Merge branch 'lt/case-insensitive'
[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 #include "exec_cmd.h"
10
11 #define MAXNAME (256)
12
13 static FILE *config_file;
14 static const char *config_file_name;
15 static int config_linenr;
16 static int config_file_eof;
17 static int zlib_compression_seen;
18
19 static int get_next_char(void)
20 {
21         int c;
22         FILE *f;
23
24         c = '\n';
25         if ((f = config_file) != NULL) {
26                 c = fgetc(f);
27                 if (c == '\r') {
28                         /* DOS like systems */
29                         c = fgetc(f);
30                         if (c != '\n') {
31                                 ungetc(c, f);
32                                 c = '\r';
33                         }
34                 }
35                 if (c == '\n')
36                         config_linenr++;
37                 if (c == EOF) {
38                         config_file_eof = 1;
39                         c = '\n';
40                 }
41         }
42         return c;
43 }
44
45 static char *parse_value(void)
46 {
47         static char value[1024];
48         int quote = 0, comment = 0, len = 0, space = 0;
49
50         for (;;) {
51                 int c = get_next_char();
52                 if (len >= sizeof(value))
53                         return NULL;
54                 if (c == '\n') {
55                         if (quote)
56                                 return NULL;
57                         value[len] = 0;
58                         return value;
59                 }
60                 if (comment)
61                         continue;
62                 if (isspace(c) && !quote) {
63                         space = 1;
64                         continue;
65                 }
66                 if (!quote) {
67                         if (c == ';' || c == '#') {
68                                 comment = 1;
69                                 continue;
70                         }
71                 }
72                 if (space) {
73                         if (len)
74                                 value[len++] = ' ';
75                         space = 0;
76                 }
77                 if (c == '\\') {
78                         c = get_next_char();
79                         switch (c) {
80                         case '\n':
81                                 continue;
82                         case 't':
83                                 c = '\t';
84                                 break;
85                         case 'b':
86                                 c = '\b';
87                                 break;
88                         case 'n':
89                                 c = '\n';
90                                 break;
91                         /* Some characters escape as themselves */
92                         case '\\': case '"':
93                                 break;
94                         /* Reject unknown escape sequences */
95                         default:
96                                 return NULL;
97                         }
98                         value[len++] = c;
99                         continue;
100                 }
101                 if (c == '"') {
102                         quote = 1-quote;
103                         continue;
104                 }
105                 value[len++] = c;
106         }
107 }
108
109 static inline int iskeychar(int c)
110 {
111         return isalnum(c) || c == '-';
112 }
113
114 static int get_value(config_fn_t fn, char *name, unsigned int len)
115 {
116         int c;
117         char *value;
118
119         /* Get the full name */
120         for (;;) {
121                 c = get_next_char();
122                 if (config_file_eof)
123                         break;
124                 if (!iskeychar(c))
125                         break;
126                 name[len++] = tolower(c);
127                 if (len >= MAXNAME)
128                         return -1;
129         }
130         name[len] = 0;
131         while (c == ' ' || c == '\t')
132                 c = get_next_char();
133
134         value = NULL;
135         if (c != '\n') {
136                 if (c != '=')
137                         return -1;
138                 value = parse_value();
139                 if (!value)
140                         return -1;
141         }
142         return fn(name, value);
143 }
144
145 static int get_extended_base_var(char *name, int baselen, int c)
146 {
147         do {
148                 if (c == '\n')
149                         return -1;
150                 c = get_next_char();
151         } while (isspace(c));
152
153         /* We require the format to be '[base "extension"]' */
154         if (c != '"')
155                 return -1;
156         name[baselen++] = '.';
157
158         for (;;) {
159                 int c = get_next_char();
160                 if (c == '\n')
161                         return -1;
162                 if (c == '"')
163                         break;
164                 if (c == '\\') {
165                         c = get_next_char();
166                         if (c == '\n')
167                                 return -1;
168                 }
169                 name[baselen++] = c;
170                 if (baselen > MAXNAME / 2)
171                         return -1;
172         }
173
174         /* Final ']' */
175         if (get_next_char() != ']')
176                 return -1;
177         return baselen;
178 }
179
180 static int get_base_var(char *name)
181 {
182         int baselen = 0;
183
184         for (;;) {
185                 int c = get_next_char();
186                 if (config_file_eof)
187                         return -1;
188                 if (c == ']')
189                         return baselen;
190                 if (isspace(c))
191                         return get_extended_base_var(name, baselen, c);
192                 if (!iskeychar(c) && c != '.')
