Only remove includes from count if they are irrelevant.

lib/kaminari/models/active_record_relation_methods.rb

@@ -12,8 +12,11 @@ module Kaminari
 
       def total_count #: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
-        c = except(:offset, :limit, :includes, :order).count
+        c = except(:offset, :limit, :order)
+        # Remove includes only if they are irrelevant
+        c = c.except(:includes) unless references_eager_loaded_tables?
         # .group returns an OrderdHash that responds to #count
+        c = c.count
         c.respond_to?(:count) ? c.count : c
       end
     end

spec/models/active_record_relation_methods_spec.rb

@@ -4,7 +4,11 @@ describe Kaminari::ActiveRecordRelationMethods do
   describe '#total_count' do
     before do
       @author = User.create! :name => 'author'
-      @books = 2.times.map { @author.books_authored.create! }
+      @author2 = User.create! :name => 'author2'
+      @author3 = User.create! :name => 'author3'
+      @books = 2.times.map {|i| @author.books_authored.create!(:title => "title%03d" % i) }
+      @books2 = 3.times.map {|i| @author2.books_authored.create!(:title => "title%03d" % i) }
+      @books3 = 4.times.map {|i| @author3.books_authored.create!(:title => "subject%03d" % i) }
       @readers = 4.times.map { User.create! :name => 'reader' }
       @books.each {|book| book.readers << @readers }
     end
@@ -14,5 +18,11 @@ describe Kaminari::ActiveRecordRelationMethods do
         @author.readers.by_read_count.page(1).total_count.should == @readers.size
       end
     end
+    context "when the scope use conditions on includes" do
+      it "should keep includes and successfully count the results" do
+        # Only @author and @author2 have books titled with the title00x partern
+        User.includes(:books_authored).where("books.title LIKE 'title00%'").page(1).total_count.should == 2
+      end
+    end    
   end
 end