let pack-objects do the writing of unreachable objects as loose objects
[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.bare")) {
354                 is_bare_repository_cfg = git_config_bool(var, value);
355                 return 0;
356         }
357
358         if (!strcmp(var, "core.ignorestat")) {
359                 assume_unchanged = git_config_bool(var, value);
360                 return 0;
361         }
362
363         if (!strcmp(var, "core.prefersymlinkrefs")) {
364                 prefer_symlink_refs = git_config_bool(var, value);
365                 return 0;
366         }
367
368         if (!strcmp(var, "core.logallrefupdates")) {
369                 log_all_ref_updates = git_config_bool(var, value);
370                 return 0;
371         }
372
373         if (!strcmp(var, "core.warnambiguousrefs")) {
374                 warn_ambiguous_refs = git_config_bool(var, value);
375                 return 0;
376         }
377
378         if (!strcmp(var, "core.loosecompression")) {
379                 int level = git_config_int(var, value);
380                 if (level == -1)
381                         level = Z_DEFAULT_COMPRESSION;
382                 else if (level < 0 || level > Z_BEST_COMPRESSION)
383                         die("bad zlib compression level %d", level);
384                 zlib_compression_level = level;
385                 zlib_compression_seen = 1;
386                 return 0;
387         }
388
389         if (!strcmp(var, "core.compression")) {
390                 int level = git_config_int(var, value);
391                 if (level == -1)
392                         level = Z_DEFAULT_COMPRESSION;
393                 else if (level < 0 || level > Z_BEST_COMPRESSION)
394                         die("bad zlib compression level %d", level);
395                 core_compression_level = level;
396                 core_compression_seen = 1;
397                 if (!zlib_compression_seen)
398                         zlib_compression_level = level;
399                 return 0;
400         }
401
402         if (!strcmp(var, "core.packedgitwindowsize")) {
403                 int pgsz_x2 = getpagesize() * 2;
404                 packed_git_window_size = git_config_int(var, value);
405
406                 /* This value must be multiple of (pagesize * 2) */
407                 packed_git_window_size /= pgsz_x2;
408                 if (packed_git_window_size < 1)
409                         packed_git_window_size = 1;
410                 packed_git_window_size *= pgsz_x2;
411                 return 0;
412         }
413
414         if (!strcmp(var, "core.packedgitlimit")) {
415                 packed_git_limit = git_config_int(var, value);
416                 return 0;
417         }
418
419         if (!strcmp(var, "core.deltabasecachelimit")) {
420                 delta_base_cache_limit = git_config_int(var, value);
421                 return 0;
422         }
423
424         if (!strcmp(var, "core.autocrlf")) {
425                 if (value && !strcasecmp(value, "input")) {
426                         auto_crlf = -1;
427                         return 0;
428                 }
429                 auto_crlf = git_config_bool(var, value);
430                 return 0;
431         }
432
433         if (!strcmp(var, "core.safecrlf")) {
434                 if (value && !strcasecmp(value, "warn")) {
435                         safe_crlf = SAFE_CRLF_WARN;
436                         return 0;
437                 }
438                 safe_crlf = git_config_bool(var, value);
439                 return 0;
440         }
441
442         if (!strcmp(var, "user.name")) {
443                 if (!value)
444                         return config_error_nonbool(var);
445                 strlcpy(git_default_name, value, sizeof(git_default_name));
446                 return 0;
447         }
448
449         if (!strcmp(var, "user.email")) {
450                 if (!value)
451                         return config_error_nonbool(var);
452                 strlcpy(git_default_email, value, sizeof(git_default_email));
453                 return 0;
454         }
455
456         if (!strcmp(var, "i18n.commitencoding"))
457                 return git_config_string(&git_commit_encoding, var, value);
458
459         if (!strcmp(var, "i18n.logoutputencoding"))
460                 return git_config_string(&git_log_output_encoding, var, value);
461
462         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
463                 pager_use_color = git_config_bool(var,value);
464                 return 0;
465         }
466
467         if (!strcmp(var, "core.pager"))
468                 return git_config_string(&pager_program, var, value);
469
470         if (!strcmp(var, "core.editor"))
471                 return git_config_string(&editor_program, var, value);
472
473         if (!strcmp(var, "core.excludesfile"))
474                 return git_config_string(&excludes_file, var, value);
475
476         if (!strcmp(var, "core.whitespace")) {
477                 if (!value)
478                         return config_error_nonbool(var);
479                 whitespace_rule_cfg = parse_whitespace_rule(value);
