Merge branch 'as/graph'
[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                 if (git_default_email[0])
452                         user_ident_explicitly_given = 1;
453                 return 0;
454         }
455
456         if (!strcmp(var, "user.email")) {
457                 if (!value)
458                         return config_error_nonbool(var);
459                 strlcpy(git_default_email, value, sizeof(git_default_email));
460                 if (git_default_name[0])
461                         user_ident_explicitly_given = 1;
462                 return 0;
463         }
464
465         if (!strcmp(var, "i18n.commitencoding"))
466                 return git_config_string(&git_commit_encoding, var, value);
467
468         if (!strcmp(var, "i18n.logoutputencoding"))
469                 return git_config_string(&git_log_output_encoding, var, value);
470
471         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
472                 pager_use_color = git_config_bool(var,value);
473                 return 0;
474         }
475
476         if (!strcmp(var, "core.pager"))
477                 return git_config_string(&pager_program, var, value);
478
479         if (!strcmp(var, "core.editor"))
480                 return git_config_string(&editor_program, var, value);
481
482         if (!strcmp(var, "core.excludesfile"))
483                 return git_config_string(&excludes_file, var, value);
484
485         if (!strcmp(var, "core.whitespace")) {
486                 if (!value)
487                         return config_error_nonbool(var);
488                 whitespace_rule_cfg = parse_whitespace_rule(value);
489                 return 0;
490         }
491         if (!strcmp(var, "branch.autosetupmerge")) {
492                 if (value && !strcasecmp(value, "always")) {
493                         git_branch_track = BRANCH_TRACK_ALWAYS;
494                         return 0;
495                 }
496                 git_branch_track = git_config_bool(var, value);
497                 return 0;
498         }
499         if (!strcmp(var, "branch.autosetuprebase")) {
500                 if (!value)
501                         return config_error_nonbool(var);
502                 else if (!strcmp(value, "never"))
503                         autorebase = AUTOREBASE_NEVER;
504                 else if (!strcmp(value, "local"))
505                         autorebase = AUTOREBASE_LOCAL;
506                 else if (!strcmp(value, "remote"))
507                         autorebase = AUTOREBASE_REMOTE;
508                 else if (!strcmp(value, "always"))
509                         autorebase = AUTOREBASE_ALWAYS;
510                 else
511                         return error("Malformed value for %s", var);
512                 return 0;
513         }
514
515         /* Add other config variables here and to Documentation/config.txt. */
516         return 0;
517 }
518
519 int git_config_from_file(config_fn_t fn, const char *filename)
520 {
521         int ret;
522         FILE *f = fopen(filename, "r");
523
524         ret = -1;
525         if (f) {
526                 config_file = f;
527                 config_file_name = filename;
528                 config_linenr = 1;
529                 config_file_eof = 0;
530                 ret = git_parse_file(fn);
531                 fclose(f);
532                 config_file_name = NULL;
533         }
534         return ret;
535 }
536
537 const char *git_etc_gitconfig(void)
538 {
539         static const char *system_wide;
540         if (!system_wide) {
541                 system_wide = ETC_GITCONFIG;
542                 if (!is_absolute_path(system_wide)) {
543                         /* interpret path relative to exec-dir */
544                         struct strbuf d = STRBUF_INIT;
545                         strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
546                         system_wide = strbuf_detach(&d, NULL);
547                 }
548         }
549         return system_wide;
550 }
551
552 int git_env_bool(const char *k, int def)
553 {
554         const char *v = getenv(k);
555         return v ? git_config_bool(k, v) : def;
556 }
557
558 int git_config_system(void)
559 {
560         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
561 }
562
563 int git_config_global(void)
564 {
565         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
566 }
567
568 int git_config(config_fn_t fn)
569 {
570         int ret = 0;
571         char *repo_config = NULL;
572         const char *home = NULL, *filename;
573
574         /* $GIT_CONFIG makes git read _only_ the given config file,
575          * $GIT_CONFIG_LOCAL will make it process it in addition to the
576          * global config file, the same way it would the per-repository
577          * config file otherwise. */
578         filename = getenv(CONFIG_ENVIRONMENT);
579         if (!filename) {
580                 if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
581                         ret += git_config_from_file(fn, git_etc_gitconfig());
582                 home = getenv("HOME");
583                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
584                 if (!filename)
585                         filename = repo_config = xstrdup(git_path("config"));
586         }
587
588         if (git_config_global() && home) {
589                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
590                 if (!access(user_config, R_OK))
591                         ret = git_config_from_file(fn, user_config);
592                 free(user_config);
593         }
594
595         ret += git_config_from_file(fn, filename);
596         free(repo_config);
597         return ret;
598 }
599
600 /*
601  * Find all the stuff for git_config_set() below.
