rustdoc: Private function is rendered with a verbose visibility

[camelid]

If I run cargo +nightly doc --document-private-items on this code:

mod foo {
    struct S;
    impl S {
        fn new() -> S { S }
    }
}

then the output looks like this:

Note that the visibility is verbose – it says pub(in foo) when it should show nothing (and used to show nothing).

This bug only occurs when the function is private and --document-private-items is passed (of course, the docs are not generated without that flag).

[camelid]

searched nightlies: from nightly-2020-11-17 to nightly-2020-11-20
regressed nightly: nightly-2020-11-19
searched commits: from c919f49 to 8256379
regressed commit: 7d747db

bisected with cargo-bisect-rustc v0.6.0

Host triple: x86_64-apple-darwin
Reproduce with:

cargo bisect-rustc --preserve --prompt --start=2020-11-17 --end=2020-11-20 -- doc --document-private-items 

---

I'm not sure if the commit it thinks has the regression is correct though. cargo-bisect-rustc printed out this during bisection:

installing c4f836ad1aceb83507810d9499f56988fd24578d
installing 87776d7d5322422e5239e153e793b687f7f9c379
installing 7d747db0d5dd8f08f2efb073e2e77a34553465a7
testing...

and then after that it asked me again about c919f49, even though it asked me about it at the start of bisection.

[jyn514]

the visibility is verbose – it says pub(in foo) when it should show nothing

This is probably the same cause as #79139, although the fix may be slightly different.

cargo bisect-rustc --preserve --prompt --start=2020-11-17 --end=2020-11-20 -- doc --document-private-items

The 'prompt' there makes me think you might have hit the wrong 'good/bad' option at some point.

[camelid]

I did the bisection twice though and both times it had the same result. I wish cargo-bisect-rustc could do this automatically somehow.

[jyn514]

@camelid you could write a script that does an xpath query on the generated documentation, maybe.

[camelid]

At that point it's faster to do it manually.

[camelid]

@jyn514 Did the formatting change happen as part of #77820?

[jyn514]

@camelid I wouldn't expect it to but I don't know without bisecting.

[camelid]

I bisected a third time, and again I got the same result. I think it might be a bug in cargo-bisect-rustc.

[jyn514]

Well I can at least confirm that the bug is not present in beta, so this is a nightly regression.