environment: stop storing "core.notesRef" globally

Stop storing the "core.notesRef" config value globally. Instead,
retrieve the value in `default_notes_ref()`. The code is never called in
a hot loop anyway, so doing this on every invocation should be perfectly
fine.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/notes.c

@@ -897,6 +897,7 @@ static int merge(int argc, const char **argv, const char *prefix)
 			      1, PARSE_OPT_NONEG),
 		OPT_END()
 	};
+	char *notes_ref;
 
 	argc = parse_options(argc, argv, prefix, options,
 			     git_notes_merge_usage, 0);
@@ -924,7 +925,8 @@ static int merge(int argc, const char **argv, const char *prefix)
 	if (do_commit)
 		return merge_commit(&o);
 
-	o.local_ref = default_notes_ref();
+	notes_ref = default_notes_ref(the_repository);
+	o.local_ref = notes_ref;
 	strbuf_addstr(&remote_ref, argv[0]);
 	expand_loose_notes_ref(&remote_ref);
 	o.remote_ref = remote_ref.buf;
@@ -953,7 +955,7 @@ static int merge(int argc, const char **argv, const char *prefix)
 	}
 
 	strbuf_addf(&msg, "notes: Merged notes from %s into %s",
-		    remote_ref.buf, default_notes_ref());
+		    remote_ref.buf, notes_ref);
 	strbuf_add(&(o.commit_msg), msg.buf + 7, msg.len - 7); /* skip "notes: " */
 
 	result = notes_merge(&o, t, &result_oid);
@@ -961,7 +963,7 @@ static int merge(int argc, const char **argv, const char *prefix)
 	if (result >= 0) /* Merge resulted (trivially) in result_oid */
 		/* Update default notes ref with new commit */
 		refs_update_ref(get_main_ref_store(the_repository), msg.buf,
-				default_notes_ref(), &result_oid, NULL, 0,
+				notes_ref, &result_oid, NULL, 0,
 				UPDATE_REFS_DIE_ON_ERR);
 	else { /* Merge has unresolved conflicts */
 		struct worktree **worktrees;
@@ -973,14 +975,14 @@ static int merge(int argc, const char **argv, const char *prefix)
 		/* Store ref-to-be-updated into .git/NOTES_MERGE_REF */
 		worktrees = get_worktrees();
 		wt = find_shared_symref(worktrees, "NOTES_MERGE_REF",
-					default_notes_ref());
+					notes_ref);
 		if (wt)
 			die(_("a notes merge into %s is already in-progress at %s"),
-			    default_notes_ref(), wt->path);
+			    notes_ref, wt->path);
 		free_worktrees(worktrees);
-		if (refs_update_symref(get_main_ref_store(the_repository), "NOTES_MERGE_REF", default_notes_ref(), NULL))
+		if (refs_update_symref(get_main_ref_store(the_repository), "NOTES_MERGE_REF", notes_ref, NULL))
 			die(_("failed to store link to current notes ref (%s)"),
-			    default_notes_ref());
+			    notes_ref);
 		fprintf(stderr, _("Automatic notes merge failed. Fix conflicts in %s "
 				  "and commit the result with 'git notes merge --commit', "
 				  "or abort the merge with 'git notes merge --abort'.\n"),
@@ -988,6 +990,7 @@ static int merge(int argc, const char **argv, const char *prefix)
 	}
 
 	free_notes(t);
+	free(notes_ref);
 	strbuf_release(&remote_ref);
 	strbuf_release(&msg);
 	return result < 0; /* return non-zero on conflicts */
@@ -1084,6 +1087,7 @@ static int prune(int argc, const char **argv, const char *prefix)
 static int get_ref(int argc, const char **argv, const char *prefix)
 {
 	struct option options[] = { OPT_END() };
+	char *notes_ref;
 	argc = parse_options(argc, argv, prefix, options,
 			     git_notes_get_ref_usage, 0);
 
@@ -1092,7 +1096,9 @@ static int get_ref(int argc, const char **argv, const char *prefix)
 		usage_with_options(git_notes_get_ref_usage, options);
 	}
 
-	puts(default_notes_ref());
+	notes_ref = default_notes_ref(the_repository);
+	puts(notes_ref);
+	free(notes_ref);
 	return 0;
 }
 

config.c

@@ -1555,14 +1555,6 @@ static int git_default_core_config(const char *var, const char *value,
 		return git_config_string(&check_roundtrip_encoding, var, value);
 	}
 
