Unescape HTML entities in oEmbed title

changelog.d/14781.misc

@@ -0,0 +1 @@
+Unescape HTML entities in Open Graph title.

synapse/rest/media/v1/oembed.py

@@ -11,6 +11,7 @@
 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
+import html as html5
 import logging
 import urllib.parse
 from typing import TYPE_CHECKING, List, Optional
@@ -161,7 +162,7 @@ def parse_oembed_response(self, url: str, raw_body: bytes) -> OEmbedResult:
 
         title = oembed.get("title")
         if title and isinstance(title, str):
-            open_graph_response["og:title"] = title
+            open_graph_response["og:title"] = html5.unescape(title)
 
         author_name = oembed.get("author_name")
         if not isinstance(author_name, str):

tests/rest/media/v1/test_oembed.py

@@ -150,3 +150,13 @@ def test_link(self) -> None:
         result = self.parse_response({"type": "link"})
         self.assertIn("og:type", result.open_graph_result)
         self.assertEqual(result.open_graph_result["og:type"], "website")
+
+    def test_title_html_entities(self) -> None:
+        """Test HTML entities in title"""
+        result = self.parse_response(
+            {"title": "Why JSON isn’t a Good Configuration Language"}
+        )
+        self.assertEqual(
+            result.open_graph_result["og:title"],
+            "Why JSON isn’t a Good Configuration Language",
+        )