Fix RenderSliverPadding setter assertion by fallintoplace · Pull Request #187353 · flutter/flutter

fallintoplace · 2026-05-30T20:08:56Z

What does this change?

Fixes RenderSliverPadding.padding so the setter validates the incoming value instead of re-validating the current padding.

Why?

The constructor already rejects negative padding values, but the setter was asserting on the old field value. That meant assigning negative padding through the setter could slip past the intended debug check.

Tests

./bin/flutter test packages/flutter/test/rendering/sliver_cache_test.dart

Notes

This also adds a regression test that verifies the setter throws an assertion for negative padding.

Fixes #187527

gemini-code-assist

Code Review

This pull request corrects an assertion in the RenderSliverPadding setter to check the incoming value instead of the existing padding property. Additionally, a unit test has been added to verify that setting negative padding triggers an assertion error. There are no review comments, and I have no feedback to provide.

Piinks · 2026-06-02T22:18:52Z

Hey @fallintoplace thanks for contributing! Is there an open issue for this?

fallintoplace · 2026-06-02T22:30:20Z

Dear @Piinks, there isn't any, should I create one?

Piinks · 2026-06-02T23:50:13Z

Dear @Piinks, there isn't any, should I create one?

Yes please file an issue, thank you!

fallintoplace · 2026-06-03T08:19:45Z

@Piinks I will file the corresponding issue later today.

Hari-07 · 2026-06-08T15:29:10Z

    expect(children.sublist(42, 60).every((RenderBox r) => r.attached), true);
  });

+  test('RenderSliverPadding setter asserts for negative padding', () {


Thank you for contribution! This looks like a good clean minimal fix, but I think this test ought to be in slivers_padding_test.dart rather than in cache

There also seems to be a CI failure from this new test

info • Omit the type annotation on a local variable when the type is obvious. Try removing the type annotation • packages/flutter/test/rendering/sliver_cache_test.dart:502:11 • omit_obvious_local_variable_types

Hari-07 · 2026-06-09T06:06:40Z

Looks like the test added still fails

Viewport+SliverPadding changing padding to negative asserts

The following TestFailure was thrown running a test:
Expected: throws <Instance of 'AssertionError'>
  Actual: <Closure: () => Future<void>>
   Which: returned a Future that emitted <null>

Hari-07 · 2026-06-09T15:56:05Z

@fallintoplace I request you to go through the AI Contribution Guidelines

Instead of simply relaying comments to AI without checking if the change made is fixing the issue

Hari-07 · 2026-06-10T05:20:54Z

01:39 +5630 ~121 -1: C:/b/s/w/ir/x/w/flutter/packages/flutter/test/widgets/slivers_padding_test.dart: (tearDownAll) [E]
  Expected: leak free
    Actual: <Instance of 'Leaks'>
     Which: contains leaks:
            # The text is generated by leak_tracker.
            # For leak troubleshooting tips open:
            # https://github.com/flutter/flutter/blob/main/docs/contributing/testing/Leak-tracking.md
            notDisposed:
              total: 5
              objects:
                _ViewportElement:
                  test: Viewport+SliverPadding changing padding to negative asserts
                  identityHashCode: 692869396
                RenderViewport:
                  test: Viewport+SliverPadding changing padding to negative asserts
                  identityHashCode: 286981433
                SingleChildRenderObjectElement:
                  test: Viewport+SliverPadding changing padding to negative asserts
                  identityHashCode: 1019697483
                RenderSliverPadding:
                  test: Viewport+SliverPadding changing padding to negative asserts
                  identityHashCode: 407477882
                OffsetLayer:
                  test: Viewport+SliverPadding changing padding to negative asserts
                  identityHashCode: 1063275793
            
            
  
  package:matcher                                              expect
  package:leak_tracker_testing/src/leak_testing.dart 69:24     LeakTesting.collectedLeaksReporter.<fn>
  package:leak_tracker_flutter_testing/src/testing.dart 74:37  maybeTearDownLeakTrackingForAll
  ===== asynchronous gap ===========================
  dart:async                                                   _CustomZone.registerBinaryCallback
  package:flutter_test/src/test_compat.dart 302:3              _tearDownForTestFile

You can run flutter test locally with --dart-define LEAK_TRACKING=true to verify this locally

fallintoplace · 2026-07-06T22:21:37Z

@Hari-07 Is there anything I can do to help this land? Thank you for your attention.

Piinks

This LGTM. In the future, please ensure to keep the PR template in place to fill out the pre-flight checklist.

