Add test for cloning a null node

test/CMakeLists.txt

@@ -2,7 +2,7 @@ add_subdirectory(gtest-1.7.0)
 include_directories(gtest-1.7.0/include)
 
 file(GLOB test_headers [a-z_]*.h)
-file(GLOB test_sources [a-z_]*.cpp)
+file(GLOB test_sources [a-z_]*.cpp node/[a-z_]*.cpp)
 file(GLOB test_new_api_sources new-api/[a-z]*.cpp)
 
 list(APPEND test_sources ${test_new_api_sources})

test/node/node_test.cpp

+#include "gtest/gtest.h"
+#include "yaml-cpp/node/node.h"
+
+namespace YAML {
+namespace {
+TEST(NodeTest, CloneNull) {
+  Node node;
+  Node clone = Clone(node);
+  EXPECT_EQ(NodeType::Null, clone.Type());
+}
+}
+}