Wrong Custom Action on Toolbar In Certain Circumstances

Reproducer:

1. Create custom action with Directories selected on Appearance tab
2. Add custom action to toolbar
3. Edit custom action and uncheck Directories option
4. Notice that the icon on the toolbar changes to next item in the Configure Toolbar items list, even thought it might not have been previously selected - some variability here depending on position in list.

A little bit of an edge case.

Running latest git version of thunar.