>   > Try just evaluating the new definitions and key bindings, 
>   > instead of trying to apply a patch etc.  That will show you
>   > the proposed behavior.  You should not see any errors,
>   > inflooping etc.
> 
>   > Someone intending to install the change to Emacs itself 
>   > can worry about applying the patch.  If you just want to
>   > evaluate the behavior, you need not do that.
> 
> I just did that, and as Eli said, this is a bad idea for built-in
> functions.

Not if you just want to check the new behavior.

I made it clear in my original post that if the new, Lisp definitions from the
patch are to be applied then the C versions need to be removed.

> But the problem with your function is far more simple:
>    (defun end-of-line (&optional n)
>      (let ((inhibit-field-text-motion  t))  (end-of-line)))
> How is this not an infloop?  ----------------^^^^^^^^^^^

About that you are right.  The patch is not correct in that regard, sorry.

I took the definition from my `end-of-line+' and just renamed it to
`end-of-line', without paying attention to the fact that it calls the original
C-coded function.  For the function to be renamed that way, it would have to
call the equivalent of the current C function (to be renamed), or some other
change would be needed.

My point to you remains, but with a change wrt the names: if you want to
evaluate the proposed behavior, then just evaluate the attached code (which is
the same as what I sent to emacs-devel for people to try this).  The attached
definitions are the same as what I included in the patch, except for the doc
strings and the command names.  (And to repeat, yes, the patch is incorrect
because of the name-capture.

HTH.