Fixes MobStateComponent not cancelling stand attempts when mob is incapacitated

Closes #4831

Content.Shared/MobState/EntitySystems/MobStateSystem.cs

@@ -3,6 +3,7 @@ using Content.Shared.MobState.Components;
 using Content.Shared.MobState.State;
 using Content.Shared.Movement;
 using Content.Shared.Pulling.Events;
+using Content.Shared.Standing;
 using Robust.Shared.GameObjects;
 
 namespace Content.Shared.MobState.EntitySystems
@@ -16,6 +17,8 @@ namespace Content.Shared.MobState.EntitySystems
             SubscribeLocalEvent<MobStateComponent, StartPullAttemptEvent>(OnStartPullAttempt);
             SubscribeLocalEvent<MobStateComponent, DamageChangedEvent>(UpdateState);
             SubscribeLocalEvent<MobStateComponent, MovementAttemptEvent>(OnMoveAttempt);
+            SubscribeLocalEvent<MobStateComponent, StandAttemptEvent>(OnStandAttempt);
+            // Note that there's no check for Down attempts because if a mob's in crit or dead, they can be downed...
         }
 
         private void OnStartPullAttempt(EntityUid uid, MobStateComponent component, StartPullAttemptEvent args)
@@ -41,5 +44,11 @@ namespace Content.Shared.MobState.EntitySystems
                     return;
             }
         }
+
+        private void OnStandAttempt(EntityUid uid, MobStateComponent component, StandAttemptEvent args)
+        {
+            if(component.IsIncapacitated())
+                args.Cancel();
+        }
     }
 }

Content.Shared/MobState/State/SharedCriticalMobState.cs

@@ -21,7 +21,7 @@ namespace Content.Shared.MobState.State
                 status.ShowAlert(AlertType.HumanCrit); // TODO: combine humancrit-0 and humancrit-1 into a gif and display it
             }
 
-            EntitySystem.Get<StandingStateSystem>().Down(entity);
+            EntitySystem.Get<StandingStateSystem>().Down(entity.Uid);
 
             if (entity.TryGetComponent(out SharedAppearanceComponent? appearance))
             {

Resources/Changelog/Parts/down.yml

@@ -0,0 +1,4 @@
+author: Zumorica
+changes:
+  - type: Fix # One of the following: Add, Remove, Tweak, Fix
+    message: Fixed mobs that die or go into crit not being downed.