bug#10398: [PATCH] Use real vfork under Cygwin: it's fine these days

[Ken Brown <kbrown@cornell.edu>]

On 4/11/2012 2:58 AM, Eli Zaretskii wrote:
>> From: Lars Magne Ingebrigtsen<larsi@gnus.org>
>> Cc: 10398@debbugs.gnu.org, Eli Zaretskii<eliz@gnu.org>
>> Date: Wed, 11 Apr 2012 01:26:56 +0200
>>
>> Daniel Colascione<dancol@dancol.org>  writes:
>>
>>> In Cygwin 1.7, vfork is an alias for fork.  The vfork the #define in
>>> cygwin.h was protecting against is gone.  It's better to use vfork now
>>> so that when Cygwin gains a new, working vfork, we use it
>>> automatically.
>>
>> [...]
>>
>>> -/* vfork() interacts badly with setsid(), causing ptys to fail to
>>> -   change their controlling terminal */
>>> -#define vfork fork
>>
>> Sounds sensible to me, but I'm no exactly (ahem) a Cygwin expert.
>>
>> Eli, what do you think?
>
> Not that _I_ am a Cygwin expert, but isn't it safer to do that only
> for Cygwin 1.7 and later?  Ken, WDYT?

I think it's a good change.  And I don't think we should make an effort 
to support Cygwin versions earlier than 1.7.  Cygwin 1.5 is no longer 
supported by Cygwin, so I don't see a reason for emacs to try to support 
it.  I suspect there have been many emacs changes that are not 
compatible with Cygwin 1.5.

Ken