#1111: ensure we remove the current backing before adding a new one

git-svn-id: https://xpra.org/svn/Xpra/trunk@13291 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/xpra/client/gl/gtk2/gl_client_window.py

@@ -69,28 +69,31 @@ def do_configure_event(self, event):
         self._backing.paint_screen = True
 
     def destroy(self):
+        self.remove_backing()
+        GTK2WindowBase.destroy(self)
+
+    def remove_backing(self):
         b = self._backing
         if b:
+            self._backing = None
             b.paint_screen = False
             b.close()
-            self._backing = None
-        GTK2WindowBase.destroy(self)
-
+            glarea = b._backing
+            if glarea:
+                try:
+                    self.remove(glarea)
+                except:
+                    pass
 
     def new_backing(self, bw, bh):
+        self.remove_backing()
         widget = GTK2WindowBase.new_backing(self, bw, bh)
         log("new_backing(%s, %s)=%s", bw, bh, widget)
         self.add(widget)
 
 
     def freeze(self):
-        b = self._backing
-        if b:
-            glarea = b._backing
-            if glarea:
-                self.remove(glarea)
-            b.close()
-            self._backing = None
+        self.remove_backing()
         GTK2WindowBase.freeze(self)