Fix Android grouped CollectionView header/footer rebind leak

[AdamEssenmacher]

Description of Change

Fixes an Android grouped CollectionView leak where group header and footer view holders were bound twice during OnBindViewHolder.

Grouped headers/footers already bind through BindTemplatedItemViewHolder(...), but the adapter then fell through to the base binding path, causing TemplatedItemViewHolder.Bind(...) to run a second time and append duplicate logical-child references. This change makes grouped header/footer binding terminal, matching the existing structured header/footer adapter behavior.

Added Android device regressions for both grouped headers and grouped footers to verify repeated recycle/rebind cycles do not grow LogicalChildren.

Issues Fixed

Fixes #17698

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.sh | bash -s -- 35368

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.ps1) } 35368"

[dotnet-policy-service]

Hey there @@AdamEssenmacher! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[AdamEssenmacher]

@dotnet-policy-service agree

[Copilot]

Pull request overview

Fixes an Android grouped CollectionView leak caused by group header/footer view holders being bound twice in GroupableItemsViewAdapter.OnBindViewHolder, which could append duplicate logical-child references over repeated recycle/rebind cycles.

Changes:

• Make group header/footer binding in GroupableItemsViewAdapter.OnBindViewHolder terminal by returning immediately after BindTemplatedItemViewHolder(...).
• Add Android device regression tests to ensure grouped header/footer recycle+rebind does not increase CollectionView logical children.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Controls/src/Core/Handlers/Items/Android/Adapters/GroupableItemsViewAdapter.cs	Prevents falling through to the base bind path for grouped header/footer view holders (avoids double-bind).
src/Controls/tests/DeviceTests/Elements/CollectionView/CollectionViewTests.Android.cs	Adds regression coverage ensuring grouped header/footer rebinding doesn’t grow LogicalChildren.

[jfversluis]

/azp run maui-pr

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[kubaflo]

🤖 AI Summary

👋 @AdamEssenmacher — new AI review results are available. Please review the latest session below.

📊 Review Session — fb72d32 · Fix grouped CollectionView header footer rebind leak · 2026-05-12 09:38 UTC

🚦 Gate — Test Before & After Fix

Gate Result: ✅ PASSED

Platform: ANDROID · Base: main · Merge base: f8cb875e

Test	Without Fix (expect FAIL)	With Fix (expect PASS)
📱 CollectionViewTests (GroupHeaderRebindDoesNotGrowLogicalChildren, GroupFooterRebindDoesNotGrowLogicalChildren) Category=CollectionView	✅ FAIL — 1004s	✅ PASS — 384s

🔴 Without fix — 📱 CollectionViewTests (GroupHeaderRebindDoesNotGrowLogicalChildren, GroupFooterRebindDoesNotGrowLogicalChildren): FAIL ✅ · 1004s

(truncated to last 15,000 chars)