193                         return -1;
194                 if (baselen > MAXNAME / 2)
195                         return -1;
196                 name[baselen++] = tolower(c);
197         }
198 }
199
200 static int git_parse_file(config_fn_t fn)
201 {
202         int comment = 0;
203         int baselen = 0;
204         static char var[MAXNAME];
205
206         for (;;) {
207                 int c = get_next_char();
208                 if (c == '\n') {
209                         if (config_file_eof)
210                                 return 0;
211                         comment = 0;
212                         continue;
213                 }
214                 if (comment || isspace(c))
215                         continue;
216                 if (c == '#' || c == ';') {
217                         comment = 1;
218                         continue;
219                 }
220                 if (c == '[') {
221                         baselen = get_base_var(var);
222                         if (baselen <= 0)
223                                 break;
224                         var[baselen++] = '.';
225                         var[baselen] = 0;
226                         continue;
227                 }
228                 if (!isalpha(c))
229                         break;
230                 var[baselen] = tolower(c);
231                 if (get_value(fn, var, baselen+1) < 0)
232                         break;
233         }
234         die("bad config file line %d in %s", config_linenr, config_file_name);
235 }
236
237 static int parse_unit_factor(const char *end, unsigned long *val)
238 {
239         if (!*end)
240                 return 1;
241         else if (!strcasecmp(end, "k")) {
242                 *val *= 1024;
243                 return 1;
244         }
245         else if (!strcasecmp(end, "m")) {
246                 *val *= 1024 * 1024;
247                 return 1;
248         }
249         else if (!strcasecmp(end, "g")) {
250                 *val *= 1024 * 1024 * 1024;
251                 return 1;
252         }
253         return 0;
254 }
255
256 int git_parse_long(const char *value, long *ret)
257 {
258         if (value && *value) {
259                 char *end;
260                 long val = strtol(value, &end, 0);
261                 unsigned long factor = 1;
262                 if (!parse_unit_factor(end, &factor))
263                         return 0;
264                 *ret = val * factor;
265                 return 1;
266         }
267         return 0;
268 }
269
270 int git_parse_ulong(const char *value, unsigned long *ret)
271 {
272         if (value && *value) {
273                 char *end;
274                 unsigned long val = strtoul(value, &end, 0);
275                 if (!parse_unit_factor(end, &val))
276                         return 0;
277                 *ret = val;
278                 return 1;
279         }
280         return 0;
281 }
282
283 static void die_bad_config(const char *name)
284 {
285         if (config_file_name)
286                 die("bad config value for '%s' in %s", name, config_file_name);
287         die("bad config value for '%s'", name);
288 }
289
290 int git_config_int(const char *name, const char *value)
291 {
292         long ret;
293         if (!git_parse_long(value, &ret))
294                 die_bad_config(name);
295         return ret;
296 }
297
298 unsigned long git_config_ulong(const char *name, const char *value)
299 {
300         unsigned long ret;
301         if (!git_parse_ulong(value, &ret))
302                 die_bad_config(name);
303         return ret;
304 }
305
306 int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
307 {
308         *is_bool = 1;
309         if (!value)
310                 return 1;
311         if (!*value)
312                 return 0;
313         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
314                 return 1;
315         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
316                 return 0;
317         *is_bool = 0;
318         return git_config_int(name, value);
319 }
320
321 int git_config_bool(const char *name, const char *value)
322 {
323         int discard;
324         return !!git_config_bool_or_int(name, value, &discard);
325 }
326
327 int git_config_string(const char **dest, const char *var, const char *value)
328 {
329         if (!value)
330                 return config_error_nonbool(var);
331         *dest = xstrdup(value);
332         return 0;
333 }
334
335 int git_default_config(const char *var, const char *value)
336 {
337         /* This needs a better name */
338         if (!strcmp(var, "core.filemode")) {
339                 trust_executable_bit = git_config_bool(var, value);
340                 return 0;
341         }
342
343         if (!strcmp(var, "core.quotepath")) {
344                 quote_path_fully = git_config_bool(var, value);
345                 return 0;
346         }
347
348         if (!strcmp(var, "core.symlinks")) {
349                 has_symlinks = git_config_bool(var, value);
350                 return 0;
351         }
352
353         if (!strcmp(var, "core.ignorecase")) {
354                 ignore_case = git_config_bool(var, value);
