Link to tree views of submodules if possible

[bohde]

This is a follow-up to #33097.

When linking a submodule at a commit in either the repo view, or a diff when adding a new submodule, link to the tree view of that submodules intead of the individual commit. This shows the user the full tree, instead of the diff of the commit.

This makes the assumption that the tree for a given SHA is at <repo_url>/tree/<sha>. This URL format is supported by both Github & Gitlab, but not Gitea. To fix this, add a redirect from <username>/<repo>/tree/<ref> to <username>/<repo>/src/<ref>, so that Gitea can support this URL structure.

[wxiaoguang]

Thank you for the update, but I think we should avoid doing that .....

Sprintf("%s/%s/%s/src/%s", AppSubURL, PathEscape(username), PathEscape(reponame), PathEscapeSegments(*)) should be good enough and it's not worth to test it because it has been widely used everywhere. We can just keep code simple.

If you don't mind, I can help to make some improvements.

[bohde]

Thank you for the update, but I think we should avoid doing that .....

Sprintf("%s/%s/%s/src/%s", AppSubURL, PathEscape(username), PathEscape(reponame), PathEscapeSegments(*)) should be good enough and it's not worth to test it because it has been widely used everywhere. We can just keep code simple.

If you don't mind, I can help to make some improvements.

Was in the process of responding to that one. I'm happy to make the change if you want, but before using paths.Join I looked through the existing code used to construct redirects to ensure the style was similar. It looked like there was a preference for using path.Join instead of fmt.Sprintf. (example).

If you still want me to replace it with fmt.Sprintf, I can.

[wxiaoguang]

It looked like there was a preference for using path.Join instead of fmt.Sprintf. (example).

That's the only (maybe a few) legacy usages. Most other code doesn't use path.Join.

Actually, you could also just use RepoLink here since you are in a RepoAssigment context.

[wxiaoguang]

Hmm, one more thing, I think the use of /tree/{CommitID} is wrong.

Because it redirects and routes to the deprecated handler /src/{CommitID} if I understand correctly.

[bohde]

Actually, you could also just use RepoLink here since you are in a RepoAssigment context.

Used this method in 92cb2a8

Because it redirects and routes to the deprecated handler /src/{CommitID} if I understand correctly.

This is correct, but intentional. Github's URL structure is <repo>/tree/<ref> not <repo>/tree/<sha>. A couple of examples:

• https://github.com/go-gitea/gitea/tree/main
• https://github.com/go-gitea/gitea/tree/a89c73530327784ce99e1e07c269ea8ff1861fdc

When hitting this in Gitea, the user will have two separate redirects to get to the canonical URL. The flow would look like this:

• https://gitea.com/gitea/gitea-mirror/tree/a89c73530327784ce99e1e07c269ea8ff1861fdc
• https://gitea.com/gitea/gitea-mirror/src/a89c73530327784ce99e1e07c269ea8ff1861fdc
• https://gitea.com/gitea/gitea-mirror/src/commit/a89c73530327784ce99e1e07c269ea8ff1861fdc

[wxiaoguang]

Then it comes to this question .... #33424 (comment)

Why we should support such /tree/ path? What's the benefit?

[bohde]

Then it comes to this question .... #33424 (comment)

Why we should support such /tree/ path? What's the benefit?

The intent of this PR is so that when a user clicks on a submodule commit, either in the repo home view, or when adding a new submodule in a diff, that shows them the tree instead of the commit.

Right now if I add a submodule of gitea.com/gitea/gitea-mirror@a89c73530327784ce99e1e07c269ea8ff1861fdc, it links to https://gitea.com/gitea/gitea-mirror/commit/a89c73530327784ce99e1e07c269ea8ff1861fdc. This updates that to show (after redirects) https://gitea.com/gitea/gitea-mirror/src/commit/a89c73530327784ce99e1e07c269ea8ff1861fdc, allowing them to browse the repo at that commit.

The issue of adding a /tree/ path comes in for submodules that are not hosted on Gitea. If I were to link out to https://github.com/go-gitea/gitea/src/commit/a89c73530327784ce99e1e07c269ea8ff1861fdc, that results in a 404 for the user, who would need to navigate to the repo, and then search for the commit. That content is instead available at https://github.com/go-gitea/gitea/tree/a89c73530327784ce99e1e07c269ea8ff1861fdc.

We could try to guess what type of forge a given submodule links out to, and then either use src/commit for Gitea or tree for others, but self-hosted deployments would make that error-prone. Adding a redirect for these tree paths allows using the same link across Gitea and other forges.

[wxiaoguang]

Thank you for the explanation, it's clear to me now.

I think we need to add the background information to comments, otherwise the future readers would still have the same question: why /tree/ is used ....

[bohde]

Thank you for the explanation, it's clear to me now.

I think we need to add the background information to comments, otherwise the future readers would still have the same question: why /tree/ is used ....

I updated the comment in 7da9b01. Is that inline with what you are thinking?

[wxiaoguang]

-> Fix "redirect link" handling #33440

Improved the path handling logic and added some tests in links_test.go