layout: Ensure accurate `FragmentFlags` when starting BoxTree layout from IFC by mrobinson · Pull Request #46033 · servo/servo

mrobinson · 2026-06-27T14:19:43Z

This change ensures that when starting a BoxTree incremental layout from an
IndependentFormattingContext that the FragmentFlags of the newly
generated box reflect the current style, rather than wrongly preserving
them between incremental layouts. This fixes an issue where restyling an
<li> element with replaced content to one that was not replaced content
did not remove the IS_REPLACED flag.

Testing: This change adds a new WPT crash test.
Fixes: #45740.

…layout from IFC This change ensures that when starting a `BoxTree` incremental layout from an `IndependentFormattingContext` that the `FragmentFlags` of the newly generated box reflect the current style, rather than wrongly preserving them between incremental layouts. This fixes an issue where restyling an `<li>` element with replaced content to one that was not replaced content did not remove the `IS_REPLACED` flag. Signed-off-by: Martin Robinson <martin@abandonedwig.info> Co-authored-by: Oriol Brufau <obrufau@igalia.com>

github-actions · 2026-06-27T14:24:01Z

🔨 Triggering try run (#28291833942) for Linux (WPT)

servo-wpt-sync · 2026-06-27T14:24:21Z

🤖 Opened new upstream WPT pull request (web-platform-tests/wpt#60951) with upstreamable changes.

servo-wpt-sync · 2026-06-27T14:28:14Z

✍ Updated existing upstream WPT pull request (web-platform-tests/wpt#60951) title and body.

github-actions · 2026-06-27T15:13:47Z

Test results for linux-wpt from try job (#28291833942):

Flaky unexpected result (39)

CRASH [expected OK] /_mozilla/mozilla/focus-scroll-when-visible.html
TIMEOUT [expected OK] /_webgl/conformance/reading/read-pixels-test.html
CRASH [expected OK] /_webgl/conformance/uniforms/no-over-optimization-on-uniform-array-06.html
CRASH [expected OK] /_webgl/conformance/uniforms/no-over-optimization-on-uniform-array-14.html
TIMEOUT [expected OK] /_webgl/conformance2/state/gl-object-get-calls.html
CRASH [expected OK] /_webgl/conformance2/transform_feedback/transform_feedback.html
CRASH [expected OK] /_webgl/conformance2/wasm/readpixels-2gb-in-4gb-wasm-memory.html
TIMEOUT /content-security-policy/inheritance/auxiliary-blank-document.html (#44821)
- PASS [expected FAIL] subtest: For transient doc, violation event occurs in auxiliary, not opener window.
CRASH [expected OK] /content-security-policy/meta/sandbox-iframe.html (#43478)
TIMEOUT [expected OK] /cookies/attributes/domain.sub.html
- TIMEOUT [expected PASS] subtest: No host cookies returned for host cookies after non-host redirect 1
```
Test timed out
```
- NOTRUN [expected PASS] subtest: No host cookies returned for host cookies after non-host redirect 2
- NOTRUN [expected PASS] subtest: No host cookies returned for host cookies after non-host redirect 3
FAIL [expected PASS] /css/css-backgrounds/background-size-042.html
OK /css/css-fonts/variations/at-font-face-font-matching.html (#20684)
- FAIL [expected PASS] subtest: Matching font-style: 'oblique -10deg' should prefer 'oblique -20deg -15deg' over 'oblique -60deg -30deg'
```
assert_equals: Unexpected font on test element expected 487 but got 532
```
- PASS [expected FAIL] subtest: Matching font-style: 'oblique -10deg' should prefer 'oblique 40deg 50deg' over 'italic'
FAIL [expected PASS] /css/css-sizing/dynamic-available-size-iframe.html (#45763)
TIMEOUT [expected PASS] /css/css-transforms/transform-percent-005.html
TIMEOUT [expected OK] /fetch/api/redirect/redirect-keepalive.https.any.html (#32153)
- TIMEOUT [expected PASS] subtest: [keepalive][iframe][load] mixed content redirect; setting up
```
Test timed out
```
TIMEOUT [expected OK] /fetch/content-encoding/br/big-br-body.https.any.html
TIMEOUT [expected OK] /fetch/content-encoding/br/big-br-body.https.any.worker.html
- TIMEOUT [expected PASS] subtest: large br data should be decompressed successfully
```
Test timed out
```
- NOTRUN [expected FAIL] subtest: large br data should be decompressed successfully with byte stream
TIMEOUT [expected OK] /fetch/content-encoding/zstd/big-window-zstd-body.tentative.https.any.html
TIMEOUT [expected OK] /fetch/content-encoding/zstd/big-window-zstd-body.tentative.https.any.worker.html
- TIMEOUT [expected FAIL] subtest: Consuming the body of a resource with too large of a zstd window size should reject
```
Test timed out
```
TIMEOUT [expected OK] /fetch/content-encoding/zstd/big-zstd-body.https.any.html
TIMEOUT [expected OK] /fetch/content-encoding/zstd/big-zstd-body.https.any.worker.html
- TIMEOUT [expected PASS] subtest: large zstd data should be decompressed successfully
```
Test timed out
```
- NOTRUN [expected FAIL] subtest: large zstd data should be decompressed successfully with byte stream
OK /html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-window-open.html (#28691)
- FAIL [expected PASS] subtest: load event does not fire on window.open('about:blank')
```
assert_unreached: load should not be fired Reached unreachable code
```
OK /html/browsers/history/the-history-interface/traverse_the_history_5.html (#21383)
- PASS [expected FAIL] subtest: Multiple history traversals, last would be aborted

