html: Run the <media> `play` seek if `loop` attribute was set after playback ended #40688

tharkum · 2025-11-17T11:20:05Z

The user agent on the internal play steps (step 2) must to seek to the earliest possible position if the playback has ended, but the definition of the ended playback prevents looping when the loop attribute was added after playback has ended (already registered whatwg html issue).

- playback ended (`ended` event)
- loop = true
- play() (no seeking - playback hasn't ended)

Currently this edge case if not yet reflected in the HTML specification so let's do the same as other browsers and ignore the loop attribute for play seek.

See https://html.spec.whatwg.org/multipage/#internal-play-steps
See whatwg/html#4487

Testing: Improvements in the following tests

html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html

github-actions · 2025-11-17T11:21:38Z

🔨 Triggering try run (#19427878425) for Linux (WPT)

tharkum · 2025-11-17T11:29:12Z

Please notice that this pull request is focusing on the play seek and ended_playback specification issue, while there are existing intermittent issue for associated WPT test, and it is related to the timing issue (slow event marshaling between the script runtime and the media engine).

So in summary this pull request is changing expected test result from TIMEOUT to OK, but not fixing the intermittent timing issue.

github-actions · 2025-11-17T11:56:34Z

Test results for linux-wpt from try job (#19427878425):

Flaky unexpected result (41)

OK /IndexedDB/idbfactory_open.any.html
- FAIL [expected PASS] subtest: Calling open() with version argument 1.5 should not throw.
```
assert_equals: version expected 1 but got 9007199254740991
```

OK /_mozilla/css/offset_properties_inline.html (#40543)

