From bc7754a70d8adec9113afe0c80ef89a5abaf2763 Mon Sep 17 00:00:00 2001
From: Leon Friedrich <60421075+ElectroJr@users.noreply.github.com>
Date: Sun, 11 Dec 2022 11:56:09 +1300
Subject: [PATCH] Fix projectile exception (#12956)

---
 .../Projectiles/SharedProjectileSystem.cs     | 12 ++++----
 .../Weapons/Ranged/Systems/GunSystem.cs       | 29 ++++++++++---------
 2 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/Content.Server/Projectiles/SharedProjectileSystem.cs b/Content.Server/Projectiles/SharedProjectileSystem.cs
index d36d3520fe..a3c12a46e0 100644
--- a/Content.Server/Projectiles/SharedProjectileSystem.cs
+++ b/Content.Server/Projectiles/SharedProjectileSystem.cs
@@ -42,27 +42,27 @@ namespace Content.Server.Projectiles
                 return;
 
             var otherEntity = args.OtherFixture.Body.Owner;
+            var otherName = ToPrettyString(otherEntity);
             var direction = args.OurFixture.Body.LinearVelocity.Normalized;
             var modifiedDamage = _damageableSystem.TryChangeDamage(otherEntity, component.Damage, component.IgnoreResistances, origin: component.Shooter);
             component.DamagedEntity = true;
+            var deleted = Deleted(otherEntity);
 
             if (modifiedDamage is not null && EntityManager.EntityExists(component.Shooter))
             {
-                if (modifiedDamage.Total > FixedPoint2.Zero)
+                if (modifiedDamage.Total > FixedPoint2.Zero && !deleted)
                 {
                     RaiseNetworkEvent(new DamageEffectEvent(Color.Red, new List<EntityUid> {otherEntity}), Filter.Pvs(otherEntity, entityManager: EntityManager));
                 }
 
                 _adminLogger.Add(LogType.BulletHit,
                     HasComp<ActorComponent>(otherEntity) ? LogImpact.Extreme : LogImpact.High,
-                    $"Projectile {ToPrettyString(uid):projectile} shot by {ToPrettyString(component.Shooter):user} hit {ToPrettyString(otherEntity):target} and dealt {modifiedDamage.Total:damage} damage");
+                    $"Projectile {ToPrettyString(uid):projectile} shot by {ToPrettyString(component.Shooter):user} hit {otherName:target} and dealt {modifiedDamage.Total:damage} damage");
             }
 
-            _guns.PlayImpactSound(otherEntity, modifiedDamage, component.SoundHit, component.ForceSound);
-
-            // Damaging it can delete it
-            if (HasComp<CameraRecoilComponent>(otherEntity))
+            if (!deleted)
             {
+                _guns.PlayImpactSound(otherEntity, modifiedDamage, component.SoundHit, component.ForceSound);
                 _sharedCameraRecoil.KickCamera(otherEntity, direction);
             }
 
diff --git a/Content.Server/Weapons/Ranged/Systems/GunSystem.cs b/Content.Server/Weapons/Ranged/Systems/GunSystem.cs
index a584c1e1ea..f70fa7dc7d 100644
--- a/Content.Server/Weapons/Ranged/Systems/GunSystem.cs
+++ b/Content.Server/Weapons/Ranged/Systems/GunSystem.cs
@@ -192,27 +192,34 @@ public sealed partial class GunSystem : SharedGunSystem
 
                         var dmg = hitscan.Damage;
 
+                        bool deleted = false;
+                        string hitName = ToPrettyString(hitEntity);
                         if (dmg != null)
                             dmg = Damageable.TryChangeDamage(hitEntity, dmg, origin: user);
 
+                        // check null again, as TryChangeDamage returns modified damage values
                         if (dmg != null)
                         {
-                            if (dmg.Total > FixedPoint2.Zero)
-                            {
-                                RaiseNetworkEvent(new DamageEffectEvent(Color.Red, new List<EntityUid> {result.HitEntity}), Filter.Pvs(hitEntity, entityManager: EntityManager));
-                            }
+                            deleted = Deleted(hitEntity);
 
-                            PlayImpactSound(hitEntity, dmg, hitscan.Sound, hitscan.ForceSound);
+                            if (!deleted)
+                            {
+                                if (dmg.Total > FixedPoint2.Zero)
+                                    RaiseNetworkEvent(new DamageEffectEvent(Color.Red, new List<EntityUid> {result.HitEntity}), Filter.Pvs(hitEntity, entityManager: EntityManager));
+
+                                // TODO get fallback position for playing hit sound.
+                                PlayImpactSound(hitEntity, dmg, hitscan.Sound, hitscan.ForceSound);
+                            }
 
                             if (user != null)
                             {
                                 Logs.Add(LogType.HitScanHit,
-                                    $"{ToPrettyString(user.Value):user} hit {ToPrettyString(hitEntity):target} using hitscan and dealt {dmg.Total:damage} damage");
+                                    $"{ToPrettyString(user.Value):user} hit {hitName:target} using hitscan and dealt {dmg.Total:damage} damage");
                             }
                             else
                             {
                                 Logs.Add(LogType.HitScanHit,
-                                    $"Hit {ToPrettyString(hitEntity):target} using hitscan and dealt {dmg.Total:damage} damage");
+                                    $"Hit {hitName:target} using hitscan and dealt {dmg.Total:damage} damage");
                             }
                         }
                     }
@@ -301,8 +308,7 @@ public sealed partial class GunSystem : SharedGunSystem
 
     public void PlayImpactSound(EntityUid otherEntity, DamageSpecifier? modifiedDamage, SoundSpecifier? weaponSound, bool forceWeaponSound)
     {
-        if (Deleted(otherEntity))
-            return;
+        DebugTools.Assert(!Deleted(otherEntity), "Impact sound entity was deleted");
 
         // Like projectiles and melee,
         // 1. Entity specific sound
@@ -310,11 +316,6 @@ public sealed partial class GunSystem : SharedGunSystem
         // 3. Nothing
         var playedSound = false;
 
-        // woops the other entity is deleted
-        // someone needs to handle this better. for now i'm just gonna make it not crash the server -rane
-        if (Deleted(otherEntity))
-            return;
-
         if (!forceWeaponSound && modifiedDamage != null && modifiedDamage.Total > 0 && TryComp<RangedDamageSoundComponent>(otherEntity, out var rangedSound))
         {
             var type = MeleeWeaponSystem.GetHighestDamageSound(modifiedDamage, ProtoManager);