Merge git://git.kernel.org/pub/scm/gitk/gitk
[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(const char *name, const char *value)
307 {
308         if (!value)
309                 return 1;
310         if (!*value)
311                 return 0;
312         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
313                 return 1;
314         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
315                 return 0;
316         return git_config_int(name, value) != 0;
317 }
318
319 int git_config_string(const char **dest, const char *var, const char *value)
320 {
321         if (!value)
322                 return config_error_nonbool(var);
323         *dest = xstrdup(value);
324         return 0;
325 }
326
327 int git_default_config(const char *var, const char *value)
328 {
329         /* This needs a better name */
330         if (!strcmp(var, "core.filemode")) {
331                 trust_executable_bit = git_config_bool(var, value);
332                 return 0;
333         }
334
335         if (!strcmp(var, "core.quotepath")) {
336                 quote_path_fully = git_config_bool(var, value);
337                 return 0;
338         }
339
340         if (!strcmp(var, "core.symlinks")) {
341                 has_symlinks = git_config_bool(var, value);
342                 return 0;
343         }
344
345         if (!strcmp(var, "core.bare")) {
346                 is_bare_repository_cfg = git_config_bool(var, value);
347                 return 0;
348         }
349
350         if (!strcmp(var, "core.ignorestat")) {
351                 assume_unchanged = git_config_bool(var, value);
352                 return 0;
353         }
354
355         if (!strcmp(var, "core.prefersymlinkrefs")) {
356                 prefer_symlink_refs = git_config_bool(var, value);
357                 return 0;
358         }
359
360         if (!strcmp(var, "core.logallrefupdates")) {
361                 log_all_ref_updates = git_config_bool(var, value);
362                 return 0;
363         }
364
365         if (!strcmp(var, "core.warnambiguousrefs")) {
366                 warn_ambiguous_refs = git_config_bool(var, value);
367                 return 0;
368         }
369
370         if (!strcmp(var, "core.loosecompression")) {
371                 int level = git_config_int(var, value);
372                 if (level == -1)
373                         level = Z_DEFAULT_COMPRESSION;
374                 else if (level < 0 || level > Z_BEST_COMPRESSION)
375                         die("bad zlib compression level %d", level);
376                 zlib_compression_level = level;
377                 zlib_compression_seen = 1;
378                 return 0;
379         }
380
381         if (!strcmp(var, "core.compression")) {
382                 int level = git_config_int(var, value);
383                 if (level == -1)
384                         level = Z_DEFAULT_COMPRESSION;
385                 else if (level < 0 || level > Z_BEST_COMPRESSION)
386                         die("bad zlib compression level %d", level);
387                 core_compression_level = level;
388                 core_compression_seen = 1;
389                 if (!zlib_compression_seen)
390                         zlib_compression_level = level;
391                 return 0;
392         }
393
394         if (!strcmp(var, "core.packedgitwindowsize")) {
395                 int pgsz_x2 = getpagesize() * 2;
396                 packed_git_window_size = git_config_int(var, value);
397
398                 /* This value must be multiple of (pagesize * 2) */
399                 packed_git_window_size /= pgsz_x2;
400                 if (packed_git_window_size < 1)
401                         packed_git_window_size = 1;
402                 packed_git_window_size *= pgsz_x2;
403                 return 0;
404         }
405
406         if (!strcmp(var, "core.packedgitlimit")) {
407                 packed_git_limit = git_config_int(var, value);
408                 return 0;
409         }
410
411         if (!strcmp(var, "core.deltabasecachelimit")) {
412                 delta_base_cache_limit = git_config_int(var, value);
413                 return 0;
414         }
415
416         if (!strcmp(var, "core.autocrlf")) {
417                 if (value && !strcasecmp(value, "input")) {
418                         auto_crlf = -1;
419                         return 0;
420                 }
421                 auto_crlf = git_config_bool(var, value);
422                 return 0;
423         }
424
425         if (!strcmp(var, "core.safecrlf")) {
426                 if (value && !strcasecmp(value, "warn")) {
427                         safe_crlf = SAFE_CRLF_WARN;
428                         return 0;
429                 }
430                 safe_crlf = git_config_bool(var, value);
431                 return 0;
432         }
433
434         if (!strcmp(var, "user.name")) {
435                 if (!value)
