On a modern webbrowser (tested OS X 10.10, Chrome 38.0.2125.104), with master as of v2.8.0-beta-253-g8950e7f ...
- Set up a course with grades, such as the 'Glorious gradebook' course in qa.moodle.net
- Open the Grader report
- Collapse any column
- Expected: a JS/CSS operation that hides the column
- Got: page reload