bug#18712: 24.3; IELM fails to move point in a working buffer that is also displayed

[Josh]

On Tue, Oct 14, 2014 at 11:53 AM, Stefan Monnier <monnier@iro.umontreal.ca> wrote:

> Is this a bug?

No, but it's a common trap.  Every buffer has as many "points" as it has
windows displaying it (plus one for the buffer itself).
So if you want to move point in a specific window, you need to either
select the window before moving, or use `set-window-point'.

What would be involved in implementing something like a 

`ielm-change-working-window-buffer' that behaved as the OP 

expected?