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`NullPointerException` in `DTDValidator.validateElementEnd()` for element undefined in DTD

See original GitHub issue

The DTDValidator class is throwing a NullPointerException when processing invalid XML. To reproduce, use this catalog: https://github.com/oasis-tcs/dita/tree/v1.3/doctypes

test.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE map PUBLIC "-//OASIS//DTD DITA Map//EN" "map.dtd">
<map>
  <topicref>
    <ditavalref>
      <val><!-- This is invalid -->
        <prop att="product" val="win" action="flag" color="black"/>
      </val>
    </ditavalref>
  </topicref>
</map>

WstxValidatorTest.java

import com.ctc.wstx.stax.WstxInputFactory;
import java.io.File;
import java.nio.file.Paths;
import javax.xml.catalog.CatalogFeatures;
import javax.xml.catalog.CatalogManager;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;

public class WstxValidatorTest {
  public static void main(String[] args) throws XMLStreamException {
    var catalog =
        CatalogManager.catalogResolver(
            CatalogFeatures.defaults(), Paths.get("path/to/catalog.xml").toUri());
    var factory = new WstxInputFactory();
    factory.setProperty(XMLInputFactory.IS_VALIDATING, true);
    factory.setProperty(XMLInputFactory.RESOLVER, catalog);

    var reader = factory.createXMLStreamReader(new File("path/to/test.xml"));
    reader.setValidationProblemHandler(p -> System.out.println(p.getMessage()));

    while (reader.hasNext()) {
      reader.next();
    }
  }
}

Undefined element <val> encountered
Undefined element <prop> encountered
Exception in thread "main" java.lang.NullPointerException
	at com.ctc.wstx.dtd.DTDValidator.validateElementEnd(DTDValidator.java:362)
	at com.ctc.wstx.sr.InputElementStack.validateEndElement(InputElementStack.java:560)
	at com.ctc.wstx.sr.BasicStreamReader.nextFromTree(BasicStreamReader.java:2730)
	at com.ctc.wstx.sr.BasicStreamReader.next(BasicStreamReader.java:1122)
	at WstxValidatorTest.main(WstxValidatorTest.java:22)

Issue Analytics

State:
Created 3 years ago
Comments:8 (8 by maintainers)

Top GitHub Comments

1reaction

cowtowncodercommented, Apr 23, 2020

Fixed for next release (either 6.1.2 or 6.2.0, depending a bit on if #103 fix is included and needs minor version bump); also backported in 5.3 branch just in case there’s need for release there.

1reaction

cowtowncodercommented, Apr 22, 2020

Thank you! Now I can reproduce this locally, and it seems to be due to undefined element, for which validateElementStart() does not add matching StructValidator (since it is undefined). Should now be able to create simpler test to reproduce, then see what is the best way to resolve.

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