Fixed bug mdev-12099.

The function mysql_derived_merge() erroneously did not mark newly formed
AND formulas in ON conditions with the flag abort_on_null. As a result
not_null_tables() calculated incorrectly for these conditions. This
could prevent conversion of embedded outer joins into inner joins.

Changed a test case from table_elim.test to preserve the former execution
plan.

5 files changed, 151 insertions, 4 deletions

diff --git a/mysql-test/r/table_elim.result b/mysql-test/r/table_elim.result
index f475198ac02..4505adab443 100644
--- a/mysql-test/r/table_elim.result
+++ b/mysql-test/r/table_elim.result
@@ -597,7 +597,8 @@ CREATE TABLE t1 (a int(11), b varchar(1)) ;
 INSERT IGNORE INTO t1 VALUES (0,'g');
 CREATE TABLE t3 ( a varchar(1)) ;
 INSERT IGNORE INTO t3 VALUES ('g');
-CREATE TABLE t2 ( a int(11) NOT NULL, PRIMARY KEY (a)) ;
+CREATE TABLE t2 ( a int(11) NOT NULL, PRIMARY KEY (a));
+INSERT INTO t2 VALUES (9), (10);
 create view v1 as SELECT t1.* FROM t1 LEFT JOIN t2 ON ( t1.a = t2.a ) WHERE t2.a <> 0;
 SELECT alias1.* FROM t3 LEFT JOIN v1 as alias1 ON ( t3.a = alias1.b );
 a	b
@@ -606,7 +607,7 @@ EXPLAIN SELECT alias1.* FROM t3 LEFT JOIN v1 as alias1 ON ( t3.a = alias1.b );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t3	system	NULL	NULL	NULL	NULL	1	
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1	Using where
-1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.a	1	Using where; Using index
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.a	1	Using index
 drop view v1;
 DROP TABLE t1,t2,t3;
 #
diff --git a/mysql-test/r/view.result b/mysql-test/r/view.result
index 6848ba30245..414de5662f3 100644
--- a/mysql-test/r/view.result
+++ b/mysql-test/r/view.result
@@ -5535,6 +5535,89 @@ Warnings:
 Warning	1356	View 'test.v1' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
 drop view v1;
 drop table t1,t2;
+#
+# MDEV-12099: usage of mergeable view with LEFT JOIN 
+#             that can be converted to INNER JOIN
+#
+create table t1 (a int, b int, key(a)) engine=myisam;
+insert into t1 values
+(3,20), (7,10), (2,10), (4,30), (8,70), 
+(7,70), (9,100), (9,60), (8,80), (7,60);
+create table t2 (c int, d int, key (c)) engine=myisam;
+insert into t2 values
+(50,100), (20, 200), (10,300),
+(150,100), (120, 200), (110,300),
+(250,100), (220, 200), (210,300);
+create table t3(e int, f int not null, key(e), unique (f)) engine=myisam;
+insert into t3 values
+(100, 3), (300, 5), (400, 4), (300,7),
+(300,2), (600, 13), (800, 15), (700, 14),
+(600, 23), (800, 25), (700, 24);
+create view v1 as
+select * from t2 left join t3 on t3.e=t2.d where t3.f is not null;
+select *
+from t1 left join v1 on v1.c=t1.b 
+where t1.a < 5;
+a	b	c	d	e	f
+2	10	10	300	300	5
+2	10	10	300	300	7
+2	10	10	300	300	2
+3	20	NULL	NULL	NULL	NULL
+4	30	NULL	NULL	NULL	NULL
+select *
+from t1 left join ( t2 left join t3 on t3.e=t2.d )
+on t2.c=t1.b and  t3.f is not null
+where t1.a < 5;
+a	b	c	d	e	f
+2	10	10	300	300	5
+2	10	10	300	300	7
+2	10	10	300	300	2
+3	20	NULL	NULL	NULL	NULL
+4	30	NULL	NULL	NULL	NULL
+explain extended
+select *
+from t1 left join v1 on v1.c=t1.b 
+where t1.a < 5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	a	a	5	NULL	3	100.00	Using index condition
