HBASE-2026 NPE in StoreScanner on compaction

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@894219 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -139,6 +139,7 @@ Release 0.21.0 - Unreleased
                its regions around
    HBASE-2065  Cannot disable a table if any of its region is opening 
                at the same time
+   HBASE-2026  NPE in StoreScanner on compaction
 
   IMPROVEMENTS
    HBASE-1760  Cleanup TODOs in HTable

src/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java

@@ -255,6 +255,7 @@ class StoreScanner implements KeyValueScanner, InternalScanner, ChangedReadersOb
 
     // Reset the state of the Query Matcher and set to top row
     matcher.reset();
-    matcher.setRow(heap.peek().getRow());
+    KeyValue kv = heap.peek();
+    matcher.setRow((kv == null ? topKey : kv).getRow());
   }
 }