Fixed bug #49322.

When not-exists optimization was applied to a table that
happened to be an inner table of two outer joins, one
embedded into another, then setting the match flag for
the embedding outer join on could be skipped. This caused
generation of extra null complemented rows.
Made sure that the match flags are set correctly in all cases
when not-exists optimization is used.  

1 files changed, 40 insertions, 0 deletions

diff --git a/mysql-test/t/join_nested.test b/mysql-test/t/join_nested.test
index 5b07d8966f1..6ae7fb6dfee 100644
--- a/mysql-test/t/join_nested.test
+++ b/mysql-test/t/join_nested.test
@@ -1196,5 +1196,45 @@ SELECT COUNT(*)
 
 DROP TABLE t1,t2,t3,t4,t5;
 
+#
+# BUG#49322: Nested left joins + not-exist optimization
+#
+
+CREATE TABLE t1 (
+  pk int NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  a int DEFAULT NULL,
+  KEY idx(a)
+);
+CREATE TABLE t2 (
+  pk int  NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  a int DEFAULT NULL,
+  KEY idx(a)
+);
+CREATE TABLE t3 (
+  pk int NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  a int DEFAULT NULL,
+  KEY idx(a)
+);
+
+INSERT INTO t1 VALUES 
+  (1,2), (2,7), (3,5), (4,7), (5,5), (6,NULL), (7,NULL), (8,9);
+INSERT INTO t2 VALUES 
+  (1,NULL), (4,2), (5,2), (3,4), (2,8);
+INSERT INTO t3 VALUES
+  (1,9), (2,2), (3,5), (4,2), (5,7), (6,0), (7,5);
+
+SELECT t1.pk, t1.a, t2.pk, t2.a,t3.pk, t3.a 
+  FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t3.a=t2.a) ON t2.a=t1.a;
+
+SELECT t1.pk, t1.a, t2.pk, t2.a,t3.pk, t3.a 
+  FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t3.a=t2.a) ON t2.a=t1.a
+  WHERE t2.pk IS NULL;
+
+SELECT t1.pk, t1.a, t2.pk, t2.a,t3.pk, t3.a 
+  FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t3.a=t2.a) ON t2.a=t1.a
+  WHERE t3.pk IS NULL;
+
+DROP TABLE t1, t2, t3;
+
 --echo End of 5.0 tests