
1749
1750        for (rmp = &ref_map; *rmp; ) {
1751                if ((*rmp)->peer_ref) {
1752                        if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1753                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1754                                struct ref *ignore = *rmp;
1755                                error("* Ignoring funny ref '%s' locally",
1756                                      (*rmp)->peer_ref->name);
1757                                *rmp = (*rmp)->next;
1758                                free(ignore->peer_ref);
1759                                free(ignore);
1760                                continue;
1761                        }
1762                }
1763                rmp = &((*rmp)->next);
1764        }
1765
1766        if (ref_map)
1767                tail_link_ref(ref_map, tail);
1768
1769        return 0;
1770}
1771
1772int resolve_remote_symref(struct ref *ref, struct ref *list)
1773{
1774        if (!ref->symref)
1775                return 0;
1776        for (; list; list = list->next)
1777                if (!strcmp(ref->symref, list->name)) {
1778                        oidcpy(&ref->old_oid, &list->old_oid);
1779                        return 0;
1780                }
1781        return 1;
1782}
1783
1784static void unmark_and_free(struct commit_list *list, unsigned int mark)
1785{
1786        while (list) {
1787                struct commit *commit = pop_commit(&list);
1788                commit->object.flags &= ~mark;
1789        }
1790}
1791
1792int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
1793{
1794        struct object *o;
1795        struct commit *old_commit, *new_commit;
1796        struct commit_list *list, *used;
1797        int found = 0;
1798
1799        /*
1800         * Both new_commit and old_commit must be commit-ish and new_commit is descendant of
1801         * old_commit.  Otherwise we require --force.
1802         */
1803        o = deref_tag(parse_object(old_oid), NULL, 0);
1804        if (!o || o->type != OBJ_COMMIT)
1805                return 0;
1806        old_commit = (struct commit *) o;
1807
1808        o = deref_tag(parse_object(new_oid), NULL, 0);
1809        if (!o || o->type != OBJ_COMMIT)
1810                return 0;
1811        new_commit = (struct commit *) o;
1812
1813        if (parse_commit(new_commit) < 0)
1814                return 0;
1815
1816        used = list = NULL;
1817        commit_list_insert(new_commit, &list);
1818        while (list) {
1819                new_commit = pop_most_recent_commit(&list, TMP_MARK);
1820                commit_list_insert(new_commit, &used);
1821                if (new_commit == old_commit) {
1822                        found = 1;
1823                        break;
1824                }
1825        }
1826        unmark_and_free(list, TMP_MARK);
1827        unmark_and_free(used, TMP_MARK);
1828        return found;
1829}
1830
1831/*
1832 * Lookup the upstream branch for the given branch and if present, optionally
1833 * compute the commit ahead/behind values for the pair.
1834 *
1835 * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
1836 * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
1837 * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
1838 * set to zero).
1839 *
1840 * The name of the upstream branch (or NULL if no upstream is defined) is
1841 * returned via *upstream_name, if it is not itself NULL.
1842 *
1843 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1844 * upstream defined, or ref does not exist).  Returns 0 if the commits are
1845 * identical.  Returns 1 if commits are different.
