Fix

Author: maropu

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Projection.scala

@@ -166,6 +166,9 @@ object UnsafeProjection
   }
 }
 
+/**
+ * A projection that could turn UnsafeRow into GenericInternalRow
+ */
 object SafeProjection extends CodeGeneratorWithInterpretedFallback[Seq[Expression], Projection] {
 
   override protected def createCodeGeneratedObject(in: Seq[Expression]): Projection = {

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/UnsafeRowConverterSuite.scala

@@ -609,19 +609,17 @@ class UnsafeRowConverterSuite extends SparkFunSuite with Matchers with PlanTestB
       MapType(StringType, IntegerType),
       MapType(MapType(IntegerType, StringType), MapType(StringType, ShortType)))
 
+    val mapResultRow = convertBackToInternalRow(mapRow, fields4).toSeq(fields4)
+    val mapExpectedRow = mapRow.toSeq(fields4)
     // Since `ArrayBasedMapData` does not override `equals` and `hashCode`,
-    // we need to take care of it to compare rows.
+    // we convert it into the two `Seq`s of keys and values for correct comparisons.
     def toComparable(d: Any): Any = d match {
-      case ar: GenericArrayData =>
-        ar.array.map(toComparable).toSeq
       case map: ArrayBasedMapData =>
         val keys = map.keyArray.array.map(toComparable).toSeq
         val values = map.valueArray.array.map(toComparable).toSeq
         (keys, values)
       case o => o
     }
-    val mapResultRow = convertBackToInternalRow(mapRow, fields4).toSeq(fields4)
-    val mapExpectedRow = mapRow.toSeq(fields4)
     assert(mapResultRow.map(toComparable) === mapExpectedRow.map(toComparable))
 
     // UDT tests