Bug#57688 Assertion `!table || (!table->write_set || bitmap_is_set(table->write_set, field

Lines below which were added in the patch for Bug#56814 cause this crash:

+      if (table->table)
+        table->table->maybe_null= FALSE;

Consider following test case:
--
CREATE TABLE t1(f1 INT NOT NULL);
INSERT INTO t1 VALUES (16777214),(0);

SELECT COUNT(*) FROM t1 LEFT JOIN t1 t2
ON 1 WHERE t2.f1 > 1 GROUP BY t2.f1;

DROP TABLE t1;
--

We set TABLE::maybe_null to FALSE for t2 table
and in create_tmp_field() we create appropriate tmp table field
using create_tmp_field_from_item() function instead of
create_tmp_field_from_field. As a result we have
LONGLONG field. As we have GROUP BY clause we calculate
group buffer length, see calc_group_buffer().
Item from group list which is used for calculation
refer to the field from real tables and have LONG type.
So group buffer length become insufficient for storing of
LONGLONG value. It leads to overwriting of wrong memory
area in do_field_int() function which is called from
end_update().
After some investigation I found out that
create_tmp_field_from_item() is used only for OLAP
grouping and can not be used for common grouping
as it could be an incompatibility between tmp
table fields and group buffer length.
We can not remove create_tmp_field_from_item() call from
create_tmp_field as OLAP needs it and we can not use this
function for common grouping. So we should remove setting
TABLE::maybe_null to FALSE from simplify_joins().
In this case we'll get wrong behaviour of
list_contains_unique_index() back. To fix it we
could use Field::real_maybe_null() check instead of
Field::maybe_null() and add addition check of
TABLE_LIST::outer_join.

mysql-test/r/group_by.result

@@ -1845,4 +1845,14 @@ SELECT SUBSTRING(a,1,10), LENGTH(a) FROM t1 GROUP BY a;
 SUBSTRING(a,1,10)	LENGTH(a)
 1111111111	1300
 DROP TABLE t1;
+#
+# Bug#57688 Assertion `!table || (!table->write_set || bitmap_is_set(table->write_set, field
+#
+CREATE TABLE t1(f1 INT NOT NULL);
+INSERT INTO t1 VALUES (16777214),(0);
+SELECT COUNT(*) FROM t1 LEFT JOIN t1 t2
+ON 1 WHERE t2.f1 > 1 GROUP BY t2.f1;
+COUNT(*)
+2
+DROP TABLE t1;
 # End of 5.1 tests

mysql-test/r/join_outer.result

@@ -1397,4 +1397,34 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 Warnings:
 Note	1003	select straight_join `test`.`jt1`.`f1` AS `f1` from `test`.`t1` `jt6` left join (`test`.`t1` `jt3` join `test`.`t1` `jt4` left join `test`.`t1` `jt5` on(1) left join `test`.`t1` `jt2` on(1)) on((`test`.`jt6`.`f1` and 1)) left join `test`.`t1` `jt1` on(1) where 1
 DROP TABLE t1;
+#
+# Bug#57688 Assertion `!table || (!table->write_set || bitmap_is_set(table->write_set, field
+#
+CREATE TABLE t1 (f1 INT NOT NULL, PRIMARY KEY (f1));
+CREATE TABLE t2 (f1 INT NOT NULL, f2 INT NOT NULL, PRIMARY KEY (f1, f2));
+INSERT INTO t1 VALUES (4);
+INSERT INTO t2 VALUES (3, 3);
+INSERT INTO t2 VALUES (7, 7);
+EXPLAIN SELECT * FROM t1 LEFT JOIN t2 ON t2.f1 = t1.f1
+WHERE t1.f1 = 4
+GROUP BY t2.f1, t2.f2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	PRIMARY	NULL	NULL	NULL	1	Using temporary; Using filesort
+1	SIMPLE	t2	ref	PRIMARY	PRIMARY	4	const	1	Using index
+SELECT * FROM t1 LEFT JOIN t2 ON t2.f1 = t1.f1
+WHERE t1.f1 = 4
+GROUP BY t2.f1, t2.f2;
+f1	f1	f2
+4	NULL	NULL
+EXPLAIN SELECT * FROM t1 LEFT JOIN t2 ON t2.f1 = t1.f1
+WHERE t1.f1 = 4 AND t2.f1 IS NOT NULL AND t2.f2 IS NOT NULL
+GROUP BY t2.f1, t2.f2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	PRIMARY	NULL	NULL	NULL	1	Using filesort
+1	SIMPLE	t2	ref	PRIMARY	PRIMARY	4	const	1	Using where; Using index
+SELECT * FROM t1 LEFT JOIN t2 ON t2.f1 = t1.f1
+WHERE t1.f1 = 4 AND t2.f1 IS NOT NULL AND t2.f2 IS NOT NULL
+GROUP BY t2.f1, t2.f2;
+f1	f1	f2
+DROP TABLE t1,t2;
 End of 5.1 tests

