Bug#528708: Not completely fixed upstream in 7.4.2

[Daniel Schepler <dschepler@gmail.com>]

I just tried compiling and installing Mesa 7.4.2 (copied the debian/ directory 
from 7.4.1-1 into an unpacked copy of 7.4.2, and added a 7.4.2-0 version to 
debian/changelog).  It does fix the crashes with the Qt OpenGL examples -- 
although with the textures example and a couple others, when I exit I get

Mesa 7.4.2 implementation error: invalid reference to a deleted texture object
Please report at bugzilla.freedesktop.org
textures: main/texobj.c:305: _mesa_reference_texobj: Assertion 
`valid_texture_object(oldTex)' failed.
Aborted

But with the application I'm developing I still get the condition where 
glGetString(GL_VERSION) returns NULL in my override of 
QGLWidget::initializeGL.  I haven't been able to reproduce that condition with 
any small programs trying to replicate the basic setup of the application, and 
wondered if anybody else might have any idea how I could try to see what's 
going on.
-- 
Daniel Schepler