merge

3 files changed, 111 insertions, 0 deletions

diff --git a/mysql-test/r/join.result b/mysql-test/r/join.result
index 77f73532474..baabf48cb2f 100644
--- a/mysql-test/r/join.result
+++ b/mysql-test/r/join.result
@@ -1063,6 +1063,60 @@ a	b	c	d
 127	NULL	127	NULL
 128	NULL	128	NULL
 DROP TABLE IF EXISTS t1,t2;
+#
+# Bug #42116: Mysql crash on specific query
+#
+CREATE TABLE t1 (a INT);
+CREATE TABLE t2 (a INT);
+CREATE TABLE t3 (a INT, INDEX (a));
+CREATE TABLE t4 (a INT);
+CREATE TABLE t5 (a INT);
+CREATE TABLE t6 (a INT);
+INSERT INTO t1 VALUES (1), (1), (1);
+INSERT INTO t2 VALUES
+(2), (2), (2), (2), (2), (2), (2), (2), (2), (2);
+INSERT INTO t3 VALUES
+(3), (3), (3), (3), (3), (3), (3), (3), (3), (3);
+EXPLAIN
+SELECT * 
+FROM 
+t1 JOIN t2 ON t1.a = t2.a 
+LEFT JOIN 
+(
+(
+t3 LEFT JOIN t4 ON t3.a = t4.a
+) 
+LEFT JOIN 
+(
+t5 LEFT JOIN t6 ON t5.a = t6.a
+) 
+ON t4.a = t5.a
+) 
+ON t1.a = t3.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
+1	SIMPLE	t3	ref	a	a	5	test.t1.a	2	Using index
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	0	
+1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	0	
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	0	
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer
+SELECT * 
+FROM 
+t1 JOIN t2 ON t1.a = t2.a 
+LEFT JOIN 
+(
+(
+t3 LEFT JOIN t4 ON t3.a = t4.a
+) 
+LEFT JOIN 
+(
+t5 LEFT JOIN t6 ON t5.a = t6.a
+) 
+ON t4.a = t5.a
+) 
+ON t1.a = t3.a;
+a	a	a	a	a	a
+DROP TABLE t1,t2,t3,t4,t5,t6;
 End of 5.0 tests.
 CREATE TABLE t1 (f1 int);
 CREATE TABLE t2 (f1 int);
diff --git a/mysql-test/t/join.test b/mysql-test/t/join.test
index 1cd05c8cb65..dbf36dedec8 100644
--- a/mysql-test/t/join.test
+++ b/mysql-test/t/join.test
@@ -730,6 +730,60 @@ SELECT * FROM t1 JOIN t2 ON a=c ORDER BY a;
 
 DROP TABLE IF EXISTS t1,t2;
 
+
+--echo #
+--echo # Bug #42116: Mysql crash on specific query
+--echo #
+CREATE TABLE t1 (a INT);
+CREATE TABLE t2 (a INT);
+CREATE TABLE t3 (a INT, INDEX (a));
+CREATE TABLE t4 (a INT);
+CREATE TABLE t5 (a INT);
+CREATE TABLE t6 (a INT);
+
+INSERT INTO t1 VALUES (1), (1), (1);
+
+INSERT INTO t2 VALUES
+(2), (2), (2), (2), (2), (2), (2), (2), (2), (2);
+
+INSERT INTO t3 VALUES
+(3), (3), (3), (3), (3), (3), (3), (3), (3), (3);
+
+EXPLAIN
+SELECT * 
+FROM 
+  t1 JOIN t2 ON t1.a = t2.a 
+  LEFT JOIN 
+  (
+   (
+    t3 LEFT JOIN t4 ON t3.a = t4.a
+   ) 
+   LEFT JOIN 
+   (
+     t5 LEFT JOIN t6 ON t5.a = t6.a
+   ) 
+   ON t4.a = t5.a
+  ) 
+  ON t1.a = t3.a;
+
+SELECT * 
+FROM 
+  t1 JOIN t2 ON t1.a = t2.a 
+  LEFT JOIN 
+  (
+   (
+    t3 LEFT JOIN t4 ON t3.a = t4.a
+   ) 
+   LEFT JOIN 
+   (
+     t5 LEFT JOIN t6 ON t5.a = t6.a
+   ) 
+   ON t4.a = t5.a
+  ) 
+  ON t1.a = t3.a;
+
+DROP TABLE t1,t2,t3,t4,t5,t6;
+
 --echo End of 5.0 tests.
 
 
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index cd4fe5d494a..3449692e41b 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -8964,7 +8964,10 @@ static void restore_prev_nj_state(JOIN_TAB *last)
       join->cur_embedding_map&= ~last_emb->nested_join->nj_map;
     else if (last_emb->nested_join->join_list.elements-1 ==
              last_emb->nested_join->counter) 
+    {
       join->cur_embedding_map|= last_emb->nested_join->nj_map;
+      break;
+    }
     else
       break;
     last_emb= last_emb->embedding;