config.con commit Merge branch 'rs/diff' (71e5585)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 * Copyright (C) Johannes Schindelin, 2005
   6 *
   7 */
   8#include "cache.h"
   9
  10#define MAXNAME (256)
  11
  12static FILE *config_file;
  13static const char *config_file_name;
  14static int config_linenr;
  15static int zlib_compression_seen;
  16
  17static int get_next_char(void)
  18{
  19        int c;
  20        FILE *f;
  21
  22        c = '\n';
  23        if ((f = config_file) != NULL) {
  24                c = fgetc(f);
  25                if (c == '\r') {
  26                        /* DOS like systems */
  27                        c = fgetc(f);
  28                        if (c != '\n') {
  29                                ungetc(c, f);
  30                                c = '\r';
  31                        }
  32                }
  33                if (c == '\n')
  34                        config_linenr++;
  35                if (c == EOF) {
  36                        config_file = NULL;
  37                        c = '\n';
  38                }
  39        }
  40        return c;
  41}
  42
  43static char *parse_value(void)
  44{
  45        static char value[1024];
  46        int quote = 0, comment = 0, len = 0, space = 0;
  47
  48        for (;;) {
  49                int c = get_next_char();
  50                if (len >= sizeof(value))
  51                        return NULL;
  52                if (c == '\n') {
  53                        if (quote)
  54                                return NULL;
  55                        value[len] = 0;
  56                        return value;
  57                }
  58                if (comment)
  59                        continue;
  60                if (isspace(c) && !quote) {
  61                        space = 1;
  62                        continue;
  63                }
  64                if (!quote) {
  65                        if (c == ';' || c == '#') {
  66                                comment = 1;
  67                                continue;
  68                        }
  69                }
  70                if (space) {
  71                        if (len)
  72                                value[len++] = ' ';
  73                        space = 0;
  74                }
  75                if (c == '\\') {
  76                        c = get_next_char();
  77                        switch (c) {
  78                        case '\n':
  79                                continue;
  80                        case 't':
  81                                c = '\t';
  82                                break;
  83                        case 'b':
  84                                c = '\b';
  85                                break;
  86                        case 'n':
  87                                c = '\n';
  88                                break;
  89                        /* Some characters escape as themselves */
  90                        case '\\': case '"':
  91                                break;
  92                        /* Reject unknown escape sequences */
  93                        default:
  94                                return NULL;
  95                        }
  96                        value[len++] = c;
  97                        continue;
  98                }
  99                if (c == '"') {
 100                        quote = 1-quote;
 101                        continue;
 102                }
 103                value[len++] = c;
 104        }
 105}
 106
 107static inline int iskeychar(int c)
 108{
 109        return isalnum(c) || c == '-';
 110}
 111
 112static int get_value(config_fn_t fn, char *name, unsigned int len)
 113{
 114        int c;
 115        char *value;
 116
 117        /* Get the full name */
 118        for (;;) {
 119                c = get_next_char();
 120                if (c == EOF)
 121                        break;
 122                if (!iskeychar(c))
 123                        break;
 124                name[len++] = tolower(c);
 125                if (len >= MAXNAME)
 126                        return -1;
 127        }
 128        name[len] = 0;
 129        while (c == ' ' || c == '\t')
 130                c = get_next_char();
 131
 132        value = NULL;
 133        if (c != '\n') {
 134                if (c != '=')
 135                        return -1;
 136                value = parse_value();
 137                if (!value)
 138                        return -1;
 139        }
 140        return fn(name, value);
 141}
 142
 143static int get_extended_base_var(char *name, int baselen, int c)
 144{
 145        do {
 146                if (c == '\n')
 147                        return -1;
 148                c = get_next_char();
 149        } while (isspace(c));
 150
 151        /* We require the format to be '[base "extension"]' */
 152        if (c != '"')
 153                return -1;
 154        name[baselen++] = '.';
 155
 156        for (;;) {
 157                int c = get_next_char();
 158                if (c == '\n')
 159                        return -1;
 160                if (c == '"')
 161                        break;
 162                if (c == '\\') {
 163                        c = get_next_char();
 164                        if (c == '\n')
 165                                return -1;
 166                }
 167                name[baselen++] = c;
 168                if (baselen > MAXNAME / 2)
 169                        return -1;
 170        }
 171
 172        /* Final ']' */
 173        if (get_next_char() != ']')
 174                return -1;
 175        return baselen;
 176}
 177
 178static int get_base_var(char *name)
 179{
 180        int baselen = 0;
 181
 182        for (;;) {
 183                int c = get_next_char();
 184                if (c == EOF)
 185                        return -1;
 186                if (c == ']')
 187                        return baselen;
 188                if (isspace(c))
 189                        return get_extended_base_var(name, baselen, c);
 190                if (!iskeychar(c) && c != '.')
