I've been investigating this further by running the xorg-edgers PPA. No luck.
It is still broken.
I then downloaded the Fedora19 Alpha Live image and tried it. It works just
fine! No artifacts visible.
I checked that the nouveau driver version in xorg-edgers PPA and Fedora19
Alpha are the same (1.0.7). My suspicion is that this problem is related to
unity depending on some bits of OpenGL that gnome-shell doesn't. To verify
that I'll need to install a gnome-shell desktop on my machine.
I've been investigating this further by running the xorg-edgers PPA. No luck.
It is still broken.
I then downloaded the Fedora19 Alpha Live image and tried it. It works just
fine! No artifacts visible.
I checked that the nouveau driver version in xorg-edgers PPA and Fedora19
Alpha are the same (1.0.7). My suspicion is that this problem is related to
unity depending on some bits of OpenGL that gnome-shell doesn't. To verify
that I'll need to install a gnome-shell desktop on my machine.