ADDITIONAL SYSTEM INFORMATION :
Tested on macos 10.13.5, JDK 8u172 and 10.0.1

A DESCRIPTION OF THE PROBLEM :
This is a followup for bug JDK-8151873, as that has been closed as incomplete. I am not the author of JDK-8151873, but I can offer example code demonstrating the problem.

Some more details: the message bundle com/sun/xml/internal/bind/v2/model/impl/Messages.properties contains improper quoting for the first format element for the messages CONFLICTING_XML_ELEMENT_MAPPING and NO_XML_ELEMENT_DECL in all languages but English (default) and pt_BR.

The English (and portuguese) version correctly quote a pair of braces that should be output as part of the message like this:

'{'{0}'}'

all other localizations replace this with the faulty

''{''{0}''}''

The outer braces are not quoted in the latter version, so {''{0}''} is interpreted as format element, resulting in a NumberFormatException when formatting ( ''{0}'' is not parseable as number ).


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile and run the attached class

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The program should exit without any output and exit code 0
ACTUAL -
The following exception terminates the program:

Exception in thread "main" java.lang.IllegalArgumentException: can't parse argument number: ''{0}''

Exit code is 1.

---------- BEGIN SOURCE ----------
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.annotation.XmlElementDecl;
import javax.xml.bind.annotation.XmlRegistry;
import javax.xml.namespace.QName;
import java.util.Locale;

public class JAXBErrorExample {

    @XmlRegistry
    public static class TheObjectFactory {
        @XmlElementDecl(name="foo")
        public JAXBElement<String> createFoo1() {
            return new JAXBElement<>(new QName(null, "foo"), String.class, "");
        }
        @XmlElementDecl(name="foo")
        public JAXBElement<String> createFoo2() {
            return new JAXBElement<>(new QName(null, "foo"), String.class, "");
        }
    }

    public static void main(String[] args) {
        try {
            Locale.setDefault(Locale.GERMAN);
            JAXBContext.newInstance(TheObjectFactory.class);

        } catch (JAXBException e) {
            // ok, should throw
        }
    }
}
---------- END SOURCE ----------

FREQUENCY : always