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