bug#36834: 27.0.50; [PATCH] password-cache.el: confuses key absence with nil password

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Date: Sat, 10 Aug 2019 05:14:22 -0400
> Cc: 36834@debbugs.gnu.org
> 
> > So I propose this patch:
> >
> > diff --git a/lisp/password-cache.el b/lisp/password-cache.el
> > index 5a09ae4859..6009fb491e 100644
> > --- a/lisp/password-cache.el
> > +++ b/lisp/password-cache.el
> > @@ -81,7 +81,8 @@ password-in-cache-p
> >    "Check if KEY is in the cache."
> >    (and password-cache
> >         key
> > -       (gethash key password-data)))
> > +       (not (eq (gethash key password-data 'password-cache-no-data)
> > +                'password-cache-no-data))))
> >  
> >  (defun password-read (prompt &optional key)
> >    "Read password, for use with KEY, from user, or from cache if wanted.
> > @@ -125,7 +126,9 @@ password-cache-remove
> >  (defun password-cache-add (key password)
> >    "Add password to cache.
> >  The password is removed by a timer after `password-cache-expiry' seconds."
> > -  (when (and password-cache-expiry (null (gethash key password-data)))
> > +  (when (and password-cache-expiry
> > +             (eq (gethash key password-data 'password-cache-no-data)
> > +                 'password-cache-no-data))
> >      (run-at-time password-cache-expiry nil
> >  		 #'password-cache-remove
> >  		 key))
> 
> Looks good to me, thanks.

Thanks.

Óscar, please push to the emacs-26 branch, and thanks.