Backtrace logging etc. is already sigsafe, but the actual FatalError message
in response is not yet, leading to amusing logs like this:
(EE) Segmentation fault at address 0x0
(EE) BUG: triggered 'if (inSignalContext)'
(EE) BUG: log.c:499 in LogVMessageVerb()
(EE) Warning: attempting to log data in a signal unsafe manner while in
signal context.
Please update to check inSignalContext and/or use LogMessageVerbSigSafe() or
ErrorFSigSafe().
The offending log format message is:
Fatal server error:
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Keith Packard <keithp@keithp.com>