Comment 109 for bug 1308105

As suggested in comment 49
I think proper solution is enable crtc upon reconnection IF it is disabled.

Here is a prototype for patch - I'm hoping maintainer (Sean?)
can suggest "correct code" to enable crtc.

diff --git a/xfsettingsd/displays.c b/xfsettingsd/displays.c
index 095e323..af70256 100644
--- a/xfsettingsd/displays.c
+++ b/xfsettingsd/displays.c
@@ -415,6 +415,7 @@ xfce_displays_helper_screen_on_event (GdkXEvent *xevent,
     XfceRROutput *output, *o;
     XEvent *e = xevent;
     gint event_num;
+ gint j;
     guint n, m, nactive = 0;
     gboolean found = FALSE, changed = FALSE;

@@ -496,9 +497,37 @@ xfce_displays_helper_screen_on_event (GdkXEvent *xevent,
                 {
                     xfsettings_dbg (XFSD_DEBUG_DISPLAYS, "New output connected: %s",
                                     output->info->name);
+ /* need to enable crtc for output ? */
+ if (output->info->crtc == None)
+ {
+ xfsettings_dbg (XFSD_DEBUG_DISPLAYS, "enabling crtc for %s", output->info->name);
+ crtc = xfce_displays_helper_find_usable_crtc (helper, output);
+ if (crtc)
+ {
+ crtc->mode = output->preferred_mode;
+ crtc->rotation = RR_Rotate_0;
+ crtc->x = crtc->y = 0;
+ /* set width and height */
+ for (j = 0; j < helper->resources->nmode; ++j)
+ {
+ if (helper->resources->modes[j].id == output->preferred_mode)
+ {
+ crtc->width = helper->resources->modes[j].width;
+ crtc->height = helper->resources->modes[j].height;
+ break;
+ }
+ }
+ xfce_displays_helper_set_outputs (crtc, output);
+ crtc->changed = TRUE;
+ }
+ }
+
                     changed = TRUE;
                 }
             }
+ if (changed)
+ xfce_displays_helper_apply_all (helper);
+
             /* Start the minimal dialog according to the user preferences */
             if (changed && xfconf_channel_get_bool (helper->channel, NOTIFY_PROP, FALSE))
                 xfce_spawn_command_line_on_screen (NULL, "xfce4-display-settings -m", FALSE,