Fix ShellOption with required

- Take 2
- Fix case with optional.
- Fixes #436

spring-shell-standard/src/main/java/org/springframework/shell/standard/StandardMethodTargetRegistrar.java

@@ -140,7 +140,7 @@ public class StandardMethodTargetRegistrar implements MethodTargetRegistrar, App
 									&& !ObjectUtils.nullSafeEquals(so.defaultValue(), ShellOption.NULL)) {
 								optionSpec.defaultValue(so.defaultValue());
 							}
-							else {
+							if (ObjectUtils.nullSafeEquals(so.defaultValue(), ShellOption.NONE)) {
 								optionSpec.required();
 							}
 						}

spring-shell-standard/src/test/java/org/springframework/shell/standard/StandardMethodTargetRegistrarTests.java

@@ -119,6 +119,29 @@ public class StandardMethodTargetRegistrarTests {
 		}
 	}
 
+	@Test
+	public void testOptionOptionalWithAnnotation() {
+		applicationContext = new AnnotationConfigApplicationContext(Sample3.class);
+		registrar.setApplicationContext(applicationContext);
+		registrar.register(catalog);
+		Map<String, CommandRegistration> registrations = catalog.getRegistrations();
+		assertThat(registrations).hasSize(1);
+
+		assertThat(registrations.get("say-hello")).isNotNull();
+		assertThat(registrations.get("say-hello").getOptions()).hasSize(1);
+		assertThat(registrations.get("say-hello").getOptions().get(0).isRequired()).isFalse();
+		assertThat(registrations.get("say-hello").getOptions().get(0).getDefaultValue()).isNull();
+	}
+
+	@ShellComponent
+	public static class Sample3 {
+
+		@ShellMethod("some command")
+		public String sayHello(@ShellOption( defaultValue = ShellOption.NULL) String what) {
+			return "hello " + what;
+		}
+	}
+
 	@Test
 	public void testAvailabilityIndicators() {
 		applicationContext = new AnnotationConfigApplicationContext(SampleWithAvailability.class);