t / t4013 / diff.diff_--cached_--_file0on commit format_commit_message: honor `color=auto` for `%C(auto)` (b15a3e0)
   1diff --git a/file0 b/file0
   2new file mode 100644
   3index 0000000..10a8a9f
   4--- /dev/null
   5+++ b/file0
   6@@ -0,0 +1,9 @@
   7+1
   8+2
   9+3
  10+4
  11+5
  12+6
  13+A
  14+B
  15+C