config.c

   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 #include "strbuf.h"
  11 #include "quote.h"
  12
  13 struct config_source {
  14         struct config_source *prev;
  15         union {
  16                 FILE *file;
  17                 struct config_buf {
  18                         const char *buf;
  19                         size_t len;
  20                         size_t pos;
  21                 } buf;
  22         } u;
  23         const char *name;
  24         const char *path;
  25         int die_on_error;
  26         int linenr;
  27         int eof;
  28         struct strbuf value;
  29         struct strbuf var;
  30
  31         int (*do_fgetc)(struct config_source *c);
  32         int (*do_ungetc)(int c, struct config_source *conf);
  33         long (*do_ftell)(struct config_source *c);
  34 };
  35
  36 static struct config_source *cf;
  37
  38 static int zlib_compression_seen;
  39
  40 static int config_file_fgetc(struct config_source *conf)
  41 {
  42         return fgetc(conf->u.file);
  43 }
  44
  45 static int config_file_ungetc(int c, struct config_source *conf)
  46 {
  47         return ungetc(c, conf->u.file);
  48 }
  49
  50 static long config_file_ftell(struct config_source *conf)
  51 {
  52         return ftell(conf->u.file);
  53 }
  54
  55
  56 static int config_buf_fgetc(struct config_source *conf)
  57 {
  58         if (conf->u.buf.pos < conf->u.buf.len)
  59                 return conf->u.buf.buf[conf->u.buf.pos++];
  60
  61         return EOF;
  62 }
  63
  64 static int config_buf_ungetc(int c, struct config_source *conf)
  65 {
  66         if (conf->u.buf.pos > 0)
  67                 return conf->u.buf.buf[--conf->u.buf.pos];
  68
  69         return EOF;
  70 }
  71
  72 static long config_buf_ftell(struct config_source *conf)
  73 {
  74         return conf->u.buf.pos;
  75 }
  76
  77 #define MAX_INCLUDE_DEPTH 10
  78 static const char include_depth_advice[] =
  79 "exceeded maximum include depth (%d) while including\n"
  80 "       %s\n"
  81 "from\n"
  82 "       %s\n"
  83 "Do you have circular includes?";
  84 static int handle_path_include(const char *path, struct config_include_data *inc)
  85 {
  86         int ret = 0;
  87         struct strbuf buf = STRBUF_INIT;
  88         char *expanded;
  89
  90         if (!path)
  91                 return config_error_nonbool("include.path");
  92
  93         expanded = expand_user_path(path);
  94         if (!expanded)
  95                 return error("Could not expand include path '%s'", path);
  96         path = expanded;
  97
  98         /*
  99          * Use an absolute path as-is, but interpret relative paths
 100          * based on the including config file.
 101          */
 102         if (!is_absolute_path(path)) {
 103                 char *slash;
 104
 105                 if (!cf || !cf->path)
 106                         return error("relative config includes must come from files");
 107
 108                 slash = find_last_dir_sep(cf->path);
 109                 if (slash)
 110                         strbuf_add(&buf, cf->path, slash - cf->path + 1);
 111                 strbuf_addstr(&buf, path);
 112                 path = buf.buf;
 113         }
 114
 115         if (!access_or_die(path, R_OK, 0)) {
 116                 if (++inc->depth > MAX_INCLUDE_DEPTH)
 117                         die(include_depth_advice, MAX_INCLUDE_DEPTH, path,
 118                             cf && cf->name ? cf->name : "the command line");
 119                 ret = git_config_from_file(git_config_include, path, inc);
 120                 inc->depth--;
 121         }
 122         strbuf_release(&buf);
 123         free(expanded);
 124         return ret;
 125 }
 126
 127 int git_config_include(const char *var, const char *value, void *data)
 128 {
 129         struct config_include_data *inc = data;
 130         const char *type;
 131         int ret;
 132
 133         /*
 134          * Pass along all values, including "include" directives; this makes it
 135          * possible to query information on the includes themselves.
 136          */
 137         ret = inc->fn(var, value, inc->data);
 138         if (ret < 0)
 139                 return ret;
 140
 141         if (!skip_prefix(var, "include.", &type))
 142                 return ret;
 143
 144         if (!strcmp(type, "path"))
 145                 ret = handle_path_include(value, inc);
 146         return ret;
 147 }
 148
 149 void git_config_push_parameter(const char *text)
 150 {
 151         struct strbuf env = STRBUF_INIT;
 152         const char *old = getenv(CONFIG_DATA_ENVIRONMENT);
 153         if (old) {
 154                 strbuf_addstr(&env, old);
 155                 strbuf_addch(&env, ' ');
 156         }
 157         sq_quote_buf(&env, text);
 158         setenv(CONFIG_DATA_ENVIRONMENT, env.buf, 1);
 159         strbuf_release(&env);
 160 }
 161
 162 int git_config_parse_parameter(const char *text,
 163                                config_fn_t fn, void *data)
 164 {
 165         struct strbuf **pair;
 166         pair = strbuf_split_str(text, '=', 2);
 167         if (!pair[0])
 168                 return error("bogus config parameter: %s", text);
 169         if (pair[0]->len && pair[0]->buf[pair[0]->len - 1] == '=')
 170                 strbuf_setlen(pair[0], pair[0]->len - 1);
 171         strbuf_trim(pair[0]);
 172         if (!pair[0]->len) {
 173                 strbuf_list_free(pair);
 174                 return error("bogus config parameter: %s", text);
 175         }
 176         strbuf_tolower(pair[0]);
 177         if (fn(pair[0]->buf, pair[1] ? pair[1]->buf : NULL, data) < 0) {
 178                 strbuf_list_free(pair);
 179                 return -1;
 180         }
 181         strbuf_list_free(pair);
 182         return 0;
 183 }
 184
 185 int git_config_from_parameters(config_fn_t fn, void *data)
 186 {
 187         const char *env = getenv(CONFIG_DATA_ENVIRONMENT);
 188         char *envw;
 189         const char **argv = NULL;
 190         int nr = 0, alloc = 0;
 191         int i;
 192
 193         if (!env)
 194                 return 0;
 195         /* sq_dequote will write over it */
 196         envw = xstrdup(env);
 197
 198         if (sq_dequote_to_argv(envw, &argv, &nr, &alloc) < 0) {
 199                 free(envw);
 200                 return error("bogus format in " CONFIG_DATA_ENVIRONMENT);
 201         }
 202
 203         for (i = 0; i < nr; i++) {
 204                 if (git_config_parse_parameter(argv[i], fn, data) < 0) {
 205                         free(argv);
 206                         free(envw);
 207                         return -1;
 208                 }
 209         }
 210
 211         free(argv);
 212         free(envw);
 213         return nr > 0;
 214 }
 215
 216 static int get_next_char(void)
 217 {
 218         int c = cf->do_fgetc(cf);
 219
 220         if (c == '\r') {
 221                 /* DOS like systems */
 222                 c = cf->do_fgetc(cf);
 223                 if (c != '\n') {
 224                         cf->do_ungetc(c, cf);
 225                         c = '\r';
 226                 }
 227         }
 228         if (c == '\n')
 229                 cf->linenr++;
 230         if (c == EOF) {
 231                 cf->eof = 1;
 232                 c = '\n';
 233         }
 234         return c;
 235 }
 236
 237 static char *parse_value(void)
 238 {
 239         int quote = 0, comment = 0, space = 0;
 240
 241         strbuf_reset(&cf->value);
 242         for (;;) {
 243                 int c = get_next_char();
 244                 if (c == '\n') {
 245                         if (quote) {
 246                                 cf->linenr--;
 247                                 return NULL;
 248                         }
 249                         return cf->value.buf;
 250                 }
 251                 if (comment)
 252                         continue;
 253                 if (isspace(c) && !quote) {
 254                         if (cf->value.len)
 255                                 space++;
 256                         continue;
 257                 }
 258                 if (!quote) {
 259                         if (c == ';' || c == '#') {
 260                                 comment = 1;
 261                                 continue;
 262                         }
 263                 }
 264                 for (; space; space--)
 265                         strbuf_addch(&cf->value, ' ');
 266                 if (c == '\\') {
 267                         c = get_next_char();
 268                         switch (c) {
 269                         case '\n':
 270                                 continue;
 271                         case 't':
 272                                 c = '\t';
 273                                 break;
 274                         case 'b':
 275                                 c = '\b';
 276                                 break;
 277                         case 'n':
 278                                 c = '\n';
 279                                 break;
 280                         /* Some characters escape as themselves */
 281                         case '\\': case '"':
 282                                 break;
 283                         /* Reject unknown escape sequences */
 284                         default:
 285                                 return NULL;