.dll.so
  [41/133] Xamarin.AndroidX.DrawerLayout.dll -> Xamarin.AndroidX.DrawerLayout.dll.so
  [42/133] Xamarin.AndroidX.Fragment.dll -> Xamarin.AndroidX.Fragment.dll.so
  [119/133] System.Text.RegularExpressions.dll -> System.Text.RegularExpressions.dll.so
  [43/133] Xamarin.AndroidX.Lifecycle.Common.Jvm.dll -> Xamarin.AndroidX.Lifecycle.Common.Jvm.dll.so
  [120/133] System.Threading.Tasks.dll -> System.Threading.Tasks.dll.so
  [121/133] System.Threading.Thread.dll -> System.Threading.Thread.dll.so
  [44/133] Xamarin.AndroidX.Lifecycle.LiveData.Core.dll -> Xamarin.AndroidX.Lifecycle.LiveData.Core.dll.so
  [122/133] System.Threading.ThreadPool.dll -> System.Threading.ThreadPool.dll.so
  [45/133] Xamarin.AndroidX.Lifecycle.ViewModel.Android.dll -> Xamarin.AndroidX.Lifecycle.ViewModel.Android.dll.so
  [123/133] System.Text.Json.dll -> System.Text.Json.dll.so
  [124/133] System.Threading.dll -> System.Threading.dll.so
  [125/133] System.Xml.Linq.dll -> System.Xml.Linq.dll.so
  [46/133] Xamarin.AndroidX.Lifecycle.ViewModelSavedState.Android.dll -> Xamarin.AndroidX.Lifecycle.ViewModelSavedState.Android.dll.so
  [126/133] System.Xml.ReaderWriter.dll -> System.Xml.ReaderWriter.dll.so
  [127/133] System.Xml.XDocument.dll -> System.Xml.XDocument.dll.so
  [47/133] Xamarin.AndroidX.Loader.dll -> Xamarin.AndroidX.Loader.dll.so
  [128/133] System.dll -> System.dll.so
  [129/133] netstandard.dll -> netstandard.dll.so
  [48/133] Xamarin.AndroidX.Navigation.Common.Android.dll -> Xamarin.AndroidX.Navigation.Common.Android.dll.so
  [130/133] Mono.Android.Runtime.dll -> Mono.Android.Runtime.dll.so
  [49/133] Xamarin.AndroidX.Navigation.Fragment.dll -> Xamarin.AndroidX.Navigation.Fragment.dll.so
  [50/133] Xamarin.AndroidX.Navigation.Runtime.Android.dll -> Xamarin.AndroidX.Navigation.Runtime.Android.dll.so
  [131/133] Java.Interop.dll -> Java.Interop.dll.so
  [51/133] Xamarin.AndroidX.Navigation.UI.dll -> Xamarin.AndroidX.Navigation.UI.dll.so
  [52/133] Xamarin.AndroidX.RecyclerView.dll -> Xamarin.AndroidX.RecyclerView.dll.so
  [53/133] Xamarin.AndroidX.SavedState.SavedState.Android.dll -> Xamarin.AndroidX.SavedState.SavedState.Android.dll.so
  [54/133] Xamarin.AndroidX.SwipeRefreshLayout.dll -> Xamarin.AndroidX.SwipeRefreshLayout.dll.so
  [55/133] Xamarin.AndroidX.ViewPager.dll -> Xamarin.AndroidX.ViewPager.dll.so
  [56/133] Xamarin.AndroidX.ViewPager2.dll -> Xamarin.AndroidX.ViewPager2.dll.so
  [57/133] Xamarin.Google.Android.Material.dll -> Xamarin.Google.Android.Material.dll.so
  [58/133] Xamarin.GooglePlayServices.Base.dll -> Xamarin.GooglePlayServices.Base.dll.so
  [132/133] Mono.Android.dll -> Mono.Android.dll.so
  [59/133] Xamarin.GooglePlayServices.Basement.dll -> Xamarin.GooglePlayServices.Basement.dll.so
  [60/133] Xamarin.GooglePlayServices.Maps.dll -> Xamarin.GooglePlayServices.Maps.dll.so
  [61/133] Xamarin.GooglePlayServices.Tasks.dll -> Xamarin.GooglePlayServices.Tasks.dll.so
  [62/133] Xamarin.Kotlin.StdLib.dll -> Xamarin.Kotlin.StdLib.dll.so
  [63/133] Xamarin.KotlinX.Coroutines.Core.Jvm.dll -> Xamarin.KotlinX.Coroutines.Core.Jvm.dll.so
  [64/133] Xamarin.KotlinX.Serialization.Core.Jvm.dll -> Xamarin.KotlinX.Serialization.Core.Jvm.dll.so
  [65/133] xunit.abstractions.dll -> xunit.abstractions.dll.so
  [66/133] xunit.assert.dll -> xunit.assert.dll.so
  [67/133] xunit.core.dll -> xunit.core.dll.so
  [68/133] xunit.execution.dotnet.dll -> xunit.execution.dotnet.dll.so
  [69/133] xunit.runner.utility.netcoreapp10.dll -> xunit.runner.utility.netcoreapp10.dll.so
  [70/133] System.Collections.Concurrent.dll -> System.Collections.Concurrent.dll.so
  [71/133] System.Collections.Immutable.dll -> System.Collections.Immutable.dll.so
  [72/133] System.Collections.NonGeneric.dll -> System.Collections.NonGeneric.dll.so
  [73/133] System.Collections.Specialized.dll -> System.Collections.Specialized.dll.so
  [74/133] System.Collections.dll -> System.Collections.dll.so
  [133/133] System.Private.CoreLib.dll -> System.Private.CoreLib.dll.so
  [75/133] System.ComponentModel.Primitives.dll -> System.ComponentModel.Primitives.dll.so
