Fix #455 (and possibly #426, #525, #567)

.github/workflows/main.yml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        java_version: ['17', '21', '24' ]
+        java_version: ['17', '21', '25' ]
         include:
           - java_version: '17'
             release_build: 'R'

release-notes/CREDITS

@@ -6,61 +6,61 @@ XML format backend (`jackson-dataformat-xml`), version 3.x
 Tatu Saloranta, tatu.saloranta@iki.fi: author
 
 Morten Olav Hansen (mortenoh@github)
-
-* Reported #25: `ACCEPT_EMPTY_STRING_AS_NULL_OBJECT` not honored in xml module
-  for attributes
- (3.0.0)
+ * Reported #25: `ACCEPT_EMPTY_STRING_AS_NULL_OBJECT` not honored in xml module
+   for attributes
+  (3.0.0)
 
 Ghenadii Batalski (@ghenadiibatalski)
-
-* Reported #793: `XmlSerializationContext`: NPE _writeCapabilities not set for
-  `SerializationContext`
- (3.0.4)
+ * Reported #793: `XmlSerializationContext`: NPE _writeCapabilities not set for
+   `SerializationContext`
+  (3.0.4)
 
 PJ Fanning (@pjfanning)
-
-* Fixed #793: `XmlSerializationContext`: NPE _writeCapabilities not set for
-  `SerializationContext`
- (3.0.4)
+ * Fixed #793: `XmlSerializationContext`: NPE _writeCapabilities not set for
+   `SerializationContext`
+  (3.0.4)
 
 Dai MIKURUBE (@dmikurube)
-
-* Reported #149: `@JacksonXmlElementWrapper` as a `@JsonCreator parameter` not working
- (3.2.0)
+ * Reported #149: `@JacksonXmlElementWrapper` as a `@JsonCreator parameter` not working
+  (3.2.0)
 
 Christopher McVay (@mcvayc)
-
-* Fixed #149: `@JacksonXmlElementWrapper` as a `@JsonCreator parameter` not working
- (3.2.0)
-* Fixed #517: XML wrapper doesn't work with java records
- (3.2.0)
-* Fixed #615: Deserialization of Xml with `@JacksonXmlText` using `@JsonCreator` (into
+ * Fixed #149: `@JacksonXmlElementWrapper` as a `@JsonCreator parameter` not working
+  (3.2.0)
+ * Fixed #517: XML wrapper doesn't work with java records
+  (3.2.0)
+ * Fixed #615: Deserialization of Xml with `@JacksonXmlText` using `@JsonCreator` (into
   `java.util.Map`) fails
- (3.2.0)
-* Fixed #735: Java Record with `@JacksonXmlText` stopped working with 2.18
- (3.2.0)
-* Fixed #795: `HttpHeader` object (= <httpHeaders>) is not wrapped by the XML `<property>` tag
- (3.2.0)
-* Fixed #306: Can not use `@JacksonXmlText` for Creator property (creator parameter)
- (3.2.0)
+  (3.2.0)
+ * Fixed #735: Java Record with `@JacksonXmlText` stopped working with 2.18
+  (3.2.0)
+ * Fixed #795: `HttpHeader` object (= <httpHeaders>) is not wrapped by the XML `<property>` tag
+  (3.2.0)
+ * Fixed #306: Can not use `@JacksonXmlText` for Creator property (creator parameter)
+  (3.2.0)
 
 Eduard Wirch (@ewirch)
+ * Reported #306: Can not use `@JacksonXmlText` for Creator property (creator parameter)
+  (3.2.0)
 
-* Reported #306: Can not use `@JacksonXmlText` for Creator property (creator parameter)
- (3.2.0)
+Jiri Mikulasek (@jimirocks)
+ * Reported #455: Can't deserialize list in JsonSubtype when type property is visible
+  (3.2.0)
 
 Josip Antoliš (@Antolius)
+ * Reported #517: XML wrapper doesn't work with java records
+  (3.2.0)
 
-* Reported #517: XML wrapper doesn't work with java records
- (3.2.0)
+Vitor Pamplona (@vitorpamplona)
+ * Reported #525: Order of XML Properties trigger different behaviors with
+  polymorphic nested objects
+  (3.2.0)
 
