Split up default "core" config parsing into helper routine

It makes the code a bit easier to read, and in theory a bit faster too
(no need to compare all the different "core.*" strings against non-core
config options).

The config system really should get something of a complete overhaul,
but in the absense of that, this at least improves on it a tiny bit.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

config.c

@@ -332,7 +332,7 @@ int git_config_string(const char **dest, const char *var, const char *value)
 	return 0;
 }
 
-int git_default_config(const char *var, const char *value, void *dummy)
+static int git_default_core_config(const char *var, const char *value)
 {
 	/* This needs a better name */
 	if (!strcmp(var, "core.filemode")) {
@@ -444,6 +444,31 @@ int git_default_config(const char *var, const char *value, void *dummy)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.pager"))
+		return git_config_string(&pager_program, var, value);
+
+	if (!strcmp(var, "core.editor"))
+		return git_config_string(&editor_program, var, value);
+
+	if (!strcmp(var, "core.excludesfile"))
+		return git_config_string(&excludes_file, var, value);
+
+	if (!strcmp(var, "core.whitespace")) {
+		if (!value)
+			return config_error_nonbool(var);
+		whitespace_rule_cfg = parse_whitespace_rule(value);
+		return 0;
+	}
+
+	/* Add other config variables here and to Documentation/config.txt. */
+	return 0;
+}
+
+int git_default_config(const char *var, const char *value, void *dummy)
+{
+	if (!prefixcmp(var, "core."))
+		return git_default_core_config(var, value);
+
 	if (!strcmp(var, "user.name")) {
 		if (!value)
 			return config_error_nonbool(var);
@@ -473,21 +498,6 @@ int git_default_config(const char *var, const char *value, void *dummy)
 		return 0;
 	}
 
-	if (!strcmp(var, "core.pager"))
-		return git_config_string(&pager_program, var, value);
-
-	if (!strcmp(var, "core.editor"))
-		return git_config_string(&editor_program, var, value);
-
-	if (!strcmp(var, "core.excludesfile"))
-		return git_config_string(&excludes_file, var, value);
-
-	if (!strcmp(var, "core.whitespace")) {
-		if (!value)
-			return config_error_nonbool(var);
-		whitespace_rule_cfg = parse_whitespace_rule(value);
-		return 0;
-	}
 	if (!strcmp(var, "branch.autosetupmerge")) {
 		if (value && !strcasecmp(value, "always")) {
 			git_branch_track = BRANCH_TRACK_ALWAYS;