Re: git init BUG when gitconfig has includeIf

> On Tue, May 21, 2024 at 04:46:23PM +0000, Heghedus Razvan wrote:
> > On Tue May 21, 2024 at 7:36 PM EEST, Junio C Hamano wrote:
> > > Heghedus Razvan <heghedus.razvan@protonmail.com> writes:
> > >
> > > > Yesterday I stumble upon a bug when doing git init. I didn't
> > > > find any references to it, so I don't know if is a known problem
> > > > or not.
> > > >
> > > > Steps to reproduce:
> > > > # git init .
> > > > BUG: refs.c:2123: reference backend is unknown
> > >
> > > Patrick, this looks similar to an earlier one during "git clone"
> > > that was discussed at
> > >
> > > https://lore.kernel.org/git/72771da0-a0ef-4fd9-8071-6467cd7b6a6b@kernel-space.org/
> > >
> > > that was fixed with 199f44cb (builtin/clone: allow remote helpers to
> > > detect repo, 2024-02-27)?  The fix was about "git clone", but the
> > > crux of the fix went to setup.c:initialize_repository_version()
> > > which is also called by setup.c:init_db() that is the workhorse of
> > > "git init", so it may already have been fixed (I didn't try).
> > 
> > I guess I forgot to mention, but I tested the current master 4365c6fcf9
> > and the issue is still present.
>
> I cannot reproduce the issue as-is, neither on Git v2.44 nor on the
> current master branch. So clearly, there must be something special to
> your setup. The following testcase and variants of it do not reproduce:
>
>     test_expect_success 'init with includeIf.onbranch condition' '
>         git config -f ./config foo.bar baz &&
>         include=$(test-tool path-utils absolute_path config) &&
>         test_when_finished "rm -rf repo" &&
>         git -c includeIf.onbranch:main.path="$(<include)" init repo
>     '
>
> Now digging into the code, the condition gets evaluated in
> `include_by_branch()`. The call to `refs_resolve_ref_unsafe()` is
> guarded by `the_repository->gitdir`, which is `NULL` the first time it
> is called by git-init(1). It does get called a second time, but at that
> point we already initialized the refdb and configured the ref storage
> format as expected.
>
> Aha! Seems like this only happens when re-initializing an already
> existent repository, that's what's missing. In that case we do already
> have `the_repository->gitdir` set even though we did not yet set up the
> ref storage format. I'll investigate and send a patch.
>
> Can you confirm that this is what you see, or do you also see this when
> creating an entirely new repository?

>
> > > Even if it is already fixed in the current version by the same
> > > 199f44cb, we may want to follow up 0eab85b9 (t5601: exercise clones
> > > with "includeIf.*.onbranch", 2024-03-12) with an additional test to
> > > cover "git init".
>
> Agreed.
>
> Patrick