Bug 63400 – svg/text/svg-zoom-large-value.xhtml ASSERTs on Chromium Linux Debug

• Component: New Bugs
• Status: RESOLVED FIXED

[WebKit Review Bot]

svg/text/svg-zoom-large-value.xhtml ASSERTs on Chromium Linux Debug
Requested by abarth on #webkit.

[Adam Barth]

Landed suppression in http://trac.webkit.org/changeset/89768

[Adam Barth]

webkit/support/webkit_support.cc:73: Failure
Failed
[20993:20993:5935657696522:FATAL:Sk64.h(46)] third_party/skia/include/core/Sk64.h:46: failed assertion "this->is32()"

Backtrace:
	base::debug::StackTrace::StackTrace() [0x972e0e]
	logging::LogMessage::~LogMessage() [0x91695e]
	SkDebugf_FileLine() [0x9fa1df]
	Sk64::get32() [0x995367]
	SkMulDiv() [0x9af0fb]
	SkScalerContext_FreeType::generateFontMetrics() [0x9f8af3]
	SkScalerContext::getFontMetrics() [0x9dae4d]
	SkGlyphCache::SkGlyphCache() [0x9ac177]
	SkGlyphCache::VisitCache() [0x9ad2ce]
	FontMetricsDescProc() [0x9b9e41]
	SkPaint::descriptorProc() [0x9baf14]
	SkPaint::getFontMetrics() [0x9b9f4f]
	WebCore::SimpleFontData::platformInit() [0xeb383d]
	WebCore::SimpleFontData::SimpleFontData() [0xe8886e]
	WebCore::FontCache::getCachedFontData() [0xe50ca0]
	WebCore::FontCache::getCachedFontData() [0xe50b17]
	WebCore::FontCache::getFontData() [0xe516e3]
	WebCore::FontFallbackList::fontDataAt() [0xe5d52d]
	WebCore::FontFallbackList::primaryFontData() [0x4d6d5a]
	WebCore::FontFallbackList::primarySimpleFontData() [0x4d6d05]
	WebCore::Font::primaryFont() [0x4d6e25]
	WebCore::WidthIterator::advance() [0xe8b76c]
	WebCore::Font::floatWidthForSimpleText() [0xe5ff12]
	WebCore::Font::width() [0xe4f13b]
	WebCore::SVGTextMetrics::SVGTextMetrics() [0x176488b]
	WebCore::SVGTextMetrics::measureCharacterRange() [0x1764cc7]
	WebCore::SVGTextLayoutAttributesBuilder::propagateLayoutAttributes() [0x175d89e]
	WebCore::SVGTextLayoutAttributesBuilder::buildLayoutAttributesForTextSubtree() [0x175d092]
	WebCore::RenderSVGText::layout() [0x1740f75]
	WebCore::SVGRenderSupport::layoutChildren() [0x1747f97]
	WebCore::RenderSVGRoot::layout() [0x184b377]
	WebCore::RenderObject::layoutIfNeeded() [0x15f74c1]
	WebCore::RenderBlock::layoutInlineChildren() [0x1616fd8]
	WebCore::RenderBlock::layoutBlock() [0x15de51c]
	WebCore::RenderBlock::layout() [0x15dde54]
	WebCore::RenderBlock::layoutBlockChild() [0x15e18da]
	WebCore::RenderBlock::layoutBlockChildren() [0x15e14f6]
	WebCore::RenderBlock::layoutBlock() [0x15de53a]
	WebCore::RenderBlock::layout() [0x15dde54]
	WebCore::RenderBlock::layoutBlockChild() [0x15e18da]
	WebCore::RenderBlock::layoutBlockChildren() [0x15e14f6]
	WebCore::RenderBlock::layoutBlock() [0x15de53a]
	WebCore::RenderBlock::layout() [0x15dde54]
	WebCore::RenderView::layout() [0x16f1e17]
	WebCore::FrameView::layout() [0x137aff5]
	WebCore::Document::implicitClose() [0x10e7ed5]
	WebCore::FrameLoader::checkCallImplicitClose() [0x12d20e7]
	WebCore::FrameLoader::checkCompleted() [0x12d1eba]
	WebCore::FrameLoader::finishedParsing() [0x12d1c13]
	WebCore::Document::finishedParsing() [0x10f0390]
	WebCore::XMLDocumentParser::end() [0x119a494]
	WebCore::XMLDocumentParser::finish() [0x119a4ce]
	WebCore::DocumentWriter::endIfNotLoadingMainResource() [0x12ccc78]
	WebCore::DocumentWriter::end() [0x12ccb9b]
	WebCore::DocumentLoader::finishedLoading() [0x12be015]
	WebCore::FrameLoader::finishedLoading() [0x12d8af5]
	WebCore::MainResourceLoader::didFinishLoading() [0x12ec5b6]
	WebCore::ResourceLoader::didFinishLoading() [0x12fda9b]
	WebCore::ResourceHandleInternal::didFinishLoading() [0x19a70e6]
	webkit_glue::WebURLLoaderImpl::Context::OnCompletedRequest() [0x18c8dc1]
	(anonymous namespace)::RequestProxy::NotifyCompletedRequest() [0x198cf25]
	DispatchToMethod<>() [0x1992753]

[Abhishek Arya]

James, I added this test in http://trac.webkit.org/changeset/89705. this looks like Skia is unable to handle clamped 1000000.0f font size. Should we have a lower limit ? Mind taking a look at the test.

float CSSStyleSelector::getComputedSizeFromSpecifiedSize(Document* document, float zoomFactor, bool isAbsoluteSize, float specifiedSize, ESmartMinimumForFontSize useSmartMinimumForFontSize)

    // Also clamp to a reasonable maximum to prevent insane font sizes from causing crashes on various
    // platforms (I'm looking at you, Windows.)
    return min(1000000.0f, zoomedSize);

[Abhishek Arya]

James, lowering down the font clamp to 10000.0f fixes the crash. I think in Skia, we should support font sizes larger than that. This is not a security bug and we don't crash in release, so we might have a fallback mechanism in skia.

[Mike Reed]

I will fix skia to not assert/crash on arbitrarily large sizes (including sizes after they are concatenated with the device matrix).

[Abhishek Arya]

(In reply to comment #5)
> I will fix skia to not assert/crash on arbitrarily large sizes (including sizes after they are concatenated with the device matrix).

Perfect, thanks a lot Mike. 

I don't think you will need clamping functions here, but if you need some, we have clampTo* function in MathExtras.h

[Stephen Chenney]

This has been fixed! Yippee. Removing from expectations.

[Stephen Chenney]

Committed r113857: <http://trac.webkit.org/changeset/113857>