Fix #39, plus a lingering short-string-optimization bug

GraphQLService.cpp

@@ -1082,10 +1082,7 @@ std::future<response::Value> Object::resolve(const SelectionSetParams & selectio
 
 			response::Value result(response::Type::Map);
 
-			if (data.size() > 0)
-			{
-				result.emplace_back(strData, std::move(data));
-			}
+			result.emplace_back(strData, std::move(data));
 
 			if (errors.size() > 0)
 			{

GraphQLTree.cpp

@@ -659,7 +659,15 @@ ast<const char*>::~ast()
 ast<std::string> parseString(std::string&& input)
 {
 	ast<std::string> result { std::move(input), nullptr };
-	memory_input<> in(result.input.c_str(), result.input.size(), "GraphQL");
+	const size_t length = result.input.size();
+
+	if (length < sizeof(result.input))
+	{
+		// Overflow the short string optimization so it uses a heap allocation.
+		result.input.resize(sizeof(result.input));
+	}
+
+	memory_input<> in(result.input.c_str(), length, "GraphQL");
 
 	result.root = parse_tree::parse<document, ast_node, ast_selector, nothing, ast_control>(std::move(in));
 

include/graphqlservice/GraphQLService.h

@@ -541,10 +541,7 @@ struct ModifiedResult
 
 				response::Value document(response::Type::Map);
 
-				if (data.size() > 0)
-				{
-					document.emplace_back(strData, std::move(data));
-				}
+				document.emplace_back(strData, std::move(data));
 
 				if (errors.size() > 0)
 				{