436                         return config_error_nonbool(var);
437                 strlcpy(git_default_name, value, sizeof(git_default_name));
438                 return 0;
439         }
440
441         if (!strcmp(var, "user.email")) {
442                 if (!value)
443                         return config_error_nonbool(var);
444                 strlcpy(git_default_email, value, sizeof(git_default_email));
445                 return 0;
446         }
447
448         if (!strcmp(var, "i18n.commitencoding"))
449                 return git_config_string(&git_commit_encoding, var, value);
450
451         if (!strcmp(var, "i18n.logoutputencoding"))
452                 return git_config_string(&git_log_output_encoding, var, value);
453
454         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
455                 pager_use_color = git_config_bool(var,value);
456                 return 0;
457         }
458
459         if (!strcmp(var, "core.pager"))
460                 return git_config_string(&pager_program, var, value);
461
462         if (!strcmp(var, "core.editor"))
463                 return git_config_string(&editor_program, var, value);
464
465         if (!strcmp(var, "core.excludesfile"))
466                 return git_config_string(&excludes_file, var, value);
467
468         if (!strcmp(var, "core.whitespace")) {
469                 if (!value)
470                         return config_error_nonbool(var);
471                 whitespace_rule_cfg = parse_whitespace_rule(value);
472                 return 0;
473         }
474         if (!strcmp(var, "branch.autosetupmerge")) {
475                 if (value && !strcasecmp(value, "always")) {
476                         git_branch_track = BRANCH_TRACK_ALWAYS;
477                         return 0;
478                 }
479                 git_branch_track = git_config_bool(var, value);
480                 return 0;
481         }
482
483         /* Add other config variables here and to Documentation/config.txt. */
484         return 0;
485 }
486
487 int git_config_from_file(config_fn_t fn, const char *filename)
488 {
489         int ret;
490         FILE *f = fopen(filename, "r");
491
492         ret = -1;
493         if (f) {
494                 config_file = f;
495                 config_file_name = filename;
496                 config_linenr = 1;
497                 config_file_eof = 0;
498                 ret = git_parse_file(fn);
499                 fclose(f);
500                 config_file_name = NULL;
501         }
502         return ret;
503 }
504
505 const char *git_etc_gitconfig(void)
506 {
507         static const char *system_wide;
508         if (!system_wide) {
509                 system_wide = ETC_GITCONFIG;
510                 if (!is_absolute_path(system_wide)) {
511                         /* interpret path relative to exec-dir */
512                         struct strbuf d = STRBUF_INIT;
513                         strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
514                         system_wide = strbuf_detach(&d, NULL);
515                 }
516         }
517         return system_wide;
518 }
519
520 int git_env_bool(const char *k, int def)
521 {
522         const char *v = getenv(k);
523         return v ? git_config_bool(k, v) : def;
524 }
525
526 int git_config_system(void)
527 {
528         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
529 }
530
531 int git_config_global(void)
532 {
533         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
534 }
535
536 int git_config(config_fn_t fn)
537 {
538         int ret = 0;
539         char *repo_config = NULL;
540         const char *home = NULL, *filename;
541
542         /* $GIT_CONFIG makes git read _only_ the given config file,
543          * $GIT_CONFIG_LOCAL will make it process it in addition to the
544          * global config file, the same way it would the per-repository
545          * config file otherwise. */
546         filename = getenv(CONFIG_ENVIRONMENT);
547         if (!filename) {
548                 if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
549                         ret += git_config_from_file(fn, git_etc_gitconfig());
550                 home = getenv("HOME");
551                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
552                 if (!filename)
553                         filename = repo_config = xstrdup(git_path("config"));
554         }
555
556         if (git_config_global() && home) {
557                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
558                 if (!access(user_config, R_OK))
559                         ret = git_config_from_file(fn, user_config);
560                 free(user_config);
561         }
562
563         ret += git_config_from_file(fn, filename);
564         free(repo_config);
565         return ret;
566 }
567
568 /*
569  * Find all the stuff for git_config_set() below.
