bug#25474: 26.0.50; Buffer content invisible

[Eli Zaretskii]

> From: "Ivor Durham" <ivor.durham@ivor.cc>
> Cc: <25474@debbugs.gnu.org>
> Date: Thu, 19 Jan 2017 09:05:19 -0800
> 
> Disabling XDBE fixes the problem. Thank you.

Thanks for testing.

Daniel, could you please look into this?  If this is something
specific to this particular X server, and it cannot be fixed/worked
around in Emacs sources, perhaps we need a run-time option to disable
double-buffering for a certain display?