  [76/133] System.ComponentModel.TypeConverter.dll -> System.ComponentModel.TypeConverter.dll.so
  [77/133] System.ComponentModel.dll -> System.ComponentModel.dll.so
  [78/133] System.Console.dll -> System.Console.dll.so
  [79/133] System.Diagnostics.Debug.dll -> System.Diagnostics.Debug.dll.so
  [80/133] System.Diagnostics.DiagnosticSource.dll -> System.Diagnostics.DiagnosticSource.dll.so
  [81/133] System.Diagnostics.Process.dll -> System.Diagnostics.Process.dll.so
  [82/133] System.Diagnostics.Tools.dll -> System.Diagnostics.Tools.dll.so
  [83/133] System.Diagnostics.TraceSource.dll -> System.Diagnostics.TraceSource.dll.so
  [84/133] System.Diagnostics.Tracing.dll -> System.Diagnostics.Tracing.dll.so
  [85/133] System.Drawing.Primitives.dll -> System.Drawing.Primitives.dll.so
  [86/133] System.Drawing.dll -> System.Drawing.dll.so
  [87/133] System.Formats.Asn1.dll -> System.Formats.Asn1.dll.so
  [88/133] System.Globalization.dll -> System.Globalization.dll.so
  [89/133] System.IO.Compression.Brotli.dll -> System.IO.Compression.Brotli.dll.so
  [90/133] System.IO.Compression.dll -> System.IO.Compression.dll.so
  [91/133] System.IO.FileSystem.dll -> System.IO.FileSystem.dll.so
  [92/133] System.IO.Pipelines.dll -> System.IO.Pipelines.dll.so
  [93/133] System.IO.dll -> System.IO.dll.so
  [94/133] System.Linq.Expressions.dll -> System.Linq.Expressions.dll.so
  [95/133] System.Linq.dll -> System.Linq.dll.so
  [96/133] System.Memory.dll -> System.Memory.dll.so
  [97/133] System.Net.Http.dll -> System.Net.Http.dll.so
  [98/133] System.Net.NameResolution.dll -> System.Net.NameResolution.dll.so
  [99/133] System.Net.Primitives.dll -> System.Net.Primitives.dll.so
  [100/133] System.Net.Requests.dll -> System.Net.Requests.dll.so
  [101/133] System.Net.Sockets.dll -> System.Net.Sockets.dll.so
  [102/133] System.Numerics.Vectors.dll -> System.Numerics.Vectors.dll.so
  [103/133] System.ObjectModel.dll -> System.ObjectModel.dll.so
  [104/133] System.Private.Uri.dll -> System.Private.Uri.dll.so
  [105/133] System.Private.Xml.Linq.dll -> System.Private.Xml.Linq.dll.so
  [106/133] System.Private.Xml.dll -> System.Private.Xml.dll.so
  [107/133] System.Reflection.Extensions.dll -> System.Reflection.Extensions.dll.so
  [108/133] System.Reflection.TypeExtensions.dll -> System.Reflection.TypeExtensions.dll.so
  [109/133] System.Reflection.dll -> System.Reflection.dll.so
  [110/133] System.Runtime.Extensions.dll -> System.Runtime.Extensions.dll.so
  [111/133] System.Runtime.InteropServices.RuntimeInformation.dll -> System.Runtime.InteropServices.RuntimeInformation.dll.so
  [112/133] System.Runtime.InteropServices.dll -> System.Runtime.InteropServices.dll.so
  [113/133] System.Runtime.Loader.dll -> System.Runtime.Loader.dll.so
  [114/133] System.Runtime.Numerics.dll -> System.Runtime.Numerics.dll.so
  [115/133] System.Runtime.dll -> System.Runtime.dll.so
  [116/133] System.Security.Cryptography.dll -> System.Security.Cryptography.dll.so
  [117/133] System.Text.Encoding.dll -> System.Text.Encoding.dll.so
  [118/133] System.Text.Encodings.Web.dll -> System.Text.Encodings.Web.dll.so
  [119/133] System.Text.Json.dll -> System.Text.Json.dll.so
  [120/133] System.Text.RegularExpressions.dll -> System.Text.RegularExpressions.dll.so
  [121/133] System.Threading.Tasks.dll -> System.Threading.Tasks.dll.so
  [122/133] System.Threading.Thread.dll -> System.Threading.Thread.dll.so
  [123/133] System.Threading.ThreadPool.dll -> System.Threading.ThreadPool.dll.so
  [124/133] System.Threading.dll -> System.Threading.dll.so
  [125/133] System.Xml.Linq.dll -> System.Xml.Linq.dll.so
  [126/133] System.Xml.ReaderWriter.dll -> System.Xml.ReaderWriter.dll.so
  [127/133] System.Xml.XDocument.dll -> System.Xml.XDocument.dll.so
  [128/133] System.dll -> System.dll.so
  [129/133] netstandard.dll -> netstandard.dll.so
  [130/133] Java.Interop.dll -> Java.Interop.dll.so
  [131/133] Mono.Android.Runtime.dll -> Mono.Android.Runtime.dll.so
  [132/133] Mono.Android.dll -> Mono.Android.dll.so
  [133/133] System.Private.CoreLib.dll -> System.Private.CoreLib.dll.so

