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, 4 insertions, 0 deletions

diff --git a/actionview/test/template/url_helper_test.rb b/actionview/test/template/url_helper_test.rb
index 50b7865f88..b8f4d13812 100644
--- a/actionview/test/template/url_helper_test.rb
+++ b/actionview/test/template/url_helper_test.rb
@@ -38,6 +38,10 @@ class UrlHelperTest < ActiveSupport::TestCase
     assert_equal "/?a=b&c=d", url_for(hash_for(a: :b, c: :d))
   end
 
+  def test_url_for_does_not_include_empty_hashes
+    assert_equal "/", url_for(hash_for(a: {}))
+  end
+
   def test_url_for_with_back
     referer = 'http://www.example.com/referer'
     @controller = Struct.new(:request).new(Struct.new(:env).new("HTTP_REFERER" => referer))