http request .write callback is never called if encoding is specified.

http-stream-test.js

var http = require('http')
  , assert = require('assert')

var port = 1337

var callbackCalled = false

var server = http.createServer(function (req, res) {
  req.pipe(res)
  server.close()
})

server.listen(port, function () {
  var req = http.request({ port: port, method: 'post' })
  req.write('test', 'ascii', function () {
    callbackCalled = true
  })
})

process.on('exit', function () {
  assert(callbackCalled, 'calback was never called')
})