fixed: fields table was not copied in Item::Function::operator=(...)

src/item.h

@@ -100,6 +100,8 @@ struct Item
 		{
 			is_function = f.is_function;
 			name        = f.name;
+			fields		= f.fields;
+			postfix		= f.postfix;
 			fun_cache   = f.fun_cache;
 			item_block  = f.item_block;
 			base_obj = f.base_obj;