Don't fail on empty bodies when sending out read receipts

changelog.d/10531.bugfix

@@ -0,0 +1 @@
+Fix a bug introduced in Synapse v1.40.0rc1 that would cause Synapse to respond with an error when clients would update their read receipts.

synapse/rest/client/v2_alpha/receipts.py

@@ -43,7 +43,7 @@ async def on_POST(self, request, room_id, receipt_type, event_id):
  if receipt_type != "m.read":
  raise SynapseError(400, "Receipt type must be 'm.read'")
 
- body = parse_json_object_from_request(request)
+ body = parse_json_object_from_request(request, allow_empty_body=True)
  hidden = body.get(ReadReceiptEventFields.MSC2285_HIDDEN, False)
 
  if not isinstance(hidden, bool):

tests/rest/client/v2_alpha/test_sync.py

@@ -418,6 +418,18 @@ def test_hidden_read_receipts(self):
  # Test that the first user can't see the other user's hidden read receipt
  self.assertEqual(self._get_read_receipt(), None)
 
+ def test_read_receipt_with_empty_body(self):
+ # Send a message as the first user
+ res = self.helper.send(self.room_id, body="hello", tok=self.tok)
+
+ # Send a read receipt for this message with an empty body
+ channel = self.make_request(
+ "POST",
+ "/rooms/%s/receipt/m.read/%s" % (self.room_id, res["event_id"]),
+ access_token=self.tok2,
+ )
+ self.assertEqual(channel.code, 200)
+
  def _get_read_receipt(self):
  """Syncs and returns the read receipt."""