Merge branch 'master' into 1.15

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

@@ -227,10 +227,7 @@ public class ListValue extends AbstractListValue implements ContainerValueInterf
         return items;
     }
 
-    public Iterator<Value> iterator()
-    {
-        return items.iterator();
-    }
+    public Iterator<Value> iterator() { return new ArrayList<>(items).iterator(); }
 
     public void extend(List<Value> subList)
     {

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

@@ -30,7 +30,7 @@ public class MapValue extends AbstractListValue implements ContainerValueInterfa
     @Override
     public Iterator<Value> iterator()
     {
-        return map.keySet().iterator();
+        return new ArrayList<>(map.keySet()).iterator();
     }
 
     @Override