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Fix null-deref/double-dispose in StretchingOverscrollIndicator (#189589) - #189667

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mbcorona merged 1 commit into
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mbcorona:fix-stretch-overscroll-null-deref
Jul 21, 2026
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Fix null-deref/double-dispose in StretchingOverscrollIndicator (#189589)#189667
mbcorona merged 1 commit into
flutter:masterfrom
mbcorona:fix-stretch-overscroll-null-deref

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@mbcorona

@mbcoronambcorona commented Jul 17, 2026

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Description

Fixes a null pointer dereference crash in _StretchController.animate(). The whenComplete callback could execute after the controller was already disposed by a subsequent pull(), animate(), or dispose() call.

The fix captures the controller instance and guards cleanup to only execute if it's still active, preventing null dereference and double-dispose.

Fixed Issues

Fixes#189589

Pre-launch Checklist

  • I read the Contributor Guide and followed the process outlined there for submitting PRs.
  • I read the Tree Hygiene wiki page, which explains my responsibilities.
  • I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
  • I signed the CLA.
  • I listed at least one issue that this PR fixes in the description above.
  • I updated/added relevant documentation (doc comments with ///).
  • I added new tests to check the change I am making, or this PR is test-exempt.
  • All existing and new tests are passing.

@flutter-dashboardflutter-dashboardBot added the CICD Run CI/CD label Jul 17, 2026
@github-actionsgithub-actionsBot added framework flutter/packages/flutter repository. See also f: labels. f: scrolling Viewports, list views, slivers, etc. labels Jul 17, 2026
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Code Review

This pull request updates _StretchController in overscroll_indicator.dart to prevent a crash when disposed during a stretch animation. It ensures that the animation's completion callback only cleans up state and disposes the controller if it remains the active controller, and sets _controller to null during disposal. A regression test has been added to verify this behavior. There are no review comments, and I have no feedback to provide.

@mbcoronambcorona mentioned this pull request Jul 17, 2026
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navaronbracke
navaronbracke approved these changes Jul 18, 2026
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LGTM with nit

Comment threadpackages/flutter/test/widgets/overscroll_indicator_test.dart

testWidgets(
'StretchingOverscrollIndicator does not crash when disposed mid stretch animation',
// Regression test for https://github.com/flutter/flutter/issues/189589

@navaronbrackenavaronbrackeJul 18, 2026

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Nit: Put the comment above the test name or in the test body? Between the name and test function is a bit weird to read

