--- a/jdk/src/java.base/windows/native/libnet/DualStackPlainSocketImpl.c	Fri Sep 04 14:16:34 2015 -0700
+++ b/jdk/src/java.base/windows/native/libnet/DualStackPlainSocketImpl.c	Mon Sep 07 10:37:00 2015 +0200
@@ -45,9 +45,10 @@
     jclass cls = (*env)->FindClass(env, "java/net/InetSocketAddress");
     CHECK_NULL(cls);
     isa_class = (*env)->NewGlobalRef(env, cls);
+    CHECK_NULL(isa_class);
     isa_ctorID = (*env)->GetMethodID(env, cls, "<init>",
                                      "(Ljava/net/InetAddress;I)V");
-
+    CHECK_NULL(isa_ctorID);
     initInetAddressIDs(env);
 
     // implement read timeout with select.