bug#22025: Emacs 25 corrupts Emacs 24 .emacs.desktop.

[Eli Zaretskii]

> Date: Fri, 27 Nov 2015 08:38:37 +0000
> From: Alan Mackenzie <acm@muc.de>
> 
> Emacs 25 has read a version 206 .desktop file, but written a version 208
> file on termination.  Emacs 24 cannot execute this version.
> 
> There was no yes-or-no-p asking "are you sure you want to convert your
> desktop to a format incompatible with previous Emacs versions?".
> 
> Manually restoring a .desktop to version 206 is fraught with
> difficulties, even for somebody (myself) who understands the issues
> reasonably well, and has an old version of .desktop saved "just in
> case".
> 
> Recommendation
> --------------
> 
> Emacs 25, having loaded a version 206 .desktop, should save it in the
> same format until the user has positively consented to it being
> converted to version 208.

This would be a nice enhancement, but it certainly isn't a bug in my
book.

Of course, if making that happen is relatively easy, it would be good
to have such a compatibility mode.  Patches welcome.

I marked it wishlist.