Button EnterKeyBehavior - set e.Handled to true

src/client/spark/view/Extensions/TextElement/TextBoxBehavior.cs

@@ -59,8 +59,10 @@ namespace mbts.ui {
             {
                EnterKeyBehavior.Commit,
                (s, e) => {
-                  if (e.Key == Key.Enter)
+                  if (e.Key == Key.Enter) {
                      BindingOperations.GetBindingExpression(s as DependencyObject, TextBox.TextProperty)?.UpdateSource();
+                     e.Handled = true;
+                  }
                }
             },
             {
@@ -69,6 +71,7 @@ namespace mbts.ui {
                   if (e.Key == Key.Enter) {
                      BindingOperations.GetBindingExpression(s as DependencyObject, TextBox.TextProperty)?.UpdateSource();
                      Keyboard.ClearFocus();
+                     e.Handled = true;
                   }
                }
             }