`super::super` shows autocompletions for `super`

mod a {
	const A: usize = 0;
	mod b {
		const B: usize = 0;
		mod c {
			use super::super::<|>; // Shows B as a completion item
		}
	}
}

Note that goto definition appears to work.

[matklad]

Huh, not sure what's going on here. The place to start would be to print path_prefix and def over here:

https://github.com/rust-analyzer/rust-analyzer/blob/1aded342266f18b519666ac512e77b0c211fff5d/crates/ra_ide_api/src/completion/complete_path.rs#L10-L17

[detrumi]

In the snippet above, path is always ModPath { kind: Super(1), ..} for one or more super's in super::super::<|>, so it's always looking at a single super::<|>.

[matklad]

That's funny! We've basically never supported nested supers in the name resolution. Recently, I've refactored paths and actually added the proper handing to the name resolution code:

https://github.com/rust-analyzer/rust-analyzer/blob/010d90202102e4e30ecd670e8500170247ef74a6/crates/ra_hir_def/src/nameres/path_resolution.rs#L159-L160

However, I didn't add a test for it, and surprise, the feature as a whole does not work because we never produce paths with nested supers in the first place. We need to fix lowering code in two places to produce nested super:

• https://github.com/rust-analyzer/rust-analyzer/blob/010d90202102e4e30ecd670e8500170247ef74a6/crates/ra_hir_def/src/path/lower/lower_use.rs#L106-L110
• https://github.com/rust-analyzer/rust-analyzer/blob/010d90202102e4e30ecd670e8500170247ef74a6/crates/ra_hir_def/src/path/lower.rs#L103-L105

(note that we do need two separate code-paths for it, because nested use trees are a separate way to express a path).

[matklad]

The test for this should go here:

https://github.com/rust-analyzer/rust-analyzer/blob/010d90202102e4e30ecd670e8500170247ef74a6/crates/ra_hir_def/src/nameres/tests.rs