Add a note on work-around for failing test #124

Author: cowtowncoder

src/test/java/com/fasterxml/jackson/dataformat/xml/failing/EmptyListDeser124Test.java

@@ -4,6 +4,8 @@
 import java.util.List;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonSetter;
+import com.fasterxml.jackson.annotation.Nulls;
 import com.fasterxml.jackson.dataformat.xml.*;
 
 // for [dataformat-xml#124]
@@ -16,11 +18,19 @@ public static class TestList {
 
     // [dataformat-xml#124]
     public  void test124() throws Exception {
-        final XmlMapper xmlMapper = new XmlMapper();
+        final XmlMapper xmlMapper = XmlMapper.builder()
+                .build();
+
+        // 14-Jan-2020, tatu: This is actual working override to resolve the issue...
+        //    Not sure if this can be otherwise resolved.
+
+//        xmlMapper.configOverride(List.class)
+//            .setSetterInfo(JsonSetter.Value.forValueNulls(Nulls.AS_EMPTY));
+
         TestList originalObject = new TestList();
         originalObject.list = new ArrayList<Object>();
         String xml = xmlMapper.writeValueAsString(originalObject);
-//System.err.println(xml); // print <TestList><list/>></TestList>
+//System.err.println(xml); // prints <TestList><list/>></TestList>
 
         TestList result = xmlMapper.readValue(xml, TestList.class);