Pulling in from empty list container returns null like for other containers. Fixes #660

src/main/java/carpet/script/value/ListValue.java

@@ -437,8 +437,16 @@ public class ListValue extends AbstractListValue implements ContainerValueInterf
     public Value get(Value value)
     {
         long index = NumericValue.asNumber(value, "'address' to a list index").getLong();
+        try
+        {
             return items.get(normalizeIndex(index, items.size()));
         }
+        catch (ArithmeticException are)
+        {
+            if (items.isEmpty()) return Value.NULL;
+            throw are;
+        }
+    }
 
     @Override
     public boolean has(Value where)