Merge branch '6.2.x'

spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java

@@ -1656,7 +1656,12 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 						if (autowiredBeanNames != null) {
 							autowiredBeanNames.add(dependencyName);
 						}
+						boolean preExisting = containsSingleton(dependencyName);
 						Object dependencyBean = getBean(dependencyName);
+						if (preExisting && dependencyBean instanceof NullBean) {
+							// for backwards compatibility with addCandidateEntry in the regular code path
+							dependencyBean = null;
+						}
 						return resolveInstance(dependencyBean, descriptor, type, dependencyName);
 					}
 				}
@@ -1736,7 +1741,6 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 			throw new BeanNotOfRequiredTypeException(name, type, candidate.getClass());
 		}
 		return result;
-
 	}
 
 	private @Nullable Object resolveMultipleBeans(DependencyDescriptor descriptor, @Nullable String beanName,

spring-beans/src/test/java/org/springframework/beans/factory/annotation/AutowiredAnnotationBeanPostProcessorTests.java

@@ -960,11 +960,34 @@ class AutowiredAnnotationBeanPostProcessorTests {
 	@Test
 	void constructorResourceInjectionWithNoCandidatesAndNoFallback() {
 		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(ConstructorWithoutFallbackBean.class));
+
 		assertThatExceptionOfType(UnsatisfiedDependencyException.class)
 				.isThrownBy(() -> bf.getBean("annotatedBean"))
 				.satisfies(methodParameterDeclaredOn(ConstructorWithoutFallbackBean.class));
 	}
 
+	@Test
+	void constructorResourceInjectionWithCandidateAndNoFallback() {
+		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(ConstructorWithoutFallbackBean.class));
+		RootBeanDefinition tb = new RootBeanDefinition(NullFactoryMethods.class);
+		tb.setFactoryMethodName("createTestBean");
+		bf.registerBeanDefinition("testBean", tb);
+
+		bf.getBean("testBean");
+		assertThat(bf.getBean("annotatedBean", ConstructorWithoutFallbackBean.class).getTestBean3()).isNull();
+	}
+
+	@Test
+	void constructorResourceInjectionWithNameMatchingCandidateAndNoFallback() {
+		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(ConstructorWithoutFallbackBean.class));
+		RootBeanDefinition tb = new RootBeanDefinition(NullFactoryMethods.class);
+		tb.setFactoryMethodName("createTestBean");
+		bf.registerBeanDefinition("testBean3", tb);
+
+		bf.getBean("testBean3");
+		assertThat(bf.getBean("annotatedBean", ConstructorWithoutFallbackBean.class).getTestBean3()).isNull();
+	}
+
 	@Test
 	void constructorResourceInjectionWithSometimesNullBeanEarly() {
 		RootBeanDefinition bd = new RootBeanDefinition(ConstructorWithNullableArgument.class);
@@ -1193,6 +1216,7 @@ class AutowiredAnnotationBeanPostProcessorTests {
 	@Test
 	void singleConstructorInjectionWithMissingDependency() {
 		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(SingleConstructorOptionalCollectionBean.class));
+
 		assertThatExceptionOfType(UnsatisfiedDependencyException.class)
 				.isThrownBy(() -> bf.getBean("annotatedBean"));
 	}
@@ -1203,6 +1227,7 @@ class AutowiredAnnotationBeanPostProcessorTests {
 		RootBeanDefinition tb = new RootBeanDefinition(NullFactoryMethods.class);
 		tb.setFactoryMethodName("createTestBean");
 		bf.registerBeanDefinition("testBean", tb);
+
 		assertThatExceptionOfType(UnsatisfiedDependencyException.class)
 				.isThrownBy(() -> bf.getBean("annotatedBean"));
 	}
@@ -3060,7 +3085,6 @@ class AutowiredAnnotationBeanPostProcessorTests {
 
 		protected ITestBean testBean3;
 
-		@Autowired(required = false)
 		public ConstructorWithoutFallbackBean(ITestBean testBean3) {
 			this.testBean3 = testBean3;
 		}
@@ -3075,7 +3099,6 @@ class AutowiredAnnotationBeanPostProcessorTests {
 
 		protected ITestBean testBean3;
 
