Fix possible NPEx

src/main/java/org/apache/maven/plugins/dependency/tree/TreeMojo.java

@@ -479,9 +479,12 @@ public static boolean containsVersion( VersionRange allowedRange, ArtifactVersio
                     return true;
                 }
             }
+            return false;
+        }
+        else
+        {
+            // only singular versions ever have a recommendedVersion
+            return recommendedVersion.compareTo( theVersion ) <= 0;
         }
-
-        // only singular versions ever have a recommendedVersion
-        return recommendedVersion.compareTo( theVersion ) <= 0;
     }
 }

src/test/java/org/apache/maven/plugins/dependency/tree/TestTreeMojo_ContainsVersion.java

@@ -0,0 +1,51 @@
+package org.apache.maven.plugins.dependency.tree;
+
+/*
+ * 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.
+ */
+
+import junit.framework.TestCase;
+import org.apache.maven.artifact.versioning.ArtifactVersion;
+import org.apache.maven.artifact.versioning.Restriction;
+import org.apache.maven.artifact.versioning.VersionRange;
+
+import java.util.Collections;
+
+import static org.apache.maven.plugins.dependency.tree.TreeMojo.containsVersion;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * Tests <code>TreeMojo.containsVersion</code>.
+ */
+public class TestTreeMojo_ContainsVersion extends TestCase
+{
+    private VersionRange range = mock( VersionRange.class );
+
+    private ArtifactVersion version = mock( ArtifactVersion.class );
+
+    public void testWhenRecommendedVersionIsNullAndNoRestrictions()
+    {
+        when( range.getRecommendedVersion() ).thenReturn( null );
+        when( range.getRestrictions() ).thenReturn( Collections.<Restriction>emptyList() );
+
+        boolean doesItContain = containsVersion( range, version );
+
+        assertFalse( doesItContain );
+    }
+}