git-gc doesn't clean up leftover objects after git-filter-branch unless you clone first

From: Avery Pennarun <apenwarr@gmail.com>
Date: Apr 23, 2008, 15:41 UTC
Message-ID: <32541b130804230841h32c07f3arc94cccfaf0b156a3@mail.gmail.com>

On 4/23/08, Johannes Sixt <j.sixt@viscovery.net> wrote:

Show 12 quoted lines

> Peter Karlsson schrieb:
> > [Not seeing any unreachable objects]
>
> > Jeff King:
> >> Did you remove refs/original/ ?
>  >
>  > That, and cloned the repository to a new location after the conversion,
>  > and removing the references to "origin" there. It does seem that the
>  > objects are still there, but I can't see them with "gitk --all".
>
> Did you clone locally? Then you must use the file:// protocol, otherwise
>  everything is hard-linked from the origin.

This question has come up at least once a week since I subscribed to the list. I can think of these solutions:

- Add a note to the git-gc and/or git-repack man page about how hidden
refs can impact the cleanup.

- Add an option to make git-clone *not* hardlink stuff; its different
behaviour for hardlinking vs. file:// seems to be very confusing.

- Make git-gc give a warning when there are some objects that are only
referenced via the reflog or refs/original.  (I suspect this would
trigger too often though.)

- Give git-gc a "really, I'm serious" option that makes it ignore the
reflog and refs/original.

Thoughts?

Avery