diff -r 6daafebf8189 -r edc729e2ee36 src/java.desktop/unix/classes/sun/awt/X11/XMSelection.java
--- a/src/java.desktop/unix/classes/sun/awt/X11/XMSelection.java	Tue Oct 30 17:06:32 2018 +0530
+++ b/src/java.desktop/unix/classes/sun/awt/X11/XMSelection.java	Tue Oct 30 15:51:10 2018 -0700
@@ -200,7 +200,7 @@
             if (log.isLoggable(PlatformLogger.Level.FINE)) {
                 log.fine("client messags = " + xce);
             }
-            long timestamp = xce.get_data(0);
+            long timestamp = xce.get_data(0) & 0xFFFFFFFFL;
             long atom = xce.get_data(1);
             long owner = xce.get_data(2);
             long data = xce.get_data(3);