bug#687: what was changed for mouse wheel? where is this documented?

[Jason Rumney]

Drew Adams wrote:
> Sorry to interject, but which code did you change?
keyboard.c. The only user visible change is that (event-modifiers 
(last-input-event)) after a wheel-up or wheel-down event returns 'click 
in the list of modifiers, where it didn't before, which causes 
mouse-avoidance-mode to ignore the wheel when deciding whether to move 
the mouse pointer.