Fix for 4185 (#4189)

Author: JooHyukKim

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

@@ -186,7 +186,7 @@ public abstract class BeanDeserializerBase
     protected UnwrappedPropertyHandler _unwrappedPropertyHandler;
 
     /**
-     * Handler that we need iff any of properties uses external
+     * Handler that we need if any of properties uses external
      * type id.
      */
     protected ExternalTypeHandler _externalTypeIdHandler;
@@ -292,6 +292,8 @@ protected BeanDeserializerBase(BeanDeserializerBase src, boolean ignoreAllUnknow
         _serializationShape = src._serializationShape;
 
         _vanillaProcessing = src._vanillaProcessing;
+
+        _externalTypeIdHandler = src._externalTypeIdHandler;
     }
 
     protected BeanDeserializerBase(BeanDeserializerBase src, NameTransformer unwrapper)
@@ -332,6 +334,8 @@ protected BeanDeserializerBase(BeanDeserializerBase src, NameTransformer unwrapp
 
         // probably adds a twist, so:
         _vanillaProcessing = false;
+
+        _externalTypeIdHandler = src._externalTypeIdHandler;
     }
 
     public BeanDeserializerBase(BeanDeserializerBase src, ObjectIdReader oir)
@@ -371,6 +375,8 @@ public BeanDeserializerBase(BeanDeserializerBase src, ObjectIdReader oir)
             _beanProperties = src._beanProperties.withProperty(idProp);
             _vanillaProcessing = false;
         }
+
+        _externalTypeIdHandler = src._externalTypeIdHandler;
     }
 
     /**
@@ -405,6 +411,8 @@ public BeanDeserializerBase(BeanDeserializerBase src,
         // 01-May-2016, tatu: [databind#1217]: Remove properties from mapping,
         //    to avoid them being deserialized
         _beanProperties = src._beanProperties.withoutProperties(ignorableProps, includableProps);
+
+        _externalTypeIdHandler = src._externalTypeIdHandler;
     }
 
     /**
@@ -435,6 +443,8 @@ protected BeanDeserializerBase(BeanDeserializerBase src, BeanPropertyMap beanPro
         _serializationShape = src._serializationShape;
 
         _vanillaProcessing = src._vanillaProcessing;
+
+        _externalTypeIdHandler = src._externalTypeIdHandler;
     }
 
     @Deprecated // since 2.12

src/test/java/com/fasterxml/jackson/databind/BaseTest.java

@@ -441,7 +441,7 @@ public String quote(String str) {
         return q(str);
     }
 
-    protected static String a2q(String json) {
+    public static String a2q(String json) {
         return json.replace("'", "\"");
     }
 

src/test/java/com/fasterxml/jackson/databind/jsontype/ext/ExternalTypeIdWithJsonIgnore4185Test.java

@@ -0,0 +1,55 @@
+package com.fasterxml.jackson.databind.jsontype.ext;
+
+import static com.fasterxml.jackson.databind.BaseMapTest.newJsonMapper;
+import static com.fasterxml.jackson.databind.BaseTest.a2q;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Unit test to verify that the following issue is fixed:
+ * [databind#4185]: @JsonIgnoreProperties with JsonTypeInfo.As.EXTERNAL_PROPERTY does not work
+ */
+class ExternalTypeIdWithJsonIgnore4185Test
+{
+
+    static class Parent {
+        @JsonIgnoreProperties("parent")
+        public Child child;
+    }
+
+    static class Child {
+        public Parent parent;
+        public String childType;
+
+        @JsonTypeInfo(
+                use = JsonTypeInfo.Id.NAME,
+                include = JsonTypeInfo.As.EXTERNAL_PROPERTY,
+                property = "childType"
+        )
+        @JsonSubTypes({
+                @JsonSubTypes.Type(name = "A", value = SubChildA.class),
+                @JsonSubTypes.Type(name = "B", value = SubChildB.class),
+        })
+        public SubChild subChild;
+    }
+
+    interface SubChild { }
+    static class SubChildA implements SubChild { }
+    static class SubChildB implements SubChild { }
+
+    private final ObjectMapper MAPPER = newJsonMapper();
+
+    @Test
+    public void testDeserialization() throws Exception
+    {
+        Parent parent = MAPPER.readValue(
+                a2q("{'child': {'childType': 'A', 'subChild':{} } }"),
+                Parent.class);
+
+        assertInstanceOf(SubChildA.class, parent.child.subChild);
+    }
+}