bug#55070: 28.1; desktop-load doesn't work in -nw (non-gui) emacs

[Eli Zaretskii]

> From: Eric Swenson <eric@swenson.org>
> Date: Sat, 23 Apr 2022 06:52:13 -0700
> Cc: 55070@debbugs.gnu.org, eric=swenson.org@groups.io
> 
> I start emacs with a single frame. I create three windows by doing, for 
> example, C-x 2, and C-x 3. In each window, I read in a file. Then I invoke 
> M-x desktop-save, and select a directory. I always use ~/.emacs.d.  Then I 
> exit emacs with C-x C-c.
> 
> Then I renter emacs and invoke C-x desktop-load.
> 
> If for both sessions, I invoke emacs with “-Q” only, on either macOS or Linux 
> with Gnome desktop, everything works fine. However, if I invoke emacs with 
> “-nw -Q”, when I run M-x desktop-load, I only get a single window with one of 
> the files loaded. The other two files are loaded into buffers, but their 
> windows were not restored.
> 
> I haven’t tried a case where I ran a GUI session first and saved the desktop 
> and then ran the non-GUI (-nw) session for the restore, but I’m pretty sure 
> it would also fail. 
> 
> I think the “issue” is that desktop-load doesn’t work in the -nw session.
> 
> And yes, you can set up the windows using C-x 4 f <filename> as well as the 
> explicitly creating a second window and splitting and then loading files into 
> each. It doesn’t really matter. 

OK, thanks for the details.  They tell me that what you see is the
intended behavior: desktop.el doesn't restore frames and windows on
text-mode terminals.  This is because restoring frames and windows in
a -nw session is problematic, especially if the desktop was saved from
a GUI session.

If this causes a lot of inconvenience, maybe we could have a user
option to allow restoring the frameset in -nw session, for those who
only ever use -nw sessions.  But we cannot allow that in general, and
not by default, IMO.