old JAVA_1_9 still works as expected

src/tests/junit/org/apache/tools/ant/util/JavaEnvUtilsTest.java

@@ -28,6 +28,7 @@ import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assume.assumeTrue;
 
 /**
  * TestCase for JavaEnvUtils.
@@ -138,4 +139,11 @@ public class JavaEnvUtilsTest {
                 JavaEnvUtils.isAtLeastJavaVersion(JavaEnvUtils.getJavaVersion()));
     }
   
+    @Test
+    public void isJavaVersionSupportsBothVersionsOfJava9() {
+        assumeTrue(JavaEnvUtils.isJavaVersion(JavaEnvUtils.JAVA_9));
+        assertTrue("JAVA_1_9 is not considered equal to JAVA_9",
+                JavaEnvUtils.isJavaVersion(JavaEnvUtils.JAVA_1_9));
+    }
+
 }