Fix pretty-printing of timezones (#2379)

Gabriella439 · web-flow · commit ecef9b7daf5b · 2022-02-03T07:55:30.000-08:00
Fixes #2368
diff --git a/dhall/src/Dhall/Pretty/Internal.hs b/dhall/src/Dhall/Pretty/Internal.hs
@@ -1354,7 +1354,7 @@ prettyPrinters characterSet =
       where
         sign = if 0 <= minutes then "+" else "-"
 
-        (_HH, _MM) = minutes `divMod` 60
+        (_HH, _MM) = abs minutes `divMod` 60
     prettyPrimitiveExpression List =
         builtin "List"
     prettyPrimitiveExpression ListBuild =
diff --git a/dhall/tests/format/negativeTimeZoneA.dhall b/dhall/tests/format/negativeTimeZoneA.dhall
@@ -0,0 +1 @@
+04:00:00-04:00
diff --git a/dhall/tests/format/negativeTimeZoneB.dhall b/dhall/tests/format/negativeTimeZoneB.dhall
@@ -0,0 +1 @@
+04:00:00-04:00
