Fix #4200: use annotations for delegating @JsonCreator (#4228)

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -6,6 +6,8 @@ Project: jackson-databind
 
 2.17.0 (not yet released)
 
+#4200: `JsonSetter(contentNulls = FAIL)` is ignored in delegating
+  `@JsonCreator` argument
 #4205: Consider types in `sun.*` package(s) to be JDK (platform) types
   for purposes of handling
 #4209: Make `BeanDeserializerModifier`/`BeanSerializerModifier`

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

@@ -11,6 +11,7 @@
 import com.fasterxml.jackson.core.JsonParser.NumberType;
 
 import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.cfg.ConfigOverride;
 import com.fasterxml.jackson.databind.deser.impl.*;
 import com.fasterxml.jackson.databind.deser.std.StdDelegatingDeserializer;
 import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
@@ -695,12 +696,29 @@ protected void _replaceProperty(BeanPropertyMap props, SettableBeanProperty[] cr
 
     @SuppressWarnings("unchecked")
     private JsonDeserializer<Object> _findDelegateDeserializer(DeserializationContext ctxt,
-            JavaType delegateType, AnnotatedWithParams delegateCreator) throws JsonMappingException
+            JavaType delegateType, AnnotatedWithParams delegateCreator)
+        throws JsonMappingException
     {
-        // Need to create a temporary property to allow contextual deserializers:
-        BeanProperty.Std property = new BeanProperty.Std(TEMP_PROPERTY_NAME,
-                delegateType, null, delegateCreator,
-                PropertyMetadata.STD_OPTIONAL);
+        // 27-Nov-2023, tatu: [databind#4200] Need to resolve PropertyMetadata.
+        //   And all we have is the actual Creator method; but for annotations
+        //   we actually need the one parameter -- if there is one
+        //   (NOTE! This would not work for case of more than one parameter with
+        //   delegation, others injected)
+        final BeanProperty property;
+
+        if ((delegateCreator != null) && (delegateCreator.getParameterCount() == 1)) {
+            AnnotatedMember delegator = delegateCreator.getParameter(0);
+            PropertyMetadata propMd = _getSetterInfo(ctxt, delegator, delegateType);
+            property = new BeanProperty.Std(TEMP_PROPERTY_NAME,
+                    delegateType, null, delegator, propMd);
+        } else {
+            // No creator indicated; or Zero, or more than 2 arguments (since we don't
+            // know which one is the  "real" delegating parameter. Although could possibly
+            // figure it out if someone provides actual use case
+            property = new BeanProperty.Std(TEMP_PROPERTY_NAME,
+                    delegateType, null, delegateCreator,
+                    PropertyMetadata.STD_OPTIONAL);
+        }
         TypeDeserializer td = delegateType.getTypeHandler();
         if (td == null) {
             td = ctxt.getConfig().findTypeDeserializer(delegateType);
@@ -720,6 +738,62 @@ private JsonDeserializer<Object> _findDelegateDeserializer(DeserializationContex
         return dd;
     }
 
+    /**
+     * Method essentially copied from {@code BasicDeserializerFactory},
+     * needed to find {@link PropertyMetadata} for Delegating Creator,
+     * for access to annotation-derived info.
+     *
+     * @since 2.17
+     */
+    protected PropertyMetadata _getSetterInfo(DeserializationContext ctxt,
+            AnnotatedMember accessor, JavaType type)
+    {
+        final AnnotationIntrospector intr = ctxt.getAnnotationIntrospector();
+        final DeserializationConfig config = ctxt.getConfig();
+
+        PropertyMetadata metadata = PropertyMetadata.STD_OPTIONAL;
+        boolean needMerge = true;
+        Nulls valueNulls = null;
+        Nulls contentNulls = null;
+
+        // NOTE: compared to `POJOPropertyBuilder`, we only have access to creator
+        // parameter, not other accessors, so code bit simpler
+        // Ok, first: does property itself have something to say?
+        if (intr != null) {
+            JsonSetter.Value setterInfo = intr.findSetterInfo(accessor);
+            if (setterInfo != null) {
+                valueNulls = setterInfo.nonDefaultValueNulls();
+                contentNulls = setterInfo.nonDefaultContentNulls();
+            }
+        }
+        // If not, config override?
+        if (needMerge || (valueNulls == null) || (contentNulls == null)) {
+            ConfigOverride co = config.getConfigOverride(type.getRawClass());
+            JsonSetter.Value setterInfo = co.getSetterInfo();
+            if (setterInfo != null) {
+                if (valueNulls == null) {
+                    valueNulls = setterInfo.nonDefaultValueNulls();
+                }
+                if (contentNulls == null) {
+                    contentNulls = setterInfo.nonDefaultContentNulls();
+                }
+            }
+        }
+        if (needMerge || (valueNulls == null) || (contentNulls == null)) {
+            JsonSetter.Value setterInfo = config.getDefaultSetterInfo();
+            if (valueNulls == null) {
+                valueNulls = setterInfo.nonDefaultValueNulls();
+            }
+            if (contentNulls == null) {
+                contentNulls = setterInfo.nonDefaultContentNulls();
+            }
+        }
+        if ((valueNulls != null) || (contentNulls != null)) {
+            metadata = metadata.withNulls(valueNulls, contentNulls);
+        }
+        return metadata;
+    }
+    
     /**
      * Helper method that can be used to see if specified property is annotated
      * to indicate use of a converter for property value (in case of container types,

src/test/java/com/fasterxml/jackson/failing/NullConversionsForContent4200Test.java renamed to src/test/java/com/fasterxml/jackson/databind/deser/filter/NullConversionsForContent4200Test.java

@@ -1,4 +1,4 @@
-package com.fasterxml.jackson.failing;
+package com.fasterxml.jackson.databind.deser.filter;
 
 import java.util.Map;