 286                         }
 287                         strbuf_addch(&cf->value, c);
 288                         continue;
 289                 }
 290                 if (c == '"') {
 291                         quote = 1-quote;
 292                         continue;
 293                 }
 294                 strbuf_addch(&cf->value, c);
 295         }
 296 }
 297
 298 static inline int iskeychar(int c)
 299 {
 300         return isalnum(c) || c == '-';
 301 }
 302
 303 static int get_value(config_fn_t fn, void *data, struct strbuf *name)
 304 {
 305         int c;
 306         char *value;
 307
 308         /* Get the full name */
 309         for (;;) {
 310                 c = get_next_char();
 311                 if (cf->eof)
 312                         break;
 313                 if (!iskeychar(c))
 314                         break;
 315                 strbuf_addch(name, tolower(c));
 316         }
 317
 318         while (c == ' ' || c == '\t')
 319                 c = get_next_char();
 320
 321         value = NULL;
 322         if (c != '\n') {
 323                 if (c != '=')
 324                         return -1;
 325                 value = parse_value();
 326                 if (!value)
 327                         return -1;
 328         }
 329         return fn(name->buf, value, data);
 330 }
 331
 332 static int get_extended_base_var(struct strbuf *name, int c)
 333 {
 334         do {
 335                 if (c == '\n')
 336                         goto error_incomplete_line;
 337                 c = get_next_char();
 338         } while (isspace(c));
 339
 340         /* We require the format to be '[base "extension"]' */
 341         if (c != '"')
 342                 return -1;
 343         strbuf_addch(name, '.');
 344
 345         for (;;) {
 346                 int c = get_next_char();
 347                 if (c == '\n')
 348                         goto error_incomplete_line;
 349                 if (c == '"')
 350                         break;
 351                 if (c == '\\') {
 352                         c = get_next_char();
 353                         if (c == '\n')
 354                                 goto error_incomplete_line;
 355                 }
 356                 strbuf_addch(name, c);
 357         }
 358
 359         /* Final ']' */
 360         if (get_next_char() != ']')
 361                 return -1;
 362         return 0;
 363 error_incomplete_line:
 364         cf->linenr--;
 365         return -1;
 366 }
 367
 368 static int get_base_var(struct strbuf *name)
 369 {
 370         for (;;) {
 371                 int c = get_next_char();
 372                 if (cf->eof)
 373                         return -1;
 374                 if (c == ']')
 375                         return 0;
 376                 if (isspace(c))
 377                         return get_extended_base_var(name, c);
 378                 if (!iskeychar(c) && c != '.')
 379                         return -1;
 380                 strbuf_addch(name, tolower(c));
 381         }
 382 }
 383
 384 static int git_parse_source(config_fn_t fn, void *data)
 385 {
 386         int comment = 0;
 387         int baselen = 0;
 388         struct strbuf *var = &cf->var;
 389
 390         /* U+FEFF Byte Order Mark in UTF8 */
 391         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 392         const unsigned char *bomptr = utf8_bom;
 393
 394         for (;;) {
 395                 int c = get_next_char();
 396                 if (bomptr && *bomptr) {
 397                         /* We are at the file beginning; skip UTF8-encoded BOM
 398                          * if present. Sane editors won't put this in on their
 399                          * own, but e.g. Windows Notepad will do it happily. */
 400                         if ((unsigned char) c == *bomptr) {
 401                                 bomptr++;
 402                                 continue;
 403                         } else {
 404                                 /* Do not tolerate partial BOM. */
 405                                 if (bomptr != utf8_bom)
 406                                         break;
 407                                 /* No BOM at file beginning. Cool. */
 408                                 bomptr = NULL;
 409                         }
 410                 }
 411                 if (c == '\n') {
 412                         if (cf->eof)
 413                                 return 0;
 414                         comment = 0;
 415                         continue;
 416                 }
 417                 if (comment || isspace(c))
 418                         continue;
 419                 if (c == '#' || c == ';') {
 420                         comment = 1;
 421                         continue;
 422                 }
 423                 if (c == '[') {
 424                         /* Reset prior to determining a new stem */
 425                         strbuf_reset(var);
 426                         if (get_base_var(var) < 0 || var->len < 1)
 427                                 break;
 428                         strbuf_addch(var, '.');
 429                         baselen = var->len;
 430                         continue;
 431                 }
 432                 if (!isalpha(c))
 433                         break;
 434                 /*
 435                  * Truncate the var name back to the section header
 436                  * stem prior to grabbing the suffix part of the name
 437                  * and the value.
 438                  */
 439                 strbuf_setlen(var, baselen);
 440                 strbuf_addch(var, tolower(c));
 441                 if (get_value(fn, data, var) < 0)
 442                         break;
 443         }
 444         if (cf->die_on_error)
 445                 die("bad config file line %d in %s", cf->linenr, cf->name);
 446         else
 447                 return error("bad config file line %d in %s", cf->linenr, cf->name);
 448 }
 449
 450 static int parse_unit_factor(const char *end, uintmax_t *val)
 451 {
 452         if (!*end)
 453                 return 1;
 454         else if (!strcasecmp(end, "k")) {
 455                 *val *= 1024;
 456                 return 1;
 457         }
 458         else if (!strcasecmp(end, "m")) {
 459                 *val *= 1024 * 1024;
 460                 return 1;
 461         }
 462         else if (!strcasecmp(end, "g")) {
 463                 *val *= 1024 * 1024 * 1024;
 464                 return 1;
 465         }
 466         return 0;
 467 }
 468
 469 static int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
 470 {
 471         if (value && *value) {
 472                 char *end;
 473                 intmax_t val;
 474                 uintmax_t uval;
 475                 uintmax_t factor = 1;
 476
 477                 errno = 0;
 478                 val = strtoimax(value, &end, 0);
 479                 if (errno == ERANGE)
 480                         return 0;
 481                 if (!parse_unit_factor(end, &factor)) {
 482                         errno = EINVAL;
 483                         return 0;
 484                 }
 485                 uval = abs(val);
 486                 uval *= factor;
 487                 if (uval > max || abs(val) > uval) {
 488                         errno = ERANGE;
 489                         return 0;
 490                 }
 491                 val *= factor;
 492                 *ret = val;
 493                 return 1;
 494         }
 495         errno = EINVAL;
 496         return 0;
 497 }
 498
 499 static int git_parse_unsigned(const char *value, uintmax_t *ret, uintmax_t max)
 500 {
 501         if (value && *value) {
 502                 char *end;
 503                 uintmax_t val;
 504                 uintmax_t oldval;
 505
 506                 errno = 0;
 507                 val = strtoumax(value, &end, 0);
 508                 if (errno == ERANGE)
 509                         return 0;
 510                 oldval = val;
 511                 if (!parse_unit_factor(end, &val)) {
 512                         errno = EINVAL;
 513                         return 0;
 514                 }
 515                 if (val > max || oldval > val) {
 516                         errno = ERANGE;
 517                         return 0;
 518                 }
 519                 *ret = val;
 520                 return 1;
 521         }
 522         errno = EINVAL;
 523         return 0;
 524 }
 525
 526 static int git_parse_int(const char *value, int *ret)
 527 {
 528         intmax_t tmp;
 529         if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int)))
 530                 return 0;
 531         *ret = tmp;
 532         return 1;
 533 }
 534
 535 static int git_parse_int64(const char *value, int64_t *ret)
 536 {
 537         intmax_t tmp;
 538         if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int64_t)))
 539                 return 0;
 540         *ret = tmp;
 541         return 1;
 542 }
 543
 544 int git_parse_ulong(const char *value, unsigned long *ret)
 545 {
 546         uintmax_t tmp;
 547         if (!git_parse_unsigned(value, &tmp, maximum_unsigned_value_of_type(long)))
 548                 return 0;
 549         *ret = tmp;
 550         return 1;
 551 }
 552
 553 NORETURN
 554 static void die_bad_number(const char *name, const char *value)
 555 {
 556         const char *reason = errno == ERANGE ?
