[PATCH v2 2/2] environment: move excludes_file into repo_config_values

[Tian Yuchen <cat@malon.dev>]

Continue the libification effort by moving the 'excludes_file' global
variable into 'struct repo_config_values'.

Since 'excludes_file' is a dynamically allocated string (char *), it
requires proper memory management. Introduce repo_config_values_clear()
to safely free the heap memory when repository instance is destroyed.

Note:

 - 'if (repo != the_repository)' fallback logic is temporarily added
in both the getter and the clear function. This prevents calling
repo_config_values() on uninitialized submodules, which triggers BUG().

 - 'attribute_file' is another string variable that was migrated
 earlier. Its FREE_AND_NULL() call is also added to
 repo_config_values_clear().

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 | 31 +++++++++++++++++++++++++------
 environment.h | 14 ++++++++++----
 repository.c  |  1 +
 3 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/environment.c b/environment.c
index 8efcaeafa6..b8dfa3e213 100644
--- a/environment.c
+++ b/environment.c
@@ -57,7 +57,6 @@ enum fsync_method fsync_method = FSYNC_METHOD_DEFAULT;
 enum fsync_component fsync_components = FSYNC_COMPONENTS_DEFAULT;
 char *editor_program;
 char *askpass_program;
-char *excludes_file;
 enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
 enum eol core_eol = EOL_UNSET;
 int global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
@@ -136,9 +135,13 @@ int is_bare_repository(void)
 
 const char *repo_excludes_file(struct repository *repo)
 {
-	if (!excludes_file)
-		excludes_file = xdg_config_home("ignore");
-	return excludes_file;
+	if (!repo || !repo->initialized || repo != the_repository)
+		return NULL;
+
+	if (!repo_config_values(repo)->excludes_file)
+		repo_config_values(repo)->excludes_file = xdg_config_home("ignore");
+
+	return repo_config_values(repo)->excludes_file;
 }
 
 int have_git_dir(void)
@@ -468,8 +471,8 @@ int git_default_core_config(const char *var, const char *value,
 	}
 
 	if (!strcmp(var, "core.excludesfile")) {
-		FREE_AND_NULL(excludes_file);
-		return git_config_pathname(&excludes_file, var, value);
+		FREE_AND_NULL(cfg->excludes_file);
+		return git_config_pathname(&cfg->excludes_file, var, value);
 	}
 
 	if (!strcmp(var, "core.whitespace")) {
@@ -722,6 +725,7 @@ int git_default_config(const char *var, const char *value,
 void repo_config_values_init(struct repo_config_values *cfg)
 {
 	cfg->attributes_file = NULL;
+	cfg->excludes_file = NULL;
 	cfg->apply_sparse_checkout = 0;
 	cfg->branch_track = BRANCH_TRACK_REMOTE;
 	cfg->trust_ctime = 1;
@@ -733,3 +737,18 @@ void repo_config_values_init(struct repo_config_values *cfg)
 	cfg->sparse_expect_files_outside_of_patterns = 0;
 	cfg->warn_on_object_refname_ambiguity = 1;
 }
+
+void repo_config_values_clear(struct repository *repo)
+{
+	struct repo_config_values *cfg;
+
+	if (repo != the_repository)
+		return;
+
+	cfg = repo_config_values(repo);
+	if (!cfg)
+		return;
+
+	FREE_AND_NULL(cfg->attributes_file);
+	FREE_AND_NULL(cfg->excludes_file);
+}
diff --git a/environment.h b/environment.h
index 52d531e4ea..2e8352de7f 100644
--- a/environment.h
+++ b/environment.h
@@ -90,6 +90,7 @@ struct repository;
 struct repo_config_values {
 	/* section "core" config values */
 	char *attributes_file;
+	char *excludes_file;
 	int apply_sparse_checkout;
 	int trust_ctime;
 	int check_stat;
@@ -133,13 +134,19 @@ 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);
 
-/*
- * TODO: This still relies on the global state.
- */
 const char *repo_excludes_file(struct repository *repo);
 
 void repo_config_values_init(struct repo_config_values *cfg);
 
+/*
+ * Frees memory allocated for dynamically loaded configuration values
+ * inside `repo_config_values`.
+ *
+ * As dynamically allocated variables are migrated into this struct,
+ * their FREE_AND_NULL() calls should be appended here.
+ */
+void repo_config_values_clear(struct repository *repo);
+
 /*
  * TODO: All the below state either explicitly or implicitly relies on
  * `the_repository`. We should eventually get rid of these and make the
@@ -213,7 +220,6 @@ extern char *git_log_output_encoding;
 
 extern char *editor_program;
 extern char *askpass_program;
-extern char *excludes_file;
 
 /*
  * The character that begins a commented line in user-editable file
diff --git a/repository.c b/repository.c
index 187dd471c4..b31f1b7852 100644
--- a/repository.c
+++ b/repository.c
@@ -388,6 +388,7 @@ void repo_clear(struct repository *repo)
 	FREE_AND_NULL(repo->parsed_objects);
 
 	repo_settings_clear(repo);
+	repo_config_values_clear(repo);
 
 	if (repo->config) {
 		git_configset_clear(repo->config);
-- 
2.43.0