2 files changed, 46 insertions, 0 deletions
diff --git a/mysql-test/r/order_by.result b/mysql-test/r/order_by.result
index 0c72f816c21..4add29a446f 100644
--- a/mysql-test/r/order_by.result
+++ b/mysql-test/r/order_by.result
@@ -1444,6 +1444,27 @@ FROM t3;
 2
 NULL
 DROP TABLE t1, t2, t3;
+#
+# Bug #42760: Select doesn't return desired results when we have null
+# values
+#
+CREATE TABLE t1 (
+a INT,
+c INT,
+UNIQUE KEY a_c (a,c),
+KEY (a));
+INSERT INTO t1 VALUES (1, 10), (2, NULL);
+# Must use ref-or-null on the a_c index
+EXPLAIN
+SELECT 1 AS col FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ref_or_null	a_c,a	a_c	10	const,const	1	Using where
+# Must return 1 row
+SELECT 1 AS col FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
+col
+1
+DROP TABLE t1;
+End of 5.0 tests
 CREATE TABLE t2 (a varchar(32), b int(11), c float, d double, 
 UNIQUE KEY a (a,b,c), KEY b (b), KEY c (c));
 CREATE TABLE t1 (a varchar(32), b char(3), UNIQUE KEY a (a,b), KEY b (b));
diff --git a/mysql-test/t/order_by.test b/mysql-test/t/order_by.test
index ac2bbaaeeac..0b42caa8703 100644
--- a/mysql-test/t/order_by.test
+++ b/mysql-test/t/order_by.test
@@ -867,6 +867,31 @@ SELECT
 DROP TABLE t1, t2, t3;
 
 
+--echo #
+--echo # Bug #42760: Select doesn't return desired results when we have null
+--echo # values
+--echo #
+
+CREATE TABLE t1 (
+  a INT,
+  c INT,
+  UNIQUE KEY a_c (a,c),
+  KEY (a));
+
+INSERT INTO t1 VALUES (1, 10), (2, NULL);
+
+--echo # Must use ref-or-null on the a_c index
+EXPLAIN
+SELECT 1 AS col FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
+--echo # Must return 1 row
+SELECT 1 AS col FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
+
+DROP TABLE t1;
+
+
+--echo End of 5.0 tests
+
+
 #
 # Bug #35206: select query result different if the key is indexed or not
 #