From 42271e424013f70534da3e2e84ca55005ac4e92c Mon Sep 17 00:00:00 2001
From: "igor@igor-inspiron.creware.com" <>
Date: Mon, 13 Jun 2005 11:24:26 -0700
Subject: [PATCH 1/2] func_if.result, func_if.test:   Added a test case for bug
 #11142. item_cmpfunc.cc:   Fixed bug #11142.   Implementation of
 Item_func_nullif::is_null was corrected.

---
 mysql-test/r/func_if.result | 27 +++++++++++++++++++++++++++
 mysql-test/t/func_if.test   | 27 +++++++++++++++++++++++++++
 sql/item_cmpfunc.cc         |  4 +---
 3 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/mysql-test/r/func_if.result b/mysql-test/r/func_if.result
index 508a50caf02..dd8f34d53d2 100644
--- a/mysql-test/r/func_if.result
+++ b/mysql-test/r/func_if.result
@@ -86,3 +86,30 @@ drop table t1;
 SELECT NULLIF(5,5) IS NULL, NULLIF(5,5) IS NOT NULL;
 NULLIF(5,5) IS NULL	NULLIF(5,5) IS NOT NULL
 1	0
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 (a CHAR(10));
+INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
+SELECT a, NULLIF(a,'') FROM t1;
+a	NULLIF(a,'')
+aaa	aaa
+NULL	NULL
+	NULL
+bbb	bbb
+SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
+a	NULLIF(a,'')
+NULL	NULL
+	NULL
+DROP TABLE t1;
+CREATE TABLE t1 (a CHAR(10));
+INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
+SELECT a, NULLIF(a,'') FROM t1;
+a	NULLIF(a,'')
+aaa	aaa
+NULL	NULL
+	NULL
+bbb	bbb
+SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
+a	NULLIF(a,'')
+NULL	NULL
+	NULL
+DROP TABLE t1;
diff --git a/mysql-test/t/func_if.test b/mysql-test/t/func_if.test
index 693773b18c8..ae820fae93b 100644
--- a/mysql-test/t/func_if.test
+++ b/mysql-test/t/func_if.test
@@ -60,3 +60,30 @@ drop table t1;
 # Bug #5595  NULLIF() IS NULL returns false if NULLIF() returns NULL
 #
 SELECT NULLIF(5,5) IS NULL, NULLIF(5,5) IS NOT NULL;
+#
+# Test to check evaluation of MULLIF when the first argument is NULL
+# (motivated by the Bug 11142)
+#
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+CREATE TABLE t1 (a CHAR(10));
+INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
+SELECT a, NULLIF(a,'') FROM t1;
+SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
+
+DROP TABLE t1;
+
+#
+# Test for bug #11142: evaluation of NULLIF when the first argument is NULL
+#
+
+CREATE TABLE t1 (a CHAR(10));
+INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
+
+SELECT a, NULLIF(a,'') FROM t1;
+SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
+
+DROP TABLE t1;
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 337ac949d35..3098e5dc77e 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -1161,9 +1161,7 @@ Item_func_nullif::val_str(String *str)
 bool
 Item_func_nullif::is_null()
 {
-  if (!cmp.compare())
-    return (null_value=1);
-  return 0;
+  return (null_value= (!cmp.compare() ? 1 : args[0]->null_value)); 
 }
 
 /*

From 754e6c05274f434211f71be6768524e426809d65 Mon Sep 17 00:00:00 2001
From: "igor@igor-inspiron.creware.com" <>
Date: Mon, 13 Jun 2005 11:38:16 -0700
Subject: [PATCH 2/2] func_if.result, func_if.test:   Correction for test case
 of bug #11142.

---
 mysql-test/r/func_if.result | 14 --------------
 mysql-test/t/func_if.test   | 15 ---------------
 2 files changed, 29 deletions(-)

diff --git a/mysql-test/r/func_if.result b/mysql-test/r/func_if.result
index dd8f34d53d2..2c8f19f1754 100644
--- a/mysql-test/r/func_if.result
+++ b/mysql-test/r/func_if.result
@@ -86,20 +86,6 @@ drop table t1;
 SELECT NULLIF(5,5) IS NULL, NULLIF(5,5) IS NOT NULL;
 NULLIF(5,5) IS NULL	NULLIF(5,5) IS NOT NULL
 1	0
-DROP TABLE IF EXISTS t1;
-CREATE TABLE t1 (a CHAR(10));
-INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
-SELECT a, NULLIF(a,'') FROM t1;
-a	NULLIF(a,'')
-aaa	aaa
-NULL	NULL
-	NULL
-bbb	bbb
-SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
-a	NULLIF(a,'')
-NULL	NULL
-	NULL
-DROP TABLE t1;
 CREATE TABLE t1 (a CHAR(10));
 INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
 SELECT a, NULLIF(a,'') FROM t1;
diff --git a/mysql-test/t/func_if.test b/mysql-test/t/func_if.test
index ae820fae93b..4333defa412 100644
--- a/mysql-test/t/func_if.test
+++ b/mysql-test/t/func_if.test
@@ -60,21 +60,6 @@ drop table t1;
 # Bug #5595  NULLIF() IS NULL returns false if NULLIF() returns NULL
 #
 SELECT NULLIF(5,5) IS NULL, NULLIF(5,5) IS NOT NULL;
-#
-# Test to check evaluation of MULLIF when the first argument is NULL
-# (motivated by the Bug 11142)
-#
-
---disable_warnings
-DROP TABLE IF EXISTS t1;
---enable_warnings
-
-CREATE TABLE t1 (a CHAR(10));
-INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
-SELECT a, NULLIF(a,'') FROM t1;
-SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
-
-DROP TABLE t1;
 
 #
 # Test for bug #11142: evaluation of NULLIF when the first argument is NULL