Andrew's git / gitweb.git / config.c
?
config.con commit Merge branch 'pb/prepare-commit-msg' (1ae419c)
   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#include "exec_cmd.h"
  10
  11#define MAXNAME (256)
  12
  13static FILE *config_file;
  14static const char *config_file_name;
  15static int config_linenr;
  16static int config_file_eof;
  17static int zlib_compression_seen;
  18
  19static int get_next_char(void)
  20{
  21        int c;
  22        FILE *f;
  23
  24        c = '\n';
  25        if ((f = config_file) != NULL) {
  26                c = fgetc(f);
  27                if (c == '\r') {
  28                        /* DOS like systems */
  29                        c = fgetc(f);
  30                        if (c != '\n') {
  31                                ungetc(c, f);
  32                                c = '\r';
  33                        }
  34                }
  35                if (c == '\n')
  36                        config_linenr++;
  37                if (c == EOF) {
  38                        config_file_eof = 1;
  39                        c = '\n';
  40                }
  41        }
  42        return c;
  43}
  44
  45static char *parse_value(void)
  46{
  47        static char value[1024];
  48        int quote = 0, comment = 0, len = 0, space = 0;
  49
  50        for (;;) {
  51                int c = get_next_char();
  52                if (len >= sizeof(value))
  53                        return NULL;
  54                if (c == '\n') {
  55                        if (quote)
  56                                return NULL;
  57                        value[len] = 0;
  58                        return value;
  59                }
  60                if (comment)
  61                        continue;
  62                if (isspace(c) && !quote) {
  63                        space = 1;
  64                        continue;
  65                }
  66                if (!quote) {
  67                        if (c == ';' || c == '#') {
  68                                comment = 1;
  69                                continue;
  70                        }
  71                }
  72                if (space) {
  73                        if (len)
  74                                value[len++] = ' ';
  75                        space = 0;
  76                }
  77                if (c == '\\') {
  78                        c = get_next_char();
  79                        switch (c) {
  80                        case '\n':
  81                                continue;
  82                        case 't':
  83                                c = '\t';
  84                                break;
  85                        case 'b':
  86                                c = '\b';
  87                                break;
  88                        case 'n':
  89                                c = '\n';
  90                                break;
  91                        /* Some characters escape as themselves */
  92                        case '\\': case '"':
  93                                break;
  94                        /* Reject unknown escape sequences */
  95                        default:
  96                                return NULL;
  97                        }
  98                        value[len++] = c;
  99                        continue;
 100                }
 101                if (c == '"') {
 102                        quote = 1-quote;
 103                        continue;
 104                }
 105                value[len++] = c;
 106        }
 107}
 108
 109static inline int iskeychar(int c)
 110{
 111        return isalnum(c) || c == '-';
 112}
 113
 114static int get_value(config_fn_t fn, char *name, unsigned int len)
 115{
 116        int c;
 117        char *value;
 118
 119        /* Get the full name */
 120        for (;;) {
 121                c = get_next_char();
 122                if (config_file_eof)
 123                        break;
 124                if (!iskeychar(c))
 125                        break;
 126                name[len++] = tolower(c);
 127                if (len >= MAXNAME)
 128                        return -1;
 129        }
 130        name[len] = 0;
 131        while (c == ' ' || c == '\t')
 132                c = get_next_char();
 133
 134        value = NULL;
 135        if (c != '\n') {
 136                if (c != '=')
 137                        return -1;
 138                value = parse_value();
 139                if (!value)
 140                        return -1;
 141        }
 142        return fn(name, value);
 143}
 144
 145static int get_extended_base_var(char *name, int baselen, int c)
 146{
 147        do {
 148                if (c == '\n')
 149                        return -1;
 150                c = get_next_char();
 151        } while (isspace(c));
 152
 153        /* We require the format to be '[base "extension"]' */
 154        if (c != '"')
 155                return -1;
 156        name[baselen++] = '.';
 157
 158        for (;;) {
 159                int c = get_next_char();
 160                if (c == '\n')
 161                        return -1;
 162                if (c == '"')
 163                        break;
 164                if (c == '\\') {
 165                        c = get_next_char();
 166                        if (c == '\n')
 167                                return -1;
 168                }
 169                name[baselen++] = c;
 170                if (baselen > MAXNAME / 2)
 171                        return -1;
 172        }
 173
 174        /* Final ']' */
 175        if (get_next_char() != ']')
 176                return -1;
 177        return baselen;
 178}
 179
 180static int get_base_var(char *name)
 181{
 182        int baselen = 0;
 183
 184        for (;;) {
 185                int c = get_next_char();
 186                if (config_file_eof)
 187                        return -1;
 188                if (c == ']')
 189                        return baselen;
 190                if (isspace(c))
 191                        return get_extended_base_var(name, baselen, c);
 192                if (!iskeychar(c) && c != '.')
