Bug 257563 – REGRESSION(264722@main) ASSERTION FAILED: forward ? nativeIndex < nativeLength : nativeIndex <= nativeLength in WTF::textUTF16ContextAwareMoveInPrimaryContext

• Component: Text
• Status: RESOLVED FIXED

[Fujii Hironori]

WinCairo-64-bit-Debug-Tests is reporting some test failures due to an assertion failure.

264727@main first bad
264721@main last good

https://build.webkit.org/results/WinCairo-64-bit-Debug-Tests/264727@main%20(20362)/results.html

ASSERTION FAILED: forward ? nativeIndex < nativeLength : nativeIndex <= nativeLength
C:\BW\WinCairo-64-bit-Debug-Build\build\Source\WTF\wtf\text\icu\UTextProviderUTF16.cpp(72) : WTF::textUTF16ContextAwareMoveInPrimaryContext
1   00007FFC154B26FB WTFCrash
2   00007FFC154B7E3D WTFCrashWithInfo
3   00007FFC1563B54E WTF::textUTF16ContextAwareMoveInPrimaryContext
4   00007FFC1563B7C8 WTF::textUTF16ContextAwareSwitchToPrimaryContext
5   00007FFC1563B1B1 WTF::uTextUTF16ContextAwareAccess
6   00000000679177F6 utext_setNativeIndex_73
7   000000006787D32E icu_73::RuleBasedBreakIterator::preceding
8   00007FFBD7C27A6B WTF::TextBreakIteratorICU::preceding
9   00007FFBD7BE9AEE `WTF::TextBreakIterator::preceding'::`2'::<lambda_1>::operator()<WTF::TextBreakIteratorICU>
10  00007FFBD7C066B8 std::invoke<WTF::Visitor<`WTF::TextBreakIterator::preceding'::`2'::<lambda_1> >,WTF::TextBreakIteratorICU const &>
11  00007FFBD7BE9E88 std::_Variant_dispatcher<std::integer_sequence<unsigned __int64,1> >::_Dispatch2<std::optional<unsigned int>,WTF::Visitor<`WTF::TextBreakIterator::preceding'::`2'::<lambda_1> >,std::variant<WTF::TextBreakIteratorICU,WTF::NullTextBreakIterator> const &,0>
12  00007FFBD7BEB463 std::_Visit_strategy<1>::_Visit2<std::optional<unsigned int>,std::_Meta_list<std::integer_sequence<unsigned __int64,0>,std::integer_sequence<unsigned __int64,1>,std::integer_sequence<unsigned __int64,2> >,WTF::Visitor<`WTF::TextBreakIterator::preceding'::`2'::<lambda_1> >,std::variant<WTF::TextBreakIteratorICU,WTF::NullTextBreakIterator> const &>
13  00007FFBD7BEB8CF std::_Visit_impl<3,std::optional<unsigned int>,std::_Meta_list<std::integer_sequence<unsigned __int64,0>,std::integer_sequence<unsigned __int64,1>,std::integer_sequence<unsigned __int64,2> >,WTF::Visitor<`WTF::TextBreakIterator::preceding'::`2'::<lambda_1> >,std::variant<WTF::TextBreakIteratorICU,WTF::NullTextBreakIterator> const &>
14  00007FFBD7C21BE1 std::visit<WTF::Visitor<`WTF::TextBreakIterator::preceding'::`2'::<lambda_1> >,std::variant<WTF::TextBreakIteratorICU,WTF::NullTextBreakIterator> const &,void>
15  00007FFBD7C17103 WTF::switchOn<std::variant<WTF::TextBreakIteratorICU,WTF::NullTextBreakIterator> const &,`WTF::TextBreakIterator::preceding'::`2'::<lambda_1> >
16  00007FFBD7C27A08 WTF::TextBreakIterator::preceding
17  00007FFBD7C27942 WTF::CachedTextBreakIterator::preceding
18  00007FFBD823D737 WebCore::RenderText::previousOffset
19  00007FFBD825FDE9 WebCore::containsOffset
20  00007FFBD823D472 WebCore::RenderText::containsCaretOffset
21  00007FFBD6C56466 WebCore::Position::isCandidate
22  00007FFBD6E719E6 WebCore::VisiblePosition::canonicalPosition
23  00007FFBD6E6FCA4 WebCore::VisiblePosition::VisiblePosition
24  00007FFBD6E77DEC WebCore::VisibleSelection::setBaseAndExtentToDeepEquivalents
25  00007FFBD6E778E9 WebCore::VisibleSelection::validate
26  00007FFBD6E758A3 WebCore::VisibleSelection::VisibleSelection
27  00007FFBD6DA9F08 WebCore::FrameSelection::moveTo
28  00007FFBD78563A6 WebCore::DOMSelection::setBaseAndExtent
29  00007FFBD45F1E0B `WebCore::jsDOMSelectionPrototypeFunction_setBaseAndExtentBody'::`62'::<lambda_3>::operator()
30  00007FFBD4628DB6 WebCore::toJS<WebCore::IDLUndefined,`WebCore::jsDOMSelectionPrototypeFunction_setBaseAndExtentBody'::`62'::<lambda_3> >
31  00007FFBD45F1BD5 WebCore::jsDOMSelectionPrototypeFunction_setBaseAndExtentBody

264722@main (bug#257469) seems like a culprit.

[Fujii Hironori]

Created attachment 466553 [details]
test case

WinCairo Debug MiniBrowser can reproduce the crash by loading this test case.
Variables in the assertion were
forward = 1
nativeIndex = 1
nativeLength = 1

[Fujii Hironori]

UText access callback has to return false if the requested index is out of bounds.
https://unicode-org.github.io/icu-docs/apidoc/dev/icu4c/utext_8h.html#a829af7190e7cee22c647af949ebb4730

[Fujii Hironori]

Pull request: https://github.com/WebKit/WebKit/pull/14578

[Radar WebKit Bug Importer]

<rdar://problem/110122162>

[EWS]

Committed 264804@main (d59f20a7765a): <https://commits.webkit.org/264804@main>

Reviewed commits have been landed. Closing PR #14578 and removing active labels.