Tk Toolkit

In Tk-Cocoa, I've observed that if one tries to reset/recreate a specified
menu, the old menu isn't updated in place, but instead has additional,
redundant entries appended to the end of the menu. Here's how I reproduce
this step:

1. Run the Tk widget demo in Wish.
2. Choose the "menu demonstration" demo.
3. Select the "see code" button from the menu demonstration.
4. The menu has these entries: File, Basic, Cascades, Icons, More, Colors.
5. Click the "see code" button in the demo window.
6. The code window pops up; select the "rerun demo" window.
7. Instead of having the menu re-created in place, the menu now appends
these entires: Basic, Icons, Colors. The entire menu looks like this:
File, Basic, Cascades, Icons, More, Colors, Basic, Icons, Colors.

The menu should not behave this way.

I first observed this behavior in IDLE, a Python/Tkinter application, when
it's linked to Tk-Cocoa. I originally thought it was a problem with IDLE's
code, but after reproducing the behavior in Tk itself, I believe it's
something that needs to be addressed in Tk.