## What does this change? Fixes `RenderSliverPadding.padding` so the setter validates the incoming `value` instead of re-validating the current padding. ## Why? The constructor already rejects negative padding values, but the setter was asserting on the old field value. That meant assigning negative padding through the setter could slip past the intended debug check. ## Tests - `./bin/flutter test packages/flutter/test/rendering/sliver_cache_test.dart` ## Notes This also adds a regression test that verifies the setter throws an assertion for negative padding. Fixes flutter#187527

…12137) Manual roll Flutter from 6995038d96ef to 91939cc4db78 (48 revisions) Manual roll requested by [email protected] flutter/flutter@6995038...91939cc 2026-07-07 [email protected] Roll Skia from 80ae1deed9ed to 075fbe4778d9 (6 revisions) (flutter/flutter#189067) 2026-07-07 [email protected] Bump customer testing version for new registrants (flutter/flutter#189070) 2026-07-07 [email protected] Roll Packages from fc00ceb to 92525f5 (2 revisions) (flutter/flutter#189069) 2026-07-07 [email protected] fix android semantics integration test hangs due to postframe callback (flutter/flutter#189043) 2026-07-07 [email protected] Bump goldctl (flutter/flutter#189030) 2026-07-07 [email protected] Roll Skia from 71db7c06c5fe to 80ae1deed9ed (2 revisions) (flutter/flutter#189060) 2026-07-07 [email protected] Collect analytics on AI agent usage (flutter/flutter#187630) 2026-07-07 [email protected] Roll Skia from 125a76cc4cf3 to 71db7c06c5fe (4 revisions) (flutter/flutter#189054) 2026-07-07 [email protected] Roll Dart SDK from 70577d6f2bba to c648e3429d76 (1 revision) (flutter/flutter#189052) 2026-07-07 [email protected] Fix RenderSliverPadding setter assertion (flutter/flutter#187353) 2026-07-07 [email protected] Roll Skia from 2dde156aec3e to 125a76cc4cf3 (3 revisions) (flutter/flutter#189037) 2026-07-07 [email protected] Explain asynchronous causes in the setState() called after dispose() error (flutter/flutter#187294) 2026-07-07 [email protected] Roll Skia from 7dccd1e79a5b to 2dde156aec3e (2 revisions) (flutter/flutter#189035) 2026-07-07 [email protected] Add `STRING_CATALOG_GENERATE_SYMBOLS = YES;` (flutter/flutter#188163) 2026-07-07 [email protected] Print warnings on Intel Macs / targeting Intel Macs (flutter/flutter#188835) 2026-07-07 [email protected] Roll Dart SDK from 4c03f64b19f6 to 70577d6f2bba (1 revision) (flutter/flutter#189031) 2026-07-07 [email protected] Roll Fuchsia Linux SDK from n1Lm2Z4DZkfC3bwj5... to 7RjQJBW3m-3Jl-7jr... (flutter/flutter#189032) 2026-07-06 [email protected] Recommend `OverlayPortal.overlayChildLayoutBuilder` over Target-Follower (flutter/flutter#188894) 2026-07-06 [email protected] Sync CHANGELOG.md from stable (flutter/flutter#189025) 2026-07-06 [email protected] Rename preferredSize to size and preferredConstraints to constraints in the windowing API (flutter/flutter#189017) 2026-07-06 [email protected] Skip locked issues in no-response check (flutter/flutter#188950) 2026-07-06 [email protected] Fix potential race condtion in android_semantics_integration_test (flutter/flutter#188830) 2026-07-06 [email protected] ci: udpate wait-for-engine-build composite action to cocoon (flutter/flutter#189020) 2026-07-06 [email protected] Roll Skia from 2b55eed5500d to 7dccd1e79a5b (3 revisions) (flutter/flutter#189021) 2026-07-06 [email protected] [AGP 9] Update Flutter Template Versions (flutter/flutter#188762) 2026-07-06 [email protected] fix(engine/windows): keep tooltip position rect alive - fix use after free (flutter/flutter#188476) 2026-07-06 [email protected] [Tool] Fix null check operator crash in currentPackageConfig (flutter/flutter#188454) 2026-07-06 [email protected] [Tool] Gracefully handle WDAC/AppLocker blocks for impellerc (flutter/flutter#188452) 2026-07-06 [email protected] [flutter_tools] Throw DaemonException if app fails to start early (flutter/flutter#188921) 2026-07-06 [email protected] Roll Dart SDK from ce7a2567eb59 to 4c03f64b19f6 (2 revisions) (flutter/flutter#189015) 2026-07-06 [email protected] [flutter_tools, engine] Add --disable-service-origin-check option to disable VM service origin checks (flutter/flutter#188745) 2026-07-06 [email protected] [flutter_tools] Fix test flakiness in widget_preview_detection_test.dart (flutter/flutter#188922) 2026-07-06 [email protected] Roll pub packages (flutter/flutter#189009) 2026-07-06 [email protected] Roll Skia from c0e2b9667d91 to 2b55eed5500d (1 revision) (flutter/flutter#189006) 2026-07-06 [email protected] Roll Packages from 2fbe873 to fc00ceb (1 revision) (flutter/flutter#189007) 2026-07-06 [email protected] Roll Skia from b68567542f81 to c0e2b9667d91 (1 revision) (flutter/flutter#189004) 2026-07-06 [email protected] Fixing multiline GetBoxesForRange (flutter/flutter#188803) 2026-07-06 [email protected] Roll Skia from e15ea7a4b927 to b68567542f81 (4 revisions) (flutter/flutter#189000) 2026-07-06 [email protected] Roll Skia from 79806692425f to e15ea7a4b927 (2 revisions) (flutter/flutter#188992) 2026-07-06 [email protected] Roll Skia from 2826ae6dc649 to 79806692425f (1 revision) (flutter/flutter#188991) 2026-07-06 [email protected] Roll Skia from 7f99eee20fd6 to 2826ae6dc649 (1 revision) (flutter/flutter#188990) 2026-07-06 [email protected] Add debugPaintFocusBoxes (flutter/flutter#188288) 2026-07-05 [email protected] Roll Fuchsia Linux SDK from bkK6BLiZDRnE7AQQj... to n1Lm2Z4DZkfC3bwj5... (flutter/flutter#188989) 2026-07-05 [email protected] Roll Skia from 75a4bf6706bd to 7f99eee20fd6 (2 revisions) (flutter/flutter#188988) ...

