Merge branch 'jp/use-diff-index-in-pre-commit-sample'

The sample pre-commit hook that tries to catch introduction of new
paths that use potentially non-portable characters did not notice
an existing path getting renamed to such a problematic path, when
rename detection was enabled.

* jp/use-diff-index-in-pre-commit-sample:
  hooks--pre-commit: detect non-ASCII when renaming