Invalid read in mpz_powm_ui

[Zimmermann Paul]

       Torbjörn,
       
> Thanks for the bug report!  A fix is in the repo (and will thus appear
> in the next snapshot).

thanks. The MPFR and MPC builds with gmp-devel work again.

>   PS: aren't the nightly builds of GMP tested against valgrind?
>   
> Nope.  Perhaps we should.  I ran it now, I and found 4 errors (including
> yours).  Two of these have not yet been analysed, but one of these
> unanalysed problems is related to code not yet used by any documented
> interface.  The 4th error was harmless and due to how we do mpn_incr_u.
> I implemented a simple workaround to silence valgrind.

I fully agree you should!

Paul