…lutter#12137) Manual roll Flutter from 6995038d96ef to 91939cc4db78 (48 revisions) Manual roll requested by [email protected] flutter/flutter@6995038...91939cc 2026-07-07 [email protected] Roll Skia from 80ae1deed9ed to 075fbe4778d9 (6 revisions) (flutter/flutter#189067) 2026-07-07 [email protected] Bump customer testing version for new registrants (flutter/flutter#189070) 2026-07-07 [email protected] Roll Packages from fc00ceb to 92525f5 (2 revisions) (flutter/flutter#189069) 2026-07-07 [email protected] fix android semantics integration test hangs due to postframe callback (flutter/flutter#189043) 2026-07-07 [email protected] Bump goldctl (flutter/flutter#189030) 2026-07-07 [email protected] Roll Skia from 71db7c06c5fe to 80ae1deed9ed (2 revisions) (flutter/flutter#189060) 2026-07-07 [email protected] Collect analytics on AI agent usage (flutter/flutter#187630) 2026-07-07 [email protected] Roll Skia from 125a76cc4cf3 to 71db7c06c5fe (4 revisions) (flutter/flutter#189054) 2026-07-07 [email protected] Roll Dart SDK from 70577d6f2bba to c648e3429d76 (1 revision) (flutter/flutter#189052) 2026-07-07 [email protected] Fix RenderSliverPadding setter assertion (flutter/flutter#187353) 2026-07-07 [email protected] Roll Skia from 2dde156aec3e to 125a76cc4cf3 (3 revisions) (flutter/flutter#189037) 2026-07-07 [email protected] Explain asynchronous causes in the setState() called after dispose() error (flutter/flutter#187294) 2026-07-07 [email protected] Roll Skia from 7dccd1e79a5b to 2dde156aec3e (2 revisions) (flutter/flutter#189035) 2026-07-07 [email protected] Add `STRING_CATALOG_GENERATE_SYMBOLS = YES;` (flutter/flutter#188163) 2026-07-07 [email protected] Print warnings on Intel Macs / targeting Intel Macs (flutter/flutter#188835) 2026-07-07 [email protected] Roll Dart SDK from 4c03f64b19f6 to 70577d6f2bba (1 revision) (flutter/flutter#189031) 2026-07-07 [email protected] Roll Fuchsia Linux SDK from n1Lm2Z4DZkfC3bwj5... to 7RjQJBW3m-3Jl-7jr... (flutter/flutter#189032) 2026-07-06 [email protected] Recommend `OverlayPortal.overlayChildLayoutBuilder` over Target-Follower (flutter/flutter#188894) 2026-07-06 [email protected] Sync CHANGELOG.md from stable (flutter/flutter#189025) 2026-07-06 [email protected] Rename preferredSize to size and preferredConstraints to constraints in the windowing API (flutter/flutter#189017) 2026-07-06 [email protected] Skip locked issues in no-response check (flutter/flutter#188950) 2026-07-06 [email protected] Fix potential race condtion in android_semantics_integration_test (flutter/flutter#188830) 2026-07-06 [email protected] ci: udpate wait-for-engine-build composite action to cocoon (flutter/flutter#189020) 2026-07-06 [email protected] Roll Skia from 2b55eed5500d to 7dccd1e79a5b (3 revisions) (flutter/flutter#189021) 2026-07-06 [email protected] [AGP 9] Update Flutter Template Versions (flutter/flutter#188762) 2026-07-06 [email protected] fix(engine/windows): keep tooltip position rect alive - fix use after free (flutter/flutter#188476) 2026-07-06 [email protected] [Tool] Fix null check operator crash in currentPackageConfig (flutter/flutter#188454) 2026-07-06 [email protected] [Tool] Gracefully handle WDAC/AppLocker