#[non_exhaustive] variants are not detected to be redundant

[Nadrieril]

Say I have the following enum in crate b:

#![feature(non_exhaustive)]
pub enum Enum {
    Unit,
    #[non_exhaustive] Struct { x: bool }
}

And I match on it in crate a:

#![deny(unreachable_patterns)]
match Enum::Unit {
    Enum::Struct { .. } => {}
    Enum::Struct { .. } => {} // This should error but doesn't
    _ => {}
}

The second branch is not detected to be unreachable. This is on current nightly; playground link (hacky).

[Nadrieril]

The reason for this behaviour is straightforward: this line reports tuple variants with non-exhaustive fields as always useful.
This line was introduced in commit 0d034a2 . I'm not quite sure what the intended semantics are so I wouldn't know how to fix it.

[Nadrieril]

Please wait for #65160 to be merged before fixing this; I'm dreading having to rebase on top of the fix

[arielb1]

cc @davidtwco