[PATCH v2 1/2] environment: move ignore_case into repo_config_values

[Tian Yuchen <cat@malon.dev>]

The 'core.ignorecase' configuration which is stored as the
global variable 'ignore_case' acts as a core filesystem
capability flag.

Move this global variable into 'struct repo_config_values' to tie it
to the specific repository instance it was read from. This reduces
global state and aligns with the ongoing libification effort.

To ensure code readability, the getter function
'repo_ignore_case()' is introduced.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Ayush Chandekar <ayu.chandekar@gmail.com>
Mentored-by: Olamide Caleb Bello <belkid98@gmail.com>
Signed-off-by: Tian Yuchen <cat@malon.dev>
---
 environment.c | 8 ++++++++
 environment.h | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/environment.c b/environment.c
index fc3ed8bb1c..bfa3cb3045 100644
--- a/environment.c
+++ b/environment.c
@@ -142,6 +142,13 @@ int is_bare_repository(void)
 	return is_bare_repository_cfg && !repo_get_work_tree(the_repository);
 }
 
+int repo_ignore_case(struct repository *repo)
+{
+	return (repo && repo->initialized) ?
+		repo_config_values(repo)->ignore_case :
+		0;
+}
+
 int have_git_dir(void)
 {
 	return startup_info->have_repository
@@ -720,5 +727,6 @@ void repo_config_values_init(struct repo_config_values *cfg)
 {
 	cfg->attributes_file = NULL;
 	cfg->apply_sparse_checkout = 0;
+	cfg->ignore_case = 0;
 	cfg->branch_track = BRANCH_TRACK_REMOTE;
 }
diff --git a/environment.h b/environment.h
index 9eb97b3869..39a8bf0b49 100644
--- a/environment.h
+++ b/environment.h
@@ -91,6 +91,7 @@ struct repo_config_values {
 	/* section "core" config values */
 	char *attributes_file;
 	int apply_sparse_checkout;
+	int ignore_case;
 
 	/* section "branch" config values */
 	enum branch_track branch_track;
@@ -123,6 +124,13 @@ int git_default_config(const char *, const char *,
 int git_default_core_config(const char *var, const char *value,
 			    const struct config_context *ctx, void *cb);
 
+/*
+ * Getter for the `ignore_case` field of `struct repo_config_values`.
+ * It checks `repo->initialized` to prevent calling repo_config_values()`
+ * before the repository setup is fully complete or in non-git environments.
+ */
+int repo_ignore_case(struct repository *repo);
+
 void repo_config_values_init(struct repo_config_values *cfg);
 
 /*
-- 
2.43.0