Add git_object_short_id API to get short id string

This finds a short id string that will unambiguously select the
given object, starting with the core.abbrev length (usually 7)
and growing until it is no longer ambiguous.

1 files changed, 44 insertions, 0 deletions

diff --git a/tests/object/shortid.c b/tests/object/shortid.c
new file mode 100644
index 000000000..fa1dac09a
--- /dev/null
+++ b/tests/object/shortid.c
@@ -0,0 +1,44 @@
+#include "clar_libgit2.h"
+
+git_repository *_repo;
+
+void test_object_shortid__initialize(void)
+{
+	cl_git_pass(git_repository_open(&_repo, cl_fixture("duplicate.git")));
+}
+
+void test_object_shortid__cleanup(void)
+{
+	git_repository_free(_repo);
+	_repo = NULL;
+}
+
+void test_object_shortid__select(void)
+{
+	git_oid full;
+	git_object *obj;
+	git_buf shorty = {0};
+
+	git_oid_fromstr(&full, "ce013625030ba8dba906f756967f9e9ca394464a");
+	cl_git_pass(git_object_lookup(&obj, _repo, &full, GIT_OBJ_ANY));
+	cl_git_pass(git_object_short_id(&shorty, obj));
+	cl_assert_equal_i(7, shorty.size);
+	cl_assert_equal_s("ce01362", shorty.ptr);
+	git_object_free(obj);
+
+	git_oid_fromstr(&full, "dea509d097ce692e167dfc6a48a7a280cc5e877e");
+	cl_git_pass(git_object_lookup(&obj, _repo, &full, GIT_OBJ_ANY));
+	cl_git_pass(git_object_short_id(&shorty, obj));
+	cl_assert_equal_i(9, shorty.size);
+	cl_assert_equal_s("dea509d09", shorty.ptr);
+	git_object_free(obj);
+
+	git_oid_fromstr(&full, "dea509d0b3cb8ee0650f6ca210bc83f4678851ba");
+	cl_git_pass(git_object_lookup(&obj, _repo, &full, GIT_OBJ_ANY));
+	cl_git_pass(git_object_short_id(&shorty, obj));
+	cl_assert_equal_i(9, shorty.size);
+	cl_assert_equal_s("dea509d0b", shorty.ptr);
+	git_object_free(obj);
+
+	git_buf_free(&shorty);
+}