config.con commit Merge branch 'ar/merge-recursive' (141d21b)
   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 get_next_char(void)
  16{
  17        int c;
  18        FILE *f;
  19
  20        c = '\n';
  21        if ((f = config_file) != NULL) {
  22                c = fgetc(f);
  23                if (c == '\r') {
  24                        /* DOS like systems */
  25                        c = fgetc(f);
  26                        if (c != '\n') {
  27                                ungetc(c, f);
  28                                c = '\r';
  29                        }
  30                }
  31                if (c == '\n')
  32                        config_linenr++;
  33                if (c == EOF) {
  34                        config_file = NULL;
  35                        c = '\n';
  36                }
  37        }
  38        return c;
  39}
  40
  41static char *parse_value(void)
  42{
  43        static char value[1024];
  44        int quote = 0, comment = 0, len = 0, space = 0;
  45
  46        for (;;) {
  47                int c = get_next_char();
  48                if (len >= sizeof(value))
  49                        return NULL;
  50                if (c == '\n') {
  51                        if (quote)
  52                                return NULL;
  53                        value[len] = 0;
  54                        return value;
  55                }
  56                if (comment)
  57                        continue;
  58                if (isspace(c) && !quote) {
  59                        space = 1;
  60                        continue;
  61                }
  62                if (!quote) {
  63                        if (c == ';' || c == '#') {
  64                                comment = 1;
  65                                continue;
  66                        }
  67                }
  68                if (space) {
  69                        if (len)
  70                                value[len++] = ' ';
  71                        space = 0;
  72                }
  73                if (c == '\\') {
  74                        c = get_next_char();
  75                        switch (c) {
  76                        case '\n':
  77                                continue;
  78                        case 't':
  79                                c = '\t';
  80                                break;
  81                        case 'b':
  82                                c = '\b';
  83                                break;
  84                        case 'n':
  85                                c = '\n';
  86                                break;
  87                        /* Some characters escape as themselves */
  88                        case '\\': case '"':
  89                                break;
  90                        /* Reject unknown escape sequences */
  91                        default:
  92                                return NULL;
  93                        }
  94                        value[len++] = c;
  95                        continue;
  96                }
  97                if (c == '"') {
  98                        quote = 1-quote;
  99                        continue;
 100                }
 101                value[len++] = c;
 102        }
 103}
 104
 105static inline int iskeychar(int c)
 106{
 107        return isalnum(c) || c == '-';
 108}
 109
 110static int get_value(config_fn_t fn, char *name, unsigned int len)
 111{
 112        int c;
 113        char *value;
 114
 115        /* Get the full name */
 116        for (;;) {
 117                c = get_next_char();
 118                if (c == EOF)
 119                        break;
 120                if (!iskeychar(c))
 121                        break;
 122                name[len++] = tolower(c);
 123                if (len >= MAXNAME)
 124                        return -1;
 125        }
 126        name[len] = 0;
 127        while (c == ' ' || c == '\t')
 128                c = get_next_char();
 129
 130        value = NULL;
 131        if (c != '\n') {
 132                if (c != '=')
 133                        return -1;
 134                value = parse_value();
 135                if (!value)
 136                        return -1;
 137        }
 138        return fn(name, value);
 139}
 140
 141static int get_extended_base_var(char *name, int baselen, int c)
 142{
 143        do {
 144                if (c == '\n')
 145                        return -1;
 146                c = get_next_char();
 147        } while (isspace(c));
 148
 149        /* We require the format to be '[base "extension"]' */
 150        if (c != '"')
 151                return -1;
 152        name[baselen++] = '.';
 153
 154        for (;;) {
 155                int c = get_next_char();
 156                if (c == '\n')
 157                        return -1;
 158                if (c == '"')
 159                        break;
 160                if (c == '\\') {
 161                        c = get_next_char();
 162                        if (c == '\n')
 163                                return -1;
 164                }
 165                name[baselen++] = c;
 166                if (baselen > MAXNAME / 2)
 167                        return -1;
 168        }
 169
 170        /* Final ']' */
 171        if (get_next_char() != ']')
 172                return -1;
 173        return baselen;
 174}
 175
 176static int get_base_var(char *name)
 177{
 178        int baselen = 0;
 179
 180        for (;;) {
 181                int c = get_next_char();
 182                if (c == EOF)
 183                        return -1;
 184                if (c == ']')
 185                        return baselen;
 186                if (isspace(c))
 187                        return get_extended_base_var(name, baselen, c);
 188                if (!iskeychar(c) && c != '.')
