HV-2135 Do not initialize the alreadyProcessedGroups unless necessary in BeanValueContext

Author: marko-bekhta

engine/src/main/java/org/hibernate/validator/internal/engine/valuecontext/BeanValueContext.java

@@ -41,7 +41,6 @@ public final class BeanValueContext<T, V> extends ValueContext<T, V> {
 	BeanValueContext(ValueContext<?, ?> parentContext, ExecutableParameterNameProvider parameterNameProvider, T currentBean, BeanMetaData<T> currentBeanMetaData, MutablePath propertyPath) {
 		super( parentContext, parameterNameProvider, currentBean, currentBeanMetaData, propertyPath );
 		this.currentBeanMetaData = currentBeanMetaData;
-		this.alreadyProcessedGroups = new HashSet<>();
 	}
 
 	public BeanMetaData<T> getCurrentBeanMetaData() {

engine/src/main/java/org/hibernate/validator/internal/engine/valuecontext/ValueContext.java

@@ -147,7 +147,9 @@ public final void setTypeParameter(Class<?> containerClass, Integer typeParamete
 	}
 
 	public final void setCurrentGroup(Class<?> currentGroup) {
-		this.previousGroup = this.currentGroup;
+		if ( this.previousGroup != this.currentGroup ) {
+			this.previousGroup = this.currentGroup;
+		}
 		this.currentGroup = currentGroup;
 	}