Bug 149459 – ASSERTION FAILED: computeMainAxisExtentForChild(child, MainOrPreferredSize, mainSize) in WebCore::RenderFlexibleBox::adjustChildSizeForMinAndMax

• Status: RESOLVED
• Resolution: FIXED
• Component: Layout and Rendering

[Renata Hodovan]

Created attachment 261742 [details]
Test

Load this with debug WebKit:

<style>
* {
    flex-direction: column-reverse;
    display: inline-flex;
    height: 0%;
}
</style>
<table>
    <caption>
        <h2></h2>
    </caption>
</table>


Backtrace:

ASSERTION FAILED: computeMainAxisExtentForChild(child, MainOrPreferredSize, mainSize)
../../Source/WebCore/rendering/RenderFlexibleBox.cpp(879) : WebCore::LayoutUnit WebCore::RenderFlexibleBox::adjustChildSizeForMinAndMax(WebCore::RenderBox&, WebCore::LayoutUnit)

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fff8effd700 (LWP 14045)]
0x00007fffec64eab6 in WTFCrash () at ../../Source/WTF/wtf/Assertions.cpp:321
321	    *(int *)(uintptr_t)0xbbadbeef = 0;
(gdb) bt
#0  0x00007fffec64eab6 in WTFCrash () at ../../Source/WTF/wtf/Assertions.cpp:321
#1  0x00007ffff3380357 in WebCore::RenderFlexibleBox::adjustChildSizeForMinAndMax (this=0x7fffd5ba6258, child=..., childSize=...) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:879
#2  0x00007ffff3380882 in WebCore::RenderFlexibleBox::computeNextFlexLine (this=0x7fffd5ba6258, orderedChildren=..., preferredMainAxisExtent=..., totalFlexGrow=@0x7fffffffafd0: 0, totalWeightedFlexShrink=@0x7fffffffafd8: 0, minMaxAppliedMainAxisExtent=..., hasInfiniteLineLength=@0x7fffffffaf7f: true) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:922
#3  0x00007ffff337f297 in WebCore::RenderFlexibleBox::layoutFlexItems (this=0x7fffd5ba6258, relayoutChildren=false, lineContexts=...) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:695
#4  0x00007ffff337d367 in WebCore::RenderFlexibleBox::layoutBlock (this=0x7fffd5ba6258, relayoutChildren=false) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:272
#5  0x00007ffff32b5922 in WebCore::RenderBlock::layout (this=0x7fffd5ba6258) at ../../Source/WebCore/rendering/RenderBlock.cpp:926
#6  0x00007ffff327d31f in WebCore::RenderElement::layoutIfNeeded (this=0x7fffd5ba6258) at ../../Source/WebCore/rendering/RenderElement.h:135
#7  0x00007ffff3305a2a in WebCore::RenderBlockFlow::layoutLineBoxes (this=0x7fffd5ba6320, relayoutChildren=true, repaintLogicalTop=..., repaintLogicalBottom=...) at ../../Source/WebCore/rendering/RenderBlockLineLayout.cpp:1642
#8  0x00007ffff32e2ebd in WebCore::RenderBlockFlow::layoutInlineChildren (this=0x7fffd5ba6320, relayoutChildren=true, repaintLogicalTop=..., repaintLogicalBottom=...) at ../../Source/WebCore/rendering/RenderBlockFlow.cpp:651
#9  0x00007ffff32e2203 in WebCore::RenderBlockFlow::layoutBlock (this=0x7fffd5ba6320, relayoutChildren=true, pageLogicalHeight=...) at ../../Source/WebCore/rendering/RenderBlockFlow.cpp:483
#10 0x00007ffff348bb42 in WebCore::RenderTableCell::layout (this=0x7fffd5ba6320) at ../../Source/WebCore/rendering/RenderTableCell.cpp:266
#11 0x00007ffff3494424 in WebCore::RenderTableRow::layout (this=0x7fffd5b95720) at ../../Source/WebCore/rendering/RenderTableRow.cpp:177
#12 0x00007ffff327d31f in WebCore::RenderElement::layoutIfNeeded (this=0x7fffd5b95720) at ../../Source/WebCore/rendering/RenderElement.h:135
#13 0x00007ffff3496a2f in WebCore::RenderTableSection::layout (this=0x7fffd5aea818) at ../../Source/WebCore/rendering/RenderTableSection.cpp:409
#14 0x00007ffff327d31f in WebCore::RenderElement::layoutIfNeeded (this=0x7fffd5aea818) at ../../Source/WebCore/rendering/RenderElement.h:135
#15 0x00007ffff347eab0 in WebCore::RenderTable::layout (this=0x7fffd5ad0000) at ../../Source/WebCore/rendering/RenderTable.cpp:466
#16 0x00007ffff327d31f in WebCore::RenderElement::layoutIfNeeded (this=0x7fffd5ad0000) at ../../Source/WebCore/rendering/RenderElement.h:135
#17 0x00007ffff337df7f in WebCore::RenderFlexibleBox::computeMainAxisExtentForChild (this=0x7fffd5ba6190, child=..., sizeType=WebCore::MinSize, size=...) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:457