FAIL [expected PASS] subtest: offsetTop

assert_equals: offsetTop of #inline-1 should be 0. expected 0 but got -1

FAIL [expected PASS] subtest: offsetLeft

assert_equals: offsetLeft of #inline-2 should be 40. expected 40 but got 25

OK /_mozilla/mozilla/getBoundingClientRect.html (#39668)
- FAIL [expected PASS] subtest: getBoundingClientRect 1
```
assert_equals: expected 62 but got 60.35
```
OK /_mozilla/webxr/create_session.https.html
- FAIL [expected PASS] subtest: create_session
```
can't access property "simulateDeviceConnection", navigator.xr.test is undefined
```
CRASH [expected OK] /_webgl/conformance/ogles/GL/lessThanEqual/lessThanEqual_001_to_008.html
CRASH [expected OK] /_webgl/conformance/ogles/GL/swizzlers/swizzlers_033_to_040.html
CRASH [expected OK] /_webgl/conformance/programs/program-test.html
CRASH [expected OK] /_webgl/conformance/rendering/gl-scissor-test.html
CRASH [expected OK] /_webgl/conformance/rendering/many-draw-calls.html
CRASH [expected OK] /_webgl/conformance/textures/image/tex-2d-alpha-alpha-unsigned_byte.html
CRASH [expected ERROR] /_webgl/conformance/textures/misc/texture-srgb-upload.html
CRASH [expected OK] /credential-management/idlharness.https.window.html
OK /custom-elements/form-associated/ElementInternals-setFormValue.html (#29174)
- PASS [expected FAIL] subtest: setFormValue with an empty FormData should submit nothing
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
```
OK /fetch/fetch-later/new-window.https.window.html (#32036)
- FAIL [expected PASS] subtest: A same-origin window[target=''][features=''] can trigger fetchLater.
```
assert_equals: Number of sent beacons does not match expected count: expected 1 but got 0
```
- FAIL [expected PASS] subtest: A same-origin window[target=''][features='popup'] can trigger fetchLater.
```
assert_equals: Number of sent beacons does not match expected count: expected 1 but got 0
```
- FAIL [expected PASS] subtest: A same-origin window[target='_blank'][features=''] can trigger fetchLater.
```
assert_equals: Number of sent beacons does not match expected count: expected 1 but got 0
```
- FAIL [expected PASS] subtest: A same-origin window[target='_blank'][features='popup'] can trigger fetchLater.
```
assert_equals: Number of sent beacons does not match expected count: expected 1 but got 0
```
ERROR /fetch/metadata/generated/serviceworker.https.sub.html (#36247)
- FAIL [expected PASS] subtest: sec-fetch-site - Same origin, no options - registration
```
promise_test: Unhandled rejection with value: object "Error: Failed to query for recorded headers."
```

OK /html/browsers/browsing-the-web/navigating-across-documents/refresh/same-document-refresh.html (#34597)

FAIL [expected PASS] subtest: Same-Document Referrer from Refresh

assert_equals: original page loads expected "http://web-platform.test:8000/html/browsers/browsing-the-web/navigating-across-documents/refresh/resources/refresh-with-section.sub.html?url=%23section" but got "http://web-platform.test:8000/html/browsers/browsing-the-web/navigating-across-documents/refresh/resources/refresh-with-section.sub.html?url=%23section#section"

OK /html/browsers/history/the-history-interface/traverse_the_history_4.html (#21383)
- PASS [expected FAIL] subtest: Multiple history traversals, last would be aborted
OK /html/browsers/history/the-history-interface/traverse_the_history_5.html (#21383)
- PASS [expected FAIL] subtest: Multiple history traversals, last would be aborted
CRASH [expected OK] /html/browsers/the-window-object/window-open-noreferrer.html

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/fill-and-stroke-styles/2d.gradient.radial.negative.html
OK /html/semantics/document-metadata/the-meta-element/pragma-directives/attr-meta-http-equiv-refresh/allow-scripts-flag-changing-2.html (#39703)
- FAIL [expected PASS] subtest: Meta refresh of the original iframe is not blocked if moved into a sandboxed iframe
```
uncaught exception: Error: assert_unreached: The iframe into which the meta was moved must not refresh Reached unreachable code
```
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/forms/form-submission-0/multipart-formdata.window.html (#28725)
- PASS [expected FAIL] subtest: multipart/form-data: 0x00 in name (formdata event)
- PASS [expected FAIL] subtest: multipart/form-data: single quote in value (formdata event)
OK /html/semantics/forms/form-submission-0/text-plain.window.html (#28687)
- FAIL [expected PASS] subtest: text/plain: Basic File test (normal form)
```
assert_equals: expected "basic=file-test.txt\r\n" but got ""
```
- PASS [expected FAIL] subtest: text/plain: Basic File test (formdata event)
- PASS [expected FAIL] subtest: text/plain: 0x00 in value (formdata event)
- PASS [expected FAIL] subtest: text/plain: single quote in filename (formdata event)
OK /html/semantics/forms/form-submission-0/urlencoded2.window.html (#28687)
- FAIL [expected PASS] subtest: application/x-www-form-urlencoded: Basic File test (normal form)
```
assert_equals: expected "basic=file-test.txt" but got ""
```
- PASS [expected FAIL] subtest: application/x-www-form-urlencoded: Basic File test (formdata event)
OK [expected CRASH] /html/semantics/forms/the-fieldset-element/disabled-003.html (#31730, #39631)
TIMEOUT [expected ERROR] /html/semantics/links/links-created-by-a-and-area-elements/target_blank_implicit_noopener_base.html (#40347)

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"])

PASS [expected FAIL] /png/apng/fcTL-dispose-none.html
CRASH [expected OK] /pointerevents/pointerevent_multiple_pointerover_no_pointer_movement.html
ERROR [expected OK] /resource-timing/cors-preflight.any.html (#28694)
CRASH [expected OK] /trusted-types/Element-setAttribute-setAttributeNS-sinks.tentative.html
TIMEOUT [expected OK] /trusted-types/trusted-types-navigation.html?01-05 (#38975)
- TIMEOUT [expected PASS] subtest: Navigate a window via anchor with javascript:-urls in report-only mode.
```
Test timed out
```
- NOTRUN [expected PASS] subtest: Navigate a window via anchor with javascript:-urls w/ default policy in report-only mode.
- NOTRUN [expected PASS] subtest: Navigate a frame via anchor with javascript:-urls in enforcing mode.
CRASH [expected TIMEOUT] /uievents/mouse/cancel-mousedown-in-subframe.html
CRASH [expected TIMEOUT] /wasm/webapi/empty-body.any.worker.html
OK [expected TIMEOUT] /webstorage/localstorage-about-blank-3P-iframe-opens-3P-window.partitioned.html (#29053)
- PASS [expected TIMEOUT] subtest: StorageKey: test 3P about:blank window opened from a 3P iframe
TIMEOUT [expected OK] /workers/nested_worker_close_from_parent_worker.html
OK /xhr/send-redirect.htm (#32026)
- FAIL [expected PASS] subtest: XMLHttpRequest: send() - Redirects (basics) (303, GET, content.py)
```
assert_equals: expected (string) "GET" but got (object) null
```

Stable unexpected results that are known to be intermittent (24)

