[PATCH] [BZ #17596] mblen return code when n is zero

[Paul Eggert]

On 11/13/2014 10:58 PM, Rajalakshmi Srinivasaraghavan wrote:
> This patch adds a check to return -2 when n is zero in mblen(),
> mbrlen(),mbrtowc() and mbrtoc16().

mblen should return -1 in this case, right?  I don't see where it's 
allowed to return -2.  Likewise for mbtowc.