Symlink Check

Here is an extract of 1.20-pre7 change log:

To improve safety, the game will now detect symbolic links used inside world directory. For a detailed explanation, check our help article.

Just as said in the help article, symbolic link attack may cause permanent data loss. However, the detection as well as the warning screen aren't ported to lower versions officially, which is the reason why I hurried this mod.

With this mod, a warning screen will show up when trying to open a world with symbolic link, unless the link target is whitelisted in allowed_symlinks.txt.