Thanks for this :)

Would you have time to add a test case to new_window.test.sh? If not, no worries, I need to add tests to a lot of things anyway. So for now I'd be happy to merge without tests :)

I'm quite busy at the moment, so I doubt I will have the time to do a proper test before a while. As for the tmux settings that would be required/useful in this test, probably something like this:

setw -g set-titles on
setw -g allow-rename on
setw -g automatic-rename on

With these settings, creating a new window and changing the current directory (for instance) should not modify the predefined name of the window.

No problem, and thanks for the pointers :)