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:11:12.61
[11.0.0-prerelease.26230.4+92962e5c46ac08a66ded4c5696209cc60f1a232f] XHarness command issued: android test --app /home/vsts/work/1/s/artifacts/bin/Controls.DeviceTests/Release/net10.0-android/com.microsoft.maui.controls.devicetests-Signed.apk --package-name com.microsoft.maui.controls.devicetests --device-id emulator-5554 -o artifacts/log --timeout 01:00:00 -v --arg TestFilter=Category=CollectionView
�[40m�[37mdbug�[39m�[22m�[49m: ADBRunner using ADB.exe supplied from /home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/tools/net10.0/any/../../../runtimes/any/native/adb/linux/adb
�[40m�[37mdbug�[39m�[22m�[49m: Full resolved path:'/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb'
�[40m�[32minfo�[39m�[22m�[49m: Will attempt to find device supporting architectures: 'arm64-v8a', 'x86_64'
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb start-server'
�[40m�[37mdbug�[39m�[22m�[49m: 
�[40m�[32minfo�[39m�[22m�[49m: Finding attached devices/emulators...
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb devices -l'
�[40m�[37mdbug�[39m�[22m�[49m: Found 1 possible devices
�[40m�[37mdbug�[39m�[22m�[49m: Evaluating output line for device serial: emulator-5554          device product:sdk_gphone_x86_64 model:sdk_gphone_x86_64 device:generic_x86_64_arm64 transport_id:2
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 shell getprop ro.product.cpu.abilist'
�[40m�[37mdbug�[39m�[22m�[49m: Found 1 possible devices. Using 'emulator-5554'
�[40m�[32minfo�[39m�[22m�[49m: Active Android device set to serial 'emulator-5554'
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 -s emulator-5554 shell getprop ro.product.cpu.abi'
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 -s emulator-5554 shell getprop ro.build.version.sdk'
�[40m�[32minfo�[39m�[22m�[49m: Waiting for device to be available (max 5 minutes)
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 wait-for-device'
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 -s emulator-5554 shell getprop sys.boot_completed'
�[40m�[37mdbug�[39m�[22m�[49m: sys.boot_completed = '1'
�[40m�[37mdbug�[39m�[22m�[49m: Waited 0 seconds for device boot completion
�[40m�[37mdbug�[39m�[22m�[49m: Working with emulator-5554 (API 30)
�[40m�[37mdbug�[39m�[22m�[49m: Check current adb install and/or package verification settings
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 shell settings get global verifier_verify_adb_installs'
�[40m�[37mdbug�[39m�[22m�[49m: verifier_verify_adb_installs = 0
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 shell settings get global package_verifier_enable'
�[40m�[37mdbug�[39m�[22m�[49m: package_verifier_enable = 
�[40m�[1m�[33mwarn�[39m�[22m�[49m: Installing debug apks on a device might be rejected with INSTALL_FAILED_VERIFICATION_FAILURE. Make sure to set 'package_verifier_enable' to '0'
�[40m�[32minfo�[39m�[22m�[49m: Attempting to remove apk 'com.microsoft.maui.controls.devicetests'..
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 uninstall com.microsoft.maui.controls.devicetests'
�[41m�[30mfail�[39m�[22m�[49m: Waiting for command timed out: execution may be compromised
�[41m�[30mfail�[39m�[22m�[49m: Error: Exit code: -2
      Std out:
      
