On Mar 7, 2025, at 12:22 PM, Stefan Kangas <stefankangas@gmail.com> wrote:

Stefan Monnier <monnier@iro.umontreal.ca> writes:

The following paragraph in the elisp manual section "Miscellaneous System
Events" describes blinding events based on the now obsolete variables
`mouse-wheel-down-event', etc.:

    The ‘wheel-up’ and ‘wheel-down’ events are generated only on some
    kinds of systems.  On other systems, other events like ‘mouse-4’
    and ‘mouse-5’ are used instead.  Portable code should handle both
    ‘wheel-up’ and ‘wheel-down’ events as well as the events specified
    in the variables ‘mouse-wheel-up-event’ and
    ‘mouse-wheel-down-event’, defined in ‘mwheel.el’.  Beware that for
    historical reasons the ‘mouse-wheel-_up_-event’ is the variable
    that holds an event that should be handled similarly to
    ‘wheel-_down_’ and vice versa.

Stefan, WDYT?

To the extent that there are still cases where mouse-4/5 is used,
I guess we can keep that almost unchanged, except to adjust the wording
to indicate what is more normal.  E.g.:

   The ‘wheel-up’ and ‘wheel-down’ events are generated on most systems.
   But in some unusual configurations, other events like ‘mouse-4’
   and ‘mouse-5’ may still be used instead.  Portable code that wants
   to accommodate those cases should handle both
   ‘wheel-up’ and ‘wheel-down’ events as well as the events specified
   in the variables ‘mouse-wheel-up-event’ and
   ‘mouse-wheel-down-event’, defined in ‘mwheel.el’.  Beware that for
   historical reasons the ‘mouse-wheel-_up_-event’ is the variable
   that holds an event that should be handled similarly to
   ‘wheel-_down_’ and vice versa.

?

Would it make sense we say something about what those "unusual
configurations" are?