[Mesa-dev] Compiz freezes when screen disconnected - advice needed

[Nikolay Martynov]

Hi.

  I'm seeing an odd behavior of compiz and I need an advice to
identify 'party at fault' and create a proper bug report.

  The problem is as follows: when I disconnect an external screen from
my laptop internal screen blinks, then comes back up with with half of
the content from first screen and half of the content from second
screen. And this image freezes on the screen, although mouse still
moves.

  I do not get any errors in dmesg, but xsession-errors contains this:

------
failed to create drawable
compiz (core) - Warn: glXCreatePixmap failed
compiz (opengl) - Error: FBO is incomplete:
GL::FRAMEBUFFER_INCOMPLETE_ATTACHMENT (0x8cd6)
compiz (opengl) - Error: FBO is incomplete:
GL::FRAMEBUFFER_INCOMPLETE_ATTACHMENT (0x8cd6)
compiz (opengl) - Error: FBO is incomplete:
GL::FRAMEBUFFER_INCOMPLETE_ATTACHMENT (0x8cd6)
------

  Messages that start with 'compiz' obviously come from compiz, but
'failed to create drawable' comes from mesa, right?

  So, I'm trying to figure out if compiz is doing something it
shouldn't or X/mesa is doing something when screen gets disconnected
and confuse compiz.

  So, I would like to kindly ask for advice: what things I should
check to be able to file proper bug report in proper place. I'm
somewhat familiar with gdb but I'm not sure I know where to start
looking.

  I'm running Ubuntu Trusty (Mint, actually) with compiz and mate on
Intel laptop with HD4000 graphics.

  I would really appreciate any help.
  Thanks!

-- 
Martynov Nikolay.
Email: mar.kolya at gmail.com