Reset @total_count on #clone

Fixes #565

lib/kaminari/models/active_record_relation_methods.rb

@@ -12,6 +12,11 @@ module Kaminari
       model_name.human.downcase
     end
 
+    def reset #:nodoc:
+      @total_count = nil
+      super
+    end
+
     def total_count(column_name = :all, options = {}) #:nodoc:
       # #count overrides the #select which could include generated columns referenced in #order, so skip #order here, where it's irrelevant to the result anyway
       @total_count ||= begin

lib/kaminari/models/mongoid_criteria_methods.rb

@@ -1,5 +1,10 @@
 module Kaminari
   module MongoidCriteriaMethods
+    def initialize_copy(other) #:nodoc:
+      @total_count = nil
+      super
+    end
+
     def entry_name
       model_name.human.downcase
     end

spec/models/active_record/active_record_relation_methods_spec.rb

@@ -14,6 +14,12 @@ if defined? ActiveRecord
         @books.each {|book| book.readers << @readers }
       end
 
+      context "when the scope is cloned" do
+        it "should reset total_coount momoization" do
+          User.page.tap(&:total_count).where(:name => 'author').total_count.should == 1
+        end
+      end
+
       context "when the scope includes an order which references a generated column" do
         it "should successfully count the results" do
           @author.readers.by_read_count.page(1).total_count.should == @readers.size

spec/models/mongoid/mongoid_spec.rb

@@ -1,6 +1,20 @@
 require 'spec_helper'
 
 if defined? Mongoid
+  describe Kaminari::MongoidCriteriaMethods do
+    describe "#total_count" do
+      before do
+        2.times {|i| User.create!(:salary => i) }
+      end
+
+      context "when the scope is cloned" do
+        it "should reset total_coount momoization" do
+          User.page.tap(&:total_count).where(:salary => 1).total_count.should == 1
+        end
+      end
+    end
+  end
+
   describe Kaminari::MongoidExtension do
     before(:each) do
       41.times do