8349516: StAXStream2SAX.handleCharacters() fails on empty CDATA

Author: JoeWang-Java

src/java.xml/share/classes/com/sun/org/apache/xalan/internal/xsltc/trax/StAXStream2SAX.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -281,7 +281,9 @@ private void handleCharacters() throws XMLStreamException {
         int textLength = staxStreamReader.getTextLength();
         char[] chars = new char[textLength];
 
-        staxStreamReader.getTextCharacters(0, chars, 0, textLength);
+        if (textLength > 0) {
+            staxStreamReader.getTextCharacters(0, chars, 0, textLength);
+        }
 
         try {
             _sax.characters(chars, 0, chars.length);

test/jaxp/javax/xml/jaxp/unittest/validation/ValidationTest.java

@@ -26,13 +26,16 @@
 
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.Reader;
+import java.io.StringReader;
 import javax.xml.XMLConstants;
 import javax.xml.parsers.SAXParserFactory;
 import javax.xml.stream.XMLInputFactory;
 import javax.xml.stream.XMLStreamReader;
 import javax.xml.stream.events.XMLEvent;
 import javax.xml.transform.Source;
 import javax.xml.transform.sax.SAXSource;
+import javax.xml.transform.stax.StAXSource;
 import javax.xml.transform.stream.StreamSource;
 import javax.xml.validation.Schema;
 import javax.xml.validation.SchemaFactory;
@@ -48,7 +51,7 @@
 
 /*
  * @test
- * @bug 8220818 8176447
+ * @bug 8220818 8176447 8349516
  * @library /javax/xml/jaxp/libs /javax/xml/jaxp/unittest
  * @run testng/othervm validation.ValidationTest
  * @summary Runs validations with schemas and sources
@@ -139,6 +142,52 @@ public void startElement(String uri, String localName, String qName, Attributes
 
     }
 
+    /**
+     * Verifies the bug fix for 8349516. The fix adds a guard against empty text
+     * since calling StreamReader.getTextCharacters with textLength=0 will result
+     * in IndexOutOfBoundsException.
+     *
+     * @throws Exception if the test fails, in which case the parser throws
+     * IndexOutOfBoundsException.
+     */
+    @Test
+    public void testValidationWithStAX() throws Exception {
+        String schema = """
+            <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+                targetNamespace="http://xxxx.com/schema/test"
+                attributeFormDefault="unqualified"
+                elementFormDefault="qualified"
+            >
+
+                <xs:element name="test">
+                    <xs:complexType>
+                    <xs:choice>
+                        <xs:element name="tag" type="xs:string" />
+                    </xs:choice>
+                    </xs:complexType>
+                </xs:element>
+
+            </xs:schema>
+            """;
+
+        String xml = """
+            <test xmlns="http://xxxx.com/schema/test">
+                <tag><![CDATA[]]></tag>
+            </test>
+            """;
+
+        Reader schemaReader = new StringReader(schema);
+        Reader xmlReader = new StringReader(xml);
+
+        Source source = new StreamSource(schemaReader);
+
+        Validator validator =
+                SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI).newSchema(source).newValidator();
+
+        XMLStreamReader xmlStreamReader = XMLInputFactory.newInstance().createXMLStreamReader(xmlReader);
+        validator.validate(new StAXSource(xmlStreamReader));
+    }
+
     private static String getTargetNamespace(String xsdFile) throws Exception {
         XMLStreamReader reader = XMLInputFactory.newInstance().createXMLStreamReader(new FileInputStream(xsdFile));
         while (reader.hasNext()) {