 191                        return -1;
 192                if (baselen > MAXNAME / 2)
 193                        return -1;
 194                name[baselen++] = tolower(c);
 195        }
 196}
 197
 198static int git_parse_file(config_fn_t fn)
 199{
 200        int comment = 0;
 201        int baselen = 0;
 202        static char var[MAXNAME];
 203
 204        for (;;) {
 205                int c = get_next_char();
 206                if (c == '\n') {
 207                        /* EOF? */
 208                        if (!config_file)
 209                                return 0;
 210                        comment = 0;
 211                        continue;
 212                }
 213                if (comment || isspace(c))
 214                        continue;
 215                if (c == '#' || c == ';') {
 216                        comment = 1;
 217                        continue;
 218                }
 219                if (c == '[') {
 220                        baselen = get_base_var(var);
 221                        if (baselen <= 0)
 222                                break;
 223                        var[baselen++] = '.';
 224                        var[baselen] = 0;
 225                        continue;
 226                }
 227                if (!isalpha(c))
 228                        break;
 229                var[baselen] = tolower(c);
 230                if (get_value(fn, var, baselen+1) < 0)
 231                        break;
 232        }
 233        die("bad config file line %d in %s", config_linenr, config_file_name);
 234}
 235
 236int git_config_int(const char *name, const char *value)
 237{
 238        if (value && *value) {
 239                char *end;
 240                int val = strtol(value, &end, 0);
 241                if (!*end)
 242                        return val;
 243                if (!strcasecmp(end, "k"))
 244                        return val * 1024;
 245                if (!strcasecmp(end, "m"))
 246                        return val * 1024 * 1024;
 247                if (!strcasecmp(end, "g"))
 248                        return val * 1024 * 1024 * 1024;
 249        }
 250        die("bad config value for '%s' in %s", name, config_file_name);
 251}
 252
 253int git_config_bool(const char *name, const char *value)
 254{
 255        if (!value)
 256                return 1;
 257        if (!*value)
 258                return 0;
 259        if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 260                return 1;
 261        if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 262                return 0;
 263        return git_config_int(name, value) != 0;
 264}
 265
 266int git_default_config(const char *var, const char *value)
 267{
 268        /* This needs a better name */
 269        if (!strcmp(var, "core.filemode")) {
 270                trust_executable_bit = git_config_bool(var, value);
 271                return 0;
 272        }
 273
 274        if (!strcmp(var, "core.quotepath")) {
 275                quote_path_fully = git_config_bool(var, value);
 276                return 0;
 277        }
 278
 279        if (!strcmp(var, "core.symlinks")) {
 280                has_symlinks = git_config_bool(var, value);
 281                return 0;
 282        }
 283
 284        if (!strcmp(var, "core.bare")) {
 285                is_bare_repository_cfg = git_config_bool(var, value);
 286                return 0;
 287        }
 288
 289        if (!strcmp(var, "core.ignorestat")) {
 290                assume_unchanged = git_config_bool(var, value);
 291                return 0;
 292        }
 293
 294        if (!strcmp(var, "core.prefersymlinkrefs")) {
 295                prefer_symlink_refs = git_config_bool(var, value);
 296                return 0;
 297        }
 298
 299        if (!strcmp(var, "core.logallrefupdates")) {
 300                log_all_ref_updates = git_config_bool(var, value);
 301                return 0;
 302        }
 303
 304        if (!strcmp(var, "core.warnambiguousrefs")) {
 305                warn_ambiguous_refs = git_config_bool(var, value);
 306                return 0;
 307        }
 308
 309        if (!strcmp(var, "core.loosecompression")) {
 310                int level = git_config_int(var, value);
 311                if (level == -1)
 312                        level = Z_DEFAULT_COMPRESSION;
 313                else if (level < 0 || level > Z_BEST_COMPRESSION)
 314                        die("bad zlib compression level %d", level);
 315                zlib_compression_level = level;
 316                zlib_compression_seen = 1;
 317                return 0;
