From 05fa552b461d270bae66aed8bd0821237f5ebdcc Mon Sep 17 00:00:00 2001
From: vikram <vikram@Vikrams-MacBook-Pro.local>
Date: Wed, 10 Apr 2019 17:44:40 +0530
Subject: [PATCH] Fixed NPE in FSWindowDataManager

---
 .../org/apache/apex/malhar/lib/wal/FSWindowDataManager.java   | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/library/src/main/java/org/apache/apex/malhar/lib/wal/FSWindowDataManager.java b/library/src/main/java/org/apache/apex/malhar/lib/wal/FSWindowDataManager.java
index f8e6f2d8c1..0d97b31be9 100644
--- a/library/src/main/java/org/apache/apex/malhar/lib/wal/FSWindowDataManager.java
+++ b/library/src/main/java/org/apache/apex/malhar/lib/wal/FSWindowDataManager.java
@@ -484,6 +484,10 @@ private Object retrieve(FSWindowReplayWAL wal, long windowId) throws IOException
 
       if (wal.retrievedWindow == null) {
         wal.retrievedWindow = readNext(reader);
+        if(wal.retrievedWindow == null &&
+           reader.getCurrentPointer().compareTo(wal.walEndPointerAfterRecovery) < 0) {
+          continue;
+        }
         Preconditions.checkNotNull(wal.retrievedWindow);
       }
       currentWindow = Longs.fromByteArray(wal.retrievedWindow.toByteArray());