 189                        return -1;
 190                if (baselen > MAXNAME / 2)
 191                        return -1;
 192                name[baselen++] = tolower(c);
 193        }
 194}
 195
 196static int git_parse_file(config_fn_t fn)
 197{
 198        int comment = 0;
 199        int baselen = 0;
 200        static char var[MAXNAME];
 201
 202        for (;;) {
 203                int c = get_next_char();
 204                if (c == '\n') {
 205                        /* EOF? */
 206                        if (!config_file)
 207                                return 0;
 208                        comment = 0;
 209                        continue;
 210                }
 211                if (comment || isspace(c))
 212                        continue;
 213                if (c == '#' || c == ';') {
 214                        comment = 1;
 215                        continue;
 216                }
 217                if (c == '[') {
 218                        baselen = get_base_var(var);
 219                        if (baselen <= 0)
 220                                break;
 221                        var[baselen++] = '.';
 222                        var[baselen] = 0;
 223                        continue;
 224                }
 225                if (!isalpha(c))
 226                        break;
 227                var[baselen] = tolower(c);
 228                if (get_value(fn, var, baselen+1) < 0)
 229                        break;
 230        }
 231        die("bad config file line %d in %s", config_linenr, config_file_name);
 232}
 233
 234int git_config_int(const char *name, const char *value)
 235{
 236        if (value && *value) {
 237                char *end;
 238                int val = strtol(value, &end, 0);
 239                if (!*end)
 240                        return val;
 241                if (!strcasecmp(end, "k"))
 242                        return val * 1024;
 243                if (!strcasecmp(end, "m"))
 244                        return val * 1024 * 1024;
 245                if (!strcasecmp(end, "g"))
 246                        return val * 1024 * 1024 * 1024;
 247        }
 248        die("bad config value for '%s' in %s", name, config_file_name);
 249}
 250
 251int git_config_bool(const char *name, const char *value)
 252{
 253        if (!value)
 254                return 1;
 255        if (!*value)
 256                return 0;
 257        if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 258                return 1;
 259        if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 260                return 0;
 261        return git_config_int(name, value) != 0;
 262}
 263
 264int git_default_config(const char *var, const char *value)
 265{
 266        /* This needs a better name */
 267        if (!strcmp(var, "core.filemode")) {
 268                trust_executable_bit = git_config_bool(var, value);
 269                return 0;
 270        }
 271
 272        if (!strcmp(var, "core.ignorestat")) {
 273                assume_unchanged = git_config_bool(var, value);
 274                return 0;
 275        }
 276
 277        if (!strcmp(var, "core.prefersymlinkrefs")) {
 278                prefer_symlink_refs = git_config_bool(var, value);
 279                return 0;
 280        }
 281
 282        if (!strcmp(var, "core.logallrefupdates")) {
 283                log_all_ref_updates = git_config_bool(var, value);
 284                return 0;
 285        }
 286
 287        if (!strcmp(var, "core.warnambiguousrefs")) {
 288                warn_ambiguous_refs = git_config_bool(var, value);
 289                return 0;
 290        }
 291
 292        if (!strcmp(var, "core.legacyheaders")) {
 293                use_legacy_headers = git_config_bool(var, value);