355                 return 0;
356         }
357
358         if (!strcmp(var, "core.bare")) {
359                 is_bare_repository_cfg = git_config_bool(var, value);
360                 return 0;
361         }
362
363         if (!strcmp(var, "core.ignorestat")) {
364                 assume_unchanged = git_config_bool(var, value);
365                 return 0;
366         }
367
368         if (!strcmp(var, "core.prefersymlinkrefs")) {
369                 prefer_symlink_refs = git_config_bool(var, value);
370                 return 0;
371         }
372
373         if (!strcmp(var, "core.logallrefupdates")) {
374                 log_all_ref_updates = git_config_bool(var, value);
375                 return 0;
376         }
377
378         if (!strcmp(var, "core.warnambiguousrefs")) {
379                 warn_ambiguous_refs = git_config_bool(var, value);
380                 return 0;
381         }
382
383         if (!strcmp(var, "core.loosecompression")) {
384                 int level = git_config_int(var, value);
385                 if (level == -1)
386                         level = Z_DEFAULT_COMPRESSION;
387                 else if (level < 0 || level > Z_BEST_COMPRESSION)
388                         die("bad zlib compression level %d", level);
389                 zlib_compression_level = level;
390                 zlib_compression_seen = 1;
391                 return 0;
392         }
393
394         if (!strcmp(var, "core.compression")) {
395                 int level = git_config_int(var, value);
396                 if (level == -1)
397                         level = Z_DEFAULT_COMPRESSION;
398                 else if (level < 0 || level > Z_BEST_COMPRESSION)
399                         die("bad zlib compression level %d", level);
400                 core_compression_level = level;
401                 core_compression_seen = 1;
402                 if (!zlib_compression_seen)
403                         zlib_compression_level = level;
404                 return 0;
405         }
406
407         if (!strcmp(var, "core.packedgitwindowsize")) {
408                 int pgsz_x2 = getpagesize() * 2;
409                 packed_git_window_size = git_config_int(var, value);
410
411                 /* This value must be multiple of (pagesize * 2) */
412                 packed_git_window_size /= pgsz_x2;
413                 if (packed_git_window_size < 1)
414                         packed_git_window_size = 1;
415                 packed_git_window_size *= pgsz_x2;
416                 return 0;
417         }
418
419         if (!strcmp(var, "core.packedgitlimit")) {
420                 packed_git_limit = git_config_int(var, value);
421                 return 0;
422         }
423
424         if (!strcmp(var, "core.deltabasecachelimit")) {
425                 delta_base_cache_limit = git_config_int(var, value);
426                 return 0;
427         }
428
429         if (!strcmp(var, "core.autocrlf")) {
430                 if (value && !strcasecmp(value, "input")) {
431                         auto_crlf = -1;
432                         return 0;
433                 }
434                 auto_crlf = git_config_bool(var, value);
435                 return 0;
436         }
437
438         if (!strcmp(var, "core.safecrlf")) {
439                 if (value && !strcasecmp(value, "warn")) {
440                         safe_crlf = SAFE_CRLF_WARN;
441                         return 0;
442                 }
443                 safe_crlf = git_config_bool(var, value);
444                 return 0;
445         }
446
447         if (!strcmp(var, "user.name")) {
448                 if (!value)
449                         return config_error_nonbool(var);
450                 strlcpy(git_default_name, value, sizeof(git_default_name));
451                 return 0;
452         }
453
454         if (!strcmp(var, "user.email")) {
455                 if (!value)
456                         return config_error_nonbool(var);
457                 strlcpy(git_default_email, value, sizeof(git_default_email));
458                 return 0;
459         }
460
461         if (!strcmp(var, "i18n.commitencoding"))
462                 return git_config_string(&git_commit_encoding, var, value);
463
464         if (!strcmp(var, "i18n.logoutputencoding"))
465                 return git_config_string(&git_log_output_encoding, var, value);
466
467         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
468                 pager_use_color = git_config_bool(var,value);
469                 return 0;
470         }
471
472         if (!strcmp(var, "core.pager"))
473                 return git_config_string(&pager_program, var, value);
474
475         if (!strcmp(var, "core.editor"))
476                 return git_config_string(&editor_program, var, value);
477
478         if (!strcmp(var, "core.excludesfile"))
479                 return git_config_string(&excludes_file, var, value);
480
481         if (!strcmp(var, "core.whitespace")) {
482                 if (!value)
483                         return config_error_nonbool(var);
484                 whitespace_rule_cfg = parse_whitespace_rule(value);
