VCS change popup content obscured by scroll bar

IntelliJ 2019.2.3 (but observed in other releases as well)

When I click on the VCS change indicator in the left gutter, I get a popup showing a diff of my local changes vs the most recent VCS revision. This is great, except that the content of the popup is obscured by a horizontal scroll bar:

I can't resize the popup or figure out any way to get the useful part of this popup. Am I missing something?