Promise not resolved if buffer is null

gistfile1.txt

var shapefile = require('shapefile')

function open (fileName) {
  shapefile.openDbf(fileName)
    .then(source => source.read()
      .then(function log(result) {
        if (result.done) return;
        console.log(result.value);
        return source.read().then(log);
      }))
    .catch(error => console.error('errror!', error.stack));
}