485                 return 0;
486         }
487         if (!strcmp(var, "branch.autosetupmerge")) {
488                 if (value && !strcasecmp(value, "always")) {
489                         git_branch_track = BRANCH_TRACK_ALWAYS;
490                         return 0;
491                 }
492                 git_branch_track = git_config_bool(var, value);
493                 return 0;
494         }
495
496         /* Add other config variables here and to Documentation/config.txt. */
497         return 0;
498 }
499
500 int git_config_from_file(config_fn_t fn, const char *filename)
501 {
502         int ret;
503         FILE *f = fopen(filename, "r");
504
505         ret = -1;
506         if (f) {
507                 config_file = f;
508                 config_file_name = filename;
509                 config_linenr = 1;
510                 config_file_eof = 0;
511                 ret = git_parse_file(fn);
512                 fclose(f);
513                 config_file_name = NULL;
514         }
515         return ret;
516 }
517
518 const char *git_etc_gitconfig(void)
519 {
520         static const char *system_wide;
521         if (!system_wide) {
522                 system_wide = ETC_GITCONFIG;
523                 if (!is_absolute_path(system_wide)) {
524                         /* interpret path relative to exec-dir */
525                         struct strbuf d = STRBUF_INIT;
526                         strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
527                         system_wide = strbuf_detach(&d, NULL);
528                 }
529         }
530         return system_wide;
531 }
532
533 int git_env_bool(const char *k, int def)
534 {
535         const char *v = getenv(k);
536         return v ? git_config_bool(k, v) : def;
537 }
538
539 int git_config_system(void)
540 {
541         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
542 }
543
544 int git_config_global(void)
545 {
546         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
547 }
548
549 int git_config(config_fn_t fn)
550 {
551         int ret = 0;
552         char *repo_config = NULL;
553         const char *home = NULL, *filename;
554
555         /* $GIT_CONFIG makes git read _only_ the given config file,
556          * $GIT_CONFIG_LOCAL will make it process it in addition to the
557          * global config file, the same way it would the per-repository
558          * config file otherwise. */
559         filename = getenv(CONFIG_ENVIRONMENT);
560         if (!filename) {
561                 if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
562                         ret += git_config_from_file(fn, git_etc_gitconfig());
563                 home = getenv("HOME");
564                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
565                 if (!filename)
566                         filename = repo_config = xstrdup(git_path("config"));
567         }
568
569         if (git_config_global() && home) {
570                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
571                 if (!access(user_config, R_OK))
572                         ret = git_config_from_file(fn, user_config);
573                 free(user_config);
574         }
575
576         ret += git_config_from_file(fn, filename);
577         free(repo_config);
578         return ret;
579 }
580
581 /*
582  * Find all the stuff for git_config_set() below.
583  */
584
585 #define MAX_MATCHES 512
586
587 static struct {
588         int baselen;
589         char* key;
590         int do_not_match;
591         regex_t* value_regex;
592         int multi_replace;
593         size_t offset[MAX_MATCHES];
594         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
595         int seen;
596 } store;
597
598 static int matches(const char* key, const char* value)
599 {
600         return !strcmp(key, store.key) &&
601                 (store.value_regex == NULL ||
602                  (store.do_not_match ^
603                   !regexec(store.value_regex, value, 0, NULL, 0)));
604 }
605
606 static int store_aux(const char* key, const char* value)
607 {
608         const char *ep;
609         size_t section_len;
610
611         switch (store.state) {
612         case KEY_SEEN:
613                 if (matches(key, value)) {
614                         if (store.seen == 1 && store.multi_replace == 0) {
615                                 fprintf(stderr,
616                                         "Warning: %s has multiple values\n",
617                                         key);
618                         } else if (store.seen >= MAX_MATCHES) {
619                                 fprintf(stderr, "Too many matches\n");
620                                 return 1;
621                         }
622
623                         store.offset[store.seen] = ftell(config_file);
624                         store.seen++;
625                 }
626                 break;
627         case SECTION_SEEN:
628                 /*
629                  * What we are looking for is in store.key (both
630                  * section and var), and its section part is baselen
631                  * long.  We found key (again, both section and var).
