title: MongoDB eval() with arguments
body: <p>I'm getting a strange result when trying to use <code>eval</code> with the <code>args</code> argument.  The following works fine:</p>
  
  <pre><code>&gt; db.eval(function(coll) {
    var res = db[coll].find({});
    return(res.count());
  }, ['KenColl'])
  1438
  </code></pre>
  
  <p>But when I pass a second argument, I always get empty results, even if I don't use it:</p>
  
  <pre><code>&gt; db.eval(function(coll, query) {
    var res = db[coll].find({});
    return(res.count());
  }, ['KenColl', {}])
  0
  </code></pre>
  
  <p>Am I misunderstanding something about <code>eval</code> and <code>args</code>?  I'm running version 2.4.3 of both <code>mongod</code> and the <code>MongoDB</code> shell.</p>