Fix list function evaluation syntax errors

rules_shipping_base.php

@@ -855,7 +855,7 @@ class ShippingRule {
 			return false;
 			
 		}
-		switch ($func) {
+		switch ($function) {
 			case "length":		return count($args[0]); break;
 			case "union": 
 			case "join":		return call_user_func_array( "array_merge" , $args); break;
@@ -915,7 +915,7 @@ class ShippingRule {
 		}
 		// List functions
 		if (in_array($func, array("length", "complement", "issubset", "contains", "union", "join", "intersection", "list_equal"))) {
-			return evaluateListFunction ($func, args);
+			return $this->evaluateListFunction ($func, $args);
 		}
 		// Functions with variable number of args
 		switch ($func) {