From 8717f0787df49080d742c366bb8e70c7527ef6bd Mon Sep 17 00:00:00 2001
From: knu <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 22 Oct 2018 11:23:56 +0000
Subject: [PATCH] Set the size of a new enumerator created by Enumerator#each
 with arguments to nil

When each() takes arguments, it is never safe to assume that the iteration
would repeat the same number of times as with each() without any
argument.  Actually, there is no way to get the exact number, so the
size should be set to nil to denote that.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65302 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 enumerator.c                 | 2 ++
 test/ruby/test_enumerator.rb | 7 +++++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/enumerator.c b/enumerator.c
index a366b75232..24444cdc53 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -550,6 +550,8 @@ enumerator_each(int argc, VALUE *argv, VALUE obj)
 	    args = rb_ary_new4(argc, argv);
 	}
 	e->args = args;
+	e->size = Qnil;
+	e->size_fn = 0;
     }
     if (!rb_block_given_p()) return obj;
     return enumerator_block_call(obj, 0, obj);
diff --git a/test/ruby/test_enumerator.rb b/test/ruby/test_enumerator.rb
index a24ff00d96..0839c2c3dd 100644
--- a/test/ruby/test_enumerator.rb
+++ b/test/ruby/test_enumerator.rb
@@ -301,8 +301,11 @@ class TestEnumerator < Test::Unit::TestCase
       yield
     end
     ary = []
-    e = o.to_enum.each(ary)
-    e.next
+    e = o.to_enum { 1 }
+    assert_equal(1, e.size)
+    e_arg = e.each(ary)
+    assert_equal(nil, e_arg.size)
+    e_arg.next
     assert_equal([1], ary)
   end