Index: src/java/org/apache/lucene/store/RAMDirectory.java
===================================================================
--- src/java/org/apache/lucene/store/RAMDirectory.java	(revision 418794)
+++ src/java/org/apache/lucene/store/RAMDirectory.java	(working copy)
@@ -198,7 +198,8 @@
     };
   }
 
-  /** Closes the store to future operations. */
+  /** Closes the store to future operations, releasing associated memory. */
   public final void close() {
+    files = null;
   }
 }