Scroll event forwarding and `ultra-scroll` (and max eval depth)

[jdtsmith]

The default event prompter (embark-keymap-prompter) hard-codes command recognition for various scrolling commands, so e.g. the help indicator popup buffer can be scrolled. Users of ultra-scroll receive errors, because the relevant commands (ultra-scroll and ultra-scroll-mac) are not recognized. It would be good to add those to the list.

Another slightly better option is to look at the event itself and forward if it's a scroll event:

 (guard (let ((sym (event-basic-type last-command-event)))
                     (and (symbolp sym)
                          (string-prefix-p "wheel-" (symbol-name sym)))))

But note, the way the prompter works is problematic for scrolling events. It recursively calls itself! Smooth scrolling can generate a hundred events per second or more, so it takes very little scrolling to reach max-lisp-eval-depth. Perhaps another solution can be found that allows the buffers to be scrolled without needing to intercept and forward events to their handlers?

[4goodapp]

Here is a demo video (hope it may help)

jdtsmith/ultra-scroll#39 (comment)

[minad]

Stack overflow by scrolling - it is a feature. I don't think we can change it since it will break someone's workflow ;)

(@jdtsmith Iirc we had been aware of this issue for years, it did just not matter...)