+1	SIMPLE	t2	ref	c	c	5	test.t1.b	2	100.00	Using where
+1	SIMPLE	t3	ref	f,e	e	5	test.t2.d	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`c` AS `c`,`test`.`t2`.`d` AS `d`,`test`.`t3`.`e` AS `e`,`test`.`t3`.`f` AS `f` from `test`.`t1` left join (`test`.`t2` join `test`.`t3`) on(((`test`.`t2`.`c` = `test`.`t1`.`b`) and (`test`.`t3`.`e` = `test`.`t2`.`d`) and (`test`.`t3`.`f` is not null) and (`test`.`t1`.`b` is not null) and (`test`.`t2`.`d` is not null))) where (`test`.`t1`.`a` < 5)
+explain extended
+select *
+from t1 left join ( t2 left join t3 on t3.e=t2.d )
+on t2.c=t1.b and  t3.f is not null
+where t1.a < 5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	a	a	5	NULL	3	100.00	Using index condition
+1	SIMPLE	t2	ref	c	c	5	test.t1.b	2	100.00	Using where
+1	SIMPLE	t3	ref	f,e	e	5	test.t2.d	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`c` AS `c`,`test`.`t2`.`d` AS `d`,`test`.`t3`.`e` AS `e`,`test`.`t3`.`f` AS `f` from `test`.`t1` left join (`test`.`t2` join `test`.`t3`) on(((`test`.`t2`.`c` = `test`.`t1`.`b`) and (`test`.`t3`.`e` = `test`.`t2`.`d`) and (`test`.`t3`.`f` is not null) and (`test`.`t1`.`b` is not null) and (`test`.`t2`.`d` is not null))) where (`test`.`t1`.`a` < 5)
+explain extended
+select *
+from t1 left join v1 on v1.c=t1.b and v1.f=t1.a
+where t1.a < 5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	a	a	5	NULL	3	100.00	Using index condition
+1	SIMPLE	t3	eq_ref	f,e	f	4	test.t1.a	1	100.00	Using where
+1	SIMPLE	t2	ref	c	c	5	test.t1.b	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`c` AS `c`,`test`.`t2`.`d` AS `d`,`test`.`t3`.`e` AS `e`,`test`.`t3`.`f` AS `f` from `test`.`t1` left join (`test`.`t2` join `test`.`t3`) on(((`test`.`t2`.`c` = `test`.`t1`.`b`) and (`test`.`t3`.`f` = `test`.`t1`.`a`) and (`test`.`t2`.`d` = `test`.`t3`.`e`) and (`test`.`t1`.`a` is not null) and (`test`.`t1`.`a` is not null) and (`test`.`t1`.`b` is not null))) where (`test`.`t1`.`a` < 5)
+explain extended
+select *
+from t1 left join ( t2 left join t3 on t3.e=t2.d )
+on t2.c=t1.b and t3.f=t1.a and t3.f is not null
+where t1.a < 5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	a	a	5	NULL	3	100.00	Using index condition
+1	SIMPLE	t3	eq_ref	f,e	f	4	test.t1.a	1	100.00	Using where
+1	SIMPLE	t2	ref	c	c	5	test.t1.b	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`c` AS `c`,`test`.`t2`.`d` AS `d`,`test`.`t3`.`e` AS `e`,`test`.`t3`.`f` AS `f` from `test`.`t1` left join (`test`.`t2` join `test`.`t3`) on(((`test`.`t2`.`c` = `test`.`t1`.`b`) and (`test`.`t3`.`f` = `test`.`t1`.`a`) and (`test`.`t2`.`d` = `test`.`t3`.`e`) and (`test`.`t1`.`a` is not null) and (`test`.`t1`.`a` is not null) and (`test`.`t1`.`b` is not null))) where (`test`.`t1`.`a` < 5)
+drop view v1;
+drop table t1,t2,t3;
 # -----------------------------------------------------------------
 # -- End of 5.5 tests.
 # -----------------------------------------------------------------
diff --git a/mysql-test/t/table_elim.test b/mysql-test/t/table_elim.test
index 24f48206013..717aecb42e2 100644
--- a/mysql-test/t/table_elim.test
+++ b/mysql-test/t/table_elim.test
@@ -534,12 +534,12 @@ INSERT IGNORE INTO t1 VALUES (0,'g');
 CREATE TABLE t3 ( a varchar(1)) ;
 INSERT IGNORE INTO t3 VALUES ('g');
 
