Fix footnote jump behavior on the issue page. (#34621)

Close #34511 
Close #34590 

Add comment ID to the footnote item's id attribute to ensure uniqueness.

---------

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

models/issues/comment_code.go

@@ -5,6 +5,7 @@ package issues
 
 import (
 	"context"
+	"strconv"
 
 	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/renderhelper"
@@ -114,7 +115,9 @@ func findCodeComments(ctx context.Context, opts FindCommentsOptions, issue *Issu
 		}
 
 		var err error
-		rctx := renderhelper.NewRenderContextRepoComment(ctx, issue.Repo)
+		rctx := renderhelper.NewRenderContextRepoComment(ctx, issue.Repo, renderhelper.RepoCommentOptions{
+			FootnoteContextID: strconv.FormatInt(comment.ID, 10),
+		})
 		if comment.RenderedContent, err = markdown.RenderString(rctx, comment.Content); err != nil {
 			return nil, err
 		}

models/renderhelper/repo_comment.go

@@ -44,6 +44,7 @@ type RepoCommentOptions struct {
 	DeprecatedRepoName  string // it is only a patch for the non-standard "markup" api
 	DeprecatedOwnerName string // it is only a patch for the non-standard "markup" api
 	CurrentRefPath      string // eg: "branch/main" or "commit/11223344"
+	FootnoteContextID   string // the extra context ID for footnotes, used to avoid conflicts with other footnotes in the same page
 }
 
 func NewRenderContextRepoComment(ctx context.Context, repo *repo_model.Repository, opts ...RepoCommentOptions) *markup.RenderContext {
@@ -53,10 +54,11 @@ func NewRenderContextRepoComment(ctx context.Context, repo *repo_model.Repositor
 	}
 	rctx := markup.NewRenderContext(ctx)
 	helper.ctx = rctx
+	var metas map[string]string
 	if repo != nil {
 		helper.repoLink = repo.Link()
 		helper.commitChecker = newCommitChecker(ctx, repo)
-		rctx = rctx.WithMetas(repo.ComposeCommentMetas(ctx))
+		metas = repo.ComposeCommentMetas(ctx)
 	} else {
 		// this is almost dead code, only to pass the incorrect tests
 		helper.repoLink = fmt.Sprintf("%s/%s", helper.opts.DeprecatedOwnerName, helper.opts.DeprecatedRepoName)
@@ -68,6 +70,7 @@ func NewRenderContextRepoComment(ctx context.Context, repo *repo_model.Repositor
 			"markupAllowShortIssuePattern": "true",
 		})
 	}
-	rctx = rctx.WithHelper(helper)
+	metas["footnoteContextId"] = helper.opts.FootnoteContextID
+	rctx = rctx.WithMetas(metas).WithHelper(helper)
 	return rctx
 }

modules/markup/common/footnote.go

@@ -409,9 +409,9 @@ func (r *FootnoteHTMLRenderer) renderFootnoteLink(w util.BufWriter, source []byt
 		_, _ = w.Write(n.Name)
 		_, _ = w.WriteString(`"><a href="#fn:`)
 		_, _ = w.Write(n.Name)
-		_, _ = w.WriteString(`" class="footnote-ref" role="doc-noteref">`)
+		_, _ = w.WriteString(`" class="footnote-ref" role="doc-noteref">`) // FIXME: here and below, need to keep the classes
 		_, _ = w.WriteString(is)
-		_, _ = w.WriteString(`</a></sup>`)
+		_, _ = w.WriteString(` </a></sup>`) // the style doesn't work at the moment, so add a space to separate the names
 	}
 	return ast.WalkContinue, nil
 }

modules/markup/html.go

@@ -320,6 +320,7 @@ func visitNode(ctx *RenderContext, procs []processor, node *html.Node) *html.Nod
 	}
 
 	processNodeAttrID(node)
+	processFootnoteNode(ctx, node) // FIXME: the footnote processing should be done in the "footnote.go" renderer directly
 
 	if isEmojiNode(node) {
 		// TextNode emoji will be converted to `<span class="emoji">`, then the next iteration will visit the "span"

modules/markup/html_issue_test.go

@@ -30,6 +30,7 @@ func TestRender_IssueList(t *testing.T) {
 		rctx := markup.NewTestRenderContext(markup.TestAppURL, map[string]string{
 			"user": "test-user", "repo": "test-repo",
 			"markupAllowShortIssuePattern": "true",
+			"footnoteContextId":            "12345",
 		})
 		out, err := markdown.RenderString(rctx, input)
 		require.NoError(t, err)
@@ -69,4 +70,22 @@ func TestRender_IssueList(t *testing.T) {
 </ul>`,
 		)
 	})
+
+	t.Run("IssueFootnote", func(t *testing.T) {
+		test(
+			"foo[^1][^2]\n\n[^1]: bar\n[^2]: baz",
+			`<p>foo<sup id="fnref:user-content-1-12345"><a href="#fn:user-content-1-12345" rel="nofollow">1 </a></sup><sup id="fnref:user-content-2-12345"><a href="#fn:user-content-2-12345" rel="nofollow">2 </a></sup></p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-1-12345">
+<p>bar <a href="#fnref:user-content-1-12345" rel="nofollow">↩︎</a></p>
+</li>
+<li id="fn:user-content-2-12345">
+<p>baz <a href="#fnref:user-content-2-12345" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>`,
+		)
+	})
 }

modules/markup/html_node.go

@@ -15,6 +15,14 @@ func isAnchorIDUserContent(s string) bool {
 	return strings.HasPrefix(s, "user-content-") || strings.Contains(s, ":user-content-")
 }
 
