thodg/libgit2

diff --git a/include/git2/notes.h b/include/git2/notes.h
index ecb37f3..7b2ac1f 100644
--- a/include/git2/notes.h
+++ b/include/git2/notes.h
@@ -102,6 +102,27 @@ GIT_EXTERN(void) git_note_free(git_note *note);
  */
 GIT_EXTERN(int) git_note_default_ref(const char **out, git_repository *repo);
 
+/**
+ * Loop over all the notes within a specified namespace
+ * and issue a callback for each one.
+ *
+ * @param repo Repository where to find the notes.
+ *
+ * @param notes_ref OID reference to read from (optional); defaults to "refs/notes/commits".
+ *
+ * @param note_cb Callback to invoke per found annotation.
+ *
+ * @param payload Extra parameter to callback function.
+ *
+ * @return GIT_SUCCESS or an error code.
+ */
+GIT_EXTERN(int) git_note_foreach(
+		git_repository *repo,
+		const char *notes_ref,
+		int (*note_cb)(const git_oid *note_oid, const git_oid *annotated_object_oid, void *payload),
+		void *payload
+);
+
 /** @} */
 GIT_END_DECL
 #endif
diff --git a/src/notes.c b/src/notes.c
index 4afdac0..e3fb91f 100644
--- a/src/notes.c
+++ b/src/notes.c
@@ -10,6 +10,7 @@
 #include "git2.h"
 #include "refs.h"
 #include "config.h"
+#include "iterator.h"
 
 static int find_subtree(git_tree **subtree, const git_oid *root,
 			git_repository *repo, const char *target, int *fanout)
@@ -282,41 +283,54 @@ static int note_get_default_ref(const char **out, git_repository *repo)
 	return ret;
 }
 
+static int normalize_namespace(const char **notes_ref, git_repository *repo)
+{
+	if (*notes_ref)
+		return 0;
+
+	return note_get_default_ref(notes_ref, repo);
+}
+
+static int retrieve_note_tree_oid(git_oid *tree_oid_out, git_repository *repo, const char *notes_ref)
+{
+	int error = -1;
+	git_commit *commit = NULL;
+	git_oid oid;
+
+	if ((error = git_reference_name_to_oid(&oid, repo, notes_ref)) < 0)
+		goto cleanup;
+
+	if (git_commit_lookup(&commit, repo, &oid) < 0)
+		goto cleanup;
+
+	git_oid_cpy(tree_oid_out, git_commit_tree_oid(commit));
+
+	error = 0;
+
+cleanup:
+	git_commit_free(commit);
+	return error;
+}
+
 int git_note_read(git_note **out, git_repository *repo,
 		  const char *notes_ref, const git_oid *oid)
 {
 	int error;
 	char *target;
-	git_reference *ref;
-	git_commit *commit;
-	const git_oid *sha;
+	git_oid sha;
 
 	*out = NULL;
 
-	if (!notes_ref && note_get_default_ref(&notes_ref, repo) < 0)
+	if (normalize_namespace(&notes_ref, repo) < 0)
 		return -1;
 
-	error = git_reference_lookup(&ref, repo, notes_ref);
-	if (error < 0)
+	if ((error = retrieve_note_tree_oid(&sha, repo, notes_ref)) < 0)
 		return error;
 
-	assert(git_reference_type(ref) == GIT_REF_OID);
-
-	sha = git_reference_oid(ref);
-	error = git_commit_lookup(&commit, repo, sha);
-
-	git_reference_free(ref);
-
-	if (error < 0)
-		return error;
-
-	sha = git_commit_tree_oid(commit);
-	git_commit_free(commit);
-
 	target = git_oid_allocfmt(oid);
 	GITERR_CHECK_ALLOC(target);
 
-	error = note_lookup(out, repo, sha, target);
+	error = note_lookup(out, repo, &sha, target);
 
 	git__free(target);
 	return error;
@@ -334,7 +348,7 @@ int git_note_create(
 	git_commit *commit = NULL;
 	git_reference *ref;
 
