bug(cdk/tree): Memory leak in CdkTreeNode

[AStrelkov]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

Next subscription is never unsubscribed in row 1398 of 'tree.ts':

this._tree
._getExpansionModel()
.changed.pipe(
map(() => this.isExpanded),
distinctUntilChanged(),
)
.subscribe(() => this._changeDetectorRef.markForCheck());

Reproduction

StackBlitz link:
Steps to reproduce:
1.
2.

Expected Behavior

Unsubscribe this subscription using pipe(takeUntilDestroy()) or in ngOnDestroy() life hook.

Actual Behavior

Subscription never unsubscribed.

Environment

• Angular: 19, 20
• CDK/Material: CDK
• Browser(s): Chrome, Edge
• Operating System (e.g. Windows, macOS, Ubuntu): Windows