Fixed #411

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -24,6 +24,8 @@ Project: jackson-dataformat-xml
 #397: `XmlReadContext` does not keep track of array index
 #403: Make `JsonNode` implicitly create `ArrayNode`s for repeated XML Elements
 #405: Mixed content not exposed through `FromXmlParser`, lost by `JsonNode`
+#411: Change default setting of `FromXmlParser.Feature.EMPTY_ELEMENT_AS_NULL`
+  from `true` to `false`
 
 2.11.1 (not yet released)
 
@@ -85,7 +87,7 @@ No changes since 2.10.x
  (reported by Sam S)
 #351: XmlBeanSerializer serializes AnyGetters field even with FilterExceptFilter
  (reported by Rohit N)
-#354: Support mapping `xsi:nul` marked elements as `null`s (`JsonToken.VALUE_NULL`)
+#354: Support mapping `xsi:nil` marked elements as `null`s (`JsonToken.VALUE_NULL`)
 
 2.9.10 (not yet released)
 

src/main/java/com/fasterxml/jackson/dataformat/xml/deser/FromXmlParser.java

@@ -55,11 +55,12 @@ public enum Feature implements FormatFeature
          * returned as `null` tokens, they will be returned as {@link JsonToken#VALUE_STRING}
          * tokens with textual value of "" (empty String).
          *<p>
-         * Default setting is `true` for backwards compatibility.
+         * Default setting was {@code true} (for backwards compatibility from 2.9 to 2.11 (inclusive)
+         * but was changed in 2.12 to be {@code false} (see [dataformat-xml#411] for details)
          *
          * @since 2.9
          */
-        EMPTY_ELEMENT_AS_NULL(true)
+        EMPTY_ELEMENT_AS_NULL(false)
         ;
 
         final boolean _defaultState;
@@ -736,11 +737,7 @@ public String nextTextValue() throws IOException
                 return null;
             }
             if (_parsingContext.inArray()) {
-                try {
-                    token = _xmlTokens.next();
-                } catch (XMLStreamException e) {
-                    StaxUtil.throwAsParseException(e, this);
-                }
+                token = _nextToken();
                 _mayBeLeaf = true;
                 continue;
             }

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

@@ -43,18 +43,20 @@ public void testEmptyString162() throws Exception
     public void testEmptyElement() throws Exception
     {
         final String XML = "<name><first/><last></last></name>";
-        // Default settings: empty element becomes `null`:
+
+        // Default settings (since 2.12): empty element does NOT become `null`:
         Name name = MAPPER.readValue(XML, Name.class);
         assertNotNull(name);
-        assertNull(name.first);
+        assertEquals("", name.first);
         assertEquals("", name.last);
 
         // but can be changed
-        XmlMapper mapper2 = new XmlMapper();
-        mapper2.disable(FromXmlParser.Feature.EMPTY_ELEMENT_AS_NULL);
+        XmlMapper mapper2 = XmlMapper.builder()
+                .enable(FromXmlParser.Feature.EMPTY_ELEMENT_AS_NULL)
+                .build();
         name = mapper2.readValue(XML, Name.class);
         assertNotNull(name);
-        assertEquals("", name.first);
+        assertNull(name.first);
         assertEquals("", name.last);
     }
 

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

@@ -44,12 +44,14 @@ public void setValue(String v) {
     /**********************************************************
      */
 
-    private final XmlMapper MAPPER = newMapper();
+    private final XmlMapper NULL_EXPOSING_MAPPER = mapperBuilder()
+            .enable(FromXmlParser.Feature.EMPTY_ELEMENT_AS_NULL)
+            .build();
 
     public void testSkipNullField1() throws Exception
     {
         // first, ok if assigning non-null to not-nullable, null for nullable
-        NullSkipField result = MAPPER.readValue(
+        NullSkipField result = NULL_EXPOSING_MAPPER.readValue(
 //"<NullSkipField><noNulls>foo</noNulls><nullsOk></nullsOk></NullSkipField>",
 "<NullSkipField><noNulls>foo</noNulls><nullsOk /></NullSkipField>",
                 NullSkipField.class);
@@ -60,15 +62,15 @@ public void testSkipNullField1() throws Exception
     public void testSkipNullField2() throws Exception
     {
         // and then see that nulls are not ok for non-nullable
-        NullSkipField result = MAPPER.readValue("<NullSkipField><noNulls /></NullSkipField>",
+        NullSkipField result = NULL_EXPOSING_MAPPER.readValue("<NullSkipField><noNulls /></NullSkipField>",
                 NullSkipField.class);
         assertEquals("b", result.noNulls);
         assertEquals("a", result.nullsOk);
     }
 
     public void testSkipNullMethod1() throws Exception
     {
-        NullSkipMethod result = MAPPER.readValue(
+        NullSkipMethod result = NULL_EXPOSING_MAPPER.readValue(
 //"<NullSkipMethod><noNulls>foo<noNulls><nullsOk></nullsOk></NullSkipMethod>",
 "<NullSkipMethod><noNulls>foo</noNulls><nullsOk /></NullSkipMethod>",
                 NullSkipMethod.class);
@@ -78,7 +80,7 @@ public void testSkipNullMethod1() throws Exception
 
     public void testSkipNullMethod2() throws Exception
     {
-        NullSkipMethod result = MAPPER.readValue("<NullSkipMethod><noNulls /></NullSkipMethod>",
+        NullSkipMethod result = NULL_EXPOSING_MAPPER.readValue("<NullSkipMethod><noNulls /></NullSkipMethod>",
                 NullSkipMethod.class);
         assertEquals("b", result._noNulls);
         assertEquals("a", result._nullsOk);
@@ -94,10 +96,12 @@ public void testSkipNullWithDefaults() throws Exception
     {
 //        String doc = "<StringValue><value></value></StringValue>";
         String doc = "<StringValue><value /></StringValue>";
-        StringValue result = MAPPER.readValue(doc, StringValue.class);
+        StringValue result = NULL_EXPOSING_MAPPER.readValue(doc, StringValue.class);
         assertNull(result.value);
 
-        ObjectMapper mapper = newMapper();
+        ObjectMapper mapper = mapperBuilder()
+                .enable(FromXmlParser.Feature.EMPTY_ELEMENT_AS_NULL)
+                .build();
         mapper.configOverride(String.class)
             .setSetterInfo(JsonSetter.Value.forValueNulls(Nulls.SKIP));
         result = mapper.readValue(doc, StringValue.class);