Variable command box logs error if variable is empty

src/core/commandzone/generic/VariableCommandBox.cpp

@@ -142,6 +142,11 @@ void VariableCommandBox::setInsideForLoop() {
 
 void VariableCommandBox::executeCommand() {
 
+	if (m_variableName == "") {
+		LogHandler::getInstance()->write(SimpleLog(common::LOG_ERROR, "Set variable error: cannot set empty variable to " + m_expression));
+		return;
+	}
+
 	try {
 		core::UserVariableManager::getInstance()->editUserVariable(m_variableName, m_expression);