Make Enumerable#many? iterate only over what is necessary

2 files changed, 17 insertions, 3 deletions

diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb
index 9b835aab9e..f67e7bf33e 100644
--- a/activesupport/lib/active_support/core_ext/enumerable.rb
+++ b/activesupport/lib/active_support/core_ext/enumerable.rb
@@ -95,9 +95,16 @@ module Enumerable
 
   # Returns true if the enumerable has more than 1 element. Functionally equivalent to enum.to_a.size > 1.
   # Can be called with a block too, much like any?, so people.many? { |p| p.age > 26 } returns true if more than 1 person is over 26.
-  def many?(&block)
-    size = block_given? ? count(&block) : to_a.size
-    size > 1
+  def many?
+    cnt = 0
+    if block_given?
+      any? do |element|
+        cnt += 1 if yield element
+        cnt > 1
+      end
+    else
+      any?{ (cnt += 1) > 1 }
+    end
   end
 
   # The negative of the Enumerable#include?. Returns true if the collection does not include the object.
diff --git a/activesupport/test/core_ext/enumerable_test.rb b/activesupport/test/core_ext/enumerable_test.rb
index 688207c91c..98f3f2f242 100644
--- a/activesupport/test/core_ext/enumerable_test.rb
+++ b/activesupport/test/core_ext/enumerable_test.rb
@@ -104,6 +104,13 @@ class EnumerableTests < Test::Unit::TestCase
     assert_equal true,  GenericEnumerable.new([ 1, 2, 2 ]).many? {|x| x > 1 }
   end
 
+  def test_many_iterates_only_on_what_is_needed
+    infinity = 1.0/0.0
+    very_long_enum = 0..infinity
+    assert_equal true, very_long_enum.many?
+    assert_equal true, very_long_enum.many?{|x| x > 100}
+  end
+
   def test_exclude?
     assert_equal true,  GenericEnumerable.new([ 1 ]).exclude?(2)
     assert_equal false, GenericEnumerable.new([ 1 ]).exclude?(1)