Remove redundant checks for valid character regexp in ActiveSupport::Multibyte#clean and #verify.

[#3181 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

activesupport/lib/active_support/multibyte/utils.rb

@@ -10,30 +10,44 @@ module ActiveSupport #:nodoc:
       end
     end
 
+    if 'string'.respond_to?(:valid_encoding?)
       # Verifies the encoding of a string
+      def self.verify(string)
+        string.valid_encoding?
+      end
+    else
       def self.verify(string)
         if expression = valid_character
           for c in string.split(//)
-         return false unless valid_character.match(c)
+            return false unless expression.match(c)
           end
         end
         true
       end
+    end
 
     # Verifies the encoding of the string and raises an exception when it's not valid
     def self.verify!(string)
       raise ActiveSupport::Multibyte::Handlers::EncodingError.new("Found characters with invalid encoding") unless verify(string)
     end
 
-   # Removes all invalid characters from the string
+    if 'string'.respond_to?(:force_encoding)
+      # Removes all invalid characters from the string.
+      #
+      # Note: this method is a no-op in Ruby 1.9
+      def self.clean(string)
+        string
+      end
+    else
       def self.clean(string)
         if expression = valid_character
           stripped = []; for c in string.split(//)
-         stripped << c if valid_character.match(c)
+            stripped << c if expression.match(c)
           end; stripped.join
         else
           string
         end
       end
     end
+  end
 end