1846 */
1847int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
1848                       const char **upstream_name, enum ahead_behind_flags abf)
1849{
1850        struct object_id oid;
1851        struct commit *ours, *theirs;
1852        struct rev_info revs;
1853        const char *base;
1854        struct argv_array argv = ARGV_ARRAY_INIT;
1855
1856        /* Cannot stat unless we are marked to build on top of somebody else. */
1857        base = branch_get_upstream(branch, NULL);
1858        if (upstream_name)
1859                *upstream_name = base;
1860        if (!base)
1861                return -1;
1862
1863        /* Cannot stat if what we used to build on no longer exists */
1864        if (read_ref(base, &oid))
1865                return -1;
1866        theirs = lookup_commit_reference(&oid);
1867        if (!theirs)
1868                return -1;
1869
1870        if (read_ref(branch->refname, &oid))
1871                return -1;
1872        ours = lookup_commit_reference(&oid);
1873        if (!ours)
1874                return -1;
1875
1876        *num_theirs = *num_ours = 0;
1877
1878        /* are we the same? */
1879        if (theirs == ours)
1880                return 0;
1881        if (abf == AHEAD_BEHIND_QUICK)
1882                return 1;
1883        if (abf != AHEAD_BEHIND_FULL)
1884                BUG("stat_tracking_info: invalid abf '%d'", abf);
1885
1886        /* Run "rev-list --left-right ours...theirs" internally... */
1887        argv_array_push(&argv, ""); /* ignored */
1888        argv_array_push(&argv, "--left-right");
1889        argv_array_pushf(&argv, "%s...%s",
1890                         oid_to_hex(&ours->object.oid),
1891                         oid_to_hex(&theirs->object.oid));
1892        argv_array_push(&argv, "--");
1893
1894        init_revisions(&revs, NULL);
1895        setup_revisions(argv.argc, argv.argv, &revs, NULL);
1896        if (prepare_revision_walk(&revs))
1897                die("revision walk setup failed");
1898
1899        /* ... and count the commits on each side. */
1900        while (1) {
1901                struct commit *c = get_revision(&revs);
1902                if (!c)
1903                        break;
1904                if (c->object.flags & SYMMETRIC_LEFT)
1905                        (*num_ours)++;
1906                else
1907                        (*num_theirs)++;
1908        }
1909
1910        /* clear object flags smudged by the above traversal */
1911        clear_commit_marks(ours, ALL_REV_FLAGS);
1912        clear_commit_marks(theirs, ALL_REV_FLAGS);
1913
1914        argv_array_clear(&argv);
1915        return 1;
1916}
1917
1918/*
1919 * Return true when there is anything to report, otherwise false.
1920 */
1921int format_tracking_info(struct branch *branch, struct strbuf *sb,
1922                         enum ahead_behind_flags abf)
1923{
1924        int ours, theirs, sti;
1925        const char *full_base;
1926        char *base;
1927        int upstream_is_gone = 0;
1928
1929        sti = stat_tracking_info(branch, &ours, &theirs, &full_base, abf);
1930        if (sti < 0) {
1931                if (!full_base)
1932                        return 0;
1933                upstream_is_gone = 1;
1934        }
1935
1936        base = shorten_unambiguous_ref(full_base, 0);
1937        if (upstream_is_gone) {
1938                strbuf_addf(sb,
1939                        _("Your branch is based on '%s', but the upstream is gone.\n"),
1940                        base);
1941                if (advice_status_hints)
1942                        strbuf_addstr(sb,
1943                                _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1944        } else if (!sti) {
1945                strbuf_addf(sb,
1946                        _("Your branch is up to date with '%s'.\n"),
1947                        base);
1948        } else if (abf == AHEAD_BEHIND_QUICK) {
1949                strbuf_addf(sb,
1950                            _("Your branch and '%s' refer to different commits.\n"),
1951                            base);
1952                if (advice_status_hints)
1953                        strbuf_addf(sb, _("  (use \"%s\" for details)\n"),
1954                                    "git status --ahead-behind");
1955        } else if (!theirs) {
1956                strbuf_addf(sb,
1957                        Q_("Your branch is ahead of '%s' by %d commit.\n",
1958                           "Your branch is ahead of '%s' by %d commits.\n",
1959                           ours),
1960                        base, ours);
1961                if (advice_status_hints)
1962                        strbuf_addstr(sb,
1963                                _("  (use \"git push\" to publish your local commits)\n"));
