Pipeline::cssRewrite() does not rewrite @import 'mystyle.css';

[pamtbaau]

When css_pipeline: true and css_rewrite: true, css files will be merged and minified and stored in /assets. Because of their new location, the urls referenced need to be rewritten.

Method Pipeline:cssRewrite() searches for strings like url('mystyle.css') or url(mystyle.css) and when found they will be rewritten into url('/user/themes/mytheme/css/mystyle.css') and url(/user/themes/mytheme/css/mystyle.css).

This will also work for imports like @import url('mystyle.css');.

Issue

However imports using syntax @import 'mystyle.css';, are equally valid, but are not found by the regex used. These import are not rewritten and therefor have an incorrect url. Because of this, the file will not be imported and an error will be thrown in the console of the browser.

A possible solution

See suggested changes in PR #3750