Merge branch 'develop' of https://github.com/almende/vis into develop

lib/timeline/component/ItemSet.js

@@ -2044,6 +2044,10 @@ ItemSet.prototype._onAddItem = function (event) {
         newItemData.end = snap ? snap(end, scale, step) : end;
       }
     } else {
+      newItemData = {
+        start: snap ? snap(start, scale, step) : start,
+        content: 'new item'
+      };
       newItemData[this.itemsData._fieldId] = util.randomUUID();
 
       // when default type is a range, add a default end date to the new item

lib/util.js

@@ -188,7 +188,7 @@ exports.selectiveExtend = function (props, a, b) {
 
     for (var p = 0; p < props.length; p++) {
       var prop = props[p];
-      if (other.hasOwnProperty(prop)) {
+      if (other && other.hasOwnProperty(prop)) {
         a[prop] = other[prop];
       }
     }