When py7zr project recognize a vulnerability advice, security professional suggest me to add a flag option to tell explicitly allow symbolic link extraction to protect from symlink attack.

When 7-zip-ed file has a symbolic link to external of target folder, such as /etc/passwd and py7zr does not check it, attacker may obtains passwd file from remote, if some web system use py7zr and attacker upload a malicious archive file.

Here is a trial of implementation.
#482

Currently I decide to extract links in default. Are there any opinions?