Fixes #20799

When `#perform_later` is called the locale isn't stored on the
queue, which results in a locale reset when the job is performed.

An example of the problem:

    I18n.locale = 'de'
    HelloJob.perform_now # german message, correct

but

    I18n.locale = 'de'
    HelloJob.perform_later # english message, incorrect

This PR attaches the current I18n.locale to every job during the
serialization process. It is then restored during deserialization
and used to perform the job with the correct locale.

It falls back to the default locale if no serialized locale is
found in order to provide backward compatibility with previously
stored jobs. It is not necessary to clear the queue for the update.

1 files changed, 17 insertions, 0 deletions

diff --git a/activejob/test/integration/queuing_test.rb b/activejob/test/integration/queuing_test.rb
index d345092dee..e1634972d1 100644
--- a/activejob/test/integration/queuing_test.rb
+++ b/activejob/test/integration/queuing_test.rb
@@ -68,4 +68,21 @@ class QueuingTest < ActiveSupport::TestCase
     refute delayed_test_job.provider_job_id.nil?,
       'Provider job id should by set for delayed jobs by provider'
   end
+
+  test 'current locale is kept while running perform_later' do
+    skip if adapter_is?(:inline)
+
+    begin
+      I18n.available_locales = [:en, :de]
+      I18n.locale = :de
+
+      TestJob.perform_later @id
+      wait_for_jobs_to_finish_for(5.seconds)
+      assert job_executed
+      assert_equal 'de', job_output
+    ensure
+      I18n.available_locales = [:en]
+      I18n.locale = :en
+    end
+  end
 end