Strange behavior with macro expanding

[ooichu]

For example (is nil ((mac () nil))) returns nil, although the macro expands to nil and this should be equivalent to (is nil nil).

The problem is that when the macro is evaluated, the value of the original form is replaced by the result of the macro expansion and create new nil object.

[thacuber2a03]

that's weird, considering there's only one nil in the entire language, and anything that returns/evaluates to nil evaluates to that nil