From mboxrd@z Thu Jan  1 00:00:00 1970
Path: news.gmane.org!not-for-mail
From: Leo Alekseyev <dnquark@gmail.com>
Newsgroups: gmane.emacs.help
Subject: around advice: why does (and ad-do-it nil) return t?
Date: Mon, 13 Feb 2012 07:43:42 -0500
Message-ID: <CADzxs1nBNR9FLrCwL3L5Au06K1DvRfBRETj2vECNPoC-01D_=g@mail.gmail.com>
NNTP-Posting-Host: plane.gmane.org
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
X-Trace: dough.gmane.org 1329137042 14767 80.91.229.3 (13 Feb 2012 12:44:02 GMT)
X-Complaints-To: usenet@dough.gmane.org
NNTP-Posting-Date: Mon, 13 Feb 2012 12:44:02 +0000 (UTC)
To: help-gnu-emacs@gnu.org
Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Mon Feb 13 13:44:01 2012
Return-path: <help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org>
Envelope-to: geh-help-gnu-emacs@m.gmane.org
Original-Received: from lists.gnu.org ([140.186.70.17])
	by plane.gmane.org with esmtp (Exim 4.69)
	(envelope-from <help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org>)
	id 1RwvG9-0000N8-JF
	for geh-help-gnu-emacs@m.gmane.org; Mon, 13 Feb 2012 13:43:57 +0100
Original-Received: from localhost ([::1]:46230 helo=lists.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org>)
	id 1RwvG9-0004eA-5A
	for geh-help-gnu-emacs@m.gmane.org; Mon, 13 Feb 2012 07:43:57 -0500
Original-Received: from eggs.gnu.org ([140.186.70.92]:35965)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <dnquark@gmail.com>) id 1RwvG0-0004dz-GB
	for help-gnu-emacs@gnu.org; Mon, 13 Feb 2012 07:43:53 -0500
Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <dnquark@gmail.com>) id 1RwvFw-0003SE-2D
	for help-gnu-emacs@gnu.org; Mon, 13 Feb 2012 07:43:48 -0500
Original-Received: from mail-pz0-f41.google.com ([209.85.210.41]:64813)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <dnquark@gmail.com>) id 1RwvFv-0003S9-Tf
	for help-gnu-emacs@gnu.org; Mon, 13 Feb 2012 07:43:44 -0500
Original-Received: by dadv6 with SMTP id v6so4680493dad.0
	for <help-gnu-emacs@gnu.org>; Mon, 13 Feb 2012 04:43:43 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma;
	h=mime-version:date:message-id:subject:from:to:content-type;
	bh=22Q18KHhzv3a77E0wQZ0zYSPfCyTMHuDfEt8e3Wq4cY=;
	b=ZpDJkFELDZDEr3gRulchCJ514Ab8liyhh/TUDFC9Ygo90zw6dXmmMSlF1awrUyNSMB
	sxGJfxQTW8xhvcOwYrLDDwFeIySUIpoUbktPuNL29c/hrkfFBBuyPk04/l0PYtzHDmnd
	dgbJByh7c72Q+cGbF5hIqgW/HWCBp+3kau1E4=
Original-Received: by 10.68.211.132 with SMTP id nc4mr26836375pbc.109.1329137022950;
	Mon, 13 Feb 2012 04:43:42 -0800 (PST)
Original-Received: by 10.143.68.14 with HTTP; Mon, 13 Feb 2012 04:43:42 -0800 (PST)
X-detected-operating-system: by eggs.gnu.org: Genre and OS details not
	recognized.
X-Received-From: 209.85.210.41
X-BeenThere: help-gnu-emacs@gnu.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Users list for the GNU Emacs text editor <help-gnu-emacs.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/help-gnu-emacs>,
	<mailto:help-gnu-emacs-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/help-gnu-emacs>
List-Post: <mailto:help-gnu-emacs@gnu.org>
List-Help: <mailto:help-gnu-emacs-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/help-gnu-emacs>,
	<mailto:help-gnu-emacs-request@gnu.org?subject=subscribe>
Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org
Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org
Xref: news.gmane.org gmane.emacs.help:83731
Archived-At: <http://permalink.gmane.org/gmane.emacs.help/83731>

Consider the following code:

(defun foobar () t)
(defadvice foobar (around foobar-advice activate)
  (and ad-do-it nil))

Evaluating the advised foobar seems to return t.  Why?  Naively, one
expects (and [whatever] nil) to evaluate to nil!