Bug#21567: mysqld doesn't react to Ctrl-C when run under GDB even with the --gdb option

Don't block SIGINT (Control-C) when --gdb is passed to mysqld.
Was broken at least on OS X.

(kudos to Mattias Jonsson)

sql/mysqld.cc

@@ -2211,10 +2211,6 @@ static void init_signals(void)
   struct sigaction sa;
   DBUG_ENTER("init_signals");
 
-  if (test_flags & TEST_SIGINT)
-  {
-    my_sigset(thr_kill_signal, end_thread_signal);
-  }
   my_sigset(THR_SERVER_ALARM,print_signal_warning); // Should never be called!
 
   if (!(test_flags & TEST_NO_STACKTRACE) || (test_flags & TEST_CORE_ON_SIGNAL))
@@ -2251,7 +2247,6 @@ static void init_signals(void)
   (void) sigemptyset(&set);
   my_sigset(SIGPIPE,SIG_IGN);
   sigaddset(&set,SIGPIPE);
-  sigaddset(&set,SIGINT);
 #ifndef IGNORE_SIGHUP_SIGQUIT
   sigaddset(&set,SIGQUIT);
   sigaddset(&set,SIGHUP);
@@ -2273,9 +2268,12 @@ static void init_signals(void)
     sigaddset(&set,THR_SERVER_ALARM);
   if (test_flags & TEST_SIGINT)
   {
+    my_sigset(thr_kill_signal, end_thread_signal);
     // May be SIGINT
     sigdelset(&set, thr_kill_signal);
   }
+  else
+    sigaddset(&set,SIGINT);
   sigprocmask(SIG_SETMASK,&set,NULL);
   pthread_sigmask(SIG_SETMASK,&set,NULL);
   DBUG_VOID_RETURN;