[gtk+/gtk-3-2] Quartz, Bug 655057: Eliminate Compiler Warning

[John Ralls <jralls src gnome org>]

commit 9aa26f0d6404bed1fccd0995f92030ad98d56afe
Author: Alex Corrado <alexander corrado gmail com>
Date:   Sun Oct 9 09:52:14 2011 -0700

    Quartz, Bug 655057: Eliminate Compiler Warning
    
    When compiled with older SDKs, the original change for this bug caused a
    compiler warning about NSWindow not being able to handle a setStyleMask
    message. This tricks the compiler into thinking that it can.

 gdk/quartz/gdkwindow-quartz.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/gdk/quartz/gdkwindow-quartz.c b/gdk/quartz/gdkwindow-quartz.c
index 9bd104d..82e79dc 100644
--- a/gdk/quartz/gdkwindow-quartz.c
+++ b/gdk/quartz/gdkwindow-quartz.c
@@ -2530,9 +2530,17 @@ gdk_quartz_window_get_frame_extents (GdkWindow    *window,
   rect->height = ns_rect.size.height;
 }
 
+/* Fake protocol to make gcc think that it's OK to call setStyleMask
+   even if it isn't. We check to make sure before actually calling
+   it. */
+
+ protocol CanSetStyleMask
+- (void)setStyleMask:(int)mask;
+ end
+
 static void
 gdk_quartz_window_set_decorations (GdkWindow       *window,
-                                   GdkWMDecoration  decorations)
+			    GdkWMDecoration  decorations)
 {
   GdkWindowImplQuartz *impl;
   NSUInteger old_mask, new_mask;
@@ -2589,7 +2597,7 @@ gdk_quartz_window_set_decorations (GdkWindow       *window,
        */
       if ([impl->toplevel respondsToSelector:@selector(setStyleMask:)])
         {
-          [impl->toplevel setStyleMask:new_mask];
+          [(id<CanSetStyleMask>)impl->toplevel setStyleMask:new_mask];
         }
       else
         {