yaml-cpp/Add-the-support-to-parsing-a-null-value.patch

diff --git a/include/yaml-cpp/node/impl.h b/include/yaml-cpp/node/impl.h
index 7a3deac..58ae529 100644
--- a/include/yaml-cpp/node/impl.h
+++ b/include/yaml-cpp/node/impl.h
@@ -112,8 +112,10 @@ template <typename S>
 struct as_if<std::string, S> {
   explicit as_if(const Node& node_) : node(node_) {}
   const Node& node;
-
+  
   std::string operator()(const S& fallback) const {
+    if (node.Type() == NodeType::Null)
+      return "null";
     if (node.Type() != NodeType::Scalar)
       return fallback;
     return node.Scalar();
@@ -142,6 +144,8 @@ struct as_if<std::string, void> {
   const Node& node;
 
   std::string operator()() const {
+    if (node.Type() == NodeType::Null)
+      return "null";
     if (node.Type() != NodeType::Scalar)
       throw TypedBadConversion<std::string>(node.Mark());
     return node.Scalar();
diff --git a/test/integration/load_node_test.cpp b/test/integration/load_node_test.cpp
index 4f4f28e..1fb8415 100644
--- a/test/integration/load_node_test.cpp
+++ b/test/integration/load_node_test.cpp
@@ -249,6 +249,8 @@ TEST(NodeTest, IncompleteJson) {
 TEST(NodeTest, LoadTildeAsNull) {
   Node node = Load("~");
   ASSERT_TRUE(node.IsNull());
+  EXPECT_EQ(node.as<std::string>(), "null");
+  EXPECT_EQ(node.as<std::string>("~"), "null");
 }
     
 TEST(NodeTest, LoadTagWithParenthesis) {