Postgres Native bindings Segfault when querying with empty buffer

```js
var pg = require('pg').native;

pg.connect(function(err, client, done) {
  if (err) throw err;

  var c = 'CREATE TABLE IF NOT EXISTS posts (body TEXT)';

  client.query(c, function(err) {
    if (err) throw err;

    c = 'INSERT INTO posts (body) VALUES ($1)';

    var body = new Buffer('foo');
    client.query(c, [body], function(err) {
      if (err) throw err;

      console.log('inserted foo');

      body = new Buffer([]);
      client.query(c, [body], function(err) {
        done();

        if (err) throw err;

        console.log('inserted empty buffer');

        pg.end();
      });
    });
  });
});
```