remote.con commit lockfile: allow reopening a closed but still locked file (93dcaea)
   1#include "cache.h"
   2#include "remote.h"
   3#include "refs.h"
   4#include "commit.h"
   5#include "diff.h"
   6#include "revision.h"
   7#include "dir.h"
   8#include "tag.h"
   9#include "string-list.h"
  10#include "mergesort.h"
  11
  12enum map_direction { FROM_SRC, FROM_DST };
  13
  14static struct refspec s_tag_refspec = {
  15        0,
  16        1,
  17        0,
  18        0,
  19        "refs/tags/*",
  20        "refs/tags/*"
  21};
  22
  23const struct refspec *tag_refspec = &s_tag_refspec;
  24
  25struct counted_string {
  26        size_t len;
  27        const char *s;
  28};
  29struct rewrite {
  30        const char *base;
  31        size_t baselen;
  32        struct counted_string *instead_of;
  33        int instead_of_nr;
  34        int instead_of_alloc;
  35};
  36struct rewrites {
  37        struct rewrite **rewrite;
  38        int rewrite_alloc;
  39        int rewrite_nr;
  40};
  41
  42static struct remote **remotes;
  43static int remotes_alloc;
  44static int remotes_nr;
  45
  46static struct branch **branches;
  47static int branches_alloc;
  48static int branches_nr;
  49
  50static struct branch *current_branch;
  51static const char *default_remote_name;
  52static const char *branch_pushremote_name;
  53static const char *pushremote_name;
  54static int explicit_default_remote_name;
  55
  56static struct rewrites rewrites;
  57static struct rewrites rewrites_push;
  58
  59#define BUF_SIZE (2048)
  60static char buffer[BUF_SIZE];
  61
  62static int valid_remote(const struct remote *remote)
  63{
  64        return (!!remote->url) || (!!remote->foreign_vcs);
  65}
  66
  67static const char *alias_url(const char *url, struct rewrites *r)
  68{
  69        int i, j;
  70        char *ret;
  71        struct counted_string *longest;
  72        int longest_i;
  73
  74        longest = NULL;
  75        longest_i = -1;
  76        for (i = 0; i < r->rewrite_nr; i++) {
  77                if (!r->rewrite[i])
  78                        continue;
  79                for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
  80                        if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
  81                            (!longest ||
  82                             longest->len < r->rewrite[i]->instead_of[j].len)) {
  83                                longest = &(r->rewrite[i]->instead_of[j]);
  84                                longest_i = i;
  85                        }
  86                }
  87        }
  88        if (!longest)
  89                return url;
  90
  91        ret = xmalloc(r->rewrite[longest_i]->baselen +
  92                     (strlen(url) - longest->len) + 1);
  93        strcpy(ret, r->rewrite[longest_i]->base);
  94        strcpy(ret + r->rewrite[longest_i]->baselen, url + longest->len);
  95        return ret;
  96}
  97
  98static void add_push_refspec(struct remote *remote, const char *ref)
  99{
 100        ALLOC_GROW(remote->push_refspec,
 101                   remote->push_refspec_nr + 1,
 102                   remote->push_refspec_alloc);
 103        remote->push_refspec[remote->push_refspec_nr++] = ref;
 104}
 105
 106static void add_fetch_refspec(struct remote *remote, const char *ref)
 107{
 108        ALLOC_GROW(remote->fetch_refspec,
 109                   remote->fetch_refspec_nr + 1,
 110                   remote->fetch_refspec_alloc);
 111        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 112}
 113
 114static void add_url(struct remote *remote, const char *url)
 115{
 116        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
 117        remote->url[remote->url_nr++] = url;
 118}
 119
 120static void add_pushurl(struct remote *remote, const char *pushurl)
 121{
 122        ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
 123        remote->pushurl[remote->pushurl_nr++] = pushurl;
 124}
 125
 126static void add_pushurl_alias(struct remote *remote, const char *url)
 127{
 128        const char *pushurl = alias_url(url, &rewrites_push);
 129        if (pushurl != url)
 130                add_pushurl(remote, pushurl);
 131}
 132
 133static void add_url_alias(struct remote *remote, const char *url)
 134{
 135        add_url(remote, alias_url(url, &rewrites));
 136        add_pushurl_alias(remote, url);
 137}
 138
 139static struct remote *make_remote(const char *name, int len)
 140{
 141        struct remote *ret;
 142        int i;
 143
 144        for (i = 0; i < remotes_nr; i++) {
 145                if (len ? (!strncmp(name, remotes[i]->name, len) &&
 146                           !remotes[i]->name[len]) :
 147                    !strcmp(name, remotes[i]->name))
 148                        return remotes[i];
 149        }
 150
 151        ret = xcalloc(1, sizeof(struct remote));
 152        ret->prune = -1;  /* unspecified */
 153        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 154        remotes[remotes_nr++] = ret;
 155        if (len)
 156                ret->name = xstrndup(name, len);
 157        else
 158                ret->name = xstrdup(name);
 159        return ret;
 160}
 161
 162static void add_merge(struct branch *branch, const char *name)
 163{
 164        ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
 165                   branch->merge_alloc);
 166        branch->merge_name[branch->merge_nr++] = name;
 167}
 168
 169static struct branch *make_branch(const char *name, int len)
 170{
 171        struct branch *ret;
 172        int i;
 173        char *refname;
 174
 175        for (i = 0; i < branches_nr; i++) {
 176                if (len ? (!strncmp(name, branches[i]->name, len) &&
 177                           !branches[i]->name[len]) :
 178                    !strcmp(name, branches[i]->name))
 179                        return branches[i];
 180        }
 181
 182        ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 183        ret = xcalloc(1, sizeof(struct branch));
 184        branches[branches_nr++] = ret;
 185        if (len)
 186                ret->name = xstrndup(name, len);
 187        else
 188                ret->name = xstrdup(name);
 189        refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 190        strcpy(refname, "refs/heads/");
 191        strcpy(refname + strlen("refs/heads/"), ret->name);
 192        ret->refname = refname;
 193
 194        return ret;
 195}
 196
 197static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
 198{
 199        struct rewrite *ret;
 200        int i;
 201
 202        for (i = 0; i < r->rewrite_nr; i++) {
 203                if (len
 204                    ? (len == r->rewrite[i]->baselen &&
 205                       !strncmp(base, r->rewrite[i]->base, len))
 206                    : !strcmp(base, r->rewrite[i]->base))
 207                        return r->rewrite[i];
 208        }
 209
 210        ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 211        ret = xcalloc(1, sizeof(struct rewrite));
 212        r->rewrite[r->rewrite_nr++] = ret;
 213        if (len) {
 214                ret->base = xstrndup(base, len);
 215                ret->baselen = len;
 216        }
 217        else {
 218                ret->base = xstrdup(base);
 219                ret->baselen = strlen(base);
 220        }
 221        return ret;
 222}
 223
 224static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
 225{
 226        ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
 227        rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
 228        rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
 229        rewrite->instead_of_nr++;
 230}
 231
 232static void read_remotes_file(struct remote *remote)
 233{
 234        FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
 235
 236        if (!f)
 237                return;
 238        remote->origin = REMOTE_REMOTES;
 239        while (fgets(buffer, BUF_SIZE, f)) {
 240                int value_list;
 241                char *s, *p;
 242
 243                if (starts_with(buffer, "URL:")) {
 244                        value_list = 0;
 245                        s = buffer + 4;
 246                } else if (starts_with(buffer, "Push:")) {
 247                        value_list = 1;
 248                        s = buffer + 5;
 249                } else if (starts_with(buffer, "Pull:")) {
 250                        value_list = 2;
 251                        s = buffer + 5;
 252                } else
 253                        continue;
 254
 255                while (isspace(*s))
 256                        s++;
 257                if (!*s)
 258                        continue;
 259
 260                p = s + strlen(s);
 261                while (isspace(p[-1]))
 262                        *--p = 0;
 263
 264                switch (value_list) {
 265                case 0:
 266                        add_url_alias(remote, xstrdup(s));
 267                        break;
 268                case 1:
 269                        add_push_refspec(remote, xstrdup(s));
 270                        break;
 271                case 2:
 272                        add_fetch_refspec(remote, xstrdup(s));
 273                        break;
 274                }
 275        }
 276        fclose(f);
 277}
 278
 279static void read_branches_file(struct remote *remote)
 280{
 281        char *frag;
 282        struct strbuf branch = STRBUF_INIT;
 283        int n = 1000;
 284        FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 285        char *s, *p;
 286        int len;
 287
 288        if (!f)
 289                return;
 290        s = fgets(buffer, BUF_SIZE, f);
 291        fclose(f);
 292        if (!s)
 293                return;
 294        while (isspace(*s))
 295                s++;
 296        if (!*s)
 297                return;
 298        remote->origin = REMOTE_BRANCHES;
 299        p = s + strlen(s);
 300        while (isspace(p[-1]))
 301                *--p = 0;
 302        len = p - s;
 303        p = xmalloc(len + 1);
 304        strcpy(p, s);
 305
 306        /*
 307         * The branches file would have URL and optionally
 308         * #branch specified.  The "master" (or specified) branch is
 309         * fetched and stored in the local branch of the same name.