480                 return 0;
481         }
482         if (!strcmp(var, "branch.autosetupmerge")) {
483                 if (value && !strcasecmp(value, "always")) {
484                         git_branch_track = BRANCH_TRACK_ALWAYS;
485                         return 0;
486                 }
487                 git_branch_track = git_config_bool(var, value);
488                 return 0;
489         }
490
491         /* Add other config variables here and to Documentation/config.txt. */
492         return 0;
493 }
494
495 int git_config_from_file(config_fn_t fn, const char *filename)
496 {
497         int ret;
498         FILE *f = fopen(filename, "r");
499
500         ret = -1;
501         if (f) {
502                 config_file = f;
503                 config_file_name = filename;
504                 config_linenr = 1;
505                 config_file_eof = 0;
506                 ret = git_parse_file(fn);
507                 fclose(f);
508                 config_file_name = NULL;
509         }
510         return ret;
511 }
512
513 const char *git_etc_gitconfig(void)
514 {
515         static const char *system_wide;
516         if (!system_wide) {
517                 system_wide = ETC_GITCONFIG;
518                 if (!is_absolute_path(system_wide)) {
519                         /* interpret path relative to exec-dir */
520                         struct strbuf d = STRBUF_INIT;
521                         strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
522                         system_wide = strbuf_detach(&d, NULL);
523                 }
524         }
525         return system_wide;
526 }
527
528 int git_env_bool(const char *k, int def)
529 {
530         const char *v = getenv(k);
531         return v ? git_config_bool(k, v) : def;
532 }
533
534 int git_config_system(void)
535 {
536         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
537 }
538
539 int git_config_global(void)
540 {
541         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
542 }
543
544 int git_config(config_fn_t fn)
545 {
546         int ret = 0;
547         char *repo_config = NULL;
548         const char *home = NULL, *filename;
549
550         /* $GIT_CONFIG makes git read _only_ the given config file,
551          * $GIT_CONFIG_LOCAL will make it process it in addition to the
552          * global config file, the same way it would the per-repository
553          * config file otherwise. */
554         filename = getenv(CONFIG_ENVIRONMENT);
555         if (!filename) {
556                 if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
557                         ret += git_config_from_file(fn, git_etc_gitconfig());
558                 home = getenv("HOME");
559                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
560                 if (!filename)
561                         filename = repo_config = xstrdup(git_path("config"));
562         }
563
564         if (git_config_global() && home) {
565                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
566                 if (!access(user_config, R_OK))
567                         ret = git_config_from_file(fn, user_config);
568                 free(user_config);
569         }
570
571         ret += git_config_from_file(fn, filename);
572         free(repo_config);
573         return ret;
574 }
575
576 /*
577  * Find all the stuff for git_config_set() below.
578  */
579
580 #define MAX_MATCHES 512
581
582 static struct {
583         int baselen;
584         char* key;
585         int do_not_match;
586         regex_t* value_regex;
587         int multi_replace;
588         size_t offset[MAX_MATCHES];
589         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
590         int seen;
591 } store;
592
593 static int matches(const char* key, const char* value)
594 {
595         return !strcmp(key, store.key) &&
596                 (store.value_regex == NULL ||
597                  (store.do_not_match ^
598                   !regexec(store.value_regex, value, 0, NULL, 0)));
599 }
600
601 static int store_aux(const char* key, const char* value)
602 {
603         const char *ep;
604         size_t section_len;
605
606         switch (store.state) {
607         case KEY_SEEN:
608                 if (matches(key, value)) {
609                         if (store.seen == 1 && store.multi_replace == 0) {
610                                 fprintf(stderr,
611                                         "Warning: %s has multiple values\n",
612                                         key);
613                         } else if (store.seen >= MAX_MATCHES) {
614                                 fprintf(stderr, "Too many matches\n");
615                                 return 1;
616                         }
617
618                         store.offset[store.seen] = ftell(config_file);
619                         store.seen++;
620                 }
621                 break;
622         case SECTION_SEEN:
623                 /*
624                  * What we are looking for is in store.key (both
625                  * section and var), and its section part is baselen
626                  * long.  We found key (again, both section and var).
