Merge with 3.4

Lib/turtledemo/__main__.py

@@ -260,12 +260,13 @@ class DemoWindow(object):
         return menu
 
     def refreshCanvas(self):
-        if not self.dirty: return
+        if self.dirty:
             self.screen.clear()
             self.dirty=False
 
     def loadfile(self, filename):
-        self.refreshCanvas()
+        self.clearCanvas()
+        turtle.TurtleScreen._RUNNING = False
         modname = 'turtledemo.' + filename
         __import__(modname)
         self.module = sys.modules[modname]
@@ -319,8 +320,6 @@ class DemoWindow(object):
             self.configGUI(NORMAL, NORMAL, DISABLED, DISABLED,
                            "STOPPED!", "red")
         turtle.TurtleScreen._RUNNING = False
-        else:
-            turtle.TurtleScreen._RUNNING = False
 
     def _destroy(self):
         self.root.destroy()

Lib/turtledemo/nim.py

@@ -219,7 +219,7 @@ def main():
     mainscreen.mode("standard")
     mainscreen.setup(SCREENWIDTH, SCREENHEIGHT)
     nim = Nim(mainscreen)
-    return "EVENTLOOP!"
+    return "EVENTLOOP"
 
 if __name__ == "__main__":
     main()