Update signs of corresponding buffer for fugitive buffers

[blueyed]

When saving a fugitive buffer, e.g. writing to the Git index for some file, the signs for the corresponding buffer in the working tree should be updated.

It is possible to get the corresponding buffer like this:

  au BufWritePost fugitive:///* call StatuslineClearCacheFugitive()

  function! StatuslineClearCacheFugitive()
      let fug_buffer = fugitive#buffer()
      let [gitdir, fug_path] = split(bufname('%'), '//')[1:2]
      let fug_path = substitute(fug_path, '\v\w*/', '', '')
      let fug_path = fug_buffer.repo().tree(fug_path)
      let bufnr = bufnr(fug_path)
      if bufnr != -1
        call QuickfixsignsSet('BufWritePost', ..., bufnr)
      endif
  endfunction

While it would be nice to have this by default, I can imagine that it's too specific. But for that the QuickfixsignsSet function needs to have support for non-current buffers.

[tomtom]

Wouldn't it be a better approach if you could mark a buffer with some "needs update" flag and to update the signs the buffer the next time it is entered?

[blueyed]

That would work, too - but it's not visible right away.

The following works for me now:

au BufWritePost fugitive:///* call StatuslineClearCacheFugitive(expand('<amatch>'))

function! StatuslineClearCacheFugitive(bufname)
  " Clear cache of corresponding real buffer when saving a fugitive buffer.
  let fug_buffer = fugitive#buffer()
  let [gitdir, fug_path] = split(a:bufname, '//')[1:2]
  let fug_path = substitute(fug_path, '\v\w*/', '', '')
  let fug_path = fug_buffer.repo().tree(fug_path)
  let bufnr = bufnr(fug_path)
  if bufnr != -1
    call StatuslineClearCache(bufnr)

    " Clear caches on / update alternative window(s).
    " https://github.com/tomtom/quickfixsigns_vim/issues/67
    let idx = 0
    let prev_alt_winnr = winnr('#')
    let prev_winnr = winnr()
    for b in tabpagebuflist()
      let idx += 1
      if b == bufnr
        exe 'noautocmd '.idx.'wincmd w'
        QuickfixsignsSet
      endif
    endfor
    if winnr() != prev_winnr || winnr('#') != prev_alt_winnr
        exe 'noautocmd '.prev_alt_winnr.'wincmd w'
        exe 'noautocmd '.prev_winnr.'wincmd w'
    endif
  endif
endfunction