---
fixes:
  - |
    Fixes `bug 1934252`_ which ignored invalid denylist patterns. The fix
    entailed checking the pattern string via regular expression compiler and
    testing for zero length.

    Previously you could create blacklist/denylist using string that cannot
    be used either as a regex or as a zone name, for example:
    patterns = ['', ``'#(*&^%$%$#@$']``

    In addition, the server will return a 400 BadRequest response to an
    invalid pattern.

    .. _Bug 1934252: https://bugs.launchpad.net/designate/+bug/1934252