code: function emitReadable(stream) {
  	  var state = stream._readableState;
  	  state.needReadable = false;
  	  if (!state.emittedReadable) {
  	    debug('emitReadable', state.flowing);
  	    state.emittedReadable = true;
  	    if (state.sync) nextTick(emitReadable_, stream);else emitReadable_(stream);
  	  }
  	}
docs: Don't emit readable right away in sync mode, because this can trigger another read() call => stack overflow.  This way, it might trigger a nextTick recursion warning, but that's not so bad.