 310         */
 311        frag = strchr(p, '#');
 312        if (frag) {
 313                *(frag++) = '\0';
 314                strbuf_addf(&branch, "refs/heads/%s", frag);
 315        } else
 316                strbuf_addstr(&branch, "refs/heads/master");
 317
 318        strbuf_addf(&branch, ":refs/heads/%s", remote->name);
 319        add_url_alias(remote, p);
 320        add_fetch_refspec(remote, strbuf_detach(&branch, NULL));
 321        /*
 322         * Cogito compatible push: push current HEAD to remote #branch
 323         * (master if missing)
 324         */
 325        strbuf_init(&branch, 0);
 326        strbuf_addstr(&branch, "HEAD");
 327        if (frag)
 328                strbuf_addf(&branch, ":refs/heads/%s", frag);
 329        else
 330                strbuf_addstr(&branch, ":refs/heads/master");
 331        add_push_refspec(remote, strbuf_detach(&branch, NULL));
 332        remote->fetch_tags = 1; /* always auto-follow */
 333}
 334
 335static int handle_config(const char *key, const char *value, void *cb)
 336{
 337        const char *name;
 338        const char *subkey;
 339        struct remote *remote;
 340        struct branch *branch;
 341        if (starts_with(key, "branch.")) {
 342                name = key + 7;
 343                subkey = strrchr(name, '.');
 344                if (!subkey)
 345                        return 0;
 346                branch = make_branch(name, subkey - name);
 347                if (!strcmp(subkey, ".remote")) {
 348                        if (git_config_string(&branch->remote_name, key, value))
 349                                return -1;
 350                        if (branch == current_branch) {
 351                                default_remote_name = branch->remote_name;
 352                                explicit_default_remote_name = 1;
 353                        }
 354                } else if (!strcmp(subkey, ".pushremote")) {
 355                        if (branch == current_branch)
 356                                if (git_config_string(&branch_pushremote_name, key, value))
 357                                        return -1;
 358                } else if (!strcmp(subkey, ".merge")) {
 359                        if (!value)
 360                                return config_error_nonbool(key);
 361                        add_merge(branch, xstrdup(value));
 362                }
 363                return 0;
 364        }
 365        if (starts_with(key, "url.")) {
 366                struct rewrite *rewrite;
 367                name = key + 4;
 368                subkey = strrchr(name, '.');
 369                if (!subkey)
 370                        return 0;
 371                if (!strcmp(subkey, ".insteadof")) {
 372                        rewrite = make_rewrite(&rewrites, name, subkey - name);
 373                        if (!value)
 374                                return config_error_nonbool(key);
 375                        add_instead_of(rewrite, xstrdup(value));
 376                } else if (!strcmp(subkey, ".pushinsteadof")) {
 377                        rewrite = make_rewrite(&rewrites_push, name, subkey - name);
 378                        if (!value)
 379                                return config_error_nonbool(key);
 380                        add_instead_of(rewrite, xstrdup(value));
 381                }
 382        }
 383
 384        if (!starts_with(key,  "remote."))
 385                return 0;
 386        name = key + 7;
 387
 388        /* Handle remote.* variables */
 389        if (!strcmp(name, "pushdefault"))
 390                return git_config_string(&pushremote_name, key, value);
 391
 392        /* Handle remote.<name>.* variables */
 393        if (*name == '/') {
 394                warning("Config remote shorthand cannot begin with '/': %s",
 395                        name);
 396                return 0;
 397        }
 398        subkey = strrchr(name, '.');
 399        if (!subkey)
 400                return 0;
 401        remote = make_remote(name, subkey - name);
 402        remote->origin = REMOTE_CONFIG;
 403        if (!strcmp(subkey, ".mirror"))
 404                remote->mirror = git_config_bool(key, value);
 405        else if (!strcmp(subkey, ".skipdefaultupdate"))
 406                remote->skip_default_update = git_config_bool(key, value);
 407        else if (!strcmp(subkey, ".skipfetchall"))
 408                remote->skip_default_update = git_config_bool(key, value);
 409        else if (!strcmp(subkey, ".prune"))
 410                remote->prune = git_config_bool(key, value);
 411        else if (!strcmp(subkey, ".url")) {
 412                const char *v;
 413                if (git_config_string(&v, key, value))
 414                        return -1;
 415                add_url(remote, v);
 416        } else if (!strcmp(subkey, ".pushurl")) {
 417                const char *v;
 418                if (git_config_string(&v, key, value))
 419                        return -1;
 420                add_pushurl(remote, v);
 421        } else if (!strcmp(subkey, ".push")) {
 422                const char *v;
 423                if (git_config_string(&v, key, value))
 424                        return -1;
 425                add_push_refspec(remote, v);
 426        } else if (!strcmp(subkey, ".fetch")) {
 427                const char *v;
 428                if (git_config_string(&v, key, value))
 429                        return -1;
 430                add_fetch_refspec(remote, v);
 431        } else if (!strcmp(subkey, ".receivepack")) {
 432                const char *v;
 433                if (git_config_string(&v, key, value))
 434                        return -1;
 435                if (!remote->receivepack)
 436                        remote->receivepack = v;
 437                else
 438                        error("more than one receivepack given, using the first");
 439        } else if (!strcmp(subkey, ".uploadpack")) {
 440                const char *v;
 441                if (git_config_string(&v, key, value))
 442                        return -1;
 443                if (!remote->uploadpack)
 444                        remote->uploadpack = v;
 445                else
 446                        error("more than one uploadpack given, using the first");
 447        } else if (!strcmp(subkey, ".tagopt")) {
 448                if (!strcmp(value, "--no-tags"))
 449                        remote->fetch_tags = -1;
 450                else if (!strcmp(value, "--tags"))
 451                        remote->fetch_tags = 2;
 452        } else if (!strcmp(subkey, ".proxy")) {
 453                return git_config_string((const char **)&remote->http_proxy,
 454                                         key, value);
 455        } else if (!strcmp(subkey, ".vcs")) {
 456                return git_config_string(&remote->foreign_vcs, key, value);
 457        }
 458        return 0;
 459}
 460
 461static void alias_all_urls(void)
 462{
 463        int i, j;
 464        for (i = 0; i < remotes_nr; i++) {
 465                int add_pushurl_aliases;
 466                if (!remotes[i])
 467                        continue;
 468                for (j = 0; j < remotes[i]->pushurl_nr; j++) {
 469                        remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
 470                }
 471                add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
 472                for (j = 0; j < remotes[i]->url_nr; j++) {
 473                        if (add_pushurl_aliases)
 474                                add_pushurl_alias(remotes[i], remotes[i]->url[j]);
 475                        remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
 476                }
 477        }
 478}
 479
 480static void read_config(void)
 481{
 482        unsigned char sha1[20];
 483        const char *head_ref;
 484        int flag;
 485        if (default_remote_name) /* did this already */
 486                return;
 487        default_remote_name = "origin";
 488        current_branch = NULL;
 489        head_ref = resolve_ref_unsafe("HEAD", sha1, 0, &flag);
 490        if (head_ref && (flag & REF_ISSYMREF) &&
 491            starts_with(head_ref, "refs/heads/")) {
 492                current_branch =
 493                        make_branch(head_ref + strlen("refs/heads/"), 0);
 494        }
 495        git_config(handle_config, NULL);
 496        if (branch_pushremote_name) {
 497                free((char *)pushremote_name);
 498                pushremote_name = branch_pushremote_name;
 499        }
 500        alias_all_urls();
 501}
 502
 503/*
 504 * This function frees a refspec array.
 505 * Warning: code paths should be checked to ensure that the src
 506 *          and dst pointers are always freeable pointers as well
 507 *          as the refspec pointer itself.
 508 */
 509static void free_refspecs(struct refspec *refspec, int nr_refspec)
 510{
 511        int i;
 512
 513        if (!refspec)
 514                return;
 515
 516        for (i = 0; i < nr_refspec; i++) {
 517                free(refspec[i].src);
 518                free(refspec[i].dst);
 519        }
 520        free(refspec);
 521}
 522
 523static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 524{
 525        int i;
 526        struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 527
 528        for (i = 0; i < nr_refspec; i++) {
 529                size_t llen;
 530                int is_glob;
 531                const char *lhs, *rhs;
 532                int flags;
 533
 534                is_glob = 0;
 535
 536                lhs = refspec[i];
 537                if (*lhs == '+') {
 538                        rs[i].force = 1;
 539                        lhs++;
 540                }
 541
 542                rhs = strrchr(lhs, ':');
 543
 544                /*
 545                 * Before going on, special case ":" (or "+:") as a refspec
 546                 * for pushing matching refs.
