[1.4.6|FTB] tonumber("_", 16) == 8

I've been trying to convert strings of characters [0-9A-Fa-f_], each to either a decimal number or false if NaN.
The expression tonumber("_", 16) or false returns 8, however.

I've tested this on the integrated server - in my script as well as in the built-in interactive interpreter to eliminate the possibility of side effects. I also tested this quirk in an external interpreter for lua 5.1.4, where the result was - as expected - false. However, I'm not sure if that means that this behaviour is indeed related to CC nor do I know if it's a bug or actually a feature I am unaware of.

To reproduce this behaviour, type tonumber("_", 16) in the interactive interpreter.

tonumber only supports chars from 0-9 and A-Z

http://www.lua.org/m...ml#pdf-tonumber

The base may be any integer between 2 and 36, inclusive.

so im guessing it wraps around?
i dont know

also something interesting:
you can compare strings
"A">"B"
its awesome

Most likely a LuaJ - not much can be done about them really - we do plan to move away from LuaJ though. You'll probably have to deal with it for now.

As a workaround for this specific case, try:

chr ~= "_" and tonumber(chr, 16) or false