use ensureAsync with forever. Fixes #622ensure_async

1 files changed, 4 insertions, 5 deletions

diff --git a/lib/async.js b/lib/async.js
index 06ede14..b8c001b 100644
--- a/lib/async.js
+++ b/lib/async.js
@@ -1255,14 +1255,13 @@
     async.applyEachSeries = doSeries(_applyEach);
 
     async.forever = function (fn, callback) {
+        var done = only_once(callback || noop);
+        var task = ensureAsync(fn);
         function next(err) {
             if (err) {
-                if (callback) {
-                    return callback(err);
-                }
-                throw err;
+                return done(err);
             }
-            fn(next);
+            task(next);
         }
         next();
     };