Redmine

The code below fixes the issue:

diff --git a/app/helpers/queries_helper.rb b/app/helpers/queries_helper.rb
index 3aef7083a..005b91f89 100644
--- a/app/helpers/queries_helper.rb
+++ b/app/helpers/queries_helper.rb
@@ -227,7 +227,7 @@ module QueriesHelper
       end
       content =
         link_to(
-          sprite_icon(icon, column.caption),
+          (icon.present? ? sprite_icon(icon, column.caption) : column.caption),
           {:params => request.query_parameters.deep_merge(sort_param)},
           link_options
         )

Before:

After:

The attached is a patch with test.