From c05251525b4849660f0a1ee50a23b941eb4cd99f Mon Sep 17 00:00:00 2001
From: Mats Rauhala <mats.rauhala@iki.fi>
Date: Wed, 15 Aug 2018 21:52:04 +0300
Subject: [PATCH] Complete functions for channels

---
 src/Database/Channel.hs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Database/Channel.hs b/src/Database/Channel.hs
index 9011863..b1dbfe9 100644
--- a/src/Database/Channel.hs
+++ b/src/Database/Channel.hs
@@ -51,10 +51,10 @@ booksChannels bookId = fromRels <$> query q
 
 attachChannel :: (MonadMask m, MonadIO m, MonadSelda m) => Username -> BookID -> Text -> m ()
 attachChannel username bookId channel = do
-  -- XXX: test what happens if channel doesn't exist
-  [Channel{identifier}] <- fromRels <$> query channelQ
-  whenM (null <$> query (attachQ identifier)) $
-    void $ insertGen bookChannels [BookChannel identifier bookId]
+  mCh <- fromRels <$> query channelQ
+  forM_ mCh $ \Channel{identifier} ->
+    whenM (null <$> query (attachQ identifier)) $
+      void $ insertGen bookChannels [BookChannel identifier bookId]
   where
     attachQ channelId = do
       (channelId' :*: bookId') <- select (gen bookChannels)