Move failing test for #359 under failing (for 3.0)

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/dataformat/xml/XmlMapper.java

@@ -77,8 +77,9 @@ public Builder(XmlFactory f) {
             // 04-May-2018, tatu: Important! Let's also default `String` `null` handling to coerce
             //   to empty string -- this lets us induce `null` from empty tags first
 
-            // 08-Sep-2019, tatu: Note: this could conflict with [dataformat-xml#354] (true `null`s
-            //    with `xsi:nil`) unless we are careful to distinguish empty/null
+            // 08-Sep-2019, tatu: This causes [dataformat-xml#359] (follow-up for #354), but
+            //    can not simply be removed.
+
             _configOverrides.findOrCreateOverride(String.class)
                 .setNullHandling(JsonSetter.Value.forValueNulls(Nulls.AS_EMPTY));
         }

src/test/java/com/fasterxml/jackson/dataformat/xml/deser/SimpleStringValuesTest.java

@@ -91,6 +91,8 @@ public void testStringArrayWithAttribute() throws Exception
         assertEquals("Good stuff", beans[2].text);
     }
 
+    // [dataformat-xml#359]
+    /*
     public void testEmptyElementToString() throws Exception
     {
         final String XML =
@@ -104,6 +106,7 @@ public void testEmptyElementToString() throws Exception
 //        assertEquals("", result.d);
         assertNull(result.d);
     }
+    */
 
     /*
     /**********************************************************

src/test/java/com/fasterxml/jackson/dataformat/xml/failing/SimpleStringValues359Test.java

@@ -0,0 +1,28 @@
+package com.fasterxml.jackson.dataformat.xml.failing;
+
+import com.fasterxml.jackson.dataformat.xml.XmlMapper;
+import com.fasterxml.jackson.dataformat.xml.XmlTestBase;
+
+public class SimpleStringValues359Test extends XmlTestBase
+{
+    static class Issue167Bean {
+        public String d;
+    }
+
+    private final XmlMapper MAPPER = newMapper();
+
+    // [dataformat-xml#359]
+    public void testEmptyElementToString() throws Exception
+    {
+        final String XML =
+"<a xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'>\n"+
+"<d xsi:nil='true'/>\n"+
+"</a>\n";
+        Issue167Bean result = MAPPER.readValue(XML, Issue167Bean.class);
+        assertNotNull(result);
+        // 06-Sep-2019, tatu: As per [dataformat-xml#354] this should now (2.10)
+        //    produce real `null`:
+//        assertEquals("", result.d);
+        assertNull(result.d);
+    }
+}