From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: David Kastrup Newsgroups: gmane.emacs.devel Subject: Re: Switching from old git tree Date: Fri, 14 Nov 2014 15:54:27 +0100 Message-ID: <87a93tq1cs.fsf@fencepost.gnu.org> References: <87ioiiotwx.fsf@fencepost.gnu.org> <87egt5q46l.fsf@fencepost.gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1415982062 1552 80.91.229.3 (14 Nov 2014 16:21:02 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 14 Nov 2014 16:21:02 +0000 (UTC) Cc: emacs To: Sven Axelsson Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Nov 14 17:20:54 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 1XpJcB-0002ME-Ou for ged-emacs-devel@m.gmane.org; Fri, 14 Nov 2014 17:20:51 +0100 Original-Received: from localhost ([::1]:37074 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XpJcB-0007Fu-BG for ged-emacs-devel@m.gmane.org; Fri, 14 Nov 2014 11:20:51 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:37306) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XpJbf-0007Es-L4 for emacs-devel@gnu.org; Fri, 14 Nov 2014 11:20:23 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XpJbd-00051N-Qc for emacs-devel@gnu.org; Fri, 14 Nov 2014 11:20:19 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:53383) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XpJbd-00051J-O6 for emacs-devel@gnu.org; Fri, 14 Nov 2014 11:20:17 -0500 Original-Received: from localhost ([127.0.0.1]:60556 helo=lola) by fencepost.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XpJbd-0004Mt-30; Fri, 14 Nov 2014 11:20:17 -0500 Original-Received: by lola (Postfix, from userid 1000) id C07CFE0B2B; Fri, 14 Nov 2014 15:54:27 +0100 (CET) In-Reply-To: (Sven Axelsson's message of "Fri, 14 Nov 2014 15:20:53 +0100") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2001:4830:134:3::e 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:177093 Archived-At: Sven Axelsson writes: > On 14 November 2014 14:53, David Kastrup wrote: >> Sven Axelsson writes: >>> I suppose you could add your old repo as a local remote to the new one, and >>> cherry-pick your commits, i.e.: >>> >>> git remote add old /local/path/to/old >>> # Fetch the data to your new repo >>> git fetch old >>> # Find the commits to pick somehow >>> git log old/master >>> # Copy to new repo >>> git cherry-pick >> >> Well, I was trying to avoid the "double your repository size or no money >> back" effect. While the file and tree blobs in two differently >> converted Emacs repositories are presumably pretty much the same, the >> entire commit history is disjoint. Once it takes root in your >> repository, it will take a long long time before it gets washed out >> again _after_ removing all branches/references to it. Going through >> patches minimizes the data the new repository gets to see from the old >> one. > > Sure, but does the repo size really matter? We are not talking about data > that is transmitted upstream. > > Also, isn't it sufficient to do > > git remote rm old > git gc > > to clean out the repo? If you did not forget any reference (like old bisect labels) this recipe should work fine once you add an additional second step. That additional second step is "wait for more than three months" with the default settings. Git is really good at not terminally losing information even when you mess up completely. Passing a branch through a repository basically imprints a backup on the repository that will take quite some time to get removed again. Often that is what you want. When you know in advance that you don't, it may make sense to make sure only the data you want gets in. -- David Kastrup