602  */
603
604 #define MAX_MATCHES 512
605
606 static struct {
607         int baselen;
608         char* key;
609         int do_not_match;
610         regex_t* value_regex;
611         int multi_replace;
612         size_t offset[MAX_MATCHES];
613         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
614         int seen;
615 } store;
616
617 static int matches(const char* key, const char* value)
618 {
619         return !strcmp(key, store.key) &&
620                 (store.value_regex == NULL ||
621                  (store.do_not_match ^
622                   !regexec(store.value_regex, value, 0, NULL, 0)));
623 }
624
625 static int store_aux(const char* key, const char* value)
626 {
627         const char *ep;
628         size_t section_len;
629
630         switch (store.state) {
631         case KEY_SEEN:
632                 if (matches(key, value)) {
633                         if (store.seen == 1 && store.multi_replace == 0) {
634                                 warning("%s has multiple values", key);
635                         } else if (store.seen >= MAX_MATCHES) {
636                                 error("too many matches for %s", key);
637                                 return 1;
638                         }
639
640                         store.offset[store.seen] = ftell(config_file);
641                         store.seen++;
642                 }
643                 break;
644         case SECTION_SEEN:
645                 /*
646                  * What we are looking for is in store.key (both
647                  * section and var), and its section part is baselen
648                  * long.  We found key (again, both section and var).
649                  * We would want to know if this key is in the same
650                  * section as what we are looking for.  We already
651                  * know we are in the same section as what should
652                  * hold store.key.
653                  */
654                 ep = strrchr(key, '.');
655                 section_len = ep - key;
656
657                 if ((section_len != store.baselen) ||
658                     memcmp(key, store.key, section_len+1)) {
659                         store.state = SECTION_END_SEEN;
660                         break;
661                 }
662
663                 /*
664                  * Do not increment matches: this is no match, but we
665                  * just made sure we are in the desired section.
666                  */
667                 store.offset[store.seen] = ftell(config_file);
668                 /* fallthru */
669         case SECTION_END_SEEN:
670         case START:
671                 if (matches(key, value)) {
672                         store.offset[store.seen] = ftell(config_file);
673                         store.state = KEY_SEEN;
674                         store.seen++;
675                 } else {
676                         if (strrchr(key, '.') - key == store.baselen &&
677                               !strncmp(key, store.key, store.baselen)) {
678                                         store.state = SECTION_SEEN;
679                                         store.offset[store.seen] = ftell(config_file);
680                         }
681                 }
682         }
683         return 0;
684 }
685
686 static int write_error(const char *filename)
687 {
688         error("failed to write new configuration file %s", filename);
689
690         /* Same error code as "failed to rename". */
691         return 4;
692 }
693
694 static int store_write_section(int fd, const char* key)
695 {
696         const char *dot;
697         int i, success;
698         struct strbuf sb;
699
700         strbuf_init(&sb, 0);
701         dot = memchr(key, '.', store.baselen);
702         if (dot) {
703                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
704                 for (i = dot - key + 1; i < store.baselen; i++) {
705                         if (key[i] == '"' || key[i] == '\\')
706                                 strbuf_addch(&sb, '\\');
707                         strbuf_addch(&sb, key[i]);
708                 }
709                 strbuf_addstr(&sb, "\"]\n");
710         } else {
711                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
712         }
713
714         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
715         strbuf_release(&sb);
716
717         return success;
718 }
719
720 static int store_write_pair(int fd, const char* key, const char* value)
721 {
722         int i, success;
723         int length = strlen(key + store.baselen + 1);
724         const char *quote = "";
725         struct strbuf sb;
726
727         /*
728          * Check to see if the value needs to be surrounded with a dq pair.
729          * Note that problematic characters are always backslash-quoted; this
730          * check is about not losing leading or trailing SP and strings that
731          * follow beginning-of-comment characters (i.e. ';' and '#') by the
732          * configuration parser.
