Allow Cucumber tests to run with PostgreSQL with a non-root user.

features/support/database_cleaner_patches.rb

@@ -2,6 +2,26 @@
 #   licensed under the Affero General Public License version 3 or later.  See
 #   the COPYRIGHT file.
 
+# disable_referential_integrity doesn't work when using PostgreSQL
+# with a non-root user.
+# See http://kopongo.com/2008/7/25/postgres-ri_constrainttrigger-error
+module ActiveRecord
+  module ConnectionAdapters
+    class PostgreSQLAdapter < AbstractAdapter
+      def disable_referential_integrity(&block)
+         transaction {
+           begin
+             execute "SET CONSTRAINTS ALL DEFERRED"
+             yield
+           ensure
+             execute "SET CONSTRAINTS ALL IMMEDIATE"
+           end
+         }
+      end
+    end
+  end
+end
+
 DatabaseCleaner::ActiveRecord::Truncation.class_eval do
   # You could argue that this technically isn't truncation. You'd be right.
   # But something in the MySQL adapter segfaults (!) on actual truncation, and we
@@ -13,4 +33,4 @@ DatabaseCleaner::ActiveRecord::Truncation.class_eval do
       end
     end
   end
-end
+end