627                  * We would want to know if this key is in the same
628                  * section as what we are looking for.  We already
629                  * know we are in the same section as what should
630                  * hold store.key.
631                  */
632                 ep = strrchr(key, '.');
633                 section_len = ep - key;
634
635                 if ((section_len != store.baselen) ||
636                     memcmp(key, store.key, section_len+1)) {
637                         store.state = SECTION_END_SEEN;
638                         break;
639                 }
640
641                 /*
642                  * Do not increment matches: this is no match, but we
643                  * just made sure we are in the desired section.
644                  */
645                 store.offset[store.seen] = ftell(config_file);
646                 /* fallthru */
647         case SECTION_END_SEEN:
648         case START:
649                 if (matches(key, value)) {
650                         store.offset[store.seen] = ftell(config_file);
651                         store.state = KEY_SEEN;
652                         store.seen++;
653                 } else {
654                         if (strrchr(key, '.') - key == store.baselen &&
655                               !strncmp(key, store.key, store.baselen)) {
656                                         store.state = SECTION_SEEN;
657                                         store.offset[store.seen] = ftell(config_file);
658                         }
659                 }
660         }
661         return 0;
662 }
663
664 static int write_error(void)
665 {
666         fprintf(stderr, "Failed to write new configuration file\n");
667
668         /* Same error code as "failed to rename". */
669         return 4;
670 }
671
672 static int store_write_section(int fd, const char* key)
673 {
674         const char *dot;
675         int i, success;
676         struct strbuf sb;
677
678         strbuf_init(&sb, 0);
679         dot = memchr(key, '.', store.baselen);
680         if (dot) {
681                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
682                 for (i = dot - key + 1; i < store.baselen; i++) {
683                         if (key[i] == '"')
684                                 strbuf_addch(&sb, '\\');
685                         strbuf_addch(&sb, key[i]);
686                 }
687                 strbuf_addstr(&sb, "\"]\n");
688         } else {
689                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
690         }
691
692         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
693         strbuf_release(&sb);
694
695         return success;
696 }
697
698 static int store_write_pair(int fd, const char* key, const char* value)
699 {
700         int i, success;
701         int length = strlen(key + store.baselen + 1);
702         const char *quote = "";
703         struct strbuf sb;
704
705         /*
706          * Check to see if the value needs to be surrounded with a dq pair.
707          * Note that problematic characters are always backslash-quoted; this
708          * check is about not losing leading or trailing SP and strings that
709          * follow beginning-of-comment characters (i.e. ';' and '#') by the
710          * configuration parser.
711          */
712         if (value[0] == ' ')
713                 quote = "\"";
714         for (i = 0; value[i]; i++)
715                 if (value[i] == ';' || value[i] == '#')
716                         quote = "\"";
717         if (i && value[i - 1] == ' ')
718                 quote = "\"";
719
720         strbuf_init(&sb, 0);
721         strbuf_addf(&sb, "\t%.*s = %s",
722                     length, key + store.baselen + 1, quote);
723
724         for (i = 0; value[i]; i++)
725                 switch (value[i]) {
726                 case '\n':
727                         strbuf_addstr(&sb, "\\n");
728                         break;
729                 case '\t':
730                         strbuf_addstr(&sb, "\\t");
731                         break;
732                 case '"':
733                 case '\\':
734                         strbuf_addch(&sb, '\\');
735                 default:
736                         strbuf_addch(&sb, value[i]);
737                         break;
738                 }
739         strbuf_addf(&sb, "%s\n", quote);
740
741         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
742         strbuf_release(&sb);
743
744         return success;
745 }
746
747 static ssize_t find_beginning_of_line(const char* contents, size_t size,
748         size_t offset_, int* found_bracket)
749 {
750         size_t equal_offset = size, bracket_offset = size;
751         ssize_t offset;
752
753 contline:
754         for (offset = offset_-2; offset > 0
755                         && contents[offset] != '\n'; offset--)
756                 switch (contents[offset]) {
757                         case '=': equal_offset = offset; break;
758                         case ']': bracket_offset = offset; break;
759                 }
760         if (offset > 0 && contents[offset-1] == '\\') {
761                 offset_ = offset;
762                 goto contline;
763         }
764         if (bracket_offset < equal_offset) {
765                 *found_bracket = 1;
766                 offset = bracket_offset+1;
767         } else
768                 offset++;
769
770         return offset;
771 }
772
773 int git_config_set(const char* key, const char* value)
774 {
775         return git_config_set_multivar(key, value, NULL, 0);
776 }
777
778 /*
779  * If value==NULL, unset in (remove from) config,
780  * if value_regex!=NULL, disregard key/value pairs where value does not match.
