[gnome-shell/gnome-3-16] authPrompt: don't allow next if entry is empty

[Ray Strode <halfline src gnome org>]

commit 54db77787421ceb2ad2e5894d0553db26c8c8a96
Author: Ray Strode <rstrode redhat com>
Date:   Wed Jul 22 14:52:22 2015 -0400

    authPrompt: don't allow next if entry is empty
    
    Normally the user isn't allowed to proceed passed
    the username question until they've filled it in.
    To ensure this, the authprompt code desensitizes
    the next button when the number of characters change to
    zero.
    
    Unfortunately it fails to desensitize the next button
    up front when the entry starts out empty.
    
    This commit addresses that bug.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=752739

 js/gdm/authPrompt.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/js/gdm/authPrompt.js b/js/gdm/authPrompt.js
index a5c6862..6e5c79f 100644
--- a/js/gdm/authPrompt.js
+++ b/js/gdm/authPrompt.js
@@ -401,7 +401,7 @@ const AuthPrompt = new Lang.Class({
     },
 
     updateSensitivity: function(sensitive) {
-        this._updateNextButtonSensitivity(sensitive);
+        this._updateNextButtonSensitivity(sensitive && this._entry.text.length > 0);
         this._entry.reactive = sensitive;
         this._entry.clutter_text.editable = sensitive;
     },