Issue description

Please read https://github.com/tmux/tmux/blob/master/.github/CONTRIBUTING.md before opening an issue.

If you have upgraded, make sure your issue is not covered in the CHANGES file for your version: https://raw.githubusercontent.com/tmux/tmux/master/CHANGES

Describe the problem and the steps to reproduce. Add a minimal tmux config if necessary. Screenshots can be helpful, but no more than one or two.

Do not report bugs (crashes, incorrect behaviour) without reproducing on a tmux built from the latest code in Git.

Required information

Please provide the following information:

• tmux version (tmux -V).
• Platform (uname -sp).
• $TERM inside and outside of tmux (echo $TERM).
• Logs from tmux (tmux kill-server; tmux -vv new).