Keith David Bershatsky <esq@lawlist.com> writes:

> A check should probably be included to see whether the
> `find-function-C-source-directory' contains C source code files before
> creating highlighting/buttons for jumping:

I chose not to do this. I think it's better to make the buttons
and give an error message when they are pressed if
'find-function-C-source-directory' is misconfigured, because then the
error message lets the user know that there is a configuration problem
so that she or he can try to fix it.

Let me know if you are able to give this a try and how it works for you.

Thanks,
Gemini