Bug 285878 – ASSERT SHOULD NEVER BE REACHED - WebCore::Layout::leadingInlineItemPositionOnLastLine

• Status: RESOLVED
• Resolution: FIXED
• Component: Layout and Rendering

[Matt Woodrow]

https://github.com/WebKit/WebKit/pull/38817 imports the render-blocking tests, and causes two of them to fail with the above assertion.

imported/w3c/web-platform-tests/html/dom/render-blocking/element-render-blocking-029.html
imported/w3c/web-platform-tests/html/dom/render-blocking/element-render-blocking-031.html

Crash log: https://ews-build.s3-us-west-2.amazonaws.com/macOS-Sequoia-Debug-WK2-Tests-EWS/a0e1a4a6-8489/results.html

I'll disable the tests for now until this is fixed.

[alan]

This is caused by not computing the first/last inline boxes correctly which confuses the invalidation logic (falls back to full invalidation)


--- a/Source/WebCore/layout/integration/inline/LayoutIntegrationInlineContentBuilder.cpp
+++ b/Source/WebCore/layout/integration/inline/LayoutIntegrationInlineContentBuilder.cpp
@@ -100,7 +100,6 @@ InlineContentBuilder::InlineContentBuilder(const RenderBlockFlow& blockFlow)
 FloatRect InlineContentBuilder::build(Layout::InlineLayoutResult&& layoutResult, InlineContent& inlineContent, const Layout::InlineDamage* lineDamage) const
 {
     inlineContent.releaseCaches();
-    computeIsFirstIsLastBoxAndBidiReorderingForInlineContent(layoutResult.displayContent.boxes);
 
     if (layoutResult.range == Layout::InlineLayoutResult::Range::Full) {
         auto damagedRect = FloatRect { };
@@ -108,6 +107,7 @@ FloatRect InlineContentBuilder::build(Layout::InlineLayoutResult&& layoutResult,
         for (auto& line : inlineContent.displayContent().lines)
             damagedRect.unite(line.inkOverflow());
 
+        computeIsFirstIsLastBoxAndBidiReorderingForInlineContent(layoutResult.displayContent.boxes);
         inlineContent.displayContent().set(WTFMove(layoutResult.displayContent));
         adjustDisplayLines(inlineContent, 0);
 
@@ -218,7 +218,9 @@ FloatRect InlineContentBuilder::build(Layout::InlineLayoutResult&& layoutResult,
 
         return damagedRect;
     };
-    return handlePartialDisplayContentUpdate();
+    auto damagedRect = handlePartialDisplayContentUpdate();
+    computeIsFirstIsLastBoxAndBidiReorderingForInlineContent(inlineContent.displayContent().boxes);
+    return damagedRect;
 }
 
 void InlineContentBuilder::updateLineOverflow(InlineContent& inlineContent) const

[alan]

Created attachment 473901 [details]
[fast-cq]Patch

[EWS]

Committed 288870@main (3b92ce0658c9): <https://commits.webkit.org/288870@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 473901 [details].

[Radar WebKit Bug Importer]

<rdar://problem/142897195>