mysql-test/t/group_by.test

@@ -1235,5 +1235,16 @@ SELECT SUBSTRING(a,1,10), LENGTH(a) FROM t1 GROUP BY a;
 SELECT SUBSTRING(a,1,10), LENGTH(a) FROM t1 GROUP BY a;
 DROP TABLE t1;
 
+--echo #
+--echo # Bug#57688 Assertion `!table || (!table->write_set || bitmap_is_set(table->write_set, field
+--echo #
+
+CREATE TABLE t1(f1 INT NOT NULL);
+INSERT INTO t1 VALUES (16777214),(0);
+
+SELECT COUNT(*) FROM t1 LEFT JOIN t1 t2
+ON 1 WHERE t2.f1 > 1 GROUP BY t2.f1;
+
+DROP TABLE t1;
 
 --echo # End of 5.1 tests

mysql-test/t/join_outer.test

@@ -981,4 +981,33 @@ EXPLAIN EXTENDED SELECT STRAIGHT_JOIN jt1.f1 FROM t1 AS jt1
 
 DROP TABLE t1;
 
+--echo #
+--echo # Bug#57688 Assertion `!table || (!table->write_set || bitmap_is_set(table->write_set, field
+--echo #
+
+CREATE TABLE t1 (f1 INT NOT NULL, PRIMARY KEY (f1));
+CREATE TABLE t2 (f1 INT NOT NULL, f2 INT NOT NULL, PRIMARY KEY (f1, f2));
+
+INSERT INTO t1 VALUES (4);
+INSERT INTO t2 VALUES (3, 3);
+INSERT INTO t2 VALUES (7, 7);
+
+EXPLAIN SELECT * FROM t1 LEFT JOIN t2 ON t2.f1 = t1.f1
+WHERE t1.f1 = 4
+GROUP BY t2.f1, t2.f2;
+
+SELECT * FROM t1 LEFT JOIN t2 ON t2.f1 = t1.f1
+WHERE t1.f1 = 4
+GROUP BY t2.f1, t2.f2;
+
+EXPLAIN SELECT * FROM t1 LEFT JOIN t2 ON t2.f1 = t1.f1
+WHERE t1.f1 = 4 AND t2.f1 IS NOT NULL AND t2.f2 IS NOT NULL
+GROUP BY t2.f1, t2.f2;
+
+SELECT * FROM t1 LEFT JOIN t2 ON t2.f1 = t1.f1
+WHERE t1.f1 = 4 AND t2.f1 IS NOT NULL AND t2.f2 IS NOT NULL
+GROUP BY t2.f1, t2.f2;
+
+DROP TABLE t1,t2;
+
 --echo End of 5.1 tests

sql/sql_select.cc

@@ -8832,13 +8832,6 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top)
         that reject nulls => the outer join can be replaced by an inner join.
       */
       table->outer_join= 0;
-      /*
-        Update TABLE::maybe_null field as it could have
-        the value(maybe_null==TRUE) based on the assumption
-        that this join is outer(see setup_table_map() func).
-      */
-      if (table->table)
-        table->table->maybe_null= FALSE;
       if (table->on_expr)
       {
         /* Add on expression to the where condition. */
@@ -13219,6 +13212,8 @@ static bool
 list_contains_unique_index(TABLE *table,
                           bool (*find_func) (Field *, void *), void *data)
 {
+  if (table->pos_in_table_list->outer_join)
+    return 0;
   for (uint keynr= 0; keynr < table->s->keys; keynr++)
   {
     if (keynr == table->s->primary_key ||
@@ -13232,7 +13227,7 @@ list_contains_unique_index(TABLE *table,
            key_part < key_part_end;
            key_part++)
       {
-        if (key_part->field->maybe_null() || 
+        if (key_part->field->real_maybe_null() || 
             !find_func(key_part->field, data))
           break;
       }