Adjust for API break in gdkkeysyms.h

The key symbols were renamed to avoid namespace conflicts with
gobject-introspection.

src/gdk-compat.h

@@ -15,4 +15,10 @@
 
 #endif /*GTK_CHECK_VERSION */
 
+
+/* Compatibility with old GDK key symbols */
+#ifndef GDK_KEY_Escape
+#define GDK_KEY_Escape GDK_Escape
+#endif /* GDK_KEY_Escape */
+
 #endif /* __GDK_COMPAT_H__ */

src/tools/mutter-mag.c

@@ -28,6 +28,7 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include <math.h>
+#include <gdk-compat.h>
 
 static GtkWidget *grab_widget = NULL;
 static GtkWidget *display_window = NULL;
@@ -191,7 +192,7 @@ key_press (GtkWidget   *invisible,
            GdkEventKey *event,
            gpointer     data)
 {  
-  if (event->keyval == GDK_Escape)
+  if (event->keyval == GDK_KEY_Escape)
     {
       shutdown_grab ();