781  * if multi_replace==0, nothing, or only one matching key/value is replaced,
782  *     else all matching key/values (regardless how many) are removed,
783  *     before the new pair is written.
784  *
785  * Returns 0 on success.
786  *
787  * This function does this:
788  *
789  * - it locks the config file by creating ".git/config.lock"
790  *
791  * - it then parses the config using store_aux() as validator to find
792  *   the position on the key/value pair to replace. If it is to be unset,
793  *   it must be found exactly once.
794  *
795  * - the config file is mmap()ed and the part before the match (if any) is
796  *   written to the lock file, then the changed part and the rest.
797  *
798  * - the config file is removed and the lock file rename()d to it.
799  *
800  */
801 int git_config_set_multivar(const char* key, const char* value,
802         const char* value_regex, int multi_replace)
803 {
804         int i, dot;
805         int fd = -1, in_fd;
806         int ret;
807         char* config_filename;
808         struct lock_file *lock = NULL;
809         const char* last_dot = strrchr(key, '.');
810
811         config_filename = getenv(CONFIG_ENVIRONMENT);
812         if (!config_filename) {
813                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
814                 if (!config_filename)
815                         config_filename  = git_path("config");
816         }
817         config_filename = xstrdup(config_filename);
818
819         /*
820          * Since "key" actually contains the section name and the real
821          * key name separated by a dot, we have to know where the dot is.
822          */
823
824         if (last_dot == NULL) {
825                 fprintf(stderr, "key does not contain a section: %s\n", key);
826                 ret = 2;
827                 goto out_free;
828         }
829         store.baselen = last_dot - key;
830
831         store.multi_replace = multi_replace;
832
833         /*
834          * Validate the key and while at it, lower case it for matching.
835          */
836         store.key = xmalloc(strlen(key) + 1);
837         dot = 0;
838         for (i = 0; key[i]; i++) {
839                 unsigned char c = key[i];
840                 if (c == '.')
841                         dot = 1;
842                 /* Leave the extended basename untouched.. */
843                 if (!dot || i > store.baselen) {
844                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
845                                 fprintf(stderr, "invalid key: %s\n", key);
846                                 free(store.key);
847                                 ret = 1;
848                                 goto out_free;
849                         }
850                         c = tolower(c);
851                 } else if (c == '\n') {
852                         fprintf(stderr, "invalid key (newline): %s\n", key);
853                         free(store.key);
854                         ret = 1;
855                         goto out_free;
856                 }
857                 store.key[i] = c;
858         }
859         store.key[i] = 0;
860
861         /*
862          * The lock serves a purpose in addition to locking: the new
863          * contents of .git/config will be written into it.
864          */
865         lock = xcalloc(sizeof(struct lock_file), 1);
866         fd = hold_lock_file_for_update(lock, config_filename, 0);
867         if (fd < 0) {
868                 fprintf(stderr, "could not lock config file\n");
869                 free(store.key);
870                 ret = -1;
871                 goto out_free;
872         }
873
874         /*
875          * If .git/config does not exist yet, write a minimal version.