 193                        return -1;
 194                if (baselen > MAXNAME / 2)
 195                        return -1;
 196                name[baselen++] = tolower(c);
 197        }
 198}
 199
 200static int git_parse_file(config_fn_t fn)
 201{
 202        int comment = 0;
 203        int baselen = 0;
 204        static char var[MAXNAME];
 205
 206        for (;;) {
 207                int c = get_next_char();
 208                if (c == '\n') {
 209                        if (config_file_eof)
 210                                return 0;
 211                        comment = 0;
 212                        continue;
 213                }
 214                if (comment || isspace(c))
 215                        continue;
 216                if (c == '#' || c == ';') {
 217                        comment = 1;
 218                        continue;
 219                }
 220                if (c == '[') {
 221                        baselen = get_base_var(var);
 222                        if (baselen <= 0)
 223                                break;
 224                        var[baselen++] = '.';
 225                        var[baselen] = 0;
 226                        continue;
 227                }
 228                if (!isalpha(c))
 229                        break;
 230                var[baselen] = tolower(c);
 231                if (get_value(fn, var, baselen+1) < 0)
 232                        break;
 233        }
 234        die("bad config file line %d in %s", config_linenr, config_file_name);
 235}
 236
 237static int parse_unit_factor(const char *end, unsigned long *val)
 238{
 239        if (!*end)
 240                return 1;
 241        else if (!strcasecmp(end, "k")) {
 242                *val *= 1024;
 243                return 1;
 244        }
 245        else if (!strcasecmp(end, "m")) {
 246                *val *= 1024 * 1024;
 247                return 1;
 248        }
 249        else if (!strcasecmp(end, "g")) {
 250                *val *= 1024 * 1024 * 1024;
 251                return 1;
 252        }
 253        return 0;
 254}
 255
 256int git_parse_long(const char *value, long *ret)
 257{
 258        if (value && *value) {
 259                char *end;
 260                long val = strtol(value, &end, 0);
 261                unsigned long factor = 1;
 262                if (!parse_unit_factor(end, &factor))
 263                        return 0;
 264                *ret = val * factor;
 265                return 1;
 266        }
 267        return 0;
 268}
 269
 270int git_parse_ulong(const char *value, unsigned long *ret)
 271{
 272        if (value && *value) {
 273                char *end;
 274                unsigned long val = strtoul(value, &end, 0);
 275                if (!parse_unit_factor(end, &val))
 276                        return 0;
 277                *ret = val;
 278                return 1;
 279        }
 280        return 0;
 281}
 282
 283int git_config_int(const char *name, const char *value)
 284{
 285        long ret;
 286        if (!git_parse_long(value, &ret))
 287                die("bad config value for '%s' in %s", name, config_file_name);
 288        return ret;
 289}
 290
 291unsigned long git_config_ulong(const char *name, const char *value)
 292{
 293        unsigned long ret;
 294        if (!git_parse_ulong(value, &ret))
 295                die("bad config value for '%s' in %s", name, config_file_name);
 296        return ret;
 297}
 298
 299int git_config_bool(const char *name, const char *value)
 300{
 301        if (!value)
 302                return 1;
 303        if (!*value)
 304                return 0;
 305        if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 306                return 1;
 307        if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 308                return 0;
 309        return git_config_int(name, value) != 0;
 310}
 311
 312int git_config_string(const char **dest, const char *var, const char *value)
 313{
 314        if (!value)
 315                return config_error_nonbool(var);
 316        *dest = xstrdup(value);
 317        return 0;
 318}
 319
 320int git_default_config(const char *var, const char *value)
 321{
 322        /* This needs a better name */
 323        if (!strcmp(var, "core.filemode")) {
 324                trust_executable_bit = git_config_bool(var, value);
 325                return 0;
 326        }
 327
 328        if (!strcmp(var, "core.quotepath")) {
 329                quote_path_fully = git_config_bool(var, value);
 330                return 0;
 331        }
 332
 333        if (!strcmp(var, "core.symlinks")) {
 334                has_symlinks = git_config_bool(var, value);
 335                return 0;
 336        }
 337
 338        if (!strcmp(var, "core.bare")) {
