function aa(a,a) return a end -> bug ?

[Domingo Alvarez Duarte <mingodad@...>]

Hello !

I just found when reading 
http://www.cse.chalmers.se/edu/year/2012/course/DAT150/lectures/plt-book.pdf 
on page 80 see bellow:

===

To be really picky, the type checker of function definitions should also
check that all variables in the parameter list are distinct. We shall 
see in the
next section that variables introduced in declarations are checked to be 
new.
Then they must also be new with respect to the function parameters.

===

I decided to check lua and found that lua/luajit accept this without 
complain:

===

function aa(a,a) return a end

print(aa(1,2))  --> 2

===

Is this the expected behavior or a bug ?

Cheers !