Bug when sending undefined from worker

[AndreasMadsen]

This one make a bug:

var cluster = require('cluster');

if (cluster.isWorker) {
  process.send(undefined);
} else {
  var child = cluster.fork();
}

Result: Unexpected token u

This is because of https://github.com/joyent/node/blob/master/lib/child_process.js#L100. It should also happen when using child_process.fork but it dose not. I suspect it has something to do with the jsonBuffer.

[bnoordhuis]

Thanks for the report, Andreas. It's fixed in 6df7bdd.