t / t4135 / diff-with tab.diffon commit lock_ref_sha1_basic(): if locking fails with ENOENT, retry (e5c223e)
   1--- post        image.txt.orig  2010-08-18 20:13:31.616002255 -0500
   2+++ post        image.txt       2010-08-18 20:13:31.616002255 -0500
   3@@ -1 +1 @@
   4-preimage
   5+postimage