HV-1598 Fix the behavior of XML default-validated-executable-types

If NONE is present, it should be removed from the Set, rather than
considering the Set as empty.

Author: gsmet

engine/src/main/java/org/hibernate/validator/internal/xml/config/BootstrapConfigurationImpl.java

@@ -16,6 +16,7 @@
 import javax.validation.BootstrapConfiguration;
 import javax.validation.executable.ExecutableType;
 
+import org.hibernate.validator.internal.util.CollectionHelper;
 import org.hibernate.validator.internal.util.stereotypes.Immutable;
 
 /**
@@ -109,15 +110,23 @@ private Set<ExecutableType> prepareValidatedExecutableTypes(EnumSet<ExecutableTy
 		if ( validatedExecutableTypes == null ) {
 			return DEFAULT_VALIDATED_EXECUTABLE_TYPES;
 		}
+
 		if ( validatedExecutableTypes.contains( ExecutableType.ALL ) ) {
 			return ALL_VALIDATED_EXECUTABLE_TYPES;
 		}
-		else if ( validatedExecutableTypes.contains( ExecutableType.NONE ) ) {
-			return EnumSet.noneOf( ExecutableType.class );
-		}
-		else {
-			return validatedExecutableTypes;
+
+		if ( validatedExecutableTypes.contains( ExecutableType.NONE ) ) {
+			if ( validatedExecutableTypes.size() == 1 ) {
+				return Collections.emptySet();
+			}
+			else {
+				EnumSet<ExecutableType> preparedValidatedExecutableTypes = EnumSet.copyOf( validatedExecutableTypes );
+				preparedValidatedExecutableTypes.remove( ExecutableType.NONE );
+				return CollectionHelper.toImmutableSet( preparedValidatedExecutableTypes );
+			}
 		}
+
+		return CollectionHelper.toImmutableSet( validatedExecutableTypes );
 	}
 
 	@Override