+func isAnchorIDFootnote(s string) bool {
+	return strings.HasPrefix(s, "fnref:user-content-") || strings.HasPrefix(s, "fn:user-content-")
+}
+
+func isAnchorHrefFootnote(s string) bool {
+	return strings.HasPrefix(s, "#fnref:user-content-") || strings.HasPrefix(s, "#fn:user-content-")
+}
+
 func processNodeAttrID(node *html.Node) {
 	// Add user-content- to IDs and "#" links if they don't already have them,
 	// and convert the link href to a relative link to the host root
@@ -27,6 +35,18 @@ func processNodeAttrID(node *html.Node) {
 	}
 }
 
+func processFootnoteNode(ctx *RenderContext, node *html.Node) {
+	for idx, attr := range node.Attr {
+		if (attr.Key == "id" && isAnchorIDFootnote(attr.Val)) ||
+			(attr.Key == "href" && isAnchorHrefFootnote(attr.Val)) {
+			if footnoteContextID := ctx.RenderOptions.Metas["footnoteContextId"]; footnoteContextID != "" {
+				node.Attr[idx].Val = attr.Val + "-" + footnoteContextID
+			}
+			continue
+		}
+	}
+}
+
 func processNodeA(ctx *RenderContext, node *html.Node) {
 	for idx, attr := range node.Attr {
 		if attr.Key == "href" {

modules/markup/markdown/markdown_test.go

@@ -223,7 +223,7 @@ This PR has been generated by [Renovate Bot](https://github.com/renovatebot/reno
 <dd>This is another definition of the second term.</dd>
 </dl>
 <h3 id="user-content-footnotes">Footnotes</h3>
-<p>Here is a simple footnote,<sup id="fnref:user-content-1"><a href="#fn:user-content-1" rel="nofollow">1</a></sup> and here is a longer one.<sup id="fnref:user-content-bignote"><a href="#fn:user-content-bignote" rel="nofollow">2</a></sup></p>
+<p>Here is a simple footnote,<sup id="fnref:user-content-1"><a href="#fn:user-content-1" rel="nofollow">1 </a></sup> and here is a longer one.<sup id="fnref:user-content-bignote"><a href="#fn:user-content-bignote" rel="nofollow">2 </a></sup></p>
 <div>
 <hr/>
 <ol>

routers/common/markup.go

@@ -76,7 +76,11 @@ func RenderMarkup(ctx *context.Base, ctxRepo *context.Repository, mode, text, ur
 		})
 		rctx = rctx.WithMarkupType(markdown.MarkupName)
 	case "comment":
-		rctx = renderhelper.NewRenderContextRepoComment(ctx, repoModel, renderhelper.RepoCommentOptions{DeprecatedOwnerName: repoOwnerName, DeprecatedRepoName: repoName})
+		rctx = renderhelper.NewRenderContextRepoComment(ctx, repoModel, renderhelper.RepoCommentOptions{
+			DeprecatedOwnerName: repoOwnerName,
+			DeprecatedRepoName:  repoName,
+			FootnoteContextID:   "preview",
+		})
 		rctx = rctx.WithMarkupType(markdown.MarkupName)
 	case "wiki":
 		rctx = renderhelper.NewRenderContextRepoWiki(ctx, repoModel, renderhelper.RepoWikiOptions{DeprecatedOwnerName: repoOwnerName, DeprecatedRepoName: repoName})

routers/web/repo/issue.go

@@ -364,7 +364,9 @@ func UpdateIssueContent(ctx *context.Context) {
 		}
 	}
 
-	rctx := renderhelper.NewRenderContextRepoComment(ctx, ctx.Repo.Repository)
+	rctx := renderhelper.NewRenderContextRepoComment(ctx, ctx.Repo.Repository, renderhelper.RepoCommentOptions{
+		FootnoteContextID: "0",
+	})
 	content, err := markdown.RenderString(rctx, issue.Content)
 	if err != nil {
 		ctx.ServerError("RenderString", err)

routers/web/repo/issue_comment.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"html/template"
 	"net/http"
+	"strconv"
 
 	issues_model "code.gitea.io/gitea/models/issues"
 	"code.gitea.io/gitea/models/renderhelper"
@@ -278,7 +279,9 @@ func UpdateCommentContent(ctx *context.Context) {
 
 	var renderedContent template.HTML
 	if comment.Content != "" {
-		rctx := renderhelper.NewRenderContextRepoComment(ctx, ctx.Repo.Repository)
+		rctx := renderhelper.NewRenderContextRepoComment(ctx, ctx.Repo.Repository, renderhelper.RepoCommentOptions{
+			FootnoteContextID: strconv.FormatInt(comment.ID, 10),
+		})
 		renderedContent, err = markdown.RenderString(rctx, comment.Content)
 		if err != nil {
 			ctx.ServerError("RenderString", err)

