t / t5100 / patch0018on commit packed_ref_iterator_begin(): iterate using `mmapped_ref_iterator` (d1cf155)
   1diff --git a/foo b/foo
   2index e69de29..d95f3ad 100644
   3--- a/foo
   4+++ b/foo
   5@@ -0,0 +1 @@
   6+content