fix bind collecting for mysql

Gemfile

@@ -12,7 +12,6 @@ gem 'jquery-rails', '~> 3.1.0'
 gem 'turbolinks'
 gem 'coffee-rails', '~> 4.0.0'
 gem 'arel', path: '/Users/aaron/git/arel'
-gem 'sprockets-rails', github: 'rails/sprockets-rails', branch: '2-1-stable'
 
 # require: false so bcrypt is loaded only when has_secure_password is used.
 # This is to avoid ActiveModel (and by extension the entire framework)

activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb

@@ -9,7 +9,6 @@ module ActiveRecord
       # Converts an arel AST to SQL
       def to_sql(arel, binds = [])
         if arel.respond_to?(:ast)
-          binds = binds.dup
           visitor.accept(arel.ast, collector).compile binds.dup
         else
           arel

activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb

@@ -193,11 +193,31 @@ module ActiveRecord
         @connection_options, @config = connection_options, config
         @quoted_column_names, @quoted_table_names = {}, {}
 
+        @visitor = Arel::Visitors::MySQL.new self
+
         if self.class.type_cast_config_to_boolean(config.fetch(:prepared_statements) { true })
           @prepared_statements = true
-          @visitor = Arel::Visitors::MySQL.new self
         else
-          @visitor = unprepared_visitor
+          @prepared_statements = false
+        end
+      end
+
+      class BindCollector < Arel::Collectors::Bind
+        def initialize(conn)
+          @conn = conn
+          super()
+        end
+
+        def compile(bvs)
+          super(bvs.map { |bv| @conn.quote(*bv.reverse) })
+        end
+      end
+
+      def collector
+        if @prepared_statements
+          Arel::Collectors::SQLString.new
+        else
+          BindCollector.new self
         end
       end