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Date: Wed, 27 Apr 2011 16:08:51 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: False positive from access("/proc/registry/...", F_OK)
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On Apr 27 12:26, Christian Franke wrote:
> access("/proc/registry/...", F_OK) returns 0 for all (including
> nonexistent) entries below a registry key which cannot be opened:
> 
> Testcase (run with admin rights):
> 
> # cygcheck -f /bin/cygwin1.dll
> cygwin-1.7.9-1
> 
> # cd /proc/registry/HKEY_LOCAL_MACHINE
> 
> # ls SECURITY
> Cache  Policy  RXACT  SAM
> 
> # cygdrop -- ls SECURITY
> ls: reading directory SECURITY: Permission denied
> 
> # test -e SECURITY/NoSuchFile && echo yes
> 
> # cygdrop -- test -e SECURITY/NoSuchFile && echo yes
> yes
> 
> 
> Problem was likely introduced by fhandler_registry.cc change 1.52:
> 
>  fhandler_registry::exists ()
>  ...
>    if (!val_only)
>      hKey = open_key (path, KEY_READ, wow64, false);
>  - if (hKey != (HKEY) INVALID_HANDLE_VALUE)
>  + if (hKey != (HKEY) INVALID_HANDLE_VALUE || get_errno () == EACCES)
>      file_type = 1;
>    else
> 
> open_key() returns INVALID_HANDLE_VALUE and EACCESS also if an upper
> level key cannot be opened. The exists() function returns 1
> (virt_directory) then, it should return 0 (virt_none).

I don't remember anymore why I did that and naturally I also didn't
write a comment.

But what you say sounds right to me.  Please create a patch.


Thanks,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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