 547                 */
 548                if (!fetch && rhs == lhs && rhs[1] == '\0') {
 549                        rs[i].matching = 1;
 550                        continue;
 551                }
 552
 553                if (rhs) {
 554                        size_t rlen = strlen(++rhs);
 555                        is_glob = (1 <= rlen && strchr(rhs, '*'));
 556                        rs[i].dst = xstrndup(rhs, rlen);
 557                }
 558
 559                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 560                if (1 <= llen && memchr(lhs, '*', llen)) {
 561                        if ((rhs && !is_glob) || (!rhs && fetch))
 562                                goto invalid;
 563                        is_glob = 1;
 564                } else if (rhs && is_glob) {
 565                        goto invalid;
 566                }
 567
 568                rs[i].pattern = is_glob;
 569                rs[i].src = xstrndup(lhs, llen);
 570                flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 571
 572                if (fetch) {
 573                        unsigned char unused[40];
 574
 575                        /* LHS */
 576                        if (!*rs[i].src)
 577                                ; /* empty is ok; it means "HEAD" */
 578                        else if (llen == 40 && !get_sha1_hex(rs[i].src, unused))
 579                                rs[i].exact_sha1 = 1; /* ok */
 580                        else if (!check_refname_format(rs[i].src, flags))
 581                                ; /* valid looking ref is ok */
 582                        else
 583                                goto invalid;
 584                        /* RHS */
 585                        if (!rs[i].dst)
 586                                ; /* missing is ok; it is the same as empty */
 587                        else if (!*rs[i].dst)
 588                                ; /* empty is ok; it means "do not store" */
 589                        else if (!check_refname_format(rs[i].dst, flags))
 590                                ; /* valid looking ref is ok */
 591                        else
 592                                goto invalid;
 593                } else {
 594                        /*
 595                         * LHS
 596                         * - empty is allowed; it means delete.
 597                         * - when wildcarded, it must be a valid looking ref.
 598                         * - otherwise, it must be an extended SHA-1, but
 599                         *   there is no existing way to validate this.
 600                         */
 601                        if (!*rs[i].src)
 602                                ; /* empty is ok */
 603                        else if (is_glob) {
 604                                if (check_refname_format(rs[i].src, flags))
 605                                        goto invalid;
 606                        }
 607                        else
 608                                ; /* anything goes, for now */
 609                        /*
 610                         * RHS
 611                         * - missing is allowed, but LHS then must be a
 612                         *   valid looking ref.
 613                         * - empty is not allowed.
 614                         * - otherwise it must be a valid looking ref.
 615                         */
 616                        if (!rs[i].dst) {
 617                                if (check_refname_format(rs[i].src, flags))
 618                                        goto invalid;
 619                        } else if (!*rs[i].dst) {
 620                                goto invalid;
 621                        } else {
 622                                if (check_refname_format(rs[i].dst, flags))
 623                                        goto invalid;
 624                        }
 625                }
 626        }
 627        return rs;
 628
 629 invalid:
 630        if (verify) {
 631                /*
 632                 * nr_refspec must be greater than zero and i must be valid
 633                 * since it is only possible to reach this point from within
 634                 * the for loop above.
 635                 */
 636                free_refspecs(rs, i+1);
 637                return NULL;
 638        }
 639        die("Invalid refspec '%s'", refspec[i]);
 640}
 641
 642int valid_fetch_refspec(const char *fetch_refspec_str)
 643{
 644        struct refspec *refspec;
 645
 646        refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
 647        free_refspecs(refspec, 1);
 648        return !!refspec;
 649}
 650
 651struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 652{
 653        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 654}
 655
 656static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 657{
 658        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 659}
 660
 661void free_refspec(int nr_refspec, struct refspec *refspec)
 662{
 663        int i;
 664        for (i = 0; i < nr_refspec; i++) {
 665                free(refspec[i].src);
 666                free(refspec[i].dst);
 667        }
 668        free(refspec);
 669}
 670
 671static int valid_remote_nick(const char *name)
 672{
 673        if (!name[0] || is_dot_or_dotdot(name))
 674                return 0;
 675        return !strchr(name, '/'); /* no slash */
 676}
 677
 678static struct remote *remote_get_1(const char *name, const char *pushremote_name)
 679{
 680        struct remote *ret;
 681        int name_given = 0;
 682
 683        if (name)
 684                name_given = 1;
 685        else {
 686                if (pushremote_name) {
 687                        name = pushremote_name;
 688                        name_given = 1;
 689                } else {
 690                        name = default_remote_name;
 691                        name_given = explicit_default_remote_name;
 692                }
 693        }
 694
 695        ret = make_remote(name, 0);
 696        if (valid_remote_nick(name)) {
 697                if (!valid_remote(ret))
 698                        read_remotes_file(ret);
 699                if (!valid_remote(ret))
 700                        read_branches_file(ret);
 701        }
 702        if (name_given && !valid_remote(ret))
 703                add_url_alias(ret, name);
 704        if (!valid_remote(ret))
 705                return NULL;
 706        ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 707        ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
 708        return ret;
 709}
 710
 711struct remote *remote_get(const char *name)
 712{
 713        read_config();
 714        return remote_get_1(name, NULL);
 715}
 716
 717struct remote *pushremote_get(const char *name)
 718{
 719        read_config();
 720        return remote_get_1(name, pushremote_name);
 721}
 722
 723int remote_is_configured(const char *name)
 724{
 725        int i;
 726        read_config();
 727
 728        for (i = 0; i < remotes_nr; i++)
 729                if (!strcmp(name, remotes[i]->name))
 730                        return 1;
 731        return 0;
 732}
 733
 734int for_each_remote(each_remote_fn fn, void *priv)
 735{
 736        int i, result = 0;
 737        read_config();
 738        for (i = 0; i < remotes_nr && !result; i++) {
 739                struct remote *r = remotes[i];
 740                if (!r)
 741                        continue;
 742                if (!r->fetch)
 743                        r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
 744                                                       r->fetch_refspec);
 745                if (!r->push)
 746                        r->push = parse_push_refspec(r->push_refspec_nr,
 747                                                     r->push_refspec);
 748                result = fn(r, priv);
 749        }
 750        return result;
 751}
 752
 753static void handle_duplicate(struct ref *ref1, struct ref *ref2)
 754{
 755        if (strcmp(ref1->name, ref2->name)) {
 756                if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 757                    ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
 758                        die(_("Cannot fetch both %s and %s to %s"),
 759                            ref1->name, ref2->name, ref2->peer_ref->name);
 760                } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
 761                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 762                        warning(_("%s usually tracks %s, not %s"),
 763                                ref2->peer_ref->name, ref2->name, ref1->name);
 764                } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
 765                           ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
 766                        die(_("%s tracks both %s and %s"),
 767                            ref2->peer_ref->name, ref1->name, ref2->name);
 768                } else {
 769                        /*
 770                         * This last possibility doesn't occur because
 771                         * FETCH_HEAD_IGNORE entries always appear at
 772                         * the end of the list.
