NSScrollView does not contract to fit document view

I have a custom view in an NSScrollView. You could imagine it to be similar to an NSTableView. This document view can reflow its data, so if the scroll view becomes narrower, the document v开发者_Python百科iew can grow in height.

It all works fine, except that if the scrollview widens, making the document view shorter in height, the scrollers do not update, and there is a big gap under the document view. Note that if the scroll view gets narrower, the document view grows in height, and the NSScrollers ARE correctly updated to adapt.

Is this a feature or a bug? How can I make the scrollers/scroll view adapt to the document view frame?