[glib] Disable refcounting type propagation with C++

[Emmanuele Bassi <ebassi src gnome org>]

commit 1a6f6487b7c7767ff3b950697e4130f922d1b3a4
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Fri Dec 8 15:44:37 2017 +0000

    Disable refcounting type propagation with C++
    
    The type propagation breaks the GRefPtr.h class in WebKitGTK, and in
    any case existing C++ code calling the C API will need to perform an
    explicit cast, as there's no automatic promotion of pointer types to
    and from void*.
    
    Tested-by: GNOME Continuous
    
    https://bugzilla.gnome.org/show_bug.cgi?id=790697

 gobject/gobject.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gobject/gobject.h b/gobject/gobject.h
index 490d926..eaefe92 100644
--- a/gobject/gobject.h
+++ b/gobject/gobject.h
@@ -508,7 +508,7 @@ GLIB_AVAILABLE_IN_ALL
 void        g_object_remove_weak_pointer      (GObject        *object, 
                                                gpointer       *weak_pointer_location);
 
-#if defined(__GNUC__) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_56
+#if defined(__GNUC__) && !defined(__cplusplus) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_56
 /* Make reference APIs type safe with macros */
 #define g_object_ref(Obj)      ((__typeof__(Obj)) (g_object_ref) (Obj))
 #define g_object_ref_sink(Obj) ((__typeof__(Obj)) (g_object_ref_sink) (Obj))