Re: [GSOC PATCH v4 2/3] environment: move access to "core.sparsecheckoutcone" into repo_settings

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 17, 2025, 16:29 UTC
Message-ID: <xmqqplf2uy9w.fsf@gitster.g>
In-Reply-To: <9a638843411d0542e240ea0dd9537f388523fb3c.1750157825.git.ayu.chandekar@gmail.com>

Ayush Chandekar <ayu.chandekar@gmail.com> writes:

Show 14 quoted lines

> The setting "core.sparsecheckoutcone" is stored in the global
> `core_sparse_checkout_cone` and is populated in config.c. Refactor the
> code to store it in the variable `sparse_checkout_cone` in the struct
> `repo_settings`.
> It's fine not to lazily load it from the config, as the variable
> is used quite commonly.
>
> This change is part of an ongoing effort to eliminate global variables,
> improve modularity and help libify the codebase.
>
> Mentored-by: Christian Couder <christian.couder@gmail.com>
> Mentored-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
> Signed-off-by: Ayush Chandekar <ayu.chandekar@gmail.com>
> ---

I think "the correctness guarantee comes from a different place now. How are we making sure that these accesses are correct?" comment applies equally here.

>  builtin/grep.c            |  2 +-
>  builtin/mv.c              |  2 +-

Looking at the output from

    $ git grep -n -e prepare_repo_settings \*.c

there are many builtin/*.c that makes a call to the function on the_repository fairly early in its start-up sequence. Unlike many others these two do not seem to have any.

>  builtin/sparse-checkout.c | 28 ++++++++++++++--------------

This one does, immediately after calling git_config(), so it should be fairly safe.

>  dir.c                     |  2 +-
>  sparse-index.c            |  2 +-

These two also need correctness guarantee.

You'd need to make sure any potential caller of the helper functions have called prepare_repo_settings(). Those who wrote an access to the global variable in the original would already have made sure that the callers would have already read the configuration file, but with the new code, that is no longer a guarantee for correctness.