bug#23092: 25.0.92; Minibuffer completion fails to resize completion window if reused during same command

[nljlistbox2@gmail.com (N. Jackson)]

Hi Eli,

At 20:28 +0200 on Tuesday 2016-03-22, Eli Zaretskii wrote:
>
>> From: nljlistbox2@gmail.com (N. Jackson)
>> Date: Tue, 22 Mar 2016 14:07:39 -0300
>> 
>>     src/emacs -Q
>> 
>>     C-x C-f            ; find-file
>>     lib/v TAB          ; A tiny window pops up with "verify.h" and "vla.h."
>>     <backspace> s TAB
>> 
>> At this point there is still a tiny completions window with about 50
>> completions most of which are not visible in the window.
>
> Press TAB repeatedly to scroll through those 50 completions.
>
> (I'm not saying this cannot or shouldn't be improved, I'm saying this
> is not "impossible to use".)

That's pretty weird, but yes, it does work (in a manner of speaking). So
as you correctly point out, it is not "impossible to use".

However, it's interesting that with the recipe reversed, the completions
window _does_ get resized.:

    src/emacs -Q

    C-x C-f            ; find-file
    lib/s TAB          ; A largish completions window is shown.
    <backspace> v TAB  ; Completions window shrinks.

So it seems that the existing implementation has logic in it for
resizing the completions window to fit the completions but it just isn't
working quite right. Unless the design is that the completions window
can only be "shrunk" but not "grown".

N.