 318        }
 319
 320        if (!strcmp(var, "core.compression")) {
 321                int level = git_config_int(var, value);
 322                if (level == -1)
 323                        level = Z_DEFAULT_COMPRESSION;
 324                else if (level < 0 || level > Z_BEST_COMPRESSION)
 325                        die("bad zlib compression level %d", level);
 326                core_compression_level = level;
 327                core_compression_seen = 1;
 328                if (!zlib_compression_seen)
 329                        zlib_compression_level = level;
 330                return 0;
 331        }
 332
 333        if (!strcmp(var, "core.packedgitwindowsize")) {
 334                int pgsz_x2 = getpagesize() * 2;
 335                packed_git_window_size = git_config_int(var, value);
 336
 337                /* This value must be multiple of (pagesize * 2) */
 338                packed_git_window_size /= pgsz_x2;
 339                if (packed_git_window_size < 1)
 340                        packed_git_window_size = 1;
 341                packed_git_window_size *= pgsz_x2;
 342                return 0;
 343        }
 344
 345        if (!strcmp(var, "core.packedgitlimit")) {
 346                packed_git_limit = git_config_int(var, value);
 347                return 0;
 348        }
 349
 350        if (!strcmp(var, "core.deltabasecachelimit")) {
 351                delta_base_cache_limit = git_config_int(var, value);
 352                return 0;
 353        }
 354
 355        if (!strcmp(var, "core.autocrlf")) {
 356                if (value && !strcasecmp(value, "input")) {
 357                        auto_crlf = -1;
 358                        return 0;
 359                }
 360                auto_crlf = git_config_bool(var, value);
 361                return 0;
 362        }
 363
 364        if (!strcmp(var, "user.name")) {
 365                strlcpy(git_default_name, value, sizeof(git_default_name));
 366                return 0;
 367        }
 368
 369        if (!strcmp(var, "user.email")) {
 370                strlcpy(git_default_email, value, sizeof(git_default_email));
 371                return 0;
 372        }
 373
 374        if (!strcmp(var, "i18n.commitencoding")) {
 375                git_commit_encoding = xstrdup(value);
 376                return 0;
 377        }
 378
 379        if (!strcmp(var, "i18n.logoutputencoding")) {
 380                git_log_output_encoding = xstrdup(value);
 381                return 0;
 382        }
 383
 384
 385        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 386                pager_use_color = git_config_bool(var,value);
 387                return 0;
 388        }
 389
 390        /* Add other config variables here and to Documentation/config.txt. */
 391        return 0;
 392}
 393
 394int git_config_from_file(config_fn_t fn, const char *filename)
 395{
 396        int ret;
 397        FILE *f = fopen(filename, "r");
 398
 399        ret = -1;
 400        if (f) {
 401                config_file = f;
 402                config_file_name = filename;
 403                config_linenr = 1;
 404                ret = git_parse_file(fn);
 405                fclose(f);
 406                config_file_name = NULL;
 407        }
 408        return ret;
 409}
 410
 411int git_config(config_fn_t fn)
 412{
 413        int ret = 0;
 414        char *repo_config = NULL;
 415        const char *home = NULL, *filename;
 416
 417        /* $GIT_CONFIG makes git read _only_ the given config file,
 418         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 419         * global config file, the same way it would the per-repository
 420         * config file otherwise. */
 421        filename = getenv(CONFIG_ENVIRONMENT);
 422        if (!filename) {
 423                if (!access(ETC_GITCONFIG, R_OK))
 424                        ret += git_config_from_file(fn, ETC_GITCONFIG);
 425                home = getenv("HOME");
 426                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 427                if (!filename)
 428                        filename = repo_config = xstrdup(git_path("config"));
 429        }
 430
 431        if (home) {
 432                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 433                if (!access(user_config, R_OK))
 434                        ret = git_config_from_file(fn, user_config);
 435                free(user_config);
 436        }
 437
 438        ret += git_config_from_file(fn, filename);
 439        free(repo_config);
 440        return ret;
 441}
 442
 443/*
 444 * Find all the stuff for git_config_set() below.
