[MISC] prop_dynamic with modified model scale and no physics object crashes the game

[Blixibon]

Describe the bug

Having a prop_dynamic with a modified model scale and no physics object will crash the game. This seems to be unique to Mapbase v7.0.

Steps to reproduce

Steps to reproduce the behavior:

1. Add a prop_dynamic into a map with a non-1 model scale and no physics object
2. Game should crash

Expected behavior

The game should not crash under these circumstances. It did not crash prior to Mapbase v7.0.

---

Additional context

This appears to be caused by some new code added to CDynamicProp::TestCollision in Mapbase v7.0:

bool CDynamicProp::TestCollision( const Ray_t &ray, unsigned int mask, trace_t& trace )
{
	if ( IsSolidFlagSet(FSOLID_NOT_SOLID) )
	{
		// if this entity is marked non-solid and custom test it must have bone followers
		if ( IsSolidFlagSet( FSOLID_CUSTOMBOXTEST ) && IsSolidFlagSet( FSOLID_CUSTOMRAYTEST ))
		{
			for ( int i = 0; i < m_BoneFollowerManager.GetNumBoneFollowers(); i++ )
			{
				CBaseEntity *pEntity = m_BoneFollowerManager.GetBoneFollower(i)->hFollower;
				if ( pEntity && pEntity->TestCollision(ray, mask, trace) )
					return true;
			}
		}
	}
+#ifdef MAPBASE // From Alien Swarm SDK
+	return BaseClass::TestCollision( ray, mask, trace );
+#else
	return false;
+#endif
}

The base function, CBaseAnimating::TestCollision, is not designed to allow a prop with a unique model scale and no physics object.

bool CBaseAnimating::TestCollision( const Ray_t &ray, unsigned int fContentsMask, trace_t& tr )
{
	// Return a special case for scaled physics objects
	if ( GetModelScale() != 1.0f )
	{
		IPhysicsObject *pPhysObject = VPhysicsGetObject();
		Vector vecPosition;
		QAngle vecAngles;
		pPhysObject->GetPosition( &vecPosition, &vecAngles );
		const CPhysCollide *pScaledCollide = pPhysObject->GetCollide();
		physcollision->TraceBox( ray, pScaledCollide, vecPosition, vecAngles, &tr );
		
		return tr.DidHit();
	}

However, the Alien Swarm SDK has its own version of this code which fixes the problem by just checking for pPhysObject first:

bool CBaseAnimating::TestCollision( const Ray_t &ray, unsigned int fContentsMask, trace_t& tr )
{
	IPhysicsObject *pPhysObject = VPhysicsGetObject();
	// Return a special case for scaled physics objects
	// FIXME: need to have scaled hitbox for scaled models for this to work, we can't assume everything has a VPhysics object
	if ( GetModelScale() != 1.0f && pPhysObject )
	{
		Vector vecPosition;
		QAngle vecAngles;
		pPhysObject->GetPosition( &vecPosition, &vecAngles );
		const CPhysCollide *pScaledCollide = pPhysObject->GetCollide();
		physcollision->TraceBox( ray, pScaledCollide, vecPosition, vecAngles, &tr );
		
		return tr.DidHit();
	}

Fixing this issue would entail either removing the new code from CDynamicProp::TestCollision or adding the additional code to CBaseAnimating::TestCollision.