agent: send MSGNTF on NO_MSG error (#1362)

* agent: send MSGNTF on NO_MSG error

* simplify

Author: epoberezkin

src/Simplex/Messaging/Agent.hs

@@ -1684,15 +1684,18 @@ ackQueueMessage :: AgentClient -> RcvQueue -> SMP.MsgId -> AM ()
 ackQueueMessage c rq@RcvQueue {userId, connId, server} srvMsgId = do
   atomically $ incSMPServerStat c userId server ackAttempts
   tryAgentError (sendAck c rq srvMsgId) >>= \case
-    Right _ -> do
-      atomically $ incSMPServerStat c userId server ackMsgs
-      whenM (liftIO $ hasGetLock c rq) $ do
-        brokerTs_ <- (Just <$> withStore c (\db -> getRcvMsgBrokerTs db connId srvMsgId)) `catchAgentError` \_ -> pure Nothing
-        atomically $ writeTBQueue (subQ c) ("", connId, AEvt SAEConn $ MSGNTF srvMsgId brokerTs_)
-    Left (SMP _ SMP.NO_MSG) -> atomically $ incSMPServerStat c userId server ackNoMsgErrs
+    Right _ -> sendMsgNtf ackMsgs
+    Left (SMP _ SMP.NO_MSG) -> sendMsgNtf ackNoMsgErrs
     Left e -> do
       unless (temporaryOrHostError e) $ atomically $ incSMPServerStat c userId server ackOtherErrs
       throwE e
+  where
+    sendMsgNtf stat = do
+      atomically $ incSMPServerStat c userId server stat
+      whenM (liftIO $ hasGetLock c rq) $ do
+        atomically $ releaseGetLock c rq
+        brokerTs_ <- eitherToMaybe <$> tryAgentError (withStore c $ \db -> getRcvMsgBrokerTs db connId srvMsgId)
+        atomically $ writeTBQueue (subQ c) ("", connId, AEvt SAEConn $ MSGNTF srvMsgId brokerTs_)
 
 -- | Suspend SMP agent connection (OFF command) in Reader monad
 suspendConnection' :: AgentClient -> ConnId -> AM ()

src/Simplex/Messaging/Agent/Client.hs

@@ -92,6 +92,7 @@ module Simplex.Messaging.Agent.Client
     hasActiveSubscription,
     hasPendingSubscription,
     hasGetLock,
+    releaseGetLock,
     activeClientSession,
     agentClientStore,
     agentDRG,
@@ -1647,8 +1648,8 @@ disableQueuesNtfs = sendTSessionBatches "NDEL" snd disableQueues_
 
 sendAck :: AgentClient -> RcvQueue -> MsgId -> AM ()
 sendAck c rq@RcvQueue {rcvId, rcvPrivateKey} msgId =
-  withSMPClient c rq ("ACK:" <> logSecret' msgId) (\smp -> ackSMPMessage smp rcvPrivateKey rcvId msgId)
-    `agentFinally` atomically (releaseGetLock c rq)
+  withSMPClient c rq ("ACK:" <> logSecret' msgId) $ \smp ->
+    ackSMPMessage smp rcvPrivateKey rcvId msgId      
 
 hasGetLock :: AgentClient -> RcvQueue -> IO Bool
 hasGetLock c RcvQueue {server, rcvId} =