Index: mozilla/security/nss/lib/util/derenc.c
===================================================================
RCS file: /cvsroot/mozilla/security/nss/lib/util/derenc.c,v
retrieving revision 1.2
diff -pU12 -r1.2 mozilla/security/nss/lib/util/derenc.c
--- mozilla/security/nss/lib/util/derenc.c
+++ mozilla/security/nss/lib/util/derenc.c
@@ -115,27 +115,29 @@ header_length(DERTemplate *dtemplate, ui
     if (encode_kind & DER_POINTER) {
 	if (dtemplate->sub != NULL) {
 	    under_kind = dtemplate->sub->kind;
 	    if (universal) {
 		encode_kind = under_kind;
 	    }
 	} else if (universal) {
 	    under_kind = encode_kind & ~DER_POINTER;
 	} else {
 	    under_kind = dtemplate->arg;
 	}
     } else if (encode_kind & DER_INLINE) {
-	under_kind = dtemplate->sub->kind;
-	if (universal) {
-	    encode_kind = under_kind;
+	if (dtemplate->sub != NULL) {
+            under_kind = dtemplate->sub->kind;
+	    if (universal) {
+	        encode_kind = under_kind;
+            }
 	}
     } else if (universal) {
 	under_kind = encode_kind;
     } else {
 	under_kind = dtemplate->arg;
     }
 
     /* This is only used in decoding; it plays no part in encoding.  */
     if (under_kind & DER_DERPTR)
 	return 0;
 
     /* No header at all for an "empty" optional.  */