Fix handling of negative zero in number_to_currency

2 files changed, 3 insertions, 1 deletions

diff --git a/activesupport/lib/active_support/number_helper.rb b/activesupport/lib/active_support/number_helper.rb
index 8f5309c824..981ab0cb36 100644
--- a/activesupport/lib/active_support/number_helper.rb
+++ b/activesupport/lib/active_support/number_helper.rb
@@ -111,7 +111,7 @@ module ActiveSupport
       unit      = options.delete(:unit)
       format    = options.delete(:format)
 
-      if number.to_f < 0
+      if number.to_f.phase != 0
         format = options.delete(:negative_format)
         number = number.respond_to?("abs") ? number.abs : number.sub(/^-/, '')
       end
diff --git a/activesupport/test/number_helper_test.rb b/activesupport/test/number_helper_test.rb
index 8bcdea7ce6..9b7d7f020c 100644
--- a/activesupport/test/number_helper_test.rb
+++ b/activesupport/test/number_helper_test.rb
@@ -64,6 +64,8 @@ module ActiveSupport
           assert_equal("$1,234,567,890.50", number_helper.number_to_currency("1234567890.50"))
           assert_equal("1,234,567,890.50 K&#269;", number_helper.number_to_currency("1234567890.50", {:unit => "K&#269;", :format => "%n %u"}))
           assert_equal("1,234,567,890.50 - K&#269;", number_helper.number_to_currency("-1234567890.50", {:unit => "K&#269;", :format => "%n %u", :negative_format => "%n - %u"}))
+          assert_equal("0.00", number_helper.number_to_currency(+0.0, {:unit => "", :negative_format => "(%n)"}))
+          assert_equal("(0.00)", number_helper.number_to_currency(-0.0, {:unit => "", :negative_format => "(%n)"}))
         end
       end