Current master does not work with sr-speedbar package (W64 build)

[Angelo Graziosi]

Current Emacs master (f745cf8c438) does not work with the sr-speedbar package 
(https://github.com/emacsorphanage/sr-speedbar/blob/master/sr-speedbar.el) from 
MELPA.

Usually I have it configured so that Emacs opens in a single frame with 2 
window: one for the text (80 characters in width showing the buffer text) and 
one for sr-speedbar (30 characters in width showing folders and files).

After the upgrade to the last Emacs master, the sr-speedbar window has the same 
width as before but it shows the buffer text... if I remove the desktop file, 
Emacs start with 2 window each containing the scratch buffer.

If, now, I allow for saving the desktop file, at the next start, I get 3 window 
(3 scratch buffers): one window 50 characters in width and 2 window 30 
characters in width. At the next start, 4 window, about: 25, 30, 30, 30 and so 
on...

It seems I see this behavior only with the Windows build (MSYS2+MINGW64).

Ciao,
Angelo.