[22703] Bug #672364 - does not properly handle XML parse errors, leading to
possible data loss

Handle return value of xmlParseDocument()
Ignoring errors can lead to data loss.
Author: Sébastien Villemot <sebastien@debian.org>
Bug-Debian: http://bugs.debian.org/696282

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/branches/2.4@22704 57a11ea4-9604-0410-9ed3-97b8803252fd