[
https://issues.apache.org/jira/browse/DAFFODIL-2363?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17168132#comment-17168132
]
Mike Beckerle commented on DAFFODIL-2363:
-----------------------------------------
Changed this to "beginner". There are quite a few things to understand in order
to fix this issue, but once those are understood, the fix should be simple.
* Daffodil's conversion of XML illegal characters into the PUA region E.g.,
U+E00B or U+E000 characters. (see:
https://daffodil.apache.org/infoset/#xml-illegal-characters)
* That this only applies to the infoset once it has been converted into XML,
not before.
* That Daffodil's internal validation (aka "limited" validation) does NOT
operate on these remapped characters, but on the original characters of the
DFDL Infoset, which allows all the XML-illegal code points.
* That the pattern used for the pattern facet must be interpretable by regular
old XML Schema (and so cannot use DFDL character entities like %NUL; or %#x0b;).
* That the pattern to be used by Daffodil's limited (internal) validation could
be expressed in terms of the remapped XML PUA characters like "" but we
can process the pattern to convert these sequences using the same PUA-to
regular-DFDL-character conversion used when converting an XML Infoset into a
DFDL Infoset when unparsing.
Ultimately this is a one-line fix: call the PUA-to-regular-DFDL-character
conversion before using the pattern in Daffodil's internal validation
mechanism.
> pattern facet can't use  notation. Makes validating NUL very hard.
> ---------------------------------------------------------------------------
>
> Key: DAFFODIL-2363
> URL: https://issues.apache.org/jira/browse/DAFFODIL-2363
> Project: Daffodil
> Issue Type: Bug
> Components: Back End
> Affects Versions: 2.7.0
> Reporter: Mike Beckerle
> Priority: Critical
> Labels: beginner
> Fix For: 3.0.0
>
>
> See test_nulPattern1.
> This bug is a real pain in the neck.
> I want to capture NUL padding regions and insure they are all NUL.
> These come through to XML as These U+E000 characters. I need to insure that
> the string contains only those.
> So I'd like to use a
> {code:xml}
> <xs:simpleType name="allNULStringType>
> <xs:restriction base="xs:string">
> <xs:pattern value="*"/>
> </xs:restriction>
> </xs:simpleType>
> {code}
> I consider this data well-formed (should parse) even if other bytes are there
> that aren't NUL, but such data is invalid. So I want the facet to check for
> all NUL chars (or these E000 things that Daffodil puts in XML because XML
> can't contain actual NUL chars).
> The test fails with
> {code:java}
> org.apache.daffodil.tdml.TDMLExceptionImpl: (Implementation: daffodil)
> Validation errors found where none were expected by the test case.
> Validation Error: ex:foo failed facet checks due to: facet pattern(s): *
> {code}
> If github does the right thing that pattern will look like the E000 box char
> and *.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
