Don't mangle files that start with the gzip magic bytes. #1307
Description
From mod-pagespeed-discuss thread: https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/mod-pagespeed-discuss/nehDfeYxlTQ/NKWKLLFPCAAJ
A site is using the GD Star Rating plugin, and the CSS for that plugin gets garbled by mod_pagespeed. I suspect this is because the plugin gzips its CSS output but does not give it content-encoding:gzip header. So mod_pagespeed attempts to parse the gzip output as plain CSS and reports lots of encoding warnings.
The output is also broken -- the CSS coming out of mod_pagespeed is not readable.
I think this is the fault of the plugin, but I can't prove it because the download link for the plugin is broken: http://www.gdstarrating.com/index.html . The customer is using GD Star 1.9.22.
As far as I can tell from that site, that whole gd-star system has not had an update in 5 years. However, the problem is avoided by telling mod_pagespeed not to touch it:
ModPagespeedDisallow */gdsr.css.php*