SQLServer: more compatible limit/offset emulation. Closes #3779.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3564 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

 *SVN*
 
+* SQLServer: more compatible limit/offset emulation.  #3779 [Tom Ward]
+
 * Polymorphic join support for has_one associations (has_one :foo, :as => :bar)  #3785 [Rick Olson]
 
 * PostgreSQL: correctly parse negative integer column defaults.  #3776 [bellis@deepthought.org]

activerecord/lib/active_record/connection_adapters/sqlserver_adapter.rb

@@ -375,7 +375,9 @@ def add_limit_offset!(sql, options)
             sql << " ) AS tmp2"
           end
         elsif sql !~ /^\s*SELECT (@@|COUNT\()/i
-          sql.sub!(/^\s*SELECT/i, "SELECT TOP #{options[:limit]}") unless options[:limit].nil?
+          sql.sub!(/^\s*SELECT([\s]*distinct)?/i) do
+            "SELECT#{$1} TOP #{options[:limit]}"
+          end unless options[:limit].nil?
         end
       end