[PATCH] repo: zero-initialize configuration values

[PATCH] repo: zero-initialize configuration values

[Joy via GitGitGadget]

From: Joy Gundu <soniqjjj@gmail.com>

Use memset() to initialize repository configuration values to
zero, removing the need for explicit zero and NULL assignments.
Keep non-zero defaults initialized separately.

Signed-off-by: Joy Gundu <soniqjjj@gmail.com>
---
    [Outreachy] repo: zero-initialize configuration values

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2298%2FJoiejoie1%2Frepo-zero-initialize-config-values-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2298/Joiejoie1/repo-zero-initialize-config-values-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/2298

 environment.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/environment.c b/environment.c
index c83cf44839..afe35cff99 100644
--- a/environment.c
+++ b/environment.c
@@ -752,34 +752,22 @@ int git_default_config(const char *var, const char *value,
 
 void repo_config_values_init(struct repo_config_values *cfg)
 {
+	memset(cfg, 0, sizeof(*cfg));
+
 	/* section "core" config values */
-	cfg->attributes_file = NULL;
-	cfg->excludes_file = NULL;
-	cfg->editor_program = NULL;
-	cfg->pager_program = NULL;
-	cfg->askpass_program = NULL;
-	cfg->apply_default_whitespace = NULL;
-	cfg->apply_default_ignorewhitespace = NULL;
 	cfg->push_default = PUSH_DEFAULT_UNSPECIFIED;
 	cfg->autorebase = AUTOREBASE_NEVER;
 	cfg->object_creation_mode = OBJECT_CREATION_MODE;
-	cfg->apply_sparse_checkout = 0;
 	cfg->trust_ctime = 1;
 	cfg->check_stat = 1;
 	cfg->zlib_compression_level = Z_BEST_SPEED;
 	cfg->pack_compression_level = Z_DEFAULT_COMPRESSION;
 	cfg->precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
-	cfg->core_sparse_checkout_cone = 0;
 	cfg->warn_on_object_refname_ambiguity = 1;
 	cfg->protect_hfs = PROTECT_HFS_DEFAULT;
 	cfg->protect_ntfs = PROTECT_NTFS_DEFAULT;
-	cfg->ignore_case = 0;
 	cfg->trust_executable_bit = 1;
 	cfg->has_symlinks = platform_has_symlinks();
-	cfg->use_nanosec = 0;
-
-	/* section "sparse" config values */
-	cfg->sparse_expect_files_outside_of_patterns = 0;
 
 	/* section "branch" config values */
 	cfg->branch_track = BRANCH_TRACK_REMOTE;

base-commit: 3de8ebe6c8cfcd312cdbfa675635810140f84c8a
-- 
gitgitgadget

Re: [PATCH] repo: zero-initialize configuration values

[Patrick Steinhardt]

On Fri, Nov 06, 2026 at 11:59:28AM +0000, Joy via GitGitGadget wrote:
> From: Joy Gundu <soniqjjj@gmail.com>
> 
> Use memset() to initialize repository configuration values to
> zero, removing the need for explicit zero and NULL assignments.
> Keep non-zero defaults initialized separately.
> 
> Signed-off-by: Joy Gundu <soniqjjj@gmail.com>
> ---
>     [Outreachy] repo: zero-initialize configuration values

So I guess this patch was split out because of our recent push to not
make further changes to `repo_config_values()`? If so, it would have
made sense to point that out explicitly both here, and in the original
thread that you've sent.

In any case, the patch is obviously correct and is a good improvement in
my opinion. So this looks good to me, thanks.

Patrick

Re: [PATCH] repo: zero-initialize configuration values

[Joie Joie]

Thanks, Patrick.

Yes, that was my reason for splitting the patch. It only changes how
the existing configuration values are initialized and doesn't add a
new struct member, so I felt it could be reviewed separately from the
changes affected by the recent direction.

You're right, though. I should have explained that more clearly in the
patch description and the original thread. I'll make sure to include
that context in future submissions.

Thanks for taking the time to review it!

On Fri, Nov 6, 2026 at 3:16 PM Patrick Steinhardt <ps@pks.im> wrote:
>
> On Fri, Nov 06, 2026 at 11:59:28AM +0000, Joy via GitGitGadget wrote:
> > From: Joy Gundu <soniqjjj@gmail.com>
> >
> > Use memset() to initialize repository configuration values to
> > zero, removing the need for explicit zero and NULL assignments.
> > Keep non-zero defaults initialized separately.
> >
> > Signed-off-by: Joy Gundu <soniqjjj@gmail.com>
> > ---
> >     [Outreachy] repo: zero-initialize configuration values
>
> So I guess this patch was split out because of our recent push to not
> make further changes to `repo_config_values()`? If so, it would have
> made sense to point that out explicitly both here, and in the original
> thread that you've sent.
>
> In any case, the patch is obviously correct and is a good improvement in
> my opinion. So this looks good to me, thanks.
>
> Patrick

Re: [PATCH] repo: zero-initialize configuration values

[Junio C Hamano]

Patrick Steinhardt <ps@pks.im> writes:

> In any case, the patch is obviously correct and is a good improvement in
> my opinion. So this looks good to me, thanks.

It however does not look good to me.  I would prefer to see

	struct foo foo = {0};

if everything is zero initialized, or if there are some members
initialized to specific values, C99 designated initializers to be
used:

	struct foo foo = {
		/* Comment on this stuff */
		.object_creation_mode = OBJECT_CREATION_MODE,

                /* Comment on this other stuff */
		.branch_track = BRANCH_TRACK_REMOTE,
	};

Now this is overwriting the passed in structure members, so how we
write the initialization is not the whole story.

Since we have avoided assuming the universal availability of the
more recent "compound literals" syntax, which is:

	*cfg = (struct foo) {
		... an initialization with designated initializers ...
	};

we seem to (ab)use struct assignment, e.g.,

	static struct foo foo_template = {
		... an initialization with designated initializers ...
	};

	*cfg = foo_template;

in a few places as a fallback in the existing code (DI is C99,
struct assignment is C89, so it has been a safer assumption than
assuming compound literals).

But I do recall we made this update to our CodingGuidelines document.

   . since late 2024 with v2.48.0-rc0~20, we have been using compound
     literals, e.g., (struct foo){ .member = value };

So perhaps it is time to switch this to assign a compound literal?