Fix #1441

Author: cowtowncoder

release-notes/CREDITS

@@ -562,6 +562,10 @@ Kevin Donnelly (kpdonn@github)
   * Reported #1432: Off by 1 bug in PropertyValueBuffer
    (2.8.5)
 
+Nathanial Ofiesh (ofiesh@github)
+  * Reported #1441: Failure with custom Enum key deserializer, polymorphic types
+   (2.8.5)
+
 Connor Kuhn (ckuhn@github)
   * Contributed #1341: FAIL_ON_MISSING_EXTERNAL_TYPE_ID_PROPERTY
    (2.9.0)

release-notes/VERSION

@@ -12,6 +12,8 @@ Project: jackson-databind
 #1432: Off by 1 bug in PropertyValueBuffer
  (reported by Kevin D)
 #1439: NPE when using with filter id, serializing `java.util.Map` types
+#1441: Failure with custom Enum key deserializer, polymorphic types
+ (reported by Nathanial O)
 - Improvements to #1411 fix to ensure consistent `null` key handling
 
 2.8.4 (14-Oct-2016)

src/main/java/com/fasterxml/jackson/databind/deser/std/StdKeyDeserializer.java

@@ -8,13 +8,15 @@
 import java.net.URL;
 import java.util.*;
 
+import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.core.io.NumberInput;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.annotation.JacksonStdImpl;
 import com.fasterxml.jackson.databind.introspect.AnnotatedMethod;
 import com.fasterxml.jackson.databind.util.ClassUtil;
 import com.fasterxml.jackson.databind.util.EnumResolver;
+import com.fasterxml.jackson.databind.util.TokenBuffer;
 
 /**
  * Default {@link KeyDeserializer} implementation used for most {@link java.util.Map}
@@ -303,16 +305,21 @@ protected DelegatingKD(Class<?> cls, JsonDeserializer<?> deser) {
             _delegate = deser;
         }
 
+        @SuppressWarnings("resource")
         @Override
         public final Object deserializeKey(String key, DeserializationContext ctxt)
-            throws IOException, JsonProcessingException
+            throws IOException
         {
             if (key == null) { // is this even legal call?
                 return null;
             }
+            TokenBuffer tb = new TokenBuffer(ctxt.getParser(), ctxt);
+            tb.writeString(key);
             try {
                 // Ugh... should not have to give parser which may or may not be correct one...
-                Object result = _delegate.deserialize(ctxt.getParser(), ctxt);
+                JsonParser p = tb.asParser();
+                p.nextToken();
+                Object result = _delegate.deserialize(p, ctxt);
                 if (result != null) {
                     return result;
                 }

src/test/java/com/fasterxml/jackson/databind/module/TestCustomEnumKeyDeserializer.java

@@ -6,6 +6,7 @@
 
 import org.junit.Test;
 
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.core.*;
 import com.fasterxml.jackson.core.type.TypeReference;
 
@@ -149,6 +150,17 @@ public void setupModule(SetupContext context) {
         }
     }
 
+    // for [databind#1441]
+
+    enum SuperTypeEnum {
+        FOO;
+    }
+
+    @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "@type", defaultImpl = SuperType.class)
+    static class SuperType {
+        public Map<SuperTypeEnum, String> someMap;
+    }
+
     /*
     /**********************************************************
     /* Test methods
@@ -190,4 +202,25 @@ public void withTree749() throws Exception
         String firstFieldName = inner.fieldNames().next();
         assertEquals("green", firstFieldName);
     }
+
+    // [databind#1441]
+    public void testCustomEnumKeySerializerWithPolymorphic() throws IOException
+    {
+        SimpleModule simpleModule = new SimpleModule();
+        simpleModule.addDeserializer(SuperTypeEnum.class, new JsonDeserializer<SuperTypeEnum>() {
+            @Override
+            public SuperTypeEnum deserialize(JsonParser p, DeserializationContext deserializationContext)
+                    throws IOException
+            {
+                return SuperTypeEnum.valueOf(p.getText());
+            }
+        });
+        ObjectMapper mapper = new ObjectMapper()
+                .registerModule(simpleModule);
+
+        SuperType superType = mapper.readValue("{\"someMap\": {\"FOO\": \"bar\"}}",
+                SuperType.class);
+        assertEquals("Deserialized someMap.FOO should equal bar", "bar",
+                superType.someMap.get(SuperTypeEnum.FOO));
+    }
 }