Fix #3091

release-notes/VERSION-2.x

@@ -25,6 +25,8 @@ Project: jackson-databind
  (reported by Asaf R)
 #3082: Dont track unknown props in buffer if `ignoreAllUnknown` is true
  (contributed by David H)
+#3091: Should allow deserialization of java.time types via opaque
+   `JsonToken.VALUE_EMBEDDED_OBJECT`
 #3099: Optimize "AnnotatedConstructor.call()" case by passing explicit null
 #3101: Add AnnotationIntrospector.XmlExtensions interface for decoupling javax dependencies
 #3117: Use more limiting default visibility settings for JDK types (java.*, javax.*)

src/main/java/com/fasterxml/jackson/databind/deser/impl/UnsupportedTypeDeserializer.java

@@ -3,6 +3,7 @@
 import java.io.IOException;
 
 import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
 import com.fasterxml.jackson.databind.DeserializationContext;
 import com.fasterxml.jackson.databind.JavaType;
 import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
@@ -14,6 +15,9 @@
  * This is used for "known unknown" types: types that we can recognize
  * but can not support easily (or support known to be added via extension
  * module).
+ *<p>
+ * NOTE: starting with 2.13, does allow deserialization from
+ * {@code JsonToken.VALUE_EMBEDDED_OBJECT} if type matches (or is {@code null}).
  *
  * @since 2.12
  */
@@ -32,7 +36,15 @@ public UnsupportedTypeDeserializer(JavaType t, String m) {
     }
 
     @Override
-    public Object deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
+    public Object deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
+    {
+        // 26-May-2021, tatu: For [databind#3091], do allow reads from embedded values
+        if (p.currentToken() == JsonToken.VALUE_EMBEDDED_OBJECT) {
+            Object value = p.getEmbeddedObject();
+            if ((value == null) || _type.getRawClass().isAssignableFrom(value.getClass())) {
+                return value;
+            }
+        }
         ctxt.reportBadDefinition(_type, _message);
         return null;
     }

src/test/java/com/fasterxml/jackson/databind/interop/DateJava8FallbacksTest.java

@@ -2,10 +2,15 @@
 
 import java.time.Instant;
 import java.time.OffsetDateTime;
+import java.time.ZoneId;
 import java.time.ZoneOffset;
 
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.ObjectCodec;
+
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
+import com.fasterxml.jackson.databind.util.TokenBuffer;
 
 // [databind#2683]: add fallback handling for Java 8 date/time types, to
 // prevent accidental serialization as POJOs, as well as give more information
@@ -42,4 +47,33 @@ public void testBetterDeserializationError() throws Exception
             verifyException(e, "add Module \"com.fasterxml.jackson.datatype:jackson-datatype-jsr310\"");
         }
     }
+
+    // But, [databind#3091], allow deser from JsonToken.VALUE_EMBEDDED_OBJECT
+    public void testAllowAsEmbedded() throws Exception
+    {
+        OffsetDateTime time = OffsetDateTime.ofInstant(Instant.now(),
+                ZoneId.of("Z"));
+        try (TokenBuffer tb = new TokenBuffer((ObjectCodec) null, false)) {
+            tb.writeEmbeddedObject(time);
+
+            try (JsonParser p = tb.asParser()) {
+                OffsetDateTime result = MAPPER.readValue(p, OffsetDateTime.class);
+                assertSame(time, result);
+            }
+        }
+
+        // but also try deser into an array
+        try (TokenBuffer tb = new TokenBuffer((ObjectCodec) null, false)) {
+            tb.writeStartArray();
+            tb.writeEmbeddedObject(time);
+            tb.writeEndArray();
+
+            try (JsonParser p = tb.asParser()) {
+                Object[] result = MAPPER.readValue(p, Object[].class);
+                assertNotNull(result);
+                assertEquals(1, result.length);
+                assertSame(time, result[0]);
+            }
+        }
+    }
 }