MDEV-241 lp:992722 - Server crashes in get_datetime_value

Create an Item_cache based on item's cmp_type, not result_type in 
subselect_engine.

Use result_field in Item_cache_temporal::cache_value(),
just like all other Item_cache*::cache_value() do.

mysql-test/r/in_datetime_241.result

+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 ( a DATE );
+SELECT * FROM t1 WHERE ( SELECT a FROM t1 ) IN ('2012-04-25','2012-04-26');
+a
+DROP TABLE t1;

mysql-test/t/in_datetime_241.test

+#
+# MDEV-241 lp:992722 - Server crashes in get_datetime_value 
+#
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+CREATE TABLE t1 ( a DATE );
+SELECT * FROM t1 WHERE ( SELECT a FROM t1 ) IN ('2012-04-25','2012-04-26');
+DROP TABLE t1;

sql/item.cc

@@ -8329,7 +8329,7 @@ bool  Item_cache_temporal::cache_value()
   value_cached= true;
  
   MYSQL_TIME ltime;
-  if (example->get_date(&ltime, TIME_FUZZY_DATE))
+  if (example->get_date_result(&ltime, TIME_FUZZY_DATE))
     value=0;
   else
     value= pack_time(&ltime);

sql/item_subselect.cc

@@ -2893,7 +2893,7 @@ void subselect_engine::set_row(List<Item> &item_list, Item_cache **row)
     item->decimals= sel_item->decimals;
     item->unsigned_flag= sel_item->unsigned_flag;
     maybe_null= sel_item->maybe_null;
-    if (!(row[i]= Item_cache::get_cache(sel_item)))
+    if (!(row[i]= Item_cache::get_cache(sel_item, sel_item->cmp_type())))
       return;
     row[i]->setup(sel_item);
  //psergey-backport-timours:   row[i]->store(sel_item);