Closing Connection closes associated XAConnection

Since upgrading to 3.5.0 we're seeing that calling

Connction c = xaConnection.getConnection();

/* ... */

c.close();

causes the physical connection to be closed. Subsequent calls to xaConnection.getConnection() return a connection in a closed state.

It's clear from the documentation of PooledConnection that the physical connection is not closed until xaConnection.close() is called.