 557                              "out of range" :
 558                              "invalid unit";
 559         if (!value)
 560                 value = "";
 561
 562         if (cf && cf->name)
 563                 die("bad numeric config value '%s' for '%s' in %s: %s",
 564                     value, name, cf->name, reason);
 565         die("bad numeric config value '%s' for '%s': %s", value, name, reason);
 566 }
 567
 568 int git_config_int(const char *name, const char *value)
 569 {
 570         int ret;
 571         if (!git_parse_int(value, &ret))
 572                 die_bad_number(name, value);
 573         return ret;
 574 }
 575
 576 int64_t git_config_int64(const char *name, const char *value)
 577 {
 578         int64_t ret;
 579         if (!git_parse_int64(value, &ret))
 580                 die_bad_number(name, value);
 581         return ret;
 582 }
 583
 584 unsigned long git_config_ulong(const char *name, const char *value)
 585 {
 586         unsigned long ret;
 587         if (!git_parse_ulong(value, &ret))
 588                 die_bad_number(name, value);
 589         return ret;
 590 }
 591
 592 static int git_config_maybe_bool_text(const char *name, const char *value)
 593 {
 594         if (!value)
 595                 return 1;
 596         if (!*value)
 597                 return 0;
 598         if (!strcasecmp(value, "true")
 599             || !strcasecmp(value, "yes")
 600             || !strcasecmp(value, "on"))
 601                 return 1;
 602         if (!strcasecmp(value, "false")
 603             || !strcasecmp(value, "no")
 604             || !strcasecmp(value, "off"))
 605                 return 0;
 606         return -1;
 607 }
 608
 609 int git_config_maybe_bool(const char *name, const char *value)
 610 {
 611         int v = git_config_maybe_bool_text(name, value);
 612         if (0 <= v)
 613                 return v;
 614         if (git_parse_int(value, &v))
 615                 return !!v;
 616         return -1;
 617 }
 618
 619 int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
 620 {
 621         int v = git_config_maybe_bool_text(name, value);
 622         if (0 <= v) {
 623                 *is_bool = 1;
 624                 return v;
 625         }
 626         *is_bool = 0;
 627         return git_config_int(name, value);
 628 }
 629
 630 int git_config_bool(const char *name, const char *value)
 631 {
 632         int discard;
 633         return !!git_config_bool_or_int(name, value, &discard);
 634 }
 635
 636 int git_config_string(const char **dest, const char *var, const char *value)
 637 {
 638         if (!value)
 639                 return config_error_nonbool(var);
 640         *dest = xstrdup(value);
 641         return 0;
 642 }
 643
 644 int git_config_pathname(const char **dest, const char *var, const char *value)
 645 {
 646         if (!value)
 647                 return config_error_nonbool(var);
 648         *dest = expand_user_path(value);
 649         if (!*dest)
 650                 die("Failed to expand user dir in: '%s'", value);
 651         return 0;
 652 }
 653
 654 static int git_default_core_config(const char *var, const char *value)
 655 {
 656         /* This needs a better name */
 657         if (!strcmp(var, "core.filemode")) {
 658                 trust_executable_bit = git_config_bool(var, value);
 659                 return 0;
 660         }
 661         if (!strcmp(var, "core.trustctime")) {
 662                 trust_ctime = git_config_bool(var, value);
 663                 return 0;
 664         }
 665         if (!strcmp(var, "core.checkstat")) {
 666                 if (!strcasecmp(value, "default"))
 667                         check_stat = 1;
 668                 else if (!strcasecmp(value, "minimal"))
 669                         check_stat = 0;
 670         }
 671
 672         if (!strcmp(var, "core.quotepath")) {
 673                 quote_path_fully = git_config_bool(var, value);
 674                 return 0;
 675         }
 676
 677         if (!strcmp(var, "core.symlinks")) {
 678                 has_symlinks = git_config_bool(var, value);
 679                 return 0;
 680         }
 681
 682         if (!strcmp(var, "core.ignorecase")) {
 683                 ignore_case = git_config_bool(var, value);
 684                 return 0;
 685         }
 686
 687         if (!strcmp(var, "core.attributesfile"))
 688                 return git_config_pathname(&git_attributes_file, var, value);
 689
 690         if (!strcmp(var, "core.bare")) {
 691                 is_bare_repository_cfg = git_config_bool(var, value);
 692                 return 0;
 693         }
 694
 695         if (!strcmp(var, "core.ignorestat")) {
 696                 assume_unchanged = git_config_bool(var, value);
 697                 return 0;
 698         }
 699
 700         if (!strcmp(var, "core.prefersymlinkrefs")) {
 701                 prefer_symlink_refs = git_config_bool(var, value);
 702                 return 0;
 703         }
 704
 705         if (!strcmp(var, "core.logallrefupdates")) {
 706                 log_all_ref_updates = git_config_bool(var, value);
 707                 return 0;
 708         }
 709
 710         if (!strcmp(var, "core.warnambiguousrefs")) {
 711                 warn_ambiguous_refs = git_config_bool(var, value);
 712                 return 0;
 713         }
 714
 715         if (!strcmp(var, "core.abbrev")) {
 716                 int abbrev = git_config_int(var, value);
 717                 if (abbrev < minimum_abbrev || abbrev > 40)
 718                         return -1;
 719                 default_abbrev = abbrev;
 720                 return 0;
 721         }
 722
 723         if (!strcmp(var, "core.loosecompression")) {
 724                 int level = git_config_int(var, value);
 725                 if (level == -1)
 726                         level = Z_DEFAULT_COMPRESSION;
 727                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 728                         die("bad zlib compression level %d", level);
 729                 zlib_compression_level = level;
 730                 zlib_compression_seen = 1;
 731                 return 0;
 732         }
 733
 734         if (!strcmp(var, "core.compression")) {
 735                 int level = git_config_int(var, value);
 736                 if (level == -1)
 737                         level = Z_DEFAULT_COMPRESSION;
 738                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 739                         die("bad zlib compression level %d", level);
 740                 core_compression_level = level;
 741                 core_compression_seen = 1;
 742                 if (!zlib_compression_seen)
 743                         zlib_compression_level = level;
 744                 return 0;
 745         }
 746
 747         if (!strcmp(var, "core.packedgitwindowsize")) {
 748                 int pgsz_x2 = getpagesize() * 2;
 749                 packed_git_window_size = git_config_ulong(var, value);
 750
 751                 /* This value must be multiple of (pagesize * 2) */
 752                 packed_git_window_size /= pgsz_x2;
 753                 if (packed_git_window_size < 1)
 754                         packed_git_window_size = 1;
 755                 packed_git_window_size *= pgsz_x2;
 756                 return 0;
 757         }
 758
 759         if (!strcmp(var, "core.bigfilethreshold")) {
 760                 big_file_threshold = git_config_ulong(var, value);
 761                 return 0;
 762         }
 763
 764         if (!strcmp(var, "core.packedgitlimit")) {
 765                 packed_git_limit = git_config_ulong(var, value);
 766                 return 0;
 767         }
 768
 769         if (!strcmp(var, "core.deltabasecachelimit")) {
 770                 delta_base_cache_limit = git_config_ulong(var, value);
 771                 return 0;
 772         }
 773
 774         if (!strcmp(var, "core.autocrlf")) {
 775                 if (value && !strcasecmp(value, "input")) {
 776                         if (core_eol == EOL_CRLF)
 777                                 return error("core.autocrlf=input conflicts with core.eol=crlf");
 778                         auto_crlf = AUTO_CRLF_INPUT;
 779                         return 0;
 780                 }
 781                 auto_crlf = git_config_bool(var, value);
 782                 return 0;
 783         }
 784
 785         if (!strcmp(var, "core.safecrlf")) {
