From d918886e50085d2359f38b5404bb2469132dd76c Mon Sep 17 00:00:00 2001
From: mch_ucchi <41606806+sohardforaname@users.noreply.github.com>
Date: Mon, 27 Mar 2023 17:29:14 +0800
Subject: [PATCH] [fix](planner) fix targetTypeDef NPE when value is null
 (#18072)

sql like:
select * from (select *, null as top from v1)t where top = 5;
select * from (select *, null as top from v1)t where top is not null;
will cause NPE because targetTypeDef is null when value is null. Now we use cast target type to the targetTypeDef.
---
 .../java/org/apache/doris/analysis/CastExpr.java  |  6 +++++-
 .../query_p0/literal_view/lietral_test.groovy     | 15 +++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/analysis/CastExpr.java b/fe/fe-core/src/main/java/org/apache/doris/analysis/CastExpr.java
index 486e14ac7228d5..d2cb8ce4421673 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/analysis/CastExpr.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/analysis/CastExpr.java
@@ -417,7 +417,11 @@ public Expr getResultValue(boolean inView) throws AnalysisException {
 
     private Expr castTo(LiteralExpr value) throws AnalysisException {
         if (value instanceof NullLiteral) {
-            return NullLiteral.create(targetTypeDef.getType());
+            if (targetTypeDef != null) {
+                return NullLiteral.create(targetTypeDef.getType());
+            } else {
+                return NullLiteral.create(type);
+            }
         } else if (type.isIntegerType()) {
             return new IntLiteral(value.getLongValue(), type);
         } else if (type.isLargeIntType()) {
diff --git a/regression-test/suites/query_p0/literal_view/lietral_test.groovy b/regression-test/suites/query_p0/literal_view/lietral_test.groovy
index 0307b0fce8bf92..0c5f8bcec0019e 100644
--- a/regression-test/suites/query_p0/literal_view/lietral_test.groovy
+++ b/regression-test/suites/query_p0/literal_view/lietral_test.groovy
@@ -116,4 +116,19 @@ suite("literal_view_test") {
         ) a
         where name != '1234';
     """
+
+    test {
+        sql "select * from (select null as top) t where top is not null"
+        result ([])
+    }
+
+    test {
+        sql "select * from (select null as top) t where top is null"
+        result ([[null]])
+    }
+
+    test {
+        sql "select * from (select null as top) t where top = 5"
+        result ([])
+    }
 }