    function testMissingExtensionFatal()
    {
        $ext = 'php_ext';
        $warn = 'The <a href="' . PMA_getPHPDocLink('book.' . $ext . '.php')
            . '" target="Documentation"><em>' . $ext
            . '</em></a> extension is missing. Please check your PHP configuration.';

        $this->expectOutputRegex('@' . preg_quote($warn) . '@');

        PMA_warnMissingExtension($ext, true);
    }
The software constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.