 786                 if (value && !strcasecmp(value, "warn")) {
 787                         safe_crlf = SAFE_CRLF_WARN;
 788                         return 0;
 789                 }
 790                 safe_crlf = git_config_bool(var, value);
 791                 return 0;
 792         }
 793
 794         if (!strcmp(var, "core.eol")) {
 795                 if (value && !strcasecmp(value, "lf"))
 796                         core_eol = EOL_LF;
 797                 else if (value && !strcasecmp(value, "crlf"))
 798                         core_eol = EOL_CRLF;
 799                 else if (value && !strcasecmp(value, "native"))
 800                         core_eol = EOL_NATIVE;
 801                 else
 802                         core_eol = EOL_UNSET;
 803                 if (core_eol == EOL_CRLF && auto_crlf == AUTO_CRLF_INPUT)
 804                         return error("core.autocrlf=input conflicts with core.eol=crlf");
 805                 return 0;
 806         }
 807
 808         if (!strcmp(var, "core.notesref")) {
 809                 notes_ref_name = xstrdup(value);
 810                 return 0;
 811         }
 812
 813         if (!strcmp(var, "core.pager"))
 814                 return git_config_string(&pager_program, var, value);
 815
 816         if (!strcmp(var, "core.editor"))
 817                 return git_config_string(&editor_program, var, value);
 818
 819         if (!strcmp(var, "core.commentchar")) {
 820                 if (!value)
 821                         return config_error_nonbool(var);
 822                 else if (!strcasecmp(value, "auto"))
 823                         auto_comment_line_char = 1;
 824                 else if (value[0] && !value[1]) {
 825                         comment_line_char = value[0];
 826                         auto_comment_line_char = 0;
 827                 } else
 828                         return error("core.commentChar should only be one character");
 829                 return 0;
 830         }
 831
 832         if (!strcmp(var, "core.askpass"))
 833                 return git_config_string(&askpass_program, var, value);
 834
 835         if (!strcmp(var, "core.excludesfile"))
 836                 return git_config_pathname(&excludes_file, var, value);
 837
 838         if (!strcmp(var, "core.whitespace")) {
 839                 if (!value)
 840                         return config_error_nonbool(var);
 841                 whitespace_rule_cfg = parse_whitespace_rule(value);
 842                 return 0;
 843         }
 844
 845         if (!strcmp(var, "core.fsyncobjectfiles")) {
 846                 fsync_object_files = git_config_bool(var, value);
 847                 return 0;
 848         }
 849
 850         if (!strcmp(var, "core.preloadindex")) {
 851                 core_preload_index = git_config_bool(var, value);
 852                 return 0;
 853         }
 854
 855         if (!strcmp(var, "core.createobject")) {
 856                 if (!strcmp(value, "rename"))
 857                         object_creation_mode = OBJECT_CREATION_USES_RENAMES;
 858                 else if (!strcmp(value, "link"))
 859                         object_creation_mode = OBJECT_CREATION_USES_HARDLINKS;
 860                 else
 861                         die("Invalid mode for object creation: %s", value);
 862                 return 0;
 863         }
 864
 865         if (!strcmp(var, "core.sparsecheckout")) {
 866                 core_apply_sparse_checkout = git_config_bool(var, value);
 867                 return 0;
 868         }
 869
 870         if (!strcmp(var, "core.precomposeunicode")) {
 871                 precomposed_unicode = git_config_bool(var, value);
 872                 return 0;
 873         }
 874
 875         if (!strcmp(var, "core.hidedotfiles")) {
 876                 if (value && !strcasecmp(value, "dotgitonly")) {
 877                         hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 878                         return 0;
 879                 }
 880                 hide_dotfiles = git_config_bool(var, value);
 881                 return 0;
 882         }
 883
 884         if (!strcmp(var, "core.fscache")) {
 885                 core_fscache = git_config_bool(var, value);
 886                 return 0;
 887         }
 888
 889         if (!strcmp(var, "core.longpaths")) {
 890                 core_long_paths = git_config_bool(var, value);
 891                 return 0;
 892         }
 893
 894         /* Add other config variables here and to Documentation/config.txt. */
 895         return 0;
 896 }
 897
 898 static int git_default_i18n_config(const char *var, const char *value)
 899 {
 900         if (!strcmp(var, "i18n.commitencoding"))
 901                 return git_config_string(&git_commit_encoding, var, value);
 902
 903         if (!strcmp(var, "i18n.logoutputencoding"))
 904                 return git_config_string(&git_log_output_encoding, var, value);
 905
 906         /* Add other config variables here and to Documentation/config.txt. */
 907         return 0;
 908 }
 909
 910 static int git_default_branch_config(const char *var, const char *value)
 911 {
 912         if (!strcmp(var, "branch.autosetupmerge")) {
 913                 if (value && !strcasecmp(value, "always")) {
 914                         git_branch_track = BRANCH_TRACK_ALWAYS;
 915                         return 0;
 916                 }
 917                 git_branch_track = git_config_bool(var, value);
 918                 return 0;
 919         }
 920         if (!strcmp(var, "branch.autosetuprebase")) {
 921                 if (!value)
 922                         return config_error_nonbool(var);
 923                 else if (!strcmp(value, "never"))
 924                         autorebase = AUTOREBASE_NEVER;
 925                 else if (!strcmp(value, "local"))
 926                         autorebase = AUTOREBASE_LOCAL;
 927                 else if (!strcmp(value, "remote"))
 928                         autorebase = AUTOREBASE_REMOTE;
 929                 else if (!strcmp(value, "always"))
 930                         autorebase = AUTOREBASE_ALWAYS;
 931                 else
 932                         return error("Malformed value for %s", var);
 933                 return 0;
 934         }
 935
 936         /* Add other config variables here and to Documentation/config.txt. */
 937         return 0;
 938 }
 939
 940 static int git_default_push_config(const char *var, const char *value)
 941 {
 942         if (!strcmp(var, "push.default")) {
 943                 if (!value)
 944                         return config_error_nonbool(var);
 945                 else if (!strcmp(value, "nothing"))
 946                         push_default = PUSH_DEFAULT_NOTHING;
 947                 else if (!strcmp(value, "matching"))
 948                         push_default = PUSH_DEFAULT_MATCHING;
 949                 else if (!strcmp(value, "simple"))
 950                         push_default = PUSH_DEFAULT_SIMPLE;
 951                 else if (!strcmp(value, "upstream"))
 952                         push_default = PUSH_DEFAULT_UPSTREAM;
 953                 else if (!strcmp(value, "tracking")) /* deprecated */
 954                         push_default = PUSH_DEFAULT_UPSTREAM;
 955                 else if (!strcmp(value, "current"))
 956                         push_default = PUSH_DEFAULT_CURRENT;
 957                 else {
 958                         error("Malformed value for %s: %s", var, value);
 959                         return error("Must be one of nothing, matching, simple, "
 960                                      "upstream or current.");
 961                 }
 962                 return 0;
 963         }
 964
 965         /* Add other config variables here and to Documentation/config.txt. */
 966         return 0;
 967 }
 968
 969 static int git_default_mailmap_config(const char *var, const char *value)
 970 {
 971         if (!strcmp(var, "mailmap.file"))
 972                 return git_config_pathname(&git_mailmap_file, var, value);
 973         if (!strcmp(var, "mailmap.blob"))
 974                 return git_config_string(&git_mailmap_blob, var, value);
 975
 976         /* Add other config variables here and to Documentation/config.txt. */
 977         return 0;
 978 }
 979
 980 int git_default_config(const char *var, const char *value, void *dummy)
 981 {
 982         if (starts_with(var, "core."))
