feat(diagnostic): don't open quickfix/loclist if no diagnostics neovi…

…m#21397

runtime/lua/vim/diagnostic.lua

@@ -478,13 +478,17 @@ local function set_list(loclist, opts)
  -- numbers beyond the end of the buffer
  local diagnostics = get_diagnostics(bufnr, opts, false)
  local items = M.toqflist(diagnostics)
+ if next(items) == nil then
+ vim.notify('No diagnostics available')
+ return
+ end
  if loclist then
  vim.fn.setloclist(winnr, {}, ' ', { title = title, items = items })
  else
  vim.fn.setqflist({}, ' ', { title = title, items = items })
  end
  if open then
- api.nvim_command(loclist and 'lopen' or 'botright copen')
+ api.nvim_command(loclist and 'lwindow' or 'botright cwindow')
  end
 end