Bug 286664 – REGRESSION(241230@main): [cairo] convertImagePixels copies wrongly if source.format.alphaFormat == destination.format.alphaFormat && source.format.pixelFormat == destination.format.pixelFormat

• Component: New Bugs
• Status: RESOLVED FIXED

[Fujii Hironori]

While creating an API test of `convertImagePixels`, I found out a bug in `convertImagePixels`.

https://github.com/WebKit/WebKit/blob/53ee544dee9b8fc6610d0ce70f23c673804bbd03/Source/WebCore/platform/graphics/PixelBufferConversion.cpp#L318-L321

>    if (source.format.alphaFormat == destination.format.alphaFormat && source.format.pixelFormat == destination.format.pixelFormat) {
>        memcpySpan(destination.rows, source.rows.first(source.bytesPerRow * destinationSize.height()));
>        return;
>    }

This code doesn't take destinationSize into account.
Also, if source.bytesPerRow != destination.bytesPerRow, this code doesn't work.

This code was added by 241230@main.

[Fujii Hironori]

I'm observing an assertion failure in the fast code path for my new API test.

ASSERTION FAILED: destination.size() >= source.size()
C:\webkit\wb\WebKitBuild\Debug\WTF\Headers\wtf/StdLibExtras.h(1036) : void WTF::memcpySpan(std::span<T, TExtent>, std::span<U, UExtent>) [T = unsigned char, TExtent = 18446744073709551615ULL, U = const unsigned char, UExtent = 18446744073709551615ULL]
1   00007FFAE51F3FE1 WTF::memcpySpan<unsigned char,18446744073709551615,const unsigned char,18446744073709551615>
2   00007FFAE97F6D4C WebCore::convertImagePixels
3   00007FF67D0A2A47 TestWebKitAPI::PixelBufferConversionTests_convertImagePixels2_Test::TestBody::<lambda_0>::operator()
4   00007FF67D0A25F7 TestWebKitAPI::PixelBufferConversionTests_convertImagePixels2_Test::TestBody
5   00007FF67D193FE0 testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test,void>
6   00007FF67D16C86A testing::internal::HandleExceptionsInMethodIfSupported<testing::Test,void>
7   00007FF67D154A63 testing::Test::Run
8   00007FF67D1552A6 testing::TestInfo::Run
9   00007FF67D155942 testing::TestSuite::Run
10  00007FF67D15F644 testing::internal::UnitTestImpl::RunAllTests
11  00007FF67D1950F0 testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl,bool>
12  00007FF67D16E4AA testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl,bool>
13  00007FF67D15F20E testing::UnitTest::Run
14  00007FF67CF76821 RUN_ALL_TESTS
15  00007FF67CF76702 TestWebKitAPI::TestsController::run
16  00007FF67D12515D main
17  00007FF67D196F00 __scrt_common_main_seh
18  00007FFBFC96259D BaseThreadInitThunk
19  00007FFBFCF4AF38 RtlUserThreadStart

[Fujii Hironori]

Pull request: https://github.com/WebKit/WebKit/pull/39673

[EWS]

Committed 289520@main (1de35d8ca5de): <https://commits.webkit.org/289520@main>

Reviewed commits have been landed. Closing PR #39673 and removing active labels.

[Radar WebKit Bug Importer]

<rdar://problem/143841035>