Positioned objects need to use the first region as the ICB and behave properly in variable width regions.
Created attachment 109387 [details] Patch
Comment on attachment 109387 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=109387&action=review > Source/WebCore/rendering/RenderBlock.h:266 > + LayoutUnit startOffsetForContent(LayoutUnit position) const { return style()->isLeftToRightDirection() ? logicalLeftOffsetForContent(position) :width() - logicalRightOffsetForContent(position); } There should be a space after the :.
Comment on attachment 109387 [details] Patch Attachment 109387 [details] did not pass chromium-ews (chromium-xvfb): Output: http://queues.webkit.org/results/9898574 New failing tests: fast/block/positioning/auto/vertical-lr/004.html fast/block/positioning/auto/vertical-rl/003.html fast/block/positioning/auto/vertical-rl/004.html fast/block/positioning/auto/vertical-lr/003.html
Fixed in r96452 (the width() in startOffsetForContent turned into a logicalWidth() to fix those failing layout tests).