Bug 85797 – REGRESSION (Safari 5.1.5 - ToT): Crash in RenderSVGRoot::computeReplacedLogicalWidth

• Component: SVG
• Status: RESOLVED FIXED

[Philip Rogers]

The following will cause a crash:

<figcaption style="width:1px;">
<svg style="width:intrinsic;"/>

In debug builds, the following assert is hit:
ASSERTION FAILED: isEmbeddedThroughFrameContainingSVGDocument()
../../third_party/WebKit/Source/WebCore/rendering/svg/RenderSVGRoot.cpp(177) : virtual WebCore::LayoutUnit WebCore::RenderSVGRoot::computeReplacedLogicalWidth(bool) const

Original bug: http://crbug.com/126416

[Alexey Proskuryakov]

Crashes ToT, but not Safari 5.1.5 for me. Release build stack trace:

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.WebCore             	0x000000010c31ee38 WebCore::RenderSVGRoot::computeReplacedLogicalWidth(bool) const + 344
1   com.apple.WebCore             	0x000000010cb53295 WebCore::RenderBox::computeLogicalWidthInRegion(WebCore::RenderRegion*, WebCore::FractionalLayoutUnit) + 485
2   com.apple.WebCore             	0x000000010c1b2c0a WebCore::RenderBox::computeLogicalWidth() + 26
3   com.apple.WebCore             	0x000000010c31eb09 WebCore::RenderSVGRoot::layout() + 169
4   com.apple.WebCore             	0x000000010cb4c461 WebCore::RenderBlock::layoutInlineChildren(bool, WebCore::FractionalLayoutUnit&, WebCore::FractionalLayoutUnit&) + 913
...

[Florin Malita]

The assert at the end of RenderSVGRoot::computeReplacedLogicalWidth() is wrong: we can also reach that point for inline SVGs when the width attribute doesn't establish the viewport (see SVGSVGElement::widthAttributeEstablishesViewport).

The release crash happens in

  return document()->frame()->ownerRenderer()->availableLogicalWidth()

because ownerRenderer() is NULL for the case of inline SVG.

This also seems to affect RenderSVGRoot::computeReplacedLogicalHeight().

I guess the question is what to do when

a) widthAttributeEstablishesViewport() == false
and
b) the SVG element is not embedded via object/iframe


Fall back to RenderReplace:::computeReplacedLogicalWidth?

[Florin Malita]

Created attachment 148647 [details]
Minimized crasher

[Florin Malita]

Created attachment 149049 [details]
Patch

[WebKit Review Bot]

Comment on attachment 149049 [details]
Patch

Clearing flags on attachment: 149049

Committed r121041: <http://trac.webkit.org/changeset/121041>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.