Merge branch 'develop' into jaywink/admin-forward-extremities

# Conflicts:
#	synapse/rest/admin/__init__.py

synapse/storage/databases/main/pusher.py

@@ -344,7 +344,9 @@ class PusherStore(PusherWorkerStore):
                 txn, self.get_if_user_has_pusher, (user_id,)
             )
 
-            self.db_pool.simple_delete_one_txn(
+            # It is expected that there is exactly one pusher to delete, but
+            # if it isn't there (or there are multiple) delete them all.
+            self.db_pool.simple_delete_txn(
                 txn,
                 "pushers",
                 {"app_id": app_id, "pushkey": pushkey, "user_name": user_id},

synapse/storage/databases/main/registration.py

@@ -360,6 +360,35 @@ class RegistrationWorkerStore(CacheInvalidationWorkerStore):
 
         await self.db_pool.runInteraction("set_server_admin", set_server_admin_txn)
 
+    async def set_shadow_banned(self, user: UserID, shadow_banned: bool) -> None:
+        """Sets whether a user shadow-banned.
+
+        Args:
+            user: user ID of the user to test
+            shadow_banned: true iff the user is to be shadow-banned, false otherwise.
+        """
+
+        def set_shadow_banned_txn(txn):
+            self.db_pool.simple_update_one_txn(
+                txn,
+                table="users",
+                keyvalues={"name": user.to_string()},
+                updatevalues={"shadow_banned": shadow_banned},
+            )
+            # In order for this to apply immediately, clear the cache for this user.
+            tokens = self.db_pool.simple_select_onecol_txn(
+                txn,
+                table="access_tokens",
+                keyvalues={"user_id": user.to_string()},
+                retcol="token",
+            )
+            for token in tokens:
+                self._invalidate_cache_and_stream(
+                    txn, self.get_user_by_access_token, (token,)
+                )
+
+        await self.db_pool.runInteraction("set_shadow_banned", set_shadow_banned_txn)
+
     def _query_for_auth(self, txn, token: str) -> Optional[TokenLookupResult]:
         sql = """
             SELECT users.name as user_id,