Fix possible NULL dereference

As reported by Kenichi Ishibashi.

diff --git a/src/hb-ot-layout-gsubgpos-private.hh b/src/hb-ot-layout-gsubgpos-private.hh
index 00bc563..40d5c57 100644 (file)
--- a/src/hb-ot-layout-gsubgpos-private.hh
+++ b/src/hb-ot-layout-gsubgpos-private.hh
@@ -92,7 +92,7 @@ struct hb_would_apply_context_t
                              glyphs (glyphs_),
                              len (len_),
                              zero_context (zero_context_),
-                             digest (*digest_),
+                             digest (digest_ ? *digest_ : hb_set_digest_t()),
                              debug_depth (0) {};
 };