fix GeometryCollection _toJSON error when options is null (#2147)

Author: deyihu

src/geometry/GeometryCollection.js

@@ -1,4 +1,4 @@
-import { isFunction, isArrayHasData, isNil } from '../core/util';
+import { isFunction, isArrayHasData, isNil, extend } from '../core/util';
 import { createFilter, getFilterFeature } from '@maptalks/feature-filter';
 import { getExternalResources } from '../core/util/resource';
 import Coordinate from '../geo/Coordinate';
@@ -416,6 +416,8 @@ class GeometryCollection extends Geometry {
     }
     //for toJSON
     _toJSON(options) {
+        //fix call from feature-filter package
+        options = extend({}, options);
         //Geometry了用的是toGeoJSON(),如果里面包含特殊图形(Circle等),就不能简单的用toGeoJSON代替了，否则反序列化回来就不是原来的图形了
         const feature = {
             'type': 'Feature',

test/geometry/GeometryCollectionSpec.js

@@ -349,6 +349,105 @@ describe('#GeometryCollection', function () {
             expect(selection.getGeometries()).to.have.length(points.length);
         });
     });
+
+    it('#2146 _toJSON(null) from feature-filter', function () {
+        const geojson = {
+            "type": "FeatureCollection",
+            "name": "aa",
+            "crs": {
+                "type": "name",
+                "properties": {
+                    "name": "EPSG:4490"
+                }
+            },
+            "features": [
+                {
+                    "type": "Feature",
+                    "geometry": {
+                        "type": "GeometryCollection",
+                        "geometries": [
+                            {
+                                "type": "Polygon",
+                                "coordinates": [
+                                    [
+                                        [113.7991529327, 23.0121665284],
+                                        [113.7605656502, 22.9686311814],
+                                        [113.8260686078, 22.9546199745],
+                                        [113.8198107317, 23.0045461461],
+                                        [113.7991529327, 23.0121665284]
+                                    ]
+                                ]
+                            },
+                            {
+                                "type": "Polygon",
+                                "coordinates": [
+                                    [
+                                        [113.8688589262, 22.9914540607],
+                                        [113.8333100818, 22.9400538911],
+                                        [113.8869830716, 22.9190765221],
+                                        [113.8939079988, 22.9690147904],
+                                        [113.8688589262, 22.9914540607]
+                                    ]
+                                ]
+                            },
+                            {
+                                "type": "Polygon",
+                                "coordinates": [
+                                    [
+                                        [113.7786088849, 22.9485879648],
+                                        [113.7591122414, 22.8866803638],
+                                        [113.8297744355, 22.8793652689],
+                                        [113.8198854714, 22.9481623574],
+                                        [113.7786088849, 22.9485879648]
+                                    ]
+                                ]
+                            },
+                            {
+                                "type": "MultiPolygon",
+                                "coordinates": [
+                                    [
+                                        [
+                                            [113.8654530057, 23.0430565973],
+                                            [113.8432406194, 23.0525926525],
+                                            [113.8218502836, 23.0236615414],
+                                            [113.870137785, 23.0034008379],
+                                            [113.8654530057, 23.0430565973]
+                                        ]
+                                    ],
+                                    [
+                                        [
+                                            [113.8561406429, 23.0607279435],
+                                            [113.8339123801, 23.0802969357],
+                                            [113.8189838691, 23.0439658919],
+                                            [113.8561406429, 23.0607279435]
+                                        ]
+                                    ]
+                                ]
+                            }
+                        ]
+                    },
+                    "properties": {
+                        "OBJECTID": 1,
+                        "SHAPE_Length": 20977.022743581954,
+                        "SHAPE_Area": 24845610.21174327
+                    }
+                }
+            ]
+        }
+        const polygons = maptalks.GeoJSON.toGeometry(geojson);
+        layer = new maptalks.VectorLayer("v").addTo(map);
+        layer.setStyle({
+            symbol: {
+                polygonFill: '#FFFFFF',
+                polygonOpacity: 1,
+                lineColor: 'blue',
+                lineWidth: 2,
+                lineDasharray: [10, 10],
+            }
+        })
+        layer.addGeometry(polygons)
+    });
+
 });
 
 function genPoints() {