Add compatibility for Ruby 2.4 `to_time` changes

In Ruby 2.4 the `to_time` method for both `DateTime` and `Time` will
preserve the timezone of the receiver when converting to an instance
of `Time`. Since Rails 5.0 will support Ruby 2.2, 2.3 and later we
need to introduce a compatibility layer so that apps that upgrade do
not break. New apps will have a config initializer file that defaults
to match the new Ruby 2.4 behavior going forward.

For information about the changes to Ruby see:
https://bugs.ruby-lang.org/issues/12189
https://bugs.ruby-lang.org/issues/12271

Fixes #24617.

1 files changed, 9 insertions, 0 deletions

diff --git a/activesupport/lib/active_support.rb b/activesupport/lib/active_support.rb
index 72777baecd..11569add37 100644
--- a/activesupport/lib/active_support.rb
+++ b/activesupport/lib/active_support.rb
@@ -26,6 +26,7 @@ require "active_support/dependencies/autoload"
 require "active_support/version"
 require "active_support/logger"
 require "active_support/lazy_load_hooks"
+require "active_support/core_ext/date_and_time/compatibility"
 
 module ActiveSupport
   extend ActiveSupport::Autoload
@@ -85,6 +86,14 @@ module ActiveSupport
   def self.halt_callback_chains_on_return_false=(value)
     Callbacks.halt_and_display_warning_on_return_false = value
   end
+
+  def self.to_time_preserves_timezone
+    DateAndTime::Compatibility.preserve_timezone
+  end
+
+  def self.to_time_preserves_timezone=(value)
+    DateAndTime::Compatibility.preserve_timezone = value
+  end
 end
 
 autoload :I18n, "active_support/i18n"