From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.bugs Subject: bug#39529: 28.0.50; Metahelp does not contain help text Date: Wed, 19 Feb 2020 01:00:37 -0800 Organization: UCLA Computer Science Department Message-ID: References: <875zgf8trz.fsf@gmail.com> <83d0and0q9.fsf@gnu.org> <83blq7d06n.fsf@gnu.org> <59be714f-1b52-a068-70c8-3204cf016ca2@cs.ucla.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="21515"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 Cc: 39529@debbugs.gnu.org, federicotedin@gmail.com To: Pip Cet Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Feb 19 10:01:12 2020 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j4LEF-0005Rh-Bz for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 19 Feb 2020 10:01:11 +0100 Original-Received: from localhost ([::1]:47560 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j4LEE-0006vu-7I for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 19 Feb 2020 04:01:10 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:40053) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j4LE7-0006ve-45 for bug-gnu-emacs@gnu.org; Wed, 19 Feb 2020 04:01:04 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j4LE6-0002oA-3H for bug-gnu-emacs@gnu.org; Wed, 19 Feb 2020 04:01:03 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]:35661) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1j4LE5-0002o5-WA for bug-gnu-emacs@gnu.org; Wed, 19 Feb 2020 04:01:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1j4LE5-0005MW-V9 for bug-gnu-emacs@gnu.org; Wed, 19 Feb 2020 04:01:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Paul Eggert Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 19 Feb 2020 09:01:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 39529 X-GNU-PR-Package: emacs Original-Received: via spool by 39529-submit@debbugs.gnu.org id=B39529.158210284720579 (code B ref 39529); Wed, 19 Feb 2020 09:01:01 +0000 Original-Received: (at 39529) by debbugs.gnu.org; 19 Feb 2020 09:00:47 +0000 Original-Received: from localhost ([127.0.0.1]:41634 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1j4LDr-0005Lr-2v for submit@debbugs.gnu.org; Wed, 19 Feb 2020 04:00:47 -0500 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:48516) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1j4LDo-0005Lc-3R for 39529@debbugs.gnu.org; Wed, 19 Feb 2020 04:00:45 -0500 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 5C456160087; Wed, 19 Feb 2020 01:00:38 -0800 (PST) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id RzfMcDnzIAp9; Wed, 19 Feb 2020 01:00:37 -0800 (PST) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id A67F41600AF; Wed, 19 Feb 2020 01:00:37 -0800 (PST) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id HY7R6nyGF-q1; Wed, 19 Feb 2020 01:00:37 -0800 (PST) Original-Received: from [192.168.1.9] (cpe-23-242-74-103.socal.res.rr.com [23.242.74.103]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 71D31160087; Wed, 19 Feb 2020 01:00:37 -0800 (PST) In-Reply-To: Content-Language: en-US X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:176239 Archived-At: On 2/18/20 6:34 PM, Pip Cet wrote: > (defun hash-equal (a b) > (let ((ht (make-hash-table :test 'equal))) > (puthash a t ht) > (gethash b ht))) > > (hash-equal (point-marker) (point-marker)) > (equal (point-marker) (point-marker)) Ah, OK, then I think we're in fundamental agreement about the problem. However, I don't agree that the Emacs 27-and-earlier approach is tenable, as means that (and (equal a b) (gethash a ht) (not (gethash b ht))) can return t, and similarly unexpected and undesirable behavior elsewhere - even if there are no side effects on hash keys and no cycles in hash key values. For now it should suffice if Emacs handles the case where hash keys don't change and don't have cycles; we can worry about the fancier problems later (if ever).