[PATCH 4/5] config.c: introduce 'git_config_color' to parse ANSI colors

[Taylor Blau <me@ttaylorr.com>]

In preparation for adding `--type=color` to the `git-config(1)` builtin,
let's introduce a color parsing utility, `git_config_color` in a similar
fashion to `git_config_<type>`.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 config.c | 10 ++++++++++
 config.h |  1 +
 2 files changed, 11 insertions(+)

diff --git a/config.c b/config.c
index 62c56099bf..d14813bef7 100644
--- a/config.c
+++ b/config.c
@@ -16,6 +16,7 @@
 #include "string-list.h"
 #include "utf8.h"
 #include "dir.h"
+#include "color.h"
 
 struct config_source {
 	struct config_source *prev;
@@ -1000,6 +1001,15 @@ int git_config_expiry_date(timestamp_t *timestamp, const char *var, const char *
 	return 0;
 }
 
+int git_config_color(char *dest, const char *var, const char *value)
+{
+	if (!value)
+		return config_error_nonbool(var);
+	if (color_parse(value, dest) < 0)
+		return -1;
+	return 0;
+}
+
 static int git_default_core_config(const char *var, const char *value)
 {
 	/* This needs a better name */
diff --git a/config.h b/config.h
index ef70a9cac1..0e060779d9 100644
--- a/config.h
+++ b/config.h
@@ -59,6 +59,7 @@ extern int git_config_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_expiry_date(timestamp_t *, const char *, const char *);
+extern int git_config_color(char *, const char *, const char *);
 extern int git_config_set_in_file_gently(const char *, const char *, const char *);
 extern void git_config_set_in_file(const char *, const char *, const char *);
 extern int git_config_set_gently(const char *, const char *);
-- 
2.17.0