Correctly read unwrapped properties during constructor creation.

Closes: #4491
Original Pull Request: #4492

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java

@@ -17,7 +17,16 @@
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
@@ -41,7 +50,13 @@
 import org.springframework.data.annotation.Reference;
 import org.springframework.data.convert.CustomConversions;
 import org.springframework.data.convert.TypeMapper;
-import org.springframework.data.mapping.*;
+import org.springframework.data.mapping.Association;
+import org.springframework.data.mapping.InstanceCreatorMetadata;
+import org.springframework.data.mapping.MappingException;
+import org.springframework.data.mapping.Parameter;
+import org.springframework.data.mapping.PersistentEntity;
+import org.springframework.data.mapping.PersistentProperty;
+import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mapping.model.ConvertingPropertyAccessor;
@@ -1961,6 +1976,8 @@ class AssociationAwareMongoDbPropertyValueProvider extends MongoDbPropertyValueP
 		@SuppressWarnings("unchecked")
 		public <T> T getPropertyValue(MongoPersistentProperty property) {
 
+			ConversionContext propertyContext = context.forProperty(property);
+
 			if (property.isDbReference() && property.getDBRef().lazy()) {
 
 				Object rawRefValue = accessor.get(property);
@@ -1977,9 +1994,16 @@ public <T> T getPropertyValue(MongoPersistentProperty property) {
 			}
 
 			if (property.isDocumentReference()) {
+
 				return (T) dbRefResolver.resolveReference(property,
-					new DocumentReferenceSource(accessor.getDocument(), accessor.get(property)),
-					referenceLookupDelegate, context::convert);
+						new DocumentReferenceSource(accessor.getDocument(), accessor.get(property)), referenceLookupDelegate,
+						context::convert);
+			}
+
+			if (property.isUnwrapped()) {
+
+				return (T) readUnwrapped(propertyContext, accessor, property,
+						mappingContext.getRequiredPersistentEntity(property));
 			}
 
 			return super.getPropertyValue(property);

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java

@@ -2350,6 +2350,24 @@ void readUnwrappedTypeWithComplexValue() {
 				.isEqualTo(expected);
 	}
 
+	@Test // GH-4491
+	void readUnwrappedTypeWithComplexValueUsingConstructor() {
+
+		org.bson.Document source = new org.bson.Document("_id", "id-1").append("stringValue", "hello").append("address",
+				new org.bson.Document("s", "1007 Mountain Drive").append("city", "Gotham"));
+
+		WithUnwrappedConstructor target = converter.read(WithUnwrappedConstructor.class, source);
+
+		Address expected = new Address();
+		expected.city = "Gotham";
+		expected.street = "1007 Mountain Drive";
+
+		assertThat(target.embeddableValue.stringValue) //
+				.isEqualTo("hello");
+		assertThat(target.embeddableValue.address) //
+				.isEqualTo(expected);
+	}
+
 	@Test // DATAMONGO-1902
 	void writeUnwrappedTypeWithComplexValue() {
 
@@ -3374,6 +3392,18 @@ static class WithNullableUnwrapped {
 		@Unwrapped.Nullable EmbeddableType embeddableValue;
 	}
 
+	static class WithUnwrappedConstructor {
+
+		private final String id;
+
+		private final @Unwrapped.Empty EmbeddableType embeddableValue;
+
+		public WithUnwrappedConstructor(String id, EmbeddableType embeddableValue) {
+			this.id = id;
+			this.embeddableValue = embeddableValue;
+		}
+	}
+
 	static class WithPrefixedNullableUnwrapped {
 
 		String id;