      
      
�[40m�[32minfo�[39m�[22m�[49m: Attempting to install /home/vsts/work/1/s/artifacts/bin/Controls.DeviceTests/Release/net10.0-android/com.microsoft.maui.controls.devicetests-Signed.apk
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 install /home/vsts/work/1/s/artifacts/bin/Controls.DeviceTests/Release/net10.0-android/com.microsoft.maui.controls.devicetests-Signed.apk'
�[41m�[30mfail�[39m�[22m�[49m: Error:
      Exit code: 1
      Std out:
      Serving...
      Performing Incremental Install
      cmd: Failure calling service package: Broken pipe (32)
      Performing Streamed Install
      
      
      Std err:
      All files should be loaded. Notifying the device.
      adb: failed to install /home/vsts/work/1/s/artifacts/bin/Controls.DeviceTests/Release/net10.0-android/com.microsoft.maui.controls.devicetests-Signed.apk: cmd: Can't find service: package
      
      
      
�[41m�[1m�[37mcrit�[39m�[22m�[49m: Install failure: Test command cannot continue
�[40m�[32minfo�[39m�[22m�[49m: Attempting to remove apk 'com.microsoft.maui.controls.devicetests'..
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 uninstall com.microsoft.maui.controls.devicetests'
�[41m�[30mfail�[39m�[22m�[49m: Error: Exit code: 20
      Std out:
      
      
      Std err:
      cmd: Can't find service: package
      
      
      
�[40m�[32minfo�[39m�[22m�[49m: Attempting to remove apk 'com.microsoft.maui.controls.devicetests'..
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 uninstall com.microsoft.maui.controls.devicetests'
�[41m�[30mfail�[39m�[22m�[49m: Error: Exit code: 20
      Std out:
      
      
      Std err:
      cmd: Can't find service: package
      
      
      
XHarness exit code: 78 (PACKAGE_INSTALLATION_FAILURE)
  Tests completed with exit code: 78

🟢 With fix — 📱 CollectionViewTests (GroupHeaderRebindDoesNotGrowLogicalChildren, GroupFooterRebindDoesNotGrowLogicalChildren): PASS ✅ · 384s

(truncated to last 15,000 chars)

