Re: git: uh-oh

On 20/08/10 21:08, Tom Lane wrote:
> Max Bowsher <maxb(at)f2s(dot)com> writes:
>>> On Fri, Aug 20, 2010 at 20:52, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>>> If I understand Max's statements correctly, there is an observable
>>>> problem in the actual git history, not just the commit log entries:
>>>> it will believe that a file added on a branch had been there since
>>>> the branch forked off, not just as of the time it got added.
>
>> Not since the branch forked off, but rather it will believe the file
>> added to the branch from the moment it was added to trunk - the issue is
>> actually in the cvs repository too - were you to ask CVS for the state
>> of the branch at the relevant time, you'd see the extra file there too.
>
> Ah. So Magnus' tests didn't catch that because he only looked at
> release tag times, and none of these event pairs occurred across a
> release.
>
>> In the specific case we've been looking at so far, the file is only
>> appearing less than a minute prematurely.
>
> Hmm. I wonder whether the "anomaly" is dependent on the order in which
> the cvs add's and cvs commit's are done in the two different branches.
>
> I'm still confused as to why this results in such massive weirdness in
> the generated git history, though. If it simply caused an extra commit
> that adds the new file slightly earlier than the commit we think of as
> adding the file, I wouldn't be complaining.

Isn't this what's happening?

> It's the fact that there
> are all those unrelated HEAD commits showing up in the log for a branch
> that bugs me.

You mean in the synthetic log message? Well, they're not exactly
unrelated - the overall effect is that the file was added on trunk,
'merged' into the branch, and then modified appropriately for that branch.

Max.