Fix time_zone_options_for_select to not mutate TimeZones array

Previous implementation of time_zone_options_for_select did not dup the
ActiveSupport::TimeZone.all array.  When :priority_zones were provided
the method would reject! the zones from the memoized TimeZones array
thus affecting future requests to the server.  Essentially whatever
zones were specified as :priority_zones would show up for the first
request but then disappear from the time zone options on future
requests.

1 files changed, 7 insertions, 0 deletions

diff --git a/actionpack/test/template/form_options_helper_test.rb b/actionpack/test/template/form_options_helper_test.rb
index c5efed3195..757b05dbc1 100644
--- a/actionpack/test/template/form_options_helper_test.rb
+++ b/actionpack/test/template/form_options_helper_test.rb
@@ -416,6 +416,13 @@ class FormOptionsHelperTest < ActionView::TestCase
                  "<option value=\"D\">D</option>",
                  opts
   end
+  
+  def test_time_zone_options_with_priority_zones_does_not_mutate_time_zones
+    original_zones = ActiveSupport::TimeZone.all.dup
+    zones = [ ActiveSupport::TimeZone.new( "B" ), ActiveSupport::TimeZone.new( "E" ) ]
+    opts = time_zone_options_for_select( nil, zones )
+    assert_equal original_zones, ActiveSupport::TimeZone.all
+  end
 
   def test_time_zone_options_returns_html_safe_string
     assert time_zone_options_for_select.html_safe?