Fix #1392 for 2.7.9 / 2.8.4

Author: cowtowncoder

release-notes/VERSION

@@ -4,6 +4,11 @@ Project: jackson-databind
 === Releases ===
 ------------------------------------------------------------------------
 
+2.7.9 (not yet released)
+
+#1392: Custom UnmodifiableSetMixin Fails in Jackson 2.7+ but works in Jackson 2.6
+ (reported by Rob W)
+
 2.7.8 (26-Sep-2016)
 
 #877: @JsonIgnoreProperties`: ignoring the "cause" property of `Throwable` on GAE

src/main/java/com/fasterxml/jackson/databind/deser/BeanDeserializerBase.java

@@ -228,6 +228,7 @@ protected BeanDeserializerBase(BeanDeserializerBuilder builder,
         _objectIdReader = builder.getObjectIdReader();
         _nonStandardCreation = (_unwrappedPropertyHandler != null)
             || _valueInstantiator.canCreateUsingDelegate()
+            || _valueInstantiator.canCreateUsingArrayDelegate() // new in 2.7
             || _valueInstantiator.canCreateFromObjectWith()
             || !_valueInstantiator.canCreateUsingDefault()
             ;

src/main/java/com/fasterxml/jackson/databind/deser/ValueInstantiator.java

@@ -53,7 +53,7 @@ public boolean canInstantiate() {
              || canCreateFromInt() || canCreateFromLong()
              || canCreateFromDouble() || canCreateFromBoolean();
     }    
-    
+
     /**
      * Method that can be called to check whether a String-based creator
      * is available for this instantiator
@@ -83,7 +83,7 @@ public boolean canInstantiate() {
      * creator is available to use (to call {@link #createFromDouble}).
      */
     public boolean canCreateFromBoolean() { return false; }
-    
+
     /**
      * Method that can be called to check whether a default creator (constructor,
      * or no-arg static factory method)
@@ -102,6 +102,8 @@ public boolean canInstantiate() {
      * Method that can be called to check whether a array-delegate-based creator
      * (single-arg constructor or factory method)
      * is available for this instantiator
+     *
+     * @since 2.7
      */
     public boolean canCreateUsingArrayDelegate() { return false; }
 
@@ -141,9 +143,11 @@ public SettableBeanProperty[] getFromObjectArguments(DeserializationConfig confi
      * non-null type is returned, deserializer will bind JSON into specified
      * type (using standard deserializer for that type), and pass that to
      * instantiator.
+     *
+     * @since 2.7
      */
     public JavaType getArrayDelegateType(DeserializationConfig config) { return null; }
-    
+
     /*
     /**********************************************************
     /* Instantiation methods for JSON Object

