7 files changed, 14 insertions, 12 deletions
diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index 8ce02afef8..228c500f0a 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -290,7 +290,7 @@ module ActiveRecord
 
       # Returns true if the collection is empty.
       #
-      # If the collection has been loaded 
+      # If the collection has been loaded
       # it is equivalent to <tt>collection.size.zero?</tt>. If the
       # collection has not been loaded, it is equivalent to
       # <tt>collection.exists?</tt>. If the collection has not already been
@@ -366,8 +366,8 @@ module ActiveRecord
         target
       end
 
-      def add_to_target(record)
-        callback(:before_add, record)
+      def add_to_target(record, skip_callbacks = false)
+        callback(:before_add, record) unless skip_callbacks
         yield(record) if block_given?
 
         if association_scope.distinct_value && index = @target.index(record)
@@ -376,7 +376,7 @@ module ActiveRecord
           @target << record
         end
 
-        callback(:after_add, record)
+        callback(:after_add, record) unless skip_callbacks
         set_inverse_instance(record)
 
         record
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 4b11ea795c..4b11ea795c 100755..100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
index 92796c996e..92796c996e 100755..100644
--- a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 15b5452850..15b5452850 100755..100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
diff --git a/activerecord/lib/active_record/migration/command_recorder.rb b/activerecord/lib/active_record/migration/command_recorder.rb
index 9782a48055..01c73be849 100644
--- a/activerecord/lib/active_record/migration/command_recorder.rb
+++ b/activerecord/lib/active_record/migration/command_recorder.rb
@@ -73,7 +73,7 @@ module ActiveRecord
       [:create_table, :create_join_table, :rename_table, :add_column, :remove_column,
         :rename_index, :rename_column, :add_index, :remove_index, :add_timestamps, :remove_timestamps,
         :change_column_default, :add_reference, :remove_reference, :transaction,
-        :drop_join_table, :drop_table, :execute_block,
+        :drop_join_table, :drop_table, :execute_block, :enable_extension,
         :change_column, :execute, :remove_columns, # irreversible methods need to be here too
       ].each do |method|
         class_eval <<-EOV, __FILE__, __LINE__ + 1
@@ -100,6 +100,7 @@ module ActiveRecord
           add_column:        :remove_column,
           add_timestamps:    :remove_timestamps,
           add_reference:     :remove_reference,
+          enable_extension:  :disable_extension
         }.each do |cmd, inv|
           [[inv, cmd], [cmd, inv]].uniq.each do |method, inverse|
             class_eval <<-EOV, __FILE__, __LINE__ + 1
diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb
index e53e8553ad..df28451bb7 100644
--- a/activerecord/lib/active_record/nested_attributes.rb
+++ b/activerecord/lib/active_record/nested_attributes.rb
@@ -465,19 +465,17 @@ module ActiveRecord
             association.build(attributes.except(*UNASSIGNABLE_KEYS))
           end
         elsif existing_record = existing_records.detect { |record| record.id.to_s == attributes['id'].to_s }
-          unless association.loaded? || call_reject_if(association_name, attributes)
+          unless call_reject_if(association_name, attributes)
             # Make sure we are operating on the actual object which is in the association's
             # proxy_target array (either by finding it, or adding it if not found)
-            target_record = association.target.detect { |record| record == existing_record }
-
+            # Take into account that the proxy_target may have changed due to callbacks
+            target_record = association.target.detect { |record| record.id.to_s == attributes['id'].to_s }
             if target_record
               existing_record = target_record
             else
-              association.add_to_target(existing_record)
+              association.add_to_target(existing_record, :skip_callbacks)
             end
-          end
 
-          if !call_reject_if(association_name, attributes)
             assign_to_or_mark_for_destruction(existing_record, attributes, options[:allow_destroy])
           end
         else
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index 8a311039d5..daccab762f 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -320,11 +320,14 @@ db_namespace = namespace :db do
     # desc "Recreate the test database from an existent schema.rb file"
     task :load_schema => 'db:test:purge' do
       begin
+        should_reconnect = ActiveRecord::Base.connection_pool.active_connection?
         ActiveRecord::Base.establish_connection(ActiveRecord::Base.configurations['test'])
         ActiveRecord::Schema.verbose = false
         db_namespace["schema:load"].invoke
       ensure
-        ActiveRecord::Base.establish_connection(ActiveRecord::Base.configurations[ActiveRecord::Tasks::DatabaseTasks.env])
+        if should_reconnect
+          ActiveRecord::Base.establish_connection(ActiveRecord::Base.configurations[ActiveRecord::Tasks::DatabaseTasks.env])
+        end
       end
     end