Test for ImportBeanDefinitionRegistrar double scan

Issue: SPR-12334

spring-context/src/test/java/org/springframework/context/annotation/spr12334/Spr12334Tests.java

+/*
+ * Copyright 2002-2014 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.spr12334;
+
+import org.junit.Test;
+
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
+import org.springframework.core.type.AnnotationMetadata;
+
+/**
+ * @author Juergen Hoeller
+ * @author Alex Pogrebnyak
+ */
+public class Spr12334Tests {
+
+	@Test
+	public void shouldNotScanTwice() {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+		context.scan(TestImport.class.getPackage().getName());
+		context.refresh();
+		context.getBean(TestConfiguration.class);
+	}
+
+
+	@Import(TestImport.class)
+	public @interface AnotherImport {
+	}
+
+
+	@Configuration
+	@AnotherImport
+	public static class TestConfiguration {
+	}
+
+
+	public static class TestImport implements ImportBeanDefinitionRegistrar {
+
+		private boolean scanned = false;
+
+		@Override
+		public void registerBeanDefinitions(AnnotationMetadata metadata, BeanDefinitionRegistry registry)  {
+			if (this.scanned) {
+				throw new IllegalStateException("Already scanned");
+			}
+			this.scanned = true;
+		}
+	}
+
+}