876          */
877         in_fd = open(config_filename, O_RDONLY);
878         if ( in_fd < 0 ) {
879                 free(store.key);
880
881                 if ( ENOENT != errno ) {
882                         error("opening %s: %s", config_filename,
883                               strerror(errno));
884                         ret = 3; /* same as "invalid config file" */
885                         goto out_free;
886                 }
887                 /* if nothing to unset, error out */
888                 if (value == NULL) {
889                         ret = 5;
890                         goto out_free;
891                 }
892
893                 store.key = (char*)key;
894                 if (!store_write_section(fd, key) ||
895                     !store_write_pair(fd, key, value))
896                         goto write_err_out;
897         } else {
898                 struct stat st;
899                 char* contents;
900                 size_t contents_sz, copy_begin, copy_end;
901                 int i, new_line = 0;
902
903                 if (value_regex == NULL)
904                         store.value_regex = NULL;
905                 else {
906                         if (value_regex[0] == '!') {
907                                 store.do_not_match = 1;
908                                 value_regex++;
909                         } else
910                                 store.do_not_match = 0;
911
912                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
913                         if (regcomp(store.value_regex, value_regex,
914                                         REG_EXTENDED)) {
915                                 fprintf(stderr, "Invalid pattern: %s\n",
916                                         value_regex);
917                                 free(store.value_regex);
918                                 ret = 6;
919                                 goto out_free;
920                         }
921                 }
922
923                 store.offset[0] = 0;
924                 store.state = START;
925                 store.seen = 0;
926
927                 /*
928                  * After this, store.offset will contain the *end* offset
929                  * of the last match, or remain at 0 if no match was found.
930                  * As a side effect, we make sure to transform only a valid
931                  * existing config file.
932                  */
933                 if (git_config_from_file(store_aux, config_filename)) {
934                         fprintf(stderr, "invalid config file\n");
935                         free(store.key);
936                         if (store.value_regex != NULL) {
937                                 regfree(store.value_regex);
938                                 free(store.value_regex);
939                         }
940                         ret = 3;
941                         goto out_free;
942                 }
943
944                 free(store.key);
945                 if (store.value_regex != NULL) {
946                         regfree(store.value_regex);
947                         free(store.value_regex);
948                 }
949
950                 /* if nothing to unset, or too many matches, error out */
951                 if ((store.seen == 0 && value == NULL) ||
952                                 (store.seen > 1 && multi_replace == 0)) {
953                         ret = 5;
954                         goto out_free;
955                 }
956
957                 fstat(in_fd, &st);
958                 contents_sz = xsize_t(st.st_size);
959                 contents = xmmap(NULL, contents_sz, PROT_READ,
960                         MAP_PRIVATE, in_fd, 0);
961                 close(in_fd);
962
963                 if (store.seen == 0)
964                         store.seen = 1;
965
966                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
967                         if (store.offset[i] == 0) {
968                                 store.offset[i] = copy_end = contents_sz;
969                         } else if (store.state != KEY_SEEN) {
970                                 copy_end = store.offset[i];
971                         } else
972                                 copy_end = find_beginning_of_line(
973                                         contents, contents_sz,
974                                         store.offset[i]-2, &new_line);
975
976                         if (copy_end > 0 && contents[copy_end-1] != '\n')
977                                 new_line = 1;
978
979                         /* write the first part of the config */
980                         if (copy_end > copy_begin) {
981                                 if (write_in_full(fd, contents + copy_begin,
982                                                   copy_end - copy_begin) <
983                                     copy_end - copy_begin)
984                                         goto write_err_out;
985                                 if (new_line &&
986                                     write_in_full(fd, "\n", 1) != 1)
987                                         goto write_err_out;
988                         }
989                         copy_begin = store.offset[i];
990                 }
991
992                 /* write the pair (value == NULL means unset) */
993                 if (value != NULL) {
994                         if (store.state == START) {
995                                 if (!store_write_section(fd, key))
996                                         goto write_err_out;
997                         }
998                         if (!store_write_pair(fd, key, value))
999                                 goto write_err_out;
1000                 }
1001
1002                 /* write the rest of the config */
1003                 if (copy_begin < contents_sz)
1004                         if (write_in_full(fd, contents + copy_begin,
1005                                           contents_sz - copy_begin) <
1006                             contents_sz - copy_begin)
1007                                 goto write_err_out;
1008
1009                 munmap(contents, contents_sz);
1010         }
1011
1012         if (commit_lock_file(lock) < 0) {
1013                 fprintf(stderr, "Cannot commit config file!\n");
1014                 ret = 4;
1015                 goto out_free;
1016         }
1017
1018         /*
1019          * lock is committed, so don't try to roll it back below.
