lightningd: refuse to upgrade db on non-released versions by default.

[rustyrussell]

This is a good sanity check that users understand that if they upgrade
to master mid-cycle they can't go back!

Suggested-by: @wtogami
Changelog-Added: Config: --database-upgrade=true required if a non-release version wants to (irrevocably!) upgrade the db.

[cdecker]

Looks like we are getting an access to uninitialized memory in options.c: ld->db_upgrade_ok seems to be uninitialized.

[Sjors]

What about release candidates? (I tend to start those using systemd so it's a slight inconvenience to relaunch with the appropriate argument)

[wtogami]

What about release candidates? (I tend to start those using systemd so it's a slight inconvenience to relaunch with the appropriate argument)

You need only launch it differently once. You could also havedatabase-upgrade=true in your config file if you rather opt into the old behavior.

[rustyrussell]

What about release candidates? (I tend to start those using systemd so it's a slight inconvenience to relaunch with the appropriate argument)

Yeah, tell systemd to stop, do lightningd --database-upgrade=true --offline and then kill it and tell systemd to restart.

But really, you can just put databse-upgrade=true in your config and be careful upgrading! I trust you @Sjors!

[rustyrussell]

Rebased on master, fixed uninitialized var.

[rustyrussell]

That was weird... First CI seemed to have the wrong version, then I seemed to push an empty tree. But I've rebased onto master now...

[cdecker]

Rebased on top of master, waiting for CI to complete before merging.

ACK 262dbf9

[cdecker]

Seems we have a false positive for memleak (guessing the bool flag?).

[rustyrussell]

Seems we have a false positive for memleak (guessing the bool flag?).

No, it's a valgrind error. But I do initialize it in this commit (I didn't initialize it previously), and indeed, I checked it's correct locally...

Trivial rebase
Ack 1cbfa92

[Sjors]

But really, you can just put databse-upgrade=true in your config and be careful upgrading! I trust you @Sjors!

Ok fine...