HV-1951 Log warning when @Valid is used twice

The specification doesn't define what should happen when `@Valid`
is used on the container and on the container type. We've decided
to log a warning.

Author: DavideD

engine/src/main/java/org/hibernate/validator/internal/metadata/provider/AnnotationMetaDataProvider.java

@@ -682,9 +682,12 @@ private Map<TypeVariable<?>, CascadingMetaDataBuilder> getTypeParametersCascadin
 			Map<TypeVariable<?>, CascadingMetaDataBuilder> nestedTypeParametersCascadingMetadata = getTypeParametersCascadingMetaDataForAnnotatedType(
 					annotatedTypeArgument );
 
+			boolean annotatedWithValid = annotatedTypeArgument.isAnnotationPresent( Valid.class );
+			if ( annotatedWithValid && annotatedParameterizedType.isAnnotationPresent( Valid.class ) ) {
+				LOG.validAppliedTwice( annotatedParameterizedType );
+			}
 			typeParametersCascadingMetadata.put( typeParameters[i], new CascadingMetaDataBuilder( annotatedParameterizedType.getType(), typeParameters[i],
-					annotatedTypeArgument.isAnnotationPresent( Valid.class ), nestedTypeParametersCascadingMetadata,
-					getGroupConversions( annotatedTypeArgument ) ) );
+					annotatedWithValid, nestedTypeParametersCascadingMetadata, getGroupConversions( annotatedTypeArgument ) ) );
 			i++;
 		}
 

engine/src/main/java/org/hibernate/validator/internal/util/logging/Log.java

@@ -12,6 +12,7 @@
 import java.lang.annotation.Annotation;
 import java.lang.annotation.ElementType;
 import java.lang.invoke.MethodHandles.Lookup;
+import java.lang.reflect.AnnotatedParameterizedType;
 import java.lang.reflect.Executable;
 import java.lang.reflect.Member;
 import java.lang.reflect.Type;
@@ -946,4 +947,8 @@ ConstraintDefinitionException getConstraintValidatorDefinitionConstraintMismatch
 	@LogMessage(level = DEBUG)
 	@Message(id = 269, value = "Unable to enable secure XML feature processing when loading %1$s: %2$s")
 	void unableToEnableSecureFeatureProcessingSchemaXml(String fileName, String message);
+
+	@LogMessage(level = WARN)
+	@Message(id = 270, value = "For a given container, the `@Valid` annotation should either be put on the container itself or on the type argument(s) of the container, but not both: %s")
+	void validAppliedTwice(AnnotatedParameterizedType annotatedParameterizedType);
 }