Only blur if at least one item is added or removed

iron-list.html

@@ -1091,9 +1091,17 @@
       } else if (change.path === 'items.splices') {
         this._adjustVirtualIndex(change.value.indexSplices);
         this._virtualCount = this.items ? this.items.length : 0;
-        // Only blur activeElement if it is a descendant of the list (#505, #507).
-        var activeElement = this._getActiveElement();
-        if (this.contains(activeElement)) activeElement.blur();
+        // Only blur if at least one item is added or removed.
+        var itemAddedOrRemoved = change.value.indexSplices.some(function(splice) {
+          return splice.addedCount > 0 || splice.removed.length > 0;
+        });
+        if (itemAddedOrRemoved) {
+          // Only blur activeElement if it is a descendant of the list (#505, #507).
+          var activeElement = this._getActiveElement();
+          if (this.contains(activeElement)) {
+            activeElement.blur();
+          }
+        }
         // Render only if the affected index is rendered.
         var affectedIndexRendered = change.value.indexSplices.some(function(splice) {
           return splice.index + splice.addedCount >= this._virtualStart &&

test/focus.html

@@ -109,6 +109,28 @@
       });
     });
 
+    test('don\'t blur if no items are added or removed', function(done) {
+      list.items = buildDataSet(100);
+
+      flush(function() {
+        getFirstItemFromList(list).focus();
+
+        assert.notEqual(document.activeElement, document.body);
+
+        list.items[0]['foo'] = 'bar';
+        list.notifySplices('items', [{
+          index: 0,
+          addedCount: 0,
+          object: list.items,
+          type: 'splice',
+          removed: []
+        }]);
+
+        assert.notEqual(document.activeElement, document.body);
+        done();
+      });
+    });
+
     test('don\'t blur when items changed (#449)', function(done) {
       list.items = buildDataSet(100);