#vulnerable code 
                                protected boolean showTagBody( String roleName ) {
        boolean hasRole = getSecurityContext().hasRole( roleName );
        return !hasRole;
    } 
                            #location 2 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                protected boolean showTagBody( String roleName ) {
        boolean hasRole = getSecurityContext() != null && getSecurityContext().hasRole( roleName );
        return !hasRole;
    }