[Openchrome-users] out-of-bounds drawing by screensavers

[Benno Schulenberg]

Bilderbeek, Manuel wrote:
> I saw some screen corruption using some 2D screensavers:
> this is most noticable when running the screensaver menu (I used
> the one in the GNOME menu, but probably xscreensaver-demo will
> show it as well): especially "Critical" draws lines at the left
> of the screen when you move the window over the right edge of the
> screen. So, clipping goes wrong or something.

Confirmed with the 'Lines' screensaver in KDE.

In the Control Center => Appearance & Themes => Screen Saver, choose 
in Flying Things the Lines.  Then watch how in the example window on 
the right some lines get drawn outside of the border.  Or click
Setup and watch it happen in the preview window.  Or click About 
and watch how the popup gets scratched all over.  All this does not 
happen when the vesa driver is used instead of via.

Also in normal full-screen operation of the Lines screensaver, 
sometimes line fragments are drawn on the opposite side of the 
screen when the lines hit the left or right side.

So this is definitely a bug in the clipping stuff of the via driver, 
probably related to the problem with a negative x value that Mark 
Huijgen posted yesterday.

CC'ing Thomas as he's the one who should know most about this stuff.

Benno