visionmedia/node-css-parse — pull request #10 by rstacruz (2012-09-01 19:13:04+00:00)
Title: Support unquoted data URLs

Takes care of cases like `background: url(data:image/png;base64,...)`.

It is valid CSS to define URLs without quotes (`url(xxx)`) so the example above is perfectly valid CSS.

For what its worth, I ran into this problem trying to parse Yahoo's CSS.