Allow creating empty config objects.

Author: arthurschreiber

ext/rugged/rugged_config.c

@@ -41,15 +41,21 @@ VALUE rugged_config_new(VALUE klass, VALUE owner, git_config *cfg)
 
 /*
  *  call-seq:
- *    Config.new(path) -> new_config
+ *    Config.new([path]) -> config
  *
- *  Open the file specified in +path+ as a +Rugged::Config+ file.
- *  If +path+ cannot be found, or the file is an invalid Git config,
- *  an exception will be raised.
+ *  Create a new config object.
+ *
+ *  If +path+ is specified, the file at this path will be used as the backing
+ *  config store. +path+ can also be an array of file paths to be used.
+ *
+ *  If +path+ is not specified, an empty config object will be returned.
  */
-static VALUE rb_git_config_new(VALUE klass, VALUE rb_path)
+static VALUE rb_git_config_new(int argc, VALUE *argv, VALUE klass)
 {
-	git_config *config = NULL;
+	git_config *config;
+	VALUE rb_path;
+
+	rb_scan_args(argc, argv, "01", &rb_path);
 
 	if (TYPE(rb_path) == T_ARRAY) {
 		int error, i;
@@ -71,8 +77,11 @@ static VALUE rb_git_config_new(VALUE klass, VALUE rb_path)
 		rugged_exception_check(
 			git_config_open_ondisk(&config, StringValueCStr(rb_path))
 		);
+	} else if(NIL_P(rb_path)) {
+		rugged_exception_check(git_config_new(&config));
 	} else {
-		rb_raise(rb_eTypeError, "Expecting a filename or an array of filenames");
+		rb_raise(rb_eTypeError, "wrong argument type %s (expected an Array, String, or nil)",
+			rb_obj_classname(rb_path));
 	}
 
 	return rugged_config_new(klass, Qnil, config);
@@ -381,7 +390,7 @@ void Init_rugged_config(void)
 	 * Config
 	 */
 	rb_cRuggedConfig = rb_define_class_under(rb_mRugged, "Config", rb_cObject);
-	rb_define_singleton_method(rb_cRuggedConfig, "new", rb_git_config_new, 1);
+	rb_define_singleton_method(rb_cRuggedConfig, "new", rb_git_config_new, -1);
 
 	rb_define_singleton_method(rb_cRuggedConfig, "global", rb_git_config_open_default, 0);
 	rb_define_singleton_method(rb_cRuggedConfig, "open_global", rb_git_config_open_default, 0);

test/config_test.rb

@@ -5,6 +5,14 @@ def setup
     @repo = FixtureRepo.from_rugged("testrepo.git")
   end
 
+  def test_empty_config
+    config = Rugged::Config.new
+    assert_nil config['not.exist']
+
+    config = Rugged::Config.new(nil)
+    assert_nil config['not.exist']
+  end
+
   def test_read_config_file
     config = @repo.config
     assert_equal 'false', config['core.bare']