#18 0x00007ffff338013e in WebCore::RenderFlexibleBox::adjustChildSizeForMinAndMax (this=0x7fffd5ba6190, child=..., childSize=...) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:872
#19 0x00007ffff3380882 in WebCore::RenderFlexibleBox::computeNextFlexLine (this=0x7fffd5ba6190, orderedChildren=..., preferredMainAxisExtent=..., totalFlexGrow=@0x7fffffffbdf0: 0, totalWeightedFlexShrink=@0x7fffffffbdf8: 0, minMaxAppliedMainAxisExtent=..., hasInfiniteLineLength=@0x7fffffffbd9f: false) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:922
#20 0x00007ffff337f297 in WebCore::RenderFlexibleBox::layoutFlexItems (this=0x7fffd5ba6190, relayoutChildren=true, lineContexts=...) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:695
#21 0x00007ffff337d367 in WebCore::RenderFlexibleBox::layoutBlock (this=0x7fffd5ba6190, relayoutChildren=true) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:272
#22 0x00007ffff32b5922 in WebCore::RenderBlock::layout (this=0x7fffd5ba6190) at ../../Source/WebCore/rendering/RenderBlock.cpp:926
#23 0x00007ffff327d31f in WebCore::RenderElement::layoutIfNeeded (this=0x7fffd5ba6190) at ../../Source/WebCore/rendering/RenderElement.h:135
#24 0x00007ffff337df7f in WebCore::RenderFlexibleBox::computeMainAxisExtentForChild (this=0x7fffd5be3c80, child=..., sizeType=WebCore::MinSize, size=...) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:457
#25 0x00007ffff338013e in WebCore::RenderFlexibleBox::adjustChildSizeForMinAndMax (this=0x7fffd5be3c80, child=..., childSize=...) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:872
#26 0x00007ffff3380882 in WebCore::RenderFlexibleBox::computeNextFlexLine (this=0x7fffd5be3c80, orderedChildren=..., preferredMainAxisExtent=..., totalFlexGrow=@0x7fffffffc3b0: 0, totalWeightedFlexShrink=@0x7fffffffc3b8: 0, minMaxAppliedMainAxisExtent=..., hasInfiniteLineLength=@0x7fffffffc35f: false) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:922
#27 0x00007ffff337f297 in WebCore::RenderFlexibleBox::layoutFlexItems (this=0x7fffd5be3c80, relayoutChildren=true, lineContexts=...) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:695
#28 0x00007ffff337d367 in WebCore::RenderFlexibleBox::layoutBlock (this=0x7fffd5be3c80, relayoutChildren=true) at ../../Source/WebCore/rendering/RenderFlexibleBox.cpp:272
#29 0x00007ffff32b5922 in WebCore::RenderBlock::layout (this=0x7fffd5be3c80) at ../../Source/WebCore/rendering/RenderBlock.cpp:926
#30 0x00007ffff32e3284 in WebCore::RenderBlockFlow::layoutBlockChild (this=0x7fffd5ae8228, child=..., marginInfo=..., previousFloatLogicalBottom=..., maxFloatLogicalBottom=...) at ../../Source/WebCore/rendering/RenderBlockFlow.cpp:709
#31 0x00007ffff32e2dc3 in WebCore::RenderBlockFlow::layoutBlockChildren (this=0x7fffd5ae8228, relayoutChildren=true, maxFloatLogicalBottom=...) at ../../Source/WebCore/rendering/RenderBlockFlow.cpp:632
#32 0x00007ffff32e2227 in WebCore::RenderBlockFlow::layoutBlock (this=0x7fffd5ae8228, relayoutChildren=true, pageLogicalHeight=...) at ../../Source/WebCore/rendering/RenderBlockFlow.cpp:485
#33 0x00007ffff32b5922 in WebCore::RenderBlock::layout (this=0x7fffd5ae8228) at ../../Source/WebCore/rendering/RenderBlock.cpp:926
#34 0x00007ffff34cbc39 in WebCore::RenderView::layoutContent (this=0x7fffd5ae8228, state=...) at ../../Source/WebCore/rendering/RenderView.cpp:253
#35 0x00007ffff34cc32c in WebCore::RenderView::layout (this=0x7fffd5ae8228) at ../../Source/WebCore/rendering/RenderView.cpp:378
#36 0x00007ffff2fe43bd in WebCore::FrameView::layout (this=0x7fffd5811000, allowSubtree=true) at ../../Source/WebCore/page/FrameView.cpp:1409
#37 0x00007ffff29175c6 in WebCore::Document::implicitClose (this=0x7fffd5803000) at ../../Source/WebCore/dom/Document.cpp:2699
#38 0x00007ffff2e79385 in WebCore::FrameLoader::checkCallImplicitClose (this=0x7fffd5aef098) at ../../Source/WebCore/loader/FrameLoader.cpp:891
#39 0x00007ffff2e790bc in WebCore::FrameLoader::checkCompleted (this=0x7fffd5aef098) at ../../Source/WebCore/loader/FrameLoader.cpp:837