 983                 return git_default_core_config(var, value);
 984
 985         if (starts_with(var, "user."))
 986                 return git_ident_config(var, value, dummy);
 987
 988         if (starts_with(var, "i18n."))
 989                 return git_default_i18n_config(var, value);
 990
 991         if (starts_with(var, "branch."))
 992                 return git_default_branch_config(var, value);
 993
 994         if (starts_with(var, "push."))
 995                 return git_default_push_config(var, value);
 996
 997         if (starts_with(var, "mailmap."))
 998                 return git_default_mailmap_config(var, value);
 999
1000         if (starts_with(var, "advice."))
1001                 return git_default_advice_config(var, value);
1002
1003         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
1004                 pager_use_color = git_config_bool(var,value);
1005                 return 0;
1006         }
1007
1008         if (!strcmp(var, "pack.packsizelimit")) {
1009                 pack_size_limit_cfg = git_config_ulong(var, value);
1010                 return 0;
1011         }
1012         /* Add other config variables here and to Documentation/config.txt. */
1013         return 0;
1014 }
1015
1016 /*
1017  * All source specific fields in the union, die_on_error, name and the callbacks
1018  * fgetc, ungetc, ftell of top need to be initialized before calling
1019  * this function.
1020  */
1021 static int do_config_from(struct config_source *top, config_fn_t fn, void *data)
1022 {
1023         int ret;
1024
1025         /* push config-file parsing state stack */
1026         top->prev = cf;
1027         top->linenr = 1;
1028         top->eof = 0;
1029         strbuf_init(&top->value, 1024);
1030         strbuf_init(&top->var, 1024);
1031         cf = top;
1032
1033         ret = git_parse_source(fn, data);
1034
1035         /* pop config-file parsing state stack */
1036         strbuf_release(&top->value);
1037         strbuf_release(&top->var);
1038         cf = top->prev;
1039
1040         return ret;
1041 }
1042
1043 static int do_config_from_file(config_fn_t fn,
1044                 const char *name, const char *path, FILE *f, void *data)
1045 {
1046         struct config_source top;
1047
1048         top.u.file = f;
1049         top.name = name;
1050         top.path = path;
1051         top.die_on_error = 1;
1052         top.do_fgetc = config_file_fgetc;
1053         top.do_ungetc = config_file_ungetc;
1054         top.do_ftell = config_file_ftell;
1055
1056         return do_config_from(&top, fn, data);
1057 }
1058
1059 static int git_config_from_stdin(config_fn_t fn, void *data)
1060 {
1061         return do_config_from_file(fn, "<stdin>", NULL, stdin, data);
1062 }
1063
1064 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
1065 {
1066         int ret = -1;
1067         FILE *f;
1068
1069         f = fopen(filename, "r");
1070         if (f) {
1071                 ret = do_config_from_file(fn, filename, filename, f, data);
1072                 fclose(f);
1073         }
1074         return ret;
1075 }
1076
1077 int git_config_from_buf(config_fn_t fn, const char *name, const char *buf,
1078                         size_t len, void *data)
1079 {
1080         struct config_source top;
1081
1082         top.u.buf.buf = buf;
1083         top.u.buf.len = len;
1084         top.u.buf.pos = 0;
1085         top.name = name;
1086         top.path = NULL;
1087         top.die_on_error = 0;
1088         top.do_fgetc = config_buf_fgetc;
1089         top.do_ungetc = config_buf_ungetc;
1090         top.do_ftell = config_buf_ftell;
1091
1092         return do_config_from(&top, fn, data);
1093 }
1094
1095 static int git_config_from_blob_sha1(config_fn_t fn,
1096                                      const char *name,
1097                                      const unsigned char *sha1,
1098                                      void *data)
1099 {
1100         enum object_type type;
1101         char *buf;
1102         unsigned long size;
1103         int ret;
1104
1105         buf = read_sha1_file(sha1, &type, &size);
1106         if (!buf)
1107                 return error("unable to load config blob object '%s'", name);
1108         if (type != OBJ_BLOB) {
1109                 free(buf);
1110                 return error("reference '%s' does not point to a blob", name);
1111         }
1112
1113         ret = git_config_from_buf(fn, name, buf, size, data);
1114         free(buf);
1115
1116         return ret;
1117 }
1118
1119 static int git_config_from_blob_ref(config_fn_t fn,
1120                                     const char *name,
1121                                     void *data)
1122 {
1123         unsigned char sha1[20];
1124
1125         if (get_sha1(name, sha1) < 0)
1126                 return error("unable to resolve config blob '%s'", name);
1127         return git_config_from_blob_sha1(fn, name, sha1, data);
1128 }
1129
1130 const char *git_etc_gitconfig(void)
1131 {
1132         static const char *system_wide;
1133         if (!system_wide)
1134                 system_wide = system_path(ETC_GITCONFIG);
1135         return system_wide;
1136 }
1137
1138 int git_env_bool(const char *k, int def)
1139 {
1140         const char *v = getenv(k);
1141         return v ? git_config_bool(k, v) : def;
1142 }
1143
1144 int git_config_system(void)
1145 {
1146         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
1147 }
1148
1149 int git_config_early(config_fn_t fn, void *data, const char *repo_config)
1150 {
1151         int ret = 0, found = 0;
1152         char *xdg_config = NULL;
1153         char *user_config = NULL;
1154
1155         home_config_paths(&user_config, &xdg_config, "config");
1156
1157         if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK, 0)) {
1158                 ret += git_config_from_file(fn, git_etc_gitconfig(),
1159                                             data);
1160                 found += 1;
1161         }
1162
1163         if (xdg_config && !access_or_die(xdg_config, R_OK, ACCESS_EACCES_OK)) {
1164                 ret += git_config_from_file(fn, xdg_config, data);
1165                 found += 1;
1166         }
1167
1168         if (user_config && !access_or_die(user_config, R_OK, ACCESS_EACCES_OK)) {
1169                 ret += git_config_from_file(fn, user_config, data);
1170                 found += 1;
1171         }
1172
1173         if (repo_config && !access_or_die(repo_config, R_OK, 0)) {
1174                 ret += git_config_from_file(fn, repo_config, data);
1175                 found += 1;
1176         }
1177
1178         switch (git_config_from_parameters(fn, data)) {
1179         case -1: /* error */
1180                 die("unable to parse command-line config");
1181                 break;
1182         case 0: /* found nothing */
1183                 break;
1184         default: /* found at least one item */
1185                 found++;
1186                 break;
1187         }
1188
1189         free(xdg_config);
1190         free(user_config);
1191         return ret == 0 ? found : ret;
1192 }
1193
1194 int git_config_with_options(config_fn_t fn, void *data,
1195                             struct git_config_source *config_source,
1196                             int respect_includes)
1197 {
1198         char *repo_config = NULL;
1199         int ret;
1200         struct config_include_data inc = CONFIG_INCLUDE_INIT;
1201
1202         if (respect_includes) {
1203                 inc.fn = fn;
1204                 inc.data = data;
1205                 fn = git_config_include;
1206                 data = &inc;
1207         }
1208
1209         /*
1210          * If we have a specific filename, use it. Otherwise, follow the
1211          * regular lookup sequence.
1212          */
1213         if (config_source && config_source->use_stdin)
1214                 return git_config_from_stdin(fn, data);
1215         else if (config_source && config_source->file)
1216                 return git_config_from_file(fn, config_source->file, data);
1217         else if (config_source && config_source->blob)
1218                 return git_config_from_blob_ref(fn, config_source->blob, data);
1219
1220         repo_config = git_pathdup("config");
1221         ret = git_config_early(fn, data, repo_config);
1222         if (repo_config)
1223                 free(repo_config);
1224         return ret;
1225 }
1226
1227 int git_config(config_fn_t fn, void *data)
1228 {
1229         return git_config_with_options(fn, data, NULL, 1);
1230 }
1231
1232 /*
1233  * Find all the stuff for git_config_set() below.