 445 */
 446
 447#define MAX_MATCHES 512
 448
 449static struct {
 450        int baselen;
 451        char* key;
 452        int do_not_match;
 453        regex_t* value_regex;
 454        int multi_replace;
 455        size_t offset[MAX_MATCHES];
 456        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 457        int seen;
 458} store;
 459
 460static int matches(const char* key, const char* value)
 461{
 462        return !strcmp(key, store.key) &&
 463                (store.value_regex == NULL ||
 464                 (store.do_not_match ^
 465                  !regexec(store.value_regex, value, 0, NULL, 0)));
 466}
 467
 468static int store_aux(const char* key, const char* value)
 469{
 470        const char *ep;
 471        size_t section_len;
 472
 473        switch (store.state) {
 474        case KEY_SEEN:
 475                if (matches(key, value)) {
 476                        if (store.seen == 1 && store.multi_replace == 0) {
 477                                fprintf(stderr,
 478                                        "Warning: %s has multiple values\n",
 479                                        key);
 480                        } else if (store.seen >= MAX_MATCHES) {
 481                                fprintf(stderr, "Too many matches\n");
 482                                return 1;
 483                        }
 484
 485                        store.offset[store.seen] = ftell(config_file);
 486                        store.seen++;
 487                }
 488                break;
 489        case SECTION_SEEN:
 490                /*
 491                 * What we are looking for is in store.key (both
 492                 * section and var), and its section part is baselen
 493                 * long.  We found key (again, both section and var).
 494                 * We would want to know if this key is in the same
 495                 * section as what we are looking for.  We already
 496                 * know we are in the same section as what should
 497                 * hold store.key.
 498                 */
 499                ep = strrchr(key, '.');
 500                section_len = ep - key;
 501
 502                if ((section_len != store.baselen) ||
 503                    memcmp(key, store.key, section_len+1)) {
 504                        store.state = SECTION_END_SEEN;
 505                        break;
 506                }
 507
 508                /*
 509                 * Do not increment matches: this is no match, but we
 510                 * just made sure we are in the desired section.
 511                 */
 512                store.offset[store.seen] = ftell(config_file);
 513                /* fallthru */
 514        case SECTION_END_SEEN:
 515        case START:
 516                if (matches(key, value)) {
 517                        store.offset[store.seen] = ftell(config_file);
 518                        store.state = KEY_SEEN;
 519                        store.seen++;
 520                } else {
 521                        if (strrchr(key, '.') - key == store.baselen &&
 522                              !strncmp(key, store.key, store.baselen)) {
 523                                        store.state = SECTION_SEEN;
 524                                        store.offset[store.seen] = ftell(config_file);
 525                        }
 526                }
 527        }
 528        return 0;
 529}
 530
 531static int write_error(void)
 532{
 533        fprintf(stderr, "Failed to write new configuration file\n");
 534
 535        /* Same error code as "failed to rename". */
 536        return 4;
 537}
 538
 539static int store_write_section(int fd, const char* key)
 540{
 541        const char *dot = strchr(key, '.');
 542        int len1 = store.baselen, len2 = -1;
 543
 544        dot = strchr(key, '.');
 545        if (dot) {
 546                int dotlen = dot - key;
 547                if (dotlen < len1) {
 548                        len2 = len1 - dotlen - 1;
 549                        len1 = dotlen;
 550                }
 551        }
 552
 553        if (write_in_full(fd, "[", 1) != 1 ||
 554            write_in_full(fd, key, len1) != len1)
 555                return 0;
 556        if (len2 >= 0) {
 557                if (write_in_full(fd, " \"", 2) != 2)
 558                        return 0;
 559                while (--len2 >= 0) {
 560                        unsigned char c = *++dot;
 561                        if (c == '"')
 562                                if (write_in_full(fd, "\\", 1) != 1)
 563                                        return 0;
 564                        if (write_in_full(fd, &c, 1) != 1)
 565                                return 0;
 566                }
 567                if (write_in_full(fd, "\"", 1) != 1)
 568                        return 0;
 569        }
 570        if (write_in_full(fd, "]\n", 2) != 2)
 571                return 0;
 572
 573        return 1;
 574}
 575
 576static int store_write_pair(int fd, const char* key, const char* value)
 577{
 578        int i;
