glamor: pixmap FBO may not be allocated (cherry-pick to 1.20)
If _glamor_create_tex()
fails to allocate the FBO because of
GL_OUT_OF_MEMORY error, the pixmap_priv->fbo
is NULL.
However, glamor_get_pixmap_texture()
doesn't actually check whether
the pixmap_priv->fbo
is NULL and will segfault with a NULL pointer
dereference trying to access the pixmap_priv->fbo->tex
.
Signed-off-by: Olivier Fourdan ofourdan@redhat.com Closes: #647 (closed) (Cherry picked from commit 74479a99)