bug#27879: Bad behavior with sr-speedbar package

[martin rudalics]

> I don't understand these technical details.. I am a simple user of the
> package. You should explain if the user has to put something in the
> init.el file. What I seem to understand is that now sr-speedbar is no
> longer compatible with current development of Emacs...

sr-speedbar wasn't compatible ever since that advice was added to it.
Stephen Berman explained how to deactivate it.  Just add

(ad-deactivate 'pop-to-buffer)

to your init file or remove the defadvice from sr-speedbar.el.

martin