BUG#28591: make the fix work for BDB tables too:

 - make ha_berkeley::cmp_ref() take into account that auto-generated PKs 
   are stored in LSB-first order. 
 - Remove the temporary code that made the bugfix work for innodb only 

mysql-test/r/bdb.result

@@ -136,8 +136,8 @@ update ignore t1 set id=1023 where id=1010;
 select * from t1 where parent_id=102 order by parent_id,id;
 id	parent_id	level
 1008	102	2
-1010	102	2
 1015	102	2
+1010	102	2
 explain select level from t1 where level=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	level	level	1	const	X	Using index

sql/ha_berkeley.cc

@@ -2646,7 +2646,11 @@ ha_rows ha_berkeley::estimate_rows_upper_bound()
 int ha_berkeley::cmp_ref(const byte *ref1, const byte *ref2)
 {
   if (hidden_primary_key)
-    return memcmp(ref1, ref2, BDB_HIDDEN_PRIMARY_KEY_LENGTH);
+  {
+    ulonglong a=uint5korr((char*) ref1);
+    ulonglong b=uint5korr((char*) ref2);
+    return  a < b ? -1 : (a > b ? 1 : 0);
+  }
 
   int result;
   Field *field;

sql/sql_select.cc

@@ -12033,7 +12033,6 @@ static int test_if_order_by_key(ORDER *order, TABLE *table, uint idx,
       */
       if (!on_primary_key &&
           (table->file->table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
-          table->s->db_type == DB_TYPE_INNODB &&
           table->s->primary_key != MAX_KEY)
       {
         on_primary_key= TRUE;

sql/table.cc

@@ -782,8 +782,7 @@ int openfrm(THD *thd, const char *name, const char *alias, uint db_stat,
 	    if (ha_option & HA_PRIMARY_KEY_IN_READ_INDEX)
             {
 	      field->part_of_key= share->keys_in_use;
-              if (share->db_type == DB_TYPE_INNODB && 
-                  field->part_of_sortkey.is_set(key))
+              if (field->part_of_sortkey.is_set(key))
                 field->part_of_sortkey= share->keys_in_use;
             }
 	  }