In url_for, never append ? when the query string is empty anyway.

It used to behave like this:

    url_for(controller: 'x', action: 'y', q: {})
    # -> "/x/y?"

We previously avoided empty query strings in most cases by removing
nil values, then checking whether params was empty.  But as you can
see above, even non-empty params can yield an empty query string.  So
I changed the code to just directly check whether the query string
ended up empty.

(To make everything more consistent, the "removing nil values"
functionality should probably move to ActionPack's Hash#to_query, the
place where empty hashes and arrays get removed.  However, this would
change a lot more behavior.)

1 files changed, 7 insertions, 0 deletions

diff --git a/actionpack/test/dispatch/url_generation_test.rb b/actionpack/test/dispatch/url_generation_test.rb
index fd4ede4d1b..8c9782bb90 100644
--- a/actionpack/test/dispatch/url_generation_test.rb
+++ b/actionpack/test/dispatch/url_generation_test.rb
@@ -129,6 +129,13 @@ module TestUrlGeneration
       )
     end
 
+    test "generating URLS with empty querystring" do
+      assert_equal "/bars.json", bars_path(
+        a: {},
+        format: 'json'
+      )
+    end
+
   end
 end