GitHub started mangling text some months ago and it bugs the hell out of me. It's also completely unnecessary as GitHub already links things like @user, #123, and deadbeef (for commit hashes). I just want to copy the exact literal text I see; why does that need to be hard?

You can set "dom.event.clipboardevents.enabled" in Firefox to disable all of that, but some websites can break horribly because they just assume it's there and will do $weird_shit if it's not. e.g. Twitter and Facebook messenger for example; it's not that you get an error either, it just behaved in really odd ways. It seems Twitter works now in quick test, and I no longer need to use Facebook Messenger, so let's try setting it again.

There's also "clipboard.plainTextOnly", but it doesn't seem to work, or maybe it does something different from what I expect.