 339                is_bare_repository_cfg = git_config_bool(var, value);
 340                return 0;
 341        }
 342
 343        if (!strcmp(var, "core.ignorestat")) {
 344                assume_unchanged = git_config_bool(var, value);
 345                return 0;
 346        }
 347
 348        if (!strcmp(var, "core.prefersymlinkrefs")) {
 349                prefer_symlink_refs = git_config_bool(var, value);
 350                return 0;
 351        }
 352
 353        if (!strcmp(var, "core.logallrefupdates")) {
 354                log_all_ref_updates = git_config_bool(var, value);
 355                return 0;
 356        }
 357
 358        if (!strcmp(var, "core.warnambiguousrefs")) {
 359                warn_ambiguous_refs = git_config_bool(var, value);
 360                return 0;
 361        }
 362
 363        if (!strcmp(var, "core.loosecompression")) {
 364                int level = git_config_int(var, value);
 365                if (level == -1)
 366                        level = Z_DEFAULT_COMPRESSION;
 367                else if (level < 0 || level > Z_BEST_COMPRESSION)
 368                        die("bad zlib compression level %d", level);
 369                zlib_compression_level = level;
 370                zlib_compression_seen = 1;
 371                return 0;
 372        }
 373
 374        if (!strcmp(var, "core.compression")) {
 375                int level = git_config_int(var, value);
 376                if (level == -1)
 377                        level = Z_DEFAULT_COMPRESSION;
 378                else if (level < 0 || level > Z_BEST_COMPRESSION)
 379                        die("bad zlib compression level %d", level);
 380                core_compression_level = level;
 381                core_compression_seen = 1;
 382                if (!zlib_compression_seen)
 383                        zlib_compression_level = level;
 384                return 0;
 385        }
 386
 387        if (!strcmp(var, "core.packedgitwindowsize")) {
 388                int pgsz_x2 = getpagesize() * 2;
 389                packed_git_window_size = git_config_int(var, value);
 390
 391                /* This value must be multiple of (pagesize * 2) */
 392                packed_git_window_size /= pgsz_x2;
 393                if (packed_git_window_size < 1)
 394                        packed_git_window_size = 1;
 395                packed_git_window_size *= pgsz_x2;
 396                return 0;
 397        }
 398
 399        if (!strcmp(var, "core.packedgitlimit")) {
 400                packed_git_limit = git_config_int(var, value);
 401                return 0;
 402        }
 403
 404        if (!strcmp(var, "core.deltabasecachelimit")) {
 405                delta_base_cache_limit = git_config_int(var, value);
 406                return 0;
 407        }
 408
 409        if (!strcmp(var, "core.autocrlf")) {
 410                if (value && !strcasecmp(value, "input")) {
 411                        auto_crlf = -1;
 412                        return 0;
 413                }
 414                auto_crlf = git_config_bool(var, value);
 415                return 0;
 416        }
 417
 418        if (!strcmp(var, "user.name")) {
 419                if (!value)
 420                        return config_error_nonbool(var);
 421                strlcpy(git_default_name, value, sizeof(git_default_name));
 422                return 0;
 423        }
 424
 425        if (!strcmp(var, "user.email")) {
 426                if (!value)
 427                        return config_error_nonbool(var);
 428                strlcpy(git_default_email, value, sizeof(git_default_email));
 429                return 0;
 430        }
 431
 432        if (!strcmp(var, "i18n.commitencoding"))
 433                return git_config_string(&git_commit_encoding, var, value);
 434
 435        if (!strcmp(var, "i18n.logoutputencoding"))
 436                return git_config_string(&git_log_output_encoding, var, value);
 437
 438        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 439                pager_use_color = git_config_bool(var,value);
 440                return 0;
 441        }
 442
 443        if (!strcmp(var, "core.pager"))
 444                return git_config_string(&pager_program, var, value);
 445
 446        if (!strcmp(var, "core.editor"))
 447                return git_config_string(&editor_program, var, value);
 448
 449        if (!strcmp(var, "core.excludesfile"))
 450                return git_config_string(&excludes_file, var, value);
 451
 452        if (!strcmp(var, "core.whitespace")) {
 453                if (!value)
 454                        return config_error_nonbool(var);
 455                whitespace_rule_cfg = parse_whitespace_rule(value);
 456                return 0;
 457        }
 458
