fix: withInfo was overwriting information in some cases (apache#780)

* add test for withInfo

* improve test

* Revert whitespace changes

* update test

* format

spark/src/test/scala/org/apache/comet/CometExpressionSuite.scala

@@ -27,6 +27,8 @@ import scala.util.Random
 
 import org.apache.hadoop.fs.Path
 import org.apache.spark.sql.{CometTestBase, DataFrame, Row}
+import org.apache.spark.sql.comet.CometProjectExec
+import org.apache.spark.sql.execution.{ColumnarToRowExec, InputAdapter, WholeStageCodegenExec}
 import org.apache.spark.sql.execution.adaptive.AdaptiveSparkPlanHelper
 import org.apache.spark.sql.functions._
 import org.apache.spark.sql.internal.SQLConf
@@ -634,6 +636,37 @@ class CometExpressionSuite extends CometTestBase with AdaptiveSparkPlanHelper {
     }
   }
 
+  test("withInfo") {
+    val table = "with_info"
+    withTable(table) {
+      sql(s"create table $table(id int, name varchar(20)) using parquet")
+      sql(s"insert into $table values(1,'James Smith')")
+      val query = sql(s"select cast(id as string) from $table")
+      val (_, cometPlan) = checkSparkAnswer(query)
+      val project = cometPlan
+        .asInstanceOf[WholeStageCodegenExec]
+        .child
+        .asInstanceOf[ColumnarToRowExec]
+        .child
+        .asInstanceOf[InputAdapter]
+        .child
+        .asInstanceOf[CometProjectExec]
+      val id = project.expressions.head
+      CometSparkSessionExtensions.withInfo(id, "reason 1")
+      CometSparkSessionExtensions.withInfo(project, "reason 2")
+      CometSparkSessionExtensions.withInfo(project, "reason 3", id)
+      CometSparkSessionExtensions.withInfo(project, id)
+      CometSparkSessionExtensions.withInfo(project, "reason 4")
+      CometSparkSessionExtensions.withInfo(project, "reason 5", id)
+      CometSparkSessionExtensions.withInfo(project, id)
+      CometSparkSessionExtensions.withInfo(project, "reason 6")
+      val explain = new ExtendedExplainInfo().generateExtendedInfo(project)
+      for (i <- 1 until 7) {
+        assert(explain.contains(s"reason $i"))
+      }
+    }
+  }
+
   test("rlike fallback for non scalar pattern") {
     val table = "rlike_fallback"
     withTable(table) {