 Severin Kistler (@kistlers)
-
-* Reported #615: Deserialization of Xml with `@JacksonXmlText` using `@JsonCreator` (into
-  `java.util.Map`) fails
- (3.2.0)
+ * Reported #615: Deserialization of Xml with `@JacksonXmlText` using `@JsonCreator` (into
+   `java.util.Map`) fails
+  (3.2.0)
 
 Charles Moulliard (@cmoulliard)
-
-* Reported #795: `HttpHeader` object (= <httpHeaders>) is not wrapped by the XML `<property>` tag
- (3.2.0)
+ * Reported #795: `HttpHeader` object (= <httpHeaders>) is not wrapped by the XML `<property>` tag
+  (3.2.0)

release-notes/VERSION

@@ -15,9 +15,24 @@ Version: 3.x (for earlier see VERSION-2.x)
 #306: Can not use `@JacksonXmlText` for Creator property (creator parameter)
  (reported by Eduard W)
  (fix by Christopher M)
+#426: `InvalidTypeIdException` when parsing XML to POJO containing nested `List<>`,
+  custom `TypeIdResolver`
+ (reported by @ankagar)
+ (fix by @cowtowncoder, w/ Claude code)
+#455: Can't deserialize list in JsonSubtype when type property is visible
+ (reported by Jiri M)
+ (fix by @cowtowncoder, w/ Claude code)
 #517: XML wrapper doesn't work with java records
  (reported by Josip A)
  (fix by Christopher M)
+#525: Order of XML Properties trigger different behaviors with
+  polymorphic nested objects
+ (reported by Vitor P)
+ (fix by @cowtowncoder, w/ Claude code)
+#567: First element in unwrapped XML array is ignored during
+  deserialization to base class
+ (reported by @tetradon)
+ (fix by @cowtowncoder, w/ Claude code)
 #615: Deserialization of Xml with `@JacksonXmlText` using `@JsonCreator` (into
   `java.util.Map`) fails
  (reported by Severin K)

src/main/java/tools/jackson/dataformat/xml/deser/FromXmlParser.java

@@ -290,11 +290,16 @@ public void addVirtualWrapping(Set<String> namesToWrap0, boolean caseInsensitive
         //   problems with Lists-in-Lists properties
         // 12-May-2020, tatu: But as per [dataformat-xml#86] NOT for root element
         //   (would still like to know why work-around needed ever, but...)
+        // 15-Mar-2026, tatu: [dataformat-xml#455] Relax the parent-root check when
+        //   we're at an element's PROPERTY_NAME (_mayBeLeaf distinguishes elements
+        //   from attributes). This handles polymorphic type resolution where the type
+        //   deserializer consumed properties before wrapping was set up, so we need
+        //   to wrap the current element retroactively.
         if (!_streamReadContext.inRoot()
-                 && !_streamReadContext.getParent().inRoot()) {
+                && (!_streamReadContext.getParent().inRoot()
+                        || (_currToken == JsonToken.PROPERTY_NAME && _mayBeLeaf))) {
             String name = _xmlTokens.getLocalName();
             if ((name != null) && namesToWrap.contains(name)) {
-//System.out.println("REPEAT from addVirtualWrapping() for '"+name+"'");
                 _xmlTokens.repeatStartElement();
             }
         }

src/main/java/tools/jackson/dataformat/xml/deser/WrapperHandlingDeserializer.java

