fix: don't apply vim.regex on --fix-strings (#2363)

Author: phanen

lua/fzf-lua/previewer/builtin.lua

@@ -1226,7 +1226,7 @@ function Previewer.buffer_or_file:set_cursor_hl(entry)
     (function()
       -- Check both the cmd and glob_args in case the user has a custom
       -- `rg_glob_fn` which uses raw args (as the wiki example)
-      for _, s in ipairs({ self.opts.cmd, glob_args }) do
+      for _, s in ipairs({ self.opts.cmd or self.opts._cmd, glob_args }) do
         if s and (s:match("%-%-fixed%-strings") or s:match("%-F")) then
           regex = utils.rg_escape(regex)
           return

lua/fzf-lua/providers/grep.lua

@@ -133,7 +133,7 @@ M.live_grep = function(opts)
   opts = normalize_live_grep_opts(opts)
   if not opts then return end
 
-  -- register opts._cmd, toggle_ignore/title_flag
+  -- register opts._cmd, toggle_ignore/title_flag/--fixed-strings
   local cmd0 = get_grep_cmd(opts, core.fzf_query_placeholder, 2)
 
   -- if multiprocess is optional (=1) and no prpocessing is required