thodg/libgit2

diff --git a/tests-clay/clay.h b/tests-clay/clay.h
index b3aae46..7210e79 100644
--- a/tests-clay/clay.h
+++ b/tests-clay/clay.h
@@ -158,6 +158,12 @@ extern void test_object_raw_size__validate_oid_size(void);
 extern void test_object_raw_type2string__check_type_is_loose(void);
 extern void test_object_raw_type2string__convert_string_to_type(void);
 extern void test_object_raw_type2string__convert_type_to_string(void);
+extern void test_object_tree_diff__addition(void);
+extern void test_object_tree_diff__cleanup(void);
+extern void test_object_tree_diff__deletion(void);
+extern void test_object_tree_diff__initialize(void);
+extern void test_object_tree_diff__modification(void);
+extern void test_object_tree_diff__more(void);
 extern void test_object_tree_frompath__cleanup(void);
 extern void test_object_tree_frompath__fail_when_processing_an_invalid_path(void);
 extern void test_object_tree_frompath__fail_when_processing_an_unknown_tree_segment(void);
diff --git a/tests-clay/clay_main.c b/tests-clay/clay_main.c
index 409ce76..ee08842 100644
--- a/tests-clay/clay_main.c
+++ b/tests-clay/clay_main.c
@@ -245,6 +245,12 @@ static const struct clay_func _clay_cb_object_raw_type2string[] = {
 	{"convert_string_to_type", &test_object_raw_type2string__convert_string_to_type},
 	{"convert_type_to_string", &test_object_raw_type2string__convert_type_to_string}
 };
+static const struct clay_func _clay_cb_object_tree_diff[] = {
+    {"addition", &test_object_tree_diff__addition},
+	{"deletion", &test_object_tree_diff__deletion},
+	{"modification", &test_object_tree_diff__modification},
+	{"more", &test_object_tree_diff__more}
+};
 static const struct clay_func _clay_cb_object_tree_frompath[] = {
     {"fail_when_processing_an_invalid_path", &test_object_tree_frompath__fail_when_processing_an_invalid_path},
 	{"fail_when_processing_an_unknown_tree_segment", &test_object_tree_frompath__fail_when_processing_an_unknown_tree_segment},
@@ -438,6 +444,12 @@ static const struct clay_suite _clay_suites[] = {
         _clay_cb_object_raw_type2string, 3
     },
 	{
+        "object::tree::diff",
+        {"initialize", &test_object_tree_diff__initialize},
+        {"cleanup", &test_object_tree_diff__cleanup},
+        _clay_cb_object_tree_diff, 4
+    },
+	{
         "object::tree::frompath",
         {"initialize", &test_object_tree_frompath__initialize},
         {"cleanup", &test_object_tree_frompath__cleanup},
@@ -493,8 +505,8 @@ static const struct clay_suite _clay_suites[] = {
     }
 };
 
-static size_t _clay_suite_count = 34;
-static size_t _clay_callback_count = 113;
+static size_t _clay_suite_count = 35;
+static size_t _clay_callback_count = 117;
 
