In latest mesa git master, I have a screen corruption since logging in to KDE. See (poorly captured) screenshot in the attachments. I've ran a git bisect and managed to find this out:
07af0abef024f8a17a00975265eff79aa069c9b5 is the first bad commit
Author: Matt Turner <email@example.com>
Date: Tue May 27 10:25:05 2014 -0700
i965/fs: Clean up fs_inst constructors.
In a fashion suggested by Ken.
Reviewed-by: Chris Forbes <firstname.lastname@example.org>
Reviewed-by: Kenneth Graunke <email@example.com>
Created attachment 100475 [details]
Screenshot of the corruption
*** This bug has been marked as a duplicate of bug 79534 ***