https://bugs.freedesktop.org/show_bug.cgi?id=97059
--- Comment #8 from Michel Dänzer michel@daenzer.net --- I suspect this is a blender bug. It clearly doesn't render at all to the corrupted parts of its window, but AFAICT it doesn't use any of the GLX_EXT_buffer_age, GLX_OML_swap_method or GLX_INTEL_swap_event extensions to find out what if any guarantees there are about the contents of the back buffer after a buffer swap. blender's assumptions about that may happen to be valid with DRI2, which can only use up to two buffers, but not with DRI3, which can use more.