join_nested.test, join_nested.result:

  Added a case for bug #4976 when one of the inner tables is empty.
select.result, join.result:
  Reversed the previous change of the erronious fix for bug #4976.
sql_select.cc:
  The previous fix for bug 4976 was reversed as it
  erroniously converted an outer join into an innner join
  when on_expression does not refer to outer tables.
  This is not valid if inner tables return an empty set.
  Setting dependency on outer tables was added for the above cases.
  To fix the crash in the test case of bug #4976  
  a guard was added that blocks running the crashing code for
  nested outer joins.


sql/sql_select.cc:
  The previous fix for bug 4976 was reversed as it
  erroniously converted an outer join into an innner join
  when on_expression does not refer to outer tables.
  This is not valid if inner tables return an empty set.
  Setting dependency on outer tables was added.
  The crash of the test case for bug #4976 was fixed
  adding a guard that blocks running the code for
  nested outer joins.
mysql-test/r/join.result:
  Reversed the previous change of the erronious fix for bug #4976.
mysql-test/r/select.result:
  Reversed the previous change of the erronious fix for bug #4976.
mysql-test/r/join_nested.result:
  Added a case for bug #4976 when one of the inner tables is empty.
mysql-test/t/join_nested.test:
  Added a case for bug #4976 when one of the inner tables is empty.

1 files changed, 98 insertions, 4 deletions

diff --git a/mysql-test/r/join_nested.result b/mysql-test/r/join_nested.result
index 81ca53cb727..09c3e67ae70 100644
--- a/mysql-test/r/join_nested.result
+++ b/mysql-test/r/join_nested.result
@@ -1218,12 +1218,106 @@ INSERT INTO t2 VALUES (NULL), (0), (1), (2), (3), (4), (5), (6), (7), (8), (9),
 INSERT INTO t3 VALUES (0), (1), (2), (3), (4), (5);
 EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON c < 3 and b = c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	index	c	c	5	NULL	6	Using where; Using index
-1	SIMPLE	t2	ref	b	b	5	test.t3.c	2	Using where; Using index
 1	SIMPLE	t1	index	NULL	a	5	NULL	21	Using index
+1	SIMPLE	t3	index	c	c	5	NULL	6	Using index
+1	SIMPLE	t2	ref	b	b	5	test.t3.c	2	Using index
 EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	b	b	5	NULL	3	Using where; Using index
-1	SIMPLE	t3	ref	c	c	5	test.t2.b	2	Using where; Using index
 1	SIMPLE	t1	index	NULL	a	5	NULL	21	Using index
+1	SIMPLE	t3	index	c	c	5	NULL	6	Using index
+1	SIMPLE	t2	ref	b	b	5	test.t3.c	2	Using index
+SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
+a	b	c
+NULL	0	0
+NULL	1	1
+NULL	2	2
+0	0	0
+0	1	1
+0	2	2
+1	0	0
+1	1	1
+1	2	2
+2	0	0
+2	1	1
+2	2	2
+3	0	0
+3	1	1
+3	2	2
+4	0	0
+4	1	1
+4	2	2
+5	0	0
+5	1	1
+5	2	2
+6	0	0
+6	1	1
+6	2	2
+7	0	0
+7	1	1
+7	2	2
+8	0	0
+8	1	1
+8	2	2
+9	0	0
+9	1	1
+9	2	2
+10	0	0
+10	1	1
+10	2	2
+11	0	0
+11	1	1
+11	2	2
+12	0	0
+12	1	1
+12	2	2
+13	0	0
+13	1	1
+13	2	2
+14	0	0
+14	1	1
+14	2	2
+15	0	0
+15	1	1
+15	2	2
+16	0	0
+16	1	1
+16	2	2
+17	0	0
+17	1	1
+17	2	2
+18	0	0
+18	1	1
+18	2	2
+19	0	0
+19	1	1
+19	2	2
+DELETE FROM t3;
+EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	NULL	a	5	NULL	21	Using index
+1	SIMPLE	t3	index	c	c	5	NULL	0	Using index
+1	SIMPLE	t2	ref	b	b	5	test.t3.c	2	Using index
+SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
+a	b	c
+NULL	NULL	NULL
+0	NULL	NULL
+1	NULL	NULL
+2	NULL	NULL
+3	NULL	NULL
+4	NULL	NULL
+5	NULL	NULL
+6	NULL	NULL
+7	NULL	NULL
+8	NULL	NULL
+9	NULL	NULL
+10	NULL	NULL
+11	NULL	NULL
+12	NULL	NULL
+13	NULL	NULL
+14	NULL	NULL
+15	NULL	NULL
+16	NULL	NULL
+17	NULL	NULL
+18	NULL	NULL
+19	NULL	NULL
 DROP TABLE t1,t2,t3;