570  */
571
572 #define MAX_MATCHES 512
573
574 static struct {
575         int baselen;
576         char* key;
577         int do_not_match;
578         regex_t* value_regex;
579         int multi_replace;
580         size_t offset[MAX_MATCHES];
581         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
582         int seen;
583 } store;
584
585 static int matches(const char* key, const char* value)
586 {
587         return !strcmp(key, store.key) &&
588                 (store.value_regex == NULL ||
589                  (store.do_not_match ^
590                   !regexec(store.value_regex, value, 0, NULL, 0)));
591 }
592
593 static int store_aux(const char* key, const char* value)
594 {
595         const char *ep;
596         size_t section_len;
597
598         switch (store.state) {
599         case KEY_SEEN:
600                 if (matches(key, value)) {
601                         if (store.seen == 1 && store.multi_replace == 0) {
602                                 fprintf(stderr,
603                                         "Warning: %s has multiple values\n",
604                                         key);
605                         } else if (store.seen >= MAX_MATCHES) {
606                                 fprintf(stderr, "Too many matches\n");
607                                 return 1;
608                         }
609
610                         store.offset[store.seen] = ftell(config_file);
611                         store.seen++;
612                 }
613                 break;
614         case SECTION_SEEN:
615                 /*
616                  * What we are looking for is in store.key (both
617                  * section and var), and its section part is baselen
618                  * long.  We found key (again, both section and var).
619                  * We would want to know if this key is in the same
620                  * section as what we are looking for.  We already
621                  * know we are in the same section as what should
622                  * hold store.key.
623                  */
624                 ep = strrchr(key, '.');
625                 section_len = ep - key;
626
627                 if ((section_len != store.baselen) ||
628                     memcmp(key, store.key, section_len+1)) {
629                         store.state = SECTION_END_SEEN;
630                         break;
631                 }
632
633                 /*
634                  * Do not increment matches: this is no match, but we
635                  * just made sure we are in the desired section.
636                  */
637                 store.offset[store.seen] = ftell(config_file);
638                 /* fallthru */
639         case SECTION_END_SEEN:
640         case START:
641                 if (matches(key, value)) {
642                         store.offset[store.seen] = ftell(config_file);
643                         store.state = KEY_SEEN;
644                         store.seen++;
645                 } else {
646                         if (strrchr(key, '.') - key == store.baselen &&
647                               !strncmp(key, store.key, store.baselen)) {
648                                         store.state = SECTION_SEEN;
649                                         store.offset[store.seen] = ftell(config_file);
650                         }
651                 }
652         }
653         return 0;
654 }
655
656 static int write_error(void)
657 {
658         fprintf(stderr, "Failed to write new configuration file\n");
659
660         /* Same error code as "failed to rename". */
661         return 4;
662 }
663
664 static int store_write_section(int fd, const char* key)
665 {
666         const char *dot;
667         int i, success;
668         struct strbuf sb;
669
670         strbuf_init(&sb, 0);
671         dot = memchr(key, '.', store.baselen);
672         if (dot) {
673                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
674                 for (i = dot - key + 1; i < store.baselen; i++) {
675                         if (key[i] == '"')
676                                 strbuf_addch(&sb, '\\');
677                         strbuf_addch(&sb, key[i]);
678                 }
679                 strbuf_addstr(&sb, "\"]\n");
680         } else {
681                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
682         }
683
684         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
685         strbuf_release(&sb);
686
687         return success;
688 }
689
690 static int store_write_pair(int fd, const char* key, const char* value)
691 {
692         int i, success;
693         int length = strlen(key + store.baselen + 1);
694         const char *quote = "";
695         struct strbuf sb;
696
697         /*
698          * Check to see if the value needs to be surrounded with a dq pair.
699          * Note that problematic characters are always backslash-quoted; this
700          * check is about not losing leading or trailing SP and strings that
701          * follow beginning-of-comment characters (i.e. ';' and '#') by the
702          * configuration parser.
