Expose FactoryBean's raw object on retrieval during post-processing

Issue: SPR-16783

spring-beans/src/main/java/org/springframework/beans/factory/support/FactoryBeanRegistrySupport.java

@@ -107,6 +107,11 @@ public abstract class FactoryBeanRegistrySupport extends DefaultSingletonBeanReg
 					}
 					else {
 						if (shouldPostProcess) {
+							if (isSingletonCurrentlyInCreation(beanName)) {
+								// Temporarily return non-post-processed object, not storing it yet..
+								return object;
+							}
+							beforeSingletonCreation(beanName);
 							try {
 								object = postProcessObjectFromFactoryBean(object, beanName);
 							}
@@ -114,6 +119,9 @@ public abstract class FactoryBeanRegistrySupport extends DefaultSingletonBeanReg
 								throw new BeanCreationException(beanName,
 										"Post-processing of FactoryBean's singleton object failed", ex);
 							}
+							finally {
+								afterSingletonCreation(beanName);
+							}
 						}
 						if (containsSingleton(beanName)) {
 							this.factoryBeanObjectCache.put(beanName, object);

spring-context/src/test/java/org/springframework/context/annotation/configuration/DuplicatePostProcessingTests.java

@@ -0,0 +1,138 @@
+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.annotation.configuration;
+
+import org.junit.Test;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextAware;
+import org.springframework.context.ApplicationEvent;
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+
+/**
+ * @author Andy Wilkinson
+ * @author Juergen Hoeller
+ */
+public class DuplicatePostProcessingTests {
+
+	@Test
+	public void testWithFactoryBeanAndEventListener() {
+		new AnnotationConfigApplicationContext(Config.class).getBean(ExampleBean.class);
+	}
+
+
+
+	static class Config {
+
+		@Bean
+		public ExampleFactoryBean exampleFactory() {
+			return new ExampleFactoryBean();
+		}
+
+		@Bean
+		public static ExampleBeanPostProcessor exampleBeanPostProcessor() {
+			return new ExampleBeanPostProcessor();
+		}
+
+		@Bean
+		public ExampleApplicationEventListener exampleApplicationEventListener() {
+			return new ExampleApplicationEventListener();
+		}
+	}
+
+
+	static class ExampleFactoryBean implements FactoryBean<ExampleBean> {
+
+		private final ExampleBean exampleBean = new ExampleBean();
+
+		@Override
+		public ExampleBean getObject() throws Exception {
+			return this.exampleBean;
+		}
+
+		@Override
+		public Class<?> getObjectType() {
+			return ExampleBean.class;
+		}
+
+		@Override
+		public boolean isSingleton() {
+			return true;
+		}
+	}
+
+
+	static class ExampleBeanPostProcessor implements BeanPostProcessor, ApplicationContextAware {
+
+		private ApplicationContext applicationContext;
+
+
+		@Override
+		public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
+			return bean;
+		}
+
+		@Override
+		public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
+			if (bean instanceof ExampleBean) {
+				this.applicationContext.publishEvent(new ExampleApplicationEvent(this));
+			}
+			return bean;
+		}
+
+		@Override
+		public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
+			this.applicationContext = applicationContext;
+		}
+	}
+
+
+	static class ExampleApplicationEvent extends ApplicationEvent {
+
+		public ExampleApplicationEvent(Object source) {
+			super(source);
+		}
+	}
+
+
+	static class ExampleApplicationEventListener implements ApplicationListener<ExampleApplicationEvent>, BeanFactoryAware {
+
+		private BeanFactory beanFactory;
+
+		@Override
+		public void onApplicationEvent(ExampleApplicationEvent event) {
+			this.beanFactory.getBean(ExampleBean.class);
+		}
+
+		@Override
+		public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
+			this.beanFactory = beanFactory;
+		}
+	}
+
+
+	static class ExampleBean {
+	}
+
+}