Handle deleted remote users when adding to a conversation

Also add corresponding test

services/galley/src/Galley/API/Update.hs

@@ -527,7 +527,8 @@ addMembers zusr zcon convId invite = do
       users <-
         runExceptT (executeFederated domain rpc)
           >>= either (throwM . federationErrorToWai) pure
-      let uids' = map (qUnqualified . User.profileQualifiedId) users
+      let uids' = map (qUnqualified . User.profileQualifiedId)
+            (filter (not . User.profileDeleted) users)
       unless (Set.fromList uids == Set.fromList uids') $
         throwM unknownRemoteUser
 

services/galley/test/integration/API.hs

@@ -113,6 +113,7 @@ tests s =
           test s "fail to add too many members" postTooManyMembersFail,
           test s "add remote members" testAddRemoteMember,
           test s "add non-existing remote members" testAddRemoteMemberFailure,
+          test s "add deleted remote members" testAddDeletedRemoteUser,
           test s "add remote members on invalid domain" testAddRemoteMemberInvalidDomain,
           test s "remove members" deleteMembersOk,
           test s "fail to remove members from self conv." deleteMembersFailSelf,
@@ -922,6 +923,26 @@ testAddRemoteMemberFailure = do
     let err = responseJsonUnsafe resp :: Object
     (err ^. at "label") @?= Just "unknown-remote-user"
 
+testAddDeletedRemoteUser :: TestM ()
+testAddDeletedRemoteUser = do
+  alice <- randomUser
+  bobId <- randomId
+  let remoteDomain = Domain "far-away.example.com"
+      remoteBob = Qualified bobId remoteDomain
+  convId <- decodeConvId <$> postConv alice [] (Just "remote gossip") [] Nothing Nothing
+  opts <- view tsGConf
+  g <- view tsGalley
+  liftIO $ do
+    (resp, _) <-
+      withTempMockFederator
+        opts
+        remoteDomain
+        [(mkProfile remoteBob (Name "bob")) { profileDeleted = True } ]
+        (postQualifiedMembers' g alice (remoteBob :| []) convId)
+    statusCode resp @?= 400
+    let err = responseJsonUnsafe resp :: Object
+    (err ^. at "label") @?= Just "unknown-remote-user"
+
 testAddRemoteMemberInvalidDomain :: TestM ()
 testAddRemoteMemberInvalidDomain = do
   alice <- randomUser