environment: stop storing `core.attributesFile` globally

The `core.attributeFile` config value is parsed in
git_default_core_config(), loaded eagerly and stored in the global
variable `git_attributes_file`. Storing this value in a global
variable can lead to it being overwritten by another repository when
more than one Git repository run in the same Git process.

Create a new struct `repo_config_values` to hold this value and
other repository dependent values parsed by `git_default_config()`.
This will ensure the current behaviour remains the same while also
enabling the libification of Git.

An accessor function 'repo_config_values()' s created to ensure
that we do not access an uninitialized repository, or an instance
of a different repository than the current one.

Suggested-by: Phillip Wood <phillip.wood123@gmail.com>
Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Usman Akinyemi <usmanakinyemi202@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Olamide Caleb Bello <belkid98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/environment.h b/environment.h
index 51898c99cd..dfc31b794d 100644
--- a/environment.h
+++ b/environment.h
@@ -84,6 +84,14 @@ extern const char * const local_repo_env[];
 
 struct strvec;
 
+struct repository;
+struct repo_config_values {
+	/* section "core" config values */
+	char *attributes_file;
+};
+
+struct repo_config_values *repo_config_values(struct repository *repo);
+
 /*
  * Wrapper of getenv() that returns a strdup value. This value is kept
  * in argv to be freed later.
@@ -107,6 +115,8 @@ const char *strip_namespace(const char *namespaced_ref);
 int git_default_config(const char *, const char *,
 		       const struct config_context *, void *);
 
+void repo_config_values_init(struct repo_config_values *cfg);
+
 /*
  * TODO: All the below state either explicitly or implicitly relies on
  * `the_repository`. We should eventually get rid of these and make the
@@ -152,7 +162,6 @@ extern int assume_unchanged;
 extern int warn_on_object_refname_ambiguity;
 extern char *apply_default_whitespace;
 extern char *apply_default_ignorewhitespace;
-extern char *git_attributes_file;
 extern int zlib_compression_level;
 extern int pack_compression_level;
 extern unsigned long pack_size_limit_cfg;