Defence Tutorial halts after Rock Monster leaves

[trigger-segfault]

Describe the issue
Playing the tutorial Defending Rock Raider H.Q. halts once the first Rock Monster has departed into the wall. After tracing the NERP script, it was found that NERPFunc__GetMonstersOnLevel was returning 1 when the value should have been 0.

Expected behaviour
The tutorial should be able to continue once bullying the Rock Monster enough (with the Pusher Beam) for them to leave. Instead, the script stays on this state and never enables the continue arrow.

NERPFunc__GetMonstersOnLevel is expected to return the current amount of Rock/Lava/Ice monsters in the level, but instead returns a higher count.

Steps to reproduce

1. Start Defending Rock Raider H.Q..
2. Play through the tutorial like normal.

Additional information

• Time played this session: 3-4 minutes.
• Level: Defending Rock Raider H.Q.
• Game speed: 0% or 100% (handled by tutorial)
• Graphics fix: dgVoodoo 2.55.4
• Using mods: None

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Solution

The issue was discovered to be the objectGlobs.objectPrevLevels array, which had a value of -1 for Rock Monster (Lv0) counts. This was because LegoObject_Remove incorrectly decrements objectGlobs.objectPrevLevels instead of incrementing the value.