Github user myui commented on a diff in the pull request:
https://github.com/apache/incubator-hivemall/pull/124#discussion_r148200058
--- Diff: core/src/main/java/hivemall/tools/list/UDAFToOrderedList.java ---
@@ -363,6 +363,9 @@ public void merge(@SuppressWarnings("deprecation")
AggregationBuffer agg, Object
throws HiveException {
QueueAggregationBuffer myagg = (QueueAggregationBuffer) agg;
Pair<List<Object>, List<Object>> tuples = myagg.drainQueue();
+ if (tuples == null) {
+ return new ArrayList<Object>();
--- End diff --
should be `return null;`.
---
