Method append_str

sql/sql_explain.cc:1762–1771

*/

const char *String_list::append_str(MEM_ROOT *mem_root, const char *str)
{
  size_t len= strlen(str);
  char *cp;
  if (!(cp = (char*)alloc_root(mem_root, len+1)))
    return NULL;
  memcpy(cp, str, len+1);
  push_back(cp, mem_root);
  return cp;
}


static void write_item(Json_writer *writer, Item *item)