Forward port references to AccessController in VirtualMethod (#12308)

lucene/core/src/java/org/apache/lucene/util/VirtualMethod.java

@@ -17,6 +17,8 @@
 package org.apache.lucene.util;
 
 import java.lang.reflect.Method;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
@@ -49,13 +51,20 @@
  *
  * <pre class="prettyprint">
  *  final boolean isDeprecatedMethodOverridden =
- *   oldMethod.getImplementationDistance(this.getClass()) &gt; newMethod.getImplementationDistance(this.getClass());
+ *   AccessController.doPrivileged((PrivilegedAction&lt;Boolean&gt;) () -&gt;
+ *    (oldMethod.getImplementationDistance(this.getClass()) &gt; newMethod.getImplementationDistance(this.getClass())));
  *
  *  <em>// alternatively (more readable):</em>
  *  final boolean isDeprecatedMethodOverridden =
- *   VirtualMethod.compareImplementationDistance(this.getClass(), oldMethod, newMethod) &gt; 0
+ *   AccessController.doPrivileged((PrivilegedAction&lt;Boolean&gt;) () -&gt;
+ *    VirtualMethod.compareImplementationDistance(this.getClass(), oldMethod, newMethod) &gt; 0);
  * </pre>
  *
+ * <p>It is important to use {@link AccessController#doPrivileged(PrivilegedAction)} for the actual
+ * call to get the implementation distance because the subclass may be in a different package. The
+ * static constructors do not need to use {@code AccessController} because it just initializes our
+ * own method reference. The caller should have access to all declared members in its own class.
+ *
  * <p>{@link #getImplementationDistance} returns the distance of the subclass that overrides this
  * method. The one with the larger distance should be used preferable. This way also more
  * complicated method rename scenarios can be handled (think of 2.9 {@code TokenStream}