[RFC PATCH] config: Introduce functions to write non-standard file

[Ramkumar Ramachandra <artagnon@gmail.com>]

Introduce two new functions corresponding to "git_config_set" and
"git_config_set_multivar" to write a non-standard configuration file.
Expose thse new functions in cache.h for other git programs to use.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
---
 Although this patch is ready for inclusion as far as I'm concerned,
 I'm marking it an RFC because I will post it along with the latest
 iteration of the Sequencer -- there's some usage examples in that
 series that can justify the creation of two new functions.

 It may be classified as a workaround -- the more we encourage patches
 like this, the more cruft config.c will accumulate, and the harder
 it'll become to refactor completely.

 cache.h  |    2 ++
 config.c |   29 ++++++++++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletions(-)

diff --git a/cache.h b/cache.h
index bc9e5eb..833ee75 100644
--- a/cache.h
+++ b/cache.h
@@ -1056,9 +1056,11 @@ extern int git_config_bool(const char *, const char *);
 extern int git_config_maybe_bool(const char *, const char *);
 extern int git_config_string(const char **, const char *, const char *);
 extern int git_config_pathname(const char **, const char *, const char *);
+extern int git_config_set_in_file(const char *, const char *, const char *);
 extern int git_config_set(const char *, const char *);
 extern int git_config_parse_key(const char *, char **, int *);
 extern int git_config_set_multivar(const char *, const char *, const char *, int);
+extern int git_config_set_multivar_in_file(const char *, const char *, const char *, int, const char *);
 extern int git_config_rename_section(const char *, const char *);
 extern const char *git_etc_gitconfig(void);
 extern int check_repository_format_version(const char *var, const char *value, void *cb);
diff --git a/config.c b/config.c
index 1fc063b..3d9da6b 100644
--- a/config.c
+++ b/config.c
@@ -1092,9 +1092,22 @@ contline:
 	return offset;
 }
 
+int git_config_set_in_file(const char *key, const char *value,
+			const char *filename)
+{
+	const char *saved;
+	int ret;
+
+	saved = config_exclusive_filename;
+	config_exclusive_filename = filename;
+	ret = git_config_set_multivar(key, value, NULL, 0);
+	config_exclusive_filename = saved;
+	return ret;
+}
+
 int git_config_set(const char *key, const char *value)
 {
-	return git_config_set_multivar(key, value, NULL, 0);
+	return git_config_set_in_file(key, value, config_exclusive_filename);
 }
 
 /*
@@ -1387,6 +1400,20 @@ write_err_out:
 
 }
 
+int git_config_set_multivar_in_file(const char *key, const char *value,
+				const char *value_regex, int multi_replace,
+				const char *filename)
+{
+	const char *saved;
+	int ret;
+
+	saved = config_exclusive_filename;
+	config_exclusive_filename = filename;
+	ret = git_config_set_multivar(key, value, value_regex, multi_replace);
+	config_exclusive_filename = saved;
+	return ret;
+}
+
 static int section_name_match (const char *buf, const char *name)
 {
 	int i = 0, j = 0, dot = 0;
-- 
1.7.4.rc1.7.g2cf08.dirty