** Tags removed: verification-needed-focal ** Tags added: verification-done-focal
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to pixman in Ubuntu. https://bugs.launchpad.net/bugs/1988796 Title: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning Status in pixman package in Ubuntu: Fix Released Status in pixman source package in Focal: Fix Committed Bug description: [ Impact ] OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering backend, always with CAIRO_OPERATOR_SATURATE and sometimes with subpixel positioning (when reading certain file formats), and Cairo in turn invokes this code. As a result, some slides incorrectly render with large blank spaces and with some pixels rendered on top of other pixels. This effectively makes OpenSlide unusable for several of the file formats it supports. No workaround is believed possible within the OpenSlide codebase. [ Test Plan ] Compile and run the pixman.c test program uploaded to this bug. It should report "OK". [ Where problems could occur ] Problems would show up as incorrect pixel output from software that renders via Cairo or pixman. [ Other Info ] While I'm not a pixman expert, it appears that the change should only affect the broken code path, and it seems unlikely that anything else depends on the incorrect math fixed by this patch. This bug hasn't previously been reported in Ubuntu, which may imply that this code path is not exercised by other packages in the distro. The affected source file has had no further commits upstream since this patch was applied in April 2019, and some basic commit grepping didn't turn up any followup fixes elsewhere in the tree. [ Original message ] pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally) has a regression that causes incorrect rendering in some circumstances. This can be triggered by the use of cairo with CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide <https://openslide.org/> to produce incorrect output. The attached test program will print "Failed" if the bug exists, or "OK" if it doesn't. This is fixed upstream in https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which is in pixman 0.40.0. See https://github.com/openslide/openslide/issues/278 for more context. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pixman/+bug/1988796/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
