Fix GeoJson polygon conversion for polygons with inner ring.

Closes: #4104
Original pull request: #4156.

Author: christophstrobl

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/GeoConverters.java

@@ -757,7 +757,9 @@ static List<Point> toListOfPoint(List listOfCoordinatePairs) {
 	 * @since 1.7
 	 */
 	static GeoJsonPolygon toGeoJsonPolygon(List dbList) {
-		return new GeoJsonPolygon(toListOfPoint((List) dbList.get(0)));
+
+		GeoJsonPolygon polygon = new GeoJsonPolygon(toListOfPoint((List) dbList.get(0)));
+		return dbList.size() > 1 ? polygon.withInnerRing(toListOfPoint((List) dbList.get(1))) : polygon;
 	}
 
 	/**

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

@@ -24,6 +24,7 @@
 import org.springframework.data.geo.Point;
 import org.springframework.data.geo.Polygon;
 import org.springframework.util.Assert;
+import org.springframework.util.ObjectUtils;
 
 /**
  * {@link GeoJson} representation of {@link Polygon}. Unlike {@link Polygon} the {@link GeoJsonPolygon} requires a
@@ -134,4 +135,28 @@ private static List<Point> asList(Point first, Point second, Point third, Point
 
 		return result;
 	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (o == null || getClass() != o.getClass()) {
+			return false;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+
+		GeoJsonPolygon that = (GeoJsonPolygon) o;
+
+		return ObjectUtils.nullSafeEquals(this.coordinates, that.coordinates);
+	}
+
+	@Override
+	public int hashCode() {
+		int result = super.hashCode();
+		result = 31 * result + ObjectUtils.nullSafeHashCode(coordinates);
+		return result;
+	}
 }