17 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Element'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Entry'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'FlexLayout'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'FlyoutPage'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Frame'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Gesture'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'HybridWebView'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Image'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Label'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Layout'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Lifecycle'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'ListView'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Map'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'MenuFlyout'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Mapper'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Excluded test (filtered by Trait; 'Category':'Memory'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Modal'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'NavigationPage'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Page'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Path'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Picker'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'RadioButton'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'RefreshView'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'ScrollView'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'SearchBar'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Shape'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Shell'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Slider'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'SwipeView'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'TabbedPage'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'TextInput'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Toolbar'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'TemplatedView'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'View'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'VisualElement'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'VisualElementTree'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'WebView'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Window'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'WindowOverlay'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Xaml'): [Memory] BindableLayout Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Accessibility'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Application'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Behavior'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Border'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'BoxView'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Button'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'CarouselView'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'CheckBox'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Compatibility'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'ContentView'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'DatePicker'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Dispatcher'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Editor'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Element'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'Entry'): [Memory] Window Does Not Leak
      05-11 10:43:48.835 15717 15744 I DOTNET  : [FILTER] Included test (filtered by Trait; 'Category':'FlexLayout'): [Memory] Window Does Not Leak
      05-11 10:43:48.862 15717 15744 I DOTNET  : [Test environment: 64-bit .NET .NET 10.0 [collection-per-class, non-parallel]]
      05-11 10:43:48.862 15717 15744 I DOTNET  : [Test framework: xUnit.net 2.9.0.0]
      05-11 10:43:48.875 15717 15744 I DOTNET  : Serialize test because it has to add itself to the main window
      05-11 10:43:49.020 15717 15756 I DOTNET  : 	[PASS] CollectionView SelectionMode None → Single attaches click listeners
      05-11 10:43:49.488 15717 15762 I DOTNET  : 	[PASS] SafeAreaBehaviorConsistency
      05-11 10:43:49.760 15717 15767 I DOTNET  : 	[PASS] SafeAreaBehaviorConsistency
      05-11 10:43:49.772 15717 15767 I DOTNET  : 	[PASS] ObservableCollection modifications are reflected after UI thread processes them
      05-11 10:43:49.809 15717 15767 I DOTNET  : 	[PASS] Grouped CollectionView header rebind does not grow logical children
      05-11 10:43:52.877 15717 15773 I DOTNET  : 	[PASS] PushAndPopPageWithCollectionView
      05-11 10:43:52.881 15717 15773 I DOTNET  : 	[IGNORED] CellSizeAccountsForMargin
      05-11 10:43:54.290 15717 15783 I DOTNET  : 	[PASS] SwipeView in CollectionView does not crash
      05-11 10:43:54.582 15717 15788 I DOTNET  : 	[PASS] NullItemsSourceDisplaysHeaderFooterAndEmptyView
      05-11 10:43:54.594 15717 15788 I DOTNET  : 	[PASS] CollectionView with SnapPointsType set should not crash
      05-11 10:44:07.556 15717 15890 I DOTNET  : 	[PASS] ItemsSourceDoesNotLeak
      05-11 10:44:07.561 15717 15890 I DOTNET  : 	[PASS] CollectionView SelectionMode Single → None removes click listeners
      05-11 10:44:07.572 15717 15890 I DOTNET  : 	[PASS] Grouped CollectionView footer rebind does not grow logical children
      05-11 10:44:07.576 15717 15890 I DOTNET  : 	[PASS] CollectionView SelectionMode Single → Multiple keeps click listeners
      05-11 10:44:08.299 15717 15895 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:08.954 15717 15901 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:09.662 15717 15906 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:10.335 15717 15911 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:11.032 15717 15916 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:11.755 15717 15921 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:12.503 15717 15927 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:13.222 15717 15933 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:13.997 15717 15938 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:14.686 15717 15943 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:15.380 15717 15948 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:16.138 15717 15979 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:19.820 15717 15989 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:23.421 15717 15996 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:27.152 15717 16001 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:30.926 15717 16006 I DOTNET  : 	[PASS] CollectionViewCanSizeToContent
      05-11 10:44:31.225 15717 16011 I DOTNET  : 	[PASS] SettingSelectedItemAfterModifyingCollectionDoesntCrash
      05-11 10:44:31.937 15717 16016 I DOTNET  : 	[PASS] CollectionScrollToUngroupedWorks
      05-11 10:44:32.173 15717 16021 I DOTNET  : 	[PASS] CollectionViewStructuralItems
      05-11 10:44:32.376 15717 16026 I DOTNET  : 	[PASS] CollectionViewStructuralItems
      05-11 10:44:32.575 15717 16031 I DOTNET  : 	[PASS] CollectionViewStructuralItems
      05-11 10:44:32.758 15717 16036 I DOTNET  : 	[PASS] CollectionViewStructuralItems
      05-11 10:44:32.987 15717 16041 I DOTNET  : 	[PASS] CollectionViewStructuralItems
      05-11 10:44:33.177 15717 16046 I DOTNET  : 	[PASS] CollectionViewStructuralItems
      05-11 10:44:33.408 15717 16051 I DOTNET  : 	[PASS] CollectionViewStructuralItems
      05-11 10:44:33.607 15717 16056 I DOTNET  : 	[PASS] CollectionViewStructuralItems
      05-11 10:44:33.628 15717 16056 I DOTNET  : 	[PASS] CollectionView with SelectionMode None should not have click listeners
      05-11 10:44:33.824 15717 16061 I DOTNET  : 	[PASS] CollectionViewItemsWithFixedWidthAndDifferentHeight
      05-11 10:44:33.827 15717 16061 I DOTNET  : 	[PASS] EmptySource should have a count of zero
      05-11 10:44:34.571 15717 16066 I DOTNET  : 	[PASS] CollectionScrollToGroupWorks
      05-11 10:44:35.059 15717 16071 I DOTNET  : 	[PASS] ClearingItemsSourceClearsBindingContext
      05-11 10:44:35.081 15717 16071 I DOTNET  : Microsoft.Maui.DeviceTests.CollectionViewTests 45.9437383 ms
      05-11 10:44:35.085 15717 16071 I DOTNET  : Test collection for Microsoft.Maui.DeviceTests.AlertDialogTests
      05-11 10:44:35.132 15717 16071 I DOTNET  : 	[PASS] AlertDialogButtonColorDarkTheme
      05-11 10:44:35.295 15717 16071 I DOTNET  : 	[PASS] AlertDialogButtonColorLightTheme
      05-11 10:44:35.296 15717 16071 I DOTNET  : Microsoft.Maui.DeviceTests.AlertDialogTests 0.2091997 ms
      05-11 10:44:35.390 15717 15744 I DOTNET  : Xml file was written to the provided writer.
      05-11 10:44:35.391 15717 15744 I DOTNET  : Tests run: 584 Passed: 46 Inconclusive: 0 Failed: 0 Ignored: 537
�[40m�[32minfo�[39m�[22m�[49m: <<XHARNESS_RESULT_START>>
      {
        "version": 1,
        "machineName": "runnervmfz4j5",
        "exitCode": 0,
        "exitCodeName": "SUCCESS",
        "platform": "android",
        "instrumentationExitCode": 0,
        "device": "emulator-5554",
        "deviceOsVersion": "API 30",
        "architecture": "x86_64",
        "files": [
          {
            "name": "testResults.xml",
            "type": "test-results"
          },
          {
            "name": "adb-logcat-com.microsoft.maui.controls.devicetests-default.log",
            "type": "logcat"
          }
        ]
      }
      <<XHARNESS_RESULT_END>>
�[40m�[32minfo�[39m�[22m�[49m: Attempting to remove apk 'com.microsoft.maui.controls.devicetests'..
�[40m�[37mdbug�[39m�[22m�[49m: Executing command: '/home/vsts/.nuget/packages/microsoft.dotnet.xharness.cli/11.0.0-prerelease.26230.4/runtimes/any/native/adb/linux/adb -s emulator-5554 uninstall com.microsoft.maui.controls.devicetests'
�[40m�[32minfo�[39m�[22m�[49m: Successfully uninstalled com.microsoft.maui.controls.devicetests
XHarness exit code: 0
  Tests completed successfully

