I intentionally have mouse support disabled in vim, as I find not being able to
select text the same way as in any other terminal screen unergonomic.
However, this has an annoying problem as a libvte / gnome-terminal user: the
terminal, on switching to an “alternate screen” application like vim that has
mouse support disabled, “helpfully” maps scroll wheel events to arrow up/down
events.
This is possibly fine, except I use the scroll wheel click as middle-button paste, and I’m constantly accidentally pasting something in the wrong place as a result.
This is unfixable from within vim, since it only sees normal arrow key
presses (not ScrollWheelUp and so on).
However, you can turn this off in libvte, by the magic escape sequence:
echo -ne '\e[?1007l'
Also known as XTERM_ALTBUF_SCROLL. This is mentioned in passing in this
ticket.
Documentation in general is - at best - sparse, but you can always go to the
source.