marijnh/CodeMirror — pull request #2250 by ZombieHippie (2014-02-12 06:24:07+00:00)
Title: Fixed cursor layers

I suspect that only z-index styles are inherited only if the parent and child are both absolute or relatively positioned. Since the cursors container is not absolutely, or relatively positioned the z-index: 3 does not affect how the cursors are rendered, which is why we saw leading cursor heads being hidden by the selection.