Bug 128541

Summary: REGRESSION: svg/text/text-overflow-ellipsis-svgfont-kerning-ligatures.html frequently asserts in ComplexTextController::offsetForPosition
Product: WebKit Reporter: Alexey Proskuryakov <ap>
Component: SVGAssignee: Nobody <webkit-unassigned>
Status: RESOLVED DUPLICATE    
Severity: Normal CC: ap, krit, mitz, mmaxfield, rniwa, zalan, zimmermann
Priority: P2 Keywords: MakingBotsRed, Regression
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   

Description Alexey Proskuryakov 2014-02-10 10:26:03 PST 
svg/text/text-overflow-ellipsis-svgfont-kerning-ligatures.html has started to ASSERT very frequently on February 7th:

SHOULD NEVER BE REACHED
/Volumes/Data/slave/mavericks-debug/build/Source/WebCore/platform/graphics/mac/ComplexTextController.cpp(261) : int WebCore::ComplexTextController::offsetForPosition(float, bool)
1   0x111d834b0 WTFCrash
2   0x11307803c WebCore::ComplexTextController::offsetForPosition(float, bool)
3   0x113685942 WebCore::Font::offsetForPositionForComplexText(WebCore::TextRun const&, float, bool) const
4   0x113669506 WebCore::Font::offsetForPosition(WebCore::TextRun const&, float, bool) const
5   0x1139c7778 WebCore::InlineTextBox::offsetForPosition(float, bool) const
6   0x1139bfe3a WebCore::InlineTextBox::placeEllipsisBox(bool, float, float, float, float&, bool&)
7   0x1139b4fe9 WebCore::InlineFlowBox::placeEllipsisBox(bool, float, float, float, float&, bool&)
8   0x1146f141e WebCore::RootInlineBox::placeEllipsisBox(bool, float, float, float, float&, bool&)
9   0x1146f1276 WebCore::RootInlineBox::placeEllipsis(WTF::AtomicString const&, bool, float, float, float, WebCore::InlineBox*)
10  0x114414995 WebCore::RenderBlockFlow::checkLinesForTextOverflow()
11  0x114414085 WebCore::RenderBlockFlow::layoutLineBoxes(bool, WebCore::LayoutUnit&, WebCore::LayoutUnit&)
12  0x114ca0561 WebCore::RenderBlockFlow::layoutInlineChildren(bool, WebCore::LayoutUnit&, WebCore::LayoutUnit&)
13  0x114c9f394 WebCore::RenderBlockFlow::layoutBlock(bool, WebCore::LayoutUnit)
14  0x1143d3e6d WebCore::RenderBlock::layout()
15  0x114ca2bbb WebCore::RenderBlockFlow::layoutBlockChild(WebCore::RenderBox&, WebCore::RenderBlockFlow::MarginInfo&, WebCore::LayoutUnit&, WebCore::LayoutUnit&)

http://webkit-test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=svg%2Ftext%2Ftext-overflow-ellipsis-svgfont-kerning-ligatures.html
Comment 1 Alexey Proskuryakov 2014-02-10 10:28:55 PST 
It's unclear when this regressed, who can investigate?

Looking at recent changes, a rollout <http://trac.webkit.org/changeset/163655> seems like the only one that touched this code.
Comment 2 Alexey Proskuryakov 2014-02-10 14:47:26 PST 
The rollout is definitely the culprit, because the test was also asserting before those changes, and started to assert again once they got rolled out.

*** This bug has been marked as a duplicate of bug 119747 ***