632                  * We would want to know if this key is in the same
633                  * section as what we are looking for.  We already
634                  * know we are in the same section as what should
635                  * hold store.key.
636                  */
637                 ep = strrchr(key, '.');
638                 section_len = ep - key;
639
640                 if ((section_len != store.baselen) ||
641                     memcmp(key, store.key, section_len+1)) {
642                         store.state = SECTION_END_SEEN;
643                         break;
644                 }
645
646                 /*
647                  * Do not increment matches: this is no match, but we
648                  * just made sure we are in the desired section.
649                  */
650                 store.offset[store.seen] = ftell(config_file);
651                 /* fallthru */
652         case SECTION_END_SEEN:
653         case START:
654                 if (matches(key, value)) {
655                         store.offset[store.seen] = ftell(config_file);
656                         store.state = KEY_SEEN;
657                         store.seen++;
658                 } else {
659                         if (strrchr(key, '.') - key == store.baselen &&
660                               !strncmp(key, store.key, store.baselen)) {
661                                         store.state = SECTION_SEEN;
662                                         store.offset[store.seen] = ftell(config_file);
663                         }
664                 }
665         }
666         return 0;
667 }
668
669 static int write_error(void)
670 {
671         fprintf(stderr, "Failed to write new configuration file\n");
672
673         /* Same error code as "failed to rename". */
674         return 4;
675 }
676
677 static int store_write_section(int fd, const char* key)
678 {
679         const char *dot;
680         int i, success;
681         struct strbuf sb;
682
683         strbuf_init(&sb, 0);
684         dot = memchr(key, '.', store.baselen);
685         if (dot) {
686                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
687                 for (i = dot - key + 1; i < store.baselen; i++) {
688                         if (key[i] == '"')
689                                 strbuf_addch(&sb, '\\');
690                         strbuf_addch(&sb, key[i]);
691                 }
692                 strbuf_addstr(&sb, "\"]\n");
693         } else {
694                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
695         }
696
697         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
698         strbuf_release(&sb);
699
700         return success;
701 }
702
703 static int store_write_pair(int fd, const char* key, const char* value)
704 {
705         int i, success;
706         int length = strlen(key + store.baselen + 1);
707         const char *quote = "";
708         struct strbuf sb;
709
710         /*
711          * Check to see if the value needs to be surrounded with a dq pair.
712          * Note that problematic characters are always backslash-quoted; this
713          * check is about not losing leading or trailing SP and strings that
714          * follow beginning-of-comment characters (i.e. ';' and '#') by the
715          * configuration parser.
