Use unique `testRestTemplate` bean name

Update `SpringBootTestContextCustomizer` to use the full qualified
TestRestTemplate as the registered bean name. Prior to this commit it
was possible that the customizer would replace the relatively common
bean name `testRestTemplate`.

Fixes gh-7711

spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootTestContextCustomizer.java

@@ -62,7 +62,7 @@ class SpringBootTestContextCustomizer implements ContextCustomizer {
 
 	private void registerTestRestTemplate(ConfigurableApplicationContext context,
 			BeanDefinitionRegistry registry) {
-		registry.registerBeanDefinition("testRestTemplate",
+		registry.registerBeanDefinition(TestRestTemplate.class.getName(),
 				new RootBeanDefinition(TestRestTemplateFactory.class));
 	}
 

spring-boot-test/src/test/java/org/springframework/boot/test/context/AbstractSpringBootTestEmbeddedWebEnvironmentTests.java

@@ -60,6 +60,10 @@ public abstract class AbstractSpringBootTestEmbeddedWebEnvironmentTests {
 	@Autowired
 	private TestRestTemplate restTemplate;
 
+	public WebApplicationContext getContext() {
+		return this.context;
+	}
+
 	public TestRestTemplate getRestTemplate() {
 		return this.restTemplate;
 	}

spring-boot-test/src/test/java/org/springframework/boot/test/context/SpringBootTestTestRestTemplateDefinedByUser.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2012-2016 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.boot.test.context;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link SpringBootTest} configured with {@link WebEnvironment#RANDOM_PORT}.
+ *
+ * @author Phillip Webb
+ * @author Andy Wilkinson
+ */
+@RunWith(SpringRunner.class)
+@DirtiesContext
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT, properties = { "value=123" })
+public class SpringBootTestTestRestTemplateDefinedByUser
+		extends AbstractSpringBootTestEmbeddedWebEnvironmentTests {
+
+	@Test
+	public void restTemplateIsUserDefined() throws Exception {
+		assertThat(getContext().getBean("testRestTemplate"))
+				.isInstanceOf(RestTemplate.class);
+	}
+
+	// gh-7711
+
+	@Configuration
+	@EnableWebMvc
+	@RestController
+	protected static class Config extends AbstractConfig {
+
+		@Bean
+		public RestTemplate testRestTemplate() {
+			return new RestTemplate();
+		}
+
+	}
+
+}