Fixes#290.
Checking for overflow should be done before integer overflows.
There are two checks:
(result > limit / base) is used for limits greater than rounded up to base,
e.g. for 65535 it will activate for 65540 and higher.
(result * base > limit - digit) is used for limit+1 to limit+n below
next base rounded number, e.g. 65536 up to 65539.
e84ab5f67c