Update harfbuzz-ng to 0.9.17

third_party/harfbuzz-ng/src/hb-graphite2.cc

 /*
  * Copyright © 2011  Martin Hosken
  * Copyright © 2011  SIL International
  * Copyright © 2011,2012  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
@@ skipping 208 matching lines @@
                      hb_font_t          *font,
                      hb_buffer_t        *buffer,
                      const hb_feature_t *features,
                      unsigned int        num_features)
 {
   hb_face_t *face = font->face;
   gr_face *grface = HB_SHAPER_DATA_GET (face)->grface;
   gr_font *grfont = HB_SHAPER_DATA_GET (font);
 
   const char *lang = hb_language_to_string (hb_buffer_get_language (buffer));
-  const char *lang_end = strchr (lang, '-');
+  const char *lang_end = lang ? strchr (lang, '-') : NULL;
   int lang_len = lang_end ? lang_end - lang : -1;
   gr_feature_val *feats = gr_face_featureval_for_lang (grface, lang ? hb_tag_from_string (lang, lang_len) : 0);
 
   while (num_features--)
   {
     const gr_feature_ref *fref = gr_face_find_fref (grface, features->tag);
     if (fref)
       gr_fref_set_feature_value (fref, features->value, feats);
     features++;
   }
@@ skipping 121 matching lines @@
     pPos[-1].x_advance += gr_seg_advance_X(seg) - curradvx;
 
   if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
     hb_buffer_reverse_clusters (buffer);
 
   if (feats) gr_featureval_destroy (feats);
   gr_seg_destroy (seg);
 
   return true;
 }