Reject bean names with factory prefix for Bean Overrides

Closes gh-33674

Author: sbrannen

spring-test/src/main/java/org/springframework/test/context/bean/override/BeanOverrideBeanFactoryPostProcessor.java

@@ -96,6 +96,13 @@ public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory)
 	}
 
 	private void registerBeanOverride(ConfigurableListableBeanFactory beanFactory, OverrideMetadata overrideMetadata) {
+		String beanName = overrideMetadata.getBeanName();
+		Field field = overrideMetadata.getField();
+		Assert.state(!BeanFactoryUtils.isFactoryDereference(beanName),() -> """
+				Unable to override bean '%s' for field '%s.%s': a FactoryBean cannot be overridden. \
+				To override the bean created by the FactoryBean, remove the '&' prefix.""".formatted(
+					beanName, field.getDeclaringClass().getSimpleName(), field.getName()));
+
 		switch (overrideMetadata.getStrategy()) {
 			case REPLACE_DEFINITION -> replaceDefinition(beanFactory, overrideMetadata, true);
 			case REPLACE_OR_CREATE_DEFINITION -> replaceDefinition(beanFactory, overrideMetadata, false);
@@ -123,18 +130,16 @@ private void replaceDefinition(ConfigurableListableBeanFactory beanFactory, Over
 		RootBeanDefinition pseudoBeanDefinition = createPseudoBeanDefinition(overrideMetadata);
 
 		String beanName = overrideMetadata.getBeanName();
-		String beanNameIncludingFactory;
 		BeanDefinition existingBeanDefinition = null;
 		if (beanName == null) {
-			beanNameIncludingFactory = getBeanNameForType(beanFactory, overrideMetadata, requireExistingDefinition);
-			if (beanNameIncludingFactory == null) {
+			beanName = getBeanNameForType(beanFactory, overrideMetadata, requireExistingDefinition);
+			if (beanName == null) {
 				// We need to generate a name for a nonexistent bean.
 				beanName = beanNameGenerator.generateBeanName(pseudoBeanDefinition, registry);
-				beanNameIncludingFactory = beanName;
 			}
 			else {
 				// We are overriding an existing bean.
-				beanName = BeanFactoryUtils.transformedBeanName(beanNameIncludingFactory);
+				beanName = BeanFactoryUtils.transformedBeanName(beanName);
 				existingBeanDefinition = beanFactory.getBeanDefinition(beanName);
 			}
 		}
@@ -149,7 +154,6 @@ else if (requireExistingDefinition) {
 						with name [%s] and type [%s]."""
 							.formatted(beanName, overrideMetadata.getBeanType()));
 			}
-			beanNameIncludingFactory = beanName;
 		}
 
 		if (existingBeanDefinition != null) {
@@ -177,7 +181,7 @@ else if (Boolean.getBoolean(AbstractAotProcessor.AOT_PROCESSING)) {
 
 		Object override = overrideMetadata.createOverride(beanName, existingBeanDefinition, null);
 		overrideMetadata.track(override, beanFactory);
-		this.overrideRegistrar.registerNameForMetadata(overrideMetadata, beanNameIncludingFactory);
+		this.overrideRegistrar.registerNameForMetadata(overrideMetadata, beanName);
 
 		// Now we have an instance (the override) that we can register. At this stage, we don't
 		// expect a singleton instance to be present. If for some reason a singleton instance

spring-test/src/test/java/org/springframework/test/context/bean/override/BeanOverrideBeanFactoryPostProcessorTests.java

@@ -56,6 +56,18 @@
  */
 class BeanOverrideBeanFactoryPostProcessorTests {
 
+	@Test
+	void beanNameWithFactoryBeanPrefixIsRejected() {
+		AnnotationConfigApplicationContext context = createContext(FactoryBeanPrefixTestCase.class);
+
+		assertThatIllegalStateException()
+				.isThrownBy(context::refresh)
+				.withMessage("""
+					Unable to override bean '&messageService' for field 'FactoryBeanPrefixTestCase.messageService': \
+					a FactoryBean cannot be overridden. To override the bean created by the FactoryBean, remove the \
+					'&' prefix.""");
+	}
+
 	@Test
 	void replaceBeanByNameWithMatchingBeanDefinition() {
 		AnnotationConfigApplicationContext context = createContext(CaseByName.class);
@@ -348,6 +360,18 @@ private AnnotationConfigApplicationContext createContext(Class<?> testClass) {
 	}
 
 
+	@FunctionalInterface
+	interface MessageService {
+		String getMessage();
+	}
+
+	static class FactoryBeanPrefixTestCase {
+
+		@DummyBean(beanName = "&messageService")
+		MessageService messageService;
+
+	}
+
 	static class CaseByName {
 
 		@DummyBean(beanName = "descriptionBean")
@@ -464,11 +488,6 @@ public boolean isSingleton() {
 		}
 	}
 
-	@FunctionalInterface
-	interface MessageService {
-		String getMessage();
-	}
-
 	static class MessageServiceTestCase {
 
 		@TestBean(name = "messageServiceBean")