 459        /* Add other config variables here and to Documentation/config.txt. */
 460        return 0;
 461}
 462
 463int git_config_from_file(config_fn_t fn, const char *filename)
 464{
 465        int ret;
 466        FILE *f = fopen(filename, "r");
 467
 468        ret = -1;
 469        if (f) {
 470                config_file = f;
 471                config_file_name = filename;
 472                config_linenr = 1;
 473                config_file_eof = 0;
 474                ret = git_parse_file(fn);
 475                fclose(f);
 476                config_file_name = NULL;
 477        }
 478        return ret;
 479}
 480
 481const char *git_etc_gitconfig(void)
 482{
 483        static const char *system_wide;
 484        if (!system_wide) {
 485                system_wide = ETC_GITCONFIG;
 486                if (!is_absolute_path(system_wide)) {
 487                        /* interpret path relative to exec-dir */
 488                        struct strbuf d = STRBUF_INIT;
 489                        strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 490                        system_wide = strbuf_detach(&d, NULL);
 491                }
 492        }
 493        return system_wide;
 494}
 495
 496int git_env_bool(const char *k, int def)
 497{
 498        const char *v = getenv(k);
 499        return v ? git_config_bool(k, v) : def;
 500}
 501
 502int git_config_system(void)
 503{
 504        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 505}
 506
 507int git_config_global(void)
 508{
 509        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 510}
 511
 512int git_config(config_fn_t fn)
 513{
 514        int ret = 0;
 515        char *repo_config = NULL;
 516        const char *home = NULL, *filename;
 517
 518        /* $GIT_CONFIG makes git read _only_ the given config file,
 519         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 520         * global config file, the same way it would the per-repository
 521         * config file otherwise. */
 522        filename = getenv(CONFIG_ENVIRONMENT);
 523        if (!filename) {
 524                if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 525                        ret += git_config_from_file(fn, git_etc_gitconfig());
 526                home = getenv("HOME");
 527                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 528                if (!filename)
 529                        filename = repo_config = xstrdup(git_path("config"));
 530        }
 531
 532        if (git_config_global() && home) {
 533                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 534                if (!access(user_config, R_OK))
 535                        ret = git_config_from_file(fn, user_config);
 536                free(user_config);
 537        }
 538
 539        ret += git_config_from_file(fn, filename);
 540        free(repo_config);
 541        return ret;
 542}
 543
 544/*
 545 * Find all the stuff for git_config_set() below.
 546 */
 547
 548#define MAX_MATCHES 512
 549
 550static struct {
 551        int baselen;
 552        char* key;
 553        int do_not_match;
 554        regex_t* value_regex;
 555        int multi_replace;
 556        size_t offset[MAX_MATCHES];
 557        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 558        int seen;
 559} store;
 560
 561static int matches(const char* key, const char* value)
 562{
 563        return !strcmp(key, store.key) &&
 564                (store.value_regex == NULL ||
 565                 (store.do_not_match ^
 566                  !regexec(store.value_regex, value, 0, NULL, 0)));
 567}
 568
 569static int store_aux(const char* key, const char* value)
 570{
 571        const char *ep;
 572        size_t section_len;
 573
 574        switch (store.state) {
 575        case KEY_SEEN:
 576                if (matches(key, value)) {
 577                        if (store.seen == 1 && store.multi_replace == 0) {
 578                                fprintf(stderr,
 579                                        "Warning: %s has multiple values\n",
 580                                        key);
 581                        } else if (store.seen >= MAX_MATCHES) {
 582                                fprintf(stderr, "Too many matches\n");
 583                                return 1;
 584                        }
 585
 586                        store.offset[store.seen] = ftell(config_file);
 587                        store.seen++;
 588                }
 589                break;
 590        case SECTION_SEEN:
 591                /*
 592                 * What we are looking for is in store.key (both
 593                 * section and var), and its section part is baselen
 594                 * long.  We found key (again, both section and var).
