fix bug for slave..

BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted

BitKeeper/etc/logging_ok

@@ -80,3 +80,4 @@ worm@altair.is.lan
 zak@balfor.local
 zak@linux.local
 zgreant@mysql.com
+vva@genie.(none)

mysys/thr_alarm.c

@@ -688,7 +688,7 @@ bool thr_got_alarm(thr_alarm_t *alrm_ptr)
 void thr_end_alarm(thr_alarm_t *alrm_ptr)
 {
   thr_alarm_t alrm= *alrm_ptr;
-  if (alrm->crono)
+  if (alarm && alrm->crono)
   {
     KillTimer(NULL, alrm->crono);
     alrm->crono = 0;