 773                         */
 774                        die(_("Internal error"));
 775                }
 776        }
 777        free(ref2->peer_ref);
 778        free(ref2);
 779}
 780
 781struct ref *ref_remove_duplicates(struct ref *ref_map)
 782{
 783        struct string_list refs = STRING_LIST_INIT_NODUP;
 784        struct ref *retval = NULL;
 785        struct ref **p = &retval;
 786
 787        while (ref_map) {
 788                struct ref *ref = ref_map;
 789
 790                ref_map = ref_map->next;
 791                ref->next = NULL;
 792
 793                if (!ref->peer_ref) {
 794                        *p = ref;
 795                        p = &ref->next;
 796                } else {
 797                        struct string_list_item *item =
 798                                string_list_insert(&refs, ref->peer_ref->name);
 799
 800                        if (item->util) {
 801                                /* Entry already existed */
 802                                handle_duplicate((struct ref *)item->util, ref);
 803                        } else {
 804                                *p = ref;
 805                                p = &ref->next;
 806                                item->util = ref;
 807                        }
 808                }
 809        }
 810
 811        string_list_clear(&refs, 0);
 812        return retval;
 813}
 814
 815int remote_has_url(struct remote *remote, const char *url)
 816{
 817        int i;
 818        for (i = 0; i < remote->url_nr; i++) {
 819                if (!strcmp(remote->url[i], url))
 820                        return 1;
 821        }
 822        return 0;
 823}
 824
 825static int match_name_with_pattern(const char *key, const char *name,
 826                                   const char *value, char **result)
 827{
 828        const char *kstar = strchr(key, '*');
 829        size_t klen;
 830        size_t ksuffixlen;
 831        size_t namelen;
 832        int ret;
 833        if (!kstar)
 834                die("Key '%s' of pattern had no '*'", key);
 835        klen = kstar - key;
 836        ksuffixlen = strlen(kstar + 1);
 837        namelen = strlen(name);
 838        ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
 839                !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
 840        if (ret && value) {
 841                const char *vstar = strchr(value, '*');
 842                size_t vlen;
 843                size_t vsuffixlen;
 844                if (!vstar)
 845                        die("Value '%s' of pattern has no '*'", value);
 846                vlen = vstar - value;
 847                vsuffixlen = strlen(vstar + 1);
 848                *result = xmalloc(vlen + vsuffixlen +
 849                                  strlen(name) -
 850                                  klen - ksuffixlen + 1);
 851                strncpy(*result, value, vlen);
 852                strncpy(*result + vlen,
 853                        name + klen, namelen - klen - ksuffixlen);
 854                strcpy(*result + vlen + namelen - klen - ksuffixlen,
 855                       vstar + 1);
 856        }
 857        return ret;
 858}
 859
 860static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
 861{
 862        int i;
 863        int find_src = !query->src;
 864
 865        if (find_src && !query->dst)
 866                error("query_refspecs_multiple: need either src or dst");
 867
 868        for (i = 0; i < ref_count; i++) {
 869                struct refspec *refspec = &refs[i];
 870                const char *key = find_src ? refspec->dst : refspec->src;
 871                const char *value = find_src ? refspec->src : refspec->dst;
 872                const char *needle = find_src ? query->dst : query->src;
 873                char **result = find_src ? &query->src : &query->dst;
 874
 875                if (!refspec->dst)
 876                        continue;
 877                if (refspec->pattern) {
 878                        if (match_name_with_pattern(key, needle, value, result))
 879                                string_list_append_nodup(results, *result);
 880                } else if (!strcmp(needle, key)) {
 881                        string_list_append(results, value);
 882                }
 883        }
 884}
 885
 886int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
 887{
 888        int i;
 889        int find_src = !query->src;
 890        const char *needle = find_src ? query->dst : query->src;
 891        char **result = find_src ? &query->src : &query->dst;
 892
 893        if (find_src && !query->dst)
 894                return error("query_refspecs: need either src or dst");
 895
 896        for (i = 0; i < ref_count; i++) {
 897                struct refspec *refspec = &refs[i];
 898                const char *key = find_src ? refspec->dst : refspec->src;
 899                const char *value = find_src ? refspec->src : refspec->dst;
 900
 901                if (!refspec->dst)
 902                        continue;
 903                if (refspec->pattern) {
 904                        if (match_name_with_pattern(key, needle, value, result)) {
 905                                query->force = refspec->force;
 906                                return 0;
 907                        }
 908                } else if (!strcmp(needle, key)) {
 909                        *result = xstrdup(value);
 910                        query->force = refspec->force;
 911                        return 0;
 912                }
 913        }
 914        return -1;
 915}
 916
 917char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 918                     const char *name)
 919{
 920        struct refspec query;
 921
 922        memset(&query, 0, sizeof(struct refspec));
 923        query.src = (char *)name;
 924
 925        if (query_refspecs(refspecs, nr_refspec, &query))
 926                return NULL;
 927
 928        return query.dst;
 929}
 930
 931int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 932{
 933        return query_refspecs(remote->fetch, remote->fetch_refspec_nr, refspec);
 934}
 935
 936static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
 937                const char *name)
 938{
 939        size_t len = strlen(name);
 940        struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
 941        memcpy(ref->name, prefix, prefixlen);
 942        memcpy(ref->name + prefixlen, name, len);
 943        return ref;
 944}
 945
 946struct ref *alloc_ref(const char *name)
 947{
 948        return alloc_ref_with_prefix("", 0, name);
 949}
 950
 951struct ref *copy_ref(const struct ref *ref)
 952{
 953        struct ref *cpy;
 954        size_t len;
 955        if (!ref)
 956                return NULL;
 957        len = strlen(ref->name);
 958        cpy = xmalloc(sizeof(struct ref) + len + 1);
 959        memcpy(cpy, ref, sizeof(struct ref) + len + 1);
 960        cpy->next = NULL;
 961        cpy->symref = ref->symref ? xstrdup(ref->symref) : NULL;
 962        cpy->remote_status = ref->remote_status ? xstrdup(ref->remote_status) : NULL;
 963        cpy->peer_ref = copy_ref(ref->peer_ref);
 964        return cpy;
 965}
 966
 967struct ref *copy_ref_list(const struct ref *ref)
 968{
 969        struct ref *ret = NULL;
 970        struct ref **tail = &ret;
 971        while (ref) {
 972                *tail = copy_ref(ref);
 973                ref = ref->next;
 974                tail = &((*tail)->next);
 975        }
 976        return ret;
 977}
 978
 979static void free_ref(struct ref *ref)
 980{
 981        if (!ref)
 982                return;
 983        free_ref(ref->peer_ref);
 984        free(ref->remote_status);
 985        free(ref->symref);
 986        free(ref);
 987}
 988
 989void free_refs(struct ref *ref)
 990{
 991        struct ref *next;
 992        while (ref) {
 993                next = ref->next;
 994                free_ref(ref);
 995                ref = next;
 996        }
 997}
 998
 999int ref_compare_name(const void *va, const void *vb)
1000{
1001        const struct ref *a = va, *b = vb;
1002        return strcmp(a->name, b->name);
1003}
1004
1005static void *ref_list_get_next(const void *a)
1006{
1007        return ((const struct ref *)a)->next;
1008}
1009
1010static void ref_list_set_next(void *a, void *next)
1011{
1012        ((struct ref *)a)->next = next;
1013}
1014
1015void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
1016{
1017        *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
1018}
1019
1020int count_refspec_match(const char *pattern,
1021                        struct ref *refs,
1022                        struct ref **matched_ref)
1023{
1024        int patlen = strlen(pattern);
1025        struct ref *matched_weak = NULL;
1026        struct ref *matched = NULL;
1027        int weak_match = 0;
1028        int match = 0;
1029
1030        for (weak_match = match = 0; refs; refs = refs->next) {
1031                char *name = refs->name;
1032                int namelen = strlen(name);
1033
1034                if (!refname_match(pattern, name))
1035                        continue;
1036
1037                /* A match is "weak" if it is with refs outside
1038                 * heads or tags, and did not specify the pattern
1039                 * in full (e.g. "refs/remotes/origin/master") or at
1040                 * least from the toplevel (e.g. "remotes/origin/master");
1041                 * otherwise "git push $URL master" would result in
1042                 * ambiguity between remotes/origin/master and heads/master
1043                 * at the remote site.
1044                 */
1045                if (namelen != patlen &&
1046                    patlen != namelen - 5 &&
1047                    !starts_with(name, "refs/heads/") &&
1048                    !starts_with(name, "refs/tags/")) {
1049                        /* We want to catch the case where only weak
1050                         * matches are found and there are multiple
1051                         * matches, and where more than one strong
1052                         * matches are found, as ambiguous.  One
1053                         * strong match with zero or more weak matches
1054                         * are acceptable as a unique match.
1055                         */
1056                        matched_weak = refs;
1057                        weak_match++;
1058                }
1059                else {
1060                        matched = refs;
1061                        match++;
1062                }
1063        }
1064        if (!matched) {
1065                if (matched_ref)
1066                        *matched_ref = matched_weak;
1067                return weak_match;
1068        }
1069        else {
1070                if (matched_ref)
1071                        *matched_ref = matched;
1072                return match;
1073        }
1074}
1075
1076static void tail_link_ref(struct ref *ref, struct ref ***tail)
1077{
1078        **tail = ref;
1079        while (ref->next)
1080                ref = ref->next;
1081        *tail = &ref->next;
1082}
1083
1084static struct ref *alloc_delete_ref(void)
1085{
1086        struct ref *ref = alloc_ref("(delete)");
1087        hashclr(ref->new_sha1);
1088        return ref;
1089}
1090
1091static int try_explicit_object_name(const char *name,
1092                                    struct ref **match)
1093{
1094        unsigned char sha1[20];
1095
1096        if (!*name) {
1097                if (match)
1098                        *match = alloc_delete_ref();
1099                return 0;
1100        }
1101
1102        if (get_sha1(name, sha1))
1103                return -1;
1104
1105        if (match) {
1106                *match = alloc_ref(name);
1107                hashcpy((*match)->new_sha1, sha1);
1108        }
1109        return 0;
1110}
1111
1112static struct ref *make_linked_ref(const char *name, struct ref ***tail)
1113{
1114        struct ref *ret = alloc_ref(name);
1115        tail_link_ref(ret, tail);
1116        return ret;
1117}
1118
1119static char *guess_ref(const char *name, struct ref *peer)
1120{
1121        struct strbuf buf = STRBUF_INIT;
1122        unsigned char sha1[20];
1123
1124        const char *r = resolve_ref_unsafe(peer->name, sha1, 1, NULL);
1125        if (!r)
1126                return NULL;
1127
1128        if (starts_with(r, "refs/heads/"))
1129                strbuf_addstr(&buf, "refs/heads/");
1130        else if (starts_with(r, "refs/tags/"))
1131                strbuf_addstr(&buf, "refs/tags/");
1132        else
1133                return NULL;
1134
1135        strbuf_addstr(&buf, name);
1136        return strbuf_detach(&buf, NULL);
1137}
1138
1139static int match_explicit_lhs(struct ref *src,
1140                              struct refspec *rs,
1141                              struct ref **match,
1142                              int *allocated_match)
1143{
1144        switch (count_refspec_match(rs->src, src, match)) {
1145        case 1:
1146                if (allocated_match)
1147                        *allocated_match = 0;
1148                return 0;
1149        case 0:
1150                /* The source could be in the get_sha1() format
1151                 * not a reference name.  :refs/other is a
1152                 * way to delete 'other' ref at the remote end.
