bug#55885: 29.0.50; missed error message

[Lars Ingebrigtsen <larsi@gnus.org>]

Andreas Röhler <andreas.roehler@easy-emacs.de> writes:

> (defvar ar-emacs-dir
>   (cond (t t)
>         (t 
>            (when ar-emacs-dir ()))))
>
> That doesn't give an error in either Emacs 28 nor Emacs 29.
>
> Hmm, but it should, or? The use of a previous undefined var in its own definition
> should raise an error.

Only if execution reaches that form, and it doesn't here because of the
`t' branch in the cond.

> Unfortunately, have some difficulty translating my init-stuff into a generic report.
>
> Here is what I --gladly-- get when starting from v28, but no longer from v29:
>
> Debugger entered--Lisp error: (void-variable ar-emacs-dir)
>   (if ar-emacs-dir (progn (kill-buffer "fns.c")))
>   (cond ((boundp 'lisp-directory) (replace-regexp-in-string "/[^/]+/$" "" lisp-directory))

lisp-directory is bound in Emacs 29 but not Emacs 28, so that branch of
the cond is taken there.

So this is all working as it should, and I'm closing this bug report.
(And you should consider using the Emacs help lists with things you
don't understand about Emacs Lisp instead of the bug tracker.)

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no