wxGUI: post wxUpdateProgressbar event only if mapWindow is not None

(merge from devbr6, https://trac.osgeo.org/grass/changeset/33110)


git-svn-id: https://svn.osgeo.org/grass/grass/trunk@33112 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/gui_modules/render.py

@@ -806,10 +806,11 @@ class Map(object):
                 if not layer.Render():
                     continue
             
-            # update progress bar
-            wx.SafeYield(mapWindow)
-            event = wxUpdateProgressBar(value=ilayer)
-            wx.PostEvent(mapWindow, event)
+            if mapWindow:
+                # update progress bar
+                wx.SafeYield(mapWindow)
+                event = wxUpdateProgressBar(value=ilayer)
+                wx.PostEvent(mapWindow, event)
             
             # add image to compositing list
             if layer.type != "overlay":