Summary:
If an effect renders a window into an offscreen texture, it's very important
that the window ends up in the offscreen render target rather than the default
framebuffer object. However, that might be not the case if the OpenGL
decoration renderer needs to create a texture atlas since the renderer calls
GLTexture::clear() method, which might clobber the current GL_DRAW_FRAMEBUFFER
binding.
Reviewers: #kwin, davidedmundson
Reviewed By: #kwin, davidedmundson
Subscribers: kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D25365
1d362d38fd