Rustdoc regression: duplicate macro in sidebar

[dtolnay]

#[macro_export]
macro_rules! repro {
    () => {};
}

pub use crate::repro as repro2;

$ cargo doc --open

In current stable, and nightly-2021-08-28:

In current beta, current nightly, and nightly-2021-08-29:

Notice that repro appears twice in the sidebar under the list of macros exported by the crate.

Bisects to #88019.

[dtolnay]

Bisect

searched nightlies: from nightly-2021-08-10 to nightly-2021-09-26
regressed nightly: nightly-2021-08-29
searched commit range: ac50a53...5eacec9
regressed commit: 05cccdc

bisected with cargo-bisect-rustc v0.6.0

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo bisect-rustc 2021-08-10 --end 2021-09-26 --prompt -- doc --open 

[camelid]

It looks like in both versions there's also a bug where repro2 is not shown.

[jyn514]

I think the fix here is to show "pub use repro as repro2" in the crate root - it sounds like currently it's being unconditionally inlined and then on top of that using the original name instead of the new one.

[Urgau]

This also affect the unstable json output of rustdoc.

If we take the example given by @dtolnay there are 3 items (1 reexport + 2 macro) instead of only two:

Module {
    is_crate: true,
    items: [
        Id("0:4"),   // pub use crate::repro as repro2;
        Id("0:3"),   // macro_rules! repro
        Id("0:3"),   // Same as above, but shouldn't be here !
    ],
}

The bug seems that the macro repro appears for whatever reason 2 times instead of only one.