Whitespaces highlighted in unite buffers even when unite filetype is blacklisted

[mat-r]

The Problem

From commit 8f488a4, whitespaces are highlighted in unite buffers. They were not before.

From what I read in the readme file, unite filetype shoud be blacklisted by default:

This replaces the filetypes from the default list of blacklisted filetypes. The default types that are blacklisted are:
['diff', 'gitcommit', 'unite', 'qf', 'help', 'markdown']

Vim version

VIM - Vi IMproved 7.4
Included patches: 1-1689
Extra patches: 8.0.0056

Minimal .vimrc

call plug#begin('~/.vim/plugged')
Plug 'Shougo/unite.vim'
Plug 'ntpeters/vim-better-whitespace'
call plug#end()

Screenshot before commit 8f488a4, using command :Unite

Screenshot after commit 8f488a4, using command :Unite

Manual blacklisting in .vimrc

I also tried just in case to blacklist unite filetype in the .vimrc (even if it should already be blacklisted by default) with:

let g:better_whitespace_filetypes_blacklist=['unite']

but it did not change anything.

If you need me to provide more information, do not hesitate to ask.

[Cimbali]

This seems to be the same as #76. Basically we enter the buffer before loading it because it is plugin-generated content and not a file, so BufWinEnter is called before FileType.

We can only check the blacklist at FileType obviously, and we need to setup the auto commands every time we enter the buffer hence we need to have made up our mind at BufWinEnter.

Adding a third case for b:better_whitespace_enabled (on / off / uninitialized) that we would use as a default at BufWinEnter if &filetype is not set should fix this. Override this uninitialized value at FileType, fallback to g:better_whitespace_enabled if we encounter it when setting up auto commands.