Index: lucene/backwards/src/test/org/apache/lucene/store/MockRAMDirectory.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/store/MockRAMDirectory.java	(revision 1040312)
+++ lucene/backwards/src/test/org/apache/lucene/store/MockRAMDirectory.java	(working copy)
@@ -47,6 +47,9 @@
   private Set<String> unSyncedFiles;
   private Set<String> createdFiles;
   volatile boolean crashed;
+  
+  // BACKWARDS-HACK: make the change in branch_3x be compatible with backwards
+  Map<String,RAMFile> fileMap;
 
   // NOTE: we cannot initialize the Map here due to the
   // order in which our constructor actually does this
@@ -54,7 +57,15 @@
   // like super is called, then our members are initialized:
   Map<String,Integer> openFiles;
 
+  @SuppressWarnings("unchecked")
   private synchronized void init() {
+    // BACKWARDS-HACK: make the change in branch_3x be compatible with backwards
+    try {
+      fileMap = (Map<String,RAMFile>) RAMDirectory.class.getDeclaredField("fileMap").get(this);
+    } catch (Exception e) {
+      throw new RuntimeException("Inavlid backwards hack", e);
+    }
+    // end BACKWARDS-HACK
     if (openFiles == null)
       openFiles = new HashMap<String,Integer>();
     if (createdFiles == null)