bug#36809: "~nosuchuser" commit breaks tramp's scp

[Yuri D'Elia]

On Fri, Jul 26 2019, Michael Albinus wrote:
>> Any idea on how to investigate where is it stuck? (there's no error
>> being triggered).
>
> Usually, you set tramp-verbose to 6 (or to 10, if it is a really nasty
> problem). There will be a debug buffer, for analysis.

Ok, this was helpful and it turned out that's actually something related
to this commit.

I have an unexpanded path based on user-emacs-directory which is
prepended to load-path:

  (concat user-emacs-directory "lisp/")

Somehow this now wreaks havoc when autoloading the 'editorconfig' elpa
package. I kept seeing this:

15:46:41.822312 tramp-do-file-attributes-with-stat (5) # file attributes with 
stat: /home/ydelia/~/.emacs.d/lisp/editorconfig-core.elc
15:46:41.822948 tramp-send-command (6) # ( (test -e 
/home/ydelia/\~/.emacs.d/lisp/editorconfig-core.elc || test -h 
/home/ydelia/\~/.emacs.d/lisp/editorconfig-core.elc) && ...
15:46:41.869461 tramp-wait-for-regexp (6) #

in the tramp log, which helped. Incidentally, this is only noticeable
when opening a remote directory even though the test path is local, for
a reason I didn't determine yet.

Note that editorconfig is actually located in ~/.emacs.d/elpa anyway.
~/.emacs.d/lisp is empty as I came to this point by culling everything
else in sight.

So, where's the issue? Something with regular ~ expansion which has
changed?