Index: src/main/java/org/apache/jackrabbit/oak/segment/file/FileStore.java
===================================================================
--- src/main/java/org/apache/jackrabbit/oak/segment/file/FileStore.java	(revision 1765406)
+++ src/main/java/org/apache/jackrabbit/oak/segment/file/FileStore.java	(working copy)
@@ -379,6 +379,9 @@
     }
 
     public void flush() throws IOException {
+        if (revisions == null) {
+            return;
+        }
         revisions.flush(new Callable<Void>() {
             @Override
             public Void call() throws Exception {
Index: src/main/java/org/apache/jackrabbit/oak/segment/file/TarRevisions.java
===================================================================
--- src/main/java/org/apache/jackrabbit/oak/segment/file/TarRevisions.java	(revision 1765406)
+++ src/main/java/org/apache/jackrabbit/oak/segment/file/TarRevisions.java	(working copy)
@@ -195,7 +195,9 @@
      * @throws IOException
      */
     public void flush(@Nonnull Callable<Void> persisted) throws IOException {
-        checkBound();
+        if (head.get() == null) {
+            return;
+        }
         if (flushLock.tryLock()) {
             try {
                 RecordId before = persistedHead.get();