Add regression test for #382

tests/Regressions.hs

@@ -187,6 +187,23 @@ issue379LazyUnionWith = do
   touch v -- makes sure that we didn't GC away the combined value
   assert $ isNothing res
 
+------------------------------------------------------------------------
+-- Issue #382
+--
+issue382 :: Assertion
+issue382 = do
+  i :: Int <- randomIO
+  let k = SC (show i)
+  weakK <- mkWeakPtr k Nothing -- add the ability to test whether k is alive
+  let f :: Int -> Int -> Int
+      f x = error ("Should not be evaluated " ++ show x)
+  let m = HML.fromListWith f [(k, 1), (k, 2)]
+  Just v <- evaluate $ HML.lookup k m
+  performGC
+  res <- deRefWeak weakK -- gives Just if k is still alive
+  touch v -- makes sure that we didn't GC away the combined value
+  assert $ isNothing res
+
 ------------------------------------------------------------------------
 -- * Test list
 
@@ -206,4 +223,7 @@ tests = testGroup "Regression tests"
           , testCase "Strict.unionWithKey" issue379StrictUnionWithKey
 #endif
           ]
+#ifdef HAVE_NOTHUNKS
+    , testCase "issue382" issue382
+#endif
     ]