OAK-9709: PropertyDelegate.isProtected() throws NPE when parent is stale

oak-jcr/src/main/java/org/apache/jackrabbit/oak/jcr/delegate/PropertyDelegate.java

@@ -92,16 +92,20 @@ public Status getStatus() {
 
     @Override
     public boolean isProtected() throws InvalidItemStateException {
-        return getParent().isProtected(name);
+        NodeDelegate p = getParent();
+        if (p != null) {
+            return p.isProtected(name);
+        } else {
+            throw newInvalidItemStateException();
+        }
     }
 
     @NotNull
     public PropertyState getPropertyState() throws InvalidItemStateException {
         if (state != null) {
             return state;
         } else {
-            throw new InvalidItemStateException(
-                    "The " + name + " property does not exist");
+            throw newInvalidItemStateException();
         }
     }
 
@@ -160,4 +164,8 @@ public String toString() {
                 .toString();
     }
 
+    private InvalidItemStateException newInvalidItemStateException() {
+        return new InvalidItemStateException(
+                "The " + name + " property does not exist");
+    }
 }

oak-jcr/src/test/java/org/apache/jackrabbit/oak/jcr/delegate/PropertyDelegateTest.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.jackrabbit.oak.jcr.delegate;
+
+import javax.jcr.InvalidItemStateException;
+
+import org.apache.jackrabbit.oak.api.Tree;
+import org.junit.Test;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class PropertyDelegateTest extends AbstractDelegatorTest {
+
+    @Test(expected = InvalidItemStateException.class)
+    public void isProtectedOnStaleParent() throws InvalidItemStateException {
+        SessionDelegate sd = mockSessionDelegate();
+        Tree t = mock(Tree.class);
+        when(t.exists()).thenReturn(false);
+        PropertyDelegate pd = new PropertyDelegate(sd, t, "p");
+        pd.isProtected();
+    }
+}