Prevent error storm when NativeWindow.get().focus() fails during Moda…

…lDialogBase load

We just ran into a situation where for some reason a DOMWindow didn't have a focus method, causing ModalDialogBase::onLoad's allActiveDialogs_.add(this) not to be called. That results in ModalDialogBase::onPreviewNativeEvent throwing an error on every browser event (such as moving the mouse!), which filled up our error logs.

src/gwt/src/org/rstudio/core/client/widget/ModalDialogBase.java

@@ -95,14 +95,14 @@ protected void beginDragging(MouseDownEvent event)
    @Override
    protected void onLoad()
    {
-      // 728: Focus remains in Source view when message dialog pops up over it
-      NativeWindow.get().focus();
-
       super.onLoad();
       allActiveDialogs_.add(this);
       if (shortcutDisableHandle_ != null)
          shortcutDisableHandle_.close();
       shortcutDisableHandle_ = ShortcutManager.INSTANCE.disable();
+
+      // 728: Focus remains in Source view when message dialog pops up over it
+      NativeWindow.get().focus();
    }
 
    @Override