- A segfault occured when the function 'kill_server' called
'my_sigset' with signal number 0. 'my_sigset' is a macro which
uses 'sigaction' to install the signal handler with an invalid
signal number will on most platforms return EINVAL but yields
a segfauilt on IRIX 6.5
- The server crash was detected by mysqld_safe and it was restarted although
a shutdown was requested.
- Semantics of kill_server(0) is not known, leaving it intact
include/my_pthread.h:
Check return value from sigaction with a DBUG_ASSERT
Also DBUG_ASSERT if signal number 0 is passed
sql/mysqld.cc:
Don't call my_sigset if signo is 0