From bdd9274aaa08fe9edf66afba1a5ded23a83d9f46 Mon Sep 17 00:00:00 2001
From: Andrey Petrov <andrey.petrov@shazow.net>
Date: Sat, 15 Dec 2018 20:37:46 -0500
Subject: [PATCH] set: Fix race condition

---
 set/set.go | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/set/set.go b/set/set.go
index 1b489ad..7a50d4d 100644
--- a/set/set.go
+++ b/set/set.go
@@ -156,19 +156,21 @@ func (s *Set) Replace(oldKey string, item Item) error {
 // Each loops over every item while holding a read lock and applies fn to each
 // element.
 func (s *Set) Each(fn IterFunc) error {
+	var err error
 	s.RLock()
-	defer s.RUnlock()
 	for key, item := range s.lookup {
 		if item.Value() == nil {
+			// Expired
 			defer s.cleanup(key)
 			continue
 		}
-		if err := fn(key, item); err != nil {
+		if err = fn(key, item); err != nil {
 			// Abort early
-			return err
+			break
 		}
 	}
-	return nil
+	s.RUnlock()
+	return err
 }
 
 // ListPrefix returns a list of items with a prefix, normalized.