Fixed GeoResultsUnitTests.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/geo/Distance.java

@@ -136,7 +136,7 @@ public class Distance {
 		StringBuilder builder = new StringBuilder();
 		builder.append(value);
 
-		if (metric != null) {
+		if (metric != Metrics.NEUTRAL) {
 			builder.append(" ").append(metric.toString());
 		}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/geo/GeoResults.java

@@ -61,6 +61,8 @@ public class GeoResults<T> implements Iterable<GeoResult<T>> {
 	}
 
 	/**
+	 * Returns the average distance of all {@link GeoResult}s in this list.
+	 * 
 	 * @return the averageDistance
 	 */
 	public Distance getAverageDistance() {

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/geo/GeoResultsUnitTests.java

@@ -15,10 +15,28 @@
  */
 package org.springframework.data.mongodb.core.geo;
 
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import java.util.Arrays;
+
+import org.junit.Test;
+
 /**
+ * Unit tests for {@link GeoResults}.
  *
  * @author Oliver Gierke
  */
 public class GeoResultsUnitTests {
 
+	@Test
+	@SuppressWarnings("unchecked")
+	public void calculatesAverageForGivenGeoResults() {
+		
+		GeoResult<Object> first = new GeoResult<Object>(new Object(), new Distance(2));
+		GeoResult<Object> second = new GeoResult<Object>(new Object(), new Distance(5));
+		GeoResults<Object> geoResults = new GeoResults<Object>(Arrays.asList(first, second));
+		
+		assertThat(geoResults.getAverageDistance(), is(new Distance(3.5)));
+	}
 }