bug#39067: shell-command-dont-erase-buffer strange behaviour

[Tino Calancha]

Michael Albinus <michael.albinus@gmx.de> writes:

Fixed the bug into emacs-27 branch with commit:
'Fix shell-command-dont-erase-buffer feature'
(2eb0b7835d1a9cd4b804436e33c71058cb38f178)

> I haven't tested yet, but some minor nits:
Thank Michael for the corrections!  I have added then but this one:

> ;; successive commands know the position where the new command starts.
>
>> +          ;; (unless (and pos (memq sym '(save-point beg-last-out)))
>
> This is superfluous, isn't it?
That is requred for a corner case: one of the new tests fails if I
remove that.