Fix UUID column with `null: true` and `default: nil`

`quote_default_expression` can be passed nil value when `null: true` and
`default: nil`. This addressed in that case.

Fixes #29222.

1 files changed, 10 insertions, 0 deletions

diff --git a/activerecord/test/cases/adapters/postgresql/uuid_test.rb b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
index 52e4a38cae..6ebe9d82a7 100644
--- a/activerecord/test/cases/adapters/postgresql/uuid_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
@@ -63,6 +63,16 @@ class PostgresqlUUIDTest < ActiveRecord::PostgreSQLTestCase
     UUIDType.reset_column_information
   end
 
+  def test_add_column_with_null_true_and_default_nil
+    assert_nothing_raised do
+      connection.add_column :uuid_data_type, :thingy, :uuid, null: true, default: nil
+    end
+    UUIDType.reset_column_information
+    column = UUIDType.columns_hash["thingy"]
+    assert column.null
+    assert_nil column.default
+  end
+
   def test_data_type_of_uuid_types
     column = UUIDType.columns_hash["guid"]
     assert_equal :uuid, column.type