703          */
704         if (value[0] == ' ')
705                 quote = "\"";
706         for (i = 0; value[i]; i++)
707                 if (value[i] == ';' || value[i] == '#')
708                         quote = "\"";
709         if (i && value[i - 1] == ' ')
710                 quote = "\"";
711
712         strbuf_init(&sb, 0);
713         strbuf_addf(&sb, "\t%.*s = %s",
714                     length, key + store.baselen + 1, quote);
715
716         for (i = 0; value[i]; i++)
717                 switch (value[i]) {
718                 case '\n':
719                         strbuf_addstr(&sb, "\\n");
720                         break;
721                 case '\t':
722                         strbuf_addstr(&sb, "\\t");
723                         break;
724                 case '"':
725                 case '\\':
726                         strbuf_addch(&sb, '\\');
727                 default:
728                         strbuf_addch(&sb, value[i]);
729                         break;
730                 }
731         strbuf_addf(&sb, "%s\n", quote);
732
733         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
734         strbuf_release(&sb);
735
736         return success;
737 }
738
739 static ssize_t find_beginning_of_line(const char* contents, size_t size,
740         size_t offset_, int* found_bracket)
741 {
742         size_t equal_offset = size, bracket_offset = size;
743         ssize_t offset;
744
745 contline:
746         for (offset = offset_-2; offset > 0
747                         && contents[offset] != '\n'; offset--)
748                 switch (contents[offset]) {
749                         case '=': equal_offset = offset; break;
750                         case ']': bracket_offset = offset; break;
751                 }
752         if (offset > 0 && contents[offset-1] == '\\') {
753                 offset_ = offset;
754                 goto contline;
755         }
756         if (bracket_offset < equal_offset) {
757                 *found_bracket = 1;
758                 offset = bracket_offset+1;
759         } else
760                 offset++;
761
762         return offset;
763 }
764
765 int git_config_set(const char* key, const char* value)
766 {
767         return git_config_set_multivar(key, value, NULL, 0);
768 }
769
770 /*
771  * If value==NULL, unset in (remove from) config,
772  * if value_regex!=NULL, disregard key/value pairs where value does not match.
773  * if multi_replace==0, nothing, or only one matching key/value is replaced,
774  *     else all matching key/values (regardless how many) are removed,
775  *     before the new pair is written.
776  *
777  * Returns 0 on success.
778  *
779  * This function does this:
780  *
781  * - it locks the config file by creating ".git/config.lock"
782  *
783  * - it then parses the config using store_aux() as validator to find
784  *   the position on the key/value pair to replace. If it is to be unset,
785  *   it must be found exactly once.
786  *
787  * - the config file is mmap()ed and the part before the match (if any) is
788  *   written to the lock file, then the changed part and the rest.
789  *
790  * - the config file is removed and the lock file rename()d to it.
791  *
792  */
793 int git_config_set_multivar(const char* key, const char* value,
794         const char* value_regex, int multi_replace)
795 {
796         int i, dot;
797         int fd = -1, in_fd;
798         int ret;
799         char* config_filename;
800         struct lock_file *lock = NULL;
801         const char* last_dot = strrchr(key, '.');
802
803         config_filename = getenv(CONFIG_ENVIRONMENT);
804         if (!config_filename) {
805                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
806                 if (!config_filename)
807                         config_filename  = git_path("config");
808         }
809         config_filename = xstrdup(config_filename);
810
811         /*
812          * Since "key" actually contains the section name and the real
813          * key name separated by a dot, we have to know where the dot is.
814          */
815
816         if (last_dot == NULL) {
817                 fprintf(stderr, "key does not contain a section: %s\n", key);
818                 ret = 2;
819                 goto out_free;
820         }
821         store.baselen = last_dot - key;
822
823         store.multi_replace = multi_replace;
824
825         /*
826          * Validate the key and while at it, lower case it for matching.
827          */
828         store.key = xmalloc(strlen(key) + 1);
829         dot = 0;
830         for (i = 0; key[i]; i++) {
831                 unsigned char c = key[i];
832                 if (c == '.')
833                         dot = 1;
834                 /* Leave the extended basename untouched.. */
835                 if (!dot || i > store.baselen) {
836                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
837                                 fprintf(stderr, "invalid key: %s\n", key);
838                                 free(store.key);
839                                 ret = 1;
840                                 goto out_free;
841                         }
842                         c = tolower(c);
843                 } else if (c == '\n') {
844                         fprintf(stderr, "invalid key (newline): %s\n", key);
845                         free(store.key);
846                         ret = 1;
847                         goto out_free;
848                 }
849                 store.key[i] = c;
850         }
851         store.key[i] = 0;
852
853         /*
854          * The lock serves a purpose in addition to locking: the new
855          * contents of .git/config will be written into it.
856          */
857         lock = xcalloc(sizeof(struct lock_file), 1);
858         fd = hold_lock_file_for_update(lock, config_filename, 0);
859         if (fd < 0) {
860                 fprintf(stderr, "could not lock config file\n");
861                 free(store.key);
862                 ret = -1;
863                 goto out_free;
864         }
865
866         /*
867          * If .git/config does not exist yet, write a minimal version.
