fix: null dereference in get_SelectionContainer when no selection container exists by Copilot · Pull Request #16091 · microsoft/react-native-windows

Copilot · 2026-05-06T14:32:04Z

Description

Type of Change

Bug fix (non-breaking change which fixes an issue)

Why

get_SelectionContainer (UIA SelectionItemPattern.SelectionContainer) crashes with a null dereference when the element has no ancestor with a selection container. GetSelectionContainer() walks the parent tree looking for a view with multiselectable and required props set; if none is found it returns nullptr, which was immediately dereferenced on the next line.

What

Added a null check on the return value of GetSelectionContainer() in get_SelectionContainer
Returns S_OK with *pRetVal == nullptr when no container is found — correct per UIA spec (element is simply not inside a selection container)

auto selectionContainerView = GetSelectionContainer();
// Per UIA spec, returning S_OK with *pRetVal == nullptr is correct when the element
// is not contained within a selection container.
if (!selectionContainerView)
  return S_OK;

Screenshots

N/A

Testing

Reproduced by calling get_SelectionContainer on a selection item whose ancestor tree contains no multiselectable container. Verified the null check prevents the crash and returns S_OK with a null provider pointer.

Changelog

Should this change be included in the release notes: yes

Fix crash (null dereference) in UIA SelectionItemPattern.get_SelectionContainer when the element has no selection container ancestor.

Microsoft Reviewers: Open in CodeFlow

github-actions · 2026-05-07T07:22:00Z

Performance Test Results

Branch: copilot/fix-null-dereference-selection-container
Commit: 09351d29
Time: 2026-05-07T17:50:33.532Z
Tests: 161/161 passed

✅ Passed

161 scenario(s) across 28 suite(s) — no regressions

SectionList

Scenario	Mean	Median	StdDev	Renders	vs Baseline
SectionList mount	5.50ms	5.00ms	±1.35ms	1	+0.0%
SectionList unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
SectionList rerender	13.00ms	12.00ms	±2.62ms	2	+14.3%
SectionList with-3-sections-15-items	5.80ms	5.00ms	±1.32ms	1	-9.1%
SectionList with-5-sections-50-items	7.90ms	8.00ms	±2.33ms	1	+33.3%
SectionList with-10-sections-200-items	6.70ms	6.00ms	±2.26ms	1	+9.1%
SectionList with-20-sections-200-items	5.00ms	5.00ms	±1.15ms	1	+0.0%
SectionList with-section-separator	2.50ms	2.00ms	±1.72ms	1	+0.0%
SectionList with-item-separator	2.70ms	2.50ms	±0.82ms	1	+25.0%
SectionList with-header-footer	2.40ms	2.00ms	±0.52ms	1	+0.0%
SectionList with-section-footer	3.00ms	2.50ms	±1.94ms	1	+25.0%
SectionList with-sticky-section-headers	2.00ms	1.50ms	±1.83ms	1	-25.0%
SectionList with-empty-list	0.50ms	0.50ms	±0.53ms	1	-50.0%
SectionList with-50-sections-1000-items	1.80ms	2.00ms	±0.63ms	1	+0.0%

FlatList

Scenario	Mean	Median	StdDev	Renders	vs Baseline
FlatList mount	4.70ms	4.00ms	±1.57ms	1	+0.0%
FlatList unmount	0.20ms	0.00ms	±0.42ms	0	+0.0%
FlatList rerender	9.70ms	10.00ms	±1.25ms	2	+11.1%
FlatList with-10-items	4.80ms	4.50ms	±1.23ms	1	+12.5%
FlatList with-100-items	4.90ms	5.00ms	±0.57ms	1	+0.0%
FlatList with-500-items	4.20ms	4.00ms	±0.42ms	1	+0.0%
FlatList with-1000-items	4.40ms	4.00ms	±0.52ms	1	+0.0%
FlatList horizontal	4.50ms	4.00ms	±1.96ms	1	-20.0%
FlatList with-separator	1.70ms	2.00ms	±0.67ms	1	+0.0%
FlatList with-header-footer	1.70ms	2.00ms	±0.48ms	1	+0.0%
FlatList with-empty-list	0.60ms	0.00ms	±1.26ms	1	-100.0%
FlatList with-get-item-layout	1.50ms	1.50ms	±0.53ms	1	+50.0%
FlatList inverted	1.40ms	1.00ms	±0.52ms	1	-33.3%
FlatList with-num-columns	3.30ms	3.00ms	±1.70ms	1	+0.0%

