Delete current buffer in Vim without closing its split.

bdelete.vim

function! s:Bdelete(bang) abort
  let l:current_buffer = bufnr("%")
  let l:alternate_buffer = bufnr("#")

  if buflisted(l:alternate_buffer)
    execute "buffer" . a:bang . " #"
  else
    execute "bnext" . a:bang
  endif

  if bufnr("%") == l:current_buffer
    new
  endif

  if buflisted(l:current_buffer)
    execute "bdelete" . a:bang . " " . l:current_buffer
  endif
endfunction

if !exists(":Bdelete")
  command -bang -bar Bdelete call <SID>Bdelete(<q-bang>)
endif