lib/drb/drb.rb: Use ruby2_keywords for keyword separation

[Bug #16634]

lib/drb/drb.rb

@@ -1131,7 +1131,7 @@ module DRb
     end
 
     # Routes method calls to the referenced remote object.
-    def method_missing(msg_id, *a, &b)
+    ruby2_keywords def method_missing(msg_id, *a, &b)
       if DRb.here?(@uri)
         obj = DRb.to_obj(@ref)
         DRb.current_server.check_insecure_method(obj, msg_id)

test/drb/test_drb.rb

@@ -349,4 +349,20 @@ class TestDRbTCP < Test::Unit::TestCase
   end
 end
 
+class TestBug16634 < Test::Unit::TestCase
+  include DRbBase
+
+  def setup
+    super
+    setup_service 'ut_drb.rb'
+  end
+
+  def test_bug16634
+    assert_equal(42, @there.keyword_test1(a: 42))
+    assert_equal("default", @there.keyword_test2)
+    assert_equal(42, @there.keyword_test2(b: 42))
+    assert_equal({:a=>42, :b=>42}, @there.keyword_test3(a: 42, b: 42))
+  end
+end
+
 end

test/drb/ut_drb.rb

@@ -148,6 +148,18 @@ class DRbEx
     end
   end
 
+  def keyword_test1(a:)
+    a
+  end
+
+  def keyword_test2(b: "default")
+    b
+  end
+
+  def keyword_test3(**opt)
+    opt
+  end
+
   private
   def call_private_method
     true