OK /IndexedDB/idbobjectstore_getAll.any.html (#39276)
- PASS [expected FAIL] subtest: Get all values with transaction.commit()
OK /IndexedDB/idbobjectstore_getAll.any.worker.html (#39400)
- PASS [expected FAIL] subtest: Get all values with transaction.commit()
OK /IndexedDB/transaction-deactivation-timing.any.html (#38772)
- PASS [expected FAIL] subtest: New transactions are deactivated before next task
FAIL [expected PASS] /_mozilla/mozilla/sslfail.html (#10760)
TIMEOUT [expected OK] /_mozilla/mozilla/window_resize_event.html (#36741)
- TIMEOUT [expected PASS] subtest: Popup onresize event fires after resizeTo
```
Test timed out
```
OK /css/css-fonts/generic-family-keywords-001.html (#37467)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted generic(kai)
OK /css/css-fonts/generic-family-keywords-003.html (#38994)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted fantasy (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted monospace (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted generic(khmer-mul) (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted ui-rounded (drawing text in a canvas)

OK /fetch/api/credentials/cookies.any.html (#40672)

FAIL [expected PASS] subtest: Include mode: 1 cookie

assert_equals: Request include cookie(s) expected "a=1" but got "a=1; domain-attribute-matches-host=0"

FAIL [expected PASS] subtest: Include mode: 2 cookies

assert_equals: Request include cookie(s) expected "b=2; c=3" but got "b=2; c=3; domain-attribute-matches-host=0"

FAIL [expected PASS] subtest: Omit mode: no cookie is stored

assert_false: Request does not have cookie(s) expected false got true

FAIL [expected PASS] subtest: Same-origin mode: 1 cookie

assert_equals: Request include cookie(s) expected "a=1" but got "a=1; domain-attribute-matches-host=0"

FAIL [expected PASS] subtest: Same-origin mode: 2 cookies

assert_equals: Request include cookie(s) expected "b=2; c=3" but got "b=2; c=3; domain-attribute-matches-host=0"

OK /fetch/fetch-later/permissions-policy/deferred-fetch-allowed-by-permissions-policy.https.window.html (#40478)
- FAIL [expected PASS] subtest: Permissions policy header: "deferred-fetch=*" allows fetchLater() in the top-level document.
```
assert_equals: Number of sent beacons does not match expected count: expected 1 but got 0
```
OK /fetch/metadata/generated/css-font-face.https.sub.tentative.html (#32732)
- PASS [expected FAIL] subtest: sec-fetch-user
- FAIL [expected PASS] subtest: sec-fetch-storage-access - Cross-site
```
promise_test: Unhandled rejection with value: object "Error: Failed to query for recorded headers."
```
OK /fetch/metadata/generated/element-img-environment-change.https.sub.html (#30111)
- PASS [expected FAIL] subtest: sec-fetch-site - Cross-site, no attributes
- FAIL [expected PASS] subtest: sec-fetch-site - Same-Origin -> Same-Site -> Same-Origin redirect, no attributes
```
promise_test: Unhandled rejection with value: object "Error: Failed to query for recorded headers."
```
- FAIL [expected PASS] subtest: sec-fetch-site - Same-Origin -> Same Origin, no attributes
```
promise_test: Unhandled rejection with value: object "Error: Failed to query for recorded headers."
```
- PASS [expected FAIL] subtest: sec-fetch-site - Same-Origin -> Same-Site, no attributes
- FAIL [expected PASS] subtest: sec-fetch-site - Same-Origin -> Cross-Site, no attributes
```
promise_test: Unhandled rejection with value: object "Error: Failed to query for recorded headers."
```
- PASS [expected FAIL] subtest: sec-fetch-site - Same-Site -> Cross-Site, no attributes
- FAIL [expected PASS] subtest: sec-fetch-mode - attributes: crossorigin=use-credentials
```
promise_test: Unhandled rejection with value: object "Error: Failed to query for recorded headers."
```
OK /fetch/metadata/generated/element-img-environment-change.sub.html (#30111)
- PASS [expected FAIL] subtest: sec-fetch-site - Not sent to non-trustworthy cross-site destination, no attributes
- PASS [expected FAIL] subtest: sec-fetch-mode - Not sent to non-trustworthy same-origin destination, no attributes
- PASS [expected FAIL] subtest: sec-fetch-dest - Not sent to non-trustworthy cross-site destination, no attributes
- FAIL [expected PASS] subtest: sec-fetch-user - Not sent to non-trustworthy same-origin destination, no attributes
```
promise_test: Unhandled rejection with value: object "Error: Failed to query for recorded headers."
```
- PASS [expected FAIL] subtest: sec-fetch-user - Not sent to non-trustworthy same-site destination, no attributes
- PASS [expected FAIL] subtest: sec-fetch-user - Not sent to non-trustworthy cross-site destination, no attributes
- PASS [expected FAIL] subtest: sec-fetch-storage-access - Not sent to non-trustworthy same-origin destination, no attributes
OK /html/browsers/browsing-the-web/navigating-across-documents/005.html (#27062)
- FAIL [expected PASS] subtest: Link with onclick navigation and href navigation
```
assert_equals: expected "href" but got "click"
```
OK /html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-cross-origin.sub.window.html (#29056)
- FAIL [expected PASS] subtest: Cross-origin navigation started from unload handler must be ignored
```
promise_test: Unhandled rejection with value: object "SecurityError: The operation is insecure."
```
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
ERROR [expected OK] /html/infrastructure/common-dom-interfaces/collections/domstringlist.html (#40665)
OK [expected TIMEOUT] /html/interaction/focus/the-autofocus-attribute/autofocus-dialog.html (#29087)
- FAIL [expected TIMEOUT] subtest: <dialog>-contained autofocus element gets focused when the dialog is shown
```
assert_equals: expected "DIV" but got "BODY"
```
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"
```
CRASH [expected OK] /pointerevents/compat/pointerevent_touch-action_two-finger_interaction.html (#40418)
OK /preload/preload-error.sub.html (#37177)
- PASS [expected FAIL] subtest: 404 (fetch): main
- PASS [expected FAIL] subtest: CORS (fetch): main
TIMEOUT [expected OK] /trusted-types/trusted-types-navigation.html?26-30 (#38807)
- TIMEOUT [expected FAIL] subtest: Navigate a window via form-submission with javascript:-urls in report-only mode.
```
Test timed out
```
- NOTRUN [expected PASS] subtest: Navigate a window via form-submission with javascript:-urls w/ default policy in report-only mode.
- NOTRUN [expected FAIL] subtest: Navigate a frame via form-submission with javascript:-urls in enforcing mode.
- NOTRUN [expected PASS] subtest: Navigate a frame via form-submission with javascript:-urls w/ default policy in enforcing mode.
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.
OK [expected ERROR] /webxr/render_state_update.https.html (#27535)
ERROR [expected OK] /workers/baseurl/alpha/import-in-moduleworker.html (#21315)