blocks for impellerc (flutter/flutter#188452) 2026-07-06 [email protected] [flutter_tools] Throw DaemonException if app fails to start early (flutter/flutter#188921) 2026-07-06 [email protected] Roll Dart SDK from ce7a2567eb59 to 4c03f64b19f6 (2 revisions) (flutter/flutter#189015) 2026-07-06 [email protected] [flutter_tools, engine] Add --disable-service-origin-check option to disable VM service origin checks (flutter/flutter#188745) 2026-07-06 [email protected] [flutter_tools] Fix test flakiness in widget_preview_detection_test.dart (flutter/flutter#188922) 2026-07-06 [email protected] Roll pub packages (flutter/flutter#189009) 2026-07-06 [email protected] Roll Skia from c0e2b9667d91 to 2b55eed5500d (1 revision) (flutter/flutter#189006) 2026-07-06 [email protected] Roll Packages from 2fbe873 to fc00ceb (1 revision) (flutter/flutter#189007) 2026-07-06 [email protected] Roll Skia from b68567542f81 to c0e2b9667d91 (1 revision) (flutter/flutter#189004) 2026-07-06 [email protected] Fixing multiline GetBoxesForRange (flutter/flutter#188803) 2026-07-06 [email protected] Roll Skia from e15ea7a4b927 to b68567542f81 (4 revisions) (flutter/flutter#189000) 2026-07-06 [email protected] Roll Skia from 79806692425f to e15ea7a4b927 (2 revisions) (flutter/flutter#188992) 2026-07-06 [email protected] Roll Skia from 2826ae6dc649 to 79806692425f (1 revision) (flutter/flutter#188991) 2026-07-06 [email protected] Roll Skia from 7f99eee20fd6 to 2826ae6dc649 (1 revision) (flutter/flutter#188990) 2026-07-06 [email protected] Add debugPaintFocusBoxes (flutter/flutter#188288) 2026-07-05 [email protected] Roll Fuchsia Linux SDK from bkK6BLiZDRnE7AQQj... to n1Lm2Z4DZkfC3bwj5... (flutter/flutter#188989) 2026-07-05 [email protected] Roll Skia from 75a4bf6706bd to 7f99eee20fd6 (2 revisions) (flutter/flutter#188988) ...

github-actions Bot added framework flutter/packages/flutter repository. See also f: labels. f: scrolling Viewports, list views, slivers, etc. labels May 30, 2026

fallintoplace marked this pull request as ready for review May 30, 2026 20:09

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RenderSliverPadding.padding setter does not validate incoming negative padding #187527

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fallintoplace added 3 commits July 6, 2026 17:57

Fix RenderSliverPadding setter assertion

6a22d24

Move sliver padding regression test

f6e044b

Fix async sliver padding assertion test

0d74594

fallintoplace added 2 commits July 6, 2026 17:57

Use takeException for sliver padding test

4deb49d

Ignore leak tracking for sliver padding assertion test

d6a8531

Piinks force-pushed the fix/render-sliver-padding-assert branch from 1ddbb40 to d6a8531 Compare July 6, 2026 22:57

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Merged via the queue into flutter:master with commit 5c6367c Jul 7, 2026
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Roll Flutter from 0c80830e465b to 7fbcc0895719 (205 revisions) flutter/packages#12126

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Fix RenderSliverPadding setter assertion#187353

Fix RenderSliverPadding setter assertion#187353
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