1153                 */
1154                if (try_explicit_object_name(rs->src, match) < 0)
1155                        return error("src refspec %s does not match any.", rs->src);
1156                if (allocated_match)
1157                        *allocated_match = 1;
1158                return 0;
1159        default:
1160                return error("src refspec %s matches more than one.", rs->src);
1161        }
1162}
1163
1164static int match_explicit(struct ref *src, struct ref *dst,
1165                          struct ref ***dst_tail,
1166                          struct refspec *rs)
1167{
1168        struct ref *matched_src, *matched_dst;
1169        int allocated_src;
1170
1171        const char *dst_value = rs->dst;
1172        char *dst_guess;
1173
1174        if (rs->pattern || rs->matching)
1175                return 0;
1176
1177        matched_src = matched_dst = NULL;
1178        if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1179                return -1;
1180
1181        if (!dst_value) {
1182                unsigned char sha1[20];
1183                int flag;
1184
1185                dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag);
1186                if (!dst_value ||
1187                    ((flag & REF_ISSYMREF) &&
1188                     !starts_with(dst_value, "refs/heads/")))
1189                        die("%s cannot be resolved to branch.",
1190                            matched_src->name);
1191        }
1192
1193        switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1194        case 1:
1195                break;
1196        case 0:
1197                if (!memcmp(dst_value, "refs/", 5))
1198                        matched_dst = make_linked_ref(dst_value, dst_tail);
1199                else if (is_null_sha1(matched_src->new_sha1))
1200                        error("unable to delete '%s': remote ref does not exist",
1201                              dst_value);
1202                else if ((dst_guess = guess_ref(dst_value, matched_src)))
1203                        matched_dst = make_linked_ref(dst_guess, dst_tail);
1204                else
1205                        error("unable to push to unqualified destination: %s\n"
1206                              "The destination refspec neither matches an "
1207                              "existing ref on the remote nor\n"
1208                              "begins with refs/, and we are unable to "
1209                              "guess a prefix based on the source ref.",
1210                              dst_value);
1211                break;
1212        default:
1213                matched_dst = NULL;
1214                error("dst refspec %s matches more than one.",
1215                      dst_value);
1216                break;
1217        }
1218        if (!matched_dst)
1219                return -1;
1220        if (matched_dst->peer_ref)
1221                return error("dst ref %s receives from more than one src.",
1222                      matched_dst->name);
1223        else {
1224                matched_dst->peer_ref = allocated_src ?
1225                                        matched_src :
1226                                        copy_ref(matched_src);
1227                matched_dst->force = rs->force;
1228        }
1229        return 0;
1230}
1231
1232static int match_explicit_refs(struct ref *src, struct ref *dst,
1233                               struct ref ***dst_tail, struct refspec *rs,
1234                               int rs_nr)
1235{
1236        int i, errs;
1237        for (i = errs = 0; i < rs_nr; i++)
1238                errs += match_explicit(src, dst, dst_tail, &rs[i]);
1239        return errs;
1240}
1241
1242static char *get_ref_match(const struct refspec *rs, int rs_nr, const struct ref *ref,
1243                int send_mirror, int direction, const struct refspec **ret_pat)
1244{
1245        const struct refspec *pat;
1246        char *name;
1247        int i;
1248        int matching_refs = -1;
1249        for (i = 0; i < rs_nr; i++) {
1250                if (rs[i].matching &&
1251                    (matching_refs == -1 || rs[i].force)) {
1252                        matching_refs = i;
1253                        continue;
1254                }
1255
1256                if (rs[i].pattern) {
1257                        const char *dst_side = rs[i].dst ? rs[i].dst : rs[i].src;
1258                        int match;
1259                        if (direction == FROM_SRC)
1260                                match = match_name_with_pattern(rs[i].src, ref->name, dst_side, &name);
1261                        else
1262                                match = match_name_with_pattern(dst_side, ref->name, rs[i].src, &name);
1263                        if (match) {
1264                                matching_refs = i;
1265                                break;
1266                        }
1267                }
1268        }
1269        if (matching_refs == -1)
1270                return NULL;
1271
1272        pat = rs + matching_refs;
1273        if (pat->matching) {
1274                /*
1275                 * "matching refs"; traditionally we pushed everything
1276                 * including refs outside refs/heads/ hierarchy, but
1277                 * that does not make much sense these days.
1278                 */
1279                if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1280                        return NULL;
1281                name = xstrdup(ref->name);
1282        }
1283        if (ret_pat)
1284                *ret_pat = pat;
1285        return name;
1286}
1287
1288static struct ref **tail_ref(struct ref **head)
1289{
1290        struct ref **tail = head;
1291        while (*tail)
1292                tail = &((*tail)->next);
1293        return tail;
1294}
1295
1296struct tips {
1297        struct commit **tip;
1298        int nr, alloc;
1299};
1300
1301static void add_to_tips(struct tips *tips, const unsigned char *sha1)
1302{
1303        struct commit *commit;
1304
1305        if (is_null_sha1(sha1))
1306                return;
1307        commit = lookup_commit_reference_gently(sha1, 1);
1308        if (!commit || (commit->object.flags & TMP_MARK))
1309                return;
1310        commit->object.flags |= TMP_MARK;
1311        ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1312        tips->tip[tips->nr++] = commit;
1313}
1314
1315static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1316{
1317        struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1318        struct string_list src_tag = STRING_LIST_INIT_NODUP;
1319        struct string_list_item *item;
1320        struct ref *ref;
1321        struct tips sent_tips;
1322
1323        /*
1324         * Collect everything we know they would have at the end of
1325         * this push, and collect all tags they have.
1326         */
1327        memset(&sent_tips, 0, sizeof(sent_tips));
1328        for (ref = *dst; ref; ref = ref->next) {
1329                if (ref->peer_ref &&
1330                    !is_null_sha1(ref->peer_ref->new_sha1))
1331                        add_to_tips(&sent_tips, ref->peer_ref->new_sha1);
1332                else
1333                        add_to_tips(&sent_tips, ref->old_sha1);
1334                if (starts_with(ref->name, "refs/tags/"))
1335                        string_list_append(&dst_tag, ref->name);
1336        }
1337        clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1338
1339        sort_string_list(&dst_tag);
1340
1341        /* Collect tags they do not have. */
1342        for (ref = src; ref; ref = ref->next) {
1343                if (!starts_with(ref->name, "refs/tags/"))
1344                        continue; /* not a tag */
1345                if (string_list_has_string(&dst_tag, ref->name))
1346                        continue; /* they already have it */
1347                if (sha1_object_info(ref->new_sha1, NULL) != OBJ_TAG)
1348                        continue; /* be conservative */
1349                item = string_list_append(&src_tag, ref->name);
1350                item->util = ref;
1351        }
1352        string_list_clear(&dst_tag, 0);
1353
1354        /*
1355         * At this point, src_tag lists tags that are missing from
1356         * dst, and sent_tips lists the tips we are pushing or those
1357         * that we know they already have. An element in the src_tag
1358         * that is an ancestor of any of the sent_tips needs to be
1359         * sent to the other side.
1360         */
1361        if (sent_tips.nr) {
1362                for_each_string_list_item(item, &src_tag) {
1363                        struct ref *ref = item->util;
1364                        struct ref *dst_ref;
1365                        struct commit *commit;
1366
1367                        if (is_null_sha1(ref->new_sha1))
1368                                continue;
1369                        commit = lookup_commit_reference_gently(ref->new_sha1, 1);
1370                        if (!commit)
1371                                /* not pushing a commit, which is not an error */
1372                                continue;
1373
1374                        /*
1375                         * Is this tag, which they do not have, reachable from
1376                         * any of the commits we are sending?
1377                         */
1378                        if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip))
1379                                continue;
1380
1381                        /* Add it in */
1382                        dst_ref = make_linked_ref(ref->name, dst_tail);
1383                        hashcpy(dst_ref->new_sha1, ref->new_sha1);
1384                        dst_ref->peer_ref = copy_ref(ref);
1385                }
1386        }
1387        string_list_clear(&src_tag, 0);
1388        free(sent_tips.tip);
1389}
1390
1391struct ref *find_ref_by_name(const struct ref *list, const char *name)
1392{
1393        for ( ; list; list = list->next)
1394                if (!strcmp(list->name, name))
1395                        return (struct ref *)list;
1396        return NULL;
1397}
1398
1399static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1400{
1401        for ( ; ref; ref = ref->next)
1402                string_list_append_nodup(ref_index, ref->name)->util = ref;
1403
1404        sort_string_list(ref_index);
1405}
1406
1407/*
1408 * Given only the set of local refs, sanity-check the set of push
1409 * refspecs. We can't catch all errors that match_push_refs would,
1410 * but we can catch some errors early before even talking to the
1411 * remote side.