 294                return 0;
 295        }
 296
 297        if (!strcmp(var, "core.compression")) {
 298                int level = git_config_int(var, value);
 299                if (level == -1)
 300                        level = Z_DEFAULT_COMPRESSION;
 301                else if (level < 0 || level > Z_BEST_COMPRESSION)
 302                        die("bad zlib compression level %d", level);
 303                zlib_compression_level = level;
 304                return 0;
 305        }
 306
 307        if (!strcmp(var, "core.packedgitwindowsize")) {
 308                int pgsz = getpagesize();
 309                packed_git_window_size = git_config_int(var, value);
 310                packed_git_window_size /= pgsz;
 311                if (packed_git_window_size < 2)
 312                        packed_git_window_size = 2;
 313                packed_git_window_size *= pgsz;
 314                return 0;
 315        }
 316
 317        if (!strcmp(var, "core.packedgitlimit")) {
 318                packed_git_limit = git_config_int(var, value);
 319                return 0;
 320        }
 321
 322        if (!strcmp(var, "user.name")) {
 323                strlcpy(git_default_name, value, sizeof(git_default_name));
 324                return 0;
 325        }
 326
 327        if (!strcmp(var, "user.email")) {
 328                strlcpy(git_default_email, value, sizeof(git_default_email));
 329                return 0;
 330        }
 331
 332        if (!strcmp(var, "i18n.commitencoding")) {
 333                git_commit_encoding = strdup(value);
 334                return 0;
 335        }
 336
 337        if (!strcmp(var, "i18n.logoutputencoding")) {
 338                git_log_output_encoding = strdup(value);
 339                return 0;
 340        }
 341
 342
 343        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 344                pager_use_color = git_config_bool(var,value);
 345                return 0;
 346        }
 347
 348        /* Add other config variables here and to Documentation/config.txt. */
 349        return 0;
 350}
 351
 352int git_config_from_file(config_fn_t fn, const char *filename)
 353{
 354        int ret;
 355        FILE *f = fopen(filename, "r");
 356
 357        ret = -1;
 358        if (f) {
 359                config_file = f;
 360                config_file_name = filename;
 361                config_linenr = 1;
 362                ret = git_parse_file(fn);
 363                fclose(f);
 364                config_file_name = NULL;
 365        }
 366        return ret;
 367}
 368
 369int git_config(config_fn_t fn)
 370{
 371        int ret = 0;
 372        char *repo_config = NULL;
 373        const char *home = NULL, *filename;
 374
 375        /* $GIT_CONFIG makes git read _only_ the given config file,
 376         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 377         * global config file, the same way it would the per-repository
 378         * config file otherwise. */
 379        filename = getenv(CONFIG_ENVIRONMENT);
 380        if (!filename) {
 381                home = getenv("HOME");
 382                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 383                if (!filename)
 384                        filename = repo_config = xstrdup(git_path("config"));
 385        }
 386
 387        if (home) {
 388                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 389                if (!access(user_config, R_OK))
 390                        ret = git_config_from_file(fn, user_config);
 391                free(user_config);
 392        }
 393
 394        ret += git_config_from_file(fn, filename);
 395        free(repo_config);
 396        return ret;
 397}
 398
 399/*
 400 * Find all the stuff for git_config_set() below.
