patch applied (packages/HaXml): During validation, allow for the possibility of all-empty choice or sequence.

[Malcolm Wallace]

Wed May 21 04:17:37 PDT 2008  Malcolm.Wallace at cs.york.ac.uk
  * During validation, allow for the possibility of all-empty choice or sequence.
  E.g. an element content spec of
      (caption?, (col*|colgroup*), thead?)
  is a sequence that could be entire empty, and it contains a choice which
  could also be entirely empty.

    M ./src/Text/XML/HaXml/Validate.hs +6

View patch online:
http://darcs.haskell.org/packages/HaXml/_darcs/patches/20080521111737-6871e-57b9e072726c55a128542493411e799330acbc2a.gz