733          */
734         if (value[0] == ' ')
735                 quote = "\"";
736         for (i = 0; value[i]; i++)
737                 if (value[i] == ';' || value[i] == '#')
738                         quote = "\"";
739         if (i && value[i - 1] == ' ')
740                 quote = "\"";
741
742         strbuf_init(&sb, 0);
743         strbuf_addf(&sb, "\t%.*s = %s",
744                     length, key + store.baselen + 1, quote);
745
746         for (i = 0; value[i]; i++)
747                 switch (value[i]) {
748                 case '\n':
749                         strbuf_addstr(&sb, "\\n");
750                         break;
751                 case '\t':
752                         strbuf_addstr(&sb, "\\t");
753                         break;
754                 case '"':
755                 case '\\':
756                         strbuf_addch(&sb, '\\');
757                 default:
758                         strbuf_addch(&sb, value[i]);
759                         break;
760                 }
761         strbuf_addf(&sb, "%s\n", quote);
762
763         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
764         strbuf_release(&sb);
765
766         return success;
767 }
768
769 static ssize_t find_beginning_of_line(const char* contents, size_t size,
770         size_t offset_, int* found_bracket)
771 {
772         size_t equal_offset = size, bracket_offset = size;
773         ssize_t offset;
774
775 contline:
776         for (offset = offset_-2; offset > 0
777                         && contents[offset] != '\n'; offset--)
778                 switch (contents[offset]) {
779                         case '=': equal_offset = offset; break;
780                         case ']': bracket_offset = offset; break;
781                 }
782         if (offset > 0 && contents[offset-1] == '\\') {
783                 offset_ = offset;
784                 goto contline;
785         }
786         if (bracket_offset < equal_offset) {
787                 *found_bracket = 1;
788                 offset = bracket_offset+1;
789         } else
790                 offset++;
791
792         return offset;
793 }
794
795 int git_config_set(const char* key, const char* value)
796 {
797         return git_config_set_multivar(key, value, NULL, 0);
798 }
799
800 /*
801  * If value==NULL, unset in (remove from) config,
802  * if value_regex!=NULL, disregard key/value pairs where value does not match.
803  * if multi_replace==0, nothing, or only one matching key/value is replaced,
804  *     else all matching key/values (regardless how many) are removed,
805  *     before the new pair is written.
806  *
807  * Returns 0 on success.
808  *
809  * This function does this:
810  *
811  * - it locks the config file by creating ".git/config.lock"
812  *
813  * - it then parses the config using store_aux() as validator to find
814  *   the position on the key/value pair to replace. If it is to be unset,
815  *   it must be found exactly once.
816  *
817  * - the config file is mmap()ed and the part before the match (if any) is
818  *   written to the lock file, then the changed part and the rest.
819  *
820  * - the config file is removed and the lock file rename()d to it.
821  *
822  */
823 int git_config_set_multivar(const char* key, const char* value,
824         const char* value_regex, int multi_replace)
825 {
826         int i, dot;
827         int fd = -1, in_fd;
828         int ret;
829         char* config_filename;
830         struct lock_file *lock = NULL;
831         const char* last_dot = strrchr(key, '.');
832
833         config_filename = getenv(CONFIG_ENVIRONMENT);
834         if (!config_filename) {
835                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
836                 if (!config_filename)
837                         config_filename  = git_path("config");
838         }
839         config_filename = xstrdup(config_filename);
840
841         /*
842          * Since "key" actually contains the section name and the real
843          * key name separated by a dot, we have to know where the dot is.
844          */
845
846         if (last_dot == NULL) {
847                 error("key does not contain a section: %s", key);
848                 ret = 2;
849                 goto out_free;
850         }
851         store.baselen = last_dot - key;
852
853         store.multi_replace = multi_replace;
854
855         /*
856          * Validate the key and while at it, lower case it for matching.
857          */
858         store.key = xmalloc(strlen(key) + 1);
859         dot = 0;
860         for (i = 0; key[i]; i++) {
861                 unsigned char c = key[i];
862                 if (c == '.')
863                         dot = 1;
864                 /* Leave the extended basename untouched.. */
865                 if (!dot || i > store.baselen) {
866                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
867                                 error("invalid key: %s", key);
868                                 free(store.key);
869                                 ret = 1;
870                                 goto out_free;
871                         }
872                         c = tolower(c);
873                 } else if (c == '\n') {
874                         error("invalid key (newline): %s", key);
875                         free(store.key);
876                         ret = 1;
877                         goto out_free;
878                 }
879                 store.key[i] = c;
880         }
881         store.key[i] = 0;
882
883         /*
884          * The lock serves a purpose in addition to locking: the new
885          * contents of .git/config will be written into it.
