Remove uses of TransformComponent.ChildEntities (#22442)

* Make output of ChildEnumerator non-nullable

* Remove uses of ChildEntities

* poke tests

---------

Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

Content.Server/Administration/Systems/AdminVerbSystem.Tools.cs

@@ -772,18 +772,20 @@ public sealed partial class AdminVerbSystem
         {
             foreach (var grid in station.Grids)
             {
-                foreach (var ent in Transform(grid).ChildEntities)
+                var enumerator = Transform(grid).ChildEnumerator;
+                while (enumerator.MoveNext(out var ent))
                 {
                     yield return ent;
                 }
             }
         }
-
         else if (HasComp<MapComponent>(target))
         {
-            foreach (var possibleGrid in Transform(target).ChildEntities)
+            var enumerator = Transform(target).ChildEnumerator;
+            while (enumerator.MoveNext(out var possibleGrid))
             {
-                foreach (var ent in Transform(possibleGrid).ChildEntities)
+                var enumerator2 = Transform(possibleGrid).ChildEnumerator;
+                while (enumerator2.MoveNext(out var ent))
                 {
                     yield return ent;
                 }
@@ -791,7 +793,8 @@ public sealed partial class AdminVerbSystem
         }
         else
         {
-            foreach (var ent in Transform(target).ChildEntities)
+            var enumerator = Transform(target).ChildEnumerator;
+            while (enumerator.MoveNext(out var ent))
             {
                 yield return ent;
             }

Content.Server/Cargo/Systems/CargoSystem.Shuttle.cs

@@ -292,7 +292,7 @@ public sealed partial class CargoSystem
         var children = xform.ChildEnumerator;
         while (children.MoveNext(out var child))
         {
-            if (!CanSell(child.Value, _xformQuery.GetComponent(child.Value)))
+            if (!CanSell(child, _xformQuery.GetComponent(child)))
                 return false;
         }
 

Content.Server/Cargo/Systems/PricingSystem.cs

@@ -342,8 +342,8 @@ public sealed class PricingSystem : EntitySystem
     {
         var xform = Transform(grid);
         var price = 0.0;
-
+        var enumerator = xform.ChildEnumerator;
-        foreach (var child in xform.ChildEntities)
+        while (enumerator.MoveNext(out var child))
         {
             if (predicate is null || predicate(child))
             {

Content.Server/Construction/Commands/FixRotationsCommand.cs

@@ -64,7 +64,9 @@ namespace Content.Server.Construction.Commands
             var changed = 0;
             var tagSystem = _entManager.EntitySysManager.GetEntitySystem<TagSystem>();
 
-            foreach (var child in xformQuery.GetComponent(gridId.Value).ChildEntities)
+
+            var enumerator = xformQuery.GetComponent(gridId.Value).ChildEnumerator;
+            while (enumerator.MoveNext(out var child))
             {
                 if (!_entManager.EntityExists(child))
                 {

Content.Server/Construction/Commands/TileWallsCommand.cs

@@ -72,7 +72,8 @@ namespace Content.Server.Construction.Commands
             var underplating = _tileDefManager[TilePrototypeId];
             var underplatingTile = new Tile(underplating.TileId);
             var changed = 0;
-            foreach (var child in _entManager.GetComponent<TransformComponent>(gridId.Value).ChildEntities)
+            var enumerator = _entManager.GetComponent<TransformComponent>(gridId.Value).ChildEnumerator;
+            while (enumerator.MoveNext(out var child))
             {
                 if (!_entManager.EntityExists(child))
                 {

Content.Server/Maps/ResaveCommand.cs

@@ -46,10 +46,9 @@ public sealed class ResaveCommand : LocalizedCommands
             {
                 loader.SaveMap(mapId, fn.ToString());
             }
-            else
+            else if (mapXform.ChildEnumerator.MoveNext(out var child))
             {
-
+                loader.Save(child, fn.ToString());
-                loader.Save(mapXform.ChildEntities.First(), fn.ToString());
             }
 
             _mapManager.DeleteMap(mapId);

Content.Server/Medical/SuitSensors/SuitSensorSystem.cs

@@ -137,7 +137,7 @@ public sealed class SuitSensorSystem : EntitySystem
                 sensor.StationId = stationUid;
             }
 
-            RecursiveSensor(child.Value, stationUid, sensorQuery, xformQuery);
+            RecursiveSensor(child, stationUid, sensorQuery, xformQuery);
         }
     }
 

Content.Server/NPC/Systems/NPCUtilitySystem.cs

@@ -454,7 +454,7 @@ public sealed class NPCUtilitySystem : EntitySystem
 
         while (enumerator.MoveNext(out var child))
         {
-            RecursiveAdd(child.Value, entities);
+            RecursiveAdd(child, entities);
         }
     }
 

Content.Server/Shuttles/Systems/ArrivalsSystem.cs

@@ -236,10 +236,9 @@ public sealed class ArrivalsSystem : EntitySystem
         }
 
         var children = xform.ChildEnumerator;
-
         while (children.MoveNext(out var child))
         {
-            DumpChildren(child.Value, ref args, pendingEntQuery, arrivalsBlacklistQuery, mobQuery, xformQuery);
+            DumpChildren(child, ref args, pendingEntQuery, arrivalsBlacklistQuery, mobQuery, xformQuery);
         }
     }
 

Content.Server/Shuttles/Systems/ShuttleSystem.FasterThanLight.cs

@@ -501,10 +501,10 @@ public sealed partial class ShuttleSystem
         var childEnumerator = xform.ChildEnumerator;
         while (childEnumerator.MoveNext(out var child))
         {
-            if (!_buckleQuery.TryGetComponent(child.Value, out var buckle) || buckle.Buckled)
+            if (!_buckleQuery.TryGetComponent(child, out var buckle) || buckle.Buckled)
                 continue;
 
-            toKnock.Add(child.Value);
+            toKnock.Add(child);
         }
     }
 

Content.Server/Shuttles/Systems/ShuttleSystem.GridFill.cs

@@ -148,7 +148,7 @@ public sealed partial class ShuttleSystem
             if (!dockQuery.TryGetComponent(child, out var dock))
                 continue;
 
-            return (child.Value, dock);
+            return (child, dock);
         }
 
         return null;

Content.Server/Temperature/Systems/TemperatureSystem.cs

@@ -341,7 +341,8 @@ public sealed class TemperatureSystem : EntitySystem
     {
         RecalculateAndApplyParentThresholds(root, temperatureQuery, transformQuery, tempThresholdsQuery);
 
-        foreach (var child in Transform(root).ChildEntities)
+        var enumerator = Transform(root).ChildEnumerator;
+        while (enumerator.MoveNext(out var child))
         {
             RecursiveThresholdUpdate(child, temperatureQuery, transformQuery, tempThresholdsQuery);
         }