> 1. Start Emacs. It starts with a single window containing the *GNU
Emacs* buffer.
>
> 2. Now toggle the sr-speedbar: M-x sr-speedbar-toggle. It contains
two windows: on the right, the sr-speedbar; on the left the *GNU Emacs*
buffer.
>
> 3. In *GNU Emacs* buffer visit a buffer: C-x C-f foo.txt. The *GNU
Emacs* buffer window is divided (as in C-x 2) and foo.txt is in the
bottom window.
>
> The last master with the right behavior is 2017-07-28 12:38:22 +0300,
f1ed31a8f5c6f19aa5e119e670533241c6375945.
sr-speedbar advises ‘pop-to-buffer’. It shouldn't do that or at least
do it in some different fashion. The current behavior just breaks it.