Officially deprecate follow-symlink-as-user

[kmk3]

@smitsohu commented 23 days ago:

For now all restrictions regarding symbolic links are gone (and
follow-symlink-as-user from firejail.config is without effect). I'm not
entirely sure if that is sustainable, but it can always be added back.

(I don't know if you're working on it, so I'm creating a task for it just to
make sure that it's not lost to time etc)

From what I gather it was removed on commit 5445d87 ("add support for
arbitrary whitelist directories") / PR #4229, and from looking at the code:

$ git show --pretty='%h %ai %s' -s master
518633eb4 2021-05-24 15:51:55 +0200 fix firejail startup race
$ git grep follow-symlink-as-user
RELNOTES:  * feature: follow-symlink-as-user runtime config option in
etc/firejail.config:# follow-symlink-as-user yes
src/firejail/checkcfg.c:                        PARSE_YESNO(CFG_FOLLOW_SYMLINK_AS_USER, "follow-symlink-as-user")
test/root/checkcfg.exp:send --  "echo \"follow-symlink-as-user yes\" >> /etc/firejail/firejail.config\r"
test/root/firejail.config:follow-symlink-as-user no
$ git grep CFG_FOLLOW_SYMLINK_AS_USER
src/firejail/checkcfg.c:                        PARSE_YESNO(CFG_FOLLOW_SYMLINK_AS_USER, "follow-symlink-as-user")
src/firejail/firejail.h:        CFG_FOLLOW_SYMLINK_AS_USER,

It seems that it's effectively deprecated/only there to keep existing configs
working (which I appreciate). So I'd suggest this:

• Mention that it's deprecated/gone on the release notes

And maybe this:

• Warn that it has no effect if found on firejail.config

[netblue30]

All done, thanks!

4909fa7