Comment 105 for bug 984785

As reported before, all the “.goutputstream-xxxxxx” files are temporary files that GLib uses in file write activities. However, these buffer files aren't deleted when an operation was cancelled. Currently, a fix was committed for this bug (see #104).

Now, let's focus on the other part of the problem. On every session close, LightDM needs to clean ~/.Xauthority. According to #28, there can be lines in .Xauthority that shouldn't be erased, though the last line seems to stand for the current session and should be deleted when the session is closed. I don't know well how it works, but some process (most likely XAuth) is called to remove the last cookie of .Xauthority. It works fine when you only close your session, but when you shutdown from an open session, it looks like LightDM doesn't take time to close it properly before shutting the whole system down. o_O

That results in a “.goutputstream-xxxxxx” containing all the ”permanent” cookies of .Xauthority. If you delete .Xauthority, these permanent cookies will disappear, so you will only get null-sized “.goutputstream-xxxxxx”... and a much lighter .Xauthority on next reboot. ;-) And it seems to cause no other problems, according to http://forum.ubuntu-fr.org/viewtopic.php?pid=11588001#p11588001