Undo/Redo not working when editing javascript (.js) files

When I edit one of the javascript (.js) files of my project in the code editor of pinegrow and choose Undo the changes made to the javascript file are not undone. Instead the last change made before editing the javascript file is undone. So basically edits to the javascript file are ignored by pinegrow undo/redo functionallity. This is really irritating.