#914574 xfce: With dual monitors, "extend to the right" setting is lost when monitors are power cycled

Package:
xfce4
Source:
xfce4
Submitter:
James Van Zandt
Date:
2018-11-25 04:30:05 UTC
Severity:
normal
#914574#5
Date:
2018-11-25 04:26:19 UTC
From:
To:
Dear Maintainer,

I have a dual monitor setup, normally configured with "extend to the
right".  I leave the computer running all the time, but I power down
the monitors when I'm not using them.  Every time I turn them on, or
after several minutes with no activity, the system has reverted to
"mirrored displays", and a four-panel dialog is displayed with these
choices:

  1. ASUS 27"
  Mirror Displays
  Extend to the right
  2. ASUS 27"

What I expected is to set up the displays once, navigating
  Applications -> Settings -> Displays
and unsetting "Mirror displays".  After that, the settings should be
preserved across monitor power-cycles, periods of inactivity, and
system restarts.

(I'm attaching screenshots of the two dialogs.)

I see the setting is stored as the relative position of the second
monitor in
  ~/.config/xfce4/xfconf/xfce-perchannel-xml/displays.xml:

    diff -r -U 8 xfce4-extended/xfconf/xfce-perchannel-xml/displays.xml
xfce4-mirrored/xfconf/xfce-perchannel-xml/displays.xml
    --- xfce4-extended/xfconf/xfce-perchannel-xml/displays.xml
2018-11-24 22:49:22.814745510 -0500
    +++ xfce4-mirrored/xfconf/xfce-perchannel-xml/displays.xml
2018-11-24 23:09:02.810708537 -0500
    @@ -77,15 +77,15 @@
         <property name="DP-2" type="string" value="2. ASUS 27"">
           <property name="Active" type="bool" value="true"/>
           <property name="Resolution" type="string" value="2560x1440"/>
           <property name="RefreshRate" type="double" value="74.924852"/>
           <property name="Rotation" type="int" value="0"/>
           <property name="Reflection" type="string" value="0"/>
           <property name="Primary" type="bool" value="false"/>
           <property name="Position" type="empty">
    -        <property name="X" type="int" value="2560"/>
    +        <property name="X" type="int" value="0"/>
             <property name="Y" type="int" value="0"/>
           </property>
         </property>
       </property>
       <property name="Notify" type="bool" value="true"/>
     </channel>

Power cycling the monitors resets the X coordinate of the Position to zero.

Incidentally, I tried both "Configure new displays when connected"
settings.  The only difference was that when this was not set, the
four-panel dialog was not displayed when the monitors were turned on,
and I had to navigate to the normal display dialog instead.  This
suggests it's not remembering the monitors - i.e. every time it wakes
up, it thinks I've installed new monitors.  Where is that part of the
configuration supposed to be saved?

       - Jim Van Zandt