[v5U] Legacy v4 object collision works (in)correctly

[MegAmi24]

One of the known bugs in Sonic Origins is that in Sonic 2, when the player jumps on the teeth of a rotating gear in Metropolis Zone, they're never properly set as grounded, so they'll continue to be in whatever state they were in the air.

origins.mp4

However, this doesn't seem to happen in the v5U decomp. The decompiled scripts weren't used here; it's the same data file and bytecode from Origins 1.04.

decomp.mp4

[Telejaba]

I think I don't need to climb here, but i got that bug in Sonic 2 (2013)

[MegAmi24]

Might have found a lead on this: removing the C_PLATFORM BoxCollisionTest line in the Large Gear object creates a similar (although not identical) effect to the bug.

decomp2.mp4