@Import'ed configuration classes get properly registered in case of same class name

Issue: SPR-9243

org.springframework.context/src/main/java/org/springframework/context/annotation/AnnotationBeanNameGenerator.java

@@ -20,6 +20,7 @@ import java.beans.Introspector;
 import java.util.Map;
 import java.util.Set;
 
+import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.beans.factory.annotation.AnnotatedBeanDefinition;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
@@ -73,7 +74,7 @@ public class AnnotationBeanNameGenerator implements BeanNameGenerator {
 			}
 		}
 		// Fallback: generate a unique default bean name.
-		return buildDefaultBeanName(definition);
+		return buildDefaultBeanName(definition, registry);
 	}
 
 	/**
@@ -119,6 +120,26 @@ public class AnnotationBeanNameGenerator implements BeanNameGenerator {
 		return (isStereotype && attributes != null && attributes.containsKey("value"));
 	}
 
+	/**
+	 * Derive a default bean name from the given bean definition.
+	 * <p>The default implementation delegates to {@link #buildDefaultBeanName(BeanDefinition)},
+	 * appending a counter suffix if necessary to make the bean name unique in the given registry.
+	 * @param definition the bean definition to build a bean name for
+	 * @param registry the registry that the given bean definition is being registered with
+	 * @return the default bean name (never <code>null</code>)
+	 */
+	protected String buildDefaultBeanName(BeanDefinition definition, BeanDefinitionRegistry registry) {
+		String generatedName = buildDefaultBeanName(definition);
+		// Increase counter until the id is unique.
+		String id = generatedName;
+		int counter = 0;
+		while (registry.containsBeanDefinition(id)) {
+			counter++;
+			id = generatedName + BeanFactoryUtils.GENERATED_BEAN_NAME_SEPARATOR + counter;
+		}
+		return id;
+	}
+
 	/**
 	 * Derive a default bean name from the given bean definition.
 	 * <p>The default implementation simply builds a decapitalized version