From e65c522cb4c537b3ad98b67c34dcf560a0336601 Mon Sep 17 00:00:00 2001
From: Peter Robins <github@peterrobins.co.uk>
Date: Sat, 19 Mar 2016 16:30:48 +0000
Subject: [PATCH] Fix geojson write GeometryCollection

---
 src/ol/format/geojsonformat.js            |  4 +++-
 test/spec/ol/format/geojsonformat.test.js | 22 ++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/ol/format/geojsonformat.js b/src/ol/format/geojsonformat.js
index dcb6881cca..594665d0de 100644
--- a/src/ol/format/geojsonformat.js
+++ b/src/ol/format/geojsonformat.js
@@ -211,7 +211,9 @@ ol.format.GeoJSON.writeGeometryCollectionGeometry_ = function(
   goog.asserts.assertInstanceof(geometry, ol.geom.GeometryCollection,
       'geometry should be an ol.geom.GeometryCollection');
   var geometries = geometry.getGeometriesArray().map(function(geometry) {
-    return ol.format.GeoJSON.writeGeometry_(geometry, opt_options);
+    var options = ol.object.assign({}, opt_options);
+    delete options.featureProjection;
+    return ol.format.GeoJSON.writeGeometry_(geometry, options);
   });
   return /** @type {GeoJSONGeometryCollection} */ ({
     type: 'GeometryCollection',
diff --git a/test/spec/ol/format/geojsonformat.test.js b/test/spec/ol/format/geojsonformat.test.js
index 95358095df..7371a064e0 100644
--- a/test/spec/ol/format/geojsonformat.test.js
+++ b/test/spec/ol/format/geojsonformat.test.js
@@ -725,6 +725,28 @@ describe('ol.format.GeoJSON', function() {
           .to.be.lessThan(0.0000001);
     });
 
+    it('transforms and encodes geometry collection', function() {
+      var collection = new ol.geom.GeometryCollection([
+        new ol.geom.Point([2, 3]),
+        new ol.geom.LineString([[3, 2], [2, 1]])
+      ]);
+      var geojson = format.writeGeometry(collection, {
+        featureProjection: 'EPSG:3857'
+      });
+      var got = format.readGeometry(geojson, {
+        featureProjection: 'EPSG:3857'
+      });
+      var gotGeometries = got.getGeometries();
+      var geometries = collection.getGeometries();
+      expect(geometries[0].getCoordinates()[0]).to.roughlyEqual(
+          gotGeometries[0].getCoordinates()[0], 1e-8);
+      expect(geometries[0].getCoordinates()[1]).to.roughlyEqual(
+          gotGeometries[0].getCoordinates()[1], 1e-8);
+      expect(geometries[1].getCoordinates()[0][0]).to.roughlyEqual(
+          gotGeometries[1].getCoordinates()[0][0], 1e-8);
+      expect(geometries[1].getCoordinates()[0][1]).to.roughlyEqual(
+          gotGeometries[1].getCoordinates()[0][1], 1e-8);
+    });
   });
 
 });