BeanWrapperImpl.setBeanInstance correctly exposes root object

Issue: SPR-14474

spring-beans/src/main/java/org/springframework/beans/AbstractNestablePropertyAccessor.java

@@ -81,7 +81,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 
 	private String nestedPath = "";
 
-	private Object rootObject;
+	Object rootObject;
 
 	/**
 	 * Map with cached nested Accessors: nested path -> Accessor instance.

spring-beans/src/main/java/org/springframework/beans/BeanWrapperImpl.java

@@ -141,6 +141,7 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 	 */
 	public void setBeanInstance(Object object) {
 		this.wrappedObject = object;
+		this.rootObject = object;
 		this.typeConverterDelegate = new TypeConverterDelegate(this, this.wrappedObject);
 		setIntrospectionClass(object.getClass());
 	}