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

[Ken Brown]

On 4/11/2012 3:26 PM, Eli Zaretskii wrote:
> I think we should put our money where our mouth is.  If we consider
> Cygwin 1.5 unsupported, we should at least warn the prospective users
> that they are building Emacs with unsupported tools.
> 
> So yes, I think we should insert a warning now.  Could you please make
> such a change?  TIA.

How's this:

=== modified file 'configure.in'
--- configure.in        2012-04-02 04:38:31 +0000
+++ configure.in        2012-04-12 02:38:52 +0000
@@ -3805,6 +3805,14 @@
    echo
 fi

+if test "${opsys}" = "cygwin"; then
+   cygwin_rel=`uname -r|sed -e 's/\(^1\.[[579]]\)\..*/\1/'`
+   if test "${cygwin_rel}" = "1.5"; then
+      echo
+      echo "*** Warning: Building Emacs on Cygwin 1.5 is not supported."
+      echo
+   fi
+fi

 # Remove any trailing slashes in these variables.
 [test "${prefix}" != NONE &&

FYI, here's what the output of `uname -r' looks like on Cygwin:

$ uname -r
1.7.14s(0.260/5/3)