The default apparmor 'X' abstraction permits access to /{,var/}run/lightdm/authority/[0-9]*, ostensibly for the xauthority file. Except on Trusty, that's not where the xauthority file is. It is instead in /run/lightdm/$USER, and named "xauthority". I have had to udpated my apparmor configuration, lest apparmor convince Evince of being a filthy script kiddie, out to corrupt my xauth file.
Please consider adding the following to the 'X' abstraction:
The default apparmor 'X' abstraction permits access to /{,var/ }run/lightdm/ authority/ [0-9]*, ostensibly for the xauthority file. Except on Trusty, that's not where the xauthority file is. It is instead in /run/lightdm/$USER, and named "xauthority". I have had to udpated my apparmor configuration, lest apparmor convince Evince of being a filthy script kiddie, out to corrupt my xauth file.
Please consider adding the following to the 'X' abstraction:
owner /{,var/ }run/lightdm/ */xauthority r,
Relevant info:
apparmor: 2430-0ubuntu5 2430-0ubuntu5 2430-0ubuntu5 0 mirrors. mit.edu/ ubuntu/ trusty/main amd64 Packages dpkg/status
Installed: 2.8.95~
Candidate: 2.8.95~
Version table:
*** 2.8.95~
500 http://
100 /var/lib/