1412 */
1413int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
1414{
1415        struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
1416        int ret = 0;
1417        int i;
1418
1419        for (i = 0; i < nr_refspec; i++) {
1420                struct refspec *rs = refspec + i;
1421
1422                if (rs->pattern || rs->matching)
1423                        continue;
1424
1425                ret |= match_explicit_lhs(src, rs, NULL, NULL);
1426        }
1427
1428        free_refspec(nr_refspec, refspec);
1429        return ret;
1430}
1431
1432/*
1433 * Given the set of refs the local repository has, the set of refs the
1434 * remote repository has, and the refspec used for push, determine
1435 * what remote refs we will update and with what value by setting
1436 * peer_ref (which object is being pushed) and force (if the push is
1437 * forced) in elements of "dst". The function may add new elements to
1438 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1439 */
1440int match_push_refs(struct ref *src, struct ref **dst,
1441                    int nr_refspec, const char **refspec, int flags)
1442{
1443        struct refspec *rs;
1444        int send_all = flags & MATCH_REFS_ALL;
1445        int send_mirror = flags & MATCH_REFS_MIRROR;
1446        int send_prune = flags & MATCH_REFS_PRUNE;
1447        int errs;
1448        static const char *default_refspec[] = { ":", NULL };
1449        struct ref *ref, **dst_tail = tail_ref(dst);
1450        struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1451
1452        if (!nr_refspec) {
1453                nr_refspec = 1;
1454                refspec = default_refspec;
1455        }
1456        rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1457        errs = match_explicit_refs(src, *dst, &dst_tail, rs, nr_refspec);
1458
1459        /* pick the remainder */
1460        for (ref = src; ref; ref = ref->next) {
1461                struct string_list_item *dst_item;
1462                struct ref *dst_peer;
1463                const struct refspec *pat = NULL;
1464                char *dst_name;
1465
1466                dst_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_SRC, &pat);
1467                if (!dst_name)
1468                        continue;
1469
1470                if (!dst_ref_index.nr)
1471                        prepare_ref_index(&dst_ref_index, *dst);
1472
1473                dst_item = string_list_lookup(&dst_ref_index, dst_name);
1474                dst_peer = dst_item ? dst_item->util : NULL;
1475                if (dst_peer) {
1476                        if (dst_peer->peer_ref)
1477                                /* We're already sending something to this ref. */
1478                                goto free_name;
1479                } else {
1480                        if (pat->matching && !(send_all || send_mirror))
1481                                /*
1482                                 * Remote doesn't have it, and we have no
1483                                 * explicit pattern, and we don't have
1484                                 * --all or --mirror.
1485                                 */
1486                                goto free_name;
1487
1488                        /* Create a new one and link it */
1489                        dst_peer = make_linked_ref(dst_name, &dst_tail);
1490                        hashcpy(dst_peer->new_sha1, ref->new_sha1);
1491                        string_list_insert(&dst_ref_index,
1492                                dst_peer->name)->util = dst_peer;
1493                }
1494                dst_peer->peer_ref = copy_ref(ref);
1495                dst_peer->force = pat->force;
1496        free_name:
1497                free(dst_name);
1498        }
1499
1500        string_list_clear(&dst_ref_index, 0);
1501
1502        if (flags & MATCH_REFS_FOLLOW_TAGS)
1503                add_missing_tags(src, dst, &dst_tail);
1504
1505        if (send_prune) {
1506                struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1507                /* check for missing refs on the remote */
1508                for (ref = *dst; ref; ref = ref->next) {
1509                        char *src_name;
1510
1511                        if (ref->peer_ref)
1512                                /* We're already sending something to this ref. */
1513                                continue;
1514
1515                        src_name = get_ref_match(rs, nr_refspec, ref, send_mirror, FROM_DST, NULL);
1516                        if (src_name) {
1517                                if (!src_ref_index.nr)
1518                                        prepare_ref_index(&src_ref_index, src);
1519                                if (!string_list_has_string(&src_ref_index,
1520                                            src_name))
1521                                        ref->peer_ref = alloc_delete_ref();
1522                                free(src_name);
1523                        }
1524                }
1525                string_list_clear(&src_ref_index, 0);
1526        }
1527        if (errs)
1528                return -1;
1529        return 0;
1530}
1531
1532void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1533                             int force_update)
1534{
1535        struct ref *ref;
1536
1537        for (ref = remote_refs; ref; ref = ref->next) {
1538                int force_ref_update = ref->force || force_update;
1539                int reject_reason = 0;
1540
1541                if (ref->peer_ref)
1542                        hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
1543                else if (!send_mirror)
1544                        continue;
1545
1546                ref->deletion = is_null_sha1(ref->new_sha1);
1547                if (!ref->deletion &&
1548                        !hashcmp(ref->old_sha1, ref->new_sha1)) {
1549                        ref->status = REF_STATUS_UPTODATE;
1550                        continue;
1551                }
1552
1553                /*
1554                 * Bypass the usual "must fast-forward" check but
1555                 * replace it with a weaker "the old value must be
1556                 * this value we observed".  If the remote ref has
1557                 * moved and is now different from what we expect,
1558                 * reject any push.
1559                 *
1560                 * It also is an error if the user told us to check
1561                 * with the remote-tracking branch to find the value
1562                 * to expect, but we did not have such a tracking
1563                 * branch.
1564                 */
1565                if (ref->expect_old_sha1) {
1566                        if (ref->expect_old_no_trackback ||
1567                            hashcmp(ref->old_sha1, ref->old_sha1_expect))
1568                                reject_reason = REF_STATUS_REJECT_STALE;
1569                }
1570
1571                /*
1572                 * The usual "must fast-forward" rules.
1573                 *
1574                 * Decide whether an individual refspec A:B can be
1575                 * pushed.  The push will succeed if any of the
1576                 * following are true:
1577                 *
1578                 * (1) the remote reference B does not exist
1579                 *
1580                 * (2) the remote reference B is being removed (i.e.,
1581                 *     pushing :B where no source is specified)
1582                 *
1583                 * (3) the destination is not under refs/tags/, and
1584                 *     if the old and new value is a commit, the new
1585                 *     is a descendant of the old.
1586                 *
1587                 * (4) it is forced using the +A:B notation, or by
1588                 *     passing the --force argument
1589                 */
1590
1591                else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
1592                        if (starts_with(ref->name, "refs/tags/"))
1593                                reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1594                        else if (!has_sha1_file(ref->old_sha1))
1595                                reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1596                        else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
1597                                 !lookup_commit_reference_gently(ref->new_sha1, 1))
1598                                reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1599                        else if (!ref_newer(ref->new_sha1, ref->old_sha1))
1600                                reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1601                }
1602
1603                /*
1604                 * "--force" will defeat any rejection implemented
1605                 * by the rules above.
1606                 */
1607                if (!force_ref_update)
1608                        ref->status = reject_reason;
1609                else if (reject_reason)
1610                        ref->forced_update = 1;
1611        }
1612}
1613
1614struct branch *branch_get(const char *name)
1615{
1616        struct branch *ret;
1617
1618        read_config();
1619        if (!name || !*name || !strcmp(name, "HEAD"))
1620                ret = current_branch;
1621        else
1622                ret = make_branch(name, 0);
1623        if (ret && ret->remote_name) {
1624                ret->remote = remote_get(ret->remote_name);
1625                if (ret->merge_nr) {
1626                        int i;
1627                        ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1628                        for (i = 0; i < ret->merge_nr; i++) {
1629                                ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1630                                ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1631                                if (remote_find_tracking(ret->remote, ret->merge[i])
1632                                    && !strcmp(ret->remote_name, "."))
1633                                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1634                        }
1635                }
1636        }
1637        return ret;
1638}
1639
1640int branch_has_merge_config(struct branch *branch)
1641{
1642        return branch && !!branch->merge;
1643}
1644
1645int branch_merge_matches(struct branch *branch,
1646                                 int i,
1647                                 const char *refname)
1648{
1649        if (!branch || i < 0 || i >= branch->merge_nr)
1650                return 0;
1651        return refname_match(branch->merge[i]->src, refname);
1652}
1653
1654static int ignore_symref_update(const char *refname)
1655{
1656        unsigned char sha1[20];
1657        int flag;
1658
1659        if (!resolve_ref_unsafe(refname, sha1, 0, &flag))
1660                return 0; /* non-existing refs are OK */
1661        return (flag & REF_ISSYMREF);
1662}
1663
1664/*
1665 * Create and return a list of (struct ref) consisting of copies of
1666 * each remote_ref that matches refspec.  refspec must be a pattern.
1667 * Fill in the copies' peer_ref to describe the local tracking refs to
1668 * which they map.  Omit any references that would map to an existing
1669 * local symbolic ref.
