Null pointer deref in FlushAllOutput with 1.19-rc1 ?

[Hans de Goede]

Hi All,

Multiple Fedora 25 users running 1.19-rc1 are reporting a backtrace
related to an InitFonts -> SendErrorToClient -> FlushAllOutput
call chain.

Since there is no trivial reproducer this is somewhat hard to debug,
hence this mail. Anyone have a clue / hint ?  See:

https://bugzilla.redhat.com/show_bug.cgi?id=1382444

Regards,

Hans