-CREATE TABLE t2 ( a int(11) NOT NULL, PRIMARY KEY (a)) ;
+CREATE TABLE t2 ( a int(11) NOT NULL, PRIMARY KEY (a));
+INSERT INTO t2 VALUES (9), (10);
 create view v1 as SELECT t1.* FROM t1 LEFT JOIN t2 ON ( t1.a = t2.a ) WHERE t2.a <> 0;
 
 SELECT alias1.* FROM t3 LEFT JOIN v1 as alias1 ON ( t3.a = alias1.b );
 EXPLAIN SELECT alias1.* FROM t3 LEFT JOIN v1 as alias1 ON ( t3.a = alias1.b );
-
 drop view v1;
 DROP TABLE t1,t2,t3;
 
diff --git a/mysql-test/t/view.test b/mysql-test/t/view.test
index ebd68587a47..aece2000cd4 100644
--- a/mysql-test/t/view.test
+++ b/mysql-test/t/view.test
@@ -5505,6 +5505,66 @@ SHOW CREATE VIEW v1;
 
 drop view v1;
 drop table t1,t2;
+
+--echo #
+--echo # MDEV-12099: usage of mergeable view with LEFT JOIN 
+--echo #             that can be converted to INNER JOIN
+--echo #
+
+create table t1 (a int, b int, key(a)) engine=myisam;
+insert into t1 values
+ (3,20), (7,10), (2,10), (4,30), (8,70), 
+ (7,70), (9,100), (9,60), (8,80), (7,60);
+
+create table t2 (c int, d int, key (c)) engine=myisam;
+insert into t2 values
+  (50,100), (20, 200), (10,300),
+  (150,100), (120, 200), (110,300),
+  (250,100), (220, 200), (210,300);
+  
+create table t3(e int, f int not null, key(e), unique (f)) engine=myisam;
+insert into t3 values
+  (100, 3), (300, 5), (400, 4), (300,7),
+  (300,2), (600, 13), (800, 15), (700, 14),
+  (600, 23), (800, 25), (700, 24); 
+
+create view v1 as
+  select * from t2 left join t3 on t3.e=t2.d where t3.f is not null;
+
+select *
+  from t1 left join v1 on v1.c=t1.b 
+    where t1.a < 5;
+
+select *
+  from t1 left join ( t2 left join t3 on t3.e=t2.d )
+          on t2.c=t1.b and  t3.f is not null
+    where t1.a < 5;
+
+explain extended
+select *
+  from t1 left join v1 on v1.c=t1.b 
+    where t1.a < 5;
+
+explain extended
+select *
+  from t1 left join ( t2 left join t3 on t3.e=t2.d )
+          on t2.c=t1.b and  t3.f is not null
+    where t1.a < 5;
+
+explain extended
+select *
+  from t1 left join v1 on v1.c=t1.b and v1.f=t1.a
+    where t1.a < 5;
+
+explain extended
+select *
+  from t1 left join ( t2 left join t3 on t3.e=t2.d )
+       on t2.c=t1.b and t3.f=t1.a and t3.f is not null
+    where t1.a < 5;
+
+drop view v1;
+drop table t1,t2,t3;
+
 --echo # -----------------------------------------------------------------
 --echo # -- End of 5.5 tests.
 --echo # -----------------------------------------------------------------
diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc
index 44395599961..20fca2de8cf 100644
--- a/sql/sql_derived.cc
+++ b/sql/sql_derived.cc
@@ -446,6 +446,9 @@ bool mysql_derived_merge(THD *thd, LEX *lex, TABLE_LIST *derived)
   {
     Item *expr= derived->on_expr;
     expr= and_conds(expr, dt_select->join ? dt_select->join->conds : 0);
+    if (expr)
+      expr->top_level_item();
+    
     if (expr && (derived->prep_on_expr || expr != derived->on_expr))
     {
       derived->on_expr= expr;