@alexmurray (cc @security) - please note that just because something doesn’t work today without classic confinement doesn’t mean that classic should be granted. When we say ‘the request for classic is understood’ we’re saying that either a) we know the path forward to make this strict by making changes to snapd or b) this isn’t going to be supported by snapd any time soon. In neither case does this mean that classic will be granted (we have Process for reviewing classic confinement snaps that lists known categories for things we’ve previously discussed; if it is listed in one of those categories, feel free to grant or deny classic but if it is not (like this one), we need to discuss further and make a call, sometimes with an architect). Put another way, we want to drive each classic request to an understanding that it fits one of the categories (adding new ones as they are discussed and fully understood) and if it does not, gather enough information that we can guide changes to snapd or guide the publisher to adjust the snap to work within the system.
In this particular case, it is known this snap will not work without classic today, but xdg-open can be updated to handle other files (see the recent https://github.com/snapcore/snapd/pull/7731#pullrequestreview-362900171). Now, xdg-open doesn’t work on file extensions, it works on URLs. Is there a URL type for F1viewer? Is there a mimetype for .m3u8 that already exists, or does F1viewer need to register a new mimetype?