TouchableOpacity

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableOpacity mount	1.20ms	1.00ms	±1.03ms	1	+0.0%
TouchableOpacity unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
TouchableOpacity rerender	1.10ms	1.00ms	±0.32ms	2	+0.0%
TouchableOpacity custom-active-opacity	0.60ms	1.00ms	±0.52ms	1	+0.0%
TouchableOpacity disabled	0.70ms	1.00ms	±0.48ms	1	+0.0%
TouchableOpacity with-all-handlers	0.70ms	1.00ms	±0.48ms	1	+0.0%
TouchableOpacity with-hit-slop	0.80ms	1.00ms	±0.42ms	1	+0.0%
TouchableOpacity with-delay	0.70ms	1.00ms	±0.48ms	1	+0.0%
TouchableOpacity nested	1.20ms	1.00ms	±0.42ms	1	+0.0%
TouchableOpacity multiple-10	5.87ms	6.00ms	±1.41ms	1	+0.0%
TouchableOpacity multiple-50	26.47ms	26.00ms	±2.64ms	1	-10.3%
TouchableOpacity multiple-100	34.27ms	35.00ms	±11.96ms	1	-30.0%

ScrollView

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ScrollView mount	0.30ms	0.00ms	±0.48ms	1	+0.0%
ScrollView unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
ScrollView rerender	0.60ms	1.00ms	±0.52ms	2	+0.0%
ScrollView children-20	3.33ms	3.00ms	±1.11ms	1	-25.0%
ScrollView children-100	16.40ms	15.00ms	±2.92ms	1	-6.3%
ScrollView horizontal	3.50ms	3.00ms	±1.27ms	1	-25.0%
ScrollView sticky-headers	2.90ms	3.00ms	±1.10ms	1	+0.0%
ScrollView scroll-indicators	0.90ms	1.00ms	±0.32ms	1	+0.0%
ScrollView nested	1.20ms	1.00ms	±0.42ms	1	+0.0%
ScrollView content-container-style	0.80ms	1.00ms	±0.42ms	1	+0.0%
ScrollView children-500	19.80ms	19.00ms	±2.76ms	1	+0.0%

TouchableHighlight

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableHighlight mount	0.50ms	0.50ms	±0.53ms	1	+0.0%
TouchableHighlight unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
TouchableHighlight rerender	0.60ms	1.00ms	±0.52ms	2	+0.0%
TouchableHighlight custom-underlay-color	0.60ms	1.00ms	±0.52ms	1	+Infinity%
TouchableHighlight custom-active-opacity	0.30ms	0.00ms	±0.48ms	1	+0.0%
TouchableHighlight disabled	0.50ms	0.50ms	±0.53ms	1	+Infinity%
TouchableHighlight with-all-handlers	0.30ms	0.00ms	±0.48ms	1	+0.0%
TouchableHighlight with-hit-slop	0.30ms	0.00ms	±0.48ms	1	+0.0%
TouchableHighlight nested-touchables	1.00ms	1.00ms	±0.00ms	1	+0.0%
TouchableHighlight multiple-touchables-10	2.80ms	3.00ms	±1.69ms	1	+0.0%
TouchableHighlight multiple-touchables-50	13.60ms	13.50ms	±1.35ms	1	+8.0%
TouchableHighlight multiple-touchables-100	24.50ms	25.00ms	±1.84ms	1	+11.1%

Pressable

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Pressable mount	0.30ms	0.00ms	±0.48ms	1	+0.0%
Pressable unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Pressable rerender	0.40ms	0.00ms	±0.52ms	2	-100.0%
Pressable with-all-handlers	0.30ms	0.00ms	±0.48ms	1	+0.0%
Pressable with-style-function	0.40ms	0.00ms	±0.52ms	1	+0.0%
Pressable disabled	0.30ms	0.00ms	±0.48ms	1	+0.0%
Pressable with-hit-slop	0.20ms	0.00ms	±0.42ms	1	+0.0%
Pressable nested	0.70ms	1.00ms	±0.48ms	1	+0.0%
Pressable multiple-10	3.27ms	3.00ms	±0.59ms	1	+0.0%
Pressable multiple-50	15.93ms	16.00ms	±1.67ms	1	+14.3%
Pressable multiple-100	16.60ms	12.00ms	±9.98ms	1	+0.0%

Modal

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Modal mount	0.20ms	0.00ms	±0.42ms	1	+0.0%
Modal unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Modal rerender	0.60ms	1.00ms	±0.52ms	2	+Infinity%
Modal slide-animation	0.30ms	0.00ms	±0.48ms	1	+0.0%
Modal fade-animation	0.00ms	0.00ms	±0.00ms	1	+0.0%
Modal transparent	0.40ms	0.00ms	±0.52ms	1	+0.0%
Modal with-callbacks	0.20ms	0.00ms	±0.42ms	1	+0.0%
Modal rich-content	1.70ms	2.00ms	±0.48ms	1	+0.0%
Modal with-accessibility	0.20ms	0.00ms	±0.42ms	1	+0.0%

