[Openchrome-users] misplacement of GL viewport -- doubled coordinates

[Benno Schulenberg]

To more precisely describe http://openchrome.org/trac/ticket/91 
(when using Mesa git from after November 10 2006):

Start glxgears, grab the top of the window and slowly move the 
window vertically down.  Notice how the viewport moves twice as 
fast as the window and the gears themselves.

Now slowly move the window horizontally to the right.  The movement 
seems smooth, but every 15 pixels or so the viewport jumps an extra 
15 pixels or so to the right, effectively making the viewport also 
move twice as fast as the window and gears themselves.

In short: Mesa thinks that the window to accelerate is located at 
double the actual coordinates.

I've submitted this as: 
https://bugs.freedesktop.org/show_bug.cgi?id=9965

The relevant diff is:
http://gitweb.freedesktop.org/?p=mesa/mesa.git;a=commitdiff;h=d7815f59134b0fb5cb3b56b72b22ba55002265ac;hp=3ce4adaa8fc0cb067dd9da3f358556490954f776

It all seems to be just a move of the coordinates stuff from the 
via_context to the via_renderbuffer structure... but somewhere 
something must be wrong.

Who has any ideas?

Benno