Item_func_like::walk() was ignoring escape_item

in particular, it caused escape_item->is_expensive() property
to be lost instead of being properly propagated up.

mysql-test/r/func_like.result

@@ -302,3 +302,8 @@ select * from (select 1 like 2 escape (1 in (select 1 from t1))) x;
 1 like 2 escape (1 in (select 1 from t1))
 0
 drop table t1;
+create table t1 (f int);
+insert t1 values (1),(2);
+create view v1 as select * from t1 where (1 like 2 escape (3 in (('h', 'b') in (select 'k', 'k' union select 'g', 'j'))) and f >= 0);
+drop view v1;
+drop table t1;

mysql-test/t/func_like.test

@@ -225,3 +225,12 @@ insert into t1 values(1);
 update (select 1 like 2 escape (1 in (select 1 from t1))) x, t1 as d set d.f1 = 1;
 select * from (select 1 like 2 escape (1 in (select 1 from t1))) x;
 drop table t1;
+
+#
+# Item_func_like::walk
+#
+create table t1 (f int);
+insert t1 values (1),(2);
+create view v1 as select * from t1 where (1 like 2 escape (3 in (('h', 'b') in (select 'k', 'k' union select 'g', 'j'))) and f >= 0);
+drop view v1;
+drop table t1;

sql/item_cmpfunc.h

@@ -2013,6 +2013,13 @@ class Item_func_like :public Item_bool_func2
     return this;
   }
 
+  bool walk(Item_processor processor, bool walk_subquery, void *arg)
+  {
+    return walk_args(processor, walk_subquery, arg)
+      ||   escape_item->walk(processor, walk_subquery, arg)
+      ||  (this->*processor)(arg);
+  }
+
   bool find_selective_predicates_list_processor(void *arg);
   
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)