<rdar://problem/16745606>
Created attachment 231893 [details] Test reduction
With render layer on (2x display) 1. container positioned at (10, 10) 2. child box with (non-compositing transform) negative top/left: (-0.25, -0.25) -> painting coordinates (-0.25, -0.25 round-> -0.5, -0.5) -> in absolute coordinates -> (9.5, 9.5) without render layer 1. container positioned at (10, 10) 2. child box with negative top/left: (-0.25, -0.25) -> painting coordinates ((-0.25, -0.25) -> (10 - 0.25, 10 - 0.25) -> (9.75, 9.75) round-> (10, 10). final painting coords (10, 10) This happens only on halfway values as the rounding direction is different for negative and positive values. (always away from zero). -non halfway values container at (10, 10) child (RenderLayer on): (-0.1, -0.1) round-> (-0, -0) -> in absolute coords (10, 10) child (RenderLayer off): (-0.1, -0.1) -> (10 - 0.1, 10 - 0.1) -> (9.9, 9.9) round-> (10, 10) child (RenderLayer on): (-0.3, -0.3) round-> (-0.5, -0.5) -> in absolute coords (9.5, 9.5) child (RenderLayer off): (-0.3, -0.3) -> (10 - 0.3, 10 - 0.3) -> (9.7, 9.7) round-> (9.5, 9.5)
*** Bug 133241 has been marked as a duplicate of this bug. ***
Created attachment 232002 [details] Patch
Attachment 232002 [details] did not pass style-queue: ERROR: Source/WebCore/platform/LayoutUnit.h:940: More than one command on the same line [whitespace/newline] [4] Total errors found: 1 in 6 files If any of these errors are false positives, please file a bug against check-webkit-style.
Comment on attachment 232002 [details] Patch Clearing flags on attachment: 232002 Committed r169309: <http://trac.webkit.org/changeset/169309>
All reviewed patches have been landed. Closing bug.