Re: [Bug] converting from hex doesn't work for large numbers

[Roberto Ierusalimschy <roberto@...>]

> I have a following bug report for you:
> 
> Consider a big number
> 
> a=math.pow(2, 32) + 14  --4294967310 in dec, 10000000e in hex
> 
> print(tonumber("4294967310") -> 4294967310
> print(tonumber("10000000e", 16) -> 4294967295 (0xffffffff, that is LONG_MAX)
> 
> tonumber() doesn't convert numbers greater than 2**31-1 from bases
> different than default decimal.
> 
> [...]
> 
> I see three ways out of this situation:
> (a) use strtoull(3) (disadvantage: AFAIK that is not in C89)
> 
> (b) check errno for ERANGE and make a run-time error when it's set.
> (advantage: simple; disadvantage: doesn't make my program work, only
> shows the bug clearly)
> 
> (c) make our own re-implementation of strtoull(3), which works for
> all possible lengths of lua_Number.

We will not make our own implementation for strtoull, but we already
made our own implementation for the hexa part of strtod. So, a call
like tonumber("0x10000000e") will work correctly. For the other cases,
we will consider the (b) option.

-- Roberto