revwalk: allow simplifying by first-parent

When enabled, only the first parent of each commit will be queued,
enabling a simple way of using first-parent simplification.

1 files changed, 51 insertions, 0 deletions

diff --git a/tests-clar/revwalk/simplify.c b/tests-clar/revwalk/simplify.c
new file mode 100644
index 000000000..c94952105
--- /dev/null
+++ b/tests-clar/revwalk/simplify.c
@@ -0,0 +1,51 @@
+#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 *expected_str[] = {
+	"a4a7dce85cf63874e984719f4fdd239f5145052f", /* 0 */
+	"c47800c7266a2be04c571c04d5a6614691ea99bd", /* 3 */
+	"8496071c1b46c854b31185ea97743be6a8774479", /* 4 */
+	"5b5b025afb0b4c913b4c338a42934a3863bf3644", /* 5 */
+};
+
+void test_revwalk_simplify__first_parent(void)
+{
+	git_repository *repo;
+	git_revwalk *walk;
+	git_oid id, expected[4];
+	int i, error;
+
+	for (i = 0; i < 4; i++) {
+		git_oid_fromstr(&expected[i], expected_str[i]);
+	}
+
+	repo = cl_git_sandbox_init("testrepo.git");
+	cl_git_pass(git_revwalk_new(&walk, repo));
+
+	git_oid_fromstr(&id, commit_head);
+	cl_git_pass(git_revwalk_push(walk, &id));
+	git_revwalk_simplify_first_parent(walk);
+
+	i = 0;
+	while ((error = git_revwalk_next(&id, walk)) == 0) {
+		git_oid_cmp(&id, &expected[i]);
+		i++;
+	}
+
+	cl_assert_equal_i(i, 4);
+	cl_assert_equal_i(error, GIT_ITEROVER);
+
+	git_revwalk_free(walk);
+	git_repository_free(repo);
+}