Fix Whoopie Cushions from lagging the game. (#39194)

Content.Shared/Movement/Systems/MovementModStatusSystem.cs

@@ -194,6 +194,16 @@ public sealed partial class MovementModStatusSystem : EntitySystem // DeltaV - M
         return TryUpdateMovementStatus(uid, status, speedModifier, speedModifier);
     }
 
+    /// <inheritdoc cref="TryAddFrictionModDuration(EntityUid,TimeSpan,float,float)"/>
+    public bool TryAddFrictionModDuration(
+        EntityUid uid,
+        TimeSpan duration,
+        float friction
+    )
+    {
+        return TryAddFrictionModDuration(uid, duration, friction, friction);
+    }
+
     /// <summary>
     /// Apply friction modifier with provided duration,
     /// or incrementing duration of existing.
@@ -214,6 +224,16 @@ public sealed partial class MovementModStatusSystem : EntitySystem // DeltaV - M
                && TrySetFrictionStatus(status.Value, friction, acceleration, uid);
     }
 
+    /// <inheritdoc cref="TryUpdateFrictionModDuration(EntityUid,TimeSpan,float,float)"/>
+    public bool TryUpdateFrictionModDuration(
+        EntityUid uid,
+        TimeSpan duration,
+        float friction
+    )
+    {
+        return TryUpdateFrictionModDuration(uid,duration, friction, friction);
+    }
+
     /// <summary>
     /// Apply friction modifier with provided duration,
     /// or update duration of existing if it is lesser than provided duration.

Content.Shared/Slippery/SlipperySystem.cs

@@ -30,10 +30,18 @@ public sealed class SlipperySystem : EntitySystem
     [Dependency] private readonly SharedPhysicsSystem _physics = default!;
     [Dependency] private readonly SpeedModifierContactsSystem _speedModifier = default!;
 
+    private EntityQuery<KnockedDownComponent> _knockedDownQuery;
+    private EntityQuery<PhysicsComponent> _physicsQuery;
+    private EntityQuery<SlidingComponent> _slidingQuery;
+
     public override void Initialize()
     {
         base.Initialize();
 
+        _knockedDownQuery = GetEntityQuery<KnockedDownComponent>();
+        _physicsQuery = GetEntityQuery<PhysicsComponent>();
+        _slidingQuery = GetEntityQuery<SlidingComponent>();
+
         SubscribeLocalEvent<SlipperyComponent, StepTriggerAttemptEvent>(HandleAttemptCollide);
         SubscribeLocalEvent<SlipperyComponent, StepTriggeredOffEvent>(HandleStepTrigger);
         SubscribeLocalEvent<NoSlipComponent, SlipAttemptEvent>(OnNoSlipAttempt);
@@ -92,7 +100,8 @@ public sealed class SlipperySystem : EntitySystem
 
     public void TrySlip(EntityUid uid, SlipperyComponent component, EntityUid other, bool requiresContact = true)
     {
-        if (HasComp<KnockedDownComponent>(other) && !component.SlipData.SuperSlippery)
+        var knockedDown = _knockedDownQuery.HasComp(other);
+        if (knockedDown && !component.SlipData.SuperSlippery)
             return;
 
         var attemptEv = new SlipAttemptEvent(uid);
@@ -111,7 +120,7 @@ public sealed class SlipperySystem : EntitySystem
         var ev = new SlipEvent(other);
         RaiseLocalEvent(uid, ref ev);
 
-        if (TryComp(other, out PhysicsComponent? physics) && !HasComp<SlidingComponent>(other))
+        if (_physicsQuery.TryComp(other, out var physics) && !_slidingQuery.HasComp(other))
         {
             _physics.SetLinearVelocity(other, physics.LinearVelocity * component.SlipData.LaunchForwardsMultiplier, body: physics);
 
@@ -120,16 +129,23 @@ public sealed class SlipperySystem : EntitySystem
         }
 
         // Preventing from playing the slip sound and stunning when you are already knocked down.
-        if (!HasComp<KnockedDownComponent>(other))
+        if (!knockedDown)
         {
+            // Status effects should handle a TimeSpan of 0 properly...
             _stun.TryUpdateStunDuration(other, component.SlipData.StunTime);
-            _stamina.TakeStaminaDamage(other, component.StaminaDamage); // Note that this can stamCrit
+
+            // Don't make a new status effect entity if the entity wouldn't do anything
+            if (!MathHelper.CloseTo(component.SlipData.SlipFriction, 1f))
+            {
                 _movementMod.TryUpdateFrictionModDuration(
                     other,
                     component.FrictionStatusTime,
-                component.SlipData.SlipFriction,
                     component.SlipData.SlipFriction
                 );
+            }
+
+            _stamina.TakeStaminaDamage(other, component.StaminaDamage); // Note that this can StamCrit
+
             _audio.PlayPredicted(component.SlipSound, other, other);
         }
 

Content.Shared/StatusEffectNew/StatusEffectSystem.API.cs

@@ -22,6 +22,13 @@ public sealed partial class StatusEffectsSystem
         TimeSpan duration
     )
     {
+        if (duration == TimeSpan.Zero)
+        {
+            statusEffect = null;
+            return false;
+        }
+
+        // We check to make sure time is greater than zero here because sometimes you want to use TryAddStatusEffect to remove duration instead...
         if (!TryGetStatusEffect(target, effectProto, out statusEffect))
             return TryAddStatusEffect(target, effectProto, out statusEffect, duration);
 
@@ -53,6 +60,12 @@ public sealed partial class StatusEffectsSystem
         TimeSpan? duration = null
     )
     {
+        if (duration <= TimeSpan.Zero)
+        {
+            statusEffect = null;
+            return false;
+        }
+
         if (!TryGetStatusEffect(target, effectProto, out statusEffect))
             return TryAddStatusEffect(target, effectProto, out statusEffect, duration);
 
@@ -83,6 +96,12 @@ public sealed partial class StatusEffectsSystem
         TimeSpan? duration = null
     )
     {
+        if (duration <= TimeSpan.Zero)
+        {
+            statusEffect = null;
+            return false;
+        }
+
         if (!TryGetStatusEffect(target, effectProto, out statusEffect))
             return TryAddStatusEffect(target, effectProto, out statusEffect, duration);
 

Content.Shared/StatusEffectNew/StatusEffectsSystem.cs

@@ -201,6 +201,10 @@ public sealed partial class StatusEffectsSystem : EntitySystem
     )
     {
         statusEffect = null;
+
+        if (duration <= TimeSpan.Zero)
+            return false;
+
         if (!CanAddStatusEffect(target, effectProto))
             return false;
 

Resources/Prototypes/Entities/Objects/Fun/toys.yml

@@ -917,6 +917,7 @@
     delay: 0.8
   - type: Slippery
     staminaDamage: 0
+    frictionStatusTime: 0
     slipData:
       stunTime: 0
       knockdownTime: 0