From 674b94938812e93958e991367c261337fe64f2f6 Mon Sep 17 00:00:00 2001
From: Gregor Kleen <gregor.kleen@ifi.lmu.de>
Date: Tue, 7 Jan 2020 16:22:52 +0100
Subject: [PATCH] fix: divide by zero

---
 messages/uniworx/de-de-formal.msg | 1 +
 messages/uniworx/en-eu.msg        | 1 +
 src/Handler/Utils/Table/Cells.hs  | 4 +++-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/messages/uniworx/de-de-formal.msg b/messages/uniworx/de-de-formal.msg
index dde4219b2..92b612528 100644
--- a/messages/uniworx/de-de-formal.msg
+++ b/messages/uniworx/de-de-formal.msg
@@ -1669,6 +1669,7 @@ CsvImportAborted: CSV-Import abgebrochen
 CsvImportExplanationLabel: Hinweise zum CSV-Import
 
 Proportion c@Text of@Text prop@Rational: #{c}/#{of} (#{rationalToFixed2 (100 * prop)}%)
+ProportionNoRatio c@Text of@Text: #{c}/#{of}
 
 CourseUserCsvName tid@TermId ssh@SchoolId csh@CourseShorthand: #{foldCase (termToText (unTermKey tid))}-#{foldedCase (unSchoolKey ssh)}-#{foldedCase csh}-teilnehmer
 ExamUserCsvName tid@TermId ssh@SchoolId csh@CourseShorthand examn@ExamName: #{foldCase (termToText (unTermKey tid))}-#{foldedCase (unSchoolKey ssh)}-#{foldedCase csh}-#{foldedCase examn}-teilnehmer
diff --git a/messages/uniworx/en-eu.msg b/messages/uniworx/en-eu.msg
index 3810b4bbe..824c95333 100644
--- a/messages/uniworx/en-eu.msg
+++ b/messages/uniworx/en-eu.msg
@@ -1667,6 +1667,7 @@ CsvImportAborted: CSV import aborted
 CsvImportExplanationLabel: Informating regarding CSV import
 
 Proportion c of prop: #{c}/#{of} (#{rationalToFixed2 (100 * prop)}%)
+ProportionNoRatio c of: #{c}/#{of}
 
 CourseUserCsvName tid ssh csh: #{foldCase (termToText (unTermKey tid))}-#{foldedCase (unSchoolKey ssh)}-#{foldedCase csh}-participants
 ExamUserCsvName tid ssh csh examn: #{foldCase (termToText (unTermKey tid))}-#{foldedCase (unSchoolKey ssh)}-#{foldedCase csh}-#{foldedCase examn}-participants
diff --git a/src/Handler/Utils/Table/Cells.hs b/src/Handler/Utils/Table/Cells.hs
index 295f6ceb6..5a53a8070 100644
--- a/src/Handler/Utils/Table/Cells.hs
+++ b/src/Handler/Utils/Table/Cells.hs
@@ -197,7 +197,9 @@ numCell :: (IsDBTable m a, ToMessage b) => b -> DBCell m a
 numCell = textCell . toMessage
 
 propCell :: (IsDBTable m a, Real b, ToMessage b) => b -> b -> DBCell m a
-propCell curr max' = i18nCell $ MsgProportion (toMessage curr) (toMessage max') (toRational curr / toRational max')
+propCell curr max'
+  | max' /= 0 = i18nCell $ MsgProportion (toMessage curr) (toMessage max') (toRational curr / toRational max')
+  | otherwise = i18nCell $ MsgProportionNoRatio (toMessage curr) (toMessage max')
 
 int64Cell :: IsDBTable m a => Int64-> DBCell m a
 int64Cell = numCell