bug#36516: Wrong dynamic abbrev expansion after space

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Date: Fri, 05 Jul 2019 21:38:39 +0300
> 
> 0. emacs -Q
> 1. Type these two lines:
> str 1
> str 2
> 2. On the third line type:
>  s                      ;; self-insert-command
>  M-/                    ;; dabbrev-expand
>  SPC                    ;; self-insert-command
>  M-/                    ;; dabbrev-expand
>  M-/                    ;; dabbrev-expand
> 3. The word after "str " is expanded to some random word.

Why did you expect something different?  The first M-/ copies "2", but
the next one after that replaces "2" with some alternative, which
exactly depends on what other buffers you have.  I see no bug here,
you are just expecting from M-/ something it cannot give you.  The
"SPC M-/" trick is already reaching too far out, IMO.