 /* Core test functions */
 static void
diff --git a/tests-clay/object/tree/diff.c b/tests-clay/object/tree/diff.c
new file mode 100644
index 0000000..471e465
--- /dev/null
+++ b/tests-clay/object/tree/diff.c
@@ -0,0 +1,150 @@
+#include "clay_libgit2.h"
+#include "tree.h"
+#include "repository.h"
+
+static unsigned int expect_idx;
+static git_repository *repo;
+static git_tree *atree, *btree;
+static git_oid aoid, boid;
+
+static void diff_cmp(const git_tree_diff_data *a, const git_tree_diff_data *b)
+{
+	cl_assert(a->old_attr - b->old_attr == 0);
+
+	cl_assert(a->new_attr - b->new_attr == 0);
+
+	cl_assert(git_oid_cmp(&a->old_oid, &b->old_oid) == 0);
+	cl_assert(git_oid_cmp(&a->new_oid, &b->new_oid) == 0);
+
+	cl_assert(a->status - b->status == 0);
+
+	cl_assert(strcmp(a->path, b->path) == 0);
+}
+
+static int diff_cb(const git_tree_diff_data *diff, void *data)
+{
+	diff_cmp(diff, data);
+	return GIT_SUCCESS;
+}
+
+void test_object_tree_diff__initialize(void)
+{
+	cl_git_pass(git_repository_open(&repo, cl_fixture("testrepo.git")));
+}
+
+void test_object_tree_diff__cleanup(void)
+{
+	git_tree_free(atree);
+	git_tree_free(btree);
+	git_repository_free(repo);
+}
+
+void test_object_tree_diff__addition(void)
+{
+	char *astr = "181037049a54a1eb5fab404658a3a250b44335d7";
+	char *bstr = "f60079018b664e4e79329a7ef9559c8d9e0378d1";
+	git_tree_diff_data expect;
+
+	memset(&expect, 0x0, sizeof(git_tree_diff_data));
+	expect.old_attr = 0;
+	expect.new_attr = 0100644;
+	git_oid_fromstr(&expect.new_oid, "fa49b077972391ad58037050f2a75f74e3671e92");
+	expect.status = GIT_STATUS_ADDED;
+	expect.path = "new.txt";
+
+	cl_must_pass(git_oid_fromstr(&aoid, astr));
+	cl_must_pass(git_oid_fromstr(&boid, bstr));
+
+	cl_must_pass(git_tree_lookup(&atree, repo, &aoid));
+	cl_must_pass(git_tree_lookup(&btree, repo, &boid));
+
+	cl_must_pass(git_tree_diff(atree, btree, diff_cb, &expect));
+}
+
+void test_object_tree_diff__deletion(void)
+{
+	char *astr = "f60079018b664e4e79329a7ef9559c8d9e0378d1";
+	char *bstr = "181037049a54a1eb5fab404658a3a250b44335d7";
+	git_tree_diff_data expect;
+
+	memset(&expect, 0x0, sizeof(git_tree_diff_data));
+	expect.old_attr = 0100644;
+	expect.new_attr = 0;
+	git_oid_fromstr(&expect.old_oid, "fa49b077972391ad58037050f2a75f74e3671e92");
+	expect.status = GIT_STATUS_DELETED;
+	expect.path = "new.txt";
+	cl_must_pass(git_oid_fromstr(&aoid, astr));
+	cl_must_pass(git_oid_fromstr(&boid, bstr));
+
+	cl_must_pass(git_tree_lookup(&atree, repo, &aoid));
+	cl_must_pass(git_tree_lookup(&btree, repo, &boid));
+
+	cl_must_pass(git_tree_diff(atree, btree, diff_cb, &expect));
+}
+
+void test_object_tree_diff__modification(void)
+{
+	char *astr = "1810dff58d8a660512d4832e740f692884338ccd";
+	char *bstr = "944c0f6e4dfa41595e6eb3ceecdb14f50fe18162";
+	git_tree_diff_data expect;
+
+	expect.old_attr = 0100644;
+	expect.new_attr = 0100644;
+	git_oid_fromstr(&expect.old_oid, "45b983be36b73c0788dc9cbcb76cbb80fc7bb057");
+	git_oid_fromstr(&expect.new_oid, "3697d64be941a53d4ae8f6a271e4e3fa56b022cc");
+	expect.status = GIT_STATUS_MODIFIED;
+	expect.path = "branch_file.txt";
+
+	cl_must_pass(git_oid_fromstr(&aoid, astr));
+	cl_must_pass(git_oid_fromstr(&boid, bstr));
+
+	cl_must_pass(git_tree_lookup(&atree, repo, &aoid));
+	cl_must_pass(git_tree_lookup(&btree, repo, &boid));
+
+	cl_must_pass(git_tree_diff(atree, btree, diff_cb, &expect));
+}
+
+static int diff_more_cb(const git_tree_diff_data *diff, void *data)
+{
+	git_tree_diff_data *expect = (git_tree_diff_data *) data;
+	diff_cmp(diff, &expect[expect_idx++]);
+
+	return GIT_SUCCESS;
+}
+
+void test_object_tree_diff__more(void)
+{
+	char *astr = "814889a078c031f61ed08ab5fa863aea9314344d";
+	char *bstr = "75057dd4114e74cca1d750d0aee1647c903cb60a";
+	git_tree_diff_data expect[3];
+
+	memset(expect, 0x0, 3 * sizeof(git_tree_diff_data));
+	/* M README */
+	expect[0].old_attr = 0100644;
+	expect[0].new_attr = 0100644;
+	git_oid_fromstr(&expect[0].old_oid, "a8233120f6ad708f843d861ce2b7228ec4e3dec6");
+	git_oid_fromstr(&expect[0].new_oid, "1385f264afb75a56a5bec74243be9b367ba4ca08");
+	expect[0].status = GIT_STATUS_MODIFIED;
+	expect[0].path = "README";
+	/* A branch_file.txt */
+	expect[1].old_attr = 0;
+	expect[1].new_attr = 0100644;
+	git_oid_fromstr(&expect[1].new_oid, "45b983be36b73c0788dc9cbcb76cbb80fc7bb057");
+	expect[1].status = GIT_STATUS_ADDED;
+	expect[1].path = "branch_file.txt";
+	/* M new.txt */
+	expect[2].old_attr = 0100644;
+	expect[2].new_attr = 0100644;
+	git_oid_fromstr(&expect[2].old_oid, "a71586c1dfe8a71c6cbf6c129f404c5642ff31bd");
+	git_oid_fromstr(&expect[2].new_oid, "fa49b077972391ad58037050f2a75f74e3671e92");
+	expect[2].status = GIT_STATUS_MODIFIED;
+	expect[2].path = "new.txt";
+
+	cl_must_pass(git_oid_fromstr(&aoid, astr));
+	cl_must_pass(git_oid_fromstr(&boid, bstr));
+
+	cl_must_pass(git_tree_lookup(&atree, repo, &aoid));
+	cl_must_pass(git_tree_lookup(&btree, repo, &boid));
+
+	cl_must_pass(git_tree_diff(atree, btree, diff_more_cb, expect));
+}