Using the new full page zoom feature in Webkit r31201, zooming twice on the page http://mooseyard.com/Jens/ (command-+ command-+) shows tearing artefacts between repeating background images, manifested as black lines. See the screenshot for details.
Note that this happens only at some zoom levels, notably zoomed in twice and five times. Zooming out also results in artefacts.
Created attachment 19947 [details]
Screenshot of the site showing tearing artefacts
*** Bug 18003 has been marked as a duplicate of this bug. ***
*** Bug 17999 has been marked as a duplicate of this bug. ***
This bug appears to be Leopard-only, and it's an issue with
The old Tiger code path (although slower) seems to be correct.
I can actually work around this, but it would mean taking the slow code path (and I think it would hurt performance way too much for zoomed pages to do this).
Created attachment 20018 [details]
This is a workaround patch. Just recording it.
Created attachment 25047 [details]
Comment on attachment 25047 [details]
Do you also want to check PLATFORM(MAC) anywhere? I see the existing #ifndef BUILDING_ON_TIGER does not do so, but maybe it should?
Fixed in r38309.
Good question about PLATFORM(MAC). It depends on what version of CG ends up
shipping with the next version of Safari on Windows whether or not the
workaround will be needed for Windows.