AI_handleStranded FAssert

[Andera412]

I'm trying to build my own mod, based on KMOD. It adds AI-compatible multiplayer-friendly revolution mechanics.
There is an FAssert during debug. It doesn't crash the game, but cargo units are called stranded in AI_cityDefenseMove.

// K-Mod
// Decide whether or not this group is stranded.
// If they are stranded, try to walk towards the coast.
// If we're on the coast, wait to be rescued!
bool CvUnitAI::AI_handleStranded(int iFlags)
{
    PROFILE_FUNC();

    if (isCargo())
    {
        // This is possible, in some rare cases, but I'm currently trying to pin down precisely what those cases are.
        FAssertMsg(false, "AI_handleStranded: this unit is already cargo.");
        getGroup()->pushMission(MISSION_SKIP);
        return true;
    }

    if (isHuman())
        return false;

    const CvPlayerAI& kOwner = GET_PLAYER(getOwnerINLINE());

    // return false if the group is not stranded.
    int iDummy;
    if (area()->getNumAIUnits(getOwnerINLINE(), UNITAI_SETTLE) > 0 && kOwner.AI_getNumAreaCitySites(getArea(), iDummy) > 0)
    {
        return false;
    }

    if (area()->getNumCities() > 0)
    {
        if (plot()->getTeam() == getTeam())
            return false;

        if (getGroup()->isHasPathToAreaPlayerCity(getOwnerINLINE(), iFlags))
        {
            return false;
        }

        if ((canFight() || isSpy()) && getGroup()->isHasPathToAreaEnemyCity(true, iFlags))
        {
            return false;
        }
    }

    // ok.. so the group is standed.
    // Try to get to the coast.
    if (!plot()->isCoastalLand())
    {
        // maybe we were already on our way?
        CvPlot* pMissionPlot = 0;
        CvPlot* pEndTurnPlot = 0;
        if (getGroup()->AI_getMissionAIType() == MISSIONAI_STRANDED)
        {
            pMissionPlot = getGroup()->AI_getMissionAIPlot();
            if (pMissionPlot && pMissionPlot->isCoastalLand() && !pMissionPlot->isVisibleEnemyUnit(this) && generatePath(pMissionPlot, iFlags, true))
            {
                // The current mission looks good enough. Don't bother searching for a better option.
                pEndTurnPlot = getPathEndTurnPlot();
            }
            else
            {
                // the current mission plot is not suitable. We'll have to search.
                pMissionPlot = 0;
            }
        }
        if (!pMissionPlot)
        {
            // look for the clostest coastal plot in this area
            int iShortestPath = MAX_INT;

            for (int i = 0; i < GC.getMapINLINE().numPlotsINLINE(); i++)
            {
                CvPlot* pLoopPlot = GC.getMapINLINE().plotByIndexINLINE(i);

                if (pLoopPlot->getArea() == getArea() && pLoopPlot->isCoastalLand())
                {
                    // TODO: check that the water isnt' blocked by ice.
                    int iPathTurns;
                    if (generatePath(pLoopPlot, iFlags, true, &iPathTurns, iShortestPath))
                    {
                        FAssert(iPathTurns <= iShortestPath);
                        iShortestPath = iPathTurns;
                        pEndTurnPlot = getPathEndTurnPlot();
                        pMissionPlot = pLoopPlot;
                        if (iPathTurns <= 1)
                            break;
                    }
                }
            }
        }

        if (pMissionPlot)
        {
            FAssert(pEndTurnPlot);
            getGroup()->pushMission(MISSION_MOVE_TO, pEndTurnPlot->getX_INLINE(), pEndTurnPlot->getY_INLINE(), iFlags, false, false, MISSIONAI_STRANDED, pMissionPlot);
            return true;
        }
    }

    // Hopefully we're on the coast. (but we might not be - if we couldn't find a path to the coast)
    // try to load into a passing boat
    // Calling AI_load will check all of our boats; so before we do that, I'm going to just see if there are any boats on adjacent plots.
    for (int i = NO_DIRECTION; i < NUM_DIRECTION_TYPES; i++)
    {
        CvPlot* pAdjacentPlot = plotDirection(getX_INLINE(), getY_INLINE(), (DirectionTypes)i);

        if (pAdjacentPlot && canLoad(pAdjacentPlot))
        {
            // ok. there is something we can load into - but lets use the (slow) official function to actually issue the load command.
            if (AI_load(NO_UNITAI, NO_MISSIONAI, NO_UNITAI, -1, -1, -1, -1, iFlags, 1))
                return true;
            else // if that didn't do it, nothing will
                break;
        }
    }

    // raise the 'stranded' flag, and wait to be rescued.
    getGroup()->pushMission(MISSION_SKIP, -1, -1, 0, false, false, MISSIONAI_STRANDED, plot());
    return true;
}
// K-Mod end

 

[Zholef]

And how is that a problem? Looks to me like that assert is there for research purposes.

 

[keldath]

remove that unit, you probably did some xml error there.

 

[Leoreth]

No, the unit is fine, apparently you ran into a rare bug that karadoc (?) wanted to look into more so he made sure the assertion would fail in this case. As you can see, the issue is handled in the code below (the unit skips the turn) so there are no immediate problems in the game. Unless you want to fix the bug itself you don't need to do anything, just ignore the assertion.