Without this patch OSX users couldn't add new help sources because the code

tried to update one item in a tuple.

Lib/idlelib/configHelpSourceEdit.py

@@ -151,6 +151,7 @@ class GetHelpSourceDialog(Toplevel):
                     pass
                 else:
                     # Mac Safari insists on using the URI form for local files
+                    self.result = list(self.result)
                     self.result[1] = "file://" + path
             self.destroy()