Created attachment 196404 [details] Reduction .
layer at (0,0) size 800x120 RenderBlock {HTML} at (0,0) size 800x120 RenderBody {BODY} at (8,16) size 784x96 RenderBlock {DIV} at (0,36) size 784x60 [bgcolor=#008000] RenderBlock (anonymous) at (0,0) size 784x30 RenderInline {DIV} at (0,0) size 0x30 RenderBlock (anonymous) at (0,30) size 784x0 RenderBlock {DIV} at (0,0) size 784x0 RenderBlock (anonymous) at (0,30) size 784x30 RenderInline {DIV} at (0,0) size 0x30 I think the problem is that the first anonymous block above has an empty inline element (which gets a linebox). This causes the subsequent anonymous block sibling to shift down.
Created attachment 196500 [details] Patch
Created attachment 196871 [details] Patch
Comment on attachment 196871 [details] Patch r=me
Comment on attachment 196871 [details] Patch Clearing flags on attachment: 196871 Committed r148121: <http://trac.webkit.org/changeset/148121>
All reviewed patches have been landed. Closing bug.