From dcfcef1cfdc476507f822b03dcb67c1256a7e3a0 Mon Sep 17 00:00:00 2001
From: knu <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 16 Nov 2015 07:41:18 +0000
Subject: [PATCH] Explain the reason for calling do_with_enum without a block
 [ci skip]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52592 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 lib/set.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/set.rb b/lib/set.rb
index 9908aa6458..a0f290ebed 100644
--- a/lib/set.rb
+++ b/lib/set.rb
@@ -151,7 +151,7 @@ class Set
       @hash.replace(enum.instance_variable_get(:@hash))
       self
     else
-      do_with_enum(enum)
+      do_with_enum(enum)  # make sure enum is enumerable before calling clear
       clear
       merge(enum)
     end