[Bug]: Tux unable to stand on / jump off frozen badguy that is bouncing on trampoline

[celeste5000]

SuperTux Version

0.6.3-1599-g6f1078d10

System Information

win11

Expected Behavior

i expected tux to be able to stand on and jump off the frozen badguy bouncing on the trampoline onto another surface while the frozen badguy is still briefly moving upwards from the trampoline.

Actual Behavior

tux was not able to stand on or jump off the frozen badguy, instead tux was stuck in the falling animation while on the frozen badguy. backflipping onto the frozen badguy made tux slide off of it while stuck in the backflipping animation rather than land on it normally.

Steps To Reproduce Actual Behavior

1. place a trampoline in a level
2. place any badguy that can be frozen (ivy, spiky, etc)
3. test the level and freeze the badguy
4. grab the frozen badguy and place it on a trampoline (portable or stationary works)
5. jump onto a solid surface and jump off it to land on the frozen badguy, or you can backflip onto it

example:

Additional Information

Guidelines For Reporting Issues

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• I have verified this isn't an issue that's already been reported.
• I have verified this isn't a discussion, or an issue about a crash or a feature request, but rather an actual bug ─ that is, the game did something not intended.
• I have verified this issue is not about wrong translations (use Transifex for those), or anything unsupported (e.g. third-party add-ons).
• In this report, I have only included details about one (1) bug.
• If I make a mistake while submitting this report, I agree to use the "Edit" feature to correct it, instead of closing this issue and opening a new one.

[Brockengespenst]

This is (partly) addressed by #2933. The approach, checking for BadGuy collision with hit.bottom to set the on_ground_flag, seems a bit too naive though. This allows at least to jump off from the frozen enemy, but there is still a nasty jittering effect.

[celeste5000]

yeah you can stand on and jump off a frozen badguy that is stationary but not if the frozen badguy is bouncing on a trampoline for some reason
portable objects bouncing on trampolines like rocks can be stood on and jumped off of but not frozen badguys