3c4645
@@ -83,7 +83,7 @@
public abstract class BaseRegionObserver implements RegionObserver {
   public InternalScanner preFlushScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> c,
       final Store store, final KeyValueScanner memstoreScanner, final InternalScanner s)
       throws IOException {
-    return null;
+    return s;
   }
 
   @Override
@@ -174,7 +174,7 @@
public abstract class BaseRegionObserver implements RegionObserver {
       final ObserverContext<RegionCoprocessorEnvironment> c, final Store store,
       List<? extends KeyValueScanner> scanners, final ScanType scanType, final long earliestPutTs,
       final InternalScanner s) throws IOException {
-    return null;
+    return s;
   }
 
   @Override
@@ -342,7 +342,7 @@
public abstract class BaseRegionObserver implements RegionObserver {
   public KeyValueScanner preStoreScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> c,
       final Store store, final Scan scan, final NavigableSet<byte[]> targetCols,
       final KeyValueScanner s) throws IOException {
-    return null;
+    return s;
   }
 
   @Override
