--- a/jdk/src/share/classes/javax/swing/ScrollPaneLayout.java	Fri Apr 11 16:25:17 2008 +0400
+++ b/jdk/src/share/classes/javax/swing/ScrollPaneLayout.java	Mon Apr 14 16:41:00 2008 +0400
@@ -488,10 +488,14 @@
         Dimension viewSize = null;
         Component view = null;
 
-        if (viewport !=  null) {
+        if (viewport != null) {
             extentSize = viewport.getPreferredSize();
             view = viewport.getView();
-            viewSize  = view.getPreferredSize();
+            if (view != null) {
+                viewSize = view.getPreferredSize();
+            } else {
+                viewSize = new Dimension(0, 0);
+            }
         }
 
         /* If there's a viewport add its preferredSize.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/swing/JScrollPane/6612531/bug6612531.java	Mon Apr 14 16:41:00 2008 +0400
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * @test
+ * @bug 6612531
+ * @summary Checks that ScrollPaneLayout.preferredLayoutSize() doesn't throw NPE.
+ * @author Mikhail Lapshin
+ * @run main bug6612531
+ */
+
+import javax.swing.*;
+
+public class bug6612531 {
+    public static void main(String[] args) {
+        ScrollPaneLayout c = new ScrollPaneLayout();
+        JViewport vp = new JViewport();
+        c.addLayoutComponent("VIEWPORT", vp);
+        c.preferredLayoutSize(new JScrollPane());
+        System.out.println("Test passed");
+    }
+}