Re: Bisect needing to be at repo top-level?

[Junio C Hamano <gitster@pobox.com>]

Lukas Fleischer <git@cryptocrack.de> writes:

>> Imagine if you start from a subdirectory foo/ but the directory did
>> not exist in the older part of the history of the project.  When
>> bisect needs to check out a revision that was older than the first
>> revision that introduced that subdirectory, what should happen?
>> Worse yet, if "foo" was a file in the older part of the history,
>> what should happen?
>
> If that is the real explanation,

No.  As the line you snipped from your quote says, it is just a
guess without running "git log -- git-bisect.sh git-bisect-script".

Also it points at things one needs to watch out for and think about
when attempting to update "git bisect" to make it possible to run it
anywhere in the working tree.

> why do we allow running git-checkout(1)
> from a subdirectory?

Oversight?

At least on Linux, if you checkout a revision with "foo/" directory,
chdir to it and then checkout a revision with "foo" file to nuke
your current place, I know "git checkout" will happily do so and you
will still be in a directory that is connected nowhere.  Your ".."
is probably pointing at the top-level, but there is no reverse, so
"cd ../foo" may or may not work from that state, and it would lead
to an interesting confusion.

We may want to check the condition and forbid such a checkout.