routers/web/repo/issue_view.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"net/url"
 	"sort"
+	"strconv"
 
 	activities_model "code.gitea.io/gitea/models/activities"
 	"code.gitea.io/gitea/models/db"
@@ -624,7 +625,9 @@ func prepareIssueViewCommentsAndSidebarParticipants(ctx *context.Context, issue
 		comment.Issue = issue
 
 		if comment.Type == issues_model.CommentTypeComment || comment.Type == issues_model.CommentTypeReview {
-			rctx := renderhelper.NewRenderContextRepoComment(ctx, issue.Repo)
+			rctx := renderhelper.NewRenderContextRepoComment(ctx, issue.Repo, renderhelper.RepoCommentOptions{
+				FootnoteContextID: strconv.FormatInt(comment.ID, 10),
+			})
 			comment.RenderedContent, err = markdown.RenderString(rctx, comment.Content)
 			if err != nil {
 				ctx.ServerError("RenderString", err)
@@ -700,7 +703,9 @@ func prepareIssueViewCommentsAndSidebarParticipants(ctx *context.Context, issue
 				}
 			}
 		} else if comment.Type.HasContentSupport() {
-			rctx := renderhelper.NewRenderContextRepoComment(ctx, issue.Repo)
+			rctx := renderhelper.NewRenderContextRepoComment(ctx, issue.Repo, renderhelper.RepoCommentOptions{
+				FootnoteContextID: strconv.FormatInt(comment.ID, 10),
+			})
 			comment.RenderedContent, err = markdown.RenderString(rctx, comment.Content)
 			if err != nil {
 				ctx.ServerError("RenderString", err)
@@ -984,7 +989,9 @@ func preparePullViewReviewAndMerge(ctx *context.Context, issue *issues_model.Iss
 
 func prepareIssueViewContent(ctx *context.Context, issue *issues_model.Issue) {
 	var err error
-	rctx := renderhelper.NewRenderContextRepoComment(ctx, ctx.Repo.Repository)
+	rctx := renderhelper.NewRenderContextRepoComment(ctx, ctx.Repo.Repository, renderhelper.RepoCommentOptions{
+		FootnoteContextID: "0", // Set footnote context ID to 0 for the issue content
+	})
 	issue.RenderedContent, err = markdown.RenderString(rctx, issue.Content)
 	if err != nil {
 		ctx.ServerError("RenderString", err)

routers/web/repo/release.go

@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strconv"
 	"strings"
 
 	"code.gitea.io/gitea/models/db"
@@ -113,7 +114,9 @@ func getReleaseInfos(ctx *context.Context, opts *repo_model.FindReleasesOptions)
 			cacheUsers[r.PublisherID] = r.Publisher
 		}
 
-		rctx := renderhelper.NewRenderContextRepoComment(ctx, r.Repo)
+		rctx := renderhelper.NewRenderContextRepoComment(ctx, r.Repo, renderhelper.RepoCommentOptions{
+			FootnoteContextID: strconv.FormatInt(r.ID, 10),
+		})
 		r.RenderedNote, err = markdown.RenderString(rctx, r.Note)
 		if err != nil {
 			return nil, err

web_src/js/markup/anchors.ts

@@ -5,21 +5,24 @@ const removePrefix = (str: string): string => str.replace(/^user-content-/, '');
 const hasPrefix = (str: string): boolean => str.startsWith('user-content-');
 
 // scroll to anchor while respecting the `user-content` prefix that exists on the target
-function scrollToAnchor(encodedId: string): void {
-  if (!encodedId) return;
-  const id = decodeURIComponent(encodedId);
-  const prefixedId = addPrefix(id);
-  let el = document.querySelector(`#${prefixedId}`);
+function scrollToAnchor(encodedId?: string): void {
+  // FIXME: need to rewrite this function with new a better markup anchor generation logic, too many tricks here
+  let elemId: string;
+  try {
+    elemId = decodeURIComponent(encodedId ?? '');
+  } catch {} // ignore the errors, since the "encodedId" is from user's input
+  if (!elemId) return;
+
+  const prefixedId = addPrefix(elemId);
+  // eslint-disable-next-line unicorn/prefer-query-selector
+  let el = document.getElementById(prefixedId);
 
   // check for matching user-generated `a[name]`
-  if (!el) {
-    el = document.querySelector(`a[name="${CSS.escape(prefixedId)}"]`);
-  }
+  el = el ?? document.querySelector(`a[name="${CSS.escape(prefixedId)}"]`);
 
   // compat for links with old 'user-content-' prefixed hashes
-  if (!el && hasPrefix(id)) {
-    return document.querySelector(`#${id}`)?.scrollIntoView();
-  }
+  // eslint-disable-next-line unicorn/prefer-query-selector
+  el = (!el && hasPrefix(elemId)) ? document.getElementById(elemId) : el;
 
   el?.scrollIntoView();
 }