8003830: NPE at BasicTreeUI$Actions.page:4470

Reviewed-by: serb, alexsch
Contributed-by: NJaroslav Tulach <jaroslav.tulach@oracle.com>

src/share/classes/javax/swing/plaf/basic/BasicTreeUI.java

@@ -4479,27 +4479,28 @@ public class BasicTreeUI extends TreeUI
                     }
                 }
                 Rectangle            newRect = ui.getPathBounds(tree, newPath);
+                if (newRect != null) {
+                    newRect.x = visRect.x;
+                    newRect.width = visRect.width;
+                    if(direction == -1) {
+                        newRect.height = visRect.height;
+                    }
+                    else {
+                        newRect.y -= (visRect.height - newRect.height);
+                        newRect.height = visRect.height;
+                    }
 
-                newRect.x = visRect.x;
-                newRect.width = visRect.width;
-                if(direction == -1) {
-                    newRect.height = visRect.height;
-                }
-                else {
-                    newRect.y -= (visRect.height - newRect.height);
-                    newRect.height = visRect.height;
-                }
-
-                if(addToSelection) {
-                    ui.extendSelection(newPath);
-                }
-                else if(changeSelection) {
-                    tree.setSelectionPath(newPath);
-                }
-                else {
-                    ui.setLeadSelectionPath(newPath, true);
+                    if(addToSelection) {
+                        ui.extendSelection(newPath);
+                    }
+                    else if(changeSelection) {
+                        tree.setSelectionPath(newPath);
+                    }
+                    else {
+                        ui.setLeadSelectionPath(newPath, true);
+                    }
+                    tree.scrollRectToVisible(newRect);
                 }
-                tree.scrollRectToVisible(newRect);
             }
         }
 

test/javax/swing/JTree/8003830/bug8003830.java

+/*
+ * Copyright (c) 2012, 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.
+ */
+
+import java.awt.EventQueue;
+import java.awt.Rectangle;
+import java.awt.event.ActionEvent;
+import javax.swing.JTree;
+import javax.swing.plaf.basic.BasicTreeUI;
+import javax.swing.tree.TreePath;
+
+
+/* Originally reported as NetBeans bug 222081.
+ *
+ * @test
+ * @bug 8003830
+ * @summary NullPointerException in BasicTreeUI.Actions when getPathBounds returns null
+ * @author Jaroslav Tulach
+ * @run main bug8003830
+ */
+
+public class bug8003830 implements Runnable {
+    public static void main(String[] args) throws Exception {
+        EventQueue.invokeAndWait(new bug8003830());
+    }
+    @Override
+    public void run() {
+        testNPEAtActionsPage();
+    }
+
+    public void testNPEAtActionsPage() {
+        JTree tree = new JTree();
+        BasicTreeUI ui = new NullReturningTreeUI();
+        tree.setUI(ui);
+        BasicTreeUI.TreePageAction tpa = ui.new TreePageAction(0, "down");
+        tpa.actionPerformed(new ActionEvent(tree, 0, ""));
+    }
+
+    private static final class NullReturningTreeUI extends BasicTreeUI {
+        @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.
+            return null;
+        }
+    }
+}