$NetBSD: patch-ag,v 1.1 1998/11/29 23:39:30 sommerfe Exp $

--- AsyncIO.c	Thu May  2 02:51:00 1996
+++ /tmp/AsyncIO.c	Sun Nov 29 18:28:44 1998
@@ -320,6 +320,7 @@
 		abort();
 	}
 	if (stackp++ == 0) {
+		sigemptyset(&set);
 		sigaddset(&set, SIGIO);
 		sigprocmask(SIG_BLOCK, &set, 0);
 	}
@@ -335,6 +336,7 @@
 		abort();
 	}
 	if (--stackp == 0) {
+		sigemptyset(&set);
 		sigaddset(&set, SIGIO);
 		sigprocmask(SIG_UNBLOCK, &set, 0);
 	}