 579        int length = strlen(key+store.baselen+1);
 580        int quote = 0;
 581
 582        /* Check to see if the value needs to be quoted. */
 583        if (value[0] == ' ')
 584                quote = 1;
 585        for (i = 0; value[i]; i++)
 586                if (value[i] == ';' || value[i] == '#')
 587                        quote = 1;
 588        if (value[i-1] == ' ')
 589                quote = 1;
 590
 591        if (write_in_full(fd, "\t", 1) != 1 ||
 592            write_in_full(fd, key+store.baselen+1, length) != length ||
 593            write_in_full(fd, " = ", 3) != 3)
 594                return 0;
 595        if (quote && write_in_full(fd, "\"", 1) != 1)
 596                return 0;
 597        for (i = 0; value[i]; i++)
 598                switch (value[i]) {
 599                case '\n':
 600                        if (write_in_full(fd, "\\n", 2) != 2)
 601                                return 0;
 602                        break;
 603                case '\t':
 604                        if (write_in_full(fd, "\\t", 2) != 2)
 605                                return 0;
 606                        break;
 607                case '"':
 608                case '\\':
 609                        if (write_in_full(fd, "\\", 1) != 1)
 610                                return 0;
 611                default:
 612                        if (write_in_full(fd, value+i, 1) != 1)
 613                                return 0;
 614                        break;
 615                }
 616        if (quote && write_in_full(fd, "\"", 1) != 1)
 617                return 0;
 618        if (write_in_full(fd, "\n", 1) != 1)
 619                return 0;
 620        return 1;
 621}
 622
 623static ssize_t find_beginning_of_line(const char* contents, size_t size,
 624        size_t offset_, int* found_bracket)
 625{
 626        size_t equal_offset = size, bracket_offset = size;
 627        ssize_t offset;
 628
 629        for (offset = offset_-2; offset > 0
 630                        && contents[offset] != '\n'; offset--)
 631                switch (contents[offset]) {
 632                        case '=': equal_offset = offset; break;
 633                        case ']': bracket_offset = offset; break;
 634                }
 635        if (bracket_offset < equal_offset) {
 636                *found_bracket = 1;
 637                offset = bracket_offset+1;
 638        } else
 639                offset++;
 640
 641        return offset;
 642}
 643
 644int git_config_set(const char* key, const char* value)
 645{
 646        return git_config_set_multivar(key, value, NULL, 0);
 647}
 648
 649/*
 650 * If value==NULL, unset in (remove from) config,
 651 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 652 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 653 *     else all matching key/values (regardless how many) are removed,
 654 *     before the new pair is written.
 655 *
 656 * Returns 0 on success.
 657 *
 658 * This function does this:
 659 *
 660 * - it locks the config file by creating ".git/config.lock"
 661 *
 662 * - it then parses the config using store_aux() as validator to find
 663 *   the position on the key/value pair to replace. If it is to be unset,
 664 *   it must be found exactly once.
 665 *
 666 * - the config file is mmap()ed and the part before the match (if any) is
 667 *   written to the lock file, then the changed part and the rest.
 668 *
 669 * - the config file is removed and the lock file rename()d to it.
 670 *
 671 */
 672int git_config_set_multivar(const char* key, const char* value,
 673        const char* value_regex, int multi_replace)
 674{
 675        int i, dot;
 676        int fd = -1, in_fd;
 677        int ret;
 678        char* config_filename;
 679        char* lock_file;
 680        const char* last_dot = strrchr(key, '.');
 681
 682        config_filename = getenv(CONFIG_ENVIRONMENT);
 683        if (!config_filename) {
 684                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 685                if (!config_filename)
 686                        config_filename  = git_path("config");
 687        }
 688        config_filename = xstrdup(config_filename);
 689        lock_file = xstrdup(mkpath("%s.lock", config_filename));
 690
 691        /*
 692         * Since "key" actually contains the section name and the real
 693         * key name separated by a dot, we have to know where the dot is.
 694         */
 695
 696        if (last_dot == NULL) {
 697                fprintf(stderr, "key does not contain a section: %s\n", key);
 698                ret = 2;
 699                goto out_free;
 700        }
 701        store.baselen = last_dot - key;
 702
 703        store.multi_replace = multi_replace;
 704
 705        /*
 706         * Validate the key and while at it, lower case it for matching.
 707         */
 708        store.key = xmalloc(strlen(key) + 1);
 709        dot = 0;
 710        for (i = 0; key[i]; i++) {
 711                unsigned char c = key[i];
 712                if (c == '.')
