Bug#52124 memory leaks like a sieve in datetime, timestamp, time, date fields + warnings

Arg_comparator initializes 'comparators' array in case of
ROW comparison and does not free this array on destruction.
It leads to memory leaks.
The fix:
-added Arg_comparator::cleanup() method which frees
 'comparators' array.
-added Item_bool_func2::cleanup() method which calls 
 Arg_comparator::cleanup() method

mysql-test/r/ps.result

@@ -2988,4 +2988,17 @@ select @plaintext;
 bcd
 deallocate prepare encode;
 deallocate prepare decode;
+#
+# Bug#52124 memory leaks like a sieve in datetime, timestamp, time, date fields + warnings
+#
+CREATE TABLE t1 (a DATETIME NOT NULL, b TINYINT);
+INSERT INTO t1 VALUES (0, 0),(0, 0);
+PREPARE stmt FROM "SELECT 1 FROM t1 WHERE
+ROW(a, b) >= ROW('1', (SELECT 1 FROM t1 WHERE a > 1234))";
+EXECUTE stmt;
+1
+EXECUTE stmt;
+1
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
 End of 5.1 tests.

mysql-test/r/row.result

@@ -457,3 +457,12 @@ abc	1	abc	1
 select host,user from mysql.user where (host,user) = ('localhost','test');
 host	user
 drop table t1,t2;
+#
+# Bug#52124 memory leaks like a sieve in datetime, timestamp, time, date fields + warnings
+#
+CREATE TABLE t1 (a DATETIME NOT NULL, b TINYINT);
+INSERT INTO t1 VALUES (0, 0),(0, 0);
+SELECT 1 FROM t1 WHERE ROW(a, b) >=
+ROW('1', (SELECT 1 FROM t1 WHERE a > 1234));
+1
+DROP TABLE t1;

mysql-test/t/ps.test

@@ -3065,4 +3065,18 @@ select @plaintext;
 deallocate prepare encode;
 deallocate prepare decode;
 
+--echo #
+--echo # Bug#52124 memory leaks like a sieve in datetime, timestamp, time, date fields + warnings
+--echo #
+CREATE TABLE t1 (a DATETIME NOT NULL, b TINYINT);
+INSERT INTO t1 VALUES (0, 0),(0, 0);
+PREPARE stmt FROM "SELECT 1 FROM t1 WHERE
+ROW(a, b) >= ROW('1', (SELECT 1 FROM t1 WHERE a > 1234))";
+--disable_warnings
+EXECUTE stmt;
+EXECUTE stmt;
+--enable_warnings
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
+
 --echo End of 5.1 tests.

mysql-test/t/row.test

@@ -255,3 +255,14 @@ select * from t1,t2 where (a,b) = (c,d);
 
 select host,user from mysql.user where (host,user) = ('localhost','test');
 drop table t1,t2;
+
+--echo #
+--echo # Bug#52124 memory leaks like a sieve in datetime, timestamp, time, date fields + warnings
+--echo #
+CREATE TABLE t1 (a DATETIME NOT NULL, b TINYINT);
+INSERT INTO t1 VALUES (0, 0),(0, 0);
+--disable_warnings
+SELECT 1 FROM t1 WHERE ROW(a, b) >=
+ROW('1', (SELECT 1 FROM t1 WHERE a > 1234));
+--enable_warnings
+DROP TABLE t1;

sql/item_cmpfunc.h

@@ -54,9 +54,9 @@ class Arg_comparator: public Sql_alloc
   /* Allow owner function to use string buffers. */
   String value1, value2;
 
-  Arg_comparator(): thd(0), a_cache(0), b_cache(0), set_null(TRUE),
+  Arg_comparator(): comparators(0), thd(0), a_cache(0), b_cache(0), set_null(TRUE),
     get_value_a_func(0), get_value_b_func(0) {};
-  Arg_comparator(Item **a1, Item **a2): a(a1), b(a2), thd(0),
+  Arg_comparator(Item **a1, Item **a2): a(a1), b(a2), comparators(0), thd(0),
     a_cache(0), b_cache(0), set_null(TRUE),
     get_value_a_func(0), get_value_b_func(0) {};
 
@@ -112,6 +112,11 @@ class Arg_comparator: public Sql_alloc
     return (owner->type() == Item::FUNC_ITEM &&
            ((Item_func*)owner)->functype() == Item_func::EQUAL_FUNC);
   }
+  void cleanup()
+  {
+    delete [] comparators;
+    comparators= 0;
+  }
 
   friend class Item_func;
 };
@@ -365,6 +370,11 @@ class Item_bool_func2 :public Item_int_func
   CHARSET_INFO *compare_collation() { return cmp.cmp_collation.collation; }
   uint decimal_precision() const { return 1; }
   void top_level_item() { abort_on_null= TRUE; }
+  void cleanup()
+  {
+    Item_int_func::cleanup();
+    cmp.cleanup();
+  }
 
   friend class  Arg_comparator;
 };