fix test failures

Author: kiszk

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

@@ -63,10 +63,11 @@ case class BoundReference(ordinal: Int, dataType: DataType, nullable: Boolean)
     val value = ctx.getValue(ctx.INPUT_ROW, dataType, ordinal.toString)
     if (ctx.currentVars != null && ctx.currentVars(ordinal) != null) {
       val oev = ctx.currentVars(ordinal)
-      ev.isNull = if (!nullable || ctx.INPUT_ROW == null) {
+      ev.isNull = if (!nullable || oev.isNull != "false" || ctx.INPUT_ROW == null) {
         oev.isNull
       } else {
-        s"((${oev.isNull}) || ${ctx.INPUT_ROW}.isNullAt($ordinal))"
+        // generate nullcheck if inputvalue is non-null and its expression is nullable
+        s"${ctx.INPUT_ROW}.isNullAt($ordinal)"
       }
       ev.value = oev.value
       val code = oev.code