OK /html/browsers/windows/embedded-opener-remove-frame.html (#23867)

FAIL [expected PASS] subtest: opener of discarded auxiliary browsing context

assert_object_equals: property "get" expected function "function opener() {
    [native code]
}" got function "function opener() {
    [native code]
}"

CRASH [expected OK] /html/canvas/element/compositing/2d.composite.transparent.destination-out.html
TIMEOUT /html/semantics/embedded-content/media-elements/autoplay-disabled-by-permissions-policy.https.sub.html (#46012)
- PASS [expected TIMEOUT] subtest: Permissions-Policy header: autoplay "none" has no effect on the top level document.
OK /html/semantics/embedded-content/media-elements/media_fragment_seek.html (#24114)
- FAIL [expected PASS] subtest: Video should seek to time specified in media fragment syntax
```
assert_equals: expected 3 but got 0
```
OK /html/semantics/forms/form-submission-0/jsurl-form-submit.tentative.html (#36489)
- PASS [expected FAIL] subtest: Verifies that form submissions scheduled inside javascript: urls take precedence over the javascript: url's return value.
OK /html/semantics/scripting-1/the-script-element/execution-timing/077.html (#22139)
- PASS [expected FAIL] subtest: adding several types of scripts through the DOM and removing some of them confuses scheduler
TIMEOUT [expected OK] /html/user-activation/navigation-state-reset-sameorigin.html (#45151)
- TIMEOUT [expected FAIL] subtest: Post-navigation state reset.
```
Test timed out
```
OK /html/webappapis/dynamic-markup-insertion/document-write/module-tla-import.html (#42419)
- FAIL [expected PASS] subtest: document.write in an imported module
```
assert_true: onload must be called expected true got false
```
TIMEOUT [expected OK] /infrastructure/testdriver/click_nested.html (#43887)
- NOTRUN [expected FAIL] subtest: TestDriver click method with multiple windows and nested iframe
TIMEOUT [expected OK] /pointerevents/compat/pointerevent_touch-action_two-finger_interaction.html (#44693)
- NOTRUN [expected PASS] subtest: touch two-finger pan on 'touch-action: pan-x pan-y'
- NOTRUN [expected FAIL] subtest: touch two-finger pan on 'touch-action: pinch-zoom'

OK /pointerevents/pointerevent_pointercapture_in_frame.html?touch (#45445)

FAIL [expected PASS] subtest: Test touchpointer capture in same-origin frame: Pointer down at inner frame and set pointer capture.
```
assert_true: Timed out waiting for lostpointercapture expected true got false
```

FAIL [expected PASS] subtest:

Test touchpointer capture in same-origin frame: Pointer down at inner frame and set pointer capture to outer frame should not capture.

assert_array_equals: Received events: innerFrame received pointerdown,innerFrame received pointermove,innerFrame received pointerup,innerFrame received lostpointercapture lengths differ, expected array ["innerFrame received pointerdown", "innerFrame received pointermove", "innerFrame received pointerup"] length 3, got ["innerFrame received pointerdown", "innerFrame received pointermove", "innerFrame received pointerup", "innerFrame received lostpointercapture"] length 4

OK /touch-events/mouseevents-after-touchend.tentative.html
- PASS [expected FAIL] subtest: Single tap should cause a click
- PASS [expected FAIL] subtest: Tapping too far points should not cause a dblclick
CRASH [expected OK] /trusted-types/TrustedTypePolicyFactory-createPolicy-unenforced.html
OK /visual-viewport/resize-event-order.html (#41981)
- PASS [expected FAIL] subtest: Popup: DOMWindow resize fired before VisualViewport.
CRASH [expected OK] /webstorage/storage_local_setitem_quotaexceedederr.window.html
CRASH [expected OK] /webstorage/storage_session_setitem_quotaexceedederr.window.html

Stable unexpected results that are known to be intermittent (27)

