Re: Commited to wrong branch

[Martin Langhoff <martin.langhoff@gmail.com>]

On Tue, Sep 15, 2009 at 12:31 PM, Howard Miller
<howard@e-learndesign.co.uk> wrote:
> I am resurrecting a discussion from a week or two back (been on
> holiday).  As follows...
>
> I had made some changes to some files and then done a commit. Only
> then did I realise that I had the wrong branch checked out. To make
> matters worse I then did a 'git reset HEAD^' which means that I can
> now no longer switch branches. I am stuck. I had some advice (thanks!)
> but it was not complete. I'd appreciate some more help.

Hi Howard,

just to make sure I understand your issue

  1 - you were on branch X, thinking your were on branch Y
  2 - edit, diff, commit, realised the mistake
  3 - git reset HEAD^

so if you now run `git status` and `git diff` it will show your
changes as if they were uncommitted and unstaged.

(Before you start with various attempts to recover below, a great
trick is to make an instant-backup in case things go wrong: cd .. / ;
cp -pr moodle.git moodle-backup.git ; cd moodle.git )

You can now try do do

  4 - git checkout Y

and if the changes are on files that don't change between X and Y,
then git will change the branches and keep your changes there. If the
files are different between X and Y, it won't work.

What I can recommend is to save your patch, as follows

  5 - git diff > tempchanges.patch
  6 - git reset --hard # this will discard your changes, careful
  7 - git checkout Y
  8 - patch -p1 < tempchanges.patch

The patch may not apply cleanly :-) -- note that patch is more
tolerant of iffy merges than git's internal implementation ("git
apply") -- so it will succeed more often... but the results need
review.

There is a more git-style approach that is to use git-stash -- it uses
git-apply and may not do what you want. The steps are

 5a - git stash # will save your changed files into a "stashed commit"
and clear out the changes from your working copy
 6a - git checkout Y
 7a - git stash apply

hth,



m
-- 
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 martin@laptop.org -- School Server Architect
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