Add failing test for #2775

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/databind/jsontype/impl/TypeDeserializerBase.java

@@ -204,10 +204,9 @@ protected final JsonDeserializer<Object> _findDeserializer(DeserializationContex
 
     protected final JsonDeserializer<Object> _findDefaultImplDeserializer(DeserializationContext ctxt) throws IOException
     {
-        /* 06-Feb-2013, tatu: As per [databind#148], consider default implementation value of
-         *   {@link java.lang.Void} to mean "serialize as null"; as well as DeserializationFeature
-         *   to do swift mapping to null
-         */
+        // 06-Feb-2013, tatu: As per [databind#148], consider default implementation value of
+        //   {@link java.lang.Void} to mean "serialize as null"; as well as DeserializationFeature
+        //   to do swift mapping to null
         if (_defaultImpl == null) {
             if (!ctxt.isEnabled(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE)) {
                 return NullifyingDeserializer.instance;

src/test/java/com/fasterxml/jackson/failing/PolymorphicEnum2775DeserTest.java

@@ -0,0 +1,41 @@
+package com.fasterxml.jackson.failing;
+
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+
+import com.fasterxml.jackson.databind.BaseMapTest;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class PolymorphicEnum2775DeserTest extends BaseMapTest
+{
+    // [databind#2775]
+    @JsonTypeInfo(use = JsonTypeInfo.Id.NAME
+// work-around:
+//            , include = JsonTypeInfo.As.WRAPPER_ARRAY
+            )
+    @JsonSubTypes(@JsonSubTypes.Type(TestEnum2775.class))
+    interface Base2775 {}
+
+    @JsonTypeName("Test")
+    enum TestEnum2775 implements Base2775 {
+        VALUE;
+    }
+
+    private final ObjectMapper MAPPER = newJsonMapper();
+
+    // [databind#2775]
+    public void testIssue2775() throws Exception
+    {
+        final Base2775 testValue = TestEnum2775.VALUE;
+        String json = MAPPER.writeValueAsString(testValue);
+//System.err.println("JSON: "+json);
+
+        Base2775 deserializedValue = MAPPER.readerFor(Base2775.class)
+                .without(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE)
+                .readValue(json);
+        assertEquals(testValue, deserializedValue);
+    }
+
+}