@@ -147,13 +147,23 @@ public Object deserializeWithType(JsonParser p, DeserializationContext ctxt, Typ
     @SuppressWarnings("resource")
     protected final void _configureParser(JsonParser p) throws JacksonException
     {
+        if (_namesToWrap == null) {
+            return;
+        }
         // 05-Sep-2019, tatu: May get XML parser, except for case where content is
         //   buffered. In that case we may still have access to real parser if we
         //   are lucky (like in [dataformat-xml#242])
-        while (p instanceof JsonParserDelegate) {
-            p = ((JsonParserDelegate) p).delegate();
+        // 15-Mar-2026, tatu: [dataformat-xml#455] Check for ElementWrappable at
+        //   each delegation level, not just at the innermost parser. This handles
+        //   the case where XmlTokenBuffer wraps the TokenBuffer.Parser with an
+        //   ElementWrappable delegate during polymorphic type resolution.
+        while (p instanceof JsonParserDelegate jpd) {
+            if (p instanceof ElementWrappable) {
+                break;
+            }
+            p = jpd.delegate();
         }
-        if ((p instanceof ElementWrappable) && (_namesToWrap != null)) {
+        if (p instanceof ElementWrappable ew) {
             // 03-May-2021, tatu: as per [dataformat-xml#469] there are special
             //   cases where we get String token to represent XML empty element.
             //   If so, need to refrain from adding wrapping as that would
@@ -165,17 +175,17 @@ protected final void _configureParser(JsonParser p) throws JacksonException
                     //    is consumed during buffering, so need to consider that too
                     //    it seems (just hope we are at correct level and not off by one...)
                     || t == JsonToken.PROPERTY_NAME) {
-                ((ElementWrappable) p).addVirtualWrapping(_namesToWrap, _caseInsensitive);
+                ew.addVirtualWrapping(_namesToWrap, _caseInsensitive);
             }
         }
     }
 
     protected BeanDeserializerBase _verifyDeserType(ValueDeserializer<?> deser)
     {
-        if (!(deser instanceof BeanDeserializerBase)) {
+        if (!(deser instanceof BeanDeserializerBase bdb)) {
             throw new IllegalArgumentException("Can not change delegate to be of type "
                     +deser.getClass().getName());
         }
-        return (BeanDeserializerBase) deser;
+        return bdb;
     }
 }

src/main/java/tools/jackson/dataformat/xml/deser/XmlDeserializationContext.java

@@ -10,6 +10,7 @@
 import tools.jackson.databind.deser.DeserializationContextExt;
 import tools.jackson.databind.deser.DeserializerCache;
 import tools.jackson.databind.deser.DeserializerFactory;
+import tools.jackson.databind.util.TokenBuffer;
 import tools.jackson.dataformat.xml.XmlFactory;
 
 /**
@@ -81,4 +82,17 @@ public String extractScalarFromObject(JsonParser p, ValueDeserializer<?> deser,
         }
         return text;
     }
+
+    /**
+     * Override to return XML-aware {@link XmlTokenBuffer} that produces
+     * parsers implementing {@link ElementWrappable}, allowing virtual wrapping
+     * to be configured even after content has been buffered (e.g., during
+     * polymorphic type resolution).
+     *
+     * @since 3.2
+     */
+    @Override
+    public TokenBuffer bufferForInputBuffering(JsonParser p) {
+        return XmlTokenBuffer.xmlBufferForInputBuffering(p, this);
+    }
 }