 595                 * We would want to know if this key is in the same
 596                 * section as what we are looking for.  We already
 597                 * know we are in the same section as what should
 598                 * hold store.key.
 599                 */
 600                ep = strrchr(key, '.');
 601                section_len = ep - key;
 602
 603                if ((section_len != store.baselen) ||
 604                    memcmp(key, store.key, section_len+1)) {
 605                        store.state = SECTION_END_SEEN;
 606                        break;
 607                }
 608
 609                /*
 610                 * Do not increment matches: this is no match, but we
 611                 * just made sure we are in the desired section.
 612                 */
 613                store.offset[store.seen] = ftell(config_file);
 614                /* fallthru */
 615        case SECTION_END_SEEN:
 616        case START:
 617                if (matches(key, value)) {
 618                        store.offset[store.seen] = ftell(config_file);
 619                        store.state = KEY_SEEN;
 620                        store.seen++;
 621                } else {
 622                        if (strrchr(key, '.') - key == store.baselen &&
 623                              !strncmp(key, store.key, store.baselen)) {
 624                                        store.state = SECTION_SEEN;
 625                                        store.offset[store.seen] = ftell(config_file);
 626                        }
 627                }
 628        }
 629        return 0;
 630}
 631
 632static int write_error(void)
 633{
 634        fprintf(stderr, "Failed to write new configuration file\n");
 635
 636        /* Same error code as "failed to rename". */
 637        return 4;
 638}
 639
 640static int store_write_section(int fd, const char* key)
 641{
 642        const char *dot;
 643        int i, success;
 644        struct strbuf sb;
 645
 646        strbuf_init(&sb, 0);
 647        dot = memchr(key, '.', store.baselen);
 648        if (dot) {
 649                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 650                for (i = dot - key + 1; i < store.baselen; i++) {
 651                        if (key[i] == '"')
 652                                strbuf_addch(&sb, '\\');
 653                        strbuf_addch(&sb, key[i]);
 654                }
 655                strbuf_addstr(&sb, "\"]\n");
 656        } else {
 657                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 658        }
 659
 660        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 661        strbuf_release(&sb);
 662
 663        return success;
 664}
 665
 666static int store_write_pair(int fd, const char* key, const char* value)
 667{
 668        int i, success;
 669        int length = strlen(key + store.baselen + 1);
 670        const char *quote = "";
 671        struct strbuf sb;
 672
 673        /*
 674         * Check to see if the value needs to be surrounded with a dq pair.
 675         * Note that problematic characters are always backslash-quoted; this
 676         * check is about not losing leading or trailing SP and strings that
 677         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 678         * configuration parser.
 679         */
 680        if (value[0] == ' ')
 681                quote = "\"";
 682        for (i = 0; value[i]; i++)
 683                if (value[i] == ';' || value[i] == '#')
 684                        quote = "\"";
 685        if (i && value[i - 1] == ' ')
 686                quote = "\"";
 687
 688        strbuf_init(&sb, 0);
 689        strbuf_addf(&sb, "\t%.*s = %s",
 690                    length, key + store.baselen + 1, quote);
 691
 692        for (i = 0; value[i]; i++)
 693                switch (value[i]) {
 694                case '\n':
 695                        strbuf_addstr(&sb, "\\n");
 696                        break;
 697                case '\t':
 698                        strbuf_addstr(&sb, "\\t");
 699                        break;
 700                case '"':
 701                case '\\':
 702                        strbuf_addch(&sb, '\\');
 703                default:
 704                        strbuf_addch(&sb, value[i]);
 705                        break;
 706                }
 707        strbuf_addf(&sb, "%s\n", quote);
 708
 709        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 710        strbuf_release(&sb);
 711
 712        return success;
 713}
 714
 715static ssize_t find_beginning_of_line(const char* contents, size_t size,
 716        size_t offset_, int* found_bracket)
 717{
 718        size_t equal_offset = size, bracket_offset = size;
 719        ssize_t offset;
 720
 721contline:
 722        for (offset = offset_-2; offset > 0
 723                        && contents[offset] != '\n'; offset--)
 724                switch (contents[offset]) {
 725                        case '=': equal_offset = offset; break;
 726                        case ']': bracket_offset = offset; break;
 727                }
 728        if (offset > 0 && contents[offset-1] == '\\') {
 729                offset_ = offset;
 730                goto contline;
 731        }
 732        if (bracket_offset < equal_offset) {
 733                *found_bracket = 1;
 734                offset = bracket_offset+1;
 735        } else
 736                offset++;
 737
 738        return offset;
 739}
 740
 741int git_config_set(const char* key, const char* value)
 742{
 743        return git_config_set_multivar(key, value, NULL, 0);
 744}
 745
 746/*
 747 * If value==NULL, unset in (remove from) config,
 748 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 749 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 750 *     else all matching key/values (regardless how many) are removed,
 751 *     before the new pair is written.
