4532: Long comment hover at the end of a diff causes flickering

solarmist

What version are you running?

2.5.6.1

What's the URL of the page containing the problem?

In the diff view of an review request

What steps will reproduce the problem?

  1. Attached video

What is the expected output? What do you see instead?

What operating system are you using? What browser?

Mac os using Chrome

Please provide any additional information below.