From fc35fd26c1eb699d6eb8aa1b9febb48641c26d05 Mon Sep 17 00:00:00 2001
From: Wolfgang Witt <Wolfgang.Witt@campus.lmu.de>
Date: Fri, 19 Feb 2021 12:13:12 +0100
Subject: [PATCH] fix: mappingDescription doesn't overlap for the first n
 rooms/with small names/matrikelnummer

---
 src/Handler/Utils/Exam.hs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Handler/Utils/Exam.hs b/src/Handler/Utils/Exam.hs
index aeb86d024..b3632453a 100644
--- a/src/Handler/Utils/Exam.hs
+++ b/src/Handler/Utils/Exam.hs
@@ -593,8 +593,8 @@ examAutoOccurrence (hash -> seed) rule ExamAutoOccurrenceConfig{..} occurrences
                     nextStart
                       | Nothing <- maybeEnd
                       = start
-                      | length start < borderLength
-                      = start <> impureNonNull [head alphabet]
+                      | (Just end) <- maybeEnd, length end < borderLength
+                      = impureNonNull $ end <> [head alphabet]
                       | (Just end) <- maybeEnd
                       = impureNonNull $ reverse $ increase $ reverse end
                     alphabetCycle :: [CI Char]
@@ -611,8 +611,8 @@ examAutoOccurrence (hash -> seed) rule ExamAutoOccurrenceConfig{..} occurrences
                         nextChar
                           | c `elem` alphabet
                           = dropWhile (/= c) alphabetCycle List.!! 1
-                          | otherwise -- shouldn't happen, simply use head alphabet
-                          = error $ "uncaught non-alphabet char: " ++ show c --TODO head alphabet
+                          | otherwise -- shouldn't happen, simply use head alphabet as a fallback
+                          = head alphabet
         
         transformTag :: Int -> [CI Char] -> [CI Char]
         transformTag l tag = case rule of