 401 */
 402
 403#define MAX_MATCHES 512
 404
 405static struct {
 406        int baselen;
 407        char* key;
 408        int do_not_match;
 409        regex_t* value_regex;
 410        int multi_replace;
 411        off_t offset[MAX_MATCHES];
 412        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 413        int seen;
 414} store;
 415
 416static int matches(const char* key, const char* value)
 417{
 418        return !strcmp(key, store.key) &&
 419                (store.value_regex == NULL ||
 420                 (store.do_not_match ^
 421                  !regexec(store.value_regex, value, 0, NULL, 0)));
 422}
 423
 424static int store_aux(const char* key, const char* value)
 425{
 426        switch (store.state) {
 427        case KEY_SEEN:
 428                if (matches(key, value)) {
 429                        if (store.seen == 1 && store.multi_replace == 0) {
 430                                fprintf(stderr,
 431                                        "Warning: %s has multiple values\n",
 432                                        key);
 433                        } else if (store.seen >= MAX_MATCHES) {
 434                                fprintf(stderr, "Too many matches\n");
 435                                return 1;
 436                        }
 437
 438                        store.offset[store.seen] = ftell(config_file);
 439                        store.seen++;
 440                }
 441                break;
 442        case SECTION_SEEN:
 443                if (strncmp(key, store.key, store.baselen+1)) {
 444                        store.state = SECTION_END_SEEN;
 445                        break;
 446                } else
 447                        /* do not increment matches: this is no match */
 448                        store.offset[store.seen] = ftell(config_file);
 449                /* fallthru */
 450        case SECTION_END_SEEN:
 451        case START:
 452                if (matches(key, value)) {
 453                        store.offset[store.seen] = ftell(config_file);
 454                        store.state = KEY_SEEN;
 455                        store.seen++;
 456                } else {
 457                        if (strrchr(key, '.') - key == store.baselen &&
 458                              !strncmp(key, store.key, store.baselen)) {
 459                                        store.state = SECTION_SEEN;
 460                                        store.offset[store.seen] = ftell(config_file);
 461                        }
 462                }
 463        }
 464        return 0;
 465}
 466
 467static int write_error()
 468{
 469        fprintf(stderr, "Failed to write new configuration file\n");
 470
 471        /* Same error code as "failed to rename". */
 472        return 4;
 473}
 474
 475static int store_write_section(int fd, const char* key)
 476{
 477        const char *dot = strchr(key, '.');
 478        int len1 = store.baselen, len2 = -1;
 479
 480        dot = strchr(key, '.');
 481        if (dot) {
 482                int dotlen = dot - key;
 483                if (dotlen < len1) {
 484                        len2 = len1 - dotlen - 1;
 485                        len1 = dotlen;
 486                }
 487        }
 488
 489        if (write_in_full(fd, "[", 1) != 1 ||
 490            write_in_full(fd, key, len1) != len1)
 491                return 0;
 492        if (len2 >= 0) {
 493                if (write_in_full(fd, " \"", 2) != 2)
 494                        return 0;
 495                while (--len2 >= 0) {
 496                        unsigned char c = *++dot;
 497                        if (c == '"')
 498                                if (write_in_full(fd, "\\", 1) != 1)
 499                                        return 0;
 500                        if (write_in_full(fd, &c, 1) != 1)
 501                                return 0;
 502                }
 503                if (write_in_full(fd, "\"", 1) != 1)
 504                        return 0;
 505        }
 506        if (write_in_full(fd, "]\n", 2) != 2)
 507                return 0;
 508
 509        return 1;
 510}
 511
 512static int store_write_pair(int fd, const char* key, const char* value)
 513{
 514        int i;
 515        int length = strlen(key+store.baselen+1);
 516        int quote = 0;
 517
 518        /* Check to see if the value needs to be quoted. */
 519        if (value[0] == ' ')
 520                quote = 1;
 521        for (i = 0; value[i]; i++)
 522                if (value[i] == ';' || value[i] == '#')
 523                        quote = 1;
 524        if (value[i-1] == ' ')
 525                quote = 1;
 526
 527        if (write_in_full(fd, "\t", 1) != 1 ||
 528            write_in_full(fd, key+store.baselen+1, length) != length ||
 529            write_in_full(fd, " = ", 3) != 3)
 530                return 0;
 531        if (quote && write_in_full(fd, "\"", 1) != 1)
 532                return 0;
 533        for (i = 0; value[i]; i++)
 534                switch (value[i]) {
