Don't use "<unknown>" for placeholders and suppress printing of empty user formats.

[git.git] / t / t4013 / diff.diff-tree_--cc_--stat_--summary_master

$ git diff-tree --cc --stat --summary master
59d314ad6f356dd08601a4cd5e530381da3e3c64
 dir/sub |    2 ++
 file0   |    3 +++
 2 files changed, 5 insertions(+), 0 deletions(-)
$