--- swab.c.bsdnew 2009-11-18 18:24:38.000000000 -0800 +++ swab.c 2009-11-18 18:40:17.000000000 -0800 @@ -45,6 +45,8 @@ swab(const void * __restrict from, void int n; char *fp, *tp; + if (len <= 0) + return; n = len >> 1; fp = (char *)from; tp = (char *)to;