[support] hide menu items without nodes

[Seitenweberei.ch]

I'm planning a site with two navigations:

first navigation:
- term1 of vocabulary1
   - term1 of vocabulary2
   - term2 of vocabulary2
- term2 of vocabulary1
   - term1 of vocabulary2
   - term2 of vocabulary2

second navigation:
- vocabulary2
   - term1 of vocabulary2
   - term2 of vocabulary2

The parent terms of the navigation will simply point to the taxonomy
term (taxonomy/term/id), the child terms to the corresponding view (if
there's a better solution, how to achieve such a navigation structure,
please let me know).

Is there a module or any code snippet to hide navigation items if the
corresponing taxonomy term or view doesn't have any nodes assigned? I
searched but couldn't find any.

Thanks.
Richard