Merge pull request #1427 from twpayne/vector-api-hosted

[vector-api] Miscellaneous fixes for hosted examples

src/ol/format/geojsonformat.js

@@ -331,7 +331,7 @@ ol.format.GeoJSON.prototype.readFeaturesFromObject = function(object) {
     return features;
   } else {
     goog.asserts.fail();
-    return null;
+    return [];
   }
 };
 

src/ol/format/xmlformat.js

@@ -79,7 +79,7 @@ ol.format.XML.prototype.readFeatures = function(source) {
     return this.readFeaturesFromDocument(doc);
   } else {
     goog.asserts.fail();
-    return null;
+    return [];
   }
 };
 

src/ol/source/vectorfilesource.js

@@ -3,6 +3,7 @@
 goog.provide('ol.source.VectorFile');
 
 goog.require('goog.asserts');
+goog.require('goog.dom.xml');
 goog.require('goog.net.XhrIo');
 goog.require('ol.format.FormatType');
 goog.require('ol.proj');
@@ -83,6 +84,9 @@ ol.source.VectorFile.prototype.handleXhrIo_ = function(event) {
       source = xhrIo.getResponseText();
     } else if (type == ol.format.FormatType.XML) {
       source = xhrIo.getResponseXml();
+      if (goog.isNull(source)) {
+        source = goog.dom.xml.loadXml(xhrIo.getResponseText());
+      }
     } else {
       goog.asserts.fail();
     }