1234  */
1235
1236 static struct {
1237         int baselen;
1238         char *key;
1239         int do_not_match;
1240         regex_t *value_regex;
1241         int multi_replace;
1242         size_t *offset;
1243         unsigned int offset_alloc;
1244         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
1245         int seen;
1246 } store;
1247
1248 static int matches(const char *key, const char *value)
1249 {
1250         return !strcmp(key, store.key) &&
1251                 (store.value_regex == NULL ||
1252                  (store.do_not_match ^
1253                   !regexec(store.value_regex, value, 0, NULL, 0)));
1254 }
1255
1256 static int store_aux(const char *key, const char *value, void *cb)
1257 {
1258         const char *ep;
1259         size_t section_len;
1260
1261         switch (store.state) {
1262         case KEY_SEEN:
1263                 if (matches(key, value)) {
1264                         if (store.seen == 1 && store.multi_replace == 0) {
1265                                 warning("%s has multiple values", key);
1266                         }
1267
1268                         ALLOC_GROW(store.offset, store.seen + 1,
1269                                    store.offset_alloc);
1270
1271                         store.offset[store.seen] = cf->do_ftell(cf);
1272                         store.seen++;
1273                 }
1274                 break;
1275         case SECTION_SEEN:
1276                 /*
1277                  * What we are looking for is in store.key (both
1278                  * section and var), and its section part is baselen
1279                  * long.  We found key (again, both section and var).
1280                  * We would want to know if this key is in the same
1281                  * section as what we are looking for.  We already
1282                  * know we are in the same section as what should
1283                  * hold store.key.
1284                  */
1285                 ep = strrchr(key, '.');
1286                 section_len = ep - key;
1287
1288                 if ((section_len != store.baselen) ||
1289                     memcmp(key, store.key, section_len+1)) {
1290                         store.state = SECTION_END_SEEN;
1291                         break;
1292                 }
1293
1294                 /*
1295                  * Do not increment matches: this is no match, but we
1296                  * just made sure we are in the desired section.
1297                  */
1298                 ALLOC_GROW(store.offset, store.seen + 1,
1299                            store.offset_alloc);
1300                 store.offset[store.seen] = cf->do_ftell(cf);
1301                 /* fallthru */
1302         case SECTION_END_SEEN:
1303         case START:
1304                 if (matches(key, value)) {
1305                         ALLOC_GROW(store.offset, store.seen + 1,
1306                                    store.offset_alloc);
1307                         store.offset[store.seen] = cf->do_ftell(cf);
1308                         store.state = KEY_SEEN;
1309                         store.seen++;
1310                 } else {
1311                         if (strrchr(key, '.') - key == store.baselen &&
1312                               !strncmp(key, store.key, store.baselen)) {
1313                                         store.state = SECTION_SEEN;
1314                                         ALLOC_GROW(store.offset,
1315                                                    store.seen + 1,
1316                                                    store.offset_alloc);
1317                                         store.offset[store.seen] = cf->do_ftell(cf);
1318                         }
1319                 }
1320         }
1321         return 0;
1322 }
1323
1324 static int write_error(const char *filename)
1325 {
1326         error("failed to write new configuration file %s", filename);
1327
1328         /* Same error code as "failed to rename". */
1329         return 4;
1330 }
1331
1332 static int store_write_section(int fd, const char *key)
1333 {
1334         const char *dot;
1335         int i, success;
1336         struct strbuf sb = STRBUF_INIT;
1337
1338         dot = memchr(key, '.', store.baselen);
1339         if (dot) {
1340                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
1341                 for (i = dot - key + 1; i < store.baselen; i++) {
1342                         if (key[i] == '"' || key[i] == '\\')
1343                                 strbuf_addch(&sb, '\\');
1344                         strbuf_addch(&sb, key[i]);
1345                 }
1346                 strbuf_addstr(&sb, "\"]\n");
1347         } else {
1348                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
1349         }
1350
1351         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
1352         strbuf_release(&sb);
1353
1354         return success;
1355 }
1356
1357 static int store_write_pair(int fd, const char *key, const char *value)
1358 {
1359         int i, success;
1360         int length = strlen(key + store.baselen + 1);
1361         const char *quote = "";
1362         struct strbuf sb = STRBUF_INIT;
1363
1364         /*
1365          * Check to see if the value needs to be surrounded with a dq pair.
1366          * Note that problematic characters are always backslash-quoted; this
1367          * check is about not losing leading or trailing SP and strings that
1368          * follow beginning-of-comment characters (i.e. ';' and '#') by the
1369          * configuration parser.
1370          */
1371         if (value[0] == ' ')
1372                 quote = "\"";
1373         for (i = 0; value[i]; i++)
1374                 if (value[i] == ';' || value[i] == '#')
1375                         quote = "\"";
1376         if (i && value[i - 1] == ' ')
1377                 quote = "\"";
1378
1379         strbuf_addf(&sb, "\t%.*s = %s",
1380                     length, key + store.baselen + 1, quote);
1381
1382         for (i = 0; value[i]; i++)
1383                 switch (value[i]) {
1384                 case '\n':
1385                         strbuf_addstr(&sb, "\\n");
1386                         break;
1387                 case '\t':
1388                         strbuf_addstr(&sb, "\\t");
1389                         break;
1390                 case '"':
1391                 case '\\':
1392                         strbuf_addch(&sb, '\\');
1393                 default:
1394                         strbuf_addch(&sb, value[i]);
1395                         break;
1396                 }
1397         strbuf_addf(&sb, "%s\n", quote);
1398
1399         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
1400         strbuf_release(&sb);
1401
1402         return success;
1403 }
1404
1405 static ssize_t find_beginning_of_line(const char *contents, size_t size,
1406         size_t offset_, int *found_bracket)
1407 {
1408         size_t equal_offset = size, bracket_offset = size;
1409         ssize_t offset;
1410
1411 contline:
1412         for (offset = offset_-2; offset > 0
1413                         && contents[offset] != '\n'; offset--)
1414                 switch (contents[offset]) {
1415                         case '=': equal_offset = offset; break;
1416                         case ']': bracket_offset = offset; break;
1417                 }
1418         if (offset > 0 && contents[offset-1] == '\\') {
1419                 offset_ = offset;
1420                 goto contline;
1421         }
1422         if (bracket_offset < equal_offset) {
1423                 *found_bracket = 1;
1424                 offset = bracket_offset+1;
1425         } else
1426                 offset++;
1427
1428         return offset;
1429 }
1430
1431 int git_config_set_in_file(const char *config_filename,
1432                         const char *key, const char *value)
1433 {
1434         return git_config_set_multivar_in_file(config_filename, key, value, NULL, 0);
1435 }
1436
1437 int git_config_set(const char *key, const char *value)
1438 {
1439         return git_config_set_multivar(key, value, NULL, 0);
1440 }
1441
1442 /*
1443  * Auxiliary function to sanity-check and split the key into the section
1444  * identifier and variable name.
1445  *
1446  * Returns 0 on success, -1 when there is an invalid character in the key and
1447  * -2 if there is no section name in the key.
1448  *
1449  * store_key - pointer to char* which will hold a copy of the key with
1450  *             lowercase section and variable name
1451  * baselen - pointer to int which will hold the length of the
1452  *           section + subsection part, can be NULL
1453  */
1454 int git_config_parse_key(const char *key, char **store_key, int *baselen_)
1455 {
1456         int i, dot, baselen;
1457         const char *last_dot = strrchr(key, '.');
1458
1459         /*
1460          * Since "key" actually contains the section name and the real
1461          * key name separated by a dot, we have to know where the dot is.
