[Interest] Webp files and QMimeType

[René J.V. Bertin]

Hi,

I just discovered that Qt 5.9 mis-identifies webp images as RIFF audio when allowed to determine type from content - and for very obvious reasons.
By Qt 5.12 this issue was addressed, and curiously it didn't exist in Qt 4.8.7 either.

I'm running a few systems that are limited to Qt 5.9, but self-built so if the fix for the issue isn't part of a  complete overhaul I could backport the patch. Grepping around in the code hasn't yet turned up any evident RIFF or Webp-specific code in QtBase though, so I'd appreciate some pointers.

Thanks,
R.