-	if (!notes_ref && note_get_default_ref(&notes_ref, repo) < 0)
+	if (normalize_namespace(&notes_ref, repo) < 0)
 		return -1;
 
 	error = git_reference_lookup(&ref, repo, notes_ref);
@@ -379,8 +393,7 @@ int git_note_remove(git_repository *repo, const char *notes_ref,
 	git_commit *commit;
 	git_reference *ref;
 
-
-	if (!notes_ref && note_get_default_ref(&notes_ref, repo) < 0)
+	if (normalize_namespace(&notes_ref, repo) < 0)
 		return -1;
 
 	error = git_reference_lookup(&ref, repo, notes_ref);
@@ -435,3 +448,102 @@ void git_note_free(git_note *note)
 	git__free(note->message);
 	git__free(note);
 }
+
+static int process_entry_path(
+	const char* entry_path,
+	git_oid note_oid,
+	int (*note_cb)(const git_oid *note_oid, const git_oid *annotated_object_oid, void *payload),
+	void *payload)
+{
+	int i = 0, j = 0, error = -1, len;
+	bool is_hex_only = true;
+	git_oid target_oid;
+	git_buf buf = GIT_BUF_INIT;
+
+	if (git_buf_puts(&buf, entry_path) < 0)
+		goto cleanup;
+	
+	len = git_buf_len(&buf);
+
+	while (i < len) {
+		if (buf.ptr[i] == '/') {
+			i++;
+			continue;
+		}
+		
+		if (git__fromhex(buf.ptr[i]) < 0) {
+			/* This is not a note entry */
+			error = 0;
+			goto cleanup;
+		}
+
+		if (i != j)
+			buf.ptr[j] = buf.ptr[i];
+
+		i++;
+		j++;
+	}
+
+	buf.ptr[j] = '\0';
+	buf.size = j;
+
+	if (j != GIT_OID_HEXSZ) {
+		/* This is not a note entry */
+		error = 0;
+		goto cleanup;
+	}
+
+	if (git_oid_fromstr(&target_oid, buf.ptr) < 0)
+		return -1;
+
+	error = note_cb(&note_oid, &target_oid, payload);
+
+cleanup:
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_note_foreach(
+	git_repository *repo,
+	const char *notes_ref,
+	int (*note_cb)(const git_oid *note_oid, const git_oid *annotated_object_oid, void *payload),
+	void *payload)
+{
+	int error = -1;
+	unsigned int i;
+	char *note;
+	git_oid tree_oid;
+	git_iterator *iter = NULL;
+	git_tree *tree = NULL;
+	git_index_entry *item;
+
+	if (normalize_namespace(&notes_ref, repo) < 0)
+		return -1;
+
+	if ((error = retrieve_note_tree_oid(&tree_oid, repo, notes_ref)) < 0)
+		goto cleanup;
+
+	if (git_tree_lookup(&tree, repo, &tree_oid) < 0)
+		goto cleanup;
+
+	if (git_iterator_for_tree(repo, tree, &iter) < 0)
+		goto cleanup;
+
+	if (git_iterator_current(iter, &item) < 0)
+		goto cleanup;
+
+	while (item) {
+		if (process_entry_path(item->path, item->oid, note_cb, payload) < 0)
+			goto cleanup;
+
+		if (git_iterator_advance(iter, &item) < 0)
+			goto cleanup;
+	}
+
+	error = 0;
+
+cleanup:
+	git_iterator_free(iter);
+	git_tree_free(tree);
+	return error;
+}
diff --git a/tests-clar/notes/notes.c b/tests-clar/notes/notes.c
index ca82ab2..228e414 100644
--- a/tests-clar/notes/notes.c
+++ b/tests-clar/notes/notes.c
@@ -1,43 +1,46 @@
 #include "clar_libgit2.h"
 
 static git_repository *_repo;
-static git_note *_note;
-static git_blob *_blob;
 static git_signature *_sig;
 
 void test_notes_notes__initialize(void)
 {
-	cl_fixture_sandbox("testrepo.git");
-	cl_git_pass(git_repository_open(&_repo, "testrepo.git"));
+	_repo = cl_git_sandbox_init("testrepo.git");
+	cl_git_pass(git_signature_now(&_sig, "alice", "alice@example.com"));
 }
 
 void test_notes_notes__cleanup(void)
 {
-	git_note_free(_note);
-	git_blob_free(_blob);
 	git_signature_free(_sig);
+	cl_git_sandbox_cleanup();
+}
+
+static void create_note(git_oid *note_oid, const char *canonical_namespace, const char *target_sha, const char *message)
+{
+	git_oid oid;
 
