Remove 1.9's String#chars also

activesupport/lib/active_support/core_ext/string/unicode.rb

 module ActiveSupport #:nodoc:
   module CoreExtensions #:nodoc:
     module String #:nodoc:
-      unless '1.9'.respond_to?(:force_encoding)
-        # Define methods for handling unicode data.
-        module Unicode
-          def self.append_features(base)
-            if '1.8.7'.respond_to?(:chars)
-              base.class_eval { remove_method :chars }
-            end
-            super
+      # Define methods for handling unicode data.
+      module Unicode
+        def self.append_features(base)
+          if '1.8.7 and later'.respond_to?(:chars)
+            base.class_eval { remove_method :chars }
           end
+          super
+        end
 
+        unless '1.9'.respond_to?(:force_encoding)
           # +chars+ is a Unicode safe proxy for string methods. It creates and returns an instance of the
           # ActiveSupport::Multibyte::Chars class which encapsulates the original string. A Unicode safe version of all
           # the String methods are defined on this proxy class. Undefined methods are forwarded to String, so all of the
@@ -44,14 +44,12 @@ def chars
           def is_utf8?
             ActiveSupport::Multibyte::Handlers::UTF8Handler.consumes?(self)
           end
-        end
-      else
-        module Unicode #:nodoc:
-          def chars
+        else
+          def chars #:nodoc:
             self
           end
 
-          def is_utf8?
+          def is_utf8? #:nodoc:
             case encoding
               when Encoding::UTF_8
                 valid_encoding?