Re: [PATCH/RFC 0/9] Pseudorefs

[Michael Haggerty <mhagger@alum.mit.edu>]

On 07/24/2015 06:45 AM, David Turner wrote:
> This series is another chunk of the pluggable refs backend work.  The
> major reason it is listed as "PATCH/RFC" is beacuse it breaks
> t9300-fast-import.sh, because fast-import wants to create a ref called
> TEMP_TAG, which would now be a pseudoref.  The commit that introduces
> this test says that cvs2svn creates a tag called TAG_FIXUP "as a branch
> name for temporary work needed to cleanup the tree prior to creating
> an annotated tag object."
> 
> It appears that cvs2svn still does this.  So I'm not quite sure what to
> do about this particular case.
> 
> As we discussed earlier, the motivation for this series is that refs
> backends other than the files-based backend need to treat per-worktree
> refs (HEAD) and pseudorefs (FETCH_HEAD) differently from other refs;
> other refs are per-repo rather than per-worktree.

Sorry, I missed this email while on vacation.

cvs2git needs to create a temporary reference for cobbling together
tagged commits. Originally I was going to use the name `TAG_FIXUP`, as
suggested by git-fast-import(1) [1]. But that functionality turned out
to be buggy in `git fast-import` at the time. So I reported the bug but
changed cvs2git to use `refs/heads/TAG.FIXUP` [2]. The bug in `git
fast-import` was fixed, including the test case that you found, but I
never changed cvs2git back to using the originally-planned name. The
fact that the test case uses a name different than `TAG_FIXUP` probably
means that Shawn thought that any references named similarly should be
allowed.

Summary: support for a reference named `TAG_FIXUP` is not needed by
cvs2git. However, its use is a documented recommendation of `git
fast-import`, so it is quite possible that other importers are using
this name.

I expect that such importers would slightly prefer that this reference
be worktree-specific, but I doubt that anybody really cares that much.
It seems unlikely that people will run `git fast-import` in multiple
worktrees simultaneously.

Michael

[1] http://git-scm.com/docs/git-fast-import#_use_tag_fixup_branches
[2]
https://github.com/mhagger/cvs2svn/blob/master/cvs2svn_lib/git_output_option.py#L502-L509

-- 
Michael Haggerty
mhagger@alum.mit.edu