better error handling of fzf exit status (nvim-fzf PR #36)

lua/fzf-lua/core.lua

@@ -40,9 +40,9 @@ M.fzf = function(opts, contents)
 
   fzf_win:attach_previewer(previewer)
   fzf_win:create()
-  local selected = fzf.raw_fzf(contents, M.build_fzf_cli(opts),
+  local selected, exit_code = fzf.raw_fzf(contents, M.build_fzf_cli(opts),
     { fzf_binary = opts.fzf_bin, fzf_cwd = opts.cwd })
-  fzf_win:check_exit_status()
+  fzf_win:check_exit_status(exit_code)
   if fzf_win:autoclose() == nil or fzf_win:autoclose() then
     fzf_win:close()
   end

lua/fzf-lua/win.lua

@@ -202,11 +202,15 @@ function FzfWin:reset_win_highlights(win, is_border)
   vim.api.nvim_win_set_option(win, 'winhighlight', hl)
 end
 
-function FzfWin:check_exit_status()
+function FzfWin:check_exit_status(exit_code)
   if not self:validate() then return end
-  local lines = vim.api.nvim_buf_get_lines(self.fzf_bufnr, 0, 1, false)
-  if lines and #lines[1]>0 then
-    utils.warn("fzf error: " .. lines[1])
+  if not exit_code or tonumber(exit_code) ~= 130 then
+    local lines = vim.api.nvim_buf_get_lines(self.fzf_bufnr, 0, 1, false)
+    -- this can happen before nvim-fzf returned exit code (PR #36)
+    if not exit_code and (not lines or #lines[1]==0) then return end
+    utils.warn(("fzf error %s: %s")
+      :format(exit_code or "<null>",
+        lines and #lines[1]>0 and lines[1] or "<null>"))
   end
 end