1020          * NOTE: Since lockfile.c keeps a linked list of all created
1021          * lock_file structures, it isn't safe to free(lock).  It's
1022          * better to just leave it hanging around.
1023          */
1024         lock = NULL;
1025         ret = 0;
1026
1027 out_free:
1028         if (lock)
1029                 rollback_lock_file(lock);
1030         free(config_filename);
1031         return ret;
1032
1033 write_err_out:
1034         ret = write_error();
1035         goto out_free;
1036
1037 }
1038
1039 static int section_name_match (const char *buf, const char *name)
1040 {
1041         int i = 0, j = 0, dot = 0;
1042         for (; buf[i] && buf[i] != ']'; i++) {
1043                 if (!dot && isspace(buf[i])) {
1044                         dot = 1;
1045                         if (name[j++] != '.')
1046                                 break;
1047                         for (i++; isspace(buf[i]); i++)
1048                                 ; /* do nothing */
1049                         if (buf[i] != '"')
1050                                 break;
1051                         continue;
1052                 }
1053                 if (buf[i] == '\\' && dot)
1054                         i++;
1055                 else if (buf[i] == '"' && dot) {
1056                         for (i++; isspace(buf[i]); i++)
1057                                 ; /* do_nothing */
1058                         break;
1059                 }
1060                 if (buf[i] != name[j++])
1061                         break;
1062         }
1063         return (buf[i] == ']' && name[j] == 0);
1064 }
1065
1066 /* if new_name == NULL, the section is removed instead */
1067 int git_config_rename_section(const char *old_name, const char *new_name)
1068 {
1069         int ret = 0, remove = 0;
1070         char *config_filename;
1071         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1072         int out_fd;
1073         char buf[1024];
1074
1075         config_filename = getenv(CONFIG_ENVIRONMENT);
1076         if (!config_filename) {
1077                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1078                 if (!config_filename)
1079                         config_filename  = git_path("config");
1080         }
1081         config_filename = xstrdup(config_filename);
1082         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1083         if (out_fd < 0) {
1084                 ret = error("Could not lock config file!");
1085                 goto out;
1086         }
1087
1088         if (!(config_file = fopen(config_filename, "rb"))) {
1089                 /* no config file means nothing to rename, no error */
1090                 goto unlock_and_out;
1091         }
1092
1093         while (fgets(buf, sizeof(buf), config_file)) {
1094                 int i;
1095                 int length;
1096                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1097                         ; /* do nothing */
1098                 if (buf[i] == '[') {
1099                         /* it's a section */
1100                         if (section_name_match (&buf[i+1], old_name)) {
1101                                 ret++;
1102                                 if (new_name == NULL) {
1103                                         remove = 1;
1104                                         continue;
1105                                 }
1106                                 store.baselen = strlen(new_name);
1107                                 if (!store_write_section(out_fd, new_name)) {
1108                                         ret = write_error();
1109                                         goto out;
1110                                 }
1111                                 continue;
1112                         }
1113                         remove = 0;
1114                 }
1115                 if (remove)
1116                         continue;
1117                 length = strlen(buf);
1118                 if (write_in_full(out_fd, buf, length) != length) {
1119                         ret = write_error();
1120                         goto out;
1121                 }
1122         }
1123         fclose(config_file);
1124  unlock_and_out:
1125         if (commit_lock_file(lock) < 0)
1126                         ret = error("Cannot commit config file!");
1127  out:
1128         free(config_filename);
1129         return ret;
1130 }
1131
1132 /*
1133  * Call this to report error for your variable that should not
1134  * get a boolean value (i.e. "[my] var" means "true").
1135  */
1136 int config_error_nonbool(const char *var)
1137 {
1138         return error("Missing value for '%s'", var);
1139 }