Github user fhueske commented on a diff in the pull request: https://github.com/apache/flink/pull/5241#discussion_r160442930 --- Diff: flink-libraries/flink-table/src/test/scala/org/apache/flink/table/runtime/batch/sql/SetOperatorsITCase.scala --- @@ -278,7 +278,14 @@ class SetOperatorsITCase( TestBaseUtils.compareResultAsText(results.asJava, expected) } + /** + * This test will checks IN for NULLs based on whether COUNT (*) and COUNT (a) are equal. Due to + * [[org.apache.flink.table.plan.rules.dataSet.DataSetAggregateWithNullValuesRule]] will + * union a NULL row in to input DataSet for non-groupBy agg. That caused COUNT (*) and COUNT(a) + * are not equal. So this test case ignored before FLINK-8355 be fixed. --- End diff -- It is correct, that the current state does not work for all queries and input data. There is a bug that needs to be fixed. However, it is working correctly for the *given* test. The test is correct and is now failing due to this PR. Hence it causes a regression. Your changes fix a bug but introduce another one.
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