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Fix Composites and Sub-Trees not ending their Children when exited #113

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Fix Composites and Sub-Trees not ending their Children when exited #113

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6f8610d
Fix missing ending of sub-trees when composites and root nodes are ex…
achynes Dec 3, 2025
c10667e
Fix a null deref when visual debugging is showing a sub-tree node wit…
achynes Dec 3, 2025
1fde21d
Allow BehaviorTreeBuilder.Splice to receive a null tree, supporting u…
achynes Dec 3, 2025
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2 changes: 1 addition & 1 deletion Assets/com.fluid.behavior-tree/Editor/BehaviorTree/Printer/VisualTask.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@ public VisualTask (ITask task, IGraphContainer parentContainer) {

AddBox(container);

if (task.Children != null) {
if (task.Children != null && task.Children.Count > 0) {
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@ashblue ashblue Dec 8, 2025

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Ah nice. Yeah I can see this was creating a graphical display bug

var childContainer = new GraphContainerHorizontal();
foreach (var child in task.Children) {
_children.Add(new VisualTask(child, childContainer));
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6 changes: 4 additions & 2 deletions Assets/com.fluid.behavior-tree/Runtime/BehaviorTree/Builder/BehaviorTreeBuilder.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
using System;
using System;
using System.Collections.Generic;
using CleverCrow.Fluid.BTs.Decorators;
using CleverCrow.Fluid.BTs.TaskParents;
Expand Down Expand Up @@ -179,7 +179,9 @@ public BehaviorTreeBuilder AddNode (ITask node) {
}

public BehaviorTreeBuilder Splice (BehaviorTree tree) {
_tree.Splice(PointerCurrent, tree);
if (tree != null && tree.Root != null) {
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@ashblue ashblue Dec 8, 2025

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Hmmm, I feel like this should technically fail if you're passing in an empty null tree as most people would probably want to fix the error in that case. Maybe throwing an intentional error here might be more appropriate? I might modify the PR to remove this but feel free to debate me on this one (seems like the best path forward to me). What specific edge case were you hitting with this?

_tree.Splice(PointerCurrent, tree);
}

return this;
}
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6 changes: 5 additions & 1 deletion Assets/com.fluid.behavior-tree/Runtime/TaskParents/Composites/CompositeBase.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
namespace CleverCrow.Fluid.BTs.TaskParents.Composites {
namespace CleverCrow.Fluid.BTs.TaskParents.Composites {
public abstract class CompositeBase : TaskParentBase {
public int ChildIndex { get; protected set; }

Expand All @@ -13,5 +13,9 @@ public override void Reset () {

base.Reset();
}

protected void NotifyChildEnd(int childEnding) {
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@ashblue ashblue Dec 8, 2025

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Is the last child not getting an End call on it when the BT tree completes? If so I'll need to get a test in to verify this and that it fixes the created bug. And also do manual regression testing.

It looks like there is code in here to call End on tasks automatically instead of manually calling like this. So I'm wondering why this would be needed?

https://github.com/ashblue/fluid-behavior-tree/blob/develop/Assets/com.fluid.behavior-tree/Runtime/Tasks/TaskBase.cs

Curious what the logic here is to forcibly call end on all the composites. If it's just not being triggered at all that would make sense. But I'm pretty sure End is firing fine in my code base last I checked. Please share more on your specific use case.

Children[childEnding].End();
}
}
}
6 changes: 5 additions & 1 deletion Assets/com.fluid.behavior-tree/Runtime/TaskParents/Composites/Selector.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
using CleverCrow.Fluid.BTs.Tasks;
using CleverCrow.Fluid.BTs.Tasks;

namespace CleverCrow.Fluid.BTs.TaskParents.Composites {
public class Selector : CompositeBase {
Expand All @@ -10,9 +10,13 @@ protected override TaskStatus OnUpdate () {

switch (child.Update()) {
case TaskStatus.Success:
NotifyChildEnd(ChildIndex);
return TaskStatus.Success;
case TaskStatus.Continue:
return TaskStatus.Continue;
case TaskStatus.Failure:
NotifyChildEnd(ChildIndex);
break;
}

ChildIndex++;
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4 changes: 4 additions & 0 deletions Assets/com.fluid.behavior-tree/Runtime/TaskParents/Composites/SelectorRandom.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -21,9 +21,13 @@ protected override TaskStatus OnUpdate () {

switch (child.Update()) {
case TaskStatus.Success:
NotifyChildEnd(ChildIndex);
return TaskStatus.Success;
case TaskStatus.Continue:
return TaskStatus.Continue;
case TaskStatus.Failure:
NotifyChildEnd(ChildIndex);
break;
}

ChildIndex++;
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15 changes: 12 additions & 3 deletions Assets/com.fluid.behavior-tree/Runtime/TaskParents/Composites/Sequence.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
using CleverCrow.Fluid.BTs.Tasks;
using CleverCrow.Fluid.BTs.Tasks;

namespace CleverCrow.Fluid.BTs.TaskParents.Composites {
public class Sequence : CompositeBase {
Expand All @@ -9,8 +9,17 @@ protected override TaskStatus OnUpdate () {
var child = Children[ChildIndex];

var status = child.Update();
if (status != TaskStatus.Success) {
return status;
switch (status) {
case TaskStatus.Success:
NotifyChildEnd(ChildIndex);
break;
case TaskStatus.Failure:
NotifyChildEnd(ChildIndex);
return status;
case TaskStatus.Continue:
return status;
default:
break;
}

ChildIndex++;
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4 changes: 3 additions & 1 deletion Assets/com.fluid.behavior-tree/Runtime/TaskParents/TaskRoot.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
using CleverCrow.Fluid.BTs.Tasks;
using CleverCrow.Fluid.BTs.Tasks;

namespace CleverCrow.Fluid.BTs.TaskParents {
public class TaskRoot : TaskParentBase {
Expand All @@ -16,6 +16,8 @@ protected override TaskStatus OnUpdate () {
}

public override void End () {
var child = Children[0];
child.End();
}
}
}