Follow-up for bug 944909. STR: Open https://bugzilla.mozilla.org/attachment.cgi?id=8340654 (testcase from bug 944909) AR: "###!!! ASSERTION: Bogus width: 'ComputedWidth() >= 0', file c:/builds/moz 2_slave/m-cen-w32-d-000000000000000000/build/layout/generic/nsHTMLReflowState.cp p, line 2122" Nightly 2014-01-09-mozilla-central-debug, Win 7 x64

This can be triggered with just a tall <video> element, by itself. Reduced testcase attached, which triggers the following debugging output when loaded: { ###!!! ASSERTION: Bogus width: 'ComputedWidth() >= 0', file /mozilla-central/layout/generic/nsHTMLReflowState.cpp, line 2122 ###!!! ASSERTION: width less than zero: 'aContainingBlockWidth >= 0', file /mozilla-central/layout/base/nsLayoutUtils.cpp, line 3281 ###!!! ASSERTION: width less than zero: 'aContainingBlockWidth >= 0', file /mozilla-central/layout/base/nsLayoutUtils.cpp, line 3281 ###!!! ASSERTION: width less than zero: 'aContainingBlockWidth >= 0', file /mozilla-central/layout/base/nsLayoutUtils.cpp, line 3281 ###!!! ASSERTION: width less than zero: 'aContainingBlockWidth >= 0', file /mozilla-central/layout/base/nsLayoutUtils.cpp, line 3281 ###!!! ASSERTION: bad width: 'metrics.Width() >= 0', file /mozilla-central/layout/generic/nsLineLayout.cpp, line 914 nsLineLayout: HTMLVideo(video)(0)@0x7fa980a1af58 metrics=0,1073741824! ###!!! ASSERTION: illegal width for combined area: 'aOverflowAreas.Overflow(otype).width >= 0', file /mozilla-central/layout/generic/nsLineBox.cpp, line 521 nsBlockReflowContext: Block(body)(1)@0x7fa980a1ac80 metrics=55740,1073741824! WARNING: Overflowed nscoord_MAX in conversion to nscoord height: file ../../../dist/include/nsRect.h, line 95 WARNING: Overflowed nscoord_MAX in conversion to nscoord height: file ../../../dist/include/nsRect.h, line 95 WARNING: Overflowed nscoord_MAX in conversion to nscoord height: file ../../../dist/include/nsRect.h, line 95 WARNING: Overflowed nscoord_MAX in conversion to nscoord height: file ../../../dist/include/nsRect.h, line 95 }