`pub use path` then `use path` silently cancels the reexport

[tomjakubowski]

mod foo {
    pub use self::bar::X;
    #[cfg(bug)]
    use self::bar::X;

    mod bar {
        pub struct X;
    }
}
fn main() {
    let _ = foo::X;
}

Just rustc 14386.rs compiles fine, but rustc --cfg bug 14386.rs fails with:

14386.rs:11:13: 11:19 error: unresolved name `foo::X`.
14386.rs:11     let _ = foo::X;
                        ^~~~~~
error: aborting due to previous error

Original report:

Re-using a re-exported item confuses the visible_private_types lint

pub use sub::Foo;
use sub::Foo;

mod sub {
    pub struct Foo;
}

pub fn blah() -> Foo {
    Foo
}

gives a warning:

private type in exported type signature, #[warn(visible_private_types)] on by default (rust)

Removing the use sub::Foo; line resolves this warning.

[huonw]

The fundamental bug here seems to be: use can "shadow"/overrule a reexport, that is, the pub use causes Foo to be reexported, but the second use cancels that. (Updated bug.)

[tomjakubowski]

This now has a much nicer error message:

foo.rs:4:9: 4:21 error: a value named `X` has already been imported in this module
foo.rs:4     use self::bar::X;
                 ^~~~~~~~~~~~
foo.rs:4:9: 4:21 error: a type named `X` has already been imported in this module
foo.rs:4     use self::bar::X;
                 ^~~~~~~~~~~~
error: aborting due to 2 previous errors

(although double-printing the error, once for a value and once for a type, seems wrong)

I think it can be closed, but might need a test.