Box2D Forums

b2AABB aabb;
aabb.lowerBound.Set(-100, -100);
aabb.upperBound.Set(100, 100);
b2World w(aabb, b2Vec2(0, -10), true);

b2BodyDef bodydef;
bodydef.type = b2BodyDef::e_dynamicBody;
bodydef.position.Set(0, 0);
b2Body * body = w.Create(&bodydef);

b2PolygonDef boxdef;
boxdef.SetAsBox(1, 1, b2Vec2(0, 0), 0);
boxdef.density = 1;
body->Create(&boxdef);
boxdef.SetAsBox(1, 1, b2Vec2(1, 0), 0);
b2Shape * shape = body->Create(&boxdef);
body->SetMassFromShapes();

bodydef.type = b2BodyDef::e_staticBody;
bodydef.position.Set(0, -10);
b2Body * ground = w.Create(&bodydef);
boxdef.SetAsBox(100, 1, b2Vec2(0, 0), 0);
boxdef.density = 0;
ground->Create(&boxdef);
ground->SetMassFromShapes();

for (int i = 0; i < 500; i ++) {
    w.Step(0.3f, 100);

    if (i == 20) // b2ContactManager.cpp:189 can't derefence a NULL body1
        body->Destroy(shape); // boom
    TCHAR szDebug[100];
    _stprintf_s(szDebug, _T("%d %f %f\n"), i,
        body->GetWorldCenter().x, body->GetWorldCenter().y);
    OutputDebugString(szDebug);
}

==== Dynamics/b2Body.cpp ====
171c171,173
<       s->m_body = NULL;
---
>       s->DestroyProxy(m_world->m_broadPhase);
>
>     s->m_body = NULL;
195d196
<       s->DestroyProxy(m_world->m_broadPhase);

==== Collision/Shapes/b2PolygonShape.cpp ====
107,108c107
<       float32 length = ux.Normalize();
<       b2Assert(length > FLT_EPSILON);
---
>       b2Assert(ux.Normalize() > FLT_EPSILON);