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Date: Tue, 21 Feb 2012 12:04:15 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
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Subject: Re: shared_info::init_obcaseinsensitive implemented incorrectly
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On Feb 21 10:26, Nick Lowe wrote:
> I have just tested this and it works. It is faster, simpler and has
> less overheads than querying the registry for a potentially stale
> value.
> 
> Just call NtOpenSymbolicLinkObject for \SYSTEMROOT with a
> DesiredAccess of 0 and no attributes flags in the OBJECT_ATTRIBUTES
> structure.
> 
> This will fail with STATUS_ACCESS_DENIED if the system is running with
> case insensitivity and STATUS_OBJECT_NAME_NOT_FOUND if running with
> case sensitivity.
> 
> For correctness, on the off chance that a successful NTSTATUS value is

That's not an off-chance.  It works for all admin accounts.

> returned, the system is running with case insensitivity and the handle
> must be closed.

Just call NtOpenDirectoryObject on \\SYSTEMROOT, rather than
NtOpenSymbolicLinkObject.  NtOpenDirectoryObject will never succeed,
rather it returns STATUS_OBJECT_TYPE_MISMATCH on a case insensitive
system and STATUS_OBJECT_NAME_NOT_FOUND on a case sensitive system.

And then there's Windows 2000 which is always case sensitive.  But I
documented to require the registry key for least surprise, see
http://cygwin.com/cygwin-ug-net/using-specialnames.html#pathnames-casesensitive

I'm going to add this to the Cygwin DLL, but right now I have to
debug another problem.


Corinna

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

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