TIMEOUT /FileAPI/url/url-in-tags-revoke.window.html (#19978)
- PASS [expected TIMEOUT] subtest: Fetching a blob URL immediately before revoking it works in <script> tags.
OK /beacon/beacon-basic.https.window.html (#41723)
- FAIL [expected PASS] subtest: Payload size restriction should be accumulated: type = string
```
assert_false: expected false got true
```
OK [expected TIMEOUT] /credential-management/credentialscontainer-frame-basics.https.html (#39430)
- FAIL [expected TIMEOUT] subtest: navigator.credentials should be undefined in documents generated from data: URLs.
```
assert_equals: expected "undefined" but got "[object CredentialsContainer]"
```
OK /css/css-animations/animation-iteration-event-001.html (#46004)
- PASS [expected FAIL] subtest: Got the expected elapsedTime in the correct order
OK /css/css-cascade/layer-font-face-override.html (#35935)
- PASS [expected FAIL] subtest: @font-face override update with appended sheet 1
- PASS [expected FAIL] subtest: @font-face override update with appended sheet 2
PASS [expected FAIL] /css/css-text-decor/text-underline-position-from-font-variable.html (#45615)
OK /dom/nodes/moveBefore/iframe-document-preserve.window.html (#43152)
- FAIL [expected PASS] subtest: moveBefore(): cross-origin iframe is preserved: remove self
```
assert_equals: iframe does not fire a second load event expected 1 but got 0
```
- FAIL [expected PASS] subtest: moveBefore(): cross-origin iframe is preserved: remove self via innerHTML
```
assert_equals: iframe does not fire a second load event expected 1 but got 0
```
ERROR [expected OK] /fetch/fetch-later/quota/same-origin-iframe/accumulated-oversized-payload.https.window.html (#41705)
TIMEOUT /fetch/metadata/generated/css-images.sub.tentative.html (#29047)
- FAIL [expected PASS] subtest: content sec-fetch-user - Not sent to non-trustworthy same-origin destination
```
assert_unreached: Reached unreachable code
```
- FAIL [expected PASS] subtest: content sec-fetch-site - HTTPS downgrade-upgrade
```
assert_unreached: Reached unreachable code
```
TIMEOUT [expected ERROR] /html/browsers/browsing-the-web/history-traversal/pageswap/pageswap-initial-navigation.html (#40387)
OK /html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/a-click.html (#28697)
- PASS [expected FAIL] subtest: aElement.click() before the load event must NOT replace
TIMEOUT [expected CRASH] /html/browsers/history/the-history-interface/001.html (#12580)
- FAIL [expected PASS] subtest: traversing history must also traverse hash changes
```
assert_equals: (this could cause other failures later on) expected "" but got "test"
```
TIMEOUT [expected ERROR] /html/browsers/history/the-location-interface/location_replace_session_history.html (#41896)
TIMEOUT [expected OK] /html/interaction/focus/the-autofocus-attribute/autofocus-dialog.html (#29087)
- TIMEOUT [expected FAIL] subtest: <dialog>-contained autofocus element gets focused when the dialog is shown
```
Test timed out
```
TIMEOUT /html/interaction/focus/the-autofocus-attribute/supported-elements.html (#24145)
- TIMEOUT [expected FAIL] subtest: Host element with delegatesFocus should support autofocus
```
Test timed out
```
- NOTRUN [expected FAIL] subtest: Host element with delegatesFocus including no focusable descendants should be skipped
TIMEOUT /html/semantics/embedded-content/media-elements/preserves-pitch.html (#40352)
- TIMEOUT [expected PASS] subtest: Speed-ups should not change the pitch when preservesPitch=true
```
Test timed out
```
- NOTRUN [expected PASS] subtest: Slow-downs should not change the pitch when preservesPitch=true
- NOTRUN [expected TIMEOUT] subtest: Speed-ups should change the pitch when preservesPitch=false
OK [expected TIMEOUT] /html/semantics/embedded-content/media-elements/src_object_blob.html (#40340)
- PASS [expected TIMEOUT] subtest: HTMLMediaElement.srcObject blob
OK [expected TIMEOUT] /html/semantics/embedded-content/the-iframe-element/iframe_sandbox_navigate_other_frame_popup.sub.html (#39702)
- FAIL [expected TIMEOUT] subtest: Sandboxed iframe can not navigate other frame's popup
```
assert_equals: expected "cannot navigate" but got "can navigate"
```
OK /html/semantics/scripting-1/the-script-element/module/choice-of-error-1.html (#44058)
- FAIL [expected PASS] subtest: Parse errors in different files should be reported depending on different roots
```
assert_not_equals: two different parse errors should be reported got disallowed value object "SyntaxError: expected expression, got '%'"
```

OK /html/webappapis/user-prompts/print-during-unload.html (#35944)

FAIL [expected PASS] subtest: print() during unload

assert_array_equals: expected property 1 to be "destination" but got "error: window.print is not a function" (expected array ["start", "destination"] got ["start", "error: window.print is not a function"])

OK /preload/prefetch-document.html (#37210)
- PASS [expected FAIL] subtest: different-site document prefetch with 'as=document' should not be consumed

OK [expected CRASH] /resource-timing/render-blocking-status-link.html (#41664)

FAIL [expected PASS] subtest: Validate render blocking status of link resources in PerformanceResourceTiming

assert_equals: render blocking status for http://web-platform.test:8000/resource-timing/resources/empty_style.css?stylesheet-head-dynamic-docWrite should be blocking expected (string) "blocking" but got (undefined) undefined

TIMEOUT /trusted-types/trusted-types-navigation.html?06-10 (#37920)
- TIMEOUT [expected FAIL] subtest: Navigate a frame via anchor with javascript:-urls in report-only mode.
```
Test timed out
```
- NOTRUN [expected TIMEOUT] subtest: Navigate a frame via anchor with javascript:-urls w/ default policy in report-only mode.
OK [expected TIMEOUT] /trusted-types/trusted-types-navigation.html?11-15 (#44834)
- PASS [expected TIMEOUT] subtest: Navigate a window via area with javascript:-urls in report-only mode.
TIMEOUT [expected OK] /trusted-types/trusted-types-navigation.html?16-20 (#44835)
- TIMEOUT [expected PASS] subtest: Navigate a frame via area with javascript:-urls w/ default policy in enforcing mode.
```
Test timed out
```
- NOTRUN [expected PASS] subtest: Navigate a frame via area with javascript:-urls in report-only mode.
- NOTRUN [expected PASS] subtest: Navigate a frame via area with javascript:-urls w/ default policy in report-only mode.
TIMEOUT /trusted-types/trusted-types-navigation.html?26-30 (#38807)
- PASS [expected TIMEOUT] subtest: Navigate a window via form-submission with javascript:-urls in report-only mode.
- PASS [expected NOTRUN] subtest: Navigate a window via form-submission with javascript:-urls w/ default policy in report-only mode.
- PASS [expected NOTRUN] subtest: Navigate a frame via form-submission with javascript:-urls in enforcing mode.
- TIMEOUT [expected NOTRUN] subtest: Navigate a frame via form-submission with javascript:-urls w/ default policy in enforcing mode.
```
Test timed out
```
TIMEOUT /trusted-types/trusted-types-navigation.html?31-35 (#38034)
- TIMEOUT [expected PASS] subtest: Navigate a frame via form-submission with javascript:-urls in report-only mode.
```
Test timed out
```
- NOTRUN [expected TIMEOUT] subtest: Navigate a frame via form-submission with javascript:-urls w/ default policy in report-only mode.

github-actions · 2026-06-27T15:14:25Z

✨ Try run (#28291833942) succeeded.

mrobinson · 2026-06-28T14:01:01Z

@Loirooriol Do you mind taking a look at this one?

mrobinson requested a review from Loirooriol as a code owner June 27, 2026 14:19

servo-highfive added the S-awaiting-review There is new code that needs to be reviewed. label Jun 27, 2026

mrobinson added the T-linux-wpt Do a try run of the WPT label Jun 27, 2026

mrobinson mentioned this pull request Jun 27, 2026

internal error: entered unreachable code: Unexpected direct descendant PositioningContext of inline. (thread Script#1, at components/layout/display_list/paint_traversal.rs:375) #45740

Closed

mrobinson changed the title ~~layout: Ensure that FragmentFlags reflect current starting BoxTree layout from IFC~~ layout: Ensure accurate FragmentFlags when starting BoxTree layout from IFC Jun 27, 2026

github-actions Bot removed the T-linux-wpt Do a try run of the WPT label Jun 27, 2026

servo-wpt-sync mentioned this pull request Jun 27, 2026

layout: Ensure accurate FragmentFlags when starting BoxTree layout from IFC web-platform-tests/wpt#60951

Merged

SimonSapin approved these changes Jun 29, 2026

View reviewed changes

servo-highfive removed the S-awaiting-review There is new code that needs to be reviewed. label Jun 29, 2026

mrobinson added this pull request to the merge queue Jun 29, 2026

servo-highfive added the S-awaiting-merge The PR is in the process of compiling and running tests on the automated CI. label Jun 29, 2026

Merged via the queue into servo:main with commit e717c19 Jun 29, 2026
74 checks passed

mrobinson deleted the marker-incremental-layout branch June 29, 2026 16:21

servo-highfive removed the S-awaiting-merge The PR is in the process of compiling and running tests on the automated CI. label Jun 29, 2026

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layout: Ensure accurate `FragmentFlags` when starting BoxTree layout from IFC - #46033

layout: Ensure accurate `FragmentFlags` when starting BoxTree layout from IFC#46033
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