868          */
869         in_fd = open(config_filename, O_RDONLY);
870         if ( in_fd < 0 ) {
871                 free(store.key);
872
873                 if ( ENOENT != errno ) {
874                         error("opening %s: %s", config_filename,
875                               strerror(errno));
876                         ret = 3; /* same as "invalid config file" */
877                         goto out_free;
878                 }
879                 /* if nothing to unset, error out */
880                 if (value == NULL) {
881                         ret = 5;
882                         goto out_free;
883                 }
884
885                 store.key = (char*)key;
886                 if (!store_write_section(fd, key) ||
887                     !store_write_pair(fd, key, value))
888                         goto write_err_out;
889         } else {
890                 struct stat st;
891                 char* contents;
892                 size_t contents_sz, copy_begin, copy_end;
893                 int i, new_line = 0;
894
895                 if (value_regex == NULL)
896                         store.value_regex = NULL;
897                 else {
898                         if (value_regex[0] == '!') {
899                                 store.do_not_match = 1;
900                                 value_regex++;
901                         } else
902                                 store.do_not_match = 0;
903
904                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
905                         if (regcomp(store.value_regex, value_regex,
906                                         REG_EXTENDED)) {
907                                 fprintf(stderr, "Invalid pattern: %s\n",
908                                         value_regex);
909                                 free(store.value_regex);
910                                 ret = 6;
911                                 goto out_free;
912                         }
913                 }
914
915                 store.offset[0] = 0;
916                 store.state = START;
917                 store.seen = 0;
918
919                 /*
920                  * After this, store.offset will contain the *end* offset
921                  * of the last match, or remain at 0 if no match was found.
922                  * As a side effect, we make sure to transform only a valid
923                  * existing config file.
924                  */
925                 if (git_config_from_file(store_aux, config_filename)) {
926                         fprintf(stderr, "invalid config file\n");
927                         free(store.key);
928                         if (store.value_regex != NULL) {
929                                 regfree(store.value_regex);
930                                 free(store.value_regex);
931                         }
932                         ret = 3;
933                         goto out_free;
934                 }
935
936                 free(store.key);
937                 if (store.value_regex != NULL) {
938                         regfree(store.value_regex);
939                         free(store.value_regex);
940                 }
941
942                 /* if nothing to unset, or too many matches, error out */
943                 if ((store.seen == 0 && value == NULL) ||
944                                 (store.seen > 1 && multi_replace == 0)) {
945                         ret = 5;
946                         goto out_free;
947                 }
948
949                 fstat(in_fd, &st);
950                 contents_sz = xsize_t(st.st_size);
951                 contents = xmmap(NULL, contents_sz, PROT_READ,
952                         MAP_PRIVATE, in_fd, 0);
953                 close(in_fd);
954
955                 if (store.seen == 0)
956                         store.seen = 1;
957
958                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
959                         if (store.offset[i] == 0) {
960                                 store.offset[i] = copy_end = contents_sz;
961                         } else if (store.state != KEY_SEEN) {
962                                 copy_end = store.offset[i];
963                         } else
964                                 copy_end = find_beginning_of_line(
965                                         contents, contents_sz,
966                                         store.offset[i]-2, &new_line);
967
968                         if (copy_end > 0 && contents[copy_end-1] != '\n')
969                                 new_line = 1;
970
971                         /* write the first part of the config */
972                         if (copy_end > copy_begin) {
973                                 if (write_in_full(fd, contents + copy_begin,
974                                                   copy_end - copy_begin) <
975                                     copy_end - copy_begin)
976                                         goto write_err_out;
977                                 if (new_line &&
978                                     write_in_full(fd, "\n", 1) != 1)
979                                         goto write_err_out;
980                         }
981                         copy_begin = store.offset[i];
982                 }
983
984                 /* write the pair (value == NULL means unset) */
985                 if (value != NULL) {
986                         if (store.state == START) {
987                                 if (!store_write_section(fd, key))
988                                         goto write_err_out;
989                         }
990                         if (!store_write_pair(fd, key, value))
991                                 goto write_err_out;
992                 }
993
994                 /* write the rest of the config */
995                 if (copy_begin < contents_sz)
996                         if (write_in_full(fd, contents + copy_begin,
997                                           contents_sz - copy_begin) <
998                             contents_sz - copy_begin)
999                                 goto write_err_out;
1000
1001                 munmap(contents, contents_sz);
1002         }
1003
1004         if (commit_lock_file(lock) < 0) {
1005                 fprintf(stderr, "Cannot commit config file!\n");
1006                 ret = 4;
1007                 goto out_free;
1008         }
1009
1010         /*
1011          * lock is committed, so don't try to roll it back below.
