"conversionService" bean gets ignored if not of type ConversionService (SPR-6916)

org.springframework.context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -856,7 +856,8 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	 */
 	protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) {
 		// Initialize conversion service for this context.
-		if (beanFactory.containsBean(CONVERSION_SERVICE_BEAN_NAME)) {
+		if (beanFactory.containsBean(CONVERSION_SERVICE_BEAN_NAME) &&
+				beanFactory.isTypeMatch(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class)) {
 			beanFactory.setConversionService(
 					beanFactory.getBean(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class));
 		}