'git rev-parse --show-toplevel' errors out with per-worktree configs

[Clement Moyroud <clement.moyroud@gmail.com>]

Hello,

I have a bare repository clone that I create worktrees off. This works
fine, including 'git rev-parse --show-toplevel'.

I enabled per-worktree configs using 'git config --local
extensions.worktreeconfig=true', and now I can't get the toplevel
anymore:
> git rev-parse --show-toplevel
fatal: this operation must be run in a work tree

Disabling per-worktree configs makes it work again. This also works
fine on a non-bare repository clone.

IOW, this works:
git clone <url> non-bare
(cd non-bare && git worktree add -b master2 ../wtree1 master)
(cd wtree1 && git rev-parse --show-toplevel)

This does not:
git clone -c extensions.worktreeConfig=true <url> bare.git
(cd bare.git && git worktree add -b master2 ../wtree2 master)
(cd wtree2 && git rev-parse --show-toplevel)

Is this a bug, or am I missing something?

Thanks,

Clément