From b06b02a0926c34112d96849ec297ecfbd6cd6510 Mon Sep 17 00:00:00 2001
From: Denis Tereshkin <denis@kasan.ws>
Date: Wed, 5 Jan 2022 12:09:20 +0700
Subject: [PATCH] junction: RemoteControl: fix incoming message polling

---
 src/ATrade/Driver/Junction/RemoteControl.hs | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/ATrade/Driver/Junction/RemoteControl.hs b/src/ATrade/Driver/Junction/RemoteControl.hs
index f00ecf9..b7e93bb 100644
--- a/src/ATrade/Driver/Junction/RemoteControl.hs
+++ b/src/ATrade/Driver/Junction/RemoteControl.hs
@@ -98,13 +98,15 @@ handleRemoteControl timeout = do
   sock <- asks peRemoteControlSocket
   logger <- asks peLogAction
   evs <- poll (fromIntegral timeout) [Sock sock [In] Nothing]
-  unless (null evs) $ do
-    rawRequest <- liftIO $ receive sock
-    case parseRemoteControlRequest rawRequest of
-      Left err      -> logErrorWith logger "RemoteControl" ("Unable to parse request: " <> (T.pack . show) err)
-      Right request -> do
-        response <- handleRequest request
-        liftIO $ send sock [] (makeRemoteControlResponse response)
+  case evs of
+    (x:_) -> unless (null x) $ do
+      rawRequest <- liftIO $ receive sock
+      case parseRemoteControlRequest rawRequest of
+        Left err      -> logErrorWith logger "RemoteControl" ("Unable to parse request: " <> (T.pack . show) err)
+        Right request -> do
+          response <- handleRequest request
+          liftIO $ send sock [] (makeRemoteControlResponse response)
+    _ -> return ()
   where
     handleRequest (StartRobot inst)          = do
       startRobot inst