don't decide on extended keys by DB_TYPE_INNODB, use hton->flags

sql/handler.h

@@ -1076,6 +1076,7 @@ inline LEX_STRING *hton_name(const handlerton *hton)
 #define HTON_TEMPORARY_NOT_SUPPORTED (1 << 6) //Having temporary tables not supported
 #define HTON_SUPPORT_LOG_TABLES      (1 << 7) //Engine supports log tables
 #define HTON_NO_PARTITION            (1 << 8) //You can not partition these tables
+#define HTON_EXTENDED_KEYS           (1 << 9) //supports extended keys
 
 class Ha_trx_info;
 

storage/innobase/handler/ha_innodb.cc

@@ -2234,7 +2234,7 @@ innobase_init(
         innobase_hton->start_consistent_snapshot=innobase_start_trx_and_assign_read_view;
         innobase_hton->flush_logs=innobase_flush_logs;
         innobase_hton->show_status=innobase_show_status;
-        innobase_hton->flags=HTON_NO_FLAGS;
+        innobase_hton->flags=HTON_EXTENDED_KEYS;
         innobase_hton->release_temporary_latches=innobase_release_temporary_latches;
 	innobase_hton->alter_table_flags = innobase_alter_table_flags;
         innobase_hton->kill_query = innobase_kill_query;

storage/xtradb/handler/ha_innodb.cc

@@ -2625,7 +2625,7 @@ innobase_init(
         innobase_hton->start_consistent_snapshot=innobase_start_trx_and_assign_read_view;
         innobase_hton->flush_logs=innobase_flush_logs;
         innobase_hton->show_status=innobase_show_status;
-        innobase_hton->flags=HTON_NO_FLAGS;
+        innobase_hton->flags=HTON_EXTENDED_KEYS;
         innobase_hton->release_temporary_latches=innobase_release_temporary_latches;
 	innobase_hton->alter_table_flags = innobase_alter_table_flags;
         innobase_hton->kill_query = innobase_kill_query;