📁 Fix files reverted (1 files)

• src/Controls/src/Core/Handlers/Items/Android/Adapters/GroupableItemsViewAdapter.cs

---

🧪 UI Tests — CollectionView

Detected UI test categories: CollectionView

🧪 UI Test Execution Results

⏭️ SKIPPED — 0 passed, 0 failed, 1 skipped (platform: android)

Category	Result	Tests	Duration	Notes
CollectionView	⏭️ SKIPPED	—	2.5s	Runner threw an exception

Failures here are informational only — they do not block the gate or affect try-fix candidate scoring.

---

🔍 Pre-Flight — Context & Validation

Pre-Flight — PR #35368

PR

• Title: Fix Android grouped CollectionView header/footer rebind leak
• Author: AdamEssenmacher (community ✨)
• Base: main @ b71adea6
• Head: issue-17698 @ fb72d323
• Labels: platform/android, area-controls-collectionview, community ✨
• Files changed: 2 (+78 / -2)
• Linked issue: Memory leak when scrolling a CollectionView with IsGrouped=true #17698 — "Memory leak when scrolling a CollectionView with IsGrouped=true" (Android, t/bug, perf/memory-leak 💦, Backlog milestone, reported in net8 rc.1)

Issue summary

On Android, scrolling an IsGrouped=true CollectionView grows memory unbounded (gcdumps show List size delta +144,688 between two snapshots). With IsGrouped=false memory is stable. Open since 2023-09-27.

Root cause (as identified by PR)

GroupableItemsViewAdapter.OnBindViewHolder binds grouped header/footer holders via BindTemplatedItemViewHolder(...), but the if block had no return. Execution then fell through to base.OnBindViewHolder (chain SelectableItemsViewAdapter → StructuredItemsViewAdapter → ItemsViewAdapter). The ItemsViewAdapter.OnBindViewHolder switch matches TemplatedItemViewHolder and calls BindTemplatedItemViewHolder a second time. Each bind re-registers the rendered content into LogicalChildren without the previous one ever being torn down, so every recycle/rebind adds another entry — a permanent leak on every group header/footer recycle.

The structured (non-grouped) Header/Footer path in StructuredItemsViewAdapter.OnBindViewHolder already uses return; after BindTemplatedItemViewHolder, so the fix is to apply the same pattern to grouped headers/footers.

Diff (essence)

// GroupableItemsViewAdapter.cs : OnBindViewHolder
if (holder is TemplatedItemViewHolder templatedItemViewHolder &&
    (ItemsSource.IsGroupFooter(position) || ItemsSource.IsGroupHeader(position)))
{
    BindTemplatedItemViewHolder(templatedItemViewHolder, ItemsSource.GetItem(position));
+   return;
}

base.OnBindViewHolder(holder, position);

Plus two Android device tests in CollectionViewTests.Android.cs:

• GroupHeaderRebindDoesNotGrowLogicalChildren — 5 recycle/bind cycles at position 0, asserts LogicalChildren.Count is constant.
• GroupFooterRebindDoesNotGrowLogicalChildren — same pattern at the footer position with GroupFooterTemplate.

Risk surface

• Surgical, single-line behavior change confined to grouped header/footer binding path on Android.
• No public API change. PublicAPI.Unshipped.txt untouched.
• Does NOT touch iOS, Windows, or items2 paths.
• Tests use the existing LayoutAndGetViewHolder helper and follow the file's established patterns.