-	git_repository_free(_repo);
-	cl_fixture_cleanup("testrepo.git");
+	cl_git_pass(git_oid_fromstr(&oid, target_sha));
+	cl_git_pass(git_note_create(note_oid, _repo, _sig, _sig, canonical_namespace, &oid, message));
 }
 
 void test_notes_notes__1(void)
 {
 	git_oid oid, note_oid;
+	static git_note *note;
+	static git_blob *blob;
 
-	cl_git_pass(git_signature_now(&_sig, "alice", "alice@example.com"));
 	cl_git_pass(git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479"));
 
 	cl_git_pass(git_note_create(&note_oid, _repo, _sig, _sig, "refs/notes/some/namespace", &oid, "hello world\n"));
 	cl_git_pass(git_note_create(&note_oid, _repo, _sig, _sig, NULL, &oid, "hello world\n"));
 
-	cl_git_pass(git_note_read(&_note, _repo, NULL, &oid));
+	cl_git_pass(git_note_read(&note, _repo, NULL, &oid));
 
-	cl_assert_equal_s(git_note_message(_note), "hello world\n");
-	cl_assert(!git_oid_cmp(git_note_oid(_note), &note_oid));
+	cl_assert_equal_s(git_note_message(note), "hello world\n");
+	cl_assert(!git_oid_cmp(git_note_oid(note), &note_oid));
 
-	cl_git_pass(git_blob_lookup(&_blob, _repo, &note_oid));
-	cl_assert_equal_s(git_note_message(_note), git_blob_rawcontent(_blob));
+	cl_git_pass(git_blob_lookup(&blob, _repo, &note_oid));
+	cl_assert_equal_s(git_note_message(note), git_blob_rawcontent(blob));
 
 	cl_git_fail(git_note_create(&note_oid, _repo, _sig, _sig, NULL, &oid, "hello world\n"));
 	cl_git_fail(git_note_create(&note_oid, _repo, _sig, _sig, "refs/notes/some/namespace", &oid, "hello world\n"));
@@ -47,4 +50,83 @@ void test_notes_notes__1(void)
 
