Setup:

1. install `ligature.el` from melpa.

2. start `emacs -Q` and execute the attached script or simply use the attached script as the `init.el`.

3. open the attached `init.el` file and execute `init-faces` or hit "C-#" to start randomizing the font faces,

4. eventually you will see some characters gets rendered with extra spaces (sample screenshots provided below), hit "C-!" to stop the randomization,