Re: can git reset or checkout be reverted?

On 2009-02-06, bill lam [off-list ref] wrote:

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?

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.