Seems like a bug with mkfifo -m

[Ken Brown]

On 5/28/2020 11:28 AM, Ken Brown via Cygwin wrote:
> On 5/28/2020 10:52 AM, Corinna Vinschen wrote:
>> On May 28 09:16, Ken Brown via Cygwin wrote:
>>> On 5/28/2020 4:12 AM, Дмитрий Есарев via Cygwin wrote:
>>>> Hi, all
>>>>
>>>> When i ran cygwin 2.x, i used mkfifo -m 0600 file to create a named pipe 
>>>> with no user and group permissions.
>>>>
>>>> in the latest cygwin the above command creates device with 0644 permissions. 
>>>> And i cant drop it to 0600:
>>>>
>>>> cygcheck.exe -V
>>>> cygcheck (cygwin) 3.1.4
>>>>
>>>> $ umask 0077
>>>> $ touch somefile; ls -l somefile
>>>> -rw------- 1 admin absent 0 may 26 18:15 somefile
>>>>
>>>> $ mkfifo -m 0600 somefifo; ls -l somefifo
>>>> prw-r--r-- 1 admin absent 0 may 26 18:16 somefifo
>>>>
>>>> $ chmod 600 somefifo; ls -l somefifo
>>>> prw-r--r-- 1 admin absent 0 may 26 18:16 somefifo
>>>>
>>>>
>>>>
>>>> In old-good cygwin 2.x the command works as expected:
>>>>
>>>> $ cygcheck.exe -V
>>>> cygcheck (cygwin) 2.9.0
>>>>
>>>> $ umask
>>>> 0022
>>>>
>>>> $ mkfifo -m 0600 somefifo; ls -l somefifo
>>>> prw------- 1 builduser Domain Users 0 May 26 18:21 somefifo
>>>
>>> Thanks for the report.  The problem isn't with mkfifo, it's with the
>>> permission information reported by ls.  I did a bisection of the Cygwin
>>> development repo and found that the regression was introduced by the
>>> following commit:
>>>
>>> commit f36262d56ac78f04de147746ce4a85c6155e4a23
>>> Author: Corinna Vinschen <corinna@vinschen.de>
>>> Date:   Wed Jan 29 15:14:05 2020 +0100
>>>
>>>      Cygwin: stat: fix st_mode of fifos
>>>
>>> I'll take a look if Corinna doesn't get to it first.
>>
>> Not sure what I was thinking at the time.  I recall having observed
>> something funny, but the patch was apparently wrong.  Just revert
>> it at your discretion, Ken.
> 
> I remember we had an IRC discussion about it, but I can't remember what the 
> issue was.  I'll look a little more closely before reverting.

OK, it turned out that part of that patch needed to be reverted.  It's done now.

Ken