make eachSeries sync w/ single item and a sync iterator. Fixes #782

Conflicts:
	test/test-async.js

2 files changed, 23 insertions, 6 deletions

diff --git a/lib/async.js b/lib/async.js
index abc1f7b..c756268 100644
--- a/lib/async.js
+++ b/lib/async.js
@@ -243,9 +243,9 @@
         callback = _once(callback || noop);
         obj = obj || [];
         var nextKey = _keyIterator(obj);
+        var key = nextKey();
         function iterate() {
             var sync = true;
-            var key = nextKey();
             if (key === null) {
                 return callback(null);
             }
@@ -254,11 +254,15 @@
                     callback(err);
                 }
                 else {
-                    if (sync) {
-                        async.nextTick(iterate);
-                    }
-                    else {
-                        iterate();
+                    key = nextKey();
+                    if (key === null) {
+                        return callback(null);
+                    } else {
+                        if (sync) {
+                            async.nextTick(iterate);
+                        } else {
+                            iterate();
+                        }
                     }
                 }
             });
diff --git a/test/test-async.js b/test/test-async.js
index 670d14a..a69b9e9 100755
--- a/test/test-async.js
+++ b/test/test-async.js
@@ -1477,6 +1477,19 @@ exports['eachSeries array modification'] = function(test) {
     setTimeout(test.done, 25);
 };
 
+// bug #782.  Remove in next major release
+exports['eachSeries single item'] = function (test) {
+    test.expect(1);
+    var sync = true;
+    async.eachSeries([1], function (i, cb) {
+        cb(null);
+    }, function () {
+        test.ok(sync, "callback not called on same tick");
+    });
+    sync = false;
+    test.done();
+};
+
 exports['eachSeries error'] = function(test){
     test.expect(2);
     var call_order = [];