If you make the viewport very small on the above test and scroll up and down the borders on the first table aren't painted properly. RenderTableSection::paintObject() needs to call paintCollapsedBorders() an extra row up beyond the one that's dirty in order to render the borders correctly I think.
Created attachment 203575 [details] Patch
Created attachment 203576 [details] Patch
Created attachment 203578 [details] Patch
Comment on attachment 203578 [details] Patch Attachment 203578 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.appspot.com/results/758287 New failing tests: fast/repaint/table-cell-collapsed-border-scroll.html
Created attachment 203582 [details] Archive of layout-test-results from webkit-ews-14 for mac-mountainlion-wk2 The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews. Bot: webkit-ews-14 Port: mac-mountainlion-wk2 Platform: Mac OS X 10.8.3
Comment on attachment 203578 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=203578&action=review r=me > Source/WebCore/ChangeLog:10 > + WHen painting collapsed borders we need to paint the borders of the row above Little typo. "WHen" should be "When"
Committed r151444: <http://trac.webkit.org/changeset/151444>