can git reset or checkout be reverted?

If I want to recall a old version of testing by

git reset --hard sha1 or git checkout sha1

then git log does not show anything beyond that commit. It does give some warning and recommend -b switch next time. If I only do that by accident or ignorance. How to revert to the original HEAD?

bill lam <cbill.lam@gmail.com> writes:

git reset is mostly about changing the place the current branch points to. If you checkout branch master, and then say "git reset --hard sha1", then, you say "OK, from now, the tip of branch master will be sha1".

This is the one you were looking for.

It does not "recommand" it, it says that _if_ you wanted to create a branch, you could have done it with -b.

Case 1: you used checkout. Then, the branch still points to where you were before the "checkout". Just "git checkout master", or replace master with where you used to be.

In any case: the reflog can help you. It keeps track of where your HEAD and other references (branches, ...) have been pointing before.

git reflog git reflog show master

to see it, and this allows you to say things like

git checkout HEAD@{1} git reset HEAD@{1}

The HEAD@{1} means "where HEAD used to be one move ago".

bill lam <cbill.lam@gmail.com> writes:

  git checkout ORIG_HEAD

or

  git checkout HEAD@{1}

You can check it out wrt. second form using "git reflog" ("git log -g").

On 2009-02-06, bill lam <cbill.lam@gmail.com> wrote:

As others have said: reflog.

I just wanted to add, I've had a lot of luck using reflog's @{now} feature:

    git reflog show @{now}

Coupled with a vague recollection of what action I did at what time, this has saved me a few times, and if I've been jumping around branches as well, then:

    git reflog show HEAD@{now}

Another good one is:

    git show-branch --sha1-name -g=5

(or some larger value depending on how big your xterm is.) This is particularly useful when I've done a lot of 'git commit --amend' or rebases; the top most '+' sign in each column, starting from the left, is your reflog -- I don't know who came up with this design but it's amazing how much useful information is condensed into that display.

Sitaram Matthieu Jakub

Many thanks for help!