We are currenlty using CAIRO_OPERATOR_SATURATE for CompositePlusDarker which is wrong. Since cairo 1.10 there's CAIRO_OPERATOR_DARKEN that we could use.
Created attachment 80062 [details]
This would allow us to unskip test fast/canvas/canvas-composite.html but bots don't have cairo 1.10 :-(
Great. Hopefully we can get the bots up to date. This may not be an issue for too much longer though: https://bugs.webkit.org/show_bug.cgi?id=43739
Comment on attachment 80062 [details]
This looks great to me, but we should also unskip the test now that the bots have the necessary Cairo version.
Created attachment 80178 [details]
Updated patch with unskipped test
Committed r76697: <http://trac.webkit.org/changeset/76697>