Re: git -- how to revert build to as-originally-cloned?

From: John Lumby <johnlumby@hotmail.com>
Date: May 19, 2011, 15:27 UTC
Message-ID: <4DD536EC.3060308@hotmail.com>
In-Reply-To: <SNT124-W3827431D13C320A4C9BF9DC48F0@phx.gbl>

On 05/18/11 19:26, Tim Mazid wrote:

Show 20 quoted lines

>> Date: Wed, 18 May 2011 18:53:01 -0400
>> From: johnlumby@hotmail.com
>> To: git@vger.kernel.org
>> Subject: git -- how to revert build to as-originally-cloned?
>>
>> I am stuck trying to revert a private kernel build back to the state in
>> which I originally cloned it,
>
>
> Normally in order to undo a merge, you would simply do a "git reset
>
> --hard HEAD^". Take note of the carat(is that correct?) character; that
>
> means the commit BEFORE head.
>
>
>
> Can you please post the commit message that you see in the first commit
>
> when doing a git log?

Here are the first three. I assume (not sure) they are what was merged into the newer clone, /b, just before I cloned it

------------------------------------------------------------------------------
commit 89c64d755fbf04d7541d526931dc4b38301946d1
Merge: 4dc6ec2 4f6290c
Author: David S. Miller <davem@davemloft.net>
Date:   Sun May 15 01:08:23 2011 -0400

     Merge branch 'master' of 
master.kernel.org:/pub/scm/linux/kernel/git/jkirsher/net-next-2.6

commit 4dc6ec26fe7d9f89349d4c0c654e2f07420f4b27
Merge: 7be799a ca06c6e
Author: David S. Miller <davem@conan.davemloft.net>
Date:   Sat May 14 22:47:51 2011 -0400

     Merge branch 'batman-adv/next' of 
git://git.open-mesh.org/ecsv/linux-merge

commit 5c5095494fb545f53b80cbb7539679a10a3472a6
Merge: 4d586b8 def5768
Author: David S. Miller <davem@davemloft.net>
Date:   Thu May 12 23:01:55 2011 -0400
------------------------------------------------------------------------------

So I now think I see the problem with using a reset based on something relating to commits - apparently (??) there is nothing in the git log to distinguish commits done by my last merge versus commits prior to that. I.e. the "merge" does not appear to be logged as an event in its own right, only as the commits inside it??

Show 5 quoted lines

> Also, if you just want to go back to a particular branch, you can
> specify it to git reset, in the form of "git reset --hard
> origin/master". This will reset (discarding any changes) YOUR branch to
> wherever origin/master happens to be, which, from reading your message
> seems to be where you want to go?

Ah - that did it, thanks Tim. I had seen that one but wasn't sure whether it would reset me back to what I cloned or the master of that clone i.e. way back to the "original" origin of this build.

It seems if I had not created a separate branch -- I would now be completely sunk?

It would be nice if there was a "git undo" which undid whatever changes to files+index were made by the immediately preceding git command, whatever it was and whatever it did.

> Be careful if you have made changes you want to keep, though.

No worries there although thanks for the warning.