This merge is incomplete and it does not include the review number of
the associated review request. It should have been pushed as a single
commit, because the merged commits were not intended to be published in
their form.
This reverts commit dcba90263069a221a5489b1915c5cf1ca39d090c, reversing
changes made to 50ae07525c7fde07794e7548c3d6e5a69cb1a89d.
Conflicts:
kwin/scene_opengl.cpp
kwin/scene_opengl.h