[GdkScreenX11] Add heuristic for pre XRandR 1.3 drivers

Currently gdk_screen_get_primary_monitor just returns the first monitor,
in this case but both the panel and now gnome-shell use an additional
heuristic to prefer LVDS as primary if present.

Move this heuristic to gdk_screen_get_primary_monitor to avoid duplicating
it all over the place.

The fallback heuristic is also used when no primary output is set.

https://bugzilla.gnome.org/show_bug.cgi?id=614894

diff --git a/gdk/x11/gdkscreen-x11.c b/gdk/x11/gdkscreen-x11.c
index 8c494aa81047a0406c3c6e52d5b7a856368b2f09..76ab17f0e9f6c9667c1a1ef813adc4067d2e7f68 100644 (file)
--- a/gdk/x11/gdkscreen-x11.c
+++ b/gdk/x11/gdkscreen-x11.c
@@ -771,7 +771,7 @@ init_randr13 (GdkScreen *screen)
       XRROutputInfo *output =
        XRRGetOutputInfo (dpy, resources, resources->outputs[i]);
 
-      if (resources->outputs[i] == primary_output)
+      if (primary_output != None && resources->outputs[i] == primary_output)
         {
           screen_x11->primary_monitor = i;
         }
@@ -785,6 +785,12 @@ init_randr13 (GdkScreen *screen)
           continue;
         }
 
+      /* No RandR1.3+ available or no primary set, fall back to prefer LVDS as primary if present */
+      if (g_ascii_strncasecmp (output->name, "LVDS", 4) == 0)
+        {
+          screen_x11->primary_monitor = i;
+        }
+
       if (output->crtc)
        {
          GdkX11Monitor monitor;