FULL PRODUCT VERSION :
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b18)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b18, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
This code always reproduce the bug https://bugs.openjdk.java.net/browse/JDK-8149097. Please reopen and fix it.


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the code specified in test case.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
org.xml.sax.SAXParseException
ACTUAL -
java.lang.InternalError

ERROR MESSAGES/STACK TRACES THAT OCCUR :
XML document structures must start and end within the same entity.
Premature end of file.
java.lang.InternalError: processing event: -1
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:506)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:643)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(SAXParserImpl.java:327)
at JDK8149097.main(JDK8149097.java:17)


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.io.*;
import javax.xml.parsers.*;
import org.xml.sax.*;
import org.xml.sax.helpers.*;

/**
 * Code to reproduce the bug <a href="https://bugs.openjdk.java.net/browse/JDK-8149097">JDK-8149097</a>.
 */
public class JDK8149097 {

    public static void main(String[] args) {
        try {
            String invalidXml = "<a>";
            SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
            saxParserFactory.setFeature("http://apache.org/xml/features/continue-after-fatal-error", true);
            SAXParser parser = saxParserFactory.newSAXParser();
            parser.parse(new InputSource(new StringReader(invalidXml)), new DefaultHandler() {
                @Override
                public void fatalError(SAXParseException e) throws SAXException {
                    System.err.printf("%s%n", e.getMessage());
                }
            });
        } catch (Throwable e) {
            e.printStackTrace();
        }
    }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Use SAX Parser provided by Xerces.