[glib] Do not detect GNUstep as Cocoa

[William Hua <williamhua src gnome org>]

commit b3f814883f460ec9b309552a501652ecdecfb2dc
Author: Alexandre Rostovtsev <tetromino gentoo org>
Date:   Sun Apr 15 22:57:25 2012 -0400

    Do not detect GNUstep as Cocoa
    
    GNUstep also installs Foundation/Foundation.h
    
    https://bugzilla.gnome.org/show_bug.cgi?id=674172
    
    Signed-off-by: William Hua <william attente ca>

 configure.ac |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 839b8a4..466cf43 100644
--- a/configure.ac
+++ b/configure.ac
@@ -179,6 +179,9 @@ glib_have_cocoa=no
 AC_MSG_CHECKING([for Mac OS X Cocoa support])
 AC_TRY_CPP([
 #include <Cocoa/Cocoa.h>
+#ifdef GNUSTEP_BASE_VERSION
+#error "Detected GNUstep, not Cocoa"
+#endif
 ], glib_have_cocoa=yes)
 
 AC_MSG_RESULT([$glib_have_cocoa])