-		@Autowired(required = false)
 		public ConstructorWithNullableArgument(@Nullable ITestBean testBean3) {
 			this.testBean3 = testBean3;
 		}

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassEnhancer.java

@@ -16,6 +16,7 @@
 
 package org.springframework.context.annotation;
 
+import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
@@ -139,14 +140,20 @@ class ConfigurationClassEnhancer {
 	}
 
 	/**
-	 * Checks whether the given config class relies on package visibility,
+	 * Checks whether the given config class relies on package visibility, either for
-	 * either for the class itself or for any of its {@code @Bean} methods.
+	 * the class and any of its constructors or for any of its {@code @Bean} methods.
 	 */
 	private boolean reliesOnPackageVisibility(Class<?> configSuperClass) {
 		int mod = configSuperClass.getModifiers();
 		if (!Modifier.isPublic(mod) && !Modifier.isProtected(mod)) {
 			return true;
 		}
+		for (Constructor<?> ctor : configSuperClass.getDeclaredConstructors()) {
+			mod = ctor.getModifiers();
+			if (!Modifier.isPublic(mod) && !Modifier.isProtected(mod)) {
+				return true;
+			}
+		}
 		for (Method method : ReflectionUtils.getDeclaredMethods(configSuperClass)) {
 			if (BeanAnnotationHelper.isBeanAnnotated(method)) {
 				mod = method.getModifiers();

spring-context/src/test/java/org/springframework/context/annotation/ConfigurationClassEnhancerTests.java

@@ -104,6 +104,31 @@ class ConfigurationClassEnhancerTests {
 		assertThat(enhancedClass.getClassLoader()).isEqualTo(classLoader.getParent());
 	}
 
+	@Test
+	void withNonPublicConstructor() {
+		ConfigurationClassEnhancer configurationClassEnhancer = new ConfigurationClassEnhancer();
+
+		ClassLoader classLoader = new URLClassLoader(new URL[0], getClass().getClassLoader());
+		Class<?> enhancedClass = configurationClassEnhancer.enhance(MyConfigWithNonPublicConstructor.class, classLoader);
+		assertThat(MyConfigWithNonPublicConstructor.class).isAssignableFrom(enhancedClass);
+		assertThat(enhancedClass.getClassLoader()).isEqualTo(classLoader.getParent());
+
+		classLoader = new OverridingClassLoader(getClass().getClassLoader());
+		enhancedClass = configurationClassEnhancer.enhance(MyConfigWithNonPublicConstructor.class, classLoader);
+		assertThat(MyConfigWithNonPublicConstructor.class).isAssignableFrom(enhancedClass);
+		assertThat(enhancedClass.getClassLoader()).isEqualTo(classLoader.getParent());
+
+		classLoader = new CustomSmartClassLoader(getClass().getClassLoader());
+		enhancedClass = configurationClassEnhancer.enhance(MyConfigWithNonPublicConstructor.class, classLoader);
+		assertThat(MyConfigWithNonPublicConstructor.class).isAssignableFrom(enhancedClass);
+		assertThat(enhancedClass.getClassLoader()).isEqualTo(classLoader.getParent());
+
+		classLoader = new BasicSmartClassLoader(getClass().getClassLoader());
+		enhancedClass = configurationClassEnhancer.enhance(MyConfigWithNonPublicConstructor.class, classLoader);
+		assertThat(MyConfigWithNonPublicConstructor.class).isAssignableFrom(enhancedClass);
+		assertThat(enhancedClass.getClassLoader()).isEqualTo(classLoader.getParent());
+	}
+
 	@Test
 	void withNonPublicMethod() {
 		ConfigurationClassEnhancer configurationClassEnhancer = new ConfigurationClassEnhancer();
@@ -160,6 +185,19 @@ class ConfigurationClassEnhancerTests {
 	}
 
 
+	@Configuration
+	public static class MyConfigWithNonPublicConstructor {
+
+		MyConfigWithNonPublicConstructor() {
+		}
+
+		@Bean
+		public String myBean() {
+			return "bean";
+		}
+	}
+
+
 	@Configuration
 	public static class MyConfigWithNonPublicMethod {