 535                case '\n':
 536                        if (write_in_full(fd, "\\n", 2) != 2)
 537                                return 0;
 538                        break;
 539                case '\t':
 540                        if (write_in_full(fd, "\\t", 2) != 2)
 541                                return 0;
 542                        break;
 543                case '"':
 544                case '\\':
 545                        if (write_in_full(fd, "\\", 1) != 1)
 546                                return 0;
 547                default:
 548                        if (write_in_full(fd, value+i, 1) != 1)
 549                                return 0;
 550                        break;
 551                }
 552        if (quote && write_in_full(fd, "\"", 1) != 1)
 553                return 0;
 554        if (write_in_full(fd, "\n", 1) != 1)
 555                return 0;
 556        return 1;
 557}
 558
 559static int find_beginning_of_line(const char* contents, int size,
 560        int offset_, int* found_bracket)
 561{
 562        int equal_offset = size, bracket_offset = size;
 563        int offset;
 564
 565        for (offset = offset_-2; offset > 0 
 566                        && contents[offset] != '\n'; offset--)
 567                switch (contents[offset]) {
 568                        case '=': equal_offset = offset; break;
 569                        case ']': bracket_offset = offset; break;
 570                }
 571        if (bracket_offset < equal_offset) {
 572                *found_bracket = 1;
 573                offset = bracket_offset+1;
 574        } else
 575                offset++;
 576
 577        return offset;
 578}
 579
 580int git_config_set(const char* key, const char* value)
 581{
 582        return git_config_set_multivar(key, value, NULL, 0);
 583}
 584
 585/*
 586 * If value==NULL, unset in (remove from) config,
 587 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 588 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 589 *     else all matching key/values (regardless how many) are removed,
 590 *     before the new pair is written.
 591 *
 592 * Returns 0 on success.
 593 *
 594 * This function does this:
 595 *
 596 * - it locks the config file by creating ".git/config.lock"
 597 *
 598 * - it then parses the config using store_aux() as validator to find
 599 *   the position on the key/value pair to replace. If it is to be unset,
 600 *   it must be found exactly once.
 601 *
 602 * - the config file is mmap()ed and the part before the match (if any) is
 603 *   written to the lock file, then the changed part and the rest.
 604 *
 605 * - the config file is removed and the lock file rename()d to it.
 606 *
 607 */
 608int git_config_set_multivar(const char* key, const char* value,
 609        const char* value_regex, int multi_replace)
 610{
 611        int i, dot;
 612        int fd = -1, in_fd;
 613        int ret;
 614        char* config_filename;
 615        char* lock_file;
 616        const char* last_dot = strrchr(key, '.');
 617
 618        config_filename = getenv(CONFIG_ENVIRONMENT);
 619        if (!config_filename) {
 620                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 621                if (!config_filename)
 622                        config_filename  = git_path("config");
 623        }
 624        config_filename = xstrdup(config_filename);
 625        lock_file = xstrdup(mkpath("%s.lock", config_filename));
 626
 627        /*
 628         * Since "key" actually contains the section name and the real
 629         * key name separated by a dot, we have to know where the dot is.
 630         */
 631
 632        if (last_dot == NULL) {
 633                fprintf(stderr, "key does not contain a section: %s\n", key);
 634                ret = 2;
 635                goto out_free;
 636        }
 637        store.baselen = last_dot - key;
 638
 639        store.multi_replace = multi_replace;
 640
 641        /*
 642         * Validate the key and while at it, lower case it for matching.
 643         */
 644        store.key = xmalloc(strlen(key) + 1);
 645        dot = 0;
 646        for (i = 0; key[i]; i++) {
 647                unsigned char c = key[i];
 648                if (c == '.')
 649                        dot = 1;
 650                /* Leave the extended basename untouched.. */
 651                if (!dot || i > store.baselen) {
 652                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 653                                fprintf(stderr, "invalid key: %s\n", key);
 654                                free(store.key);
 655                                ret = 1;
 656                                goto out_free;
 657                        }
 658                        c = tolower(c);
 659                }
 660                store.key[i] = c;
 661        }
 662        store.key[i] = 0;
 663
 664        /*
 665         * The lock_file serves a purpose in addition to locking: the new
 666         * contents of .git/config will be written into it.
