backend gtk and gtk3: destroy figure save dialog after use

Author: efiring

lib/matplotlib/backends/backend_gtk.py

@@ -739,7 +739,9 @@ def get_filechooser(self):
         return fc
 
     def save_figure(self, *args):
-        fname, format = self.get_filechooser().get_filename_from_user()
+        chooser = self.get_filechooser()
+        fname, format = chooser.get_filename_from_user()
+        chooser.destroy()
         if fname:
             try:
                 self.canvas.print_figure(fname, format=format)

lib/matplotlib/backends/backend_gtk3.py

@@ -543,11 +543,13 @@ def get_filechooser(self):
         return fc
 
     def save_figure(self, *args):
-        fname, format = self.get_filechooser().get_filename_from_user()
+        chooser = self.get_filechooser()
+        fname, format = chooser.get_filename_from_user()
+        chooser.destroy()
         if fname:
             try:
                 self.canvas.print_figure(fname, format=format)
-            except Exception, e:
+            except Exception as e:
                 error_msg_gtk(str(e), parent=self)
 
     def configure_subplots(self, button):