src/main/java/tools/jackson/dataformat/xml/deser/XmlTokenBuffer.java

@@ -0,0 +1,94 @@
+package tools.jackson.dataformat.xml.deser;
+
+import java.util.Set;
+
+import tools.jackson.core.JsonParser;
+import tools.jackson.core.ObjectReadContext;
+import tools.jackson.core.util.JsonParserDelegate;
+
+import tools.jackson.databind.util.TokenBuffer;
+
+/**
+ * XML-specific {@link TokenBuffer} sub-class that ensures parsers created
+ * from buffered content implement {@link ElementWrappable}, allowing
+ * virtual wrapping to be configured on the underlying XML parser even
+ * when content has been buffered (e.g., during polymorphic type resolution).
+ *
+ * @since 3.2
+ */
+public class XmlTokenBuffer extends TokenBuffer
+{
+    /**
+     * Reference to the original XML parser that implements {@link ElementWrappable},
+     * if one was found when this buffer was created.
+     */
+    protected final ElementWrappable _wrappableParser;
+
+    protected XmlTokenBuffer(JsonParser p, ObjectReadContext ctxt)
+    {
+        super(p, ctxt);
+        // Find the ElementWrappable parser by unwrapping delegates
+        JsonParser unwrapped = p;
+        while (unwrapped instanceof JsonParserDelegate del) {
+            unwrapped = del.delegate();
+        }
+        _wrappableParser = (unwrapped instanceof ElementWrappable ew) ? ew : null;
+    }
+
+    public static XmlTokenBuffer xmlBufferForInputBuffering(JsonParser p,
+            ObjectReadContext ctxt) {
+        return new XmlTokenBuffer(p, ctxt);
+    }
+
+    /*
+    /**********************************************************************
+    /* Parser construction overrides
+    /**********************************************************************
+     */
+
+    @Override
+    public JsonParser asParser(ObjectReadContext readCtxt)
+    {
+        return _wrapIfNeeded(super.asParser(readCtxt));
+    }
+
+    @Override
+    public JsonParser asParser(ObjectReadContext readCtxt, JsonParser p0)
+    {
+        return _wrapIfNeeded(super.asParser(readCtxt, p0));
+    }
+
+    protected JsonParser _wrapIfNeeded(JsonParser p) {
+        return (_wrappableParser == null) ? p
+                : new ElementWrappableParser(p, _wrappableParser);
+    }
+
+    /*
+    /**********************************************************************
+    /* Helper classes
+    /**********************************************************************
+     */
+
+    /**
+     * A thin parser delegate that implements {@link ElementWrappable} by
+     * forwarding wrapping configuration to the original XML parser.
+     * This allows {@link WrapperHandlingDeserializer} to find and configure
+     * virtual wrapping even when the active parser is reading from a
+     * {@link TokenBuffer}.
+     */
+    static class ElementWrappableParser extends JsonParserDelegate
+        implements ElementWrappable
+    {
+        protected final ElementWrappable _wrappable;
+
+        ElementWrappableParser(JsonParser delegate, ElementWrappable wrappable) {
+            super(delegate);
+            _wrappable = wrappable;
+        }
+
+        @Override
+        public void addVirtualWrapping(Set<String> namesToWrap, boolean caseInsensitive) {
+            _wrappable.addVirtualWrapping(namesToWrap, caseInsensitive);
+        }
+    }
+}

src/test/java/tools/jackson/dataformat/xml/tofix/TypeInfoOrder525Test.java → src/test/java/tools/jackson/dataformat/xml/deser/TypeInfoOrder525Test.java

@@ -1,4 +1,4 @@
-package tools.jackson.dataformat.xml.tofix;
+package tools.jackson.dataformat.xml.deser;
 
 import java.util.List;
 
@@ -9,8 +9,6 @@
 import tools.jackson.databind.ObjectMapper;
 
 import tools.jackson.dataformat.xml.XmlTestUtil;
-import tools.jackson.dataformat.xml.testutil.failure.JacksonTestFailureExpected;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 // Tests for [dataformat-xml#525], related to relative order of "type"
@@ -49,7 +47,7 @@ static class BindingInfo525 {
             .defaultUseWrapper(false)
             .build();
 
-    @JacksonTestFailureExpected
+    // [dataformat-xml#525]
     @Test
     public void testTypeAfterOtherProperties() throws Exception {
         String xml =

src/test/java/tools/jackson/dataformat/xml/tofix/PolymorphicList426Test.java → src/test/java/tools/jackson/dataformat/xml/lists/PolymorphicList426Test.java

@@ -1,4 +1,4 @@
-package tools.jackson.dataformat.xml.tofix;
+package tools.jackson.dataformat.xml.lists;
 
 import java.util.List;
 
@@ -13,8 +13,6 @@
 import tools.jackson.dataformat.xml.XmlTestUtil;
 import tools.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
 import tools.jackson.dataformat.xml.annotation.JacksonXmlProperty;
-import tools.jackson.dataformat.xml.testutil.failure.JacksonTestFailureExpected;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
@@ -91,7 +89,6 @@ public JsonTypeInfo.Id getMechanism() {
     private final ObjectMapper MAPPER = newMapper();
 
     // [dataformat-xml#426]
-    @JacksonTestFailureExpected
     @Test
     public void testPolymorphicList426() throws Exception
     {