--- firefox-45.0.1-orig/gfx/harfbuzz/src/hb-font-private.hh	2016-03-15 23:37:28.000000000 +0100
+++ firefox-45.0.1/gfx/harfbuzz/src/hb-font-private.hh	2016-05-13 17:20:25.836258108 +0200
@@ -80,7 +80,7 @@ struct hb_font_funcs_t {
       HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
 #undef HB_FONT_FUNC_IMPLEMENT
     } f;
-    void (*array[]) (void);
+    void (*array[VAR]) (void);
   } get;
 };
 
--- firefox-45.0.1-orig/gfx/harfbuzz/src/hb-private.hh	2016-03-15 23:37:28.000000000 +0100
+++ firefox-45.0.1/gfx/harfbuzz/src/hb-private.hh	2016-05-13 17:20:55.909655179 +0200
@@ -1010,5 +1010,7 @@ hb_options (void)
   return _hb_options.opts;
 }
 
+/* Size signifying variable-sized array */
+#define VAR 1
 
 #endif /* HB_PRIVATE_HH */