Skeleton for end-document not escaped in SubFilter

[Former user]

Original issue 287 created by @ysavourel on 2012-10-25T13:43:03.000Z:

Sergei: for when you get the chance.

Using the sub-filter in the XML Filer seem to not escape the skeleton of the end-document event.

See testSubFilter unit test in XMLFilterTest file (in html5 branch, but I'll merge it into dev soon)
The output does not escape the </doc2> end-tag.

-ys