--- au.c.orig	Sun Mar 21 19:40:43 1999
+++ au.c	Sun Mar 21 19:41:56 1999
@@ -302,6 +302,8 @@
 	wblong(ft, magic);
 
 	/* hdr_size = SUN_HDRSIZE;		 + strlen(ft->comment); */
+	if (ft->comment == NULL)
+		ft->comment = "";
 	hdr_size = SUN_HDRSIZE + strlen(ft->comment);
 	wblong(ft, hdr_size);
 
