bug#66514: start-process explorer.exe open wrong directory

[Eli Zaretskii]

> From: Shynur Xie <one.last.kiss@outlook.com>
> Date: Fri, 13 Oct 2023 11:40:44 +0000
> msip_labels: 
> 
> (Emacs v29.1 on MS-Windows)
> 
> Reproduce:
> 
>   1. $ emacs.exe -Q
>   2. (start-process "Explorer" nil "explorer.exe" "C:/Users/username")
> 
> I think it should open the HOME folder,
> but it actually opened "C:/Users/username/Documents".

Try

  (start-process "Explorer" nil "explorer.exe" "C:\\Users\\username")

> When I use shell-mode or eshell, explorer works as expected.

How exactly do you "use shell-mode or eshell" to start the Explorer?