in lib/gitlab_git/commit.rb [122:136]
def diff_from_parent(rugged_commit, options = {})
options ||= {}
break_rewrites = options[:break_rewrites]
actual_options = Diff.filter_diff_options(options)
diff = if rugged_commit.parents.empty?
rugged_commit.diff(actual_options.merge(reverse: true))
else
rugged_commit.parents[0].diff(rugged_commit, actual_options)
end
diff.find_similar!(break_rewrites: break_rewrites)
diff
end