 713                        dot = 1;
 714                /* Leave the extended basename untouched.. */
 715                if (!dot || i > store.baselen) {
 716                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 717                                fprintf(stderr, "invalid key: %s\n", key);
 718                                free(store.key);
 719                                ret = 1;
 720                                goto out_free;
 721                        }
 722                        c = tolower(c);
 723                } else if (c == '\n') {
 724                        fprintf(stderr, "invalid key (newline): %s\n", key);
 725                        free(store.key);
 726                        ret = 1;
 727                        goto out_free;
 728                }
 729                store.key[i] = c;
 730        }
 731        store.key[i] = 0;
 732
 733        /*
 734         * The lock_file serves a purpose in addition to locking: the new
 735         * contents of .git/config will be written into it.
 736         */
 737        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 738        if (fd < 0 || adjust_shared_perm(lock_file)) {
 739                fprintf(stderr, "could not lock config file\n");
 740                free(store.key);
 741                ret = -1;
 742                goto out_free;
 743        }
 744
 745        /*
 746         * If .git/config does not exist yet, write a minimal version.
 747         */
 748        in_fd = open(config_filename, O_RDONLY);
 749        if ( in_fd < 0 ) {
 750                free(store.key);
 751
 752                if ( ENOENT != errno ) {
 753                        error("opening %s: %s", config_filename,
 754                              strerror(errno));
 755                        ret = 3; /* same as "invalid config file" */
 756                        goto out_free;
 757                }
 758                /* if nothing to unset, error out */
 759                if (value == NULL) {
 760                        ret = 5;
 761                        goto out_free;
 762                }
 763
 764                store.key = (char*)key;
 765                if (!store_write_section(fd, key) ||
 766                    !store_write_pair(fd, key, value))
 767                        goto write_err_out;
 768        } else {
 769                struct stat st;
 770                char* contents;
 771                size_t contents_sz, copy_begin, copy_end;
 772                int i, new_line = 0;
 773
 774                if (value_regex == NULL)
 775                        store.value_regex = NULL;
 776                else {
 777                        if (value_regex[0] == '!') {
 778                                store.do_not_match = 1;
 779                                value_regex++;
 780                        } else
 781                                store.do_not_match = 0;
 782
 783                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 784                        if (regcomp(store.value_regex, value_regex,
 785                                        REG_EXTENDED)) {
 786                                fprintf(stderr, "Invalid pattern: %s\n",
 787                                        value_regex);
 788                                free(store.value_regex);
 789                                ret = 6;
 790                                goto out_free;
 791                        }
 792                }
 793
 794                store.offset[0] = 0;
 795                store.state = START;
 796                store.seen = 0;
 797
 798                /*
 799                 * After this, store.offset will contain the *end* offset
 800                 * of the last match, or remain at 0 if no match was found.
 801                 * As a side effect, we make sure to transform only a valid
 802                 * existing config file.
 803                 */
 804                if (git_config_from_file(store_aux, config_filename)) {
 805                        fprintf(stderr, "invalid config file\n");
 806                        free(store.key);
 807                        if (store.value_regex != NULL) {
 808                                regfree(store.value_regex);
 809                                free(store.value_regex);
 810                        }
 811                        ret = 3;
 812                        goto out_free;
 813                }
 814
 815                free(store.key);
 816                if (store.value_regex != NULL) {
 817                        regfree(store.value_regex);
 818                        free(store.value_regex);
 819                }
 820
 821                /* if nothing to unset, or too many matches, error out */
 822                if ((store.seen == 0 && value == NULL) ||
 823                                (store.seen > 1 && multi_replace == 0)) {
 824                        ret = 5;
 825                        goto out_free;
 826                }
 827
 828                fstat(in_fd, &st);
 829                contents_sz = xsize_t(st.st_size);
 830                contents = xmmap(NULL, contents_sz, PROT_READ,
 831                        MAP_PRIVATE, in_fd, 0);
 832                close(in_fd);
 833
 834                if (store.seen == 0)
 835                        store.seen = 1;
 836
 837                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 838                        if (store.offset[i] == 0) {
 839                                store.offset[i] = copy_end = contents_sz;
 840                        } else if (store.state != KEY_SEEN) {
 841                                copy_end = store.offset[i];
 842                        } else
 843                                copy_end = find_beginning_of_line(
 844                                        contents, contents_sz,
 845                                        store.offset[i]-2, &new_line);
 846
 847                        /* write the first part of the config */
