Roll HarfBuzz to 1.3.0

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 34 matching lines @@
  * passed hb_shape(), and after shaping they hold the output glyphs.
  **/
 
 /**
  * hb_segment_properties_equal:
  * @a: first #hb_segment_properties_t to compare.
  * @b: second #hb_segment_properties_t to compare.
  *
  * Checks the equality of two #hb_segment_properties_t's.
  *
- * Return value: (transfer full):
+ * Return value:
  * %true if all properties of @a equal those of @b, false otherwise.
  *
  * Since: 0.9.7
  **/
 hb_bool_t
 hb_segment_properties_equal (const hb_segment_properties_t *a,
                              const hb_segment_properties_t *b)
 {
   return a->direction == b->direction &&
          a->script    == b->script    &&
@@ skipping 110 matching lines @@
   return true;
 }
 
 bool
 hb_buffer_t::shift_forward (unsigned int count)
 {
   assert (have_output);
   if (unlikely (!ensure (len + count))) return false;
 
   memmove (info + idx + count, info + idx, (len - idx) * sizeof (info[0]));
+  if (idx + count > len)
+  {
+    /* Under memory failure we might expose this area.  At least
+     * clean it up.  Oh well... */
+    memset (info + len, 0, (idx + count - len) * sizeof (info[0]));
+  }
   len += count;
   idx += count;
 
   return true;
 }
 
 hb_buffer_t::scratch_buffer_t *
 hb_buffer_t::get_scratch_buffer (unsigned int *size)
 {
   have_output = false;
@@ skipping 223 matching lines @@
 
     memmove (out_info + out_len, info + idx, count * sizeof (out_info[0]));
     idx += count;
     out_len += count;
   }
   else if (out_len > i)
   {
     /* Tricky part: rewinding... */
     unsigned int count = out_len - i;
 
+    /* This will blow in our face if memory allocation fails later
+     * in this same lookup... */
     if (unlikely (idx < count && !shift_forward (count + 32))) return false;
 
     assert (idx >= count);
 
     idx -= count;
     out_len -= count;
     memmove (info + idx, out_info + out_len, count * sizeof (out_info[0]));
   }
 
   return true;
@@ skipping 1362 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);
 }