After using goyo, tabnew creates a nomodifiable buffer.

[itchyny]

To reproduce:

:Goyo
:Goyo
:tabnew

Problem:
The new buffer is nomodifiable.

To fix:
Use setlocal in the two set statement in the function setup_pad.

I don't read the whle code well so I don't get why this function is called on tabnew.

[junegunn]

Whoa, you're right, setlocal fixes the problem. Thanks
(The function is not called though as autocommand groups are properly cleared when Goyo tab is closed.)