xscreensaver Warning message "This version of xscreensaver is VERY OLD! Please upgrade!" on waking my lunar box this morning

[ Impact ]

The XScreenSaver author appears to be quite intent on getting people to use the latest version of XScreenSaver that he publishes, and as such has built checks into XScreenSaver that detects if the version of XScreenSaver in use is outdated. These checks cause alarming warnings to appear on the user's screen that encourage them to update XScreenSaver.

While this is likely helpful for users of rolling-release distros, or for advanced users who intentionally compile XScreenSaver from source, this is detrimental for Ubuntu, as it may lead inexperienced users to attempt to install XScreenSaver from source code and possibly break their system in so doing. Ubuntu doesn't need the user to update XScreenSaver to a newer upstream version since we backport fixes, so this message does nothing except scare the user and possibly lead them to do something dangerous.

There are two messages that are displayed by these checks - one of them appears when one opens xscreensaver-settings. It appears in a pop-up dialog box, and reads as follows:

    This version of xscreensaver is VERY OLD!
    Please upgrade!

    https://www.jwz.org/xscreensaver/

    (If this is the latest version that your distro ships, then
    your distro is doing you a disservice. Build from source.)

The other one appears on the lock screen in solid red text just above the username and password fields:

    Update available!
    This version is very old.

The Kinetic SRU for this bug comments out the code snippets responsible for displaying these messages, with a bit of explanation as for why the code has been commented out. An "else if" statement is also changed to an "if" statement in order to avoid a syntax error resulting from commenting out one of the code snippets.

[ Test Plan ]

1. Install any flavor of Ubuntu 22.10 into a virtual machine, fully update the system, and install XScreenSaver into it. (Lubuntu works particularly well here since it ships XScreenSaver by default.)
2. Open the Application Menu, and search for "Screensaver".
3. Open the Screensaver app. You will see the first warning message.
4. Click File -> Lock Screen Now, wait for the screensaver to start, then move the mouse. You will see the second warning message.
5. Enable -proposed.
6. Run "sudo apt update && sudo apt install xscreensaver".
7. Close the screensaver settings app, and re-open it. This time you should not see the first warning message.
8. Click File -> Restart Daemon.
9. Wait for XScreenSaver to restart, then click File -> Lock Screen Now, wait for the screen aver to start, then move the mouse. You should not see the second warning message.
10. Ensure that all basic functionality (Blank Screen Now, Lock Screen Now, automatic screen blanking, automatic screen locking, Preview, Settings, Documentation) is still operational.

[ Where problems could occur ]

A typo in the code changes could cause XScreenSaver to become unable to launch, or could possibly cause critical functionality to break (i.e., the screen could fail to lock automatically even if the system has been idle for an extended period of time). The above test plan is designed to catch any glaring errors.

The sections of code being patched appear to be dedicated purely to warning about the age of the current XScreenSaver version, and they also appear to be entirely skipped over by default if XScreenSaver is young enough. It is therefore unlikely that anything will go wrong, as commenting out these sections of code will likely do hardly anything different than what the code usually does.

[ Other Info ]

Due to the possible scare this could cause our users, and the possible damage users may do to their systems as a result of this bug, I believe it is reasonable to fast-track this SRU.

---------------------------------------------------------------------------

Original bug report:

On waking my lunar box today; instead of just entering the password into xscreensaver I got a warning box

---
Warning:

This version of xscreensaver is VERY OLD!
Please upgrade!

https://www.jwz.org/xscreensaver/

(If this is the latest version that your distro ships, then
 your distro is doing you a disservice. Build from source.)
---

This isn't ideal on a unreleased product, esp. if it's there still at day 1 of release.

On opening xscreensaver settings the same error message also shows.

ProblemType: Bug
DistroRelease: Ubuntu 23.04
Package: xscreensaver 6.02+dfsg1-2ubuntu1
ProcVersionSignature: Ubuntu 6.1.0-16.16-generic 6.1.6
Uname: Linux 6.1.0-16-generic x86_64
ApportVersion: 2.26.0-0ubuntu2
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: LXQt
Date: Mon Mar 6 10:18:25 2023
InstallationDate: Installed on 2023-01-25 (39 days ago)
InstallationMedia: Lubuntu 23.04 "Lunar Lobster" - Alpha amd64 (20230124)
SourcePackage: xscreensaver
UpgradeStatus: No upgrade log present (probably fresh install)