@mbcorona
mbcorona added this pull request to the merge queueJul 21, 2026
Merged via the queue into flutter:master with commit 801c2c6Jul 21, 2026
19 of 20 checks passed
@mbcorona
mbcorona deleted the fix-stretch-overscroll-null-deref branch July 21, 2026 16:36
This was referenced Jul 22, 2026
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auto-submitBot pushed a commit to flutter/packages that referenced this pull request Jul 22, 2026
@engine-flutter-autoroll
Roll Flutter from 1ac2e82fa65c to 2a2a79d36624 (22 revisions) (#12272)
6ec25c3
flutter/flutter@1ac2e82...2a2a79d
2026-07-22 21270878+elliette@users.noreply.github.com Clear cached directional focus history on a non-directional focus request (flutter/flutter#187957)
2026-07-22 chris@bracken.jp ci: Include root pubspec.yaml in pub cache key (flutter/flutter#189826)
2026-07-22 6655696+guidezpl@users.noreply.github.com Remove codecov badge from README (flutter/flutter#189728)
2026-07-22 116356835+AbdeMohlbi@users.noreply.github.com Clean android engine/embedding tests (flutter/flutter#189276)
2026-07-22 50643541+Mairramer@users.noreply.github.com Add barrierBuilder support to showDialog and showGeneralDialog (flutter/flutter#187992)
2026-07-22 matt.boetger@gmail.com Fix Mockito dynamic agent loading warnings in Robolectric tests (flutter/flutter#189804)
2026-07-22 chris@bracken.jp [iOS] Remove dead RasterThreadMerger plumbing from platform views (flutter/flutter#189753)
2026-07-22 737941+loic-sharma@users.noreply.github.com Add OverlayPortal.overlayChildLayoutBuilder sample (flutter/flutter#188930)
2026-07-22 katelovett@google.com Automate recurring tasks via workflows - localizations (flutter/flutter#189750)
2026-07-21 chris@bracken.jp [iOS] Remove dead parameters and no-op overrides (flutter/flutter#189754)
2026-07-21 chris@bracken.jp [iOS] Inject DisplayLinkManager into FlutterViewController (flutter/flutter#189764)
2026-07-21 46920873+gabrimatic@users.noreply.github.com Support custom BoxBorder animation in BoxDecoration (flutter/flutter#186348)
2026-07-21 chingjun@google.com Rename CpuArch.x86_64 to CpuArch.x64 (flutter/flutter#189478)
2026-07-21 engine-flutter-autoroll@skia.org Roll Skia from 569534e9fa59 to 5e183e5aeac5 (3 revisions) (flutter/flutter#189795)
2026-07-21 engine-flutter-autoroll@skia.org Roll Dart SDK from 3b2f5ad7718d to 1e65011ee004 (4 revisions) (flutter/flutter#189791)
2026-07-21 jacksongardner@google.com Run delete-bot-branches.yaml on `pull_request_target` instead of `pull_request` so that we can access secrets. (flutter/flutter#189793)
2026-07-21 jmccandless@google.com Batch release directory correction (flutter/flutter#189738)
2026-07-21 brackenavaron@gmail.com [flutter_test][Test cross imports] Move TestWidgetsApp to flutter_test (flutter/flutter#189435)
2026-07-21 brunocorona.alcantar@gmail.com Fix null-deref/double-dispose in StretchingOverscrollIndicator (#189589) (flutter/flutter#189667)
2026-07-21 engine-flutter-autoroll@skia.org Roll Packages from 611899b to 8260a1e (10 revisions) (flutter/flutter#189782)
2026-07-21 chris@bracken.jp [iOS] Inject DisplayLinkManager into FlutterMetalLayer (flutter/flutter#189752)
2026-07-21 jason-simmons@users.noreply.github.com Derive the SkImage size used by ImageEncodingImpeller::ConvertDlImageToSkImage from the size of the underlying texture, not the size of the DlImage (flutter/flutter#189739)
If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-packages
Please CC bmparr@google.com,stuartmorgan@google.com on the revert to ensure that a human
is aware of the problem.
To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose
To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622
Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md
Zubii12 pushed a commit to Zubii12/packages that referenced this pull request Jul 23, 2026
@engine-flutter-autoroll@Zubii12
Roll Flutter from 1ac2e82fa65c to 2a2a79d36624 (22 revisions) (flutte…
1d44fde
…r#12272)
flutter/flutter@1ac2e82...2a2a79d
2026-07-22 21270878+elliette@users.noreply.github.com Clear cached directional focus history on a non-directional focus request (flutter/flutter#187957)
2026-07-22 chris@bracken.jp ci: Include root pubspec.yaml in pub cache key (flutter/flutter#189826)
2026-07-22 6655696+guidezpl@users.noreply.github.com Remove codecov badge from README (flutter/flutter#189728)
2026-07-22 116356835+AbdeMohlbi@users.noreply.github.com Clean android engine/embedding tests (flutter/flutter#189276)
2026-07-22 50643541+Mairramer@users.noreply.github.com Add barrierBuilder support to showDialog and showGeneralDialog (flutter/flutter#187992)
2026-07-22 matt.boetger@gmail.com Fix Mockito dynamic agent loading warnings in Robolectric tests (flutter/flutter#189804)
2026-07-22 chris@bracken.jp [iOS] Remove dead RasterThreadMerger plumbing from platform views (flutter/flutter#189753)
2026-07-22 737941+loic-sharma@users.noreply.github.com Add OverlayPortal.overlayChildLayoutBuilder sample (flutter/flutter#188930)
2026-07-22 katelovett@google.com Automate recurring tasks via workflows - localizations (flutter/flutter#189750)
2026-07-21 chris@bracken.jp [iOS] Remove dead parameters and no-op overrides (flutter/flutter#189754)
2026-07-21 chris@bracken.jp [iOS] Inject DisplayLinkManager into FlutterViewController (flutter/flutter#189764)
2026-07-21 46920873+gabrimatic@users.noreply.github.com Support custom BoxBorder animation in BoxDecoration (flutter/flutter#186348)
2026-07-21 chingjun@google.com Rename CpuArch.x86_64 to CpuArch.x64 (flutter/flutter#189478)
2026-07-21 engine-flutter-autoroll@skia.org Roll Skia from 569534e9fa59 to 5e183e5aeac5 (3 revisions) (flutter/flutter#189795)
2026-07-21 engine-flutter-autoroll@skia.org Roll Dart SDK from 3b2f5ad7718d to 1e65011ee004 (4 revisions) (flutter/flutter#189791)
2026-07-21 jacksongardner@google.com Run delete-bot-branches.yaml on `pull_request_target` instead of `pull_request` so that we can access secrets. (flutter/flutter#189793)
2026-07-21 jmccandless@google.com Batch release directory correction (flutter/flutter#189738)
2026-07-21 brackenavaron@gmail.com [flutter_test][Test cross imports] Move TestWidgetsApp to flutter_test (flutter/flutter#189435)
2026-07-21 brunocorona.alcantar@gmail.com Fix null-deref/double-dispose in StretchingOverscrollIndicator (#189589) (flutter/flutter#189667)
2026-07-21 engine-flutter-autoroll@skia.org Roll Packages from 611899b to 8260a1e (10 revisions) (flutter/flutter#189782)
2026-07-21 chris@bracken.jp [iOS] Inject DisplayLinkManager into FlutterMetalLayer (flutter/flutter#189752)
2026-07-21 jason-simmons@users.noreply.github.com Derive the SkImage size used by ImageEncodingImpeller::ConvertDlImageToSkImage from the size of the underlying texture, not the size of the DlImage (flutter/flutter#189739)
If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-packages
Please CC bmparr@google.com,stuartmorgan@google.com on the revert to ensure that a human
is aware of the problem.
To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose
To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622
Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md
@PiinksPiinks mentioned this pull request Jul 24, 2026
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@navaronbrackenavaronbrackenavaronbracke approved these changes
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Crash in OverscrollIndicator

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