Lua 5.4.0 (work1), undef and metatable

[Sergey Zakharchenko <doublef.mobile@...>]

Hello,

I'd like to note that operations with undef seem to ignore metatables:

Lua 5.4.0 (work1)  Copyright (C) 1994-2018 Lua.org, PUC-Rio
> =undef
stdin:1: 'undef' is not a value!!
> a=setmetatable({},{__index=print,__newindex=print})
> a[1]=1
table: 0x93cc280        1       1
> a[1]=undef
> a[2]=nil
table: 0x93cc280        2       nil
> a[3]=undef
> =a[1]==nil
table: 0x93cc280        1
true
> =a[1]==undef
true

No metamethod calls occur for the undef assignment and check. This
doesn't seem right.

Best regards,

-- 
DoubleF