fix(actions): pass nil to can_replace_buf instead of 0

In Lua, 0 is truthy so `buf = buf or nvim_get_current_buf()` never
falls back, and `getbufinfo(0)` returns an empty table where `changed`
is nil. Since `nil ~= 0` is true, `buffer_is_dirty` always reports
dirty, causing `can_replace_buf` to always return false when
`hidden=false` — breaking file_edit for every selection.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

lua/fzf-lua/actions.lua

@@ -192,7 +192,6 @@ end
 
 ---@return boolean
 local can_replace_buf = function(buf)
-  buf = buf or vim.api.nvim_get_current_buf()
   return vim.o.hidden
       or vim.o.confirm
       or vim.o.autowriteall
@@ -239,7 +238,7 @@ M.vimcmd_entry = function(vimcmd, selected, opts, bufedit)
         end
         if layoutcmd then
           vim.cmd(layoutcmd)
-        elseif not is_curbuf(entry.bufnr, fullpath) and not can_replace_buf(0) then
+        elseif not is_curbuf(entry.bufnr, fullpath) and not can_replace_buf() then
           return utils.warn("Unable to add buffer %s", fullpath)
         end
         -- NOTE: URI entries only execute new buffers (new|vnew|tabnew)

lua/fzf-lua/utils.lua

@@ -1116,7 +1116,7 @@ end
 ---@param only_if_last_buffer? boolean
 ---@return boolean
 function M.buffer_is_dirty(bufnr, warn, only_if_last_buffer)
-  bufnr = bufnr or vim.api.nvim_get_current_buf()
+  bufnr = (bufnr == nil or bufnr == 0) and vim.api.nvim_get_current_buf() or bufnr
   local info = bufnr and M.getbufinfo(bufnr)
   if info and info.changed ~= 0 then
     if only_if_last_buffer and 1 < #vim.fn.win_findbuf(bufnr) then