Re: [PATCH v6 0/6] Sparse checkout: fix bug with worktree of bare repo

[Elijah Newren <newren@gmail.com>]

On Mon, Feb 7, 2022 at 1:33 PM Derrick Stolee via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> This series is now based on v2.35.0 since that contains all of the necessary
> topics.
>
> 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 or core.worktree are set in the
> common config file. This series fixes this, but also puts in place some
> helpers to prevent this from happening in the future.
>
> ATTENTION: I have significantly redesigned the series since previous
> versions, so most of this cover letter is new.
>
>  * Patch 1 updates documentation around extensions.worktreeConfig in a few
>    places to improve discoverability. Several cross links are added to make
>    it easy to find the related areas. (The documentation for the changes to
>    'git sparse-checkout' are delayed to patch 4.)
>
>  * Patch 2 introduces the init_worktree_config() helper which follows the
>    documented instructions to enable extensions.worktreeConfig as well as
>    move the core.bare and core.worktree config values. This update does not
>    modify core.repositoryFormatVersion, since this is not needed
>    specifically for extensions.worktreeConfig.
>
>  * Patch 3 adds a new repo_config_set_worktree_gently() helper method so we
>    can internally adjust a config value within a worktree, at least if
>    extensions.worktreeConfig is enabled. (It will write to the common config
>    file if the extension is not enabled.)
>
>  * Patch 4 modifies the sparse-checkout builtin to use
>    init_worktree_config() and repo_config_set_worktree_gently() in ways that
>    fix the reported bug. The behavior change here is that it will no longer
>    upgrade the repository format version, since that is not needed for
>    extensions.worktreeConfig.
>
>  * Patch 5 updates 'git worktree add' to copy the worktree config from the
>    current worktree to the new one (while unsetting core.bare=true and
>    core.worktree=*) along with copying the sparse-checkout patterns file.
>
> [1]
> https://lore.kernel.org/git/CABceR4bZmtC4rCwgxZ1BBYZP69VOUca1f_moJoP989vTUZWu9Q@mail.gmail.com/
> [2]
> https://lore.kernel.org/git/CAPig+cQ6U_yFw-X2OWrizB1rbCvc4bNxuSzKFzmoLNnm0GH8Eg@mail.gmail.com/
>
>
> Updates in v6
> =============
>
>  * Updated documentation to use "working tree" over "worktree" and "" over
>    ""

Not sure what "" over "" means.

>  * Delay some allocations to avoid leaking memory in error conditions.
>  * Use "main worktree" over "base worktree" in comments.
>  *

Was the empty bullet point meant to cover the new patch 6?  Anyway,
comments on the cover letter aside, the patches themselves are:

Reviewed-by: Elijah Newren <newren@gmail.com>