From 99d112b31c27f848472791b2867b83b2a01265a0 Mon Sep 17 00:00:00 2001
From: Gregor Kleen <gkleen@yggdrasil.li>
Date: Thu, 26 Apr 2018 18:28:26 +0200
Subject: [PATCH] Don't attempt to dequeue corrector who isn't (also)
 proportional

---
 src/Handler/Utils/Submission.hs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/Handler/Utils/Submission.hs b/src/Handler/Utils/Submission.hs
index 169fbcc05..6c14cb496 100644
--- a/src/Handler/Utils/Submission.hs
+++ b/src/Handler/Utils/Submission.hs
@@ -50,7 +50,7 @@ instance Exception AssignSubmissionException
 assignSubmissions :: SheetId -> YesodDB UniWorX ()
 assignSubmissions sid = do
     correctors <- selectList [SheetCorrectorSheet ==. sid] []
-    let (corrsGroup, corrsProp) = partition (is _ByTutorial . sheetCorrectorLoad . entityVal) correctors
+    let (corrsGroup, (filterNonPositive -> corrsProp)) = partition (is _ByTutorial . sheetCorrectorLoad . entityVal) correctors
         countsToLoad' :: UserId -> Bool
         countsToLoad' uid = fromMaybe (error "Called `countsToLoad'` on entity not element of `corrsGroup`") $ listToMaybe [sheetCorrectorLoad | Entity _ SheetCorrector{..} <- corrsGroup, sheetCorrectorUser == uid] >>= preview _ByTutorial
     subs <- E.select . E.from $ \(submission `E.LeftOuterJoin` user) -> do
@@ -74,7 +74,7 @@ assignSubmissions sid = do
     subTutor <- fmap fst . flip execStateT (Map.empty, queue) . forM_ (Map.toList subTutor') $ \case
       (smid, Just tutid) -> do
         _1 %= Map.insert smid tutid
-        when (countsToLoad' tutid) $
+        when (any ((== tutid) . sheetCorrectorUser . entityVal) corrsProp && countsToLoad' tutid) $
           _2 %= delFirst (Just tutid)
       (smid, Nothing) -> do
         (q:qs) <- use _2
@@ -87,6 +87,8 @@ assignSubmissions sid = do
         
     return ()
     where
+      filterNonPositive = filter $ (> 0) . load . sheetCorrectorLoad . entityVal
+
       delFirst _ [] = []
       delFirst x (y:ys)
         | x == y = ys