1012          * NOTE: Since lockfile.c keeps a linked list of all created
1013          * lock_file structures, it isn't safe to free(lock).  It's
1014          * better to just leave it hanging around.
1015          */
1016         lock = NULL;
1017         ret = 0;
1018
1019 out_free:
1020         if (lock)
1021                 rollback_lock_file(lock);
1022         free(config_filename);
1023         return ret;
1024
1025 write_err_out:
1026         ret = write_error();
1027         goto out_free;
1028
1029 }
1030
1031 static int section_name_match (const char *buf, const char *name)
1032 {
1033         int i = 0, j = 0, dot = 0;
1034         for (; buf[i] && buf[i] != ']'; i++) {
1035                 if (!dot && isspace(buf[i])) {
1036                         dot = 1;
1037                         if (name[j++] != '.')
1038                                 break;
1039                         for (i++; isspace(buf[i]); i++)
1040                                 ; /* do nothing */
1041                         if (buf[i] != '"')
1042                                 break;
1043                         continue;
1044                 }
1045                 if (buf[i] == '\\' && dot)
1046                         i++;
1047                 else if (buf[i] == '"' && dot) {
1048                         for (i++; isspace(buf[i]); i++)
1049                                 ; /* do_nothing */
1050                         break;
1051                 }
1052                 if (buf[i] != name[j++])
1053                         break;
1054         }
1055         return (buf[i] == ']' && name[j] == 0);
1056 }
1057
1058 /* if new_name == NULL, the section is removed instead */
1059 int git_config_rename_section(const char *old_name, const char *new_name)
1060 {
1061         int ret = 0, remove = 0;
1062         char *config_filename;
1063         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1064         int out_fd;
1065         char buf[1024];
1066
1067         config_filename = getenv(CONFIG_ENVIRONMENT);
1068         if (!config_filename) {
1069                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1070                 if (!config_filename)
1071                         config_filename  = git_path("config");
1072         }
1073         config_filename = xstrdup(config_filename);
1074         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1075         if (out_fd < 0) {
1076                 ret = error("Could not lock config file!");
1077                 goto out;
1078         }
1079
1080         if (!(config_file = fopen(config_filename, "rb"))) {
1081                 /* no config file means nothing to rename, no error */
1082                 goto unlock_and_out;
1083         }
1084
1085         while (fgets(buf, sizeof(buf), config_file)) {
1086                 int i;
1087                 int length;
1088                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1089                         ; /* do nothing */
1090                 if (buf[i] == '[') {
1091                         /* it's a section */
1092                         if (section_name_match (&buf[i+1], old_name)) {
1093                                 ret++;
1094                                 if (new_name == NULL) {
1095                                         remove = 1;
1096                                         continue;
1097                                 }
1098                                 store.baselen = strlen(new_name);
1099                                 if (!store_write_section(out_fd, new_name)) {
1100                                         ret = write_error();
1101                                         goto out;
1102                                 }
1103                                 continue;
1104                         }
1105                         remove = 0;
1106                 }
1107                 if (remove)
1108                         continue;
1109                 length = strlen(buf);
1110                 if (write_in_full(out_fd, buf, length) != length) {
1111                         ret = write_error();
1112                         goto out;
1113                 }
1114         }
1115         fclose(config_file);
1116  unlock_and_out:
1117         if (commit_lock_file(lock) < 0)
1118                         ret = error("Cannot commit config file!");
1119  out:
1120         free(config_filename);
1121         return ret;
1122 }
1123
1124 /*
1125  * Call this to report error for your variable that should not
1126  * get a boolean value (i.e. "[my] var" means "true").
1127  */
1128 int config_error_nonbool(const char *var)
1129 {
1130         return error("Missing value for '%s'", var);
1131 }