Index: ql/src/test/results/clientpositive/udf_acos.q.out IDEA additional info: Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP <+>US-ASCII =================================================================== --- ql/src/test/results/clientpositive/udf_acos.q.out (date 1501289763000) +++ ql/src/test/results/clientpositive/udf_acos.q.out (revision ) @@ -58,4 +58,4 @@ POSTHOOK: type: QUERY POSTHOOK: Input: default@src #### A masked pattern was here #### -NaN +NULL Index: ql/src/java/org/apache/hadoop/hive/ql/udf/UDFAcos.java IDEA additional info: Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP <+>UTF-8 =================================================================== --- ql/src/java/org/apache/hadoop/hive/ql/udf/UDFAcos.java (date 1501289763000) +++ ql/src/java/org/apache/hadoop/hive/ql/udf/UDFAcos.java (revision ) @@ -44,8 +44,13 @@ */ @Override protected DoubleWritable doEvaluate(DoubleWritable a) { - result.set(Math.acos(a.get())); - return result; + double d = a.get(); + if (d < -1 || d > 1) { + return null; + } else { + result.set(Math.acos(d)); + return result; + } } }