fix broken avatar checks when server_name contains a port

changelog.d/13927.bugfix

@@ -0,0 +1 @@
+Fix a bug which prevented setting an avatar on homeservers which have an explicit port in their `server_name` and had avatar's size or image type restrictions configured. Contributed by @ashfame.

synapse/handlers/profile.py

@@ -307,7 +307,11 @@ async def check_avatar_size_and_mime_type(self, mxc: str) -> bool:
         if not self.max_avatar_size and not self.allowed_avatar_mimetypes:
             return True
 
-        server_name, _, media_id = parse_and_validate_mxc_uri(mxc)
+        host, port, media_id = parse_and_validate_mxc_uri(mxc)
+        if port is not None:
+            server_name = host + ":" + str(port)
+        else:
+            server_name = host
 
         if server_name == self.server_name:
             media_info = await self.store.get_local_media(media_id)

tests/handlers/test_profile.py

@@ -327,6 +327,47 @@ def test_avatar_constraint_mime_type(self) -> None:
         )
         self.assertFalse(res)
 
+    @unittest.override_config({"allowed_avatar_mimetypes": ["image/png"]})
+    def test_avatar_fetching_metadata_right_source(self) -> None:
+        """Tests that local and remote file are rightly fetched for metadata
+        when checking for avatar size and mime type"""
+        remote_server = "test:8080"
+        store = self.hs.get_datastores().main
+
+        self.get_success(
+            store.store_local_media(
+                media_id="local",
+                media_type="image/png",
+                media_length=50,
+                time_now_ms=self.clock.time_msec(),
+                upload_name=None,
+                user_id=UserID.from_string("@whatever:test"),
+            )
+        )
+        self.get_success(
+            store.store_cached_remote_media(
+                media_id="remote",
+                media_type="image/png",
+                media_length=50,
+                origin=remote_server,
+                time_now_ms=self.clock.time_msec(),
+                upload_name=None,
+                filesystem_id="remote",
+            )
+        )
+
+        res = self.get_success(
+            self.handler.check_avatar_size_and_mime_type("mxc://test/local")
+        )
+        self.assertTrue(res)
+
+        res = self.get_success(
+            self.handler.check_avatar_size_and_mime_type(
+                "mxc://" + remote_server + "/remote"
+            )
+        )
+        self.assertTrue(res)
+
     def _setup_local_files(self, names_and_props: Dict[str, Dict[str, Any]]):
         """Stores metadata about files in the database.