thodg/libgit2

diff --git a/include/git2/revwalk.h b/include/git2/revwalk.h
index 7ab0827..af425c0 100644
--- a/include/git2/revwalk.h
+++ b/include/git2/revwalk.h
@@ -263,7 +263,7 @@ GIT_EXTERN(git_repository *) git_revwalk_repository(git_revwalk *walk);
 
 /**
 * This is a callback function that user can provide to hide a
-* commit and its parents. If the callback function returns true,
+* commit and its parents. If the callback function returns non-zero value,
 * then this commit and its parents will be hidden.
 *
 * @param commit_id oid of Commit
@@ -274,7 +274,7 @@ typedef int(*git_revwalk_hide_cb)(
 	void *payload);
 
 /**
-* Adds a callback function to hide a commit
+* Adds a callback function to hide a commit and its parents
 *
 * @param walk the revision walker
 * @param hide_cb  callback function to hide a commit and its parents
diff --git a/tests/revwalk/hidecb.c b/tests/revwalk/hidecb.c
new file mode 100644
index 0000000..b674758
--- /dev/null
+++ b/tests/revwalk/hidecb.c
@@ -0,0 +1,199 @@
+#include "clar_libgit2.h"
+/*
+*   a4a7dce [0] Merge branch 'master' into br2
+|\
+| * 9fd738e [1] a fourth commit
+| * 4a202b3 [2] a third commit
+* | c47800c [3] branch commit one
+|/
+* 5b5b025 [5] another commit
+* 8496071 [4] testing
+*/
+static const char *commit_head = "a4a7dce85cf63874e984719f4fdd239f5145052f";
+
+static const char *commit_strs[] = {
+	"a4a7dce85cf63874e984719f4fdd239f5145052f", /* 0 */
+	"9fd738e8f7967c078dceed8190330fc8648ee56a", /* 1 */
+	"4a202b346bb0fb0db7eff3cffeb3c70babbd2045", /* 2 */
+	"c47800c7266a2be04c571c04d5a6614691ea99bd", /* 3 */
+	"8496071c1b46c854b31185ea97743be6a8774479", /* 4 */
+	"5b5b025afb0b4c913b4c338a42934a3863bf3644", /* 5 */
+};
+
+#define commit_count 6
+
+static git_oid commit_ids[commit_count];
+static git_oid _head_id;
+static git_repository *_repo;
+
+
+void test_revwalk_hidecb__initialize(void)
+{
+	int i;
+
+	cl_git_pass(git_repository_open(&_repo, cl_fixture("testrepo.git")));
+	cl_git_pass(git_oid_fromstr(&_head_id, commit_head));
+
+	for (i = 0; i < commit_count; i++)
+	{
+		cl_git_pass(git_oid_fromstr(&commit_ids[i], commit_strs[i]));
+	}
+
+}
+
+void test_revwalk_hidecb__cleanup(void)
+{
+	git_repository_free(_repo);
+	_repo = NULL;
+}
+
+/* Hide all commits */
+static int hide_every_commit_cb(const git_oid *commit_id, void *data)
+{
+	return 1;
+}
+
+/* Do not hide anything */
+static int hide_none_cb(const git_oid *commit_id, void *data)
+{
+	return 0;
+}
+
+/* Hide some commits */
+static int hide_commit_cb(const git_oid *commit_id, void *data)
+{
+	if (0 == git_oid_cmp(commit_id, &commit_ids[3]))
+		return 1;
+	else
+		return 0;
+
+}
+
+/* In payload data, pointer to a commit id is passed */
+static int hide_commit_use_payload_cb(const git_oid *commit_id, void *data)
+{
+	git_oid *hide_commit_id = data;
+	if (0 == git_oid_cmp(commit_id, hide_commit_id))
+		return 1;
+	else
+		return 0;
+}
+
