FULL PRODUCT VERSION :
java version "9-ea"
Java(TM) SE Runtime Environment (build 9-ea+152)
Java HotSpot(TM) 64-Bit Server VM (build 9-ea+152, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Linux dstathink 4.4.0-31-generic #50-Ubuntu SMP Wed Jul 13 00:07:12 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
There is a testcase as part of Apache POI which generates HTML using javax.xml.transform.Transfomer. This test-case ran fine up to JDK 9ea-148, but started to fail in JDK9 ea-152 due to a small change in generated blanks as part of the generated HTML text.



STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Use the provided test-case to reproduce the problem.

Note: For some strange reason, when I do some changes to the test-case, e.g. refactor the test into multiple modules, then the error goes away. Very strange and indicates that this might actually be some deeper compiler-error.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I would expect the generated HTML/XML from javax.xml.transform.Transfomer. to stay the same between Java releases, but it seems the latest JDK 9 build breaks this.
ACTUAL -
Previously the contents " " lead to a blank being included in the output, but now it is not generated any more.

REPRODUCIBILITY :
This bug can be reproduced always.

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import org.junit.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.StringWriter;

import static org.junit.Assert.assertEquals;

/**
 * Test-Class which reproduces a difference in the text produced by java.xml.transform.Transformer
 * starting with JDK 9 ea-152 (still working in JDK 9 ea-148!)
 *
 * We use a Transformer to create a simple HTML structure and noticed that there is a slight
 * difference in produced text, i.e. a blank that was rendered before is now omitted.
 */
public class TestJDK9 {
    @Test
    public void testTransformBlank() throws Exception {
        Document document = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();

        Element note = document.createElement( "div" );
        document.appendChild( note );

        note.appendChild(document.createElement("a"));
        note.appendChild(document.createTextNode(" "));
        note.appendChild(document.createElement("span"));

        Transformer transformer = TransformerFactory.newInstance()
                .newTransformer();
        transformer.setOutputProperty( OutputKeys.INDENT, "yes");
        transformer.setOutputProperty( OutputKeys.METHOD, "html");

        StringWriter stringWriter = new StringWriter();
        transformer.transform(
                new DOMSource(document),
                new StreamResult( stringWriter ));

        assertEquals( "Had: " + stringWriter.toString(),
                "<div>\n" +
                "<a></a> <span></span>\n" +
                "</div>\n", stringWriter.toString());
    }
}

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