 */
int re_yyget_lineno  (yyscan_t yyscanner)
{
    struct yyguts_t * yyg = (struct yyguts_t*)yyscanner;

        if (! YY_CURRENT_BUFFER)
            return 0;
    
    return yylineno;
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.