environment: move "core.attributesFile" into repo-setting

When handling multiple repositories within the same process, relying on
global state for accessing the "core.attributesFile" configuration can
lead to incorrect values being used. It also makes it harder to isolate
repositories and hinders the libification of git.
The functions `bootstrap_attr_stack()` and `git_attr_val_system()`
retrieve "core.attributesFile" via `git_attr_global_file()`
which reads from global state `git_attributes_file`.

Move the "core.attributesFile" configuration into the
`struct repo_settings` instead of relying on the global state.
A new function `repo_settings_get_attributesfile_path()` is added
and used to retrieve this setting in a repository-scoped manner.
The functions to retrieve "core.attributesFile" are replaced with
the new accessor function `repo_settings_get_attributesfile_path()`
This improves multi-repository behaviour and aligns with the goal of
libifying of Git.

Note that in `bootstrap_attr_stack()`, the `index_state` is used only
if it exists, else we default to `the_repository`.

Based-on-patch-by: Ayush Chandekar <ayu.chandekar@gmail.com>
Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Usman Akinyemi <usmanakinyemi202@gmail.com>
Signed-off-by: Olamide Caleb Bello <belkid98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

attr.c

@@ -879,14 +879,6 @@ const char *git_attr_system_file(void)
 	return system_wide;
 }
 
-const char *git_attr_global_file(void)
-{
-	if (!git_attributes_file)
-		git_attributes_file = xdg_config_home("attributes");
-
-	return git_attributes_file;
-}
-
 int git_attr_system_is_enabled(void)
 {
 	return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
@@ -912,6 +904,8 @@ static void bootstrap_attr_stack(struct index_state *istate,
 {
 	struct attr_stack *e;
 	unsigned flags = READ_ATTR_MACRO_OK;
+	const char *attributes_file_path;
+	struct repository *repo;
 
 	if (*stack)
 		return;
@@ -927,8 +921,13 @@ static void bootstrap_attr_stack(struct index_state *istate,
 	}
 
 	/* home directory */
-	if (git_attr_global_file()) {
-		e = read_attr_from_file(git_attr_global_file(), flags);
+	if (istate && istate->repo)
+		repo = istate->repo;
+	else
+		repo = the_repository;
+	attributes_file_path = repo_settings_get_attributesfile_path(repo);
+	if (attributes_file_path) {
+		e = read_attr_from_file(attributes_file_path, flags);
 		push_stack(stack, e, NULL, 0);
 	}
 

attr.h

@@ -232,9 +232,6 @@ void attr_start(void);
 /* Return the system gitattributes file. */
 const char *git_attr_system_file(void);
 
-/* Return the global gitattributes file, if any. */
-const char *git_attr_global_file(void);
-
 /* Return whether the system gitattributes file is enabled and should be used. */
 int git_attr_system_is_enabled(void);
 

builtin/var.c

@@ -72,7 +72,7 @@ static char *git_attr_val_system(int ident_flag UNUSED)
 
 static char *git_attr_val_global(int ident_flag UNUSED)
 {
-	char *file = xstrdup_or_null(git_attr_global_file());
+	char *file = xstrdup_or_null(repo_settings_get_attributesfile_path(the_repository));
 	if (file) {
 		normalize_path_copy(file, file);
 		return file;

environment.c

@@ -53,7 +53,6 @@ char *git_commit_encoding;
 char *git_log_output_encoding;
 char *apply_default_whitespace;
 char *apply_default_ignorewhitespace;
-char *git_attributes_file;
 int zlib_compression_level = Z_BEST_SPEED;
 int pack_compression_level = Z_DEFAULT_COMPRESSION;
 int fsync_object_files = -1;
@@ -363,11 +362,6 @@ static int git_default_core_config(const char *var, const char *value,
 		return 0;
 	}
 
-	if (!strcmp(var, "core.attributesfile")) {
-		FREE_AND_NULL(git_attributes_file);
-		return git_config_pathname(&git_attributes_file, var, value);
-	}
-
 	if (!strcmp(var, "core.bare")) {
 		is_bare_repository_cfg = git_config_bool(var, value);
 		return 0;

environment.h

@@ -152,7 +152,6 @@ 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;

repo-settings.c

@@ -5,6 +5,7 @@
 #include "midx.h"
 #include "pack-objects.h"
 #include "setup.h"
+#include "path.h"
 
 static void repo_cfg_bool(struct repository *r, const char *key, int *dest,
 			  int def)
@@ -158,6 +159,7 @@ void repo_settings_clear(struct repository *r)
 	struct repo_settings empty = REPO_SETTINGS_INIT;
 	FREE_AND_NULL(r->settings.fsmonitor);
 	FREE_AND_NULL(r->settings.hooks_path);
+	FREE_AND_NULL(r->settings.attributes_file_path);
 	r->settings = empty;
 }
 
@@ -230,3 +232,11 @@ void repo_settings_reset_shared_repository(struct repository *repo)
 {
 	repo->settings.shared_repository_initialized = 0;
 }
+const char *repo_settings_get_attributesfile_path(struct repository *repo)
+{
+	if (!repo->settings.attributes_file_path) {
+		if (repo_config_get_pathname(repo, "core.attributesfile", &repo->settings.attributes_file_path))
+			repo->settings.attributes_file_path = xdg_config_home("attributes");
+	}
+	return repo->settings.attributes_file_path;
+}

repo-settings.h

@@ -68,6 +68,7 @@ struct repo_settings {
 	unsigned long big_file_threshold;
 
 	char *hooks_path;
+	char *attributes_file_path;
 };
 #define REPO_SETTINGS_INIT { \
 	.shared_repository = -1, \
@@ -99,4 +100,11 @@ int repo_settings_get_shared_repository(struct repository *repo);
 void repo_settings_set_shared_repository(struct repository *repo, int value);
 void repo_settings_reset_shared_repository(struct repository *repo);
 
+/*
+ * Read the value for "core.attributesfile".
+ * Defaults to xdg_config_home("attributes") if the core.attributesfile
+ * which is set via repo config isn't available.
+ */
+const char *repo_settings_get_attributesfile_path(struct repository *repo);
+
 #endif /* REPO_SETTINGS_H */