 667         */
 668        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 669        if (fd < 0 || adjust_shared_perm(lock_file)) {
 670                fprintf(stderr, "could not lock config file\n");
 671                free(store.key);
 672                ret = -1;
 673                goto out_free;
 674        }
 675
 676        /*
 677         * If .git/config does not exist yet, write a minimal version.
 678         */
 679        in_fd = open(config_filename, O_RDONLY);
 680        if ( in_fd < 0 ) {
 681                free(store.key);
 682
 683                if ( ENOENT != errno ) {
 684                        error("opening %s: %s", config_filename,
 685                              strerror(errno));
 686                        ret = 3; /* same as "invalid config file" */
 687                        goto out_free;
 688                }
 689                /* if nothing to unset, error out */
 690                if (value == NULL) {
 691                        ret = 5;
 692                        goto out_free;
 693                }
 694
 695                store.key = (char*)key;
 696                if (!store_write_section(fd, key) ||
 697                    !store_write_pair(fd, key, value))
 698                        goto write_err_out;
 699        } else {
 700                struct stat st;
 701                char* contents;
 702                int i, copy_begin, copy_end, new_line = 0;
 703
 704                if (value_regex == NULL)
 705                        store.value_regex = NULL;
 706                else {
 707                        if (value_regex[0] == '!') {
 708                                store.do_not_match = 1;
 709                                value_regex++;
 710                        } else
 711                                store.do_not_match = 0;
 712
 713                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 714                        if (regcomp(store.value_regex, value_regex,
 715                                        REG_EXTENDED)) {
 716                                fprintf(stderr, "Invalid pattern: %s\n",
 717                                        value_regex);
 718                                free(store.value_regex);
 719                                ret = 6;
 720                                goto out_free;
 721                        }
 722                }
 723
 724                store.offset[0] = 0;
 725                store.state = START;
 726                store.seen = 0;
 727
 728                /*
 729                 * After this, store.offset will contain the *end* offset
 730                 * of the last match, or remain at 0 if no match was found.
 731                 * As a side effect, we make sure to transform only a valid
 732                 * existing config file.
 733                 */
 734                if (git_config_from_file(store_aux, config_filename)) {
 735                        fprintf(stderr, "invalid config file\n");
 736                        free(store.key);
 737                        if (store.value_regex != NULL) {
 738                                regfree(store.value_regex);
 739                                free(store.value_regex);
 740                        }
 741                        ret = 3;
 742                        goto out_free;
 743                }
 744
 745                free(store.key);
 746                if (store.value_regex != NULL) {
 747                        regfree(store.value_regex);
 748                        free(store.value_regex);
 749                }
 750
 751                /* if nothing to unset, or too many matches, error out */
 752                if ((store.seen == 0 && value == NULL) ||
 753                                (store.seen > 1 && multi_replace == 0)) {
 754                        ret = 5;
 755                        goto out_free;
 756                }
 757
 758                fstat(in_fd, &st);
 759                contents = xmmap(NULL, st.st_size, PROT_READ,
 760                        MAP_PRIVATE, in_fd, 0);
 761                close(in_fd);
 762
 763                if (store.seen == 0)
 764                        store.seen = 1;
 765
 766                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 767                        if (store.offset[i] == 0) {
 768                                store.offset[i] = copy_end = st.st_size;
 769                        } else if (store.state != KEY_SEEN) {
 770                                copy_end = store.offset[i];
 771                        } else
 772                                copy_end = find_beginning_of_line(
 773                                        contents, st.st_size,
 774                                        store.offset[i]-2, &new_line);
 775
 776                        /* write the first part of the config */
 777                        if (copy_end > copy_begin) {
 778                                if (write_in_full(fd, contents + copy_begin,
 779                                                  copy_end - copy_begin) <
 780                                    copy_end - copy_begin)
 781                                        goto write_err_out;
 782                                if (new_line &&
 783                                    write_in_full(fd, "\n", 1) != 1)