github-actions · 2025-11-17T11:56:42Z

✨ Try run (#19427878425) succeeded.

TimvdLippe

1 nit about the boolean, the rest LGTM. After merging, can you monitor the intermittent issue and see if it remains intermittent after 7 days? That way we can know if it is resolved or not.

components/script/dom/html/htmlmediaelement.rs

tharkum · 2025-11-17T12:48:15Z

1 nit about the boolean, the rest LGTM. After merging, can you monitor the intermittent issue and see if it remains intermittent after 7 days? That way we can know if it is resolved or not.

It will not be resolved by this PR - #33778 (comment)

…layback ended The user agent on the `internal play steps` (step 2) must to seek to the earliest possible position if the playback has ended, but the definition of the `ended playback` prevents looping when the loop attribute was added after playback has ended (already registered whatwg html issue). ``` - playback ended (`ended` event) - loop = true - play() (no seeking - playback hasn't ended) ``` Currently this edge case if not yet reflected in the HTML specification so let's do the same as other browsers and ignore the `loop` attribute for `play` seek. See https://html.spec.whatwg.org/multipage/#internal-play-steps See whatwg/html#4487 Testing: Improvements in the following tests - html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html Signed-off-by: Andrei Volykhin <andrei.volykhin@gmail.com>

tharkum requested a review from gterzian as a code owner November 17, 2025 11:20

servo-highfive added the S-awaiting-review There is new code that needs to be reviewed. label Nov 17, 2025

tharkum requested review from TimvdLippe and jdm and removed request for gterzian and jdm November 17, 2025 11:20

tharkum added the T-linux-wpt Do a try run of the WPT label Nov 17, 2025

github-actions bot removed the T-linux-wpt Do a try run of the WPT label Nov 17, 2025

TimvdLippe approved these changes Nov 17, 2025

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components/script/dom/html/htmlmediaelement.rs Outdated Show resolved Hide resolved

servo-highfive removed the S-awaiting-review There is new code that needs to be reviewed. label Nov 17, 2025

tharkum force-pushed the html-media-play-seek-ignore-loop-attribute branch from 822a7d6 to dc3815a Compare November 17, 2025 13:21

servo-highfive added the S-awaiting-review There is new code that needs to be reviewed. label Nov 17, 2025

TimvdLippe approved these changes Nov 17, 2025

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servo-highfive removed the S-awaiting-review There is new code that needs to be reviewed. label Nov 17, 2025

TimvdLippe added this pull request to the merge queue Nov 17, 2025

servo-highfive added the S-awaiting-merge The PR is in the process of compiling and running tests on the automated CI. label Nov 17, 2025

Merged via the queue into servo:main with commit 1301dbf Nov 17, 2025
35 checks passed

servo-highfive removed the S-awaiting-merge The PR is in the process of compiling and running tests on the automated CI. label Nov 17, 2025

tharkum deleted the html-media-play-seek-ignore-loop-attribute branch November 17, 2025 16:50

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html: Run the <media> `play` seek if `loop` attribute was set after playback ended #40688

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html: Run the <media> `play` seek if `loop` attribute was set after playback ended #40688

html: Run the <media> `play` seek if `loop` attribute was set after playback ended #40688