fix: Allow patterns to pass through the geojsonReader

Continue support for polygon patterns

Author: manthey

src/geojsonReader.js

@@ -68,6 +68,7 @@ var geojsonReader = function (arg) {
           strokeWidth: 2,
           strokeOpacity: 1,
           uniformPolygon: true,
+          pattern: undefined,
           ...arg.polygonStyle
         }
       };

src/webgl/polygonFeature.js

@@ -78,6 +78,9 @@ var webgl_polygonFeature = function (arg) {
     if (val === undefined) {
       val = func(d, idx);
     }
+    if (!val) {
+      return [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
+    }
     if (val.fillColor === undefined) {
       fillColor = util.convertColor(m_this.style.get('strokeColor')(v0, 0, d, idx));
       fillColor.a = m_this.style.get('strokeOpacity')(v0, 0, d, idx);