1462          */
1463
1464         if (last_dot == NULL || last_dot == key) {
1465                 error("key does not contain a section: %s", key);
1466                 return -CONFIG_NO_SECTION_OR_NAME;
1467         }
1468
1469         if (!last_dot[1]) {
1470                 error("key does not contain variable name: %s", key);
1471                 return -CONFIG_NO_SECTION_OR_NAME;
1472         }
1473
1474         baselen = last_dot - key;
1475         if (baselen_)
1476                 *baselen_ = baselen;
1477
1478         /*
1479          * Validate the key and while at it, lower case it for matching.
1480          */
1481         *store_key = xmalloc(strlen(key) + 1);
1482
1483         dot = 0;
1484         for (i = 0; key[i]; i++) {
1485                 unsigned char c = key[i];
1486                 if (c == '.')
1487                         dot = 1;
1488                 /* Leave the extended basename untouched.. */
1489                 if (!dot || i > baselen) {
1490                         if (!iskeychar(c) ||
1491                             (i == baselen + 1 && !isalpha(c))) {
1492                                 error("invalid key: %s", key);
1493                                 goto out_free_ret_1;
1494                         }
1495                         c = tolower(c);
1496                 } else if (c == '\n') {
1497                         error("invalid key (newline): %s", key);
1498                         goto out_free_ret_1;
1499                 }
1500                 (*store_key)[i] = c;
1501         }
1502         (*store_key)[i] = 0;
1503
1504         return 0;
1505
1506 out_free_ret_1:
1507         free(*store_key);
1508         *store_key = NULL;
1509         return -CONFIG_INVALID_KEY;
1510 }
1511
1512 /*
1513  * If value==NULL, unset in (remove from) config,
1514  * if value_regex!=NULL, disregard key/value pairs where value does not match.
1515  * if multi_replace==0, nothing, or only one matching key/value is replaced,
1516  *     else all matching key/values (regardless how many) are removed,
1517  *     before the new pair is written.
1518  *
1519  * Returns 0 on success.
1520  *
1521  * This function does this:
1522  *
1523  * - it locks the config file by creating ".git/config.lock"
1524  *
1525  * - it then parses the config using store_aux() as validator to find
1526  *   the position on the key/value pair to replace. If it is to be unset,
1527  *   it must be found exactly once.
1528  *
1529  * - the config file is mmap()ed and the part before the match (if any) is
1530  *   written to the lock file, then the changed part and the rest.
1531  *
1532  * - the config file is removed and the lock file rename()d to it.
1533  *
1534  */
1535 int git_config_set_multivar_in_file(const char *config_filename,
1536                                 const char *key, const char *value,
1537                                 const char *value_regex, int multi_replace)
1538 {
1539         int fd = -1, in_fd;
1540         int ret;
1541         struct lock_file *lock = NULL;
1542         char *filename_buf = NULL;
1543
1544         /* parse-key returns negative; flip the sign to feed exit(3) */
1545         ret = 0 - git_config_parse_key(key, &store.key, &store.baselen);
1546         if (ret)
1547                 goto out_free;
1548
1549         store.multi_replace = multi_replace;
1550
1551         if (!config_filename)
1552                 config_filename = filename_buf = git_pathdup("config");
1553
1554         /*
1555          * The lock serves a purpose in addition to locking: the new
1556          * contents of .git/config will be written into it.
1557          */
1558         lock = xcalloc(1, sizeof(struct lock_file));
1559         fd = hold_lock_file_for_update(lock, config_filename, 0);
1560         if (fd < 0) {
1561                 error("could not lock config file %s: %s", config_filename, strerror(errno));
1562                 free(store.key);
1563                 ret = CONFIG_NO_LOCK;
1564                 goto out_free;
1565         }
1566
1567         /*
1568          * If .git/config does not exist yet, write a minimal version.
1569          */
1570         in_fd = open(config_filename, O_RDONLY);
1571         if ( in_fd < 0 ) {
1572                 free(store.key);
1573
1574                 if ( ENOENT != errno ) {
1575                         error("opening %s: %s", config_filename,
1576                               strerror(errno));
1577                         ret = CONFIG_INVALID_FILE; /* same as "invalid config file" */
1578                         goto out_free;
1579                 }
1580                 /* if nothing to unset, error out */
1581                 if (value == NULL) {
1582                         ret = CONFIG_NOTHING_SET;
1583                         goto out_free;
1584                 }
1585
1586                 store.key = (char *)key;
1587                 if (!store_write_section(fd, key) ||
1588                     !store_write_pair(fd, key, value))
1589                         goto write_err_out;
1590         } else {
1591                 struct stat st;
1592                 char *contents;
1593                 size_t contents_sz, copy_begin, copy_end;
1594                 int i, new_line = 0;
1595
1596                 if (value_regex == NULL)
1597                         store.value_regex = NULL;
1598                 else {
1599                         if (value_regex[0] == '!') {
1600                                 store.do_not_match = 1;
1601                                 value_regex++;
1602                         } else
1603                                 store.do_not_match = 0;
1604
1605                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
1606                         if (regcomp(store.value_regex, value_regex,
1607                                         REG_EXTENDED)) {
1608                                 error("invalid pattern: %s", value_regex);
1609                                 free(store.value_regex);
1610                                 ret = CONFIG_INVALID_PATTERN;
1611                                 goto out_free;
1612                         }
1613                 }
1614
1615                 ALLOC_GROW(store.offset, 1, store.offset_alloc);
1616                 store.offset[0] = 0;
1617                 store.state = START;
1618                 store.seen = 0;
1619
1620                 /*
1621                  * After this, store.offset will contain the *end* offset
1622                  * of the last match, or remain at 0 if no match was found.
1623                  * As a side effect, we make sure to transform only a valid
1624                  * existing config file.
1625                  */
1626                 if (git_config_from_file(store_aux, config_filename, NULL)) {
1627                         error("invalid config file %s", config_filename);
1628                         free(store.key);
1629                         if (store.value_regex != NULL) {
1630                                 regfree(store.value_regex);
1631                                 free(store.value_regex);
1632                         }
1633                         ret = CONFIG_INVALID_FILE;
1634                         goto out_free;
1635                 }
1636
1637                 free(store.key);
1638                 if (store.value_regex != NULL) {
1639                         regfree(store.value_regex);
1640                         free(store.value_regex);
1641                 }
1642
1643                 /* if nothing to unset, or too many matches, error out */
1644                 if ((store.seen == 0 && value == NULL) ||
1645                                 (store.seen > 1 && multi_replace == 0)) {
1646                         ret = CONFIG_NOTHING_SET;
1647                         goto out_free;
1648                 }
1649
1650                 fstat(in_fd, &st);
1651                 contents_sz = xsize_t(st.st_size);
1652                 contents = xmmap(NULL, contents_sz, PROT_READ,
1653                         MAP_PRIVATE, in_fd, 0);
1654                 close(in_fd);
1655
1656                 if (chmod(lock->filename, st.st_mode & 07777) < 0) {
1657                         error("chmod on %s failed: %s",
1658                                 lock->filename, strerror(errno));
1659                         ret = CONFIG_NO_WRITE;
1660                         goto out_free;
1661                 }
1662
1663                 if (store.seen == 0)
1664                         store.seen = 1;
1665
1666                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
1667                         if (store.offset[i] == 0) {
1668                                 store.offset[i] = copy_end = contents_sz;
1669                         } else if (store.state != KEY_SEEN) {
1670                                 copy_end = store.offset[i];
1671                         } else
1672                                 copy_end = find_beginning_of_line(
1673                                         contents, contents_sz,
1674                                         store.offset[i]-2, &new_line);
1675
1676                         if (copy_end > 0 && contents[copy_end-1] != '\n')
1677                                 new_line = 1;
1678
1679                         /* write the first part of the config */
1680                         if (copy_end > copy_begin) {
1681                                 if (write_in_full(fd, contents + copy_begin,
1682                                                   copy_end - copy_begin) <
1683                                     copy_end - copy_begin)
1684                                         goto write_err_out;
1685                                 if (new_line &&
1686                                     write_str_in_full(fd, "\n") != 1)
1687                                         goto write_err_out;
1688                         }
1689                         copy_begin = store.offset[i];
1690                 }
1691
1692                 /* write the pair (value == NULL means unset) */
1693                 if (value != NULL) {
1694                         if (store.state == START) {
1695                                 if (!store_write_section(fd, key))
1696                                         goto write_err_out;
1697                         }
1698                         if (!store_write_pair(fd, key, value))
1699                                 goto write_err_out;
1700                 }
1701
1702                 /* write the rest of the config */
1703                 if (copy_begin < contents_sz)
1704                         if (write_in_full(fd, contents + copy_begin,
1705                                           contents_sz - copy_begin) <
1706                             contents_sz - copy_begin)
1707                                 goto write_err_out;
1708
1709                 munmap(contents, contents_sz);
1710         }
1711
1712         if (commit_lock_file(lock) < 0) {
1713                 error("could not commit config file %s", config_filename);
1714                 ret = CONFIG_NO_WRITE;
1715                 goto out_free;
1716         }
1717
1718         /*
1719          * lock is committed, so don't try to roll it back below.