 752 *
 753 * Returns 0 on success.
 754 *
 755 * This function does this:
 756 *
 757 * - it locks the config file by creating ".git/config.lock"
 758 *
 759 * - it then parses the config using store_aux() as validator to find
 760 *   the position on the key/value pair to replace. If it is to be unset,
 761 *   it must be found exactly once.
 762 *
 763 * - the config file is mmap()ed and the part before the match (if any) is
 764 *   written to the lock file, then the changed part and the rest.
 765 *
 766 * - the config file is removed and the lock file rename()d to it.
 767 *
 768 */
 769int git_config_set_multivar(const char* key, const char* value,
 770        const char* value_regex, int multi_replace)
 771{
 772        int i, dot;
 773        int fd = -1, in_fd;
 774        int ret;
 775        char* config_filename;
 776        struct lock_file *lock = NULL;
 777        const char* last_dot = strrchr(key, '.');
 778
 779        config_filename = getenv(CONFIG_ENVIRONMENT);
 780        if (!config_filename) {
 781                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 782                if (!config_filename)
 783                        config_filename  = git_path("config");
 784        }
 785        config_filename = xstrdup(config_filename);
 786
 787        /*
 788         * Since "key" actually contains the section name and the real
 789         * key name separated by a dot, we have to know where the dot is.
 790         */
 791
 792        if (last_dot == NULL) {
 793                fprintf(stderr, "key does not contain a section: %s\n", key);
 794                ret = 2;
 795                goto out_free;
 796        }
 797        store.baselen = last_dot - key;
 798
 799        store.multi_replace = multi_replace;
 800
 801        /*
 802         * Validate the key and while at it, lower case it for matching.
 803         */
 804        store.key = xmalloc(strlen(key) + 1);
 805        dot = 0;
 806        for (i = 0; key[i]; i++) {
 807                unsigned char c = key[i];
 808                if (c == '.')
 809                        dot = 1;
 810                /* Leave the extended basename untouched.. */
 811                if (!dot || i > store.baselen) {
 812                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 813                                fprintf(stderr, "invalid key: %s\n", key);
 814                                free(store.key);
 815                                ret = 1;
 816                                goto out_free;
 817                        }
 818                        c = tolower(c);
 819                } else if (c == '\n') {
 820                        fprintf(stderr, "invalid key (newline): %s\n", key);
 821                        free(store.key);
 822                        ret = 1;
 823                        goto out_free;
 824                }
 825                store.key[i] = c;
 826        }
 827        store.key[i] = 0;
 828
 829        /*
 830         * The lock serves a purpose in addition to locking: the new
 831         * contents of .git/config will be written into it.
 832         */
 833        lock = xcalloc(sizeof(struct lock_file), 1);
 834        fd = hold_lock_file_for_update(lock, config_filename, 0);
 835        if (fd < 0) {
 836                fprintf(stderr, "could not lock config file\n");
 837                free(store.key);
 838                ret = -1;
 839                goto out_free;
 840        }
 841
 842        /*
 843         * If .git/config does not exist yet, write a minimal version.
