review fix

Author: yjshen

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

@@ -99,7 +99,7 @@ case class CreateNamedStruct(children: Seq[Expression]) extends Expression {
     StructType(fields)
   }
 
-  override def foldable: Boolean = children.forall(_.foldable)
+  override def foldable: Boolean = valExprs.forall(_.foldable)
 
   override def nullable: Boolean = false
 
@@ -111,7 +111,8 @@ case class CreateNamedStruct(children: Seq[Expression]) extends Expression {
         nameExprs.filterNot(e => e.foldable && e.dataType == StringType && !nullable)
       if (invalidNames.size != 0) {
         TypeCheckResult.TypeCheckFailure(
-          s"Non String Literal fields at odd position : ${invalidNames.mkString(",")}")
+          s"Odd position only allow foldable and not-null StringType expressions, got :" +
+            s" ${invalidNames.mkString(",")}")
       } else {
         TypeCheckResult.TypeCheckSuccess
       }

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/ExpressionTypeCheckingSuite.scala

@@ -165,8 +165,10 @@ class ExpressionTypeCheckingSuite extends SparkFunSuite {
     assertError(
       CreateNamedStruct(Seq("a", "b", 2.0)), "even number of arguments")
     assertError(
-      CreateNamedStruct(Seq(1, "a", "b", 2.0)), "Non String Literal fields")
+      CreateNamedStruct(Seq(1, "a", "b", 2.0)),
+        "Odd position only allow foldable and not-null StringType expressions")
     assertError(
-      CreateNamedStruct(Seq('a.string.at(0), "a", "b", 2.0)), "Non String Literal fields")
+      CreateNamedStruct(Seq('a.string.at(0), "a", "b", 2.0)),
+        "Odd position only allow foldable and not-null StringType expressions")
   }
 }