hi, Kristian:
This patch block the startup of desktop-shell client in weston.
Panel surface and background surface share a common context.
First when client redraw panel surface, _mesa_make_current will set
brw->ctx.ViewportInitialized to true.
Later when client redraw background surface
Commit 05da4a7a5e7d5bd988cb31f94ed8e1f053d9ee39 attempts to eliminate the
call to intel_update_renderbuffer() in the case where we already have a
drawbuffer for the drawable. Unfortunately this only checks the
back left renderbuffer, which breaks in case of single buffer drawables.
This means tha
