fix(previewer): prefer winopts.winhl (useful with non-float window as previewer)

Author: phanen

lua/fzf-lua/types.lua

@@ -279,8 +279,8 @@ _G.FzfLua = require("fzf-lua")
 ---@field scrolloff? integer
 
 ---@class fzf-lua.config.Keymap
----@field builtin table<string, string>
----@field fzf table<string, string>
+---@field builtin? table<string, string>
+---@field fzf? table<string, string>
 
 ---@class fzf-lua.config.Previewer
 ---@field cmd string|fun():string?

lua/fzf-lua/win.lua

@@ -519,13 +519,16 @@ end
 function FzfWin:reset_win_highlights(win)
   -- derive the highlights from the window type
   local key = "main"
+  local hl
   if win == self.preview_winid then
     key = "prev"
+    hl = self._previewer:gen_winopts().winhl
   end
-  local hl
-  for _, h in ipairs(self.winopts.__winhls[key]) do
-    if h[2] then
-      hl = string.format("%s%s:%s", hl and hl .. "," or "", h[1], h[2])
+  if not hl then
+    for _, h in ipairs(self.winopts.__winhls[key]) do
+      if h[2] then
+        hl = string.format("%s%s:%s", hl and hl .. "," or "", h[1], h[2])
+      end
     end
   end
   utils.wo[win].winhl = hl