Fix that batched :include would pull in duplicate records in some cases. Closes #11215 [Catfish]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8942 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 5 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/association_preload.rb b/activerecord/lib/active_record/association_preload.rb
index a89f5f5459..cc657dc433 100644
--- a/activerecord/lib/active_record/association_preload.rb
+++ b/activerecord/lib/active_record/association_preload.rb
@@ -10,7 +10,7 @@ module ActiveRecord
       # preload_options is passed only one level deep: don't pass to the child associations when associations is a Hash
       protected
       def preload_associations(records, associations, preload_options={})
-        records = [records].flatten.compact
+        records = [records].flatten.compact.uniq
         return if records.empty?
         case associations
         when Array then associations.each {|association| preload_associations(records, association, preload_options)}
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index cfdd33d6e8..5162f859aa 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1536,8 +1536,10 @@ module ActiveRecord
                   is_collection = [:has_many, :has_and_belongs_to_many].include?(reflection.macro)
 
                   parent_records = records.map do |record|
-                    next unless record.send(reflection.name)
-                    is_collection ? record.send(reflection.name).target.uniq! : record.send(reflection.name)
+                    descendant = record.send(reflection.name)
+                    next unless descendant
+                    descendant.target.uniq! if is_collection
+                    descendant
                   end.flatten.compact
 
                   remove_duplicate_results!(reflection.class_name.constantize, parent_records, associations[name]) unless parent_records.empty?