From 30614511a5eae39c99f998e1b9c491a36f95abf3 Mon Sep 17 00:00:00 2001
From: SJost <jost@tcs.ifi.lmu.de>
Date: Fri, 25 Jan 2019 10:40:18 +0100
Subject: [PATCH] Fixes #277

---
 src/Foundation.hs | 33 ++++++++++++++++++---------------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/src/Foundation.hs b/src/Foundation.hs
index f60ca5e3b..08aedb126 100644
--- a/src/Foundation.hs
+++ b/src/Foundation.hs
@@ -1326,15 +1326,18 @@ pageActions (CourseR tid ssh csh SheetListR) =
                                                  ])
       , menuItemModal = False
       , menuItemAccessCallback' = do
-          uid <- requireAuthId
-          [E.Value ok] <- runDB . E.select . return . E.exists . E.from $ \(course `E.InnerJoin` sheet `E.InnerJoin` submission) -> do
-            E.on $ submission E.^. SubmissionSheet E.==. sheet  E.^. SheetId
-            E.on $ sheet      E.^. SheetCourse     E.==. course E.^. CourseId
-            E.where_ $ submission E.^. SubmissionRatingBy E.==. E.just (E.val uid)
-              E.&&. course E.^. CourseTerm      E.==. E.val tid
-              E.&&. course E.^. CourseSchool    E.==. E.val ssh
-              E.&&. course E.^. CourseShorthand E.==. E.val csh
-          return ok
+          muid <- maybeAuthId
+          case muid of
+            Nothing -> return False
+            (Just uid) -> do
+              [E.Value ok] <- runDB . E.select . return . E.exists . E.from $ \(course `E.InnerJoin` sheet `E.InnerJoin` submission) -> do
+                E.on $ submission E.^. SubmissionSheet E.==. sheet  E.^. SheetId
+                E.on $ sheet      E.^. SheetCourse     E.==. course E.^. CourseId
+                E.where_ $ submission E.^. SubmissionRatingBy E.==. E.just (E.val uid)
+                  E.&&. course E.^. CourseTerm      E.==. E.val tid
+                  E.&&. course E.^. CourseSchool    E.==. E.val ssh
+                  E.&&. course E.^. CourseShorthand E.==. E.val csh
+              return ok
       }
   , MenuItem
       { menuItemType = PageActionPrime
@@ -1494,9 +1497,9 @@ pageActions (CorrectionsR) =
       , menuItemIcon = Nothing
       , menuItemRoute = SomeRoute CorrectionsCreateR
       , menuItemModal = False
-      , menuItemAccessCallback' = runDB $ do
-          uid <- liftHandlerT requireAuthId
-          [E.Value sheetCount] <- E.select . E.from $ \(course `E.InnerJoin` sheet) -> do
+      , menuItemAccessCallback' = runDB . maybeT (return False) $ do
+          uid <- MaybeT $ liftHandlerT maybeAuthId
+          [E.Value sheetCount] <- lift . E.select . E.from $ \(course `E.InnerJoin` sheet) -> do
             E.on $ course E.^. CourseId E.==. sheet E.^. SheetCourse
             let
               isCorrector' = E.exists . E.from $ \sheetCorrector -> E.where_
@@ -1534,9 +1537,9 @@ pageActions (CorrectionsGradeR) =
       , menuItemIcon = Nothing
       , menuItemRoute = SomeRoute CorrectionsCreateR
       , menuItemModal = False
-      , menuItemAccessCallback' = runDB $ do
-          uid <- liftHandlerT requireAuthId
-          [E.Value sheetCount] <- E.select . E.from $ \(course `E.InnerJoin` sheet) -> do
+      , menuItemAccessCallback' = runDB . maybeT (return False) $ do
+          uid <- MaybeT $ liftHandlerT maybeAuthId
+          [E.Value sheetCount] <- lift . E.select . E.from $ \(course `E.InnerJoin` sheet) -> do
             E.on $ course E.^. CourseId E.==. sheet E.^. SheetCourse
             let
               isCorrector' = E.exists . E.from $ \sheetCorrector -> E.where_