A more aesthetically pleasing implementation and changelog entry

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3549 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activesupport/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Make String#last return the string instead of nil when it is shorter than the limit [Scott Barron].
+
 * Added delegation support to Module that allows multiple delegations at once (unlike Forwardable in the stdlib) [DHH]. Example:
 
     class Account < ActiveRecord::Base

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

@@ -50,10 +50,9 @@ module ActiveSupport #:nodoc:
         #   "hello".last(2)  # => "lo"
         #   "hello".last(10) # => "hello"
         def last(limit = 1)
-          return self if self.length < limit
-          self[(-limit)..-1]
+          self[(-limit)..-1] || self
         end
       end
     end
   end
-end
+end