On Apr 16 21:49, Denis Excoffier wrote:
> On 2015-04-16 à 18:43, Corinna Vinschen wrote:
> > On Apr 16 18:21, Corinna Vinschen wrote:
> >> On Apr 16 08:17, Jim Reisert AD1C wrote:
> >>> I am unable to start Cywin/X X-server 1.17.1 with this version.
> >>> Previous releases of 2.0.0.x were OK.  I had to revert to 1.7.35-1 for
> >>> the time being.
> >>> 
> >>> Other than updating to 2.0.0.5, I also installed the April 2015 "Patch
> >>> Tuesday" updates from Microsoft.  I don't know if the two are related.
> >>>  Windows 7 Home Premium, 64-bit
> >>> 
> >>> Exception: STATUS_ACCESS_VIOLATION at eip=77C50F8A
> >>> eax=00000000 ebx=612D67B0 ecx=00001000 edx=612D2648 esi=00000000 edi=0028C790
> >>> ebp=0028C608 esp=0028C604 program=C:\Cygwin\bin\XWin.exe, pid 1660, thread main
> >>> cs=0023 ds=002B es=002B fs=0053 gs=002B ss=002B
> >>> Stack trace:
> >>> Frame     Function  Args
> >>> 0028C608  77C50F8A (00000000, 612D2648, 00000000, 612D67B0)
> >>> 0028C738  610CDA1F (000043FF, 00000000, 00000000, 80012428)
> > 
> > On second thought, if I can trust the args output, that would be an
> > fchmod(0,0).  If there's no uid or gid 0, which there isn't unless you
> > explicitely created them in the passwd/group files, the uid and gid have
> > no SID connected to.  This may be the culprit here.
> > 
> >> I could add an extra check which refuses to change permissions if
> >> the account's SID can't be found, but since this occurs very deep
> >> in the call stack, the error message might be pretty vapid.
> >> 
> >> Alternatively I just let this slip through and you might wonder
> >> why the group hasn't changed in this case.
> > 
> > I added a change to this effect, but it occuurs to me that this may
> > be really just a missing test if the uid and gid values are backed by
> > a real Windows account.  It seems better to return EPERM here.
> > 
> I applied the patch indicated (see in
> https://cygwin.com/ml/cygwin-cvs/2015-q2/msg00033.html) and X11 now works
> back again.
> 
> Thank you 1000 times.

Thanks for the early feedback.  Still, I changed it for -0.6 again,
because that's what had happened in the old code, too:  If the uid or
gid can't be resolved to a Windows SID, the function fails now with
ENOENT.  That's a non-POSIX extension because the problem just doesn't
exist on real POSIX systems.  Please give it a try.


Thanks,
Corinna

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