Use 0 as EEK_INVALID_KEYCODE/KEYSYM instead of -1.

eek/eek-keysym.h

@@ -29,7 +29,7 @@ G_BEGIN_DECLS
  *
  * Pseudo keysym used for error reporting.
  */
-#define EEK_INVALID_KEYSYM ((guint)(-1))
+#define EEK_INVALID_KEYSYM (0)
 
 #define EEK_TYPE_KEYSYM (eek_keysym_get_type())
 #define EEK_KEYSYM(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), EEK_TYPE_KEYSYM, EekKeysym))

eek/eek-types.h

@@ -96,7 +96,7 @@ typedef enum
  *
  * Pseudo keycode used for error reporting.
  */
-#define EEK_INVALID_KEYCODE ((guint)(-1))
+#define EEK_INVALID_KEYCODE (0)
     
 typedef struct _EekElement EekElement;
 typedef struct _EekContainer EekContainer;