Less error not handled properly

In the render method:

    less.render(input, lessOpts, function(err, output) {
      if (err) {
        self.emit('error', new Error(err.message + ': ' + err.filename + '(' + err.line + ')'));
      } else {
        self.queue(jsToLoad(output.css));
      }
      output.imports.forEach(function(f) {
        self.emit('file', f);
      });
      self.queue(null);
    });

It properly emits an error event should one occurs, however the code continues to execute resulting in another error upon output.imports.forEach(...) due to output being null. A simple output && output.import... should fix this issue.

Currently we are using this plugin with browserify and gulp. In the case of a less compilation error, the actual error is handled but the null reference error occurs outside of the event system and will result in a crash of the gulp process.

Start at the render method and inspect the less.render callback shown in the issue, especially the error path and subsequent import handling. Reproduce a Less compilation error through the Browserify or gulp usage, then verify the error is handled without a null-reference crash or process termination.