Re: colors messed up after X screen lock (buster with xfce)

["Roland Winkler" <winkler@gnu.org>]

On Sat, Aug 28 2021, Cindy Sue Causey wrote:
> On 8/26/21, Roland Winkler <winkler@gnu.org> wrote:
>> I am running debian 10 (buster with xfce).  Graphics works fine
>> initially.  Yet after an X screen lock, all colors are messed up.
>> The same hardware was previoulsy running fine when I was xubuntu 16.04.
>> What can be causing this?  Thanks!
>
> Hi! I don't have an answer as to what's causing it. I just wanted to
> chime in that I think I've probably experienced what you're
> describing. In fact, I did about 2 days ago again, and it's on XFCE4
> here, too.
>
> This has been for both Buster and Bookworm now. It happens when I
> first open the Einstein "card" game.

Interesting! - I thought I want to see what happens with a different
version of the OS.  Now I am yet more curious.  But I'll have to wait a
few days till I'll sit again at the console of that computer.

> The initial screen will fritz then the entire system stays that way if
> I can find the exit button to escape out of Einstein. It's a hard job
> trying to hunt and poke for the right buttons to attempt a safe,
> normal reboot that doesn't harm data any more than necessary.

I "only" need to logout and login (still annoying), but a reboot is not
required.

The whole thing reminds me of old days when some X applications would
use what was called (if I remember correctly) a "private colormap".
Then colors were fine for the application using the private colormap.
But colors for anything else visible on this screen were messed up.  Yet
this problem generally existed only while the application was running
that used the private colormap.  Terminating the application brought
things back to normal.  I cannot remember how many years ago I last
encountered the private-colormap problem.

Here it looks as if the X screen lock used a private colormap that
screws up things after unlocking the screen.  If I go back to a locked
screen, I get back normal colors.  (This game can be repeated multiple
times, as if the X screen lock was holding on to the private colormap
till I logout.  - I am using the default xfce screen lock.)

> The only fix I've been able to find is to reinstall my Debian. 

I have not yet tested a reinstallation.  And right now I do not see a
justification for this either (except for possibly trying a different
version of debian).

I am new to the debian ecosystem.  Is there possibly another mailing
list (say, for xfce) that may be better suited for discussing this?  Or
should I file a bug report (against which package)?

Thanks,

Roland