Web Compatibility Support • Re: httpbrowser-compat.turnstile.workers.dev/ makes Pale Moon crash

34.2.2: Crashes immediately, seemingly while checking Canvas.

I did by chance get an immediate crash on our master branch this morning, and the immediate one seems to be related to doing something weird with simulating range selection with "thumb dragging" (a mobile concept) in a way that would never occur in the real world... so they are doing something really really niche there; but a nullcheck should fix that.