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