uncatchable pool exceptions

If for example, a query with an undefined value is executed on a pool connection, this throws an uncatchable exception that kills the node process. This is because the exception is not happening on the calling "thread".

See line 177 in lib/pool.js

execute(sql, values, cb) {
    // TODO construct execute command first here and pass it to connection.execute
    // so that polymorphic arguments logic is there in one place
    if (typeof values === 'function') {
      cb = values;
      values = [];
    }
    this.getConnection((err, conn) => {
      if (err) {
        return cb(err);
      }
      try {
        conn.execute(sql, values, cb).once('end', () => {
          conn.release();
        });
      } catch (e) {
        conn.release();
        throw e; // <------ How is this going to be caught anywhere ?
      }
    });
  }

Read lib/pool.js around line 177 and trace the execute callback and connection path. Reproduce the issue with a query containing an undefined value; done means the pool error is catchable by the caller and no longer terminates the Node.js process.