[gnome-shell] screenShield: Handle signal 'StatusChanged' when lockscreen is active

[Florian Müllner <fmuellner src gnome org>]

commit 6e317a54fd65dbaabcc3ee34358c67150ccc7004
Author: Xiaoguang Wang <xwang suse com>
Date:   Fri Mar 15 09:13:27 2019 +0800

    screenShield: Handle signal 'StatusChanged' when lockscreen is active
    
    When lockscreen is active, screen can't be dimed if signal
    'StatusChanged' is ignored. We need to handle this signal.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/issues/900

 js/ui/screenShield.js | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)
---
diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index 3f45b8acf..a005a206b 100644
--- a/js/ui/screenShield.js
+++ b/js/ui/screenShield.js
@@ -810,16 +810,8 @@ var ScreenShield = class {
 
         this._maybeCancelDialog();
 
-        if (this._longLightbox.actor.visible ||
-            this._isActive) {
-            // We're either shown and active, or in the process of
-            // showing.
-            // The latter is a very unlikely condition (it requires
-            // idle-delay < 20), but in any case we have nothing
-            // to do at this point: either isActive is true, or
-            // it will soon be.
-            // isActive can also be true if the lightbox is hidden,
-            // in case the shield is down and the user hasn't unlocked yet
+        if (this._longLightbox.actor.visible) {
+            // We're in the process of showing.
             return;
         }