fix(markup): link team mentions that use a different org name case (#39436) (#39588)

Backport #39436 by @breken-ai

The `org` render meta is lower-cased (`Repository.composeCommonMetas`
sets `metas["org"] = strings.ToLower(repo.OwnerName)`), but
`mentionProcessor` compares it with the org part of the mention exactly
as typed, while the team part is lower-cased before its lookup. So in a
repository of the org `MyOrg`, `@MyOrg/developers` stays plain text,
although `ResolveIssueMentionsByVisibility` lower-cases the name and
still notifies that team.

This compares the org part case-insensitively and adds a render test for
team mentions.

The code is the same on `release/v1.27`, so it could be backported.

### Verification
- `go test ./modules/markup/ -run TestRender_TeamMention -count=1`: the
`@Org1/Developers` case renders as plain text on current main and as the
team link with this change; `go test ./modules/markup/...` passes.
- `golangci-lint run ./modules/markup/` (v2.13.2): 0 issues.

### AI assistance
This contribution was prepared with AI assistance. The behavior, the
metas and mention-resolution code paths, the patch and the test were
reviewed manually.

> Built by breken, your AI support engineer - breken.ai - this one's on
us.

Co-authored-by: breken <support@brekfuz.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/markup/html_mention.go

@@ -5,6 +5,7 @@ package markup
 
 import (
 	"fmt"
+	"net/url"
 	"strings"
 
 	"gitea.dev/modules/references"
@@ -26,12 +27,13 @@ func mentionProcessor(ctx *RenderContext, node *html.Node) {
 		loc.Start += start
 		loc.End += start
 		mention := node.Data[loc.Start:loc.End]
-		teams, ok := ctx.RenderOptions.Metas["teams"]
+		orgLowerTeams, checkOrgTeams := ctx.RenderOptions.Metas["teams"] // in format ",team1,team2,...,team-n,", always lowercase
 
-		if ok && strings.Contains(mention, "/") {
-			mentionOrgAndTeam := strings.Split(mention, "/")
-			if mentionOrgAndTeam[0][1:] == ctx.RenderOptions.Metas["org"] && strings.Contains(teams, ","+strings.ToLower(mentionOrgAndTeam[1])+",") {
-				link := fmt.Sprintf("/:root/org/%s/teams/%s", ctx.RenderOptions.Metas["org"], mentionOrgAndTeam[1])
+		if checkOrgTeams && strings.Contains(mention, "/") {
+			mentionOrg, teamName, _ := strings.Cut(mention, "/")
+			orgName := mentionOrg[1:] // remove the '@' prefix
+			if strings.EqualFold(orgName, ctx.RenderOptions.Metas["org"]) && strings.Contains(orgLowerTeams, ","+strings.ToLower(teamName)+",") {
+				link := fmt.Sprintf("/:root/org/%s/teams/%s", url.PathEscape(orgName), url.PathEscape(teamName))
 				replaceContent(node, loc.Start, loc.End, createLink(ctx, link, mention, "" /*mention*/))
 				node = node.NextSibling.NextSibling
 				start = 0
@@ -43,7 +45,7 @@ func mentionProcessor(ctx *RenderContext, node *html.Node) {
 		mentionedUsername := mention[1:]
 
 		if DefaultRenderHelperFuncs != nil && DefaultRenderHelperFuncs.IsUsernameMentionable(ctx, mentionedUsername) {
-			link := "/:root/" + mentionedUsername
+			link := "/:root/" + url.PathEscape(mentionedUsername)
 			replaceContent(node, loc.Start, loc.End, createLink(ctx, link, mention, "" /*mention*/))
 			node = node.NextSibling.NextSibling
 			start = 0

modules/markup/html_test.go

@@ -605,3 +605,18 @@ func TestIssue18471(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, `<a href="`+markup.TestAppURL+`org/repo/compare/783b039...da951ce" class="compare"><code>783b039...da951ce</code></a>`, res.String())
 }
+
+func TestRender_TeamMention(t *testing.T) {
+	// the "org" meta is lower-cased, see Repository.composeCommonMetas
+	metas := map[string]string{"user": "Org1", "repo": "repo1", "org": "org1", "teams": ",developers,"}
+	test := func(input, expected string) {
+		rctx := markup.NewTestRenderContext(markup.TestAppURL, metas).WithRelativePath("a.md")
+		buffer, err := testRenderString(rctx, input)
+		assert.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(buffer))
+	}
+	test("@org1/developers", `<p><a href="/org/org1/teams/developers" rel="nofollow">@org1/developers</a></p>`)
+	test("@Org1/Developers", `<p><a href="/org/Org1/teams/Developers" rel="nofollow">@Org1/Developers</a></p>`)
+	test("@org2/developers", `<p>@org2/developers</p>`)
+	test("@org1/testers", `<p>@org1/testers</p>`)
+}

modules/references/references.go

@@ -240,7 +240,7 @@ func FindAllMentionsBytes(content []byte) []RefSpan {
 }
 
 // FindFirstMentionBytes matches the first mention in then given content
-// and returns the location of the unvalidated user name, including the @ prefix.
+// and returns the location of the unvalidated username, including the @ prefix.
 func FindFirstMentionBytes(content []byte) (bool, RefSpan) {
 	mention := mentionPattern.FindSubmatchIndex(content)
 	if mention == nil {