Keyboard input impossible in screensaver, if active window before locking was xfreerdp(v2) or Virtualbox

[sunweaver]

Expected behaviour

When running a remote RDP session via xfreerdp (v2) and then the mate-screensaver kicks it, I'd expect that I'd be able to unlock the session by entering a password. Similarly, I would expect this from a Virtualbox session running in foreground while the screensaver kicks in.

Actual behaviour

When running a remote RDP session via xfreerdp (v2) and then the mate-screensaver kicks it, I cannot type anything into mate-screensaver's password field. Mouse clicks work, but keyboard input is still attached/locked to the underlying FreeRDP session window. Same situation occurs, if Virtualbox is my foreground application when mate-screensaver kicks in.

Steps to reproduce the behaviour

• launch a MATE desktop session
• either: connect to an RDP server using xfreerdp
• or: launch a VirtualBox session
• lock the session so that mate-screensaver kicks in
• try to enter your password to unlock the screensaver

MATE general version

• this bug has been occurring since MATE 1.8 (this was the first version I used)
• it currently occurs with MATE 1.20 from Debian stretch-backports

Package version

• mate-screensaver 1.20.2-1~bpo9+1

Linux Distribution

• Debian

Link to downstream report of your Distribution

• none

[sunweaver]

Feedback from FreeRDP upstream: they do a XGrabKeyboard when the mouse moves into the RDP session window.

Maybe, the screensaver should that, too. To assure, that the keyboard is grabbed by the password dialog field?

[tari01]

@sunweaver

Actually, this is not caused only by the applications you mention. Quite a few "focus grabbing" applications prevent the unlock input field from getting focus. Related to issue #156.