Address some comments

Author: wangshuo128

sql/core/src/main/scala/org/apache/spark/sql/execution/basicPhysicalOperators.scala

@@ -173,11 +173,7 @@ case class FilterExec(condition: Expression, child: SparkPlan)
     // TODO: revisit this. We can consider reordering predicates as well.
     val generatedIsNotNullChecks = new Array[Boolean](notNullPreds.length)
 
-    val extraIsNotNullReferences = mutable.Set[Attribute]()
-
-    def outputContainsNotNull(ref: Attribute): Boolean = {
-      output.exists { attr => attr.exprId == ref.exprId }
-    }
+    val extraIsNotNullAttrs = mutable.Set[Attribute]()
 
     val generated = otherPreds.map { c =>
       val nullChecks = c.references.map { r =>
@@ -186,8 +182,8 @@ case class FilterExec(condition: Expression, child: SparkPlan)
           generatedIsNotNullChecks(idx) = true
           // Use the child's output. The nullability is what the child produced.
           genPredicate(notNullPreds(idx), input, child.output)
-        } else if (outputContainsNotNull(r) && !extraIsNotNullReferences.contains(r)) {
-          extraIsNotNullReferences += r
+        } else if (notNullAttributes.contains(r.exprId) && !extraIsNotNullAttrs.contains(r)) {
+          extraIsNotNullAttrs += r
           genPredicate(IsNotNull(r), input, child.output)
         } else {
           ""

sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala

@@ -3193,8 +3193,7 @@ class SQLQuerySuite extends QueryTest with SharedSparkSession {
     }
   }
 
-  test("SPARK-29213 Make it consistent when get notnull output and generate null " +
-    "checks in FilterExec") {
+  test("SPARK-29213: FilterExec should not throw NPE") {
     withView("t1", "t2", "t3") {
       sql("select ''").as[String].map(identity).toDF("x").createOrReplaceTempView("t1")
       sql("select * from values 0, cast(null as bigint)")