Re: [PATCH 0/4] Sparse checkout: fix bug with worktree of bare repo

From: Eric Sunshine <sunshine@sunshineco.com>
Date: Dec 20, 2021, 16:21 UTC
Message-ID: <CAPig+cTVzMtiHzkJq7VRg4Xa3xhrq7KKCdK5OSDY6bvwKu_ynA@mail.gmail.com>
In-Reply-To: <pull.1101.git.1640015844.gitgitgadget@gmail.com>

On Mon, Dec 20, 2021 at 10:57 AM Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com> wrote:

Show 8 quoted lines

> This patch series includes a fix to the bug reported by Sean Allred [1] and
> diagnosed by Eric Sunshine [2].
>
> The root cause is that 'git sparse-checkout init' writes to the worktree
> config without checking that core.bare might need to be set. This only
> matters when the base repository is bare, since creating the config.worktree
> file and enabling extensions.worktreeConfig will cause Git to treat the base
> repo's core.bare=false as important for this worktree.

Thanks for jumping on this so quickly. Unfortunately, however, as mentioned in [1] and [2], I think the approach implemented here of setting `core.bare=false` in the worktree-specific config is fundamentally flawed since it only addresses the problem for worktrees in which `git sparse-checkout init` has been run, but leaves all other worktrees potentially broken (both existing and new worktrees). As far as I can see, the _only_ correct solution is for the new helper function to enable `extensions.worktreeConfig` _and_ relocate `core.bare` and `core.worktree` from .git/config to .git/worktree.config, thus implementing the requirements documented in git-worktree.txt.

I also raised a separate question in [2] about whether `git sparse-checkout init` or the new helper function should be warning the user that upgrading the repository format and setting `extensions.worktreeConfig` might break third-party tools. However, that question is tangential to the fix being addressed here and doesn't need to be addressed by this series.

[1]: https://lore.kernel.org/git/CAPig+cQ6U_yFw-X2OWrizB1rbCvc4bNxuSzKFzmoLNnm0GH8Eg@mail.gmail.com/ [2]: https://lore.kernel.org/git/CAPig+cQPUe9REf+wgVNjyak_nk3V361h-48rTFgk6TGC7vJgOA@mail.gmail.com/