Function alloc_buffer

sql/item_strfunc.cc:2131–2150

inline String* alloc_buffer(String *res,String *str,String *tmp_value,
			    ulong length)
{
  if (res->alloced_length() < length)
  {
    if (str->alloced_length() >= length)
    {
      (void) str->copy(*res);
      str->length(length);
      return str;
    }
    if (tmp_value->alloc(length))
      return 0;
    (void) tmp_value->copy(*res);
    tmp_value->length(length);
    return tmp_value;
  }
  res->length(length);
  return res;
}