JAXB: Marshaller.marshall throws NullPointerException if an adapter adapts a non-null bound value to null.

Issue

• I'm getting an exception that has the following root cause:

  Caused by: java.lang.NullPointerException
      at com.sun.xml.bind.v2.runtime.output.Encoded.setEscape(Encoded.java:107)
      at com.sun.xml.bind.v2.runtime.output.UTF8XmlOutput.doText(UTF8XmlOutput.java:305)
      at com.sun.xml.bind.v2.runtime.output.UTF8XmlOutput.text(UTF8XmlOutput.java:294)
      at com.sun.xml.bind.v2.runtime.XMLSerializer.leafElement(XMLSerializer.java:319)
      at com.sun.xml.bind.v2.model.impl.RuntimeBuiltinLeafInfoImpl$1.writeLeafElement(RuntimeBuiltinLeafInfoImpl.java:209)
      at com.sun.xml.bind.v2.model.impl.RuntimeBuiltinLeafInfoImpl$1.writeLeafElement(RuntimeBuiltinLeafInfoImpl.java:208)
      at com.sun.xml.bind.v2.runtime.reflect.TransducedAccessor$CompositeTransducedAccessorImpl.writeLeafElement(TransducedAccessor.java:250)
      at com.sun.xml.bind.v2.runtime.property.SingleElementLeafProperty.serializeBody(SingleElementLeafProperty.java:98)
      at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:322)
      at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsSoleContent(XMLSerializer.java:587)
      at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeRoot(ClassBeanInfoImpl.java:312)
      at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsRoot(XMLSerializer.java:488)
      at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:317)
      at com.sun.xml.bind.v2.runtime.MarshallerImpl.marshal(MarshallerImpl.java:247)
      at javax.xml.bind.helpers.AbstractMarshallerImpl.marshal(AbstractMarshallerImpl.java:76)