handle nils for equa;s

lib/searchlogic/named_scopes/column_conditions.rb

@@ -159,11 +159,13 @@ def create_primary_condition(column_name, condition)
         # Kepp in mind that the lambdas get cached in a method, so you want to keep the contents of the lambdas as
         # fast as possible, which is why I didn't do the case statement inside of the lambda.
         def scope_options(condition, column, sql, options = {})
+          equals = !(condition.to_s =~ /^equals/).nil?
+          does_not_equal = !(condition.to_s =~ /^does_not_equal/).nil?
+
           case condition.to_s
           when /_(any|all)$/
             any = $1 == "any"
             join_word = any ? " OR " : " AND "
-            equals = condition.to_s =~ /^equals_/
             searchlogic_lambda(column.type, :skip_conversion => options[:skip_conversion]) { |*values|
               unless values.empty?
                 if equals && any
@@ -194,6 +196,12 @@ def scope_options(condition, column, sql, options = {})
             searchlogic_lambda(column.type, :skip_conversion => options[:skip_conversion]) { |*values|
               values.collect! { |value| value_with_modifier(value, options[:value_modifier]) }
 
+              if does_not_equal && values == [nil]
+                sql.gsub!('!=', 'IS NOT')
+              elsif equals && values == [nil]
+                sql.gsub!('=', 'IS')
+              end
+
               {:conditions => [sql, *values]}
             }
           end

spec/searchlogic/named_scopes/column_conditions_spec.rb

@@ -18,7 +18,9 @@
   context "comparison conditions" do
     it "should have equals" do
       (5..7).each { |age| User.create(:age => age) }
+      nil_user = User.create
       User.age_equals(6).all.should == User.find_all_by_age(6)
+      User.age_equals(nil).all.should == User.find_all_by_age(nil)
     end
 
     it "should have does not equal" do