fixed in Space: set_empty_string(), set_empty_wstring(), set_empty_table() and set_empty_object() didn't clear its object

if the same kind of object already existed

src/space/space.cpp

@@ -187,24 +187,53 @@ void Space::set_null()
 	initialize_value_null_if_needed();
 }
 
+
 void Space::set_empty_string()
 {
-	initialize_value_string_if_needed();
+	if( type == type_string )
+	{
+		value.value_string.clear();
+	}
+	else
+	{
+		initialize_value_string_if_needed();
+	}
 }
 
 void Space::set_empty_wstring()
 {
-	initialize_value_wstring_if_needed();
+	if( type == type_wstring )
+	{
+		value.value_wstring.clear();
+	}
+	else
+	{
+		initialize_value_wstring_if_needed();
+	}
 }
 
 void Space::set_empty_table()
 {
-	initialize_value_table_if_needed();
+	if( type == type_table )
+	{
+		value.value_table.clear();
+	}
+	else
+	{
+		initialize_value_table_if_needed();
+	}
 }
 
 void Space::set_empty_object()
 {
-	initialize_value_object_if_needed();
+	if( type == type_object )
+	{
+		value.value_object.clear();
+	}
+	else
+	{
+		initialize_value_object_if_needed();
+	}
 }
 
 
@@ -1542,6 +1571,11 @@ const Space * Space::get_object_field(const wchar_t * field) const
 }
 
 
+Space * Space::get_object_field(const std::wstring & field)
+{
+	return get_object_field(field.c_str());
+}
+
 const Space * Space::get_object_field(const std::wstring & field) const
 {
 	return get_object_field(field.c_str());

src/space/space.h

@@ -430,6 +430,11 @@ public:
 
 	// getters from object
 	Space * get_object_field(const wchar_t * field); // may a better name?
+	const Space * get_object_field(const wchar_t * field) const; // may a better name?
+	Space * get_object_field(const std::wstring & field);
+	const Space * get_object_field(const std::wstring & field) const; // may a better name?
+
+
 	bool * get_bool(const wchar_t * field);
 	long long * get_llong(const wchar_t * field);
 	long long * get_long_long(const wchar_t * field);
@@ -455,8 +460,6 @@ public:
 	bool has_key(const wchar_t * field) const; // may has_key() would be a better name?
 	bool has_key(const std::wstring & field) const;
 
-	const Space * get_object_field(const wchar_t * field) const; // may a better name?
-	const Space * get_object_field(const std::wstring & field) const; // may a better name?
 
 	const bool * get_bool(const wchar_t * field) const;
 	const long long * get_llong(const wchar_t * field) const;