 	cl_git_fail(git_note_remove(_repo, NULL, _sig, _sig, &note_oid));
 	cl_git_fail(git_note_remove(_repo, "refs/notes/some/namespace", _sig, _sig, &oid));
+
+	git_note_free(note);
+	git_blob_free(blob);
+}
+
+static struct {
+	const char *note_sha;
+	const char *annotated_object_sha;
+} list_expectations[] = {
+	{ "1c73b1f51762155d357bcd1fd4f2c409ef80065b", "4a202b346bb0fb0db7eff3cffeb3c70babbd2045" },
+	{ "1c73b1f51762155d357bcd1fd4f2c409ef80065b", "9fd738e8f7967c078dceed8190330fc8648ee56a" },
+	{ "257b43746b6b46caa4aa788376c647cce0a33e2b", "a65fedf39aefe402d3bb6e24df4d4f5fe4547750" },
+	{ "1ec1c8e03f461f4f5d3f3702172483662e7223f3", "c47800c7266a2be04c571c04d5a6614691ea99bd" },
+	{ NULL, NULL }
+};
+
+#define EXPECTATIONS_COUNT (sizeof(list_expectations)/sizeof(list_expectations[0])) - 1
+
+static int note_list_cb(const git_oid *note_oid, const git_oid *annotated_object_oid, void *payload)
+{
+	git_oid expected_note_oid, expected_target_oid;
+
+	int *count = (int *)payload;
+
+	cl_assert(*count < EXPECTATIONS_COUNT);
+
+	cl_git_pass(git_oid_fromstr(&expected_note_oid, list_expectations[*count].note_sha));
+	cl_assert(git_oid_cmp(&expected_note_oid, note_oid) == 0);
+
+	cl_git_pass(git_oid_fromstr(&expected_target_oid, list_expectations[*count].annotated_object_sha));
+	cl_assert(git_oid_cmp(&expected_target_oid, annotated_object_oid) == 0);
+
+	(*count)++;
+
+	return 0;
+}
+
+/*
+ * $ git notes --ref i-can-see-dead-notes add -m "I decorate a65f" a65fedf39aefe402d3bb6e24df4d4f5fe4547750
+ * $ git notes --ref i-can-see-dead-notes add -m "I decorate c478" c47800c7266a2be04c571c04d5a6614691ea99bd
+ * $ git notes --ref i-can-see-dead-notes add -m "I decorate 9fd7 and 4a20" 9fd738e8f7967c078dceed8190330fc8648ee56a
+ * $ git notes --ref i-can-see-dead-notes add -m "I decorate 9fd7 and 4a20" 4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+ *
+ * $ git notes --ref i-can-see-dead-notes list
+ * 1c73b1f51762155d357bcd1fd4f2c409ef80065b 4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+ * 1c73b1f51762155d357bcd1fd4f2c409ef80065b 9fd738e8f7967c078dceed8190330fc8648ee56a
+ * 257b43746b6b46caa4aa788376c647cce0a33e2b a65fedf39aefe402d3bb6e24df4d4f5fe4547750
+ * 1ec1c8e03f461f4f5d3f3702172483662e7223f3 c47800c7266a2be04c571c04d5a6614691ea99bd
+ *
+ * $ git ls-tree refs/notes/i-can-see-dead-notes
+ * 100644 blob 1c73b1f51762155d357bcd1fd4f2c409ef80065b    4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+ * 100644 blob 1c73b1f51762155d357bcd1fd4f2c409ef80065b    9fd738e8f7967c078dceed8190330fc8648ee56a
+ * 100644 blob 257b43746b6b46caa4aa788376c647cce0a33e2b    a65fedf39aefe402d3bb6e24df4d4f5fe4547750
+ * 100644 blob 1ec1c8e03f461f4f5d3f3702172483662e7223f3    c47800c7266a2be04c571c04d5a6614691ea99bd
+*/
+void test_notes_notes__can_retrieve_a_list_of_notes_for_a_given_namespace(void)
+{
+	git_oid note_oid1, note_oid2, note_oid3, note_oid4;
+	int retrieved_notes = 0;
+
+	create_note(&note_oid1, "refs/notes/i-can-see-dead-notes", "a65fedf39aefe402d3bb6e24df4d4f5fe4547750", "I decorate a65f\n");
+	create_note(&note_oid2, "refs/notes/i-can-see-dead-notes", "c47800c7266a2be04c571c04d5a6614691ea99bd", "I decorate c478\n");
+	create_note(&note_oid3, "refs/notes/i-can-see-dead-notes", "9fd738e8f7967c078dceed8190330fc8648ee56a", "I decorate 9fd7 and 4a20\n");
+	create_note(&note_oid4, "refs/notes/i-can-see-dead-notes", "4a202b346bb0fb0db7eff3cffeb3c70babbd2045", "I decorate 9fd7 and 4a20\n");
+
+	cl_git_pass(git_note_foreach(_repo, "refs/notes/i-can-see-dead-notes", note_list_cb, &retrieved_notes));
+
+	cl_assert_equal_i(4, retrieved_notes);
+}
+
+void test_notes_notes__retrieving_a_list_of_notes_for_an_unknown_namespace_returns_ENOTFOUND(void)
+{
+	int error,	retrieved_notes = 0;
+
+	error = git_note_foreach(_repo, "refs/notes/i-am-not", note_list_cb, &retrieved_notes);
+	cl_git_fail(error);
+	cl_assert_equal_i(GIT_ENOTFOUND, error);
+
+	cl_assert_equal_i(0, retrieved_notes);
 }