x/pkgsite: /<path> should show the contents for the latest version of the containing module

[hhrutter]

What is the URL of the page with the issue?

https://godoc.org/github.com/pdfcpu/pdfcpu asks to switch to go.dev

What is your user agent?

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36

What did you do?

Go to pdfcpu and click on the godoc badge.
Then accept to switch to go.dev

What did you expect to see?

The go.dev page showing the latest release (v0.3.3) of pdfcpu

What did you see instead?

It shows the old release v0.1.11 with a blue badge latest which is false.

[findleyr]

The reason this gets the 'latest' badge is because the redirect takes you to the package page for the package github.com/pdfcpu/pdfcpu, which I'm guessing last existed at v0.1.11 at that specific path. Pkg.go.dev does in fact have v0.3.3 of the module: https://pkg.go.dev/mod/github.com/pdfcpu/pdfcpu?tab=versions

So there are two problems here, AFAICT:

1. The UX of viewing the latest version of a package that has been moved/removed is confusing. This is already being worked on in x/pkgsite: flag packages that are no longer present in the latest version of the containing module #37631
2. The pkg.go.dev redirector doesn't take you to the correct page in this case. When you're viewing a directory (not a package) on godoc.org, it should take you to that subdirectory in the latest version of the module. I'm not sure if that issue has yet been raised.

CC @julieqiu @jba

[julieqiu]

Thanks for the feedback, @hhrutter! We're working fixes for both the points that @findleyr raised. This issue is specially related to the second point - the latest version of a given path should show what exists in the latest version of the module that it corresponds to.

[hhrutter]

Thanks for looking into this!