From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=) Newsgroups: gmane.lisp.guile.bugs Subject: bug#20087: 'gensym' is not guaranteed to return a fresh symbol Date: Wed, 11 Mar 2015 18:15:02 +0100 Message-ID: <87a8zjxxpl.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1426094183 29640 80.91.229.3 (11 Mar 2015 17:16:23 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 11 Mar 2015 17:16:23 +0000 (UTC) To: 20087@debbugs.gnu.org Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Wed Mar 11 18:16:12 2015 Return-path: Envelope-to: guile-bugs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1YVkEs-00080j-Vn for guile-bugs@m.gmane.org; Wed, 11 Mar 2015 18:16:11 +0100 Original-Received: from localhost ([::1]:55979 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVkEs-0002r5-1b for guile-bugs@m.gmane.org; Wed, 11 Mar 2015 13:16:10 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:59451) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVkEn-0002op-Sh for bug-guile@gnu.org; Wed, 11 Mar 2015 13:16:06 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YVkEk-0003Vm-OJ for bug-guile@gnu.org; Wed, 11 Mar 2015 13:16:05 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:44462) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVkEk-0003Vh-Lu for bug-guile@gnu.org; Wed, 11 Mar 2015 13:16:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1YVkEk-0004X2-GD for bug-guile@gnu.org; Wed, 11 Mar 2015 13:16:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=) Original-Sender: "Debbugs-submit" Resent-CC: bug-guile@gnu.org Resent-Date: Wed, 11 Mar 2015 17:16:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: report 20087 X-GNU-PR-Package: guile X-GNU-PR-Keywords: X-Debbugs-Original-To: bug-guile@gnu.org Original-Received: via spool by submit@debbugs.gnu.org id=B.142609412217355 (code B ref -1); Wed, 11 Mar 2015 17:16:02 +0000 Original-Received: (at submit) by debbugs.gnu.org; 11 Mar 2015 17:15:22 +0000 Original-Received: from localhost ([127.0.0.1]:43030 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1YVkE5-0004Vq-FJ for submit@debbugs.gnu.org; Wed, 11 Mar 2015 13:15:21 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:57500) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1YVkE4-0004Ve-It for submit@debbugs.gnu.org; Wed, 11 Mar 2015 13:15:20 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YVkDy-00031K-Im for submit@debbugs.gnu.org; Wed, 11 Mar 2015 13:15:15 -0400 Original-Received: from lists.gnu.org ([2001:4830:134:3::11]:39854) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVkDy-00031A-GX for submit@debbugs.gnu.org; Wed, 11 Mar 2015 13:15:14 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:59201) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVkDx-0001rj-LW for bug-guile@gnu.org; Wed, 11 Mar 2015 13:15:14 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YVkDu-0002zw-Cp for bug-guile@gnu.org; Wed, 11 Mar 2015 13:15:13 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:57767) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVkDu-0002zr-As for bug-guile@gnu.org; Wed, 11 Mar 2015 13:15:10 -0400 Original-Received: from reverse-83.fdn.fr ([80.67.176.83]:47174 helo=pluto) by fencepost.gnu.org with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1YVkDt-0005Qb-Q3 for bug-guile@gnu.org; Wed, 11 Mar 2015 13:15:10 -0400 X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 21 =?UTF-8?Q?Vent=C3=B4se?= an 223 de la =?UTF-8?Q?R=C3=A9volution?= X-PGP-Key-ID: 0xEA52ECF4 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 83C4 F8E5 10A3 3B4C 5BEA D15D 77DD 95E2 EA52 ECF4 X-OS: x86_64-unknown-linux-gnu User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-guile@gnu.org List-Id: "Bug reports for GUILE, GNU's Ubiquitous Extension Language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Original-Sender: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.bugs:7747 Archived-At: =E2=80=98gensym=E2=80=99 returns interned symbols, but the algorithm to det= ermine the new symbol is simplistic and predictable. Thus, one can arrange to produce a symbol before =E2=80=98gensym=E2=80=99 d= oes, leading =E2=80=98gensym=E2=80=99 to return a symbol that=E2=80=99s not fresh (in te= rms of =E2=80=98eq?=E2=80=99), as is the case with the second call to =E2=80=98gensym=E2=80=99 here: --8<---------------cut here---------------start------------->8--- scheme@(guile-user)> (gensym "x") $1 =3D x379 scheme@(guile-user)> 'x405 $2 =3D x405 scheme@(guile-user)> (gensym "x") $3 =3D x405 --8<---------------cut here---------------end--------------->8--- Should we worry about it? I think it may have hard to anticipate security implications. Ludo=E2=80=99.