Re: git is screwed

[Harald Hanche-Olsen <hanche@math.ntnu.no>]

Maybe it is time to revisit this one, in light of what we have learned 
since.

Richard Stallman wrote:
> I committed some changes using C-x v v in vc-dir.
> Something went wrong with lisp/ChangeLog.
>
> It appears that my change log entries went into an old version of that
> file; I don't know why this happened, since I wrote them today after
> doing 'git pull'.

(“today” in this email is March 22)

Ah, but we have the output of git reflog now:

dca743f HEAD@{0}: commit: Recognize more format variation. Automatically 
reshow decrypted text.
1a80be1 HEAD@{1}: commit: Echo area shows when displaying a mime message.
414e79f HEAD@{2}: commit: Prefer IceCat to Firefox and Iceweasel.
f1cea3e HEAD@{3}: checkout: moving from TEST to master
f1cea3e HEAD@{4}: checkout: moving from master to TEST
f1cea3e HEAD@{5}: pull: Fast-forward
3517da7 Head@{6}: clone: from rms@git.sv.gnu.org:/srv/git/emacs.git

and there are no traces here of a successful pull after those three 
commits, which by the wat were all done in quick succession on March 22. 
The commit they are based on is f1cea3e, which is indeed about 8 weeks 
old. So it appears that your git pull failed, and you did edit an old 
lisp/ChangeLog.

> After this, I did 'git pull' again, and it said there was a merge
> conflict in lisp/ChangeLpg.  A lot of text appears to be missing from
> the file.  It said, "fix conflicts and then commit the result."
>
> I edited lisp/ChangeLog and tried to commit it with C-x v v.
> That gave me the error message
>
>    fatal: cannot do a partial commit during a merge.
>
> I am now stuck.  […]
>
> How can I get this unwedged?

We have also learned that “git ls-files -u” produces no output. That 
simplifies the available options somewhat, I think, since there are no 
unmerged files to deal with (they complicate the index quite a lot, 
since there may be several versions of these files there).

The only file different in the index and your working tree is 
lisp/ChangeLog. If you run “git diff”, you should see the difference 
between those two (in that order), and nothing else. If based on the 
output, you think the version in your working tree is more appropriate 
than the one in the index, you should go ahead and run “git add 
lisp/ChangeLog”. Otherwise, edit it further until satisfied, then run 
“git add lisp/ChangeLog”, at which point your working tree and index are 
in agreement (and “git diff” should produce no output).

The next thing you could try, is to run this command:

   git diff origin/master

This shows the difference between what is now in the working tree and 
what got fetched on your last I expect you will see all the changes you 
have made in your recent work, and nothing else. If so, go ahead and run 
“git commit“, but don't try to push yet. Your repository should now be 
in a sane state.

The only problem is that your latest additions – the ones you tried to 
commit with the initial C-x v v – will now be mixed in with the merge 
commit, which obscures the history. We might want to look into fixing 
that next.

– Harald