Enables first article author to be subject owner

[pieer]

• UI Enhancements: Polishes the article editor interface and incorporates a new article creation banner to guide users. Introduces a "Create the first article" bubble view, providing visual guidance for new subjects.
• Subject Search: Enhances subject search by displaying exact matches and similar results distinctly, and providing an option to create a subject if no exact match is found.
• Permissions: Adds comprehensive security tests to ensure article routes correctly enforce permissions, preventing unauthorized access to editing and file operation functionalities.
• Empty Repo Handling: Modifies repository history rendering to accommodate empty/broken repos by showing the "Create first article" bubble.

Fixes #61 and #70.

[taoeffect]

Great work @pieer and @pedrogaudencio!

Opus 4.5 review ready:

Critical Issues

1. Duplicate Route Registration (Bug)

In routers/web/web.go, the same route group is registered twice:

// Article-based file operation routes - mirror the repository-based routes but use subject name
m.Group("/article/{username}/{subjectname}", func() {
    registerRepoFileEditorRoutes(m, reqRepoCodeWriter)
}, reqSignIn, context.RepoAssignmentByOwnerAndSubject, reqUnitCodeReader)
// end "/article/{username}/{subjectname}": article-based file operations

// Article-based file operation routes - mirror the repository-based routes but use subject name
m.Group("/article/{username}/{subjectname}", func() {
    registerRepoFileEditorRoutes(m, reqRepoCodeWriter)
}, reqSignIn, context.RepoAssignmentByOwnerAndSubject, reqUnitCodeReader)
// end "/article/{username}/{subjectname}": article-based file operations

Fix: Remove the duplicate block entirely (lines 1219-1222 in the diff).

---

2. Context Cancellation in Goroutine (Bug)

In services/repository/push.go, the goroutine captures ctx which may be canceled after the HTTP request completes:

go func() {
    c := cache.GetCache()
    if c != nil {
        // Trigger stats generation asynchronously (will be cached for future use)
        _, _ = GetContributorStats(ctx, c, repo, repo.DefaultBranch)
    }
}()

Fix: Use a detached context:

go func() {
    c := cache.GetCache()
    if c != nil {
        // Use background context since this runs after the request may complete
        bgCtx := context.Background()
        _, _ = GetContributorStats(bgCtx, c, repo, repo.DefaultBranch)
    }
}()

---

Potential Bugs

3. Go Version Compatibility Issue

In models/repo/subject.go, strings.FieldsSeq is used which is only available in Go 1.24+:

words := strings.FieldsSeq(subjectName)
for word := range words {
    if strings.HasPrefix(word, keyword) {
        return 2
    }
}

Fix: If targeting earlier Go versions, use strings.Fields instead:

words := strings.Fields(subjectName)
for _, word := range words {
    if strings.HasPrefix(word, keyword) {
        return 2
    }
}

---

4. Empty Repository Name Passed to Fork

In routers/web/repo/editor.go, getUniqueRepositoryName can return an empty string on database errors, which would cause a confusing error downstream:

forkedRepo := ForkRepoTo(ctx, ctx.Doer, repo_service.ForkRepoOptions{
    BaseRepo:     baseRepo,
    Name:         getUniqueRepositoryName(ctx, ctx.Doer.ID, baseRepo.Name),  // Can be ""
    Description:  baseRepo.Description,
    SingleBranch: baseRepo.DefaultBranch,
})

Fix: Check the return value before proceeding:

repoName := getUniqueRepositoryName(ctx, ctx.Doer.ID, baseRepo.Name)
if repoName == "" {
    ctx.ServerError("getUniqueRepositoryName", errors.New("failed to generate unique repository name"))
    return
}
forkedRepo := ForkRepoTo(ctx, ctx.Doer, repo_service.ForkRepoOptions{
    BaseRepo:     baseRepo,
    Name:         repoName,
    Description:  baseRepo.Description,
    SingleBranch: baseRepo.DefaultBranch,
})

---

5. Missing Null Check in Template

In custom/templates/shared/subject/list.tmpl (and the duplicate templates/shared/subject/list.tmpl), there's a missing case when searching yields neither exact match nor similar results but user hasn't searched:

{{/* No results message */}}
{{if and (not .ExactMatch) (not .SimilarSubjects)}}
    <div>
        {{ctx.Locale.Tr "search.no_results"}}
    </div>
{{end}}

This shows "no results" even when there's a search keyword and the "create new subject" button is already shown. Consider:

{{/* No results message - only show if we don't already have the create button */}}
{{if and (not .ExactMatch) (not .SimilarSubjects) .ExactMatch}}
    {{/* This condition can never be true - remove or fix logic */}}
{{end}}

Fix: The no-results message is already handled by the create button section. Remove the redundant {{if and (not .ExactMatch) (not .SimilarSubjects)}} block at the end of the search keyword section since the create button serves as the "no exact match" indicator.

---

Code Improvements

6. Missing Import for errors Package

In the fix for issue #4 above, you'll need to add:

import "errors"

Or use fmt.Errorf:

ctx.ServerError("getUniqueRepositoryName", fmt.Errorf("failed to generate unique repository name"))

---

7. Inefficient Loop in Similarity Scoring

In models/repo/subject.go, the similarity scoring function iterates through results that were already filtered by the database:

func FindSimilarSubjects(ctx context.Context, keyword string, limit int, excludeIDs []int64) ([]*Subject, error) {
    // ...
    subjects := make([]*Subject, 0, limit)
    sess := db.GetEngine(ctx).
        Where("LOWER(name) LIKE ? AND LOWER(name) != ?", "%"+keyword+"%", keyword)
    // ...
    err := sess.OrderBy("updated_unix DESC").
        Limit(limit).
        Find(&subjects)

The Limit(limit) is applied before scoring, so you might miss better matches. Consider fetching more results for scoring:

err := sess.OrderBy("updated_unix DESC").
    Limit(limit * 2).  // Fetch more for better scoring
    Find(&subjects)
// ... then trim to limit after sorting by score

---

8. Race Condition Note in Tests

The concurrent test TestFirstArticleBecomesRoot_ConcurrentEmptyCreation is testing concurrent creation of empty repos. The comment says:

// All 3 should succeed and none should be forks (because all are empty)
assert.Equal(t, 3, successCount, "Expected all 3 repositories to be created successfully")

This is correct behavior but consider adding a test for concurrent creation where one becomes non-empty during the race to ensure the transaction isolation works correctly.

---

Template Duplication Note

Both custom/templates/shared/subject/list.tmpl and templates/shared/subject/list.tmpl contain the same changes. If custom/templates is meant to override templates, you may only need changes in one location. Verify this is intentional.

---

Summary

Severity	Issue	Location
🔴 Critical	Duplicate route registration	routers/web/web.go
🔴 Critical	Context cancellation in goroutine	services/repository/push.go
🟡 Medium	Go 1.24+ requirement (FieldsSeq)	models/repo/subject.go
🟡 Medium	Empty repo name not validated	routers/web/repo/editor.go
🟢 Low	Template duplication	shared/subject/list.tmpl

[pieer]

Note on opus review:

• Since requirement is Go 1.25; I dismissed Go Version Compatibility Issue
• We want to show no result even if the button "create subject is showed"