#40 validate the canonical form in Xhtml2Dtbook

[Romain Deltour]

It would be nice if the Xhtml2Dtbook transformer could validate that the Xhtml input is in the expected canonial form (using Schematron?) before applying the XSLT.

I came against an input file that was a valid Xhtml but not in the canonical form and which made the whole Pipeline not responding. The XSLT somehow went into a loop and the job couldn't be aborted.

see http://forums.daisy.org/viewtopic.php?f=16&t=108#p232