Guard potential null dereference in recursive initialization calls.

We now assign the repository field before resolving the persistent entity through the mapping context to avoid a potential NPE caused by a getObject(…) invocation through an application event.

Closes spring-projects#2068

Author: mp911de

src/main/java/org/springframework/data/repository/core/support/RepositoryFactoryBeanSupport.java

@@ -320,11 +320,11 @@ public void afterPropertiesSet() {
 
 		this.repositoryMetadata = this.factory.getRepositoryMetadata(repositoryInterface);
 
+		this.repository = Lazy.of(() -> this.factory.getRepository(repositoryInterface, repositoryFragmentsToUse));
+
 		// Make sure the aggregate root type is present in the MappingContext (e.g. for auditing)
 		this.mappingContext.ifPresent(it -> it.getPersistentEntity(repositoryMetadata.getDomainType()));
 
-		this.repository = Lazy.of(() -> this.factory.getRepository(repositoryInterface, repositoryFragmentsToUse));
-
 		if (!lazyInit) {
 			this.repository.get();
 		}