Fix reflection hint generation for properties nested in superclass

Fixes gh-36406

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/BindableRuntimeHintsRegistrar.java

@@ -317,7 +317,8 @@ public class BindableRuntimeHintsRegistrar implements RuntimeHintsRegistrar {
 		 * @return whether the specified {@code propertyType} is a nested type
 		 */
 		private boolean isNestedType(String propertyName, Class<?> propertyType) {
-			if (this.type.equals(propertyType.getDeclaringClass())) {
+			Class<?> declaringClass = propertyType.getDeclaringClass();
+			if (declaringClass != null && declaringClass.isAssignableFrom(this.type)) {
 				return true;
 			}
 			Field field = ReflectionUtils.findField(this.type, propertyName);

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/BindableRuntimeHintsRegistrarTests.java

@@ -34,6 +34,7 @@ import org.springframework.aot.hint.predicate.RuntimeHintsPredicates;
 import org.springframework.boot.context.properties.BoundConfigurationProperties;
 import org.springframework.boot.context.properties.ConfigurationPropertiesBean;
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
+import org.springframework.boot.context.properties.bind.BindableRuntimeHintsRegistrarTests.BaseProperties.InheritedNested;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.EnvironmentAware;
@@ -243,6 +244,21 @@ class BindableRuntimeHintsRegistrarTests {
 					"setBravo"));
 	}
 
+	@Test
+	void registerHintsWhenHasInheritedNestedProperties() {
+		RuntimeHints runtimeHints = registerHints(ExtendingProperties.class);
+		assertThat(runtimeHints.reflection().typeHints()).hasSize(3);
+		assertThat(runtimeHints.reflection().getTypeHint(BaseProperties.class)).satisfies((entry) -> {
+			assertThat(entry.getMemberCategories()).isEmpty();
+			assertThat(entry.methods()).extracting(ExecutableHint::getName)
+				.containsExactlyInAnyOrder("getInheritedNested", "setInheritedNested");
+		});
+		assertThat(runtimeHints.reflection().getTypeHint(ExtendingProperties.class))
+			.satisfies(javaBeanBinding(ExtendingProperties.class, "getBravo", "setBravo"));
+		assertThat(runtimeHints.reflection().getTypeHint(InheritedNested.class))
+			.satisfies(javaBeanBinding(InheritedNested.class, "getAlpha", "setAlpha"));
+	}
+
 	private Consumer<TypeHint> javaBeanBinding(Class<?> type, String... expectedMethods) {
 		return javaBeanBinding(type, type.getDeclaredConstructors()[0], expectedMethods);
 	}
@@ -665,4 +681,46 @@ class BindableRuntimeHintsRegistrarTests {
 
 	}
 
+	public abstract static class BaseProperties {
+
+		private InheritedNested inheritedNested;
+
+		public InheritedNested getInheritedNested() {
+			return this.inheritedNested;
+		}
+
+		public void setInheritedNested(InheritedNested inheritedNested) {
+			this.inheritedNested = inheritedNested;
+		}
+
+		public static class InheritedNested {
+
+			private String alpha;
+
+			public String getAlpha() {
+				return this.alpha;
+			}
+
+			public void setAlpha(String alpha) {
+				this.alpha = alpha;
+			}
+
+		}
+
+	}
+
+	public static class ExtendingProperties extends BaseProperties {
+
+		private String bravo;
+
+		public String getBravo() {
+			return this.bravo;
+		}
+
+		public void setBravo(String bravo) {
+			this.bravo = bravo;
+		}
+
+	}
+
 }