-# rename detection options for git-diff and git-diff-tree
-# - default is '-M', with the cost proportional to
-# (number of removed files) * (number of new files).
-# - more costly is '-C' (or '-C', '-M'), with the cost proportional to
-# (number of changed files + number of removed files) * (number of new files)
-# - even more costly is '-C', '--find-copies-harder' with cost
-# (number of files in the original tree) * (number of new files)
-# - one might want to include '-B' option, e.g. '-B', '-M'
-our @diff_opts = ('-M'); # taken from git_commit
-