Re: cygcheck -s segfaults in cygwin64 on Win7Pro-64

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

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On Oct 21 04:03, Andrew Schulman wrote:
> > Instead, I found that COMSPEC needs to be set in the environment or I get a 
> > segfault as shown in my previous email below.  I don't know why that is, 
> > but I can easily demonstrate it.
> 
> Confirmed here.  I had actually already seen this segfault too, but I
> hadn't figured out it was caused by empty COMSPEC.

That's interesting.  I just debugged this a bit.  As you know, cygcheck
is a native Windows application (it's supposed to work even if Cygwin
is entirely broken).

At one point it tries to fetch information about the installed services
by calling cygrunsrv --list --verbose.  It tries to accomplish that by
calling the MSVCRT version of popen(2).  And it's that call to popen
which crashes if COMSPEC is not set, or not set correctly.

I applied a patch to cygcheck, which enforces setting COMSPEC if the
variable is unset.  That doesn't help against *wrong* settings of COMSPEC,
but that's really user's fault alone, I think :)

I also created a new snapshot on https://cygwin.com/snapshots/ which
comes with a cygcheck containing that patch.


HTH,
Corinna

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

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