1964        } else if (!ours) {
1965                strbuf_addf(sb,
1966                        Q_("Your branch is behind '%s' by %d commit, "
1967                               "and can be fast-forwarded.\n",
1968                           "Your branch is behind '%s' by %d commits, "
1969                               "and can be fast-forwarded.\n",
1970                           theirs),
1971                        base, theirs);
1972                if (advice_status_hints)
1973                        strbuf_addstr(sb,
1974                                _("  (use \"git pull\" to update your local branch)\n"));
1975        } else {
1976                strbuf_addf(sb,
1977                        Q_("Your branch and '%s' have diverged,\n"
1978                               "and have %d and %d different commit each, "
1979                               "respectively.\n",
1980                           "Your branch and '%s' have diverged,\n"
1981                               "and have %d and %d different commits each, "
1982                               "respectively.\n",
1983                           ours + theirs),
1984                        base, ours, theirs);
1985                if (advice_status_hints)
1986                        strbuf_addstr(sb,
1987                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1988        }
1989        free(base);
1990        return 1;
1991}
1992
1993static int one_local_ref(const char *refname, const struct object_id *oid,
1994                         int flag, void *cb_data)
1995{
1996        struct ref ***local_tail = cb_data;
1997        struct ref *ref;
1998
1999        /* we already know it starts with refs/ to get here */
2000        if (check_refname_format(refname + 5, 0))
2001                return 0;
2002
2003        ref = alloc_ref(refname);
2004        oidcpy(&ref->new_oid, oid);
2005        **local_tail = ref;
2006        *local_tail = &ref->next;
2007        return 0;
2008}
2009
2010struct ref *get_local_heads(void)
2011{
2012        struct ref *local_refs = NULL, **local_tail = &local_refs;
2013
2014        for_each_ref(one_local_ref, &local_tail);
2015        return local_refs;
2016}
2017
2018struct ref *guess_remote_head(const struct ref *head,
2019                              const struct ref *refs,
2020                              int all)
2021{
2022        const struct ref *r;
2023        struct ref *list = NULL;
2024        struct ref **tail = &list;
2025
2026        if (!head)
2027                return NULL;
2028
2029        /*
2030         * Some transports support directly peeking at
2031         * where HEAD points; if that is the case, then
2032         * we don't have to guess.
2033         */
2034        if (head->symref)
2035                return copy_ref(find_ref_by_name(refs, head->symref));
2036
2037        /* If refs/heads/master could be right, it is. */
2038        if (!all) {
2039                r = find_ref_by_name(refs, "refs/heads/master");
2040                if (r && !oidcmp(&r->old_oid, &head->old_oid))
2041                        return copy_ref(r);
2042        }
2043
2044        /* Look for another ref that points there */
2045        for (r = refs; r; r = r->next) {
2046                if (r != head &&
2047                    starts_with(r->name, "refs/heads/") &&
2048                    !oidcmp(&r->old_oid, &head->old_oid)) {
2049                        *tail = copy_ref(r);
2050                        tail = &((*tail)->next);
2051                        if (!all)
2052                                break;
2053                }
2054        }
2055
2056        return list;
2057}
2058
2059struct stale_heads_info {
2060        struct string_list *ref_names;
2061        struct ref **stale_refs_tail;
2062        struct refspec *rs;
2063};
2064
2065static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2066                              int flags, void *cb_data)
2067{
2068        struct stale_heads_info *info = cb_data;
2069        struct string_list matches = STRING_LIST_INIT_DUP;
2070        struct refspec_item query;
2071        int i, stale = 1;
2072        memset(&query, 0, sizeof(struct refspec_item));
2073        query.dst = (char *)refname;
2074
2075        query_refspecs_multiple(info->rs, &query, &matches);
2076        if (matches.nr == 0)
2077                goto clean_exit; /* No matches */
2078
2079        /*
2080         * If we did find a suitable refspec and it's not a symref and
2081         * it's not in the list of refs that currently exist in that
2082         * remote, we consider it to be stale. In order to deal with
2083         * overlapping refspecs, we need to go over all of the
2084         * matching refs.
