Index: sql_table.cc
===================================================================
--- sql_table.cc	(revision 21155)
+++ sql_table.cc	(working copy)
@@ -5973,6 +5973,9 @@
 
   switch (keys_onoff) {
   case ENABLE:
+    VOID(pthread_mutex_lock(&LOCK_open));
+    wait_while_table_is_used(thd, table, HA_EXTRA_FORCE_REOPEN);
+    VOID(pthread_mutex_unlock(&LOCK_open));
     error= table->file->ha_enable_indexes(HA_KEY_SWITCH_NONUNIQ_SAVE);
     break;
   case LEAVE_AS_IS:
@@ -5980,6 +5983,9 @@
       break;
     /* fall-through: disabled indexes */
   case DISABLE:
+    VOID(pthread_mutex_lock(&LOCK_open));
+    wait_while_table_is_used(thd, table, HA_EXTRA_FORCE_REOPEN);
+    VOID(pthread_mutex_unlock(&LOCK_open));
     error= table->file->ha_disable_indexes(HA_KEY_SWITCH_NONUNIQ_SAVE);
   }
 
@@ -7231,9 +7237,6 @@
   }
   else
   {
-    VOID(pthread_mutex_lock(&LOCK_open));
-    wait_while_table_is_used(thd, table, HA_EXTRA_FORCE_REOPEN);
-    VOID(pthread_mutex_unlock(&LOCK_open));
     thd_proc_info(thd, "manage keys");
     alter_table_manage_keys(table, table->file->indexes_are_disabled(),
                             alter_info->keys_onoff);