Image

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Image mount	0.30ms	0.00ms	±0.48ms	1	+0.0%
Image unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Image rerender	0.10ms	0.00ms	±0.32ms	2	+0.0%
Image with-resize-mode	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image with-border-radius	0.20ms	0.00ms	±0.42ms	1	+0.0%
Image with-tint-color	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image with-blur-radius	0.40ms	0.00ms	±1.26ms	1	+0.0%
Image with-accessibility	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image multiple-10	1.00ms	1.00ms	±0.00ms	1	+0.0%
Image multiple-50	4.00ms	4.00ms	±0.93ms	1	+33.3%
Image multiple-100	8.40ms	8.00ms	±1.18ms	1	+0.0%

ActivityIndicator

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ActivityIndicator mount	0.10ms	0.00ms	±0.32ms	1	+0.0%
ActivityIndicator unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
ActivityIndicator rerender	0.30ms	0.00ms	±0.48ms	2	+0.0%
ActivityIndicator size-large	0.50ms	0.00ms	±1.27ms	1	+0.0%
ActivityIndicator size-small	0.10ms	0.00ms	±0.32ms	1	+0.0%
ActivityIndicator with-color	0.10ms	0.00ms	±0.32ms	1	+0.0%
ActivityIndicator not-animating	0.20ms	0.00ms	±0.42ms	1	+0.0%
ActivityIndicator with-accessibility	0.10ms	0.00ms	±0.32ms	1	+0.0%
ActivityIndicator multiple-10	1.00ms	1.00ms	±0.00ms	1	+0.0%
ActivityIndicator multiple-50	4.07ms	4.00ms	±1.10ms	1	+0.0%
ActivityIndicator multiple-100	8.00ms	8.00ms	±1.00ms	1	+14.3%

Switch

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Switch mount	0.70ms	1.00ms	±0.48ms	1	+Infinity%
Switch unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
Switch rerender	0.60ms	1.00ms	±0.52ms	2	+100.0%
Switch value-true	0.60ms	1.00ms	±0.52ms	1	+Infinity%
Switch disabled	0.50ms	0.50ms	±0.53ms	1	+Infinity%
Switch custom-colors	0.40ms	0.00ms	±0.52ms	1	+0.0%
Switch on-value-change	0.40ms	0.00ms	±0.52ms	1	+0.0%
Switch with-accessibility	0.30ms	0.00ms	±0.48ms	1	+0.0%
Switch multiple-10	3.47ms	3.00ms	±1.60ms	1	+50.0%
Switch multiple-50	9.20ms	9.00ms	±2.11ms	1	+0.0%
Switch multiple-100	18.20ms	17.00ms	±2.88ms	1	+6.3%

Button

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Button mount	0.60ms	1.00ms	±0.52ms	1	+0.0%
Button unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Button rerender	1.00ms	1.00ms	±0.47ms	2	+0.0%
Button disabled	0.60ms	1.00ms	±0.52ms	1	+0.0%
Button with-color	0.70ms	1.00ms	±0.48ms	1	+100.0%
Button with-accessibility	0.90ms	1.00ms	±1.20ms	1	+0.0%
Button multiple-10	5.47ms	5.00ms	±1.19ms	1	-16.7%
Button multiple-50	21.73ms	25.00ms	±8.09ms	1	-7.4%
Button multiple-100	15.40ms	15.00ms	±2.03ms	1	-21.1%

TextInput

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TextInput mount	0.40ms	0.00ms	±0.97ms	1	+0.0%
TextInput unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
TextInput rerender	0.20ms	0.00ms	±0.42ms	2	+0.0%
TextInput multiline	0.20ms	0.00ms	±0.42ms	1	+0.0%
TextInput with-value	0.10ms	0.00ms	±0.32ms	1	+0.0%
TextInput styled	0.10ms	0.00ms	±0.32ms	1	+0.0%
TextInput multiple-100	8.00ms	8.00ms	±1.31ms	1	+14.3%

View

Scenario	Mean	Median	StdDev	Renders	vs Baseline
View mount	0.50ms	0.00ms	±1.27ms	1	+0.0%
View unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
View rerender	0.30ms	0.00ms	±0.48ms	2	+0.0%
View nested-50	3.33ms	3.00ms	±0.62ms	1	+0.0%
View nested-100	7.93ms	8.00ms	±1.49ms	1	+14.3%
View shadow	0.10ms	0.00ms	±0.32ms	1	+0.0%
View border-radius	0.20ms	0.00ms	±0.42ms	1	+0.0%
View nested-500	17.07ms	10.00ms	±13.41ms	1	+0.0%

