SCI: SQ6: Frequent softlock at Delta Burksilon elevator

[Twixxi691]

ScummVM 2.7.0
Space Quest 6 DOS/English

On the third visit to Delta Burksilon, the elevator (room 500) has a tendancy to softlock. When this happens, Roger cannot move away from the control panel even if you travel to a different floor. All you can do is restart the game.

I can't figure out a pattern to it. It happens (at least to me) in about 1 in 3 runs that get this far. A twenty second comparison of four runs - two that softlock and two that don't - can be found here: ​https://www.youtube.com/watch?v=q9VG68NFA1A

[Twixxi691]

Save game attached at point of softlock

[m-kiewitz]

Video

[sluicebox]

Hello! Thank you for reporting this and providing footage; once again speedrunners make the best bug reporters. =)

I think I see what's going on here, but I don't know the trigger to reproduce. If you have full footage of one of your failed runs that would be a huge help.

The problem is that the Walk cursor gets screwed up and thinks it's the Exit Right cursor. We've already seen a game-breaking script bug with the SQ6 exit cursors: #11640 (I'm really hoping my patch for that bug didn't cause this...)

I believe that this bug occurs much earlier than the elevator. I watched one of your speedruns, and the previous Exit Right cursor is for the liquor store, which is underneath the transport inventory item you click on, and then you didn't use the Walk cursor again until the elevator. I suspect that the cursor broke there, and if you'd try to walk anywhere before the elevator you wouldn't have been able to.

Footage of a full failed run would show where you're mousing and clicking in the rooms before the elevator, and I suspect that's going to be the subtle trigger.

[Twixxi691]

Hi there!

Too big to upload the file directly here, so I've uploaded a full run that softlocked to YouTube. On this particular attempt, I also tried moving to other floors after softlocking and using those exits which also didn't work. ​https://www.youtube.com/watch?v=oZRklJuD0tY

I just noticed the exit280 thing as you edited your comment. The inventory item only partially covers the exit, so that would also explain why only some runs softlock.

I know the bug has been known about since at least June 2021, as Admiral Jay mentions slowing down in the elevator hoping to avoid the bug in his previous WR run.

[sluicebox]

You're so fast! I just reproduced it, the bug occurs outside the liquor store.

Workaround: when you use the transport inventory item, click the upper left of that icon so that your cursor isn't also on top of the liquor store's exit. That's what breaks Walk, you just didn't use Walk until the elevator so you didn't notice.

[sluicebox]

Fixed in ​https://github.com/scummvm/scummvm/commit/6a83bcbd95c8f816d11981323f1eede543da2fe4

I found more ways to trigger the bug, and this patch will fix them all. It won't fix save games where you're already stuck in the elevator.

This fix will appear in the next daily build. It will not appear in the upcoming 2.7.1 release; we're already passed the cut-off for that. Even if hadn't, I would want this to be tested more before I'd include it. It's an obscure bug in the original, and I think for speedrunning purposes the important thing is knowing how to avoid it. (Don't click on the right side of the signaler!)

Thanks again for reporting this and helping reproduce!