1670 */
1671static struct ref *get_expanded_map(const struct ref *remote_refs,
1672                                    const struct refspec *refspec)
1673{
1674        const struct ref *ref;
1675        struct ref *ret = NULL;
1676        struct ref **tail = &ret;
1677
1678        for (ref = remote_refs; ref; ref = ref->next) {
1679                char *expn_name = NULL;
1680
1681                if (strchr(ref->name, '^'))
1682                        continue; /* a dereference item */
1683                if (match_name_with_pattern(refspec->src, ref->name,
1684                                            refspec->dst, &expn_name) &&
1685                    !ignore_symref_update(expn_name)) {
1686                        struct ref *cpy = copy_ref(ref);
1687
1688                        cpy->peer_ref = alloc_ref(expn_name);
1689                        if (refspec->force)
1690                                cpy->peer_ref->force = 1;
1691                        *tail = cpy;
1692                        tail = &cpy->next;
1693                }
1694                free(expn_name);
1695        }
1696
1697        return ret;
1698}
1699
1700static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1701{
1702        const struct ref *ref;
1703        for (ref = refs; ref; ref = ref->next) {
1704                if (refname_match(name, ref->name))
1705                        return ref;
1706        }
1707        return NULL;
1708}
1709
1710struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1711{
1712        const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1713
1714        if (!ref)
1715                return NULL;
1716
1717        return copy_ref(ref);
1718}
1719
1720static struct ref *get_local_ref(const char *name)
1721{
1722        if (!name || name[0] == '\0')
1723                return NULL;
1724
1725        if (starts_with(name, "refs/"))
1726                return alloc_ref(name);
1727
1728        if (starts_with(name, "heads/") ||
1729            starts_with(name, "tags/") ||
1730            starts_with(name, "remotes/"))
1731                return alloc_ref_with_prefix("refs/", 5, name);
1732
1733        return alloc_ref_with_prefix("refs/heads/", 11, name);
1734}
1735
1736int get_fetch_map(const struct ref *remote_refs,
1737                  const struct refspec *refspec,
1738                  struct ref ***tail,
1739                  int missing_ok)
1740{
1741        struct ref *ref_map, **rmp;
1742
1743        if (refspec->pattern) {
1744                ref_map = get_expanded_map(remote_refs, refspec);
1745        } else {
1746                const char *name = refspec->src[0] ? refspec->src : "HEAD";
1747
1748                if (refspec->exact_sha1) {
1749                        ref_map = alloc_ref(name);
1750                        get_sha1_hex(name, ref_map->old_sha1);
1751                } else {
1752                        ref_map = get_remote_ref(remote_refs, name);
1753                }
1754                if (!missing_ok && !ref_map)
1755                        die("Couldn't find remote ref %s", name);
1756                if (ref_map) {
1757                        ref_map->peer_ref = get_local_ref(refspec->dst);
1758                        if (ref_map->peer_ref && refspec->force)
1759                                ref_map->peer_ref->force = 1;
1760                }
1761        }
1762
1763        for (rmp = &ref_map; *rmp; ) {
1764                if ((*rmp)->peer_ref) {
1765                        if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1766                            check_refname_format((*rmp)->peer_ref->name, 0)) {
1767                                struct ref *ignore = *rmp;
1768                                error("* Ignoring funny ref '%s' locally",
1769                                      (*rmp)->peer_ref->name);
1770                                *rmp = (*rmp)->next;
1771                                free(ignore->peer_ref);
1772                                free(ignore);
1773                                continue;
1774                        }
1775                }
1776                rmp = &((*rmp)->next);
1777        }
1778
1779        if (ref_map)
1780                tail_link_ref(ref_map, tail);
1781
1782        return 0;
1783}
1784
1785int resolve_remote_symref(struct ref *ref, struct ref *list)
1786{
1787        if (!ref->symref)
1788                return 0;
1789        for (; list; list = list->next)
1790                if (!strcmp(ref->symref, list->name)) {
1791                        hashcpy(ref->old_sha1, list->old_sha1);
1792                        return 0;
1793                }
1794        return 1;
1795}
1796
1797static void unmark_and_free(struct commit_list *list, unsigned int mark)
1798{
1799        while (list) {
1800                struct commit_list *temp = list;
1801                temp->item->object.flags &= ~mark;
1802                list = temp->next;
1803                free(temp);
1804        }
1805}
1806
1807int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
1808{
1809        struct object *o;
1810        struct commit *old, *new;
1811        struct commit_list *list, *used;
1812        int found = 0;
1813
1814        /*
1815         * Both new and old must be commit-ish and new is descendant of
1816         * old.  Otherwise we require --force.
1817         */
1818        o = deref_tag(parse_object(old_sha1), NULL, 0);
1819        if (!o || o->type != OBJ_COMMIT)
1820                return 0;
1821        old = (struct commit *) o;
1822
1823        o = deref_tag(parse_object(new_sha1), NULL, 0);
1824        if (!o || o->type != OBJ_COMMIT)
1825                return 0;
1826        new = (struct commit *) o;
1827
1828        if (parse_commit(new) < 0)
1829                return 0;
1830
1831        used = list = NULL;
1832        commit_list_insert(new, &list);
1833        while (list) {
1834                new = pop_most_recent_commit(&list, TMP_MARK);
1835                commit_list_insert(new, &used);
1836                if (new == old) {
1837                        found = 1;
1838                        break;
1839                }
1840        }
1841        unmark_and_free(list, TMP_MARK);
1842        unmark_and_free(used, TMP_MARK);
1843        return found;
1844}
1845
1846/*
1847 * Compare a branch with its upstream, and save their differences (number
1848 * of commits) in *num_ours and *num_theirs.
1849 *
1850 * Return 0 if branch has no upstream (no base), -1 if upstream is missing
1851 * (with "gone" base), otherwise 1 (with base).
1852 */
1853int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1854{
1855        unsigned char sha1[20];
1856        struct commit *ours, *theirs;
1857        char symmetric[84];
1858        struct rev_info revs;
1859        const char *rev_argv[10], *base;
1860        int rev_argc;
1861
1862        /* Cannot stat unless we are marked to build on top of somebody else. */
1863        if (!branch ||
1864            !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1865                return 0;
1866
1867        /* Cannot stat if what we used to build on no longer exists */
1868        base = branch->merge[0]->dst;
1869        if (read_ref(base, sha1))
1870                return -1;
1871        theirs = lookup_commit_reference(sha1);
1872        if (!theirs)
1873                return -1;
1874
1875        if (read_ref(branch->refname, sha1))
1876                return -1;
1877        ours = lookup_commit_reference(sha1);
1878        if (!ours)
1879                return -1;
1880
1881        /* are we the same? */
1882        if (theirs == ours) {
1883                *num_theirs = *num_ours = 0;
1884                return 1;
1885        }
1886
1887        /* Run "rev-list --left-right ours...theirs" internally... */
1888        rev_argc = 0;
1889        rev_argv[rev_argc++] = NULL;
1890        rev_argv[rev_argc++] = "--left-right";
1891        rev_argv[rev_argc++] = symmetric;
1892        rev_argv[rev_argc++] = "--";
1893        rev_argv[rev_argc] = NULL;
1894
1895        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1896        strcpy(symmetric + 40, "...");
1897        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1898
1899        init_revisions(&revs, NULL);
1900        setup_revisions(rev_argc, rev_argv, &revs, NULL);
1901        prepare_revision_walk(&revs);
1902
1903        /* ... and count the commits on each side. */
1904        *num_ours = 0;
1905        *num_theirs = 0;
1906        while (1) {
1907                struct commit *c = get_revision(&revs);
1908                if (!c)
1909                        break;
1910                if (c->object.flags & SYMMETRIC_LEFT)
1911                        (*num_ours)++;
1912                else
1913                        (*num_theirs)++;
1914        }
1915
1916        /* clear object flags smudged by the above traversal */
1917        clear_commit_marks(ours, ALL_REV_FLAGS);
1918        clear_commit_marks(theirs, ALL_REV_FLAGS);
1919        return 1;
1920}
1921
1922/*
1923 * Return true when there is anything to report, otherwise false.
