Disabling repairing namespaces makes the serializer fail with JsonGenerationException: Unbound namespace URI ''

[mvysny]

The following code:

        val mapper: XmlMapper = XmlMapper().apply {
            enable(SerializationFeature.INDENT_OUTPUT)
            enable(ToXmlGenerator.Feature.WRITE_XML_DECLARATION)
            setSerializationInclusion(JsonInclude.Include.NON_NULL)
//            factory.xmlOutputFactory.setProperty(XMLInputFactory.IS_NAMESPACE_AWARE, false)
            factory.xmlOutputFactory.setProperty(WstxOutputProperties.P_USE_DOUBLE_QUOTES_IN_XML_DECL, true)
            factory.xmlOutputFactory.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, false)
        }
        mapper.writeValue(file, this)

Fails with:

com.fasterxml.jackson.core.JsonGenerationException: Unbound namespace URI ''

	at com.fasterxml.jackson.dataformat.xml.util.StaxUtil.throwAsGenerationException(StaxUtil.java:47)
	at com.fasterxml.jackson.dataformat.xml.ser.ToXmlGenerator.writeString(ToXmlGenerator.java:613)
	at com.fasterxml.jackson.databind.ser.std.StringSerializer.serialize(StringSerializer.java:41)
	at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:727)
	at com.fasterxml.jackson.dataformat.xml.ser.XmlBeanSerializerBase.serializeFields(XmlBeanSerializerBase.java:202)
	at com.fasterxml.jackson.dataformat.xml.ser.XmlBeanSerializer.serialize(XmlBeanSerializer.java:117)
	at com.fasterxml.jackson.dataformat.xml.ser.XmlSerializerProvider.serializeValue(XmlSerializerProvider.java:107)
	at com.fasterxml.jackson.databind.ObjectMapper._configAndWriteValue(ObjectMapper.java:3905)
	at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:3159)
Caused by: javax.xml.stream.XMLStreamException: Unbound namespace URI ''
	at com.ctc.wstx.sw.BaseStreamWriter.throwOutputError(BaseStreamWriter.java:1589)
	at com.ctc.wstx.sw.SimpleNsStreamWriter.writeAttribute(SimpleNsStreamWriter.java:77)
	at com.fasterxml.jackson.dataformat.xml.ser.ToXmlGenerator.writeString(ToXmlGenerator.java:589)
	... 72 more

woodstox-core-5.1.0.jar, jackson-dataformat-xml-2.9.9.jar.

It looks to me as if the serializer was complaining about the default empty prefix '' not being mapped, which sounds like something that should be mapped by default.

[mvysny]

Workaround is to set WstxInputProperties.P_RETURN_NULL_FOR_DEFAULT_NAMESPACE to true:

xmlMapper.factory.xmlOutputFactory.setProperty(WstxInputProperties.P_RETURN_NULL_FOR_DEFAULT_NAMESPACE, true)

[cowtowncoder]

That sounds like a problem, but what would be needed would be reproduction including value being serialized. "No namespace" case (URI of "") should definitely be handled by writers correctly

One thing I would suggest would be using a later woodstox version (I think 5.3.0 is that latest/last 5.x), although that may not solve this issue.

So: with little bit more code I might be able to figure out what is going on.

[cowtowncoder]

Forgot to mention: disabling of namespace-repairing is NOT supported -- it must be left enabled.
That is by design; otherwise xml format module would need to try to deal with complexities of binding namespace URIs and so on.

Reference to WstxInputProperties.P_RETURN_NULL_FOR_DEFAULT_NAMESPACE is helpful: this might be a bug in Woodstox (as per other issue you filed), not recognizing 2 possible values to mean essentially same thing.

[cowtowncoder]

So, as per my earlier note, this may be outside of supported usage, but if I could get bit more complete reproduction (just basically POJO being serialized), I could rule it out.
This could also possibly be related to #395 that I just fixed.

[cowtowncoder]

Can not reproduce currently, closing; may be reopened with reproduction.