 784                                        goto write_err_out;
 785                        }
 786                        copy_begin = store.offset[i];
 787                }
 788
 789                /* write the pair (value == NULL means unset) */
 790                if (value != NULL) {
 791                        if (store.state == START) {
 792                                if (!store_write_section(fd, key))
 793                                        goto write_err_out;
 794                        }
 795                        if (!store_write_pair(fd, key, value))
 796                                goto write_err_out;
 797                }
 798
 799                /* write the rest of the config */
 800                if (copy_begin < st.st_size)
 801                        if (write_in_full(fd, contents + copy_begin,
 802                                          st.st_size - copy_begin) <
 803                            st.st_size - copy_begin)
 804                                goto write_err_out;
 805
 806                munmap(contents, st.st_size);
 807                unlink(config_filename);
 808        }
 809
 810        if (rename(lock_file, config_filename) < 0) {
 811                fprintf(stderr, "Could not rename the lock file?\n");
 812                ret = 4;
 813                goto out_free;
 814        }
 815
 816        ret = 0;
 817
 818out_free:
 819        if (0 <= fd)
 820                close(fd);
 821        free(config_filename);
 822        if (lock_file) {
 823                unlink(lock_file);
 824                free(lock_file);
 825        }
 826        return ret;
 827
 828write_err_out:
 829        ret = write_error();
 830        goto out_free;
 831
 832}
 833
 834int git_config_rename_section(const char *old_name, const char *new_name)
 835{
 836        int ret = 0;
 837        char *config_filename;
 838        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
 839        int out_fd;
 840        char buf[1024];
 841
 842        config_filename = getenv(CONFIG_ENVIRONMENT);
 843        if (!config_filename) {
 844                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 845                if (!config_filename)
 846                        config_filename  = git_path("config");
 847        }
 848        config_filename = xstrdup(config_filename);
 849        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
 850        if (out_fd < 0) {
 851                ret = error("Could not lock config file!");
 852                goto out;
 853        }
 854
 855        if (!(config_file = fopen(config_filename, "rb"))) {
 856                ret = error("Could not open config file!");
 857                goto out;
 858        }
 859
 860        while (fgets(buf, sizeof(buf), config_file)) {
 861                int i;
 862                int length;
 863                for (i = 0; buf[i] && isspace(buf[i]); i++)
 864                        ; /* do nothing */
 865                if (buf[i] == '[') {
 866                        /* it's a section */
 867                        int j = 0, dot = 0;
 868                        for (i++; buf[i] && buf[i] != ']'; i++) {
 869                                if (!dot && isspace(buf[i])) {
 870                                        dot = 1;
 871                                        if (old_name[j++] != '.')
 872                                                break;
 873                                        for (i++; isspace(buf[i]); i++)
 874                                                ; /* do nothing */
 875                                        if (buf[i] != '"')
 876                                                break;
 877                                        continue;
 878                                }
 879                                if (buf[i] == '\\' && dot)
 880                                        i++;
 881                                else if (buf[i] == '"' && dot) {
 882                                        for (i++; isspace(buf[i]); i++)
 883                                                ; /* do_nothing */
 884                                        break;
 885                                }
 886                                if (buf[i] != old_name[j++])
 887                                        break;
 888                        }
 889                        if (buf[i] == ']') {
 890                                /* old_name matches */
 891                                ret++;
 892                                store.baselen = strlen(new_name);
 893                                if (!store_write_section(out_fd, new_name)) {
 894                                        ret = write_error();
 895                                        goto out;
 896                                }
 897                                continue;
 898                        }
 899                }
 900                length = strlen(buf);
 901                if (write_in_full(out_fd, buf, length) != length) {
 902                        ret = write_error();
 903                        goto out;
 904                }
 905        }
 906        fclose(config_file);
 907        if (close(out_fd) || commit_lock_file(lock) < 0)
 908                        ret = error("Cannot commit config file!");
 909 out:
 910        free(config_filename);
 911        return ret;
 912}
 913