Question: About a limit that don't give the result

Hi all,

> f := exp(s*(-1+s)^(-1))*s^(x-1)*(-(-1+s)^(-1))^x*(-1+s)^(-1);

                                                        x
                            /  s   \  (x - 1) /    1   \ 
                         exp|------| s        |- ------| 
                            \-1 + s/          \  -1 + s/ 
                    f := --------------------------------
                                      -1 + s             
> subs(s = 0, f);

                                      0
> `assuming`([limit(f, s = 0)], [x::real]);

                    /                               x       \
                    |   /  s   \  (x - 1) /    1   \        |
                    |exp|------| s        |- ------|        |
                    |   \-1 + s/          \  -1 + s/        |
               limit|--------------------------------, s = 0|
                    \             -1 + s                    /

Why the limit don't get the value of 0 ?

Thanks for any help!

Mario