-	if (!strcmp(var, "core.notesref")) {
-		if (!value)
-			return config_error_nonbool(var);
-		free(notes_ref_name);
-		notes_ref_name = xstrdup(value);
-		return 0;
-	}
-
 	if (!strcmp(var, "core.editor")) {
 		FREE_AND_NULL(editor_program);
 		return git_config_string(&editor_program, var, value);

environment.c

@@ -67,7 +67,6 @@ enum push_default_type push_default = PUSH_DEFAULT_UNSPECIFIED;
 #define OBJECT_CREATION_MODE OBJECT_CREATION_USES_HARDLINKS
 #endif
 enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE;
-char *notes_ref_name;
 int grafts_keep_true_parents;
 int core_apply_sparse_checkout;
 int core_sparse_checkout_cone;

environment.h

@@ -203,8 +203,6 @@ enum object_creation_mode {
 };
 extern enum object_creation_mode object_creation_mode;
 
-extern char *notes_ref_name;
-
 extern int grafts_keep_true_parents;
 
 extern int repository_format_precious_objects;

notes.c

@@ -992,15 +992,16 @@ static int notes_display_config(const char *k, const char *v,
 	return 0;
 }
 
-const char *default_notes_ref(void)
+char *default_notes_ref(struct repository *repo)
 {
-	const char *notes_ref = NULL;
+	char *notes_ref = NULL;
+
 	if (!notes_ref)
-		notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
+		notes_ref = xstrdup_or_null(getenv(GIT_NOTES_REF_ENVIRONMENT));
 	if (!notes_ref)
-		notes_ref = notes_ref_name; /* value of core.notesRef config */
+		repo_config_get_string(repo, "core.notesref", &notes_ref);
 	if (!notes_ref)
-		notes_ref = GIT_NOTES_DEFAULT_REF;
+		notes_ref = xstrdup(GIT_NOTES_DEFAULT_REF);
 	return notes_ref;
 }
 
@@ -1010,13 +1011,14 @@ void init_notes(struct notes_tree *t, const char *notes_ref,
 	struct object_id oid, object_oid;
 	unsigned short mode;
 	struct leaf_node root_tree;
+	char *to_free = NULL;
 
 	if (!t)
 		t = &default_notes_tree;
 	assert(!t->initialized);
 
 	if (!notes_ref)
-		notes_ref = default_notes_ref();
+		notes_ref = to_free = default_notes_ref(the_repository);
 	update_ref_namespace(NAMESPACE_NOTES, xstrdup(notes_ref));
 
 	if (!combine_notes)
@@ -1033,7 +1035,7 @@ void init_notes(struct notes_tree *t, const char *notes_ref,
 
 	if (flags & NOTES_INIT_EMPTY ||
 	    repo_get_oid_treeish(the_repository, notes_ref, &object_oid))
-		return;
+		goto out;
 	if (flags & NOTES_INIT_WRITABLE && refs_read_ref(get_main_ref_store(the_repository), notes_ref, &object_oid))
 		die("Cannot use notes ref %s", notes_ref);
 	if (get_tree_entry(the_repository, &object_oid, "", &oid, &mode))
@@ -1043,6 +1045,9 @@ void init_notes(struct notes_tree *t, const char *notes_ref,
 	oidclr(&root_tree.key_oid, the_repository->hash_algo);
 	oidcpy(&root_tree.val_oid, &oid);
 	load_subtree(t, &root_tree, t->root, 0);
+
+out:
+	free(to_free);
 }
 
 struct notes_tree **load_notes_trees(struct string_list *refs, int flags)
@@ -1105,7 +1110,7 @@ void load_display_notes(struct display_notes_opt *opt)
 
 	if (!opt || opt->use_default_notes > 0 ||
 	    (opt->use_default_notes == -1 && !opt->extra_notes_refs.nr)) {
-		string_list_append(&display_notes_refs, default_notes_ref());
+		string_list_append_nodup(&display_notes_refs, default_notes_ref(the_repository));
 		display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
 		if (display_ref_env) {
 			string_list_add_refs_from_colon_sep(&display_notes_refs,

notes.h

@@ -4,6 +4,7 @@
 #include "string-list.h"
 
 struct object_id;
+struct repository;
 struct strbuf;
 
 /*
@@ -70,7 +71,7 @@ extern struct notes_tree {
  * 3. The value of the core.notesRef config variable, if set
  * 4. GIT_NOTES_DEFAULT_REF (i.e. "refs/notes/commits")
  */
-const char *default_notes_ref(void);
+char *default_notes_ref(struct repository *repo);
 
 /*
  * Flags controlling behaviour of notes tree initialization