886          */
887         lock = xcalloc(sizeof(struct lock_file), 1);
888         fd = hold_lock_file_for_update(lock, config_filename, 0);
889         if (fd < 0) {
890                 error("could not lock config file %s", config_filename);
891                 free(store.key);
892                 ret = -1;
893                 goto out_free;
894         }
895
896         /*
897          * If .git/config does not exist yet, write a minimal version.
898          */
899         in_fd = open(config_filename, O_RDONLY);
900         if ( in_fd < 0 ) {
901                 free(store.key);
902
903                 if ( ENOENT != errno ) {
904                         error("opening %s: %s", config_filename,
905                               strerror(errno));
906                         ret = 3; /* same as "invalid config file" */
907                         goto out_free;
908                 }
909                 /* if nothing to unset, error out */
910                 if (value == NULL) {
911                         ret = 5;
912                         goto out_free;
913                 }
914
915                 store.key = (char*)key;
916                 if (!store_write_section(fd, key) ||
917                     !store_write_pair(fd, key, value))
918                         goto write_err_out;
919         } else {
920                 struct stat st;
921                 char* contents;
922                 size_t contents_sz, copy_begin, copy_end;
923                 int i, new_line = 0;
924
925                 if (value_regex == NULL)
926                         store.value_regex = NULL;
927                 else {
928                         if (value_regex[0] == '!') {
929                                 store.do_not_match = 1;
930                                 value_regex++;
931                         } else
932                                 store.do_not_match = 0;
933
934                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
935                         if (regcomp(store.value_regex, value_regex,
936                                         REG_EXTENDED)) {
937                                 error("invalid pattern: %s", value_regex);
938                                 free(store.value_regex);
939                                 ret = 6;
940                                 goto out_free;
941                         }
942                 }
943
944                 store.offset[0] = 0;
945                 store.state = START;
946                 store.seen = 0;
947
948                 /*
949                  * After this, store.offset will contain the *end* offset
950                  * of the last match, or remain at 0 if no match was found.
951                  * As a side effect, we make sure to transform only a valid
952                  * existing config file.
953                  */
954                 if (git_config_from_file(store_aux, config_filename)) {
955                         error("invalid config file %s", config_filename);
956                         free(store.key);
957                         if (store.value_regex != NULL) {
958                                 regfree(store.value_regex);
959                                 free(store.value_regex);
960                         }
961                         ret = 3;
962                         goto out_free;
963                 }
964
965                 free(store.key);
966                 if (store.value_regex != NULL) {
967                         regfree(store.value_regex);
968                         free(store.value_regex);
969                 }
970
971                 /* if nothing to unset, or too many matches, error out */
972                 if ((store.seen == 0 && value == NULL) ||
973                                 (store.seen > 1 && multi_replace == 0)) {
974                         ret = 5;
975                         goto out_free;
976                 }
977
978                 fstat(in_fd, &st);
979                 contents_sz = xsize_t(st.st_size);
980                 contents = xmmap(NULL, contents_sz, PROT_READ,
981                         MAP_PRIVATE, in_fd, 0);
982                 close(in_fd);
983
984                 if (store.seen == 0)
985                         store.seen = 1;
986
987                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
988                         if (store.offset[i] == 0) {
989                                 store.offset[i] = copy_end = contents_sz;
990                         } else if (store.state != KEY_SEEN) {
991                                 copy_end = store.offset[i];
992                         } else
993                                 copy_end = find_beginning_of_line(
994                                         contents, contents_sz,
995                                         store.offset[i]-2, &new_line);
996
997                         if (copy_end > 0 && contents[copy_end-1] != '\n')
998                                 new_line = 1;
999
1000                         /* write the first part of the config */
1001                         if (copy_end > copy_begin) {
1002                                 if (write_in_full(fd, contents + copy_begin,
1003                                                   copy_end - copy_begin) <
1004                                     copy_end - copy_begin)
1005                                         goto write_err_out;
1006                                 if (new_line &&
1007                                     write_in_full(fd, "\n", 1) != 1)
1008                                         goto write_err_out;
1009                         }
1010                         copy_begin = store.offset[i];
1011                 }
1012
1013                 /* write the pair (value == NULL means unset) */
1014                 if (value != NULL) {
1015                         if (store.state == START) {
1016                                 if (!store_write_section(fd, key))
1017                                         goto write_err_out;
1018                         }
1019                         if (!store_write_pair(fd, key, value))
1020                                 goto write_err_out;
1021                 }
1022
1023                 /* write the rest of the config */
1024                 if (copy_begin < contents_sz)
1025                         if (write_in_full(fd, contents + copy_begin,
1026                                           contents_sz - copy_begin) <
1027                             contents_sz - copy_begin)
1028                                 goto write_err_out;
1029
1030                 munmap(contents, contents_sz);
1031         }
1032
1033         if (commit_lock_file(lock) < 0) {
1034                 error("could not commit config file %s", config_filename);
1035                 ret = 4;
1036                 goto out_free;
1037         }
1038
1039         /*
1040          * lock is committed, so don't try to roll it back below.
