When xscreensaver is activated any part of window which gets repainted (e.g.spectrum analyzer, web page animation, etc.) is drawn over (into) screensaver picture instead the repaint being hidden below.
This problem has started and spans thru xfce 4.4.x and xorg 7.x. With alternate WM (Beryl) the problem does not appear.
nvidia driver module version: 100.14.19
card: nVIDIA GeForceGo 7600
X Window System Version 7.2.0
Release Date: 22 January 2007
X Protocol Version 11, Revision 0, Release 7.2
Build Operating System: UNKNOWN
Current Operating System: Linux Texoft 2.6.23-ARCH #1 SMP PREEMPT Sat Oct 27 09:04:14 UTC 2007 i686
Build Date: 08 April 2007
composite extensions enabled & in use
After reading the http://bugzilla.xfce.org/show_bug.cgi?id=2476 thread tried disabling the compositor in Advanced WM settings and it makes the problem go away.
Leaving the compositor enabled and disabling the "use direct rendering for fullscreen windows" also get rid of the repainting problem, but the screensaver is transparent now, which is also not desired behavior.
The screensaver is transparent because you set "opacity of popup windows" - Yes, screensaver maps a fullscreen override redirect window on top of others.
Disabling direct rendering for fullscreen windows and setting pop-up windows to opaque solves the problem for me.
However, when direct rendering is enabled and some pop-up windows are somewhat transparent, the screensaver is opaque and the updates are drawn above/into screensaver canvas. This IMO shouldn't happen.
Set pop up windows to opaque. Xscreensaver maps an override redirect window to hide other apps windows, so you must set popup windows to opaque.
the screensaver should be handled diffrent from the other popups with compositor.
It's part of the system somehow.
And a privacy risk if your programs are visible (I was suprised actually seeing this effect, after coming back from lunch).
(In reply to comment #5)
> the screensaver should be handled diffrent from the other popups with
> It's part of the system somehow.
> And a privacy risk if your programs are visible (I was suprised actually seeing
> this effect, after coming back from lunch).
I was likewise surprised when a notification about an update for a Firefox add-on was displayed on blank screen when screen was locked by xscreensaver. I have not come across this with any other screen locker, except xtrlock, which leaves the whole desktop visible deliberately. I am not aware of any general way to set pop-up windows opaque.