@vanvugt you were right that glPixelStorei was to blame. In ShmBuffer Mir uses glPixelStorei to change the GL_UNPACK_ALIGNMENT from 4 (that Qt set) to 1 (that Mir sets, as it is more careful about stride).
Mir fails to restore the state the Qt set, which broke Qt's rendering from then on. ShmBuffer only used for clients that do not use GL to draw, so Gtk and mir demos like fingerpaint, which is why this bug was "random" Could Mir be patched to revert any GL state changes it makes, when called into by Qt? ** Changed in: unity8 (Ubuntu) Status: Confirmed => Invalid ** Changed in: qtmir (Ubuntu) Status: Confirmed => In Progress ** Changed in: qtmir (Ubuntu) Assignee: (unassigned) => Gerry Boland (gerboland) ** Description changed: - Corrupted characters in text rendering, mainly in Unity8 window - titlebars. + Corrupted characters in text rendering. - I think this is a new issue. It only started happening (on xenial - desktop) in the past month or two. + Only happens after starting non-GL application, like GTK application or + mir_demo_client_fingerpaint. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1583088 Title: Randomly corrupt font / text / characters in Unity8 To manage notifications about this bug go to: https://bugs.launchpad.net/canonical-devices-system-image/+bug/1583088/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs