Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/5140#discussion_r158738627
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/join/JoinAwareCollector.scala
---
@@ -0,0 +1,68 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.table.runtime.join
+
+import org.apache.flink.table.runtime.types.CRow
+import org.apache.flink.types.Row
+import org.apache.flink.util.Collector
+
+/**
+ * Collector to track whether there's a joined result.
+ */
+class JoinAwareCollector extends Collector[Row]{
+
+ private var emitted = false
+ private var emittedThisTurn = false
+ private var innerCollector: Collector[CRow] = _
+ private val cRow: CRow = new CRow()
--- End diff --
explicitly set `change` value of`CRow`
---
