Vim-airline: Extra separator on tab/buffer line right

[tnguyen14]

I enable tab line, with the following config

let g:airline#extensions#tabline#enabled = 1
" Show just the filename
let g:airline#extensions#tabline#fnamemod = ':t'

let g:airline#extensions#syntastic#enabled = 1

let g:airline_theme = 'base16'
let g:airline_left_sep = ''
let g:airline_left_alt_sep = ''
let g:airline_right_sep = ''
let g:airline_right_alt_sep = ''
if !exists('g:airline_symbols')
    let g:airline_symbols = {}
endif
let g:airline_symbols.branch = ''
let g:airline#extensions#tabline#left_sep = ''
let g:airline#extensions#tabline#left_alt_sep = ''

sorry for the symbols, here's the screenshot of the config

However, on the tab line, on the right side, next to the words "buffers", I see an extra left-pointing triangle separator. Am I doing something wrong/ missing something here?

[chrisbra]

Cannot reproduce

[tnguyen14]

Here is my entire .vimrc, I am not sure if it's an overkill, but might help reproduce it? https://github.com/tnguyen14/dotfiles/blob/master/home/.vimrc

[chrisbra]

what terminal is this? Please check the output of :echo $TERM and :set t_Co?

[chrisbra]

I believe this is a problem with the base16 theme. I think that some of the highlighting groups are not defined correctly for your terminal. Can you show the output of :hi airline_tabfill_to_airline_tabfill?

[tnguyen14]

:echo $TERM
xterm-256colors

:set t_Co?
t_Co=256

:hi airline_tabfill_to_airline_tabfill
airline_tabfill_to_airline_tabfill xxx ctermfg=18 ctermbg=18

[chrisbra]

and what terminal are you using?

[chrisbra]

Have you modified your terminal color configuration? That should be a straight dark blue color

[tnguyen14]

I am using iTerm, with the Terminal Type set to xterm-256colors.

[chrisbra]

and what color is airline_tabfill_to_airline_tabfill xxx ctermfg=18 ctermbg=18? This should be a dark blue

[tnguyen14]

Attached is the screenshot if that's helpful?

[chrisbra]

That is interesting. Did you configure the colors there (or is this even possible)? See the two numbers, that are the same? Defining a foreground color and background color with the exact same number should make it a solid color and not display the xxx, i would expect. Also in true xterms this is supposed to be a dark blue color. I am not sure to fix this, except for defining your own color scheme with custom colors.
I don't have a Mac, so I can't really check. However I have a feeling, that this is really broken here. Can you try with an updated terminal? Or Is iTerm2 working better?

[tnguyen14]

I am actually using iTerm2.

Is there any way I could debug this further? Maybe it's the base16 theme that is the issue here.

[klaernie]

@chrisbra: to a certain extend it is.
@tnguyen14: try terminalcolors.py to see how your colors behave without vim in play.

[tnguyen14]

@klaernie I just ran it. should I take screenshots and share here?

[klaernie]

Yeah, sure. I don't know if I found the exact version I have in my repo, but it should show if any of the color is behaving strangely

[klaernie]

as a small comparison: that is my urxvt under linux (ignore the first 16, they are configured specially):

[tnguyen14]

Mine definitely looks very different. It's spread out over a very long output. Here's some of the screenshots

[tnguyen14]

Running the colortest from here https://github.com/chriskempson/base16-shell gives me this

[klaernie]

@tnguyen14 : am I assuming right you use somthing like https://github.com/chriskempson/base16-shell#shells ? If I use the base16-colors.dark.sh from @chriskempson it reconfigures my current urxvt-instance to use different colors for the first 21 entries in the palette. In your last screenshot I can see that your terminal is having a different color for the foreground and the background. Hence you have a problem with the base16 theme in vim, it expects that foreground and background are the same.

Take a look at the example screenshot in base16-shell, there shouldn't be lines visible. I would suspect now, that your terminal colors are off. For some reason the foreground is behaving differently than the background. For some really obscure reason the terminal doesn't paint the right color if background and foreground are identical. I would suspect any advanced feature with an intention to keep the text legible. Did you check your terminals settings?

[klaernie]

Just for further reference: the colortest left side is painted with foreground of the said color, the right side just set additionally the background color. As soon as they match the terminal does shift the foreground color to a lighter or darker shade.

[klaernie]

@chrisbra : there you can take a look how to reconfigure the color palette via ANSI Escape Sequences. Damnit, I enjoy tinkering with this low-level stuff too much - just took an hour to deduce this problem.

[tnguyen14]

@klaernie wow thanks for epic exploration. You'e right, I am using the base16-colors.dark.sh https://github.com/tnguyen14/dotfiles/blob/master/home/.bashrc#L39

I am not sure what settings from iTerm2 that I have, other than the xterm-256colors, and then setting the Colors profile of base16-tomorrow.dark from here https://github.com/chriskempson/base16-iterm2

[chrisbra]

@klaernie Thanks for stepping in. I wouldn't be able to further debug it. It's nice to see, that all this is possible, but as we see, this means it breaks in subtle ways if one does not know what all this means.

I am closing this issue, as it is clear, that this is not an airline issue.

[tnguyen14]

Just wanna post an update here, just in case it's helpful for someone else.

I couldn't figure out what is wrong with my terminal, but adjusting the "Minimum contrast" level on iTerm to the lowest possible value helps with this issue.

There is now still a small weirdness in the separator at the bottom, that could possibly be due to the semi-transparency of my iTerm window. However, this is much less noticeable and sticking out than the previous issue.