File gnome-shell-lock-bg-on-primary.patch of Package gnome-shell.160

diff -Npur gnome-shell-3.10.4/js/ui/screenShield.js gnome-shell-3.10.4-new/js/ui/screenShield.js
--- gnome-shell-3.10.4/js/ui/screenShield.js	2014-10-30 04:33:15.473559466 +0800
+++ gnome-shell-3.10.4-new/js/ui/screenShield.js	2014-10-30 04:33:53.425560368 +0800
@@ -525,6 +525,7 @@ const ScreenShield = new Lang.Class({
                                                 reactive: true,
                                                 pivot_point: new Clutter.Point({ x: 0.5, y: 0.5 }),
                                                 name: 'lockDialogGroup' });
+        this._lockDialogGroup.add_constraint(new Layout.MonitorConstraint({ primary: true }));
 
         this.actor.add_actor(this._lockDialogGroup);
         this.actor.add_actor(this._lockScreenGroup);