Introspect originating bean definition as configuration class candidate

Issue: SPR-16756

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

 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -122,8 +122,8 @@ class ConfigurationClassBeanDefinitionReader {
 	 * Read a particular {@link ConfigurationClass}, registering bean definitions
 	 * for the class itself and all of its {@link Bean} methods.
 	 */
-	private void loadBeanDefinitionsForConfigurationClass(ConfigurationClass configClass,
-			TrackedConditionEvaluator trackedConditionEvaluator) {
+	private void loadBeanDefinitionsForConfigurationClass(
+			ConfigurationClass configClass, TrackedConditionEvaluator trackedConditionEvaluator) {
 
 		if (trackedConditionEvaluator.shouldSkip(configClass)) {
 			String beanName = configClass.getBeanName();
@@ -140,6 +140,7 @@ class ConfigurationClassBeanDefinitionReader {
 		for (BeanMethod beanMethod : configClass.getBeanMethods()) {
 			loadBeanDefinitionsForBeanMethod(beanMethod);
 		}
+
 		loadBeanDefinitionsFromImportedResources(configClass.getImportedResources());
 		loadBeanDefinitionsFromRegistrars(configClass.getImportBeanDefinitionRegistrars());
 	}

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

@@ -288,9 +288,12 @@ class ConfigurationClassParser {
 						this.componentScanParser.parse(componentScan, sourceClass.getMetadata().getClassName());
 				// Check the set of scanned definitions for any further config classes and parse recursively if needed
 				for (BeanDefinitionHolder holder : scannedBeanDefinitions) {
-					if (ConfigurationClassUtils.checkConfigurationClassCandidate(
-							holder.getBeanDefinition(), this.metadataReaderFactory)) {
-						parse(holder.getBeanDefinition().getBeanClassName(), holder.getBeanName());
+					BeanDefinition bdCand = holder.getBeanDefinition().getOriginatingBeanDefinition();
+					if (bdCand == null) {
+						bdCand = holder.getBeanDefinition();
+					}
+					if (ConfigurationClassUtils.checkConfigurationClassCandidate(bdCand, this.metadataReaderFactory)) {
+						parse(bdCand.getBeanClassName(), holder.getBeanName());
 					}
 				}
 			}

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

 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,7 +39,7 @@ import org.springframework.lang.Nullable;
 import org.springframework.stereotype.Component;
 
 /**
- * Utilities for processing @{@link Configuration} classes.
+ * Utilities for identifying @{@link Configuration} classes.
  *
  * @author Chris Beams
  * @author Juergen Hoeller
@@ -60,7 +60,7 @@ abstract class ConfigurationClassUtils {
 
 	private static final Log logger = LogFactory.getLog(ConfigurationClassUtils.class);
 
-	private static final Set<String> candidateIndicators = new HashSet<>(4);
+	private static final Set<String> candidateIndicators = new HashSet<>(8);
 
 	static {
 		candidateIndicators.add(Component.class.getName());

spring-context/src/test/java/org/springframework/context/annotation/spr16756/ScannedComponent.java

+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.annotation.spr16756;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Scope;
+import org.springframework.context.annotation.ScopedProxyMode;
+import org.springframework.stereotype.Component;
+
+@Component
+public class ScannedComponent {
+
+	@Autowired
+	private State state;
+
+	public String iDoAnything() {
+		return state.anyMethod();
+	}
+
+
+	public interface State {
+
+		String anyMethod();
+	}
+
+
+	@Component
+	@Scope(proxyMode = ScopedProxyMode.INTERFACES, value = "prototype")
+	public static class StateImpl implements State {
+
+		public String anyMethod() {
+			return "anyMethod called";
+		}
+	}
+
+}

spring-context/src/test/java/org/springframework/context/annotation/spr16756/ScanningConfiguration.java

+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.annotation.spr16756;
+
+import org.springframework.context.annotation.ComponentScan;
+
+@ComponentScan
+public class ScanningConfiguration {
+
+}

spring-context/src/test/java/org/springframework/context/annotation/spr16756/Spr16756Tests.java

+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.annotation.spr16756;
+
+import org.junit.Test;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+/**
+ * @author Juergen Hoeller
+ */
+public class Spr16756Tests {
+
+	@Test
+	public void shouldNotFailOnNestedScopedComponent() {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+		context.register(ScanningConfiguration.class);
+		context.refresh();
+		context.getBean(ScannedComponent.class);
+		context.getBean(ScannedComponent.State.class);
+	}
+
+}