#40 0x00007ffff2e78e2c in WebCore::FrameLoader::finishedParsing (this=0x7fffd5aef098) at ../../Source/WebCore/loader/FrameLoader.cpp:758
#41 0x00007ffff29215fa in WebCore::Document::finishedParsing (this=0x7fffd5803000) at ../../Source/WebCore/dom/Document.cpp:4898
#42 0x00007ffff2cccb33 in WebCore::HTMLConstructionSite::finishedParsing (this=0x7fffd5af7920) at ../../Source/WebCore/html/parser/HTMLConstructionSite.cpp:404
#43 0x00007ffff2d0c38a in WebCore::HTMLTreeBuilder::finished (this=0x7fffd5af7900) at ../../Source/WebCore/html/parser/HTMLTreeBuilder.cpp:2937
#44 0x00007ffff2cd5c90 in WebCore::HTMLDocumentParser::end (this=0x7fffd58165c0) at ../../Source/WebCore/html/parser/HTMLDocumentParser.cpp:402
#45 0x00007ffff2cd5d5e in WebCore::HTMLDocumentParser::attemptToRunDeferredScriptsAndEnd (this=0x7fffd58165c0) at ../../Source/WebCore/html/parser/HTMLDocumentParser.cpp:411
#46 0x00007ffff2cd497b in WebCore::HTMLDocumentParser::prepareToStopParsing (this=0x7fffd58165c0) at ../../Source/WebCore/html/parser/HTMLDocumentParser.cpp:132
#47 0x00007ffff2cd5d95 in WebCore::HTMLDocumentParser::attemptToEnd (this=0x7fffd58165c0) at ../../Source/WebCore/html/parser/HTMLDocumentParser.cpp:423
#48 0x00007ffff2cd5e43 in WebCore::HTMLDocumentParser::finish (this=0x7fffd58165c0) at ../../Source/WebCore/html/parser/HTMLDocumentParser.cpp:451
#49 0x00007ffff2e68c78 in WebCore::DocumentWriter::end (this=0x7fffd58360a0) at ../../Source/WebCore/loader/DocumentWriter.cpp:247
#50 0x00007ffff2e5264a in WebCore::DocumentLoader::finishedLoading (this=0x7fffd5836000, finishTime=0) at ../../Source/WebCore/loader/DocumentLoader.cpp:430
#51 0x00007ffff2e523a8 in WebCore::DocumentLoader::notifyFinished (this=0x7fffd5836000, resource=0x7fffd580f9c0) at ../../Source/WebCore/loader/DocumentLoader.cpp:377
#52 0x00007ffff2f10f7d in WebCore::CachedResource::checkNotify (this=0x7fffd580f9c0) at ../../Source/WebCore/loader/cache/CachedResource.cpp:297
#53 0x00007ffff2f1108c in WebCore::CachedResource::finishLoading (this=0x7fffd580f9c0) at ../../Source/WebCore/loader/cache/CachedResource.cpp:313
#54 0x00007ffff2f0d28a in WebCore::CachedRawResource::finishLoading (this=0x7fffd580f9c0, data=0x7fffd5bfde80) at ../../Source/WebCore/loader/cache/CachedRawResource.cpp:103
#55 0x00007ffff2ebd812 in WebCore::SubresourceLoader::didFinishLoading (this=0x7fffd5836c00, finishTime=0) at ../../Source/WebCore/loader/SubresourceLoader.cpp:372
#56 0x00007ffff2eb828b in WebCore::ResourceLoader::didFinishLoading (this=0x7fffd5836c00, finishTime=0) at ../../Source/WebCore/loader/ResourceLoader.cpp:631
#57 0x00007ffff38e70f6 in WebCore::readCallback (asyncResult=0x8dd9b0, data=0x7fffd5bb7300) at ../../Source/WebCore/platform/network/soup/ResourceHandleSoup.cpp:1340
#58 0x00007fffe945796a in async_ready_callback_wrapper (source_object=0xa35db0, res=0x8dd9b0, user_data=0x7fffd5bb7300) at ginputstream.c:529
#59 0x00007fffe947d453 in g_task_return_now (task=0x8dd9b0) at gtask.c:1088
#60 0x00007fffe947d489 in complete_in_idle_cb (task=0x8dd9b0) at gtask.c:1102
#61 0x00007fffe8eb7a9d in g_main_dispatch (context=0x492400) at gmain.c:3122
#62 g_main_context_dispatch (context=context@entry=0x492400) at gmain.c:3737
#63 0x00007fffe8eb7e70 in g_main_context_iterate (context=0x492400, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3808
#64 0x00007fffe8eb8192 in g_main_loop_run (loop=0x5fff50) at gmain.c:4002
#65 0x00007ffff406313f in WTF::RunLoop::run () at ../../Source/WTF/wtf/glib/RunLoopGLib.cpp:67
#66 0x00007ffff2300a23 in WebKit::ChildProcessMain<WebKit::WebProcess, WebKit::WebProcessMain> (argc=2, argv=0x7fffffffd5b8) at ../../Source/WebKit2/Shared/unix/ChildProcessMain.h:61
#67 0x00007ffff2300880 in WebKit::WebProcessMainUnix (argc=2, argv=0x7fffffffd5b8) at ../../Source/WebKit2/WebProcess/gtk/WebProcessMainGtk.cpp:77
#68 0x00000000004008da in main (argc=2, argv=0x7fffffffd5b8) at ../../Source/WebKit2/WebProcess/EntryPoint/unix/WebProcessMain.cpp:44

