Magit and Dired: fall back to current directory if not on file

[kisaragi-hiu]

This is most noticeable in magit-status, where you'd have to visit a random file to be able to jump to the repository page with git-link. In Dired, it's also noticeable if git-link is run when point isn't over a file, for instance on Dired's current directory heading.

This PR makes it so that, for example, running git-link in magit-status will fall back to visiting the repository at the current branch or commit. Then, as a special case, if current directory is project root (ie. git-link--relative-filename returns ""), visit the homepage instead.

Now git-link in Magit and Dired always goes somewhere sensible, instead of returning an error.

Before

• It works in an ordinary file
• "Cannot figure out what to link to" on the Dired header
• "Cannot figure out what to link to" in magit-status
• Can link to file under point in Dired

before.mp4

After

• It works in an ordinary file
• Can link to file under point in Dired
• Links to repository homepage instead in Dired when file under point is ..
• ...or when on the Dired header.
• Links to repository homepage in magit-status

after.mp4

[sshaw]

Thanks for the PR —with videos! 📼

Will have an in-depth look next week (please message if you do not hear from me!) but my initial thoughts on this line is that, all things being equal, this is a reasonable default but, one upgrading from existing versions could deem this a bug: "Link missing path". But, it is also possible I'm missing some broader context here that negates this.

There is also a plan for v1.0, where breaking changes will be make to existing defaults and this kinda thing may be more acceptable.

Thoughts?

[kisaragi-hiu]

This is the special case for repository root, but this also ended up discarding branch / commit information.

The main motivator for me to put the special case in is that, at least for GitHub, an empty path after /blob (.../blob/main/) causes a file not found error instead of redirecting to /tree (as is done for eg. .../blob/main/filename).

It's probably better do it properly, though, and adapt the handlers to return the right url for this.

[sethidden]

@sshaw Is this ok to merge? I as well came across the issue where running (git-link) in a magit-status: * buffer prints Can't figure out where to link to

[sshaw]

I as well came across the issue where running (git-link) in a magit-status: * buffer prints

In magit-status it will link to a file; if you're on the file. I.e., Staged/Unstged files. You want to link to something has no link but a link is generated anyways. Some may call this a bug. Which looks like the same outstanding question as last time

If you want to link to the homepage can you call git-link-homepage?

[sshaw]

Can link to file under point in Dired
After ... Links to repository homepage instead in Dired when file under point is ..

Dired will work but yes, if you try to link to a parent directory outside the repo root then what is there to link to? I think a better default here would be the username page not the repos root because you're not trying to link to that: you're trying to link to the parent directory.

Under what circumstances would one generate a "cannot link to error" then?