10 files changed, 31 insertions, 8 deletions
diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 96bce53999..e0d154271f 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,6 +1,12 @@
+*   Fix the `ActiveSupport::Duration#instance_of?` method to return the right
+    value with the class itself since it was previously delegated to the
+    internal value.
+
+    *Robin Dupret*
+
 *   Fix rounding errors with #travel_to by resetting the usec on any passed time to zero, so we only travel
     with per-second precision, not anything deeper than that.
-    
+
     *DHH*
 
 *   Fix ActiveSupport::TestCase not to order users' test cases by default.
diff --git a/activesupport/lib/active_support/core_ext/object/itself.rb b/activesupport/lib/active_support/core_ext/object/itself.rb
index adedc20169..d71cea6674 100644
--- a/activesupport/lib/active_support/core_ext/object/itself.rb
+++ b/activesupport/lib/active_support/core_ext/object/itself.rb
@@ -1,6 +1,9 @@
 class Object
-  unless respond_to?(:itself) # TODO: Remove this file when we drop support for Ruby < 2.2
-    # Returns the object itself. Useful when dealing with a chaining scenario, like Active Record scopes:
+  # TODO: Remove this file when we drop support for Ruby < 2.2
+  unless respond_to?(:itself)
+    # Returns the object itself.
+    #
+    # Useful for chaining methods, such as Active Record scopes:
     #
     #   Event.public_send(state.presence_in([ :trashed, :drafted ]) || :itself).order(:created_at)
     #
diff --git a/activesupport/lib/active_support/deprecation.rb b/activesupport/lib/active_support/deprecation.rb
index ab16977bda..46e9996d59 100644
--- a/activesupport/lib/active_support/deprecation.rb
+++ b/activesupport/lib/active_support/deprecation.rb
@@ -32,7 +32,7 @@ module ActiveSupport
     # and the second is a library name
     #
     #   ActiveSupport::Deprecation.new('2.0', 'MyLibrary')
-    def initialize(deprecation_horizon = '4.2', gem_name = 'Rails')
+    def initialize(deprecation_horizon = '5.0', gem_name = 'Rails')
       self.gem_name = gem_name
       self.deprecation_horizon = deprecation_horizon
       # By default, warnings are not silenced and debugging is off.
diff --git a/activesupport/lib/active_support/duration.rb b/activesupport/lib/active_support/duration.rb
index 0ae641d05b..1a6c02a39b 100644
--- a/activesupport/lib/active_support/duration.rb
+++ b/activesupport/lib/active_support/duration.rb
@@ -39,6 +39,10 @@ module ActiveSupport
     end
     alias :kind_of? :is_a?
 
+    def instance_of?(klass) # :nodoc:
+      Duration == klass || value.instance_of?(klass)
+    end
+
     # Returns +true+ if +other+ is also a Duration instance with the
     # same +value+, or if <tt>other == value</tt>.
     def ==(other)
diff --git a/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb b/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb
index 01597b288a..dcf9a567e8 100644
--- a/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb
+++ b/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb
@@ -33,7 +33,7 @@ module ActiveSupport
             a, b = s.split('.', 2)
             a + '.' + b[0, precision]
           else
-            "%01.#{precision}f" % rounded_number
+            "%00.#{precision}f" % rounded_number
           end
 
         delimited_number = NumberToDelimitedConverter.convert(formatted_string, options)
@@ -59,7 +59,7 @@ module ActiveSupport
         end
 
         def digit_count(number)
-          (Math.log10(absolute_number(number)) + 1).floor
+          number.zero? ? 1 : (Math.log10(absolute_number(number)) + 1).floor
         end
 
         def strip_insignificant_zeros
diff --git a/activesupport/test/caching_test.rb b/activesupport/test/caching_test.rb
index 8287e62f4c..5945605f7b 100644
--- a/activesupport/test/caching_test.rb
+++ b/activesupport/test/caching_test.rb
@@ -939,8 +939,8 @@ class MemCacheStoreTest < ActiveSupport::TestCase
 
   def test_read_should_return_a_different_object_id_each_time_it_is_called
     @cache.write('foo', 'bar')
-    assert_not_equal @cache.read('foo').object_id, @cache.read('foo').object_id
     value = @cache.read('foo')
+    assert_not_equal value.object_id, @cache.read('foo').object_id
     value << 'bingo'
     assert_not_equal value, @cache.read('foo')
   end
diff --git a/activesupport/test/core_ext/duration_test.rb b/activesupport/test/core_ext/duration_test.rb
index 31af3c4521..a89202f518 100644
--- a/activesupport/test/core_ext/duration_test.rb
+++ b/activesupport/test/core_ext/duration_test.rb
@@ -20,6 +20,12 @@ class DurationTest < ActiveSupport::TestCase
     assert !d.is_a?(k)
   end
 
+  def test_instance_of
+    assert 1.minute.instance_of?(Fixnum)
+    assert 2.days.instance_of?(ActiveSupport::Duration)
+    assert !3.second.instance_of?(Numeric)
+  end
+
   def test_threequals
     assert ActiveSupport::Duration === 1.day
     assert !(ActiveSupport::Duration === 1.day.to_i)
@@ -35,6 +41,9 @@ class DurationTest < ActiveSupport::TestCase
   end
 
   def test_eql
+    rubinius_skip "Rubinius' #eql? definition relies on #instance_of? " \
+                  "which behaves oddly for the sake of backward-compatibility."
+
     assert 1.minute.eql?(1.minute)
     assert 2.days.eql?(48.hours)
     assert !1.second.eql?(1)
diff --git a/activesupport/test/number_helper_test.rb b/activesupport/test/number_helper_test.rb
index bb51cc68f2..50d84a9470 100644
--- a/activesupport/test/number_helper_test.rb
+++ b/activesupport/test/number_helper_test.rb
@@ -135,6 +135,7 @@ module ActiveSupport
           assert_equal("111.23460000000000000000", number_helper.number_to_rounded(BigDecimal(111.2346, Float::DIG), :precision => 20))
           assert_equal("111.2346" + "0"*96, number_helper.number_to_rounded('111.2346', :precision => 100))
           assert_equal("111.2346", number_helper.number_to_rounded(Rational(1112346, 10000), :precision => 4))
+          assert_equal('0.00', number_helper.number_to_rounded(Rational(0, 1), :precision => 2))
         end
       end
 
diff --git a/activesupport/test/test_test.rb b/activesupport/test/test_case_test.rb
index c93192f207..c93192f207 100644
--- a/activesupport/test/test_test.rb
+++ b/activesupport/test/test_case_test.rb
diff --git a/activesupport/test/transliterate_test.rb b/activesupport/test/transliterate_test.rb
index e0f85f4e7c..6833ae68a7 100644
--- a/activesupport/test/transliterate_test.rb
+++ b/activesupport/test/transliterate_test.rb
@@ -11,7 +11,7 @@ class TransliterateTest < ActiveSupport::TestCase
   end
 
   def test_transliterate_should_approximate_ascii
-    # create string with range of Unicode"s western characters with
+    # create string with range of Unicode's western characters with
     # diacritics, excluding the division and multiplication signs which for
     # some reason or other are floating in the middle of all the letters.
     string = (0xC0..0x17E).to_a.reject {|c| [0xD7, 0xF7].include?(c)}.pack("U*")