[lxml-dev] lxml XSD Schema validation problem

[Richard Smith]

Hi guys,

I'm getting an error using the lxml objectification API and XSD Validation.

Am using lxml and from distribution on standard hardy lib versions.

Here's the boilerplate version info from the FAQ:

lxml.etree:        (2, 1, 2, 0)
libxml used:       (2, 6, 31)
libxml compiled:   (2, 6, 31)
libxslt used:      (1, 1, 22)
libxslt compiled:  (1, 1, 22)

The code I'm testing with is as follows:


############################ >8 ############################
#!/usr/bin/python

from lxml import objectify
from lxml import etree

SCHEMA_FILE = 'nvdcve.xsd'
DATA_FILE = 'nvdcve-recent.xml'

schema_file = open(SCHEMA_FILE)
data_file = open(DATA_FILE)

schema = etree.XMLSchema(file=schema_file)
parser = objectify.makeparser(schema=schema)

tree = objectify.parse(data_file, parser)
############################ 8< ############################

The XSD I'm validating against is the XSD provided by NIST for CVE posts and
the XML doc is the recent NVDs:

http://nvd.nist.gov/schema/nvdcve.xsd
http://nvd.nist.gov/download/nvdcve-recent.xml

The error I'm getting from lxml is:

lxml.etree.XMLSyntaxError: Element '{http://nvd.nist.gov/feeds/cve/1.2}ref',
attribute 'url': [facet 'pattern'] The value
'http://www.securitytracker.com/id?1021107' is not accepted by the pattern
'(news|(ht|f)tp(s)?)://.+'.

The problem is that on every implementation of regex patterns I can think of
(Python, Perl, egrep etc) the regex validates... Indeed on my win32 xml
editors (LiquidXML and OxygenXML) the data validates with no problems.

$ egrep "(news|(ht|f)tp(s)?)://.+" nvdcve-recent.xml | wc -l
497

pcretest comes back fine too:

$ pcretest
PCRE version 7.4 2007-09-21

  re> #(news|(ht|f)tp(s)?)://.+#
data> http://www.securitytracker.com/id?1021107
 0: http://www.securitytracker.com/id?1021107
 1: http
 2: ht

Is this a libxml2 problem, my code or, dare I say, an evil bug?

Thanks

-- 
Richard