 848                        if (copy_end > copy_begin) {
 849                                if (write_in_full(fd, contents + copy_begin,
 850                                                  copy_end - copy_begin) <
 851                                    copy_end - copy_begin)
 852                                        goto write_err_out;
 853                                if (new_line &&
 854                                    write_in_full(fd, "\n", 1) != 1)
 855                                        goto write_err_out;
 856                        }
 857                        copy_begin = store.offset[i];
 858                }
 859
 860                /* write the pair (value == NULL means unset) */
 861                if (value != NULL) {
 862                        if (store.state == START) {
 863                                if (!store_write_section(fd, key))
 864                                        goto write_err_out;
 865                        }
 866                        if (!store_write_pair(fd, key, value))
 867                                goto write_err_out;
 868                }
 869
 870                /* write the rest of the config */
 871                if (copy_begin < contents_sz)
 872                        if (write_in_full(fd, contents + copy_begin,
 873                                          contents_sz - copy_begin) <
 874                            contents_sz - copy_begin)
 875                                goto write_err_out;
 876
 877                munmap(contents, contents_sz);
 878                unlink(config_filename);
 879        }
 880
 881        if (rename(lock_file, config_filename) < 0) {
 882                fprintf(stderr, "Could not rename the lock file?\n");
 883                ret = 4;
 884                goto out_free;
 885        }
 886
 887        ret = 0;
 888
 889out_free:
 890        if (0 <= fd)
 891                close(fd);
 892        free(config_filename);
 893        if (lock_file) {
 894                unlink(lock_file);
 895                free(lock_file);
 896        }
 897        return ret;
 898
 899write_err_out:
 900        ret = write_error();
 901        goto out_free;
 902
 903}
 904
 905static int section_name_match (const char *buf, const char *name)
 906{
 907        int i = 0, j = 0, dot = 0;
 908        for (; buf[i] && buf[i] != ']'; i++) {
 909                if (!dot && isspace(buf[i])) {
 910                        dot = 1;
 911                        if (name[j++] != '.')
 912                                break;
 913                        for (i++; isspace(buf[i]); i++)
 914                                ; /* do nothing */
 915                        if (buf[i] != '"')
 916                                break;
 917                        continue;
 918                }
 919                if (buf[i] == '\\' && dot)
 920                        i++;
 921                else if (buf[i] == '"' && dot) {
 922                        for (i++; isspace(buf[i]); i++)
 923                                ; /* do_nothing */
 924                        break;
 925                }
 926                if (buf[i] != name[j++])
 927                        break;
 928        }
 929        return (buf[i] == ']' && name[j] == 0);
 930}
 931
 932/* if new_name == NULL, the section is removed instead */
 933int git_config_rename_section(const char *old_name, const char *new_name)
 934{
 935        int ret = 0, remove = 0;
 936        char *config_filename;
 937        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
 938        int out_fd;
 939        char buf[1024];
 940
 941        config_filename = getenv(CONFIG_ENVIRONMENT);
 942        if (!config_filename) {
 943                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 944                if (!config_filename)
 945                        config_filename  = git_path("config");
 946        }
 947        config_filename = xstrdup(config_filename);
 948        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
 949        if (out_fd < 0) {
 950                ret = error("Could not lock config file!");
 951                goto out;
 952        }
 953
 954        if (!(config_file = fopen(config_filename, "rb"))) {
 955                /* no config file means nothing to rename, no error */
 956                goto unlock_and_out;
 957        }
 958
 959        while (fgets(buf, sizeof(buf), config_file)) {
 960                int i;
 961                int length;
 962                for (i = 0; buf[i] && isspace(buf[i]); i++)
 963                        ; /* do nothing */
 964                if (buf[i] == '[') {
 965                        /* it's a section */
 966                        if (section_name_match (&buf[i+1], old_name)) {
 967                                ret++;
 968                                if (new_name == NULL) {
 969                                        remove = 1;
 970                                        continue;
 971                                }
 972                                store.baselen = strlen(new_name);
 973                                if (!store_write_section(out_fd, new_name)) {
 974                                        ret = write_error();
 975                                        goto out;
 976                                }
 977                                continue;
 978                        }
 979                        remove = 0;
 980                }
 981                if (remove)
 982                        continue;
 983                length = strlen(buf);
 984                if (write_in_full(out_fd, buf, length) != length) {
 985                        ret = write_error();
 986                        goto out;
 987                }
 988        }
 989        fclose(config_file);
 990 unlock_and_out:
 991        if (close(out_fd) || commit_lock_file(lock) < 0)
 992                        ret = error("Cannot commit config file!");
 993 out:
 994        free(config_filename);
 995        return ret;
 996}