[Sergio Villar Senin]

Created attachment 262980 [details]
Patch

[Darin Adler]

Comment on attachment 262980 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=262980&action=review

> Source/WebCore/rendering/RenderFlexibleBox.cpp:872
> +        LayoutUnit contentSize = computeMainAxisExtentForChild(child, MinSize, Length(MinContent)).value();

What guarantees Optional<LayoutSize> is never null?

> Source/WebCore/rendering/RenderFlexibleBox.cpp:878
> +            LayoutUnit resolvedMainSize = computeMainAxisExtentForChild(child, MainOrPreferredSize, mainSize).value();

Ditto.

[Darin Adler]

Comment on attachment 262980 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=262980&action=review

>> Source/WebCore/rendering/RenderFlexibleBox.cpp:872
>> +        LayoutUnit contentSize = computeMainAxisExtentForChild(child, MinSize, Length(MinContent)).value();
> 
> What guarantees Optional<LayoutSize> is never null?

I guess the old code was asserting it, and the new code does too, just in a different way.

[Sergio Villar Senin]

(In reply to comment #3)
> Comment on attachment 262980 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=262980&action=review
> 
> >> Source/WebCore/rendering/RenderFlexibleBox.cpp:872
> >> +        LayoutUnit contentSize = computeMainAxisExtentForChild(child, MinSize, Length(MinContent)).value();
> > 
> > What guarantees Optional<LayoutSize> is never null?
> 
> I guess the old code was asserting it, and the new code does too, just in a
> different way.

Correct.

[Sergio Villar Senin]

Committed r191336: <http://trac.webkit.org/changeset/191336>

[zalan]

(In reply to Sergio Villar Senin from comment #4)
> (In reply to comment #3)
> > Comment on attachment 262980 [details]
> > Patch
> > 
> > View in context:
> > https://bugs.webkit.org/attachment.cgi?id=262980&action=review
> > 
> > >> Source/WebCore/rendering/RenderFlexibleBox.cpp:872
> > >> +        LayoutUnit contentSize = computeMainAxisExtentForChild(child, MinSize, Length(MinContent)).value();
> > > 
> > > What guarantees Optional<LayoutSize> is never null?
> > 
> > I guess the old code was asserting it, and the new code does too, just in a
> > different way.
> 
> Correct.
I don't see how this was correct in the original commit. It does not seem to be guaranteed that computeMainAxisExtentForChild() always returns with a valid value (see webkit.org/b/189232)