t / t4013 / diff.diff_--no-index_--raw_--abbrev=4_dir2_diron commit submodule: check for NULL return of get_submodule_ref_store() (74b6bda)
   1$ git diff --no-index --raw --abbrev=4 dir2 dir
   2:000000 100644 0000... 0000... A        dir/sub
   3$