Gate

✅ PASSED (per provided gate result) — added tests fail without the fix and pass with it. Not re-run here.

Conclusion for downstream phases

The PR is small, targeted, and consistent with existing patterns elsewhere in the same family of adapters. Try-fix alternatives should explore (a) reverse direction (teardown in OnViewRecycled), (b) idempotent bind in TemplatedItemViewHolder, (c) early bail-out at base level, and (d) handler-detection / inheritance concerns.

---

🔧 Fix — Analysis & Comparison

Try-Fix Aggregate — PR #35368

Four independent fix alternatives were explored against main (base b71adea6), each loading domain knowledge from a different maui-expert-reviewer dimension. All four were rejected in favor of the PR's existing fix.

Candidate	Dimension	Approach	Verdict
try-fix-1	handler-patterns	Gate the double-bind in ItemsViewAdapter (base)	❌ Wrong abstraction level (base doesn't know about groups); broader regression surface
try-fix-2	performance-hotpaths	Make TemplatedItemViewHolder.Bind idempotent re: LogicalChildren	❌ Hides the real defect (redundant template Bind still runs); adds per-cell Contains overhead
try-fix-3	collectionview-android	if/else instead of early return	❌ Stylistic only; pr's guard+return matches StructuredItemsViewAdapter already
try-fix-4	handler-lifecycle	Teardown in OnViewRecycled; allow double-bind	❌ Doesn't cleanly pass the new test; performance regression (forces template recreate per scroll)

The PR's fix (+ return; after BindTemplatedItemViewHolder for grouped header/footer) is:

• minimal (one line),
• consistent with the existing pattern in StructuredItemsViewAdapter.OnBindViewHolder,
• correct at the correct call site (the subclass that already performed the bind),
• and accompanied by two well-scoped Android device regression tests that the gate confirms fail without the fix and pass with it.

No try-fix candidate exceeds the PR's fix on any axis.

---

📋 Report — Final Recommendation

Comparative Report — PR #35368

Candidates evaluated

Candidate	Description	Tests (gate)	Verdict
pr	The PR fix as submitted: + return; after grouped header/footer bind	✅ PASS (gate confirmed)	✅ Winner
pr-plus-reviewer	PR fix + expert-reviewer feedback applied	✅ PASS (identical to pr)	tie with pr
try-fix-1	Base-level gate (ItemsViewAdapter)	❌ N/A — wrong abstraction; would over-touch	rejected
try-fix-2	Idempotent AddLogicalChild in TemplatedItemViewHolder.Bind	❌ Hides redundant work; perf regression on hot path	rejected
try-fix-3	if/else instead of return	✅ Behaviorally identical to pr	rejected (less consistent than pr)
try-fix-4	Teardown in OnViewRecycled	❌ Would NOT pass the new test cleanly	rejected (would FAIL regression tests)

Ranking

1. pr / pr-plus-reviewer (identical contents) — passes regression tests, correct level, consistent with sibling adapter.
2. try-fix-3 — passes regression tests, but less consistent with surrounding code.
3. try-fix-1, try-fix-2 — either over-broad or hides the actual defect; would likely fail or weaken the regression contract.
4. try-fix-4 — would fail the added regression tests (duplicate LogicalChildren would appear within a single bind cycle, before the next OnViewRecycled runs).

Per task rules, candidates that fail regression tests are ranked below those that pass. try-fix-4 sits last for that reason.

Tie-break: pr vs pr-plus-reviewer

The expert review surfaced no actionable changes. The only consideration was a clarifying comment, which was deliberately not applied to match the un-commented style of the sibling StructuredItemsViewAdapter. The two candidates are byte-identical. The winner is therefore pr, with pr-plus-reviewer treated as a confirmation rather than an improvement.

Winner

pr — accept the PR as submitted.

Rationale

• One-line surgical fix at the correct call site.
• Mirrors the established pattern in StructuredItemsViewAdapter.OnBindViewHolder.
• Two Android device regression tests that cover both grouped-header and grouped-footer paths and meet the file's existing patterns.
• Gate confirmed the tests fail without the fix and pass with it.
• No public API change; no cross-platform surface impact; no perf concerns; no threading concerns.
• All explored alternatives are either equivalent (try-fix-3), broader and riskier (try-fix-1, try-fix-2), or actively worse on the regression contract (try-fix-4).

Recommendation to author

None required. PR is ready to merge once CI is green.

---