Merge from branch - possibly avoid null-pointer dereference.

diff --git a/common/discover.c b/common/discover.c
index c11abb9ce2a87b1aae5eb5dada457f823393271b..b11bb095f12cded10d163cdc4610bcfa2833f8e9 100644 (file)
--- a/common/discover.c
+++ b/common/discover.c
@@ -43,7 +43,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: discover.c,v 1.44 2001/06/27 00:29:44 mellon Exp $ Copyright (c) 1995-2001 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: discover.c,v 1.45 2002/06/09 22:49:51 murray Exp $ Copyright (c) 1995-2001 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -407,8 +407,11 @@ void discover_interfaces (state)
                                           name, isc_result_totext (status));
                        tmp -> flags = ir;
                        strncpy (tmp -> name, name, IFNAMSIZ);
-                       interface_reference (&tmp -> next, interfaces, MDL);
-                       interface_dereference (&interfaces, MDL);
+                       if (interfaces) {
+                               interface_reference (&tmp -> next,
+                                                    interfaces, MDL);
+                               interface_dereference (&interfaces, MDL);
+                       }
                        interface_reference (&interfaces, tmp, MDL);
                        interface_dereference (&tmp, MDL);
                        tmp = interfaces;