bug#18545: 24.4.50: Bug - forward-line inside with-selected-window

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> Why does
>> (with-selected-window (get-buffer-window "*Completions*")
>> (recenter 5))
>> require an explicit call to wset_redisplay from recenter, whereas
>> (with-selected-window (get-buffer-window "*Completions*")
>> (forward-line 1))
>> doesn't need an explicit call to wset_redisplay (or bset_redisplay) from
>> forward-line?
> I think that's because forward-line moves point, while recenter
> doesn't.

But I don't see why moving point would help: calling wset_redisplay
should only change the fact that this window is considered for
redisplay, so if it's needed for the recenter case, that means that
without it, the window would not be considered at all, which in turn
should imply that in the forward-line case we wouldn't notice that point
has changed, unless set_point_both ends up calling bset_redisplay
somehow (but I fail to see how).

> But if you'd like to add wset_redisplay to forward-line, I won't
> object.

If it's not needed, I'd rather not add it.


        Stefan