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

@@ -172,14 +172,24 @@ public CollectionDeserializer createContextual(DeserializationContext ctxt,
     {
         // May need to resolve types for delegate-based creators:
         JsonDeserializer<Object> delegateDeser = null;
-        if ((_valueInstantiator != null) && _valueInstantiator.canCreateUsingDelegate()) {
-            JavaType delegateType = _valueInstantiator.getDelegateType(ctxt.getConfig());
-            if (delegateType == null) {
-                throw new IllegalArgumentException("Invalid delegate-creator definition for "+_collectionType
-                        +": value instantiator ("+_valueInstantiator.getClass().getName()
-                        +") returned true for 'canCreateUsingDelegate()', but null for 'getDelegateType()'");
+        if (_valueInstantiator != null) {
+            if (_valueInstantiator.canCreateUsingDelegate()) {
+                JavaType delegateType = _valueInstantiator.getDelegateType(ctxt.getConfig());
+                if (delegateType == null) {
+                    throw new IllegalArgumentException("Invalid delegate-creator definition for "+_collectionType
+                            +": value instantiator ("+_valueInstantiator.getClass().getName()
+                            +") returned true for 'canCreateUsingDelegate()', but null for 'getDelegateType()'");
+                }
+                delegateDeser = findDeserializer(ctxt, delegateType, property);
+            } else if (_valueInstantiator.canCreateUsingArrayDelegate()) {
+                JavaType delegateType = _valueInstantiator.getArrayDelegateType(ctxt.getConfig());
+                if (delegateType == null) {
+                    throw new IllegalArgumentException("Invalid array-delegate-creator definition for "+_collectionType
+                            +": value instantiator ("+_valueInstantiator.getClass().getName()
+                            +") returned true for 'canCreateUsingArrayDelegate()', but null for 'getArrayDelegateType()'");
+                }
+                delegateDeser = findDeserializer(ctxt, delegateType, property);
             }
-            delegateDeser = findDeserializer(ctxt, delegateType, property);
         }
         // [databind#1043]: allow per-property allow-wrapping of single overrides:
         // 11-Dec-2015, tatu: Should we pass basic `Collection.class`, or more refined? Mostly
@@ -204,7 +214,7 @@ public CollectionDeserializer createContextual(DeserializationContext ctxt,
         }
         return withResolved(delegateDeser, valueDeser, valueTypeDeser, unwrapSingle);
     }
-    
+
     /*
     /**********************************************************
     /* ContainerDeserializerBase API
@@ -236,9 +246,9 @@ public Collection<Object> deserialize(JsonParser p, DeserializationContext ctxt)
             return (Collection<Object>) _valueInstantiator.createUsingDelegate(ctxt,
                     _delegateDeserializer.deserialize(p, ctxt));
         }
-        /* [JACKSON-620]: empty String may be ok; bit tricky to check, however, since
-         *  there is also possibility of "auto-wrapping" of single-element arrays.
-         *  Hence we only accept empty String here.
+        /* Empty String may be ok; bit tricky to check, however, since
+         * there is also possibility of "auto-wrapping" of single-element arrays.
+         * Hence we only accept empty String here.
          */
         if (p.hasToken(JsonToken.VALUE_STRING)) {
             String str = p.getText();

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

@@ -262,19 +262,27 @@ public Object createFromObjectWith(DeserializationContext ctxt, Object[] args) t
     @Override
     public Object createUsingDelegate(DeserializationContext ctxt, Object delegate) throws IOException
     {
+        // 04-Oct-2016, tatu: Need delegation to work around [databind#1392]...
+        if (_delegateCreator == null) {
+            if (_arrayDelegateCreator != null) {
+                return _createUsingDelegate(_arrayDelegateCreator, _arrayDelegateArguments, ctxt, delegate);
+            }
+        }
         return _createUsingDelegate(_delegateCreator, _delegateArguments, ctxt, delegate);
     }
 
     @Override
     public Object createUsingArrayDelegate(DeserializationContext ctxt, Object delegate) throws IOException
     {
-        if (_arrayDelegateCreator == null) { // sanity-check; caller should check
-            // fallback to the classic delegate creator
-            return createUsingDelegate(ctxt, delegate);
+        if (_arrayDelegateCreator == null) {
+            if (_delegateCreator != null) { // sanity-check; caller should check
+                // fallback to the classic delegate creator
+                return createUsingDelegate(ctxt, delegate);
+            }
         }
         return _createUsingDelegate(_arrayDelegateCreator, _arrayDelegateArguments, ctxt, delegate);
     }
-    
+
     /*
     /**********************************************************
     /* Public API implementation; instantiation from JSON scalars

src/test/java/com/fasterxml/jackson/failing/UnmodifiableSetTyping1392Test.java renamed to src/test/java/com/fasterxml/jackson/databind/creators/ArrayDelegatorCreatorForCollectionTest.java

@@ -1,4 +1,4 @@
-package com.fasterxml.jackson.failing;
+package com.fasterxml.jackson.databind.creators;
 
 import java.util.Collections;
 import java.util.Set;
@@ -7,7 +7,7 @@
 
 import com.fasterxml.jackson.databind.*;
 
-public class UnmodifiableSetTyping1392Test extends BaseMapTest
+public class ArrayDelegatorCreatorForCollectionTest extends BaseMapTest
 {
     @JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY)
     abstract static class UnmodifiableSetMixin {