--- ppp-2.4.5.ori/pppd/main.c	2009-11-16 22:26:07.000000000 +0000
+++ ppp-2.4.5/pppd/main.c	2010-07-10 23:50:45.225155782 +0100
@@ -1571,7 +1571,8 @@
 	/* Executing in the child */
 	sys_close();
 #ifdef USE_TDB
-	tdb_close(pppdb);
+	if (pppdb != NULL)
+		tdb_close(pppdb);
 #endif
 
 	/* make sure infd, outfd and errfd won't get tromped on below */