Remove synthetic attribute from SharedEntityManager.

AOT no longer needs this bean to be synthetic to work properly. And this attribute hampers BeanPostProcessors from being applied.

See #2730
Original Pull Request: #2866

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/config/JpaRepositoryConfigExtension.java

@@ -217,7 +217,6 @@ private String registerSharedEntityMangerIfNotAlreadyRegistered(BeanDefinitionRe
 
 			AbstractBeanDefinition entityManager = getEntityManagerBeanDefinitionFor(config, null);
 			entityManager.setRole(BeanDefinition.ROLE_SUPPORT);
-			entityManager.setSynthetic(true);
 			entityManager.setPrimary(false);
 			entityManager.setAutowireCandidate(false);
 

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/config/JpaRepositoryConfigExtensionUnitTests.java

@@ -31,6 +31,7 @@
 import org.mockito.junit.jupiter.MockitoSettings;
 import org.mockito.quality.Strictness;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionReaderUtils;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.support.RootBeanDefinition;
@@ -48,6 +49,7 @@
  * @author Oliver Gierke
  * @author Mark Paluch
  * @author Jens Schauder
+ * @author Yanming Zhou
  */
 @ExtendWith(MockitoExtension.class)
 @MockitoSettings(strictness = Strictness.LENIENT)
@@ -147,6 +149,20 @@ void exposesJpaAotProcessor() {
 				.isEqualTo(JpaRepositoryConfigExtension.JpaRepositoryRegistrationAotProcessor.class);
 	}
 
+	@Test // GH-2730
+	void shouldNotRegisterEntityManagerAsSynthetic() {
+
+		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
+
+		RepositoryConfigurationExtension extension = new JpaRepositoryConfigExtension();
+		extension.registerBeansForRoot(factory, configSource);
+
+		AbstractBeanDefinition bd = (AbstractBeanDefinition) factory.getBeanDefinition("jpaSharedEM_"
+				+ configSource.getAttribute("entityManagerFactoryRef").orElse("entityManagerFactory"));
+
+		assertThat(bd.isSynthetic()).isEqualTo(false);
+	}
+
 	private void assertOnlyOnePersistenceAnnotationBeanPostProcessorRegistered(DefaultListableBeanFactory factory,
 			String expectedBeanName) {