Merge branch 'release-v1.13.0' of github.com:matrix-org/synapse into dinsic-release-v1.14.x

* 'release-v1.13.0' of github.com:matrix-org/synapse: (257 commits)
  Update changelog based on feedback.
  Move warnings in the changelog and re-iterate changes to branches.
  1.13.0
  update dh-virtualenv (#7526)
  1.13.0rc3
  Hash passwords earlier in the registration process (#7523)
  1.13.0rc2
  1.13.0rc2
  Stop `get_joined_users` corruption from custom statuses (#7376)
  Do not validate that the client dict is stable during UI Auth. (#7483)
  Fix new flake8 errors (#7489)
  Don't UPGRADE database rows
  RST indenting
  Put rollback instructions in upgrade notes
  Fix changelog typo
  Oh yeah, RST
  Absolute URL it is then
  Fix upgrade notes link
  Provide summary of upgrade issues in changelog. Fix )
  Move next version notes from changelog to upgrade notes
  ...

1 files changed, 5 insertions, 2 deletions

diff --git a/synapse/push/mailer.py b/synapse/push/mailer.py

index 73580c1c6c..ab33abbeed 100644
--- a/synapse/push/mailer.py
+++ b/synapse/push/mailer.py
@@ -19,6 +19,7 @@ import logging
 import time
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
+from typing import Iterable, List, TypeVar
 
 from six.moves import urllib
 
@@ -41,6 +42,8 @@ from synapse.visibility import filter_events_for_client
 
 logger = logging.getLogger(__name__)
 
+T = TypeVar("T")
+
 
 MESSAGE_FROM_PERSON_IN_ROOM = (
     "You have a message on %(app)s from %(person)s in the %(room)s room..."
@@ -638,10 +641,10 @@ def safe_text(raw_text):
     )
 
 
-def deduped_ordered_list(l):
+def deduped_ordered_list(it: Iterable[T]) -> List[T]:
     seen = set()
     ret = []
-    for item in l:
+    for item in it:
         if item not in seen:
             seen.add(item)
             ret.append(item)