Mount and Unmount are both visible for USB devices

The context menu entries "Mount" and "Unmount" for removable devices should be exclusive.

Version: 4.15.3

added 1. Regression 5. Side Pane - Shortcuts labels

Meh, sorry, that one is on me. Looks like gtk_widget_show_all() was to invasive to fix #423 (closed) (b12247c2) :F ... I'll provide a more subtle fix.

closed with commit 96e9cfe1