Fix 'bhead is not a function' for forks (#145)

Author: natefaubion

src/Control/Monad/Aff.js

@@ -372,15 +372,15 @@ var Aff = function () {
             break;
 
           case FORK:
-            status = STEP_BIND;
+            status = STEP_RESULT;
             tmp    = Fiber(util, supervisor, step._2);
             if (supervisor) {
               supervisor.register(tmp);
             }
             if (step._1) {
               tmp.run();
             }
-            step = tmp;
+            step = util.right(tmp);
             break;
 
           case SEQ:

test/Test/Main.purs

@@ -634,7 +634,7 @@ test_scheduler_size = assert "scheduler" do
   eq 100000 <$> readRef ref
 
 test_lazy ∷ ∀ eff. TestAff eff Unit
-test_lazy = assert "Lazy Aff" do
+test_lazy = assert "lazy" do
   varA ← makeEmptyVar
   varB ← makeEmptyVar
   fiberA <- forkAff $ fix \loop -> do
@@ -653,6 +653,13 @@ test_lazy = assert "Lazy Aff" do
   putVar 0 varA
   eq "done" <$> joinFiber fiberB
 
+test_regression_return_fork ∷ ∀ eff. TestAff eff Unit
+test_regression_return_fork = assert "regression/return-fork" do
+  bracket
+    (forkAff (pure unit))
+    (const (pure unit))
+    (const (pure true))
+
 main ∷ TestEff () Unit
 main = do
   test_pure
@@ -698,3 +705,4 @@ main = do
     -- Turn on if we decide to schedule forks
     -- test_scheduler_size
     test_parallel_stack
+    test_regression_return_fork