return error

stepmania/src/LuaReference.cpp

@@ -138,23 +138,20 @@ void LuaReference::Unregister()
 	m_iReference = LUA_NOREF;
 }
 
-void LuaReference::SetFromExpression( const RString &sExpression )
+bool LuaReference::SetFromExpression( const RString &sExpression )
 {
 	RString sFullExpression = "return " + sExpression;
 	SetName( sFullExpression );
 
 	Lua *L = LUA->Get();
 
-	if( !LuaHelpers::RunScript(L, sFullExpression, "expression", 1) )
-	{
+	bool bSuccess = LuaHelpers::RunScript(L, sFullExpression, "expression", 1);
+	if( !bSuccess )
 		this->SetFromNil();
-		LUA->Release( L );
-		return;
-	}
-
-	/* Store the result. */
-	this->SetFromStack( L );
+	else
+		this->SetFromStack( L );
 	LUA->Release( L );
+	return bSuccess;
 }
 
 RString LuaReference::Serialize() const

stepmania/src/LuaReference.h

@@ -22,8 +22,9 @@ public:
 	void SetFromNil();
 
 	/* Evaluate an expression that returns an object; store the object in a reference.
-	 * For example, evaluating "{ 1, 2, 3 }" will result in a reference to a table. */
-	void SetFromExpression( const RString &sExpression );
+	 * For example, evaluating "{ 1, 2, 3 }" will result in a reference to a table.
+	 * On success, return true.  On error, set to nil and return false. */
+	bool SetFromExpression( const RString &sExpression );
 
 	/* Deep-copy tables, detaching this reference from any others. */
 	void DeepCopy();