From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Stephen J. Turnbull" Newsgroups: gmane.emacs.devel Subject: Re: preferring mercurial Date: Sat, 11 Jan 2014 04:20:40 +0900 Message-ID: <8738kvfxtj.fsf@uwakimon.sk.tsukuba.ac.jp> References: <3905544.suqMZffgM5@descartes> <874n5d6whz.fsf@gaia.iap.fr> <87iottf4fe.fsf@uwakimon.sk.tsukuba.ac.jp> <1389366228.5784.14.camel@Iris> 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 1389381655 26989 80.91.229.3 (10 Jan 2014 19:20:55 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 10 Jan 2014 19:20:55 +0000 (UTC) Cc: =?utf-8?Q?R=C3=BCdiger?= Sonderfeld , Neal Becker , =?utf-8?Q?Fran=C3=A7ois?= Orieux , emacs-devel@gnu.org To: Jordi =?utf-8?Q?Guti=C3=A9rrez?= Hermoso Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Jan 10 20:21:01 2014 Return-path: Envelope-to: ged-emacs-devel@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 1W1hdb-00089N-Km for ged-emacs-devel@m.gmane.org; Fri, 10 Jan 2014 20:20:59 +0100 Original-Received: from localhost ([::1]:58629 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W1hdb-000288-7K for ged-emacs-devel@m.gmane.org; Fri, 10 Jan 2014 14:20:59 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:50465) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W1hdR-000273-Q6 for emacs-devel@gnu.org; Fri, 10 Jan 2014 14:20:56 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W1hdL-0003gK-L9 for emacs-devel@gnu.org; Fri, 10 Jan 2014 14:20:49 -0500 Original-Received: from mgmt2.sk.tsukuba.ac.jp ([130.158.97.224]:41691) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W1hdK-0003g6-QB for emacs-devel@gnu.org; Fri, 10 Jan 2014 14:20:43 -0500 Original-Received: from uwakimon.sk.tsukuba.ac.jp (uwakimon.sk.tsukuba.ac.jp [130.158.99.156]) by mgmt2.sk.tsukuba.ac.jp (Postfix) with ESMTP id 5C4C7970A20; Sat, 11 Jan 2014 04:20:40 +0900 (JST) Original-Received: by uwakimon.sk.tsukuba.ac.jp (Postfix, from userid 1000) id 515121A2E82; Sat, 11 Jan 2014 04:20:40 +0900 (JST) In-Reply-To: <1389366228.5784.14.camel@Iris> X-Mailer: VM undefined under 21.5 (beta34) "kale" 2a0f42961ed4 XEmacs Lucid (x86_64-unknown-linux) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 130.158.97.224 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:168034 Archived-At: Jordi Guti=C3=A9rrez Hermoso writes: > Furthermore, hg's internal data structures aren't that hard to > understand either. Commit -> tree -> blob -> ref, meet changelog -> > manifest -> filelog -> revlog. Besides the fact that blob->ref is nonsense, look whose terminology makes more sense here. > > Nothing has more respect for history than git. >=20 > This isn't very respectful of history: >=20 > http://www.infoq.com/news/2013/11/use-the-force/ First, note that the culprit, Gerrit, does not use git to access git repos, and by *default* does push --force. Blaming this particular disaster on git itself is unfair. Second, from hg help push: -f --force force push Note: Extra care should be taken with the -f/--force option, which will push all new heads on all branches, an action which will almost always cause confusion for collaborators. IOW, this is a people problem, which Mercurial would be subject to as well. > > History isn't *changed*, it is recreated >=20 > Same in hg. New history means new hashes. Old history is still > lying around. Where? How do you get at it? Eg (some output deleted): $ mkdir hgtest && cd hgtest && hg init $ echo foo >> foo && hg add foo && hg commit -m 1 && hg heads changeset: 0:ead82a170088 $ echo foo >> foo && hg commit -m 2 && hg heads changeset: 1:e5790bc8b230 $ hg rollback repository tip rolled back to revision 0 (undo commit) $ hg heads changeset: 0:ead82a170088 $ hg log -r ead82a170088 changeset: 0:ead82a170088 $ hg log -r e5790bc8b230 abort: unknown revision 'e5790bc8b230'! Oops. The same thing happened with "commit --amend". > > AFAIK hg and bzr *do* destroy history when they perform operations > > like commit --amend, strip, and rebase. >=20 > I hope I helped you to know better now. Unfortunately, no. The actual behavior of hg is indeed immediately destructive in some cases, unlike git.