bug#19817: 24.4; cmdproxy fails on some .exe when given a path argument

[Eli Zaretskii]

> From: "Fabio Leimgruber" <fabio.leimgruber@web.de>
> Date: Sun, 8 Feb 2015 15:57:28 +0100
> 
> To reproduce, first copy `C:\Windows\System32\write.exe' to
> `C:\Windows\System32\write.test.exe'.  Then from a Command Prompt
> (i.e. cmd.exe, I will use `$' for distinction nonetheless):
> 
> $ cd D:\opt\emacs\libexec\emacs\24.4\x86_64-w64-mingw32
> 
> $ cmdproxy.exe -c "\"write\" \"d:/asdf.txt\""
> 
> works, whereas:
> 
> $ cmdproxy.exe -c "\"write.test\" \"d:/asdf.txt\""
> 
> fails with:
> 
> 'write.test" "d:' is not recognized as an internal or external command,
> operable program or batch file.

You are not supposed to invoke cmdproxy directly, only via Emacs
functions that invoke shell commands.  So please show a test case
which works with "write" or "write.exe" or "write.test.exe", but fails
with "write.test".

Also, why are you quoting file names that don't require any quotes?