1041          * NOTE: Since lockfile.c keeps a linked list of all created
1042          * lock_file structures, it isn't safe to free(lock).  It's
1043          * better to just leave it hanging around.
1044          */
1045         lock = NULL;
1046         ret = 0;
1047
1048 out_free:
1049         if (lock)
1050                 rollback_lock_file(lock);
1051         free(config_filename);
1052         return ret;
1053
1054 write_err_out:
1055         ret = write_error(lock->filename);
1056         goto out_free;
1057
1058 }
1059
1060 static int section_name_match (const char *buf, const char *name)
1061 {
1062         int i = 0, j = 0, dot = 0;
1063         for (; buf[i] && buf[i] != ']'; i++) {
1064                 if (!dot && isspace(buf[i])) {
1065                         dot = 1;
1066                         if (name[j++] != '.')
1067                                 break;
1068                         for (i++; isspace(buf[i]); i++)
1069                                 ; /* do nothing */
1070                         if (buf[i] != '"')
1071                                 break;
1072                         continue;
1073                 }
1074                 if (buf[i] == '\\' && dot)
1075                         i++;
1076                 else if (buf[i] == '"' && dot) {
1077                         for (i++; isspace(buf[i]); i++)
1078                                 ; /* do_nothing */
1079                         break;
1080                 }
1081                 if (buf[i] != name[j++])
1082                         break;
1083         }
1084         return (buf[i] == ']' && name[j] == 0);
1085 }
1086
1087 /* if new_name == NULL, the section is removed instead */
1088 int git_config_rename_section(const char *old_name, const char *new_name)
1089 {
1090         int ret = 0, remove = 0;
1091         char *config_filename;
1092         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1093         int out_fd;
1094         char buf[1024];
1095
1096         config_filename = getenv(CONFIG_ENVIRONMENT);
1097         if (!config_filename) {
1098                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1099                 if (!config_filename)
1100                         config_filename  = git_path("config");
1101         }
1102         config_filename = xstrdup(config_filename);
1103         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1104         if (out_fd < 0) {
1105                 ret = error("could not lock config file %s", config_filename);
1106                 goto out;
1107         }
1108
1109         if (!(config_file = fopen(config_filename, "rb"))) {
1110                 /* no config file means nothing to rename, no error */
1111                 goto unlock_and_out;
1112         }
1113
1114         while (fgets(buf, sizeof(buf), config_file)) {
1115                 int i;
1116                 int length;
1117                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1118                         ; /* do nothing */
1119                 if (buf[i] == '[') {
1120                         /* it's a section */
1121                         if (section_name_match (&buf[i+1], old_name)) {
1122                                 ret++;
1123                                 if (new_name == NULL) {
1124                                         remove = 1;
1125                                         continue;
1126                                 }
1127                                 store.baselen = strlen(new_name);
1128                                 if (!store_write_section(out_fd, new_name)) {
1129                                         ret = write_error(lock->filename);
1130                                         goto out;
1131                                 }
1132                                 continue;
1133                         }
1134                         remove = 0;
1135                 }
1136                 if (remove)
1137                         continue;
1138                 length = strlen(buf);
1139                 if (write_in_full(out_fd, buf, length) != length) {
1140                         ret = write_error(lock->filename);
1141                         goto out;
1142                 }
1143         }
1144         fclose(config_file);
1145  unlock_and_out:
1146         if (commit_lock_file(lock) < 0)
1147                 ret = error("could not commit config file %s", config_filename);
1148  out:
1149         free(config_filename);
1150         return ret;
1151 }
1152
1153 /*
1154  * Call this to report error for your variable that should not
1155  * get a boolean value (i.e. "[my] var" means "true").
1156  */
1157 int config_error_nonbool(const char *var)
1158 {
1159         return error("Missing value for '%s'", var);
1160 }