Polish contribution

 - Rename local variable to avoid shadowing field with the same name
 - Add a test to verify that local.mongo.port is set on the parent
   context

Closes gh-3955

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/embedded/EmbeddedMongoAutoConfiguration.java

@@ -154,9 +154,9 @@ public class EmbeddedMongoAutoConfiguration {
 		setPortProperty(this.context, port);
 	}
 
-	private void setPortProperty(ApplicationContext context, int port) {
-		if (context instanceof ConfigurableApplicationContext) {
-			ConfigurableEnvironment environment = ((ConfigurableApplicationContext) context)
+	private void setPortProperty(ApplicationContext currentContext, int port) {
+		if (currentContext instanceof ConfigurableApplicationContext) {
+			ConfigurableEnvironment environment = ((ConfigurableApplicationContext) currentContext)
 					.getEnvironment();
 			MutablePropertySources sources = environment.getPropertySources();
 			Map<String, Object> map;
@@ -173,8 +173,8 @@ public class EmbeddedMongoAutoConfiguration {
 			}
 			map.put("local.mongo.port", port);
 		}
-		if (context.getParent() != null) {
-			setPortProperty(context.getParent(), port);
+		if (currentContext.getParent() != null) {
+			setPortProperty(currentContext.getParent(), port);
 		}
 	}
 

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/embedded/EmbeddedMongoAutoConfigurationTests.java

@@ -25,6 +25,7 @@ import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfigurati
 import org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration;
 import org.springframework.boot.autoconfigure.mongo.MongoDataAutoConfiguration;
 import org.springframework.boot.test.EnvironmentTestUtils;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -38,6 +39,8 @@ import de.flapdoodle.embed.mongo.distribution.Feature;
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.hasItems;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
 import static org.junit.Assert.assertThat;
 
 /**
@@ -93,6 +96,27 @@ public class EmbeddedMongoAutoConfigurationTests {
 						"local.mongo.port"))));
 	}
 
+	@Test
+	public void portIsAvailableInParentContext() {
+		ConfigurableApplicationContext parent = new AnnotationConfigApplicationContext();
+		parent.refresh();
+		try {
+			this.context = new AnnotationConfigApplicationContext();
+			this.context.setParent(parent);
+			EnvironmentTestUtils.addEnvironment(this.context,
+					"spring.data.mongodb.port=0");
+			this.context.register(EmbeddedMongoAutoConfiguration.class,
+					MongoClientConfiguration.class,
+					PropertyPlaceholderAutoConfiguration.class);
+			this.context.refresh();
+			assertThat(parent.getEnvironment().getProperty("local.mongo.port"),
+					is(notNullValue()));
+		}
+		finally {
+			parent.close();
+		}
+	}
+
 	private void assertVersionConfiguration(String configuredVersion,
 			String expectedVersion) {
 		this.context = new AnnotationConfigApplicationContext();