The transformation of layer geometry is done multiple times when there are nested ContainerLayers. This leads to invalid geometry in some cases.

Comment on attachment 8830548 [details] Bug 1333934 - Transform layer geometry only once https://reviewboard.mozilla.org/r/107298/#review108422

Pushed by cbook@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/a3fc19cd30d8 Transform layer geometry only once r=mattwoodrow

Miko, can you request uplift in this bug also since you mention it should go with bug 1335159 to aurora?

Comment on attachment 8830548 [details] Bug 1333934 - Transform layer geometry only once Approval Request Comment [Feature/Bug causing the regression]: Plane splitting implementation for OpenGL (bug 1286716, bug 689498) [User impact if declined]: Webpages with elements that have nested CSS 3D transforms might show incorrectly. [Is this code covered by automated tests?]: Yes, the patch adds a reftest for the specific problem encountered. Also the previous reftest suite testing 3D CSS transforms covers this code and passes. [Has the fix been verified in Nightly?]: Yes, I have verified that the fix works in Nightly. [Needs manual test from QE? If yes, steps to reproduce]: Optional - there is an automated reftest. Manual testing can be done by visiting http://www.simulationcurriculum.com/ and comparing the carousel transition with other browsers. Previously the last two stripes of the transition animation were rotating incorrectly. [List of other uplifts needed for the feature/fix]: Bug 1335159 [Is the change risky?]: Medium. [Why is the change risky/not risky?]: Similarly to bug 1335159, this change affects all the CSS 3D transforms. [String changes made/needed]: None.

Comment on attachment 8830548 [details] Bug 1333934 - Transform layer geometry only once This is required to fix bug 1335159. Aurora53+.