Ensure ActiveRecord::Base.find_in_batches fires doesnt fire an extra query unless needed

1 files changed, 4 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/batches.rb b/activerecord/lib/active_record/batches.rb
index 4ea932f34d..03bd4f9f93 100644
--- a/activerecord/lib/active_record/batches.rb
+++ b/activerecord/lib/active_record/batches.rb
@@ -49,12 +49,15 @@ module ActiveRecord
         raise "You can't specify a limit, it's forced to be the batch_size"  if options[:limit]
 
         start = options.delete(:start).to_i
+        batch_size = options.delete(:batch_size) || 1000
 
-        with_scope(:find => options.merge(:order => batch_order, :limit => options.delete(:batch_size) || 1000)) do
+        with_scope(:find => options.merge(:order => batch_order, :limit => batch_size)) do
           records = find(:all, :conditions => [ "#{table_name}.#{primary_key} >= ?", start ])
 
           while records.any?
             yield records
+
+            break if records.size < batch_size
             records = find(:all, :conditions => [ "#{table_name}.#{primary_key} > ?", records.last.id ])
           end
         end