Double Recall teleports units to displaced position

[Ahli-1603]

Issue

When units are recalled by the Nexus and the Mothership at the same time, the second recall can teleport to a displaced position.
In the end, the units are teleported far from the 2nd recaller.

This video shows how this is done and how it can be exploited (Feardragon’s Useless Facts #75):

Gamebreaking recall bug to teleport anywhere? Useless Facts #75

Fix

The issue occurs when units are teleported twice. To fix this, the potential second recall can be aborted for units that teleported in the first recall. If the first recall fails, it would still be nice for the units to be teleported to the second location.

I’ve implemented that here:

    <!--  Effects-->
    <CEffectSet id="MothershipStrategicRecallSet">
        <EffectArray value="MothershipStrategicRecallSetPrevent2ndRecall"/>
    </CEffectSet>
    <CEffectSet id="NexusMassRecallSet">
        <EffectArray value="NexusMassRecallSetPrevent2ndRecall"/>
    </CEffectSet>
    <CEffectRemoveBehavior id="NexusMassRecallSetPrevent2ndRecall">
        <ValidatorArray index="0" value="NexusRecallSucceeded"/>
        <EditorCategories value=""/>
        <BehaviorLink value="MothershipStrategicWarpOut"/>
        <Count value="1"/>
    </CEffectRemoveBehavior>
    <CEffectRemoveBehavior id="MothershipStrategicRecallSetPrevent2ndRecall">
        <ValidatorArray index="0" value="MothershipRecallSucceeded"/>
        <EditorCategories value=""/>
        <BehaviorLink value="NexusMassRecallWarpOut"/>
        <Count value="1"/>
    </CEffectRemoveBehavior>



   <!--  Validators-->
    <CValidatorLocationCompareRange id="NexusRecallSucceeded">
        <WhichLocation Value="TargetUnit"/>
        <Compare value="GT"/>
        <Value Effect="NexusMassRecallSet" Value="TargetPoint"/>
    </CValidatorLocationCompareRange>
    <CValidatorLocationCompareRange id="MothershipRecallSucceeded">
        <WhichLocation Value="TargetUnit"/>
        <Compare value="GT"/>
        <Value Effect="MothershipStrategicRecallSet" Value="TargetPoint"/>
    </CValidatorLocationCompareRange>

Video of the fix in action:

StarCraft II - Fix for double Recall displacement bug

Test Map with above fix and more info:

Recall via Nexus and Mothership teleports units to displaced position