Roll HarfBuzz to 1.2.1

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

 /*
  * Copyright © 1998-2004  David Turner and Werner Lemberg
  * Copyright © 2004,2007,2009,2010  Red Hat, Inc.
  * 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 389 matching lines @@
 
 bool
 hb_buffer_t::move_to (unsigned int i)
 {
   if (!have_output)
   {
     assert (i <= len);
     idx = i;
     return true;
   }
+  if (unlikely (in_error))
+    return false;
 
   assert (i <= out_len + (len - idx));
 
   if (out_len < i)
   {
     unsigned int count = i - out_len;
     if (unlikely (!make_room_for (count, count))) return false;
 
     memmove (out_info + out_len, info + idx, count * sizeof (out_info[0]));
     idx += count;
@@ skipping 1447 matching lines @@
   }
 }
 
 bool
 hb_buffer_t::message_impl (hb_font_t *font, const char *fmt, va_list ap)
 {
   char buf[100];
   vsnprintf (buf, sizeof (buf),  fmt, ap);
   return (bool) this->message_func (this, font, buf, this->message_data);
 }