Fix bug in Range comparisons when comparing to excluded-end Range

Before:
```ruby
(1..10).cover?(1...11) => false
```

After:
```ruby
(1..10).cover?(1...11) => true
```

See https://git.io/fjTtz for the commit against Ruby core that added
support for Range arguments, with similar handling of this case.

1 files changed, 6 insertions, 2 deletions

diff --git a/activesupport/test/core_ext/range_ext_test.rb b/activesupport/test/core_ext/range_ext_test.rb
index 4b8efb8a93..16d6a4c2f2 100644
--- a/activesupport/test/core_ext/range_ext_test.rb
+++ b/activesupport/test/core_ext/range_ext_test.rb
@@ -57,7 +57,7 @@ class RangeTest < ActiveSupport::TestCase
   end
 
   def test_should_include_other_with_exclusive_end
-    assert((1..10).include?(1...10))
+    assert((1..10).include?(1...11))
   end
 
   def test_should_compare_identical_inclusive
@@ -69,7 +69,7 @@ class RangeTest < ActiveSupport::TestCase
   end
 
   def test_should_compare_other_with_exclusive_end
-    assert((1..10) === (1...10))
+    assert((1..10) === (1...11))
   end
 
   def test_exclusive_end_should_not_include_identical_with_inclusive_end
@@ -93,6 +93,10 @@ class RangeTest < ActiveSupport::TestCase
     assert range.method(:include?) != range.method(:cover?)
   end
 
+  def test_should_cover_other_with_exclusive_end
+    assert((1..10).cover?(1...11))
+  end
+
   def test_overlaps_on_time
     time_range_1 = Time.utc(2005, 12, 10, 15, 30)..Time.utc(2005, 12, 10, 17, 30)
     time_range_2 = Time.utc(2005, 12, 10, 17, 00)..Time.utc(2005, 12, 10, 18, 00)