do not assume that there is no space between

leading */* and comma

Signed-off-by: José Valim <jose.valim@gmail.com>

actionpack/lib/action_dispatch/http/mime_negotiation.rb

@@ -48,7 +48,7 @@ def formats
         @env["action_dispatch.request.formats"] ||=
           if parameters[:format]
             Array(Mime[parameters[:format]])
-          elsif xhr? || (accept && accept !~ /,\s*\*\/\*|\*\/\*,/)
+          elsif xhr? || (accept && accept !~ /,\s*\*\/\*|\*\/\*\s*,/)
             accepts
           else
             [Mime::HTML]

actionpack/test/controller/mime_responds_test.rb

@@ -254,6 +254,10 @@ def test_json_or_yaml_with_leading_star_star
     @request.accept = "*/*, application/json"
     get :json_xml_or_html
     assert_equal 'HTML', @response.body
+
+    @request.accept = "*/* , application/json"
+    get :json_xml_or_html
+    assert_equal 'HTML', @response.body
   end
 
   def test_json_or_yaml