From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Packham Subject: Re: Git: Unexpected behaviour? Date: Sat, 12 Nov 2011 10:31:20 +1300 Message-ID: <4EBD9428.3030506@gmail.com> References: <1321044904175-6986736.post@n2.nabble.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: git@vger.kernel.org To: Jvsrvcs X-From: git-owner@vger.kernel.org Fri Nov 11 22:31:31 2011 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ROyh6-0008GE-P1 for gcvg-git-2@lo.gmane.org; Fri, 11 Nov 2011 22:31:29 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757305Ab1KKVbY (ORCPT ); Fri, 11 Nov 2011 16:31:24 -0500 Received: from mail-vw0-f46.google.com ([209.85.212.46]:58657 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757016Ab1KKVbX (ORCPT ); Fri, 11 Nov 2011 16:31:23 -0500 Received: by vws1 with SMTP id 1so3789409vws.19 for ; Fri, 11 Nov 2011 13:31:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=9XoSUj7EKOExytTdS6Q+h4itNh47iexE1vDuuWYonLg=; b=NN1fijdRf4/c0Vbz3yw56AtMMVrEsmxdIMUCIwICanag7/aheeq/VQsEpMb6uUtMRB L8hqU141ZlH6VIznqKpj1he1WV9NJ4aBSUQarwTlASb/zoQ56RVSkMhUW7hJ+4sqCnkE BQLB4ERbG21q0UF83FKaHSNliDg5Wfho5Om+M= Received: by 10.52.94.102 with SMTP id db6mr24054186vdb.118.1321047082918; Fri, 11 Nov 2011 13:31:22 -0800 (PST) Received: from laptop.site (115-188-15-163.jetstream.xtra.co.nz. [115.188.15.163]) by mx.google.com with ESMTPS id p7sm18793095vdh.9.2011.11.11.13.31.20 (version=SSLv3 cipher=OTHER); Fri, 11 Nov 2011 13:31:22 -0800 (PST) User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.9.2.23) Gecko/20110920 SUSE/3.1.15 Thunderbird/3.1.15 In-Reply-To: <1321044904175-6986736.post@n2.nabble.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Hi, On 12/11/11 09:55, Jvsrvcs wrote: > Unexpected git behaviour > > --- > # First create a local git repo > > $mkdir gitexample > $git config --global user.name "my name" > $git config --global user.email "me@me.com" > $git init > $git add . > $git commit -m 'initial commit' > > # Create/Edit an empty file > $vi readme.txt > > # add a single line: "this was added in the master branch." > $git commit -a One thing to remember is that this is the same as "git add readme.txt" and "git commit" (I'll explain why below). > > # create and checkout a new branch (from master) > $git branch test > $git checkout test > > # edit the readme.txt file and do not commit > # add the text: "this was added in the test branch.", save and exit > $vi readme.txt At this point the changes are in the work tree. They aren't added to the test branch until you commit them. > > #now switch back to master > $git checkout master When you have uncommited changes in the work tree that don't conflict with the contents of the branch you are checking out git will happily carry them along for you. If they did conflict then git would refuse to switch to the new branch. > $cat readme.txt > > #You will see both lines in the master. > > Question #1: > Why was this line added in the *master branch? Because the second change hasn't been committed it isn't in either branch. It's in the work tree. > --- even further surprising > In the master branch, now do a commit > $git commit -a > > cat readme.txt ( you will see the line in the master now that was added in > the test branch ) > > Question #2: > Why did this happen? Because you asked for it to happen. > > # Now switch back to the test branch > $git checkout test > $cat readme.txt > > You will only see the one line: "This was added in the master branch" > > Question #3: > Why did this happen? Because the second change was committed (in the master branch) it is no-longer floating in the work tree so when you switch branches you get the contents of the file in that branch. > > and NOT the line added in that branch: "this was added in the test branch" > <= this line is gone > > What is the reason for this? > > 1) Why do I see uncommitted changes in the branches made off master in the > master branch? > 2) Why, if I commit them in the master, do the disappear in the branch in > which they were made? > > This is confusing, I would think the * master branch would be left > untouched. This would solve issue #2. > Hopefully this will explain things a little better [work-tree] -- git add -> [index] -- git commit --> [HEAD] work-tree: the area on the file system where your code is checked out. index: also known as the staging area, this is represents what will end up in the next commit. HEAD: a general term for the current branch. As you can see that until a change is committed it isn't in _any_ branch. When you type "git checkout test" or "git checkout master" HEAD will be updated. Changes in the work-tree or the index will be carried along (provided they don't conflict with the new HEAD). Hope that helps.