1924 */
1925int format_tracking_info(struct branch *branch, struct strbuf *sb)
1926{
1927        int ours, theirs;
1928        const char *base;
1929        int upstream_is_gone = 0;
1930
1931        switch (stat_tracking_info(branch, &ours, &theirs)) {
1932        case 0:
1933                /* no base */
1934                return 0;
1935        case -1:
1936                /* with "gone" base */
1937                upstream_is_gone = 1;
1938                break;
1939        default:
1940                /* with base */
1941                break;
1942        }
1943
1944        base = branch->merge[0]->dst;
1945        base = shorten_unambiguous_ref(base, 0);
1946        if (upstream_is_gone) {
1947                strbuf_addf(sb,
1948                        _("Your branch is based on '%s', but the upstream is gone.\n"),
1949                        base);
1950                if (advice_status_hints)
1951                        strbuf_addf(sb,
1952                                _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1953        } else if (!ours && !theirs) {
1954                strbuf_addf(sb,
1955                        _("Your branch is up-to-date with '%s'.\n"),
1956                        base);
1957        } else if (!theirs) {
1958                strbuf_addf(sb,
1959                        Q_("Your branch is ahead of '%s' by %d commit.\n",
1960                           "Your branch is ahead of '%s' by %d commits.\n",
1961                           ours),
1962                        base, ours);
1963                if (advice_status_hints)
1964                        strbuf_addf(sb,
1965                                _("  (use \"git push\" to publish your local commits)\n"));
1966        } else if (!ours) {
1967                strbuf_addf(sb,
1968                        Q_("Your branch is behind '%s' by %d commit, "
1969                               "and can be fast-forwarded.\n",
1970                           "Your branch is behind '%s' by %d commits, "
1971                               "and can be fast-forwarded.\n",
1972                           theirs),
1973                        base, theirs);
1974                if (advice_status_hints)
1975                        strbuf_addf(sb,
1976                                _("  (use \"git pull\" to update your local branch)\n"));
1977        } else {
1978                strbuf_addf(sb,
1979                        Q_("Your branch and '%s' have diverged,\n"
1980                               "and have %d and %d different commit each, "
1981                               "respectively.\n",
1982                           "Your branch and '%s' have diverged,\n"
1983                               "and have %d and %d different commits each, "
1984                               "respectively.\n",
1985                           theirs),
1986                        base, ours, theirs);
1987                if (advice_status_hints)
1988                        strbuf_addf(sb,
1989                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
1990        }
1991        return 1;
1992}
1993
1994static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
1995{
1996        struct ref ***local_tail = cb_data;
1997        struct ref *ref;
1998        int len;
1999
2000        /* we already know it starts with refs/ to get here */
2001        if (check_refname_format(refname + 5, 0))
2002                return 0;
2003
2004        len = strlen(refname) + 1;
2005        ref = xcalloc(1, sizeof(*ref) + len);
2006        hashcpy(ref->new_sha1, sha1);
2007        memcpy(ref->name, refname, len);
2008        **local_tail = ref;
2009        *local_tail = &ref->next;
2010        return 0;
2011}
2012
2013struct ref *get_local_heads(void)
2014{
2015        struct ref *local_refs = NULL, **local_tail = &local_refs;
2016        for_each_ref(one_local_ref, &local_tail);
2017        return local_refs;
2018}
2019
2020struct ref *guess_remote_head(const struct ref *head,
2021                              const struct ref *refs,
2022                              int all)
2023{
2024        const struct ref *r;
2025        struct ref *list = NULL;
2026        struct ref **tail = &list;
2027
2028        if (!head)
2029                return NULL;
2030
2031        /*
2032         * Some transports support directly peeking at
2033         * where HEAD points; if that is the case, then
2034         * we don't have to guess.
2035         */
2036        if (head->symref)
2037                return copy_ref(find_ref_by_name(refs, head->symref));
2038
2039        /* If refs/heads/master could be right, it is. */
2040        if (!all) {
2041                r = find_ref_by_name(refs, "refs/heads/master");
2042                if (r && !hashcmp(r->old_sha1, head->old_sha1))
2043                        return copy_ref(r);
2044        }
2045
2046        /* Look for another ref that points there */
2047        for (r = refs; r; r = r->next) {
2048                if (r != head &&
2049                    starts_with(r->name, "refs/heads/") &&
2050                    !hashcmp(r->old_sha1, head->old_sha1)) {
2051                        *tail = copy_ref(r);
2052                        tail = &((*tail)->next);
2053                        if (!all)
2054                                break;
2055                }
2056        }
2057
2058        return list;
2059}
2060
2061struct stale_heads_info {
2062        struct string_list *ref_names;
2063        struct ref **stale_refs_tail;
2064        struct refspec *refs;
2065        int ref_count;
2066};
2067
2068static int get_stale_heads_cb(const char *refname,
2069        const unsigned char *sha1, int flags, void *cb_data)
2070{
2071        struct stale_heads_info *info = cb_data;
2072        struct string_list matches = STRING_LIST_INIT_DUP;
2073        struct refspec query;
2074        int i, stale = 1;
2075        memset(&query, 0, sizeof(struct refspec));
2076        query.dst = (char *)refname;
2077
2078        query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
2079        if (matches.nr == 0)
2080                goto clean_exit; /* No matches */
2081
2082        /*
2083         * If we did find a suitable refspec and it's not a symref and
2084         * it's not in the list of refs that currently exist in that
2085         * remote, we consider it to be stale. In order to deal with
2086         * overlapping refspecs, we need to go over all of the
2087         * matching refs.
2088         */
2089        if (flags & REF_ISSYMREF)
2090                goto clean_exit;
2091
2092        for (i = 0; stale && i < matches.nr; i++)
2093                if (string_list_has_string(info->ref_names, matches.items[i].string))
2094                        stale = 0;
2095
2096        if (stale) {
2097                struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2098                hashcpy(ref->new_sha1, sha1);
2099        }
2100
2101clean_exit:
2102        string_list_clear(&matches, 0);
2103        return 0;
2104}
2105
2106struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map)
2107{
2108        struct ref *ref, *stale_refs = NULL;
2109        struct string_list ref_names = STRING_LIST_INIT_NODUP;
2110        struct stale_heads_info info;
2111        info.ref_names = &ref_names;
2112        info.stale_refs_tail = &stale_refs;
2113        info.refs = refs;
2114        info.ref_count = ref_count;
2115        for (ref = fetch_map; ref; ref = ref->next)
2116                string_list_append(&ref_names, ref->name);
2117        sort_string_list(&ref_names);
2118        for_each_ref(get_stale_heads_cb, &info);
2119        string_list_clear(&ref_names, 0);
2120        return stale_refs;
2121}
2122
2123/*
2124 * Compare-and-swap
2125 */
2126void clear_cas_option(struct push_cas_option *cas)
2127{
2128        int i;
2129
2130        for (i = 0; i < cas->nr; i++)
2131                free(cas->entry[i].refname);
2132        free(cas->entry);
2133        memset(cas, 0, sizeof(*cas));
2134}
2135
2136static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2137                                      const char *refname,
2138                                      size_t refnamelen)
2139{
2140        struct push_cas *entry;
2141        ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2142        entry = &cas->entry[cas->nr++];
2143        memset(entry, 0, sizeof(*entry));
2144        entry->refname = xmemdupz(refname, refnamelen);
2145        return entry;
2146}
2147
2148int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2149{
2150        const char *colon;
2151        struct push_cas *entry;
2152
2153        if (unset) {
2154                /* "--no-<option>" */
2155                clear_cas_option(cas);
2156                return 0;
2157        }
2158
2159        if (!arg) {
2160                /* just "--<option>" */
2161                cas->use_tracking_for_rest = 1;
2162                return 0;
2163        }
2164
2165        /* "--<option>=refname" or "--<option>=refname:value" */
2166        colon = strchrnul(arg, ':');
2167        entry = add_cas_entry(cas, arg, colon - arg);
2168        if (!*colon)
2169                entry->use_tracking = 1;
2170        else if (get_sha1(colon + 1, entry->expect))
2171                return error("cannot parse expected object name '%s'", colon + 1);
2172        return 0;
2173}
2174
2175int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2176{
2177        return parse_push_cas_option(opt->value, arg, unset);
2178}
2179
2180int is_empty_cas(const struct push_cas_option *cas)
2181{
2182        return !cas->use_tracking_for_rest && !cas->nr;
2183}
2184
2185/*
2186 * Look at remote.fetch refspec and see if we have a remote
2187 * tracking branch for the refname there.  Fill its current
2188 * value in sha1[].
2189 * If we cannot do so, return negative to signal an error.
2190 */
2191static int remote_tracking(struct remote *remote, const char *refname,
2192                           unsigned char sha1[20])
2193{
2194        char *dst;
2195
2196        dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
2197        if (!dst)
2198                return -1; /* no tracking ref for refname at remote */
2199        if (read_ref(dst, sha1))
2200                return -1; /* we know what the tracking ref is but we cannot read it */
2201        return 0;
2202}
2203
2204static void apply_cas(struct push_cas_option *cas,
2205                      struct remote *remote,
2206                      struct ref *ref)
2207{
2208        int i;
2209
2210        /* Find an explicit --<option>=<name>[:<value>] entry */
2211        for (i = 0; i < cas->nr; i++) {
2212                struct push_cas *entry = &cas->entry[i];
2213                if (!refname_match(entry->refname, ref->name))
2214                        continue;
2215                ref->expect_old_sha1 = 1;
2216                if (!entry->use_tracking)
2217                        hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
2218                else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2219                        ref->expect_old_no_trackback = 1;
2220                return;
2221        }
2222
2223        /* Are we using "--<option>" to cover all? */
2224        if (!cas->use_tracking_for_rest)
2225                return;
2226
2227        ref->expect_old_sha1 = 1;
2228        if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
2229                ref->expect_old_no_trackback = 1;
2230}
2231
2232void apply_push_cas(struct push_cas_option *cas,
2233                    struct remote *remote,
2234                    struct ref *remote_refs)
2235{
2236        struct ref *ref;
2237        for (ref = remote_refs; ref; ref = ref->next)
2238                apply_cas(cas, remote, ref);
2239}