Insoluble
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File: Bad times with mimic sticks.hold (1.3 KB)
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License: Public Domain

As the topic states, the player can be pushed across a diagonal gentryii chain. This happened for me in build 5.1.0.6501, but uncopy2002 was able to verify that it's still a problem in 6512. Bomber50 did some further testing and it doesn't seem to matter who is doing the pushing or what the weapon is, but a short hold is attached with a mimic and a stick. I think we can all agree that this is horrible and should be fixed in the next build. Meanwhile, please no one make an actual puzzle based on this.

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uncopy2002
Level: Smiter
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Two example uses of this bug:

hyperme
Level: Smitemaster

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So I looked deep into the DROD source code and found the problem.

In CCurrentGame:: PushPlayerInDirection() we have this:

CMonster *pMonster = this->pRoom->GetMonsterAtSquare(wDestX, wDestY);
if (pMonster != NULL && pMonster->wType != M_FLUFFBABY)
    return false;
if (!this->pRoom->CanPushOntoOTile(wDestX, wDestY))
    return false;
if (!this->pRoom->CanPushOntoTTile(wDestX, wDestY))
    return false;
if (!this->pRoom->CanPushOntoFTile(this->swordsman.wX, this->swordsman.wY, wDestX, wDestY))
    return false;

if (!this->swordsman.Move(wDestX, wDestY))
    return false;

This checks to see if the destination tile is free of anything that blocks the push. What it doesn't do, however, is check for blocking Gentryii chains. By adding an extra check, to get this:

CMonster *pMonster = this->pRoom->GetMonsterAtSquare(wDestX, wDestY);
if (pMonster != NULL && pMonster->wType != M_FLUFFBABY)
    return false;
if (!this->pRoom->CanPushOntoOTile(wDestX, wDestY))
    return false;
if (!this->pRoom->CanPushOntoTTile(wDestX, wDestY))
    return false;
if (!this->pRoom->CanPushOntoFTile(this->swordsman.wX, this->swordsman.wY, wDestX, wDestY))
    return false;
if (this->pRoom->DoesGentryiiPreventDiagonal(this->swordsman.wX, this->swordsman.wY, wDestX, wDestY))
    return false;


if (!this->swordsman.Move(wDestX, wDestY))
    return false;

It is no longer possible to push the player past Gentryii chains, as the call to CDbRoom:: DoesGentryiiPreventDiagonal() allows the function to end correctly when a blocking Gentryii is present.

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[Last edited by hyperme at 12-06-2016 07:16 PM]

NiroZ
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I've checked and this seems to be fixed in 5.1.1.alpha.2020-09-24 on windows 10.