x/pkgsite: golang.org/x/tools/gopls/internal/regtest@master resolves to wrong module

[bcmills]

What is the URL of the page with the issue?

https://pkg.go.dev/golang.org/x/tools/gopls/internal/regtest@master

What is your user agent?

Mozilla/5.0 (X11; CrOS x86_64 14909.79.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.0.0 Safari/537.36

Screenshot

What did you do?

Navigate to the aforementioned URL.

What did you expect to see?

A documentation node for the directory internar/regtest (which contains test-only Go packages but is not itself a Go package) in module golang.org/x/tools/gopls on the master branch:
https://cs.opensource.google/go/x/tools/+/master:gopls/internal/regtest/;drc=178fdf98da63010b55ff90c04614e0ca9a69a2cd

Ideally, the documentation node would provide the option to view the doc comments for exported identifiers within the nested tests.

What did you see instead?

A redirect to the master branch of a parent module hosted in the same repository (https://pkg.go.dev/golang.org/x/tools/gopls@v0.0.0-20220725165529-005c07ac5af6/internal/regtest), with an “Oops!” page showing that that module indeed does not contain the requested path.