1720          * NOTE: Since lockfile.c keeps a linked list of all created
1721          * lock_file structures, it isn't safe to free(lock).  It's
1722          * better to just leave it hanging around.
1723          */
1724         lock = NULL;
1725         ret = 0;
1726
1727 out_free:
1728         if (lock)
1729                 rollback_lock_file(lock);
1730         free(filename_buf);
1731         return ret;
1732
1733 write_err_out:
1734         ret = write_error(lock->filename);
1735         goto out_free;
1736
1737 }
1738
1739 int git_config_set_multivar(const char *key, const char *value,
1740                         const char *value_regex, int multi_replace)
1741 {
1742         return git_config_set_multivar_in_file(NULL, key, value, value_regex,
1743                                                multi_replace);
1744 }
1745
1746 static int section_name_match (const char *buf, const char *name)
1747 {
1748         int i = 0, j = 0, dot = 0;
1749         if (buf[i] != '[')
1750                 return 0;
1751         for (i = 1; buf[i] && buf[i] != ']'; i++) {
1752                 if (!dot && isspace(buf[i])) {
1753                         dot = 1;
1754                         if (name[j++] != '.')
1755                                 break;
1756                         for (i++; isspace(buf[i]); i++)
1757                                 ; /* do nothing */
1758                         if (buf[i] != '"')
1759                                 break;
1760                         continue;
1761                 }
1762                 if (buf[i] == '\\' && dot)
1763                         i++;
1764                 else if (buf[i] == '"' && dot) {
1765                         for (i++; isspace(buf[i]); i++)
1766                                 ; /* do_nothing */
1767                         break;
1768                 }
1769                 if (buf[i] != name[j++])
1770                         break;
1771         }
1772         if (buf[i] == ']' && name[j] == 0) {
1773                 /*
1774                  * We match, now just find the right length offset by
1775                  * gobbling up any whitespace after it, as well
1776                  */
1777                 i++;
1778                 for (; buf[i] && isspace(buf[i]); i++)
1779                         ; /* do nothing */
1780                 return i;
1781         }
1782         return 0;
1783 }
1784
1785 static int section_name_is_ok(const char *name)
1786 {
1787         /* Empty section names are bogus. */
1788         if (!*name)
1789                 return 0;
1790
1791         /*
1792          * Before a dot, we must be alphanumeric or dash. After the first dot,
1793          * anything goes, so we can stop checking.
1794          */
1795         for (; *name && *name != '.'; name++)
1796                 if (*name != '-' && !isalnum(*name))
1797                         return 0;
1798         return 1;
1799 }
1800
1801 /* if new_name == NULL, the section is removed instead */
1802 int git_config_rename_section_in_file(const char *config_filename,
1803                                       const char *old_name, const char *new_name)
1804 {
1805         int ret = 0, remove = 0;
1806         char *filename_buf = NULL;
1807         struct lock_file *lock;
1808         int out_fd;
1809         char buf[1024];
1810         FILE *config_file;
1811         struct stat st;
1812
1813         if (new_name && !section_name_is_ok(new_name)) {
1814                 ret = error("invalid section name: %s", new_name);
1815                 goto out;
1816         }
1817
1818         if (!config_filename)
1819                 config_filename = filename_buf = git_pathdup("config");
1820
1821         lock = xcalloc(1, sizeof(struct lock_file));
1822         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1823         if (out_fd < 0) {
1824                 ret = error("could not lock config file %s", config_filename);
1825                 goto out;
1826         }
1827
1828         if (!(config_file = fopen(config_filename, "rb"))) {
1829                 /* no config file means nothing to rename, no error */
1830                 goto unlock_and_out;
1831         }
1832
1833         fstat(fileno(config_file), &st);
1834
1835         if (chmod(lock->filename, st.st_mode & 07777) < 0) {
1836                 ret = error("chmod on %s failed: %s",
1837                                 lock->filename, strerror(errno));
1838                 goto out;
1839         }
1840
1841         while (fgets(buf, sizeof(buf), config_file)) {
1842                 int i;
1843                 int length;
1844                 char *output = buf;
1845                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1846                         ; /* do nothing */
1847                 if (buf[i] == '[') {
1848                         /* it's a section */
1849                         int offset = section_name_match(&buf[i], old_name);
1850                         if (offset > 0) {
1851                                 ret++;
1852                                 if (new_name == NULL) {
1853                                         remove = 1;
1854                                         continue;
1855                                 }
1856                                 store.baselen = strlen(new_name);
1857                                 if (!store_write_section(out_fd, new_name)) {
1858                                         ret = write_error(lock->filename);
1859                                         goto out;
1860                                 }
1861                                 /*
1862                                  * We wrote out the new section, with
1863                                  * a newline, now skip the old
1864                                  * section's length
1865                                  */
1866                                 output += offset + i;
1867                                 if (strlen(output) > 0) {
1868                                         /*
1869                                          * More content means there's
1870                                          * a declaration to put on the
1871                                          * next line; indent with a
1872                                          * tab
1873                                          */
1874                                         output -= 1;
1875                                         output[0] = '\t';
1876                                 }
1877                         }
1878                         remove = 0;
1879                 }
1880                 if (remove)
1881                         continue;
1882                 length = strlen(output);
1883                 if (write_in_full(out_fd, output, length) != length) {
1884                         ret = write_error(lock->filename);
1885                         goto out;
1886                 }
1887         }
1888         fclose(config_file);
1889 unlock_and_out:
1890         if (commit_lock_file(lock) < 0)
1891                 ret = error("could not commit config file %s", config_filename);
1892 out:
1893         free(filename_buf);
1894         return ret;
1895 }
1896
1897 int git_config_rename_section(const char *old_name, const char *new_name)
1898 {
1899         return git_config_rename_section_in_file(NULL, old_name, new_name);
1900 }
1901
1902 /*
1903  * Call this to report error for your variable that should not
1904  * get a boolean value (i.e. "[my] var" means "true").
1905  */
1906 #undef config_error_nonbool
1907 int config_error_nonbool(const char *var)
1908 {
1909         return error("Missing value for '%s'", var);
1910 }
1911
1912 int parse_config_key(const char *var,
1913                      const char *section,
1914                      const char **subsection, int *subsection_len,
1915                      const char **key)
1916 {
1917         int section_len = strlen(section);
1918         const char *dot;
1919
1920         /* Does it start with "section." ? */
1921         if (!starts_with(var, section) || var[section_len] != '.')
1922                 return -1;
1923
1924         /*
1925          * Find the key; we don't know yet if we have a subsection, but we must
1926          * parse backwards from the end, since the subsection may have dots in
1927          * it, too.
1928          */
1929         dot = strrchr(var, '.');
1930         *key = dot + 1;
1931
1932         /* Did we have a subsection at all? */
1933         if (dot == var + section_len) {
1934                 *subsection = NULL;
1935                 *subsection_len = 0;
1936         }
1937         else {
1938                 *subsection = var + section_len + 1;
1939                 *subsection_len = dot - *subsection;
1940         }
1941
1942         return 0;
1943 }