Improve HandlerMethod#resolvedFromHandlerMethod initialization

Ensure the original instance is always the one returned no matter how
many times the HandlerMethod is re-created.

Make the constructor protected to allow subclasses to re-create the
HandlerMethod as the concrete subclass.

See gh-34375

spring-web/src/test/java/org/springframework/web/method/HandlerMethodTests.java

@@ -25,6 +25,7 @@ import jakarta.validation.constraints.NotEmpty;
 import jakarta.validation.constraints.Size;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.util.ClassUtils;
 import org.springframework.validation.annotation.Validated;
 
@@ -79,6 +80,23 @@ class HandlerMethodTests {
 		assertThat(handlerMethod.createWithResolvedBean()).isSameAs(handlerMethod);
 	}
 
+	@Test
+	void resolvedFromHandlerMethod() {
+		StaticApplicationContext context = new StaticApplicationContext();
+		context.registerSingleton("myClass", MyClass.class);
+
+		MyClass target = new MyClass();
+		Method method = ClassUtils.getMethod(target.getClass(), "addPerson", (Class<?>[]) null);
+
+		HandlerMethod hm1 = new HandlerMethod("myClass", context.getBeanFactory(), method);
+		HandlerMethod hm2 = hm1.createWithValidateFlags();
+		HandlerMethod hm3 = hm2.createWithResolvedBean();
+
+		assertThat(hm1.getResolvedFromHandlerMethod()).isNull();
+		assertThat(hm2.getResolvedFromHandlerMethod()).isSameAs(hm1);
+		assertThat(hm3.getResolvedFromHandlerMethod()).isSameAs(hm1);
+	}
+
 	private static void testValidateArgs(Object target, List<String> methodNames, boolean expected) {
 		for (String methodName : methodNames) {
 			assertThat(getHandlerMethod(target, methodName).shouldValidateArguments()).isEqualTo(expected);