pg, `default_sequence_name` respects schema. Closes #7516.

activerecord/CHANGELOG.md

+*   PostgreSQL `default_sequence_name` respects schema. Fixes #7516.
+
+    *Yves Senn*
+
 *   Fixed `columns_for_distinct` of postgresql adapter to work correctly
     with orders without sort direction modifiers.
 

activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb

@@ -273,9 +273,9 @@ def client_min_messages=(level)
         def default_sequence_name(table_name, pk = nil) #:nodoc:
           result = serial_sequence(table_name, pk || 'id')
           return nil unless result
-          result.split('.').last
+          Utils.extract_schema_qualified_name(result)
         rescue ActiveRecord::StatementInvalid
-          "#{table_name}_#{pk || 'id'}_seq"
+          PostgreSQL::Name.new(nil, "#{table_name}_#{pk || 'id'}_seq")
         end
 
         def serial_sequence(table, column)

activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb

@@ -134,18 +134,18 @@ def test_serial_sequence
       end
 
       def test_default_sequence_name
-        assert_equal 'accounts_id_seq',
+        assert_equal PostgreSQL::Name.new('public', 'accounts_id_seq'),
           @connection.default_sequence_name('accounts', 'id')
 
-        assert_equal 'accounts_id_seq',
+        assert_equal PostgreSQL::Name.new('public', 'accounts_id_seq'),
           @connection.default_sequence_name('accounts')
       end
 
       def test_default_sequence_name_bad_table
-        assert_equal 'zomg_id_seq',
+        assert_equal PostgreSQL::Name.new(nil, 'zomg_id_seq'),
           @connection.default_sequence_name('zomg', 'id')
 
-        assert_equal 'zomg_id_seq',
+        assert_equal PostgreSQL::Name.new(nil, 'zomg_id_seq'),
           @connection.default_sequence_name('zomg')
       end
 
@@ -153,8 +153,7 @@ def test_pk_and_sequence_for
         with_example_table do
           pk, seq = @connection.pk_and_sequence_for('ex')
           assert_equal 'id', pk
-          expected = PostgreSQL::Name.new("public", @connection.default_sequence_name('ex', 'id'))
-          assert_equal expected, seq
+          assert_equal @connection.default_sequence_name('ex', 'id'), seq
         end
       end
 
@@ -162,8 +161,7 @@ def test_pk_and_sequence_for_with_non_standard_primary_key
         with_example_table 'code serial primary key' do
           pk, seq = @connection.pk_and_sequence_for('ex')
           assert_equal 'code', pk
-          expected = PostgreSQL::Name.new("public", @connection.default_sequence_name('ex', 'code'))
-          assert_equal expected, seq
+          assert_equal @connection.default_sequence_name('ex', 'code'), seq
         end
       end