Improve check to skip bean validation in DataBinder

DataBinder should skip any jakarta.validation.Validator yielding
to method validation when that is expected. This change improves
the check to skip by unwrapping the validator from in a
SmartValidator before checking if it is for bean validation.

Closes gh-31711

spring-web/src/test/java/org/springframework/web/bind/support/DefaultDataBinderFactoryTests.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.bind.support;
+
+import jakarta.validation.Valid;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.core.MethodParameter;
+import org.springframework.core.ResolvableType;
+import org.springframework.validation.Errors;
+import org.springframework.validation.SmartValidator;
+import org.springframework.validation.Validator;
+import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
+import org.springframework.web.bind.WebDataBinder;
+import org.springframework.web.context.request.ServletWebRequest;
+import org.springframework.web.testfixture.method.ResolvableMethod;
+import org.springframework.web.testfixture.servlet.MockHttpServletRequest;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * Unit tests for {@link DefaultDataBinderFactory}.
+ */
+public class DefaultDataBinderFactoryTests {
+
+	@Test
+	void jakartaValidatorExcludedWhenMethodValidationApplicable() throws Exception {
+		DefaultDataBinderFactory binderFactory = new DefaultDataBinderFactory(null);
+		binderFactory.setMethodValidationApplicable(true);
+
+		MethodParameter parameter = ResolvableMethod.on(DefaultDataBinderFactoryTests.class)
+				.named("handle").build().annotPresent(Valid.class).arg();
+
+		WebDataBinder dataBinder = binderFactory.createBinder(
+				new ServletWebRequest(new MockHttpServletRequest()), new Foo(), "foo",
+				ResolvableType.forMethodParameter(parameter));
+
+		Validator springValidator = mock(Validator.class);
+		when(springValidator.supports(Foo.class)).thenReturn(true);
+		dataBinder.addValidators(springValidator);
+
+		LocalValidatorFactoryBean beanValidator = new LocalValidatorFactoryBean();
+		beanValidator.afterPropertiesSet();
+		dataBinder.addValidators(beanValidator);
+
+		WrappedBeanValidator wrappedBeanValidator = new WrappedBeanValidator(beanValidator);
+		dataBinder.addValidators(wrappedBeanValidator);
+
+		assertThat(dataBinder.getValidatorsToApply()).containsExactly(springValidator);
+	}
+
+
+	@SuppressWarnings("unused")
+	private void handle(@Valid Foo foo) {
+	}
+
+
+	private static class WrappedBeanValidator implements SmartValidator {
+
+		private final jakarta.validation.Validator validator;
+
+		private WrappedBeanValidator(jakarta.validation.Validator validator) {
+			this.validator = validator;
+		}
+
+		@Override
+		public boolean supports(Class<?> clazz) {
+			return true;
+		}
+
+		@Override
+		public void validate(Object target, Errors errors, Object... validationHints) {
+		}
+
+		@Override
+		public void validate(Object target, Errors errors) {
+		}
+
+		@Override
+		public <T> T unwrap(Class<T> type) {
+			return (T) this.validator;
+		}
+	}
+
+
+	private static class Foo {}
+
+}