The ItemsControlItemAutomationPeer leads memory leaks

[alexdi220]

Description

Hello, I encountered a memory leak issue with our components. During my research, I found that the key issue is caused by
System.Windows.Automation.Peers.ItemsControlItemAutomationPeer.
It holds a reference to the user control (ViewA) via the field _itemsControlAutomationPeer.

How it works:

• We use a ContentControl and two views — ViewA and ViewB.
• On a button click, I change ContentControl.Content to a new instance of the view.
• In this case, I expect that the previous instance of the view (ViewA) should be collected, because it has been unloaded from the visual tree.

And this works until I start showing any popups.
At that moment, setting the new RootVisual causes the EnsureAutomation call.
This method forces the creation of the automation tree, and from that moment on, ItemsControlItemAutomationPeer holds a reference to ViewA.

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Now, I’m looking for any help, solution, or workaround.
This is just a test sample, but we have a real-world scenario where our customer is suffering from this issue.

Reproduction Steps

• Run MemoryLeakTestApp
• Click ShowPopup a couple of times
• Take the first snapshot
• Click ChangeView
• Take the second snapshot
• Compare them and find the ViewA

MemoryLeakTestApp.zip

Expected behavior

The ViewA should be collected by the GC

Actual behavior

The ViewA remains in memory

Regression?

YES.
Under NET 6, it can't be reproduced, but there is another memory leak here (it is caused by AutomationPeer. _children.
I also tried to reproduce it under Framework 4.8, but it works properly without leaks

Known Workarounds

No response

Impact

No response

Configuration

WPF NET 9. This issue can be reproduced under NET 8 and higher.

Other information

No response