[GtkListBox] setting margins result in black areas
Submitted by Marinus Schraal
Created attachment 338388 black margins
With Gtk 3.22 setting margins on a GtkListBox results in black areas.
Easy to reproduce in gtk3-demo with some added css (see attached screenshot).
I also check master from git and gtk4-demo showed just one big black area for ListBox, maybe the same issue?