 844         */
 845        in_fd = open(config_filename, O_RDONLY);
 846        if ( in_fd < 0 ) {
 847                free(store.key);
 848
 849                if ( ENOENT != errno ) {
 850                        error("opening %s: %s", config_filename,
 851                              strerror(errno));
 852                        ret = 3; /* same as "invalid config file" */
 853                        goto out_free;
 854                }
 855                /* if nothing to unset, error out */
 856                if (value == NULL) {
 857                        ret = 5;
 858                        goto out_free;
 859                }
 860
 861                store.key = (char*)key;
 862                if (!store_write_section(fd, key) ||
 863                    !store_write_pair(fd, key, value))
 864                        goto write_err_out;
 865        } else {
 866                struct stat st;
 867                char* contents;
 868                size_t contents_sz, copy_begin, copy_end;
 869                int i, new_line = 0;
 870
 871                if (value_regex == NULL)
 872                        store.value_regex = NULL;
 873                else {
 874                        if (value_regex[0] == '!') {
 875                                store.do_not_match = 1;
 876                                value_regex++;
 877                        } else
 878                                store.do_not_match = 0;
 879
 880                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 881                        if (regcomp(store.value_regex, value_regex,
 882                                        REG_EXTENDED)) {
 883                                fprintf(stderr, "Invalid pattern: %s\n",
 884                                        value_regex);
 885                                free(store.value_regex);
 886                                ret = 6;
 887                                goto out_free;
 888                        }
 889                }
 890
 891                store.offset[0] = 0;
 892                store.state = START;
 893                store.seen = 0;
 894
 895                /*
 896                 * After this, store.offset will contain the *end* offset
 897                 * of the last match, or remain at 0 if no match was found.
 898                 * As a side effect, we make sure to transform only a valid
 899                 * existing config file.
 900                 */
 901                if (git_config_from_file(store_aux, config_filename)) {
 902                        fprintf(stderr, "invalid config file\n");
 903                        free(store.key);
 904                        if (store.value_regex != NULL) {
 905                                regfree(store.value_regex);
 906                                free(store.value_regex);
 907                        }
 908                        ret = 3;
 909                        goto out_free;
 910                }
 911
 912                free(store.key);
 913                if (store.value_regex != NULL) {
 914                        regfree(store.value_regex);
 915                        free(store.value_regex);
 916                }
 917
 918                /* if nothing to unset, or too many matches, error out */
 919                if ((store.seen == 0 && value == NULL) ||
 920                                (store.seen > 1 && multi_replace == 0)) {
 921                        ret = 5;
 922                        goto out_free;
 923                }
 924
 925                fstat(in_fd, &st);
 926                contents_sz = xsize_t(st.st_size);
 927                contents = xmmap(NULL, contents_sz, PROT_READ,
 928                        MAP_PRIVATE, in_fd, 0);
 929                close(in_fd);
 930
 931                if (store.seen == 0)
 932                        store.seen = 1;
 933
 934                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 935                        if (store.offset[i] == 0) {
 936                                store.offset[i] = copy_end = contents_sz;
 937                        } else if (store.state != KEY_SEEN) {
 938                                copy_end = store.offset[i];
 939                        } else
 940                                copy_end = find_beginning_of_line(
 941                                        contents, contents_sz,
 942                                        store.offset[i]-2, &new_line);
 943
 944                        if (copy_end > 0 && contents[copy_end-1] != '\n')
 945                                new_line = 1;
 946
 947                        /* write the first part of the config */
 948                        if (copy_end > copy_begin) {
 949                                if (write_in_full(fd, contents + copy_begin,
 950                                                  copy_end - copy_begin) <
 951                                    copy_end - copy_begin)
 952                                        goto write_err_out;
 953                                if (new_line &&
 954                                    write_in_full(fd, "\n", 1) != 1)
 955                                        goto write_err_out;
 956                        }
 957                        copy_begin = store.offset[i];
 958                }
 959
 960                /* write the pair (value == NULL means unset) */
 961                if (value != NULL) {
 962                        if (store.state == START) {
 963                                if (!store_write_section(fd, key))
 964                                        goto write_err_out;
 965                        }
 966                        if (!store_write_pair(fd, key, value))
 967                                goto write_err_out;
 968                }
 969
 970                /* write the rest of the config */
 971                if (copy_begin < contents_sz)
 972                        if (write_in_full(fd, contents + copy_begin,
 973                                          contents_sz - copy_begin) <
 974                            contents_sz - copy_begin)
 975                                goto write_err_out;
 976
 977                munmap(contents, contents_sz);
 978        }
 979
 980        if (commit_lock_file(lock) < 0) {
 981                fprintf(stderr, "Cannot commit config file!\n");
 982                ret = 4;
 983                goto out_free;
 984        }
 985
 986        /*
 987         * lock is committed, so don't try to roll it back below.
