Fix work packages sidebar hook after query filter refactoring (#2395)

doc/CHANGELOG.md

@@ -36,6 +36,7 @@ See doc/COPYRIGHT.rdoc for more details.
 
 # Changelog
 
+* `#2395` [Work Package Tracking] Internal Error when entering a character in a number field in a filter
 * Adaptations for new icon font
 * Fix: Backlog data existence check
 

lib/open_project/backlogs/hooks.rb

@@ -55,9 +55,9 @@ module OpenProject::Backlogs::Hooks
 
       q = context[:request].session[:query]
       if q && q[:filters]
-        sprint = q[:filters]['fixed_version_id']
-        if sprint && sprint[:operator] == '=' && sprint[:values].size == 1
-          locals[:sprint] = Sprint.find_by_id(sprint[:values][0])
+        sprint = q[:filters].detect{|f| f.field == :fixed_version_id}
+        if sprint && sprint.operator == '=' && sprint.values.size == 1
+          locals[:sprint] = Sprint.find_by_id(sprint.values[0])
         end
       end