Text

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Text mount	0.20ms	0.00ms	±0.42ms	1	+0.0%
Text unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Text rerender	0.20ms	0.00ms	±0.42ms	2	+0.0%
Text long-1000	0.10ms	0.00ms	±0.32ms	1	+0.0%
Text nested	0.20ms	0.00ms	±0.42ms	1	+0.0%
Text styled	0.20ms	0.00ms	±0.42ms	1	+0.0%
Text multiple-100	8.73ms	9.00ms	±1.39ms	1	+28.6%

SectionList.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
SectionList native mount	4.52ms	4.37ms	±0.50ms	1	-32.7%

FlatList.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
FlatList native mount	4.52ms	4.25ms	±0.99ms	1	-54.0%

TouchableHighlight.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableHighlight native mount	1.35ms	1.26ms	±0.18ms	1	-39.6%

TouchableOpacity.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableOpacity native mount	1.68ms	1.45ms	±0.64ms	1	-53.9%

Pressable.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Pressable native mount	1.36ms	1.30ms	±0.14ms	1	-48.1%

ScrollView.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ScrollView native mount	3.18ms	3.03ms	±0.56ms	1	-25.2%

ActivityIndicator.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ActivityIndicator native mount	1.34ms	1.15ms	±0.44ms	1	-53.8%

TextInput.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TextInput native mount	2.10ms	2.07ms	±0.14ms	1	-49.4%

Switch.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Switch native mount	1.42ms	1.41ms	±0.19ms	1	-18.6%

Button.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Button native mount	2.05ms	1.95ms	±0.41ms	1	-25.2%

Modal.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Modal native mount	1.12ms	1.03ms	±0.28ms	1	-15.0%

Image.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Image native mount	2.05ms	1.74ms	±0.81ms	1	-22.9%

View.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
View native mount	1.05ms	0.95ms	±0.24ms	1	-33.2%

Text.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Text native mount	1.38ms	1.33ms	±0.24ms	1	-23.6%

Agent-Logs-Url: https://github.com/microsoft/react-native-windows/sessions/dee66731-6253-459a-8ba1-f733d5bee554 Co-authored-by: vineethkuttan <66076509+vineethkuttan@users.noreply.github.com>

Copilot AI assigned Copilot and vineethkuttan May 6, 2026

Copilot created this pull request from a session on behalf of vineethkuttan May 6, 2026 14:32 View session

vineethkuttan marked this pull request as ready for review May 6, 2026 14:40

vineethkuttan requested a review from a team as a code owner May 6, 2026 14:40

acoates-ms approved these changes May 6, 2026

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vineethkuttan added the AutoMerge Causes a PR to be automatically merged once all requirements are passed (label drives bot activity) label May 7, 2026

microsoft-github-policy-service Bot enabled auto-merge (squash) May 7, 2026 07:46

Copilot AI and others added 2 commits May 7, 2026 10:20

fix: null dereference in get_SelectionContainer when no container found

57d9565

Agent-Logs-Url: https://github.com/microsoft/react-native-windows/sessions/dee66731-6253-459a-8ba1-f733d5bee554 Co-authored-by: vineethkuttan <66076509+vineethkuttan@users.noreply.github.com>

Change files

6ad847b

vmoroz force-pushed the copilot/fix-null-dereference-selection-container branch from 716e8c3 to 6ad847b Compare May 7, 2026 17:20

microsoft-github-policy-service Bot merged commit 2269a19 into main May 7, 2026
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Description

Type of Change

Why

What

Screenshots

Testing

Changelog

Microsoft Reviewers: Open in CodeFlow

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Performance Test Results

✅ Passed

SectionList

FlatList

TouchableOpacity

ScrollView

TouchableHighlight

Pressable

Modal

Image

ActivityIndicator

Switch

Button

TextInput

View

Text

SectionList.native-perf-test.ts

FlatList.native-perf-test.ts

TouchableHighlight.native-perf-test.ts

TouchableOpacity.native-perf-test.ts

Pressable.native-perf-test.ts

ScrollView.native-perf-test.ts

ActivityIndicator.native-perf-test.ts

TextInput.native-perf-test.ts

Switch.native-perf-test.ts

Button.native-perf-test.ts

Modal.native-perf-test.ts

Image.native-perf-test.ts

View.native-perf-test.ts

Text.native-perf-test.ts

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Copilot AI commented May 6, 2026 •

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