Language: PHP
Label: safe
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
            } elseif ($def) {
                // This will occur even if $new_def is standalone. In practice,
                // this will usually result in a full replacement.
                $def->mergeIn($new_def);
            } else {