PostgreSQLAdapter: set time_zone to UTC when Base.default_timezone == :utc so that Postgres doesn't incorrectly offset-adjust values inserted into TIMESTAMP WITH TIME ZONE columns [#3777 state:resolved]

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *Edge*
 
+* PostgreSQLAdapter: set time_zone to UTC when Base.default_timezone == :utc so that Postgres doesn't incorrectly offset-adjust values inserted into TIMESTAMP WITH TIME ZONE columns. #3777 [Jack Christensen]
+
 * Allow relations to be used as scope.
 
   class Item

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -998,7 +998,7 @@ module ActiveRecord
           configure_connection
         end
 
-        # Configures the encoding, verbosity, and schema search path of the connection.
+        # Configures the encoding, verbosity, schema search path, and time zone of the connection.
         # This is called by #connect and should not be called manually.
         def configure_connection
           if @config[:encoding]
@@ -1010,6 +1010,10 @@ module ActiveRecord
           end
           self.client_min_messages = @config[:min_messages] if @config[:min_messages]
           self.schema_search_path = @config[:schema_search_path] || @config[:schema_order]
+          
+          # If using ActiveRecord's time zone support configure the connection to return
+          # TIMESTAMP WITH ZONE types in UTC.
+          execute("SET time zone 'UTC'") if ActiveRecord::Base.default_timezone == :utc
         end
 
         # Returns the current ID of a table's sequence.

activerecord/test/cases/datatype_test_postgresql.rb

@@ -21,6 +21,9 @@ end
 class PostgresqlOid < ActiveRecord::Base
 end
 
+class PostgresqlTimestampWithZone < ActiveRecord::Base
+end
+
 class PostgresqlDataTypeTest < ActiveRecord::TestCase
   self.use_transactional_fixtures = false
 
@@ -50,6 +53,8 @@ class PostgresqlDataTypeTest < ActiveRecord::TestCase
 
     @connection.execute("INSERT INTO postgresql_oids (obj_id) VALUES (1234)")
     @first_oid = PostgresqlOid.find(1)
+    
+    @connection.execute("INSERT INTO postgresql_timestamp_with_zones (time) VALUES ('2010-01-01 10:00:00-1')")
   end
 
   def test_data_type_of_array_types
@@ -201,4 +206,38 @@ class PostgresqlDataTypeTest < ActiveRecord::TestCase
     assert @first_oid.reload
     assert_equal @first_oid.obj_id, new_value
   end
+
+  def test_timestamp_with_zone_values_with_rails_time_zone_support
+    old_tz         = ActiveRecord::Base.time_zone_aware_attributes
+    old_default_tz = ActiveRecord::Base.default_timezone
+
+    ActiveRecord::Base.time_zone_aware_attributes = true
+    ActiveRecord::Base.default_timezone = :utc
+
+    @connection.reconnect!
+
+    @first_timestamp_with_zone = PostgresqlTimestampWithZone.find(1)
+    assert_equal Time.utc(2010,1,1, 11,0,0), @first_timestamp_with_zone.time
+  ensure
+    ActiveRecord::Base.default_timezone = old_default_tz
+    ActiveRecord::Base.time_zone_aware_attributes = old_tz
+    @connection.reconnect!
+  end
+
+  def test_timestamp_with_zone_values_without_rails_time_zone_support
+    old_tz         = ActiveRecord::Base.time_zone_aware_attributes
+    old_default_tz = ActiveRecord::Base.default_timezone
+
+    ActiveRecord::Base.time_zone_aware_attributes = false
+    ActiveRecord::Base.default_timezone = :local
+
+    @connection.reconnect!
+
+    @first_timestamp_with_zone = PostgresqlTimestampWithZone.find(1)
+    assert_equal Time.utc(2010,1,1, 11,0,0), @first_timestamp_with_zone.time
+  ensure
+    ActiveRecord::Base.default_timezone = old_default_tz
+    ActiveRecord::Base.time_zone_aware_attributes = old_tz
+    @connection.reconnect!
+  end
 end

activerecord/test/schema/postgresql_specific_schema.rb

@@ -1,7 +1,7 @@
 ActiveRecord::Schema.define do
 
   %w(postgresql_arrays postgresql_moneys postgresql_numbers postgresql_times postgresql_network_addresses postgresql_bit_strings
-      postgresql_oids postgresql_xml_data_type defaults geometrics).each do |table_name|
+      postgresql_oids postgresql_xml_data_type defaults geometrics postgresql_timestamp_with_zones).each do |table_name|
     execute "DROP TABLE  IF EXISTS #{quote_table_name table_name}"
   end
 
@@ -101,6 +101,13 @@ _SQL
   );
 _SQL
   
+  execute <<_SQL
+  CREATE TABLE postgresql_timestamp_with_zones (
+    id SERIAL PRIMARY KEY,
+    time TIMESTAMP WITH TIME ZONE
+  );
+_SQL
+
   begin
     execute <<_SQL
     CREATE TABLE postgresql_xml_data_type (