address comment

Author: ulysses-you

sql/core/src/main/scala/org/apache/spark/sql/execution/adaptive/AQEUtils.scala

@@ -62,7 +62,7 @@ object AQEUtils {
   // Analyze the given plan and calculate the required ordering of this plan w.r.t. the
   // user-specified sort.
   def getRequiredOrdering(p: SparkPlan): Seq[SortOrder] = p match {
-    // User-specified repartition is only effective when it's the root node, or under
+    // User-specified sort is only effective when it's the root node, or under
     // Project/Filter/CollectMetrics.
     case f: FilterExec => getRequiredOrdering(f.child)
     case c: CollectMetricsExec => getRequiredOrdering(c.child)

sql/core/src/test/scala/org/apache/spark/sql/execution/adaptive/AdaptiveQueryExecSuite.scala

@@ -2583,6 +2583,8 @@ class AdaptiveQueryExecSuite
       ("key", "key", true),
       ("key, value", "key", true)
     ).foreach { case (project, sort, required) =>
+      // During re-optimize in AQE, the sort will be converted to local relation if it's empty
+      // So this test ensure we will add sort back if it is User-specified
       val (origin, adaptive) = runAdaptiveAndVerifyResult(
         s"""
            |SELECT $project FROM testdata where key < 0 ORDER BY $sort