thodg/libgit2

diff --git a/src/transports/git.c b/src/transports/git.c
index 3e7e5a0..6c6acf9 100644
--- a/src/transports/git.c
+++ b/src/transports/git.c
@@ -130,12 +130,15 @@ static int git_proto_stream_write(
 
 static void git_proto_stream_free(git_smart_subtransport_stream *stream)
 {
-	git_proto_stream *s = (git_proto_stream *)stream;
-	git_subtransport *t = OWNING_SUBTRANSPORT(s);
+	git_proto_stream *s;
+	git_subtransport *t;
 
 	if (!stream)
 		return;
 
+	s = (git_proto_stream *)stream;
+	t = OWNING_SUBTRANSPORT(s);
+
 	t->current_stream = NULL;
 
 	git_stream_close(s->io);