Make QGLFramebufferObject crash-proof if QGLContext destroyed first

Sometimes it isn't possible to arrange for the QGLFramebufferObject
to be destroyed before the QGLContext group in which it was created.
Especially during application shutdown or in applications with
multiple shared contexts.

This change modifies QGLFramebufferObject to use QGLSharedResourceGuard,
which ensures that when the last QGLContext in a sharing group is
destroyed, any remaining FBO's will revert to !isValid().  It is now
safe to destroy the context before the FBO, or the FBO before the context.

Unit test included.

Reviewed-by: Sarah Smith

0 files changed, 0 insertions, 0 deletions