[gnome-shell] ScreenShield: don't allow events through the lock dialog

[Giovanni Campagna <gcampagna src gnome org>]

commit ef095966486258a200c334ba40dd53e72d308ac4
Author: Giovanni Campagna <gcampagna src gnome org>
Date:   Mon Aug 12 15:14:37 2013 +0200

    ScreenShield: don't allow events through the lock dialog
    
    Make the lock dialog group reactive, to intercept any events
    before they go to the actors below.
    In the future, we may restructure our chrome to have a clear
    layer system, but for now it fixes a security issue in the lock
    screen (you can see the contents of the windows by dragging
    if the screen was locked with the overview active)
    
    https://bugzilla.gnome.org/show_bug.cgi?id=705840

 js/ui/screenShield.js |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index 5e7693c..910462a 100644
--- a/js/ui/screenShield.js
+++ b/js/ui/screenShield.js
@@ -518,6 +518,7 @@ const ScreenShield = new Lang.Class({
 
         this._lockDialogGroup = new St.Widget({ x_expand: true,
                                                 y_expand: true,
+                                                reactive: true,
                                                 opacity: 0,
                                                 pivot_point: new Clutter.Point({ x: 0.5, y: 0.5 }),
                                                 name: 'lockDialogGroup' });