Comment 1 for bug 389652

The code has never been design to handle values other than 0 or 1. For sure, transition from 1 to 2 and 2 to 1 should fail to update the prefix. Inside the code, the change of value is handle by:

if ( !srv_memcached_enable ) {

This is less than adequate, I will implement a handler for the variable like innodb_memcached_servers.