[gnome-shell] loginDialog: Fix session button can be clicked

[Ray Strode <halfline src gnome org>]

commit fcbb942e2479a16cb2c60e34330d68d18ca095ff
Author: Xiaoguang Wang <xwang suse com>
Date:   Wed Apr 19 13:29:59 2017 +0800

    loginDialog: Fix session button can be clicked
    
    When session menu button is hidden, button can be clicked and show popup
    menu.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=781482

 js/gdm/loginDialog.js |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/js/gdm/loginDialog.js b/js/gdm/loginDialog.js
index 0b6c0b5..094a1f9 100644
--- a/js/gdm/loginDialog.js
+++ b/js/gdm/loginDialog.js
@@ -775,10 +775,12 @@ const LoginDialog = new Lang.Class({
     },
 
     _onPrompted: function() {
-        this._sessionMenuButton.updateSensitivity(true);
-
-        if (this._shouldShowSessionMenuButton())
+        if (this._shouldShowSessionMenuButton()) {
+            this._sessionMenuButton.updateSensitivity(true);
             this._authPrompt.setActorInDefaultButtonWell(this._sessionMenuButton.actor);
+        } else {
+            this._sessionMenuButton.updateSensitivity(false);
+        }
         this._showPrompt();
     },
 
@@ -881,6 +883,7 @@ const LoginDialog = new Lang.Class({
                                                       }));
         this._updateCancelButton();
 
+        this._sessionMenuButton.updateSensitivity(false);
         this._authPrompt.updateSensitivity(true);
         this._showPrompt();
     },