716          */
717         if (value[0] == ' ')
718                 quote = "\"";
719         for (i = 0; value[i]; i++)
720                 if (value[i] == ';' || value[i] == '#')
721                         quote = "\"";
722         if (i && value[i - 1] == ' ')
723                 quote = "\"";
724
725         strbuf_init(&sb, 0);
726         strbuf_addf(&sb, "\t%.*s = %s",
727                     length, key + store.baselen + 1, quote);
728
729         for (i = 0; value[i]; i++)
730                 switch (value[i]) {
731                 case '\n':
732                         strbuf_addstr(&sb, "\\n");
733                         break;
734                 case '\t':
735                         strbuf_addstr(&sb, "\\t");
736                         break;
737                 case '"':
738                 case '\\':
739                         strbuf_addch(&sb, '\\');
740                 default:
741                         strbuf_addch(&sb, value[i]);
742                         break;
743                 }
744         strbuf_addf(&sb, "%s\n", quote);
745
746         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
747         strbuf_release(&sb);
748
749         return success;
750 }
751
752 static ssize_t find_beginning_of_line(const char* contents, size_t size,
753         size_t offset_, int* found_bracket)
754 {
755         size_t equal_offset = size, bracket_offset = size;
756         ssize_t offset;
757
758 contline:
759         for (offset = offset_-2; offset > 0
760                         && contents[offset] != '\n'; offset--)
761                 switch (contents[offset]) {
762                         case '=': equal_offset = offset; break;
763                         case ']': bracket_offset = offset; break;
764                 }
765         if (offset > 0 && contents[offset-1] == '\\') {
766                 offset_ = offset;
767                 goto contline;
768         }
769         if (bracket_offset < equal_offset) {
770                 *found_bracket = 1;
771                 offset = bracket_offset+1;
772         } else
773                 offset++;
774
775         return offset;
776 }
777
778 int git_config_set(const char* key, const char* value)
779 {
780         return git_config_set_multivar(key, value, NULL, 0);
781 }
782
783 /*
784  * If value==NULL, unset in (remove from) config,
785  * if value_regex!=NULL, disregard key/value pairs where value does not match.
786  * if multi_replace==0, nothing, or only one matching key/value is replaced,
787  *     else all matching key/values (regardless how many) are removed,
788  *     before the new pair is written.
789  *
790  * Returns 0 on success.
791  *
792  * This function does this:
793  *
794  * - it locks the config file by creating ".git/config.lock"
795  *
796  * - it then parses the config using store_aux() as validator to find
797  *   the position on the key/value pair to replace. If it is to be unset,
798  *   it must be found exactly once.
799  *
800  * - the config file is mmap()ed and the part before the match (if any) is
801  *   written to the lock file, then the changed part and the rest.
802  *
803  * - the config file is removed and the lock file rename()d to it.
804  *
805  */
806 int git_config_set_multivar(const char* key, const char* value,
807         const char* value_regex, int multi_replace)
808 {
809         int i, dot;
810         int fd = -1, in_fd;
811         int ret;
812         char* config_filename;
813         struct lock_file *lock = NULL;
814         const char* last_dot = strrchr(key, '.');
815
816         config_filename = getenv(CONFIG_ENVIRONMENT);
817         if (!config_filename) {
818                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
819                 if (!config_filename)
820                         config_filename  = git_path("config");
821         }
822         config_filename = xstrdup(config_filename);
823
824         /*
825          * Since "key" actually contains the section name and the real
826          * key name separated by a dot, we have to know where the dot is.
827          */
828
829         if (last_dot == NULL) {
830                 fprintf(stderr, "key does not contain a section: %s\n", key);
831                 ret = 2;
832                 goto out_free;
833         }
834         store.baselen = last_dot - key;
835
836         store.multi_replace = multi_replace;
837
838         /*
839          * Validate the key and while at it, lower case it for matching.
840          */
841         store.key = xmalloc(strlen(key) + 1);
842         dot = 0;
843         for (i = 0; key[i]; i++) {
844                 unsigned char c = key[i];
845                 if (c == '.')
846                         dot = 1;
847                 /* Leave the extended basename untouched.. */
848                 if (!dot || i > store.baselen) {
849                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
850                                 fprintf(stderr, "invalid key: %s\n", key);
851                                 free(store.key);
852                                 ret = 1;
853                                 goto out_free;
854                         }
855                         c = tolower(c);
856                 } else if (c == '\n') {
857                         fprintf(stderr, "invalid key (newline): %s\n", key);
858                         free(store.key);
859                         ret = 1;
860                         goto out_free;
861                 }
862                 store.key[i] = c;
863         }
864         store.key[i] = 0;
865
866         /*
867          * The lock serves a purpose in addition to locking: the new
868          * contents of .git/config will be written into it.
869          */
870         lock = xcalloc(sizeof(struct lock_file), 1);
871         fd = hold_lock_file_for_update(lock, config_filename, 0);
872         if (fd < 0) {
873                 fprintf(stderr, "could not lock config file\n");
874                 free(store.key);
875                 ret = -1;
876                 goto out_free;
877         }
878
879         /*
880          * If .git/config does not exist yet, write a minimal version.
