8004298: NPE in WindowsTreeUI.ensureRowsAreVisible

Reviewed-by: serb

src/share/classes/com/sun/java/swing/plaf/windows/WindowsTreeUI.java

@@ -93,6 +93,11 @@ public class WindowsTreeUI extends BasicTreeUI {
                             counter = endRow;
                         }
                     }
+
+                    if (testRect == null) {
+                        return;
+                    }
+
                     tree.scrollRectToVisible(new Rectangle(visRect.x, beginY, 1,
                                                       testRect.y + testRect.height-
                                                       beginY));

test/javax/swing/JTree/8004298/bug8004298.java

+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8004298
+ * @summary NPE in WindowsTreeUI.ensureRowsAreVisible
+ * @author Alexander Scherbatiy
+ * @library ../../regtesthelpers
+ * @build Util
+ * @run main bug8004298
+ */
+
+import java.awt.*;
+import java.awt.event.InputEvent;
+import javax.swing.*;
+import javax.swing.tree.*;
+import java.util.concurrent.Callable;
+import sun.awt.SunToolkit;
+import com.sun.java.swing.plaf.windows.WindowsLookAndFeel;
+import com.sun.java.swing.plaf.windows.WindowsTreeUI;
+
+public class bug8004298 {
+
+    private static JTree tree;
+
+    public static void main(String[] args) throws Exception {
+        Robot robot = new Robot();
+        robot.setAutoDelay(50);
+        SunToolkit toolkit = (SunToolkit) Toolkit.getDefaultToolkit();
+        UIManager.setLookAndFeel(new WindowsLookAndFeel());
+
+        SwingUtilities.invokeAndWait(new Runnable() {
+
+            @Override
+            public void run() {
+                createAndShowGUI();
+            }
+        });
+
+        toolkit.realSync();
+
+        Point point = Util.invokeOnEDT(new Callable<Point>() {
+
+            @Override
+            public Point call() throws Exception {
+                Rectangle rect = tree.getRowBounds(2);
+                Point p = new Point(rect.x + rect.width / 2, rect.y + rect.height / 2);
+                SwingUtilities.convertPointToScreen(p, tree);
+                return p;
+            }
+        });
+
+        robot.mouseMove(point.x, point.y);
+        robot.mousePress(InputEvent.BUTTON1_MASK);
+        robot.mouseRelease(InputEvent.BUTTON1_MASK);
+        robot.mousePress(InputEvent.BUTTON1_MASK);
+        robot.mouseRelease(InputEvent.BUTTON1_MASK);
+        toolkit.realSync();
+
+    }
+
+    private static void createAndShowGUI() {
+        JFrame frame = new JFrame();
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+        DefaultMutableTreeNode root = new DefaultMutableTreeNode("root");
+        root.add(new DefaultMutableTreeNode("colors"));
+        DefaultMutableTreeNode sports = new DefaultMutableTreeNode("sports");
+        sports.add(new DefaultMutableTreeNode("basketball"));
+        sports.add(new DefaultMutableTreeNode("football"));
+        root.add(sports);
+
+        tree = new JTree(root);
+        tree.setUI(new NullReturningTreeUI());
+
+        frame.getContentPane().add(tree);
+        frame.pack();
+        frame.setVisible(true);
+
+    }
+
+    private static final class NullReturningTreeUI extends WindowsTreeUI {
+
+        @Override
+        public Rectangle getPathBounds(JTree tree, TreePath path) {
+            // the method can return null and callers have to be ready for
+            // that. Simulate the case by returning null for unknown reason.
+            if (path != null && path.toString().contains("football")) {
+                return null;
+            }
+
+            return super.getPathBounds(tree, path);
+        }
+    }
+}
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