bug#27325: Using '&rest' without a trailing parameter causes an error in emacs 26.0.50

bug#27325: Using '&rest' without a trailing parameter causes an error in emacs 26.0.50

[isaac lewis]

If my understanding is correct, the functions (lambda (&rest) t)
and (lambda () t) should behave similarly.

In emacs 25:

(equal (apply (lambda (&rest) t) nil)
           (apply (lambda () t) nil))
=>
t

as expected.  But evaluating the same sexp in emacs 26.0.50
causes an error.

--
Isaac Lewis

bug#27325: Using '&rest' without a trailing parameter causes an error in emacs 26.0.50

[Philipp Stephani]

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isaac lewis <isaac.b.lewis@gmail.com> schrieb am So., 11. Juni 2017 um
09:24 Uhr:

> If my understanding is correct, the functions (lambda (&rest) t)
> and (lambda () t) should behave similarly.
>

From where did you get this understanding? The Elisp manual says about
&rest:
"To specify a list of zero or more extra arguments, include the
keyword &rest before one final argument."
and
"The keyword &rest (which must be followed by a single
argument name) indicates that any number of arguments can follow."
i.e. the parameter after &rest isn't optional.

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bug#27325: Using '&rest' without a trailing parameter causes an error in emacs 26.0.50

[npostavs]

tags 27325 notabug wontfix
close 27325
quit

Philipp Stephani <p.stephani2@gmail.com> writes:

> "The keyword &rest (which must be followed by a single
> argument name) indicates that any number of arguments can follow."
> i.e. the parameter after &rest isn't optional.

I'm therefore closing this bug.  Note that omitting the parameter
doesn't work with edebug even in Emacs versions 25 and earlier (which
was the main motivation to make Emacs 26 more strict about this, if I
remember correctly).