From 235a74aef24fb17f9e4c707a00a6907fedb91455 Mon Sep 17 00:00:00 2001
From: Kazuaki Ishizaki <ishizaki@jp.ibm.com>
Date: Tue, 7 Aug 2018 03:56:15 +0900
Subject: [PATCH] use LiteralTrue/LiteralFalse instead of String

---
 .../expressions/codegen/GenerateUnsafeProjection.scala      | 2 +-
 .../spark/sql/catalyst/expressions/stringExpressions.scala  | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateUnsafeProjection.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateUnsafeProjection.scala
index 8f2a5a0dce943..998a675eecc62 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateUnsafeProjection.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateUnsafeProjection.scala
@@ -87,7 +87,7 @@ object GenerateUnsafeProjection extends CodeGenerator[Seq[Expression], UnsafePro
       // For top level row writer, it always writes to the beginning of the global buffer holder,
       // which means its fixed-size region always in the same position, so we don't need to call
       // `reset` to set up its fixed-size region every time.
-      if (inputs.map(_.isNull).forall(_ == "false")) {
+      if (inputs.map(_.isNull).forall(_ == FalseLiteral)) {
         // If all fields are not nullable, which means the null bits never changes, then we don't
         // need to clear it out every time.
         ""
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringExpressions.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringExpressions.scala
index 1838b9fca02db..e1549d3dee539 100755
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringExpressions.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringExpressions.scala
@@ -91,7 +91,7 @@ case class ConcatWs(children: Seq[Expression])
       val args = ctx.freshName("args")
 
       val inputs = strings.zipWithIndex.map { case (eval, index) =>
-        if (eval.isNull != "true") {
+        if (eval.isNull != TrueLiteral) {
           s"""
              ${eval.code}
              if (!${eval.isNull}) {
@@ -123,14 +123,14 @@ case class ConcatWs(children: Seq[Expression])
         child.dataType match {
           case StringType =>
             ("", // we count all the StringType arguments num at once below.
-             if (eval.isNull == "true") {
+             if (eval.isNull == TrueLiteral) {
                ""
              } else {
                s"$array[$idxVararg ++] = ${eval.isNull} ? (UTF8String) null : ${eval.value};"
              })
           case _: ArrayType =>
             val size = ctx.freshName("n")
-            if (eval.isNull == "true") {
+            if (eval.isNull == TrueLiteral) {
               ("", "")
             } else {
               (s"""