 988         * NOTE: Since lockfile.c keeps a linked list of all created
 989         * lock_file structures, it isn't safe to free(lock).  It's
 990         * better to just leave it hanging around.
 991         */
 992        lock = NULL;
 993        ret = 0;
 994
 995out_free:
 996        if (lock)
 997                rollback_lock_file(lock);
 998        free(config_filename);
 999        return ret;
1000
1001write_err_out:
1002        ret = write_error();
1003        goto out_free;
1004
1005}
1006
1007static int section_name_match (const char *buf, const char *name)
1008{
1009        int i = 0, j = 0, dot = 0;
1010        for (; buf[i] && buf[i] != ']'; i++) {
1011                if (!dot && isspace(buf[i])) {
1012                        dot = 1;
1013                        if (name[j++] != '.')
1014                                break;
1015                        for (i++; isspace(buf[i]); i++)
1016                                ; /* do nothing */
1017                        if (buf[i] != '"')
1018                                break;
1019                        continue;
1020                }
1021                if (buf[i] == '\\' && dot)
1022                        i++;
1023                else if (buf[i] == '"' && dot) {
1024                        for (i++; isspace(buf[i]); i++)
1025                                ; /* do_nothing */
1026                        break;
1027                }
1028                if (buf[i] != name[j++])
1029                        break;
1030        }
1031        return (buf[i] == ']' && name[j] == 0);
1032}
1033
1034/* if new_name == NULL, the section is removed instead */
1035int git_config_rename_section(const char *old_name, const char *new_name)
1036{
1037        int ret = 0, remove = 0;
1038        char *config_filename;
1039        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1040        int out_fd;
1041        char buf[1024];
1042
1043        config_filename = getenv(CONFIG_ENVIRONMENT);
1044        if (!config_filename) {
1045                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1046                if (!config_filename)
1047                        config_filename  = git_path("config");
1048        }
1049        config_filename = xstrdup(config_filename);
1050        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1051        if (out_fd < 0) {
1052                ret = error("Could not lock config file!");
1053                goto out;
1054        }
1055
1056        if (!(config_file = fopen(config_filename, "rb"))) {
1057                /* no config file means nothing to rename, no error */
1058                goto unlock_and_out;
1059        }
1060
1061        while (fgets(buf, sizeof(buf), config_file)) {
1062                int i;
1063                int length;
1064                for (i = 0; buf[i] && isspace(buf[i]); i++)
1065                        ; /* do nothing */
1066                if (buf[i] == '[') {
1067                        /* it's a section */
1068                        if (section_name_match (&buf[i+1], old_name)) {
1069                                ret++;
1070                                if (new_name == NULL) {
1071                                        remove = 1;
1072                                        continue;
1073                                }
1074                                store.baselen = strlen(new_name);
1075                                if (!store_write_section(out_fd, new_name)) {
1076                                        ret = write_error();
1077                                        goto out;
1078                                }
1079                                continue;
1080                        }
1081                        remove = 0;
1082                }
1083                if (remove)
1084                        continue;
1085                length = strlen(buf);
1086                if (write_in_full(out_fd, buf, length) != length) {
1087                        ret = write_error();
1088                        goto out;
1089                }
1090        }
1091        fclose(config_file);
1092 unlock_and_out:
1093        if (commit_lock_file(lock) < 0)
1094                        ret = error("Cannot commit config file!");
1095 out:
1096        free(config_filename);
1097        return ret;
1098}
1099
1100/*
1101 * Call this to report error for your variable that should not
1102 * get a boolean value (i.e. "[my] var" means "true").
1103 */
1104int config_error_nonbool(const char *var)
1105{
1106        return error("Missing value for '%s'", var);
1107}