2085         */
2086        if (flags & REF_ISSYMREF)
2087                goto clean_exit;
2088
2089        for (i = 0; stale && i < matches.nr; i++)
2090                if (string_list_has_string(info->ref_names, matches.items[i].string))
2091                        stale = 0;
2092
2093        if (stale) {
2094                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2095                oidcpy(&ref->new_oid, oid);
2096        }
2097
2098clean_exit:
2099        string_list_clear(&matches, 0);
2100        return 0;
2101}
2102
2103struct ref *get_stale_heads(struct refspec *rs, struct ref *fetch_map)
2104{
2105        struct ref *ref, *stale_refs = NULL;
2106        struct string_list ref_names = STRING_LIST_INIT_NODUP;
2107        struct stale_heads_info info;
2108
2109        info.ref_names = &ref_names;
2110        info.stale_refs_tail = &stale_refs;
2111        info.rs = rs;
2112        for (ref = fetch_map; ref; ref = ref->next)
2113                string_list_append(&ref_names, ref->name);
2114        string_list_sort(&ref_names);
2115        for_each_ref(get_stale_heads_cb, &info);
2116        string_list_clear(&ref_names, 0);
2117        return stale_refs;
2118}
2119
2120/*
2121 * Compare-and-swap
2122 */
2123static void clear_cas_option(struct push_cas_option *cas)
2124{
2125        int i;
2126
2127        for (i = 0; i < cas->nr; i++)
2128                free(cas->entry[i].refname);
2129        free(cas->entry);
2130        memset(cas, 0, sizeof(*cas));
2131}
2132
2133static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2134                                      const char *refname,
2135                                      size_t refnamelen)
2136{
2137        struct push_cas *entry;
2138        ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2139        entry = &cas->entry[cas->nr++];
2140        memset(entry, 0, sizeof(*entry));
2141        entry->refname = xmemdupz(refname, refnamelen);
2142        return entry;
2143}
2144
2145static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2146{
2147        const char *colon;
2148        struct push_cas *entry;
2149
2150        if (unset) {
2151                /* "--no-<option>" */
2152                clear_cas_option(cas);
2153                return 0;
2154        }
2155
2156        if (!arg) {
2157                /* just "--<option>" */
2158                cas->use_tracking_for_rest = 1;
2159                return 0;
2160        }
2161
2162        /* "--<option>=refname" or "--<option>=refname:value" */
2163        colon = strchrnul(arg, ':');
2164        entry = add_cas_entry(cas, arg, colon - arg);
2165        if (!*colon)
2166                entry->use_tracking = 1;
2167        else if (!colon[1])
2168                oidclr(&entry->expect);
2169        else if (get_oid(colon + 1, &entry->expect))
2170                return error("cannot parse expected object name '%s'", colon + 1);
2171        return 0;
2172}
2173
2174int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2175{
2176        return parse_push_cas_option(opt->value, arg, unset);
2177}
2178
2179int is_empty_cas(const struct push_cas_option *cas)
2180{
2181        return !cas->use_tracking_for_rest && !cas->nr;
2182}
2183
2184/*
2185 * Look at remote.fetch refspec and see if we have a remote
2186 * tracking branch for the refname there.  Fill its current
2187 * value in sha1[].
2188 * If we cannot do so, return negative to signal an error.
2189 */
2190static int remote_tracking(struct remote *remote, const char *refname,
2191                           struct object_id *oid)
2192{
2193        char *dst;
2194
2195        dst = apply_refspecs(&remote->fetch, refname);
2196        if (!dst)
2197                return -1; /* no tracking ref for refname at remote */
2198        if (read_ref(dst, oid))
2199                return -1; /* we know what the tracking ref is but we cannot read it */
2200        return 0;
2201}
2202
2203static void apply_cas(struct push_cas_option *cas,
2204                      struct remote *remote,
2205                      struct ref *ref)
2206{
2207        int i;
2208
2209        /* Find an explicit --<option>=<name>[:<value>] entry */
2210        for (i = 0; i < cas->nr; i++) {
2211                struct push_cas *entry = &cas->entry[i];
2212                if (!refname_match(entry->refname, ref->name))
2213                        continue;
2214                ref->expect_old_sha1 = 1;
2215                if (!entry->use_tracking)
2216                        oidcpy(&ref->old_oid_expect, &entry->expect);
2217                else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2218                        oidclr(&ref->old_oid_expect);
2219                return;
2220        }
2221
2222        /* Are we using "--<option>" to cover all? */
2223        if (!cas->use_tracking_for_rest)
2224                return;
2225
2226        ref->expect_old_sha1 = 1;
2227        if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2228                oidclr(&ref->old_oid_expect);
2229}
2230
2231void apply_push_cas(struct push_cas_option *cas,
2232                    struct remote *remote,
2233                    struct ref *remote_refs)
2234{
2235        struct ref *ref;
2236        for (ref = remote_refs; ref; ref = ref->next)
2237                apply_cas(cas, remote, ref);
2238}