Re: Why do dates in refspecs require the reflog?

From: Stefan Beller <sbeller@google.com>
Date: Dec 30, 2014, 20:16 UTC
Message-ID: <CAGZ79kZteMXLaQowxNdrXd-ULbmZQ=AuyCyz0w6dLJC68ThxnA@mail.gmail.com>
In-Reply-To: <CAHd499Cvy=zi=9utoZ2bEgdSUTjkveHMP2OvVFPBHq7W2MuoZQ@mail.gmail.com>

On Tue, Dec 30, 2014 at 12:12 PM, Robert Dailey <rcdailey.lists@gmail.com> wrote:

Show 15 quoted lines

> I was surprised to find today that the following didn't work as expected:
>
> $ git show master@{"1 year ago"}:Path/To/File.h
>
> It gave me the following warning which did not make the problem obvious at all:
> warning: Log for 'master' only goes back to Mon, 8 Sep 2014 12:08:44 -0500.
>
> What it is trying to tell me (and I only found this out after a lot of
> poking and prodding around Google) is that I can't refer to a commit
> by date if it extends beyond the range of the reflog.
>
> I don't understand why this requirement is in place. Each commit has a
> time stamp, so in theory it should be possible to calculate an
> absolute date from the duration specified in the refspec and grab the
> commit from `git log` from that.

Because the commit may have existed at a certain date, but not in the branch. It may have been merged at a later time. I am not sure if this is the actual reason though.

Show 9 quoted lines

>
> I can only assume I'm oversimplifying things and that there is a good
> reason for this. If I can't get this to work, how can I view the
> contents of a file at a specified relative time frame as I have done
> above?
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