Bug #45989 take 2 : memory leak after explain encounters an

error in the query.

Fixes a leak after materializing a GROUP BY subquery to a 
temp table when the subquery has a blob column in the SELECT
list.
Fixed by correctly destructing temporary buffers after doing
the conversion.

mysql-test/r/subselect.result

@@ -4602,4 +4602,16 @@ SELECT 1 FROM t1 GROUP BY
 1
 1
 DROP TABLE t1;
+#
+# Bug #45989 take 2 : memory leak after explain encounters an 
+# error in the query
+#
+CREATE TABLE t1(a LONGTEXT);
+INSERT INTO t1 VALUES (repeat('a',@@global.max_allowed_packet));
+INSERT INTO t1 VALUES (repeat('b',@@global.max_allowed_packet));
+EXPLAIN EXTENDED SELECT DISTINCT 1 FROM t1,
+(SELECT DISTINCTROW a AS away FROM t1 GROUP BY a WITH ROLLUP) AS d1  
+WHERE t1.a = d1.a;
+ERROR 42S22: Unknown column 'd1.a' in 'where clause'
+DROP TABLE t1;
 End of 5.1 tests.

mysql-test/t/subselect.test

@@ -3585,4 +3585,21 @@ SELECT 1 FROM t1 GROUP BY
   (SELECT LAST_INSERT_ID() FROM t1 ORDER BY MIN(a) ASC LIMIT 1);
 DROP TABLE t1;
 
+--echo #
+--echo # Bug #45989 take 2 : memory leak after explain encounters an 
+--echo # error in the query
+--echo #
+
+CREATE TABLE t1(a LONGTEXT);
+INSERT INTO t1 VALUES (repeat('a',@@global.max_allowed_packet));
+INSERT INTO t1 VALUES (repeat('b',@@global.max_allowed_packet));
+
+--error ER_BAD_FIELD_ERROR
+EXPLAIN EXTENDED SELECT DISTINCT 1 FROM t1,
+(SELECT DISTINCTROW a AS away FROM t1 GROUP BY a WITH ROLLUP) AS d1  
+WHERE t1.a = d1.a;
+
+DROP TABLE t1;
+
+
 --echo End of 5.1 tests.

sql/sql_select.cc

@@ -5824,6 +5824,8 @@ JOIN::make_simple_join(JOIN *parent, TABLE *tmp_table)
   const_table_map= 0;
   tmp_table_param.field_count= tmp_table_param.sum_func_count=
     tmp_table_param.func_count= 0;
+  if (tmp_table_param.copy_field)
+    delete [] tmp_table_param.copy_field;
   tmp_table_param.copy_field= tmp_table_param.copy_field_end=0;
   first_record= sort_and_group=0;
   send_records= (ha_rows) 0;