Re: git: uh-oh

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Tue, Sep 7, 2010 at 5:47 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> BTW, why is this commit shown as being a predecessor of refs/tags/REL8_4_4
>> and not refs/tags/REL8_4_3?

> I think this is another result of the same basic problem. Since
> cvs2git thinks it.po was added to REL8_4_STABLE on 2010-02-28 rather
> than 2010-05-13,the REL8_4_STABLE version that existed on to
> 2010-03-12, when 8.4.3 was tagged, includes that file. But cvs2git
> also knows that 8.4.3 does NOT include that file, so it picks the
> commit on the 8.4.3 branch that most closely matches the contents of
> the tag (namely, Marc's "tag 8.4.3" commit) and then shoves a
> manufactured commit on top of that to make the contents of the 8.4.3
> tag match what actually got tagged. But that manufactured commit is
> only there to make the tag contents match; it's not actually part of
> the branch. If the conversion correctly made it.po get added on
> 2010-05-13 rather than 2010-02-28 then Marc's "tag 8.4.3" commit would
> match the tag contents exactly and no manufactured commit would be
> created.

Hmm. Some further looking in the git log output shows that that
"manufactured commit" is actually the ONLY commit shown as being a
predecessor of REL8_4_3. Everything else after 8.4.2 was tagged is
shown as reached from refs/tags/REL8_4_4. This is at the least pretty
weird, and I have to suppose it's the manufactured commit causing it.
It does appear to agree with your explanation: the "8.4.3" state is
not part of the branch's main evolution, but is a little side branch
all by itself.

> The effect of all of this is that if someone checks out a git commit
> between 2010-02-28 and 2010-05-13, it.po will be there, even though
> file didn't exist on that CVS branch at that time.

Yeah, that's what it's doing for me.

> Max's contention
> seems to be that this is a CVS problem rather than a cvs2git problem.

No doubt. However, the facts on the ground are that it.po is provably
not there in REL8_4_0, REL8_4_1, REL8_4_2, or REL8_4_3, and is there in
REL8_4_4, and that no commit on the branch touched it before 2010-05-13
(just before 8.4.4). I will be interested to see the argument why
cvs2git should consider the sanest translation of these facts to involve
adding it.po to the branch after 8.4.2 and removing it again before
8.4.3.

regards, tom lane