881          */
882         in_fd = open(config_filename, O_RDONLY);
883         if ( in_fd < 0 ) {
884                 free(store.key);
885
886                 if ( ENOENT != errno ) {
887                         error("opening %s: %s", config_filename,
888                               strerror(errno));
889                         ret = 3; /* same as "invalid config file" */
890                         goto out_free;
891                 }
892                 /* if nothing to unset, error out */
893                 if (value == NULL) {
894                         ret = 5;
895                         goto out_free;
896                 }
897
898                 store.key = (char*)key;
899                 if (!store_write_section(fd, key) ||
900                     !store_write_pair(fd, key, value))
901                         goto write_err_out;
902         } else {
903                 struct stat st;
904                 char* contents;
905                 size_t contents_sz, copy_begin, copy_end;
906                 int i, new_line = 0;
907
908                 if (value_regex == NULL)
909                         store.value_regex = NULL;
910                 else {
911                         if (value_regex[0] == '!') {
912                                 store.do_not_match = 1;
913                                 value_regex++;
914                         } else
915                                 store.do_not_match = 0;
916
917                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
918                         if (regcomp(store.value_regex, value_regex,
919                                         REG_EXTENDED)) {
920                                 fprintf(stderr, "Invalid pattern: %s\n",
921                                         value_regex);
922                                 free(store.value_regex);
923                                 ret = 6;
924                                 goto out_free;
925                         }
926                 }
927
928                 store.offset[0] = 0;
929                 store.state = START;
930                 store.seen = 0;
931
932                 /*
933                  * After this, store.offset will contain the *end* offset
934                  * of the last match, or remain at 0 if no match was found.
935                  * As a side effect, we make sure to transform only a valid
936                  * existing config file.
937                  */
938                 if (git_config_from_file(store_aux, config_filename)) {
939                         fprintf(stderr, "invalid config file\n");
940                         free(store.key);
941                         if (store.value_regex != NULL) {
942                                 regfree(store.value_regex);
943                                 free(store.value_regex);
944                         }
945                         ret = 3;
946                         goto out_free;
947                 }
948
949                 free(store.key);
950                 if (store.value_regex != NULL) {
951                         regfree(store.value_regex);
952                         free(store.value_regex);
953                 }
954
955                 /* if nothing to unset, or too many matches, error out */
956                 if ((store.seen == 0 && value == NULL) ||
957                                 (store.seen > 1 && multi_replace == 0)) {
958                         ret = 5;
959                         goto out_free;
960                 }
961
962                 fstat(in_fd, &st);
963                 contents_sz = xsize_t(st.st_size);
964                 contents = xmmap(NULL, contents_sz, PROT_READ,
965                         MAP_PRIVATE, in_fd, 0);
966                 close(in_fd);
967
968                 if (store.seen == 0)
969                         store.seen = 1;
970
971                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
972                         if (store.offset[i] == 0) {
973                                 store.offset[i] = copy_end = contents_sz;
974                         } else if (store.state != KEY_SEEN) {
975                                 copy_end = store.offset[i];
976                         } else
977                                 copy_end = find_beginning_of_line(
978                                         contents, contents_sz,
979                                         store.offset[i]-2, &new_line);
980
981                         if (copy_end > 0 && contents[copy_end-1] != '\n')
982                                 new_line = 1;
983
984                         /* write the first part of the config */
985                         if (copy_end > copy_begin) {
986                                 if (write_in_full(fd, contents + copy_begin,
987                                                   copy_end - copy_begin) <
988                                     copy_end - copy_begin)
989                                         goto write_err_out;
990                                 if (new_line &&
991                                     write_in_full(fd, "\n", 1) != 1)
992                                         goto write_err_out;
993                         }
994                         copy_begin = store.offset[i];
995                 }
996
997                 /* write the pair (value == NULL means unset) */
998                 if (value != NULL) {
999                         if (store.state == START) {
1000                                 if (!store_write_section(fd, key))
1001                                         goto write_err_out;
1002                         }
1003                         if (!store_write_pair(fd, key, value))
1004                                 goto write_err_out;
1005                 }
1006
1007                 /* write the rest of the config */
1008                 if (copy_begin < contents_sz)
1009                         if (write_in_full(fd, contents + copy_begin,
1010                                           contents_sz - copy_begin) <
1011                             contents_sz - copy_begin)
1012                                 goto write_err_out;
1013
1014                 munmap(contents, contents_sz);
1015         }
1016
1017         if (commit_lock_file(lock) < 0) {
1018                 fprintf(stderr, "Cannot commit config file!\n");
1019                 ret = 4;
1020                 goto out_free;
1021         }
1022
1023         /*
1024          * lock is committed, so don't try to roll it back below.
