<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!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>218579</bug_id>
          
          <creation_ts>2020-11-04 11:51:49 -0800</creation_ts>
          <short_desc>[Interop 2021][css-flexbox] flex item margins not included in flex container overflow</short_desc>
          <delta_ts>2026-01-09 13:07:21 -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>Layout and Rendering</component>
          <version>WebKit Nightly Build</version>
          <rep_platform>Unspecified</rep_platform>
          <op_sys>Unspecified</op_sys>
          <bug_status>RESOLVED</bug_status>
          <resolution>FIXED</resolution>
          
          
          <bug_file_loc>https://github.com/w3c/csswg-drafts/issues/4577</bug_file_loc>
          <status_whiteboard></status_whiteboard>
          <keywords>BrowserCompat, InRadar, WPTImpact</keywords>
          <priority>P2</priority>
          <bug_severity>Normal</bug_severity>
          <target_milestone>---</target_milestone>
          <dependson>302717</dependson>
          <blocked>212046</blocked>
    
    <blocked>292022</blocked>
    
    <blocked>305219</blocked>
          <everconfirmed>1</everconfirmed>
          <reporter name="fantasai">fantasai.bugs</reporter>
          <assigned_to name="fantasai">fantasai.bugs</assigned_to>
          <cc>baba</cc>
    
    <cc>bfulgham</cc>
    
    <cc>commit-queue</cc>
    
    <cc>karlcow</cc>
    
    <cc>koivisto</cc>
    
    <cc>ntim</cc>
    
    <cc>simon.fraser</cc>
    
    <cc>smoley</cc>
    
    <cc>webkit-bug-importer</cc>
    
    <cc>webkit-bugzilla</cc>
    
    <cc>zalan</cc>
          

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>1704546</commentid>
    <comment_count>0</comment_count>
    <who name="fantasai">fantasai.bugs</who>
    <bug_when>2020-11-04 11:51:49 -0800</bug_when>
    <thetext>Spec requires flex item margins (and the flex container&apos;s padding) to be included in the flex container&apos;s overflow area.
This is tested in 
  https://wpt.fyi/results/css/css-flexbox/overflow-area-001.html?label=experimental&amp;label=master&amp;aligned
  https://wpt.fyi/results/css/css-flexbox/overflow-area-002.html?label=experimental&amp;label=master&amp;aligned
and it definitely bugs authors. (The spec bugs about including margins/padding were some of the most flagged issues in the CSSWG repo.)</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>1704553</commentid>
    <comment_count>1</comment_count>
    <who name="Radar WebKit Bug Importer">webkit-bug-importer</who>
    <bug_when>2020-11-04 12:08:26 -0800</bug_when>
    <thetext>&lt;rdar://problem/71046552&gt;</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>1903663</commentid>
    <comment_count>2</comment_count>
    <who name="Tim Nguyen (:ntim)">ntim</who>
    <bug_when>2022-10-05 20:50:09 -0700</bug_when>
    <thetext>    if (isGridItem()) {
        // As per https://github.com/w3c/csswg-drafts/issues/3653, child&apos;s margins should contribute to the scrollable overflow area.
        // FIXME: Expand it to non-grid cases when applicable.
        rect.setWidth(rect.width() + std::max(0_lu, marginEnd()));
    }

in RenderBox::layoutOverflowRectForPropagation is a good first place to look at.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>2151765</commentid>
    <comment_count>3</comment_count>
    <who name="fantasai">fantasai.bugs</who>
    <bug_when>2025-10-16 12:22:43 -0700</bug_when>
    <thetext>Pull request: https://github.com/WebKit/WebKit/pull/52498</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>2152615</commentid>
    <comment_count>4</comment_count>
    <who name="EWS">ews-feeder</who>
    <bug_when>2025-10-20 10:12:13 -0700</bug_when>
    <thetext>Committed 301814@main (37c111e7fc47): &lt;https://commits.webkit.org/301814@main&gt;

Reviewed commits have been landed. Closing PR #52498 and removing active labels.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>2152658</commentid>
    <comment_count>5</comment_count>
    <who name="EWS">ews-feeder</who>
    <bug_when>2025-10-20 12:16:44 -0700</bug_when>
    <thetext>Committed 301765.29@safari-7623-branch (c274d802a94c): &lt;https://commits.webkit.org/301765.29@safari-7623-branch&gt;

Reviewed commits have been landed. Closing PR #3808 and removing active labels.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>2154378</commentid>
    <comment_count>6</comment_count>
    <who name="Karl Dubost">karlcow</who>
    <bug_when>2025-10-26 23:15:04 -0700</bug_when>
    <thetext>*** Bug 258354 has been marked as a duplicate of this bug. ***</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>2159599</commentid>
    <comment_count>7</comment_count>
    <who name="WebKit Commit Bot">commit-queue</who>
    <bug_when>2025-11-18 09:21:23 -0800</bug_when>
    <thetext>Re-opened since this is blocked by bug 302717</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>2170177</commentid>
    <comment_count>8</comment_count>
    <who name="fantasai">fantasai.bugs</who>
    <bug_when>2026-01-07 22:13:58 -0800</bug_when>
    <thetext>Pull request: https://github.com/WebKit/WebKit/pull/56240</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>2170331</commentid>
    <comment_count>9</comment_count>
    <who name="EWS">ews-feeder</who>
    <bug_when>2026-01-08 09:59:47 -0800</bug_when>
    <thetext>Committed 305294@main (b7b9c435e3b7): &lt;https://commits.webkit.org/305294@main&gt;

Reviewed commits have been landed. Closing PR #56240 and removing active labels.</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>