bug#4041: 23.0.92; Emacs 23: buffer point is no longer frame-local

[martin rudalics]

> How inconvenient can "M-x <up> RET" be?

Very because it's not auto-repeatable.

>> In my experience, the buffer isn't too far away, usually.
>
> Maybe so, but I don't want to waste my time wading through buffers I
> am not interested in.  If I need to see dispextern.h, I want to get
> there, pronto.

It's not about "If I need to see dispextern.h".  It's about "If I need
to see the dispextern.h where I left off in the same window."

>>  > What is necessary is a way to switch to a buffer by name and have the
>>  > window remember its previous window-point.  If the buffer was never
>>  > displayed in this window, "C-x b" should choose some value of
>>  > window-point that was used before and is not already displayed in some
>>  > other window.  (If there's a window for every possible value of
>>  > window-point for the buffer, i.e. the user opens yet another window
>>  > with the same buffer, just choose one of the values, e.g., the first
>>  > or the last.)  For the important use case of having 2 windows with the
>>  > same buffer, this strategy will do _exactly_ what the user wants.
>>
>> Using the window-point from some other window will be utterly
>> disconcerting if you later want to display the buffer in _that_ other
>> window.
>
> Are you talking about the rare case in parentheses?

No.  I was talking about choosing "some value of window-point that was
used before" when switching to a buffer that was not shown in the
selected window yet.  If you next switch to the buffer in the window
where window-point was stolen from, you get the window-point from yet
another window.

> That's a marginal
> use case.  Let's not destroy convenience in 90% of cases for the sake
> of 10%.
>
>> Recording window-points of deleted windows to implement the "used
>> before" approach might be expensive - these are markers into that
>> buffer.
>
> So let's record only a few, up to a limit.  Again, having a lot of
> such deleted windows is a rare case.

So we record only a few but `switch-to-prev-buffer' isn't good enough to
get you to your buffer quickly.

>>  > Yes, but it works satisfactorily only if you switch between 2 buffers
>>  > in the same window.  Switch to a third, and you are screwed.
>>
>> Try them.
>
> I did, before I responded.

If you have auto-repeatable bindings it works very well.  I use them for
quite some time now and never had any complaints from my side so far.

martin