1025          * NOTE: Since lockfile.c keeps a linked list of all created
1026          * lock_file structures, it isn't safe to free(lock).  It's
1027          * better to just leave it hanging around.
1028          */
1029         lock = NULL;
1030         ret = 0;
1031
1032 out_free:
1033         if (lock)
1034                 rollback_lock_file(lock);
1035         free(config_filename);
1036         return ret;
1037
1038 write_err_out:
1039         ret = write_error();
1040         goto out_free;
1041
1042 }
1043
1044 static int section_name_match (const char *buf, const char *name)
1045 {
1046         int i = 0, j = 0, dot = 0;
1047         for (; buf[i] && buf[i] != ']'; i++) {
1048                 if (!dot && isspace(buf[i])) {
1049                         dot = 1;
1050                         if (name[j++] != '.')
1051                                 break;
1052                         for (i++; isspace(buf[i]); i++)
1053                                 ; /* do nothing */
1054                         if (buf[i] != '"')
1055                                 break;
1056                         continue;
1057                 }
1058                 if (buf[i] == '\\' && dot)
1059                         i++;
1060                 else if (buf[i] == '"' && dot) {
1061                         for (i++; isspace(buf[i]); i++)
1062                                 ; /* do_nothing */
1063                         break;
1064                 }
1065                 if (buf[i] != name[j++])
1066                         break;
1067         }
1068         return (buf[i] == ']' && name[j] == 0);
1069 }
1070
1071 /* if new_name == NULL, the section is removed instead */
1072 int git_config_rename_section(const char *old_name, const char *new_name)
1073 {
1074         int ret = 0, remove = 0;
1075         char *config_filename;
1076         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1077         int out_fd;
1078         char buf[1024];
1079
1080         config_filename = getenv(CONFIG_ENVIRONMENT);
1081         if (!config_filename) {
1082                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1083                 if (!config_filename)
1084                         config_filename  = git_path("config");
1085         }
1086         config_filename = xstrdup(config_filename);
1087         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1088         if (out_fd < 0) {
1089                 ret = error("Could not lock config file!");
1090                 goto out;
1091         }
1092
1093         if (!(config_file = fopen(config_filename, "rb"))) {
1094                 /* no config file means nothing to rename, no error */
1095                 goto unlock_and_out;
1096         }
1097
1098         while (fgets(buf, sizeof(buf), config_file)) {
1099                 int i;
1100                 int length;
1101                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1102                         ; /* do nothing */
1103                 if (buf[i] == '[') {
1104                         /* it's a section */
1105                         if (section_name_match (&buf[i+1], old_name)) {
1106                                 ret++;
1107                                 if (new_name == NULL) {
1108                                         remove = 1;
1109                                         continue;
1110                                 }
1111                                 store.baselen = strlen(new_name);
1112                                 if (!store_write_section(out_fd, new_name)) {
1113                                         ret = write_error();
1114                                         goto out;
1115                                 }
1116                                 continue;
1117                         }
1118                         remove = 0;
1119                 }
1120                 if (remove)
1121                         continue;
1122                 length = strlen(buf);
1123                 if (write_in_full(out_fd, buf, length) != length) {
1124                         ret = write_error();
1125                         goto out;
1126                 }
1127         }
1128         fclose(config_file);
1129  unlock_and_out:
1130         if (commit_lock_file(lock) < 0)
1131                         ret = error("Cannot commit config file!");
1132  out:
1133         free(config_filename);
1134         return ret;
1135 }
1136
1137 /*
1138  * Call this to report error for your variable that should not
1139  * get a boolean value (i.e. "[my] var" means "true").
1140  */
1141 int config_error_nonbool(const char *var)
1142 {
1143         return error("Missing value for '%s'", var);
1144 }