From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Fredrik Kuivinen" <frekui@gmail.com>
Subject: Re: fatal: unable to create '.git/index': File exists
Date: Sat, 6 Jan 2007 10:24:24 +0100
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Cc: "Len Brown" <lenb@kernel.org>, git@vger.kernel.org
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To: "Johannes Schindelin" <Johannes.Schindelin@gmx.de>
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On 1/5/07, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> Hi,
>
> On Fri, 5 Jan 2007, Len Brown wrote:
>
> > I kicked off a pull.
> > Realized I was on the wrong branch
> > and immediately did a ^C
> >
> > Now I can't change branches:
> >
> > # git checkout release
> > fatal: unable to create '.git/index': File exists
>
> This usually means that .git/index.lock exists. Try removing that file.
>
> However, it _should_ be removed by the atexit() handler, methinks. I have
> no idea why it does not.

We will get SIGINT when the user hits ^C so I don't think the atexit handler
will run. However, we also install a signal handler for SIGINT which removes
the lock file, so I don't really see how it can be left around...

There is a small race condition between open and signal as we do

    fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
    ...
    signal(SIGINT, remove_lock_file_on_signal);
    atexit(remove_lock_file);

in lock_file:lockfile.c. But I think it is very improbable that the user hits ^C
between  "open" and "signal". It might be worth fixing though.

Are there any other signals we might get when the user hits ^C? SIGPIPE?

- Fredrik