NEW 159794
Non-integer top / left on parent causes child with transform to be positioned incorrectly 
https://bugs.webkit.org/show_bug.cgi?id=159794
Summary Non-integer top / left on parent causes child with transform to be positioned...
Russell Bicknell
Reported 2016-07-14 16:34:59 PDT
Created attachment 283706 [details] examples In the attached page, the cases labelled "scale3d transform" exhibit 140535 (no clipping) but also an issue where the transformed child (transparent red) is not aligned to its parent (cyan). Zooming causes the offset to change in all of the examples and, for the last two, the clipping behavior changes.
Attachments
examples (2.71 KB, text/html)
2016-07-14 16:34 PDT, Russell Bicknell 		no flags
Details
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Simon Fraser (smfr)
Comment 1 2016-07-14 17:20:41 PDT
Zalan loves stuff like this.
alan
Comment 2 2016-07-14 18:08:36 PDT
I do!
Alec Larson
Comment 3 2017-07-10 17:48:07 PDT
I'm experiencing something possibly related to this. The parent <div> with a non-integer height and `overflow: hidden` is clipping borders of overflowing descendants using `ceil` while the parent is rendered using `floor`. This result in one pixel of the descendant's border to be rendered outside of the clipped area. The workaround involves setting `transform: translate3d(0, 0, 0)` on the parent <div> to force compositing, which makes clipping work as expected.
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