Tumbler triggers assert (false) near end of collision()

[SimonN]

Version 0.1.26.
Unknown circumstances, this bug is elusive right now. It should be investigated once replays can be loaded from disk.

Effect of the bug: The assert in lix.skill.tumbler is triggered:

final Collision collision()
{
    [...]
    // No collisions found at this pixel.
    if (isSolid(0, 1))
        assert (false, "copy more from tumbler.cpp:213, v2015-09-02.");

[SimonN]

Possibly related issue in C++ Lix:
Landing on square block from below

Can't replay this right now in D Lix, because D Lix doesn't play back replay files yet.

[SimonN]

Reproduced the crash in D Lix, with lots of cubing and fling-exploding:

core.exception.AssertError@src/lix/skill/tumbler.d(214):
copy more from tumbler.cpp:213, v2015-09-02. BallisticFlyer speedX=0, speedY=-17

Another repro in 0.1.30:

src/lix/skill/tumbler.d:214:
copy more from tumbler.cpp:213, v2015-09-02. BallisticFlyer speedX=12, speedY=-8

So far, all assert hits have been with speedY << 0. Probably closely missing an edge, see post above this one for the C++ bug.

[SimonN]

When (every lix who hit the assert) was flying upwards, and the assert triggered upon floor existing, that floor probably isn't interesting for the lix. I'll close this for now. Create a new issue in case a concrete problem comes up.