bug#51883: 29.0.50; Command to get accidentally deleted frames back

[Eli Zaretskii]

> Date: Sat, 27 Nov 2021 11:53:10 +0000
> From: Gregory Heytings <gregory@heytings.org>
> cc: Eli Zaretskii <eliz@gnu.org>, 51883@debbugs.gnu.org, juri@linkov.net
> 
> > But I noticed that C-x 5 u without prefix arg errors.  This is probably 
> > not intended.  I think you rather want to test the raw prefix arg with 
> > `consp', not with `listp'.  But why not just use (interactive "p")?
> >
> 
> This is intended, it's what Eli wanted, unless I misunderstood what he 
> meant.  In a previous version of the patch C-x 5 u without prefix arg 
> undeleted the last deleted frame.  Now an explicit numerical prefix 
> argument between 1 and 16 is required.

No, that's a misunderstanding, sorry.  I meant "C-x 5 u" to undelete
the most recently deleted frame, and 1 to 16 to mean undelete the
penultimate frame etc.  Basically ARG of N means undelete the N+1st
previously deleted frame.  I just didn't want the ARG of zero to be
handled specially.