DATACMNS-1208 - AbstractMappingContext.hasPersistentEntityFor(…) now properly considers cached absence.

AbstractMappingContext.hasPersistentEntityFor(…) now also properly consideres the empty Optional as non-presence as that is held to allow to distinguish between a type completely unkown to the context, or already known but not considered a persistent entity.

Related pull request: #258.

src/main/java/org/springframework/data/mapping/context/AbstractMappingContext.java

@@ -181,7 +181,9 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 
 		Assert.notNull(type, "Type must not be null!");
 
-		return persistentEntities.containsKey(ClassTypeInformation.from(type));
+		Optional<E> entity = persistentEntities.get(ClassTypeInformation.from(type));
+
+		return entity == null ? false : entity.isPresent();
 	}
 
 	/*