RFR: 8169631: [JAXP] XALAN: transformation of XML via namespace-unaware SAX input yields a different result than namespace-unaware DOM input (original) (raw)

Joe Wang huizhe.wang at oracle.com
Tue Nov 22 19:11:27 UTC 2016


Hi Christoph,

Once you're able to run all tests, feel free to push the changeset. Frank has fixed the Smoke test.

Thanks, Joe

On 11/18/16, 3:37 PM, Joe Wang wrote:

Hi Christoph,

Thanks for explaining the customer's dilemma with regard to their legacy process. The testcase I sent you was extracted from an internal SQE smoke test. I agree with your analysis, the 'golden' file which has been in there for over 10 years turns out to be wrong and needs to be updated. To fix this issue, we need to get that test fixed, and the check-in of your patch and that of the test need needs to happen simultaneously. Would you mind wanting for me to go through an internal process to get a patch ready, then we can check in almost at the same time? Best, Joe On 11/18/16, 2:51 PM, Langer, Christoph wrote: Hi Joe,

thanks for the feedback. I've now understood the testcase that you've sent over and the reason that it is reporting failure after my fix is that the output of its transform operation is rather correct now. And before it was wrong. :) The test is comparing the actual result to a "golden" result file in the end and both of these were not looking healthy so far. The reason is that your test is using a namespace unaware SAX Parser as input. With the current JDK XALAN, you could already modify your smoketest to use a namespace aware parser. E.g. replace lines 82 // Use the JAXP way to get an XMLReader 83 XMLReader reader = SAXParserFactory.newInstance().newSAXParser().getXMLReader(); with 82 // Use the JAXP way to get an XMLReader 83 SAXParserFactory spf = SAXParserFactory.newInstance(); 84 spf.setNamespaceAware(true); 85 XMLReader reader = spf.newSAXParser().getXMLReader(); ...and you would already get correct results that also DOM input or Stream Input would yield. So, are there other concerns/issues with this fix? Do you want me to include a transformation operation like the one that your SmokeTest does to TransformerTest which would illustrate the problem with namespace unaware SAX input data? Best regards Christoph

-----Original Message----- From: Joe Wang [mailto:huizhe.wang at oracle.com] Sent: Freitag, 18. November 2016 05:53 To: Langer, Christoph<christoph.langer at sap.com> Cc: core-libs-dev at openjdk.java.net Subject: Re: RFR: 8169631: [JAXP] XALAN: transformation of XML via namespace-unaware SAX input yields a different result than namespace- unaware DOM input

On 11/14/16, 11:43 PM, Langer, Christoph wrote: Hi Joe, thanks for looking. Can you let me know which smoke test is failing? I didn't see issues so far - I was merely running the jtreg unittests for transformer. I sent the test to your mailbox. I stepped back from replacing Vector with ArrayList for mprefixMappings because the code is using methods indexOf() with a start index and setSize() for which ArrayList has no direct matchings. One could, for sure, add some other coding, e.g. use ArrayList's subList() method for the index based search - but I wouldn't want to run the risk of adding a regression here just because I modified the code and did not well test it. But if you insist, I could have another look. Ok, that's fine. subList would do, but setSize may need a bit more work. Best, Joe Best regards Christoph -----Original Message----- From: Joe Wang [mailto:huizhe.wang at oracle.com] Sent: Dienstag, 15. November 2016 03:23 To: Langer, Christoph<christoph.langer at sap.com> Cc: core-libs-dev at openjdk.java.net Subject: Re: RFR: 8169631: [JAXP] XALAN: transformation of XML via namespace-unaware SAX input yields a different result than namespace- unaware DOM input Hi Christoph, Not all tests have finished yet, but there's at least one failure in the smoke test. I'll get to the details when I have time. Any reason why mprefixMappings can not be replaced with ArrayList? Thanks, Joe On 11/14/16, 6:10 AM, Langer, Christoph wrote: Hi, please review this fix for bug 8169631. Bug: https://bugs.openjdk.java.net/browse/JDK-8169631 Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8169631.0/ When XALAN is handling namespace unaware input, it behaves differently while using SAX input compared to DOM input. With both input source types, the class com.sun.org.apache.xml.internal.dtm.ref.sax2dtm.SAX2DTM2 converts SAX input into a DTM representation for processing by the XALAN transformer. Its method startElement takes URI, localname and qName as attribute. In case of missing feature namespaces, startElement and localname can be empty. However, the function uses the localname value for the call to mexpandedNameTable.getExpandedTypeID() and further processing. In the case where only qName has data, this leads to issues. When using DOM input, the class com.sun.org.apache.xalan.internal.xsltc.trax.DOM2SAX converts the DOM input into SAX input. In the case of empty localname, it fills localname with qname data. See method getLocalName() [1], called by parse() [2]. When directly using SAX input, the SAX parser calls the startElement() function on XALAN's handler with empty uri and localname - which seems correct, as per the spec. Both paths end up in SAX2DTM2's startElement(). So I suggest to change this method to handle the case when uri and localname are empty and then set qname as localname. Maybe one should even change DOM2SAX's getLocalName handling to not fill localname with qname in case it is empty after SAX2DTM was changed.. Generally, JavaDoc for SAXSource says that "Attempting to transform an input source that is not generated with a namespace-aware parser may result in errors." But why not fix some of these :) Furthermore I did some cleanups in the code. Thanks and best regards Christoph [1] http://hg.openjdk.java.net/jdk9/dev/jaxp/file/71558b38bad7/src/java.xml/shar e/classes/com/sun/org/apache/xalan/internal/xsltc/trax/DOM2SAX.java#l139 [2] http://hg.openjdk.java.net/jdk9/dev/jaxp/file/71558b38bad7/src/java.xml/shar e/classes/com/sun/org/apache/xalan/internal/xsltc/trax/DOM2SAX.java#l279 [3] https://docs.oracle.com/javase/8/docs/api/javax/xml/transform/sax/SAXSource .html



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