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<!DOCTYPE bugzilla SYSTEM "https://bugs.webkit.org/page.cgi?id=bugzilla.dtd">

<bugzilla version="5.0.4.1"
          urlbase="https://bugs.webkit.org/"
          
          maintainer="admin@webkit.org"
>

    <bug>
          <bug_id>287793</bug_id>
          
          <creation_ts>2025-02-17 06:28:31 -0800</creation_ts>
          <short_desc>[scroll-animations] WPT test `scroll-animations/scroll-timelines/scroll-animation-effect-phases.tentative.html` is a failure</short_desc>
          <delta_ts>2025-02-17 06:29:51 -0800</delta_ts>
          <reporter_accessible>1</reporter_accessible>
          <cclist_accessible>1</cclist_accessible>
          <classification_id>1</classification_id>
          <classification>Unclassified</classification>
          <product>WebKit</product>
          <component>New Bugs</component>
          <version>WebKit Nightly Build</version>
          <rep_platform>Unspecified</rep_platform>
          <op_sys>Unspecified</op_sys>
          <bug_status>RESOLVED</bug_status>
          <resolution>DUPLICATE</resolution>
          <dup_id>284545</dup_id>
          
          <bug_file_loc></bug_file_loc>
          <status_whiteboard></status_whiteboard>
          <keywords></keywords>
          <priority>P2</priority>
          <bug_severity>Normal</bug_severity>
          <target_milestone>---</target_milestone>
          
          
          <everconfirmed>1</everconfirmed>
          <reporter name="Antoine Quint">graouts</reporter>
          <assigned_to name="Nobody">webkit-unassigned</assigned_to>
          
          

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>2095144</commentid>
    <comment_count>0</comment_count>
    <who name="Antoine Quint">graouts</who>
    <bug_when>2025-02-17 06:28:31 -0800</bug_when>
    <thetext>We fail the &quot;Playback rate affects whether active phase boundary is inclusive&quot; subtest in `scroll-animations/scroll-timelines/scroll-animation-effect-phases.tentative.html`. There are two issues here.

The first issue is a faulty assertion function where `assert_phase` does not deal with `currentTime = 100%` being in the &quot;active&quot; phase for animations associated with a progress-based timeline.

After fixing this we hit a debug ASSERT in WebKit though. Under `setBindingsTimeline()` at the very end of this test, when we change to the document timeline, we end up in a bad state where after calling `setCurrentTime()` the hold time is 0s but the start time is 100%. After that we set the hold time to the unresolved value since the start time is resolved. Then we&apos;re in a state where all the timing values are time-based except for the start time which remains progress-based.

The test attempts to resolve this by setting `animation.currentTime = 0` right after, but we hit the debug assertion before being able to set that value.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>2095146</commentid>
    <comment_count>1</comment_count>
    <who name="Antoine Quint">graouts</who>
    <bug_when>2025-02-17 06:29:51 -0800</bug_when>
    <thetext>

*** This bug has been marked as a duplicate of bug 284545 ***</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>