notes: honor core.notesRef

Setting core.notesRef allows to change the default notes reference used
by Git. Check if set before using GIT_NOTES_DEFAULT_REF. Fixes #649.

src/notes.c

@@ -9,6 +9,7 @@
 
 #include "git2.h"
 #include "refs.h"
+#include "config.h"
 
 static int find_subtree(git_tree **subtree, const git_oid *root,
 			git_repository *repo, const char *target, int *fanout)
@@ -262,6 +263,25 @@ static int note_remove(git_repository *repo,
 	return error;
 }
 
+static int note_get_default_ref(const char **out, git_repository *repo)
+{
+	int error;
+	git_config *cfg;
+
+	*out = NULL;
+
+	if (git_repository_config__weakptr(&cfg, repo) < 0)
+		return -1;
+
+	error = git_config_get_string(cfg, "core.notesRef", out);
+	if (error == GIT_ENOTFOUND) {
+		*out = GIT_NOTES_DEFAULT_REF;
+		return 0;
+	}
+
+	return error;
+}
+
 int git_note_read(git_note **out, git_repository *repo,
 		  const char *notes_ref, const git_oid *oid)
 {
@@ -273,8 +293,11 @@ int git_note_read(git_note **out, git_repository *repo,
 
 	*out = NULL;
 
-	if (!notes_ref)
-		notes_ref = GIT_NOTES_DEFAULT_REF;
+	if (!notes_ref) {
+		error = note_get_default_ref(&notes_ref, repo);
+		if (error < 0)
+			return error;
+	}
 
 	error = git_reference_lookup(&ref, repo, notes_ref);
 	if (error < 0)
@@ -314,8 +337,11 @@ int git_note_create(
 	git_commit *commit = NULL;
 	git_reference *ref;
 
-	if (!notes_ref)
-		notes_ref = GIT_NOTES_DEFAULT_REF;
+	if (!notes_ref) {
+		error = note_get_default_ref(&notes_ref, repo);
+		if (error < 0)
+			return error;
+	}
 
 	error = git_reference_lookup(&ref, repo, notes_ref);
 	if (error < 0 && error != GIT_ENOTFOUND)
@@ -359,8 +385,11 @@ int git_note_remove(git_repository *repo, const char *notes_ref,
 	git_commit *commit;
 	git_reference *ref;
 
-	if (!notes_ref)
-		notes_ref = GIT_NOTES_DEFAULT_REF;
+	if (!notes_ref) {
+		error = note_get_default_ref(&notes_ref, repo);
+		if (error < 0)
+			return error;
+	}
 
 	error = git_reference_lookup(&ref, repo, notes_ref);
 	if (error < 0)

tests-clar/notes/notesref.c

+#include "clar_libgit2.h"
+
+static git_repository *_repo;
+static git_note *_note;
+static git_signature *_sig;
+static git_config *_cfg;
+
+void test_notes_notesref__initialize(void)
+{
+	cl_fixture_sandbox("testrepo.git");
+	cl_git_pass(git_repository_open(&_repo, "testrepo.git"));
+}
+
+void test_notes_notesref__cleanup(void)
+{
+	git_note_free(_note);
+	git_signature_free(_sig);
+	git_config_free(_cfg);
+
+	git_repository_free(_repo);
+	cl_fixture_cleanup("testrepo.git");
+}
+
+void test_notes_notesref__config_corenotesref(void)
+{
+	git_oid oid, note_oid;
+
+	cl_git_pass(git_signature_now(&_sig, "alice", "alice@example.com"));
+	cl_git_pass(git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479"));
+
+	cl_git_pass(git_repository_config(&_cfg, _repo));
+
+	cl_git_pass(git_config_set_string(_cfg, "core.notesRef", "refs/notes/mydefaultnotesref"));
+
+	cl_git_pass(git_note_create(&note_oid, _repo, _sig, _sig, NULL, &oid, "test123test\n"));
+
+	cl_git_pass(git_note_read(&_note, _repo, NULL, &oid));
+	cl_assert(!strcmp(git_note_message(_note), "test123test\n"));
+	cl_assert(!git_oid_cmp(git_note_oid(_note), &note_oid));
+
+	git_note_free(_note);
+
+	cl_git_pass(git_note_read(&_note, _repo, "refs/notes/mydefaultnotesref", &oid));
+	cl_assert(!strcmp(git_note_message(_note), "test123test\n"));
+	cl_assert(!git_oid_cmp(git_note_oid(_note), &note_oid));
+}