bug#12632: file permissions checking mishandled when setuid

[Andy Moreton]

On Tue 23 Oct 2012, Paul Eggert wrote:

> On 10/23/2012 09:44 AM, Eli Zaretskii wrote:
>> Others, like "//.", are downright dangerous, because "\\.\" begins a
>> device name on Windows.  With these arcana notoriously
>> under-documented by MS, it is anybody's guess what such names can do
>> in what APIs.
>
> OK, thanks for explaining: I did not know about that syntax,
> or about the behavior being undocumented and undefined.
> Also, come to think of it, there will be problems with
> drive prefixes.

FYI it is documented - see "Win32 Device Namespaces":
http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247%28v=vs.85%29.aspx

Of course as Eli suggests, this documentation may not be the whole
story, as you still need to know which names and namespaces are
supported by a given API (and on which versions of Windows).

    AndyM