Created attachment 104473 [details] Screenshot When using some compositor animations such as the workspaces and windows overviews (see screenshot) the screen does not lock. Reproduce: 1) Enter some of those animated full screen window switchers (screenshot), for example by using one of the hot corners (move the mouse pointer to one of the upper screen corners (assuming a vanilla configuration)). The compositor has to be enabled for this. 2) Try to lock the screen (close the laptop lid, trigger the appropriate key combination, etc.) Expected: screen does lock Result: it doesn't Possible dangers of this bug: User closes laptop lid, expects the screen to be locked, goes away. -> Stranger/attacker has access to user account System used: fedora 25, plasma 5.8.6
I'm sorry this is an old conceptional problem of the X11 windowing system. On wayland the problem is fixed. For X11 there is nothing we can do. The situation is for example explained in this blog post by yours truly: https://blog.martin-graesslin.com/blog/2014/05/screenlocker-architecture-in-plasma-next/