From 4cbc5e113ca5a82b8f99c91a0722fe664213ea94 Mon Sep 17 00:00:00 2001
From: Alexey Smishlayev <smishlayev@gmail.com>
Date: Sun, 31 Mar 2013 17:08:25 +0300
Subject: [PATCH] Update app.py

Handle situation when Window is None (e.g. when App's build() returned nothing). Error message could be better, but it does the job.
---
 kivy/app.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kivy/app.py b/kivy/app.py
index 6519aa3c9..cde382ad2 100644
--- a/kivy/app.py
+++ b/kivy/app.py
@@ -579,6 +579,10 @@ class App(EventDispatcher):
             if icon:
                 window.set_icon(icon)
             self._install_settings_keys(window)
+        else:
+            Logger.critical("Application: No window is created."
+                " Terminating application run.")
+            return
 
         self.dispatch('on_start')
         runTouchApp()