Undo after File closing about ci_edit HOT 1 OPEN

Thanks for asking. Here's what I just tried (to check whether it's working for me)
On OSX:

1. we file_name
2. type "one" (or any text), ctrl+s, ctrl+q
3. reopen the file with we file_name
4. ctrl+z to undo (works), ctrl+y to redo (works)
   Please let me know if the above works for you (i.e. it may take something more for me to see the issue - it's super helpful to see the issue for me to fix it).

What's happening to make it work:

• When ci_edit starts up it (tries to) creates a directory in the user's home directory called ".ci_edit".
• It will then save undo information at "$HOME/.ci_edit/history.dat".
• The code that saves the file history (undo info) is in "ci_edit/app/history.py" (if you're a programmer you're invited to have a look, if you're not a programmer no worries - I'm happy to help)
• Something that's a bit iffy is that the file history is stored entirely by the file contents (hash). So if two files have the identical content they are considered the same file in the eyes of the undo history. If you're using two files with identical content and one seems to lose undo information, this could be the issue (and would be something I'd want to fix/change).

from ci_edit.