+void test_revwalk_hidecb__hide_all_cb(void)
+{
+	git_revwalk *walk;
+	git_oid id;
+
+	cl_git_pass(git_revwalk_new(&walk, _repo));
+	cl_git_pass(git_revwalk_add_hide_cb(walk, hide_every_commit_cb, NULL));
+	cl_git_pass(git_revwalk_push(walk, &_head_id));
+
+	/* First call to git_revwalk_next should return GIT_ITEROVER */
+	cl_assert_equal_i(GIT_ITEROVER, git_revwalk_next(&id, walk));
+
+	git_revwalk_free(walk);
+}
+
+
+void test_revwalk_hidecb__hide_none_cb(void)
+{
+	git_revwalk *walk;
+	int i, error;
+	git_oid id;
+
+	cl_git_pass(git_revwalk_new(&walk, _repo));
+	cl_git_pass(git_revwalk_add_hide_cb(walk, hide_none_cb, NULL));
+	cl_git_pass(git_revwalk_push(walk, &_head_id));
+
+	/* It should return all 6 commits */
+	i = 0;
+	while ((error = git_revwalk_next(&id, walk)) == 0)
+		i++;
+
+	cl_assert_equal_i(i, 6);
+	cl_assert_equal_i(error, GIT_ITEROVER);
+
+	git_revwalk_free(walk);
+}
+
+void test_revwalk_hidecb__add_hide_cb_multiple_times(void)
+{
+	git_revwalk *walk;
+
+	cl_git_pass(git_revwalk_new(&walk, _repo));
+	cl_git_pass(git_revwalk_add_hide_cb(walk, hide_every_commit_cb, NULL));
+	cl_git_fail(git_revwalk_add_hide_cb(walk, hide_every_commit_cb, NULL));
+
+	git_revwalk_free(walk);
+}
+
+void test_revwalk_hidecb__add_hide_cb_during_walking(void)
+{
+	git_revwalk *walk;
+	git_oid id;
+	int error;
+
+	cl_git_pass(git_revwalk_new(&walk, _repo));
+	cl_git_pass(git_revwalk_push(walk, &_head_id));
+
+	/* Start walking without adding hide callback */
+	cl_git_pass(git_revwalk_next(&id, walk));
+
+	/* Now add hide callback */
+	cl_git_pass(git_revwalk_add_hide_cb(walk, hide_none_cb, NULL));
+
+	/* walk should be reset */
+	error = git_revwalk_next(&id, walk);
+	cl_assert_equal_i(error, GIT_ITEROVER);
+
+	git_revwalk_free(walk);
+}
+
+void test_revwalk_hidecb__hide_some_commits(void)
+{
+	git_revwalk *walk;
+	git_oid id;
+	int i, error;
+
+	cl_git_pass(git_revwalk_new(&walk, _repo));
+	cl_git_pass(git_revwalk_push(walk, &_head_id));
+
+	/* Add hide callback */
+	cl_git_pass(git_revwalk_add_hide_cb(walk, hide_commit_cb, NULL));
+
+	i = 0;
+	while ((error = git_revwalk_next(&id, walk)) == 0) {
+		cl_assert_equal_i(git_oid_cmp(&id, &commit_ids[i]), 0);
+		i++;
+	}
+
+	cl_assert_equal_i(i, 3);
+	cl_assert_equal_i(error, GIT_ITEROVER);
+
+	git_revwalk_free(walk);
+}
+
+void test_revwalk_hidecb__test_payload(void)
+{
+	git_revwalk *walk;
+	git_oid id;
+	int i, error;
+
+	cl_git_pass(git_revwalk_new(&walk, _repo));
+	cl_git_pass(git_revwalk_push(walk, &_head_id));
+
+	/* Add hide callback, pass id of parent of initial commit as payload data */
+	cl_git_pass(git_revwalk_add_hide_cb(walk, hide_commit_use_payload_cb, &commit_ids[5]));
+
+	i = 0;
+	while ((error = git_revwalk_next(&id, walk)) == 0) {
+		cl_assert_equal_i(git_oid_cmp(&id, &commit_ids[i]), 0);
+		i++;
+	}
+
+	/* walker should return four commits */
+	cl_assert_equal_i(i, 4);
+	cl_assert_equal_i(error, GIT_ITEROVER);
+
+	git_revwalk_free(walk);
+}