Add a test for #3822

1 files changed, 17 insertions, 0 deletions

diff --git a/testsuite/tests/ghc-regress/arrows/should_run/T3822.hs b/testsuite/tests/ghc-regress/arrows/should_run/T3822.hs
new file mode 100644
index 0000000000..93e6dc5797
--- /dev/null
+++ b/testsuite/tests/ghc-regress/arrows/should_run/T3822.hs
@@ -0,0 +1,17 @@
+
+{-# LANGUAGE Arrows #-}
+
+import Control.Arrow
+import qualified Control.Category as Cat
+
+test :: Int -> Int
+test = proc x -> do
+    let neg = x < 0
+    case x of
+        x | neg -> returnA -< 0           -- GHC panics
+        --x | x < 0 -> returnA -< 0       -- GHC doesn't panic
+        _       -> returnA -< 10
+
+main = do
+    print $ test (-1)
+    print $ test 1