Enable ftruncate() on the Mac.
(Jack)
diff --git a/Objects/fileobject.c b/Objects/fileobject.c
index b744ab4..76f5318 100644
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -44,6 +44,12 @@
 #define HAVE_FTRUNCATE
 #endif
 
+#ifdef macintosh
+#ifdef USE_GUSI
+#define HAVE_FTRUNCATE
+#endif
+#endif
+
 #ifdef THINK_C
 #define HAVE_FOPENRF
 #endif