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flame-engine
When remove component : Null check operator used on a null value.
What happened?
Non-fatal Exception: io.flutter.plugins.firebase.crashlytics.FlutterError: Null check operator used on a null value. Error thrown .
at Component._remove.<fn>(component.dart:971)
at Iterable.every(dart:core)
at Component.propagateToChildren(component.dart:374)
at Component._remove(component.dart:961)
at Component.handleLifecycleEventRemove(component.dart:820)
at ComponentTreeRoot.processLifecycleEvents(component_tree_root.dart:95)
at FlameGame.updateTree(flame_game.dart:158)
at FlameGame.update(flame_game.dart:152)
at GameWidgetState.build.<fn>.<fn>.<fn>(game_widget.dart:387)
at GameWidgetState._protectedBuild(game_widget.dart:228)
at GameWidgetState.build.<fn>.<fn>(game_widget.dart:376)
at _LayoutBuilderElement._layout.layoutCallback(layout_builder.dart:139)
at BuildOwner.buildScope(framework.dart:2844)
at _LayoutBuilderElement._layout(layout_builder.dart:173)
at RenderObject.invokeLayoutCallback.<fn>(object.dart:2686)
at PipelineOwner._enableMutationsToDirtySubtrees(object.dart:1097)
at RenderObject.invokeLayoutCallback(object.dart:2686)
at RenderConstrainedLayoutBuilder.rebuildIfNecessary(layout_builder.dart:248)
at _RenderLayoutBuilder.performLayout(layout_builder.dart:331)
at RenderObject._layoutWithoutResize(object.dart:2414)
at PipelineOwner.flushLayout(object.dart:1051)
at PipelineOwner.flushLayout(object.dart:1064)
at RendererBinding.drawFrame(binding.dart:582)
at WidgetsBinding.drawFrame(binding.dart:991)
at RendererBinding._handlePersistentFrameCallback(binding.dart:448)
at SchedulerBinding._invokeFrameCallback(binding.dart:1386)
at SchedulerBinding.handleDrawFrame(binding.dart:1311)
at SchedulerBinding._handleDrawFrame(binding.dart:1169)
What do you expect?
void _remove() {
assert(_parent != null, 'Trying to remove a component with no parent');
_parent!.children.remove(this);
propagateToChildren(
(Component component) {
component
..onRemove()
.._unregisterKey()
.._clearMountedBit()
.._clearRemovingBit()
.._setRemovedBit()
.._removeCompleter?.complete() // here is async func call. when exec, where jump other code and may change _parent value, it cause null pointer check error?
.._removeCompleter = null
// .._parent!.onChildrenChanged(component, ChildrenChangeType.removed) // error in here
.._parent?.onChildrenChanged(component, ChildrenChangeType.removed) // may use ? instead !
.._parent = null;
return true;
},
includeSelf: true,
);
}
How can we reproduce this?
on flame-1.17.0 and flutter 3.19.5
What steps should take to fix this?
No response
Do have an example of where the bug occurs?
No response
Relevant log output
No response
Execute in a terminal and put output into the code block below
Output of: flutter doctor -v
Affected platforms
Android
Other information
No response
Are you interested in working on a PR for this?
- [X] I want to work on this
You're trying to remove a component that doesn't have a parent, if running in debug mode you would have hit the assertion in the top before this. I'd suggest you look into where you're trying to remove an unmounted component.
