[GITEA] convert feed items' titles to plain text

Refs: https://codeberg.org/forgejo/forgejo/pulls/1595

(cherry picked from commit 35b962e6313df748e8855b4dfbf748f095ea1003)
(cherry picked from commit 1004e35b84a4a0deae999cb8a4c2924b85b47c8b)
(cherry picked from commit af51dd594db229f7a986325a6070d33782d85d28)
(cherry picked from commit 7fb66b455647f2df592ace354cc65cb6eca6ec2a)
(cherry picked from commit 0c409950f14e0eee576e7206a838126cf810a494)
(cherry picked from commit edf1cb72b4494549c96ad1bed4e9de0143b1b27c)
(cherry picked from commit d1e5d9d664)

routers/web/feed/convert.go

@@ -21,6 +21,7 @@ import (
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/gorilla/feeds"
+	"github.com/jaytaylor/html2text"
 )
 
 func toBranchLink(ctx *context.Context, act *activities_model.Action) string {
@@ -239,8 +240,15 @@ func feedActionsToFeedItems(ctx *context.Context, actions activities_model.Actio
 			content = desc
 		}
 
+		// It's a common practice for feed generators to use plain text titles.
+		// See https://codeberg.org/forgejo/forgejo/pulls/1595
+		plainTitle, err := html2text.FromString(title, html2text.Options{OmitLinks: true})
+		if err != nil {
+			return nil, err
+		}
+
 		items = append(items, &feeds.Item{
-			Title:       title,
+			Title:       plainTitle,
 			Link:        link,
 			Description: desc,
 			Author: &feeds.Author{

tests/integration/api_feed_plain_text_titles_test.go

@@ -0,0 +1,40 @@
+// Copyright 2023 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"net/http"
+	"testing"
+
+	"code.gitea.io/gitea/tests"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFeedPlainTextTitles(t *testing.T) {
+	// This test verifies that items' titles in feeds are generated as plain text.
+	// See https://codeberg.org/forgejo/forgejo/pulls/1595
+
+	t.Run("Feed plain text titles", func(t *testing.T) {
+		t.Run("Atom", func(t *testing.T) {
+			defer tests.PrepareTestEnv(t)()
+
+			req := NewRequest(t, "GET", "/user2/repo1.atom")
+			resp := MakeRequest(t, req, http.StatusOK)
+
+			data := resp.Body.String()
+			assert.Contains(t, data, "<title>the_1-user.with.all.allowedChars closed issue user2/repo1#4</title>")
+		})
+
+		t.Run("RSS", func(t *testing.T) {
+			defer tests.PrepareTestEnv(t)()
+
+			req := NewRequest(t, "GET", "/user2/repo1.rss")
+			resp := MakeRequest(t, req, http.StatusOK)
+
+			data := resp.Body.String()
+			assert.Contains(t, data, "<title>the_1-user.with.all.allowedChars closed issue user2/repo1#4</title>")
+		})
+	})
+}