Use color.ui variable in scripts too

Signed-off-by: Matthias Kestenholz <mk@spinlock.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin-config.c b/builtin-config.c
index c34bc8b..eccb7e7 100644
--- a/builtin-config.c
+++ b/builtin-config.c
@@ -224,6 +224,10 @@
 		get_diff_color_found =
 			git_config_colorbool(var, value, stdout_is_tty);
 	}
+	if (!strcmp(var, "color.ui")) {
+		git_use_color_default = git_config_colorbool(var, value, stdout_is_tty);
+		return 0;
+	}
 	return 0;
 }
 
@@ -251,7 +255,7 @@
 		if (!strcmp(get_color_slot, "color.diff"))
 			get_colorbool_found = get_diff_color_found;
 		if (get_colorbool_found < 0)
-			get_colorbool_found = 0;
+			get_colorbool_found = git_use_color_default;
 	}
 
 	if (argc == 1) {