ll.git2: Add revparse_single interface

This permits a wider range of git revision specifications
to be parsed without falling back to the command-line.

1 files changed, 25 insertions, 0 deletions

diff --git a/lib/gall/ll/git2.c b/lib/gall/ll/git2.c
index ce72244..785f1dc 100644
--- a/lib/gall/ll/git2.c
+++ b/lib/gall/ll/git2.c
@@ -398,6 +398,30 @@ static int L_get_tree_table(lua_State *L)
 }
 
 /**
+ * Lookup the SHA1 pointed at by a sha1ish.
+ *
+ * @function revparse_single
+ * @tparam llrepo repository The repository to look up the reference in.
+ * @tparam string ref The sha1ish to look up.
+ * @treturn string The OID (SHA1) of the referent (or nil on error).
+ * @treturn string The error message if the OID is nil.
+ */
+
+static int L_revparse_single(lua_State *L)
+{
+	git_repository *repo = to_repo(L, 1);
+	const char *sha1ish = luaL_checkstring(L, 2);
+	git_object *obj;
+	int ret;
+	if ((ret = git_revparse_single(&obj, repo, sha1ish)) != 0) {
+		return push_git2_error(L, ret);
+	}
+	ret = format_oid(L, git_object_id(obj));
+        git_object_free(obj);
+        return ret;
+}
+
+/**
  * The version of libgit2 which this instance of gall was built against.
  *
  * When Gall is compiled, the version of libgit2 is baked into the C binding
@@ -443,6 +467,7 @@ int luaopen_gall_ll_git2(lua_State *L)
 	BASIC_FUNC(get_object_type);
 	BASIC_FUNC(get_object_raw);
 	BASIC_FUNC(get_tree_table);
+	BASIC_FUNC(revparse_single);
 
 #if LIBGIT2_SOVERSION > 22
 	git_libgit2_init();