Re: Can we make set_point_both less expensive?

[Eli Zaretskii]

> Date: Sat, 21 Mar 2015 10:59:28 +0100
> From: martin rudalics <address@hidden>
> CC: address@hidden, address@hidden
> 
>  > This will only work if pre-redisplay-function is called in a way that
>  > guarantees it will catch the position of point after the previous
>  > command.
> 
> This command, I presume.

The command that preceded redisplay.  "This command" is ambiguous.

>  > Another, related, requirement is that we never call
>  > pre-redisplay-function when point is in a position that is not
>  > supposed to be visible by the user.
> 
> Do you mean invisible text here?

No, I mean positions traversed while "this command" is executed.  The
position shown to the user is the last one of those, but how do we
ensure that pre-redisplay-function is never run for those?